Study of Ceramic Perovskites-type Oxides (ABO3)

Study of Ceramic Perovskites-type Oxides (ABO3) 2.0 LITERATURE REVIEW 2.1 Introduction Ceramic perovskites-type oxides (ABO3) have been studied extensively due to the high conductivity and low activation energy. Among of perovskite type-oxide, an investigation of cerate zirconate attracts great attention to the researcher. It is well known as ion conductor and good chemical stability at intermediate temperature. It properties give big impact for development in technological applications like fuel cells, solar cells, batteries, etc. In addition, one advantages of perovskite is low cost as it can be made from common metals and industrial chemicals. According to Abdullah et al (2012), due to their low activation energy for proton conduction, the perovskite structure with proton-conducting electrolyte material important for development of Solid Oxide Fuel Cell (SOFCs) at intermediate temperature. The investigation of proton conductivity in perovskite has started more than two decades ago. Nd doped BaCeO3 and Y doped BaZrO3 indicate good proton conducting properties under humid at elevated temperature (Azad Irvine, 2007). Meanwhile, alkaline earth zirconates has lower proton conductivity but generally, better chemical and mechanical stability corresponding cerates (Abdullah, Hasan, Osman, 2013). SOFCs enable to convert chemical fuels directly into electrical power. The using SOFC used a ceramic electrolyte requires operating at high temperature and it will put this type of SOFC very great demands on the materials and technology lead to significant challenge for further development of the SOCF. Previous report has shown that the high temperature sintering resulted in large particle aggregation and growth and also consumed cost and time. Wet chemical methods (WCMs) used was able to lower the temperature as well as synthesizing time but the impurities that needed to be avoided still exist. Thus, many researchers analyze on the using of chelating agent to hinder the impurities (Abdullah, Hasan, Osman Nordin, 2012). 2.2 Hartree-Fock Hartree-Fock (HF) is the basis of molecular orbital (MO) Theory. HF method is an approximation method for determining the energies and wave functions in quantum mechanics. Unlike Density Functional Theory (DFT), the approximation of HF theory involves only exchange functional. It often gives qualitatively correct result. It can be systematically improved the result by carried out an MP2 or MP4 calculation, for example. HF theory was developed to solve the electronic Schrodinger equation resulted from time-dependent Schrodinger equation after refer to Bohn-Oppenheimer. The energy and many other properties of the particles can be obtained by solving Schrodinger Equation for wavefunction,. The Schrodinger equation describes the wavefunction of a particle: (1) = wavefunction m = mass of particle h = Planck’s constant V = potential field in which the particle is moving In molecular system, is a function of the positions of the electrons and the nuclei within the molecule, which will be designated as and, respectively. 2.2.1 Molecular Hamiltonian The Hamiltonian is made up of kinetic and potential energy. The kinetic energy is a summation ofover all the particles in the molecular and the potential energy component is the Coulomb repulsion between each pair of charged entities. T: (2) (3) (4) whereis the distance between two particles, and ej and ek are the charges on particles j dan k. For an electron, the charge is negative, e while for the nucleus the charge is positive, Ze, where Z is the atomic number for that atom. The full Hamiltonian can be written as: (5) From Born-Oppenheimer approximation which allows two parts of the problem to be solved independently, the kinetic energy for nuclei in Hamiltonian. 2.3 Density Functional Theory Density functional theory (DFT) is a quantum mechanical method that be used in physics field and has become one of the most commonly used techniques in computational chemistry. DFT is a well-known quantum mechanical method to investigate complex many-body problems at the electronics structure level such as charge, bond length, density and energy. Various names for DFT models are named through combination of exchange and correlation functional. DFT has two functional which is traditional functional and hybrid functional. The traditional functionals consist two types correlation components which are correlation functional and gradient-corrected functional. Correlation functionals involve only the values of the electron spin densities while gradient-corrected functionals involve both the values of the electron spin densities and their gradients. For the hybrid functional, it consist the combination of Hartree-Fock exchange and DFT exchange-correlation. For B3LYP, it contains the Becke Three Parameter Hybrid Functionals that using non-local correlation provided by Lee, Yang and Parr functionals, abbreviated as B3LYP. B3LYP exchange-correlation functional is: (6) Where a0 = 0.20, aX = 0.72, and aC = 0.81, while the and are generalized gradient approximation (GGA), is the VWN local density approximation (LDA) to the correlation functional. GGA originally are called nonlocals approximations or semilocal approximations. The gradient of density is usually determined numerically. However, GGA has limited applicapability. It cannot describe rlimit of xc-energy density and the xc-potential simultaneously correctly. Eschrig (1996) said the DFT method was important in providing the interested mathematician with the physicist’s view on the logical roots of the theory and also for those who want to get deeper insight into the meaning of the results of practical calculations. In addition, from previous study, DFT method was able to justify the interaction between ligands and metal fragments in coordination compound (Chermette, 1998). 2.4 Basis Set A basis set defined as the mathematical description of the orbitals within a system used to perform the theoretical calculation. Standard basis sets for electronic structure calculations use linear combinations of Gaussian functions to create the molecular orbitals. There are few types of basis set effects such as minimal basis sets, split valence basis sets, polarized basis sets and diffuse functions basis sets. Minimal basis sets on each atom in the molecules contain minimum number of basis function and they are fixed-size atomic-type orbital. Split valence basis sets can be made larger by increase the number of basis functions of each atom. The orbital is allowed to change the size but not the shape. In contrast with polarized basis sets that allow orbital to change size and shape by adding orbitals with angular momentum beyond what is required for the ground state to the description of each atom. The molecular orbitals are fixed linear combinations from one-electron functions and known as basis functions. They are centered on the nuclei of atom and share some similarity to atomic orbitals. An individual molecular orbital is defined as: (7) The coefficients c µi are known as the molecular orbital expansion coefficients. The further explanation for the above equation can be obtained in â€Å"Exploring Chemistry with Electronic Structure Method† books. 2.6 Metal Ligand Complexes The metal chelate has its own unique properties. The same ligand with different metal chelates share similar properties. The chelating agent complexes with the metal cation, forming a three-dimensional structure that blocks the ion’s normal reactive sites and prevents it from reacting as it normally would (â€Å"Chemical Properties of Chelates,† n.d.). The chelating agents can form coordination compounds with a metal ion as it is usually contain donor atoms like nitrogen and oxygen (Leopold et al., 2008). One of the acti ve investigations of the synthesizing methods for the formation of a single- phase cerate zirconate powder is the lowering of the processing temperature. Using different chelating agent can lower the temperature processing. Different strength of chelating agent gives different interaction during the chelation process(Abdullah et al., 2013). A recent report shows that the temperature can be lowered by combining TETA and Ba2+ cation in forming the ligand-metal complexes solution. The chelating agent of TETA effectively reduces the formation of BaCO3 in final powder (Abdullah et al., 2012).

