Individual Assignment Environmental Fundamentals Paper Essay Example for Free

Individual identification Environmental Fundamentals Paper Essay How do you define environmental acquisition ? How does the kinship between science and technology affect environmental problems and solutions in todays hostelry? Why is the concept of environmental sustainability important, and why should it be canvas? What are the historical patterns surrounding sustainable and unsustainable human interactions with the environment? In general, how do human values affect sustainability given current challenges liner inn?After reviewing the research on the environment, how do environmental hazards affect human health? Provide at least two examples. It is important to remember that college is non all about studying. College is a significant step into adulthood and should be treated as such. While you should non party the night away, do not keep your nose in your books to the point that you do not get to enjoy this time of your life.This work comprises ENV 100 Week 1 Individua l Assignment Environmental Fundamentals Paper superior general Questions General General QuestionsWrite a 700- to 1,050-word paper in which you discuss the fundamental principles of environment science. In your paper, dissolve the followingquestions How do you define environmental science ? How does the relationship between science and technology affect environmental problems and solutions in todays society? Why is the concept of environmental sustainability important, and why should it be studied? What are the historical patterns surrounding sustainable anTo get this material copy and paste connect to browser https//bitly.com/1xptIgOIt is important to remember that college is not all about studying. College is a significant step into adulthood and should be treated as such. While you should not party the night away, do not keep your nose in your books to the point that you do not get to enjoy this time of your life. General Questions General General QuestionsWrite a 700- to 1 ,050-word paper in which you discuss the fundamental principles of environment science. In your paper, answer the following questions How do you define environmental science ? How does the relationship between science and technology affect environmental problems and solutions in todays society? Why is the concept of environmental sustainability important, and why should it be studied? What are the historical patterns surrounding sustainable and unsustainable human interactions with the environment? In general, how do human values affect sustainability given current challenges facing society?After reviewing the research on the environment, how do environmental hazards affect human health? Provide at least two examples.

Drinking Milk Essay Example for Free

Drinking draw EssayIntroduction A Gaining Attention Give the audience most question as 1. how many people in the audience have a habit drinking milk for daily diet? 2. argon you take care of your family or yourself by the way drinking milk? Why? B Motivating The Audience Comparing the differences between people drink milk and not. C Establishing credibleness give the audience some popular benefits when drinking milk from some famous expert nutrients in the world.D Preview Of Main Ideasnow I will attest you bebefits of drinking milk, it n ot only supply nutrient for people health, kick upstairs tumefy being for all people especially with long-suffering but also build strong bones and teeth. Body Main idea 1 Milk Supply Nutrients For People Health Milk arrest more than and more mineral, protein, atomic number 20, iron, vitamin, phosphoric and so on , according to surface known nutrition expert Dr wendy Bazilian, author of the superfoodrx diet and co-owner of san diego- based bazilians health clinic. Milk contains 87. 5% of water, 3. 9% milk fat, 8. 8% solid non fat which includes protein, lactose, minerals and acids, enzyms and vitamins.Proteins include caseins, whey proteins, lactabumin and lactoglobulin. The main sugar present in the milk is lactose. It also contains vitamins A,C,D and amino group acids. ? With baby ? With adult.. ? With old people Main idea 2 Promote Well Being For All People Milk is very demand for people. Specially, milk is very good for patient. Its not only supplies eough energies minerals, proteins, but also it increase resistance and promote well being for all people. With prevalent people, milk plays inportance for both health , skin, and intestine. With patient, it promotes well being very quickly.For example, reducing blood pressure and diabetes, calcium, magnesium and potassium content in milk helps to burn the blood pressure and diabetes. Reducing the stake of colon cancer, consuming at least one glass of milk per day reduce 15% risk of developing colon type of cancer. And buiding intestinal health. In the market, there are many kinds of milk. It is not only suitable with many kinds of diseases but also promote well being for people. For example with patient,they need more nutrients to improve the health but maybe they can not eat some nutrients food because it containt some matter that not good for their diseases.Milk will help them to supply every necessary nutrients, it can instead of the daily diet. -As you know the popular milk for pateint as ensure,.. , Main idea 3 Milk Buids Strong Bones And Teeth. According to nutrition expert Bazililan, there are 99% of body is calcium is stored and hundreds of studies have shown that calcium in milk help improve bone densty, balance of other nutrients that have been proven to buid bones and teeth as well as promote the legal function of blood usels. More milk-stronger bones, as it contains abundant calcium.Calcium also acids in muscular and circulatory function, prevents osteoporosis Fighting cavities protein, calcium, phosphorous content in the milk products the tooth enamel, stimulates saliva production, and neutralizes food acids. Milk containtsupply % calcium per day for health. Arcording to studies show that percent peole drinking milk are live more longevity than people dont drinking milk. In modern life,people drinking milk hold approximate 85%. It show that the inportant of drinking milk in life. ( So drinking milk is the convinience, quickly,save money for modern life.Conclusion A Signaling The Ending Im exit to the finish this topic. B preview of main points I found it very convinience and good for us if drinking milk everyday. It supply nutrients for people health, promote well being for all people, and buid strong bones and teeth. CReference To Introduction Give some web adress a bout effect of milk with healthy to audience D Ending With Impact Change your habit by the way drink milk everyday, you can change your health more and more strong and young,your life will more quality because it prevent your health out of some hard diseases in the future.

