Cloud Development Essay Example | Topics and Well Written Essays - 1500 words

Cloud Development - Essay Example As the temperature decreases the molecules lose some of their energy, and compress onto particles in the atmosphere, shaping clouds. Water molecules are stored in the atmosphere in all three states of matter. Water vapor in the atmosphere is commonly referred to as humidity. If liquid and solid forms of water can overcome atmospheric updrafts they can fall to the Earth's surface as precipitation. The formation of ice crystals and water droplets occurs when the atmosphere is cooled to a temperature that causes condensation or deposition. Four processes that can trigger such atmospheric cooling are oro-graphic uplift; convectional uplift; air mass convergence; and energy loss. [01] Precipitation can be defined as any aqueous deposit, in liquid or solid form, that develops in a saturated atmospheric environment and generally falls from clouds. A number of different precipitation types have been classified by meteorologists including rain, freezing rain, snow, ice pellets, snow pellets, and hail. Fog represents the saturation of air near the ground surface. Classification of fog types is accomplished by the identific ation of the mechanism that caused the air to become saturated. [01] The distribution of precipitation on the Earth's surface is generally controlled by the absence or presence of mechanisms that lift air masses to cause saturation. It is also controlled by the amount of water vapor held in the air, which is a function of air temperature. A figure is presented that illustrates global precipitation patterns. Clouds and Their Formation: A cloud can be defined as a visible mass of condensed droplets, frozen crystals suspended in the atmosphere above the surface of the Earth. More importantly, these clouds can also occur as masses of material in interstellar space, where they are called interstellar clouds and nebulae. [02] On Earth the condensing substance is typically water vapor, which forms small droplets or ice crystals, typically 0.01 mm in diameter. [02] When surrounded by billions of other droplets or crystals they become visible as clouds. Dense deep clouds exhibit a high reflectance (70% to 95%) throughout the visible range of wavelengths: they thus appear white, at least from the top. Cloud droplets tend to scatter light efficiently, so that the intensity of the solar radiation decreases with depth into the cloud, hence the gray or even sometimes dark appearance of the clouds at their base. [02] Thin clouds may appear to have acquired the color of their environment or background, and clouds illuminated by n on-white light, such as during sunrise or sunset, may be colored accordingly. In the near-infrared range, clouds would appear darker because the water that constitutes the cloud droplets strongly absorbs solar radiation at those wavelengths. [02] Types of Clouds: Although there are many types of clouds with respect to their different characteristics, clouds are mainly divided into three major classifications. These are as under, Cirrus Clouds: The name originates from the Latin word meaning "curl of hair". These feathery clouds form very high up in the sky (at altitudes between 5 km and 14 km) where it is very cold. [03] They are therefore made up of tiny ice crystals rather than water droplets. Cirrus clouds occur in warm air which is being slowly lifted over a large area by an approaching cold front, and they

Phonetics Case Essay Example for Free

Phonetics Case Essay Introduction The aim of this thesis is to give a systematic description of some aspects of English morphophonemic. The thesis falls into 2 chapters: The first chapter, which is an introduction, presents a short sketch of the title, the problem, the purpose of the study,phonological rules. The second chapter is devoted to some of the basic concepts required in the study of morphophonemic. It starts with various definitions of morpheme, allomorph. The thesis ends with some conclusions, a list of bibliography. Morphophonemic Analysis designates the analytic procedures whereby paradigms with phonological alternations are reduced to underlying representations and phonological rules. The term morphophonemic analysis has a now obscure origin. In the 1940s and 1950s, many phonologists worked with a theory in which (roughly) all neutralizing rules were assumed to apply before all allophonic rules. This in effect divided the phonology into two components: a neutralizing component, whose units were called morphophonemes, and a non-neutralizing component, which dealt with phonemes and allophones. This bifurcated-phonology theory is widely considered untenable today, but  morphophonemics remains a useful term for characterizing the study of neutralizing phonological rules as they apply in paradigms. When we conduct morphophonemic analysis, we seek to establish a connection between data and theory. The theory in question is that morphemes are stored in the lexicon in an invariant phonemic form, are strung together by morphological and syntactic rules, and are then converted to their surface forms by a sequence of phonological rules (often neutralizing), applied in a particular order. The purpose of morphophonemic analysis is to discover a set of underlying forms and ordered rules that are consistent with the data; and the payoff is that seemingly complex patterns are often reduced to simplicity. Morphophonemic analysis may be contrasted with phonemic analysis. Phonemic analysis is a more limited form of phonological analysis that seeks only to discover the non-neutralizing (allophonic) rules of the phonology. In phonemic analysis, only the distribution and similarity of the phones is examined. Therefore, the data need not be grouped in paradigms, but need only comprise a sufficiently large and representative set of words. Like phonemic analysis, morphophonemic analysis can be pursued with a systematic method. The main purpose of my work consists in making exact definition of a phoneme and allophone and be able to distinguish them. To understand what is morphophonemic?   