Constitutive modeling of Hugoniot for a highly porous material

2008 ◽  
Vol 104 (9) ◽  
pp. 093511 ◽  
Author(s):  
A. D. Resnyansky
Keyword(s):  
Porous Material ◽  
Constitutive Modeling ◽  
Highly Porous ◽  
Highly Porous Material

scholarly journals Hierarchically structured, highly porous nickel synthesized in sintering–evaporation process from a metal nanopowder and a space holder

2019 ◽  
Vol 484 (4) ◽  
pp. 436-440
Author(s):  
A. G. Gnedovets ◽  
V. A. Zelenskii ◽  
A. B. Ankudinov ◽  
M. I. Alymov
Keyword(s):  
Powder Metallurgy ◽  
Porous Material ◽  
Ammonium Bicarbonate ◽  
Evaporation Process ◽  
Porous Nickel ◽  
Space Holder ◽  
Nickel Nanopowder ◽  
Powder Metallurgy Methods ◽  
Highly Porous ◽  
Highly Porous Material

This paper reports on the creation of a highly porous material with a hierarchical structure using powder metallurgy methods based on nickel nanopowder and ammonium bicarbonate NH4HCO3 as a space holder.

Effects of Heat Treatment on Thermal Conductivity of Highly Porous Copper/Silver Systems

2007 ◽  
Author(s):  
Brian A. Murtha ◽  
Anil K. Kulkarni ◽  
Jogender Singh
Keyword(s):  
Thermal Conductivity ◽  
Heat Treatment ◽  
Porous Material ◽  
Grain Boundaries ◽  
Phonon Scattering ◽  
Particle Diffusion ◽  
Conductive Heat ◽  
Material Particle ◽  
Highly Porous ◽  
Highly Porous Material

The phenomenon of sintering has a significant impact on the thermal conductivity of a highly porous material. Particle diffusion greatly reduces the number of grain boundaries that are normally present in porous materials. In turn, fewer grain boundaries imply fewer sites for phonon scattering during conductive heat transfer. Therefore, during heat treatment of a highly porous material, particle diffusion accounts for a changing thermal conductivity. This occurs with no bulk densificiation of the material. In fact, SEM images show that the microstructure of a porous material changes from many individual particles with small pores between the particles to diffused particles with large pores in between large chunks of material. To model such a phenomenon, standard equations were scaled with unitless weighting functions to account for variable microstructures during heating. By weighting standard equations, the effects of microstructure could be more accurately described as a function of porosity and time.

scholarly journals Revisiting Soil Aquifer Treatment: Improving Biodegradation and Filtration Efficiency Using a Highly Porous Material

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3593
Author(s):  
Joshua Brooks ◽  
Noam Weisbrod ◽  
Edo Bar-Zeev
Keyword(s):  
Porous Material ◽  
Urban Areas ◽  
Water Reuse ◽  
Filtration Efficiency ◽  
Natural Material ◽  
Soil Aquifer Treatment ◽  
Bacterial Phyla ◽  
Custom Made ◽  
Highly Porous ◽  
Highly Porous Material

Soil aquifer treatment (SAT) is an established and sustainable wastewater treatment approach for water reuse that has been gaining increased attention in various countries around the world. Increasing volumes of domestic wastewater and escalating real estate prices around urban areas emphasize the urgent need to maximize the treatment efficiency by revisiting the SAT setup. In this study, a novel approach was examined to increase biodegradation rates and improve the quality of SAT topsoil effluent. Experiments with midscale, custom-made columns were carried out with sand collected from an operational SAT and a highly permeable natural material with high internal porosity, tuff, which was maturated (i.e., buried in the SAT infiltration basin) for 3 months. The filtration efficiency, biodegradation rates of organic material, microbial diversity, and outflow quality were compared between the operational SAT sand and the tuff using state-of-the-art approaches. The results of this study indicate that biodegradation rates (9.2 µg C g−1d−1) and filtration efficiency were up to 2.5-fold higher within the tuff than the SAT sand. Furthermore, the biofilm community was markedly different between the two media, giving additional insights into the bacterial phyla responsible for biodegradation. The results highlight the advantage of using highly porous material to enhance the SAT filtration efficiency without extending the topsoil volume. Hence, infusing a permeable medium, comprising highly porous material, into the SAT topsoil could offer a simple approach to upgrade an already advantageous SAT in both developed and developing countries.

