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Se, Golpayegani Motamedi Aida. "Caractérisation du bois de Mûrier blanc (Morus alba L.) en référence à son utilisation dans les luths Iraniens". Thesis, Montpellier 2, 2011. http://www.theses.fr/2011MON20157.
Pełny tekst źródłaThis work aims at studying the several divers properties (Physico-mechanical, biological and chemical) of white Mulberry (Morus alba L.), as the leading material used in fabrication of Iranian lutes. The vibrational characteristic of this species is measured in relation with secondary metabolites (extractives) as well as three artisanal hygro-thermal treatments adapted to laboratory scale.White Mulberry wood is characterized with a moderate specific modulus, less than expected damping and a low anisotropy between three directions. It is specified that this species cannot be described with the same standards as other woods used in European classical instruments. Using independent and successive extractions reveal that two types of extraneous compounds govern the damping in this wood, some raising it, when the rest have a decreasing effect. These compounds are not all extractable by the same solvents.Long time immersion in water at ambient temperature hardly changes mechanical properties of the species, however, it can leave wood with irreversible defects. Hot water treatment at 70°C results for damping and moduli to be increased and decreased respectively. These changes are time related. Several mild desorption and adsorption cycles, seem to reduce damping without greatly endangering the moduli. White Mulberry wood is found to be very durable towards fungi, even in extreme conditions. Water leaching seems to be affectless on this species resistance towards basidiomycetes. This wood is rated moderately durable towards termites and becomes sensible after water leaching. Extractives seem to play important role in this wood natural resistance, as they are found to have toxic effect on termites. Resorcinol, a phenol, is the leading compound in the extractives of white Mulberry. Fatty acids, sterols, higher hydrocarbons, and aromatic compounds are also found as the constituents of secondary metabolites. Resorcinol is documented to cause irritations close to what is normally experienced by the fabricants working with white Mulberry for a long time
Daher, Suzanne. "Optimisation de la formulation d'un béton de chanvre : effet des interactions physico-chimiques entre les particules végétales et le liant". Electronic Thesis or Diss., Amiens, 2022. http://www.theses.fr/2022AMIE0041.
Pełny tekst źródłaHemp concrete is one of the most popular bio-based building materials in France. It is often used as a filling and / or insulation material, in an eco-construction system. Given its high porosity, this concrete has particularly advantageous thermal and hygric performance. However, the lighter this hemp concrete, the higher its level of thermal insulation, while its mechanical properties decrease. This is why it is necessary to optimize its formulation, in order to obtain the best compromise between its mechanical, hygric and thermal performance, depending on the field of use (carrier and / or insulator). The first optimization approach considered consists in varying the rate of plant aggregates in the composition of the concrete, but also the nature and quantity of binder used. The objective of this thesis is to study the mechanical, thermal and hygric properties of a hemp concrete according to its formulation. In this thesis, we are interested in the feasibility of lightweight building materials based on hemp particles and a lime-based binder, which present good mechanical performances. The main objective is to overcome the migration process of free Ca2+ to the lumen of hemp particles that are responsible for their degradation and which, consequently, induce the loss of mechanical performance of the final composite material. To achieve this, a fraction of the base binder is replaced by metakaolin. First, we studied the influence of different percentages of metakaolin on the carbonation of two lime-based control mortars: NHL5 lime and Tradical PF70 pre-formulated lime. Then, we measured their mechanical resistances in compression and flexion in order to define an optimal formulation. Thus, the finished composite materials are tested for different volume percentages (2v and 3v) of hemp particles. The results of the characterization of the physico-mechanical properties of the specimens are presented and argued. A close relationship between the metakaolin content and the physico-mechanical properties of the hemp concrete has been observed, due to the additional hydration products derived from pozzolanic reaction mechanism. The MEB and EDX analyses have shown the enhancement of hemp particles-binder Interfacial Zone Transition, while the pozzolanic reaction leads to reduce the migration process of free Ca2+ to lumen of vegetable particles thus reducing their mineralization. Then, we compared the hygro-thermal performances of hemp concretes formulated with respectively 2 volumes and 3 volumes of plant particles for one volume of binder, without or with 20% metakaolin, the optimal percentage defined previously. This study is particularly useful to establish the adequate proportions of admixtures to be used in concretes intended for renovation works or new constructions. Generally speaking, and depending on the formulation, we obtain a material that is a good or even excellent regulator of ambient humidity, with interesting thermal performances for the insulation of buildings. This characterization work completes the many works already carried out on biobased concrete with different types of plants, and should make it possible to feed the databases essential for the simulation of the behavior of a wall or of the envelope of a building under different climates and guarantee the comfort of the occupants
Saetung, Anuwat. "Preparation of polyurethane foams from hydroxytelechelic oligoisoprenes obtained by controlled degradation of natural rubber : study of their physico-mechanical, thermal, and acoustic properties". Le Mans, 2009. http://cyberdoc.univ-lemans.fr/theses/2009/2009LEMA1006.pdf.
