Дисертації з теми "Thermal properties of porous foam"
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Anghelescu, Mihnea S. "Thermal and Mechanical Analysis of Carbon Foam." View abstract, 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:3353337.
Повний текст джерелаPiquemal, Philippe. "Élaboration d'un nouveau matériau isolant phonique et thermique en verre expansé et mise au point d'un procédé utilisant un chauffage diélectrique." Nancy 1, 1988. http://www.theses.fr/1988NAN10203.
Повний текст джерелаVijay, Dig. "Forced convective heat transfer through open cell foams." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2017. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-226330.
Повний текст джерелаRodeheaver, Bret Alan. "Open-celled microcellular themoplastic foam." Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/18914.
Повний текст джерелаGeiger, Derek M. "AN EXPERIMENT ON INTEGRATED THERMAL MANAGEMENT USING METALLIC FOAM." DigitalCommons@CalPoly, 2009. https://digitalcommons.calpoly.edu/theses/75.
Повний текст джерелаMahasaranon, Sararat. "Acoustic and thermal properties of recycled porous media." Thesis, University of Bradford, 2011. http://hdl.handle.net/10454/5516.
Повний текст джерелаMueller, Jennifer Elizabeth. "Determining the Role of Porosity on the Thermal Properties of Graphite Foam." Thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/34110.
Повний текст джерелаMaster of Science
Bai, Chengying. "Highly porous geopolymer components." Doctoral thesis, Università degli studi di Padova, 2018. http://hdl.handle.net/11577/3427257.
Повний текст джерелаI geopolimeri, polimeri inorganici silicoalluminati tridimensionali semi-cristallini, hanno attirato crescente attenzione da una vasta gamma di interessi scientifici. L'argomento di questo studio riguarda la sintesi, la caratterizzazione e le potenziali applicazioni di geopolimeri porosi (PG) o schiume di geopolimeri (GF, porosità totale> 70% vol), realizzati attraverso diversi percorsi di lavorazione. In primo luogo, i processi sono suddivisi in cinque categorie: (i) schiumatura diretta, (ii) metodo di replica, (iii) modello sacrificale, (iv) stampa 3D e (v) altri. Anche la microstruttura, la porosità e le proprietà dei geopolimeri porosi sono state confrontate e discusse. In secondo luogo, i geopolimeri porosi basati su K sono stati prodotti mediante schiumatura diretta utilizzando perossido di idrogeno come agente chimico di formazione dei pori (PFA) combinato con tre tipi di agente stabilizzante (SA, bianco d'uovo, Tween 80, oli vegetali) e mediante schiumatura diretta più reattivo emulsione che modella. Inoltre, geopolimeri porosi a base di fosfato a cellule aperte sono stati ottenuti con un semplice metodo di schiumatura diretta (usando Triton X-100 come agente fisico di formazione dei pori). Sono state studiate la porosità, la morfologia dei pori, le prestazioni ad alte temperature, l'adsorbimento, le proprietà meccaniche e isolanti delle PG. I PG ad alta resistenza con porosità adattata e struttura macroporosa controllata sono stati fabbricati con diversi processi. I risultati suggeriscono che i geopolimeri porosi promettono candidati altamente porosi a basso costo per potenziali applicazioni come catalizzatori o supporti a membrana (elevata porosità aperta e alta resistenza), adsorbimento (alta efficienza di rimozione e capacità di adsorbimento con elevata porosità aperta) e isolanti (basso materiali di conducibilità termica, elevata porosità e resistenza accettabile).
Zahedi, Maryam. "Meshfree Method for Prediction of Thermal Properties of Porous Ceramic Materials." FIU Digital Commons, 2013. http://digitalcommons.fiu.edu/etd/954.
Повний текст джерелаZihms, Stephanie Gabriele. "Smouldering and thermal remediation effects on properties and behaviour of porous media." Thesis, University of Strathclyde, 2013. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=23194.
Повний текст джерелаZhang, Lizhong. "Physical, mechanical, thermal, and viscoelastic properties of water-blown rigid polyurethane foam containing soy flours /." free to MU campus, to others for purchase, 1998. http://wwwlib.umi.com/cr/mo/fullcit?p9924871.
Повний текст джерелаSanthosh, Balanand. "Thermal properties of polymer derived Si-O-C-N ceramics." Doctoral thesis, Università degli studi di Trento, 2020. http://hdl.handle.net/11572/267913.
Повний текст джерелаSanthosh, Balanand. "Thermal properties of polymer derived Si-O-C-N ceramics." Doctoral thesis, Università degli studi di Trento, 2020. http://hdl.handle.net/11572/267913.
Повний текст джерелаHudiono, Yeny C. "Thermal transport properties of nanoporous zeolite thin films." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24748.
Повний текст джерелаCommittee Chair: Prof. Sankar Nair; Committee Co-Chair: Prof. Samuel Graham; Committee Member: Prof. Amyn S. Teja; Committee Member: Prof. Mo Li; Committee Member: Prof. Peter Ludovice.
