Research on Student Difficulties in Understanding Chemical Reactions

ASSIGMNET 1| Research on student difficulties in Understanding Chemical reactions| Misconceptions on Strength of Acids and Bases| | Mariyam Zaina, 015482| | | TITLE & INTRODUCTION Title: Misconceptions on Strength of Acids and Bases Researches shows that students often develops new theories about how the natural world works, prior to formal science education and frequently those theories are different to those of scientists(Demircioglu et al. , 2005).Students develop those scientific conceptions from many sources such as personal experiences (eg: observations), gender, peer interaction, media, language, symbolic representations, textbooks etc†¦ In addition, sometimes teachers also serve as major sources for alternative conceptions (Chiu, 2005) and such self-constructed conceptions are referred as misconceptions. Misconceptions are ideas which are not in agreement with accepted scientific ideas (Demircioglu et al. 2005). If students have misconceptions they are then likely to rej ect the scientist’s viewpoints, thus it would be very important for teachers to find about the misconceptions about the concepts to be taught (Khurshid & Iqbal, 2009) It is known that secondary schools students found chemistry as one of the most difficult subjects and thus many students have difficulty in understanding the most basic concepts in the subject.Researches shows that students have lot of topic in chemistry with misconceptions and one such examined topic includes acids and bases (Demircioglu et al. , 2005). Many studies show that students have a lot of complexity in understanding the right concepts in acids and bases. Some of them include that students often fail to give examples of weak acids and bases and also claims that pH is the tool more measuring acidity. And students often refer acids as chemicals hat are corrosive or chemicals that eat away everything. Furthermore students think that the more hydrogen ions present in a chemical the strength of its acidity increase. And such misconceptions make the topic acids and bases more abstract, boring and difficult to understand (Halim et al. , 2010). This research is conducted to clarify students such misconceptions or alternative theories on the concept â€Å"Strength of acids and Bases† under the topic Acids and Bases.The misconceptions taken into consideration are: * Substances containing H are acidic and substances containing OH are basic * A strong acid doesn’t dissociate in water solution, because its intra-molecular bonds are very strong * Concentrated acids are dangerous but concentrated bases are not * As the value of pH increases, acidity increases * As the number of hydrogen atoms increases in the formula of an acid, its acidity becomes stronger * All acids burn and melt everything * All acids and bases are harmful and poisonous * Alkalis are strong bases * Strength and concentration mean the same thing The strongest acid is the most concentrated acid (Demircioglu et a l. , 2005). Some important key term used in this research include misconceptions (defined in the first paragraph), Strong acid, weak acid, dilute acid, concentrated acid, This is a topic usually confused by students and most of the time they accidently confuse the specific terms such as â€Å"strong acid† with contracted acid or corrosive acid. In fact it means neither of those things. A strong acid is an acid which is fully ionized in solution and a weak acid is an acid which partially dissociates in solution.Similarly a strong base is base which ionizes fully in solution and weak bases get partially ionized in solution (Strong and Weak Acids and Bases, n. d). Concentrated acid has a relatively large amount of solute dissolved in the solvent. A dilute acid has a relatively smaller amount of solute dissolved in the solvent (Acid Strength, n. d) In this research it is assumed that all the students who participated in the survey are students who studied chemistry and thus would be thorough with the topic acids and bases. And also the students have answered all the uestions individually without any help or guidance and have given honest answers according to their levels of understanding. Furthermore it is assumed that students would be able to draw the molecular representation of the dissociations of ions in water by showing the molecules or ions present. The Rationale From various researchers done on student’s understanding of the topic acids and bases it is found that lot of secondary schools students have very different ideas or misconceptions on the concept strong and weak acids and bases.In a lot of situations students often describe ‘strong’ and ‘weak’ as being synonymous with ‘concentrated’ and ‘dilute’. And most of the time these misconceptions arise because teachers are not aware of students prior or existing knowledge about a concept or do not address to such alternative theories they hav e about the concept. Which lead to students into more confusion and let them go ahead with their wrong concept. So the purpose of this investigation was to find students misconceptions on the concept of strong and weak acids and bases via a questionnaire.Furthermore the purpose of the research is to find the students misconceptions on the concept acids and bases in Maldivian schools and thus find ways to implement lesson which could address their misconceptions as future teachers. Procedure Research was conducted using a probing tool to find students misconceptions. And the tool used was a questionnaire with multiple choices, fill in the blanks using the best word from the words give and a question where students have to draw and show their ideas on the concept. The questionnaire was given to grade 25 students of grade 9 from Dharumavantha School.Students were chosen randomly from five classes of 9. From each class 5 students were just chosen randomly and asked to fill the questionn aire (Refer appendix for all the questionnaire students have filled). After that the forms were collected and the data was analyzed and percentage of the students choices were found and presented in the result sections RESULT Question 1 – Misconception; Substances containing H are acidic and substances containing OH are basic Figure 1: Percentage of students’ choices for the question number one. According to 62. 5% students A is the best choice.And no students have chosen D as the answer Question 2 – Misconception; Concentrated acids are dangerous but concentrated bases are not Figure 2: Percentage of students’ choices for the Question number 2. 52% students have chosen A as the answer while the rest of the students think the correct answer is D Questions 3- Misconception; as the number of hydrogen atoms increases in the formula of an acid, its acidity becomes stronger Figure 2: Percentage of students’ choices for the Question number 3 according to highest percentage of students’ choice B which is phosphoric acid is the strongest acidQuestion 4 – Misconception; Alkalis are strong Bases Figure 2: Percentage of students’ choices for the Question number 4 the highest percentages of students have chosen A as the answer. But there isn’t a huge difference between students choices Question 5 – all the acids and alkalis are harmful and poisonous Figure 2: Percentage of students’ choices for the Question number 5 it shows that for this question different student had different views. And most of the students with 36% chosed A as the answer Question 6 – Misconception; All the acids will eat and burn everything awayFigure 2: Percentage of students’ choices for the Question number 6 According to 84% students not all acids will burn and eat everything away. Only some acids will burn and eat everything away. Question 7 – Misconception; Strength and Concentration means the same t hing Figure 2: Percentage of students’ choices for the Question number 7 Result shows that most of the students do not have this misconception; only about 24% students have the misconception while 76% are well aware of the concept strength and concentrated Question 8- Misconception; as pH increases acidity also increases.Figure 2: Percentage of students’ choices for the Question number 8 Almost all the students were clear about this concept that as pH increases acidity decreases Questions 9 – Misconception; A strong acid doesn’t dissociate in water solution, because its intra-molecular bonds are very strong. Figure 2: Percentage of students’ choices for the Question number 9 – 44% students were able to draw and show the microscopic dissociation of ions in strong and weak acids with all criterions present. And 8% students drew with some criteria missing.And the rest of the 48% students had misconceptions about the dissociation of strong and w eak acids in water Question 10 –Misconception; the strongest acid is the most concentrated acid Figure 2: Percentage of students’ choices for the Question number 9 – it shows that most of the students is quite clear with this misconception. Yet 36% students still have the misconception that the strongest acid is the most concentrated acid DISCUSSION The first misconception dealt in the research was one of the very basic concepts under acids and bases.That is the definition for an acid and a base. A common misconception is that acids are chemicals with hydrogen (H) in the chemical formula and bases are chemicals with OH in the formula. 62. 5% students think that C2H5OH is basic as it has OH in its formula. 4. 2% students think C6H12O6 is both acidic and basic as it has both H and OH in its formula. While the rest of the 33. 3% gave the correct answer which is C6H12O6 and C2H5OH is neither acidic nor basic even though they have H and OH in the formula.But the resu lt also shows that all the students are aware that ammonia is not an acid even if it has H in its formula. Acid is a substance that gives H+ ions when dissolved in water. Acids are compounds that contain hydrogen, however there are compounds that contains hydrogen in their formulas but does not act as acids; for an example water, H2O, ammonia NH3. A base in definition is that substance which gives OH- ions when dissolved in water. Thus they are not substance with OH present.There are many substances that contain OH and H, yet does not act as acids or bases (Acids, Bases and Salts, 2005). For an example Sucrose, C6H12O6, contains H and OH, however, when dissolved in water it dissolves as intact molecules and does not ionize to produce any H+ or OH- ions, as shown by the equation: C6H12O6(s) + H2O(l) C6H12O6(aq). Since sugar molecules do not lose any H+ or OH- ions, sugar is not considered an acid. Alcohols (C2H5OH) have a characteristic hydroxyl group, OH, covalently bonded to the re st of the molecule.When alcohols dissolve in water they also dissolve molecularly and do not ionize. Since no OH- ions are released, alcohols are not bases (Concept or Skills Development, n. d). However from the research it shows that students are not very clear about this idea and because of that most of the students have chosen A as the answer. A student’s misconception is that only concentrated acids are dangerous while concentrated bases are not. This misconception also was proven from question 2, as 52% students have chosen concentrated HCl only as most dangerous.Yet, the result also talks to two sides because almost half of the students have chosen the correct choice (D) which says that both concentrated acid and base is dangerous. Choice A was a misconception. Weak acids and weak bases are not dangerous, but both strong acids and strong bases can both be harmful to human tissue. For an example lime is very strong base and that is the reason why a very small amount of l ime is present in concrete and mortar. And construction workers have to be very careful not to get it on their skins (Strong and Weak Acids and Bases).Another misconception was that as number of hydrogen in the chemical formula increases the strength of acid increases. According to 65% students this is true and thus they have chosen H3PO4 as the strongest acid and almost all the students have given the reason for their choice as having the most number of hydrogen in the formula. 31% students have chosen the correct answer which is sulfuric acid which is the strongest out of the three and have given the correct reason as, it could fully ionize in solution. Only 3% students have chosen nitric acid as the strongest acid.According to students the more hydrogen present it can contribute to more H+ to the solution, thus it would become stronger. The strength of an acid is determined by its ionization power which determined by the pKa value. The lower the pKa value the stronger the acid. T hus H2SO4 is the strongest ith pKa = -3. 