Comparing My Papas Waltz by Theodore Roethke and Those Winter Sundays by Robert Hayden :: Comparison Compare Contrast Essays

Comparing "My Papa's Waltz" by Theodore Roethke and "Those Winter Sundays" by Robert Hayden My Papa's Waltz, by Theodore Roethke, and Those Winter Sundays, by Robert Hayden, are two somewhat similar poems about respected fathers. To most people a father is not just the man who fertilizes their mother's egg, but a man that spends time with and takes care of them. While doing this, he gains their love and respect. In these two poems Roethke and Hayden take an admiring look back at the actions of their fathers, although; they both imply that their parents were not perfect. In My Papa's Waltz, Theodore Roethke describes an episode in his childhood. In this, what seems to be regular, occurrence his drunken father comes home for the night reeking of alcohol and begins dancing with him. Roethke describes his father's hands as being battered on one knuckle and extremely soiled. They "romped until the pans slid from the kitchen shelf" (5-6). This made his mother so upset that she could do nothing but frown. Finally, his father "waltzed" him on to bed.   Ã‚  Ã‚  Ã‚  Ã‚  In ?Those Winter Sundays'; by Robert Hayden, the poet also relinquishes on a regular occurrence in his childhood. On Sunday mornings, just as any other morning, his father rises early and puts on his clothes in the cold darkness. He then goes out in the cold and splits fire wood with which he uses to start a fire in the house. After the entire house is warm he calls the rest of his family out of bed. He does not get any thanks for doing this, but that does not seem to matter.   Ã‚  Ã‚  Ã‚  Ã‚  In both poems the poets seem to look back on their childhoods with much love and respect for their fathers. In ?My Papa?s Waltz'; the title suggests a sense of love and honor. Usually when a child calls his father Papa they have a very close relationship in which the child respects and admires his father. Also, the use of the word Waltz suggests a Happy dance of high class people. This is ironic because Roethke?s father is drunken and dirty when this dance takes place, but when one thinks of the waltz they think of a dance between two high-classed people in an extravagant ballroom. Another example of the child?s love and respect for his father is illustrated in the things he overlooks just to be able to carryout the dance. Although ?The whiskey your [his father?s] breath could make a small boy dizzy'; (1-2), the child ?hung on like death'; (3). The speaker also overlooks the pain of his ear