According to alderman

According to aldermanAccording to Alderman (1999), pauperization can be wreakd by self-perception (Zimmerman, 2000). Self-perception can destroy ones demand to accomplish a given task based on the thought that the ability to do the task is lacking or the motivation is suppressed because of the belief that the task lacks challenging components (Alderman, 1999 Bandura, 1997 Calder Staw, 1975). Research indicates that students perceive themselves as more, the more challenging the goals they pursue will be (Zimmerman, Bandura Martinez-Pons, 1992). According to Zimmerman (2000), research during the past two decades has revealed that self-efficacy is a highly successful predictor of a students motivation and cultivation.Self-efficacy is a performance-based measure of ones perceived ability and therefore differs theoretically from motivational constructs such as vector sum expectations or self- imagination (Zimmerman, 2000). Frequently, the terms self-efficacy and self concept are m isunderstood to have the same meaning. Self-efficacy pertains to ones perceived abilities to accomplish a specific task whereas, self concept is a composite look at oneself believed to have been formed from ones experiences and accepted evaluations from family and / or friends. Self-concept and self-efficacy may both be used outside the context of learning (Bandura, 1997 Zimmerman, 2000). The role self-efficacy plays in ones motivation and attitude toward verbiage learning is an important one having influence on ones performance (Bandura, 1997 Drnyei, 2001a Ehrman, 1996). When looking at language learning many learners feel they have to be risk-takers because their self is put before others to perform. Those with low self-efficacy perceive tasks of difficulty as threats these are people that exist on their deficiencies and remember the obstacles they encounter when pursuing challenging tasks (Drnyei, 2001a). There is a reason for connecting the concept of self-efficacy with the m otivation to learn an additional language. For students to be able to concentrate on the task of learning with all their might and determination, they must have a healthy view of themselves as learners (Drnyei, 2001).Although prior successes combined with other cosmopolitan measures of ones ability are considered exemplary predictors of achievement, (Zimmerman, 2000) many studies suggest that self-efficacy beliefs add to the predictability of these measures. One such study was that of students self-monitoring. The findings pointed to the fact that the efficacious students monitored their working time more efficaciously and were more persistent. The study also indicated the more efficacious students to be better at solving problems than inefficacious students of equal aptitude (Zimmerman, 2000).Zimmerman Bandura (1994) did a path analytic study for writing and found that self-efficacy for writing was a considerable predictor of college students standards for the quality of writi ng measured as self-satisfying. The self-efficacy beliefs also motivated the students use of learning strategies. According to Zimmerman Martinez- Pons (1992), there was a substantial relation between efficacy beliefs and strategy use across the grade levels being studied. The greater the motivation and self-regulation of learning in students with a high self-efficacy the higher the academic achievement according to a range of measures. (Zimmerman, 2000, p. 88) Another study Zimmerman (2000) notes illustrates a finding of an boilers suit effect size of .38 which this indicates that self-efficacy accounts for approximately 14% of the variance in students academic outcome across various sets of student samples and criterion measures. Concerning the effects of perceived self-efficacy on persistence, research has shown that it influences the learners skill acquisition by increasing persistence (Schunk, 1981 2003 Zimmerman, 2000). Observably, self-efficacy plays a mediational role in m otivation, persistence and academic achievement. The findings signify evidence of the validity of self-efficacy beliefs and their influence on a students method of learning and motivational process (Zimmerman, 2000).

Analysis Of A Linear Accelerator

Analysis Of A Linear Accelerator like a shot longanimous with genus Cancer argon ploughed by radiation syndrome, surgery, chemotherapy or with a combination of these options. The radiotherapy treatment unit used to deliver radiation to cancerous cells and tissues is the one-dimensional hired gun, likewise known as bilinear catalyst.The elongated accelerator has been defined by Khan F. M. (2003) as a device that uses soaring-frequency electroattractionic waves to accelerate negatrons, to high energies by a linear tube. The electron direct itself can be used for treating superficial toumors, or it can strike a target to produce x-rays for treating ingrained toumors. The energy used for the radiotherapy treatment of deep situated tissues varies from 6-15 MV (photons) and the treatment of superficial toumors (less than 5cm deep) is between 6-20MeV. (Khan, 2003)The purpose of this essay is to describe a linear accelerator, analyse its components in the stand and the gantry of the linac, and explain the principles of operation and then discuss why it is best situated to the task for which it was designed. Some advantages and disadvantages of the linac give also be included in the discussion part of the essay.Main bodyFigure 1http//www.cerebromente.org.br/As you can experience from the schematic moving picture above, the major components of a linac areKlystron source of microwave powerElectron gun source of electrons.Wave engineer ( carry and accelerating wave guide) microwaves travel through the feed wave guide and then to the accelerating waveguide, where electrons are accelerated from the electron gun.Circulator a device that pr take downts microwaves of being reflected back from the accelerator.Cooling water system cools the components of the linac.Bending magnet A plication magnet is used to change the direction of the accelerated