Problems of my work are: morphophonemic and morphophonological rules, types of morphophonological changes, relation between phonology and morphophonology, isolation forms, rule ordering, morphophonology and orthography. Morphophonology (also morphophonemics, morphonology) is a branch of linguistics which studies the interaction between morphological and phonological or phonetic processes. Its chief focus is the sound changes that take place in morphemes (minimal meaningful units) when they combine to form words. Morphophonological analysis often involves an attempt to give a series of formal rules that successfully predict the regular sound changes occurring in the morphemes of a given language. Such a series of rules  converts a theoretical underlying representation into a surface form that is actually heard. The units of which the underlying representations of morphemes are composed are sometimes called morphophonemes. The surface form produced by the morphophonological rules may consist of phonemes (which are then subject to ordinary phonological rules to produce speech sounds or phones), or else the morphophonological analysis may bypass the phoneme stage and produce the phones itself. Morphop honemes and morphophonological rules When morphemes combine, they influence each others sound structure (whether analyzed at a phonetic or phonemic level), resulting in different variant pronunciations for the same morpheme. Morphophonology attempts to analyze these processes. A languages morphophonological structure is generally described with a series of rules which, ideally, can predict every morphophonological alternation that takes place in the language. An example of a morphophonological alternation in English is provided by the plural morpheme, written as -s or -es. Its pronunciation alternates between [s], [z], and [É ªz], as in cats, dogs, and horses respectively. A purely phonological analysis would most likely assign to these three endings the phonemic representations /s/, /z/, /É ªz/. On a morphophonological level, however, they may all be considered to be forms of the underlying object //z//, which is a morphophoneme. The different forms it takes are dependent on the segment at the end of the morpheme to which it attaches – these dependencies are described by morphophonological rules. (The behaviour of the English past tense ending -ed is similar – it can be pronounced [t], [d] or [É ªd], as in hoped, bobbed and added.) Note that the plural suffix -s can also influence the form taken by the preceding morpheme, as in the case of the words leaf and knife, which end with [f] in the singular, but have [v] in the plural (leaves, knives). On a morphophonological level these morphemes may be analyzed as ending in a morphophoneme //F//, which becomes voiced when a voiced consonant (in this case the //z// of the plural ending) is attached to it. This rule may be written symbolically as: /F/ - [ÃŽ ±voice] / __ [ÃŽ ±voice]. In the International Phonetic Alphabet, pipes (| |) are often used to indicate a morphophonemic rather than phonemic representation. Another common convention is double slashes (// //), as  above, implying that the transcription is more phonemic than simply phonemic. Other conventions sometimes seen are double pipes (|| ||) and curly brackets ({ }). Types of morphophonological changes Inflected and agglutinating languages may have extremely complicated systems of morphophonemics. Examples of complex morphophonological systems include: 1. Sandhi, the phenomenon behind the English examples of plural and past tense above, is found in virtually all languages to some degree. Even Mandarin, which is sometimes said to display no morphology, nonetheless displays tone sandhi, a morphophonemic alternation. 2. Consonant gradation, found in some Uralic languages such as Finnish, Estonian, Northern Sà ¡mi, and Nganasan. 3. Vowel harmony, which occurs in varying degrees in languages all around the world, notably Turkic languages. 3. Ablaut, found in English and other Germanic languages. Ablaut is the phenomenon wherein stem vowels change form depending on context, as in English sing, sang, sung. Relation between phonology and morphophonology Until the 1950s, many phonologists assumed that neutralizing rules generally applied before allophonic rules. Thus phonological analysis was split into two parts: a morphophonological part, where neutralizing rules were developed to derive phonemes from morphophonemes; and a purely phonological part, where phones were derived from the phonemes. Since the 1960s (in particular with the work of the generative school, such as Chomsky and Halles The Sound Pattern of English) many linguists have moved away from making such a split, instead regarding the surface phones as being derived from the underlying morphophonemes (which may be referred to using various terminology) through a single system of (morpho)phonological rules. The purpose of both phonemic and morphophonemic analysis is to produce simpler underlying descriptions for what appear on the surface to be complicated patterns. In purely phonemic analysis the data is just a set of words in a language, while for the purposes of morphophonemic analysis the words must be considered in grammatical paradigms to take account of the underlying morphemes. It is postulated that morphemes are recorded in the speakers lexicon in an invariant (morphophonemic) form, which, in a given environment, is converted by rules into a surface form. The analyst attempts  to present as completely as possible a system of underlying units (morphophonemes) and a series of rules that act on them, so as to produce surface forms consistent with the linguistic data. Isolation forms The isolation form of a morpheme is the form in which that morpheme appears in isolation (when not subject to the effects of any other morpheme). In the case of a bound morpheme, such as the English past tense ending -ed, it will generally not be possible to identify an isolation form, since such a morpheme does not occur in isolation. It is often reasonable to assume that the isolation form of a morpheme provides its underlying representation. For example, in some American English, plant is pronounced [plà ¦nt], while planting is [ˈplà ¦nÉ ªÃ…‹], where the morpheme plant- appears in the form [plà ¦n]. Here the underlying form can be assumed to be //plà ¦nt//, corresponding to the isolation form, since rules can be set up to derive the reduced form [plà ¦n] from this (while it would be difficult or impossible to set up rules that would derive the isolation form [plà ¦nt] from an underlying //plà ¦n//). This is not always the case, however; sometimes the isolation form itself is subject to neutralization that does not apply to some other instances of the morpheme. For example, the French word petit (small) is pronounced in isolation without the final [t] sound, although in certain derived forms (such as the feminine petite) the [t] is heard. If the isolation form were adopted as the underlying form, the information that there is a final t would be lost, and it would be hard to explain the appearance of the t in the inflected forms. Rule ordering Morphophonological rules are generally considered to apply in a set order. This means that the application of one rule may sometimes either prevent or enable the application of another rule provided the rules are appropriately ordered. If the ordering of two rules is such that the application of the first rule can have the effect of making it possible to apply the second, then the rules are said to be in feeding order. For example, if a language has an apocope rule (A) which deletes a final vowel, and a cluster reduction rule (CR) that reduces a final consonant cluster, then the rules are in feeding order if A precedes CR, since the application of A can enable application of CR (for example, a word ending /-rpa/ is not itself subject  to CR, since the consonant cluster is not final, but if A is applied to it first, leaving /-rp/, then CR can apply). Here rule A is said to feed rule CR. If the rules are ordered such as to avoid possible feeding (in this case, if CR applies before A) then they are said to be in counter-feeding order. On