Macroeconomics Of Japan Essay

Japan is the greatest economy in Asia, in terms of GDP, as well as human resources and technology. The nation was once predicted to be the next superpower nation exceeding the United Sates and countries of the European Union. Today, it is the world’s third-largest economy after the United States and People’s Republic of China. It is also the second-largest economy by real GDP and market exchange rates. The economy is highly efficient and competitive especially in the services industry, which is originated from a good cooperation between the government and the industry, a strong work ethic and the mastery of high technology. Recent analysis however, revealed that the economy is currently under serious problems. Observers and even Japan’s own officials have admitted that the economy is no longer ‘first class’. There are even worries that Japan has no longer sustain the capacity to be one of the world’s greatest economies anymore, and the economy will slowly degrade into one of the typical Asian economies. Analysts stated that such an occurrence has happened before, when Argentina which were once considered one of the strongest economies in the world degraded into typical third world economies today. Is this the case with Japan? In this paper I am discussing the problems that stayed within Japan’s economy and elaborating their probable causes. Afterwards, I will elaborate the macroeconomic policies which have been performed by the Japanese government in response to these issues and how these policies have affected the economy. The period of discussion is 1997 -2007, which are the years after the ‘Japan economic bubble’ bursts, to the present day. II. Japan Economic Issues 1997-2007 II. 1. Background of the Issues – Japan Economic Bubble Japanese growth rates have been nothing less than spectacular for decades. In the 60’s the average real economic growth rate was 10%, in the 70’s it was 5% and in the 80’s it was 4%. Japanese financial system however, was based on a bureaucratic fiat. The government believes that by injecting sufficient amount of capital into the market, the economy will experience a rapid rate of growth. Thus, the financial system was set to inject cheap capital into the business sector (Hamada, 2004). In support of this policy, banks even reluctant to report –in bad loans. In short, companies were encouraged to borrow and expand continuously. Companies would then borrow using assets like land and then invest the money into the stock market. After the market rises, the company would have latent profits which will be used to buy more land and therefore, the cycle continues. These cycles were the origins of the huge real estate and stock market bubbles. These bubbles however, cannot be sustained forever, and when the Bank of Japan (BOJ) raised interests rates, the bubble bursts in 1989 and leaving commercial banks in Japan with a mountain of bad loans. II. 2. Stagnant Economic Growth Afterwards, assets prices began to decline rapidly. Japan’s economy was going through a long period of deflation since then, partly caused by the appreciation of yen. Because of this appreciation, the CPI increase rate dropped into negative in 1995. The expanding deflation caused Japan’s economy to remain in a static condition. Moreover, the deepening deflation was accompanied with weakening state of real economy like growth rates declines and increased unemployment rates. Between 1992 and 1994, real growth rates are below 1%. It even dropped toward a negative range in 1998. Jobless rate have also suffered a rise of 3. 4 % from 2 % in 1990 to 5. 4% in 2003. The economic downsizing in 1997 put Japanese economy into a new state of deflation (Oliver, 2002). II. 3. Deflationary Trap It was not considered serious until the inflation rate slipped to below zero in 1997. In this phase, observers believed that Japan was in a ‘deflationary trap’. However, because of various long-term considerations, the government has implemented policies to maintain inflation stable near the zero mark. In this situation however, the central bank cannot use its traditional instruments to deal with the issue. As a result, deflation deepens even further and the market intensified expectations toward further and longer period of deflation. Due to the increase in real rate of interest, consumer spending and corporate investments were discouraged. Unfortunately, the shrinking total demand in the macro economy further worsen the deflation. If not dealt with accordingly, this could lead into self-sustaining deflationary process (Campbell, 1992).