electron beam of light from horizontal to vertical. (Hendee et al, 2005)X-ray target electrons hit the target and produce x-rays.Flattening carry even out the intensity of the beam. ionization chambers they control the dose leaving the head of the linac.Beam collimation shape the radiation beam to a certain sizingKlystronThere are devil types of microwave power. The klystron and the magnetron. Magnetrons are used for begin energy linacs. In the high energy linear accelerator klystron is used. All contemporary linacs have klystrons. Both klystron and magnetron are special types of evacuated tubes that are used to produce microwave power to accelerate electrons. (Karzmark and Morton, 1998). The tube requires a low-power radiofrequency oscillator to supply radiofrequency power to the first-year cavity called the buncher. (Hendee et al, 2005) In the bunching cavity, electrons produced from the electron gun, are bunched together to regulate their speed.The microwave frequency is thousands times higher than ordinary radio wave frequency. For a linac to work, the microwave frequency needed is 3 billion cycles per second. (3000MHz) (Karzmark and Morton, 1998)Electron gunThe electron gun is part of the klystron. hither, electrons are produced and then accelerated to radiofrequency cavities. The source of electrons is a directly heated filament made from tungsten, which will release electrons by thermionic emission. (Bomford, 2003) Tungsten is used because it is a good thermionic emitter with high atomic tour, providing a good source of electrons. Klystrons usually have 3-5 cavities, used to bunch electrons together and increase microwave power amplification.WaveguideThere are two different types of waveguides used in linacs. The first is the feed waveguide and the second is the accelerating waveguide. The first one connects the klystron to the main part of the linac. Sulphur hexafluoride (SF6) is used in the feed waveguide, to stop the arcing of electrons, caused by the microwaves that piddle strong electric fields.A circulator is placed in the waveguide system, to pre vent microwaves being reflected back.Microwaves travel then to the accelerating waveguide. The accelerator guide of a linac requires a high vacuum to prevent power loss and electrical arcing, caused by interactions of electrons with gas molecules.(Cook, 1998)The acceleration of electrons takes place here. The accelerator waveguide bunch and accelerate the electrons with the microwaves. Electrons travel with a high velocity to almost the speed of light. (98% of speed of light) Microwaves travel to the speed of light, so irises are used to in arrears them down, so that electrons can keep up with the microwaves and be accelerated.There are two types of accelerator waveguide the travelling and the rest waveguide. The difference between the standing and the travelling wave accelerators is the design of the accelerator waveguide. In the travelling wave accelerator, electrons travel towards the machine and microwaves are absorbed, precisely in the standing wave accelerator microwaves ar e reflected back upon themselves. The standing wave accelerator is the main type used in medical linear accelerators.Bending magnetThe electron beam leaving from the accelerator waveguide continues through the bending magnet. This is used to change the direction of the electron beam, to exit through the treatment head. The bending magnet deflects the beam in a loop of 270o, or 90o. The most common degree of bending magnet used in linacs is the 270o achromatic magnet. The important property of this magnet is that the electrons are brought together despite the difference in energies. They are brought back together to the same position, angle, and beam cross section at the target, as they were when they odd the accelerator waveguide.X-rays targetThe target is made of tungsten because of its high atomic number. When electrons, with their high speed, hit the target, made up from a high atomic number material, they undergo rapid deceleration. This sudden loss of energy results in the for mation of x-rays and photons. To maximise the X-ray beam intensity, the transmission target will be slow enough to stop all the electrons bombarding it but thin enough to minimise the self absorption.( Bomford, 2003)In coordinate to switch from photon to electron therapy, the target is re conk outd to forfeit the electron stream to continue into the head of the machine.Flattening filterIn order to make the beam intensity uniform across the field a flattening filter is used. It is usually made of lead, although tungsten, uranium, steel, aluminium, or a combination has also been used or suggested. The flattening filter absorbs more photons from the centre of the beam and someer from the periphery of the beam.Ionisation chambersIonisation champers measure the amount of radiation leaving the machine, quantified in units Monitor units. any linac has two ionization chambers for safety reasons. The ionisation is a round, flat mental synthesis, filled with gas, divided into a number of segments, where each segment contains electrodes. When radiation passes through the gas, it is then ionised creating a high supercharged density that is controlled by the electrodes. The treatment terminates when the readings from the electrodes have reached a pre-set M.U value.CollimationA primary collimator limits the maximum field size for x-ray therapy (40 x 40cm). It ensures that x-rays leaving the target cast off in a forward direction in order to minimise radiation leakage through the head.The treatment field size is defined by the secondary collimator. This collimator reduces the transmission penumbra, since radiation must travel through the entire collimator thickness. It consists of four thick metal blocks, called jaws. There are two pairs of jaws, upper and lower jaws. With the use of asymmetric jaws, by moving each jaw individually, asymmetric field sizes can be produced. Half beam blocking can also be enabling. Different intensity patterns can be produced, from th e standard flat beam profile, by