Facile preparation and strong adhesive strength of honeycomb polyurethane films with small pore diameter

2020 ◽  
Vol 138 (2) ◽  
pp. 49657
Author(s):  
Zhen Hong ◽  
Mingshan Xue ◽  
Yidan Luo ◽  
Zuozhu Yin ◽  
Chan Xie ◽  
...  
Keyword(s):  
Adhesive Strength ◽  
Pore Diameter ◽  
Small Pore ◽  
Small Pore Diameter ◽  
Facile Preparation

Through-hole AAO-SA templates with a small pore diameter prepared by the voltage pulse detachment method

2019 ◽  
Vol 283 ◽  
pp. 73-81 ◽  
Author(s):  
Anna Brudzisz ◽  
Grzegorz D. Sulka ◽  
Agnieszka Brzózka
Keyword(s):  
Voltage Pulse ◽  
Pore Diameter ◽  
Small Pore ◽  
Small Pore Diameter ◽  
Through Hole

PHYSICAL PROPERTIES OF GLEYSOLIC SOILS IN THE LOWLANDS OF QUEBEC

1979 ◽  
Vol 59 (1) ◽  
pp. 69-78 ◽  
Author(s):  
C. R. DE KIMPE ◽  
G. R. MEHUYS
Keyword(s):  
Organic Matter ◽  
Pore Diameter ◽  
Organic Matter Content ◽  
Aggregate Stability ◽  
Total Porosity ◽  
Matter Content ◽  
Soil Series ◽  
Mean Values ◽  
Small Pore ◽  
Agricultural Areas

Clay-rich soils were sampled in the agricultural areas of Montreal, Quebec and Lake St-Jean. Undisrupted soil blocks and bulk samples were taken by horizon in the Ste-Rosalie, Kamouraska and Normandin soil series. Aggregate stability increased with the organic matter content. Bulk density was generally highest in the B horizons. Porosity ranged from 39 to 56% of the total soil volume and the most representative pore diameter varied from 0.706 to 0.048 μm with the largest diameter being found in the Ap horizons. The distribution of porosity among large, medium and small pores in the Ste-Rosalie soil differed from that in the Kamouraska and Normandin soils. In the former, medium pores accounted for only a few percent of total porosity, while the pores were more evenly distributed in the latter soils. Medium pore contents decreased, while small pore contents increased, with increasing clay contents. No significant relationship was observed between large pores and clay percentages. Hydraulic conductivity, with mean values ranging from 3.5 to 109.3 cm/h, was significantly related to the large pore class.

Manufactory and Properties of Poly(p-Phenylenebenzobisoxazole) Aerogels Prepared by a Simple Freeze-Drying Procedure

2020 ◽  
Vol 993 ◽  
pp. 662-668
Author(s):  
Yu Nong Wei ◽  
Guang Li ◽  
Sheng Lin Yang ◽  
Jun Hong Jin
Keyword(s):  
High Performance ◽  
Freeze Drying ◽  
Sol Gel ◽  
Fire Retardant ◽  
Decomposition Temperature ◽  
High Specific Surface Area ◽  
High Porosity ◽  
Cellulose Aerogel ◽  
Small Pore ◽  
Small Pore Diameter

Aerogels based on organic high performance fibers have been attracted great attention due to its excellent thermal and mechanical properties. Here, PBO nanofiber aerogel were prepared from the super-fiber PBO through a top-down process with a sol-gel process and a simple freeze-drying process, followed by thermal cross-linking. The prepared aerogel has a small volume shrinkage, a high specific surface area of 168.9 m2 /g and a small pore diameter of 1.356 nm. Because of its 3D porous structure, it results in a low density of 6 to 30 mg/cm3 and a high porosity (98%). The aerogel retains the molecular structure of PBO at the same time, which gives it initial thermal decomposition temperature up to 500 °C and a superior fire-retardant capability. PBO aerogel possesses good compressive properties with a yield stress of 0.44MPa at 80% strain and an elasticity modulus of 1.98 MPa which is higher than SiO2 and cellulose aerogel reported.

