Overview of Infrared Spectroscopy

Overview of Infrared Spectroscopy Infrared spectroscopy is the most powerful technique use in the analytical laboratory. Infrared spectroscopy is associated with the infrared region. There are number of compounds (organic and inorganic), which absorbed various frequency of electromagnetic radiation. Infrared region divided into three types; near- IR, mid- IR, far- IR. In terms of the wave length near-IR region extends from 1400cm-1-4000cm-1, mid-IR from 4000cm-1-400cm-1 and far -IR from 400-10cm-1 . Main function of the infrared spectroscopy is to identify all the type of the organic and inorganic compounds. Functional group and molecular composition of the compound also find out by the infrared spectroscopy. Its also help in quantitative determination of compound mixture. In infrared spectroscopy the molecule absorbed specific frequencies that are the characteristic of their structure. This absorption is resonant frequencies. i.e the frequency of the absorbed radiation matches the frequency of the bond or group that vibrates. In order to absorb IR radiation, a molecule must undergo a net change in dipole moment as a consequence of its vibration. IR spectrum generally presented in the either wavelength or wavenumbers. Wavelength is inversely proportional to the frequency and wavenumber s is directly proportional to the frequency as well as the energy of the IR absorption. Infrared spectrum is a graph of wavelength vs. absorbance (A), but for IR region as wavenumber (in cm-1) on X-axis and percent transmittance (%T) on Y-axis. Transmittance is the ratio of the radiant power (I) transmitted by a sample to the radiant power incident on the sample (I0). Absorbance (A) is the logarithm to the base 10 of the reciprocal of the transmittance (T). A = log10 (1/T ) = -log10T = -log10I /I0 The transmittance spectra provide better contrast between intensities of strong and weak bands because transmittance ranges from 0 to 100% T whereas absorbance ranges from infinity to zero. The analyst should be aware that the same sample will give quite different profiles for the IR spectrum, which is linear in wavenumber, and the IR plot, which is linear in wavelength. It will appear as if some IR bands have been contracted or expanded. Molecular vibrations The positions of atoms in molecules are not fixed; they are subject to a number of different vibrations. There are two types of vibration; Stretching:Â  Change in inter-atomic distance along bond axis; there are two types of stretching; Asymmetric stretching Symmetric stretching Bending:Â  Change in angle between two bonds. There are four types of bend: Rocking Scissoring Wagging Twisting In the organic molecule each bond having its characteristics stretching and bending frequency and capable of absorbing light of that frequency. Stretching absorption of a bond appears at higher frequencies in the infrared spectrum than the bending absorptions of the same bond. The position of absorption bands depends on the relative masses of the atoms, the force constants of the bonds and the geometry of the atom. The HOOKE S law, which gives frequency with bond strength and atomic masses, since For a diatomic molecule A-B, the wavenumber (in cm-1) of the absorption ; There are two useful regions in the IR spectrum. The group frequency region encompasses 3600 to 1200 cm-1 region, where the identical functional groups fingerprint region from 1200 to 700 cm-1 and it reflects the absorptions from the skeletal structure of the molecule. Small differences in the structure result in significant changes in fingerprint region so it leads to great evidence for the identity of the compounds yielding the spectra. Only stereoisomers absorb exactly in the same way in this region. There are several instrument used to determine the absorption for a compound is called an infrared spectrometer. There are two types of infrared spectrometer; Dispersive infrared spectrometer Fourier transfer infrared spectrometer (FT-IR) Both the instrument measures the spectra of the compounds in the range of 4000 to 400cm-1. Now a day, number of industries and laboratories worked on the FT-IR. Because dispersive infrared spectrometer has many limitation, like it suffer from sensitivity, speed and wavelength accuracy. FT-IR gives infrared spectrum within a second. The main advantage of use of FT-IR is that FT-IR does not have the slits. This is present in the dispersive infrared. Because the some of the light is pass through the slit, so there is loss of light. Fourier transfer infrared spectrometer (FT-IR) The main components of the FT-IR are radiation source, interferometer and detector. Source :- The sources are rod in shape. They are heated by electronically around 1800 oc. The sources rods are made up from the Nernst glower (Zr,Th, Ce, Er, etc), Globar (silicon carbide) an other ceramic materials. The light comes from these sources are passed through the interferometer. The interferometer is a design in which two optical paths gets divided and then recombines them and produce wave type pattern, which contain all the frequencies. Those form the infrared spectrum. Interferometer The interferometer used in the FT-IR is called as the Michelson interferometer. Michelson interferometer consist three basic components; moving mirror, fixed mirror and Beam splitter. The beam splitter is a semi reflecting device and is often made by depositing a thin film of germanium onto a flat KBr substrate. The light comes from the sources and its strikes on beam splitter. Which is designed to split the beam (A) exactly in half. The beam (B) is