moving during treatment. Multi-leaf collimators are finger like projections, 1cm thick. These fingers like projections move independently in order to form the field shape more closely to the shape of the planning target volume. By using MLCs, less radiation is given to normal tissues.DiscussionFrom the introduction of this essay, the definition of the linac was given. A linac is a high voltage machine, used for the treatment of cancerous cells and tissues. With the structure of a linac this is achieved. By radiating cancerous tissues, with daily radiation treatment, cancerous tissues can be destroyed and then replaced by normal tissues.Every component in the linac is carefully selected for the function for which it is designed. First of all, the klystron is used to produce microwaves, because it is better than a magnetron that is used for lower energy linear accelerators. Because linear accelerators have higher energy beam, klystron are used for prod uction of x-rays.Continuing to the electron gun, tungsten wire or filament is used, because of its high melting point, high atomic number, and it is ductile. With this features tungsten is a good thermionic emitter, is a good source of electrons and can be easily shaped into spiral, in order to create a larger surface area for the electrons to be emitted.In the feed waveguide Sulphur hexafluoride (SF6) is placed with the intention of stopping the arcing of electrons. At the end of the waveguide a circulator is placed so as microwaves can non be reflected back.As we move on to the accelerating waveguide, and the standing wave accelerator used in linacs, we can see why the standing wave accelerator is used. The backward travelling wave interferes with the forward travelling wave, alternatively constructively and destructively. The resulting standing wave has a magnitude of approximately double that of the travelling wave, and the peak intensity travels along the waveguide at the phas e velocity of the travelling wave.(Knapp et al, 1968)Following the waveguide is the bending magnet. Here we have the achromatic magnet where its main task is to change the direction of the electrons, but more important to bring the electrons together despite the difference in energies.A flattening filter is used to make the beam even from the central axis to its peripheral edges, to have homogenous distribution of the dose.Ionisation chambers are essential in a linac. They monitor the dose leaving the treatment head, so that the linear accelerator knows when to end the treatment.Collimation in a linear accelerator is necessary. Without the primary and secondary radiation a linac wouldnt be as suitable for the task for which it was designed. The field size and shape is vital in order to radiate only the cancerous tissues and not normal tissues. Nowadays with the advances of technology and the use not only of MLCs, but also IMRT and IGRT, survival rates of cancer have increased.Last b ut not least, a linear accelerator can treat a patient with different energy modalities. By removing the target, the electron stream can continue into the head of the machine and then be used for the treatment of superficial toumors. By leaving the target, photons are produced to treat deep-situated toumors.Nowadays most linacs have virtual wedges, compared to some decades ago, where there where only manual wedges. Now radiographers with the use of virtual wedges dont have to concern about manual handling, as they dont have to do anything.I believe that linear accelerators are not perfect. Linacs are extremely expensive to buy, so poor countries dont have the opportunity to treat their patients from cancer. It is hard to keep up with the advances of technology, as everything is very expensive to buy, and only wealthy countries can buy the latest equipment. A disadvantage of switching from photon to electron modalities is that applicators and blocks are used to direct the electrons a nd shape the beam. Applicators are very heavy. Blocks are made of lead which may cause lead poisoning if they are not handled with care. The only disadvantage with MLCs is that when conforming the beam shape to the PTV, some radiation will be leaking, even when using the tongue and groove effect. Last but not least the linacs to work efficiently they need daily quality assurance tests and maintenance from physicists.ConclusionLinear accelerator is the main treatment unit used for the treatment of abnormal tissues. With its precise position of the beam, shaped differently for every patient individually, it certainly is the best machine for the treatment of cancer.A linac uses microwaves to accelerate electrons and then hit the target where x-rays are produced. This x-rays are collected and then form the shape of the beam. Nowadays with the rapid advances of technology, linacs in a few years time will be even more efficient than today.Definitely linear accelerators are best suited for the task for which they were designed. All the components of a linear accelerator are carefully selected for its needs. From the smallest to the bigger parts of the linac, are designed for the best outcome.ReferencesBOMFORD, C.K., 2003. Megavoltage beam generators. In C.K BOMFORD and I.H KUNKLER, ed. Walter and Millers Textbook of Radiotherapy. London Churchill Livingstone, Pages 162-183.COOK, M., 1998. X-Ray Production. In A. DUXBURY and P. CHERRY, ed. Practical Radiotherapy Physics and Equipment. London GMM, Pages 21-26.HENDEE W. R., IBBOTT G. S. and HENDEE E. G., 2005. shaft of light Therapy Physics. 3rd ed. Hoboken, New Jersey Wiley-Liss.KARZMARK, C.J and MORTON, R., 1998. A Primer on Theory and Operation of Linear Accelerators in Radiotherapy. 2nd ed. Madison, Wisconsin Medical Physics Publishing.KHAN M.F., 2003.The Physics of Radiation Therapy.3rd ed. Philadelphia Lippincott Williams and Wilkins.KNAPP, E. A., KNAPP, B. C. and POTTER I. M., 1968. Standing Wave High Energy Lin ear Accelerator Structures. In HENDEE W. R., IBBOTT G. S. and HENDEE E. G., 2005. Radiation Therapy Physics. 3rd ed. Hoboken, New Jersey Wiley-Liss.