Guynn, Jerome Hamilton. "Estimation of thermal properties in a medium with conduction and radiation heat transfer." Diss., Virginia Tech, 1996. http://hdl.handle.net/10919/39292.
Повний текст джерелаPh. D.
Morgan, Nathaniel Ray. "A porous medium for structural support and multiphase cooling of high-frequency conductors." Thesis, Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/16335.
Повний текст джерелаEsen, Ziya. "Production And Characterization Of Porous Titanium Alloys." Phd thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/3/12608964/index.pdf.
Повний текст джерелаa long plateau stage
and a densification stage. Whereas, curves of loose powder sintered samples were similar to that of bulk alloy. Shearing failure in foam samples occurred as series of deformation bands formed in the direction normal to the applied load and cell collapsing occured in discrete bands. Average neck size of samples sintered in loose or compacted condition were found to be different even when they had the same porosity, and the strength was observed to change linearly with the square of neck size ratio. The relation between mechanical properties of the foam and its relative density, which is calculated considering the micro porous cell wall, was observed to obey power law. The proportionality constant and the exponent reflect the structure and properties of cell walls and edges and macro pore character.
Wilson, Scott E. "Investigation of Copper Foam Coldplates as a High Heat Flux Electronics Cooling Solution." Thesis, Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/6944.
Повний текст джерелаCunsolo, Salvatore. "Radiative properties computational modeling of porous cellular materials." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEI005/document.
Повний текст джерелаCellular media such as plastic, ceramic and metal foams present specific characteristics that make them interesting for a number of applications related to thermal engineering. Their ability to minimize natural convection makes them ideal candidates for insulation applications, while the high specific surface and permeability to fluid of open cell foams makes them interesting heat transfer enhancers. In addition, their permeability to light makes them an ideal candidate for thermal radiation based applications, such as porous burners or solar energy collectors. In many of these application, thermal radiation heat transfer can have a significant influence on the heat transfer process. Both accurate radiation models and accurate morphological models of the structure of the foam are required. This work provides an original contribution on both these accounts. A discussion of the literature on numerical methods for radiation heat transfer in cellular media is presented, with focus on Monte Carlo methods. Homogeneous Phase (HPA) and Multi Phase (MPA) methods are discussed. Further efforts are required to accurately model and digitally replicate of foam morphologies. Our goal is to digitally generate three commonly occurring types of foam structures, covering a large range of real materials: high-porosity open cell foams, high-porosity closed cell foams, low-porosity open-cell structures. For high-porosity open cell foams, the automated parametric digital generation technique was validated against a dataset consisting of raw morphological data obtained by tomographic analysis. The generation capabilities were then applied to parametrically investigate the influence of morphological parameters on the radiative properties (namely, the extinction coefficient) of an opaque open-cell foam. Highly accurate analytical relationships were subsequently deduced and validated by comparison with results obtained from tomography samples. Modeling radiation in foams with a semi-transparent solid phase is substantially more complex. A Direct Monte-Carlo Homogenization reference technique is proposed, that allows to simulate radiation within arbitrary cavities and calculate macroscopic radiative quantities based on a Representative Elementary Volume (REV) of cellular material. The technique is validated against full scale Monte Carlo simulations. Improvements of the existing Homogeneous Phase and Multi Phase approach are proposed, through extensive use of inverse methods and the addition of one equation to take into account specific phenomena taking place in the semi-transparent solid phase. The resulting Improved Homogenized Approaches are extensively tested by comparing them with Direct Monte Carlo Homogenization simulations and existing homogenized models, on a varied set of morphologies making full use of the previously developed digital generation techniques. The improved models consistently outperform existing homogenized models
Mohiti, Asli Ali. "Analyze and Rebuild an Apparatus to Gauge Evaporative Cooling Effectiveness of Micro-Porous Barriers." Thesis, University of North Texas, 2008. https://digital.library.unt.edu/ark:/67531/metadc9750/.
Повний текст джерелаCrimm, Robert Prentiss. "Experimental apparatus for measuring moisture transfer in porous materials subject to relative humidity and temperature differences." Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-01122010-020146/.
Повний текст джерелаXu, Wenyue. "Towards numerical modeling of two-phase flow in seafloor hydrothermal systems." Diss., Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/26014.
Повний текст джерелаLi, Yang. "Application of cellulose nanowhisker and lignin in preparation of rigid polyurethane nanocomposite foams." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/44746.
Повний текст джерелаKong, Lingjun. "Characterization of Mineral Oil, Coal Tar and Soil Properties and Investigation of Mechanisms That Affect Coal Tar Entrapment in and Removal from Porous Media." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/5093.
Повний текст джерелаGrosu, Yaroslav G. "Thermodynamics and operational properties of nanoporous heterogeneous lyophobic systems for mechanical and thermal energy storage/dissipation." Thesis, Clermont-Ferrand 2, 2015. http://www.theses.fr/2015CLF22579/document.