1 followed by nitric acid (pKa= -1. 3) and phosphoric acid (pKa = 2. 12) (William, n. d) The reason for this misconception might be because students have not learnt the pKa values and not gone into such details which would help to explain why an acid is becoming stronger.To clarify the misconception could give the pKa values as an extra information for the students or could make the students clearer on the concept that the strength depends on the amount of dissociation. Fourth question is about the misconception that alkalis are strong bases. Some students have the misconception that as alkalis is basic substances that dissolves in water they are strong bases. And from the survey it shows that 24% students do have this misconception.But it shows that apart from this misconception, most (36%) students have another wrong concept that alkalis and bases are same. 28% students do know the right answer from the choices given. Results of 5th questio n show that just 24% of students had the misconception that all the acids and alkalis were harmful and poisonous. Majority of students (36%) think that only concentrated HCl and concentrated NaOH will be harmful and poisonous, which was the correct choice out of the acids and bases is given.Dilute ethanoic acid would not be harmful as it would be used in many of the foods items as well. Also would not be dilute ammonia. Thus the result coveys the message that majority of students are clear about the above misconception. Yet there are few students with different views so as teachers need to show students the differences by showing examples as such. Sometimes students are not aware of the idea that they eat and drink acids, so if they know better acids such as citric acids, acetic acids would e able to clear this misconception Sixth, seventh and eight questions it shows that majority students do not have the misconception identified. Sixth question 84% students know the correct answer s for the blank which is â€Å"some† acids would burn and eat everything away. Seventh question was check whether students really knows the difference between concentrated and strong acids. It was an application question and 76% students have given the right answer which is â€Å"concentrated†. Only 24% students had the misconception that ‘concentrated’ and ‘strong’ means the same.The students might have given the correct answer because two concentrations were given. For those who have given the correct answer whether they really know the difference, a different type of question with the same misconception was given (question 10). The correct answer for the 10th question was C which shows the full dissociated acid and thus it would be the strongest. 64% students have chosen this as the answer. Which shows some students knows that strong acids are those which dissociate fully.However majority of students from that 64% has given the reason for t heir answers wrong. According to them C is correct because it contains the most number of molecules. So that means students do have the misconception about the strong and concentrated acids. Also 36% students chose D as the answer and most of their reason was that it has no water. This shows that their think strongest acid is the acid with least water present or otherwise the most concentrated acid. Eighth question none of the students had the misconception that as pH increases acidity increases.Some students might think as pH is the measure concentration of H+ ions as the pH increases the number H+ ions might increase thus would increase the acidity. Yet, all the students gave the correct answer for this question. For the 9th question a variety of answers were given. The misconception check was â€Å"the stronger the acid the lower the dissociation because the inter-molecular bond would be stronger and weak acids would dissociate more†. For this question it was checked wheth er the students had the following criteria’s.In weak acid shown the H-F not dissociated and very few H+ and F_ ions dissociated and in strong acid H-Cl fully dissociated into H+ and Cl- ions. And even if students have shown the water molecules or not shown it is correct. 44% students did draw the diagrams correctly with all the criteria given and have given the reasons as strong acid dissociate fully while weak acids would do partially. 8% students drew almost correct dissociations, but they most of them have not shown the ionic forms. (Refer appendix for students’ answers). And majority of students had misconceptions.Most of these students have shown more number of molecules in the strong acid side while less molecules’ in the weak side. Students have the concept that strong acids have more molecules’ and weak acid would have less. Only one student has given the reason as the stronger acid would have stronger bonds so dissociation would be lesser. Thus i t can be concluded that majority does not have that misconception but they do have another misconception which is mostly related to now knowing the actual meaning of strong and weak acids and also confusing it with concentrate and dilute.Considering the misconceptions it is important as teachers to take actions to eliminate such misconceptions. Firstly the students should be given instructions which foster conceptual understanding rather than rote memorization. Students are just given definitions of acids bases and they have memorized it, does not get any understanding as to how an acid becomes stronger weaker, concentrated or diluted (Yezdan, 2009). For an example students show the difference in this four by comparing the pH of the four types of acids; concentrated, dilute, weak and strong.In the class the students could be given discussion with teacher or peers to reflect on what they learnt and thus come up with the conceptions they have and thus the teacher can help in correctin g them (Yezdan, 2009) Students misunderstanding arises generally from their experience s in everyday life and such experiences could be used to even eliminate the misconceptions. For an examples from early child hood onwards by watching cartoons and all students think that an acid is something which will make a hole where ever put and it is always dangerous.But could brainstorm students’ understanding about the weak acids present in the materials that are used in day today lives and relate it to weak acids being harmless. Also demonstrating student the difference between a strong acid and concentrated acid rather than just giving definitions ((Demircioglu et al. , 2005). Also could establish analogical thinking between real life examples and the unknown while learning new information could discard misconceptions. For example, teacher asks to the students if there is a relationship between the number of hydrogen atoms that the acid contains and acidic strength.After taking stu dents responses and guiding the discussions till getting the true answer go one step further and asks â€Å"Is H3P04 stronger than HCl? â€Å". Then allows students to discuss again and reach the answer. In order to establish an analogical thinking with real life situations can ask â€Å"how do we measure the strength of the bulbs that we use at our homes? † and guide the discussions until students reach the fact that â€Å"If a bulb gives off a lot of light it is strong, a little Light it is weak† and then helps students to establish the analogy of if an acid ionizes a lot, it is strong; ionizes a little, it is weak like in the case of bulbs.Similarly, provide students to realize that only one bulb sometimes may give more light/ may be more powerful than the two or more bulbs like in the case of the acidic strength and the number of hydrogen atoms that an acid contain i. e. HCl is stronger acid than the H3P04 because it gives more hydrogen ions than H3P04 when disso ciates in water although it contains smaller number of hydrogen atom. Some limitations of this research include that the research is based only onto answer of 25 students which is a very small sample size to know the extent of overall students understanding.Also the sample is from one school, even the students understanding may differ in schools because of the differences in methodologies used in teaching same concept. Also even though it was assumed that students have given honest answers without help from anyone some students answers were very similar which should be because of copying or discussion so the authenticity is not very effective, need to make sure students do it individually. ConclusionsThe purpose of the research was to find whether the misconceptions stated in the introductions were there in the students and to check the extent of students’ understanding on the concept ‘strength of acids and bases’. According to the results majority of students ha ve a deeper understanding of the topic and does not have the most of the misconceptions stated. However some concepts such as â€Å"concentration is same as strength†, â€Å"as number of Hydrogen increases the acidity increase† and â€Å"substances with H in the formula is acidic and OH is basic†.These three misconceptions were found in majority of students and thus need to be dealt as they are one of the very basic and important concepts. And since chemistry as the topics are very much interrelated if the misconception persists it can lead into further misconceptions. So during teaching need to give more attention of those areas and try to use methods such as analogical thinking, demonstrations, applications questions which would help to clarify their misconceptions. Furthermore need to check students’ prior knowledge before going into the new concepts as it would be the foundation for the new knowledge.REFERENCES Acids, Bases and Salts. (2005). Retrieve d on August 17, 2011 from http://www. krysstal. com/acidbase. html Acid Strength. (n. d). Retrieved on August 17, 2011 from http://media. rsc. org/Misconceptions/Miscon%20acid%20strength. pdf Chiu. ,M. H. (2005). National Survey of Students’ Conceptions in chemistry in Taiwan. Retrieved on August 17, 2011 from http://old. iupac. org/publications/cei/vol6/07_Chiu. pdf Concept or Skills Development. (n. d). Retrieved on August 17, 2011 from http://www. okstate. edu/jgelder/acidPage25. htmlDemircioglu. G. , Ayas. A and Demircioglu. H. (2005). Conceptual change achieved through a new teaching program on acids and bases. Retrieved on August 17, 2011 from http://www. rsc. org/images/p3_Demircioglu_tcm18-31135. pdf Khurshid. , M and Iqbal. , M. Z. (2009). Children’s Misconceptions about Units on Changes, Acids and Laboratory Preparation of CO2. Retrieved on August 17, 2011 from http://pu. edu. pk/images/journal/ier/PDF-FILES/4-Childrens%20Misconceptions. pdf Halim. , N. D. A. , Ali. , M. B. , Yahaya. , N and Junaidi. , J. (2010).Learning acids and Bases through Inquiry Bases Website. Retrieved on August 17, 2011 from http://teknologimalaysia. academia. edu/noordayana/Papers/393231/Learning_Acids_and_Bases_Through_Inquiry_Based_Website Strong and Weak Acids and Bases. (n. d). Retrieved on August 17, 2011 from http://www. sky-web. pwp. blueyonder. co. uk/Science/strongacids. htm William. , R. (n. d). pKa Data. Retrieved on August 17, 2011 from http://research. chem. psu. edu/brpgroup/pKa_compilation. pdf APPENDIX Raw data of the survey conducted | QUESTION 1| | QUESTION 6|Choice | No. of students| %| | Choice | No. of students| %| A| 15| 62. 5| | Some| 21| 84. 0| B| 1| 4. 2| | All| 4| 16. 0| C| 8| 33. 3| |   | 25|   | D| 0| 0| | | | | | 24|   | | | | | | | | | | | | QUESTION 2| | QUESTION 7| Choice | No. of students| %| | Choice | No. of students| %| A| 13| 52. 0| | Concentrated| 19| 76. 0| B| 0| 0. 0| | stronger| 6| 24. 0| C| 0| 0. 0| | TOTAL| 25| 100. 0| D| 12| 48| | | | | TOTAL| 25| 100. 0| | | | | | | | | | | | QUESTION 3| | QUESTION 8| Choice | No. of students| %| | Choice | No. of students| %| A| 7| 30. | | Increase| 25| 100. 0| B| 15| 65. 2| | Decrease| 0| 0. 0| C| 1| 4. 3| | TOTAL| 25| 100. 0| TOTAL| 23| 100. 0| | | | | | | | | | | | QUESTION 4| | QUESTION 9| Choice | No. of students| %| | Choice | No. of students| %| A| 2| 8. 0| | shown all the criteas | 11| 44. 0| B| 19| 76. 0| | Some criteria missing| 2| 8. 0| C| 2| 8. 0| | misinterpretation of the concept| 12| 48. 0| D| 2| 8| | TOTAL| 25| 100. 0| TOTAL| 25| 100. 0| | | | | | | | | | | | QUESTION 5| | QUESTION 10| Choice | No. of students| %| | Choice | No. of students| %| A| 9| 36. 0| | A| 0| 0. 0|