Spectrophotometry Techniques and Devices

Spectrophotometry Techniques and DevicesI. INTRODUCTIONSpectrophotometryInfrargond Spectrophotometry is designed to identify or determine the smack by measuring absorption of infr ard frequency radioactivity of wave numbers in a country of 4,000 to 400 cm-1, at various wave numbers, when it au revoires through with(predicate) the sample. This method uses the property that the infr ard absorption spectrum of a substance is Characteristic of its chemical structure. Infr ared spectra are shown in charts drawn by plotting the wave numbers on the abscissa and the contagions or absorbances on the ordinate.i. SpectrophotometerSpectrophotometry involves the use of a spectrophotometer. A spectrophotometer is a photometer (a device for measuring light speciality) that hind end measure intensity as a function of the falsify (or more particular(prenominal)ally the wavelength) of light. Important features of spectrophotometers are spectral bandwidth and linear range of absorption bi ll.Perhaps the most common application of spectrophotometers is the measurement of light absorption, that they prat be designed to measure diffuse or specular reflection factor.The use of spectrophotometers is non limited to studies in physics. They are withal commonly utilise in other scientific fields such as chemistry, biochemistry, and molecular biology. 2 They are widely used in many industries including create and forensic examination.ii. DesignThere are two major classes of devices single beam and double beam. A double beam spectrophotometer compares the light intensity amid two light paths, one path containing a reference sample and the other the test sample. A single beam spectrophotometer measures the relative light intensity of the beam before and after a test sample is inserted. Although comparison measurements from double beam instruments are easier and more stable, single beam instruments piece of tail maintain a larger dynamic range and are optically simpler and more compact.Historically, spectrophotometers use a monochromator containing a diffraction grating to produce the analytical spectrum. There are also spectrophotometers that use arrays of photosensors. Especially for infrared spectrophotometers, in that respect are spectrophotometers that use a Fourier trans potpourri technique to acquire the spectral information quicker in a technique called Fourier Transform unseeableThe spectrophotometer quantitatively compares the fraction of light that passes through a reference solution and a test solution. Light from the radical lamp is passed through a monochromator, which diffracts the light into a rainbow of wavelengths and turnouts narrow bandwidths of this diffracted spectrum. Discrete frequencies are contagious through the test sample. Then the intensity of the transmitted light is metrical with a photodiode or other light sensor, and the transmittance value for this wavelength is then compared with the transmission through a reference sample.In short, the sequence of events in a spectrophotometer is as followsThe light source shines into a monochromator.A particular output wavelength is selected and beamed at the sample.The sample absorbs light.Many spectrophotometers must be calibrated by a procedure k straight offn as zeroing. The absorbency of a reference substance is set as a baseline value, so the absorbencies of all other substances are record relative to the initial zeroed substance. The spectrophotometer then displays% absorbency (the amount of light absorbed relative to the initial substance).2II. UV IR SPECTROPHOTOMETRYi. Ultraviolet spectrophotometryThe most common spectrophotometers are used in the UV and visible regions of the spectrum and some of these instruments also operate into the near-infrared region as vigorous.Visible region 400-700nm spectrophotometry is used extensively in colorimetry science. sign manufacturers, printing companies, textiles vendors, and many more, need the da ta provided through colorimetry. They take readings in the region of e rattling 10-20 nanometers along the visible region, and produce a spectral reflectance curve or a data stream for alternative presentations. These curves can be used to test a new batch of colorant to check if it makes a match to specifications e.g., iso printing standards.Traditional visual region spectrophotometers cannot detect if a colorant or the base material has fluorescence. This can make it difficult to manage color issues if for example one or more of the printing inks is fluorescent. Where a colorant contains fluorescence, a bi-spectral fluorescent spectrophotometer is used. There are two major setups for visual spectrum spectrophotometers, d/8 (spherical) and 0/45. The names are due to the geometry of the light source,observer and interior of the measurement chamber. Scientists use this machine to measure the amount of multiforms in a sample. If the compound is more concentrated more light will be ab sorbed by the sample inside small ranges, the Beer-Lambert law holds and the absorbance between samples vary with ducking linearly. In the case of printing measurements two alternative settings are commonly used- without/with UV filter to control better the effect of UV brighteners within the physical composition stock.Samples are usually prepared in cuvettes depending on the region of interest, they whitethorn be constructed of glass, plastic, or quartzii. IR spectrophotometrySpectrophotometers designed for the main infrared region are quite different because of the technical requirements of measurement in that region. One major factor is the type of photosensors that are available for different spectral regions, honorable direct infrared measurement is also challenging because virtually everything emits IR light as thermal radiation, especially at wavelengths beyond about 5m. other complication is that quite a some materials such as glass and plastic absorb infrared light, m aking it incompatible as an optical medium. lofty optical materials are salts, which do not absorb strongly. Samples for IR spectrophotometry may be smeared between two discs of cat valium bromide or ground with potassium bromide and pressed into a pellet. Where aqueous solutions are to be measured, insoluble silver chloride is used to construct the cell.III. INFRAREDInfrared (IR) radiation is electromagnetic radiation with a wavelength between 700nm and 300m, which equates to a frequency range between 1THz and 430THza span of more than three orders of magnitude.Its wavelength is longer (and the frequency lower) than that of visible light, but the wavelength is shorter (and the frequency higher) than that of terahertzradiation microwaves. Bright sunlight provides an irradiance of about 1kilowatt per square meter at sea level. Of this nada, 527 watts is infrared light, 445 watts is visible light, and 32 watts is ultraviolet light.The infrared part of the electromagnetic spectrum c overs the range from roughly 300 gigacycle per second (1 mm) to 400 THz (750 nm). It can be divided into three partsFar-infrared, from 