Correlation between the particle size, pore size, and porous structure of sintered tungsten

1988 ◽  
Vol 27 (12) ◽  
pp. 941-947
Author(s):  
V. V. Skorokhod ◽  
O. I. Get'man ◽  
A. E. Zuev ◽  
S. P. Rakitin
Keyword(s):  
Particle Size ◽  
Porous Structure ◽  
Pore Size ◽  
Sintered Tungsten

Dissolution of gypsum, monocalcium phosphate, and superphosphate fertilizers in relation to particle size and porous structure

Soil Research ◽  
1971 ◽  
Vol 9 (1) ◽  
pp. 21 ◽  
Author(s):  
LAG Aylmore ◽  
M Karim ◽  
JP Quirk
Keyword(s):  
Particle Size ◽  
Porous Structure ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Granule Size ◽  
Significant Part ◽  
Monocalcium Phosphate ◽  
Rate Of Dissolution ◽  
Physical Form

The effect of variations in physical form such as particle size and mixing with other materials, on the rate of dissolution of sulphate and phosphate from solid fertilizers, has been investigated. It is apparent from these results that the degree of subdivision of a solid fertilizer is particularly important in determining its susceptibility to leaching. It has been demonstrated that leaching of sulphate is appreciably restricted when the granule size is 2 mm or greater in diameter. Except when leached immediately after application, the retention of phosphate is determined largely by 'reversion' to the relatively insoluble dicalcium phosphate form. combination of sulphate with phosphate in superphosphate or the addition of various additives to gypsum markedly reduces the rate of sulphate leaching in comparison to pure gypsum. A comparison of pore size distribution suggests that pores within the intermediate range from approximately 500 A to 105 A play a significant part in the dissolution process.

scholarly journals The adsorption characteristics and porous structure of bentonite adsorbents, determined from the adsorption isotherms of benzene vapor

2004 ◽  
Vol 69 (2) ◽  
pp. 145-151 ◽  
Author(s):  
Snezana Brezovska ◽  
Biljana Marina ◽  
Biljana Panova ◽  
Donco Burevski ◽  
Vasa Bosevska ◽  
...  
Keyword(s):  
Free Energy ◽  
Porous Structure ◽  
Pore Size ◽  
Adsorption Isotherms ◽  
Micropore Volume ◽  
Benzene Vapor ◽  
Free Energy Of Adsorption ◽  
Volume Filling ◽  
Activated Bentonite ◽  
Characteristic Values

The adsorption of benzene vapor on natural and acid activated bentonites was treated by the theory of volume filling of micropores. The micropore volume and characteristic values of the free energy of adsorptionwere determined from the adsorption isotherms. The Dubinin?Radushkevish?Stoeckli and Dubinin?Astakhov equations were used for this purpose. The results showed that natural bentonite has a more homogeneous micropore structure than the acid activated ones. The characteristic values of the free energy of adsorption for the natural bentonite were higher than those of the acid activated bentonite. This is due to differences in its structure and the pore size.

scholarly journals The Influence of Loop Heat Pipe Evaporator Porous Structure Parameters and Charge on Its Effectiveness for Ethanol and Water as Working Fluids

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7029
Author(s):  
Krzysztof Blauciak ◽  
Pawel Szymanski ◽  
Dariusz Mikielewicz
Keyword(s):  
Porous Structure ◽  
Pore Size ◽  
Heat Pipe ◽  
Capillary Pressure ◽  
Pressure Difference ◽  
Working Fluid ◽  
Loop Heat Pipe ◽  
Working Fluids ◽  
Integral Characteristics ◽  
Sintered Stainless Steel

This paper presents the results of experiments carried out on a specially designed experimental rig designed for the study of capillary pressure generated in the Loop Heat Pipe (LHP) evaporator. The commercially available porous structure made of sintered stainless steel constitutes the wick. Three different geometries of the porous wicks were tested, featuring the pore radius of 1, 3 and 7 µm. Ethanol and water as two different working fluids were tested at three different evaporator temperatures and three different installation charges. The paper firstly presents distributions of generated pressure in the LHP, indicating that the capillary pressure difference is generated in the porous structure. When installing with a wick that has a pore size of 1 μm and water as a working fluid, the pressure difference can reach up to 2.5 kPa at the installation charge of 65 mL. When installing with a wick that has a pore size of 1 μm and ethanol as a working fluid, the pressure difference can reach up to 2.1 kPa at the installation charge of 65 mL. The integral characteristics of the LHP were developed, namely, the mass flow rate vs. applied heat flux for both fluids. The results show that water offers larger pressure differences for developing the capillary pressure effect in the installation in comparison to ethanol. Additionally, this research presents the feasibility of manufacturing inexpensive LHPs with filter medium as a wick material and its influence on the LHP’s thermal performance.