Повний текст джерелаThe thesis is devoted to the theoretical and experimental investigations of thermodynamic and operational properties of nanoporous Heterogeneous Lyophobic Systems (HLS) and their temperature dependences in order to determine optimal conditions and increase efficiency of HLS-based energetical devices. The thesis reflects results obtained in three main directions of research: 1. Thermodynamic analysis; 2. Characteristics of HLS in a wide temperature range; 3. Stability of HLS under different operational conditions. Maximum temperature range investigated is to 2 - 150 ° C. Pressure range is 0.1 - 120 MPa. Particularly, results include proposed equation of state for real HLS, which takes into account pore size distribution function; the energetic characteristics of four (two mesoporous and two microporous) HLSs collected in a wide temperature range; some new operation regimes of HLSs were investigated under controlled isobaric conditions; proposed concept of usage of HLS as a system with pronounced negative thermal expansion
SANTOS, WILSON N. dos. "Contribuicao ao estudo da condutividade termica do material ceramico concreto refratario utilizando a tecnica de fio quente com ajustes por regressao nao linear." reponame:Repositório Institucional do IPEN, 1988. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9901.
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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
Pathak, Mihir Gaurang. "Periodic flow physics in porous media of regenerative cryocoolers." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/49056.
Повний текст джерелаKumar, Prashant. "Investigation of Kelvin-like solid foams for potential engineering applications : an attractive set of geometrical and thermo-hydraulic properties." Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM4730/document.
Повний текст джерелаOpen cell foams have diverse industrial applications e.g. heat exchangers, structured reactors, filtration due to their unique properties such as high porosity and high specific surface area. In order to theoretically determine the geometric specific surface area and relationships between geometrical parameters of isotropic open cell foams, a generalized mathematical correlation was developed. For this purpose the tetrakaidecahedron geometry was used and different shapes of strut cross-sections of foam structures were taken explicitly into account. The derived correlation to predict geometrical properties can be easily extended to different strut shapes. 3-D numerical simulations at pore scale were performed to study the pressure drop characteristics and effective thermal conductivity. Fluid flow through open cell foam was performed in three different regimes: Darcy regime, transition regime and inertia regime. Importance of geometrical properties on fluid flow characteristics and their inclusion in the proposed correlations for predicting pressure drop is discussed. "Can Ergun parameters have constant numerical values or not" is also extensively discussed. Three different correlations were derived to predict the effective thermal conductivity for both, isotropic and anisotropic open cell foams. Geometrical parameters of foam matrix were introduced in the correlations to predict effective thermal conductivity
Jorge, Alexandre Fonseca. "Fabricação, por tixo-infiltração, de materiais de baixa densidade a partir da liga AA7075 e caracterizacao de suas propriedades físicas e mecânicas." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/263689.
Повний текст джерелаTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
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Resumo: Este trabalho teve como objetivo estudar o processo de produção de esponjas metálicas e compósitos de baixa densidade por tixoinfiltracao. A liga metálica AA7075 foi submetida a uma analise de tixohabilidade, na qual foi observada sua adequação ao processo e foi definida a temperatura de trabalho para a infiltração. A produção das amostras consistiu em infiltrar a pasta tixotropica da liga AA7075 sobre bloqueadores removíveis (partículas de NaCl), para a produção das esponjas, e sobre bloqueadores não-removíveis de materiais cerâmicos porosos (vermiculita e cinasita), para a produção dos compósitos. Todas as esponjas metálicas e compósitos produzidos foram caracterizados quanto a sua arquitetura interna, propriedades físicas, térmicas e mecânicas. Os resultados mostraram em todos os casos uma boa qualidade geral dos produtos e uma boa repetibilidade do processo. O comportamento de todos os materiais produzidos em compressão estática ou dinâmica se mostrou próximo do comportamento típico de materiais celulares, com grande platô de deformação plástica ocorrendo com valores relativamente baixos de tensão. A analise das curvas obtidas nos ensaios de compressão semi-estática e compressão dinâmica, em conjunto com imagens de amostras parcialmente comprimidas, forneceu informações sobre os prováveis mecanismos de deformação envolvidos, incluindo o papel dos materiais de reforço. Adicionalmente, foi proposto um equacionamento para a condutividade térmica, dos compósitos, cujos resultados se mostraram satisfatoriamente correlacionados com os experimentais
Abstract: This work had the objective to study the process of production of open-cell metallic foams and low-density composites by thixoinfiltration. The AA7075 alloy underwent a thixoability analysis, in which it was observed its adequation to the process, and the working temperature for the infiltration was defined. The samples production consisted in infiltrating the thixotropic slurry of AA7075 alloy into removable space-holders (NaCl particles) for the production of the foams, and into non-removable space-holders of porous ceramic materials (vermiculite and expanded clay) for the production of the composites. All the foams and composites produced were characterized according to their internal architecture, physical, thermal, and mechanical properties. The results in all cases showed a good quality of the products in general, and a good repeatability of the process. The behavior of all the produced materials under semi-static and dynamic compression remained similar to the typical behavior of cellular materials, with a large plastic deformation plateau occurring with relatively low stress levels. The analysis of the obtained curves from the semi-static and dynamic tests, together with images from partially compressed samples, gave information about the possible deformation mechanisms involved, including the role of the reinforcement materials. Furthermore, a calculation for the thermal conductivity of the composites was proposed, with their results satisfactorily correlated to experimental data
Doutorado
Materiais e Processos de Fabricação
Doutor em Engenharia Mecânica
Imbert, Claire. "Matériaux à propriétés mécaniques et thermiques améliorées sous pression hydrostatique en utilisation aquatique." Thesis, Montpellier 2, 2010. http://www.theses.fr/2010MON20019.
