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1

Iacomi, Paul Adrian. "Exploring sources of variability in metal organic frameworks through high throughput adsorption and calorimetric methods." Thesis, Aix-Marseille, 2018. http://www.theses.fr/2018AIXM0415/document.

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Les réseaux métallo-organiques (MOF) sont une nouvelle classe de matériaux poreux hybrides. Néanmoins leurs propriétés uniques introduisent également des difficultés significatives dans la caractérisation par adsorption de gaz. Dans cette thèse, la création d'un code source libre est détaillé, pour standardiser le traitement des isothermes. En utilisant ce code, un traitement à haut débit de plus de 18 000 isothermes est utilisé pour explorer l'échelle d'incertitude présente dans les données publiées sur l'adsorption dans les matériaux poreux. De plus, la mesure directe de l'enthalpie différentielle de l'adsorption en utilisant la microcalorimétrie s'avère être un excellent moyen d'obtenir la contribution des interactions particulières sur l'énergie d'adsorption. Ensemble, ces méthodes peuvent être utilisées pour étudier les sources d'incertitude des MOF. On étudie d’abord l’impact des défauts structurels au moyen d’une méthode post-synthétique alternative de génération de linker/cluster manquants dans l'UiO-66(Zr). Le traitement des matériaux pour leurs utilisations dans un environnement industriel par façonnage est étudié ici sous l’effet de la granulation par voie humide sur trois MOF topiques (UiO-66(Zr), MIL-100(Fe) et MIL-127(Fe)). Enfin, les comportements contre-intuitifs intrinsèques aux cristaux poreux «souples» sont étudiés, où la structure elle-même est responsable de la fluctuation dans les isothermes d'adsorption. Ici, une étude fondamentale sur un matériau flexible DUT-49 (Cu), apporte des informations sur la source de flexibilité induite par adsorption et sa changeabilité par modification structurelle<br>Metal organic frameworks (MOF) are novel adsorption materials with unique and desirable properties. However, structural defects, processing and structural compliance can lead to irreproducibility in adorption measurements. In this thesis, the creation of an open-source codebase is detailed, which is intended to standardize the processing of isotherms. Using this framework, high throughput processing of over 18 000 isotherms is used to explore the scale of uncertainty present in published adsorption data. Then, direct measurement of the differential enthalpy of adsorption using microcalorimetry is shown to be an excellent avenue of obtaining further insight into the contribution of guest-host and host-host interactions to the overall energetics of adsorption. Together, these methods are used to study some of the sources of the variability of MOFs, and quantify their effect. First, the impact of structural defects is investigated, through an alternative post-synthetic method of missing linker/cluster generation in the prototypical UiO-66(Zr) MOF. The processing of materials for their use in an industrial environment through shaping is another potential source of performance modification, which is here studied as the effect of wet granulation on three topical MOFs (UiO-66(Zr), MIL-100(Fe) and MIL-127(Fe)). Finally, counterintuitive behaviours intrinsic to ``soft'' porous crystals are investigated, where the structure itself is responsible for fluctuation in adsorption isotherms. A fundamental study on a copper paddlewheel based material, DUT-49(Cu) yields know-how on the source of adsorption induced compliance and its tunability through structural modification
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Starkie, Andrew John. "Calorimetric methods for the determination of kinetic and thermometric data for safe chemical manufacture." Thesis, London South Bank University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386234.

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3

Åberg, Jonas. "On the Experimental Determination of Damping of Metals and Calculation of Thermal Stresses in Solidifying Shells." Doctoral thesis, KTH, Materialvetenskap, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4038.

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This thesis explores experimentally and theoretically two different aspects of the properties and behaviour of metals: their ability to damp noise and their susceptibility to crack when solidifying. The first part concerns intrinsic material damping, and is motivated by increased demands from society for reductions in noise emissions. It is a material’s inherent ability to reduce its vibration level, and hence noise emission, and transform its kinetic energy into a temperature increase. To design new materials with increased intrinsic material damping, we need to be able to measure it. In this thesis, different methods for measurement of the intrinsic damping have been considered: one using Fourier analysis has been experimentally evaluated, and another using a specimen in uniaxial tension to measure the phase-lag between stress and strain has been improved. Finally, after discarding these methods, a new method has been developed. The new method measures the damping properties during compression using differential calorimetry. A specimen is subjected to a cyclic uniaxial stress to give a prescribed energy input. The difference in temperature between a specimen under stress and a non-stressed reference sample is measured. The experiments are performed in an insulated vacuum container to reduce convective losses. The rate of temperature change, together with the energy input, is used as a measure of the intrinsic material damping in the specimen. The results show a difference in intrinsic material damping, and the way in which it is influenced by the internal structure is discussed. The second part of the thesis examines hot cracks in solidifying shells. Most metals have a brittle region starting in the two-phase temperature range during solidification and for some alloys this region extends as far as hundreds of degrees below the solidus temperature. To calculate the risk of hot cracking, one needs, besides knowledge of the solidifying material’s ability to withstand stress, knowledge of the casting process to be able to calculate the thermal history of the solidification, and from this calculate the stress. In this work, experimental methods to measure and evaluate the energy transfer from the solidifying melt have been developed. The evaluated data has been used as a boundary condition to numerically calculate the solidification process and the evolving stress in the solidifying shell. A solidification model has been implemented using a fixed-domain methodology in a commercial finite element code, Comsol Multiphysics. A new solidification model using an arbitrary Lagrange Eulerian (ALE) formulation has also been implemented to solve the solidification problem for pure metals. This new model explicitly tracks the movement of the liquid/solid interface and is much more effective than the first model.<br>QC 20100929
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RIBEIRO, MARCOS S. "Sistema calorimétrico e software para análise da polimerização de compostos de metacrilato de metila, pela variação da exotermia da reação." reponame:Repositório Institucional do IPEN, 2013. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10583.

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Made available in DSpace on 2014-10-09T12:42:14Z (GMT). No. of bitstreams: 0<br>Made available in DSpace on 2014-10-09T14:04:44Z (GMT). No. of bitstreams: 0<br>Dissertação (Mestrado)<br>IPEN/D<br>Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Shamsadeen, B. N. "The accurate measurement of losses in small cage induction motors using a balance calorimetric method." Thesis, University of Liverpool, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316922.

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6

Zhao, Xing. "CURIE TEMPERATURE MEASUREMENT OF FERROMAGNETIC NANOPARTICLES BY USING CALORIMETRY." Wright State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=wright1421085560.

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7

Nowottny, Jonas [Verfasser]. "High-Pressure Calorimetry: Evaluation of Methods and Measurement of Heat Capacities / Jonas Nowottny." Düren : Shaker, 2021. http://nbn-resolving.de/urn:nbn:de:101:1-2021080805214165615907.

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8

Silva, Danilo Anacleto Arruda da. "Desenvolvimento de algoritmo de clusterização para calorímetro frontal do experimento ALICE no LHC." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-05122014-110857/.

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O Grande Colisor de Hádrons (Large Hadron Collider - LHC) é um acelerador de prótons e íons pesados localizado no CERN (Conseil Européen pour la Recherche Nucléaire). Em um de seus experimentos, ALICE (A Large Ion Collider Experiment ), está sendo projetado um detector dedicado a explorar os aspectos únicos de colisões núcleo-núcleo. A principal finalidade do ALICE é estudar a formação de um novo estado da matéria, o plasma de quarks e glúon. Para isto devem-se ter medidas precisas de hádrons, elétrons, múons e fótons produzidos em colisões chumbo-chumbo. Assim está sendo proposto um calorímetro frontal (Foward Calorimeter - FoCal) como um upgrade para o ALICE. A função deste calorímetro é o estudo das funções de distribuição de pártons (Partons distribuction Functions - PDF) no regime de pequenos valores do x de Bjorken. Nesta região é esperado que estas PDFs tenham um comportamento não linear devido ao processo de saturação de glúons. Para o estudo desta região é necessária a medida de fótons diretos produzidos na colisão. Estes, por sua vez, ficam mascarados pelo fundo de fótons provenientes do decaimento de píon, o que leva a uma necessidade de suas identificações. Com isto surge a oportunidade para a utilização do método de clusterização que é uma ferramenta de mineração de dados. Este trabalho contribuiu para o desenvolvimento inicial de um algoritmo de clusterização para o calorímetro FoCal.<br>The Large Hadron Collider (LHC) is a CERN\'s accelerator that collides protons and heavy ions. One of its experiments, ALICE, is building a new detector to explore new aspects of heavy ions collisions. The Alice\'s main goal is to study the formation of quark-gluon plasma (QGP). To do that it\'s necessary to get accurate data on hadrons, electrons, muons and gammas created in lead-lead collision. So, to accomplish that a new calorimeter is in study to scan the foward region of experiment, the Foward Calorimeter (FoCal). It\'s proposed to study Parton Distribution Functions (PDFs) in a regime of very small Bjorken-x, where it is expected that the PDFs evolve non-linearly due to the high gluon densities, a phenomena referred to as gluon saturation.But to do that it\'s required to measure the direct gammas created on collision. These fotons are blended on by fotons descendant of pion. So there\'s a need to separate it from the direct gammas. One way to solve this problem is to use clustering methods (a type of mining data algorithm). This work helped on early stages of development that clustering algorithm.
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9

Babaee, Koochaksaraee Sima, and Sara Ghahremanpour. "Using Design of Experiments in Validation of a new calorimetric method for the specific heat capacity determination." Thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-19555.

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Total Quality Management as a holistic management system is widely practical inevery organization these days and one of the foundations of TQM which should betaken into account in all functions of the company is continuous improvement.Customer satisfaction is an important topic in which continuous improvement play akey role and leads to enhance it. Therefore, it is very worthwhile for the organizationto define the designing new products/methods based on recent and future customerneeds as one of its main activities.Generally, during the development and before launching a new product/method,validation is a useful process to improve the quality and establish the qualification ofthat product/method.This project was conducted to perform a validation for a new calorimetric method byuse of DOE (Design Of Experiments) in “SP Technical Research Institute of Sweden”.The study have presented the results of implementing DOE in such a way that thenew calorimetric method is validated; besides it could determine the best condition inwhich the intended results could be achieved.This thesis is a completion part of the master program in Industrial Engineering with aspecialization in Quality and Environmental Management at University of Borås.
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Bracewell, Kathryn Vanessa. "An exploration of new methods to assess energy availability in the English oak (Quercus robur)." Thesis, Cranfield University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.323884.

