Uphill: Question and End

Angela Wigger Rosebrough English Comp II October 5, 2012 Explication Essay â€Å"Uphill† written by Christina Rossetti, this poem is explaining life as a journey and life’s unavoidable death. This poem tells the reader that no matter what we face in life there is going to be hard times that we must endure. Life’s road will never be easy and no matter how we choose to live our life, death is the ultimate price we must pay. We must try to live life the best we know how so that in the end we will find comfort in our resting place. Rossetti sets the tone of this poem as conversational.A question is asked by her and someone then answers her. This pattern is used throughout the entire poem. Four stanzas are used, two questions are asked and two answers are given. The rhythm of this poem gives the reader the feel as if they were climbing â€Å"uphill†. The rhythm used is ABAB. The meter used in this poem gives the reader a feeling of pacing steps as if they were climbing. There is an alternating pattern of five stresses per line (pentameter) then three stresses per line (trimester). â€Å"Uphill† starts by asking a question â€Å"Does the road wind uphill all the way? Rossetti is simply asking if life’s journey is uphill. Then in the second line someone answers her back saying, â€Å"Yes, to the very end. † This gives the reader a feeling of sadness, thinking that life will be a long journey with many challenges ahead. In line three and four there is another question with an answer. â€Å"Will the journey take the whole day long? †(3)/ â€Å"From morn to night, my friend. †(4) The words in these four lines continue to give the reader a feeling of uneasiness. They are telling the reader that life is difficult and will be long.As we come to the second stanza Rossetti begins to ask questions about the challenges that may be faced as the journey is travelled. In line five â€Å"But is there for a night a res ting place? † Then in line six is answered â€Å"A roof for when the slow dark hours begin. † In line five Rossetti is asking if there will be place to rest at the end of her journey of life. The response is yes there will be a roof where you will find a sort of peace. In line seven Rossetti is asking how she will be able to find this place, â€Å"May not the darkness hide it from my face? † The author is hoping she will find this place.The answer in line eight reassures her that she will find the place, â€Å"You cannot miss that inn. † By the end of line eight the reader can assume that there is an end to the journey, some place, somewhere the reader believes in when the end of life comes. As the reader continues to read lines nine and ten, we see that the author is asking questions about ones who have travelled this long road before. The question asked is, â€Å"Shall I meet other wayfarers at night? † Is then answered with, â€Å"Those who have gone before. † This answer tells her that the ones who have travelled this road will be there waiting in the end.As we read line eleven the question is returned back to the subject of the â€Å"inn†. â€Å"Then must I knock, or call when just in sight? † Again this question makes the reader think about the end of the journey. â€Å"They will not keep you standing at that door. † The answer lets her know that the travelers that have past will not leave her there, they will take her in. In the fourth stanza the reader sees the true question being asked. The author finally asks the main question, â€Å"Shall I find comfort, travel-sore and weak? † This question is asked to find out if in the end she is going to end up where she should be.She wants to know if this place is going to be comfortable for her or if she will even like it there. Line fourteen gives her the answer, â€Å"Of labor you shall find the sum. † This answer is telling her that depending on the way she lives her life is going to determine how comfortable she will be. The last lines of the poem the author is trying to bring back her original question of comfort by asking, â€Å"Will there be beds for me and all who seek? † The answer she receives is, simply, †Yea, beds for all who come. † As the reader comes to the end of this poem, we wonder, who is answering these questions.Is it someone who has travelled this road before? Rossetti left this question for the reader to answer for themselves. Whatever entity we choose it to be. Whether it be God, or Jesus, or whatever the reader believes in. Rossetti writes this poem with very simple rhythm and conversation. This is her view of life’s journey, with all the challenges we face, in the end hopefully peace and comfort will be found. UPHILL by: Christina Rossetti (1830-1894) Does the road wind up-hill all the way? Yes, to the very end. Will the day's journey take the whole long day? Fr om morn to night, my friend. But is there for the night a resting-place?A roof for when the slow dark hours begin. May not the darkness hide it from my face? You cannot miss that inn. Shall I meet other wayfarers at night? Those who have gone before. Then must I knock, or call when just in sight? They will not keep you standing at that door. Shall I find comfort, travel-sore and weak? Of labor you shall find the sum. Will there be beds for me and all who seek? Yea, beds for all who come. Work Cited Kennedy, X. J. , and Dana Gioia. Backpack literature: an introduction to fiction, poetry, drama, and writing. 4th ed. Boston: Pearson, 2012. Print. MLA formatting by BibMe. org.

Ethos, Pathos, and Logos, as suggested by Aritotle

The writer with whom I felt rapport was presenting his argument in a clear and consistent way, backing each point with relevant and sufficient evidence. The writer did not attempt to manipulate the reader, and the text contained no apparent bias. On the contrary, a writer who employs every trick to persuade the reader seems far less credible. Writer’s credibility ca be analyzed through the prism of three classical modes of persuasion — Ethos (appeal to authority), Pathos (appeal to emotion), and Logos (appeal to logic), as suggested by Aritotle (1989).As concerns Ethos, audience tends to believe speakers that elicit respect and demonstrate their credibility. Personal qualities that render speakers such credibility encompass a sense of wisdom (phronesis), goodwill (eunoia), and strong moral character (arete). Pathos, for its part, implies that a speaker possesses the ability to arouse strong feeling and emotional reactions in his or her listeners. While Aristotle acknowl edges the importance of the aforementioned modes of persuasion, he strongly deems that Logos is the most important and effective.Logical corollaries and evidences presented in a clear and consistent manner should persuade the reader of the effectiveness of the speaker’s thesis rater than author’s impressive credentials or emotional appeal. No doubt, writer’s qualification and expertise play a role, yet well structured argument is of greater importance to me. I would rather believe a talented university student offering an interesting and well researched thesis than a world famous professor arguing that global warming is a myth. Therefore, the most important aspects of persuasive writing are logic, evidence, and structure.

The Reform Program of John Calvin in the City of Geneva Comparing it Research Paper

The Reform Program of John Calvin in the City of Geneva Comparing it with either the Enlish or the Catholic Reformation - Research Paper Example When the Religious tension raised up and took a dangerous course Calvin fled to Basel in Switzerland where he published his first book â€Å"The Institute of the Christian Religion† in 1936. In the following year, he was hired to help reform the Church in Geneva. He was expelled from his duty but he continued his efforts for reform and soon he was called to take over his duties back and lead the church. On his return to his duties, he made several prominent changes in church government and Liturgy regardless of some influential families who were against his policies. Calvin suffered harassment and criticism but remained focused on his mission of improving and bringing in new reforms. In his way, he was supported by the refugees during the election of city council. Calvin tried hard and did his best to promote new reforms both in Geneva and Europe. Calvin’s reforms and ideology is known as Calvinism. CALVINISM: Calvinism is all about doctrine of Predestination and absolu te sovereignty of God which is greatly influenced by Augustinian. (Thomas, 1963) The theology of Calvinism was infused in Europe in 16th century, which is based on five basic reforms, which is recalled by an acrostic TULIP: T: Total Depravity explains that mankind has no power to choose right or wrong paths as people are all helplessly sinners and only God can choose them for the right path. Catholics preaches that this mankind has free will and can choose between right and wrong path, God has given a liberty to people to choose the way they want and will be rewarded accordingly (Steele, 1963). U: Unconditional Election states that People who go to heaven is not because of their good deeds or faith but they were unconditionally chosen by God to be sent to heaven and the rest are lost forever. Catholics says that it is the faith that lived and exists and people will be rewarded in regard of their deeds. L: Limited Atonement says that Jesus gave his life for specific sins of selected people, who will ultimately go to heaven and the God has already chosen people for heaven. Catholicism teaches that Jesus sacrificed his life for all mankind regardless of any favor to specific people and people have to believe it without any doubt. I: Irresistible Grace explains that whoever is selected by God will get the virtue of knowledge of God and the elected person cannot resist the call. Catholicism says that Grace is a divine gift for all mankind but people can resist the call. P: Perseverance of the Saints states that the one who received the call of communion will remain in that state until reach heaven, it is impossible for any person to lose his Salvation. Catholicism says that as human we are all sinful and somehow make mistakes but God is there to forgive and deliver us in heaven. All these five points were strongly condemned by the Roman Catholic Church and they present different view or interpretation of the verses of Gospel from which Calvin supported and spread h is own perceptions. There are different theologies over same verses but the interpretation completely differs to what Calvin tried to prove. ARMINIANSM: (Stanglin, 2009) Armenian theology also has some conflicts with what Calvin’s reforms say. Armenians rejects the idea of predestination and it says that a person is not

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Policy Brief - Research Paper Example It is however regrettable that to some extent, human actions and activities have promoted the rise of the aspect or issue of climate change. Conversely, empirical evidence and studies have pointed to the direction that as much as there are natural causes or acts of God which are beyond human control. For instance, when the volcanic eruptions occur or there a significant drift in the plate tectonics, it follows that climatic patterns would change considerably. There are also biotic processes and conditionalities alongside the instances of solar radiation. However, a keen interest lies on the contribution of the human activities to this phenomenon and how we as the human race could reverse the situation. It is important to note and mention that the human activities bring to the fore the aspect of global warming whose effects need no over-emphasis at this point in time. Thus, curative measures and approaches ought to be taken to ensure climate change is brought under control and measures taken to correct the same. It is my guided view and opinion that the virtue of your position as the executive director of the United Nations Environmental Programme, you could oversee the policy framework and borderlines to help address the issue of climate change. It is a public knowledge and common fact that once your office with your interests takes a matter of interest, then the whole world would listen to it. Thus, it would be important if the organization which you head, takes the matter so as to give the notion and the whole concept of climate change global attention. It goes without saying that as much as the consequences and the effects of global change are dire, without proper attention to address it then the effects would continue to affect the society as a whole (Caney, 750). Empirical studies and evidence have suggested that when a volcano erupts, there is a sufficient amount of sulphur dioxide, dust, water vapor and ash which are

Organisational Design and Change Essay Example | Topics and Well Written Essays - 2000 words

Organisational Design and Change - Essay Example Secondly, the framework makes clear of the choices and the plans an organisation makes and evaluation is easier. For instance, if a company pursued a strategy earlier, the executive can look at the result against the set framework to see whether the plan worked or not. This is beneficial because it provides vital information on sales (Hamel, n.d.). Thirdly, through the SWOT tool, the decision made becomes visible throughout all level of management. An SWOT analysis which establishes organisation’s strengths and weaknesses together with peripheral threats and prospects it faces. These modalities help executives generate strategies to utilise strengths or curtail weaknesses to rip the opportunity and shun risks (Eisenhardt, n.d). On the other hand, adherence to a specified strategy enables managers, first to build a shared collective intuition that augments the capacity of the top administration team to spot risks and opportunity more rapidly and more precisely. It also stimulates rapid conflict to advance the quality of strategic judgement without sacrificing considerable time and maintaining disciplined swiftness to oblige the decision course to a well-timed termination. Politically, the tax imposed on farmers in the countries producing the coffee essentially means that as by 2013, the Starbucks pays a huge price for all the coffee they procure. Therefore, any imposition or changes in taxation levels in the company are all passed to the consumers. For instance, if other countries revenue authorities impose a tariff it not only outcomes in loss of efficiency for Starbucks, but also enormous income transfers can turn incoherent with equity. Economic: An increase in interest rates derails Starbucks expansion strategies thus resulting in declining sales for Starbucks and sales of their suppliers. Consequently, if the nation where Starbucks of located is experiencing slows growth,

Inspiring historical figure Essay Example | Topics and Well Written Essays - 500 words

Inspiring historical figure - Essay Example e can see that Delany’s interest in political activism, added with his active participation in the protest against human rights violation faced by the African Americans, transformed him to an eminent abolitionist and political activist. To be specific, Delany co-operated with the abolitionist movement in America in 1840s, and made use of the newspaper named as North Star to propagate his ideas on the problems faced by the African Americans. Junius P. Rodriguez stated that, â€Å"During his time in Pittsburgh, Delany participated in the abolitionist movement, newspaper editing, moral reform, and the practice of medicine† (251). Later, Delany came to realize the fact that African Americans cannot expect freedom and equality in America. So, he considered that the African Americans can gain freedom by immigrating to other nations. Besides, Delany was an eminent leader of an African America movement named as Black Nationalism. Delany’s direct involvement (say, as a ne wspaper reporter and as an African American leader) in the problems faced by his fellow beings helped him to realize that indigenous nationalism can help the African Americans to gain political and social freedom in the mainstream society. In short, Delany’s involvement in the abolitionist movement and American Black Nationalism helped the African Americans to realize the importance of political activism within the context of anti-slavery movement. One can see that Delany did not neglect his duty towards his motherland. This awareness eventually led Delany to take the decision to serve the Army during the Civil War. Besides, he acted the role of a recruiter and served the Union Army. In 1850s, Delany decided to enter medical profession by enrolling at the Harvard Medical School. But racial segregation based on skin color limited Delany’s scope as a medical student in Harvard Medical School. But he did not try to abandon his profession as a physician. For instance, his role as a physician in

Interpret the law of secured transactions Essay Example | Topics and Well Written Essays - 500 words - 1

Interpret the law of secured transactions - Essay Example According to common jurisdictions, the lender in this case who is the First Savings Bank can accept intangibles as security for loans borrowed. This mostly applies where the accounts receivable are traded to the creditor just like in the case of Money Games Incorporation. According to the scenario, the accounts receivable acts as collateral whether the financial statement is filed or not (Miller, 2011). A security interest arises in exchange of the loan whereby the debtor agrees that the secured party may take collateral owned by the debtor if he or she defaults in the payment of the loan (Miller, 2011). Security agreements are contracts according to the law of business (Legal Information Institute, 2000). The collateral interest of the bank vests upon the signing of the guarantee contract. In this case, the bank security is attached. However, it has not perfected its collateral interest. In most situations, perfection can be easily achieved through filing of a financial statement. This document should include the signature of the debtor, a brief description of the collateral item and addresses of both the creditor and the debtor (Cheeseman, 2009). In normal circumstances, when the debtor delivers the note and executes the security agreement, the bank swiftly authorizes for liberation of the funds that are being borrowed. When the money is released to the debtor, then the bank’s security is attached since, it has executed a security agreement that describes the collateral and has also offered valuable security that applies to the loan. The bank is required to perfect its security interest and its claim against the accounts receivable which subordinates to the claims against the accounts receivable. This is because the bank’s security interest attaches from the agreement that secures the payment of the debt. For instance, the beneficiary of the security interest has certain rights in