Pełny tekst źródłaPolyurethane foam (PUF) is the largest of polyurethane materials widely studied and used in many applications such as furniture, automobile, insulation, acoustic absorber. Hydroxyl compounds currently used in the production of PUF are petrochemical products (polyester and polyether polyols). However, they have some disadvantages as they are non-renewable resources, they may cause environmental pollution, and they tend to be exhausted in the near future. Natural rubber (NR) is an interesting choice to use as a starting material in PUF synthesis, due to the fact that they are renewable source, abundant polymer and they have good mechanical properties and are easy to chemically modify. In this work, a new hydroxytelechelic natural rubber (HTNR) having a hydroxyl functionality of 2 was successfully performed via controlled epoxidation and cleavage of natural rubber, following by a selective reduction reaction of the obtained carbonyltelechelic oligoisoprenes. These HTNR with different molecula r weights (1000-3400 g mol-1) were reproducible obtained with high yields. Chemical modifications on HTNR were performed by epoxidation (10-35%, EHTNR), hydrogenation and oxirane opening reactions. The different microstructures of these oligomers were evidenced by the characterization techniques FT-IR, NMR, SEC and MALDI-TOF MS. Their thermal properties were also investigated by TGA and DSC. Polyurethane foams were successfully prepared from a renewable source, HTNR with different molecular weights and EHTNR having a variation of epoxide content, by one shot technique. The chemical structure and cell structure as well as physico-mechanical, thermal and acoustic properties were characterized to compare with commercial polyol analogues. It was investigated that the obtained HTNR based foams are open cell structures and have cell dimensions between 0. 38 and 0. 47 mm. Concerning, physico-mechanical properties, HTNR1000 based foam exhibits higher tensile and compressive strengths than commercial polyol analogue, but the elongation at break is lower. However, HTNR3400 based foam shows the best for elastic properties. In series of EHTNR based foams, the tensile and compressive strengths give a trendy increasing with increasing the epoxide content. Same results were observed with increasing amount of 1,4-butanediol. For thermal properties, HTNR based foams show better low temperature flexibility than that based on commercial polyol. Moreover, HTNR based polyurethane foams give an excellent acoustic absorber
Apreutesei, Mihai. "Temperature impact on thermal evolution of advanced PVD ceramic and metallic glass thin films : Physico-chemical and microstructural analysis". Thesis, Lyon, INSA, 2015. http://www.theses.fr/2015ISAL0009/document.
Pełny tekst źródłaIn the recent years the industrial requirements to develop new functional materials able to overcome the severe conditions during machining operation are continuously increasing. Researchers then must find novel solutions to respond to their severe industrial requirements. To coat the tool surface with advanced coatings is the most efficient solution. New nanostructured materials may nowadays exhibit unique mechanical, physical and chemical properties ensuring notable degradation resistance where the surface protection of materials against corrosion, wear, friction or oxidation is a key issue, particularly when operating in hostile environments. Within the scope of this Ph.D. thesis the influence of the temperature on the structural stability of two different PVD ceramic and metallic glass thin films is proposed. The main goal consists in the development of two distinct classes of thin films, with a wide range of properties. In order to prepare these films, the project will be focused on the study on the influence of PVD deposition conditions in the particular film’s growth characteristics: chemical composition, structure, morphology and the subsequent changes in the main properties of the thin films, namely oxidation and crystallization resistance, especially. For that purpose we adopted the multiscale approach. The first part is related to the ceramic CrN-based coatings to give new functionalities and improve the tools’ surface with the primary aim to increase their lifetime. Secondly, new protective materials able to better protect the exposed surfaces against high temperature oxidation have been proposed, namely CrAlN and CrAlYN coatings as will be evidenced in this manuscript. The second part of the manuscript is dedicated to the innovative Zr-Cu thin films metallic glasses prepared by a PVD magnetron co-sputtering method with the objective to investigate the amorphization ability and their structural properties. Their excellent properties at room temperature have recently attracted attention as a new class of materials with great potential for engineering applications due to unique mechanical and physico-chemical characteristics (high elastic strain limit, corrosion resistance…). Finally, an important approach during the course of this thesis was the real time observation of the structure and surface modifications during heating by means of in situ methods. The thin films proposed during the course of the work could be straightforward used as surface engineering solutions to protect and extend the lifetime of the materials and components
Sani, Rababe. "Étude des transformations microstructurales de mélanges argile/Combustibles Solides de Récupération (CSR) lors de la cuisson : relations entre propriétés physico-chimiques, mécaniques et thermiques". Thesis, Ecole nationale des Mines d'Albi-Carmaux, 2018. http://www.theses.fr/2018EMAC0005/document.