Linguistics and their realationship to Teaching Essay

The Relationship Between Linguistics and Language Teaching. Fiona Le Maitre Thongsook College May 2013 Abstract This paper is an attempt to analyze the relationship between linguistics and language teaching. Linguistics is a science and teaching while technical is also an art yet they are closely related to each other in the case of language teaching. The foreign language teachers need to include ‘selection’, ‘grading’ and ‘presentation’ as their main steps. Linguistics plays an important role in the whole process of teaching by helping to facilitate a teacher’s understanding of the workings and systems of the language they teach. Applied Linguistics is really about the melding of these 2 actions. The Relationship between Linguistics and Language Teaching. Linguistics is defined as the scientific study of language. Linguistics is then divided into several branches which study different accepts of its use. Descriptive linguistics, historical and comparative linguistics, which it is based on methodology. Synchronic and Diachronic linguistics, which it is based on the aspect of changes over time. Phonetics, phonology, morphology, syntax and semantics, which is based on a language as a system. Sociolinguistics this is related to or combined with the disciplines of linguistics and sociology. Its interest is in the relationship between language and society. It works to explains why people Use different speech in different social contexts. It’s area of study is the social functions of language to convey social meaning. The social relationships in a community, and the way people signal aspects of their social identity through their language (Jenet Holmes, 2001). Sociolinguistics also is concerned with the interaction of language and settings. (Carol M. Eastman, 1975; 113). The other expert defines it as the study that is concerned with investigating the relationship between language and society with the goal of a better  understanding of the structure of language and of how languages function in communication ( Ronald Wardhaugh, 1986 : 12) Psycholinguistics relates to the combined disciplines of psychology and linguistics. Psychology is defined as the systematic study of human experience and behavior or as the science that studies the behavior of men and other animals. Knight and Hilgert in Abu Ahmadi,(1992). It covers language development. (Lim Kiat Boey). The other definition of psycholinguistics is that it is the study of human language-to-language comprehension, language production, and language acquisition (E.M.Hatch) The research done on the relationship between linguistic theory and language teaching can be traced back to the late 19th century. Its relationship has been discussed and debated for many years and researched extensively. Since this time different research proposed by different scholars has been disputable and found to be largely inconclusive. In the 1960s it was decided that there needed to be a reassessment. The conclusion that was formed went in two two main directions of thought with differing points of view. One viewpoint was that linguistics is not as relevant as it was first thought to be, and its importance was overrated. Such linguists as Lamendella (1969) and Johnson (1967) expressed their disagreement to regard linguistics as the basis of a strategy of learning. Lamendella (1969) thought that it was a mistake to look to transformational grammar or any other theory of linguistic description to provide the theoretical basis for second language pedagogy. What is needed in the field of language teaching are not applied linguists but rather applied psychologists. The other point of view was to recognize that the general contribution of linguistics was important. This came though with a proviso that teaching language was not to be bound to only follow one theory alone. The idea being that different linguistic theories can offer different perspectives on language, and they can all be treated as equivalent resources useful for teaching. Levenson (1979 ) once said, ‘no one school of linguistic analysis has a monopoly of truth in the description of the phenomena of speech†¦traditional school grammar, TG grammar, †¦all these and more can be  shown to have their own particular relevance to the language teaching situation. By1960 the United States, reached its peak of the influence of structural linguistics upon language Teaching. Structural linguistics stressed the importance of language as a system and investigates the place that linguistic units such as sounds, words and sentences have within this system. This then associated with behaviorism provided the principal theoretical basis of the audio lingual theory. This then influenced language teaching materials, techniques and the teachers educations. Behaviorism led to theories, which explained how an external event, causes a change in the behavior, without any kind of mental interaction. It also stressed the importance of repetition and practice in learning a second language, this I think is a vital factor in learning a foreign language. If we look at the audio-lingual method, it emphasizes: (1) The teaching of speaking and listening before reading and writing; (2) The use of dialogues and drills; (3) The avoidance of the use of the mother tongue in the classroom. Audio-lingual method regards speaking and listening as the basic skills, this is in line with today’s English teaching situation. The Mentalist Approach In the 1960s Chomsky formulated the mentalist approach. The hypothesis was considered that human behavior is much more complex than animal behavior. Chomsky, felt that we are born with a Language Acquisition Device (LAD), which enables a child to make a hypotheses about the structures of a language in general, and also the structure of the language being learned more importantly. By the end of the sixties’, there were new developments in teaching language starting to occur. The TG theory had a big impact resulting in a change in teaching methods. It was opposed to the empiricist theory, that is, teaching audio linguistics, linguistically structuralism and psychologically behaviorism. TG theory. 1 It stresses mental activity. 2 It postulates that all human beings have an innate ability to learn a language. 3 That it is an inborn instinctual ability and not practice that made human beings obtain the rules of a language and understand and can produce countless numbers of sentences. The Natural Method was successfully used in various language schools in the USA and Europe in the late 19th and the early 20th century. In the post-World War I decades, the direct method was adopted into English language teaching (ELT) this laid a solid intellectual and practical foundation for developing ELT as an autonomous profession. Some linguists, like Diller (1970), openly declared his preference for the cognitive position; while others, like Chastain (1976) and Rivers (1981:25-27) held that the two theories were complementary and served different types of learners or teachers or represented different phases of the language learning process. Applied Linguists brought about the situational approach and the notional/functional method. It is based on a broader framework for the description of language use called communicative competence proposed by Hymes, This brought about the communicative approach to language teaching came into being. In 1970s, a group of scholars including Oller (1970) and Widdowson (1978), were linguists but at also closely in touch with teaching practice. They gave language teaching and language pedagogy the linguistic direction they regarded as necessary. Since they were in touch with language teaching practice and linguistic so had a two-way view of the problem, they placed emphasis on real language and its communication and use. To take Oller’s interest in pragmatics as an example. Oller (1970:507) claimed that pragmatics has implications for language teaching; it defines the goal of teaching a language as prompting the students not merely to manipulate meaningless sound sequences, but to send and receive messages in the language. The students in China start English when they are in primary school. In the past, more attention was paid to the grammar, the result was very disappointing: Now the emphases is on speaking and listening. The audio-lingual method is now used in the classroom. In China, more people need to learn English in order to have the ability to communicate with foreigners. In this case, speaking and listening is much more important than being able to read and write. They are not expected to have a high level of English and their aim is simple, they need to communicate with a foreigner so they can understand their words and express themselves well. This is based on simple daily conversation. A market sale and business or being able to work in the tourism industries. Basic conversation and understanding can be very helpful in everyday conversation exchanges. The Audio-lingual method stressed the repetition and it theorizes that a language is learnt through the formation of habits. To speak English fluently, without constant practice, is impossible. So in our English teaching, we must help our students speak and listen well. Expressing ourselves properly is not always an easy thing, especially if it’s an emotionally charged topic. Even an English major may sometimes find it problematic to express exactly what they mean so it is understood by the other person in a way that is understood by all. When I go to Cambodia I find the generally that the population though not taught English in school has good English conversation capacity. They may not read or write but I feel if they had the opportunity to learn now they have grasped the basic language that they would with more ease. There is a need for them to talk and sell to foreigners so they have had a need and incentive to learn and the fact that their using it every day also helps. Though there are of course talented students I find in Thailand the communication level is not good as a lot of emphases is but on reading, writing and grammar, that many times, is not really understood or comprehended. Thai students learn form primary but they do not always have a reason to speak out of the classroom. One lesson a week in speaking and 3 of grammar I find makes the students scared to use the language. I teach with Thailand teachers and due to a some general pronunciation problems the students are confused about the sounds of the words and how to string them  together. Confidence helps a lot just talking even if it is wrong. I always attempt to inspire confidence as I feel it is very important for speech. In my opinion, linguistics and language teaching relationship is a dual one. There are some theories of linguistics that can be applied to language teaching, i.e. linguistics guides in development of language teaching theory. On the other hand, a language teaching theory expresses or implies answers to questions about the nature of language. It is necessary for a language teacher has some knowledge about, the systems of languages. A teacher should understand how the language works and expresses meaning and the structures that are used in the language being taught. A teacher needs to know how to make the phonic sounds and the mechanics to produce these sounds. This helps with pronunciation problems that students will encounter. By studying linguistics a teacher will have a deeper insight into the nature of language and the language the student speaks as they’re first language. If we agree that the use of a language is a matter of habits and practice, then a teacher needs to implant the habit of using it for communication until it becomes second nature. Conclusion Linguistic theory is continually developing and teaching theories are constantly changing as is the language itself. This alone demands a permanent study of languages and the relationships between linguistic theory and language teaching methods. There are many techniques and theories but no one concept or technique can take in the Different needs student may have and the differing ways people learn. This is a science in its self. There can be many differences in understanding between the L1 and L2 language from different cultural understandings and different sounds that may be new to the learner. There are many ways a culture will express its self along with idiosyncrasies and local knowledge of the everyday life in the culture. They say when you understand humor you start to know a language. If one could take every student as an individual and teach them the best way they  learnt one would be assured of good results. Knowing the basic individual attributes the child had can enable to teacher to create classes designed for their individual needs. This is a luxury that tutors can give their students but in the classroom one dose not have so much control. A practical framework designed to suit the most students and the context that is the most appropriate. The Relationship of Linguistic Materials for the Second Language Teacher. Because of political, economic and also technical changes, English has become widely taught as an official business language worldwide, also as a second language to immigrants in English-speaking countries to gain entry and work, and as a foreign language in many non-English-speaking countries. This is also largely due to the computer so there is a universal language for coding and business. There are many theories on different ways to teach and different scholarly thoughts on the best process. I feel that this depends on the type of English you are teaching. Since there are many different needs a student may have. In China the emphases is on communication with foreigners on a daily basis like selling them something in a market or doing business. In other countries such as Thailand the emphases is put on Grammar and writing and reading and only a small part into communication. So while there are still many theories on the best way to teach I feel in my knowledge so far that it is best to learn as many ways as possible and how they work in the different environments. Applied Linguistics is really about the melding of these two actions but not the scope of this essay. One of the most fantastic Linguistic help I think the corpus is one of the best ways to get relevant vocabulary for your students. This is helpful for Syllabus and curriculum planning and for all areas of language teaching. References Chastain, K. (1976). Developing Second-Language Skills: Theory to Practice. Chicago: Rand McNally. Diller, K.C. (1970). ‘Linguistic theories of language acquisition’ in Hester 1970:1-32. Johnson, M. (1967). Definitions and models in curriculum theory. Educational Theory, 17:127-40. Lamendella, J.T. (1969). On the irrelevance of transformational grammar to second language pedagogy. Language Learning, 19:255-70. Levenson, E.A. (1979). Second language lexical acquisition: issues and problems. Interlanguage Studies Bulletin, 4:147-60. Oller, J.W. (1970). Transformational theory and pragmatics. Modern Language Journal, 54:504-507. Rivers, W.M. (1981). Teaching Foreign-Language Skills. Second edition. Chicago and London: University of Chicago Press. Widdowson, H.G.. (1978). Teaching Language as Communication. Oxford: Oxford University Press. .†Ã¢â‚¬ ¨Zeki Hamawand, Z. Morphology in English: Word formation in cognitive grammar. continuum. Publishing. ( Zeki Hamawand, Z. (2011).