Response to 3 students with 2 references for each response Coursework

Response to 3 students with 2 references for each response - Coursework Example Streeter is comprehensive in comparing surveys, and experiments, by exploring both similarities and differences such as variations in intentions of the methods. The post corresponds to other literature’s opinion that experimental methods focus on relationships while survey focuses on descriptive features of data (McConville and Chui, 2007). I therefore feel that the writer has comprehensive background information on the subject (Creswell, 2003). Another post, written by Butler Mirlande, is titled ‘A comparison between survey and experimental strategies of inquiry.’ Butler succeeds in organizing the post that systematically reviews scopes and similarities of the two methods. The author for example identifies the need to collect reliable and valid data as a common objective of both methods even though their approaches vary as Gropper, Smith, and Groff (2007) and McConville and Chui (2007) explain. I strongly agree with Butler’s post because it is deeply explorative and its reliability is supported by triangulation of

Business Plan Assignment Example | Topics and Well Written Essays - 4500 words

Business Plan - Assignment Example We are a socially responsible organization with policies relating to health & safety, training and the environment thereby providing assurance to our customers that they are working with a professional company, fluent in handling the industry's changing requirements while maintaining the traditions of customer satisfaction and quality by offering high end services. WYR Ltd willfully understands the challenges facing the house builders in the current market. This company is going to develop an enviable host of policies and procedures to manage customer requirements, backed up by vision and a financially astute management team. WYRL will be the part of The Intelligent Membrane Trade Association (IMA) which is a top UK based organisation which lists expert contractors as its members. The listing criteria of IMA are tough and only those contractors are listed which have successfully demonstrated highest quality standards. BehBehind the IMA is the strength of Icopal which is the largest manufacturer of roofing and building membranes in the world. Icopal has been manufacturing plants in the UK, Finland, Norway, Sweden, Denmark, Germany, Poland, Czech Republic, Belgium, France and the USA. Products are distributed by 7 offices across Europe, North America, the Middle East and Asia. Icopal is the largest construction membrane company in the UK and Eire offering the widest possible choice of specification products that include: Built up Flat Roofing, Pitched Roofing, Acoustic Flooring Systems, Structural Waterproofing, and Geomembranes. WYRL aspires to be registered with Icopal in order to achieve industry wide quality standards. WYR Ltd. will be constant in its commitment to delivering high quality expertise and customer service to achieve the Programme requirements. This company can also mobilise its skilled workforce to service the needs of any project in any Wales and UK location. Product & Service Waterproof Your Roof Limited (WYRL) is a service oriented organization offering services to wide range of costumers belonging to both to our Industrial customers as well as general public. The basic services will include water-proof roofing, water-leakage roofing as well as installation of leak proof roofing. All the services may be availed as a complete package or can also be availed as standalone services. In order to further establish ourselves in the business, we shall be striving to develop our unique selling proposition of delivering high quality services at low costs. For this purpose, we will not charge our margins on the products purchased from third parties rather, our aim will be to offer high quality services backed up by inexpensive but highly effective material which can ensure high quality but durable roofline services. All such services will be delivered through highly trained experts who will be delivering all such services within allotted time period mutually agreed between our customers and us. WYRL shall also be cross selling

Character Analysis of Connie Essay Example for Free

Character Analysis of Connie Essay Then one day her family leaves her alone and she notices the boy in the car comes to her house and she finds out that he seems to know everything about her. He demands that Connie come to him and in then th story ends as Connie walks out the house toward the mysterious boy. Connie is sexually active, scared, and deceitful. Connie is sexually active. Oates states how Connie knows she is beautiful and she gets a great deal of attention from boys. Connie knows she is gorgeous, so when she goes out, she shows off her body more. When Connie meets the older boy in the resturant, she spends hours with him, and they went in an abandoned alley. Connie often states that she believes sex is a beautiful and fun feeling. Going with this stranger Connie has just met for hours implies she is sexually active in some way. What Oates is trying to say about young girls in general is that by showing off their bodies and meeting with older boys, sex will be pressured onto them. More young females will want to become more sexually active by assuming sex is all good and fun. Connie is scared. Connie does not seem to be afraid of anything. However, once this stranger appears at her house, she becomes a bit more frightened. Connie was always used to doing what she wanted with whomever she wanted. Along came Arnold, who commanded her to come to him and do things with him. Suddenly, Connie does not have the choice anymore. He threatens to harm her family so she is scared and cannot bring herself to even call for help. What Oates is trying to say about being scared is that one will not be scared until the option of deciding for ones self gets taken away. Connie is deceitful. Connies mother often degrades Connie for being vain. Her mother does this because she is worried about Connie and knows Connie gets a great deal of attention from males. Connies mother knows what can happen to her if she does not start being careful. Connie still goes out grabbing the attention of boys even though her mother says otherwise. What Oates is trying to say is that children should always listen to their parents, or they may end up in danger. Oates tries to get the reader to understand that parents have been through it all, and children should learn to listen more. In the short story Where Are You Going, Where Have You Been? Oates shows that Connie is sexually active. She is sexually active because she shows off her body and is curious about sex. Connie is scared because she had no choice in what she wanted to do. Connie is deceitful because she did not care or listen to her mother.

The Space Race and Apollo 11

The Space Race and Apollo 11 The Most Successful Space Mission of all Times Apollo 11 JAMES CHAN Introduction to the Cold War and Space Race Prior to the 1960s, there has always been a dream to travel to the outer space. Research has been done continuously around the world to investigate methods for space travel. At that time, there was a dramatic competition between countries and each nation wanted to demonstrate their superiority in technology and military power. After the World War II drew a conclusion in the mid-20th century, a conflict began between the Soviet Unions and United States known as the Cold War. The Cold War was a competition between the two rivalries and had been on-going for many years. The two nations extended military funding’s to compete against each other on military forces and technological competition which initiated the Space Race. The Space Race was a crucial arena for the competition between the two epic rivalries (Collins, 1999). Space Race happened between 1957 and 1975 where the two rivalries focused on attaining to be the first in space exploration. This supremacy was seen to be necessary in terms of national security and it was a symbolic of ideological superiority (Cram101 Textbook Reviews, 2013). The race involved efforts on launching satellites and human missions orbiting around the Earth, as well as unmanned probes to the Moon, Venus and Mars. Out of all the mankind achievements in the space race and 20th century, it was said that the Apollo 11 mission where humans finally escaped from the earth’s gravity and landed on the moon was the most groundbreaking and dominating milestone in the history of space travel (Brooks, et al., 2012). Timeline of the Space Race Figure 1: Timeline for Space Race The first race into space started in 1957 after the Soviet Union successfully launched the ‘Sputnik’ satellite. It was the first manmade object to leave the Earth (Bille Lishock, 2004). As a response, the US launched its first satellite, Explorer I, four months after the Russians which initiated the competition between the two nations. Momentarily the space race started to heat up and in 1959, the Soviet space program took the lead again with the launch of Luna 2, the first probe that reached the lunar surface (Kuhn, 2007). In 1961, the Soviet spacecraft Vostok 1 successfully sent the first person into orbit around Earth and on the other side, the US managed to send its first mankind into space three weeks later with the Freedom 7 without achieving orbit (Schefter, 2000). It was nearly a year after, in 1962, the US was able to catch up with the Russians and send its first person to orbit around the Earth with the Friendship 7 spacecraft. At that time, the US President John F. Kennedy recognized the problem and suggested more work should be done for the US to reach a leadership position in this space race. Kennedy believes that the US could first achieve crewed lunar landing and soon started to fund NASA’s lunar landing program – Project Apollo (History.com, 2010). The ultimate goal of Project Apollo was to be the first country to safety send mankind on the moon and return them back to Earth by the end of 1960s (Brennan Vecchi, 2001). Project Apollo Shortly after Kennedy’s full support on the US lunar space programs, NASA has an increasing budget of 500% from 1961 to 1964 with 34,000 employees involved in the Apollo program (History.com, 2010). In conjunction with Project Apollo the US launched several programs such as the Gemini and Mercury program to develop the technology needed for the Apollo mission. From these programs, the Americans not only learnt how to change orbit of a spacecraft, but also performed the first rendezvous and docking of two spacecraft and accomplished the first spacewalk which are all necessity for the success of Project Apollo (Chaikin, 1999). After many years of flight testing and experiments conducted on the initial modules of the Apollo spacecraft, the launch of Apollo 8 in 1968 was the first manned space mission to orbit around the moon. Meanwhile, the Soviet Union’s Soyuz lunar landing mission proceeded alongside with Project Apollo to put the first man on the moon. The Soviet had planned for manned circumlunar flights around the moon in 1967 and manned lunar landings in 1968. However, the Soviet made four unsuccessful and one successful unmanned circumlunar mission between 1967 and 1970. In addition, four failed efforts to launch a lunar landing spacecraft between 1969 and 1972. The most significant setback was the launch pad explosion of the N-1 rocket on 3rd July, 1969 where the launch rocket hits the pad and destroyed the launching facility. Without the N-1 rocket, the Soviet was not able perform space launches anytime soon. In the same month, the US surpassed the Russians and won the race by landing on the moon with Apollo 11. Apollo 11 Mission In 16th July 1969, US astronauts Neil Armstrong, Edwin Aldrin and Michael Collins was set off on Apollo 11 for the first lunar landing attempt (Brennan Vecchi, 2001). The spacecraft consist of three parts namely Command Module, Service Module and Lunar Module. The Command Module is the cabin for the three astronauts, the Service Module supplies electricity, oxygen and water to the Command Module and the Lunar Module is used for lunar landing. The Apollo 11 spacecraft was launched from the Kennedy Space Center in Florida and was the fifth manned space mission of Project Apollo. Apart from sending astronauts to the moon and return them safety back to Earth, the secondarily objective of Apollo 11 was to perform human experiments on the lunar surface and return moon samples back to Earth. By studying the moon rocks and gathered data, it would greatly advance our scientific understanding of the moon’s history and what it consists of. (Moskowitz, 2009). Figure 2: Apollo 11 Components After launch, the spacecraft entered lunar orbit about 76 hours into the mission. On 20th July 1969, the Lunar Module started to descend after undocking with the Command Module. The US ended the space race on the same day by successfully landing the lunar module on the moon. It was the first manned lunar landing and first time mankind had experienced lunar gravity. After 6.5 hours after landing, Neil Armstrong was the first to step out of the spacecraft. He became the first human to set foot on the moon and his famously quote â€Å"Thats one small step for man, one giant leap for mankind† was symbolic (Brennan Vecchi, 2001). 500 million people gathered around television and countless audience listened via radios around the world to witness this historical moment. There were never so many people tuned in for a single event at the same time before. After a short period of time, President Richard Nixon connected with the astronauts via a telephone call from the White House. It w as the most historic telephone call and longest distance call ever. After two and a half hours of lunar surface exploration, the crew collected 21.5 kg of lunar materials and started its mission back to Earth. Eventually, the Apollo 11 mission landed in Pacific Ocean on July 24. Figure 3: Apollo 11 on the moon (Image by NASA) The US clearly won the space race by landing the first human on the moon and leapedto a commanding position in space competition. Subsequently, the Soviet decided to cancel their space program in 1970 after the successful moon landings by the US. Challenges Faced Although the Apollo 11 mission seems to be successfully, there were many challenges during the mission. After landing on the moon, the astronauts weren’t able to open the hatch due to unexpected low atmosphere pressure outside. They had trouble depressurizing the cabin and it took longer than expected to open the hatch (Wilford, 2010). The most risky and fatal challenge faced by the Apollo 11 spacecraft was for it to return to earth safety. While the astronauts were moving back to the cabin to prepare for its way back to Earth, Aldrin unintentionally broke the circuit breaker which was important to start up the engine (Jones, 1995). Fortunately, a felt-tip pen in the cabin fit into the slot and successfully activated the switch to fire the engine. In addition, the spacecraft was designed to be powered by a single engine for it to depart from the lunar surface. Based on previous testing’s performed in space, the engine has a high failure rate and it was a gamble for the engine to work actually as planned. If the engine did not work properly, it was impossible for the astronauts to return and there was no way to rescue them. Lessons learnt During the space race, both the US and the Soviet Unions were rushing to be the first to land on the moon. Both nations performed countless human experiments and activities which involves high investments and high risk (Harland, 2010). The fail attempts sacrificed lives and a high portion of the governments spending’s has gone to make these programs possible. During the 1960s, some Americans did not believe that the Apollo mission was worth its cost. People protest against the use of funding’s and many others quietly opposed the space missions (Madrigal, 2012). Despite Apollo 11 worked out the best, the Apollo team soon realized how lucky they were for the mission to succeed. As a result, lessons were learnt and the risk and flexibility of such missions should be taken into consideration for future space missions. Moreover, the space programs were conducted within individual countries during the space race. In the future, it is expected that international joint efforts between countries should be made for space explorations (Malik, 2008). Reason of Success The reason why the US can achieve such accomplishment in such short period of time is because of the government’s determination. The government sees the Apollo mission to be a long term strategic decision as it will benefit the US on both the administrative leadership and international politics standings. The US government has a clear goal and gives fully financial support to the NASA space programs. In addition, NASA works closely with industrial contractors and universities to make the program possible. Argument to be the Most Successful Space Mission The Apollo 11 success demonstrated both economic and technological superiority of the US over rival nations. Project Apollo was a triumph for NASA engineers to design, build and operate innovative spacecraft engineering systems in an environmental where humans wasn’t able to explore before. The integration and organization of the program demonstrated the superiority in engineering and technology of the US. The mission not only the first manned lunar landing, but is also a technological challenge and groundbreaking inventive in spacecraft engineering. The Apollo program achieved enormous achievements as well as leaving legacy for NASA and the spacecraft engineering industry. The mission will not be repeated and the findings of the mission will benefit the world of astronomy, science and engineering forever. It acts as an important milestone and motivation for future space exploration projects. No matter how many lunar landings will be performed in the future, it would never be comparable to the first step on the moon. It will always be remembered in the history of space exploration and thus I believe the Apollo 11 is the most successful space mission of all times. Conclusion During the years of space race, numerous space programs has been accomplished and the technology developed throughout the course of the space race has opened up new applications to space that would change the quality of life on Earth (Bille Lishock, 2004). Despite Apollo 11 being a success and was the first lunar landing on human’s history, lessons were learnt and sacrifices were made to achieve its goals. The Apollo 11 achievement was a great leap for mankind and I believe that Apollo 11 is the most successful space mission ever. Word Count: 1983 Bibliography Bille, M. Lishock, E., 2004. The First Space Race: Launching the Worlds First Satellites. Texas: AM University Press. Brennan, L. Vecchi, A., 2001. The Business of Space: The Next Frontier of International Competition. s.l.:Palgrave Macmillan. Brooks, C. G., Grimwood, J. M. Swenson, L. S., 2012. Chariots for Apollo: The NASA History of Manned Lunar Spacecraft to 1969. s.l.:Courier Dover Publications. Chaikin, A., 1999. Greatest Space Events of the 20th Century: The 60s. s.l.:s.n. Collins, M. J., 1999. Space Race: The U.S.-U.S.S.R. Competition to Reach the Moon. s.l.:Pomegranate. Cram101 Textbook Reviews, 2013. e-Study Guide for Give Me Liberty!: An American History, Vol. 2, textbook by Eric Foner: World history, United States. s.l.:Cram101 Textbook Reviews. Harland, D. M., 2010. NASAs Moon Program: Paving the Way for Apollo 11. s.l.:Springer. History.com, 2010. The Space Race. [Online] Available at: http://www.history.com/topics/space-race [Accessed 13 May 2014]. Jones, E. M., 1995. Trying to Rest. Apollo 11 Lunar Surface Journal. Kuhn, B., 2007. The Race for Space: The United States and the Soviet Union Compete for the New Frontier. s.l.:Twenty-First Century Books. Madrigal, A. C., 2012. Moondoggle: The Forgotten Opposition to the Apollo Program. [Online] Available at: http://www.theatlantic.com/technology/archive/2012/09/moondoggle-the-forgotten-opposition-to-the-apollo-program/262254/ [Accessed 16 May 2014]. Malik, T., 2008. NASAs Most Memorable Missions. [Online] Available at: http://www.space.com/5853-nasa-memorable-missions.html [Accessed 2014 May 14]. Moskowitz, C., 2009. NASA’s 10 Greatest Science Missions. [Online] Available at: http://www.space.com/6378-nasas-10-greatest-science-missions.html [Accessed 2014 May 16]. Schefter, J., 2000. The Race: The Complete True Story of How America Beat Russia to the Moon. s.l.:Anchor. Wilford, J. N., 2010. Men Walk On Moon. [Online] Available at: http://www.nytimes.com/learning/general/onthisday/big/0720.html [Accessed 2014 May 16]. 1 | Page

