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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Vyšetření počtu buněčných elementů v mozkomíšním moku na analyzátoru Sysmex XE-5000 metodou "Body Fluid". / Examination of Cellular Elements in the Cerebrospinal Fluid on the Analyser Sysmex XE-5000 by Method of "Body Fluid".

Davídková, Jana January 2014 (has links)
Cerebrospinal fluid is examined using a variety of methods, which also include determining the number and type of each cell. Now the method of the first choice to determine the cellular elements is a microscopic method. This determination, however, can also be done using the analyzer method, which is not yet so widespread. The aim of my thesis was to compare these two methods and determine whether the examination of cerebrospinal fluid on the analyzer Sysmex XE-5000 in the "Body Fluid" mode can replace commonly used microscopic methods. To this purpose, we gathered the laboratory data measured by using both these methods. These data was compared, evaluated and statistically processed. The resulting data suggest that the values measured on the analyzer Sysmex XE-5000 are more accurate than from microscopic determination, especially at highly cell samples of cerebrospinal fluid. To this end, we came evaluation of Bland-Altman graphs and comparison graphs with marked of limits of physiological oligocytosis. For checking of the accuracy of measurements, we verified the repeatability of the analyzer for the values of leukocytes and erythrocytes, coefficients of variation corresponding to the values specified by the manufacturer's documentation. We also investigated the stability of samples of...
22

Conception d'outils bioinformatiques pour la modélisation de voies métaboliques et de leur régulation / Designing bioinformatic tools to model metabolic pathways and their regulation

Dupont, Pierre-Yves 15 December 2011 (has links)
La biologie des systèmes actuelle s’appuie sur des techniques d’analyse biologique à haut débit comme la transcriptomique ou la métabolomique. Cependant, ces techniques haut débit ont leurs limites et peuvent générer des erreurs. En croisant les résultats de différentes techniques d’analyse biologique, nous espérons pallier une partie de leurs limites. À cet effet, nous avons commencé à développer une plateforme de modélisation, MPSA (Metabolic Pathways Software Analyzer), permettant d’intégrer les données générées à des réseaux métaboliques. MPSA permet de représenter les graphes de voies métaboliques, d’effectuer des simulations basées sur la résolution de systèmes d’équations différentielles et d’étudier la structure des réseaux métaboliques par le calcul et la représentation des modes élémentaires. Nous avons développé différentes applications web permettant, d’une part, l’interprétation des résultats biologiques en utilisant des bases de données et, d’autre part, leur export vers MPSA. La base de données centrale de ce développement est myKegg, incluant l’ensemble des voies métaboliques humaines de la base de données publique KEGG ainsi qu’une base de synonymes construite elle aussi à partir de KEGG. Cette base permet d’identifier des voies métaboliques et de les importer dans MPSA. Une base de données de métabolomique, BioNMR, a aussi été construite spécifiquement pour organiser les résultats générés à partir de spectres de RMN. Une autre application web, GeneProm, a été développée pour l’analyse de promoteurs de gènes ou promotologie. Un protocole d’étude a été mis au point et testé sur un groupe de 4 gènes codant pour les isoformes 1 à 4 de la protéine ANT, transporteur mitochondrial d’ATP, chacune ayant un rôle et un profil d’expression spécifique dans la bioénergétique cellulaire. L’étude par promotologie de ces 4 gènes a permis d’identifier des éléments de régulation spécifiques dans leurs séquences promotrices et d’identifier des gènes potentiellement co-régulés. Ces gènes peuvent ensuite être exportés vers notre plateforme MPSA. L’ensemble de ce développement sera inclus au projet de plateforme intégrative de l’Unité de Nutrition Humaine de l’INRA. / Current systems biology relies on high-throughput biological analysis techniques such as transcriptomics or metabolomics. However, these techniques may generate errors. By crossing results from different analysis techniques, we hope to avoid at least part of these limits. For that purpose, we started to develop a modeling platform, MPSA (Metabolic Pathways Software Analyzer). MPSA allows integrating biological data on metabolic pathways. MPSA also ensures the display of metabolic pathways graphs, the simulation of models based on ordinary differential equations systems solving and the study of network structures using elementary flux modes. We have developed several web applications allowing on the one hand to interpret biological results by using databases, and on the other hand to export these data to MPSA. The main database of this work is myKegg. It includes all human KEGG metabolic pathways and a list of synonyms for human KEGG entries. This base allows to identify metabolic pathways from a list of biological compounds and to import them in MPSA. Another database, BioNMR, has been developed to organize the data extracted from NMR spectra. Another web application named GeneProm has been developed to analyze gene promoters. A promotology protocol was developed and tested on a set of four genes coding for the four ANT (adenine nucleotide translocator) protein isoforms. Each ANT isoform has a specific expression profile and role in cell bioenergetics. The promotology study of these four genes led us to construct specific regulatory models from identified regulatory elements in their promoter sequence. Potentially co-regulated genes were deduced from these models. Then they can be exported to our MPSA platform. This whole development will be included in the project of Integrative Biology platform in the INRA Human Nutrition Unit.
23