the other hand, if rules are ordered such that the application of the first rule can have the effect of preventing application of the second, then the rules are said to be in bleeding order. For example, if a language has an epenthesis rule (E) that inserts a /w/ before certain vowels, and a vowel deletion rule (D) that deletes one of two consecutive vowels, then the rules are in bleeding order if E precedes D, since the application of E can prevent application of D (for example, a word containing /-iu-/ would be subject to D, but if E is applied to it first, leaving /-iwu-/, then D can no longer apply). Here rule E is said to bleed rule D. If the rules are ordered such as to avoid possible bleeding (in this case, if D applies before E) then they are said to be in counter-bleeding order. The terminology of feeding and bleeding is also applied to other linguistic rules, such as those of historical sound changes. Morphophonology and orthography The principle behind alphabetic writing systems is that the letters (graphemes) represent phonemes. However in many orthographies based on such systems the correspondences between graphemes and phonemes are not exact, and it is sometimes the case that certain spellings better represent a words morphophonological structure rather than the purely phonological. An example of this is that the English plural morpheme is written -s regardless of whether it is pronounced as /s/ or /z/; we write cats and dogs, not dogz. The above example involves active morphology (inflection), and morphophonemic spellings are common in this context in many languages. Another type of spelling that can be described as morphophonemic is the kind that reflects the etymology of words. Such spellings are particularly common in English; examples include science /saÉ ª/ vs. unconscious /ÊÆ'/, prejudice /prÉ›/ vs. prequel /priË /, sign /saÉ ªn/ signature /sÉ ªÃ‰ ¡n/, nation /neÉ ª/ vs. nationalism /nà ¦/, and special /spÉ›/ vs. species /spiË /. Conclusions according to this chapter Morphophonology (also morphophonemics, morphonology) is a branch of linguistics which studies: 1. The phonological structure of morphemes. 2. The combinatory phonic modifications of morphemes which happen when they are combined. 3. The alternative series which serve a morphological function. Examples of a morphophonological alternatives in English include these distinctions: Plurals -es and -s, as in bus, buses, vs. bun, buns. Plural of -f is -ves, as in leaf, leaves. Different pronunciations for the past tense marker -ed. English, having lost its inflection, does not have much morphophonology. Inflected and agglutinating languages may have extremely complicated systems, e.g., consonant gradation. A morphophonemic rule has the form of a phonological rule, but is restricted to a particular morphological environment. Morphophonemic rules are sensitive to their environment, unlike phonological rules. Whenever morphological information is required to specify the environment for an allophonic rule, the rule is morphophonemic. The prefix /in-/ has the allomorphs [il] and [ir]: /in-/ + responsible irresponsible /in-/ + logical illogical Therefore, there must be a morphophonemic rule which determines the allomorphs [il] and [ir] of the prefix /in-/. The purpose of both phonemic and morphophonemic analysis is to produce simpler underlying descriptions for what appear on the surface to be complicated patterns. When morphemes are clustered or grouped in words than changes in the phonological structures of these words occur. Such changes are called morphophonemic changes. Assuming that we allow phonological rules to apply in sequence, we can cycle through them using the output of the first rule as the input to the second. For many cases in the data set, at most one phonological rule introduces a structural change. But in cog, tail, or comb we see a single derivation that involves both rules. Furthermore, such cases are not rare in English. Any word that begins with a voiceless stop and contains a vowel that precedes a voiced consonant will require the application of both rules. We use cog as an illustrative example: Allophone Central to the concept of the phoneme is the idea that it may be pronounced in many different ways. In English (BBC pronunciation) we take it for granted that the r sounds in ‘ray’ and ‘tray’ are â€Å"the same sound† (i.e. the same phoneme), but in reality the two sounds are very different – the r in ‘ray’ is voiced and non-fricative, while the r sound in ‘tray’ is voiceless and fricative. In phonemic transcription we use the same symbol r for both, but we know that the allophones of r include the voiced nonfricative sound É ¹ and the voiceless fricative one . In theory a phoneme can have an infinite number of allophones, but in practice for descriptive purposes we tend to concentrate on a small number that occur most regularly. Phoneme This is the fundamental unit of phonology, which has been defined and used in many different ways. Virtually all theories of phonology hold that spoken language can be broken down into a string of sound units (phonemes), and that each language has a small, relatively fixed set of these phonemes. Most phonemes can be put into groups; for example, in English we can identify a group of plosive phonemes p, t, k, b, d a group of voiceless fricatives f, ÃŽ ¸, s, ÊÆ', h, and so on. An important question in phoneme theory is how the analyst can establish what the phonemes of a language are. The most widely accepted view is that phonemes are contrastive and one must find cases where the difference between two words is dependent on the difference between two phonemes: for example, we can prove that the difference between ‘pin’ and ‘pan’ depends on the vowel and that i and are different phonemes. Pairs of words that differ in just one phoneme are known as minimal pairs. We can establish the same fact about p and b by citing ‘pin’ and ‘bin’. Of course, you can only start doing commutation tests like this when you have a provisional list of possible phonemes to test, so some basic phonetic analysis must precede this stage. Other fundamental concepts used in phonemic analysis of this sort are complementary distribution, free variation, distinctive feature and allophone. Different analyses of a language are possible: in the case of English some phonologists claim that there are only six vowel phonemes, others that there are twenty or more (it depends on whether you count diphthongs and long vowels as single phonemes or as combinations of two phonemes). It used to be said that learning the  pronunciation of a language depended on learning the individual phonemes of the language, but this â€Å"building-block† view of pronunciation is looked on no wadays as an unhelpful oversimplification. Phonemics When the importance of the phoneme became widely accepted, in the 1930s and 40s, many attempts were made to develop scientific ways of establishing the phonemes of a language and listing each phoneme’s allophones; this was known as phonemics. Nowadays little importance is given to this type of analysis, and it is considered a minor branch of phonology, except for the practical purpose of devising writing systems for previously unwritten languages. Conclusion: An allophone is a phonetic variant of a phoneme in a particular language. A phoneme is the smallest contrastive unit in the sound system of a language. A phone is one of many possible sounds in the languages of the world. Phonemics a branch of linguistic analysis involving the study of phonemes, the structure of a language in terms of phonemes. General conclusion Morphophonemics, in linguistics, study of the relationship between morphology and phonology. Morphophonemics involves an investigation of the phonological variations within morphemes, usually marking different grammatical functions; e.g., the vowel changes in â€Å"sleep† and â€Å"slept,† â€Å"bind† and â€Å"bound,† â€Å"vain† and â€Å"vanity,† and the consonant alternations in â€Å"knife† and â€Å"knives,† â€Å"loaf† and â€Å"loaves.