Effect of the Pores in Porous Rubber on Water Flow at the Contact Area

2016 ◽  
Vol 44 (1) ◽  
pp. 22-35 ◽  
Author(s):  
Takumi Komiyama ◽  
Tomoaki Iwai ◽  
Yutaka Shoukaku
Keyword(s):  
Water Flow ◽  
Coefficient Of Friction ◽  
Contact Area ◽  
Capillary Force ◽  
Pore Diameter ◽  
Real Contact Area ◽  
Cold Temperatures ◽  
Small Pore ◽  
The Difference ◽  
Surface Increase

ABSTRACT Porous rubber has a higher coefficient of friction on ice than nonporous rubber. Therefore, it is used as the tread rubber for studless winter tires. There are two reasons why porous rubber demonstrates a high coefficient of friction: (1) the modulus of rubber is low at cold temperatures, and (2) the pores that exist on the rubber surface increase the real contact area to absorb water. We have already reported water flow over pore with a diameter of about 1 mm. However, it is said that the smaller the pore diameter, the larger the influence of capillary force. The influence of capillary force in small pore size is investigated. Furthermore, the pores were made by drilling on the surface of rubber for the frictional experiment. This pore diameter mimicked the pores of porous rubber. Visualization of water flow at these pores and at those of the surface of porous rubber is conducted by “particle tracking velocimetry method.” The total internal reflection method is performed. The contact area is determined by using the difference of the critical angle of each substance: rubber, air, and water. As a result, it is found that the pores included air at the water lubrication contact area. The absorption of water in the pores is observed in this experiment. The influence of capillary force is also investigated.

Facile Preparation of Highly Ordered Small Pore Mesoporous Silicas

2014 ◽  
Vol 43 (7) ◽  
pp. 1170-1172 ◽  
Author(s):  
Yan-Mei Zhu ◽  
Ren-Liang Wang ◽  
Wen-Ping Zhang ◽  
Hai-Yan Ge ◽  
Li Li
Keyword(s):  
Mesoporous Silicas ◽  
Small Pore ◽  
Facile Preparation

scholarly journals Monitoring of the Variation in Pore Sizes of Woven Geotextiles with Uniaxial Tensile Strain

2021 ◽  
Vol 12 (1) ◽  
pp. 374
Author(s):  
Wenfang Zhao ◽  
Xiaowu Tang ◽  
Keyi Li ◽  
Jiaxin Liang ◽  
Weikang Lin ◽  
...  
Keyword(s):  
Pore Size ◽  
Tensile Strain ◽  
Pore Diameter ◽  
Filter Design ◽  
Uniaxial Tensile ◽  
Distribution Diagram ◽  
Pore Sizes ◽  
Large Pore ◽  
Small Pore ◽  
Pore Opening

Characteristic pore-opening size O95 or O90 has been widely used in the filter design of woven geotextiles. These manufactured products have different pore size proportions of large pore diameters, medium pore diameters, and small pore diameters, respectively. Therefore, uncertainties still exist regarding the prediction of geotextile pore diameter variations under the uniaxial tensile strain. This paper investigates the variations in five characteristic pore-opening sizes O95, O80, O50, O30, and O10, with uniaxial tensile strain by using the image analysis method. The large pore diameters, medium pore diameters, and small pore diameters show different variation behaviors as the uniaxial tensile strain increases. Fifteen specific pores are selected and then their pore diameter variations are monitored under each tensile strain of 1%. The colorful pore size distribution diagram is a visual way to identify the variation of pores arranged in the tension direction (warp direction) and the direction perpendicular to tensile loads (weft direction). The various pore diameters are proved to agree well with the bell-shaped Gaussian distribution. The results exhibit an accurate prediction of the variation in large pore sizes, medium pore sizes, and small pore sizes, respectively, for all tested woven geotextiles with uniaxial tensile strain.

Load-Carrying Capacity of the Lubricating Film in the Gap Between Surfaces Textured by Hemispherical Pores

2021 ◽  
Vol 9 (2) ◽  
pp. 1-23
Author(s):  
Leonid Burstein
Keyword(s):  
Carrying Capacity ◽  
Reynolds Equation ◽  
Pore Diameter ◽  
Pore Radius ◽  
Load Carrying Capacity ◽  
Mechanical Parts ◽  
Lubricating Film ◽  
Small Pore ◽  
Cell Dimensions ◽  
Load Carrying

The load support of a lubricating film that separates the surfaces textured by identical equidistant spaced hemispherical pores was investigated. Two-dimensional time-dependent Reynolds equation is solved numerically for different pore-radius-to-gap and cell-dimension-to-pore-radius ratios and for different relative pore positions of opposite surfaces. The results are compared with the data obtained for the case when only one of the opposite surfaces is covered with pores. The obtained data show a maximum in the carrying capacity of the lubricating film when the cell-to-pore-radii ratio is approximately equal to two, in the case of two opposite surfaces with pores. At small pore radii and with increasing cell dimensions, the load support of two surfaces with pores is much greater than in the case of one surface with pores. This behavior reverses with increasing pore diameter. The presented analysis and the provided MATLAB programs are applicable for mechanisms having rubbing mechanical parts with surfaces covered with pores.

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