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11

Metcalf, Kristen M. "Accelerometer positioning issues and contemporary analysis methods." Diss., University of Iowa, 2018. https://ir.uiowa.edu/etd/6210.

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Purpose: Accelerometry is commonly used to objectively measure physical activity (PA), however, differential data collection methods and analysis techniques yield dissimilar outcomes. The aims of this research were to (1) understand how accelerometer output varies among accelerometers worn on the non-dominant wrist (NDW), dominant wrist (DW), and hip; (2) develop site-specific algorithms to predict activity type classification, activity intensity classification, and estimates of metabolic intensity; and (3) compare the algorithms in a free-living setting. Methods: Forty participants (16.8 – 64.2 yr) completed a sequence of sedentary and physical activities in a laboratory while wearing accelerometers on the NDW, DW, and hip. Participants also wore a portable metabolic analyzer to objectively measure oxygen consumption (VO2). One-second accelerometer output was compared across wear locations by activity type and intensity classifications (Aim 1). Accelerometer output data were transformed into variables related to the magnitude (ϒ), horizontal angle (φ), and inclination (θ) of acceleration, and used to develop algorithms for the NDW, DW, and hip. Random forest algorithms were developed to predict activity type classification (i.e., sedentary, lifestyle, and ambulatory) and activity intensity classification (i.e., sedentary, light, moderate, and vigorous), and regression models were built to predict VO2 (Aim 2). Following the laboratory visit, participants simultaneously wore an accelerometer at each of the three locations for three days of free-living data collection. The site-specific algorithms developed in Aim 2 were compared for equivalence (Aim 3). Aim 1 Results: Analysis of variance indicated that accelerometer output differed between the NDW, DW, and hip for all activities completed, except for lying supine. Differences were expected; thus, Pearson correlation coefficients were calculated between the NDW, DW, and hip, and compared across activity type and intensity classifications. For activity type, the relationships between all wear locations were different for all activity types (i.e., sedentary, lifestyle PA, and ambulatory PA). For activity intensity, the relationships between the wrists were significantly different between sedentary and light activities. Additionally, relationships between the NDW, DW, and hip differed between light and moderate, and light and vigorous PA for all wear locations. The disparate correlations indicated that accelerometer signals do not just increase in magnitude as intensity increases; rather they increase differentially by wear location and activity type. Aim 2 Results: Site-specific random forest algorithms were developed to predict activity type and intensity classification. The algorithms utilized 10-15 features of the accelerometer signal related to variability, location, and central tendency. The hip had prediction accuracies of 84.9% for activity type classification and 80.2% for activity intensity classification. The dominant wrist had activity type prediction accuracy of 83.6% and intensity prediction accuracy of 78.9%. The non-dominant wrist had prediction accuracies of 83.1% and 78.0% for activity type and intensity, respectively. The VO2 prediction algorithms had Mean Absolute Errors of 2.96 ml/kg/min for the hip, 3.34 ml/kg/min for the NDW, and 3.49 ml/kg/min for the DW. This equates to an average error of 0.93 metabolic equivalents (METs); algorithms currently used in practice yield errors of 0.89 to 2.00 METs. Aim 3 Results: The site-specific prediction algorithms were applied to free-living data. Using the random forest algorithms, activity type classification estimates differed by 2 to 82 minutes/day, and activity intensity classification estimates differed by 0 to 83 minutes/day; however, these differences were not significantly different. The VO2 prediction models provided estimates of PA within 0 to 57 minutes/day of one another. The hip provided the lowest estimates of MVPA, while the NDW provided the highest estimates, however the VO2 estimates from all wear locations were statistically equivalent to one another. Conclusion: The differential relationships among accelerometer outputs from the NDW, DW, and hip indicate that output differs based on activity type and intensity. This non-systematic error prevents scaling or comparing data collected at different wear locations and supports the need for site-specific analysis methods. Site-specific prediction algorithms provided comparable to improved performance over currently-utilized analysis methods in PA research, and the PA estimates were equivalent across wear locations. This research provides a more nuanced understanding of the impact of wear location on accelerometer output and alternative methods for analysis. Importantly, the algorithms created allow for comparisons to be made among data collected at the NDW, DW, and hip, which has not previously been possible.
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Hoyle, N. D. "The characterisation of the adsorptive and catalytic properties of supported platinum metal catalysts by methods including differential scanning calorimetry." Thesis, Brunel University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370135.

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13

Liang, Changnian. "A new surface resistance measurement method with ultrahigh sensitivity." Diss., Virginia Tech, 1993. http://hdl.handle.net/10919/40299.

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A superconducting niobium triaxial cavity has been designed and fabricated to study residual surface resistance of planar superconducting materials. Unlike many other structures where the test samples are placed in strong magnetic field positions, the edge of a 25.4 mm or larger diameter sample in the triaxial cavity is located outside the strong field region. Therefore, the edge effects and possible losses between the thin film and the substrate have been minimized in this design, ensuring that the induced RF losses are intrinsic to the test material. The fundamental resonant frequency of the cavity is 1.5 GHz, the same as the working frequency of CEBAF cavities. The cavity has a compact size compared to its TE₀₁₁ counterpart, which makes it more sensitive to the sample's loss.<br>Ph. D.
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Tukaew, Panyawat. "Outdoor Gas Emission Sampling System: A Novel Method for Quantification of Fires in Outdoor Conditions." Digital WPI, 2017. https://digitalcommons.wpi.edu/etd-theses/656.

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This study presents the design, construction and testing of an Outdoor Gas Emission Sampling (OGES) System capable of gas sampling and calorimetry in outdoor conditions with wind. In large-scale, outdoor fire tests, wind-driven emission plumes present a challenge in heat release rate quantification because the emission plume rises upward at an angle. A new gas sampling system with a flexible hood design and smaller control volume has been designed and tested. Bulk flow rate, oxygen, carbon dioxide, and carbon monoxide concentrations are measured for heat release rate calculations. Two stages of experimentation are described. Experiments at intermediate-scale (indoor only) that were conducted to evaluate the performance of a smaller control volume for measurements, and large-scale (indoor and outdoor) experiments, to demonstrate feasibility in realistic field conditions as well as the new flexible hood design. Experiments show that the OGES system is capable of calculating the heat release rate of pool fires with an accuracy of 23% using oxygen consumption (OC) and carbon dioxide generation (CDG) methods. Further improvements of the OGES system for outdoor field deployment are also discussed.
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Velásquez, Armijo Cristián Jesús. "Aplicação de métodos termo-analíticos e espectroscóspicos na avaliação do comportamento do fármaco isoniazida frente a adjuvantes tecnológicos." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2003. http://hdl.handle.net/10183/144233.

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Os métodos termo-analíticos são ferramentas úteis na avaliação da compatibilidade entre fármacos e adjuvantes, com destaque à calorimetria exploratória diferencial. Neste trabalho foram avaliados a compatibilidade e o comportamento térmico entre a isoniazida e adjuvantes tecnológicos primários usualmente empregados em formas farmacêuticas sólidas. A compatibilidade foi examinada por meio da preparação de misturas físicas binárias do tipo fármaco/adjuvante. Foi investigada também a influência da granulação por via úmida e do processo de compactação para as misturas de isoniazida e adjuvantes com função de material de enchimento e carga e deslizante. A isoniazida apresentou um comportamento térmico não encontrado na literatura. Os adjuvantes avaliados foram: ácido esteárico, amido, celulose microcristalina, crospovidona, croscarmelose sódica, dióxido de silício coloidal estearato de magnésio, glicolato de amido sódico, hipromelose, lactose, manitol, polidona e talco. Para as misturas físicas, a maioria dos adjuvantes mostrou-se compatível com o fármaco em questão. Foram verificadas interações com o ácido esteárico, o glicolato de amido sódico, a lactose, o manitol e a povidona. A isoniazida mostrou a formação de uma mistura eutética com o manitol e de interação química com a lactose. A agregação por via úmida e o processo de compactação não mostraram influências adicionais na compatibilidade das misturas avaliadas. Os resultados observados foram confirmados por métodos não-térmicos como difratometria de raios X, espectroscopia de infravermelho e ressonância nuclear magnética.<br>Thermo-analytical methods, and specially Differential Scanning Calorimetry, are useful support for the evaluation of compatibility between drug substances and pharmaceutical excipients. In this work were studied the compatibility and the thermal behavior of isoniazid and pharmaceutical excipients, commonly used for the formulation of solid dosage forms. Colloidal silicon dioxide, corn starch, crospovidone, hypromellose, lactose, magnesium stearate, mannitol, microcrystalline cellulose, povidone, sodium croscarmellose, sodium starch glycolate, stearic acid and talc were the excipients employed in these experiments. The compatibility was analyzed testing binary physical drug/excipient admixtures. The effect of wet granulation and compression was also investigated, in this case especially between isoniazid, fillers and lubricant. For almost all excipients no incompatibilities with isoniazid were observed. Interactions were detected when the drug substance was added to stearic acid, sodium starch glycolate, lactose, mannitol and povidone. Isoniazid formed a euthetic mixture with mannitol, whereas a possible chemical reaction occurred between isoniazid and lactose. Wet granulation and compaction of the tested admixtures did not affect the results observed above. These observations were confirmed by non-thermal techniques, such as X-Ray diffractometry, infrared spectroscopy and nuclear magnetic resonance.
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Moskalenko, Cendrine. "Étude des transitions de phases de fluides confinés dans le silicium poreux : mesures par calorimétrie différentielle et diffraction haute résolution des rayons X." Université Joseph Fourier (Grenoble ; 1971-2015), 1998. http://www.theses.fr/1998GRE10150.

