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Merheb, Graciela de Amaral. "Estudo do processo de cristalização de sacarose a partir de soluções provenientes de cana-de-açúcar por resfriamento controlado." Universidade Federal de São Carlos, 2009. https://repositorio.ufscar.br/handle/ufscar/4015.
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Previous issue date: 2009-06-29Today, Brazil is the major producer and exporter of sugar in the world. In the last harvest 2008/2009, 31.5 millions tons were produced, of which 60% were exported providing a 40% of international market share. However, sugar is a product that has commercial difficulties, due to the hard restrictions, such as rates, subsidizes and technical barriers like the use of sulfur (input) in laundering. Because of this, the development of a technology for the production of sugar with superior quality, less cost and without sulfur for the laundering would be of great interest for the productive sector. The present work aims to study the process of crystallization of sucrose from sugar solutions of syrup and sugar cane by controlled cooling. A laboratory plant with production capacity of 1 kg of sugar per batch, installed in the laboratory of industrial development of the Sugarcane Technology Center (CTC) in Piracicaba was used for the present work. The results regarding the reduction of impurities initially present in sugar crystals through crystallization by controlled cooling were: 95% in color, 85% in starch and 80% in dextran. For the syrup classified as VVHP, reductions obtained in crystals through crystallization by controlled cooling were: 96% of the final color of the sugar (from 10,100 IU to 361 IU), 98% in the amount of ash conductivity, 84% in the amount of starch and 52% in the amount of dextran. Obtained the results led to the construction of a pilot plant by scaling the process that will be implemented in an industrial unit.
O Brasil, hoje, é o principal produtor e exportador de açúcar do mundo. Foram produzidas na última safra 2008/2009, 31,5 milhões de toneladas de açúcar, das quais cerca de 60% foram exportadas, gerando ao país um domínio de 40% do mercado internacional. No entanto, o açúcar é um produto de relativa dificuldade para comercialização internacional, em razão de fortes restrições, como cotas, subsídios e barreiras técnicas, como a utilização do enxofre (insumo), para o branqueamento. Por isso, o desenvolvimento de uma tecnologia de produção de açúcar de melhor qualidade, com redução de custos e que não necessite de enxofre para o branqueamento seriam de grande interesse para o setor produtivo. O presente trabalho tem por objetivo o estudo do processo de cristalização de sacarose a partir de soluções provenientes de açúcar e xarope de cana-de-açúcar por resfriamento controlado, através de uma planta laboratorial, com capacidade de produção de 1 kg de açúcar por batelada, instalada no laboratório de desenvolvimento industrial do Centro de Tecnologia Canavieira (CTC) em Piracicaba. Os resultados quanto à redução de impurezas presentes inicialmente nos cristais de açúcar através da cristalização por resfriamento controlado foram: de 95% de cor; 85% de amido e 80% de dextrana. Para o xarope classificado como VVHP, as reduções obtidas nos cristais através da cristalização por resfriamento controlado foram: de 96% na cor do açúcar final (de 10.100 UI para 361 UI), de 98% na quantidade de cinzas condutimétricas, de 84% na quantidade de amido e de 52% na quantidade de dextrana. A partir dos resultados obtidos, motivou-se a construção de uma unidade piloto através do scale-up do processo laboratorial, a ser implantada em uma unidade industrial.
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Merheb, Graciela de Amaral. "Influência da contaminação combinada de dextrana e amido na cristalização do açúcar." Universidade Federal de São Carlos, 2014. https://repositorio.ufscar.br/handle/ufscar/3961.
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Previous issue date: 2014-10-08Introduced during the colonial period in Brazil, nowadays sugar cane is one of the main crops of the country's economy, generating more than 2 billion dollars per year in the Brazilian trade balance. Despite the benefits of expanding the sugarcane sector every year, the environmental impacts caused by burning straw cane sugar made the State of São Paulo Government create the Protocol of Agro-Environmental Cooperation in 2007, which aims the total elimination of cane burning by 2017. However, when the sugar cane stops being burned, some components of the plant, which remained in the field due to the burning, will start being in larger quantities in the process, and the effects of this future reality in sugar quality have not been studied In this doctoral thesis, the two components of great impact on the specifications or quality of the sugar were chosen: starch and dextran which were studied in the crystallization unit operation (by controlled cooling and vacuum evaporation), so that the impact on the final product (sugar) were evaluated. This current study used a reponse surface methodology, with 2 levels (309 and 1062 ppm), two factors (dextran and starch), 3 center points (one central point in triplicate) and 4 axial points, totaling 11 trials per type of crystallization. The experiments were conducted with sugar Type 2 solutions contaminated with starch and dextran, in an agitated and jacketed crystallizer (8 liters) in the laboratory. When the crystallization was performed, the matters were centrifuged, the sugars were separated from the honeys, and forwarded to the physico-chemical, textural and optical microscopy analyzes. In relation to the physicochemical analyzes of sugar, starch and dextran contamination interfered directly in the responses: starch, dextran, color, turbidity and alcoholic floc in both crystallization techniques, however, the controlled cooling under the same conditions of contamination (0-2000 ppm), presented sugars to lower rates, which kept the product according to the market specifications. The results of grain size analysis showed frequency curves with accumulation of smaller crystals at the opening of 0.5 mm, according to the increase of dextran in the tests. And the optical microscopy analysis identified the existence of a relationship between the amount of contaminants, and the appearance of agglomerated crystals, besides "needle-like" crystals were not observed. The experimental chosen design collaborated in the identification of starch and dextran agents, in the increase or decrease of the analyzed responses, besides suggesting the collaboration of the combined effect on the quality of sugar. Concerning the product quality, the use of crystallization technique by controlled cooling proved to be the most suitable in the reduction of contaminants in the sugar, particularly in solutions containing 2,000 ppm of dextran and starch. Given the crop of sugarcane in the coming years, and that the contamination of dextran and starch may be higher than those found in syrups of industrial processes currently, this work may contribute to the knowledge of the contaminants and their combined actions in the crystallization and in understanding of the differences in the product quality.
Introduzida no período colonial no Brasil, a cana-de-açúcar é hoje uma das principais culturas da economia do país, gerando mais de 2 bilhões de dólares por ano na balança comercial brasileira. Apesar dos benefícios da expansão do setor sucroalcooleiro a cada ano, os impactos ambientais causados pelas queimadas da palha de cana-de-açúcar, levaram o Governo Estadual Paulista a criar em 2007, o Protocolo de Cooperação Agroambiental, que visa a eliminação total da queima de cana até 2017. No entanto, quando a cana-de-açúcar deixar de ser queimada, alguns componentes da planta que ficavam no campo com a queima passarão a entrar no processo em maiores quantidades, e os efeitos dessa futura realidade na qualidade do açúcar ainda não foram estudados. Nesse trabalho de doutorado, foram escolhidos dois componentes de grande impacto nas especificações ou qualidade do açúcar: o amido e a dextrana, os quais foram estudados na operação unitária de cristalização (por resfriamento controlado e por evaporação a vácuo), para que o impacto no produto final (açúcar) fosse avaliado. O presente trabalho utilizou um delineamento composto rotacional, com 2 níveis (309 e 1062 ppm), dois fatores (dextrana e amido), 3 pontos centrais (1 ponto central em triplicata) e 4 axiais, totalizando 11 experimentos por tipo de cristalização. Os experimentos foram realizados com soluções de açúcar Tipo 2, contaminadas com amido e dextrana, em um cristalizador agitado e encamisado (8 litros), em laboratório. Realizadas as cristalizações, as massas foram centrifugadas, e os açúcares separados dos méis, e encaminhados para as análises físico-químicas, granulométricas e de microscopia óptica. Em relação às análises físico-químicas do açúcar, as contaminações de dextrana e amido interferiram diretamente nas respostas: amido, dextrana, cor, floco alcoólico e turbidez, nas duas técnicas de cristalização, no entanto, o resfriamento controlado, nas mesmas condições de contaminação (0 a 2000 ppm), apresentou açúcares com os menores índices, o que manteve o produto nas especificações do mercado. Os resultados das análises granulométricas demonstraram curvas de frequência com acúmulo de cristais menores na abertura de 0,5 mm, conforme o aumento de dextrana nos testes. E as análises de microscopia óptica identificaram a existência de uma relação entre a quantidade de contaminantes, e o aparecimento dos cristais aglomerados, além de não serem observados cristais tipo agulha . O planejamento experimental adotado colaborou na identificação dos agentes amido e dextrana, no aumento ou na diminuição das respostas analisadas, além de sugerir a colaboração do efeito combinado desses na qualidade do açúcar. Em termos de qualidade do produto, a aplicação da técnica de cristalização por resfriamento controlado mostrou-se mais indicada na redução dos contaminantes no açúcar, principalmente em soluções com 2000 ppm de dextrana e amido. Tendo em vista a colheita de cana crua nos próximos anos, e que as contaminações de dextrana e amido poderão ser superiores as encontradas nos xaropes dos processos industriais hoje, o presente trabalho pode contribuir no conhecimento dos contaminantes e de suas ações combinadas na cristalização, e no entendimento das diferenças na qualidade do produto.
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Marques, João Erivando Soares. "Aplicação da lógica fuzzy no controle da cristalização de um sistema de refrigeração por absorção com par brometo de lítio." Universidade Federal da Paraíba, 2010. http://tede.biblioteca.ufpb.br:8080/handle/tede/5400.
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Previous issue date: 2010-12-01Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
This work presents theoretical and experimental study of a system of control for a steam generator. This system was developed to control the crystallization of a cooling system for absorption. The control system maintains the pressure generator above the zone of crystallization of diagram temperature pressure-saturated solution concentration of LiBr-water. The control is accomplished through simultaneous use of the relay and the frequency converter. The frequency converter acts in engine speed of pump firing of condenser cooling tower, while the relay operates directly into the burner of the generator, consecutively in thermal power of combustion. The control system can act in any pressure reference values above the zone of crystallization of absorption cooling system. In the control flow control techniques were used and fuzzy Modeling and control power thermal combustion, on-off control. Ten different experiments were conducted, which proved the efficiency of the system of control.
Neste trabalho apresenta-se o estudo teórico e experimental de um sistema de controle para um gerador de vapor. Este sistema foi desenvolvido para controlar a cristalização de um sistema de refrigeração por absorção. O sistema de controle mantém a pressão do gerador acima da zona de cristalização do diagrama temperatura-pressãoconcentração de solução saturadas do LiBr-água. O controle é realizado por meio do uso simultâneo do relé e o conversor de freqüência. O conversor de freqüência atua na velocidade do motor de acionamento da bomba da torre de resfriamento do condensador, enquanto o relé opera no queimador do gerador, consecutivamente na potência térmica de combustão. O sistema de controle pode atuar em quaisquer valores de referência de pressão acima da zona de cristalização do sistema de refrigeração por absorção. No controle da vazão foram utilizados técnicas de controle e modelagem Fuzzy e para controlar a potência térmica combustão, o controle on-off. Foram realizados dez experimentos diferentes, que comprovam a eficiência do sistema de controle.
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Shore, Mark. "Cooling and crystallization of komatiite flows." Thesis, University of Ottawa (Canada), 1996. http://hdl.handle.net/10393/10267.