† The ways in which the morphemes of a language are variously represented by phonemic shapes can be regarded as a kind of code. This code is the morphophonemic system of the language. The morphophonemics of English is never so simple. There are always many instances of two or more morphemes represented by the same phonemic shape, and there are always cases in which a single morpheme is represented now by one phonemic shape, now by another. Therefore the morphophonemics of English is never trivial. Literature: 1. Hayes, Bruce (2009). Morphophonemic Analysis Introductory Phonology, pp. 161–185. Blackwell. 2. R. Jakobson, C. G. Fant, and M. Halle, Preliminaries to Speech Analysis, Fundamentals of Language (Mouton and Company, The Hague, 1956). 3. P. Roach (2004). â€Å"English Phonetics and Phonology†, Cambridge. 4. www.wikipedia.ru 5. www.sil.org 6. www.msu.edu

Chemical Warfare :: essays research papers

Chemical warfare What is Chemical Warfare: To understand chemical warfare you must first understand what a chemical agent is. A United Nations report from 1969 defines chemical warfare agents as " ... chemical substances, whether gaseous, liquid or solid, which might be employed because of their direct toxic effects on man, animals and plants ... ". This means basically that any chemical that is used to directly effect and harm a person, plant, or animal would be an act of chemical warfare. Some commonly confused Chemical Agents: Agents such as napalm and phosphorus are not considered to be Chemical agents since they achieve their effect mainly through thermal energy. Certain types of smoke screen may be poisonous in extremely high concentrations but smoke ammunition is not classified as a chemical weapon since the poisonous effect is not the main reason for their use. Another common misconception is that biological agents such as viruses or microorganisms (small pox etc.) are considered a chemical agent, but this is not the case. Effects of chemical agents and biological agents may be similar but they different in production. Chemical agents are created and biological agents are found naturally in nature or cultured for use. Different types of Chemical agents: Nerve Agents: Source: A FOA Briefing Book on Chemical Weapons Nerve agents acquired their name because they affect the transmission of nerve impulses in the nervous system. They are stable, easily spread, highly toxic and have rapid effects when absorbed through the skin and respiratory track. Nerve agents can be manufactured by means of fairly simple chemical techniques. The materials are inexpensive and generally readily available. It was not until the early 1930's that German chemists discovered the effects of certain phosphorus compounds to be toxic. Two years later a phosphorus compound with extremely high toxicity was produced for the first time. This phosphorus compound, given the name tabun, was one the first substances later referred to as nerve agents. Physical and chemical properties The most important nerve agents included in modern arsenals are: „h Tabun, O-ethyl dimethylamidophosphorylcyanide, This nerve agent is the easiest to manufacture. Therefore, it is more likely that developing countries start their arsenal with this nerve agent „h Sarin, isopropyl methylphosphonofluoridate, a toxic substance mainly afflicting the respiratory system. „h Soman, pinacolyl methylphosphonofluoridate, a moderately toxic substance which can be taken up by inhalation or skin contact. „h Cyclohexyl methylphosphonofluoridate, a gas or Liquid substance with low volatility which is taken up through skin contact and inhalation of the substance

The Capricious Camera Essay -- Germany Nazis Phototgraphy Papers

The Capricious Camera In the years between 1933 and 1945, Germany was engulfed by the rise of a powerful new regime and the eventual spoils of war. During this period, Hitler's quest for racial purification turned Germany not only at odds with itself, but with the rest of the world. Photography as an art and as a business became a regulated and potent force in the fight for Aryan domination, Nazi influence, and anti-Semitism. Whether such images were used to promote Nazi ideology, document the Holocaust, or scare Germany's citizens into accepting their own changing country, the effect of this photography provides enormous insight into the true stories and lives of the people most affected by Hitler's racism. In fact, this photography has become so widespread in our understanding and teaching of the Holocaust that often other factors involved in the Nazi's racial policy have been undervalued in our history textbooks-especially the attempt by Nazi Germany to establish the Nordic Aryans as a master race thro ugh the Lebensborn experiment, a breeding and adoption program designed to eliminate racial imperfections. This other side of the story, so to speak, is evident in Nazi photography, but is not easily accessible or even immediately apparent to viewers. The photograph Mounted Nazi Troops on the Lookout for Likely Polish Children would not be so shocking or historically suggestive without the caption to describe its significance. Who is this young white girl surrounded by armed soldiers? Is she being protected, watched, persecuted? It would be easy enough to assume that she is Jewish, but unlike photos documenting the Holocaust, with this image the intent is uncertain. In our general ignorance of the events surrounding th... ...saw the image as artistic, subsequent events compel us to try and see the image of the Polish girl with Nazis as journalism. In this endeavor, we must uncover as much as possible about the surrounding context. As much as we can, we need to know this girl's particular story. Without a name, date, place, or relevant data, this girl would fall even further backwards into the chapters of unrecorded history. Works Cited "Mounted Nazi Troops on the Lookout for Likely Polish Children." Clay and Leapman. Clay, Catrine and Michael Leapman. Master Race: The Lebensborn Experiment in Nazi Germany. London: Hodder and Stoughton, 1995. Milton, Sybil. "The Camera as Weapon: Documentary Photography and the Holocaust." Multimedia Learning Center ÂÂ ­ Museum of Tolerance. The Simon Wiesenthal Center. 1999<http:// motlc.wiesenthal.com/resources/books/ annual1/chap03.html>.