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La propriete originale du silicium poreux d'etre a la fois nanoporeux et monocristallin nous a permis d'obtenir des informations nouvelles en utilisant la diffraction des rayons x. Les resultats concernent l'etude structurale des couches de type p#+ formees sur un substrat oriente (111), la mesure du coefficient de dilatation thermique du silicium poreux et les deformations induites par la presence de cds dans les pores. La deuxieme motivation de cette these concernait l'etude plus fondamentale des changements de phases de fluides confines dans le silicium poreux. Du point de vue du fluide, la calorimetrie differentielle a ete utilisee pour mesurer les decalages en temperature des transitions de phases, lies aux effets de confinement. Un modele decrivant les mecanismes thermodynamiques de la transition confinee et tenant compte de la geometrie des pores, a permis de bien decrire les resultats experimentaux et de deduire la distribution de tailles des pores. Ce travail a pu etre applique a differents effets tels que la dissolution chimique ou l'homogeneite des couches. Du point de vue de la matrice poreuse, les deformations induites par les transitions liquide-vapeur et solide-liquide du fluide confine ont ete mesurees in situ par diffraction des rayons x. Dans le cas de l'adsorption, la valeur de la pression de vapeur correspondant a une amplitude de deformation maximale a ete mesuree et reliee a la taille des pores par l'equation de kelvin. En considerant les proprietes elastiques du silicium poreux, les contraintes capillaires induites par la presence de menisques dans les pores ont ete estimees lors de l'evaporation, et les resultats ont pu etre appliques au probleme du sechage de couches tres poreuses. D'autre part, la construction au cours de ma these d'un nouveau diffractometre a permis de mesurer in situ des deformations de la couche poreuse lors de la solidification du fluide organique au sein des pores, liees a l'existence de contraintes capillaires.
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Fischer, Sabine. "Charakterisierung von exothermen Zersetzungsreaktionen mit thermoanalytischen und numerischen Methoden." Tönning Lübeck Marburg Der Andere Verl, 2008. http://d-nb.info/988248646/04.

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Gundogar, Sati Asli. "Thermal Characterization And Kinetics Of Crude Oils By Tga And Dsc Methods." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12611502/index.pdf.

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In recent years, the application of thermal analysis to study the combustion and pyrolysis behavior of fossil fuels has gained a wide acceptance because of its significance for industry and economy. In this thesis, the thermal and kinetic analysis of different origin crude oil samples are performed by two well-known thermal analysis techniques: Differential Scanning Calorimetry (DSC) and Thermogravimetry (TG/DTG). The investigation of combustion and pyrolysis behaviors, kinetic analysis of oil samples and the determination of heating rate effect are the main objectives of this study. Six different crude oils from the Southeastern region of Turkey are analyzed throughout the study. All experiments are performed at different heating rates (5, 10 and 15&ordm<br>C/min) and air is used for combustion and nitrogen for pyrolysis experiments. In combustion experiments, TGA and DSC techniques indicate that the combustion process of crude oils studied is composed of two main reaction regions. These are low-temperature (LTO) and high-temperature oxidation (HTO) regions. In LTO, huge mass loss occurs (from 69 to 87 %) due to high amount of free moisture and volatile hydrocarbons contained in oil samples. Combustion reactions continue up to 900 K. On DSC curves, two exothermic regions of oxidation regimes are detected. Comparing TG/DTG and DSC curves, it can be understood that the mass loss under combustion is accompanied by exothermic peaks because of the oxidative degradation of crude oil components. As in combustion, two distinct reaction regions are revealed under pyrolysis for all samples. The first region indicates distillation and the second one is due to thermal cracking reactions occur at high temperatures and completed up to 840 K. As expected, lighter crude oils have relatively higher amounts of mass loss in distillation region as compared to heavier ones. Besides, residue amount and burn-out temperatures are higher for heavier oils with higher asphaltene content in cracking region. DSC curves for both reactions show endothermic effects. In combustion and pyrolysis experiments, it is noticed that higher heating rates are resulted in higher reaction regions. Distinguishing peaks of samples shift to higher temperatures with an increase in heating rate. Heat of reaction amount under DSC curves is related to asphaltene content and &amp<br>#730<br>API gravity of crude oils. It is deduced that, when &amp<br>#730<br>API gravity of crude oils decreases, the heat value of this reaction increases. The kinetic parameters are evaluated by different kinetic models and mean activation energies (Em) of samples are obtained. At the end, a correlation is established between Em and &amp<br>#730<br>API gravity of oil samples. It is concluded that heavier oils have higher activation energy and Arrhenius constant values for each reaction region. Besides, it is proved that the activation energy is mostly insensitive to the heating rate.
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Perrodo, Pascal. "Etude du calorimètre à argon liquide de l'expérience H1 à HERA : simulation rapide des gerbes produites par les hadrons dans un calorimètre, et étude des méthodes de pondération pour la mesure de l'énergie initiale des hadrons." Palaiseau, Ecole polytechnique, 1988. http://www.theses.fr/1988EPXX0003.

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Gul, Kiymet Gizem. "Thermal Characterization And Kinetic Analyis Of Sara Fractions Of Crude Oils By Tga And Dsc Methods." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613614/index.pdf.

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In this thesis, four different crude oil samples and their saturate, aromatic and resin fractions were analyzed by two different thermoanalytical methods, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The experiments were performed at three different heating rates (5, 10 and 15 &deg<br>C/min) under air atmosphere. Same gas flow rate and same pressure were applied to all samples. The aim is to determine the kinetic analysis and combustion behavior of crude oils and their fractions and also determining the effect of heating rate on all samples. For all samples two main reaction regions were observed in thermogravimetry (TG), differential thermogravimetry (DTG) and DSC curves due to the oxidative degradation of crude oil components. It was deduced that the free moisture, volatile hydrocarbons were evaporated from the crude oils, light hydrocarbons were burned and fuel was formed in the first reaction region. The second reaction region was the main combustion region where the fuel was burned. From the TGA curves, it was detected that the heavier fraction, resins, lost considerable amounts of their initial mass, approximately 35%, while saturates lost only approximately 3% of their initial mass in the second reaction region. DSC curves of the samples were also examined and observed that as the sample got heavier, the heat of the reaction increased. Saturates, lightest part of the crude oil fractions, gave minimum heat of reaction. As the heating rate increased, shift of peak temperatures to high values and higher reaction regions were observed. The kinetic analysis of crude oils and their fractions were also performed using different kinetic methods. Activation energies (E), mean activation energies (Emean) and Arrhenius constants were found for crude oils and fractions. It was deduced that the resins gave the highest activation energy and Arrhenius constant for both reaction regions. Moreover, it was encountered that heating rate has no effect on activation energies.
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21

Mouloudj, Noureddine. "Contribution à l'étude des propriétés thermodynamiques des alliages liquides selenium-tellure : relations avec les propriétés structurales." Paris 13, 1987. http://www.theses.fr/1987PA132012.

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On mesure l'activité du tellure en fonction de la température et de la concentration, à partir des mesures de F. E. M. On en déduit l'enthalpie libre de formation d'alliages se-te. On détermine également l'enthalpie molaire de mélange à 623, 673 et 733k. Influence de la coordinence sur ces propriétés thermodynamiques
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22

Brito, Neto Francisco Maciel de, and 92-98270-0137. "Síntese de Ortoniobatos de Samário (SmNbO4) polimórficos por moagem de alta energia." Universidade Federal do Amazonas, 2018. https://tede.ufam.edu.br/handle/tede/6532.

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Submitted by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2018-08-06T15:17:49Z No. of bitstreams: 1 DISSERTAÇÃO-Francisco Maciel de Brito Neto PPGCEM.pdf: 4657821 bytes, checksum: bfb975014ce10e6a646fdd1c54e9758b (MD5)<br>Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2018-08-06T15:18:13Z (GMT) No. of bitstreams: 1 DISSERTAÇÃO-Francisco Maciel de Brito Neto PPGCEM.pdf: 4657821 bytes, checksum: bfb975014ce10e6a646fdd1c54e9758b (MD5)<br>Made available in DSpace on 2018-08-06T15:18:13Z (GMT). No. of bitstreams: 1 DISSERTAÇÃO-Francisco Maciel de Brito Neto PPGCEM.pdf: 4657821 bytes, checksum: bfb975014ce10e6a646fdd1c54e9758b (MD5) Previous issue date: 2018-05-17<br>CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico<br>Samples of samarium oxide (Sm2O3) and niobium oxide (Nb2O5) were submitted to Mechanical alloying technique and their structural evolution was accompanied by x-ray diffraction (XRD) measurements. In a few hours of milling SmNbO4 crystals were identified with two polymorphisms, one monoclinic and the other tetragonal. The diffractograms were simulated by Rietveld method and all crystallographic parameters were obtained, as well as the respective amounts of phases. The average crystallite sizes were estimated by the single-line method, indicating that both polymorphs have nanosized dimensions, that is, they are nanostructured. Combining calorimetric measurements, thermal treatments and x-ray diffraction the structural stability of the samples was studied. It was observed that the monoclinic structure undergoes phase transition to tetragonal structure in an exothermic process around 850 °C. The energy needed to promote the process was obtained by the Kissinger method and the XRD measurements indicate that the transition is irreversible.<br>Amostras de óxido de samário (Sm2O3) e óxido de nióbio (Nb2O5) foram submetidas à técnica moagem mecânica de alta energia e sua evolução estrutural foi acompanhada por medidas de difração de raios X (DRX). Em poucas horas de moagem foram identificados cristais de SmNbO4 com dois polimorfismos, um monoclínico e outro tetragonal. Os difratogramas foram simulados por método de Rietveld e todos os parâmetros cristalográficos foram obtidos, assim como as respectivas quantidades de fases. Os tamanhos médios de cristalitos foram estimados pelo método da linha única (single-line) indicando que ambos polimorfos possuem dimensões nanométricas, ou seja, são nanoestruturados. Combinando medidas calorimétricas, tratamentos térmicos e difração de raios x a estabilidade estrutural das amostras foi estudada. Foi observado que a estrutura monoclínica sofre transição de fase para estrutura tetragonal em um processo exotérmico em torno de 850°C. A energia necessária para promover o processo foi obtida pelo método de Kissinger e as medidas de DRX indicam que a transição é irreversível.
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23

HILDESHEIM, WOLFGANG. "Introduction d'une nouvelle methode de simulation des calorimetres. Application a l'etude de la mesurabilite de la fonction de structure f#2 du proton dans l'experience h1 aupres de hera." Paris 7, 1993. http://www.theses.fr/1993PA077061.