Free Essays on International Business

ADCP International Marketing/Special Studies 1. a. Customers are the focal point of all marketing activities. Organizations have to define products not as what they make or produce but as what they do to satisfy customers. Marketing Barbie dolls would require a marketer to consider the socioculture of its consumers. Sociocultural forces are the influences in a society and its culture that bring about change in attitudes, beliefs, norms, customs, and lifestyles. There are three issues that need to be addressed in decided who will purchase a Barbie doll in international markets. First, there are constant changes in population demographic characteristics-age, gender, race, and ethnicity. The U. S. has entered into another baby boom, with 76 million Americans aged 18 or younger. Other nations may have this same occurrence and this information would help in directing attention to those areas that have a high representation of children wanting a Barbie doll. Another population trend is the increasing multicultural nature of U .S. society. The number of immigrants into the United States has steadily risen during the last thirty years, thus, the emergence of cultures emulating the U.S. Another thing to consider would be the modification of marketing practices to reach ethnically diverse customers to eliminate language barriers. Second, cultural values need to be addressed so that marketers can try to monitor changes in consumers’ needs for Barbie dolls and its products (clothes, accessories, etc.) in the near future. For instance, Barbie dolls were very popular when I was younger (not that I played with them, I had a sister) and today, they are not because of increased competition of other toy and doll makers. Video games have also become very popular in favor of toys. b. When marketing beer internationally, a marketer may have to consider the political/legal environment of the country they are trying to solicit. Some politic... Free Essays on International Business Free Essays on International Business The term Globalization was first coined in the 1980’s. However, the definition of globalization varies in cultural, economical, environmental, political and social studies. According to Williamson, globalization in economical studies refers to an increasing integration of the global economy through factor and product markets by way of direct investment, financial flow and trade greatly aided by the deregulation of markets as well as the liberation of capital movement and trade (Williamson 1998,1). It is a driving force that is expected to affect the countries well being in terms of trade, employment and income as well as the values of dollar in relative to other currencies and so on. Based on a study on the globalization’s rankings in the world, New Zealand is currently rank at number 23. (Graham, Crocombe. Michael, Enright and Michael, Porter 1991,12) In the following paragraphs, there will be an explanation how the globalization affects the New Zealand’s trade with other countries, especially for multinational company’s competition in international trade, employment opportunities for New Zealanders and some reasons which are beneficial and harmful to New Zealand as a whole as well as some policies that should be taken into consideration by other businesses and the government in order to benefit from it. According to the definition of globalization above, it also is simply to understand that globalization refers to the shift a more integrated and interdependent world economy. Globalization has two main components: the globalization of markets and the globalization of production (Charles, Hill 2003,6). The globalization of markets means each the merging of distinct and separate national markets into one huge global marketplace. Each country can sell its products internationally by falling trade barriers. It provides a chance for local companies to compete in international trade by offering qualified goods and services. Wh... Free Essays on International Business ADCP International Marketing/Special Studies 1. a. Customers are the focal point of all marketing activities. Organizations have to define products not as what they make or produce but as what they do to satisfy customers. Marketing Barbie dolls would require a marketer to consider the socioculture of its consumers. Sociocultural forces are the influences in a society and its culture that bring about change in attitudes, beliefs, norms, customs, and lifestyles. There are three issues that need to be addressed in decided who will purchase a Barbie doll in international markets. First, there are constant changes in population demographic characteristics-age, gender, race, and ethnicity. The U. S. has entered into another baby boom, with 76 million Americans aged 18 or younger. Other nations may have this same occurrence and this information would help in directing attention to those areas that have a high representation of children wanting a Barbie doll. Another population trend is the increasing multicultural nature of U .S. society. The number of immigrants into the United States has steadily risen during the last thirty years, thus, the emergence of cultures emulating the U.S. Another thing to consider would be the modification of marketing practices to reach ethnically diverse customers to eliminate language barriers. Second, cultural values need to be addressed so that marketers can try to monitor changes in consumers’ needs for Barbie dolls and its products (clothes, accessories, etc.) in the near future. For instance, Barbie dolls were very popular when I was younger (not that I played with them, I had a sister) and today, they are not because of increased competition of other toy and doll makers. Video games have also become very popular in favor of toys. b. When marketing beer internationally, a marketer may have to consider the political/legal environment of the country they are trying to solicit. Some politic...

