The Experts below are selected from a list of 261 Experts worldwide ranked by ideXlab platform
Milford A. Hanna - One of the best experts on this subject based on the ideXlab platform.
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Properties of extruded starch-based Plastic Foam
Industrial Crops and Products, 1995Co-Authors: Sandeep Bhatnagar, Milford A. HannaAbstract:Abstract Plastic Foam was made with 25% amylose corn starch and polystyrene or polymethylmethacrylate. The Foam was formed with a commercial extruder at 120 °C barrel temperature, 140 rpm screw speed and 6% moisture content. X-ray diffraction analysis indicated grafting between starch and Plastics. Shipping bulk density, water solubility index, spring index and compressibility of extruded loose-fills were determined and compared with commercially available polystyrene and starch loose-fills. Loose-fills also were compared with various tests used by the loose-fill packaging industry such as flowability, electrostatic adhesion, loaded bulk density, compressive creep and compressive set. Except for the densities, the properties of the starch-based loose-fills compared favorably with the commercial products.
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Physical, Mechanical, and Thermal Properties of Starch-Based Plastic Foams
Transactions of the ASAE, 1995Co-Authors: Sandeep Bhatnagar, Milford A. HannaAbstract:Normal corn starch was extruded with polystyrene or polymethyl methacrylate and blowing and cross-linking agents in a single screw C. W. Brabender laboratory scale extruder at 140° C barrel temperature, 140 rpm screw speed and 16% moisture content. Expansion ratio, unit density, water solubility index, spring index, compressibility, specific heat and thermal conductivity of the resultant products were studied. Physical, mechanical, and thermal properties depended upon the type of additives used. The results indicated suitability of different Foams for packaging and insulation applications. Keywords. Extrusion, Starch-based, Plastic, Foam, Properties.
Sandeep Bhatnagar - One of the best experts on this subject based on the ideXlab platform.
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Properties of extruded starch-based Plastic Foam
Industrial Crops and Products, 1995Co-Authors: Sandeep Bhatnagar, Milford A. HannaAbstract:Abstract Plastic Foam was made with 25% amylose corn starch and polystyrene or polymethylmethacrylate. The Foam was formed with a commercial extruder at 120 °C barrel temperature, 140 rpm screw speed and 6% moisture content. X-ray diffraction analysis indicated grafting between starch and Plastics. Shipping bulk density, water solubility index, spring index and compressibility of extruded loose-fills were determined and compared with commercially available polystyrene and starch loose-fills. Loose-fills also were compared with various tests used by the loose-fill packaging industry such as flowability, electrostatic adhesion, loaded bulk density, compressive creep and compressive set. Except for the densities, the properties of the starch-based loose-fills compared favorably with the commercial products.
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Physical, Mechanical, and Thermal Properties of Starch-Based Plastic Foams
Transactions of the ASAE, 1995Co-Authors: Sandeep Bhatnagar, Milford A. HannaAbstract:Normal corn starch was extruded with polystyrene or polymethyl methacrylate and blowing and cross-linking agents in a single screw C. W. Brabender laboratory scale extruder at 140° C barrel temperature, 140 rpm screw speed and 16% moisture content. Expansion ratio, unit density, water solubility index, spring index, compressibility, specific heat and thermal conductivity of the resultant products were studied. Physical, mechanical, and thermal properties depended upon the type of additives used. The results indicated suitability of different Foams for packaging and insulation applications. Keywords. Extrusion, Starch-based, Plastic, Foam, Properties.
Kurt Kielsgaard Hansen - One of the best experts on this subject based on the ideXlab platform.
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moisture uptake in a chair seat as a response to daily rh variations in the indoor air climatic chamber measurements and calculations
Building and Environment, 2008Co-Authors: Kaisa Svennberg, Johan Claesson, Kurt Kielsgaard HansenAbstract:In the indoor environment there are a number of materials with potential to act as moisture buffers including both building materials and furnishing materials. For daily moisture variations in the indoor air furniture with upholstery can play an important role as moisture buffers. Material properties and calculation models describing the response to moisture variations in the ambient climate for these material combinations are limited. In this project the moisture properties for a chair seat with a wool fabric and Plastic Foam padding were determined. The moisture penetration in the chair seat was measured using small temperature and relative humidity sensors. A numerical calculation model describing the step-response as well as the response to ramp variations is described. A comparison between measurements and theoretical calculations was performed. The difficulties with determination of material properties for highly permeable materials are also discussed as well as suitable methods and special considerations.
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Moisture penetration in a chair seat as a response to daily RH variations in the indoor air
2005Co-Authors: Kaisa Svennberg, Lars Wadsö, Kurt Kielsgaard HansenAbstract:In the indoor environment there are a number of materials with potential to act as moisture buffers including both building materials and furnishing materials. For daily moisture variations in the indoor air furniture with upholstery can play an important role as moisture buffers. Material properties and calculation models describing the response to moisture variations in the ambient climate for these material combinations are limited. In this project the moisture properties for a chair seat with a wool fabric and Plastic Foam padding were determined. The moisture penetration in the chair seat was measured using small temperature and relative humidity sensors. A numerical calculation model describing the step-response as well as the response to ramp variations is described. A comparison between measurements and theoretical calculations was performed. The difficulties with determination of material properties for highly permeable materials are also discussed as well as suitable methods and special considerations. (Less)
Claude Depollier - One of the best experts on this subject based on the ideXlab platform.