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Dans une simulation ordinaire d'un calorimetre l'energie n'est pas conservee, c'est-a-dire la somme sur toutes les energies deposees n'est pas egale a l'energie initiale. Ici un nouveau mode de simulation, appele les energies calibrees, qui conserve l'energie, est propose pour les calorimetres de l'experience h1 aupres du collisionneur electron-proton hera. Ce mode correspond a une comptabilite parfaite des energies deposees ce qui est particulierement interessant pour un calorimetre non-compense. Sa realisation et ces avantages pour le developpement de la reconstruction et pour l'analyse physique sont presentes. Ensuite une application des energies calibrees a l'etude de la mesurabilite de la fonction de structure f#2 du proton aupres de hera est discutee
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24

Wang, Wenhu. "Effect of Fullerene Nano-spheres on Evaporation Kinetics of Fluids." Wright State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=wright1323918423.

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25

Amari, Djilali. "Calorimétrie d'adsorption de CO2 et C2H4 dans une zéolite de type A échangée." Grenoble INPG, 1990. http://www.theses.fr/1990INPG0079.

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L'etude structurale et texturale (diffraction des rayons x, microscopie electronique a balayage et adsorption de gaz), de zeolites a echangees, a montre que la presence des cations nickel ou cuivre dans le reseau zeolitique, entraine une instabilite structurale au-dela de trois cations sodium echanges par maille. Par contre, les cations lithium, cobalt et zinc ont peu d'influence sur la cristallinite quand ils remplacent les cations sodium. La calorimetrie d'adsorption montre que le dioxyde de carbone est chimisorbe sous forme de carboxylates bidentates sur un nombre de sites tres limites (moins de 0,3 par maille), aussi bien avec naa originale qu'avec linaa. Ce nombre de sites diminue progressivement par echange avec des cations divalents et tend vers zero quand plus de deux cations sodium sont remplaces. Lors de l'adsorption de l'ethylene, par contre, c'est l'introduction des cations divalents dans le reseau zeolitique qui fait apparaitre des relativement fortes chaleurs. Celles-ci augmentent avec le taux d'echange mais n'interessent qu'un nombre de sites tres inferieur au nombre de cations divalents presents par maille. Ces fortes chaleurs sont dues a une polarisation plus importante des electrons delocalises de la double liaison carbone-carbone
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26

García, Romero Iván. "Kombinatorische Methoden zur Bestimmung der chemischen Heterogenität und der Phasenseparation von statistischen Copolymeren." [S.l.] : [s.n.], 2006. http://elib.tu-darmstadt.de/diss/000754.

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27

Amorim, Paulo Roberto dos Santos. "Energy expenditure and physical activity patterns in children : applicability of simultaneous methods." Queensland University of Technology, 2007. http://eprints.qut.edu.au/16692/.

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Consistently, reports in the literature have identified that a sedentary lifestyle contributes to the progression of a range of chronic degenerative diseases. The measurement of energy expenditure and physical activity pattern in children is a challenge for all professionals interested in paediatric health and from a broader perspective, the public health fraternity charged with considering longer term health consequences of physical inactivity. The primary objective of this thesis was to identify a suitable indirect and objective measurement technique for the assessment of energy expenditure and physical activity pattern in children. The ideal characteristics of such a technique are that it should be reproducible and have been validated against a criterion reference method. To achieve this goal, a series of methodological studies were undertaken (Chapters II and III). This work was essential to increase accuracy during the individualised laboratory calibration process and further minimise prediction errors when analysing data from 7 days of monitoring under free-living conditions in the second part of the study (Chapters IV and V). In the first study to verify the combined effect of body position, apparatus and distraction on children's resting metabolic rate (RMR), experiments were carried out on 14 children aged 8-12 (mean age = 10.1 years ± 1.4). Each participant underwent 2 test sessions, one week apart under three different situations: a) using mouthpiece and nose-clip (MN) or facemask (FM); b) sitting (SEAT) or lying (LY) and c) TV viewing (TV) or no TV viewing. In the first session, following 20 min rest and watching TV, the following protocol was used: LY: 20 min - stabilisation; 10 min using MN and 10 min using FM. Body position was then changed to seated: 20 min stabilisation; 10 min using FM; 10 min using MN. In the second session, FM and MN order was changed and participants did not watch TV. Data were analysed according to the eight combinations among the three studied parameters. Repeated measures ANOVA indicated statistically significant differences for &VO2 (p=0.01) and RMR (p=0.02), with TVMNSEAT showing higher values than TVFMLY. Bland-Altman analysis showed a bias for &VO2, &VCO2, RQ and RMR between TVFMLY and TVMNSEAT of -17.8±14.5 ml.min-1, -8.8±14.5 ml. min-1, 0.03±0.05 and -115.2±101.9 kcal.d-1, respectively. There were no differences in RMR measurements due to body position and apparatus when each variable was isolated. Analyses of distraction in three of four combinations indicated no difference between TV and no TV. In summary, different parameter combinations can result in increased bias and variability and thereby reported differences among children's RMR measurement. The second study dealt with treadmill adaptation and determination of self-selected (SS) walking speed. Assessment of individual and group differences in metabolic energy expenditure using oxygen uptake requires that individuals are comfortable with, and can accommodate to, the equipment being utilised. In this study, a detailed proposal for an adaptation protocol based on the SS was developed. Experiments were carried out on 27 children aged 8-12 (mean age = 10.3±1.2 yr). Results from three treadmill tests following the adaptation protocol showed similar results for step length with no significant differences among tests and lower and no statistically significant variability within- and between-days. Additionally, no statistically significant differences between SS determined over-ground and on a treadmill were verified. These results suggest that SS speed determined over-ground is reproducible on a treadmill and the 10 min familiarisation protocol based on this speed provided sufficient exposure to achieve accommodation to the treadmill. The purpose of the third study was to verify within- and between-day repeatability and variability in children's oxygen uptake ( &VO2), gross economy (GE) [ &VO2 divided by speed] and heart rate (HR) during treadmill walking based on SS. 14 children (mean age = 10.2±1.4 yr) undertook 3 testing sessions over 2 days in which four walking speeds, including SS, were tested. Within- and between-day repeatability was assessed using the Bland and Altman method and coefficients of variability (CV) were determined for each child across exercise bouts and averaged to obtain a mean group CV value for &VO2, GE and HR per speed. Repeated measures ANOVA showed no statistically significant differences in within- or between-day CV for &VO2, GE or HR at any speed. Repeatability within and between-day for &VO2, GE and HR for all speeds was verified. These results suggest that submaximal &V O2 during treadmill walking is stable and reproducible at a range of speeds based on children's SS. In the fourth study, the objective was to establish the effect of walking speed on substrate oxidation during a treadmill protocol based on SS. Experiments were carried out on 12 girls aged 8-12 (mean age = 9.9±1.4 yr). Each participant underwent 2 test sessions, one week apart. Workloads on the treadmill included 2 speeds slower than SS (1.6 [V1] and 0.8 km.h-1 [V2] slower than SS), SS (V3), and a speed 0.8 km.h-1 faster than SS (V4). Indirect calorimetry from respired gas measurements enabled total fat (FO) and carbohydrate (CHO) oxidation rates to be calculated according to the non-protein respiratory quotient (Peronnet and Massicote, 1991) and percentage of CHO and FO calculations using equations from McGilvery and Goldstein (1983). Repeated measures ANOVA followed by a Tukey Post Hoc test (p< 0.05) was used to verify differences in CHO and FO rates among speeds. Paired T-test was used to verify differences in CHO and FO rates between tests per velocity. The reliability between-day was assessed using intraclass correlation coefficient (ICC). Results showed significant differences for CHO among all speeds, as well as significant differences for FO between V1 and V2 against V3 and V4 in both tests. Analyses between trials per velocity showed no significant substrate use differences as well as acceptable reliability. At the self-selected speed (V3) there was an accentuation in FO reduction as well as an increase in CHO oxidation. The purpose of the fifth study was to determine whether there were differences in substrate oxidation between girls (G) and women (W) during a treadmill protocol based on SS. Experiments were carried out on 12 G aged 8-12 (mean age = 9.9±1.4 yr) and 12 W aged 25-38 (mean age = 32.3±3.8 yr). The treadmill protocol included 6 min workloads followed by 5 min rest periods. Workloads included 2 speeds slower than SS (1.6 (V1) and 0.8 km.h-1 (V2) slower than SS), SS (V3), and a speed 0.8 km.h-1 faster than SS (V4). Total fat and carbohydrate (CHO) oxidation rates were calculated from indirect calorimetry according to the non-protein respiratory quotient. Repeated measures ANOVA followed by a Tukey Post Hoc test was used to verify intra-test differences in CHO and fat oxidation rates among speeds. Intergroup differences were analysed using paired T-test. Fat utilisation in W achieved a plateau at a relative velocity 0.8 km.h-1 slower than SS, but for G, fat utilisation increased until SS, and then stabilised upon reaching the higher velocity. CHO oxidation curves rose abruptly above V2 for W, while for G the acute increase occurred after SS (V3). Collectively, these results indicate that as walking intensity increases G are able to meet the energy demands of the work by increasing fat oxidation together with the increased CHO oxidation up to SS. In contrast for W, increasing CHO oxidation is associated with an early decrease in fat utilisation at a velocity slower than the self-selected speed. The sixth study dealt with validation of indirect techniques for the measurement of energy expenditure in free-living conditions against the DLW technique. Experiments were carried out on 19 children aged 8-12 (mean age = 10.3±1.0 yr). To indirectly predict energy expenditure 12 different procedures were used. Only one procedure, combining activity and heart rate (AHbranched), was based on a group equation, the others were based on individualised regression. Three of the individually-based techniques were able to accurately predict energy expenditure in free-living conditions. These tecniques were HRPAnetRMR using HRnet [HR exercise minus sleep HR (SHR)] against PAnet (measured PA exercise minus measured RMR) and upper and lower body equations corrected by RMR; HRPAnet4act using the same procedure but corrected by the mean resting &VO2 for 4 resting activities [(4act) = supine watching TV, sitting watching TV, sitting playing computer games and standing], and HRPALBnet4act using only lower body activities and corrected by 4act. HRPAnetRMR was only slightly more accurate than HRPAnet4act and HRPALBnet4act, but this technique is only adjusted by RMR whereas the other two are heavily dependent on more complex laboratory calibration. Bland and Altman (1986) analyses showed no significant differences between AHbranched predicted and measured TEE using the DLW technique. A SEE of 79 kcal.d-1 and a mean difference of 72 kcal.d-1, with a 95% CI ranging from -238 to 93.9 kcal.d-1 was found. In addition, no significant differences between predicted HRPAnetRMR and measured TEE using DLW were found, showing an SEE of 99 kcal.d-1 and a mean difference of -67 kcal.d-1, and a 95% CI ranging from -276.6 to 141.9 kcal.d-1. AHbranched and HRPAnetRMR were both valid and similarly suitable for the prediction of energy expenditure in children under free-living conditions. Significant associations between DLWAEE and the after-school time window indicated that this time window as an important discretionary period representative of children physical activity. However, the duration of the after-school time windows should be more carefully considered. Accelerometer data showed a better association between the largest after-school time window (3.5 hr) and measured TEE. The final study, completed with 19 children aged 8-12 (10.3±1.0 yr) highlighted, under laboratory conditions across a range of walking and running speeds, the inadequacy of the use of the standard MET in children. This traditional approach overestimates energy expenditure with an increased difference linearly related to speed increments. Minute-by-minute analyses of 7 days of free-living monitoring showed an average overestimation of 64 minutes per day for moderate-to-vigorousphysical- activity (MVPA) using the standard MET compared with the individually measured MET. For all intensities, these differences were statistically significant (p< 0.001). The second part of this study showed a variability of 20% in the average time spent at MVPA when comparing HR I 140 bpm and HR > 50%P &VO2 (P &VO2 = the highest &VO2 observed during an exercise test to exhaustion). Results of the current study compared to observations in the literature showed that HR I 140 bpm consistently estimates lower MVPA time than HR > 50%P &VO2. When these two PA indices were compared with individual and standard MET measured minute-byminute, statistically significant differences were verified among all of them at MPA, but no differences were verified at VPA, except between individual and standard METs. However, whether each one of the PA indices used are under- or overestimating time at MVPA is still debatable due to the lack of a gold standard. Finally, each index used in this study classified different numbers of participants as achieving the PA target of 60 min.d-1. The wide variability between indices when attempting to classify children who are achieving the recommended target is cause for great concern because habitually these indices are utilised as screening tools in paediatric and public health settings and used to guide behavioural interventions.
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28

