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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 63 for “"polyurethane foam"”.
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Smoldering combustion of flexible polyurethane foam
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 1980
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Structural characterization of polyurethane foam and implications of aging
Polyurethane (PU) foam is used as a shock mitigation material in the national stockpile, which degrades over time. A replacement foam, ReCrete was shown to exhibit acceptable mechanical properties after aging, but fractured with impact testing. Previously, processing ReCrete foam at elevated …
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The extraction of trichlorostannato-rhodium complexes by polyurethane foam
Polyurethane foam (polyether based) has been found to efficiently extract rhodium from hydrochloric acid solutions containing stannous chloride. The amount of rhodium extracted is significantly influenced by inter alia temperature, acid concentration, the Sn(II):Rh mol ratio and the presence of …
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The influence of morphology on polyurethane foam heat transfer
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1994.
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Chemical Kinetics and Heat Transfer in Polyurethane Foam and Resin Composites
… <p>For this work, the chemical kinetics of the polyurethane foam and the fiberglass-reinforced resin is investigated individually. An adiabatic method, which is commonly used by many investigators, is used for the polyurethane foam, while an isothermal degree and the rate of cure relationship is …
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Impact sound insulation of flooring systems with polyurethane foam on concrete floors
… floating floors comprising flexible open cell polyurethane foam resilient layers have been developed. These systems are attractive for refurbishment projects since they can simply be placed on existing floors in order to improve their impact sound insulation whilst raising the existing floor …
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The relationship of cell morphology, density, and mechanical properties in a rigid polyurethane foam
Polyurethane foam, used as a supporting or insulating material, is sometimes formed in complex molds with significant variations in geometry and size. This work investigates the relationships between cell morphology, density, and mechanical properties in a molded polyurethane material using …
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Physical and acoustic properties of petroleum and renewable based polyurethane foam filled with shorea leprosula
… and acoustic properties of petroleum-based polyurethane (PU) and renewable based polyurethane (RPU) foam composites filled with Shorea Leprosula (Red Meranti) fiber filler has been investigated. Shorea Leprosula wood dust namely as SL was used as the filler. RPU was used with hope to …
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Polyurethane foam from oil palm fruit waste: synthesis and characterization of biopolyol and foam properties
… The aim of this research is to produce of polyurethane (PU) foams with biopolyols from liquefied oil palm fruit waste (PW). Three parts of oil palm fruit waste (PW): oil palm mesocarp fiber (PM), oil palm shell (PS) and oil palm kernel (PK) was liquefied using liquefaction solvent with …
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Modelling and Measurement of the Response of a Beam Interacting with a Polyurethane Foam Foundation
… behavior under different conditions. Flexible polyurethane foams used for cushioning in the furniture and automotive industries also serve as foundations, but they exhibit even more complex nonlinear and viscoelastic behavior. It is challenging to develop models that can be used to predict the …
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Temperature and mold size effects on density gradients and mechanical properties in a polyurethane foam system
Rigid polyurethane foams can be used as a thermal or vibration insulator and energy absorption material. They are often molded directly in place, where a smooth, thin skin forms between the mold and the cellular structure of the foam. Density gradients and the skin are shown to have an effect on …
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Selective preconcentration of platinum and rhodium from hydrochloric acid media containing tin (II) chloride using polyurethane foam
… and -rhodium (III/I) complex anions by polyurethane foams has been examined. Quantitative separation of platinum(II) from iridium and ruthenium has been achieved. Rhodium( III) is similarly sorbed by polyurethane foam in the presence of sufficient tin(II) chloride and-its clean …
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Face Sheet/core Debonding In Sandwich Composites Under Static And Fatigue Loading
… crack growth behavior in E-glass face sheet/polyurethane foam core sandwich composite with pre-existing initial delamination crack at a face sheet/core interface under static and fatigue for mode I and mixed mode loading. For mode I static loading two types of delamination experiments, namely …
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Screw fixation of implants to the spine
… 0.16 g.cm\(^{-3}\) and 0.09 g.cm\(^{-3}\) polyurethane foam enabled them to be used as models for normal, osteoporotic and very low density osteoporotic, human cancellous bone, respectively. The screw pullout force from these bone models decreased with polyurethane foam density, implying …
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Investigation of new phase change material based thermal management systems for Li-ion batteries
… in the required range. n-Octadecane and polyurethane foam are used to make 3 mm and 6 mm thick plates. The battery pack is tested with the developed phase change material based plates. Carbon nanotubes are used to improve the thermal conductivity of the phase change material, along with …
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Modeling full-scale fire test behaviour of polyurethane foams using cone calorimeter data
Flexible polyurethane foam (PUF) is a very versatile material ever created. The material is used for various applications and consumer end-use products such as upholstered furniture and mattresses. The increased use of these polymeric materials causes fire safety concerns. This has led to the …
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Feasibility study of a hybrid passive/active noise absorption system
… used in the system was the partially-reticulated polyurethane foam. This material was characterized using its sound propagation constant and its characteristic impedance which were empirically determined. Three different control strategies were investigated for the Passive! Active system. These …
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Structure-Property Relationships of Flexible Polyurethane Foams
… several structure-property features of flexible polyurethane foams that are important aspects of foam production. AFM and WAXS were used to demonstrate the existence, for the first time in typical polyurethane foam systems, of lamellae-like polyurea structures ca. 0.2 mm long and ca 5-10 nm …
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Development of a sandcasting process for an Atlantic Marine Engine
… make high quality patterns out of high-density polyurethane foam.
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