transmitted towards fixed mirror and its get reflected back towards the beam splitter, other beam (C) is transmitted towards moving mirror and its also get reflected back towards the beam splitter. Both the beam is recombine at the beam splitter and high intensity radiation will reach the detector. Fig:- Michelson interferometer Michelson interferometer an optical path difference is introduced between the two beams by translating the moving mirror away from the beam splitter. A general property of (optical) waves is that their amplitudes are additive. When the beams that have reflected off the fixed and moving mirrors recombine at the beam splitter are in phase, an intense beam leaves the interferometer as a result of constructive interference. When the fixed and moving mirrors beams are recombined at the beam splitter and the waves are completely out of phase, a low intensity beam leaves the interferometer as a result of destructive interference. The sample is placed between the source and the beam splitter. Detectors In the FT-IR to get the good sensitivity and speed in recording the spectrum must be matched in the speed and photometric accuracy of the detectors; this is achieved by thermal detectors based on pyroelectric materials or on solid state semiconductor devices based on photovoltaic or photoconductive principles. The main advantages of an FT-IR instrument is that it collect dozens of interferogram of the sample and accumulate them in the memory of a computer. To obtain a spectrum of a compound, the chemist first obtain an interferogram of the background which consists of the infrared-active atmospheric gases, carbon dioxide and water vapour (oxygen and nitrogen are not infrared active). The interferogram is subjected into a Fourier transform, which yield the spectrum of the background. Then the chemist places the compound (sample) and obtains the spectrum resulting from the Fourier transform of the interferogram. This spectrum contains absorption bans for both the compound and background. The computer software automatically subtracts the spectrum of the background from the sample spectrum, and the obtain spectrum of the compound being analyzed. An infrared spectrometer determines the position and relatives sizes of all the absorptions, or peaks, in the infrared region and plots them on a piece of paper. The spectrum gives at least two strongly absorbing peaks at about 3000 and 1715 cm-1 for the C-H and C=O stretching frequencies respectively. The given table show the frequency of the different functional group to identify the peaks of the band, which obtain in the spectrum.

Negative Effects of Globalization Essay

Globalization is not a new phenomena. It was primarily formed long time ago, when Greeks, Romans conquered other countries and spread their power to them. However, the nature of globalization has been changed over time and reached to the stage of modern globalization. In the article â€Å"Spiritual perspective on globalization†, Ira Rifkin (2003) says that the modern globalization could be identified from a meeting on 1944 in Bretton Woods where forty five nations agreed to establish the IMF and the World Bank. The renovation of information technology, especially the spread of Internet has pushed the globalization process to happen faster than ever before and changed the whole world dramatically. Many countries are taking advantage of globalization to stimulate their economic growth, create more jobs and improve social benefits. However, they are also suffering several negative effects of globalization: the disappearance of some traditional culture, the destruction of environm ent, and the disparities between rich and poor. The first negative effect of globalization is that it is reducing the diversity of traditional culture of some small nations. Each country has its own identical culture. However, with the development of advance technology as well as international trade, a lot of multinational corporations are established; result in an interconnected world and the removal of national borders. Some countries are unable to resist the cultural interaction with other countries as well as the cultural imperialism of developed countries. Their traditional culture is losing and replaced by Americans and Western styles. Rifkin writes that the Americans and Western culture have affected or even obliterated the traditional culture of some countries. People in these countries are more and more prefer McDonald’s fast food, Hollywood films or Disney entertainments. In â€Å"The deadly noodle†, Hasting, Thiel and Thomas also mention that the American processed food may be one kind of American cultural sovereign. It has changed the food habits of many countries. In addition, in some extend, globalization also impacts on the way people consider knowledge. In this Information Age, it is easy to get all necessary information on the Internet and they are often formal modern knowledge. Thus, traditional knowledge is disappearing. In â€Å"Exiled to Cyberia†, Kunda Dixit says that we have paid too much attention on formal  modern knowledge, and overlooked the traditional knowledge. These cultural changes also happen in Vietnam. Young people now like to listen to the songs of the world famous singers like Celine Dion, Micheal Jackson or Lady Gaga and keep away most of Vietnamese traditional music. A lot of traditional games are no longer their favorite things. They like to spend their free time playing games online or chatting with friends on the Internet. At cinemas, Hollywood films are advertised everywhere but it is difficult to find a Vietnam