Immobilization of Amylase on Magnetic Nanoparticles Essay

Abstract ÃŽ ±-amylase was immobilized covalently on iron oxide magnetic nanoparticles. The synthesis of magnetic nanoparticles was done by the coprecipitation conventional method. The chemical composition and particle size of the synthesized particles was confirmed via X-ray diffraction. Tyrosine, Lucien and chitosan and glutaraldehyde were investigated to make a covalent binding between the iron oxide magnetic core and the immobilized enzyme. Immobilization using chitosan and glutaraldehyde show the best result. Finally the immobilization efficiency was tested by determination of protein concentration in a solution before and after mixing with the magnetic nanoparticles. Introduction In the last two decades, new terms with the prefix `nano’ have rushed into the scientific vocabulary; nanoparticle, nanostructure, nanotechnology, nanomaterial, nanocluster, nanochemistry, nanocolloids, nanoreactor and so on. Nanoparticles, are defined as particulate dispersions with a size in the range of 10-100nm (Gubin et al, 2005). Magnetic nanoparticles have gained a remarkable interest in the last years both for basic research and applied studies. The use of magnetic nanostructures has been proven in biochemistry, biomedicine, and waste treatment among other fields. This broad range of applications is based on the fact that magnetic particles have very large magnetic moments, which allow them to be transported and driven by external magnetic fields. The magnetic nanostructures have also a great potential in biotechnological processes taking into account that they can be utilized as a carrier for enzymes during different biocatalytic transformations (Dussà ¡n et al, 2007 ). Different types of biomolecules such as proteins, enzymes, antibodies, and anticancer agents can be immobilized on these nanoparticles. Magnetic supports for immobilization purpose are either prepared by incorporating magnetic particles during the synthesis of the supporting polymer or magnetic particles itself be coated with common support materials such as dextran or agarose. Recently, a new method for the direct binding of proteins on magnetic nanoparticles via carbodiimide activation was proposed (Ren et al, 2011). Immobilization is one of the efficient methods to improve enzyme stability. There are various methods for immobilization of enzymes on many different types of supports. It can be a chemical method in which ionic or covalent bond formations occur between the enzyme and the carrier, or it can be a physical method, such as adsorption or entrapment of the enzyme in or on a solid support material. Magnetic nanoparticles as immobilization materials have advantage based on its property and size that make it desirable for using it in various applications (Mateo et al, 2007). Iron oxide nanoparticles, Fe3O4, are one of the widely used types of magnetic nanoparticles and have great potential for applications in biology and medicine due to their strong magnetic properties and low toxicity (Jalal et al, 2011) Review of literature I) Magnetic nanoparticles: The historical development of nanoparticles starting with Paul Ehrlich and then first attempts by Ursula Scheffel and colleagues and the extensive work by the group of Professor Peter Speiser at the ETH Zà ¼rich in the late 1960s and early 1970s (Jà ¶rg Kreuter 2007). They are solid particles with a size from 10 to 100nm which can be manipulated using magnetic field. Such particles commonly consist of magnetic elements such as iron, nickel and cobalt. They have been used in catalysis, biomedicine, magnetic resonance imaging, magnetic particle imaging, data storage , environmental remediation and optical filters (Gubin et al, 2005). Magnetic nanoparticles as immobilization materials have the following advantages: simple and inexpensive production, can be released in controlled manner, stable magnetic properties of complexed nanoparticles and easy isolation steps in short time. Among these materials, Fe3O4 magnetic nanoparticles are the most commonly studied. Fe3O4 magnetic nanoparticles have good biocompatibility, strong superparamagnetism, low toxicity, and an easy preparation process, and their use in biosensors has already shown attractive prospects (Sheng-Fu Wang and Yu-Mei Tan, 2007). II) Magnetic core material: There are many magnetic materials available with a wide range of magnetic properties. such as cobalt, chromium and iron oxide-based materials such as magnetite and maghemite. The suitable magnetic materials depend on applications the MNP will apply in (Dobson et al, 2007). Magnetite Fe3O4: Magnetite is a common mineral which exhibits ferro (ferri) magnetic properties. The structure of magnetite belongs to the spinel group, which has a formula of AB2O4. Its ferromagnetic structures arise from alternating lattices of Fe(II) and Fe(III). This gives it a very strong magnetization compared to naturally occurring antiferromagnetic compounds such as the ferrihydrite core of the ferritin protein (McBain et al, 2008). III) Synthesis of iron Magnetic nanoparticles: There were many synthesis methods for magnetic nanoparticles one of these is Co-precipitation. This method may be the most promising one because of its simplicity and productivity (zhao et al., 2008). It is widely used for biomedical applications because of ease of implementation and need for less hazardous materials and procedures. Co-precipitation is specifically the precipitation of an unbound â€Å"antigen along with an antigen-antibody complex† in terms of medicine (Indira and Lakshmi, 2010).The reaction principle is simply as: Fe2+ + 2Fe3+ + 8OH– ⇔ Fe (OH)2 + 2Fe(OH)3 → Fe3O4 + 4H2O (Guo et al., 2009). Other method used for synthesis like: Thermolysis of metal-containing compounds, synthesis of magnetic nanoparticles at a gas-liquid interface, synthesis in reverse micelles and sol-gel method (Gubin et al, 2005). IV) Characterization of MNP: There is no unique