Pełny tekst źródłaThe valorization of co-products rich in organic and inorganic materials as additives in formulations based on clay matrix can improve both the mechanical and thermal performances of ceramic materials as well as the energy balance of the manufacturing processes of these products. This study focused on the incorporation of Solid Recovered Fuels (SRF) into the clay ceramics for civil engineering in close collaboration with TERREAL as part of the ANR funded LabCom RESPECTc project. Firstly, two SRF were selected and used as additives to improve the properties of ceramic materials from to clay mixture deposits named ML and MC from TERREAL. The influence of the nature, the amount of SRF, the grain size of SRF and the nature of clay matrix on the physico-chemical, mechanical and thermal properties of the clay/SRF mixtures were studied between 30°C and 1100°C. In all cases, the addition of SRF into the clay mixture (ML or MC) has enhanced the insulating nature of the ceramic materials by reducing their thermal conductivity. The addition of SRF has also improved the mechanical properties of the ceramic materials, depending on the nature and the amount of SRF added, the rate and the nature (shape, size and distribution) of the porosity created. The study demonstrated that interactions between clay minerals and inorganic elements of SRF have a significant effect on mechanical and thermal properties. The results showed that the addition of 4 wt.% of SRF15-1 containing an ash content of 65.7 wt.% into clay matrix ML led to increase the mechanical strength of the material based on the clay matrix ML of the order of 32%. Then, a kinetic model of thermal sintering based on the dimensional variations of ceramic materials between 650°C and 1000°C was developed from thermomechanical analysis (TMA) of the clay mixtures (with or without SRF). The main objective is to better understand the mechanism of the thermal sintering involved. The model developed showed a good adequacy with the experimental data. The results showed that the thermal sintering step of these mixtures is carried out by the presence of a liquid phase and that the addition of SRF has accelerated the densification of ceramic materials. This has led to decrease the usual firing temperature of ceramic materials, allowing a significant energy savings. Finally, an environmental assessment was carried out during the firing of clay/SRF mixtures. This study was particularly focused on the contribution of SRF to the energy balance and impact of critical gas emissions such as CO2, CO and HCl. The results showed that CO2 and CO emissions during firing of clay/SRF mixtures increased due to the thermal decomposition of the organic matter of SRF and that less than 50 wt.% of chlorine was converted to HCl (18-31 ppm). The energy balance showed that the addition of SRF into the ML matrix compensates for a significant part of the natural gas usually used as fuel during firing of these ceramic materials. This was reflected by a thermal energy saving and reduction of CO2 emissions from the decarbonatation of the clay matrix
Conley, Jill Anne. "Hygro-thermo-mechanical behavior of fiber optic apparatus". Thesis, Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/17308.
Pełny tekst źródłaSani, Rababe. "Étude des transformations microstructurales de mélanges argile/Combustibles Solides de Récupération (CSR) lors de la cuisson : relations entre propriétés physico-chimiques, mécaniques et thermiques". Electronic Thesis or Diss., Ecole nationale des Mines d'Albi-Carmaux, 2018. http://www.theses.fr/2018EMAC0005.
Pełny tekst źródłaThe valorization of co-products rich in organic and inorganic materials as additives in formulations based on clay matrix can improve both the mechanical and thermal performances of ceramic materials as well as the energy balance of the manufacturing processes of these products. This study focused on the incorporation of Solid Recovered Fuels (SRF) into the clay ceramics for civil engineering in close collaboration with TERREAL as part of the ANR funded LabCom RESPECTc project. Firstly, two SRF were selected and used as additives to improve the properties of ceramic materials from to clay mixture deposits named ML and MC from TERREAL. The influence of the nature, the amount of SRF, the grain size of SRF and the nature of clay matrix on the physico-chemical, mechanical and thermal properties of the clay/SRF mixtures were studied between 30°C and 1100°C. In all cases, the addition of SRF into the clay mixture (ML or MC) has enhanced the insulating nature of the ceramic materials by reducing their thermal conductivity. The addition of SRF has also improved the mechanical properties of the ceramic materials, depending on the nature and the amount of SRF added, the rate and the nature (shape, size and distribution) of the porosity created. The study demonstrated that interactions between clay minerals and inorganic elements of SRF have a significant effect on mechanical and thermal properties. The results showed that the addition of 4 wt.% of SRF15-1 containing an ash content of 65.7 wt.% into clay matrix ML led to increase the mechanical strength of the material based on the clay matrix ML of the order of 32%. Then, a kinetic model of thermal sintering based on the dimensional variations of ceramic materials between 650°C and 1000°C was developed from thermomechanical analysis (TMA) of the clay mixtures (with or without SRF). The main objective is to better understand the mechanism of the thermal sintering involved. The model developed showed a good adequacy with the experimental data. The results showed that the thermal sintering step of these mixtures is carried out by the presence of a liquid phase and that the addition of SRF has accelerated the densification of ceramic materials. This has led to decrease the usual firing temperature of ceramic materials, allowing a significant energy savings. Finally, an environmental assessment was carried out during the firing of clay/SRF mixtures. This study was particularly focused on the contribution of SRF to the energy balance and impact of critical gas emissions such as CO2, CO and HCl. The results showed that CO2 and CO emissions during firing of clay/SRF mixtures increased due to the thermal decomposition of the organic matter of SRF and that less than 50 wt.% of chlorine was converted to HCl (18-31 ppm). The energy balance showed that the addition of SRF into the ML matrix compensates for a significant part of the natural gas usually used as fuel during firing of these ceramic materials. This was reflected by a thermal energy saving and reduction of CO2 emissions from the decarbonatation of the clay matrix
Cunha, Paulo Waldemiro Soares. "Estudo sobre as potencialidades de comp?sitos ? base de gesso e fibras de coco seco para aplica??o na constru??o civil". Universidade Federal do Rio Grande do Norte, 2012. http://repositorio.ufrn.br:8080/jspui/handle/123456789/12847.