Um estudo da sorção de \'SO IND.2\' por calcário em analisador termogravimétrico e na combustão de carvão em leito fluidizado / A Study of the \'SO IND.2\' sorption by limestone in thermogravimetric analyser and coal combustion in fluidized bed

Ávila, Ivonete 29 August 2008 (has links)
Nesta tese investiga-se a sorção de \'SO IND.2\' por um calcário dolomítico brasileiro em duas diferentes configurações experimentais: um analisador termogravimétrico e um combustor de carvão em leito fluidizado atmosférico borbulhante. Os experimentos termogravimétricos foram realizados em condições tão próximas quanto possível àquelas observadas no processo de combustão em leito fluidizado. Coeficientes intrínsecos de taxa de reação, efetividades e conversões foram determinados através de termogravimetria em atmosfera contendo 65% de ar sintético, 15% de \'CO IND.2\' e 20% de \'SO IND.2\', para quatro diferentes granulometrias do calcário dolomítico (385, 545, 725 e 775 µm) em quatro diferentes temperaturas de processo (800, 830, 860 e 890 graus Celsius). Os coeficientes intrínsecos de taxa de reação, na condição de máxima taxa de reação, resultaram entre 3,86 x \'10 POT.-3\' e 7,07 x \'10 POT.-3\' m/s. As efetividades médias para 200 segundos de reação resultaram entre 0,37 e 0,49/s. As conversões após 600 segundos de sulfatação resultaram entre 0,40 e 0,49 kmol(\'SO IND.2\')/kmol(\'CA\'+\'MG\') . Nos experimentos em combustor de leito fluidizado obteveram-se coeficientes globais de taxa de reação, conversões e eficiência de sorção de \'SO IND.2\'. Considerou-se um calcário dolomítico em cinco diferentes granulometrias médias (385, 545, 718, 725 e 775 µm) e um carvão mineral brasileiro (CE4500) com granulometria média de 385 µm. Aplicaram-se temperaturas entre 798,2 e 886,6 graus Celsius, U/Umf entre 5,6 e 10,8 m/s, e relações molares (\'CA\'+\'MG\')/S na alimentação entre 3,7 e 11,9 kmol(\'CA\'+\'MG\')/kmol(s). O coeficiente global de taxa de reação resultou entre 0,009 e 0,072 m/s, a conversão resultou entre 0,020 e 0,064 kmol(\'SO IND.2\')/kmol(\'CA\'+\'MG\'), e a eficiência de sorção de \'SO IND.2\' resultou entre 46,4 e 83,9%. Os coeficientes globais de taxa de sulfatação obtidos em leito fluidizado foram comparados com os coeficientes intrínsecos de taxa de reação obtidos via termogravimetria. Concluiu-se que condições termogravimétricas mais realistas são necessárias para que a composição de coeficientes de taxa de reação intrínsecos e globais permita análises de controle de reação em reatores de leito fluidizado. / This thesis investigates the sorption of \'SO IND.2\' by a brazilian dolomite in two different experimental setups: a thermogravimetric analyzer and an atmospheric bubbling fluidized bed coal combustor. The thermogravimetric experiments were carried out in conditions as close as possible to those observed in the fluidized bed combustion process. Intrinsic coefficient of reaction rate, effectiveness and conversion were determined through thermogravimetry in synthetic atmosphere containing 65% of air 15% of \'CO IND.2\' and 20% of \'SO IND.2\' for four different dolomite particle sizes (385, 545, 725 and 775 µm) and four different temperatures (800, 830, 860 and 890 Celsius degrees). The results of the intrinsic reaction rate coefficient in the maximum reaction rate conditions were between 3.86 x \'10 POT.-3\' and 7.07 x \'10 POT.-3\' m/s, while the resuls of the average effectiveness for 200 seconds of reaction were between 0.37 and 0.49/s. The values of conversion after 600 seconds of sulfation were between 0.40 and 0.49 kmol(\'SO IND.2\')/kmol(\'CA\'+\'MG\') . Global reaction rate coefficient, conversion and \'SO IND.2\' sorption efficiency were obtained from the fluidized bed combustor experiments for five different dolomite particulate sizes (average diameters of 385, 545, 718, 725 and 775 µm) and a brazilian coal (CE4500) with particle size of 383 \'mü\'m. Temperatures between 798.2 and 886.6 Celsius degrees, U/Umf between 5.6 and 10.8 m/s, and (\'CA\'+\'MG\')/S molar feeding ratios between 3.7 and 11.9 kmol(\'CA\'+\'MG\')/kmol(s) were applied. The results of the global reaction rate coefficient were between 0.009 and 0.072 m/s, the ones of the conversion were between 0.020 and 0.064 kmol(\'SO IND.2\')/kmol(\'CA\'+\'MG\'), and those of the \'SO IND.2\' sorption efficiency were between 46.4 and 83.9%. The global sulfation rate coefficients obtained in fluidized bed were compared to the intrinsic reaction rate coefficients obtained through thermogravimetry. It was concluded that more realistic thermogravimetric conditions are required so that the composition of intrinsic and global reaction rate coefficients can allow for the analyses of reaction rate control in fluidized bed reactors.
24