film. Gradually, many countries are losing their cultural diversity and identity. And there wi ll be no big differences between countries’ culture because of the powerful spread of America and Western culture. Perhaps the next generations will not be aware that they used to have an unique traditional culture in their society. Another problem which countries are facing with under the effects of globalization is the degradation of environment. Human can be considered the owner of natural environment and have power to change it. However, the impacts of human on environment are more and more aggressive because of the explosion of population and economic growth. Global environment has been destroying in many different ways. In â€Å"Poverty and Environmental Degradation†, Mabogunje writes that the world’s population has increased rapidly, especially in developing countries and urban areas due to medical achievements. This population explosion has put many people in the poor standards of living. As a result, to make a living, they have cut trees in forests and over cultivated their farmlands. Therefore, a lot of species have no place to survive and then be extinct, a wide range of lands become desertification, and losses of topsoil are happening in many countries. The global ecosystem is becoming imbalanced and the environment is seriously degraded. Also, globalization has brought serious pollution for many countries in the world. Air pollution, water pollution and climate changes are now a big issue which requires all countries to cooperate to resolve. There are several factors causing pollution. One cause of air pollution and global warming is the increase in numbers of vehicles in cities, especially in developing countries. In â€Å"If poor get richer, does world see progress†, Knickerbocker tells us that Chinese economy has been quickly developing. In Shanghai, numbers of cars have been increasing significantly every week while the bicycles may be not permitted on some big roads. This change is making  global atmosphere polluted. The situation of Vietnam is as same as other developing countries. Recently, numbers of vehicles have been growing faster in big cities and they are a main cause of air pollution in Vietnamese urban areas. The consumption of the poor people also results in pollution. According to Maboguje, the biomass fuels and other products consumed by the poor are causing serious air pollution. The broad uses of chemicals, fertilizers and pesticides are another cause of pollution. Maboguje says that in order to produce more agricultural products, farmers in many countries have broadly used fertilizers and pesticides which pollute water sources and are harmful to environment as well as people’s health. Lastly, globalization is widening the gap between the rich and the poor. It has affected all the participants who involved in globalization process in many ways. Although some countries have already got out of poverty and developed their economy, wealth countries are those who have taken most benefits from globalization and become richer and more powerful. Multinational corporations in developed countries make huge profits from outsourcing their productions to developing countries where labor costs are very cheap and other production conditions are more favorable. As results, the gap between rich countries and poor countries are increasing. According to Rifkin, the unequal difference between the rich and the poor are widening. More than one billion people in the world are ling in very poor conditions. The rapidly economic growth in developing countries also results in the inequality in income and living standards of people living in cities and those living in rural areas. In fact, the economic growth often happens first in industrial areas and in cities, so people who have good education or working skills can get higher income and improve their lives. In rural areas, on the other hand, people’s lives basically depend on agriculture which is slowly developed so their incomes do not change very much or even decrease because of the impact of environment changes on their agricultural production. Moreover, when economy is growing, the goods price and standards of living are also higher. These things affect seriously to the poor people and make their lives become harder. In conclusion, globalization is  unavoidable trend in this advanced technology era. Most countries in the world were involved in this spiral of globalization. Although globalization has created a lot of significant benefits to these countries, helped them increase the economic growth, improve people’s living standards, it also has brought many challenges and disadvantages for these countries, in which the dismissal of traditional culture, environmental degradation, and disparities between rich and poor are notable issues. Each country suffers the negative effects of globalization on different levels. Thus, many countries may have different solutions to their problems. However, in order to reach to the sustainable development, every country needs to coordinate together to solve the issues and minimize the disadvantage effects. References Dixit, K. Exiled to Cyberia. Global Envision.org. Hastings, M and Thiel, S and Thomas, D. (2003, January 20). The deadly noodle. Newsweek, 141, 3. Knickerboker, B. (2004, January). If poor get richer, does world see progress. Christian Science Monitor. Mabogunje, A. L. (2002, January/February). Poverty and environmental degradation.Environment, 44, 1. Rifkin, I. (2003). Spiritual perspectives on globalization. Woodstock: Skylight Paths Publishers.