Pełny tekst źródłaThe use of gypsum, one of the oldest building materials for the construction industry in the country has been experiencing a significant and steady growth, due to its low cost and some of its properties that confer comparative advantage over other binder materials. Its use comprises various applications including the coating of walls and the production of internal seals and linings. Moreover, the fibers are being increasingly incorporated into arrays fragile in an attempt to improve the properties of the composite by reducing the number of cracks, the opening of the same and its propagation velocity. Other properties, depending on the function of the component material or construction, among these thermal and acoustic performances, are of great importance in the context of buildings and could be improved, that is, having better performance with this embodiment. Conduct a comparative study of physico-mechanical, thermal and acoustic composite gypsum incorporating dry coconut fiber, in the form of blanket, constituted the main objective of this work. Improving the thermal and acoustic performances of precast gypsum, used for lining and internal vertical fences of buildings, was the purpose of development of these composites. To evaluate the effect of fiber content on the properties of the composites were used to manufacture the composite layer with different thicknesses. The composites were fabricated in the form of plates with dimensions of 500x500x24mm. To facilitate the comparative study of the properties were also made with material gypsum boards only. We then determined the physico-mechanical, thermal and acoustical plaster and composites. The results indicated that the composites were significant gains in relation to thermal performance and also acoustic, in certain frequency range, increasing the thickness of the blanket. Concerning other physical-mechanical properties, the results showed that although the compressive strength was lower than for the composite did not occur after a fracture catastrophic failure. The same trend was observed with regard to resistance to bending, since the composites have not suffered sudden rupture and still continued after the load supporting point of maximum load
A utiliza??o do gesso, um dos mais antigos materiais de constru??o, pela ind?stria da constru??o civil no Pa?s, vem experimentando um sens?vel e constante crescimento, em fun??o do seu baixo custo e de algumas de suas propriedades que lhe conferem vantagem comparativa em rela??o a outros materiais ligantes. Sua utiliza??o compreende diversas aplica??es entre as quais o revestimento de paredes e a confec??o de veda??es internas e de forros. Por outro lado, as fibras v?m sendo, cada vez mais, incorporadas em matrizes fr?geis, na tentativa de melhorar as propriedades do comp?sito, atrav?s da redu??o do n?mero de fissuras, da abertura das mesmas e da sua velocidade de propaga??o. Dependendo da fun??o do material ou do componente da constru??o, os desempenhos t?rmico e ac?stico, assumem grande import?ncia no contexto das edifica??es e tamb?m poderiam ser melhoradoscom a incorpora??o de fibras. Dentre as fibras vegetais, a fibra de coco seco apresenta um grande potencial, superior ?s vantagens comparativas das demais fibras, tal como uma maior resist?nciafrente ? alcalinidade caracter?stica das matrizes ciment?cias. Realizar um estudo comparativo das propriedades f?sico-mec?nicas, t?rmicas e ac?sticas de comp?sitos ? base de gesso com incorpora??o de fibra de coco seco, sob a forma de manta, constituiu-se no objetivo geral deste trabalho. Para tanto os materiais comp?sitos foram confeccionados em forma de placas, pain?is sandu?ches, com dimens?es de 500x500x24mm, sendo as camadas externas constitu?das pelogesso e a central (recheio) pela manta de fibra de coco seco. Para avaliar a influ?ncia do teor de fibras nas propriedades dos comp?sitos foram utilizadas na confec??o dos mesmos mantas com espessuras de 8 e 10 mm. Para possibilitar o estudo comparativo das propriedades foram tamb?m confeccionadas placas apenas com gesso. Foram ent?o determinadas as propriedades f?sico-mec?nicas, t?rmicas e ac?sticas do gesso e dos comp?sitos. Os resultados indicaram que para os comp?sitos ocorreram ganhos significativos em rela??o aos desempenhos t?rmico e tamb?m ac?stico, na faixa de frequ?ncia de 102,28 Hz a 1.150,00 Hz, ganhos esses crescentes com a espessura da manta. Em rela??o ?s demais propriedades f?sico-mec?nicas, os resultados mostraram que embora a resist?ncia ? compress?o tenha sido inferior para os comp?sitos, as fibras apenas evitaram um rompimento brusco, uma vez que as mesmas n?o atuam como refor?o para esse tipo de solicita??o. O mesmo comportamento ocorreu em rela??o ? resist?ncia ? flex?o, uma vez que os comp?sitos n?o sofreram ruptura brusca e ainda continuaram suportando carga depois do ponto de carga m?xima
Cisse, Ousseynou. "Caractérisation du comportement hygro-mécanique des fibres liberiennes élémentaires issues du chanvre". Thesis, Besançon, 2014. http://www.theses.fr/2014BESA2031/document.