I Am Someone :: English Literature Essays

I Am Someone I chose the poem "I Am Someone" by Annastasia Aressia. The author use simplistic words in this poem, which it is a multiple understanding meaning. Each reader can have an opinion on what it is being read, I will give details on the sentences that shows general meaning. Her choices of words were a few, but very mean full. For example, in example of line two, â€Å"I walked past a dead face.† She, the author, starts using these words by explaining that she is in a terrible life time, going on hard times in life, by this line at the beginning of the poem; she starts telling the reader that what the poem is all about, it has some kind of sadness ideas. In line three â€Å"even though the person was alive† she shows the irony of life and the order of life. She shows that for one thing to live another must die. Yet, on the other hand she also shows the important thing that a life means because it says that she does not says if she is alive or not; she still suffering from something, but she still awake. Also, in sentence number four and five she says some similarities â€Å"I saw my eyes in the mirror and cried at the sight† I think that she means that she looks back her self and she still in a bad moon. In lines thirteen and fourteen â€Å"when I thought about love, I got hit bad† She means that not everything is loosen there is always something that it not there but It could be at any time. In the following lines it starts to contradict the meaning of the poem by saying differences and opposite things such as lines twenty-one and twenty-two, â€Å"I realized I was strong when I didn’t cry when it hurt.† Means that not everything is over because she notices that she is really a person, as same as other people, strong, she is someone. Finally she explains that she founds who is she, what she was doing and she also noticed that it is a someone who has a personality by this words; â€Å"I thought I was lost forever when a friend found me.† Line twenty-five. The title of the poem is a very good point. The title describes the poem almost to perfection. The title â€Å"I am someone†, it shows the grand main points of a life.

Franny And Zooey And The Razor :: essays research papers

Franny And Zooey & The Razor’s Edge   Ã‚  Ã‚  Ã‚  Ã‚  Many novels use religion as the central object of their plot. Franny and Zooey, by J.D Salinger and The Razor’s Edge, by W. Somerset Maugham both display religion as having they key role in their novels. Religion is the main guide in Franny and Zooey and The Razor’s Edge for the search of meaning. During the search for meaning the two main characters Franny Glass and Larry Darrel, use religion as an escape from everyday life and from bad memories. Secondly, these two characters put important factors of their lives on hold, which leads their loved ones to disagree with their search for meaning. Nevertheless, both characters benefit from their religious experiences.   Ã‚  Ã‚  Ã‚  Ã‚  Both Franny Glass of Franny and Zooey and Larry Darrel of The Razor’s Edge turn to religion as an escape rout from their everyday lives and disturbing memories. They have become annoyed and dissatisfied with their ordinary lives and the individual values and goals in their everyday lives. While Franny was dining with her boyfriend, Lane, she describes the atmosphere around her and how she feels about the theatre department and how sick she is of everyone close to her. “I’m not afraid to compete. It’s just the opposite. Don’t you see that? I’m afraid I will – compete – that’s what scares me. That’s why I quit the theatre department. Just because I’m so horribly conditioned and people to rave about me, doesn’t make it right. I’m ashamed of it. I’m sick of not having the courage to be an absolute nobody. I’m sick of myself and everybody else that wants to make some kind of splash.';1 This also occurs in The Razor’s Edge. After Elliot Templeton’s death, Larry describes how worthless Elliot’s life really was. “An old, kind friend. It made me sad to think how silly, useless, and trivial his life had been. It mattered very little now that he had gone to so many parties and has hobnobbed with all those princes, dukes, and counts. They had forgotten him already.';2 Both of theses examples show how, Franny and Larry do not want to be a part of the stylized like of their societies. Franny was part of a large family in which each sibling was an actor or actress at one point in their lives. Franny was expected to lead a very prestigious life. Attending university in honors program, and becoming a wonderful actress.

Buddhist and Christians

Two of the most sought religion in the world is Buddhism and Christianity. Followers of the two aforementioned religions are very lenient when it comes to certain beliefs and practices. They preserve the sanctity of their chosen faith and ensure that the symbols of worship and history are well respected through the years. Tibetan Buddhism is mostly followed in the regions of Himalayas. Countries that adhere to the said religion were India, Bhutan and Nepal. People in China, Russia and Mongolia are also Tibetan Buddhists. This religion has four main traditions namely Sakya, Kagyu, Nyingma and Sakya.All of th aforementioned division includes teachings of the three vehicles of Buddhism: Vajrayana, Mahayana and Foundation Vehicle (Coleman, 10). Achieving enlightenment is the main goal of Tibetan Buddhists. The right term for people who already gained enlightenment is Buddhahood. It is a state of mind wherein the nature of reality as well as mental obscurations is freed. Buddhists are con sidered as internalist because their state of mind is of great importance in the religion (Coleman, 22). Buddha is their god and they uses texts like Pali Canon, Tibetan Canon and Chinese Canon (Conze 35).Christianity on the other hand is a monotheistic religion which centers on Jesus Christ and his teachings. Christians are the followers of this religion who believes that Jesus is the only begotten son of God (Woodhead 7). Unlike Tibetan Buddhism which believes in karma, Christians believes that a life worth livings is when you adhere to the same way Jesus cared and sacrificed for others. It may incorporate similitude between the two religion because both belief aims to do well towards other people. In Christianity, Buddhahood is achieved when everlasting life is granted to its followers.Unlike Tibetan Buddhism which uses three different texts, Christianity uses The Holy Bible which is divided into two: The Old and The New Testaments (Woodhead). One of the famous symbols of worship in among Christians is the cross. It is being look upon by followers of Christianity as a significant affirmation of all the hardships of Christ (Padgett 18). It leads to the salvation of souls and forgiveness of sins. Christians even come up with the practice of the sign of the cross which affirms the sacredness of the symbol.Another symbol of worship for Christians is the fish which is often seen on tombs during the early times. It contains the Greek word Icththys which claims Christ’s character and professes the worship of believers (Padgett). The use of images and statues of Christ and other saints are also part of the symbols of worship for Christianity. Tibetan Buddhists look upon the Kalachara or the Tenfold powerful logo as their symbol of worship (Dagyab & Thurman 46-55). It can be found everywhere in places where Tibetan Buddhism is present.It comes in various forms and represents the teachings of the religion. It contains representation of letters in Lantsa script discussing about the outer world and the human body (Dagyab & Thurman 46-55). Typically, Tibetan Buddhists uses flags to decorate monasteries, houses and even mountains. They believe that the prayer flags contain mantras that can be spread out by the wind. These flags contain auspicious symbols, special prayers and mantras (Dagyab & Thurman). Wind horse and Prayer wheels are also part of the symbols of worship for Tibetan Buddhists.It is also similar to prayer flags which contain special powers once the wheel is turned (Conze). Apart from Christianity, Buddhist relies too much on symbol rather than working out for their faith. Regardless of the difference of the two religions, what keeps them the same in religiosity is the willingness of their followers to stick to their belief and treasure the worship symbols. The concept of faith is given meaning in their respective ways and makes way for their goal of achieving enlightenment (Buddhists) and salvation (Christians).Works Cited Col eman, Graham, ed. A Handbook of Tibetan Culture. Boston: Shambhala Publications, Inc, 1993. Conze, Edward. A Short History of Buddhism. Oneworld. 1993 Padgett, Alan G. ; Sally Bruyneel. Introducing Christianity. Maryknoll, N. Y. : Orbis Books, 2003. Rinpoche, Dagyab & Thurman, Robert Buddhist Symbols in Tibetan Culture. USA: Wisdom Publication, 1993. Woodhead, Linda. Christianity: a very short introduction. U. S: Oxford [Oxfordshire]: Oxford University Press, 2004.