Pitani, Lavanya. "SOLUBILITY ENHANCEMENT OF MODEL COMPOUNDS." Scholarly Commons, 2017. https://scholarlycommons.pacific.edu/uop_etds/2985.

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Solubility is the amount of solute in the solvent system at phase equilibrium with certain temperature and pressure. Many of the new chemical entities are lipophilic molecules that require techniques to enhance solubility. Solubility enhancement can be achieved by either physical and/or chemical modification of the drug. Various techniques are available for solubility enhancement of poorly soluble drugs include particle size reduction, salt formation, solid dispersions, use of surfactants, prodrug, crystal modification, etc. In this study, the three model drugs belong to BCS class II and IV having low solubility with a certain range of physicochemical properties were studies in solubility enhancement using fusion method, co-precipitation, nano-milling and spray drying techniques. The two different polymers employed for solubility enhancement are PEG 8000 and PVP 40,000. Solubility was determined by Shake Flask method at the temperature of 37±0.1 °C. The objective is to investigate the enhancement of solubility of the three model drugs namely Glipizide, Carvedilol and Furosemide in 1:1, 1:5 and 1:10 drug-polymer ratios and are characterized by Differential Scanning Calorimetry (DSC). The Solubility of Glipizide was enhanced from 11.18 ± 1.78 µg/ml to 35.73 ± 0.04 µg/ml by 219 % increase with nano-milling technique at 1:5 ratio with PEG 8000 as carrier whereas with PVP 40000 as carrier, 286 % increase in solubility to 43.26 ± 7.87 µg/ml was observed at 1:1 ratio by fusion method. The solubility of Carvedilol was enhanced from 5.04 ± 0.55 µg/ml to 17.51 ± 0.94 µg/ml by 246 % at 1:5 ratio by fusion method with PEG8000 as carrier and 2924 % enhancement in solubility to 152.70 ± 9.09 µg/ml at 1:10 ratio by nano-milling with PVP40000 as the carrier. Furosemide showed an increase in solubility from 55.94 ± 2.48 µg/ml to 164.11 ± 9.18 µg/ml by 193 % at 1:10 ratio by nano-milling technique with PEG8000 as carrier whereas with PVP40000 as carrier, 444 % increase was observed at 1:1 ratio by nano-milling technique with solubility of 304.52 ± 23.11 µg/ml. The data showed that the decrease in percentage crystallinity and enthalpy of fusion of the model drugs upon implementing solubility enhancement techniques with the effect of particle size and the carrier used resulted in the increase of aqueous solubility of the model drugs.
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29

Sjöstrand, Linda. "Method Development for Thermal Stability Analysis by Circular Dichroism : Application to the Abp1p SH3 domain from yeast." Thesis, Linköpings universitet, Kemi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-148286.

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Thermal stability is an important and interesting physical property of proteins. A common method to study it by is circular dichroism (CD) spectroscopy. The aim of this study was to test methods to improve thermal stability analysis by CD spectroscopy. Experiments were performed using the Abp1p SH3 domain from yeast as a model protein. Thermal denaturation was monitored at multiple wavelengths. It was concluded that for data sets of reasonable quality the choice of wavelength does not affect the results. An approach to estimate stability of thermophilic proteins was tested where thermal stability was measured at different concentrations of the denaturant GuHCl. The thermochemical data was used to estimate the stability in absence of GuHCl by extrapolation. The results were compared to those obtained from CD spectroscopy and differential scanning calorimetry. It was found that a stabilizing effect from low concentrations of GuHCl complicated the extrapolation. It is likely that this method is more successful if there is no stabilizing effect. The effect of ΔCp in stability parameter calculations was investigated with an experimentally and theoretically determined ΔCp. This was further investigated with synthetic data sets. The ΔCp used in calculations had no notable effect, as long as there was no cold denaturation. Although ΔCp is not necessary in calculations, it is an interesting parameter itself. ΔCp can be calculated from the thermochemical data used for extrapolation. The results in this study demonstrate robustness in thermal stability analysis by CD spectroscopy and a potential for development.
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30

Němečková, Lenka. "Hodnocení stability vybraných rostlinných olejů." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2010. http://www.nusl.cz/ntk/nusl-216588.

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This diploma thesis is focused on issues concerning the stability of selected vegetable oils which are used in cosmetic industry. The stability of eight oils without additives were determined by a differential scanning calorimeter. In the first phase, the temperatures of oil degradation were determined for different rates of heating, i.e. nonisothermal stabilities. They were consequetly used to calculate isothermal stabilities alias induction periods. The calculation of induction periods was completed by using integral isoconversional methods, which applied four different temperature functions. One of the temperature functions corresponded to Arrhenius equation while the others to non-Arrhenius functions. The confrontation of induction periods under standart conditions showed that an optimal temperature function to calculate oil stabilities is one of the non-Arrhenius functions in exponential form. We can state that all oils are degraded by similar, if not the same, mechanism. The specified stabilities, in periods of months, have proved the importance of using stabilizers and other additives in the commercial and technological use of vegetable oils.
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31

Ivanova, Vesselka Petrova. "Theoretical and experimental study of protein lipid interactions." Doctoral thesis, [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=961248726.

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32

Barale, Sébastien. "Étude des procédés de synthèse et des modes d’action de produits pétroliers tels que les lubrifiants et les graisses." Thesis, Nice, 2015. http://www.theses.fr/2015NICE4075.

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Les travaux de recherche présentés dans cette thèse sont orientés vers la compréhension des mécanismes réactionnels propres aux produits pétroliers tels que les lubrifiants et les graisses par analyse thermique. La technique d’analyse thermique principalement utilisée était la calorimétrie de réaction. Dans un premier temps, une étude approfondie de la réponse instrumentale a été conduite. Une nouvelle méthode d’étalonnage a été proposée en se basant sur l’étalonnage par effet Joule. Avec ce type de correction, une étude cinétique plus précise peut alors être conduite, elle permet en outre d’étudier la cinétique de mécanisme complexes comme celles rencontrées avec les produits pétroliers. Dans un second temps, l’étude de la neutralisation de l’acide sulfurique par un lubrifiant marin a été effectuée. Cette étude a permis de développer une méthode d’analyse de routine permettant de comparer l’efficacité d’un lubrifiant à neutraliser une quantité précise d’acide sulfurique. Il devient alors possible d’estimer le temps nécessaire pour neutraliser l’acide afin d’éviter qu’il n’endommage l’intégrité des parties métalliques sensées être protégées par le lubrifiant marin. Une étude cinétique du phénomène de neutralisation, par l’intermédiaire des méthodes isoconversionnelles, a permis d’avoir une indication sur le modèle réactionnel pilotant ce mécanisme. Pour finir, l’influence du choix des paramètres tels que la température, les vitesses de chauffe où les temps de cuisson de graisse, a été étudié par en mêlant des techniques d’analyses thermique et rhéologiques<br>The research work presented in this thesis are oriented on the understanding of reactional mechanisms occurring in the field of oil products, such as lubricants and greases, by thermal analysis. The main thermal analysis technique used was the reaction calorimetry. Firstly, the instrumental response study of the calorimeter was led. A new calibration method have been proposed, this method is based on the calibration by Joule effect. From this correction, a more accurate kinetic evaluation can be done in order to study the complex mechanisms as those met with oil products. In a second time, the study of the neutralization of sulfuric acid by a marine cylinder lubricant was carried out. This work allowed to develop a routine analysis method to compare the lubricant ability to neutralize a precise amount of sulfuric acid. The time estimation is important to determine the frequency of lubricant replacement and to avoid the damage on the metallic parts. A kinetic study of the neutralization phenomena using isoconversional kinetic method, allowed to obtain the reactional model. Finally, the influence of parameters choice such as temperature, heating rate or cooking time have been evaluated by thermal and rheological analysis. Greases have been produced in a reaction calorimeter using a stirring system specifically developed. Information obtained allow to choose accurately the parameters used during the manufacturing processes in order to save time and decrease production costs
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33

Ohaňka, Zdeněk. "Vliv velikosti částic a způsobu přípravy na hydrataci vápenato-hlinitých fází." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2018. http://www.nusl.cz/ntk/nusl-376802.