How does Shakespeare present Hamlet in Act III scene II and III Essays

How does Shakespeare present Hamlet in Act III scene II and III Essays How does Shakespeare present Hamlet in Act III scene II and III Paper How does Shakespeare present Hamlet in Act III scene II and III Paper you can see who he likes or respects by the way he treats them. He is suspicious of people and thinks people are plotting against him. I think the play shows Hamlet as quite a lonely person because he has lost his father, we dont know if he loves Ophelia or not and he does not appear to trust anyone except Horatio.

Marketing Essay Example | Topics and Well Written Essays - 3750 words

Marketing - Essay Example Marketing has been defined differently by various authors. As per Eztel, Walker and Stanton (2003), ‘Marketing is a total system of business activities designed to plan, price, promote, and distribute want-satisfying products to target markets in order to achieve organisational objectives’. On the other hand, Kotler (2003) defines marketing as ‘a societal process by which individuals and groups obtain what they need and want through creating, offering, and freely exchanging products and services of value with each others’. These two definitions provide significant insight into the main operations of marketing, vis-Ã  -vis planning, pricing, promotion and distribution. The American Marketing Association provides another definition of marketing as ‘the process of planning and executing the conception, pricing, promotion, and distribution of ideas, goods, and services to create exchanges that satisfy individual and organisational goals’ (Bennett, 1995). There are three main eras through which marketing has evolved as a revolutionary concept and has taken its current form. These include product orientation period (Eztel, Walker and Stanton, 2003) in which demand were greater than supply, manufacturing and production were limited and industries were not fully developed or capable to take care of the needs of the market. In this period, the main focus of the companies were on producing large quantities of products to satisfy the ever more increasing wants and needs of the target market. Little, if at all, efforts were used to be put in the marketing of products through searching the customers. This was followed by sale orientation stage (Eztel, Walker and Stanton, 2003). In this period, customers used to have relatively lower purchasing power, hence companies began hard selling through overly aggressive advertising and heavy reliance on promotional activities. In the post world war II era of 1950s and onwards, market orientation has emerged as

My Writing Style Essay Example | Topics and Well Written Essays - 1000 words

My Writing Style - Essay Example Writing is not an easy process, it takes time. To write in a manner that is appreciative and commendable, a person is required to read literary works. However, at any stage, it cannot be said that one has learned about writing and its techniques completely. Writing is a prolonged process and one has to continue writing for a long time in order to make his writing inspirational and persuasive. George Orwell in his writing, â€Å"Why I write† informs that he got engaged in the writing process by reading literary works and by trying to write himself when he was a child (Orwell 1). Writing process was not known to him as a revelation but because of a continuous struggle that he did to learn writing. Therefore, one cannot claim that the writing process is easy and anyone can do it without any hard work. As Orwell has explained that he did a lot of struggle to learn to write, similarly, every aspirant of the writing process has to struggle too much. I also consider myself an aspiran t but I feel that I have to do a lot of hard work to start writing something that is commendable. The writing process involves the representation of self as the writer intentionally or unintentionally exposes his own self in his writing. As far as my writing is concerned, I feel that my writing is also expressive of me as a person. A person who is sensitive and kind, his writing will be indicative of his nature. Similarly, different kinds of people can be known with the help of their writing. According to Joan Didion, â€Å"In many ways, writing is the act of saying I, of imposing oneself upon other people, of saying listen to me, see it my way, change your mind† (1). It means that writing is a personal process in which, the writer shows what he likes or dislikes, what is his idea or notion of a situation and what are the facts according to the writer. Therefore, writing for me is the representation of self as while writing, we see the world with our viewpoints and narrate wh at we feel about different aspects due to which, we reveal our personalities. People usually write with some aims such as for fame, for counseling of people, for self-expression and much more. Eliot Stephen says, â€Å"There are other great reasons to write. To tell a story, to be heard, to create art, to participate, to add to the generational discussion, to make a political point, to make the world a richer place (7)†.