scholarly journals ZnTiO3 ceramic nanopowder microstructure changes during compaction

2013 ◽  
Vol 45 (2) ◽  
pp. 209-221
Author(s):  
N. Labus ◽  
J. Krstic ◽  
S. Markovic ◽  
D. Vasiljevic-Radovic ◽  
M.V. Nikolic ◽  
...  
Keyword(s):  
Particle Size ◽  
Pore Size ◽  
Size Distribution ◽  
Mercury Porosimetry ◽  
Critical Diameter ◽  
Nitrogen Adsorption ◽  
Powder Particle Size ◽  
Scanning Electron Micrographs ◽  
Force Microscopy ◽  
Scanning Electron

ZnTiO3 nanopowder as a constitutive component in compact production was primarily characterized. Scanning electron micrographs of as received powder were recorded. Mercury porosimetry and nitrogen adsorption were also performed on loose powder. Particle size distribution in a water powder suspension was determined with a laser particle size analyser. Compaction was performed on different pressures in a range from 100 to 400 MPa using the uniaxial double sided compaction technique without binder and lubricant. Micrographs of compacted specimens were obtained using scanning electron microscopy and atomic force microscopy. Pore size distribution was also determined by mercury porosimetry and nitrogen adsorption. Results revealed that with increasing pressure during compaction interagglomerate pores diminish in size until they reach some critical diameter related to the intra-agglomerate pore size.

scholarly journals Interphase Surface Stability in Liquid-Liquid Membrane Contactors Based on Track-Etched Membranes

Membranes ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 949
Author(s):  
Stepan Bazhenov ◽  
Olga Kristavchuk ◽  
Margarita Kostyanaya ◽  
Anton Belogorlov ◽  
Ruslan Ashimov ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Porous Structure ◽  
Pore Size ◽  
Aqueous Phase ◽  
Liquid Membrane ◽  
Target Component ◽  
Interphase Surface ◽  
Asymmetric Membrane ◽  
Interface Stability ◽  
Membrane Contactors

A promising solution for the implementation of extraction processes is liquid–liquid membrane contactors. The transfer of the target component from one immiscible liquid to another is carried out inside membrane pores. For the first time, highly asymmetric track-etched membranes made of polyethylene terephthalate (PET) of the same thickness but with different pore diameters (12.5–19 nm on one side and hundreds of nanometers on the other side) were studied in the liquid–liquid membrane contactor. For analysis of the liquid–liquid interface stability, two systems widely diverging in the interfacial tension value were used: water–pentanol and water–hexadecane. The interface stability was investigated depending on the following process parameters: the porous structure, the location of the asymmetric membrane in the contactor, the velocities of liquids, and the pressure drop between them. It was shown that the stability of the interface increases with decreasing pore size. Furthermore, it is preferable to supply the aqueous phase from the side of the asymmetric membrane with the larger pore size. The asymmetry of the porous structure of the membrane makes it possible to increase the range of pressure drop values between the phases by at least two times (from 5 to 10 kPa), which does not lead to mutual dispersion of the liquids. The liquid–liquid contactor based on the asymmetric track-etched membranes allows for the extraction of impurities from the organic phase into the aqueous phase by using a 1% solution of acetone in hexadecane as an example.

Porous structure of sintered tungsten

1977 ◽  
Vol 16 (12) ◽  
pp. 950-951 ◽  
Author(s):  
V. V. Panichkina ◽  
V. V. Skorokhod ◽  
N. P. Pavlenko
Keyword(s):  
Porous Structure ◽  
Sintered Tungsten

Blood clot initiation by mesoporous silica nanoparticles: dependence on pore size or particle size?

2016 ◽  
Vol 4 (44) ◽  
pp. 7146-7154 ◽  
Author(s):  
Zihao Chen ◽  
Fan Li ◽  
Changjun Liu ◽  
Jing Guan ◽  
Xiao Hu ◽  
...  
Keyword(s):  
Particle Size ◽  
Mesoporous Silica ◽  
Pore Size ◽  
Silica Nanoparticles ◽  
Mesoporous Silica Nanoparticles ◽  
Blood Clot

The hemostatic efficiency of mesoporous silica nanoparticles depends on pore size more than particle size, and biocompatibility is more related to particle size.

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