Savannah Cats

A Savannah Cat is actually a hybrid between a Siamese cat and a Serval The Savannah cats name is given to the off spring of a domestic cat and several medium sized, large-eared Wild African cats. The unusual offspring became popular among breeders at the end of the 20th century, and in 2001 the I. C. A (International Cat Association) accepted it as a new registered breed. Savannahs are much more social than other breeds of cats they are often compared to dogs because of their loyalty and the fact that you can train them to walk on leashes and to do tricks.The Bengal breeder Judee Frank crossbred a male Serval belonging to Suzi Woods and a Siamese cat to produce the first Savannah cat named Savannah on April 7, 1986. Franks’ Savannah attracted the attention of Patrick Kelly who pushes one of Savannahs kittens in 1989 Kelly was the first enthusiast who worked toward establishing a new domestic breed . He approached many Serval breeders to help to develop this new breed and final ly garnered the help of breeder Joyce Sroufe to work with him in taking the steps he needed to get the breed recognized.In 1996 Patrick Kelley and Joyce Sroufe wrote the original version of the Savannah breed standard and presented it to the I. C. A in 01 the board accepted the breed as a new type of Cat. 010 brought a significant event for the breed when the first female F1 Savannah was born and bred in the UK by Rosanne Boyle of Hotspotexotics name â€Å"Amazing Grace she was registered with the I. C. A from 06 the breed has seen significant growth throughout the UK as a result the breed of being so well received. As Savannahs are produced by crossbreeding Servals and domestic cats, each generation of Savannahs is marked with a filial number.For example, the cats produced directly from a Serval/domestic Cat cross are the, and they are 50% serval. F1 generation Savannahs are very difficult to produce, due to the significant difference in gestation periods between the Serval and a domestic cat and sex chromosomes. Servals can be very picky in choosing mates, and often will not mate with a domestic cat. Females of the F1-F3 generation are usually held back for breeding, with only the males being offered as pets. The reverse occurs when you reach F5-F7 generation, but to a lesser degree, with the males being held as breeding cats, and females primarily offered as petsPhysical features Savannah Cats are one of the larger breeds of cats. The Savannahs tall and skinny appearance makes it look a great deal bigger than it actually weighs. Size varies on the gender and generation male Savannahs are usually bigger and weigh more than females. Because of random factors in Savannah hybrid genetics there can be different changes in size even in one litter. The coat of a Savannah depends a lot on what breed of domestic cars is used for the cross earlier generation have some form of dark spotting on a lighter coat early breeders used words like â€Å"Wild† to descri be it. sing spotted breeds such as the Bengal and Egyptian Mau for the cross will preserve the very few Savannahs that look like they did in earlier Generations. Some of the colors include (cool to warm brown, tan or gold with black or dark brown spots), silver spotted tabby (silver coat with black or dark grey spots), black (black with black spots), and black smoke (black tipped silver with black spots) in additions the Savannah can come in unusual color variations such as the classic or marble patterns or snow coloration and blue or other thinner colors from domestic sources.Most breeders are trying to cull these unusual colors out of the gen pool by selling unusual colored cats as pets but some Savannah Breeders are interested in working with the colors to introduce them as new traits The overall look of the Savannah Cat depends greatly on generation the older generations often have a more wild look the domestic breed that is used influences the appearance as well the domestic ou t crosses for the Savannah breed that are permissible in the ICA are Egyptian Mau the Ociat the Oriental Shorthair and the Domestic Shorthair.In addition some Savannah breeders are non permit able breeds such as the Bengal for size or the Maine Coon cats for size for the domestic parentage but these non permit able outcrosses can bring many unwanted genes as well Outcrosses are rarely used these days at there are now many fertile males available and as well most breeders are exclusively doing Savannah to Savannah breeding. A Savannahs wild look depends mostly on the generation of the cat.The body of Savannahs are long and leggy when a Savannah is standing, their hind end is often higher than they’re neck the back of their ears have a central light band bordered by the black, dark gray or brown giving an eye like effect the short tail has black rings with a solid black tip the eyes are blue as a kitten and may be green brown gold or blended shad as an adult. The eyes have a bo omerang shape with a hooded brow to protect from harsh sunlight. The Savannah cats behavior Savannahs are commonly compared to dogs in their loyalty, and they will follow their owners around the house like a canine.They can also be trained to walk on a leash, and even fetch. Some Savannahs are reported to be very social and friendly with new people and with other cats and dogs, while others may run and hide or revert to hissing and growling when seeing a stranger. Exposure to other people and pets is most likely the key factor in sociability as the Savannah kitten grows up. Owners of Savannahs say that they are very impressed with the animal intelligence of this breed of cat. An often-noted trait of the Savannah is its jumping ability. Savannahs are known to jump up on top of doors, refrigerators and high cabinets.Some Savannahs can leap about 8 feet (2. 5 m) high from a standing position. Savannahs are very inquisitive, and have been known to get into all sorts of things. They ofte n learn how to open doors and cupboards, and owners of a Savannah will likely need to take special precautions to prevent the cat from getting into things. Many Savannah cats do not fear water, and will play or even immerse themselves in water. Some owners even shower with their Savannah cats. Presenting a water bowl to a Savannah may also prove a challenge, as some will promptly begin to â€Å"bat† all the water out of the bowl until it is empty, using their front paws.Another quirk Savannahs have is to fluff out the base of their tail in a greeting gesture. This is not to be confused with the fluffing of fur along the back and full length of the tail in fear. Savannahs will also often flick or wag their tails in excitement or pleasure. Vocally, Savannahs may either chirp like their Serval fathers, meow like their domestic mothers, or do both, sometimes producing sounds which are a mixture of the two. Chirping is observed more often in earlier generations. Savannahs may also â€Å"hiss†Ã¢â‚¬â€a Serval-like hiss quite different from a domestic cat's hiss, sounding more like a very loud snake.It can be alarming to humans not acquainted to such a sound coming from a cat. Health considerations Different individuals contain different amounts of Serval and of varied domestic cat breeds, and there are currently no established Savannah breed-specific health issues. Some veterinarians have noted that Servals have smaller livers relative to their body size than domestic cats, and some Savannahs inherit this. For this reason, care is advised in prescribing some medications. Lower doses per weight of the cat may be necessary.In addition, the blood values of Savannahs may vary from the typical domestic cat, due to the serval genes. There is anecdotal evidence, though no completed scientific studies, that Savannahs and other domestic hybrids (such as Bengals) do not respond well to anesthesia containing Ketamine Many Savannah breeders request in their contra cts that Ketamine not be used for surgeries] Some (but not all) Savannah breeders believe strongly that modified live vaccines should not be used on Savannahs, that only killed virus vaccines should be used.Others are the complete opposite, having had poor reactions to killed vaccines, and no vaccine reaction (lethargy, illness, etc. ) to the modified live vaccines. This, also, has not been studied, and opinions vary widely from breeder to breeder Some breeders state that Savannah cats have no known special care or food requirements, while others recommend a very high quality diet with no grains or by-products. Some recommend a partial or complete raw feeding/raw food diet with at least 32% protein and no by-products.Some Savannah breeders recommend calcium and other supplements, especially for growing cats and earlier generations. Others consider it unnecessary, or even harmful. Most Savannah breeders agree that Savannahs have a need for more taurine than the average domestic cat, and therefore recommend taurine supplement which can be added to any food type. Laws and Regulations Laws governing ownership of Savannah cats in the United States vary according to state. The majority of states follow the code set by the United States Department of Agriculture, which defines wild or domesticated hybrid crosses as domesticated.Some states have set more restrictive laws on hybrid cat ownership, including Hawaii, Massachusetts, and Georgia. Some cities may have laws that differ from the state. For example, Savannahs more than five generations from the serval are allowed to be owned in New York state, but not in the city of New York. [9] The Australian Federal government has banned the importation into Australia of the Savannah cat, as the larger cats could potentially threaten species of the country's native wildlife not threatened by smaller domestic cats.

