Global ETD Search
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 13 of 13 for “"Acoustic absorption"”.
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Acoustic and Thermal Properties of Recycled Porous Media
… tyre shred residue and polyurethane binder for acoustic absorption and thermal insulation applications. The resultant materials contains a high proportion of open, interconnected cells that are able to absorb incident sound waves through viscous friction, inertia effects and thermal energy …
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Absorção acústica na qualidade do ambiente construído: da sala de estar ao estúdio de som
… assisting to the resolution of certain acoustical question, current in architecture as, for instance, the ambient reverberation. It consists in the approach of basic concepts in architectonic acoustics as well as, tecnical files of the acoustic absorption performance of certain …
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Investigating Acoustic Properties of Biocomposite from Waste Streams
… for developing reliable products. Sound absorption coefficients for frequencies ranging from 300 to 3000 Hz were recorded following ASTM E1050 (2012) standard. The data was analyzed and modeled mathematically. Using regression functions that combined distribution curves and polynomials to …
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Analyzing Skid Resistance and Tire/Road Noise on Porous Pavement Using Numerical Modeling
… drainage and reduces tire/road noise through acoustic absorption. This study attempts to explore the development of numerical models in predicting skid resistance and tire/road noise on porous pavements. The drainage capacity of a porous surface is modeled by a simplified pore structure. This …
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Study on single and double layers micro-perforated panel absorbers and optimal design by genetic algorithm
… theory of micro-perforated panel absorber, the acoustic absorption performance of single and double layers MPP absorbers are investigated. The analytical formula for calculating the absorption coefficient of single and double layers micro-perforated panel are derived by the equivalent circuit …
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ADDITIVELY MANUFACTURED METALLIC CELLULAR STRUCTURES
… with excellent mechanical, thermal, and acoustic properties. They offer promise in a series of applications, including lightweight applications, sandwich cores, mechanical damping, acoustic absorption, strain isolation, and thermal management. The manufacturing of these complex cellular …
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An investigation of the structurally induced acoustic field in a car passenger compartment
… range of interest to below 200 Hz. Firstly, the acoustic modes of a Rover Metro passenger compartment are predicted using the finite element method. A new method for the experimental acoustic modal analysis of cavities is introduced and verified for a rectangular rigid walled room. The method is …
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Universal sound attenuation in amorphous solids at low-temperatures
… purpose of this study is to derive the universal acoustic absorption and related quantities observed in disordered solids by starting from a many-body quantum theory of unspecified amorphous blocks that mutually interact through the strain field. Based on very generic assumptions and having no …
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EARTH & FIBERS. Local Technologies Earthen Composites (LoTEC). Local reuse of by-products for zero-waste building materials. Appropriate building solutions in vernacular and contemporary architecture.
… thermal conductivity, vapor permeability, acoustic absorption, and fire response—have been systematically evaluated. Medium-scale prototypes constructed and monitored under real conditions confirm their technical feasibility and architectural applicability. Results indicate that LoTEC …
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Transient analyses of viscoelastic materials with applications to numerical models
… to illuminate the role of viscoelasticity in acoustic absorption. A new solver type for time-domain viscoelastic finite elements is also presented. Rather than step through time in a time marching scheme, the solver expresses the solution of the equation of motion in the form of a Taylor …
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Fabrication and Evaluation of Specialty Nonwoven Materials
… materials with high performance on chemical absorption, adsorption and on acoustic absorption and insulation using natural fiber nonwovens via carbonization and activation. Evaluation of these textile materials includes tensile strength, thermogravimetric analysis, sound absorption and …
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Optimal design of sound absorbing systems with microperforated panels
… <p>This tendency is also obvious in the acoustics area, where there are continuing attempts to replace fiber-glass sound absorbers with fiber-free materials. The combination of microperfoated panels (MPP) (one of the fiber-free sound absorbing materials), usually in the form of a thin …