Повний текст джерелаMaterials nowadays used for thermal insulation in aquatic environment under hydrostatic pressure are either rubber flexible foams or rigid foams, especially syntactic foams, depending on depth. These flexible materials were analyzed through classical mechanical and thermal tests. However, methods and results were adapted to the final usage of the product, particularly to the aquatic environment at the surface and under depth. Relationships between structures and properties characteristics were studied to define appropriate properties within relevant criteria. Moreover, to underline thermal properties under hydrostatic pressure, a testing instrument has been developed: an innovating hyperbaric test chamber, dedicated to under water pressure thermal resistance and thickness measurements, from 0 to 50 m depth. Strengths and weak points of these classical materials have been clearly established. Results analysis lead to a new concept of composite material for the defined usage. This innovating material, a syntactic foam, has been developed. By varying the particle type added to a thermoplastic elastomer matrix, the cellular structure has been refined in order to obtain a similar behaviour in aquatic environment, at the surface like in depth. This material has been tested, parallel to its industrial production, to identify relationships between structures and properties
Khan, Amir. "Vibro-acoustic products from re-cycled raw materials using a cold extrusion process : a continuous cold extrusion process has been developed to tailor a porous structure from polymeric waste, so that the final material possesses particular vibro-acoustic properties." Thesis, University of Bradford, 2008. http://hdl.handle.net/10454/4289.
Повний текст джерелаVaněk, Lukáš. "Vývoj pokročilých tepelně izolačních omítek s možností uplatnění jako sanační omítky dle WTA." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2014. http://www.nusl.cz/ntk/nusl-226722.
Повний текст джерелаRAMBO, CARLOS R. "Sintese e caracterizacao de ceramicas biomorficas." reponame:Repositório Institucional do IPEN, 2001. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10973.
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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
Perret, Anouk. "Méthodologie de caractérisation microstructurale 3D de matériaux poreux structurés pour la thermique." Thesis, Lyon, INSA, 2015. http://www.theses.fr/2015ISAL0042/document.
Повний текст джерелаThe national objectives on the reduction of the rejections of greenhouse gases bring to the necessity of a thermal renovation for 75 % of the French buildings. As the requirements for old and new buildings increase their standards, design thinner and more efficient insulation materials is of great and increasing interest. New insulating materials with thermal conductivities lower than the still dry air (25 mW / (m. K)), such as based silica xerogel products (15 mW / ( m.K )), recently developed, are an interesting choice to answer those new fonctionnalities. In our study, silica xerogels (porosity > 80 %, specific surface > 600 m ²/g) are available as granular materials and binded stiff composite boards (xerogels / latex). The optimization of these materials requires to understand the link between their microstructure, their thermal conductivity and their mechanical behaviour
Hannaoui, Rachid. "Simulation par Dynamique Moléculaire des Propriétés de Transport (Masse et Chaleur) de Fluides Confinés." Thesis, Pau, 2012. http://www.theses.fr/2012PAUU3010/document.
Повний текст джерелаThe aim of this work was to study how a fluid confined in a low permeability porous medium (micro- and meso-porous) behaves concerning its properties of mass diffusion, thermal conductivity and thermal diffusion. For this purpose, non-equilibrium molecular dynamics simulations have been performed on simple binary mixtures placed in various thermodynamic conditions, confined in a porous medium of lamellar geometry of different types (structure-less or atomistic, more or less adsorbent) in __//_ and grand canonical ensembles. The results show that the effects of porous medium on transport properties are more pronounced when the pore size is small, the adsorption is strong and the temperature is low. The results allowed to evaluate these effects quantitatively. In addition, it has been found that the wall roughness has a major impact on the mass diffusion coefficient and a non negligible one on the thermal diffusion coefficient
Juvenal, Frank. "Polymères de coordination luminescents 1D et 2D avec des ligands rigides contenant du Pt(II) montrants des propriétés d’adsorption du CO2." Mémoire, Université de Sherbrooke, 2017. http://hdl.handle.net/11143/10578.