New quantitative methods in analyser-based phase contrast X-ray imaging

Vine, David John January 2008 (has links)
New quantitative methods are developed for analyser-based phase contrast imaging (ABI) with hard X-rays. In the first instance we show that quantitative ABI may be implemented using an extended incoherent source. Next, we outline how complex Green’s functions may be reconstructed from phase contrast images and we apply this method to reconstruct the thick perfect crystal Green’s function associated with an ABI imaging system. The use of quantitative ABI with incoherent X-ray sources is not widespread and the first set of results pertains to the feasibility of quantitative ABI imaging and phase retrieval using a rotating anode X-ray source. The necessary conditions for observation of ABI phase contrast are deduced from elementary coherence considerations and numerical simulations. We then focus on the problem of extracting quantitative information from ABI images recorded using an extended incoherent X-ray source. The results of an experiment performed at Friedrich-Schiller University, Germany using a rotating anode X-ray source demonstrate the validity of our approach. It is shown that quantitative information may be extracted from such images under quite general and practicable conditions. We then develop a new use for phase contrast imaging systems that allows the Green’s function associated with a linear shift-invariant imaging system to be deduced from two phase contrast images of a known weak object. This new approach is applied to X-ray crystallography where the development of efficient methods of inferring the phase of rocking curves is an important open problem. We show how the complex Green’s function describing Bragg reflection of a coherent scalar X-ray wavefield from a crystal may be recovered from a single image over a wide range of reciprocal space simultaneously. The solution we derive is fast, non-iterative and deterministic. When applied to crystalline structures for which the kinematic scattering approximation is valid, such as thin crystalline films, our technique is shown to solve the famous one-dimensional phase retrieval problem which allows us to directly invert the Green’s function to retrieve the depth-dependent interplanar spacing. Finally we implement our Green’s function retrieval method on experimental data collected at the SPring-8 synchrotron in Hyogo, Japan. In the experiment we recorded analyser-based phase contrast images of a known weak object using a thick perfect silicon analyser crystal. It is then demonstrated that these measurements can be inverted to recover the complex Green’s function associated with the analyser crystal Bragg peak. The reconstructed Green’s function is found to be in good agreement with the prediction of dynamical diffraction theory.
25

