Experimental study of flow and heat exchange in highly porous structures

1987 ◽  
Vol 53 (3) ◽  
pp. 987-990 ◽  
Author(s):  
Yu. F. Gortyshov ◽  
G. B. Murav'ev ◽  
I. N. Nadyrov
Keyword(s):  
Experimental Study ◽  
Heat Exchange ◽  
Porous Structures ◽  
Highly Porous

scholarly journals Enhancing Density-Based Mining Waste Alkali-Activated Foamed Materials Incorporating Expanded Cork

CivilEng ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 523-540
Author(s):  
Imed Beghoura ◽  
Joao Castro-Gomes
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Pore Size ◽  
Physical And Mechanical Properties ◽  
Critical Parameters ◽  
Porous Structures ◽  
Foaming Agent ◽  
Al Powder ◽  
Highly Porous ◽  
Alkali Activated

This study focuses on the development of an alkali-activated lightweight foamed material (AA-LFM) with enhanced density. Several mixes of tungsten waste mud (TWM), grounded waste glass (WG), and metakaolin (MK) were produced. Al powder as a foaming agent was added, varying from 0.009 w.% to 0.05 w.% of precursor weight. Expanded granulated cork (EGC) particles were incorporated (10% to 40% of the total volume of precursors). The physical and mechanical properties of the foamed materials obtained, the effects of the amount of the foaming agent and the percentage of cork particles added varying from 10 vol.% to 40% are presented and discussed. Highly porous structures were obtained, Pore size and cork particles distribution are critical parameters in determining the density and strength of the foams. The compressive strength results with different densities of AA-LFM obtained by modifying the foaming agent and cork particles are also presented and discussed. Mechanical properties of the cured structure are adequate for lightweight prefabricated building elements and components.

Experimental study of local heat exchange between an inclined plate and an immobile

1977 ◽  
Vol 33 (4) ◽  
pp. 1132-1135
Author(s):  
N. Ya. Romanenko ◽  
D. A. Kazenin
Keyword(s):  
Experimental Study ◽  
Heat Exchange ◽  
Local Heat ◽  
Inclined Plate

scholarly journals Porous Ni Photocathodes Obtained by Selective Corrosion of Ni-Cu Films: Synthesis and Photoelectrochemical Characterization

Catalysts ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 453 ◽  
Author(s):  
Laura Mais ◽  
Simonetta Palmas ◽  
Michele Mascia ◽  
Elisa Sechi ◽  
Maria Francesca Casula ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Relaxation Times ◽  
Synthesis Method ◽  
Porous Structures ◽  
Porous Nickel ◽  
Cu Films ◽  
Simulated Solar Light ◽  
Photoelectrochemical Characterization ◽  
Nickel Electrodes ◽  
Highly Porous

In this work, a dealloying technique is proposed as a synthesis method to obtain highly porous Nickel electrodes starting from Ni-Cu co-deposit: pulsed corrosion is applied adopting different corrosion and relaxation times. Different morphologies, pore size distribution and residual copper amount were obtained depending on the corrosion conditions. For the developed electrodes, the surface roughness factor, Rf, was evaluated by electrochemical impedance spectroscopy (EIS). The hydrogen evolution reaction (HER) on these electrodes was evaluated by means of steady-state polarization curves, and the related parameters were derived by Tafel analysis. Finally, a thin layer of NiO on the porous structures was obtained to exploit the semiconductor characteristic of the oxide, so that an extra-photopotential was obtained by the simulated solar light action. Results demonstrate greater apparent activity of the developed electrodes towards HER in comparison with commercial smooth Ni electrode, which can be mainly attributed to the large Rf obtained with the proposed technique.

scholarly journals Expansion volume of alkali activated foamed cork composites from tungsten mining mud waste with aluminium

2019 ◽  
Vol 274 ◽  
pp. 03002
Author(s):  
Imed Beghoura ◽  
Joao Castro-Gomes ◽  
Haroon Ihsan ◽  
John Pickstone ◽  
Nuno Estrada
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Physical And Mechanical Properties ◽  
Mechanical And Thermal Properties ◽  
Porous Structures ◽  
Expansion Process ◽  
Foaming Agent ◽  
Al Powder ◽  
Highly Porous ◽  
Alkali Activated

Several mixes of alkali activated foams from tungsten mud waste (MW), grounded glass (GG) and metakaolin (MK) were developed incorporating expanded granulated cork (EGC). This study presents preliminary results of the expansion process obtained with the addition of aluminium (AL) powder as a foaming agent. 0.3 wt.%, 0.4 wt.% to 0.5wt.% of AL powder were added to the alkali activated matrix. The physical and mechanical properties of the obtained foams, the effects of the type and amount of the foaming agent added are presented and discussed. Highly porous structures were obtained, with overall expansion up to 68.2% when the AL powder was added. The size and distribution of pores are shown. The compressive strength of foams in the case of highly porous structures achieved of 1.2 MPa for the samples containing 0.5 wt.% of AL powder. Mechanical and thermal properties of the cured structure are good and can therefore be used for applications in acoustic panels and lightweight prefabricated components for thermal insulation purposes.

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