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Despite their $\sim$2710 Ma age, thin komatiite lava flows in Munro township, NE Ontario have sufficiently well-preserved primary structures, textures, mineralogy, and whole-rock geochemistry to constrain the physical processes of cooling and crystal growth. Seawater convection drove a cooling and fracturing front through the upper surface and was the dominant mechanism of heat loss, leading to pronounced textural asymmetry within flows. Large plate-like crystals of olivine in the upper layers of flows grew by constrained crystallization arising from strong thermal pradients and the high lattice thermal conductivity and near-infrared transparency of olivine (3-5 times greater than that of the surrounding melt). Such crystals exhibit a very strong preferred orientation with the a crystallographic axis perpendicular to flow surfaces. Major and minor-element zoning within olivine crystals is closely modeled by fractional crystallization from the bulk liquid, and whole-rock geochemical variations within flows by crystal fractionation of highly magnesian olivine. The high chromium content of olivine is of mineralogical and technological interest, and is due to two substitutional mechanisms: $\sp{\lbrack 6\rbrack}$Cr$\sp{3+} + \sp{\lbrack 4\rbrack}$Al$\sp{3+} \rightleftharpoons\ \sp{\lbrack 6\rbrack}$Mg$\sp{2+} + \sp{\lbrack 4\rbrack}$Si$\sp{4+}$ and 2 $\sp{\lbrack 6\rbrack}$Cr$\sp{3+} + \sp{\lbrack 6\rbrack}\square \rightleftharpoons 3 \sp{\lbrack 6\rbrack}$Mg$\sp{2+}.$ Dendritic chromian spinel crystals nucleated heteroepitaxially on olivine substrates; the crystallographic relationship between the phases is (111) $\sb{\rm sp} \parallel$ (100) $\sb{\rm ol}$, (110) $\sb{\rm sp}\ \parallel$ (001) $\sb{\rm ol}\ \parallel$, and (211) $\sb{\rm sp}\ \parallel$ (010) $\sb{\rm ol}$. The Cr-spinel crystals have features typical of metallic, ionic, and organic crystal dendrites, but rarely found in minerals. Immobility of Mg and Si and a systematic loss of Ca in these altered rocks is due to a serpentinization reaction buffered by the desilication of glass or fine-grained plagioclase in the groundmass. Serpentinization occurred under conditions of low confining pressure, caused up to 30% expansion of the basal portions of flows, and predated tectonism at $\sim$2700 Ma.
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Renner, Rebecca. "Cooling and crystallization of komatiite flows from Zimbabwe." Thesis, University of Cambridge, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292223.
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Wohlgemuth, Kerstin [Verfasser]. "Induced Nucleation Processes during Batch Cooling Crystallization / Kerstin Wohlgemuth." München : Verlag Dr. Hut, 2012. http://d-nb.info/1028786751/34.
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Li, Huayu. "Process measurements and kinetics of unseeded batch cooling crystallization." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/53503.
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This thesis describes the development of an empirical model of focus beam reflectance measurements (FBRM) and the application of the model to monitoring batch cooling crystallization and extracting information on crystallization kinetics.
Batch crystallization is widely used in the fine chemical and pharmaceutical industries to purify and separate solid products. The crystal size distribution (CSD) of the final product greatly influences the product characteristics, such as purity, stability, and bioavailability. It also has a great effect on downstream processing. To achieve a desired CSD of the final product, batch crystallization processes need to be monitored, understood, and controlled.
FBRM is a promising technique for in situ determination of the CSD. It is based on scattering of laser light and provides a chord-length distribution (CLD), which is a complex function of crystal geometry. In this thesis, an empirical correlation between CSDs and CLDs is established and applied in place of existing first-principles FBRM models. Built from experimental data, the empirical mapping of CSD and CLD is advantageous in representing some effects that are difficult to quantify by mathematical and physical expressions. The developed model enables computation of the CSD from measured CLDs, which can be followed during the evolution of the crystal population during batch cooling crystallization processes.
Paracetamol, a common drug product also known as acetaminophen, is selected as the model compound in this thesis study. The empirical model was first established and verified in a paracetamol-nonsolvent (toluene) slurry, and later applied to the paracetamol-ethanol crystallization system. Complementary to the FBRM measurements, solute concentrations in the liquid phase were determined by in situ infrared spectra, and they were jointly implemented to monitor the crystallization process.
The framework of measuring the CSD and the solute concentration allows the estimation of crystallization kinetics, including those for primary nucleation, secondary nucleation, and crystal growth. These parameters were determined simultaneously by fitting the full population balance model to process measurements obtained from multiple unseeded paracetamol-ethanol crystallization runs.
The major contributions of this thesis study are (1) providing a novel methodology for using FBRM measurements to estimate CSD; (2) development of an experimental protocol that provided data sets rich in information on crystal growth and primary and secondary nucleation; (3) interpretation of kinetics so that appropriate model parameters could be extracted from fitting population balances to experimental data; (4) identification of the potential importance of secondary nucleation relative to primary nucleation. The protocol and methods developed in this study can be applied to other systems for evaluating and improving batch crystallization processes.
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Rajam, S. "Controlled crystallization of calcium carbonate under Langmuir monolayers." Thesis, University of Bath, 1990. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.760610.
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Diao, Ying Ph D. Massachusetts Institute of Technology. "Design of polymeric substrates for controlled molecular crystallization." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/70408.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2012.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 171-175).
It is essential to control crystallization in many areas of science and technology, such as the production of pharmaceuticals, pigments, concrete, semiconductors, as well as the formation of biominerals. In most practical circumstances, crystallization starts with heterogeneous nucleation at a foreign surface. Despite its widespread occurrence, mechanistic understanding of the role of a surface in heterogeneous nucleation is limited, especially in a solution environment. My thesis aims at elucidating the roles of surface chemistry and nanostructure on nucleation to enable rational design of surfaces for controlling crystallization from solution. To this end, I systematically investigated the role of surface chemistry, morphology, in particular porous structures of various polymeric materials on heterogeneous nucleation using small organic molecules as model compounds. I have demonstrated quantitatively the significance of surface chemistry to nucleation kinetics using a variety of polymer surfaces. By tuning the surface composition of the polymers, aspirin nucleation was promoted by up to an order of magnitude compared to the bulk. Further mechanistic investigations revealed that, macroscopically, it is through interfacial free energies that the surfaces influence the surface nucleation activity. Equipped with nucleation induction time statistics as a powerful tool, I found that nanoscopic pores of 50-100 nm accelerated nucleation by up to two orders of magnitude compared with surfaces without pores. Moreover, I demonstrated for the first time that the shape of surface nanopores is essential in determining the nucleation behavior, using lithographic methods for nanopatterning the polymer films. A molecular mechanism was further proposed based on additional mechanistic investigations. Furthermore, the nanoconfinement effect on nucleation was studied using polymeric microgels with tunable nanostructures and chemistry, whose mesh sizes range from 0.7-2 nm. We presented the first experimental evidence for the existence of an optimum confinement size at which the rate of nucleation was dramatically enhanced by up to four orders of magnitude. The degree of nucleation enhancement depends on the extent of polymer-solute interactions, whose role was elucidated from the perspective of adsorptive partitioning and nucleation-templating effect. In addition, the microgel nanostructure was also shown to play an important role in determining the crystal polymorphism of pharmaceutical compounds.
by Ying Diao.
Ph.D.
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Encarnacion-Gomez, Luis G. "Design and operation of enzymatic reactive crystallization: Applications in chiral purity and kinetically controlled synthesis." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/54322.
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The work presented in this thesis is aimed to design efficient reactive crystallization operations that could potentially be implemented in the manufacture of enantiomerically pure compounds and β-lactam antibiotics. Multiple aspects of solution thermodynamics, reaction engineering and crystallization from complex solutions are involved and will be discussed in detail through the following chapters.
The first piece of this work utilizes reactive crystallization for the manufacture of enantiomerically pure amino acids. Chemo-enzymatic stereoiversion reactions are used to enrich saturated or supersaturated solutions to favor the selection of a desired enantiomer. L-Methionine and L-Phenylalanine were resolve successfully from racemic mixtures by cyclic stereoinversion. r D-amino acids were oxidized by D-amino acid oxidase (D-AAO) and the resulting ketoacid was subsequently reduced by ammonia borane producing a racemic-mixture After the necessary enantiomeric enrichment was reached, system conditions were changed to induce supersaturation and promote crystal formation. In each case crystals with chemical and enantiomeric purities greater than 99% wt. were recovered. experimental information about reaction and crystallization kinetics was used to developed models. Such models were used to design model-based optimizations in which the productivity of the operation was enhanced by selecting an optimal temperature profile.
The second example is a reactive crystallization towards the manufacture of β-lactam antibiotics. One of the major drawbacks of the utilization of enzymes towards the manufacture of β-lactam antibiotics is the fact that the same enzyme that catalyzes the synthesis of the antibiotic also catalyzes its hydrolysis and thus, its degradation. The reaction scheme is a kinetically controlled synthesis in which the desired product is an intermediate within the network. Hence, the focus of this work is to design an efficient reactive crystallization in which the product is crystallized before it is consumed by hydrolysis. In order to accomplish this goal we have study solution equilibria, reaction kinetics, and crystallization kinetics. Even though crystallization kinetics of ampicillin has been previously reported; the reported models are not applicable to a reactive crystallization scheme for a variety of reasons. In this work, we have developed a robust model that can be applied to multiple crystallization protocols that are consistent with the conditions at which the enzymatic reaction can be performed.
Finally, a reactive-crystallization scheme in which ampicillin was successfully recovered from solution was developed. In this work, crystal seeds were used to promote crystallization of the desired product from the complex media. The results indicated that is possible to perform the reaction and crystallization in parallel, and still recover crystals with high purity. This work is the first example in which ampicillin was produced and recovered with high purity in a single stage. Previous work on reaction crystallization of antibiotics reported ampicillin crystallization; however, this was accompanied by precipitation of by-products which greatly reduces the applicability of the operation as product purification is required after the reaction.
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Zhang, Chunhui. "Controlled cooling of permanent mold castings of aluminum alloys." Thesis, McGill University, 2003. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=19619.
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The permanent mold casting process is a relatively popular and effective casting technology that can produce near-net-shape aluminum components with integrity, particularly for the automotive and aerospace industries. It is well recognized by the casting industry that it is essential to control the cooling of permanent mold castings in order to improve the quality of the castings, so there is a considerable incentive to develop a more effective method of mold cooling to control the temperature distribution of the mold and the casting. The current technologies for controlled cooling are air or water cooling passages and chill inserts. Each of these cooling methods presents certain disadvantages, and none offer optimum cooling control. Based on these considerations, a novel, effective and controllable water-based heat pipe has been successfully developed to be used as a new method of permanent mold cooling where high heat fluxes are normally encountered. Heat pipes featuring this design have been incorporated in an experimental permanent mold made of HI3 tool steel that contains three symmetric steps. Computer modeling for the permanent mold casting process has been accomplished to predict the effect and potential of heat pipe cooling for permanent mold casting. Castings of A3 56 alloy have been produced by this permanent mold. The effects of heat pipe cooling on permanent mold castings have been evaluated by analyzing the temperature distribution of the mold and the casting, as well as by measuring the dendrite arm spacing and shrinkage distribution of the castings. The effect of heat pipe cooling on the mold solidification time of castings of A356 alloy with different coating types was also studied. Industrial trials have been carried out to evaluate this new cooling technology on an industrial scale casting machine. Because the space around the mold installed on a low pressure die casting machine is very limited, it is often very difficult to install the heat pipe in the specific desired location in the mold. A new version flexible heat pipe cooling system has been developed for the industrial casting process. Preliminary and industrial tests of the heat pipe cooling system have been performed. The effects of heat pipe cooling, as well as the effects of using traditional water and air cooling on the low pressure die casting were studied. Data on the cooling rates obtained by heat pipes, as well as some microstructures and measurements of the dendrite arm spacing are presented in this thesis. Modeling and experimental results have shown that the water based heat pipe can provide high cooling rates in casting processes. The dendrite arm spacing (DAS) of A356 alloy is refined considerably by the heat pipes, and changes in the shrinkage pattern are provided by the dramatic changes in the heat flow patterns.
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Vagenas, Alexios. "Actively controlled cooling jets for application to IC engines." Thesis, University of Bath, 2003. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.426146.
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Jiang, Mo. "Pharmaceutical crystallization design using micromixers, multiphase flow, and controlled dynamic operations." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/98708.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Chemical Engineering, 2015.Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 198-214).