Ion Energy Measurements in Plasma Immersion Ion Implantation

Allan, Scott Young January 2009 (has links)
Doctor of Philosophy (PhD) / This thesis investigates ion energy distributions (IEDs) during plasma immersion ion implantation (PIII). PIII is a surface modification technique where an object is placed in a plasma and pulse biased with large negative voltages. The energy distribution of implanted ions is important in determining the extent of surface modifications. IED measurements were made during PIII using a pulse biased retarding field energy analyser (RFEA) in a capacitive RF plasma. Experimental results were compared with those obtained from a two dimensional numerical simulation to help explain the origins of features in the IEDs. Time resolved IED measurements were made during PIII of metal and insulator materials and investigated the effects of the use of a metal mesh over the surface and the effects of insulator surface charging. When the pulse was applied to the RFEA, the ion flux rapidly increased above the pulse-off value and then slowly decreased during the pulse. The ion density during the pulse decreased below values measured when no pulse was applied to the RFEA. This indicates that the depletion of ions by the pulsed RFEA is greater than the generation of ions in the plasma. IEDs measured during pulse biasing showed a peak close to the maximum sheath potential energy and a spread of ions with energies between zero and the maximum ion energy. Simulations showed that the peak is produced by ions from the sheath edge directly above the RFEA inlet and that the spread of ions is produced by ions which collide in the sheath and/or arrive at the RFEA with trajectories not perpendicular to the RFEA front surface. The RFEA discriminates ions based only on the component of their velocity perpendicular to the RFEA front surface. To minimise the effects of surface charging during PIII of an insulator, a metal mesh can be placed over the insulator and pulse biased together with the object. Measurements were made with metal mesh cylinders fixed to the metal RFEA front surface. The use of a mesh gave a larger ion flux compared to the use of no mesh. The larger ion flux is attributed to the larger plasma-sheath surface area around the mesh. The measured IEDs showed a low, medium and high energy peak. Simulation results show that the high energy peak is produced by ions from the sheath above the mesh top. The low energy peak is produced by ions trapped by the space charge potential hump which forms inside the mesh. The medium energy peak is produced by ions from the sheath above the mesh corners. Simulations showed that the IED is dependent on measurement position under the mesh. To investigate the effects of insulator surface charging during PIII, IED measurements were made through an orifice cut into a Mylar insulator on the RFEA front surface. With no mesh, during the pulse, an increasing number of lower energy ions were measured. Simulation results show that this is due to the increase in the curvature of the sheath over the orifice region as the insulator potential increases due to surface charging. The surface charging observed at the insulator would reduce the average energy of ions implanted into the insulator during the pulse. Compared to the case with no mesh, the use of a mesh increases the total ion flux and the ion flux during the early stages of the pulse but does not eliminate surface charging. During the pulse, compared to the no mesh case, a larger number of lower energy ions are measured. Simulation results show that this is caused by the potential in the mesh region which affects the trajectories of ions from the sheaths above the mesh top and corners and results in more ions being measured with trajectories less than ninety degrees to the RFEA front surface.
26

Further Development of an Audio Analyzer / Vidareutveckling av en audioanalysator

Klevhamre, Benny, Nilsson, Peter January 2002 (has links)
En del av en Audioanalystor har blivit utveckladoch implementerad som en applikation i det hårdvarubeskrivande språket VHDL. Denna del har sedan programmerats in i en PLD-krets på ett kretskort som används i audiotester för mobiltelefoner på Flextronics. Applikationen konverterar data så att det ska gå att skicka information mellan telefonen och olika mätinstrument. Applikationen består av två äldre applikationer. Av dessa två har en blivit helt implementerad. I den andra kvarstår att finna orsaken till varför den ger ifrån sig felaktigt data i form av oönskat brus. Arbetet avbröts p.g.a. slutdatum. A part of an audio analyzer has been developed and implemented as an application in the hardware description language VHDL. This part has later been programmed into a PLD device on a circuit board used for audio tests on mobile telephones at Flextronics. The application converts data, making it possible to send information between the telephone and different measuring instruments. The application consists of two older applications. One of them has been fully implemented. What is left in the other part is to find the cause why it is sending wrong data as unwanted noise. The work had to be stopped when deadline was reached / A part of an audio analyzer has been developed and implemented as an application in the hardware description language VHDL. This part has later been programmed into a PLD device on a circuit board used for audio tests on mobile telephones at Flextronics. The application converts data, making it possible to send information between the telephone and different measuring instruments. The application consists of two older applications. One of them has been fully implemented. What is left in the other part is to find the cause why it is sending wrong data as unwanted noise. The work had to be stopped when deadline was reached.
27

Tillgänglighet i flerbostadshus från 1990 till nutid : Analyser av projekt i Uddevalla / Accessibility in block of flats from 1990 until today : Analyses of projects in Uddevalla