Chemistry Investigatory Project

CHEM. RES. CHINESE UNIVERSITIES 2012, 28(3), 415—418 Determination of Nicotine in Tobacco by Capillary Electrophoresis with Electrochemical Detection SUN Jin-ying1, XU Xiao-yu1,2, YU Huan1 and YOU Tian-yan1* 1. State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China; 2. Ministry of Public Security of Jilin Province, Changchun 130051, P. R.China Abstract A sensitive, simple and low-cost method based on capillary electrophoresis(CE) with electrochemical(EC) detection at a carbon fiber microdisk electrode(CFE) was developed for the determination of nicotine. Effects of detection potential, concentration and pH value of the phosphate buffer, and injection time as well as separation voltage were investigated. Under the optimized conditions: a detection potential of 1. 20 V, 40 mmol/L phosphate buffer(pH 2. 0), a sample injection time of 10 s at 10 kV and a separation voltage of 16 kV, the linear range obtained was from 5. 0? 10–7 mol/L to 1. 0? 0–4 mol/L with a correlation coefficient of 0. 9989 and the limit of detection(LOD, S/N=3) obtained was 5. 0? 10–8 mol/L. The method was also used to determine the nicotine in cigarettes. Nicotine amount ranged from 0. 211 mg/g to 0. 583 mg/g in the pipe tobacco of seven brands of cigarette and the amount in one cigarette varied from 0. 136 mg/cigarette to 0. 428 mg/cigarette. Keywords Capillary electrophoresis; Electrochemical detection; Nicotine; Tobacco Article ID 1005-9040(2012)-03-415-04 1 Introduction Nicotine accounts for about 98%(mass fraction) of the total alkaloids and presents in a concentration of 0. %? 8% (mass fraction) in tobacco[1,2]. And nicotine addiction is related with higher risk for many kinds of diseases such as Alzheimer’s, Parkinson’s and even suicide[3,4]. Thus it’s necessary to control nicotine amount in tobacco products. Determination of nicotine is ver y important in both the tobacco industry and toxicology area[5]. A lot of analytical methods have been established for the analysis of nicotine and related alkaloids, such as radioimmunoassay[6], spectrophotometry[5], near-infrared spectroscopy[7], and recently flow injection(FI) with electrochemiluminescence(ECL) detection[8].The most frequently used analytical techniques for nicotine and its relative compounds determination are high performance liquid chromatography(HPLC)[9? 15] and gas chromatography (GC)[16? 23] with mass spectrometry(MS). Besides, HPLC coupled with UV-visible absorption(UV)[24? 28] or GC with flame ionization detector(FID)[1,29,30] and atomic emission detector(AED)[31] have also been developed to determine nicotine and related alkaloids. Capillary electrophoresis(CE) is characterized by high separation efficiency, short analysis time and a small amount of reagent consumed.Moreover, capillary column is flexible for use, easy to be treated with and cost effective . CE has been considered as an efficient alternative for HPLC technique[32]. Up to now, various detectors have been combined with CE separation for nicotine analysis, such as CE-MS[33,34], nonaqueous CE(NACE)-MS[35], CE-UV[36? 38], microchip mi- cellar electrokinetic chromatography(microchip MEKC)-UV[39] and CE with dual light-emitting diode induced fluorescence (LEDIF) and ECL detection[40]. Electrochemical(EC) detection has received more attention due to the simple manipulation and good selectivity.Electrocatalytic oxidation properties of nicotine have been investigated at multi-walled carbon nanotube-alumina-coated silica nanocomposite modified glassy carbon electrode(MWCNTACS-GCE), MWCNT-GCE and pencil graphite electrode[3,41,42]. HPLC with EC detection has been used for nicotine assay in plasma and hair[43,44]. NACE-EC was also established for tobacco nicotine detection[45]. In this paper, a simple CE-EC analytical procedure at a carbon fiber microdisk electrode(CFE) was develo ped. The linear range was 5. 0? 10–7? 1. 0? 10–4 mol/L, with a correlation coefficient of 0. 989. The limit of detection(LOD, S/N=3) obtained was 5. 0? 10–8 mol/L. To evaluate the applicability of the proposed CE-EC method, seven different cigarette brands were tested. Nicotine amounts ranged from 0. 211 mg/g to 0. 583 mg/g in pipe tobacco of seven brands of cigarette and the amount in one cigarette varied from 0. 136 mg/cigarette to 0. 428 mg/cigarette. 2 2. 1 Experimental Reagents All the reagents were of analytical grade that were used as received without further purification. Nicotine(purity 99. 7%) was obtained from Alfa Aesar(USA). Stock solution of 1. ? 10–3 mol/L nicotine was prepared in doubly distilled water ——————————— *Corresponding author. E-mail: [email  protected] jl. cn Received June 20, 2011; accepted November 24, 2011. Supported by the National Natural Science Foundation of China(No. 20875085). 416 CHEM. RES. CHINESE UNIVERSITIES Vol. 28 and stored at 4  °C. Na2HPO4, NaH2PO4, H3PO4 and NaOH were used for phosphate buffer solutions(PBS) preparation. All the solutions were prepared and diluted with doubly distilled water unless otherwise indicated. PBS was prepared daily with doubly distilled water.All the solutions were filtered through a 0. 22 ? m membrane before use. Different brands of cigarette were purchased from local market. high detection sensitivity. As shown in Fig. 2, with the increase of the applied detection potential, the current response increased slowly between 0. 70 and 1. 00 V, and then increased quickly between 1. 00 and 1. 20 V. Higher detection potential than 1. 20 V led to a peak current decrease and background noise increase. To achieve high detection sensitivity, 1. 20 V was selected as the optimum applied detection potential. 2. 2 ApparatusEC experiment was conducted with a Voltammetric Analyzer(CHI 800, USA). A conventional three-electrode system was employed with a 33-? m CFE as working electrode, a Pt wire as counter electrode and an Ag/AgCl electrode as reference electrode. An uncoated fused-silica capillary with i. d. of 25 ? m and length of 45 cm(Ruifeng Chromatogram Equipment Co. , Ltd. , Hebei, China) was used for sampling and separation. Capillary was rinsed in 0. 1 mol/L NaOH overnight before use. Every day before experiments, it was flushed with doubly distilled water for about 10 min and balanced with running buffer for about 15 min.CE-EC was conducted on a self-assembly instrument including a Voltammetric Analyzer(CHI 800, USA) and a high voltage supplier(MPI-A, Remax Electronic Co. , Ltd. , Xi’an, China). Sample injection was performed electrokinetically for 10 s at 10 kV. Fig. 2 HDV investigation of nicotine c(Nicotine)=1. 0? 10–5 mol/L; sample injection: 10 s at 10 kV; separation voltage: 20 kV; CE buffer: 40 mmol/L PBS(pH 2. 0); cell buffer: 0. 1 mol/L PBS(pH 8. 0). 3. 3 Optimization of CE-EC Conditions 3 3. 1 Results and Discussion Cyclic Voltammetry(CV) CV was used to investigate the electrochemical behavior of nicotine.A dramatic current increased from 0. 70 V was observed for nicotine(Fig. 1, curve b) compared with that of background electrolyte(Fig. 1, curve a), indicating that nicotine had high electroactivity at CFE. The adsorption property of CFE for nicotine was also investigated under CV experiment, however, no adsorption phenomenon of nicotine was observed. Since the oxidation potential of nicotine was not high at CFE, CE coupled with EC at CFE is practical for nicotine determination. Some other important factors including buffer concentration and buffer pH as well as separation voltage were investigated.Running buffer pH value influences the charge-mass ratio of the analyte and then influences the electrophoresis behavior of the analyte. We investigated the effect of pH values on the detection between pH 2. 0 and pH 10. 0 as shown in Fig. 3. Fig. 3 Effect of pH of CE buffer on detection of nicotine pH: a. 2; b. 4; c. 6; d. 8; e. 10. Separation voltage: 14 kV; other conditions were the same as those in Fig. 2. Fig. 1 Cyclic voltammetry curve of nicotine a. Background electrolyte, 0. 1 mol/L PBS(pH 8. 0); b. 1. 0? 10–3 mol/L nicotine; scan rate: 0. 05 V/s. 3. Hydrodynamic Voltammogram(HDV) Investigation Since applied detection potentials influence the detection sensitivity, thus we investigated the HDV of nicotine to achieve At pH 2. 0, nicotine was fully protonated and electroosmotic flow(EOF) was well restrained. EC response was the highest at pH 2. 0, and then decreased with the increase of pH value. With the increase of pH value, the migration time decreased correspondingly. Strong acidic CE buffer pH is more beneficial to sensitive and selective determination of nicotine. In consideration of the detection sensitivity, pH 2. was selected as the proper CE buffer pH value. Separation voltage is an important factor that influences the detection sensitivity and the migration time. When the separation voltage was changed from 10 kV to 20 kV, the migration time decreased from 14 min to 7 min correspondingly. No. 3 SUN Jin-ying et al. 417 As for EC response, when the separation voltage increased from 10 kV to 18 kV, the EC intensity of nicotine increased quickly, after that it decreased quickly from 18 kV to 20 kV(shown in Fig. 4). Detection sensitivity at 16 kV was higher than that at 18 kV.In consideration of the detection sensitivity, 16 kV was selected as the optimum separation voltage. supermarket. Pipe tobacco of 0. 1 g was weighed and placed in a polyethylene tube, in which 10 mL of solvent was added for nicotine extraction. Then, 10  µL of the extraction solution was transferred into a new polyethylene tube and diluted 100 times by doubly distilled water and the diluted extraction solution was used for analysis. 4. 2 Investigation of Extraction Solvents Fig. 4 Effect of separation voltage on detection of nicotine Applied detection potential: 1. 20 V; other conditions are as those in Fig. . 3. 4 Linear Range and LOD To obtain high extraction efficiency, solvents including water, methanol, chloroform and ethyl acetate were investigated. Current response of nicotine extracted with different solvents is shown in Fig. 5. Current response of nicotine was the highest when water was used as solvent. Methanol was also efficient for the extraction of nicotine from pipe tobacco. However, when methanol was used as solvent, migration time prolonged and the baseline shifted. When chloroform was used for extraction, current response was about 36% of that when water was used for extraction.Only very low response was found when ethyl acetate was used as solvent. Water was selected as nicotine extraction solvent for the highest nicotine current response obtained. Under the selected conditions: an applied detection potential of 1. 20 V; sample injection for 10 s a t 10 kV; a separation voltage of 16 kV; 40 mmol/L PBS(pH 2. 0) as running buffer and 0. 1 mol/L PBS(pH 8. 0) as detection buffer, EC response of nicotine was linear with concentration from 5. 0? 10–7 mol/L to 1. 0? 10–4 mol/L(81? 16200  µg/L)(y = –0. 2566+0. 4884x, R2= 0. 9978) and LOD(S/N=3) of nicotine was determined to be 5. 0? 10–8 mol/L(8.  µg/L). The proposed CE-EC method was compared with HPLC-MS[9,10], HPLC-UV[24,28], CE-UV[38,39], CE-MS[34], CE-LEDIF-ECL[40], microchip CE-UV[39], NACE-MS[35] and NACE-EC[45] methods(Table 1). From Table 1 we can know that linear range and LOD of CE-EC are nearly comparable with those of HPLC-MS[9] and UV[24] or NACE-EC[45] methods and CE-EC is almost 2000 times more sensitive than microchip CE method. Table 1 Method HPLC-MS HPLC-MS FI-ECL HPLC-UV HPLC-UV CE-MS NACE-MS CE-UV Micorchip CE-UV CE-LEDIF-ECL NACE-EC CE-EC Fig. 5 Extraction solvent comparison a. Water; b. methanol; c. chloroform; d. ethyl acetate.Sep aration voltage: 16 kV; injection: 10 s at 10 kV; applied detection potential: 1. 20 V; cell buffer: 0. 1 mol/L PBS(pH 8. 0); CE buffer: 40 mmol/L PBS(pH 2. 0). 4. 3 Extraction Time Investigation Comparison of CE-EC with other methods for nicotine determination Linear range/(? g ·L–1) 10? 10000 1? 100 0? 16000 25? 500 250? 100000 — 500? 100000 1724? 17240 — — 100? 10000 81? 16200 LOD/(? g ·L–1) 10 1 0. 19 8 100 0. 55 20 — 16000 259. 2 13 8. 1 Ref. [9] [8] [22] [24] [28] [34] [35] [38] [39] [40] [45] Our method The influence of extraction time on nicotine detection was investigated between 2 and 7 h.When extraction time was increased from 2 h to 4 h, the nicotine response kept increasing. But when extraction time continued to increase, the current response decreased, which may be due to the nicotine decomposition under room conditions. We chose 4 h as proper extraction time based on the experiment result. 4. 4 Tobacco Analysis 4 4. 1 Ciga rette Analysis Extraction Procedure Seven brands of cigarettes were purchased from local Pipe tobacco of 0. 1 g of each seven brands of cigarettes was weighed respectively and 10 mL of doubly distilled water was used for nicotine extraction.Nicotine amounts ranged from 0. 211 mg/g to 0. 583 mg/g in the pipe tobacco of each of seven brands of cigarettes. Nicotine amount in one cigarette varied from 0. 136 mg/cigarette to 0. 428 mg/cigarette(as listed in Table 2). The results obtained are slightly less than the amounts reported in the literature[46]. With the increase of nicotine concentration, the recovery decreased. For 5. 0? 10–6, 5. 0? 10–5 and 5. 0? 10–4 mol/L of nicotine, the recoveries were 80%, 75% and 418 CHEM. RES. CHINESE UNIVERSITIES [20] [21] [22] [23] [24] [25] [26] [27] B, 2006, 844, 322 Vol. 28 72%, respectively(n=3).Table 2 Nicotine amounts in pipe tobacco and cigarette obtained by CE-EC analysis Number of tobacco sample 1 2 3 4 5 6 7 Nicotine amo unt in pipe tobacco/(mg ·g–1) 0. 518 0. 502 0. 454 0. 211 0. 583 0. 454 0. 421 Nicotine amount in cigarette/ (mg ·cigarette–1) 0. 337 0. 355 0. 316 0. 136 0. 428 0. 327 0. 276 Man C. N. , Gam L. H. , Ismail S. , Lajis R. , Awang R. , J. Chromatogr. Lafay F. , Vulliet E. , Flament-Waton M. M. , Anal. Bioanal. Chem. , 2010, 396, 937 Shrivas K. , Patel D. K. , Food Chem. , 2010, 122, 314 Bao M. L. , Joza P. , Rickert W. S. , Lauterbach J. H. , Anal. Chim. Acta, 2010, 663, 49 Sharp M. P. , Hale T.W. , Hackett L. P. , Kristensen J. H. , Ilett K. F. , J. Chromatogr. B, 2003, 796, 173 Jablonski J. E. , Schlesser J. E. , Mariappagoudar P. , J. Agric. Food Chem. , 2006, 54, 7460 Nakajima M. , Kwon J. T. , Tanaka E. , Yokoi T. , Anal. 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Quality Engineering And Management Systems Education Essay