Crystallization is a key unit operation in the pharmaceutical industry. Control of crystallization processes can be challenging when undesirable phenomena such as particle attrition and breakage occur. This thesis describes the controlled crystallization of pharmaceuticals and amino acids for more efficient manufacturing processes and better efficacy of products. Crystallization equipment is designed so that (1) the undesirable phenomena do not occur at all, and/or (2) the phenomena that do occur are carefully controlled. One key strategy is to exploit dual-impinging jets and multiphase flow to decouple nucleation and growth so that they can be individually controlled. Various configurations of micromixers were designed to provide controlled nucleation. Based on the dual-impinging-jet (DIJ) configuration, a physical explanation was provided for the discovery that a cooling micromixer can generate small crystals of uniform size and shape. An alternative design replaces the micromixing with the application of ultrasonication to decouple nucleation and flow rates. Based on these nucleation methods, a novel continuous crystallizer is designed where the slurry flow is combined with an air flow to induce a multiphase hydrodynamic instability that spontaneously generates slugs where the crystals continue to grow. These slugs are well-mixed without having the mixing blades in traditional crystallizer designs that induce undesirable uncontrolled crystallization phenomena. Another key strategy is to increase the degrees of freedom in the dynamic operation of the crystallizers. In the slug-flow continuous crystallizer, extra degrees of freedom for control of the crystal growth are created by spatially varying the temperature profile along the tube. In a semi-continuous crystallizer configuration, continuous seeding using a DIJ mixer is combined with growth rate control in a stirred tank to experimentally demonstrate the manufacture of uniform-sized crystals. In addition, temperature-cycling experiments are designed in batch crystallizers to substantially change crystal shape with only a small number of cycles. Experimental validation confirms that the proposed crystallizer designs reduce production time and equipment cost by orders of magnitude while suppressing secondary nucleation, attrition, and aggregation/agglomeration-dominant but undesired phenomena that worsen the ability to control the properties of crystals produced by most existing crystallizer designs.
by Mo Jiang.
Ph. D.
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Wang, Jianwei. "An experimental investigation of droplet impact cooling at controlled surface temperatures." Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/17329.
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Zhou, Jun Hu Zhibing. "Stimuli-responsive microgels for self-assembled crystalline structures and controlled drug release." [Denton, Tex.] : University of North Texas, 2009. http://digital.library.unt.edu/permalink/meta-dc-11001.
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Li, Jicong Ph D. Massachusetts Institute of Technology. "Novel continuous crystallization configurations for improved yield, purity and controlled crystal size distribution." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/104210.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Chemical Engineering, 2016.Cataloged from PDF version of thesis.
Includes bibliographical references.
Continuous crystallization process has potential advantages such as lower cost and improved flexibility in pharmaceutical production when compared to batch crystallization. A good continuous crystallization process should achieve a high product yield and purity comparable to current batch crystallization processes. The aim of this thesis is to develop novel continuous crystallization process to enhance the final yield while control the quality of the crystal product. Three different approaches were studied: (1) the use of continuous solids recycle to enhance the yield by increasing the crystal surface area and total crystal mass deposition; (2) the optimization of multistage continuous mixed-suspension, mixed-product removal (MSMPR) crystallization to minimize the number of stages and total residence time; (3) the combination of impurity complexation and organic solvent nanofiltration to remove the impurity that has similar molecular weight and structure to the active pharmaceutical ingredient (API). For the first two approaches, continuous crystallization processes of cyclosporine were developed. The first method, solids recycle, successfully increased the surface area of crystals in the crystallizer thus increasing the mass deposition rate. With solids recycle to the second stage and both stages, 75.3% and 79.8% in yield were achieved, respectively. The product purity remained the same while the yield was enhanced. The second method proved that optimization of stage conditions could help obtain high yield and purity within short residence time. Different behaviors of the impurities were investigated and the impurity distribution model helped estimate the highest product purity achievable of the process. The results showed that optimization in stage number and stage temperatures could improve the yield close to the batch yield at equilibrium. In the third method, fenofibrate and fenofibric acid system with 1,3-di-otolylguanidine (DOTG) as complexing agent was studied. Complexing agent firstly formed hydrogen bonds with the impurity specifically, thus reduced the structure similarity of the API and impurity. It became more difficult for the impurity molecules to incorporate into the API crystal lattice. Then organic solvent nanofiltration membrane separated the API and complex in the mother liquor. By recycling the purified mother liquor back to the crystallizer, the final yield of the process was improved.
by Jicong Li.
Ph. D.
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Plachynta, Maksym. "Studies on cryopreservation of zebrafish (Danio rerio) oocytes using controlled slow cooling." Thesis, University of Bedfordshire, 2007. http://hdl.handle.net/10547/622016.
Full textAbstract:
Cryopreservation of fish germ cells has important applications in aquaculture, conservation of endangered species and human genomic studies. Although investigations on cryopreservation of fish sperm and embryos have been carried out extensively, cryopreservation of fish oocytes has not been studied systematically. The objective of the present study was to develop successful cryopreservation protocol for zebrafish oocytes at temperature of liquid nitrogen (-196°C), or if unachieved, to investigate the limiting factors associated with fish oocytes cryopreservation. In this study, the effects of cryoprotectants exposure and enzymatic treatments on oocytes survival were studied, and new viability tests for zebrafish oocytes were developed. The effects of controlled slow cooling with different cryoprotective agents, in different freezing media and at different cooling rates on cryosurvival of zebrafish (D. rerio) oocytes were investigated. Cryomicroscopic observations on zebrafish oocytes were also carried out. Three reliable vital tests -trypan blue (TB) staining, ATP assay, and in vitro maturation followed by germinal vesicle breakdown observation (GVBD) were found suitable for assessment of oocytes viability. Vitellogenesis (stage III) was found to be the optimal developmental stage for cryopreservation. Methanol was found to be the best CPA for zebrafish oocytes. Combination of 4M methanol and 0.2M glucose in potassium chloride (KCI) buffer was found to be the optimal cryoprotective solution. Controlled slow cooling at 0.3°C/min rate, combined with seeding at -12.5°C and plunge to liquid nitrogen (LN) at-40°C were found to be the optimal conditions for cryopreservation of stage III oocytes. However, even with the optimal protocol, TB-assessed viability, Le. the ratio of oocytes with intact plasma membrane after cooling to -196°C was 19.6±8%. Furthermore, GVBD experiments showed that none of the cryopreserved oocytes can be matured in vitro, and their ATP levels were decreased dramatically, indicating that successful cryopreservation of fish oocytes at liquid nitrogen temperature still remains elusive. Cryomicroscopic observations demonstrated, that the damages of oocytes are associated with intracellular ice formation (lIF). IIF occurred simultaneously with extracellular ice formation (ElF) in nearly 100% of the cases, and formation of lethal hexagonal type of ice was observed. This study was the first systematic attempt to cryopreserve fish oocytes at liquid nitrogen temperature. The results provided will undoubtedly assist successful protocol design for cryopreservation of fish oocytes in the future.
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Campbell, Peter Cameron. "Application of microstructural engineering to the controlled cooling of steel wire rod." Thesis, University of British Columbia, 1989. http://hdl.handle.net/2429/29065.
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The concept of microstractural engineering has been applied to Stelmor cooling of steel wire rod. The Stelmor process is situated immediately following the rod mill and utilizes forced air to cool steel rod from the rolling temperature, through austenite transformation, down to a temperature suitable for handling. A mathematical model has been developed for the prediction of the mechanical properties of the steel rod as a function of cooling parameters in the process and steel composition. The model is based on one-dimensional heat conduction within the rod and is limited to plain-carbon eutectoid and hypoeutectoid steels. Phase transformation kinetics in the model, for both the austenite-ferrite and austenite-pearlite reactions, have been characterized through the use of the Avrami equation. A combination of experimental and literature data have been employed for the development of equations to quantitatively predict the microstructure formed in the steel rod after transformation. A modified Gladman equation was adopted for the strength predictions.
Validation of the model has been achieved with controlled cooling experiments conducted in the laboratory. The experiments were designed to simulate the Stelmor process, involving a range of steel grades, rod diameters and air velocities. Thermal histories in steel rod samples during forced air cooling were acquired by mounting a thermocouple at the centreline of each rod. After cooling, the rod samples were subjected to microstructural examination and mechanical testing. Results from this investigation were utilized to develop relationships among steel composition, thermal history and ferrite fraction, ferrite grain diameter and pearlite interlamellar spacing. The laboratory data was also utilized to modify the strength predictions of the Gladman equation.
In order to obtain information on cooling conditions in an industrial setting, a series of experiments has been conducted on an operating Stelmor line at the No. 2 Rod Mill of Stelco Hilton Works. The technique followed in the plant trials was similar to that employed in the laboratory and the thermal histories of the test rods allowed the mathematical model to be "tuned" to operating conditions. Mechanical properties for several industrial steel grades were also measured during the plant trials, and have been applied to test the predictive capability of the model.
Comparisons of the model-predicted thermal histories, microstructures and mechanical properties with those measured in both the laboratory and plant tests have been made. The results of the thermal history comparison for both laboratory and plant conditions showed good agreement between the model-predicted and measured centreline temperatures of control-cooled steel rod. Predicted temperatures during the austenite-ferrite and austenite-pearlite phase transformations were within the expected error associated with prediction of transformation kinetics. Good agreement was obtained between model-predicted and measured ferrite fraction, ferrite grain diameter and interlamellar pearlite spacing. Yield strengths and ultimate tensile strengths predicted by the model for the laboratory and plant tests displayed excellent agreement with measured strengths.
In order to obtain a test of the predictive capability of the model under Stelmor line conditions, an independent set of ultimate tensile strengths for Stelmor-cooled steel grades was obtained. These samples were taken directly from grades being processed on the line. A comparison between model-predicted and measured UTS for these grades yielded excellent agreement in the 1020-1040 and eutectoid composition range, with a fair prediction obtained for 1055-1065 grades.Applied Science, Faculty of
Materials Engineering, Department of
Graduate
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Giacomelli, Gene, and Kathryn Hahne. "Evaporative Cooling in Semi-Arid Climates." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2008. http://hdl.handle.net/10150/146294.
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2 pp.In the semi-arid climate of southern AZ, evaporative cooling systems are commonly used and very effective for cooling homes (swamp coolers), outdoor areas (misters), and for greenhouses used for commercial and horticultural plant production (pad-and-fan, high-pressure-fog). The purpose of this brochure is to educate users about strategies they can employ to save water and improve the performance of evaporative cooling systems. Principles of operation, a list of advantages and disadvantages, and a comparison of common systems is also included, to help users decide the best system for them.
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Aybar, Sultan. "Solidification And Crystallization Behaviour Of Bulk Glass Forming Alloys." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608922/index.pdf.
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The aim of the study was to investigate the crystallization kinetics and solidification behaviour of Fe60Co8Mo5Zr10W2B15 bulk glass forming alloy. The solidification behaviour in near-equilibrium and non-equilibrium cooling conditions was studied.
The eutectic and peritectic reactions were found to exist in the solidification sequence of the alloy. The bulk metallic glass formation was achieved by using two
methods: quenching from the liquid state and quenching from the semi-state.
Scanning electron microscopy, x-ray diffraction and thermal analysis techniques
were utilized in the characterization of the samples produced throughout the study.
The choice of the starting material and the alloy preparation method was found to be
effective in the amorphous phase formation.
The critical cooling rate was calculated as 5.35 K/s by using the so-called Barandiaran and Colmenero method which was found to be comparable to the best glass former known to date.
The isothermal crystallization kinetics of the alloy was studied at temperatures
chosen in the supercooled liquid region and above the first crystallization
temperature. The activation energies for glass transition and crystallization events
were determined by using different analytical methods such as Kissinger and Ozawa
methods.
The magnetic properties of the alloy in the annealed, amorphous and as-cast states
were characterized by using a vibrating sample magnetometer. The alloy was found
to have soft magnetic properties in all states, however the annealed specimen was
found to have less magnetic energy loss as compared to the others.