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experimental determination of the viscous flow permeability of porous materials by measuring reflected low frequency acoustic waves
Journal of Applied Physics, 2016Co-Authors: A Berbiche, M Sadouki, M Fellah, Z.e.a Fellah, Erick Ogam, F G Mitri, Claude DepollierAbstract:An acoustic reflectivity method is proposed for measuring the permeability or flow resistivity of air-saturated porous materials. In this method, a simplified expression of the reflection coefficient is derived in the Darcy's regime (low frequency range), which does not depend on frequency and porosity. Numerical simulations show that the reflection coefficient of a porous material can be approximated by its simplified expression obtained from its Taylor development to the first order. This approximation is good especially for resistive materials (of low permeability) and for the lower frequencies. The permeability is reconstructed by solving the inverse problem using waves reflected by Plastic Foam samples, at different frequency bandwidths in the Darcy regime. The proposed method has the advantage of being simple compared to the conventional methods that use experimental reflected data, and is complementary to the transmissivity method, which is more adapted to low resistive materials (high permeability).
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Inverse estimation of the permeability of porous materials using experimental data via reflected waves at low frequencies
Journal of Applied Physics, 2016Co-Authors: A Berbiche, M Sadouki, M Fellah, Z.e.a Fellah, Erick Ogam, Farid Mitri, Claude DepollierAbstract:An acoustic reflectivity method is proposed for measuring the permeability or flow resistivity of air-saturated porous materials. In this method, a simplified expression of the reflection coefficient is derived in the Darcy's regime (low frequency range), which does not depend on frequency and porosity. Numerical simulations show that the reflection coefficient of a porous material can be approximated by its simplified expression obtained from its Taylor development to the first order. This approximation is good especially for resistive materials (of low permeability) and for the lower frequencies. The permeability is reconstructed by solving the inverse problem using waves reflected by Plastic Foam samples, at different frequency bandwidths in the Darcy regime. The proposed method has the advantage of being simple compared to the conventional methods that use experimental reflected data, and is complementary to the transmissivity method which is more adapted to low resistive materials (high permeability).
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Determination of the flow resistivity and thickness of porous materials with rigid frames via transmitted waves at Darcy's regime
2015Co-Authors: M Sadouki, M Fellah, Z.e.a Fellah, Erick Ogam, Claude DepollierAbstract:An acoustic method is proposed for measuring the flow resistivity and the thickness of air-saturated porous materials. The conventional methods [14, 16, 17] for the measurement of the flow resistivity (or the viscous permeability) require the prior knowledge of the porosity. The method presented in this work is based on a temporal model of the direct problem in which a simplified expression (independent of frequency and porosity) of the transmission coefficient at the Darcy’s regime (low frequency range) is established, this expression depends only on the viscous permeability (or the flow resistivity) and the thickness of a porous sample. The inverse problem is solved based on the leastsquare numerical method using experimental transmitted wave in time domain. Tests are performed using two samples of different thicknesses to same industrial Plastic Foam, thereby enabling the determination the thickness and flow resistivity of Foam Plastic. This method has the advantage of being simple, fast and efficient.
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Ultrasonic waves Reflected at Oblique Incidence by Porous Rigid Medium.
2015Co-Authors: M Sadouki, M Fellah, Z.e.a Fellah, Claude DepollierAbstract:An ultrasonic reflected wave at oblique incidence by porous medium with rigid frames is considered using equivalent fluid model. The viscous and thermal losses of the medium are described by two susceptibility kernels which depend on the viscous and thermal characteristic lengths. Analytical derivation of reflection coefficient is given in frequency domain. The simulated reflected wave is obtained at time domain by convolution between the reflected operator and the incident field. Experimental results for Plastic Foam samples of air-saturated porous media are given and compared with theoretical prediction.
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A time domain model of transient acoustic wave propagation in double-layered porous media
Journal of the Acoustical Society of America, 2005Co-Authors: Z.e.a Fellah, M Fellah, Claude Depollier, Armand Wirgin, Naima Sebaa, Walter LauriksAbstract:This paper concerns a time-domain model of transient wave propagation in double-layered porous materials. An analytical derivation of reflection and transmission scattering operators is given in the time domain. These scattering kernels are the medium’s responses to an incident acoustic pulse. The expressions obtained take into account the multiple reflections occurring at the interfaces of the double-layered material. The double-layered porous media consist of two slabs of homogeneous isotropic porous materials with a rigid frame. Each porous slab is described by a temporal equivalent fluid model, in which the acoustic wave propagates only in the fluid saturating the material. In this model, the inertial effects are described by the tortuosity; the viscous and thermal losses of the medium are described by two susceptibility kernels which depend on the viscous and thermal characteristic lengths. Experimental and numerical results are given for waves transmitted and reflected by double-layered porous media formed by air-saturated Plastic Foam samples.
R. B. Bennett - One of the best experts on this subject based on the ideXlab platform.
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A Structural Plastic Foam Thermal Insulation for Cryogenic Service
Advances in Cryogenic Engineering, 1995Co-Authors: R. B. BennettAbstract:Today, with the impending energy crisis and the rush to construct LNG facilities as one method to alleviate the energy shortage, it is not surprising that we find Plastic Foams and other thermal insulating materials playing a leading and necessary role in cryogenic applications. Obviously, the cost of thermal insulating materials is a minor part of an LNG contract when compared to the total project cost. However, the proper selection of thermal insulations in their various forms can be a determining factor in the overall success and performance of an LNG facility. Plastic Foam insulation can play a significant and vital part in the performance and economics of each LNG installation.