method for determination of the nanoparticle composition and dimensions; as a rule, a set of methods including X-ray diffraction, Transmission electron microscope and Extended X-ray Absorption Fine Structure (EXAFS) Spectroscopy are used (Gubin et al, 2005). X-Ray diffraction analysis of nanomaterial seldom produces diffraction patterns with a set of narrow reflections adequate for identification of the composition of the particles they contain. Some X-ray diffraction patterns exhibit only two or three broadened peaks of the whole set of reflections typical of the given phase (Moroz 2011). In the case of larger particles (provided that high-quality X-ray diffraction patterns can be obtained), it is often possible not only to determine the phase composition but also to estimate, based on the reflection width, the size of coherent X-ray scattering areas, corresponding to the average crystallite (nanoparticle) size. This is usually done by the Scherer formula (Gubin et al, 2005). The nanoparticle dimensions are determined most often using Transmission electron microscope, which directly shows the presence of nanoparticles in the material under examination and their arrangement relative to one another. The phase composition of nanoparticles can be derived from electron diffraction patterns recorded for the same sample during the investigation. Note that in some cases, TEM investigations of dynamic processes are also possible. For example, the development of dislocations and disclinations in the nanocrystalline during the mechanochemical treatment has been observed (Woehrle et al, 2000). More comprehensive information is provided by high resolution transmission electron microscopy, which allows one to study the structure of both the core and the shell of a nanoparticle with atomic resolution, and in some cases, even to determine their stoichiometric composition (Woehrle et al, 2000). The structures of non-crystalline samples are often studied by EXAFS spectroscopy. An important advantage of these methods is its selectivity, because it provides the radial distribution (RDA) curve for the atoms of the local environment of the chosen chemical element in the sample. The interatomic distances (R) and coordination numbers (N) obtained by EXAFS are then compared with the known values for the particular phase (Gubin et al, 2005). Other methods are used more rarely to study the nanoparticle structures. Integrated research makes it possible to determine rather reliably the structures of simple nanoparticles; however, determination of the structures of nanoparticles composed of a core and a shell of different compositions are often faced with difficulties (Gubin et al, 2005). V) Stabilization of Magnetic Nanoparticles: Although there have been many significant developments in the synthesis of magnetic nanoparticles, maintaining the stability of these particles for a long time without agglomeration or precipitation is an important issue. Stability is a crucial requirement for almost any application of magnetic nanoparticles. Especially pure metals, such as Fe, Co, and Ni and their metal alloys, are very sensitive to air. Thus, the main difficulty for the use of pure metals or alloys arises from their instability towards oxidation in air, and the susceptibility towards oxidation becomes higher the smaller the particles are (Lu et al, 2007). Therefore, it is necessary to develop efficient strategies to improve the chemical stability of magnetic nanoparticles: Surface Passivation by Mild Oxidation: A very simple approach to protect the magnetic particles is to induce a controlled oxidation of a pure metal core, a technique long known for the passivation of air-sensitive supported catalysts. This oxidation can be achieved by various methods (Peng et al, 1999). For example, Peng et al. developed a method for oxidizing gas-phase nanoparticles by using a plasma-gas-condensation-type cluster deposition apparatus. Demonstrated that very good control over the chemical state of the cobalt nanoparticles was achieved by their exposure to an oxygen plasma. The control of the oxide layer has a tremendous impact on exchange-biased systems, where a well-defined thickness of the ferromagnetic core and the anti-ferromagnetic shell are desirable. Moreover, a direct correlation of the structure and magnetism in the small particles can be determined. developed a mild oxidation method, using synthetic air to smoothly oxidize the as-synthesized cobalt nanoparticles to form a stable outer layer which can stabilize the nanoparticles against further oxidation (Peng et al, 1999). Other methods: Matrix-Dispersed Magnetic Nanoparticles, Carbon Coating, Silica Coating , Precious-Metal Coating and Surfactant and Polymer Coating Typical strategies for immobilizing catalysis enzyme onto MNPs rely on surface grafting via low molecular weight linkers or polymers containing amino or epoxy functional groups to which enzyme are reacted via covalent conjugation methods (Ren et al, 2011). Due to their high specific surface area and easy separation from the reaction medium by the use of a magnetic field, they have been employed in enzymatic catalysis applications ex amylase EC 3.2.1 (Ren et al, 2011). The maximum reported loading capacity of amylase is approximately 81.97 mg/g (AktaÅŸ et al, 2011). One drawback of existing immobilization technologies is that the activity of enzyme decreases significantly upon immobilization due possibly to changes in enzyme secondary structure, or limited access of substrate to the active site of the surface bound enzyme (Lei et al, 2009). Thus, despite numerous reported approaches for immobilization of catalysis enzyme on magnetic nanoparticles, there is still the need for simple, cost-effective and high loading capacity methods. Aim of work Is to Synthesis of iron magnetic nanoparticle (MNP) then immobilize amylase on MNP and test the efficiency of immobilization method then study the activity of immobilized amylase.