Arvidsson, Jessica January 2010 (has links)
The built environment should be accessible for everyone. A residence shall be functional without creating a handicap for people who have a disability from birth, caused by an accident or of old age. A residence that is accessible creates equal conditions for everyone. In this report the accessibility of newly built blocks of flats in Uddevalla city from 1990 until today are interpreted. One project that is yet to be built is interpreted and compared with the already existing projects. The apartments of seven projects have been analyzed according to today’s regulations of accessibility. The Swedish politics regarding disablement and a historical overview of the building regulations from the 1980’s till 2010 give the foundation of the analyses of the projects. One type-apartment in each project has been furnished to be able to interpret how the accessibility demands are fulfilled. In the study the conditions of the seven projects are different. Two of the projects, that have been built 8 years apart, are two-story apartment blocks. These projects separate from the other projects that are four-seven story apartment block buildings. One of the buildings has the concept of being able to keep living in and using the apartment when ageing. The four project that remains are all block of flats with 26-45 apartments each, with the difference of when they were built, or is going to be built. The result of how accessible the different apartments are in each project depends on how well thought-out the floor plan is. The oldest project is comparable to and even better than two of the younger projects when it comes to accessibility. A neutral hallway or accessing a bedroom from the living room is a recurring design that is found in five of the seven projects. In three of the projects a failing design or different building regulations causes the bathroom to fail the accessibility demands. The recurring center- to- center distance between the toilet and washbasin in each projects determines if the accessibility demands are achieved. When a kitchen, dining area and living room are in an open connection with each other they create practicability, but depending on the measurements of each space the accessibility demands can be fulfilled or shattered by collisions, created when furnishing.
28

Tillämpning av CBA inom sjöfartsnäringen / Applying CBA Methodology in Swedish Maritime

Jusufbegovic, Jasmin, Ottoson, Johan January 2010 (has links)
Den första april 2010 bildades myndigheten Trafikverket som har till uppgift att ansvara för infrastrukturinvesteringar inom sjöfart, luftfart, väg och järnväg. I denna brytningstid för infrastrukturinvesteringar inom transportsektorn har vi valt att undersöka hur cb-analyser skulle kunna användas inom sjöfartsnäringen. Vi har med hjälp av CBA-teori resonerat kring hur detta skulle kunna användas inom sjöfarten i praktiken. Till hjälp har vi haft den mest använda litteraturen om CBA samt rapporter främst från SIKA (Statens institut för kommunikationsanalys) och Sjöfartsverket. En viktig poäng med den här uppsatsen är att alla infrastrukturprojekt inom transportsektorn ska utredas likvärdigt. Om inte trafikslagen bedöms på liknande grunder riskerar de lönsammaste investeringsprojekten att felaktigt bortprioriteras. En likvärdig bedömning är därmed nödvändig för en effektiv resursallokering. Idag används ASEK 4-rapporten som manual för CBA inom väg- och järnväg och därmed måste även CBA inom sjöfarten utgå från ASEK 4:s rekommendationer, även om manualen inte kan ses som fullständig. Näst efter en likvärdig bedömning i prioriteringsordningen är att införa Monte Carlo-analys som standard. Monte Carlo-analysen är en bra metod för känslighetsanalyser. Vi har i denna uppsats kunnat påvisa att Monte Carlo-analys kan genomföras med enkla statistiska programvaror. Förutom dessa två åtgärder finns ett flertal andra utvecklingsområden som identi-fierats i denna uppsats. Först och främst måste intrångskostnaderna värderas monetärt och nya prognosmodeller utvecklas för att möjliggöra värdering av överflyttning mellan trafikslag. Ett annat prioriterat område är att omvärdera kostnaden för koldioxidutsläpp. Ytterligare ett område som behöver ses över är bullervärdering för havsmiljö. Mindre viktiga utvecklingsområden är en omvärdering av ventilationsfaktorn för hamnnära utsläpp och bedömning av den allmänna olycksrisken vid sjötransporter.
29

Further Development of an Audio Analyzer / Vidareutveckling av en audioanalysator