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Barthe, Stephanie Cecile. "Investigation and modeling of the mechanisms involved in batch cooling crystallization and polymorphism through efficient use of the FBRM." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24752.
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Thesis (Ph.D.)--Chemical Engineering, Georgia Institute of Technology, 2009.Committee Chair: Dr Rousseau, Ronald W; Committee Co-Chair: Dr Grover Gallivan, Martha; Committee Member: Dr Realff, Matthew; Committee Member: Dr Garmestani, Hamid; Committee Member: Dr Nenes, Athanasios.
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Lührmann, Marie-Christine [Verfasser]. "A Contribution to the Design and Operation of an MSMPR Cascade for Cooling Crystallization / Marie-Christine Lührmann." München : Verlag Dr. Hut, 2019. http://d-nb.info/1202169686/34.
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BROCKMAN, TRACY. "Dynamics of Cooling and Plagioclase Crystallization in a Feeder Dike of the Columbia River Flood Basalt Group." University of Cincinnati / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1213234666.
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Guan, Mo. "Studies on cryopreservation of zebrafish (Danio rerio) oocytes using controlled slow cooling and vitrification." Thesis, University of Bedfordshire, 2009. http://hdl.handle.net/10547/134933.
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Cryopreservation of gametes provides a promising method to preserve fish genetic materials, which offers many benefits to the fields of aquaculture, conservation and biomedicine. Although successful cryopreservation of spermatozoa of about 200 fish species has been achieved, systematic studies on cryopreservation of fish oocytes have only recently been undertaken. The objective of the present studies was to use zebrafish as a model system to develop a cryopreservation protocol for fish oocytes and to develop reliable viability assessment methods for monitoring zebrafish oocyte viability both before and after cryopreservation. A simple and rapid enzymatic method for zebrafish oocytes isolation was developed and the investigations on cryopreservation of zebrafish oocytes using improved controlled slow cooling and vitrification were carried out. Oocyte viability following cryopreservation was investigated by ATP assay, oocyte viability molecular signature (OVMS) and cryomicroscopic observation in addition to staining methods. The optimum conditions for oocyte enzymatic separation were identified as 0.4mg/ml collagenase or 1.6mg/ml hyaluronidase treatment for 10min at 22ºC and this method can be used for oocytes at all stages. The use of sodium free medium (KCl buffer), fast warming and 4-step removal of cryoprotectants in an improved controlled slow cooling protocol significantly enhanced oocyte viability (67.5 ± 1.7%) when compared with a previous study (16.3 ± 2.3%) in this laboratory. Mixtures of cryoprotectants (methanol, Me2SO and propylene glycol), stepwise addition and removal of cryoprotectants in combination of a new vitrification system (CVA65 vitrification system) were used in vitrification studies. Oocyte survivals after vitrification assessed by trypan blue staining were relatively high (76.5 ± 6.3%) shortly after warming in KCl buffer. Furthermore, the result of ATP assay showed that ATP levels in oocytes decreased significantly after cryopreservation indicating the bioenergetic systems of oocytes were damaged. Cryomicroscopic observations demonstrated that Intracellular ice formation (IIF) is the main factor causing injuries during cryopreservation of zebrafish oocytes. The results provided by the present study will assist successful protocol design for cryopreservation of fish oocytes in the future.
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Yang, Huaiyu. "Investigations intothe crystallization of butyl paraben." Licentiate thesis, KTH, Teknisk strömningslära, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-34051.
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In thisproject, solubility of butyl paraben in 7 puresolvents and 5 ethanol aqueous solvents has been determined at from 1 ℃to 50 ℃. Thermodynamic properties of butyl paraben have been measured by DifferentialScanning Calorimetey. Relationship between molar solubility of butyl paraben in6 pure solvents and thermodynamic properties has been analyzed. Thisrelationship suggests a method of estimating activity of solute at equilibrium fromcombining solubility data with DSC measurements. Then, activity coefficient accordingto the solubility at different temperatures can be estimated. Duringthe solubility measurements in ethanol aqueous solvents, it is found that whenbutyl paraben is added into aqueous solutions with certain proportion ethanol,solutions separates into two immiscible liquid layers in equilibrium. Water andethanol are primary in top layer, while the butyl paraben is primary in bottomlayer, but the solution turns to cloudy when two layers of solution are mixed. Theaim of this work was to present the phase behaviour of liquid-liquid-phaseseparation for (butyl paraben + water + ethanol) ternary system from 1 ℃ to 50 ℃at atmospheric pressure. Thearea of liquid-liquid-phase separation region in the ternary phase diagram increaseswith the increasing temperature from 10 ℃to 50 ℃. In thisstudy, more than several hundreds of nucleation experiments of butyl paraben havebeen investigated in ethyl acetate, propanol, acetone and 90% ethanol aqueoussolution. Induction time of butyl paraben has been determined at 3 differentsupersaturation levels in these solvents, respectively. Free energy ofnucleation, solid-liquid interfacial energy, and nuclei critical radius havebeen determined according to the classical nucleation theory. Statistical analysis ofinduction time reveals that the nucleation is a stochastic process with widevariation even at the same experiment condition. Butyl paraben nucleates most difficultlyin 90 % ethanol than in other 3 solvents, and most easily in acetone. The interfacialenergy of butyl paraben in these solvents tends to increasing with decreasemole fraction solubility in these solvents. Coolingcrystallizations with different proportions of butyl paraben, water and ethanolhave been observed by Focused Beam Reflectance Method, Parallel VirtualMachine, and On-line Infrared. The FBRM, IR curves and the PVM photos show someof the solutions appeared liquid-liquid phase separation during coolingcrystallization process. The results suggest that if solutions went throughliquid-liquid phase separation region during the cooling crystallizationprocess the distribution of crystals crystal was poor. Droplets from solutions withsame proportion butyl paraben but different proportions of water and ethanolhave been observed under microscope. Induction time of the droplets has been determinedunder the room temperature. Droplets from top layer or bottom layer of solutionwith liquid-liquid phase separation on small glass or plastic plates were alsoobserved under microscope. The microscope photos show that the opposite flows ofcloudy solution on the glass and the plastic plate before nucleation. The resultsof the cooling and evaporation crystallization experiments both revealed thatnucleation would be prevented by the liquid-liquid phase separation.QC 20110630
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Reiber, Andreas. "Nanostructuring by templated synthesis of nanowires and controlled crystallization of calcium phosphate on self-assembled monolayers." [S.l. : s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=976057190.
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Ieong, Nag Sze. "Strain-controlled photoreactivity of (1)ferrocenophanes and living crystallization-driven self-assembly of polyferrocene-based block copolymers." Thesis, University of Bristol, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.503875.
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This Thesis describes three major projects which cover three distinctive areas, namely, organometallic, polymer and materials chemistry. Chapter 1 provides an introduction to the Thesis. First, an overview of strained cycles is given, with particular emphasis on strained [1]ferrocenophanes which includes an overall description of strain related structural properties and their influence in ring-opening reactions. Then strained rings as precursors to polymers by ring-opening polymerization (ROP) is discussed with special focus on the polyferrocenylsilane (PFS) based homopolymers and block polymers obtained from ROP of strained sila[1]ferrocenophane monomers.
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Barker, Michael Francis. "Crystallization of lithium alumino-silicate glasses and the formation of photomachinable glass ceramics of controlled thermal expansion." Thesis, University of Sheffield, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362506.
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Zulkurnain, Musfirah. "Crystallization of Lipids under High Pressure for Food Texture Development." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1500557652861233.
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de, Oliveira Mónica Sandra Abrantes. "The use of air assisted atomised water spray systems for controlled cooling of high temperature forgings." Thesis, University of South Wales, 1999. https://pure.southwales.ac.uk/en/studentthesis/the-use-of-air-assisted-atomised-water-spray-systems-for-controlled-cooling-of-high-temperature-forgings(46c7cbe3-4bc5-443a-b9ea-de43af504fcc).html.
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This thesis describes the work undertaken by the author in collaboration with Wyman-Gordon Forgings, USA, to assist in the development of a cooling system,based on air assisted atomised water sprays primarily for the quenching of aerospace components from high temperatures. The mechanical properties of forgings used in aircraft engines depend on the rate of cooling from the heat treatment solution temperature. It is well known that water quenching produces high cooling rate. Although, the severity of the quench can sometimes produce unacceptable distortion and high residual stresses in the component. For this reason water quenching is only used when a high cooling rate is definitely needed and it is often replaced by a less severe oil quench. However, over the last 10 years the trend to reduce manufacturing costs has led to the forging of parts that are closer to the net shape. In these cases even oil quenching can lead to residual stresses being developed that result in difficulties during the final machining of the engine component. Forced air cooling has been adopted in problem cases where the part is thin enough to attain the desired cooling rate. In many instances, however, the component is of intermediate size or varying in cross section and fan cooling cannot provide the cooling rate which is needed to obtain the desired mechanical properties, whilst oil quenching produces an unacceptable level of residual stresses. The use of air assisted atomised water sprays can provide heat transfer coefficients whose values lie between those for air cooling and oil quenching. Another advantage is that control of the air pressure enables the spray nozzle to operate with a much wider range of water flow rates so that the cooling rate can be readily controlled over the range. This study describes the investigation of the heat transfer characteristics of air assisted atomised water sprays to quench aeroengine components from temperatures of approximately 850°C. New data were obtained at high temperatures for air assisted atomised water sprays operating over a wide range of water mass fluxes, (8.01>w 0 >0kg/m2 .s). In practice the geometry of a component can be complex in shape. Therefore an investigation was also carried out into the application of spray cooling on recessed surfaces. It was found that the surface recess contributes significantly to the reduction in the rate of heat transfer at low and high water mass fluxes, but had little effect at intermediate flow rates. Pulsed sprays were investigated and proposed as a means of controlling heat transfer coefficients for both plane and recessed surfaces. The use of a pulsed spray makes it possible to control the amount of water impacting on a surface per second. It was found that "water off periods of 5 and 10 seconds resulted in a reduction in heat transfer coefficients at low temperatures and also reduced considerably the differences in cooling previously observed between plane and recessed surfaces. A finite element code was used to predict the residual stresses produced in a forged component for a range of spray parameters, and spray arrangements. The data were compared with cooling rates and stress patterns produced by both air and oil quenching. It was found that spray cooling resulted in cooling rates which met the mechanical property specification and provided residual stresses lower than those obtained during oil quenching. Furthermore, simulations of residual stress formation using two different spray arrangements in a typical forging indicated that spray non uniformities can substantially disturb the resultant residual stress patterns which could result in less predictable distortions during final machining. The study of spray cooling presented here suggests that the use of air assisted atomised water sprays has considerable potential and could provide the required cooling rate for individual forgings.
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Clogston, Jeffrey. "Applications of the lipidic cubic phase from controlled release and uptake to in meso crystallization of membrane proteins /." Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1117564268.
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Thesis (Ph.D.)--Ohio State University, 2005.Title from first page of PDF file. Document formatted into pages; contains xxii, 352 p.; also includes graphics. Includes bibliographical references (p. 346-352). Available online via OhioLINK's ETD Center
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Clogston, Jeffrey. "Applications of the lepidic cubic phase: from controlled release and uptake to in meso crystallization of membrane proteins." The Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=osu1117564268.
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Zhou, Jun. "Stimuli-responsive microgels for self-assembled crystalline structures and controlled drug release." Thesis, University of North Texas, 2009. https://digital.library.unt.edu/ark:/67531/metadc11001/.