SamplingA is that portion ofA statisticalA pattern concerned with the choice of an indifferent orA randomA subset of single observations within a population of persons intended to give some cognition about theA populationA of concern, particularly for the intents of doing anticipations based onA statistical illation. Sampling is an of import facet ofA informations collection.AL The three chief advantages of trying are that the cost is lower, informations aggregation is faster, and since the information set is smaller it is possible to guarantee homogeneousness and to better the truth and quality of the informations. EachA observationA mensurate one or more belongingss ( such as weight, location, colour ) of discernible organic structures distinguished as independent objects or persons. InA study sampling, study weights can be applied to the informations to set for theA sample design. Results fromA chance theoryA andA statistical theoryA are employed to steer pattern. Stipulating aA trying frame, aA setA of points or events possible to mensurate Stipulating aA trying methodA for choosing points or events from the frame Successful statistical pattern is based on focussed job definition. In trying, this includes specifying theA populationA from which our sample is drawn. A population can be defined as including all people or points with the characteristic one want to understand. Because there is really seldom adequate clip or money to garner information from everyone or everything in a population, the end becomes happening a representative sample ( or subset ) of that population. Although the population of involvement frequently consists of physical objects, sometimes we need to try over clip, infinite, or some combination of these dimensions. For case, an probe of supermarket staffing could analyze check-out procedure line length at assorted times, or a survey on endangered penguins might take to understand their use of assorted runing evidences over clip. For the clip dimension, the focal point may be on periods or distinct occasions.Sampling frameIn the most straightforward instance, such as the sentencing of a batch of stuff from production ( credence sampling by tonss ) , it is possible to place and mensurate every individual point in the population and to include any one of them in our sample. However, in the more general instance this is non possible. There is no manner to place all rats in the set of all rats. Not all frames explicitly list population elements. For illustration, a street map can be used as a frame for a door-to-door study ; although i t does n't demo single houses, we can choose streets from the map and so see all houses on those streets. The sampling frame must be representative of the population and this is a inquiry outside the range of statistical theory demanding the judgement of experts in the peculiar capable affair being studied. All the above frames omit some people who will vote at the following election and incorporate some people who will non ; some frames will incorporate multiple records for the same individual. Peoples non in the frame have no chance of being sampled. Statistical theory Tells us about the uncertainnesss in generalizing from a sample to the frame. In generalizing from frame to population, its function is motivational and implicative. A frame may besides supply extra ‘auxiliary information ‘ about its elements ; when this information is related to variables or groups of involvement, it may be used to better study design.Probability and non chance tryingAA chance samplingA strategy is one in which every unit in the population has a opportunity ( greater than zero ) of being selected in the sample, and this chance can be accurately determined. The combination of these traits makes it possible to bring forth indifferent estimations of population sums, by burdening sampled units harmonizing to their chance of choice. Probability trying includes: Simple Random Sampling, Systematic Sampling, and Stratified Sampling, Probability Proportional to Size Sampling, and Cluster or Multistage Sampling. These assorted ways of chance trying have two things in common: Every component has a known nonzero chance of being sampled and Involves random choice at some point. Nonprobability samplingA is any trying method where some elements of the population haveA noA opportunity of choice, or where the chance of choice ca n't be accurately determined. It involves the choice of elements based on premises sing the population of involvement, which forms the standard for choice. Hence, because the choice of elements is nonrandom, nonprobability sampling does non let the appraisal of trying mistakes. These conditions place bounds on how much information a sample can supply about the population. Information about the relationship between sample and population is limited, doing it hard to generalize from the sample to the population. Nonprobability Sampling includes: A Accidental Sampling, A Quota SamplingA andA Purposive Sampling. In add-on, nonresponse effects may turnA anyA chance design into a nonprobability design if the features of nonresponse are non good understood, since nonresponse efficaciously modifies each component ‘s chance of being sampled.Sampling methodsWithin any of the types of frame identified above, a assortment of trying methods can be employed, separately or in combination. Factors normally act uponing the pick between these designs include: Nature and quality of the frame Handiness of subsidiary information about units on the frame Accuracy demands, and the demand to mensurate truth Whether detailed analysis of the sample is expected Cost/operational concernsSimple random tryingIn aA simple random sampleA ( ‘SRS ‘ ) of a given size, all such subsets of the frame are given an equal chance. Each component of the frame therefore has an equal chance of choice: the frame is non subdivided or partitioned. Furthermore, any givenA pairA of elements has the same opportunity of choice as any other such brace ( and likewise for three-base hits, and so on ) . This minimises prejudice and simplifies analysis of consequences. In peculiar, the discrepancy between single consequences within the sample is a good index of discrepancy in the overall population, which makes it comparatively easy to gauge the truth of consequences. However, SRS can be vulnerable to trying mistake because the entropy of the choice may ensue in a sample that does n't reflect the make-up of the population. For case, a simple random sample of 10 people from a given state willA on averageA produce five work forces and five adult females, but any given test is likely to overrepresent one sex and underrepresent the other.A SRS may besides be cumbrous and boring when trying from an remarkably big mark population. In some instances, research workers are interested in research inquiries specific to subgroups of the population. For illustration, research workers might be interested in analyzing whether cognitive ability as a forecaster of occupation public presentation is every bit applicable across racial groups. SRS can non suit the demands of research workers in this state of affairs because it does non supply subsamples of the population.Systematic samplingSystematic samplingA relies on set uping the mark population harmonizing to some telling strategy and so choosing elements at regular intervals through that ordered list. Systematic trying involves a random start and so returns with the choice of everyA kth component from so onwards. In this instance, A k= ( population size/sample size ) . It is of import that the starting point is non automatically the first in the list, but is alternatively indiscr iminately chosen from within the first to theA kth component in the list. Equally long as the get downing point isA randomized, systematic sampling is a type ofA chance trying. It is easy to implement and theA stratificationA induced can do it efficient, A ifA the variable by which the list is ordered is correlated with the variable of involvement. However, systematic sampling is particularly vulnerable to cyclicities in the list. If cyclicity is present and the period is a multiple or factor of the interval used, the sample is particularly likely to beA unrepresentative of the overall population, doing the strategy less accurate than simple random sampling. Another drawback of systematic sampling is that even in scenarios where it is more accurate than SRS, its theoretical belongingss make it hard toA quantifyA that truth. Systematic sampling is an EPS method, because all elements have the same chance of choice.Stratified samplingWhere the population embraces a figure of distinguishable classs, the frame can be organized by these classs into separate â€Å" strata. † Each stratum is so sampled as an independent sub-population, out of which single elements can be indiscriminately selected. There are several possible benefits to stratified sampling. First, spliting the population into distinguishable, independent strata can enable research workers to pull illations about specific subgroups that may be lost in a more generalised random sample. Second, using a graded sampling method can take to more efficient statistical estimations ( provided that strata are selected based upon relevancy to the standard in inquiry, alternatively of handiness of the samples ) . Even if a graded sampling attack does non take to increased statistical efficiency, such a maneuver will non ensue in less efficiency than would simple random sampling, provided that each stratum is relative to the group ‘s size in the population. Third, it is sometimes the instance that informations are more readily available for single, preexistent strata within a population than for the overall population ; in such instances, utilizing a graded sampling attack may be more convenient than aggregating informations across groups ( though this may potentially be at odds with the antecedently noted importance of using criterion-relevant strata ) . Finally, since each stratum is treated as an independent population, different trying attacks can be applied to different strata, potentially enabling research workers to utilize the attack best suited ( or most cost-efficient ) for each identified subgroup within the population.A graded sampling attack is most effectual when three conditions are metVariability within strata are minimized Variability between strata are maximized The variables upon which the population is stratified are strongly correlated with the coveted dependant variable.Advantages over other trying methodsFocuss on of import subpopulations and ignores irrelevant 1s. Allows usage of different trying techniques for different subpopulations. Improves the accuracy/efficiency of appraisal. Licenses greater reconciliation of statistical power of trials of differences between strata by trying equal Numberss from strata changing widely in size.DisadvantagesRequires choice of relevant stratification variables which can be hard. Is non utile when there are no homogenous subgroups. Can be expensive to implement.Probability proportional to size samplingIn some instances the sample interior decorator has entree to an â€Å" subsidiary variable † or â€Å" size step † , believed to be correlated to the variable of involvement, for each component in the population. This information can be used to better truth in sample design. One option is to utilize the subsidiary variable as a footing for stratification, as discussed above. Another option is probability-proportional-to-size ( ‘PPS ‘ ) sampling, in which the choice chance for each component is set to be relative to its size step, up to a upper limit of 1. In a simple PPS design, these choice chances can so be used as the footing forA Poisson sampling. However, this has the drawbacks of variable sample size, and different parts of the population may still be over- or under-represented due to opportunity fluctuation in choices. To turn to this job, PPS may be combined with a systematic attack. The PPS attack can better truth for a given sample size by concentrating sample on big elements that have the greatest impact on population estimations. PPS sampling is normally used for studies of concerns, where component size varies greatly and subsidiary information is frequently available – for case, a study trying to mensurate the figure of guest-nights spent in hotels might utilize each hotel ‘s figure of suites as an subsidiary variable. In some instances, an older measuring of the variable of involvement can be used as an subsidiary variable when trying to bring forth more current estimations.Bunch tryingSometimes it is cheaper to ‘cluster ‘ the sample in some manner e.g. by choosing respondents from certain countries merely, or certain time-periods merely. ( About all samples are in some sense ‘clustered ‘ in clip – although this is seldom taken into history in the analysis. ) Cluster samplingA is an illustration of ‘two-stage trying ‘ or ‘multistage trying ‘ : in the first phase a sample of countries is chosen ; in the 2nd phase a sample of respondentsA withinA those countries is selected. This can cut down travel and other administrative costs. It besides means that one does non necessitate aA trying frameA naming all elements in the mark population. Alternatively, bunchs can be chosen from a cluster-level frame, with an element-level frame created merely for the selected bunchs. Cluster trying by and large increases the variableness of sample estimations above that of simple random sampling, depending on how the bunchs differ between themselves, as compared with the within-cluster fluctuation. However, some of the disadvantages of bunch trying are the trust of sample estimation preciseness on the existent bunchs chosen. If bunchs chosen are biased in a certain manner, illations drawn about population parametric quantities from these sample estimations will be far off from being accurate.Matched random tryingA method of delegating participants to groups in which brace of participants are foremost matched on some characteristic and so separately assigned indiscriminately to groups. The process for matched random sampling can be briefed with the following contexts, Two samples in which the members are clearly paired, or are matched explicitly by the research worker. For illustration, IQ measurings or braces of indistinguishable twins. Those samples in which the same property, or variable, is measured twice on each topic, under different fortunes. Normally called perennial steps. Examples include the times of a group of jocks for 1500m before and after a hebdomad of particular preparation ; the milk outputs of cattles before and after being fed a peculiar diet.Quota tryingInA quota sampling, the population is foremost segmented intoA reciprocally exclusiveA sub-groups, merely as inA stratified trying. Then judgement is used to choose the topics or units from each section based on a specified proportion. For illustration, an interviewer may be told to try 200 females and 300 males between the age of 45 and 60. It is this 2nd measure which makes the technique one of non-probability sampling. In quota trying the choice of the sample is non-random. For illustration interviewers might be tempted to interview those who look most helpful. The job is that these samples may be biased because non everyone gets a opportunity of choice. This random component is its greatest failing and quota versus chance has been a affair of contention for many old agesConvenience samplingConvenience samplingA is a type of nonprobability trying which involves the sample being drawn from that portion of the population which is close to manus. That is, a sample population selected because it is readily available and convenient. The research worker utilizing such a sample can non scientifically do generalisations about the entire population from this sample because it would non be representative plenty. For illustration, if the interviewer was to carry on such a study at a shopping centre early in the forenoon on a giv en twenty-four hours, the people that he/she could interview would be limited to those given there at that given clip, which would non stand for the positions of other members of society in such an country, if the study was to be conducted at different times of twenty-four hours and several times per hebdomad. This type of trying is most utile for pilot proving. Several of import considerations for research workers utilizing convenience samples include: Are there controls within the research design or experiment which can function to decrease the impact of a non-random, convenience sample whereby guaranting the consequences will be more representative of the population? Is at that place good ground to believe that a peculiar convenience sample would or should react or act otherwise than a random sample from the same population? Is the inquiry being asked by the research 1 that can adequately be answered utilizing a convenience sample?Panel samplingPanel samplingA is the method of first choosing a group of participants through a random trying method and so inquiring that group for the same information once more several times over a period of clip. Therefore, each participant is given the same study or interview at two or more clip points ; each period of informations aggregation is called a â€Å" moving ridge † . This trying methodological analysis is frequently chosen for big graduated table or nation-wide surveies in order to estimate alterations in the population with respect to any figure of variables from chronic unwellness to occupation emphasis to weekly nutrient outgos. Panel sampling can besides be used to inform research workers about within-person wellness alterations due to age or aid explicate alterations in uninterrupted dependent variables such as bridal interaction. There have been se veral proposed methods of analysing panel sample informations, including MANOVA, growing curves, and structural equation patterning with lagged effects.Replacement of selected unitsSampling strategies may beA without replacementA orA with replacing. For illustration, if we catch fish, mensurate them, and instantly return them to the H2O before go oning with the sample, this is a WR design, because we might stop up catching and mensurating the same fish more than one time. However, if we do non return the fish to the H2O ( e.g. if we eat the fish ) , this becomes a WOR design.FormulasWhere the frame and population are indistinguishable, statistical theory outputs exact recommendations onA sample size. However, where it is non straightforward to specify a frame representative of the population, it is more of import to understand theA cause systemA of which the population are results and to guarantee that all beginnings of fluctuation are embraced in the frame. Large Numberss of observ ations are of no value if major beginnings of fluctuation are neglected in the survey. In other words, it is taking a sample group that matches the study class and is easy to study. Research Information Technology, Learning, and Performance JournalA that provides an account of Cochran ‘s expression. A treatment and illustration of sample size expressions, including the expression for seting the sample size for smaller populations, is included. A tabular array is provided that can be used to choose the sample size for a research job based on three alpha degrees and a set mistake rate.Stairss for utilizing sample size tabular arraiesContend the consequence size of involvement, I ± , and I? . Check sample size tabular array Choose the tabular array matching to the selected I ± Locate the row matching to the coveted power Locate the column matching to the estimated consequence size The intersection of the column and row is the minimal sample size required.Sampling and informations aggregationGood informations aggregation involves: Following the defined sampling procedure Keeping the information in clip order Noting remarks and other contextual events Recording non-responses Most sampling books and documents written by non-statisticians focused merely in the informations aggregation facet, which is merely a little though of import portion of the sampling procedure.Mistakes in researchThere are ever mistakes in a research. By trying, the entire mistakes can be classified into trying mistakes and non-sampling mistakes.Sampling mistakeSampling mistakes are caused by trying design. It includes: ( 1 ) A Selection mistake: Incorrect choice chances are used. ( 2 ) A Estimation mistake: Biased parametric quantity estimation because of the elements in these samples.Non-sampling mistakeNon-sampling mistakes are caused by the errors in informations processing. It includes: ( 1 ) A Overcoverage: Inclusion of informations from exterior of the population. ( 2 ) A Undercoverage: Sampling frame does non include elements in the population. ( 3 ) A Measurement mistake: The respondents misunderstand the inquiry. ( 4 ) A Processing mistake: Mistakes in informations cryptography. In many state of affairss the sample fraction may be varied by stratum and informations will hold to be weighted to right stand for the population. Thus for illustration, a simple random sample of persons in the United Kingdom might include some in distant Scots islands who would be extraordinarily expensive to try. A cheaper method would be to utilize a graded sample with urban and rural strata. The rural sample could be under-represented in the sample, but weighted up suitably in the analysis to counterbalance. More by and large, informations should normally be weighted if the sample design does non give each person an equal opportunity of being selected. For case, when families have equal choice chances but one individual is interviewed from within each family, this gives people from big families a smaller opportunity of being interviewed. This can be accounted for utilizing study weights. Similarly, families with more than one telephone line have a greater opportunity of being selected in a random figure dialing sample, and weights can set for this.