Klevhamre, Benny, Nilsson, Peter January 2002 (has links)
<p>En del av en Audioanalystor har blivit utveckladoch implementerad som en applikation i det hårdvarubeskrivande språket VHDL. Denna del har sedan programmerats in i en PLD-krets på ett kretskort som används i audiotester för mobiltelefoner på Flextronics. Applikationen konverterar data så att det ska gå att skicka information mellan telefonen och olika mätinstrument. Applikationen består av två äldre applikationer. Av dessa två har en blivit helt implementerad. I den andra kvarstår att finna orsaken till varför den ger ifrån sig felaktigt data i form av oönskat brus. Arbetet avbröts p.g.a. slutdatum. A part of an audio analyzer has been developed and implemented as an application in the hardware description language VHDL. This part has later been programmed into a PLD device on a circuit board used for audio tests on mobile telephones at Flextronics. The application converts data, making it possible to send information between the telephone and different measuring instruments. The application consists of two older applications. One of them has been fully implemented. What is left in the other part is to find the cause why it is sending wrong data as unwanted noise. The work had to be stopped when deadline was reached</p> / <p>A part of an audio analyzer has been developed and implemented as an application in the hardware description language VHDL. This part has later been programmed into a PLD device on a circuit board used for audio tests on mobile telephones at Flextronics. The application converts data, making it possible to send information between the telephone and different measuring instruments. The application consists of two older applications. One of them has been fully implemented. What is left in the other part is to find the cause why it is sending wrong data as unwanted noise. The work had to be stopped when deadline was reached.</p>
30

Gas detection by use of Sagnac interferometer

McConnell, Sean R. January 2008 (has links)
Gas composition and analysis forms a large field of research whose requirements demand that measurement equipment be as affordable, uncomplicated and convenient as possible. The precise quantitative composition of an atmospheric, industrial or chemically synthesised sample of gas is of utmost importance when inferring the properties and nature of the environment from which the sample was taken, or for inferring how a prepared sample will react in its application. The most popular and widely used technique to achieve this is Gas Chromatography-Mass Spectrometry (GCMS) and, without a doubt, this technique has set the standard for gas analysis. Despite the accuracy of the GCMS technique, the equipment itself is bulky, expensive and cannot be applied readily to field work. Instead, most field work is conducted using a single gas detector, capable only of detecting one particular molecule or element at a time. Presented here is an interferometric technique that theoretically, has the ability to address all three issues of bulkiness, affordability and convenience, whilst not being limited to one particular element or molecule in its analysis. Identifying the unknown constituents of a gaseous mixture using the proposed method, employs the optical refractive properties of the mixture to determine its composition. A key aspect of this technique is that the refractive index of an arbitrary mixture of gases will vary depending on pressure and wavelength1. The Lorentz-Lorenz formula and the Sellmeier equations form the foundation of the theoretical background. The optical refractive properties of air and other atmospheric gases have been well established in the literature. The experimental investigations described here have been conducted based on this, insofar as no analysis has been conducted on gases that do not naturally occur in reasonable abundance in the atmosphere. However this does not in any way preclude the results and procedure developed from applying to a synthesised gas mixture. As mentioned, the platform of this technique relies on the pressure and wavelength dependence of the refractivity of the gas. The pressure dependence of the system is easily accounted for, in making this claim however it is still imperative the mixture be impervious to contamination from the wider atmosphere. Wavelength dependence however is perhaps slightly more difficult to accommodate. Multiple lasers, of differing wavelength form the radiative sources which underpin the method developed. Laser sources were chosen because of their coherence, making it easy to produce interference, when combined with the inherent stability of the Sagnac interferometer, provides for a very user friendly system that is able to quickly take results. The other key part of the experimental apparatus is the gas handling system, the gas(es) of interest need to be contained within an optical medium in the path of one of the beams of the interferometer. Precise manipulation of the pressure of the gas is critical in determining concentration, this has been achieved through the use of a gas syringe whose plunger is moved on a finely threaded screw, and measured on a digital manometer. The optical setup has also been explored, specifically in ruling out the use of such radiative sources as passing an incandescent source through a monochromator or the use of LED's to produce interference before settling on lasers to produce the required interference. Finally, a comprehensive theoretical background has been presented using classical electromagnetic theory as well as confirmation from a quantum perspective. The theoretical background for this study relies upon the Lorentz-Lorenz formula. It is commonly presented either from a classical or quantum perspective, in this work both classical and quantum mechanical treatments are given whilst also showing how each confirms the other. Furthermore, a thorough investigation into the dispersion functions of each of the major components of the atmosphere has been compiled from the study of refractivity on individual gases from other authors, in some cases, where no work has been done previously, this has been derived. The technique developed could be considered an ample addition to gas analysis techniques in certain circumstances in terms of expense, convenience and accuracy. The system can predict relative quantities of constituents of the atmosphere to at least 3%. The method described here would allow researchers more time to concentrate on actual results and more resources to allocate to broadening intellectual horizons. This would certainly justify further development.

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