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Tissue response to PNIPAM and HPC nanoparticles has been studied by implantation method. The results suggest that both PNIAPM and HPC nanoparticles possess good biocompatibility and they may serve as a good carrier for the applications of controlled delivery. Rheological properties of dispersions of IPN microgels composed of PNIPAM and PAAc have been studied. It is found that the IPN microgel dispersion can undergo a sol-gel transition at temperature above 33°C. In vivo drug release experiments suggest that the gelation procedure creates a diffusion barrier and thus leads to slow release. An emulsion method has been used to grow columnar crystals by mixing PNIPAM microgel dispersions with organic solvents. Effect of both temperature and microgel concentration on formation of columnar crystals has been studied. PNIPAM-co-NMA microgels have been used for the fabrication of crystalline hydrogel films by self-crosslinking microgels. The hydrogel film exhibits an iridescent. The thermally responsive properties and mechanical properties of this film have been studied. Melting temperature (Tm) of colloidal crystals self-assembled with PNIPAM-co-AAc microgels has been investigated as a function of pH, salt concentration and microgel concentration. It is revealed that Tm increases as pH value increases; Tm decreases with increase of salt concentration; Tm increases as microgel concentration increases. Phase behavior of PNIPAM-co-HEAc microgel dispersions has been investigated. It is observed that these microgel dispersions exhibit liquid, crystal, and glass phase. As microgel size increases, crystal phase shifts to low concentration range. As temperature increases, crystal phase shifts to high concentration ranges. These colloidal crystals can be stabilized by NaOH-induced gelation. Effect of NaOH concentration on formation of physical gelation has been investigated.
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Erdiller, Emrah Salim. "Investigation Of Solidification And Crystallization Of Iron Based Bulk Amorphous Alloys." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/3/1096585/index.pdf.
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The aim of this study is to form a theoretical model for simulation of glass forming ability of Fe �
Based bulk amorphous alloys, to synthesize Fe &
#65533
based multicomponent glassy alloys by using the predictions of the theoretical study, and to analyze the influence of crystallization and solidification kinetics on the microstructural features of this amorphous alloys. For this purpose, first, glass forming ability of Fe &
#65533
(Mo, B, Cr, Nb, C) &
#65533
X ( X = various alloying elements, selected from the periodic table) ternary alloy systems were simulated for twenty different alloy compositions by using the electronic theory of alloys in pseudopotential approximation and regular solution theory. Then, by using the results of the theoretical study, systematic casting experiments were performed by using centrifugal casting method. The alloying elements were melted with induction under argon atmosphere in alumina crucibles and casted into copper molds of different shapes. Characterization of the cast specimens were performed by using DSC, XRD, SEM, and optical microscopy. Comparison of equilibrium and nonequilibrium solidification structures of cast specimens were also performed so as to verify the existence of the amorphous phase. Good agreement of the results of experimental work, with the predictions of the theoretical study, and the related literature was obtained.
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Tippetts, Megan. "Effect of Processing and Formulation Conditions on Physicochemical Characteristics of Food Emulsions." DigitalCommons@USU, 2008. https://digitalcommons.usu.edu/etd/147.
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The objective of this research was to systematically study the effect of processing conditions on crystallization behavior and destabilization mechanisms of oil-in-water (o/w) emulsions. The effects of oil content (20 and 40 wt %); crystallization temperature (Tc = 10, 5, 0, -5, -10 °C); homogenization conditions, such as high shear (HS), very low pressure homogenization (VLPH), and high pressure homogenization (HPH); and cooling rate (0.2 and 30 °C/min) on both thermal behavior and destabilization mechanisms were analyzed. Docosahexaenoic acid (DHA) was added to VLPH emulsions and its effect on the physicochemical and oxidative stabilities and flavor was studied. Emulsions with 20% oil were less stable than those with 40% oil with a fast-cooling rate; however, stability increased when the emulsions were cooled slowly. Stability was also affected by oil and droplet size; the smaller the droplet the more stable the system. Smaller droplets (i.e., VLPH, HPH) had an effect on crystallization by delaying the onset of the crystal formation, which was promoted in emulsions with larger droplets (i.e., HS); 20% o/w emulsion crystallization was delayed more than 40%; and in emulsions crystallized using a slow-cooling rate, the crystal formation was less inhibited (i.e., crystals formed at a higher onset temperature [Ton], but at lower Tc) than when using a fast-cooling rate. The formation of lipid crystals either helped stabilize (small droplets) the emulsion and melted in a less fractionated manner or destabilized (big droplets) the emulsion. In addition, fast-cooling rates have greater fractionation than slow-cooling rates. Due to the greater stability of VLPH emulsions after thawing from being at -10 °C for 3 h, DHA was added to evaluate its effect on flavor (besides the effect on stability) of the emulsion. A descriptive panel was used to evaluate four attributes: oxidized, rancid, fishy, and buttery. The panelists were given samples after 72 h, because contrary to the TBA analysis which showed no significant differences between samples with and without DHA, the fishy smell was evident. The sensory evaluation results showed that there was a significant (p < 0.05) difference in fishiness between the VLPH emulsions with and without DHA, and that the odor was repulsive. No significance was seen for rancid and buttery flavors, and only a marginal significance was seen for oxidized.
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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.QC 20130515
investigate nucleation and crystallization of drug-like organic molecules
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Huang, Gang. "Synthesis and study of crystalline hydrogels, guided by a phase diagram." Thesis, University of North Texas, 2004. https://digital.library.unt.edu/ark:/67531/metadc4698/.
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Monodispersed nanoparticles of poly-N-isopropylacrylamide-co-allylamine (PNIPAM-co-allylamine) and PNIPAM-co-acrylic acid (AA) have been synthesized and used as building blocks for creating three-dimensional networks. The close-packed PNIPAM-co-allylamine and PNIPAM-co-AA nanoparticles were stabilized by covalently bonding neighboring particles at room temperature and at neutral pH; factors which make these networks amicable for drug loading and release. Controlled release studies have been performed on the networks using dextran markers of various molecular weights as model macromolecular drugs. Drug release was quantified under various physical conditions including a range of temperature and molecular weight. These nanoparticle networks have several advantages over the conventional bulk gels for controlling the release of biomolecules with large molecular weights. Monodispersed nanoparticles of poly-N-isopropylacrylamide-co-allylamine (PNIPAM-co-allylamine) can self-assemble into crystals with a lattice spacing on the order of the wavelength of visible light. By initiating the crystallization process near the colloidal crystal melting temperature, while subsequently bonding the PNIPAM-co-allylamine particles below the glass transition temperature, a nanostructured hydrogel has been created. The crystalline hydrogels exhibit iridescent patterns that are tunable by the change of temperature, pH value or even protein concentration. This kind of soft and wet hydrogel with periodic structures may lead to new sensors, devices, and displays operating in aqueous solutions, where most biological and biomedical systems reside. The volume-transition equilibrium and the interaction potential between neutral PINPAM particles dispersed in pure water were investigated by using static and dynamic light-scattering experiments. From the temperature-dependent size and energy parameters, the Sutherland-like potential provides a reasonable representation of the inter-particle potential for PNIPAM particles in swollen and in collapsed phases. An aqueous dispersion of PNIPAM particles can freeze at both high and low temperatures. At low temperatures, the freezing occurs at a large particle volume fraction, similar to that in a hard-sphere system; while at high temperature, the freezing occurs at low particle concentrations, driven by the strong van der Waals attraction due to the collapsed microgel particles. The calculated phase diagram has been confirmed semi-quantitatively by experiments.
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Anaya, Fernandez Silvia Cristina 1982. "Produção e caracterização de micropartículas lipídicas obtidas por spray cooling compostas por cera de caranaúba, ácido oleico e lecitina na encapsulação de solução de glicose e glicose sólida." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/255989.
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Orientador: Carlos Raimundo Ferreira GrossoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: Apesar da facilidade da produção e da possibilidade de fabricação em escala industrial, as micropartículas lipídicas apresentam desvantagens como a baixa capacidade de encapsula-ção e a possibilidade de expulsão do material de recheio durante o armazenamento. Foram propostas micropartículas lipídicas contendo lipídios sólidos e líquidos como mate-riais de parede com o objetivo de minimizar a expulsão do material de recheio. Desta forma o presente trabalho teve como finalidade estudar a formação de microcápsulas lipídicas produzidas pelo processo Spray Cooling, compostas por misturas, em diferentes proporções de ácido oleico, linolênico e cera de carnaúba como matriz, lecitina de soja como surfactante e solução de glicose e glicose sólida como materiais de recheio. O objetivo foi aumentar a eficiência de encapsulação, avaliando e verificando o efeito da composição e estrutura da matriz lipídica, testando o comportamento da partícula com a inclusão de um novo compo-nente na matriz lipídica como é a cera de carnaúba. Nas micropartículas foram avaliadas a morfologia de superfície e microestrutura por microscopia eletrônica de varredura, tamanho e distribuição de partícula, quantidade de glicose superficial (não encapsulada), eficiência de encapsulação e comportamento de liberação do recheio em solução aquosa. As micro-partículas apresentaram formas esféricas com paredes rugosas, os diâmetros médios situa-ram-se numa faixa de 36 e 58 µm. Os resultados de eficiência de encapsulação nas misturas com a glicose em solução encontraram-se numa faixa de 52 a 62%, e nas misturas contendo o recheio sólido os valores de eficiência de encapsulação situaram-se numa faixa de 54 a 66%. As maiores quantidades de glicose superficial foram encontradas nas formulações nas quais foram adicionadas quantidades de recheio sólido. A liberação do recheio foi avaliada a cada 30 minutos durante 2 horas, observando-se que nos primeiros 30 minutos, as formu-lações que continham a glicose sólida apresentaram valores acima de 86% (efeito burst), enquanto que a liberação do recheio nas misturas contendo a glicose em solução apresentou valores de 22 a 72%. Ao término desse período, nestas misturas foi observado que a libera-ção de recheio ocorreu progressivamente. A utilização da matriz lipídica nas formulações parece responsável pelos resultados, considerando que a adição do lipídio liquido à cera de carnaúba foi um fator determinante na modificação da cristalização da mistura lipídica pro-porcionando uma melhoria na eficiência de encapsulação destas partículas
Abstract: The manufacturing and large scale production of micro particles is easy; however these products show some disadvantages such as poor encapsulation and deficient core material expulsion during storage. To avoid this problem the use of nanostructured lipids have been proposed with the purpose of minimizing the expulsion of core material. This work was conducted to study the formation of lipid microcapsules, produced during spray cooling, from mixtures which contained different proportions of: oleic acid and carnauba wax as matrices, soybean lecithin as a surfactant and glucose solution and solid glucose as core materials. The objective of this study was to increase the efficiency of encapsulation by assessing and verifying the effect of composition and structure of the lipid matrix. The per-formance was evaluated with the addition of a new compound, carnauba wax, in the lipid matrix. In the micro particles the following variables were assessed: superficial morphology and microstructure by electron microscopy, size and particle distribution, amount of super-ficial glucose (not encapsulated), efficiency of encapsulation and performance of releasing core material in an aqueous solution. The micro particles showed spherical shapes with rough walls, the average diameters varied from 36 and 58 µm. Results of encapsulation efficiency were from 52 - 62% for mixtures of glucose solution and from 54 - 66% for mix-tures with solid core. More superficial glucose quantities were found in formulations in which solid cores were added. Core releasing was assessed every 30 minutes during 2 hours; during the first 30 minutes, the formulations containing solid glucose showed values > 86% (burst effect) while the releasing of core material from mixtures containing glucose solution varied from 22-72% where the release increased progressively during this time. The use of a lipid matrix in the formulations may be responsible for these results because the addition of a liquid lipid (AO) to carnauba wax was a crucial factor in the crystallization modification of the lipid mixture providing reasonable encapsulation efficiency
Mestrado
Consumo e Qualidade de Alimentos
Mestra em Alimentos e Nutrição
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Ghahremanian, Shahriar, and Setareh Janbakhsh. "Construction and Evaluation of a Controlled Active Mass (CAM) : A new cooling system design for increased thermal comfort using low exergy sources." Thesis, University of Gävle, Department of Technology and Built Environment, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-146.