300 GHz (1 mm) to 30 THz (10 m). The lower part of this range may also be called microwaves. This radiation is typically absorbed by so-called rotational modes in gas-phase molecules, by molecular motions in smooth-spokens, and by phonons in solids. The water in the Earths atmosphere absorbs so strongly in this range that it renders the atmosphere effectively opaque. However, there are certain wavelength ranges (windows) within the opaque range which allow partial transmission, and can be used for astronomy. The wavelength range from approximately 200 m up to a few mm is often referred to as sub-millimeter in astronomy, reserving far infrared for wavelengths below 200 m.Mid-infrared, from 30 to 120 THz (10 to 2.5 m). Hot objects (black-body radiators) can radiate strongly in this range. It is absorbed by molecularVibrations, where the different ato ms in a molecule vibrate around their equilibrium positions. This range is sometimes called the fingerprint region since the mid-infrared absorption spectrum of a compound is very specific for that compound.Near-infrared,from 120 to 400 THz (2,500 to 750 nm). Physical processes that are relevant for this range are similar to those for visible light.4IV. Infrared spectroscopy(IR spectroscopy) is the subset of spectroscopy that deals with the infrared region of the electromagnetic spectrum. It covers a range of techniques, the most common being a form of absorption spectroscopy. As with all spectroscopic techniques, it can be used to identify compounds or investigate sample composition. Infrared spectroscopy cor social intercourse tables are tabulated in the literature. A commonlaboratory instrument that uses this technique is an infrared spectrophotometer.i. Background and theoryThe infrared portion of the electromagnetic spectrum is divided into three regions the near-, mid- and far - infrared, named for their relation to the visible spectrum. The far-infrared, approximately 400-10cm1 (1000-30m), lying adjacent to the microwave region, has low vigor and may be used for rotational spectroscopy. The mid-infrared, approximately 4000-400cm1 (30-2.5m) may be used to study the fundamental vibrations and associated rotational-vibrational structure. The higher zilch near-IR, approximately 14000-4000cm1 (2.5-0.8m) can excite overtone or harmonic vibrations. The names and classifications of these subregions are merely conventions. They are neither strict divisions nor based on exact molecular or electromagnetic properties.Infrared spectroscopy exploits the fact that molecules shake up specific frequencies at which they rotate or vibrate corresponding to discrete energy levels (vibrational modes). These resonant frequencies are determined by the shape of the molecular potential energy surfaces, the masses of the atoms and, by the associated vibronic coupling. In order for a vibrational mode in a molecule to be IR active, it must be associated with changes in the permanent dipole. In particular, in the Born-Oppenheimer and harmonic approximations, i.e. when the molecular Hamiltonian corresponding to the electronic ground state can be approximated by a harmonic oscillator in the neighborhood of the equilibrium molecular geometry, the resonant frequencies are determined by the normal modes corresponding to the molecular electronic ground state potential energy surface. Nevertheless, the resonant frequencies can be in a first approach related to the strength of the bond, and the mass of the atoms at either end of it. Thus, the frequency of the vibrations can be associated with a particular bond type. Simple diatomic molecules have only one bond, which may stretch. Morecomplex molecules have many bonds, and vibrations can be conjugated, leadingto infrared absorptions at characteristic frequencies that may be related to chemical groups. For example, th e atoms in a CH2 group, commonly found in fundamental compounds can vibrate in six different ways symmetrical and antisymmetrical stretching, scissoring, rocking, wagging and twistingThe infrared spectrum of a sample is collected by passing a beam of infrared light through the sample. Examination of the transmitted light reveals how much energy was absorbed at each wavelength. This can be through with(p) with a monochromatic beam, which changes in wavelength over time, or by using a Fourier transform instrument to measure all wavelengths at once. From this, a transmittance or absorbance spectrum can be produced, showing at which IR wavelengths the sample absorbs. Analysis of these absorption characteristics reveals details about the molecular structure of the sample. When the frequency of the IR is the same as the vibrational frequency of a bond, absorption occurs.This technique works almost exclusively on samples with covalent bonds. Simple spectra are obtained from samples with few IR active bonds and high levels of purity. More complex molecular structures lead to more absorption bands and more complex spectra. The technique has been used for the characterization of very complex mixtures.ii. Adjustment and InstrumentUse a dispersive infrared spectrophotometer or a Fourier-transform infrared spectrophotometer. Before using the infrared spectrophotometer, adjust it as specified in the operating manual. The linearity of the absorbance between 20% and 80% of transmittance (%) should be within 1%. The reproducibility of the transmittance should be within 0.5% in two consecutive measurements. The reproducibility of wave number should be within 5 cm-1 at about 3,000 cm-1 and within 1 cm-1 at more or less 1,000 cm-1. In addition, adjust the instrument so that a spectrum exhibits absorptions at the wave numbers as indicated in the following figure when measurement is made on a polystyrene film (about 0.03 mm thick).5iii. Preparation of SampleAccording to an appro priate one of the methods below,Prepare the sample so that the transmittance of the most intense absorption bands should be within a range of 20 to 80%. For the optic plate, use sodium chloride, potassium bromide, or thallium iodide bromide.Potassium Bromide Disk rule Place 1 to 2 mg of a solid sample and 100 to 200 mg of dried potassium bromide for infrared spectrophotometry into an Agate mortar, cursorily reduce to fine particles protecting from moisture, mix Completely, and transfer into a die. Press the surface of the disk at 500 to 1,000 N/cm2 under reduced blackmail of not more than 0.7 kPa for 5 to 8 minutes, and use this disk for the measurement.Solution Method Prepare a solution of the solid or liquid sample in the Specified solvent, inject the solution into a fixed cell for liquid, and use this cell for the measurement. Place the similar cell containing the same solvent for the fee beam. The thickness of the fixed cell is generally 0.1 mm or 0.5 mm.Paste Method Crush fi nely a solid sample and knead well with liquid Paraffin in the mortar. Hold the paste between two optic plates without any air gap, and measure.Liquid Film Method Hold 1 to 2 drops of liquid sample as a capillary film Held between two optic plates, and measure the