Повний текст джерелаAbstract: The design of new functional materials has a long history. For the past two decades, the field of organic and inorganic polymers has attracted attention of researchers. More importantly, porous materials such as Metal Organic Frameworks (MOFs), Covalent Organic Frameworks (COFs) as well as porous coordination polymers are now being intensively studied due to their potential applications including gas storage, gas separations, catalyst and sensing. On another hand, Pt-containing polymers have shown potential applications in solar cells and light emitting diodes. The masters’ thesis is mainly divided into three main sections presenting new results. In the first section; Chapter 2 mainly discusses the formation of coordination polymers with CuX salts (X= Cl, Br, I) and trans-[p-MeSC6H4C≡C-Pt(PMe3)2-C≡CC6H4SMe] (L1), in either PrCN or PhCN. The resulting polymers obtained were 2D (bidimensional) CPs or 1D (unidimensional) CPs in all cases. However, 2D CPs obtained when CuBr salt is used by either using PrCN or PhCN did not incorporate the solvents in their cavities. On the other hand, the 2D CP and the rest of 1D CPs obtained had either the crystallization molecules in the cavities or coordinated to the copper cluster. The copper-halide clusters were either the rhomboids Cu2X2 fragments or the step cubane Cu4I4. The photophysical measurements in the presence and absence of solvent crystallization molecules were performed. In addition, the porosity of the CPs was evaluated by adsorption isotherms. The vapochromism of the solvent-free 2D and 1D CPs were investigated as well as CO2 sorption measurements were perfomed. Furthermore, we then attempted to use CuCN and L1 in MeCN which is reported in the second section as Chapter 3. The obtained CP was unexpected as L1 broke and a cyanide (CN‾) ion coordinated to the Pt atom leading to the formation of zigzag 1D CP. The coordination bonds Cu-S or/and Cu([eta]2-C≡C) were generally observed with L1, but not in the CuCN case. Instead a 1D chain of (CuCN)n was made and the broken L1 now binds the chain via a Cu-N bond. The photophysical and thermal stability properties were studied. Lastly, the third section, Chapter 4 deals with a potential predictability of CP formation by using CuX salts (X= Cl, Br, I) and either trans-[p-MeSC6H4C≡C-Pt(PMe3)2-C≡CC6H4SMe] (L1) or trans-[p-MeSC6H4C≡C-Pt(PEt3)2-C≡CC6H4SMe] (L2) in MeCN as the solvent. The use of L1 resulted in either 2D or 1D CPs with the MeCN trapped inside of the cavities while L2 resulted in 1D CPs without MeCN being present in their cavities. The thermogravimetric, photophysical as well as gas sorption measurements (only for those with crystalisation molecules) were perfomed.
Fedosse, Zornio Clarice. "Ionic liquids as multifuncional additives for poly(methyl methacrylate)-based materials." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEI041/document.
Повний текст джерелаThe large array of cation/anion combinations, and the excellent intrinsic properties of ionic liquids (ILs) open a large range of possibilities in their use as additives to polymer materials. Thus, the main objective of this work is to explore the role of both the cation and anion of a series of ILs on the properties of poly(methyl methacrylate) (PMMA)-based materials. In a first approach, low amounts of imidazolium and ammonium-based ILs were incorporated as additives to PMMA in the molten state. Morphological and structural characterizations were developed in order to understand the impact of the presence of such ILs on the thermal and mechanical properties of the resulting materials. Then, in the following section, the ability of the same imidazolium and ammonium-based ILs as physical modifiers of silica surface was evaluated. In such an approach, ILs were supposed to act as interfacial agents. Sub-micron and nanosize silica particles were used to prepare PMMA composites. Thus, the extents of each IL improve the interfacial interaction between PMMA and silica particles were discussed. In addition, supercritical carbon dioxide (scCO2) was used as foaming agent to produce foamed PMMA-based composites. In such a case, the combined effect of the presence of ILs and silica particles was analyzed regarding the morphology of the foamed structures. In the last section, scCO2 was used as reaction medium, in an environmental friendly approach, to chemically modify silica nanoparticles using a series of imidazolium IL-functionalized silanes (with different alkyl chain lengths). Thermogravimetric analysis (TGA) was used to highlight the effect of the working pressure and the content of such ILs in the reaction medium. The effect of the alkyl chain length on the grafting density of the resulting nanoparticles was also discussed. Finally, novel PMMA-based nanocomposites were prepared by the incorporation of such grafted nanoparticles. Transmission electron microscopy (TEM) and small-angle neutron scattering (SANS) analyses were used to evaluate the state of dispersion of the particles into the polymer matrix. Moreover, the thermal, rheological and mechanical properties of the materials were studied
Abuaisha, Murad S. "Géothermie profonde : stimulation de la perméabilité par fracturation hydraulique dans un cadre thermo-poroélastique." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENI016/document.