Compare and contrast the ways in which both writers deal with these themes Essay

Hardy and Hill both present the reader with female characters who are isolated and ostracized by society. Compare and contrast the ways in which both writers deal with these themes. Susan Hill and Thomas Hardy are clearly both interested in the role of women and their position in society. The female protagonists, in `I’m the King of the Castle and `The Withered Arm’, are insecure as they lack a man to provide them with social status and respect. As a consequence of their troubled pasts, they are rejected from society, and are both left vulnerable and desperate. Helena Kingshaw represents a certain class of women in post-war England, the setting for Susan Hill’s novel, who found themselves lacking the emotional and financial support of a man. The superstition in those days left these genteel, unskilled women in a shameful position. Society rejected those spurned by men and many became objects of gossip of a malicious nature. Similar nonsensical teachings in Victor ian times, the setting for `The Withered Arm’, also left abandoned women, such as Rhoda Brook, viewed as social outcasts. Thomas Hardy is clearly sympathetic to such women, especially those reaching the stages of their lives where he suggests, through a careful adjective selection â€Å"worn†, they may be becoming desperate for a husband. He seems to consider them as isolated victims of the stereotypical image of women as a possession, classed by looks and fortune, and his novel exposes the hypocrisy in society. The isolation of the female protagonists is immediately obvious in their places of residence. Warings is â€Å"some distance away from any other house† and Brook lives in â€Å"a lonely spot high above the water meads†. Also, references to their past hint at their isolated feelings, â€Å"Tis hard for she†, and this is confirmed in how they act around others. Brook’s way of coping is to silently work â€Å"somewhat apart from the rest.† Conversely, Kingshaw tends to babble and desperately try to please others and make a new start in life. Hill’s language choices for Mrs. Kingshaw’s affected speeches reflect her desperation to belong to a certain class. This is the opposite of Brook, who would rather survive without pity and stay in isolation. Neither woman ever admits that it is isolation and loneliness which make them act as they do, for example, their unusual attitudes towards their sons. Kingshaw practises superficial mothering gestures, â€Å"she always wanted to lean over him†¦,† whereas Brooks’ life is completely lacking in affection towards anyone, until she meets Gertrude Lodge. However, at least then it is genuine, unlike Kingshaw’s desperate attempts to `do things by the book,’ without actually meaning any of it. She just wants to be satisfied that she has all she can get, while Brook is more accepting of her fate. Brook is however similar to Kingshaw, in that she is extremely self-absorbed; she asks her son to discover, â€Å"if she’s tall, tall as I,† and was, â€Å"not observing that he was cutting a notch†¦in the chair.† This could be compared to how Kingshaw never realises the trauma Edmund Hooper puts her son through, as again she is not observant enough. In spite of the women’s preoccupation, both children are very accepting and obedient to their mothers. The more archaic language of Hardy’s novel makes it easier for us to identify with Rhoda’s concerns which seem, especially to the modern reader, to be over small things, such as how â€Å"ladylike† a woman is, and this again promotes the roles of women in both societies. In `I’m the King of the Castle’ it is frowned upon for a woman, with the status of housekeeper, to wear make-up and dress up. As in `The Withered Arm’ this is because a woman’s dress sense reflected their position in society. We see how the Farmer Lodge’s pretty wife’s wealth gives her the right to wear, â€Å"a silver coloured gown†. On the other hand, the affect a woman’s appearance on the male protagonists of each novel is different in that Hooper’s opinion of her looks seems relatively insignificant to how he had been â€Å"impressed by the graceful letters of Mrs. Helena Kingshaw.† Whereas, Gertrude was worried about her disfigurement because in `The Withered Arm’, â€Å"men think so much of personal appearance.† Both writers also convey to the reader how lack of status generates a fear within the women to change from their set principles. We notice this in Kingshaw’s displays of stereotypical motherly affection and more subtly in Brook, through her indignancy when her son suggests she goes to see her successor; â€Å"I, go to see her!