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Nowadays, office buildings often have large temperature variations during the day and building envelope acts as an energy storing mass and damp these effects and so Offices need more cooling because of internal heat sources. But we know that cooling is more expensive than heating and it uses the very good quality of energy sources (exergy). Controlled Active Mass (CAM) is new approach to absorb radiant heating and acts as a passive cooling device. It has direct cooling effect and reduces the peak load. CAM is a new cooling system design with applying the low energy sources and operates at water temperature close to room temperature and increase the efficiency of heat pumps and other systems.
In this project, we calculated the transient heat transfer analysis for CAM in a very well insulated test room with façade wall, Internal heat generators (such as Manikin, Computer simulator & lighting) and ventilation.
Then Polished (shiny) CAM constructed from Aluminum sheets with 0.003 m thickness. It is cube shape with 0.6 m length. This size of CAM is according to 2.5 times larger than human body volume and initial water temperature assumed near half of human body temperature. Then in order to more radiation damping (absorption) by CAM, it painted black (also based on color analysis in heat transfer calculation).
Some velocity and temperature measurement have been carried out on both polished CAM and black CAM, after visualization by smoke and Infrared Camera. And more cases tested to see the effect of façade wall, IHG’s and ventilation inlet temperature. Thermal comfort measurement also have been done for finding PMV, PPD and temperature equivalent for a seated person which is doing an office job with normal closing.
At the end results discussed which includes the effect of CAM in room, differences between polished CAM and black CAM and effect of main heat sources on both CAM types (Polished / Black).
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Carreau, Thomas. "Modeling the (proto)neutron star crust : toward a controlled estimation of uncertainties." Thesis, Normandie, 2020. http://www.theses.fr/2020NORMC206.
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L’objectif principal de cette thèse est de fournir des prédictions réalistes et d’étudier les sources d’incertitudes sur les observables des étoiles à neutrons froides isolées et des protoétoiles à neutrons chaudes, en utilisant les contraintes actuelles fournies par les expériences en physique nucléaires, les développements en théorie des perturbations chirales et les observations astrophysiques. Une approche unifiée de métamodélisation a été introduite pour calculer la composition et l’équation d’état des étoiles à neutrons froides isolées pour toute fonctionnelle de matière nucléaire. Une détermination bayésienne des paramètres de l’équation d’état a été effectuée, conduisant à des prédictions réalistes pour les observables de l’étoile. À température finie, l’équilibre statistique complet des ions dans la croûte a été considéré, permettant, entre autres, le calcul du paramètre d’impureté. Les résultats sont compatibles avec les contraintes déduites de GW170817, et tendent à indiquer que lephénomène de glitch ne peut pas uniquement tirer son origine de la physique de la croûte. Des déviations dans la composition de la croûte par rapport à la matière catalysée froide sont observées à la température de cristallisation. Les résultats montrent que la contribution des impuretés n’est pas négligeable, ce qui pourrait avoir un impact sur les propriétés de transport dans la croûte. Une plus grande précision dans la détermination des dérivées d’ordre élevé de l’énergie de symétrie dans les expériences et/ou la théorie des perturbations chirales, et dans la connaissance de l’énergie de surface à des isospins extrêmes est nécessaire pour réduire les incertitudes sur les observables de la croûte. Le cadre numérique développé au cours de cette thèse peut servir de base à des recherches futuresThe main aim of this thesis is to make realistic predictions and to investigate the sources of uncertainties in the observables of nonaccreting cold neutron stars and warm protoneutron stars, using the present day constraints provided by nuclear experiments, developments in chiral effective field theory, and astrophysical observations. A unified metamodeling approach was introduced to calculate the stellar composition and equation of state of cold nonaccreting neutron stars for any functional of nuclear matter. A Bayesian determination of the equation of state parameters was carried out, leading to realistic predictions for neutron star observables. At finite temperature, a full statistical equilibrium of ions in the crust was considered, allowing in particular for the computation of the impurity parameter. The results are compatible with constraints inferred from GW170817, and suggest that a full crustal origin of pulsar glitches should be excluded. Deviations in the crust composition from cold catalyzed matter are observed at the crystallization temperature. Results show that the contribution of impurities is nonnegligible, thus potentially having an impact on transport properties in the crust. Higher precision in the determination of high-order isovector empirical parameters through nuclear experiments or low-density effective field theory predictions, and in the experimental and/or theoretical knowledge of the surface energy at extreme isospin ratios are needed to reduce the uncertainties of crustal observables. The numerical framework developed during this thesis can be used as a basis for future studies
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Bazi, Wail El. "Cristallisation discontinue et semi-continue de la glycine : Etude de l’influence d’un anti-solvant." Thesis, Paris, CNAM, 2011. http://www.theses.fr/2011CNAM0786/document.
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La maîtrise et le contrôle de la cristallisation afin d’obtenir des cristaux de taille, de forme et du polymorphisme désirés reste une exigence de l’industrie pharmaceutique. La présence d’anti-solvant dans le milieu de cristallisation modifie les grandeurs fondamentales et les mécanismes de cette opération unitaire et peut être un outil permettant son contrôle. L’éthanol est l’un des anti-solvants qu’on peut utiliser dans la cristallisation de la glycine.Ce travail porte sur la cristallisation discontinue de la glycine dans des mélanges (eau/éthanol) par un procédé de cristallisation par refroidissement direct, ou par un procédé de cristallisation semi-continue isotherme de cette molécule en réalisant la sursaturation par ajout d’éthanol. On a étudié l’effet de la quantité et du débit d’éthanol sur différentes grandeurs fondamentales et son influence sur les différents mécanismes de cristallisation de la glycine, ainsi que sur les formes polymorphiques obtenuesCrystallization is widely used in pharmaceutical industry; however it is necessary to control size, shape and crystal polymorphism. Anti-solvent presence in crystallization media is known to influence these separation process mechanisms, magnitudes and polymorphism. Consequently, anti-solvent use can be a way for crystallization control. For example ethanol can be used on glycine crystallization. In this thesis, we study the glycine crystallisation process in aqueous solutions with anti-solvent. The process takes place in a batch cooling crystallizer and in an isotherm semi batch crystallizer. We check ethanol amount and ethanol addition rate effects on different crystallization magnitudes and mechanisms; we check also the effect on polymorphism
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Skaisgirytė, Beata. "Kontroliuojamos pakaitinės kartotinės pasyvios hipertermijos ir hipotermijos poveikis aklimacijos požymių kaitai." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2013. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2013~D_20130910_151304-80758.
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Žmogaus organizmas yra linkęs aklimuotis ir prie besikartojančių šilumos ir prie besikartojančių šalčio stimulų (Michael, 2001). Tai sukelia skirtingus fiziologinius atsakus organizme.
Žmogaus organizmas aklimuodamasis šilumai siekia sušvelninti šilumos sukeltą fiziologinį stresą, ir pagerinti šiluminį komfortą bei treniravimosi galimybes. Aklimacija yra sukeliama pakartotinių šilumos stimulų, kurie sukelia pakankamą stresą, galintį pakelti odos ir vidines temperatūras, padidinti prakaitavimą. Dažniausiai aklimacija kasdien pasikartojantiems šilumos stimulams atsiranda per pirmas 4 dienas ir galutinai susiformuoja per 3 savaites. Šilumos aklimacijos sukelti požymiai – žemesnė vidinė temperatūra, padidėjęs prakaitavimas ir odos kraujotaka, sumažėjusi metabolinė medžiagų apykaita, sumažėjęs širdies ir kraujagyslių sistemai sukeliamas krūvis, pagerėjęs skysčių balansas ir padidėjusi šiluminė tolerancija (Michael ir kt., 2001).
Šiais laikais profesinė ir rekreacinė veikla šaltomis oro sąlygomis yra gana dažna. Šalčio poveikis sukelia termoreguliacijos atsakus, kurie pasireiškia elgesiu arba fiziologiniais pokyčiais, kad išlaikytų šiluminę pusiausvyrą- padidėjusia metabolinė šilumos gamyba drebant arba vazokonstrikcija- sumažėjusiu šilumos atidavimu. Šie fiziologiniai atsakai priklauso nuo asmens individualių savybių- amžiaus, kūno sudėjimo, bendro prisitaikymo šalčiui. Stiprus šalčio stimulas gali sukelti medicinines traumas ar net mirtį (Launay, 2009). Aklimacija šalčiui yra... [toliau žr. visą tekstą]Human body tends to acclimate to repeated heat or cold stimulus (Michael, 2001). This leads to different physiological responses in the body. During acclimation to heat the body seeks to soften heat-induced physiological stress, to improve thermal comfort and increase training opportunities. Acclimation is induced by repeated heat stimuli that cause sufficient stress, that can raise skin and core temperature, increase sweating. Usually the acclimation to daily repeated heat stimuli occurs within the first 4 days and finally forms during 3 weeks. Heat acclimation causes symptoms such as lower core temperature, increased sweating and skin blood circulation, decreased metabolism, decreased stress for cardiovascular system, improved fluid balance and increased thermal tolerance (Michael et al., 2001). Nowadays, professional and recreational activities in cold weather conditions are quite common. Cold exposures cause thermoregulatory responses that affects behaviour or physiological changes to maintain thermal balance- increased metabolic heat production while shivering, or vasoconstriction- reduced heating. These physiological responses depend on the person’s individual characteristics- age, body composition and general adaptation to cold. A strong cold stimulus can cause medical injuries or even death (Launey, 2009). Acclimation to cold is classified into several categories- metabolic, insulation, hypothermic and intermediate versions (Bittel, 1992). Acclimation to cold may... [to full text]
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Wang, Haoting. "Experimental and Modeling Study of the Thermal Management of Li-ion Battery Packs." Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/79660.
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This work reports the experimental and numerical study of the thermal management of Li-ion battery packs under the context of electric vehicle (EV) or hybrid EV (HEV) applications. Li-ion batteries have been extensively demonstrated as an important power source for EVs or HEVs. However, thermal management is a critical challenge for their widespread deployment, due to their highly dynamic operation and the wide range of environments under which they operate. To address these challenges, this work developed several experimental platforms to study adaptive thermal management strategies. Parallel to the experimental effort, multi-disciplinary models integrating heat transfer, fluid mechanics, and electro-thermal dynamics have been developed and validated, including detailed CFD models and lumped parameter models. The major contributions are twofold. First, this work developed actively controlled strategies and experimentally demonstrated their effectiveness on a practical sized battery pack and dynamic thermal loads. The results show that these strategies effectively reduced both the parasitic energy consumption and the temperature non-uniformity while maintaining the maximum temperature rise in the pack. Second, this work established a new two dimensional lumped parameter thermal model to overcome the limitations of existing thermal models and extend their applicable range. This new model provides accurate surface and core temperatures simulations comparable to detailed CFD models with a fraction of the computational cost.Ph. D.
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Lerond, Lionel. "Optimisation de la cristallisation d'un sel diastéréoisomère lors d'une résolution optique en réacteur fermé, et développement d'un mode de cristallisation continu." Thesis, Vandoeuvre-les-Nancy, INPL, 2008. http://www.theses.fr/2008INPL092N/document.