Повний текст джерелаThe application of the Hydraulic Fracturing (HF) technology to exploit geothermal energy from Hot Dry Rocks (HDR) reservoirs is addressed. HF is achieved by extensively pumping geothermal fluids to already existing fractured HDR reservoirs of low permeability. High fluid pressures are expected to drive cracks to evolve and connect. The newly created burgeoning hydraulic conduits should supposedly enhance the permeability of the existing HDR reservoirs. The flow rate/pressure values at which geothermal fluids should be pumped, as well as the pumping schedule to initiate HF, depend primarily on the existing geostatic conditions (geostatic stresses, initial HDR pressure and temperature) as well as on HDR fracture properties (initial mean fracture length, mean fracture aperture, density and orientational distribution of fractures). While these components, in addition to their effects on borehole stability, are scrutinized in this research, focus is on the evolution during circulation processes of the fracture properties. A fracturing model that is capable of tracking fracture evolution in all possible spatial orientations is used to obtain the time course of the anisotropic permeability tensor. This evolving property is integrated into a domestic finite element code which is developed to solve thermo–poroelastic BVPs: emphasis is laid on the efficiency of the doublet flow technique where a fluid gains thermal energy by circulating through the HDR reservoir from the injection well to the production well. The spurious oscillations in the hyperbolic solutions of the approximated finite element approach that are commensal with the phenomenon of forced heat convection are healed/mitigated through several stabilization approaches
Sulong, Mohd Ayub. "Characterisation of advanced porous materials." Thesis, 2015. http://hdl.handle.net/1959.13/1309835.
Повний текст джерелаAdvanced porous materials are a new group of materials where the desired properties can be controlled and even tailored. These interesting materials offer a vast field of applications, thanks to their multi-functional abilities. Several types of advanced porous structures including cellular metals and ceramic porous materials are the focus of the present investigation. Corevo® foam and perlite metallic syntactic foam are investigated in this thesis and manufactured from infiltration casting. In addition, advanced pore morphology foam elements are addressed that are fabricated using thermal expansion of a thin wire-shaped precursor. Ceramic porous structures specially developed (via foam replication) for tissue engineering scaffolds are also studied within the scope of this work. Given the similarity of the geometrical structure of all these materials, the same mechanical characterisation approaches are adopted to assess their mechanical properties. The materials properties are determined for quasi-static and dynamic compression for both small and large strain deformation. Numerical simulations are performed by making use of the highly accurate models obtained from micro-computed tomography data. Where possible, numerical results are verified by the findings of experimental testing. Detailed analysis is included in each chapter elaborating the result from the numerical simulations and the compressive loading test. Versatile tools such as electron microscopy, image based geometry analyser software and IR-thermal imaging are utilised to assist the study. The results show that all cellular metals investigated in this thesis exhibit the characteristic stress-strain curve of metallic foams. This means that a linear slope is found in the beginning of the compression loading, this is followed by a long plateau region indicating energy absorption capability and ends with a steep slope at the end representing the densification. Corevo® foam exhibits a significant amount of mechanical anisotropy in casting direction under quasi-static compressive loading. The degree of mechanical anisotropy is considered mild for perlite metallic syntactic foam in the casting direction under the same loading condition. Foam materials (Corevo® and advanced pore morphology foam element) characterised under dynamic loading show a strain-rate dependence property. Last, but not least, a possible extension of the present research is proposed at the end of this thesis in the Conclusions and Outlook section.
Vijay, Dig. "Forced convective heat transfer through open cell foams." Doctoral thesis, 2016. https://tubaf.qucosa.de/id/qucosa%3A23120.
Повний текст джерелаLIhsing-Lee and 李力行. "Thermal properties of porous silicon and metal membranes." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/85340930466279658590.
Повний текст джерела中國文化大學
材料科學與奈米科技研究所
95
Present day, many of the 3C product become more and more small and powerful so that the plenty of heat will be bring out from computer or other 3C products as we use. In this study, using chemical etching wafer to produce porous silicon and to determine their thermal properties was main idea. There are four part of this essay. There were different kinds of subject to discuss in first part which was discussed different structures from using lighting or heating to etching wafer. In the second part, by using super crystal fluid (SCF), the reduction of particle of silver would be put into pore of porous silicon. And then, there was discussed annealing porous silicon after SCF in the third part. The last step, it was determined structure, thermal properties, and relation of voltage-current. Finally, the specimen which was decided that thermolysis property was better than others was prepared by heating chemical etching for 1hr at 65℃.And specimen was improved thermolysis property and relation of voltage-current by filled in nano-silver though SCF.
Huang, Szu-Yao, and 黃思瑤. "Thermal properties of thermoplastic polyurethanes foam composed with different soft segments." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/c97cjv.