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This work focuses on the hydration of four calcium aluminate phases – C3A, C12A7, CA and CA2. Above all, the influence of particle size and method of preparation on hydration behaviour were studied. Influence of these factors on hydration products were also investigated. Calcium aluminates were prepared by solid state synthesis and amorphous citrate method. Both methods were described in detail. The particle size was determined by laser diffraction. Isothermic calorimetry was used to investigate the process of hydration. Hydration products were identified by X-ray diffraction analysis and simultaneous thermogravimetric and differential thermal analysis.
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34

Frank, Nicole. "Untersuchungen zu Eigenschaften und Funktionen ausgewählter (Bio-)Tenside beim mikrobiellen Schadstoffabbau mittels kalorimetrischer und oberflächenanalytischer Methoden." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2013. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-106839.

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Im Rahmen der vorliegenden Arbeit wurden die Wechselwirkungen im System Bakterium –Tensid – Schadstoff mittels kalorimetrischer Untersuchungen (ITC, DSC) sowie mit XPS-Analysen und durch Zeta-Potential-Messungen an Bakterienoberflächen charakterisiert. Für die Untersuchungen wurden zwei Gram-positive Rhodococcus-Stämme und ein Gram-negativer Pseudomonas putida-Stamm verwendet. Als Biotenside wurden das Rhamnolipid JBR 425 und der von Rhodococcus erythropolis B7g produzierte Trehalosetetraester (THL-4) ausgewählt. Das synthetische Tensid SDS diente als Referenzsubstanz. Aus den kalorimetrischen Experimenten konnte eine starke Wechselwirkung zwischen den Tensiden und den aktiven Bakterienkulturen abgeleitet werden. THL-4 führte beim Wachstum der Rhodococcen auf n-Hexadecan zur Verkürzung der lag-Phase. SDS wies hingegen eine toxische Wirkung für die Bakterienstämme auf. Thermodynamische Betrachtungen ergaben, dass Wechselwirkungen des SDS mit den Bakterienzellen gegenüber der Mizellbildung bevorzugt werden.
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35

Crépé-Renaudin, Sabine. "Mesure du temps des désintégrations K->(pi)0(pi)0 et étiquetage des KL et des KS dans l'expérience NA48 au CERN." Université Joseph Fourier (Grenoble), 1998. http://www.theses.fr/1998GRE10059.

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L'experience na48 a pour but de mesurer, dans le systeme des kaons neutres et avec une precision de 0,0002, la partie reelle du rapport des amplitudes des violations directe et indirecte de la symetrie cp. Pour atteindre cette precision, na48 a choisi de minimiser les incertitudes systematiques en detectant simultanement et dans la meme zone fiducielle les desintegrations en deux pions neutres ou charges des kaons a vie longue et courte (kl et ks). L'etiquetage des kaons est effectue par des coincidences temporelles entre ces desintegrations et les protons a l'origine des ks. Comme les erreurs d'etiquetage entrainent un biais important sur la mesure de na48, elles doivent etre evaluees et etudiees avec attention. Elles proviennent d'inefficacites des detecteurs ou de coincidences fortuites entre les kl et les protons. Les performances temporelles du calorimetre a krypton liquide, utilise pour l'etiquetage des modes neutres, ont ete etudiees sur les donnees de 1996 et 1997. Elles sont excellentes : pour les desintegrations en deux pions, la resolution est meilleure que 250 ps et l'inefficacite plus petite que 0,0001. D'autre part, les coincidences fortuites entre les protons et les kl sont proportionnelles aux taux instantane du faisceau de protons. L'etude des structures temporelles de ce dernier a mis en evidence plusieurs frequences. De plus la duree effective du deversement des protons mesuree ne represente que 75 pour cent de la duree totale. Enfin, les incertitudes sur le rapport des violations de cp dues a l'etiquetage ont ete evaluees. Elles sont inferieures a l'incertitude statistique.
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36

Gilles, Geoffrey. "Recherche de résonances W' → tb dans le canal lepton plus jets avec le détecteur ATLAS au LHC." Thesis, Clermont-Ferrand 2, 2015. http://www.theses.fr/2015CLF22576/document.

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Le travail de recherche réalisé au cours de cette thèse s’inscrit dans le contexte de l’expérience ATLAS, l’une des quatre grandes expériences auprès du collisionneur LHC. Il fut principalement dédié à la recherche de nouveaux bosons de jauge lourds chargés, appelé W' et prédits par de nombreuses extensions du Modèle Standard de la physique des particules. Ce manuscrit présente une recherche du boson W' se désintégrant en un quark top et un quark beau à travers une approche de couplage effectif, dans des états finals de désintégrations leptoniques du quark top. Cette recherche fut réalisée avec 20.3 fb−1 de données de collision proton-proton, produits par le LHC à une énergie dans le centre de masse de 8 TeV et collectées par le détecteur ATLAS en 2012. Plusieurs scénarios d’études sont envisagés où le boson W' se couple soit à des fermions de chiralité gauche (W'L) soit de chiralité droite (W'R). Une technique d’analyse multivariée utilisant des arbres de décision boostés (BDT) est utilisée afin de mettre évidence un excès de processus de signal dans les données enregistrées. Aucun excès n’est observé au-delà des incertitudes expérimentales pour la statistique de données analysées jusque-là. Une analyse statistique est réalisée afin d’extraire des limites d’exclusion sur la masse et la section efficace de production de la particule. Des masses inférieures à 1.92, 1.80 et 1.70 TeV furent exclues respectivement pour des bosons W'R et W'L, en tenant compte ou non d’effets d’interférence. Les limites d’exclusion sur les sections efficaces de production sont réinterprétées en matière de limite d’exclusion sur le couplage effectif g'/g de la particule. Les limites d’exclusion les plus basses observées sur le rapport g'/g, respectivement de 0.20 et 0.16 pour les recherches de bosons W'R et W'L, furent obtenues pour une masse de boson W'R/L de 0.75 TeV. Une recherche de bosons de Higgs chargés se désintégrant en un quark top et un quark beau est également présentée dans ce manuscrit. Cette dernière repose sur une approche de couplage effectif décrivant un modèle à deux doublets de Higgs de type II. Cette analyse réutilise l’infrastructure développée pour la recherche du boson W' est complétée d’études phénoménologiques liées au calcul de la section efficace de ce processus ainsi que sur la caractérisation des effets de largeur de la résonance recherchée. Les premiers résultats obtenus sur la limite d’exclusion sur la section efficace de production pp → H+→ tb montrent toutefois que cette analyse ne semble pas être en mesure d’exclure un signal de boson H+ pour l’ensemble des scénarios théoriques considérés, compte tenu des faibles sections efficaces de production prédites. En parallèle de ces activités, des développements ont été réalisés pour la simulation rapide du système de calorimétrie FastCaloSim du détecteur ATLAS afin de pallier ses limitations. En particulier, un nouveau modèle de paramétrisation et de simulation rapide de la réponse en énergie du système de calorimétrie est présenté dans ce manuscrit. Ce modèle, toujours en développement, montre des résultats très encourageant pour la simulation d’événements à pion unique et permet de réduire considérablement l’empreinte mémoire de la paramétrisation en comparaison avec des versions précédentes de FastCaloSim, tout en permettant aux futures reparamétrisations d’être plus rapides et automatisées<br>The research work carried out during this Ph.D thesis has been performed in the context of the ATLAS experiment, one of the four major LHC experiments, and was primarily dedicated to the search for a new chaged heavy gauge boson, called W' and predicted by many extensions of the Standard Model of particle physics. This manuscript presents a search for W' boson decaying into a top and a bottom quark through an effective coupling approach, in the lepton plus jets final states. This search is performed with 20.3 fb−1 of proton-proton collision data, produced by the LHC with a center-of-mass energy of 8 TeV and collected by the ATLAS detector in 2012. Several scenarios are considered where the W boson can couple to left-handed (W'L) or right-handed (W'R) fermions. A multivariate techniques based on boosted decision trees is used to search for an excess of W signal process in the recorded data. No excess is observed beyond the experimental uncertainties for the data analysed so far. A statistical analysis is performed in order to extract exclusion limits on the mass and the production cross section of the particle. Masses below 1.92, 1.80 and 1.70 TeV are excluded, respectively for W'R and W'L bosons taking into account or not interference effects. These exclusion limits on the production cross section are also reinterpreted in terms of exclusion limits on the effective coupling g'/g of the particle. The lowest exclusion limits observed on the ratio g'/g are equal to 0.20 and 0.16, respectively, for W'R and W'L searches, and are obtained for a W'R/L mass of 0.75 TeV. A search for charged Higgs boson decaying into a top and a bottom quark is presented in this manuscript. This search is based on an effective coupling approach describing a type II Two Doublet Higgs Model. It reuses the analysis infrastructure developed for the W' search and is completed by phenomenological studies related to the production cross section calculation for the process and the characterisation of the resonance width effects affecting the analysis. Preliminary results on the excluded cross section limits pp → H+→ tb show that the analysis is not able to exclude a signal a H+ boson for all theoretical scenarios considered, due to low production cross sections predicted. In parallel of these activities, several developments have been performed on the fast simulation of the ATLAS calorimeter system in order to overcome its limitations. In particular, a new parametrisation and fast simulation model for the energy response of the calorimeter is presented in this manuscript. This model, still under development, shows encouraging results for simulated single pion event and allows to reduce considerably the memory footprint of the parametrisation compared to previous versions of FastCaloSim, while enabling future reparametrisations to be faster and automated
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37

Diyadi, Jaouad. "Contribution à l'étude de propriétés thermophysiques de composés amorphes Ni1-xPx." Nancy 1, 1989. http://www.theses.fr/1989NAN10147.

