A Study on the Drag Reduction Performance and NaCl Solution Robustness according to the Wetting Characteristics of Bottom Surface of Water Vehicle

2020 ◽  
Vol 37 (4) ◽  
pp. 297-303
Author(s):  
Kihwan Kim ◽  
Kwangseok Lee ◽  
Jaehyun Choi ◽  
Woonbong Hwang
Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Xiaoze Yu ◽  
Baofeng Zhang ◽  
Jiahan You

In order to study drag reduction mechanism in mud parts’ operation of surface machine tools for paddy field, this paper takes floating plate, the main working part of laminating mechanism, as the research object and systematically analyzes the mechanism of action of elevation angle, curved angle, penetrating angle, and local microstructure of floating plate on working resistance and local fluid flow characteristics of the laminating structure based on VOF model in Fluent. Using ship mechanics theory and fluid lubrication theory, the drag reduction mechanism under different structural parameters of the floating plate is analyzed. The results show that, compared with the ordinary floating plate, the pressure difference resistance can be reduced by increasing the elevation angle by 60°, curved angle by 20°, and mud separation angle by 20°. The increase of the concave nonsmooth bottom surface structure can reduce viscous frictional resistance, and the total working resistance after structural optimization is comparatively reduced by 48.3%, with lowered hilling height in the forward direction and improved lubrication condition of the bottom surface, forming liquid lubrication effect. This study can provide theoretical references for the optimization design of muddy soil mud parts, mud-machine interaction research, and the development of paddy field laminating mechanism.


Author(s):  
W. Liebrich

HeLa cells were grown for 2-3 days in EAGLE'S minimum essential medium with 10% calf serum (S-MEM; Seromed, München) and then incubated for 24 hours in serum free medium (MEM). After detaching the cells with a solution of 0. 14 % EDTA and 0. 07 % trypsin (Difco, 1 : 250) they were suspended in various solutions (S-MEM = control, MEM, buffered salt solutions with or without Me++ions, 0. 9 % NaCl solution) and allowed to settle on glass tube slips (Leighton-tubes). After 5, 10, 15, 20, 25, 30, 1 45, 60 minutes 2, 3, 4, 5 hours cells were prepared for scanning electron microscopy as described by Paweletz and Schroeter. The preparations were examined in a Jeol SEM (JSM-U3) at 25 KV without tilting.The suspended spherical HeLa cells are able to adhere to the glass support in all solutions. The rate of attachment, however, is faster in solutions without serum than in the control. The latter is in agreement with the findings of other authors.


Author(s):  
Charles L. Sanders ◽  
Roy R. Adee

Asbestos is a generic name for a group of hydrated mineral silicates that occur naturally in a fibrous form. The early interactions of asbestos fibers with alveolar cells in large part determines their long-term toxicity. Young adult, SPF, Fischer rats were given a single intratracheal instillation of 2 mg crocidolite asbestos suspended in 0.5 ml of 0.9% NaCl solution. About 80% of the fibers had lengths of less than 10 ym as measured on light micrographs of the fiber suspension. Two rats were killed at 3 hr, 1 d and 1, 4, 8, 12 and 16 wk after instillation and the lungs instilled with 8 ml McDowell - Trumps at 20 cm H2O. Lung tissue was dehydrated and sputtered coated with palladium-gold for SEM or post-fixed in osmium tetroxide, embedded in epoxy resin and sections stained with uranyl acetate and lead citrate for TEM.


1969 ◽  
Vol 68 (1, Pt.1) ◽  
pp. 38-44 ◽  
Author(s):  
Genaro M. Palmieri ◽  
Samuel Taleisnik

The intensification of the work of open gutter by applying textured shells to their bottom surface, forming an artificial roughness, is considered. It is shown that the presence of corrugated surfaces contributes to vortex formation during water flow and improves the separation and transportation of mineral impurities previously dropped into the bottom of the gutters. The implementation of operations to improve the structure of the gutters is possible during the repair and restoration works with the use of modern polymer materials. The design of a small-sized hydraulic stand, which makes it possible to study the transport capacity of flows containing solid inclusions, is presented. The method of research is hydraulic testing, accompanied by the use of chiaroscuro effect, as well as photo and film equipment. The optimal structure of the inner surface of the gutters and pipes providing vortex formation, which will improve the ability of the flow to carry out and transport foreign dispersed inclusions (sand) of different granulometric compositions, is determined.


2015 ◽  
Vol 30 (6) ◽  
pp. 627
Author(s):  
YE Zuo-Yan ◽  
LIU Dao-Xin ◽  
LI Chong-Yang ◽  
ZHANG Xiao-Hua ◽  
ZANG Xiao-Ming ◽  
...  

2003 ◽  
Vol 766 ◽  
Author(s):  
Kosuke Takenaka ◽  
Masao Onishi ◽  
Manabu Takenshita ◽  
Toshio Kinoshita ◽  
Kazunori Koga ◽  
...  

AbstractAn ion-assisted chemical vapor deposition method by which Cu is deposited preferentially from the bottom of trenches (anisotropic CVD) has been proposed in order to fill small via holes and trenches. By using Ar + H2 + C2H5OH[Cu(hfac)2] discharges with a ratio H2 / (H2 + Ar) = 83%, Cu is filled preferentially from the bottom of trenches without deposition on the sidewall and top surfaces. The deposition rate on the bottom surface of trenches is experimentally found to increase with decreasing its width.


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