Повний текст джерела國立臺灣科技大學
材料科學與工程系
106
Thermoplastic polyurethanes (TPU) are linear segment block coploymers composed of soft and hard segments, the thermodynamic incompatibility between the soft and hard segments causes microphase separation. Such a microstructure provides TPU various properties. In recent years, expanded TPU (ETPU) bead foam appeared on the market, which has the advantages of lightweight, wear resistance, high elasticity and recyclable. The most important advantage of bead foam material is that it can prepare 3D foaming material with high expansion ratio. The foam beads are sintered using high temperature steam. The double melting peaks is the important feature for elastomeric or crystalline polymers to be sintered. In this experiment, three different soft segments of TPUs were synthesized to prepare low-density foam materials. TPU was synthesized by the two-step method using PTMEG, PPG and PBA three different polyols as soft segments. MDI and BD were applied as hard segments. The synthesized TPUs were foamed by the one-step batch foaming using CO2 as the blowing agent. TPU was saturated at high temperature for a certain period of time before foaming. It is known that thermal processing has a great influence on the TPU structure. Therefore, series heat treatments were performed on the solid and foamed TPU and then analyzed by DSC. The results showed that the three TPUs has almost the same trend with saturation temperature. The relationship between different saturation temperature and saturation time and cell morphology is discussed. After foaming, two distinct endothermic peaks were observed on DSC graph, which is suitable for bead foam sintering.
Benkreira, Hadj, Amir Khan, and Kirill V. Horoshenkov. "Sustainable acoustic and thermal insulation materials from elastomeric waste residues." 2011. http://hdl.handle.net/10454/9042.
Повний текст джерелаThis study presents the data elements to develop a new processing route to transform elastomeric waste residue (particulates) into acoustic and thermal insulation materials that can compete with commercial products. The approach is to bind these grain and fibre particulates with a foaming polyurethane or a similar polymer, the chemistry of which can be manipulated to control the structure stiffness and the evolution of the foaming gas into open or closed cells. Here the study uses two examples of such residues, tyre and carpet shreds both composed of fibres trapping grains of either rubber or PVC. Compounds were made from these systems with different PU binders and the structural properties (density, porosity, air flow resistivity, tortuosity and stiffness) and performance properties (sound absorption, sound transmission, impact sound insulation and thermal conductivity) were measured as a function of binder loading and chemistry. The data obtained show clearly that performance can be tailored by tailoring structural properties resulting with materials that match or even outperform commercial products. The data set obtained here can be usefully exploited with available acoustic and thermal insulation materials model to take the approach further and extended to other waste systems.
Zhang, Zhong Xing, and 張中興. "Investigation of flow and thermal properties of porous medium flow." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/57570842203612560959.
Повний текст джерелаChen, Shin-Liang, and 陳信良. "Thermal Properties of Porous Aluminum Plates Fabriced by Recycled Aluminum Alloy." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/12306505536661647406.
Повний текст джерелаLin, Shing-An, and 林信安. "Analysis on the thermal properties of asymmetric porous silicon using phonon Boltzmann equation." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/48408959424408511327.
Повний текст джерела國立中央大學
機械工程學系
104
Porous silicon has tremendous applications in different engineering fields, especially its low thermal conductivity property which can be used as insulated materials. Besides, such low thermal conductivity also has potential applications in thermoelectric materials and thermal rectification. When it comes to small size scale, that is, when the characteristic length is smaller than the mean free path of the heat carrier, the description of conventional heat conduction is no longer applied due to the size effects and the quantum effects. Heat conduction in solids can be considered as the propagation of quantized energy due to lattice vibration called phonons. The transport behavior of phonons can be described using the Boltzmann Transport equation. In our study, the phonon Boltzmann transport equation is solved using Finite Element Method and Discrete Ordinates Method to simulate the thermal behavior of nano porous silicon films. First, we study the two dimensional thin film and unit cell structure of silicon and discover a transition zone between the porous structure and the bulk material where the heat transport is affected by the pores. The numerical results show that the length of transition zone is independent of porous structure length and bulk material length. Then, we consider symmetric porous silicon with aligned and staggered pores. The simulated thermal conductivities are compared with the results from theoretical models for different porosities. The deviations are less than 20% . Finally, we discuss the thermal properties of asymmetric porous silicon with different porous density distributions. Consider that the porosity and pore diameter are constants, the numerical results show that as the porous density increases, the thermal conductivity will decline. As the separation between pores becomes smaller than 50 nm, pores will have increasingly impact on the propagation of phonon scattering. Using the thermal circuit concept, the thermal conductivities of asymmetric porous materials can be modeled by thermal resistance in series connection, but the results will have large deviation for large asymmetric cases.
Kusumawardani, Dana Mutiara, and 古貝華. "Evaluations of Performance and Thermal Properties in Porous Asphalt Concrete Containing Steel Slag." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/22313211576137486539.