Integrated Health Promotion Plan Case Study Example | Topics and Well Written Essays - 1000 words

Integrated Health Promotion Plan - Case Study Example Despite having an advantage of increased patient outcome, health promotion reduces morbidity and lowers health liabilities cost in the health care at large. Health promotion is in three levels that include primary level, secondary level, and tertiary level. These levels are regularly used in nursing to enhance an individual overall well-being. The primary prevention main goal is to prevent an individual from developing a disease; it entails the provision of  education on healthy lifestyle habits. The secondary level main goal is to avert disease from escalating to complication; it involves reducing the disease progress or halting the disease in the early stages. The main aim at this level is to move an individual from negative lifestyle behaviours to healthy habits. The tertiary level aims at helping an individual with a chronic disease to cope with the disease, and if possible reverse or halt the progression of the disease to adverse levels (Whitehead, 2011). In an attempt to prevent hypertension disease from occurring, it is important to recognise different practices in health care that predisposes individuals to developing the disease. An associated wellness programme is then instituted to help in curbing the unhealthy practices among the community members. The interventions to promote health and prevent hypertension include behaviour modification as well as screening. Wu et al., (2012) study showed that hypertension was linked to an accumulation of cholesterol in the intima of the blood vessels, kidney diseases and cardiovascular diseases. To prevent accumulation of the cholesterol in the body an individual should eat food that are having low cholesterol. They include all vegetable foodstuffs, plant proteins like beans and peas, white meat such as meat of fish and poultry among others. Other foodstuff that contains a high level of cholesterol should be taken in limitation as per the nutritionist recommendation. In

Principles of Microeconomics Research Paper Example | Topics and Well Written Essays - 1250 words

Principles of Microeconomics - Research Paper Example a single buyer in the entire business setting. Entry in such a market is restricted as a result of high cost or due to impediments which may be social, economic or even political. For instance the government can opt to create a monopoly over an industry. On the other side, monopolistic competition is generally a type of imperfect competition in that the competing producers sell products which are totally different from each other as goods but not necessarily perfect substitutes (Kamien 1982). Therefore, in a monopolistically competitive market, different firms can behave as if they are monopolies in the short-run by using market power to generate more profits. Later in the long-run, once other firms enter the same market, the benefits will be shared among them and the overall profit due to differential will considerably decrease with increase in competition. Having understood the basic principles about monopoly and monopolistically market structure, now it is very easy to anally the case in hand. As mentioned in the question, that in the year 2007 potato chip industry was operating as under monopolistically market. ... In most cases, it is argued that a multi-producer monopolist will always charge a lower price as compared tom firms operating separately producing the same complement products (Ralf 2000). As a result of lower pricing, demand will be higher since more customers are encouraged to buy at a lower price. The result is that, in the long run is that there will be a shortage of production because monopolistic generally produces less product than that society efficient level of output. In the long run, the price of commodities will be much higher due to less supply in the market. The strategy here is that, profit made earlier and being part of the surplus, it is transferred from consumers to the producers and this creates a social cost which arises from inefficiency low output that ends up to a dead weight loss. Immediately after transformation into a monopoly market the result would be realized within a short duration. For instance, due to monopoly the prices charged are much higher because there is no close substitute for the product. Those are at a disadvantage are the low income consumers who might be exploited by such a monopoly market where prices are a bit higher (Mckenzie 2008) Thought to producer high prices contribute to increase in the profit made by the firm. These benefits will be transferred to stakeholders whose main objective is after profit maximization. Though that may be the case, but sometime, a firm may not enjoy the domestic monopoly power, rather face an intense competition from other oversee producers. This tends to limit their market power and instead help in keeping prices lower for the consumers. Once manager has received such profits both in the short run and in the long run, they will distribute it

Role Of Women In Ancient Egypt Essay Example | Topics and Well Written Essays - 250 words

Role Of Women In Ancient Egypt - Essay Example Hatshepsut reigned until her death in 1457 B. C, despite the constant threat by her co-ruler Thutmose III, who was at the time old enough and ready to take back his throne. Upon her death, most of her monuments were destroyed, and her name erased from the Egyptian records. Ancient Egyptians were religious, and women had several roles to play in religious activities. First, there were several female goddesses worshiped by the Egyptians. Women were also musicians and priestesses in the temples where religious ceremonies were held. In the role of the temple, women were musician-priestesses and held an important and honorable place in Egyptian religious society. They performed music and sung for the god Amum for his entertainment. In the social role, women were supposed to offer companionship and love to the Egyptian men. They also held the role of childbirth. During child delivery, other women acted as midwives to help the expectant woman through the whole process. Women were also responsible for the raising up of the children. Economically, women were allowed to start and run businesses of their own. In addition to this, several jobs were available to them. They included perfume makers, bakers, and weavers among others (Flux 19). To sum it up, in ancient Egypt, unlike other ancient societies, women were given same legal and economic right. Women were allowed to own, manage and even sell their private properties. Through building projects, Hatshepsut ensured the divine property of both herself and her people.

Greek Civilization Essay Example | Topics and Well Written Essays - 1500 words

Greek Civilization - Essay Example The roles which have been assigned to men and women are natural and that they should live by them. It is imperative that whatever roles that exist between a man and a wife, they are not to be substituted; this is because various adaptations have been given to either of them so that they can be able to perform the assigned responsibilities. In making a man and a wife, God did it with the intention that there will be the concept of one party giving and the other party receiving. For instance, a wife was made with little ability for outdoor activities, instead, she was given the will and knowledge for indoor activities, these include housekeeping, the nurturing of new born babies and a great affection for the new born and the family at large. For the wife to be comfortable, the man provides security in the home, he has been given the ability to provide courage to the wife. All these things work well where sharing is done. When these two parties stick to their various roles, there is bound to be ultimate success. Ischomachus became a great wealthy farmer because he was able to train his wife to manage house chores, rule and train slaves. This made him concentrate on managing those activities that were more outdoor and hence succeeded. In a definite case, it needs to be that way. When a man and a wife concentrate in the areas of their expertise, they often excel. For instance, in his conversation with his wife, Ischomachus points that a shelter is very important for people, they should have a cover on their heads. Unfortunately, as soon as these things have been done, new needs will always come again, hence the need for one who will constantly do it, who in this case is the man. Ischomachus notes that the couple ought to procreate. The man and the wife grow old and at one point in time, their efforts need to be complemented. Having children gives them a chance to

Information Searches Research Paper Example | Topics and Well Written Essays - 1000 words

Information Searches - Research Paper Example Some of the purchases that entail low involvement decisions are made without any previous though or planning and involve impulse buying. Medium involvement involves limited problem solving where the consumers already have some information about a good or a service and the continue searching for more information.Most of high involvementpurchases are not often purchased but are very vital to the consumer. Marketers should provide enough information concerning the attributes of the product. The marketers should also consider pricing their products in a manner that will entice the consumers into making a purchase decision. Medium involvement is the kind of involvement that falls between high involvement and low involvement purchasing decisions. This kind of medium involvement involves limited problem solving where the consumers already have some information about a good or a service and the continue searching for more information. High involvement purchases involve a lot of risks to the buyers if at all they fail and they are complex in nature and have high price tags. Some of the examples of high involvement purchases include a house, a car and insurance policy. Most of these purchases are not often purchased but are very vital to the consumer. While making a purchase decision, a buyer engages in an extended problem solving where they take a lot of time comparing different features, i.e. the feature of the prices, products and warranties. Every marketer has to analyze and consider the buying behavior of the customers therefore before making any decision; one has to consider the consumer’s level of involvement so as to come up with the sales strategy. As in the case of low involvement purchases, the marketers should use sales and promotion as a strategy since this will spur them into making purchase decisions. As discussed earlier, low involvement purchasers always make impulse buying therefore appealing sales promotions motivates them to buy more of the com pany’s products and services. Furthermore, the use of sales promotions like use of coupons can reach may customers at the same time therefore spurring into making a purchase decision. On the other hand, the marketers should also consider pricing their products in a manner that will entice the consumers into making a purchase decision. The company should also ensure that are low involving are available in most outlets as much as possible For, the case of medium involvement purchasers, most of them are considering the alternatives of the products. Understanding the choices made by this group assists the marketers in coming up with a sales strategy. Medium involvement consumers are in the third stage of evaluation of the alternatives before a purchase decision. The marketers should provide enough information about the product and its attributes. They should provide more of the advantages of the product or a service so as to entice the consumer into making a purchase decision. Th e customers who fall into the category of high involvement should be handled with a lot of care since they tend to make more and lengthy decisions before making a purchase. Since any purchase made by consumer requires extensive information, marketers should develop a strategy that is tailor made for this group. For example, when it comes into buying a car, the marketer must employ in broad problem solving techniques and also be willing to consider different types of brands. Since buying a car involve high involvement, brand name is very important for them. This is the reason as to why most of the manufacturers of those goods that require high involvement decisions cannot become satisfied about the value of their brands and

Competitive Strategy Essay Example | Topics and Well Written Essays - 500 words

Competitive Strategy - Essay Example It will also be necessary to strengthen our intellectual property rights protection in our targeted markets, as well as strengthen our products' safety. 2. Managing Global Trends: Global inflation rates are trending upwards, impacting on commodity pricing and reducing profit as increased costs for transport, material and labour as passed along the value chain. We are also seeing higher foreign exchange volatility, which could erode the value of our overseas investments and threatens our expansion plans. Of particular concern is the credit crunch originating in the USA, where the fall-out from the collapse of the sub-prime housing market has projected downward pressure on consumer spending. Recent reports indicate that the market for luxury goods and services will be hard hit as a consequence. 3. Moving Forwards: We foresee focusing on regions and countries which will weather the expected global economic depression well. Within such regions as Asia- particularly China and India where strong growth is expected - we will concentrate on high net-worth clients who are self-aware and focused on a healthy lifestyle. We anticipate that this will result in greater demand for our branded massage chair and exercise devices. Our distribution network will be remodelled to reflect this, with a review of the environmental and product safety laws of each country being a key part of each country's/region's feasibility study.