† The two women are forced into these ways of dealing with their isolation by their shared insecurity. Their two different ways of coping both have their drawbacks: Kingshaw is so busy trying a good impression and secure her future with Kingshaw that she cannot form a proper relationship with her son. Brook is so busy ignoring her past and avoiding her problems that she bottles up her bitterness, again destroying a relationship, with her friend, Gertrude Lodge. Eventually, their sad positions lead both women to make a â€Å"last, desperate effort† to conquer the things on their minds, but in both cases it results in another’s unhappiness. For Kingshaw, achieving a life with Mr. Hooper lead to her son’s suicide. For Brook, trying to overpower the â€Å"confronting spectre† in her dream lead to disfigurement of her only friend. This also shows how, like Kingshaw, her isolation makes her romanticise things and let her imagination get carried away. However, where Brook gets upset by guilt of what she brings upon others, â€Å"I hope your arm is well again ma’am?†, Kingshaw is portrayed as a much shallower character and never notices her effect on others. Instead, she romanticises things such as her relationship with Mr. Hooper; â€Å"He likes me.† Effective grouping of words, such as the description of Brook being held to Gertrude Lodge by a â€Å"gruesome fascination† also show the obsessive behaviour of the female characters, due to the amount of time they spend alone, thinking. Kingshaw is obsessed with determination to believe that her â€Å"life is changing, everything is turning out for the best.† In contrast the simple platitudes of her speech, Hardy writes in long, complex sentences, allowing us to see the depth of Brook’s worried fixations. Through these obsessions, there is an underlying fear for both women that they will lose the person in their lives who means something to them, and could save them from complete ostracization. This adds a sense of dread to both novels, and pathetic fallacy reflects this darkness in the hostile environments surrounding them; â€Å"the wind howled dismally over the heath.† Hardy is able to convince us of Brook’s isolation through her introspective t houghts and memories. However, the limited capacity of Mrs. Kingshaw to think and understand leaves even her speech artificial. So Hill uses `flashback’, interspersed with the episodic narrative to emphasise Kingshaw’s troubled past, showing us how her life has been shaped and influenced, convincing us of her isolation. Also, being a rather claustrophobic text, we given an increasing fear of unavoidable disaster in `I’m the King of the Castle’, as all the action takes place over a ten-month period. On the other hand, ‘The Withered Arm’ is set over a much longer period of time and informs the reader of ill-feeling towards Rhoda from outside the immediate circle of protagonists. Through these very different structures, Hardy and Hill both create an increasing sense of doom for the two female protagonists. The absence of love in both characters’ lives undermines their confidence and relationships, resulting in isolation. Warings reinforces the theme of isolation as it is completely set apart from events in the normal world and, as in `The Withered Arm’, the accumulation of hostile imagery of the surrounding countryside further emphasises their loneliness and vulnerability. In both novels the main requirement of women was dynasties, so those rejected by men were despised and ostracized from society. This put both Brook and Kingshaw lacking status and in a very pitiable position. Nevertheless, due to the way the two writers deal with the themes of isolation and ostracization of the female protagonists, as a reader I never felt for Kingshaw quite the sympathy I did for Brook. As Hill presents Helena Kingshaw as so shallow a character, we feel so much anger at her dismissive attitude to her son that it is almost as though she deserves anything. By contrast, Hardy deliberately presents Rhoda Brook, â€Å"her red eyes weeping†, as a more pitiful character who seems much more the victim of her bad luck.

Open System Definition in Chemistry

In science, an open system is a system that can freely exchange matter and energy with its surroundings. An open system may appear to violate conservation laws because it can gain or lose matter and energy. Open System Example A good example of an open system is energy transfer in an automobile. Chemical energy in​ the fuel is converted into mechanical energy. Heat is lost to the surroundings, to it may appear matter and energy are not conserved. A system such as this, which loses heat or other energy to its surroundings, is also known as a dissipative system.