Повний текст джерела國立中央大學
土木工程學系
102
Porous asphalt concrete (PAC) is one alternative solution to the problem of stormwater drainage from parking and other low traffic density areas. The overall benefits of porous asphalt concrete may include both environmental and safety benefits including improved stormwater management, improved skid resistance, reduction of spray to drivers and pedestrians, reduction in light reflection and headlight glare, as well as a potential for noise reduction. However, there are disadvantages of this pavement type such as has lower service life than dense mixes. Steel slag is the material generated from purifying metal, their casting and alloying. It is steel slag that can be used as an aggregate substitution. The objective of this study was to evaluate the performance and thermal properties of porous asphalt concrete containing steel slag. Two types of steel slag were used to subtitute coarse aggregate, including Basic Oxygen Furnace (BOF) and Baoshan Slag Short Flow (BSSF). Three different percentages of steel slag, namely 0%, 30%, and 50%, were mixed. Two main aspects are investigated in this study. One is mixture performance, including resilient modulus, rutting potential, skid resistance, and moisture susceptibility test. The other is thermal properties characteristic, including thermal conductivity, thermal heat capacity, and thermal diffusivity. Statistical were utilized to determine which treatment has the best performance result. The test results show that steel slag has higher specific gravity, high absorption, but lower L.A. abrasion, and soundness compared with natural aggregate. PAC containing steel slag may enhance the resilient modulus, skid resistance, rutting potential, and moisture susceptibility. However the application of high percentage of steel slag may decrease the performance of PAC, such as decrease skid resistance, rutting potential, and moisture susceptibility. The statistical analysis results show that PAC containing 30% of BOF slag has the best performance results, however this kind of pavement had the highest thermal conductivity and thermal diffusivity compared with others. The conclusions indicate that both BOF and BSSF slag are suitable to used as coarse aggregate substitution in PAC.
Hsu, Hung-Che, and 許宏哲. "The Studies of Physical Properties and Model of Thermal Conductivity of Open Cell Rigid Polyurethane Foam." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/08151362582502812722.
Повний текст джерела中國文化大學
材料科學與製造研究所
88
The objectives of this research are to identify the factors which influence the physical properties of open cell rigid polyurethane foam and find the model of thermal conductivity of PU foam. The physical properties performances of the open cell rigid PU foam were experimently inuestigated. The effect factors for the physical properties of PU foam include the ratio of isocynate , polyether and water mixing temperature, and the additives. The model of thermal conductivity of PU foam is fowrd as below: The thermal conductivities data between the thereotical caculation of model and experinently inuertigated are within 12%.
Chen, Po-Ting, and 陳柏廷. "Effect of Nanoclay Addition on the Thermal and Fire Properties of LDPE foam and EVA Copolymer." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/zmb8n2.
Повний текст джерела國立臺北科技大學
化學工程研究所
95
The main objective of this study was to investigate the effect of organoclay addition on thermal and fire properties of low density polyethylene (LDPE) foam and Ethylene Vinyl Acetate copolymer (EVA). Nanoclay、P-N type intumescent flame retardant、cross-linking agent and blow agent have been mixed with LDPE to prepare flame-retarded LDPE foam. LOI and cone calorimeter (CONE) experiments showed that the presence of organoclay in the flame-retarded LDPE foam was not only improve its thermal stability but also reduce its maximum heat release rate and extinction coefficient. EVA/CLAY hybrids have been prepared by melt-blending. The exfoliated structures of clay in the hybrid were characterized by XRD and TEM. TGA and cone calorimeter data shown that nanoclay improve the degradation pathway and also improve its thermal stability.
Lee, Ying-Kuan, and 李盈寬. "A Study of Sn-Based Solders on the Bonding and Thermal Properties of Graphite Foam/Copper." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/jthy47.
Повний текст джерела國立臺北科技大學
製造科技研究所
95
Graphite foam has high heat transfer specific areas and lightweight and it’s suitable for the micro-processes heat sink. However, the graphite foam is brittle and its surface is rough. To enhance the thermal contact between the bottom of the heat sink and heat source, the bonding of the graphite-foam and copper is good for the demand. However, the thermal resistance of the solder layers will affect the cooling performance of the graphite-foam heat sink. The aim of the research is to investigate the effects of different Sn-based solders (Sn-Ag、Sn-Ag-Cu、Sn-Bi and S-Bond)with 1wt% copper powders for 240℃,260℃ and 5~30min on the bonding quality of graphite foam/copper and thermal property. The results show that the contact angles and extending index of Sn-based solders are higher than those of Sn-based solders with 1wt% copper powders. The EPMA data also indicate that the intermetallic phase (Cu3Sn is close to the copper substrate; Cu6Sn5 is closer to interface of solders) exists between Sn-based solders and copper substrates. In addition, the intermetallic layer is increasing with higher temperature and time. The order of the thickness of the intermetallics is as following Sn-Bi>Sn-Ag-Cu>Sn-Ag. The thermal resistance test of the heat sink composed of graphite foam and copper shows that the thermal resistance of Sn-Bi layers is higher and the thermal resistance can be reduced by adding 1wt% copper powders. The thermal resistance of graphite foam/copper powders is lower than that of Al and Copper heat sink identified by natural convention test. Due to the folw resistance accrue, the thermal resistance of graphite-foam is higher than that of heat sink identified by force test.