Global stability for thermal convection in a fluid overlying a highly porous material

2008 ◽  
Vol 465 (2101) ◽  
pp. 207-217 ◽  
Author(s):  
Antony A Hill ◽  
Brian Straughan
Keyword(s):  
Porous Medium ◽  
Porous Material ◽  
Nonlinear Stability ◽  
Thermal Convection ◽  
Linear Instability ◽  
Brinkman Equation ◽  
Onset Of Convection ◽  
Unconditional Nonlinear Stability ◽  
Highly Porous ◽  
Highly Porous Material

This paper investigates the instability thresholds and global nonlinear stability bounds for thermal convection in a fluid overlying a highly porous material. A two-layer approach is adopted, where the Darcy–Brinkman equation is employed to describe the fluid flow in the porous medium. An excellent agreement is found between the linear instability and unconditional nonlinear stability thresholds, demonstrating that the linear theory accurately emulates the physics of the onset of convection.

Thermal Conductivity Measurements of Gas Diffusion Layer Under Controlled Temperature, Humidity and Stress

2009 ◽  
Author(s):  
Jun-ichi Miyamoto ◽  
Junpei Ooyama ◽  
Yoshiaki Yamamoto
Keyword(s):  
Thermal Conductivity ◽  
Porous Material ◽  
Diffusion Layer ◽  
Gas Diffusion Layer ◽  
Gas Diffusion ◽  
Conductivity Measurements ◽  
Anisotropic Thermal Conductivity ◽  
Plane Direction ◽  
Highly Porous ◽  
Highly Porous Material

In this work, thermal conductivities of gas diffusion layer (GDL) under controlled temperature, humidity and stress are measured. Additionally, we investigated the anisotropic thermal conductivity of GDLs. The experimental results showed that thermal conductivity of in-plane direction was much higher than that of trough-plane direction for all the samples that were measured. This result indicated thermal conductivity of GDLs to be strongly anisotropic since GDL is a highly porous material which contains large amount of air inside the GDL. Moreover, we found that thermal conductivity of GDL in the through-plane direction increased as the compression on the GDL was increased.

scholarly journals Study of H2S Removal Capability from Simulated Biogas by Using Waste-Derived Adsorbent Materials

Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1030 ◽  
Author(s):  
Hua Lun Zhu ◽  
Davide Papurello ◽  
Marta Gandiglio ◽  
Andrea Lanzini ◽  
Isil Akpinar ◽  
...  
Keyword(s):  
Porous Material ◽  
Physical Adsorption ◽  
Mesoporous Structure ◽  
H2s Removal ◽  
X Ray ◽  
Thermogravimetric Analyzer ◽  
Removal Capacity ◽  
Highly Porous ◽  
Highly Porous Material ◽  
Adsorbent Materials

Three waste-derived adsorbent materials (wood-derived biochar, sludge-derived activated carbon and activated ash) were pre-activated at the laboratory scale to apply them for the removal of H2S from a biogas stream. The H2S removal capabilities of each material were measured by a mass spectrometer, to detect the H2S concentration after the adsorption in an ambient environment. The activated ash adsorbent has the highest removal capacity at 3.22 mgH2S g−1, while wood-derived biochar has slightly lower H2S removal capability (2.2 mgH2S g−1). The physicochemical properties of pristine and spent materials were characterized by the thermogravimetric analyzer, elemental analysis, X-ray fluorescence spectroscopy and N2 adsorption and desorption. Wood-derived biochar is a highly porous material that adsorbs H2S by physical adsorption of the mesoporous structure. Activated ash is a non-porous material which adsorbs H2S by the reaction between the alkaline compositions and H2S. This study shows the great potential to apply waste-derived adsorbent materials to purify a biogas stream by removing H2S.

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