Pełny tekst źródłaThe thesis work joins in the framework in joint supervision between the Polytechnic school in Thies (Sénégal) and the University of Franche-Comté (France)[...]The aim of this thesis is to contribute to the characterization of thermo-hygro-mechanical behaviour of elementary hemp fibres. These fibres used in this work have an average diameter approximately 20µm and useful length of only 10 mm. The méchanical, hygroscopic and thermal coupling testing are realized to provide some understanding of the behaviour of the hemp fibres and to collect details from a database on their mechanical performance.From the uniaxial quasi static tensile tests and creep tests, three categories of behaviours are measured and observed. How ever subject to constant environmental conditions, a fibre hardening is observed under cyclic tensile loading. It was also found that a drop of the initial Young 's modulus of the hemp fibres when the relative humidity gradually increases. Thus, the strain rates measured on the fibres during creep exhibited a speeding up relative humidity cycles are imposed . We found also that the mechanical properties of the fibres decrease under temperature effects. It depends directly on the level and exposure time to temperature
Cohen, Ellann. "Thermal properties of advanced aerogel insulation". Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/67795.
Pełny tekst źródłaCataloged from PDF version of thesis.
Includes bibliographical references (p. 74-76).
Buildings consume too much energy. For example, 16.6% of all the energy used in the United States goes towards just the heating and cooling of buildings. Many governments, organizations, and companies are setting very ambitious goals to reduce their energy use over the next few years. Because the time periods for these goals are much less than the average lifetime of a building, existing buildings will need to be retrofitted. There are two different types of retrofitting: shallow and deep. Shallow retrofits involve the quickest and least expensive improvements often including reducing infiltration around windows, under doors, etc and blowing more insulation into the attic. Deep retrofits are those that involve costly renovation and typically include adding insulation to the walls and replacing windows. A new, easily installable, inexpensive, and thin insulation would move insulating the walls from the deep retrofit category to the shallow retrofit category and thus would revolutionize the process of retrofitting homes to make them more energy efficient. This thesis provides an overview of a concept for a new, easily installable, inexpensive, thin aerogel-based insulation and goes into detail on how the thermal properties of the aerogel were measured and validated. The transient hot-wire method for measuring the thermal conductivity of very low thermal conductivity silica aerogel (1 0mW/m K at 1 atm) along with a correction for end effects was validated with the NIST (National Institute of Standards and Technology) Standard Reference Material 1459, fumed silica board to within 1 mW/mK. Despite the translucence of the aerogel at certain wavelengths, radiation is not an issue through the aerogel during the hot-wire test but may be an issue in actual use as an insulation. The monolithic aerogel thermal conductivity drops significantly with slightly reduced pressure (3.2 mW/m K at 0.1atm). For the final composite insulation, the new silica aerogel formula is a great choice and it is recommended to reduce the pressure around the aerogel to 1 / 1 0 th. In the future, a prototype of an insulation panel combining a 3-D truss structure, monolithic or granular silica aerogel, and reduced pressure will be constructed and tested.
by Ellann Cohen.
S.M.
Yun, Tae Sup. "Mechanical and Thermal Study of Hydrate Bearing Sediments". Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7247.
Pełny tekst źródłaHovell, Ian. "Dynamic mechanical thermal properties of moulded poly(vinylchloride) swollen with organic liquids". Thesis, Loughborough University, 1987. https://dspace.lboro.ac.uk/2134/33149.
Pełny tekst źródłaWain, Susan Elizabeth. "Thermal and mechanical properties of pulverised fuel boiler slags". Thesis, Imperial College London, 1991. http://hdl.handle.net/10044/1/8209.
Pełny tekst źródłaCurran, J. A. "Thermal and mechanical properties of plasma electrolytic oxide coatings". Thesis, University of Cambridge, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.598226.
Pełny tekst źródłaJohnson, Jeremy A. (Jeremy Andrew). "Optical characterization of complex mechanical and thermal transport properties". Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/68543.
Pełny tekst źródłaPage 176 blank. Cataloged from PDF version of thesis.
Includes bibliographical references (p. 163-175).