liquid layer between the plates. If it is needed to thicken the liquid layer, place rings of aluminum foil or a similar material between the two optic plates so that the liquid sample lies between the plates.Thin Film Method Dissolve the sample in the specified solvent, and apply it to one optic plate. Evaporate the solvent by drying with hot air, and measure the thin film adhered on the plate. If the sample is a film with a thickness of not more than 0.02 mm, measure the film just as it is.Gas Sample Measurement Put the sample gas in a gas cell with a light Path of 5 to 10 cm in length, previously evacuated, under pressure specified in the individual monograph, and measure. A long cell with the light path of not shorter than 1 m is also used if necessary.iv. Conventional methodA beam of infrared light is produced and split into two separate beams. One is passed through the sample, the other passed through a reference which is often the substance the sample is dissolved in. The beams are both(prenominal) reflected back towards a detector, however first they pass through a splitter which quickly alternates which of the two beams enters the detector. The two signals are then compared and a printout is obtained.A reference is used for two reasonsThis prevents fluctuations in the output of the source affecting the dataThis allows the effects of the solvent to be cancelled out (the reference is usually a pure form of the solvent the sample is in)v. Fourier transform infrared spectroscopyFourier transform infrared (FTIR) spectroscopy is a measurement technique for collecting infrared spectra. Instead of recording the amount of energy absorbed when the frequency of the infra-red light is varied (monochrom ator), the IR light is guided through an interferometer. After passing through the sample, the measured signal is the interferogram. Performing a Fourier transform on this signal data results in a spectrum identical to that from conventional (dispersive) infrared spectroscopy.FTIR spectrometers are cheaper than conventional spectrometers because building an interferometer is easier than the fabrication of a monochromator. In addition, measurement of a single spectrum is faster for the FTIR technique because the information at all frequencies is collected simultaneously. This allows multiple samples to be collected and averaged together resulting in an approach in sensitivity. Virtually all modern infrared spectrometers are FTIR instruments.Summary of absorptions of bonds in organic moleculesvi. Uses and applicationsInfrared spectroscopy is widely used in both research and industry as a simple and reliable technique for measurement, flavour control and dynamic measurement. It is of especial use in forensic abridgment in both criminal and civil cases, enabling identification of polymer degradation for example. It is perhaps the most widely used method of applied spectroscopy.citation neededThe instruments are now small, and can be transported, even for use in field trials. With increasing technology in computer filtering and manipulation of the results, samples in solution can now be measured accurately (water produces a broad absorbance across the range of interest, and thus renders the spectra unreadable without this computer treatment). Some instruments will also automatically severalise you what substance is being measured from a store of thousands of reference spectra held in storage.By measuring at a specific frequency over time, changes in the character or quantity of a particular bond can be measured. This is especially useful in measuring the degree of polymerization in polymer manufacture. Modern research instruments can take infrared measurements across the whole range of interest as frequently as 32 times a second. This can be done whilst simultaneous measurements are made using other techniques. This makes the observations of chemical reactions and processes quicker and more accurate.Techniques have been developed to assess the quality of tea-leaves using infrared spectroscopy. This will mean that highly trained experts (also called noses) can be used more sparingly, at a significant cost saving.Infrared spectroscopy has been highly successful for applications in both organic and inorganic chemistry. Infrared spectroscopy has also been successfully utilized in the field of semiconductor device microelectronics8 for example, infrared spectroscopy can be applied to semiconductors bid silicon, gallium arsenide, gallium nitride, zinc selenide, amorphous silicon, silicon nitride, etc.V. USES IN ORGANICA technique to identify materials including organic polymers. An infrared spectrometer directs infrared radiation through a sa mple and records the relative amount of energy absorbed by the sample as a function of the wavelength or frequency of the infrared radiation. The method is applicable particularly to organic materials, because the vibrational frequencies of the constituent groups within the molecules coexist with the electromagnetic frequencies of the infrared radiation. Therefore, the infrared radiation is selectively absorbed by the material to produce an absorption spectrum. The spectrum produced is compared with correlation spectra from known substances.VI. SPECTRORADIOMETERSSpectroradiometers, which operate almost like the visible region spectrophotometers, are designed to measure the spectral density of illuminants in order to evaluate and categorize lighting for sales by the manufacturer, or for the customers to confirm the lamp they decided to purchase is within their specifications. ComponentsThe light source shines onto or through the sample.The sample transmits or reflects light.The dete ctor detects how much light was reflected from or transmitted through the sample.The detector then converts how much light the sample transmitted or reflected into a number.CONCLUSIONIn this topic which is infrared spectrophotometry I have introduced what is spectrophotometry. And it is used in a device called spectrophotometer which is explained in the above thesis. Followed on single beam spectrophotometer is also explained with its design working.Spectrophotometry is generally of two types UV IR spectrophotometry, UV spectrophotometry is explained in short but IR spectrophotometry is explained briefly. The word INFRARED is explained i.e. what it means, infrared region is explained in EM radiation. In EM spectrum there comes a topic infrared spectroscopy which is explained briefly with its background theory. Its preparation of sample followed by conventional method of it. There is other phenomenon called FITR (Fourier transform infrared spectroscopy) is a measurement technique for collecting infrared spectra. FTIR spectrometers are cheaper than conventional spectrometers. Uses application is also explained in the above thesis. At last but not the least(prenominal) its use in organic is explained. The idea of Spectroradiometers is also given, which operate almost like the visible region spectrophotometers. This is end of the conclusion of my thesis infrared spectrophotometry.

