The Effect of Surface Finish on Zinc Whisker Growth

2012 ◽  
Vol 472-475 ◽  
pp. 2756-2759
Author(s):  
Wen Cui ◽  
Shao Jun Qi

To understand the relationship between surface finish and zinc whisker growth, this study investigated the growth of whiskers on two mild steel substrates of different surface finish by Field Emission Gun Scanning Electron Microscope (FEG SEM). Results show that, under the same experimental conditions, deposits on substrates with a mirror finish grew less whiskers and nodules than substrates with a rough surface finish.

1970 ◽  
Vol 7 (3) ◽  
pp. 695-709
Author(s):  
C. H. O'NEILL ◽  
E. A. C. FOLLETT

The relationship between culture density and the number of microvilli on the cell surface has been studied using BHK21 cells in established monolayer culture. The number of microvilli can be estimated quantitatively by a scanning electron-microscope technique. It can be increased by applying specific antiserum, but whether antibody is applied or not a significant number of cells regularly bear microvilli. This number is characteristic of the culture density. In sparse cultures above a certain minimum density it is relatively high, and in confluent cultures it is much reduced. These results indicate that microvilli may be inhibited by cell contact.


2019 ◽  
Vol 295 ◽  
pp. 93-97
Author(s):  
Chang Zhao ◽  
Man Zhao ◽  
Su Ye Lv ◽  
Qing Jun Liu ◽  
Guang Jian Xing

This study prepared an SiC thin film by using the ratio frequency magnetron sputtering method, investigated the effects of different sputtering powers on the SiC material and analysed the changes in crystal morphology and photoluminescence characteristics caused by changes in the growth conditions used. It was considered that there was 6H-SiC crystal morphologies in the SiC thin film under the experimental conditions prevailing in this study. The SiC morphologies with small grain sizes intermingled and therefore formed anSiC thin film. The analyses of the photoluminescence spectra and Scanning Electron Microscope indicated that the SiC thin film materials with preferable crystal compositions could be prepared under appropriate power inputs.


2007 ◽  
Vol 33 (2) ◽  
pp. 51-58 ◽  
Author(s):  
Manal M. Shalabi ◽  
Johannes G. C. Wolke ◽  
Anja J. E. de Ruijter ◽  
John A. Jansen

Abstract The aim of the study was to assess the effects of surgical technique and implant surface roughness on implant fixation. A total of 48 screw implants with machined or etched surface topographies were placed into the femoral condyles of goats. The implant sites were prepared by a conventional technique, by undersized preparation, or by the osteotome technique. Bone tissue responses were evaluated after 12 weeks of healing by removal torque testing and histologic analysis using scanning electron microscope. The cumulative removal torque value of the etched implants placed with the undersized technique (98 ± 29 Ncm) was higher (50 ± 35 Ncm) to a level of statistical significance than machined surface implants placed by the osteotome technique. Scanning electron microscope evaluation indicated that all implants showed interfacial bone contact. The torque test resulted in fracture at the bone-implant interface for all experimental conditions. Installation of etched implants using an undersized preparation of the implant bed resulted in superior bonding strength with the surrounding bone at 12 weeks after surgery. Evidently, the undersized preparation technique improved the early fixation of oral implants in this study.


1974 ◽  
Vol 96 (4) ◽  
pp. 591-594 ◽  
Author(s):  
D. D. Ratnagar ◽  
H. S. Cheng ◽  
J. A. Schey

The influences of lubricant viscosity and loading velocity on the surface finish of plastically compressed 6061 aluminum alloy cylinders were studied. Specimens with polished end faces were subjected to compression between two flat, chromium plated dies, with lubricants of a viscosity ranging from 42 cp to 1207 cp at 38 deg C. The deformed surfaces were studied under a scanning electron microscope and by stylus tracings and CLA readings. With the lighter lubricants surface roughening resulted from preferential yielding leading to a clear delineation of grain boundaries and slip lines. With the heavier lubricants, localized “hydrodynamic pockets” formed in addition to the above features. The depth of pockets increased with viscosity and/or velocity.


2012 ◽  
Vol 557-559 ◽  
pp. 1322-1325 ◽  
Author(s):  
Yi He Li ◽  
Hua Xiao ◽  
Gong Yi Li ◽  
Jian Feng ◽  
Xiao Dong Li

A novel femtosecond laser directly writing method was utilized to fabricate microchannels on silicon carbide (SiC) substrate. The micro patterns were transferred to a Polydimethylsiloxane (PDMS) stamp, characterized by both optical microscope and scanning electron microscope (SEM). The relationship between size (depth and width) of channels and power of laser pulse were discussed in detail.


1997 ◽  
Vol 506 ◽  
Author(s):  
J. Giménez ◽  
M. Molera ◽  
I. Casas ◽  
M.E. Torrero ◽  
J. de Pablo

ABSTRACTExperiments of spent fuel dissolution performed in presence of iron show, for uranium as well as for some radionuclides, lower final concentrations than measured in similar experiments but in absence of iron. So far, only the final concentrations obtained in these experiments have been published. In this work, we have focused our study on the reduction of uranium (VI) due to the presence of iron and the subsequent precipitation of Uranium (IV) due to its lower solubility. This behavior has been confirmed using a Scanning Electron Microscope by observing an uranium phase precipitated on the iron surface and assuming, under the experimental conditions, that it most likely corresponds to U02(s). We have modeled this process assuming a first-order kinetic.


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