Synthesis And Characterization Of Strontium Ferrite Environmental Sciences Essay

Strontium ferrite is a ferromagnetic stuff and reported as holding hexangular magnetoplumbite type ( M-type ) construction. It is the most widely used lasting magnets throughout the universe, which account for approximately 90wt % of the one-year production of lasting magnets. In this survey, the Sr ferrite is synthesized utilizing sol-gel methods and the magnetic belongingss were analyzed. Chapter 1 gave debut about the construction of M-type hexangular Sr ferrite. Besides, some general magnetic belongingss will be discussed. Commercial applications of Sr ferrite would be discussed every bit good. Chapter 2 is all about the experimental inside informations, including the man-made techniques used for Sr ferrite, description of instrument used and processs carried out. Chapter 3 concentrated on the consequences on magnetic susceptibleness of hexangular Sr ferrite. Comparison between Sr ferrite and cation-substituted Sr ferrite was made. Chapter 4 concluded the whole probe of this survey. Suggestions for future surveies were besides discussed. Better apprehension of the belongingss and practical applications of Sr ferrite can be achieved through this survey.AbstractionThe belongingss of magnetoplumbite type ( M-type ) hexangular Sr ferrite has been investigated. The effort of permutation of Co ( II ) oxide and Ti ( IV ) oxide in order to bring forth a quaternate system of the type SrO-Fe2O3-XO where Ten represents the dopant cation was made. The synthesis is based on sol-gel method where ethene ethanediol is the gel precursor. This technique was employed because it was found to be able to bring forth nanoparticles of cation substituted Sr ferrite. Furthermore, sol-gel method can bring forth high outputs of Sr ferrite atoms. Overall, the magnetic belongingss were observed to be alteration after the cation permutation. Co ( II ) -Ti ( IV ) permutation in SrFe12O19 with different ratios were made in this survey to look into the consequence of cation permutation in magnetic belongingss of Sr ferrite. Co ( II ) -Ti ( IV ) permutation in Sr ferrite with mole ratio of 0.4 showed the best magnetic belongingss that we desired for. The mass susceptibleness where X = 0.4 was found to be increase aggressively compared to the unsubstituted 1. Except the Co Ti permutation with mole ratio of 0.4, other cation permutation ratios showed lessening in mass susceptibleness which is non desirable. Therefore the cobalt-titanium permutation for SrCoxTixFe12-2xO19 with X = 0.4 is the best to better magnetic belongingss of Sr ferrite for assorted commercial applications. Reappraisal Strontium ferrite has been a topic of uninterrupted involvement and intensive survey for several decennaries due to the fact that this compound has been the the most widely used lasting magnets, which account for approximately 90wt % of the one-year production of lasting magnets since shortly after its find in the fiftiess. Strontium hexaferrite, SrFe12O19, is a ferrimagnet and is besides known as ceramic lasting magnet. When compared with alnico-magnets, Sr ferrite has high coercivity, moderate remenance, corrosion opposition and first-class chemical stableness [ 5 ] . Iron ( III ) oxide ( Fe2O3 ) is the chief constituents in SrFe12O19 which gives rise to its magnetic belongingss. Within the five different crystallographic sites of Sr ferrite, the Fe ions are coupled antiferromagnetically. Due to its high magnetocrystalline anisotropy field in its construction, SrFe12O19 exhibits high impregnation magnetisation and high coercivity [ 1 ] . The high magnetic permeableness in Sr ferrit e enables it to hive away strong magnetic Fieldss, which is stronger than Fe. Strontium ferrite is frequently produced as nanoscale size pulverization, which can be sintered into solid nucleuss. Strontium ferrite has been used for several of import industrial applications, such as lasting magnets, microwave devices and high denseness perpendicular entering media, with proper doping in order to better belongingss of Sr ferrite [ 1 ] . SrFe12O19 has besides been investigated as a medium for magnetic recording and magneto-optical recording and for long ( millimeter ) -wave devices [ 2 ] . Attempts have made to the development of fresh man-made methods which facilitate the production of all right hexangular ferrite atoms and to possible ways of cut downing their high intrinsic magnetocrystalline anisotropy. The aim in this survey was to try the synthesis of cation substituted M-type hexangular ferrite SrCoxTixFe12-2xO19 utilizing the sol-gel method. The sol-gel method has been used widely to bring forth all right atoms of a assortment of oxides. The consequence of doping Sr ferrite with Co ( II ) and Ti ( IV ) oxides to bring forth quaternate systems of SrO-Fe2O3-XO, where Ten represents the dopant cation would be tested. The all right atoms of cation substituted ferrite produced by utilizing sol-gel technique is desirable because the grain size of the stuffs used in magnetic recording is the chief factor finding the degree of background noise at low denseness. Magnetic belongingss of Sr ferrite would be focus in this survey. Magnetic susceptibleness balance would be used to find the mass susceptibleness for both strontium ferrite and cation-substituted Sr ferrite produced utilizing the sol-gel method. The mass susceptiblenesss of the samples were compared to find the optimal sum of cation needed to dope to ferrite to give the best magnetic behavior.CRYSTAL STRUCTURE OF M-TYPE HEXAGONAL SrFe12O19Harmonizing to crystalline construction, hexaferrite can be classified into four types, these include M, W, Y and Z types hexaferrites which correspond to ( SrO + MeO ) : Fe2O3 ratios of 1:6, 3:8, 4:6 and 5:12 severally. SrFe12O19 is classified as M-type hexaferrite. The hexangular SrFe12O19 was foremost prepared by AdelskA?old in 1938 [ 2 ] . He besides confirmed that the crystal construction of this compound to be iso-structural with the of course happening ferrite mineral magnetoplumbite, and hence it has the M-type construction. Subsequently structural polishs for Sr hexaferrite have confirmed his finding [ 2 ] . Strontium ferrite is classified as hexangular ferrite. It is denoted as holding the infinite group P63/mmc. Harmonizing to the research made by Kimura et Al, the lattice parametric quantities measured are found to be: a = 0.588 36nm and c = 2.303 76nm at room temperature [ 2 ] . As shown for M-type hexaferrite BaFe12O19 in Fig. 1.1, the crystalline constructions of different types of hexaferrites are unusually complex. The unit cell contains 10 O beds. A unit cell is consecutive constructed for four blocks, they are S ( spinel ) , R ( hexangular ) , S* and R* . The S and R blocks have tantamount atomic agreements and are rotated around the c-axis at 180A ° with regard to S* and R* blocks. Roentgen or R* block consists of three O2a?’A beds while S or S* block contains two O2a?’A beds ; with one O site in the in-between bed substituted by a Ba2+A ion [ 16 ] . The construction of Sr ferrite is similar to that of Ba ferrite, by merely replacing the Ba ion with strontium ion. Fig.A 1.1: A Structure of Ba hexaferrite Occasionally, a unit cell is comprises of two formula units. The unit cell consists of 64 ions per hexangular unit cell, which are 2 strontium ions, 38 O ions and 24 ferrous ions. The construction of magnetoplumbite are made of a bed of hexangular close jammed agreement of O and Sr ions, which is sandwiched between two spinal blocks incorporating a three-dimensional close-packed agreement of O atoms with Fe atoms. The Fe atoms are positioned at five interstitial crystallographically different cation sites of the close-packed beds, viz. 4f1 ( tetrahedral site, A sites ) , 12k, 4f2, 2a ( octahedral sites, B sites ) and 2b ( rhombohedral bipyramidal site ) [ 15 ] . The tetrahedral Fe oxide is FeO4, octahedral Fe oxide consists of six O ions, which is FeO6, and the expression for rhombohedral bipyramidal Fe oxide is FeO5. A conventional M-type structural representation and the five Fe3+ sites are shown in Fig. 1.2 by Collomb et Al. [ 15 ] . Figure 1.2: The crystal construction study map of the hexangular M-type stage and the five Fe sites with their milieus are displayed. The 2b sites merely occur in the same bed with strontium ion. 12k site is the octahedral site of S and R blocks. There are two tetrahedral ( 4f1 ) sites and one octahedral ( 2a ) site in Centre of S block. The two octahedral ( 4f2 ) sites are found in the R block, adjacent to the strontium-containing bed. The M-type construction of strontium ferrite gives rise to its magnetic belongingss. Cation permutation to strontium ferrite may give opportunities whereby changing the construction and therefore act upon the magnetic belongingss.MAGNETIC PROPERTIES OF M-TYPE HEXAGONAL SrFe12O19Strontium hexaferrite is a ferrimagnetic stuff. Since the free negatrons in SrFe12O19 are in close propinquity and remain aligned even the external magnetic field have been removed, it is able to retain a lasting magnetic field and is recognized as ferrimagnetic stuff. In 1950s Gorter predicted that the Fe ions at the rhombohedral bipyramidal ( 2b ) and octahedral ( 2a, 12k ) sites have their spin orientation antiparallel to that of the Fe ions at the 4f sites [ 2 ] . The antiparallel 4f1 and 4f2 and parallel 2a, 12k and 2b sublattices form the ferrimagnetic construction. The magnetic ordination corresponding to the magnetoplumbite construction of hexangular Sr ferrite is good illustrated in Fig. 1.3. In S block, the bulk I ±-sublattice consists of four octahedral ions and the minority I?-sublattice contains two tetrahedral ions whereas R block contributes three octahedral ions and one rhombohedral ion to the bulk sublattice and two octahedral ions to the minority sublattice. Figure 1.3: The conventional construction ( left ) of the SrFe12O19 with Gorter ‘s magnetic ordination ( in-between ) along the c-axis. The big unfastened circles are oxygen ions, the big broken circles are Sr ions ; little circles with a cross inside represent Fe ions at 12k, little circles incorporating a filled circle inside represent Fe ions at 4f2, little unfilled circles represent Fe ions at 4f1, filled little circles represent Fe ions at 2a and little circles with a unfilled circle inside represent Fe ions at 2b. The magnetic construction suggested by Gorter is shown on the right, where the pointers represent the way of spin polarisation. From Fig. 1.3, we can sum up the sites of Fe ( III ) ions matching to the spin way, as in Table 1.1. Site Coordination Occupancy Direction of spin polarisation 12k Octahedral 12 Up 2a Octahedral 2 Up 2b Trigonal Bypiramidal 2 Up 4f1 Tetrahedral 4 Down 4f2 Octahedral 4 Down Table 1.1: Fe ( III ) ion sites in M-type hexangular ferriteHysteresis LoopThe magnetic belongingss of Sr ferrite can be examined through hysteresis cringles. Hysteresis cringle can be measured utilizing instruments such as Vibrating Sample Magnetometer ( VSM ) and SQUID Magnetometry Measurements. When a magnetic stuff is placed in a magnetic field, the flux denseness ( B ) would dawdle behind the magnetising force ( H ) that causes it, and this signifier hysteresis cringle. From a hysteresis cringle, we can place the magnetic belongingss of the stuff, they are saturation magnetisation, remanence or besides known as remnant magnetisation, and coercivity. A typical hysteresis cringle is good illustrated in Fig. 1.4. Figure 1.4: Typical hysteresis cringle ( B-H curve ) Initially, there is no applied magnetic field and it is known as unmagnetized province. After magnetic field is applied, it causes alignment. Until maximal magnetising force applied, maximal flux denseness achieved at the same clip and this phenomenon is known as impregnation magnetisation. At this point, the maximal figure of spin has mobilized. Saturation magnetisation is defined as the maximal possible magnetization of a stuff. It is besides a step of strongest magnetic field a magnet can bring forth. The unit of impregnation magnetisation is in amperes per metre. Strontium ferrite is holding high impregnation magnetisation at which it can hive away high sum of magnetising force. As the magnetizing force being easy removed, the alliance stays at the point where H = 0, this is known as remnant magnetisation. Remnant magnetisation is the magnetisation left in a lasting magnet after an external magnetic field is removed. When a magnet is â€Å" magnetic † , it has remanence. I t is normally measured in unit Tesla. Strong lasting magnet such as Sr ferrite has high leftover magnetisation which means the high sum of magnetic force remains in it even after the magnetizing force is removed. As signifier Fig. 1.4, negative magnetic field is applied to demagnetise the lasting magnet. When the flux denseness ( B ) = 0, there is no magnetising force remain in the magnet and the negative H needed to demagnetise the magnet is known as coercivity. Negative H is the magnetic field applied in opposite way. Coercivity is measured in unit amperes per metre. Due to its high uniaxial magnetocrystalline anisotropy with an easy axis of magnetisation along the hexangular c-axis in the construction, SrFe12O19 has high coercivity. Anisotropy is directional or orientational effects in crystal construction of stuffs which can supply better magnetic public presentation along certain preferable axis. Therefore, we need to use high negative magnetising force to demagnetise Sr ferrite. Attempts have to be made to take down down the coercivity of Sr ferrite for use. Unit of measurements in Magnetism The units used in magnetic attraction can be divided chiefly into two classs, SI system and c.g.s system. The transition table shown in Table 1.2 is to clear up the magnetic attraction expression in both SI and c.g.s systems and the transition factors between them. Measure Symbol SI Unit SI Equation c.g.s Unit c.g.s Equation Conversion Factor Magnetic Initiation Bacillus tesla ( T ) B=A µo ( H+M ) gauss ( G ) B = H+4IˆM 1 T = 104A G Magnetic Field Strength Hydrogen ampere/meterA ( A/m ) H = NA-I/lcA ( lc – magneticA way, m ) oersted ( Oe ) H = 0.4IˆNA-I/lc ( lc – magneticA way, centimeter ) 1 A/m =A 4 IˆA-10-3A Oe Magnetic Flux I ¦ Wb ( Wb ) I ¦ = BA-Ac ( Ac – country, m2A ) Mx ( M ) I ¦ = BA-Ac ( Ac – country, cm2A ) 1 Wb = 108A M