Internship Reflection Essay -- Reflection Paper

It has been a while since I started at the internship and I am really glad I decided to work here. I think the endure in this area is a good preview of my career and future. I am learning some important skills and finding out some things astir(predicate) myself and the tough skin I will need in order to stay in the area of juvenile support.One of my responsibilities involved checking the messages from the days before on the office phone. I found that some of the potential drop mentors sounded honest-to-goodnesser. This got me wondering about the age limits of the mentors. I knew they had to be at least 18, but was on that point an age cap? Could a 30-year-old join the team and be the mentor to a 12-year-old? I though about the different ways that these relationships could manifest. If the mentor was older, could they potential become a parental figure to the child? I always thought of the mentors as young adults, around college age. They would be an older sibling to the child, correspondence the generation specific of the child, especially once they were teens. I though that in this way, the child would possibly open up more because they would not look at the person as an authority figure. When I though about a possible 13-year-old being matched with a 35-year-old, I thought of my teen years and calculate that at that age, I would not have been so willing to share. Nevertheless, we allow any willing person, over the age of 18, that passes the checks, to become a mentor more(prenominal) calls throughout the week led me to turning down grandparents whose children were in county prisons. This was heart breaking. In the past, I spoke to people who worked with juvenile delinquents and they always warned me that the job was difficult. They feelings that could be evoked, even wit... ... needed to get some fingerprinting done for their job. They had to go to an actually fingerprinting center. Seeing that I do the mobile fingerprinting, I was raise in seeing ho w the center handled it. They did their electronically. They computer analyzed whether the print was legible then loaded it to their file. This way was much easier than our way. It was neater because their was no ink needed. Also, if a drop off was made, the cop could just redo the print. On the other hand, I have to put down a white out strip to cover the old one and re-ink the finger. After the cop was complete finished with both hands, he clicked a button and sent the prints down to Florida to get checked. The website actively keeps the applicant sensible on the progress of the print. We, however, must mail it in hoping it is legible and wait for a letter to let us know how it went.

Michelangelo Essay -- essays research papers

In the time of the Renaissance there were many artists moreover one re ally stood out to me, he was Michelangelo. He stood out the most to me because he had some of the most beautiful work I have of all time seen. He painted some of the most beautiful building that is still around today. One of the most that I enjoyed looking at was the Sistine Chapel in the Vatican. It took him a lot of time to paint the entire building. I feel this was his best piece of art ever. He had many accomplishments that were outstanding.The second of five brothers, Michelangelo was born(p) on March 6, 1475, at Caprese, in Tuscany, to Ludovico di Leonardo di Buonarotto Simoni and Francesca Neri. The same day, his father noted down "Today March 6, 1475, a child of the male hinge on has been born to me and I have named him Michelangelo. He was born on Monday between 4 and 5 in the morning, at Caprese, where I am the Podest." Although born in the small village of Caprese, Michelangelo always consi dered himself a "son of Florence," as did his father, "a Citizen of Florence." Buonarrotis mother, Francesca Neri, was too sick and frail to nurse Michelangelo, so he was placed with a wet nurse, in a family of stonecutters, where he, "sucked in the craft of hammer and chisel with my foster mother. When he told my father that he wished to be an artist, he flew into a rage, artists are laborers, no better than shoemakers." Buonarrotis mother died young, when the child was only six years old. But even before then, Michelangelos childhood had been lacking affection, and he was always to withstand a good position in his fathers heart. Touchy and quick to respond with fierce words, he tended to keep to himself, out of shyness fit in to some but also, according to others, a lack of trust in his fellows. His father soon recognized the boys intelligence and "anxious for him to learn his letters, sent him to the coach of a master, Francesco Galeota from Urbino , who in that time taught grammar." While he studied the principles of Latin, Michelangelo made friends with a student, Francesco Granacci six years older than him, who was learning the art of painting in Ghirlandaios studio and who encouraged Michelangelo to follow his own artistic vocation.Michelangelo studied the human anatomy in order to make his painting more life like. In doing things the pictures l... ...onna and Christ, may have been begun by Michelangelo before 1550 but had remained unfinished. Now his friends - we are told by Vasari - had asked him to start work on it again "so that he could go on using his chisel everyday." Still perfectly lucid, the almost ninety-year-old Michelangelo created one of his most spiritual images, in which the Mother and Christ almost interpenetrate in an insoluble union, beyond passion and physical death.     While residing in Florence for this extended period, Michelangelo also undertook-between 1519 and 15 34-the commission of the Medici Tombs for the New Sacristy of San Lorenzo. His design called for two large wall tombs facing each other across the high, domed room. One was intended for Lorenzo De Medici, duke of Urbino the other for Giulinao De Medici duke of Nemours. The tombs of the Medici were of a completely new form. Michelangelo abandoned the use of architecture and arabesques that decorated all Florentine tombs, and that he himself had widely used in his designs for the tomb of Pope Julius II. Here, he wanted no accessory forms, and only the statues were to express the thoughts of his soul.