European Expansionism Essay Example for Free

European Expansionism Essay Identify and discuss the factors responsible for European expansionism from the 15th century. What were the social, political and economic effects of this expansionism on Europe, Africa and the Americas? There were three chief factors in the 15th century European expansionism. European nations such as Spain, France, Portugal, Italy, and England sought out to expand to new lands in an effort to spread Christianity, reap economic benefits, and to gain notoriety and respect throughout the world as World leaders. The expansion caused the world to change socially, politically and economically. As a result of many trade routes passing the coasts of Africa, Asia and the Americas, European adventurers began to report their findings and sightings of new lands to the monarchs of their home countries. European countries saw the potential of economic growth and market development in the new lands that they traveled to, so it became necessary for them to establish settlements and ownership in these new lands in order to capitalize on the potential. The Europeans were attracted to the natural, human, and technological resources that these new worlds possessed and knew that obtaining them would give them a new level of control in the world. Europeans would travel to parts of Asia in search of spices in order to flavor and preserve their foods. They explored America after its â€Å"discovery†, by Christopher Columbus, for its vast landscape and potential to build colonies and use the lands natural resources to maintain and run an econom. Africa was first ventured to by Europeans for trade of jewels, gems  and other sought after commodities, but then became targeted for its native people to be used as workers in their new lands. Once Europeans began to take action in moving into these new worlds, it became necessary for them to set up colonies, economic systems, rules, and almost most importantly, religion. Since all law was governed by the church in European countries, the need to establish the same type of system in colonized lands was very important as a form of maintaining control and discipline. Many European conquests throughout the world stemmed from or led to the forcible spread of religion. The method used by Europeans was a sure-fire way to recruit new converts. They would tell the natives of which ever land they were conquering that they had no choice but to convert to Christianity, or else they would be killed as an example for anyone else who refused their new religion. By conquering and exploring new l ands scattered throughout both the eastern and western hemisphere, European powers now had control in every area of the world. The colonies that were set up in the continents outside of Europe were governed by the same laws, language, and principles of those in their home countries. This social change caused regions to adopt new languages, and accept new, usually oppressive, lifestyles. Political systems were added and changed in colonized countries as well. A country that may have had its own ruler within the country or region now had to answer to the law of the country colonizing it. This completely took the power out of the hands of native people, for they had no connection or true knowledge about the form of government they had been forced to live in. In most cases of European expansion, the colonized country was exploited for economic gain. In some cases the countries people were used as enslaved workers for production of goods, while in other cases Europeans would obtain control of the resources that were indigenous to the land in order to trade with other countries as well as have a supply for their home countries. The European expansionism changed the way the world worked up until that time. Though many negative events took place in the expansion, it cau sed the world to become a global marketplace. Looking at the way the world began to change during the expansion of European powers lets us see today how the world and its economy have been shaped by it. What is the Columbian Exchange? Discuss its effects on both sides of the  Atlantic Ocean. The Columbian Exchange (Term coined by historian, Alfred W. Crosby) was a global exchange of goods and ideas between the Old World (Europe, Asia and Africa) and the New World (America). When Columbus first discovered America, Spain wanted to set up colonies. Columbus found some people that he named â€Å"Indians.† They colonies started to trade with each other, and by doing do, they started the Columbian Exchange. Many countries were involved in this trade, including China, Africa and Italy. This exchange of new ideas, traditions, food, religion and diet changed cultures everywhere. The Native Americans gave and received many items. One of the most important items that the Indians received was horses. Before horses, Indians had no way of carrying heavy loads from place to place. When the Europeans arrived in America, they gave them the horses, and then transporting goods was much easier . The plains Indians also used horses to hunt and herd the buffalo. Another important item was that the Europeans introduced to them were different types of medicine. The Indians already had medicine and healing (herbs) of their own, but the European way was much more effective. In return, the Indians also gave the Europeans some herbal treatments. Europe, Asia, and Africa received many goods, such as sweet potatoes, potatoes and tobacco. Both types of potato influenced many countries diets including China and Ireland. Tobacco was another important addition to Europe and other places in the Old World. Many people loved it. They could chew it, smoke it and snuff it. These who sold the tobacco made a lot of money. Also, many new vegetables from the New World such as tomatoes, peppers and corn went to the Old World and added to people’s diets, which resulted in better health because they received more nutrition and vitamins from the new foods. Along with all the positive things that the Columbian Exchange, there were negative things passed between the two worlds. Europeans diseases came to the New World. Diseases such as typhus, chicken pox, small pox and influenza plagued the Native Americans. Since they had never been exposed to these diseases, most of them were virtually wiped out from the sickness. In Europe, tobacco love was growing and soon it became a problem. Many people were getting sick or dying from starting to make and smoke cigars with the tobacco. Today, America, Asia, Europe, Japan and Africa still trade with each other. Many goods are received, like chocolate. Every country used chocolate in some way. Europeans had used sugar for what  they called â€Å"a cup of chocolate.† So instead out going out for a cup of coffee, they went out for a cup of chocolate. The Indians had coco. They pounded it and then added peppers and put the mix into water and drank it. Chocolate is one of the most popular trade items that are traded today. As you can see, the Columbian trade is still active and important today. Christopher Columbus Columbus was the Italian navigator who is given credit for the discovery of the Americas. He originally set out to find the West Indies, but miscalculated his routing. He is noted as the first person to come in contact with America’s Native People, which he called Indiana because of his misunderstanding of where the West Indies actually was. He completed four voyages across the Atlantic Ocean which gave him vast information to return to Europe with about America. The voyages, along with his efforts to colonize Hispaniola, led to the Spanish colonization of the New World. The Reconqusita The reconqusita was a 781 year long period in the Iberian peninsula after the original Islamic conquest to the fall of Granada. It began with the battle of Covadonga, where a small army led by Visigothic nobleman Pelagius defeated an Umayyad army in the mountains of Iberia. Captain James Cook James Cook was a British explorer, captain, and navigator. He Joined the British merchant navy and saw action in the Seven Years war. He is noted for making detailed maps of Newfoundland before making several voyages to the Pacific Ocean. While traveling the pacific, he became the first European to contact with the Eastern coastline of Australia and the Hawaiian Islands, as well as the first to cricumnavigant New Zealand. The Seven Years War The seven Years War was a war that involved Europe, North America, Central America, the West African coast, India, and the Philippines. The war took place between 1754 and1763, with its main years of conflict taking place in the seven year period of 1756 through 1763. The war is known in America as  the French and Indian War. The war was driven by all of the World Powers at the time competing in interests, usually being over trade of colonies or control of territories. Vasco Da Gama Vasco Da Gama was a Portuguese explorer who is famous for being the first European to reach India by sea. This navigation helped Portugal establish a colonial empire in Asia. His newly discovered route meant that the Portuguese would not need to cross the highly disputed and dangerous Mediterrianean and that they would no longer have to travel by land to make it to India.