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L’énantiomère R (énantiomère cible) d’un mélange racémique d’une molécule organique est isolé par cristallisation du sel diastéréoisomère qu’il forme préférentiellement en s’associant à l’acide énantiomériquement pur R-acétyl(L)valine. Cependant l’énantiomère S (contre-énantiomère) peut aussi cristalliser sous forme d’un sel de R-acétyl(L)valine. Les solubilités des deux sels sont déterminées par des cristallisations par refroidissement en réacteur fermé. La modélisation de ces données expérimentales permet de maximiser la quantité d’énantiomère R cristallisé en sel pur en réacteur fermé à une température choisie. Cette température est ensuite augmentée : la durée de filtration des cristaux, systématiquement obtenus sous forme d’aiguilles, est avantageusement réduite. Une réduction est encore obtenue en appliquant un profil de refroidissement favorisant la croissance des cristaux : au final, l’amélioration de la filtrabilité des cristaux est corrélée aux augmentations conjointes du facteur d’élongation et de la longueur des cristaux. La cristallisation est ensuite transposée à un mode de fonctionnement continu en injectant les réactifs séparément dans un réacteur ouvert. Afin d’atteindre des performances égales à celles du réacteur fermé, le temps de passage et la concentration de la solution de R-acétyl(L)valine sont ajustés : il en résulte une productivité accrue de la cristallisation. La filtrabilité des cristaux obtenus en réacteur continu reste cependant médiocre. Bien que toujours inférieur à celui atteint en réacteur fermé optimal, le facteur d’élongation des cristaux est tout de même augmenté en optant pour une configuration de cascade de deux réacteurs continusThe R enantiomer (target enantiomer) of the racemic mixture of an organic molecule is isolated by a preferential crystallization of the salt it forms by association with the enantiomerically pur acid R-acetyl(L)valine. The S enantiomer (counter enantiomer) may somehow also crystallize under the form a R-acetyl(L)valinate salt. Solubilities of the two salts are measured by cooling crystallizations in a batch reactor, carried out for various stoechiometric conditions. The interpretation and the modelisation of the experimental data gathered lead to the maximisation of the quantity of R enantiomer crystallized as a pur salt in a batch reactor by cooling crystallization to a given temperature. This temperature is then increased : the filtration duration of the crystals, always exhibiting the shape of needles, is thus advantageously decreased. A further decrease is made possible by applying a temperature cooling profile that promotes the growth of crystals. Finally, the enhancement of the filterability of crystals is correlated to an increase of the elongation factor of crystals. The crystallization is then transposed to a continuous operating mode : reactants are injected separately in a continuous stirred tank reactor. With a view to match the results of the optimized batch reactor, the residence time and the R-acetyl(L)valine concentration are adjusted : a better productivity is then obtained, though filterability remains lower. The elongation factor is slightly increased by implementing two continous stirred tank in serie. The complete range of possible enhancements of crystals morphology by such cascades could be further studied for such needle-like crystals
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Comisso, Tiago Boni. "Estudo experimental do processo de rotomoldagem: efeitos sobre a morfologia e estabilidade dimensional." UNIVERSIDADE ESTADUAL DE PONTA GROSSA, 2011. http://tede2.uepg.br/jspui/handle/prefix/1451.
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Previous issue date: 2011-10-03In the present study the warpage of rotationally molded parts of a linear low density polyethylene (LLDPE) was investigated. The effect of different processing factors as part thickness, cooling condition and diameter of the venting tube was evaluated. In addition to the rotational molding experiments, an alternative experimental technique, denominated “Hot Press”, was also applied to investigate the warpage of two different grades of LLDPE under typical rotational molding conditions, which means slow cooling from only one side. Crystallinity and spherulitic morphology along the thickness of the rotationally molded parts were studied by Differential Scanning Calorimetry and Polarized Light Optical Microscopy. It is shown that the warpage increases with the increase of the cooling rate. Increase of diameter of the venting tube is more effective in reducing the warpage of rotationally molded parts mainly for lower cooling rates. In hot press experiments the grade of LLDPE with lower melt flow index and higher flexural strength presented lower warpage. Part thickness affects the warpage in hot press experiments only for faster cooling rates. In general, crystallinity and spherulitic diameter are lower in positions along the rotationally molded part thickness where the cooling rate is faster.
No presente estudo o empenamento de peças de polietileno linear de baixa densidade (PELBD) moldadas por rotomoldagem foi investigado. O efeito de diferentes fatores como espessura da peça, taxa de resfriamento e diâmetro de tubo de ventilação foi avaliado. Em adição aos experimentos de rotomoldagem, uma técnica alternativa denominada “Hot Press” foi também aplicada para investigar o empenamento de dois diferentes PELBD sob condições típicas da rotomoldagem quanto ao resfriamento assimétrico. Cristalinidade e morfologia esferulítica ao longo da espessura das peças rotomoldadas foram avaliadas por Calorimetria Exploratória Diferencial (DSC) e Microscopia Ótica de Luz Polarizada. Verificou-se que o grau de empenamento aumenta com o aumento da taxa de resfriamento. O aumento do diâmetro do tubo de ventilação é mais efetivo na redução do empenamento principalmente em menores taxas de resfriamento. Nos experimentos de “Hot Press” o PELBD com menor índice de fluidez e maior módulo de flexão apresentou menor empenamento. Nos experimentos de “Hot Press” a espessura das peças afetou o empenamento somente para taxas de resfriamento mais rápidas. Em geral, a cristalinidade e o tamanho de esferulitos se mostraram menores nas posições ao longo da espessura das peças rotomodadas onde as taxas de resfriamento eram mais rápidas.
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Heidrich, Dario, and Michael Gehde. "Kalorimetrische Untersuchung des Kristallisationsverhaltens unter dynamischer Abkühlung." Technische Universität Chemnitz, 2019. https://monarch.qucosa.de/id/qucosa%3A36101.
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Eine kalorimetrische Kristallisationsuntersuchung unter dynamischer Abkühlung ist bisher noch nicht erfolgt, auch weil die klassischen DSC-Messsysteme hierfür thermisch zu träge sind und die Einschwingzeiten zu lang sind. Durch die Weiterentwicklung der Prüftechnik, insbesondere auf dem Gebiet der Hochgeschwindigkeitskalorimetrie, erscheint es jedoch erstmals möglich, das dynamische Abkühlverhalten prozessnah nachbilden zu können und die Auswirkung auf die Kristallisation zu untersuchen.
Im Rahmen dieser Arbeit wurde daher versucht die dynamische Abkühlung einer Kunststoffschmelze aus PBT kalorimetrisch in Abhängigkeit der Werkzeugtemperatur und der Bauteilgeometrie nachzubilden, jeweils bei Betrachtung verschiedener Bauteiltiefen. Hierfür wurden numerisch nichtlineare Kühlratenverläufe bestimmt, die im Anschluss durch Segmentierung linearisiert und somit in ein FSC-Programm überführt werden konnten. Anhand der resultierenden Wärmestromverläufe konnte gezeigt werden, dass eine Interpretation der kalorimetrischen Erfassung unter dynamischer Abkühlung möglich ist und der Verlauf der Kristallisation in verschiedenen Bauteiltiefen in Abhängigkeit der weiteren Randbedingungen nachvollzogen werden kann.A calorimetric investigation of the crystallization of thermoplastics under dynamic cooling has not performed yet, also because the classical DSC measuring systems are thermally too slow for this purpose and the corresponding settling times are too long. However, as a result of the further development of testing technology, especially in the field of high-speed calorimetry, it seems possible to simulate the dynamic cooling behavior of real processing and to investigate its effects on crystallization. In this work the dynamic cooling of a polymer melt was simulated calorimetrically depending on the tool temperature and the part geometry, in each case considering the different cooling behavior of different part depths. Therefore, numerically nonlinear cooling rate profiles were determined, which could then be linearized by segmentation and thus converted into a calorimetric program. On the basis of the resulting heat flow characteristics it could be shown that an interpretation of the calorimetric detection under dynamic cooling is possible and the course of the crystallization in different part depths can be reconstructed in dependence on the further boundary conditions.
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Xie, Zhong Jian. "Effet élastocalorique dans le caoutchouc naturel." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEI025/document.
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Les effets caloriques représentent la capacité d’un matériau à voir son entropie varier sous l’effet d’une sollicitation externe et peuvent être utilisés pour des systèmes de refroidissement à l'état solide en remplacement (ou complément) des dispositifs traditionnels à base de fluides frigorifiques. Dans cette thèse, nous avons cherché à étudier l'effet élastocalorique du caoutchouc naturel. Après une présentation des différents matériaux caloriques et du caoutchouc naturel, le chapitre 2 détaille la caractérisation élastocalorique du caoutchouc naturel, et les résultats sont interprétés à partir de la notion de cristallisation induite par la déformation. Le changement de température adiabatique élastocalorique et la variation d’entropie associée atteignent 9K et 50kJ.m-3.K-1, ce qui est très important comparé aux autres matériaux caloriques. L’effet élastocalorique étant maximum pour une déformation voisine de 4,5, une pré-déformation peut être appliquée pour éviter la zone moindre activité élastocalorique. La mesure directe de l’effet élastocalorique est ensuite comparée à une méthode indirecte déduite du facteur de Clapeyron, et les divergences sont discutées. Dans le chapitre 3, la contrainte et la température élastocalorique sont simulées par un modèle de Flory modifié sur la base de la cristallisation. Il est possible de prédire le comportement contrainte-déformation à différentes températures, ainsi que les variations de température élastocaloriques à température ambiante. Dans le chapitre 4, les effets de la fatigue sur l’effet élastocalorique du caoutchouc naturel sont ensuite étudiés. La résistance à la fatigue pour de grandes amplitudes de déformation est très faible (< 800 cycles). Trois régimes de déformation intermédiaire sont ensuite testés : 0-3, 2-5, et 4-7, et permet d’établir que le régime 2-5 est le plus performant (jusqu’à 100 000 cycles). Dans le dernier chapitre, un modèle de système régénératif de refroidissement à base de matériaux caloriques est développé afin d’établir des lignes directrices pour le choix des matériaux élastocaloriquesIn this thesis, we aimed to study the eC effect of natural rubber (NR) and to prove its potential to act as an eC material primarily. The method for improving the eC effect efficiency and fatigue life of NR were also proposed. The eC effect of NR is characterized directly, and interpretation based on the theory of strain-induced crystallization/crystallite (SIC) is proposed. The eC adiabatic temperature change and isothermal entropy change of NR can be up to 9 K and 50 kJ.m-3.K-1 (56 J.kg-1.K-1), which are larger than most of caloric materials. Two coefficients, eC strain coefficient and eC stress coefficient , are defined for evaluating the eC performance at different strains, where is the specific entropy, is the engineering strain, is the temperature and is the stretching stress. It’s found that both coefficients are maximum for a strain around 4.5, indicating that the highest eC performance occurred at middle strain, which is attributed to the occurrence of SIC. To improve the eC performance, it is proposed to apply a pre-strain, so that the low strain regime where eC performance is low can be skipped. Moreover, the large needed deformation can be reduced by the pre-strain and thus the possibility of a compact cooling system designed based on NR is improved. The fatigue property of eC effect of NR is then investigated. The fatigue life at large deformation strain amplitudes (strain of 1-6) is about 800 cycles for the tested NR, which is too short to be used for a cooling system. Decreasing strain amplitude is necessary to extend fatigue life up to requirement of a cooling device. For the same small strain amplitude of 3, the fatigue property is compared at amorphous strain regime (strain of 0-3), onset strain of melting (strain of 2-5) and high strain of SIC (strain of 4-7). It’s found that a larger eC temperature change and a better fatigue property can be obtained at two SIC strain regimes (strain of 2-5 and 4-7) than amorphous strain regime. Especially, the fatigue property at the onset strain of melting (strain of 2-5) is better than that at high strain of SIC (strain of 4-7). A high-cycle fatigue was applied at the strain of 2-5 (most promising strain regime) up to 1.7×105 cycles. It was observed that there is no crack of the sample, as well as a degradation degree of 12% of the eC temperature change. Furthermore, the eC stress coefficient (4.4 K/MPa) at onset strain of melting is larger than that at high strain of SIC (1.6 K/MPa). As a result, the middle strain regime (onset strain regime of melting) can get a higher eC performance, larger temperature change, and better fatigue life, which should be chosen for eC cooling system
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Ngonge, Emmanuel Donald. "Distribuição do tamanho de cristais (DTC) e trama de plagioclásio em diques máficos Mesozóicos das Praias das Conchas e de Lagoinha (Municípios de Cabo Frio e Arraial de Búzios, RJ)." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/44/44141/tde-27072011-172926/.