7 Easy Rules for Writing an Amazing Personal Statement

7 Easy Rules for Writing an Amazing Personal Statement For many people, the thought of writing a personal statement is so intimidating it fuels the kind of procrastination that inspires them to reorganize their cabinets or closets. Many people fret about personal statements because they are self-conscious about their writing skills or do not even know where to begin when asked to write a personal statement. The unfortunate paradox of the college admissions process is the expectation that applicants will write a powerful and compelling personal statement although most seventeen- or eighteen-year-olds have not yet had the life exposure or experience that would allow them to read other peoples personal statements, so they havent had the opportunity to create a personal understanding of what features set the good ones apart.Thankfully for this generation of applicants, the Internet provides guidance and actual examples of stellar personal statements. I have edited and written many personal statements over the years, so I will combine my pers onal knowledge with trusted Internet resources to identify seven easy rules for writing an amazing personal statement.Rule #1 - Start earlyEven if you are a person who thrives under the pressure of the last minute of a deadline, do not wait until the last minute to start your personal statement. Your personal statement could make the difference between being accepted to the university of your dreams or getting waitlisted (or denied). Since this document has the potential to significantly affect your future, make sure you allow ample time to write, edit, re-write, re-edit, and re-write again. If you have trouble starting when a deadline seems far in advance, below are some tips to help you stay on track:Create a false early deadline for yourself, or create a series of deadlines to force yourself to start the process.If you need accountability, talk with a friend or group of friends about creating an accountability group where you ask each other for progress updates and inspire each o ther to start writing. This method has the double benefit of getting you started on the process and providing you with a valid accountability response if you are blessed with parents who repeatedly ask if youve finished your personal statement yet.Create a false early deadline for yourself, or create a series of deadlines to force yourself to start the process.Rule #2 - Read the instructions clearly and answer any questions posed in the promptThis is critically important. If you do not follow the guidelines expressed in the instructions, you will have wasted all that time you spent worrying, procrastinating, and working on your personal statement.The instructions are included because they expect you to follow them. If you do not follow them, you send the message that you are not the type of student or employee that will excel in their institution.If the prompt includes questions, make sure that you answer those questions in your personal statement. Failure to do so is a great way to ensure a rejection letter.Rule #3 - Avoid clichà ©sYou have probably heard people refer to the fact that clichà ©s weaken your writing, but you may not recognize that you are even using clichà ©s.A clichà © is any kind of saying or phrase that you could search on the Internet in quotes and find pages of results with links to books, magazines, webpages, and interviews where people have used that phrase.Clichà ©s became overused because they are either true or valuable in some way, but that doesnt mean you need to use them in your writing. If you realize youve included clichà ©s or overused phrases, simply spend some time figuring out a different and unique way to express the notion. It will strengthen your writing, which will strengthen your personal statement.Online resources such as freedictionary.com provide comprehensive lists if you want to review a list of most used clichà ©s.Rule # 4 - Create an intriguing and personal introduction that makes people want to keep readin gWhen most of us search the Internet for information, we click on a link and read the first few sentences to decide if the site contains what were looking for and if it is written in a manner that resonates with us. We decide after only a sentence or two if were going to hit the back button on our browser and find another site. Your personal statement is valuable and precious to you, so make sure to convey that to the person reading it as part of your application.Write the introduction to your personal statement in an intriguing yet professional manner so no one would want to stop reading after a few sentences.When you review and edit your personal statement, ask yourself, If this was a website Id just clicked on or a book Id just started, would I keep reading?Remember that admissions counselors and hiring authorities have to sift through countless applications every day. If they are choosing from a large group of skilled applicants, they often make their decision to keep reading af ter just the first few sentences. Make sure that yours is well written and engaging so it is one of the ones they keep reading.Rule #5 - Give readers a behind-the-scenes view of who you arePersonal statements are important in the admissions process- and sometimes the hiring process- because they provide a behind-the-scenes view of the applicant. It can be difficult for admissions counselors or hiring authorities to glean a clear picture of you as an individual from the dry facts on your resume and/or transcript. Remember this as you draft your personal statement.It should not be a translation of your resume or transcript. This is your opportunity to show who you are, what motivates you, and how you view the world.You may quickly reference certain items from your resume or transcript, but take full advantage of the opportunity to showcase things about you that are not evident from your resume or transcript.If you have large gaps in employment or other items in your resume or transcri pt that might seem questionable, address those items in the personal statement in a professional and logical manner that is not dramatic. If youve experienced personal struggles that are not evident from your transcript or resume, you do not need to address it.Rule #6 - Employ the valuable writing motto Show, dont tellYour personal statement gives you the opportunity to shape the narrative of your life. Show, dont tell is one of the fundamental guidelines for storytelling or writing.Consider the difference between these two statements: I am a hard worker, and During high school, I learned to use a detailed calendar to manage my time so I could work at the YMCA to gain experience working with youth while ensuring I had the necessary study time to maintain my 4.0 GPA. The first sentence simply tells the reader that the individual is a hard worker, but the second sentence provides enough detailed and rich information that it clearly shows the reader that the individual is indeed a hard worker who has also acquired the important skill of time management.To apply this guideline in your personal statement, think of a few snapshots of your life that show the kind of person you are. Brainstorm stories that summarize you or aspects you want to highlight and make a