Magnetization Meter ampere/meter ( A/m ) M=m/V ( m- sum magnetic minute, A V- volume, m3A ) emu/cm3 M=m/V ( m- sum magnetic minute, A V- volume, cm3A ) 1 A/m = 10-3A electromagnetic unit / cm3 Magnetic Permeability of Vaccum A µo newton/ampere2 A µo= 4IˆA-10-7 1–4IˆA-10-7 Induction Liter H L=I?oI?N2Ac/lc ( Ac- country, M2, A lc – magnetic way, m ) H L=0.4IˆI?N2Ac/lcA-10-8 ( Ac-area, cm2, A lc – magnetic way, centimeter ) 1 Emf ( electromotive force ) Volt V V=-NA-dI ¦/dt V V=-10-8NA-dI ¦/dt 1 Note: In the above equations, I = current ( in As ) , N = bends Table 1.2: Magnetism expressions in SI and c.g.s systems and their transition factors for the magnetic units.1.4 PHOTOLUMINESCENCE PROPERTIES OF SrFe12O19Harmonizing to the survey of G. B. Teh et.al [ 3 ] on Sr ferrite, Sr ferrite was found to exhibit photoluminescence behaviour. When a sample of Sr ferrite is excited at a certain wavelength, highest strength of photoluminescence emanation extremums was obtained. The ability of Sr ferrite to photoluminesce could be due to the O vacancies in their lattice construction. The O vacancies are assumed to do the atoms to exhibit photoluminescence behaviour by moving as traps for nomadic excitement. The O vacancies have effectual +2 charges, doing them powerful electron gaining control centres. Valence negatron would derive sufficient energy to leap from the valency set to the conductivity set and go forthing a spread known as hole during excitement. F-centers, which is the part where contain high sum of negatrons would organize when the aro used negatrons being trapped in O vacancies. These rich negatron centres would take to emanation of luminescence when the holes and negatrons recombine.1.5 SYNTHESIS ROUTE OF SrFe12O19The processing paths used for synthesis of Sr ferrite affect its belongingss much. Traditionally, this ferrite pulverization is synthesized by a assorted oxide ceramic method, which involves the solid-state reaction between SrCO3 and Fe2O3 at a high calcination temperature ( about 1300A °C ) . However, uncontrolled atom morphology, larger atom size and agglomerates would be the biggest disadvantages of this technique. Besides, taint would be introduced to the sample while subsequent milling of the calcined ferrite pulverization and this would impact the magnetic belongingss become less desirable. Therefore, the narrowed atom size distribution, refined atom size and minimum atom agglomeration has been the chief concern during the synthesis of Sr ferrite. In order to better the magnetic belongingss, legion nonconventional soft man-made paths have been carried out, including sol-gel synthesis [ 3 ] , hydrothermal reaction [ 6 ] , co-precipitation [ 7 ] , citric acid method [ 8 ] and microemulsion processing [ 10 ] . In this survey, the synthesis of Sr ferrite employed the sol-gel technique. It is a wet chemical path using ethylene ethanediol as gel precursor. Sol-gel technique is the technique of utilizing chemical substances which have high solubility in organic dissolvers to synthesise precursor compounds. The compounds are easy transformed into hydrated oxides on hydrolysis. The metal alkoxides formed can be removed easy utilizing hydrolysis and thermic intervention and therefore consequences in hydrous oxides which are extremely purify. Sol-gel method is used in this survey because of its many advantages. Sol-gel technique is able to bring forth homogenous nanosized crystallites. This method is tend to give molded stuffs straight from a solution without go throughing through the pulverization processing and the fact that the annealing temperature is really low compared with other conventional engineering. The crystalline size and belongingss of the ferrite produced are mostly affected by calcinations temperature [ 3 ] . Sol gel method has the advantage that the crystal growing of atoms is easier to command by changing the heat intervention [ 11 ] . It was reported that at 500EsC it produced merely maghemite, I?-Fe2O3. A assorted merchandise of magnetic I ±-Fe2O3 and M-type SrFe12O19 were obtained at 600EsC. As the calcination temperature addition to 800EsC and supra, there are merely M-type SrFe12O19 stage was observed. Sol-gel synthesis is able to bring forth high outputs of SrFe12O19 nanoparticles. It is besides able to bring forth nanocrystallite of cation substituted SrFe12O19. Nanoparticle size of Sr ferrite is desirable and aimed to synthesise because nanoparticles tend to give better magnetic belongingss. Nanoparticles give few magnetic spheres, likely individual sphere. Single sphere tends to give higher magnetic initiation because there are no oppose magnetic sphere. Single sphere aligns in one way merely. These belongingss are ideal for the devising of lasting magnet.1.6 CATION SUBSTITUTION IN SrFe12O19In order to better the magnetic belongingss of Sr ferrite, many surveies have been carried out. One of them is cation permutation in Sr ferrite. Rare Earth and other metal cations are used for permutation for Sr and Fe severally [ 5 ] . The brace doping of SrFe12O19 such as a La-Co brace to replace a Sr-Fe brace has been tested [ 14 ] . The doping, or known as cation permutation, is aim to better the magnetic belongingss of Sr ferrite. Cation permutation consequences in structural al terations in Sr ferrite. As the physical belongingss of ferrite alteration, the magnetic belongingss would be affected due to the fact that magnetic belongingss are determined by the agreement of Fe ions in crystal construction. In this survey, Co-Ti brace will be doped to the Sr ferrite. Cobalt Ti permutation will bring forth a quaternate system of the type SrO-Fe2O3-AO where A represents the dopant cation.The Co Ti permutation gives rise to the new expression, SrCoxTixFe12-2xO19 where Ten is the figure of mole of cation substituted in.1.7 Commercial ApplicationsStrontium ferrite is widely used as lasting magnet because it has way of easy magnetisation and the hexangular c-axis which are perpendicular to the plane of the home base. The belongingss that are desirable in utilizing as lasting magnet include high impregnation magnetisation, high leftover magnetisation, high coercivity, high Curie temperature and high magnetocrystalline anisotropy. Besides, SrFe12O19 is besides normally used in high-density informations storage magnetic entering media. Nanoparticles of SrFe12O19 with individual sphere and low coercivity are important in used for magnetic recording media. M-type Sr ferrite nanoparticles have attracted much attending due to their good frequence characteristic, low noise, high end product, in peculiar, first-class high frequence characteristic and broad dynamic frequence scope [ 4 ] . There are two types of entering medium, viz. particulates and thin movies. Tape and floppy is categorized in particulate and difficult thrust is belongs to thin movie. Information is stored by magnetising stuff. The entering caput can use magnetic field ( H ) and align spheres to magnetise the medium. It can besides observe a alteration in the magnetisation of the medium. Magnetic entering media prefers high impregnation magnetisation ; do it to hive away as much information. High value of remnant magnetisation is required in enterin g media to do certain that all stuffs stored in the difficult disc still remained even the power supply ( applied magnetic field ) is switched away. Low coercivity is of import in magnetic recording media. When the positive magnetic field is applied, this charging manages the medium to hive away informations. On the other manus, negative magnetic field applied to recover back the information, this is called discharges. Therefore, less current is needed to recover the information in the low coercivity medium. As a consequence, less heat generated and this saves the electricity. In general, Sr ferrite has high value of uniaxial anisotropy field, high coercive force and high impregnation magnetisation. The high coercivity of Sr ferrite has to be lowered down and impregnation magnetisation has to be at the same time increased if it is to be utile for magnetic recording intents. It has been reported that the permutation of cations such as Co ( II ) for the ion Fe ( III ) in Sr ferrite has lowered the coercive force. Therefore, many surveies were carried out to accomplish better magnetic belongingss of Sr ferrite for commercial applications.Chapter 2: EXPERIMENTALSample PreparationSynthesis of M-type SrFe12O19 Synthesis of Cation Substituted SrFe12O19Sample CharacterizationMagnetic Susceptibility Balance MK12.1 Sample Preparation2.1.1 Synthesis of M-type SrFe12O19The sol-gel technique was used to synthesise M-type SrFe12O19 whereby the ethene ethanediol acts as gel precursor. The starting stuffs, Sr nitrate, Sr ( NO3 ) 2 and Fe ( III ) nitrate-9-hydrates, Fe ( NO3 ) 3A ·9H2O were used due to their high solubility in ethylene ethanediol. Calculation below was made to find the weight of stuffs needed to be used. Relative Molecular Mass of stuffs: Strontium nitrate, Sr ( NO3 ) 2 = 211.63 g/mol Iron ( III ) nitrate-9-hydrates, Fe ( NO3 ) 3A ·9H2O = 404 g/mol ( Note: All replies have to be converted into 3 important figures. ) No. of mol of 1 g Sr ( NO3 ) 2 = Mass of Sr ( NO3 ) 2 RMM of Sr ( NO3 ) 2 = 1g 211.63g/mol = 4.7252Ãâ€"10-3 mol Strontium: Fe = 1: 12 No. of mol of Fe ( NO3 ) 3A ·9H2O needed = 4.7252Ãâ€"10-3 mol x 12 = 5.6702Ãâ€"10-2 mol Mass of Fe ( NO3 ) 3A ·9H2O needed = No. of mol of Fe ( NO3 ) 3A ·9H2O needed ten RMM of Fe ( NO3 ) 3A ·9H2O = 5.6702Ãâ€"10-2 mol x 404g/mol = 22.9 g From the computation, 1g of Sr nitrate and 22.9g of Fe ( III ) nitrate-9-hydrates were needed in the synthesis and were weighted. Strontium nitrate would supply 1 mol of Sr ions and Fe ( III ) nitrate-9-hydrates would supply 12 mol of Fe ions in the synthesis of Sr ferrite, which matched the molecular expression of SrFe12O19. The Sr nitrate and Fe ( III ) nitrate-9-hydrates were readily dissolved in ethene ethanediol with little heat applied due to their high solubility in it. The mixture was heated somewhat and stirred with a magnetic saloon until the mixture was to the full dissolved. The attendant solution is in crystalline ruddy colour. The magnetic stirring saloon was removed. The mixture was heated to 100A °C and it would easy transform into a gel signifier. The gel was dried with uninterrupted heating at 100A °C for 3 hours. The dried gel was so transferred to a crucible to take hints of organic precursor. A mixture of metal oxides in spread nanoclusters signifier was obtained. The dried gel was so annealed in a furnace at 800A °C for 3 yearss with extended land with a stamp in a howitzer after annealed at interval of each twenty-four hours.2.1.2 Synthesis of Cation Substituted SrFe12O19Cation substituted strontium ferrite was synthesized by utilizing Co ( II ) ions and Ti ( IV ) ions to replace the Fe ions in M-type hexangular Sr ferrite. The permutation of Co ( II ) and Ti ( IV ) gives the compound a new molecular expression, which is SrCoxTixFe12-2xO19 where the x denoted different ratios. In the synthesis of cation substituted SrFe12O19, the ratios of cations used, x, is in between 0.2 to 6.0 ( 0.2 a†°Ã‚ ¤ x a†°Ã‚ ¤ 6.0 ) , where ten = 0.2, 0.4, 0.6, 0.8, 1.0, 2.0, 3.0, 4.0, 5.0 and 6.0. The same method described in subdivision 2.1.1 was used for the synthesis, by merely adding two new get downing stuffs, which are the Co ( II ) nitrate and Ti ( IV ) ethoxide to give the Co2+ and Ti4+ cations. Calculation as described below was made to cipher the weight of stuffs needed severally. Relative Molecular Mass of stuffs: Strontium nitrate, Sr ( NO3 ) 2 = 211.63 g/mol Iron ( III ) nitrate-9-hydrates, Fe ( NO3 ) 3A ·9H2O = 404 g/mol Cobalt ( II ) nitrate, Co ( NO3 ) 2.6H2O = 291.04 g/mol Titanium ( IV ) ethoxide, Ti ( CC2H5 ) 4 = 228.11 g/mol ( Note: All replies have to be converted into 3 important figures. ) Examples used for the computation: SrCo0.2Ti0.2Fe11.6O19, x= 0.2 No. of mol of 1 g Ti ( CC2H5 ) 4 = Mass of Ti ( CC2H5 ) 4 RMM of Ti ( CC2H5 ) 4 = 1g 228.11g/mol = 4.3838Ãâ€"10-3 mol 0.2 mol of Ti needed 1 mol of Sr. 4.3838Ãâ€"10-3 mol of Ti needed ( 4.3838Ãâ€"10-3 mol x 1 ) mol of Sr. 0.2 Therefore, 0.021919 mol of Sr is needed. Mass of Sr ( NO3 ) 2 needed = 0.021919mol ten 211.63 g/mol = 4.64 g 0.2 mol of Ti needed 11.6 mol of Fe. 4.3838Ãâ€"10-3 mol of Ti needed ( 4.3838Ãâ€"10-3 mol x 11.6 ) mol of Sr. 0.2 Therefore, 0.25426 mol of Fe is needed. Mass of Fe ( NO3 ) 3A ·9H2O needed = 0.25426mol ten 404g/mol = 103 g Mass of Co ( NO3 ) 2.6H2O needed = 4.3838Ãâ€"10-3 mol x 291.04g/mol = 1.28 g The computation above were used to cipher the weight of get downing stuffs needed for other cation ratios, ten for 0.4, 0.6, 0.8, 1.0, 2.0, 3.0, 4.0, 5.0 and 6.0 severally every bit good. The weight needed for each stuff was tabulated in Table 2.1. ten Weight of stuffs needed ( g ) Sr ( NO3 ) 2 Fe ( NO3 ) 3A ·9H2O Co ( NO3 ) 2.6H2O 0.2 4.64 103 1.28 0.4 2.32 51.4 1.28 0.6 1.55 31.9 1.28 0.8 1.11 23.0 1.28 1.0 0.93 17.7 1.28 2.0 0.46 7.08 1.28 3.0 0.31 3.54 1.28 4.0 0.23 1.77 1.28 5.0 0.19 0.71 1.28 6.0 0.15 0.00 1.28 Table 2.1: Weight of stuffs needed for synthesis of Co ( II ) -Ti ( IV ) substituted Sr ferrite For the series of different permutation ratios ( ten ) , the corresponding Sr nitrate, Fe ( III ) nitrate-9-hydrates, Co ( II ) nitrate and Ti ( IV ) ethoxide were weighed and dissolved in 100ml ethene ethanediol. The oxides obtained after ignition were so annealed in a furnace at 800A °C for 3 yearss with extended land with a stamp in a howitzer after annealed at interval of each twenty-four hours. The readying for Sr ferrite and cation substituted strontium ferrite is shown in Fig. 2.1 in flow chart array. Figure 2.1: Conventional diagram of the process for synthesis of Sr ferrite and cobalt-titanium substituted SrFe12O19.Sample CharacterizationMagnetic Susceptibility Balance MK1The magnetic belongingss of Sr ferrite and cobalt-titanium substituted Sr ferrite produced by the method described above were examined utilizing the Magnetic Susceptibility Balance MARK 1 ( MK1 ) by Sherwood Scientific Ltd, England. The magnetic susceptibleness balance setup was shown in Fig. 2.2. Figure 2.2: Magnetic Susceptibility Balance MK1 by Sherwood Scientific Ltd, England. The basic design rule of Magnetic Susceptibility Balance MK1 was shown in Figure 2.3. Magnetic Susceptibility Balance determines the magnetic belongingss by puting two twosome of traveling magnets with the beam in between where the stationary sample is ready to be measured. Basically, the possible warp in the beam and the motion being made of a peculiar sample either solid or liquid could be observed in a balanced system which possesses a magnetic field. Meanwhile, the spiral within the instrument is conducted with current required in order to do compensation of the magnetic force produced by the sample. Either paramagnetic or diamagnetic could be resolved in a asset or minus comparatively on show with the assistance of the way that the beam Swift. Figure 2.3: Basic design rule of Magnetic Susceptibility Balance MK1 by Sherwood Scientific Ltd, England. Magnetic susceptibleness is defined as when the magnetising field is applied to the sample, how much is the ratio of the strength of magnetic attraction induced by the sample in response to the magnetising field which it is capable. In this experiment, mass susceptibleness was the chief concern. Mass susceptibleness, xg, is defines by the mathematical expression below: ?