Full textAbstract:
A técnica da Distribuição do Tamanho de Cristais - DTC (Crystal Size Distribution - CSD), que relaciona a densidade de cristais com a distribuição do tamanho, foi aplicada à população de plagioclásio de diques máficos do Enxame de Cabo Frio - Búzios (RJ). Os diques possuem larguras variáveis, de alguns centímetros a 20 metros, e orientação em torno de N45E. A textura dos diques é geralmente fina, localmente microporfirítica e intergranular no centro dos diques mais largos. Bordas resfriadas de alguns centímetros de largura são frequentes nos contatos com as rochas metamórficas encaixantes. Foram estudados dois diques na Praia das Conchas com espessura de 0,8m e 8,2m e, um outro na Praia da Lagoinha, com 2m de largura. As amostras foram coletadas junto às margens (~10 cm do contato) e no centro dos diques. O tamanho médio dos cristais de plagioclásio varia de 0,07 a 0,13 mm na borda dos diques mais finos (<= 2 m de largura) e de 0,09 a 0,20 mm na borda do dique mais largo. No centro do dique de Lagoinha e no dique largo de Praia das Conchas o tamanho de plagioclásio é da ordem de 0,19 ± 0,02 mm e 0,60 ± 0,07 mm, respectivamente. As DTCs nas bordas dos diques, independentemente de sua largura, mostraram um padrão tipicamente encurvado, e que tem sido atribuído na literatura como evidência para misturas de magmas com populações de cristais de tamanhos distintos. No entanto, no centro do dique largo (8,2m) de Praia das Conchas, a DTC é log-linear consistente com uma cristalização magmática simples. A química mineral mostrou que os cristais maiores (precoces) de plagioclásio apresentam um teor mais elevado em An (bytownita-labradorita) que os cristais menores (tardios) da matriz (labradorita-andesina). Além disso, a olivina é mais rica em Fo na borda que no centro do dique e, respectivamente, o piroxênio mais enriquecido em Ca. Esses resultados indicam que as margens resfriadas são mais máficas que o centro sugerindo uma evolução química normal com o resfriamento do magma. Portanto, as DTCs encurvadas provavelmente refletem taxas de cristalização heterogêneas possivelmente induzidas pela despressurização durante a ascensão do magma basáltico seguida de rápido resfriamento. O padrão da DTC log-linear no centro do dique de 8,2m de largura é atribuído ao maior tempo de residência do magma que favoreceria os processos de difusão química e re-equilíbrio textural. Os cálculos da taxa de resfriamento utilizando a inclinação da DTC permitiram estimar que o centro do dique largo da Praia das Conchas estaria completamente cristalizado (~ 900 °C) em torno de 73 dias. O estudo da Orientação Preferencial de Forma (OPF) de plagioclásio mostrou que a petrotrama tende a isotrópica nas margens dos diques com largura menor que 2 metros, o que poderia refletir uma rápida cristalização de plagioclásio por despressurização. Quando a trama é localmente definida, como no dique largo da Praia das Conchas, a lineação de plagioclásio é subhorizontal sugerindo que o fluxo magmático moveu-se predominantemente na lateral do dique.The method of Crystal Size Distribution (CSD), which relates crystal density with size distribution, has been applied on the plagioclase population of the Mafic Dyke Swarm of Cabo Frio-Búzios (RJ). The dykes are NE-trending with widths from a few centimetres to 20m. The texture is generally fine grained and locally microporphyritic and intergranular at the center of the larger dykes. Chilled margins of a few centimetres in width are common at contacts with the metamorphic basement. Two dykes of 0.8m and 8.2m in width of the Conchas Beach and another of 2m in width at the Lagoinha Beach have been studied. Samples were collected at the margins (~10cm from the contact) and at the center of the dykes. The average characteristic size of the plagioclase crystals varies from 0.07 to 0.13mm at the margins of the narrow dykes (<=2m of width) and from 0.09 to 0.20mm at the margins of the large dyke. At the center of the Lagoinha and Conchas dykes the plagioclase size varies from 0.19 ±0.02mm and 0.60±0.07mm respectively. The CSDs at the dyke margins, irrespective of the dyke width, are typically concave-up, and in literature such patterns have been attributed as evidence of magma mixing with distinct crystal populations. However, at the center of the largest dyke (8.2m) of Conchas Beach, the CSD is log-linear, consistent with simple steady-state crystallization pattern. The mineral chemistry shows that the plagioclase phenocrysts have a high An content (bytownite-labradorite) than the groundmass grains (labradorite-andesine). At the margins olivine is richer in Fo than at the center, and respectively, pyroxene is richer in Ca. These results indicate that the chilled margin is more mafic than the center suggesting a normal chemical evolution in a cooling magma. Nevertheless, the concave-up CSDs probably depict heterogeneous crystallization rates possibly induced by depressurization during the ascent of the basaltic magma followed by rapid cooling. The log-linear CSD pattern at the center of the Conchas dyke (8.2m width) is attributed to a higher residence time of the magma which favors the processes of chemical diffusion and textural re-equilibration. The calculated cooling rates using the CSD slope enables us to estimate that the larger dyke of Conchas would be completely crystallized (at ~900oC) in 73 days. The study of the Shape Preferred Orientation (SPO) in plagioclase shows an isotropic petrofabric at the margins of the dykes <=2m, which could reflect a rapid crystallization of plagioclase by depressurization. When the fabric is defined, as in the larger Conchas Beach dyke, the plagioclase lineation is subhorizontal, suggesting that the magma flow was predominantly lateral to the dyke plane.
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Albino, Filho Nilton. "Uma análise energética da cristalização por resfriamento na indústria da cana-de-açúcar." reponame:Repositório Institucional do FGV, 2012. http://hdl.handle.net/10438/9888.
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Os mercados dos produtos oriundos da cana-de-açúcar no mundo vêm sofrendo nos últimos anos mudanças estruturais significativas. No cenário brasileiro, houve grande expansão da produção de cana-de-açúcar, impulsionados pela demanda dos carros flex –fuel, além da oportunidade de suprir o volume de açúcar que a União Europeia deixara de colocar no mercado mundial pela eliminação da subvenção aos exportadores de açúcar do bloco. As incertezas dos mercados exigem mudanças de estratégias de negócio, usinas projetadas para produção exclusiva de etanol, alteram sua estratégia para produção conjunta etanol e açúcar. Apesar dos processos comuns para produção de açúcar e etanol, não significa que essa mudança de estratégia seja fácil de ser efetivada, principalmente pelo aspecto energético. Estudos de processo de produção de açúcar mais eficientes energeticamente, com custos menores tem ganhado força na União Europeia, dentre elas a cristalização do açúcar por resfriamento. Vários cenários produtivos inclusive integrados a produção de etanol tem sido desenvolvidos ao longo dos anos. O objetivo do trabalho foi verificar por comparação de cenários, duas tecnologias de cristalização do açúcar (cozimento e resfriamento), em relação ao impacto nos excedentes de energia elétrica quando a produção de açúcar é adicionada a unidades que produzem somente etanol e energia elétrica. Por meio de simulações dos balanços térmicos dos cenários, observou-se uma restrição importante quando adotado a cristalização por cozimento, no que se refere aos volumes de excedentes de energia elétrica, e que pode ser minimizado se adotado o processo de cristalização por resfriamento, podendo assim ser uma alternativa quando se deseja mudar a estratégia do negócio, de produção exclusiva de etanol e energia elétrica para etanol, açúcar e energia elétrica.
Significant structural changes have been occurred in the markets of sugarcane derived products in the world in recent years. Regarding Brazilian scenario, there was a great expansion of sugarcane production due the high demand by flex-fuel cars. In addition the opportunity to meet the volume of sugar that the European Union had failed to put on the world market by eliminating the subvention to sugar exporters in the block. The uncertainties of the markets requires changes in the previus business strategies. Those mills designed for the exclusive production of ethanol, change your strategy to produce both ethanol and sugar. Despite the common processes for the production of sugar and ethanol, it does not mean that this change in strategy is easy to be effected mainly by the energy consumption. New developments in more energy efficient sugar production process, with lower costs have gained strength in the European Union, among them a sugar crystallization by cooling. Many scenarios production and integrated ethanol production have been developed over the past years. The objective of this study was to compare two technologies of sugar production such as boiling and cooling crystallization. The impact on electricity surplus when the production of sugar is added to units that produce only ethanol and electricity is discussed. By simulating the thermal balance of the scenarios, we observed an important restriction adopted when the crystallization by boiling, in terms of electricity surplus amount, which can be minimized by adopting the process of crystallization by cooling. It may therefore be an alternative when a change in the business strategy is desired from an exclusive production of ethanol and electricity to sugar, ethanol and electricity production.
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Yoshida, Yukihiro. "Effet élastocalorique dans le caoutchouc naturel et le terpolymère : Mécanismes responsables de la variation de température et bilan énergétique sous déformation." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEI070.
Full textAbstract:
Les effets électrocaloriques, qui se traduisent par une variation de température induite par une variation d’entropie ont été étudiés comme alternative aux systèmes de réfrigération utilisant un cycle de compression/détente. Le travail de thèse se focalise sur l’étude de l’effet élastocalorique dans le caoutchouc naturel et le terpolymère (P(VDF-TrFE-CTFE). En premier lieu, l’effet élastocalorique dans le caoutchouc naturel qui compte parmi les meilleurs candidats, a été évalué pour des cycles de déformation réalisés avec différentes valeurs d’allongement. Une variation de température de 4 °C a pu être observée. Il est usuel d’utiliser la relation déformation/contrainte en fonction de la variation de température pour évaluer l’effet élastocalorique. Il a été démontré que cette méthode ne peut pas être utilisée dans le cas du caoutchouc naturel et qu’elle doit être remplacée par la mesure de la variation de l’énergie mécanique en fonction de la température. Et dans ce cas, une variation linéaire entre ces deux dernières grandeurs a été observée. En réalisant un bilan d’énergie pendant l’essai, non seulement, le rendement énergétique a pu être évalué mais il a été aussi possible de prendre en compte l’effet Mullins et la cristallisation induite par la déformation pour le caoutchouc naturel. Dans un second temps, l’effet élastocalorique a été étudié sur le terpolymère (P(VDF-TrFE-CTFE), ce qui a permis de montrer qu’il était possible d’obtenir une variation de température de 2.1 °C sous réserver de pré-déformer le terpolymère à plus de 1050 % avant. Par comparaison avec d’autres matériaux présentant une bonne conversion élastocalorique, le fort potentiel de ce matériau a pu être mis en évidence. Enfin, il a été mis en évidence que la plus grande partie de l’énergie mécanique était bien convertie en énergie thermiqueCaloric effects (CEs), which are the phenomena that temperature variation is caused by entropy change, have been investigated for the novel system which might be able to replace conventional vapor compression refrigeration system. In the present thesis, the elastocaloric effect (ElCE) of natural rubber (NR) and terpolymer, poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) (P(VDF-TrFE-CTFE)), was focused. First of all, NR, which is an excellent candidate material for ElCE, was evaluated in cyclic deformation with different strain levels. It was found that NR exhibits temperature variation of around 4.0 °C. In general, the relation between stress/strain versus temperature variation is used to evaluate ElCE. The unsuitability of such evaluation method for NR was demonstrated. The evaluation method for ElCE which uses energy balance was then proposed. A linear relation between the temperature variation caused by ElCE and the applied mechanical energy by deformation was experimentally found. This fact verifies the suitability of the proposed method. Using the energy balance, besides, not only the conversion efficiency but also the influences of the Mullins effect and the strain-induced crystallization on the ElCE of NR were discussed. ElCE of P(VDF-TrFE-CTFE) was also evaluated in order to find out the potential of polymer. It was found that present terpolymer which is not one of the elastomers can also exhibit a large temperature variation, 2.1 °C, caused by ElCE if a large pre-stretch such as more than 1050 % is applied in advance. By comparison with other materials for ElCE, it was demonstrated that P(VDF-TrFE-CTFE) can be a high potential material for ElCE. It was also shown that P(VDF-TrFE-CTFE) converts most of the applied mechanical energy into the heat energy