Time-resolved impulsive stimulated light scattering (ISS), also known as transient grating spectroscopy, was used to investigate phonon mediated thermal transport in semiconductors and mechanical degrees of freedom linked to structural relaxation in supercooled liquids. In ISS measurements, short optical pulses are crossed to produce a periodic excitation profile in or at the surface of the sample. Light from a probe beam that diffracts off the periodic material response is monitored to observe the dynamics of interest. A number of improvements were put into practice including the ability to separate so-called amplitude and phase grating signal contributions using heterodyne detection. This allowed the measurement of thermal transport in lead telluride and gallium arsenide-aluminum arsenide superlattices, and also provided the first direct observation of the initial crossover from diffusive to ballistic thermal transport in single crystal silicon and gallium arsenide at room temperature. Recent first-principles calculations of the thermal conductivity accumulation as a function of phonon mean free path allowed direct comparison to our measured results. In an effort to test theoretical predictions of the prevailing first principles theory of the glass transition, the mode coupling theory (MCT), photoacoustic measurements throughout much of the MHz acoustic frequency range were conducted in supercooled liquids. Longitudinal and shear acoustic waves were generated and monitored in supercooled liquid triphenyl phosphite in order to compare the dynamics. An additional interferometric technique analogous to ISS was developed to probe longitudinal acoustic waves at lower frequencies than was typically accessible with ISS. Lower frequency acoustic data were collected in supercooled tetramethyl tetraphenyl trisiloxane in conjunction with piezotransducer, ISS, and picosecond ultrasonics measurements to produce the first truly broadband mechanical spectra of a viscoelastic material covering frequencies continuously from mHz to hundreds of GHz. This allowed direct testing of the MCT predicted connection between fast and slow relaxation in supercooled liquids. Measurements of the quasi-longitudinal speed of sound in the energetic material cyclotrimethylene trinitramine (RDX) were also performed with ISS and picosecond ultrasonics from 0.5 to 15 GHz in order to resolve discrepancies in published low and high frequency elastic constants.
by Jeremy A. Johnson.
Ph.D.
Cerezo, Frances Therese, i francestherese_cerezo@hotmail com. "Thermal stability and mechanical property of polymer layered graphite oxide composites". RMIT University. Applied Sciences, 2006. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080627.161157.
Pełny tekst źródłaGril, Joseph. "Une modelisation du comportement hygro-rheologique du bois a partir de sa microstructure". Paris 6, 1988. http://www.theses.fr/1988PA066271.
Pełny tekst źródłaSkow, Erik (Erik Dean). "Processing and thermal properties of molecularly oriented polymers". Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/40368.
Pełny tekst źródłaIncludes bibliographical references (p. 61-63).
High molecular weight polymers that are linear in molecular construction can be oriented such that some of their physical properties in the oriented direction are enhanced. For over 50 years polymer orientation and processing has been extensively studied to improve the mechanical properties of polymers. In more recent history the anisotropic thermal properties of oriented polymers have been studied. This thesis investigates the thermal properties of Ultra High Molecular Weight Polyethylene (UHMW-PE) and explores applications for the same. This thesis details an effective means of aligning the molecules in bulk polyethylene sheets through stretching in the gel state. Tests have shown that bulk UHMW-PE can be stretched 50-80 times in xylene. The thermal conductivity of bulk UHMW-PE is 0.3 W/mK, while that of a sample stretched 20-25 times is over 4.5 W/mK.
by Erik Skow.
S.M.in Mechanical Engineering and Naval Architecture and Marine Engineering
El-Khoja, Amal M. N. "Mechanical, thermal and acoustic properties of rubberised concrete incorporating nano silica". Thesis, University of Bradford, 2019. http://hdl.handle.net/10454/18351.
Pełny tekst źródłaLibyan Ministry of Higher Education
Kamani, Sandeep Kumar. "Influence of defects on thermal and mechanical properties of metals". [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-2901.
Pełny tekst źródłaAksel, Cemail. "Thermal shock behaviour and mechanical properties of magnesia-spinel composites". Thesis, University of Leeds, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.275609.
Pełny tekst źródłaBarlow, Lyndsey J. "Thermal, mechanical and electrical properties of liquid crystalline polymer electrolytes". Thesis, University of Aberdeen, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.401497.
Pełny tekst źródłaOkeke, George Obiora Ugochukwu. "Physico-thermal properties of TiO2 nanoparticles using molecular dynamics simulations with relevance to thermal conductance of nanofluids". Thesis, University of Leeds, 2013. http://etheses.whiterose.ac.uk/6302/.
Pełny tekst źródłaRummel, Nicholas J. "Dynamic mechanical analysis of magnetic tapes at ultra-low frequencies". Scholarly Commons, 2011. https://scholarlycommons.pacific.edu/uop_etds/773.
Pełny tekst źródłaXie, Weidong. "Thermo-mechanical evaluation of interfacial integrity in multilayered microelectronic packages". Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/17380.
Pełny tekst źródłaZhao, Yang. "Evaluation and characterisation of thermal barrier coatings". Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/evaluation-and-characterisation-of-thermal-barrier-coatings(b6b8d5ef-0cd3-4257-9563-6a6b1626cb49).html.
Pełny tekst źródłaOthuman, Mydin Md Azree. "Lightweight foamed concrete (LFC) thermal and mechanical properties at elevated temperatures and its application to composite walling system". Thesis, University of Manchester, 2010. https://www.research.manchester.ac.uk/portal/en/theses/lightweight-foamed-concrete-lfc-thermal-and-mechanical-properties-at-elevated-temperatures-and-its-application-to-composite-walling-system(5a13ec7f-d460-4354-a296-6d1ffecff971).html.
Pełny tekst źródłaDames, Christopher Eric. "Thermal properties of nanowires and nanotubes : modeling and experiments". Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/38259.