The Environmental Problems Of Guwahati Environmental Sciences Essay

The Environmental Problems Of Guwahati Environmental Sciences Essay Guwahati, the largest city of Northeastern region of India with an area of 216 sq.km, It is the fifth fastest growing city of India in terms of urbanization. Guwahati being the only city of North eastern region, the city witnessed many changes like rapid increase of population, depletion of forest cover, spread of diseases which resulted many environmental problems akin to land, air, water and society. Most of the changes have taken place due to the effect of changing natural environment, tremendous growth of population particularly after shifting of the capital from Shillong to Dispur, hill slope destabilization due to construction of roads, dwelling houses, public institutions and also for encroachment in wetlands and low lying areas. As the city of Guwahati is bounded on three sides by hills and the other side by the mighty river Brahmaputra, the horizontal expansion is restricted for which many multistoried buildings have come up in recent years just to accommodate ever increasing population (1991- 2001 decadal growth rate is 38.6%) . On the other hand, required infrastructure and city amenities necessary for city dwellers and city us ers have not developed accordingly. As a result many problems arisen in the city, such as traffic congestion, water logging, dusty atmosphere, water borne and airborne diseases etc. In this study an attempt has been given to highlight the environmental problems arisen in Guwahati, their causes and consequences. Introduction The city of Guwahati is said to be the legendary Pragjyotispur, the city of eastern light. Guwahati is said to be the gateway of Northeast India. The city is situated between 260 1025 north latitude and 910 450 east longitude. The southern, eastern and a part of western sides of Guwahati are surrounded by hills and hillocks. The mighty river Brahmaputra in the north is flowing in north-east to south-west direction. Other important rivers in and around Guwahati are Bharalu, Mora-bharalu, Basistha-bahini etc. The city is dotted with swamps, marshes and water bodies like Dipor beel, Dighali pukhuri, Silsaku bill etc. The city falls under humid, subtropical region characterized by warm humid climate with heavy rainfall (average rainfall 1600mm) and a relatively cool winter with rather scanty rainfall. The maximum and minimum temperature recorded in the city is 38 degree and 16 degree respectively with relative humidity of more than 76.6%. As the city is the commercial nerve centre of the Northeast has developed road (National Highway No31, No37 and No 40), rail and air connectivity with rest of the country. Main problems identified in the city are different types of pollution caused due to man induced activities, increase of population, water logging, soil erosion etc. Aims This study aims at creating such an environment in Guwahati that the city could be made livable and lovable one. With this aim the objective this study has been designed Objectives To analyze the geo-ecological setup of Guwahati. To highlight the environmental problems associated with planning process of the city. To examine the cause and effect of various problems, and To throw light on the remedial measures to be taken to minimize the miseries of the city dwellers and city users. Methodology Here, in the study both primary and secondary sources of data have been used. Primary data were collected by spot visit and direct observation of the phenomena. On the other hand secondary data have been collected from various published works such as books, journals research articles, reports etc. Topographical maps (No 78N/12 16) and satellite imageries (SPOT MLA P-238, R-298 Dated 18/10/1990 and Landsat TM P-137, R -042 Dated 10/06/1988) have been used to examine the nature of the city growth, understand the environmental issues and to find out solutions for minimizing the miseries of the city dwellers. Collected data have been summarized, analyzed and presented in various forms like graphs, tables, maps etc. for easy understanding of the content of the paper. Data Analysis and Findings 1. Locational peculiarity of the city invites many environmental problems. Back in time the city was known as Pragjyotishpur, which finds mention in Mahabharata, Ramayana, Raghuvansha of Kalidas. Chinese traveler Hiuen Tsang visited the city in 640 AD and described in details about the customs and manners of the people of Guwahati. Located on strategic point the city has always been a bone of contention between rival political powers. A number of bloody wars were fought between Ahom and Mughal rulers for Guwahatis possession. Deforestation Increase in surface run off HILLS Hill slope destabilization Soil erosion Land slide/ land slip Rock fall Hill land Siltation in low lying areas and storm water encroachment drains PLAINS Decrease in water Wetland retention capacity Inundation of new areas encroachment Hampers free flow of water Degeneration of water WETLANDS bodies Dwindling Flora Fauna Fig. 1 : Schematic Diagram showing impact of human activities on the environmental problems of Guwahati With the weakening of Ahom power in Assam, the city passed into the hands of British in 1826. During the British days political pre-eminence of Guwahati shifted to Shillong, which they chose as State Capital. In 1971 with the reorganization of Assam State and shifting of capital to Guwahati (Dispur) it again recovered its political pre-eminence in north east region [1]. Since then Guwahati has made a rapid progress as far as demographic, commercial and industrial activities are concerned. All these activities are responsible for many environmental problems in the city (Fig.1). . 2. Geographical and geological setups are responsible to a great extent for the problems like water-logging, landslide etc. in the city. The general shape of the city is just like a bowl surrounded by hills and hillocks in three sides and river side roads on the remaining side. The altitude in the plain areas of the city varies from 49.5m to 55.5m. . There are a number of small hillocks in the city of which Sarania (193m), Nabagraha (217m), Nilachal (193m), and Chunsali (293m) are important. The hills are composed of Granite, Quartzite, Hornblende-Biotic-Schist, Pegmatite and Quartz. On the other hand the plain areas of the city covered by old and new alluvium. Most part of the city composed of light yellowish to red soil. When the soils completely water saturated during the monsoon months accelerate the rate of landslide hazards. The granitic rocks on the hills gradually exposed due to hill soil erosion. Quite often rock fall occur during the end part of the monsoon months and take precious human lives and damage property. Since August 1987 to August 2005 as many as 22 cases of landslide and rock fall cases recorded in different locations of Guwahati. 3. Climatic condition particularly rainfall concentration in monsoon months from June to September cause many inconvenience like water-logging, dusty atmosphere, spread of water borne and airborne dieses . Usually June rainfall is always alarming but the downpour absorbed by soil. At this stage landslide, rock fall and water logging etc. do not arise. But from July onwards in each heavy shower cause water logging in the areas like Narengi, Satgaon, Saimail, Khanapara, Noonmati, Bamunimaidam, Chandmari, Silpukhuri, Guwahati Club, Uzanbazar, Panbazar, Fancy Bazar, Paltan Bazar, Athgaon, Bharalumukh, Maligaon, Adabari, Jalukbari, G.S. Road, Zoo Road Tinali, Rajgarj Road, Bhangagarh, Dispur. When hill soils become saturated landslide and rock fall occur. Again, immediately after water logging, road surface become muddy and roadside drains clogged with silt derived from the hills. Soon after, dry mud on the roads create dusty atmosphere and increase air pollution. Moreover, storm water ca use mixing of drain water and septic tank effluents with drinking water sources aggravate the health hazards in the city. 4. Almost all the problems of the city related to the population growth. The decadal growth of population in Guwahati Metropolitan Development Authority (GMDA) clearly indicates how population may create problems in the city (Table- 1) The urban sprawl map since 1911 also indicate how city has been expanded (Fig-4). This has drastically changed the land use pattern in the city (Table-2).More particularly slums and squatters have increased manifold in last few years. As a result many inconvenience and problems have arisen in the city. 5. Defective planning and lacuna in executing the development schemes aggravate the problems in the city. In this regard, inadequate road space, lack of parking facility, undersized roadside drains, haphazardly laid utility wires and pipes are worth mentioning. Almost all the important roads, viz. GNB Road, GS Road, MG Road and most of the traffic point face acute traffic congestion. Up to 1975 the number of motorized vehicles in the city was only 27,000 which has increased to 1,29,856 in the year 1990. After that the rate of increase accelerated and by 2003 it records 3,13,387. As such around one lakh motor vehicle added to the roads of Guwahati every year [2]. On the other hand the city area has increased by only 46 sq km in last twenty years. Most of the streets in the city are only 4.8m wide. There are many lanes, which have only 3.6m or even 3.0m width. Theses should be at least 8.0m for light and medium vehicles and at least 9.0m for heavy vehicles [3]. The results of the vehic ular emission show the violation in emission limit by 53 percent and 81 percent in case of petrol and diesel vehicles respectively [4 5]. It clearly indicates the magnitude of pollution level in the city. 6. Lack of awareness and tendency of violating the norms and rules in constructing houses, disposing household wastes and abiding traffic rules cause many problems in the city. 7. Slackness in enforcing laws also responsible for the problems of traffic congestion, waste disposal, hill slope destabilization, wetland encroachment and various types of pollution in the city. Table- 1: Population Growth in Guwahati (from 1971 to 2001) Year Population 1971 2,93,219 1981 4,51,200 1991 6,93,660 2001 10,67,400 1200000 1000000 800000 600000 Population 400000 200000 0 1971 1981 1991 2001 Fig. 3: Population Growth in Guwahati (from 1971 to 2001) Land Use Category 1990 2001 Residential 8904 (71.04%) 6600 Commercial 202 (1.62%) 660 Industrial 516 (4.14%) 1375 Public Semi Public 1504 (12.08%) 2475 Transport 1053 (8.47%) 3399 Communication Parks Recreation 14 (0.11%) 1450 Special Use/Others 257 (2.06%) Table- 2: Area under Various Land Uses 1990 to 2001