‘?g= ‘?v/d Where vitamin D = denseness of substance ?‘?v is the volume susceptibleness, calculated by utilizing the expression: ?‘?v = I/H Where I = strength of magnetic attraction produced in a substance H = strength of applied magnetic field Based on the magnetic belongingss of magnetic substances, they can be classified into one of the three groups. Among them, there is paramagnetic stuff which would pull by a strong magnetic field, diamagnetic which repelled by magnetic field and ferromagnetic which is alone to retain their ain magnetic field. After the external magnetic field is removed, ferromagnetic stuffs are still able to retain a lasting magnetic field. This is happened due to their free negatrons are in close propinquity and remain aligned without the magnetic field. Strontium ferrite and cobalt-titanium substituted Sr ferrite were found to be ferromagnetic due to the overshooting value observed on the show when the samples were introduced. To get the better of this job, a non-magnetic stuff Na chloride, was used to ‘dilute ‘ the big magnetic attraction induced by the samples. Procedure was carried out. First, the scope boss of Magnetic Susceptibility Balance MK1 was turned to the x1 graduated table and was allowed to warm up for 10 proceedingss before usage. The nothing boss is adjusted until the show reads 000. An empty sample tubing of known weight was placed into the tubing usher and the reading, Ro was taken. 0.0005g sample + 0.2820g NaCl ( sample length, fifty =3cm ) was packed into the sample column. The weight of samples and Na chloride were fixed for all measurings made. The jammed sample tubing was placed into tubing usher and the reading, R was taken. The stairss were repeated for all the 11 samples. The mass susceptibleness, ‘?g is calculated utilizing the expression: ?‘?g= CBal* cubic decimeter * ( R-Ro ) 109 * m Where: cubic decimeter = length of sample ( centimeter ) m = mass of sample ( gm ) R = balance reading for sample + tubing Ro = balance reading for empty tubing CBal = the balance standardization changeless ( =1 )Chapter 3: Consequence AND DISCUSSION3.1 Consequences of Mass Susceptibility3.1.1 Mass susceptibleness of M-type SrFe12O19 3.1.2 Mass susceptibleness of Cation Substituted SrFe12O19 3.1.3 Table of mass susceptibleness of SrFe12O19 and Co ( II ) -Ti ( IV ) substituted SrFe12O19 3.1.4 Graph of mass susceptibleness, ‘?g ( cgs ) against Co ( II ) -Ti ( IV ) ratio3.2 Findingss and Discussion3.1 RESULTS OF MASS SUSCEPTIBILITYMass susceptiblenesss of the samples were calculated utilizing the expression: ?‘?g= CBal* cubic decimeter * ( R-Ro ) 109 * m Where: cubic decimeter = sample length ( centimeter ) m = sample mass ( gm ) R = balance reading for sample in tubing Ro = balance reading for empty tubing CBal = the balance standardization changeless ( =1 ) * All the replies are adjusted to 4 important figures.3.1.1 Mass Susceptibility of M-type SrFe12O19?‘?g = CBal* cubic decimeter * ( R-Ro ) 109 * m = 1 ten 3cm ten [ 936- ( -036 ) ] 109 x 0.0005 = 1.944Ãâ€"10-43.1.2 Mass Susceptibility of Cation Substituted SrFe12O19SrCo0.2Ti0.2Fe11.6O19 ?‘?g = CBal* cubic decimeter * ( R-Ro ) 109 * m = 1 ten 3cm ten [ 798- ( -036 ) ] 109 x 0.0005 = 1.668Ãâ€"10-4 SrCo0.4Ti0.4Fe11.2O19 ?‘?g = CBal* cubic decimeter * ( R-Ro ) 109 * m = 1 ten 3cm ten [ 671- ( -036 ) ] 109 x 0.0005 = 1.414Ãâ€"10-4 SrCo0.6Ti0.6Fe10.8O19 ?‘?g = CBal* cubic decimeter * ( R-Ro ) 109 * m = 1 ten 3cm ten [ 654- ( -036 ) ] 109 x 0.0005 = 1.380Ãâ€"10-4 SrCo0.8Ti0.8Fe10.4O19 ?‘?g = CBal* cubic decimeter * ( R-Ro ) 109 * m = 1 ten 3cm ten [ 542- ( -036 ) ] 109 x 0.0005 = 1.156Ãâ€"10-4 SrCo1.0Ti1.0Fe10O19 ?‘?g = CBal* cubic decimeter * ( R-Ro ) 109 * m = 1 ten 3cm ten [ 441- ( -036 ) ] 109 x 0.0005 = 0.954Ãâ€"10-4 SrCo2.0Ti2.0Fe8O19 ?‘?g = CBal* cubic decimeter * ( R-Ro ) 109 * m = 1 ten 3cm ten [ 236- ( -036 ) ] 109 x 0.0005 = 0.544Ãâ€"10-4 SrCo3.0Ti3.0Fe6O19 ?‘?g = CBal* cubic decimeter * ( R-Ro ) 109 * m = 1 ten 3cm ten [ 162- ( -036 ) ] 109 x 0.0005 = 0.396Ãâ€"10-4 SrCo4.0Ti4.0Fe4O19 ?‘?g = CBal* cubic decimeter * ( R-Ro ) 109 * m = 1 ten 3cm ten [ 145- ( -036 ) ] 109 x 0.0005 = 0.362Ãâ€"10-4 SrCo5.0Ti5.0Fe2O19 ?‘?g = CBal* cubic decimeter * ( R-Ro ) 109 * m = 1 ten 3cm ten [ -006- ( -036 ) ] 109 x 0.0005 = 0.060Ãâ€"10-4 SrCo6.0Ti6.0O19 ?‘?g = CBal* cubic decimeter * ( R-Ro ) 109 * m = 1 ten 3cm ten [ -066- ( -036 ) ] 109 x 0.0005 = -0.060Ãâ€"10-43.1.3 Table of mass susceptibleness of SrFe12O19 and Co ( II ) -Ti ( IV ) substituted SrFe12O19The mass susceptiblenesss of the samples calculated were summarized in Table 1. Samples Sample length, cubic decimeter ( centimeter ) Sample mass, m ( gm ) Empty tubing reading, R0 Reading for tubing + sample, R Mass susceptibleness, xg SrFe12O19 0.1 0.0005 -036 936 1.944Ãâ€"10-4 SrCo0.2Ti0.2Fe11.6O19 0.1 0.0005 -036 798 1.668Ãâ€"10-4 SrCo0.4Ti0.4Fe11.2O19 0.1 0.0005 -036 671 1.414Ãâ€"10-4 SrCo0.6Ti0.6Fe10.8O19 0.1 0.0005 -036 654 1.380Ãâ€"10-4 SrCo0.8Ti0.8Fe10.4O19 0.1 0.0005 -036 542 1.156Ãâ€"10-4 SrCo1.0Ti1.0Fe10O19 0.1 0.0005 -036 441 0.954Ãâ€"10-4 SrCo2.0Ti2.0Fe8O19 0.1 0.0005 -036 236 0.544Ãâ€"10-4 SrCo3.0Ti3.0Fe6O19 0.1 0.0005 -036 162 0.396Ãâ€"10-4 SrCo4.0Ti4.0Fe4O19 0.1 0.0005 -036 145 0.362Ãâ€"10-4 SrCo5.0Ti5.0Fe2O19 0.1 0.0005 -036 -006 0.060Ãâ€"10-4 SrCo6.0Ti6.0O19 0.1 0.0005 -036 -066 -0.060Ãâ€"10-4 Table 3.1: Mass susceptibleness, xg of SrFe12O19 and Co ( II ) -Ti ( IV ) substituted SrFe12O193.1.4 Graph of mass susceptibleness, ‘?g ( cgs ) against Co ( II ) -Ti ( IV ) ratioA graph of mass susceptibleness of SrFe12O19 and Co ( II ) -Ti ( IV ) substituted SrFe12O19 against Co ( II ) -Ti ( IV ) ratio was plotted and shown in Graph 3.1. Figure 3.1: Graph of mass susceptibleness, ‘?g ( cgs ) against Co ( II ) -Ti ( IV ) ratio3.2 FINDINGS AND DISCUSSIONMagnetic susceptibleness is a step of response of negatrons in sample to an applied magnetic field. Electrons produce magnetic minutes at where the negatrons spin circularly around the karyon following right-thumb regulation. The net magmetic minute is the amount of minutes from all negatrons. There are three types of magnetic attraction ; they are ferromagnetic or ferrimagnetic, paramagnetic and diamagnetic. Strontium ferrite is a ferrimagnetic compound due to its high magnetic initiation, B when magnetic field, H is applied. The magnetic minutes of ferrimagnetic Sr ferrite is aligned parallel with applied magnetic field. It is a of course magnet because the magnetic minutes are point at one way even there is no magnetic field is applied. The magnetic minute of M-type hexangular ferrites strongly prefer the hexangular axis way, which is the c-axis. Within the grain boundaries of ferrimagnetic atoms, the spheres are aligned in two waies opposing when there is no magnetic field applied. As the magnetic field is applied and strength of applied field ( H ) increases, the magnetic minute of ferrimagnetic stuff become aligns with H. The magnetic spheres with aligned magnetic minute grow at disbursal of ill aligned 1s. In the terminal, the magnetic spheres become individual sphere when the applied magnetic field additions until a point. Single magnetic sphere is desirable as it is easy to revolve the atoms for use. Single sphere besides gives higher magnetic initiation because there are no oppose magnetic sphere, the individual sphere align in one way merely. These belongingss are ideal for doing of lasting magnet. To a higher opportunity of obtaining individual sphere in atoms of a compound, the compound frequently produced in nanoparticles. Nanoparticles tend to give few magnetic spheres, likely individual sphere. This is due to the really little size of atoms tend to give the smallest sum of grain boundary, hence the opportunity of acquiring magnetic spheres in opposite way is little comparison to the big size atoms which have more grain boundaries. Therefore in this survey, sol-gel technique which is able to bring forth nano-sized atoms was employed. The magnetic belongingss of the hexangular Sr ferrites are strongly dependent upon the synthesis conditions and the site penchant of the substituted cations among the five different Fe3+ sublattices viz. , tetrahedral ( 4f1 ) , rhombohedral bipyramidal ( 2b ) and octahedral ( 12k, 2a and 4f2 ) of hexangular construction [ 13 ] . Mass susceptibleness is the ratio of the strength of magnetic attraction induced in the sample to the magnetizing field applied in response to the denseness of the substance. In commercial application, the mass susceptibleness is desirable as holding high value, for the use of strong lasting magnet and entering media. For the composing where x = 0.2, the substituted Sr ferrite recorded lessening in mass susceptibleness. The magnetic belongingss were non every bit desirable as the value of susceptibleness demands to be comparatively high. In the specimen with x = 0.4, a dramatically addition in mass susceptibleness was measured. The addition in susceptibleness indicated that the permutation of Co ( II ) -Ti ( IV ) had filled up the minor I?-sublattice ( spin-down ) of the magnetoplumbite construction and therefore enhanced the measured magnetization along the I ±-sublattice ( spin-up ) axis. In the specimen with x = 0.6, the mass susceptibleness decreased. The big lessening of susceptibleness indicated that at this ratio, the Co ( II ) -Ti ( IV ) cations may good hold occupied the cation sites which were in the I ±-sublattice ( spin-up ) . For x = 0.8 to 5.0, it was found that both specimens recorded similar values of susceptibleness. As the permutation of Co ( II ) -Ti ( IV ) increased, the susceptibleness showed a rapid lessening. It might hence be expected that farther permutation will later bring forth a superparamagnetic-like Sr ferrite. Superparamagnetism is a phenomenon by which magnetic stuffs may exhibit a behaviour similar to paramagnetism at temperatures below the Curie temperature. For x = 6.0 shows negative value of mass susceptibleness, indicates the formation of Co oxide and Ti dioxide which are diamagnetic. There are no Fe oxides which gives ferromagnetic belongingss. From the old published survey, the partial permutation of Fe3+ ions with a Co2+ + Ti4+ brace was attempted [ 4 ] . However, the coercive force reduces and at the same time impregnation magnetisation besides reduces. Therefore, the ratio of substituted cations is really of import in modifying the magnetic belongingss of ferrite. Single sphere atoms of Ti-Co substituted M-type hexaferrite posses attractive belongingss for the recording media applications [ 13 ] . Such permutations at Fe site are effectual in cut downing the coercivity and magnetocrystalline anisotropy but require higher annealing temperature for the individual stage formation. It has besides been reported that when synthesising Ti-Co substituted hexaferrites, it is hard to avoid the formation of Co ferrite. Although the coercivity lessening by the permutation of Co-Ni but at the same clip the impregnation magnetisation of the stuffs lessening which limit their applications in the high denseness entering media.Chapter 4: Decisions4.1 Decisions4.2 Future Work4.1 DecisionThe consequence of cation permutation on magnetic belongingss of Sr ferrite is discussed in the old chapter. The magnetic belongingss are differing matching to the different cation permutation ratios. There existed important tendency which corresponded to the alterations in perm utation ratio in Sr ferrite. The mass susceptibleness is the highest at x = 0.4 in SrCoxTixFe12-2xO19. This indicates that this cation permutation ratio gives best magnetic behavior where the magnetisation is the highest. This phenomenon is favorable for commercial application such as doing of lasting magnet and magnetic recording media.4.2 FUTURE WORKIn this survey, the magnetic belongingss of M-type hexangular SrFe12O19 and cation substituted SrFe12O19 was studied. One of the magnetic belongingss, mass susceptibleness of the ferrites was determined in this survey, by utilizing magnetic susceptibleness balance. Besides magnetic susceptibleness balance, the survey on magnetic belongingss can be improved by utilizing SQUID gaussmeter or vibrating sample gaussmeter ( VSM ) [ 12 ] to look into the impregnation magnetization, remnant magnetization and coercivity. These three magnetic belongingss are the indispensable one to find their magnetic behavior for assorted applications. However , these two instruments are non available in our research lab. The cobalt-titanium permutation is replacing the Fe sites alternatively of Sr sites. The Sr site could be substituted with other passage elements or rare earth elements with the similar atomic radii, illustration for Bi and rare earth. In future, farther survey could be carried out by substituted rare earth wholly to replace strontium ferrite to look into whether the M-type hexangular construction remains. One of the ways to heighten magnetic belongingss is to bring forth individual sphere atoms by partner offing the divalent-tetravalent permutation in Sr ferrite with appropriate man-made methods. Besides cation permutation by Co2+-Ti4+ brace, sol gel derived strontium ferrite with Fe substituted by Zn2+ , Ti4+ and Ir4+ have been carried out [ 9 ] . They are Zn2+-Ti4+ brace and Zn2+-Ir4+ brace. If this is true, it will hold a great impact on the engineering of tomorrow.