Pełny tekst źródłaIncludes bibliographical references.
Nanowires and nanotubes have drawn a great deal of recent attention for such potential applications as lasers, transistors, biosensors, and thermoelectric energy converters. Although the thermal properties of nanowires can differ greatly from their bulk counterparts, the theoretical and experimental understanding of these differences is still limited. Thermal performance is especially important for nanowire thermoelectrics, which are expected to have energy conversion efficiencies far superior to bulk materials. This efficiency increase may lead to a broad range of applications for reliable, solid-state energy conversion, including household refrigeration and waste heat scavenging for power generation. In this thesis, the fundamental thermal properties of nanowires and nanotubes are explored from both theoretical and experimental perspectives. Modeling and experiments on titanium dioxide nanotubes confirm that quantum size effects can cause enhancements in the specific heat at low temperature, while modeling of classical size effects in nanowires and superlattice nanowires shows that the thermal conductivity can be reduced by several orders of magnitude compared to bulk, in agreement with available experimental data.
(cont.) To facilitate further experimental studies of individual nanowires, the "3-omega" methods for thermal properties measurements were made more rigorous, simpler to implement, and generalized to 1-omega and 2-omega methods which may be advantageous for nanoscale systems. These methods are used to deduce the thermal properties of a system from its electrical response at the first, second, or third harmonic of a driving current. Finally, a detailed design and preliminary measurements are presented for a new type of hot-wire probe based on Wollaston wire and used to measure the thermoelectric properties of individual nanowires and nanotubes inside a transmission electron microscope.
by Christopher Eric Dames.
Ph.D.
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.
Pełny tekst źródłaPakiela, Z., L. Jarosz, K. Nowak i L. Olejnik. "Thermal Stability and Mechanical Properties of 5483 Al Alloy Processed by ECAP". Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35435.
Pełny tekst źródłaDuerr, Joachim Karl Wilhelm. "Finite element analysis of thermal stresses in semiconductor devices". PDXScholar, 1990. https://pdxscholar.library.pdx.edu/open_access_etds/4215.
Pełny tekst źródłaDeshpande, Girish Nilkanth. "Effect of polysiloxane side groups on chemistry and kinetics of degradation and evolution of pores in the resultant polymer". Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/11845.
Pełny tekst źródłaGauthier, Sylvie 1955. "Synthesis and physical properties of styrene-vinylpyridinium ionomers of various architectures". Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=72029.
Pełny tekst źródłaThe Tg's of the random ionomers were found to increase regularly with increasing ion content, at a rate of about 3.5(DEGREES)C per mole % of ions. In contrast with other ionomeric systems studied before, however, these materials showed only one peak in their tan delta curves, associated with the Tg of the matrix. The absence of a second, high temperature peak suggests the absence of clusters in these vinylpyridinium ionomers, at least at temperatures above their Tg. The storage modulus curves were in agreement with this conclusion.
An elaborate polymerization line was constructed for the production of the block copolymers by living anionic polymerization; a basic design was modified considerably and two new units were completely designed in this laboratory. Only one Tg, associated with the Tg of the polystyrene phase, was observed in DSC measurements for the resulting ionomers. The glass transition of the ionic domains was detected in dynamic mechanical measurements as a shoulder on the low temperature side of the polystyrene transition. This unexpected low value for the Tg of the ionic domains was attributed to plasticization by water.
Weisenberger, Matthew Collins. "APPLICATIONS OF MULTIWALL CARBON NANOTUBE COMPOSITES: MECHANICAL, ELECTRICAL AND THERMAL PROPERTIES". Lexington, Ky. : [University of Kentucky Libraries], 2007. http://hdl.handle.net/10225/738.
Pełny tekst źródłaTitle from document title page (viewed on March 24, 2008). Document formatted into pages; contains: ix, 97 p. : ill. (some col.). Includes abstract and vita. Includes bibliographical references (p. 91-95).
Ghazinezami, Ali. "Fire retardancy, thermal stability and mechanical properties of polymeric based nanocomposites". Thesis, Wichita State University, 2013. http://hdl.handle.net/10057/10631.
Pełny tekst źródłaThesis (M.S.)--Wichita State University, College of Engineering, Dept. of Mechanical Engineering
O'Reilly, Michael Patrick. "Mechanical properties of granular materials for use in thermal energy stores". Thesis, University of Nottingham, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.353925.
Pełny tekst źródłaDeszczynski, Marcin. "Effects of sugars on the mechanical and thermal properties of biopolymers". Thesis, University of Nottingham, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289482.
Pełny tekst źródłaThompson, Ian. "Mechanical properties in liquid environments and thermal shock resistance of aluminas". Thesis, Imperial College London, 1989. http://hdl.handle.net/10044/1/47686.
Pełny tekst źródłaPlunkett, Richard. "Assessment of residual composite properties as influenced by thermal mechanical aging". Thesis, This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-11072008-063142/.
Pełny tekst źródłaPan, Deng. "Mechanical properties of diffusion aluminide bond coats for thermal barrier coatings". Available to US Hopkins community, 2003. http://wwwlib.umi.com/dissertations/dlnow/3080741.