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Étude des propriétés dans les alliages amorphes Ni1-xPx pout X compris entre 0,14 et 0,25 depuis la température de l'hélium liquide jusqu'à la température ambiante. Mesure de la chaleur massique. Cette mesure nécessite la mise au point d'un calorimètre adiabatique à surfaces d'échange sphériques. Détermination des différentes contributions à la chaleur massique. Évaluation à partir de ces résultats de la conductivité thermique
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38

Löschner, Tina. "Synthese nanostrukturierter, organisch-anorganischer Hybridmaterialien über Zwillingspolymerisation." Doctoral thesis, Universitätsbibliothek Chemnitz, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-119796.

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Im Fokus dieser Arbeit stand die Methode Zwillingspolymerisation zur Synthese organisch-anorganischer Hybridmaterialien. Die simultane Zwillingspolymerisation wird als neues Konzept zur gezielten Herstellung homogener, nanostrukturierter Hybridmaterialien unterschiedlicher Zusammensetzung vorgestellt. Hierfür wurden die Zwillingsmonomere 2,2’-Spirobi[4H-1,3,2-benzodioxasilin] und 2,2 Dimethyl-4H-1,3,2-benzodioxasilin in einem Arbeitsschritt gemeinsam polymerisiert. Die erhaltenen Phenolharz-Siliciumdioxid/Dimethylsiloxan-Hybridmaterialien weisen aufgrund einstellbarer Syntheseparameter unterschiedliche Eigenschaftsprofile auf, die systematisch analysiert wurden. Die Charakterisierung der Produkte erfolgte mit Hilfe der Festkörper-NMR-Spektroskopie, Elektronenmikroskopie, DSC, TGA-MS, sowie durch Extraktionsversuche und die Erzeugung und Analyse poröser Materialien. Neben der simultanen Zwillingspolymerisation wird die Synthese, Charakterisierung und thermisch induzierte Polymerisation literaturunbekannter Silicium-Spiroverbindungen mit einfach- oder zweifach substituierter Salicylalkohol-Einheit beschrieben. Hierbei wurden nanostrukturierte Hybridmaterialien mit teils hohem löslichen Anteil erhalten. Die Produktbildung wird in Abhängigkeit von der Entstehung und Weiterreaktion gefundener Chinonmethid-Strukturen diskutiert.
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39

Huaiyu, Yang. "Crystallization of Parabens : Thermodynamics, Nucleation and Processing." Doctoral thesis, KTH, Teknisk strömningslära, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-122228.

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In this work, the solubility of butyl paraben in 7 pure solvents and in 5 different ethanol-water mixtures has been determined from 1 ˚C to 50 ˚C. The solubility of ethyl paraben and propyl paraben in various solvents has been determined at 10 ˚C. The molar solubility of butyl paraben in pure solvents and its thermodynamic properties, measured by Differential Scanning Calorimetry, have been used to estimate the activity of the pure solid phase, and solution activity coefficients. More than 5000 nucleation experiments of ethyl paraben, propyl paraben and butyl paraben in ethyl acetate, acetone, methanol, ethanol, propanol and 70%, 90% ethanol aqueous solution have been performed. The induction time of each paraben has been determined at three different supersaturation levels in various solvents. The wide variation in induction time reveals the stochastic nature of nucleation. The solid-liquid interfacial energy, free energy of nucleation, nuclei critical radius and pre-exponential factor of parabens in these solvents have been determined according to the classical nucleation theory, and different methods of evaluation are compared. The interfacial energy of parabens in these solvents tends to increase with decreasing mole fraction solubility but the correlation is not very strong. The influence of solvent on nucleation of each paraben and nucleation behavior of parabens in each solvent is discussed. There is a trend in the data that the higher the boiling point of the solvent and the higher the melting point of the solute, the more difficult is the nucleation. This observation is paralleled by the fact that a metastable polymorph has a lower interfacial energy than the stable form, and that a solid compound with a higher melting point appears to have a higher solid-melt and solid-aqueous solution interfacial energy. It has been found that when a paraben is added to aqueous solutions with a certain proportion of ethanol, the solution separates into two immiscible liquid phases in equilibrium. The top layer is water-rich and the bottom layer is paraben-rich. The area in the ternary phase diagram of the liquid-liquid-phase separation region increases with increasing temperature. The area of the liquid-liquid-phase separation region decreases from butyl paraben, propyl paraben to ethyl paraben at the constant temperature. Cooling crystallization of solutions of different proportions of butyl paraben, water and ethanol have been carried out and recorded using the Focused Beam Reflectance Method, Particle Vision and Measurement, and in-situ Infrared Spectroscopy. The FBRM and IR curves and the PVM photos track the appearance of liquid-liquid phase separation and crystallization. The results suggest that the liquid-liquid phase separation has a negative influence on the crystal size distribution. The work illustrates how Process Analytical Technology (PAT) can be used to increase the understanding of complex crystallizations. By cooling crystallization of butyl paraben under conditions of liquid-liquid-phase separation, crystals consisting of a porous layer in between two solid layers have been produced. The outer layers are transparent and compact while the middle layer is full of pores. The thickness of the porous layer can reach more than half of the whole crystal. These sandwich crystals contain only one polymorph as determined by Confocal Raman Microscopy and single crystal X-Ray Diffraction. However, the middle layer material melts at lower temperature than outer layer material.<br><p>QC 20130515</p><br>investigate nucleation and crystallization of drug-like organic molecules
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40

Gachon, Jean-Claude. "Enthalpies de formation des composés binaires de métaux de transition par réaction directe dans un calorimètre 1800 K. : Discussion de méthodes de prévisions thermodynamiques et structurales." Nancy 1, 1986. http://www.theses.fr/1986NAN10055.

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Mise au point d'un nouveau calorimètre pouvant fonctionner depuis la température ambiante jusqu'à 1800K. Application à des mesures de capacité calorifique et d'enthalpie de formation ainsi qu'à l'analyse thermique différentielle. Caractérisation de l'enthalpie de 27 composés binaires de métaux de transition. Étude à partir des résultats de plusieurs modèles de prévision des enthalpies de formation d'alliages. Discussion des résultats. Proposition d'un modèle prévisionnel de stoechiométries et des structures des phases binaires susceptibles d'apparaître dans un système métallique
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41

Liao, Yi-An, and 廖乙安. "Effect of Heat Conduction Model on Measurement of Thermal Diffusivity Using AC Calorimetric Method." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/64026786407943926799.

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碩士<br>中華大學<br>機械與航太工程研究所<br>94<br>Ac calorimetric method is a popular method for measuring thermal diffusivity. The measuring theory is based on classical diffusion model. However, it has been pointed that diffusion mosel is not valid for rapid or high frequency heating sources. This study analyzes the two dimensional heat transport for a two-layered slab subjected to periodic heating source in a finite region of the upper layer so as to investigate the effect of heat conduction model on accuracy of the measurement of thermal diffusivity by Ac calorimetric method. The effect of parameters on both amplitude and phase of the temperature is discussed in terms of ratio of delay times (B). On accuracy for measuring thermal diffusivity, results show that the measurement based on temperature amplitude is better than that based on temperature phase.
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42

Jhu, Can-Yong, and 朱璨雍. "Thermal explosion evaluation of 18650 Li-ion batteries by calorimetry method." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/73259927928384219984.

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碩士<br>國立雲林科技大學<br>環境與安全衛生工程系碩士班<br>99<br>Safety is the most concern subject of lithium-ion batteries progress. In this study, hazards of thermal runaway reactions on lithium-ion batteries are conducted via Vent Sizing Package 2 (VSP2) with a customized stainless steel test can. Self-heating rate of thermal runaway is observed and compared at adiabatic conditions by calorimetric methodology. The commercial 18650 lithium-ion batteries with LiCoO2 and LiMnCoNi cathode material were selected in our test, including Sony, Sanyo, Samsung, and LG, that are experimented at 4.2 V and 3.7 V , respectively. The experimental data such as adiabatic rise temperature, heat of reaction, maximum pressure, etc., were obtained via VSP2 trails. Thermodynamic data of thermal runaway reaction was estimated to obtain the initial exothermic temperature (T0), self-heating rate (dT/dt), pressure rise rate (dP/dt), etc. The results showed that self-heating reaction of lithium-ion batteries were occurred at ca. 130 oC. The dT/dt and the dP/dt of 4.2 V of lithium-ion battery are measured to be over 10,000 oC/min and 10,000 psi/min, respectively, and the maximum temperature is over 600 oC. This result led to a thermal explosion and the heat of reaction was 26.2 kJ. The thermokinetic parameters by the reaction of LiCoO2 battery were also determined using Arrhenius model. Therefore, the runaway reaction is extremely serious when lithium-ion battery is exothermic at condition of 4.2 V. This result also demonstrated that the VSP2 is an alternative method of thermal hazards assessment for battery safety research.
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43

Hong, Huei-Fen, and 洪慧芬. "Studies of Thermal Denaturation of Bovine Serum Albumin using Differential Scanning Calorimetry and Laser Flash Method." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/92595916187777663911.

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碩士<br>國立中央大學<br>機械工程學系<br>103<br>Bovine serum albumin, BSA, is often used in molecular biology, immunology, nutritional science or protein chemistry, due to its stability, inhibition of lipid peroxidation, emulsification and antifreeze effects. In addion, BSA’s low cost and easy to purify make it a good candidate for experiment and as a reference protein. BSA has a spherical structure that formed by the tightly folding of the secondary structures. In the elevated temperature, the native BSA gains kinetic and results in a strong vibration causing the damage of the molecule bonding. The 3D structure is then unfolds and turned into the denatured state. In order to study the thermal denaturation of protein, researchers commonly use differential scanning calorimetry method, DSC, to investigate the changes in enthalpy, entropy and specific heat by measuring the heat flow in the elevated temperature. The thermal denaturation effects on the heat transport properties of proteins, however, that is seldom investigated and may have potential impacts on biomedical applications. In this study, we used DSC to explore the relationship between BSA solutions and the heat flow in the thermal denaturation process. Additionally, laser flash analysis, LFA, was use to study the effective thermal diffusivity of BSA solutions with various concentrations. The time dependence of the thermal diffusivity was also considered. Experiments had performed to measure the density, specific heat, and effective thermal diffusivity of BSA solutions with concentrations 5 ~ 20 wt%. The effective thermal conductivity was then calculated. We found that the energy required in the denaturation process increased with BSA concentration. Same trend can be found in the variation of specific heat. In the thermal diffusivity analysis, LFA couldn’t reveal the true thermal diffusivity when undego denaturation, but reflected the impact of different degrees of thermal denaturation process on heat transfer phenomena. The variation of thermal diffusivity caused by the thermal denaturation process was more dramatic with the increasing concentration. It also showed a linear relation between the thermal diffusivity and durtaion time. The change rate of thermal diffusivity increased with temperature and concentration, which means the increase in the degree of thermal denaturation process.
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44

Xu, Junkai. "Nanocalorimetric sensor for ultra-low biological measurements and calibration by chemical method." Diss., 2007. http://etd.library.vanderbilt.edu/ETD-db/available/etd-09132007-093035/.