list so you can choose one or two that best represent the values and attributes you want to include.Perhaps you have a story that shows your persistence because you didnt make the basketball team the first three years of high school, so you practiced long hours and finally made it senior year.Perhaps you have a story that provides insight about why you want to pursue a certain career based on a childhood experience that shaped your life.Your personal stories should not be long or elaborate; choose experiences that you can express in a concise but powerful manner.Do not choose stories involving altercations that would require you to put yourself or anyone else in a negative light.Perhaps you have a story that provides insight about why you want to pursue a certain career based on a childhood experience that shaped your life.Rule #7 - Ask family members and friends for feedback and inputMost high school seniors and college students have reached the age where they no longer want their parents help on anything. You may be ready to embrace your independence and show the world that youre a competent adult who can accomplish things on your own, but your parents probably have experience that can benefit you.Create the first draft of your personal statement on your own, but then you should ask your parents and other trusted adults (perhaps your English teacher, guidance counselor, or advisor) to review your personal statement for content, grammar, and punctuation.If you do not want to ask family members, friends, or colleagues, submit your personal statement to an editor for review.If you are embarrassed to show your personal statement to family members or friends, consider the reason. Is it bec ause they will be able to tell you havent put enough effort into it? If your family members and friends can recognize this, admissions counselors and hiring authorities certainly will.Someone else can often catch mistakes that you have become immune to during the writing process.Read your personal statement aloud to make sure it sounds as good as it did when you were writing. Reading aloud also gives you a different viewpoint that might allow you to catch mistakes you previously overlooked.Hopefully those seven easy rules for writing an amazing personal statement make you feel prepared and ready to start the process. My last piece of advice is be confident! Confidence (not to be confused with arrogance) is evident in your writing, so give yourself a pep talk if you need one. With the proper mindset and enough time, you will write a personal statement that gets you through the doors to your chosen school or career.Ive included some links below for more resources and examples of perso nal statements from websites or institutions that I trust:Purdue Universitys Online Writing Lab is a fantastic online writing resource for all kinds of writing. Visit their personal statement advice page for tips and for links to personal statement examples.The University of Illinois Center for Writing Studies also provides excellent tips for writing personal statements.If you are applying for medical school and need help crafting your medical school personal statement, check out the Princeton Reviews 15 Tips for Your Medical School Personal Statement.

Essay about Politics and Right

Essay about Politics and Right Essay about Politics and Right Politics and what is Right It is impossible to discuss a platonic statement without first examining its context. Each word is carefully placed and should therefore be taken as a whole group rather than as individual parts. Accordingly, in order to analyze Plato’s declaration in Apology 32a, we must also look at Apology as a whole as a reference to this sample. Several significant dialogue advancements evolve Socrates’ reasoning towards this statement, each pertaining to his own life. Personal experience, therefore, is the driving force behind, if not the solitary reason for, his assertion. The first two experiences that lead to this revelation are contained in his first and second rebuttals. When the first group accuses him of â€Å"[being] a criminal . . . prying into things under the earth and up in the heavens, and making the weaker argument the stronger, and teaching these same things to others,† he responds by explaining the negative opinions towards him - which led to these accusations – by narrating his divine enlightenment. (Apology, 19b) The oracle at Delphi had prophesized that he was the wisest of men. Socrates, therefore, concluded that his wisdom must stem from the fact that he understands that he knows nothing and considered this to be a calling to expose the â€Å"false wisdom† of others. As is customary with self-concept, these men blamed Socrates for their uncovered shortcomings and responded by â€Å"repeat[ing] the stock charges against philosophers, ‘underground lore and up-in-the-air lore, atheists, making the weaker argument the stronger,’† thus validating the aggravating nature of the Socratic Method. (Apology, 23d) As for his second accusers, their contestation is that â€Å"Socrates is a criminal who corrupts the young and does not believe in gods whom the state believes in, but other new spiritual things instead.† (Apology, 24b) In response, Socrates cross-examines Mel etus, as he is accustomed to doing in private circles. He is marginally more focused on embarrassment than arriving at the truth here but this dialogue still further illustrates the legitimacy behind his claims that his method upsets those who encounter its revealing nature. His defense is succeeded by the regression and the third occurrence that brings about his revelation. Here, Socrates affirms his willingness to defy authority of any form. He disregards the jurors’ power by minimalizing their greatest penalty, death, by not only showing fearlessness regarding it but also saying that â€Å"to fear death †¦is only to think that you are wise when you are not,† thereby calling them fools for thinking that this was a power at all. (Apology, 29a) He goes on to say that if they release him on the condition that he cannot practice philosophy he would rather die than conform to it, both showing his absolute commitment to the his cause and confirming that he would no t respect any determination that would force him to cease the behavior that his accusers claim is unlawful. This shows that he has an irrational non-fear of the government as an entity that has power over him. These three developments contain the relevant details that Apology gives its readers that can be used in order to formulate a reasonable understanding of the roots of Apology 32a, in which he argues: â€Å"It is necessary that one who really and truly fights for the right, if he is to survive even for a short time, shall act as a private man, not as a public man.† (Apology, 32a) This statement comes in a few parts and is derived from Socrates’ personal experience. First is â€Å"the man who really and truly fights.† Socrates’ unwillingness to forgo his disputed actions, despite any consequence or penalty, communicates that he relentlessly or â€Å"really and truly† fights. Furthermore, his complete dedication to his cause, his belief that it was divinely inspired, and his assertions that his actions are a gift to the state imply that he believes himself to fight â€Å"for the right.† Lastly, it