Pełny tekst źródłaShin, Hyun Doug. "Expanding ultrafast photoacoustics for investigation of mechanical properties and thermal transport". Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/122716.
Pełny tekst źródłaCataloged from PDF version of thesis.
Includes bibliographical references (pages 123-135).
To address the need for broadband mechanical spectroscopy, femtosecond laser pulses were used to generate and detect acoustic waves. To expand the acoustic phonon frequency bandwidth and range, a thin metal film, a strongly magnetostrictive galfenol film, and strained piezoelectric InGaN/GaN multiple quantum wells were used as transducers. Acoustic wave detection methods included monitoring of optical transmittance/ reflectance, polarization, and diffraction over time. A magnetostrictive material galfenol (Fe₁₋[subscript x] Ga[subscript x]) with 80 percent iron and 20 percent gallium was used as an acoustic transducer using demagnetostriction effect. Galfenol showed great potential as an optimal transducer for the ultrafast magnetostriction in both longitudinal and shear modes. Strained piezoelectric InGaN/GaN semiconductor superlattices were used to generate and to study longitudinal THz acoustic phonons in GaN based structures. During the investigation of the lifetime of up to a 1.4 THz frequency acoustic phonons, specular reflection from an air/GaN free surface was observed. The photo-excitation of THz acoustic phonons in layered structures was introduced as an effective noninvasive tool to investigate the integrity of the fabrication process. This study opened many possibilities for studying mechanical properties and thermal phonons. Next, thermal conductivity reduction due to carrier-phonon interactions was presented. Phonon contributions are critical in heat transport in semiconductors and insulators. To isolate the carrier contributions to the scattering events, photo-excited carriers were generated in silicon through pulsed laser excitation. To measure thermal conductivity changes, time-domain thermoreflectance and transient thermal grating techniques were employed with a, carefully timed additional excitation pulse for carrier generation.
by Hyun Doug Shin.
Ph. D.
Ph.D. Massachusetts Institute of Technology, Department of Chemistry
Karimzadeh, F., V. Rastar i M. H. Enayati. "Thermal Stability and Mechanical Properties of Al-Al2O3 Nanocomposite Produced by Mechanical Milling and Hot-Pressing". Thesis, Sumy State University, 2012. http://essuir.sumdu.edu.ua/handle/123456789/34932.
Pełny tekst źródłaKulamarva, Arun. "Rheological and thermal properties of sorghum dough". Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=98740.
Pełny tekst źródłaBailey, Jacob (Jacob S. ). "Experimental determination of the thermal properties of multi-layered surfaces". Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/83683.
Pełny tekst źródłaCataloged from PDF version of thesis.
Includes bibliographical references (page 23).
This paper outlines a project which aims to use Certified Reduced Basis and General Empirical Interpolation Methods to conduct rapid, inexpensive, computationally simple thermal property estimation for the purpose of material identification. In this specific case, thermal conductivity and diffusivity were the parameters of interest. Towards this end, an experimental apparatus was constructed which applied a thermal load to various materials and observed their thermal responses. Bugs in the experimental apparatus were compensated for by way of a MATLAB script, until the data produced by individual tests became highly repeatable. Software was developed which simulated these thermal responses for given thermal loads and "true" parameter values. The materials were put through multiple tests (Laser Flash Test, Transient Plane Source) to independently identify possible values for these thermal properties. The "true" values were then chosen from these possible values based on how well they allowed the simulated response to fit the measured response. It was found that implementation of the CRB and GEIM allowed for an accurate estimate of these "true values," and did so without exhaustively carrying out a finite element analysis for every possible combination of parameters, creating an exponential increase in performance.
by Jacob Bailey.
S.B.
Guan, Juan. "Investigations on natural silks using dynamic mechanical thermal analysis (DMTA)". Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:c16d816c-84e3-4186-8d6d-45071b9a7067.
Pełny tekst źródłaXu, Shuangyan. "Evaluating Thermal and Mechanical Properties of Electrically Conductive Adhesives for Electronic Applications". Diss., Virginia Tech, 2002. http://hdl.handle.net/10919/27112.
Pełny tekst źródłaPh. D.
DeVincent, Sandra Marie. "Interfacial effects on the thermal and mechanical properties of graphite/copper composites". Case Western Reserve University School of Graduate Studies / OhioLINK, 1994. http://rave.ohiolink.edu/etdc/view?acc_num=case1061300766.
Pełny tekst źródłaLeBaut, Yann P. "Thermal aspect of stereolithography molds". Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/15991.
Pełny tekst źródłaPitié, Frédéric. "High temperature thermal energy storage : encapsulated phase change material particles : determination of thermal and mechanical properties". Thesis, University of Warwick, 2012. http://wrap.warwick.ac.uk/57108/.
Pełny tekst źródłaLankford, Maggie E. "Measurement of Thermo-Mechanical Properties of Co-Sputtered SiO2-Ta2O5 Thin Films". University of Dayton / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1627653071556618.
Pełny tekst źródła