Proton-proton Coupling Constant

Proton-proton Coupling Constant Easily recognized splitting patterns found in various spectra provide the chemical shifts of the different sets of hydrogen that generate the signals differ by two or more ppm. The patterns are symmetrically distributed on both sides of the proton chemical shift, and the central lines are always stronger than the outer lines. The most commonly observed patterns have been given descriptive names, such as doublet (two equal intensity signals), triplet (three signals with an intensity ratio of 1:2:1) and quartet (a set of four signals with intensities of 1:3:3:1). The line separation is always constant within a given multiplet, and is called the coupling constant (J). The magnitude of J, usually given in units of Hz, is magnetic field independent. Coupling constants play an immense role in configurational and conformational studies. The relative position of protons is determining factor for Vicinal coupling constant between two protons. For example, in 1,2-disubstituted ethenes, the lar ger vicinal coupling constant was observed between the olefinic protons for the trans isomer 82a than for the cis isomer 82b [127,134]. The vicinal coupling constant depends on the dihedral angle between the protons in saturated systems. Karplus [118] gave equations 1 and 2 relating the coupling constant with dihedral angles. J1 = k1cos2à ¯Ã‚ Ã‚ ¦ c (0 à ¯Ã¢â‚¬Å¡Ã‚ £ à ¯Ã‚ Ã‚ ¦ à ¯Ã¢â‚¬Å¡Ã‚ £ 90 °) †¦ (1) J2 = k2cos2à ¯Ã‚ Ã‚ ¦ c (0 à ¯Ã¢â‚¬Å¡Ã‚ £ à ¯Ã‚ Ã‚ ¦ à ¯Ã¢â‚¬Å¡Ã‚ £ 180 °)†¦ (2) These equations were later modified as equation 3. J2 = A cos2à ¯Ã‚ Ã‚ ¦ B cos2à ¯Ã‚ Ã‚ ¦ + C †¦ (3) In equation 3, J is the coupling constant and A, B and C are constants related to the electro-negativities of the substituents attached to the C-C segment. The J value decreases markedly with increase in the electronegativities of the substituents [135-140]. 13C-NMR: Transitions of only 13C nuclei are noticed in 13C-NMR spectroscopy. Figure 3 represents different ÃŽ ´ values (in ppm), couplings, coupling constants (in Hz) and chemical shifts of 13C nuclei processing in different chemical environments. Usually, ÃŽ ´ value scale of 13C-NMR ranges from 0-220 ppm with respect to TMS as internal standard. 13C-NMR spectral interpretation can be best understood from chart given in figure 3 [126,127]. 13C Chemical shift As in the same ways of proton NMR spectrum, Chemical Shift in 13C NMR spectrum provides the hybridization (sp3, sp2, sp) of each carbon nucleus due to shielding and deshielding effects. Each carbon nucleus has its own electronic environment, different from the environment of other, non-equivalent nuclei. Figure 3: Chart representing 13C nuclei chemical shift due to different chemical environments. Electronegative atoms and pi bonds cause downfield shifts (â€Å"Thinkbook†). Spin-spin coupling provides the number of protons attached to the 13C nuclei. (i.e., primary, secondary tertiary or quaternary carbon) [126,127]. Carbon (13C) has a much broader chemical shift range. One important difference is that the aromatic and alkene regions overlap to a significant extent [126,127].Many factors such as inductive effects of substituent, hybridization state of the observed nucleus, Van der Wall’s and steric effects between closely spaced nuclei, electric fields originating from molecular dipoles or point charges, hyperconjugation, mesomeric interactions in à ¯Ã‚ Ã‚ ° electron systems (delocalization effects), diamagnetic shielding due to heavy substituents (heavy-atom effect) and anisotropy effects is known to influence the 13C Chemical shift of six-membered ring compounds. Among those factor, electrostatic effects due to the presence of a heteroatom in the cyclohexane moiety and steric perturbation effects being intrinsic importance. Lambert et al. [141] documented the effect of heteroatom in monoheterocyclohexanes 83 on the shifts of ring carbons. The à ¯Ã‚ Ã‚ ¡-shift is a steep function of electronegativity of heteroatom X. A high frequency shift of about 50 ppm is produced by an increase in one unit electronegativity. However, a small effects of heteroatom electronegativity on à ¯Ã‚ Ã‚ ¢ and à ¯Ã‚ Ã‚ §-carbons are produced, a shift of -2.5 ppm/electronegativity unit for à ¯Ã‚ Ã‚ ¢ and -5.0 ppm/electronegativity unit for à ¯Ã‚ Ã‚ §-carbon, respectively. Ramalingam et al have demonstrated the effect of introduction of heteroatom in 84a-84e [86]. The decreasing order of the deshielding effect of heteroatom on the benzylic carbon is O > NMe > NH > S. because of a field effect, the heteroatom generates a low frequency an upfield shift in the ca rbonyl resonance. Contrary to à ¯Ã‚ Ã‚ ¡ and à ¯Ã‚ Ã‚ ¢ effects, the à ¯Ã‚ Ã‚ §-effect is being a property of at least four atoms and it has a torsional component. All ÃŽ ³ anti substituents cause increased shielding on C-5 due to the presence of ÃŽ ± and ÃŽ ³ protons. The ÃŽ ³ anti effect C-3 is found to be rather deshielding. The resonating carbon and perturbing à ¯Ã‚ Ã‚ § substituent showed the dihedral angle arrangement ranging from 0-180 °. à ¯Ã‚ Ã‚ §-gauche effects is found to be almost independent of the nature of the perturbing group X and generally occur in the 60-80 ° regions, whereas à ¯Ã‚ Ã‚ §-anti effect in the 150-180 ° regions. The introduction of an axial substituent shifts the resonance of a à ¯Ã‚ Ã‚ §-carbon to lower frequencies. The à ¯Ã‚ Ã‚ §-anti effect (introduction of an equatorial substituent) is small. Interpretation of the substituent effects mainly depends on the steric and polar effects [142-144]. Based on the 13C NMR spectrum of vinylcyclohexane at low temperature, Buchanan observed the low frequency shifts in 85a relative to the equatorial counterpart 85b [145]. Based on the 13C NMR spectrum of various di-and tri-methylcyclohexanes, Dalling and Grant [146] observed an axial methyl group shifts the resonance of C(2), C(3) and C(4) at 1.40, 5.41 and 6.37 ppm and the corresponding resonance shifts for an equatorial methyl group at 5.96, 9.03 and 0.05 ppm, respectively. The shielding by an axial methyl group relative to an equatorial methyl group has been ascribed to steric interactions [142]. Furthermore, The 13C NMR data of 4 hydroxypiperidines results indicate that substituent effects are markedly influenced by steric interaction. Eliel et al. [147] study on à ¯Ã‚ Ã‚ §-effect of heteroatoms in heteracyclohexanes 86a-86d provide evidence that the à ¯Ã‚ Ã‚ §-carbon located anti to a second-row heteroatom (X=O; NH) resonates at significantly lower frequency than the analogo us carbon anti to a methylene group or a third-row heteroatom. Pandiarajan et al. [13] suggested a method of assigning the configuration of a sub ­stituent in saturated six–membered ring compounds, existing in chair conformation, from 13C chemical shift of a single epimer. Furthermore, the influence of the nearby substituents on the substituent parameters of equatorial methyl, gem-dimethyl, and equatorial and axial hydroxyl groups in several six-membered ring compounds 87a-87g has been suggested by Pandiarajan et al [13]. The magnitude of the à ¯Ã‚ Ã‚ ¡ effect of a particular substituent is significantly reduced by a nearby substituent and the magnitude of the à ¯Ã‚ Ã‚ ¡ effect decreases as the number of gauche interactions increases. Though, the à ¯Ã‚ Ã‚ ¢ and à ¯Ã‚ Ã‚ § effects are not influenced by the nearby substituents [13]. Nuclear Overhauser effect (nOe) The change in intensity of one NMR resonance that occurs when another is saturated is known as the nuclear Overhauser effect (NOE). NOE arises from dipole–dipole cross-relaxation between nuclei, and its usefulness. The strength of a given NOE enhancement is approximately correlated with internuclear separation (actually r−6 where r is the internuclear distance). However, the NOE also depends on other factors such as molecular motions [148]. In small molecules in solution, the NOE is positive and causes affected resonances to increase in intensity. NOE for small molecules is generally measured using one-dimensional experiments. In small molecules, NOE determins particular stereochemical relationships, such as substitution or ring fusion patterns in largely rigid systems. The NOE is negative for larger molecules and cause affected resonances decrease in intensity. NOE for larger molecules is usually measured using the two-dimensional NOESY experiment or one of its multidimensional variants. Using the NOE to Development of three-dimensional structural information using NOE generally depends on interpretation of an overlapping, redundant network of enhancements, rather than on calibrating precisely the distance dependence of individual enhancements. NOE determine accurate three-dimensional solution structures of biomacromoleculs such as DNA, RNA, or other proteins [149]. A spin-excited nucleus is known to transfer its spin energy to that of an adjacent nucleus resulting in spin relaxation. The efficiency of energy transfer is directly related to the distance between the two nuclei. The nOe grosses advantage of the spin energy transfer [149]. The nOe decreases as the inverse of the sixth power of the distance between the protons. An interesting application of nOe to a structural problem has been described by Hunter et al. [150] When styrene is polymerized in the presence of 4-methoxyphenol, in addition to the polymer, a 1:1 adduct is obtained by the addition of a styrene molecule to 4-methoxyphenol. However, the question of whether the addition occurs at C-2 or C-3 could not be answered from either the 1H or 13C NMR spectrum. The nOe experiment provided a decision in favour of structure 88. Irradiating the OCH3 resonance gave an increase in the intensities of the signals of the ring protons HA and HB. From this it is obvious that both these protons are ortho to the OCH3 group. In contrast the signal of the third ring proton HC showed a negative nOe. This is a case of an indirect nOe in a multi spin system. In further, nOe experiment it was shown that saturating the OH resonance increased the intensity of the HC signal, providing additional evidence for structure 88. TWO-DIMENSIONAL NMR SPECTROSCOPY COSY, a homonuclear 2D NMR correlation spectroscopy, correlates chemical shift of two hydrogen nuclei located on two different carbons that are separated by a single bond via j coupling. Thus it detects the chemical shift for hydrogen’s on both F1 and F2 axis. The most important two-dimensional NMR spectra show either 1h vs 1h or 1h vs 13c chemical shift correlations [126,127]. Here, we attempt to discuss about the some of the important types of 2-D experiments. Principle In 2D-NMR, the structural information are obtained from the interactions between two nuclei, either through the bonds which connect them (J-coupling interaction) or directly through space (NOE interaction). These interactions occur at a time by irradiating one resonance in the proton spectrum (either during the relaxation delay or during acquisition) and provide the effect on the intensity or coupling pattern of another resonance. 2D NMR essentially allows us to irradiate all of the chemical shifts in one experiment and gives us a matrix or two-dimensional map of all of the affected nuclei. All possible pairs of nuclei in the sample processed at the same time [128,129]. The basic steps in 2D experiment are as follows. 1. Preparation: Excite nucleus A, creating magnetization in the x-y plane 2. Evolution: Measure the chemical shift of nucleus A. 3. Mixing: Transfer magnetization from nucleus A to nucleus B (via J or NOE). 4. Detection: Measure the chemical shift of nucleus B. Preparation and Evolution: A 90o pulse excites all of the sample nuclei simultaneously. Detection is simply recording an FID and finding the frequency of nucleus B by Fourier transformation. To get a second dimension, we have to measure the chemical shift of nucleus A before it passes its magnetization to nucleus B. This is accomplished by simply waiting a period of time (called t1, the evolution period) and letting the nucleus A magnetization rotate in the x-y plane. The experiment is repeated many times over (for example, 512 times), recording the FID each time with the delay time t1 incremented by a fixed amount. The time course of the nucleus A magnetization as a function of t1 (determined by its effect on the final FID) is used to define how fast it rotates and thus its chemical shift. Mixing is a combination of RF pulses and/or delay periods which induce the magnetization to jump from A to B as a result of either a J coupling or an NOE interaction (close proximity in space). Di fferent 2D experiments (e.g., NOESY, COSY, HETCOR, etc.) differ primarily in the mixing sequence, since in each one we are trying to define the relationship between A and B within the molecule in a different way [128,129].

Homers The Odyssey Essay -- Homer Odyssey Epic Poem Essays

Homer's "The Odyssey" The Odyssey is a companion to The Iliad, a story of the Trojan War. Both The Iliad and The Odyssey are epic poems written by Homer. In The Odyssey, Homer relates the misadventures of Odysseus, king of Ithaca, that occur during the decade following the defeat of Troy. In doing so, the fates of his fellow warriors are also made known. The Odyssey begins on Mount Olympus, in the palace of Zeus, king of the gods, where a discussion takes place regarding the woes of humans and their determination to blame it on the gods. Athene, daughter of Zeus, appeals to her father to help Odysseus, who through no fault of his own, has been kept prisoner on the island of Ogygia for seven years by Calypso, daughter of the god Atlas. After receiving sanction to help Odysseus, Athene visits Telemachus, Odysseus' son, to motivate him to begin searching for his father. It is here that we learn of the situation awaiting Odysseus at home in Ithaca. Penelope, Odysseus' wife, is besieged by suitors who wish to marry her. She has no desire to remarry because she still laments for Odysseus and prays that he will return, even though it's been twenty years since he left to fight against Troy. These suitors, rather than courting her from afar, have taken up residence in her palace and are eating her and her son out of house and home. It is under these circumstances that Telemachus, directed by Athene, leaves Ithaca to search for news of his father. Meanwhile, Calypso is sent word that she must release Odysseus and allow him to return home. It is during his trip home that we learn of all that has befallen Odysseus since he left Troy. His journey home is not without incident either. However, with the help of Athene, Odysseus finally arriv... ...his voyage, The Ulysses Voyage, which describes his findings. Even people who have never read The Odyssey have been influenced by Homer because the books they read or the movies they watch are written by people who were influenced by Homer, and the languages they speak have words and expressions that have come down to us from Homer. Xenophanes, quoted in Scott's book, says it the best: "From the beginning, for all have learned from him." (Scott 93) Ifwe read Homer's The Odyssey, we can learn from him too. Works Cited: Finley, M. I. The World of Odysseus. New York: The Viking Press, 1954 , Lefkowitz, Mary R. The Lives of the Greek Poets. Baltimore: The John Hopkins University Press, 1981. Scott, John Adams Scott. Homer and His Influence. New York: Cooper Square Publishers, Inc., 1963. Severin, Tim. The Ulysses Voyage. New York: E. P. Dutton, 1987