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45

Pêcego, Inês Gonçalves. "Synthesis of glibenclamide cocrystals through grinding methods." Master's thesis, 2018. http://hdl.handle.net/10451/40057.

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Tese de mestrado, Engenharia Farmacêutica, Universidade de Lisboa, Faculdade de Farmácia, 2018<br>The pharmaceutical industry has been struggling against problems related with drugs with low solubility as this is a very limiting factor in the development of drug products. Co-crystals are solid forms known for a very long time although they have not been fully explored in their potentialities. Co-crystals can be defined as crystalline homogenous structures composed of two or more compounds, held together by noncovalent bonds, usually hydrogen bonds, and solid at room temperature. These structures can change the physicochemical properties of drugs, like solubility, dissolution rate, stability and particle properties, which could be interesting for the drug development process. It is still difficult to identify the optimal co-crystallization method for each situation and typically this process is evaluated on a case-by-case basis. Reported studies show that the most commonly used method is solvent evaporation. However, the main drawback of solvent evaporation is the scale-up difficulty. Therefore, this work explored milling as an alternative method. This method can more easily be scaled-up. This work is based on the co-crystallization of glibenclamide, a sulfonylurea used in the treatment of non-insulin-dependent diabetes mellitus. Glibenclamide is categorized as a class II drug (low solubility, high permeability) by the Biopharmaceutical Classification System. The formation of co-crystals was attempted with six different co-formers – adenine (ADE), nicotinamide (NICO), malic acid (MAL), mannitol (MAN), p-aminobenzoic acid (PABA) and tromethamine (TRIS). The grinding assisted co-crystallization method was performed on a ball mill. Grinding products were characterized by differential scanning calorimetry and vibrational spectroscopy (near and mid-infrared) and compared with glibenclamide, co-formers and physical mixtures. It was concluded that the most suitable co-formers for the formation of a glibenclamide co-crystals were MAL, PABA (without solvent) and TRIS.<br>A indústria farmacêutica tem ao longo do tempo enfrentado problemas relacionados com a fraca biodisponibilidade de muitos fármacos, nomeadamente os integrantes de formas orais. Muitos destes problemas estão relacionados com a baixa solubilidade ou fraca velocidade de dissolução. A abordagem para minimização de problemas relacionados com estes fatores tem sido muito variada, e estão documentadas várias abordagens físicas e químicas. Neste contexto, a produção de co-cristais, ou co-cristalização, é uma técnica de alteração de estado sólido e tem apresentado resultados vantajosos relativamente à melhoria da solubilidade de fármacos. Os co-cristais são formas sólidas homogéneas compostas por duas ou mais moléculas, contidas numa única estrutura cristalina, sendo sólidos à temperatura ambiente. Tais compostos apresentam uma estequiometria bem definida e estão ligados entre si através de ligações não-covalentes, normalmente pontes de hidrogénio. Existem várias metodologias para produção de co-cristais sendo que as mais utilizadas (p.e., evaporação por solvente) têm desvantagens ao nível da transposição de escala e por isso dificuldade de utilização a uma escala de produção. A opção de produção de co-cristais por moagem tem sido documentada ao longo dos últimos anos embora não seja ainda uma técnica muito utilizada e por isso ainda razoavelmente desconhecida em termos do seu potencial, nomeadamente no que respeita à pureza dos co-cristais obtidos assim como o impacto que as condições de fabrico têm nos co-cristais. Esta tese pretende aumentar o conhecimento na área da produção de co-cristais pela técnica de moagem, nomeadamente aferindo a sua capacidade em produzir co-cristais com caraterísticas de pureza adequadas fazendo a ponte com outros métodos como a evaporação de solvente. A glibenclamida foi o fármaco selecionado como caso de estudo. Está categorizado como um fármaco de classe II pelo Sistema de Classificação Biofarmacêutica, isto é, apresenta baixa solubilidade e elevada permeabilidade. Tal fármaco é uma sulfonilureia utilizada para o tratamento da diabetes mellitus, sendo esta uma doença do foro metabólico, caracterizada por níveis elevados de açúcar no sangue (hiperglicemia), exibindo duas categorias etiopatogénicas: diabetes mellitus tipo 1 ou auto-imune e diabetes mellitus tipo 2 ou não-dependente de insulina. A diabetes mellitus tipo 2 afeta mais de 9% da população mundial, sendo que as opções terapêuticas de primeira-linha incluem a administração de metformina (biguanida), numa fase inicial, à qual se equaciona a simultaneidade com sulfonilureias (por exemplo, glibenclamida) com o agravamento da condição. A produção de co-cristais de glibenclamida nesta tese foi executada através do método de co-cristalização por moagem utilizando um moinho de bolas. O fármaco alvo foi testado em combinação com seis potenciais co-formadores distintos: adenina, nicotinamida, ácido málico, manitol, ácido p-aminobenzóico e trometamina. Os testes foram realizados utilizando 1mmol de fármaco e de potencial co-formador utilizando duas bolas de moagem de 12mm durante 3 horas a uma velocidade de 600 rpm. Os os produtos obtidos foram caracterizados quanto a propriedades de estado sólido por calorimetria diferencial de varrimento e por espectroscopia de infravermelho médio e infravermelho-próximo quanto ao seu perfil químico. Tendo em conta que, em princípio, um co-cristal apresenta características físicas e químicas diferentes dos precursores, todos os produtos obtidos após moagem foram caracterizados em comparação com a glibenclamida, respectivo potencial co-formador e mistura física de ambos. Verificou-se que no caso da nicotinamida e manitol não se obtiveram co-cristais. No sistema envolvendo adenina verificaram-se alterações nos espetros de infravermelho, embora esses resultados não fossem confirmados através de uma alteração visível do perfil de calorimetria térmica. A utilização de ácido p-aminobenzóico revelou também resultados promissores indicados por todas as técnicas analíticas usadas. Os sistemas que sobressaíram por apresentarem resultados bastante conclusivos relativamente à formação de co-cristais nestas condições envolveram os co-formadores ácido málico e trometamina. Os resultados obtidos pelo método de moagem encontram-se em linha com os obtidos por evaporação de solvente descritos na literatura. A utilização de condições de moagem diferentes, nomeadamente no que respeita à velocidade e tipologia das esferas de moagem deverá no futuro ser avaliada consistentemente para que sejam identificadas zonas ótimas de operação para produção de co-cristais, tendo em vista o rendimento e a sua pureza.
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46

Knopp, M. M., L. Tajber, Y. Tian, et al. "Comparative study of different methods for the prediction of drug-polymer solubility." 2015. http://hdl.handle.net/10454/14340.

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Yes<br>In this study, a comparison of different methods to predict drug−polymer solubility was carried out on binary systems consisting of five model drugs (paracetamol, chloramphenicol, celecoxib, indomethacin, and felodipine) and polyvinylpyrrolidone/vinyl acetate copolymers (PVP/VA) of different monomer weight ratios. The drug−polymer solubility at 25 °C was predicted using the Flory−Huggins model, from data obtained at elevated temperature using thermal analysis methods based on the recrystallization of a supersaturated amorphous solid dispersion and two variations of the melting point depression method. These predictions were compared with the solubility in the low molecular weight liquid analogues of the PVP/VA copolymer (N-vinylpyrrolidone and vinyl acetate). The predicted solubilities at 25 °C varied considerably depending on the method used. However, the three thermal analysis methods ranked the predicted solubilities in the same order, except for the felodipine−PVP system. Furthermore, the magnitude of the predicted solubilities from the recrystallization method and melting point depression method correlated well with the estimates based on the solubility in the liquid analogues, which suggests that this method can be used as an initial screening tool if a liquid analogue is available. The learnings of this important comparative study provided general guidance for the selection of the most suitable method(s) for the screening of drug−polymer solubility.<br>The Irish Research Council and Eli Lilly S.A. through an Irish Research Council Enterprise Partnership Scholarship for C.M.B., in part by The Royal Society in the form of Industrial Fellowship awarded to G.A., and in part by a research grant from Science Foundation Ireland (SFI) under Grant Number SFI/12/RC/2275 (for A.M.H., L.T., K.P., and A.K.).
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47

Ayoade, Deborah. "Net energy of wheat-corn distillers dried grains with solubles for growing pigs as determined by the comparative slaughter, indirect calorimetry, and the chemical composition methods." 2012. http://hdl.handle.net/1993/5101.

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ABSTRACT Two experiments were conducted to determine the net energy (NE) of wheat-corn distillers dried grains with solubles (wcDDGS) using the comparative slaughter (CS), the indirect calorimetry (IC) and the chemical composition (CH) methods. Based on the CS method, NE values of 2,407, and 2,424 kcal/kg DM were obtained for wcDDGS included at 15% and 30%, respectively. For the IC method, the NE values of 2,407, and 2,403 kcal/kg DM were obtained for wcDDGS included at 15% and 30%, respectively; corresponding values for the CH method were 2,536 and 2,197 kcal/kg DM, respectively. It is concluded that NE value of wcDDGS ranges from 2,367 kcal/kg DM to 2,416 kcal/kg DM depending on the method used. As the values obtained from the various methods were not different, the average NE value for the wcDDGS evaluated was 2,396 ± 25.71 kcal/kg DM.
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48

Alvarenga, Maria Leonor Mendes Godinho de [Verfasser]. "Innovative analytical tools in the biopharmaceutical development : applying SPR, Biacore, calorimetry and light scattering methods to the study of interactions between anticancer antibodies and the EGFR / vorgelegt von Maria Leonor Mendes Godinho de Alvarenga." 2010. http://d-nb.info/1010856472/34.

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