On the electrochemical migration mechanism of tin in electronics

Electrochemical migration (ECM) of tin can result in the growth of a metal deposit with a dendritic structure from cathode to anode. In electronics, such growth can lead to short circuit of biased electrodes, potentially leading to intermittent or complete failure of an electronic device. In this paper, mechanistic aspects of ECM of tin are discussed in detail, using experimental results on ECM of tin in various environments and varying potential bias. Results on the formation of local pH changes by the electrodes and experiments observations are combined with thermodynamic stability of tin species as depicted in the Pourbaix diagram.     

Mating-induced mating-type cassette conversion in Saccharomyces cerevisiae

We have previously reported that the HMRa-bearing restriction fragment of a rho degrees sir4-11 strain (HMLalpha-MATalpha-HMRa), which acts as an alpha-mater because of being rho degrees , changes its electrophoretic mobility when the strain mates with a certain group of a-mating strains (HMLalpha-MATa-HMRa). In this study, we found that the sir4-11 strain being rho degrees was not essential for this phenomenon and also that the altered form of the fragment contained HMRalpha in place of HMRa. Furthermore, we observed conversion of HMLa to HMLalpha in the cross in which a sir4-11 HMLa-MATalpha-HMRalpha strain was mated with a representative of the above-mentioned a-mating strain. In addition, when this a-mating strain was mated with a SIR(+) HMLalpha-MATa-HMRalpha strain, the resultant diploid was found to be HMLalpha/HMLalpha MATa/MATalphaHMRa/HMRalpha, indicating that conversion of MATa to MATalpha had taken place in the course of mating. From all these observations, we conclude that there is a group of S. cerevisiae strains that carries factor(s) that induces conversion of a mating-type cassette of the mating partner to alpha mating-type cassette and that this mating type cassette conversion takes place in all three mating type loci, HML, MAT and HMR, if the loci are in the non-silenced condition.     

Mobile machinery team for strengthening of soil foundations

A review is presented for the up-to-date special-purpose construction techniques for bar-re-enforcement of a soil mass, strengthening of soil foundations and removal of the defects in motor and railway roadbeds by injection. It is shown that a promising tool of solving these tasks is an air percussion machine with an end-to-end axial channel. The air distribution system that ensures decrease of the air unit rate is considered. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 6, pp. 49–57, November–December, 2007.     

机械镀主机设备的设计研究

根据机械镀主机设备的工作原理，分析现有机械镀设备的优缺点，介绍采用行星变速机构的新型机械镀主机设备之设计方案，并对其运动原理和技术参数的选取进行理论计算和分析研究。     

Stains. Trace—Cloth—Symptom

A stain is the evidence of something that was. It is a trace. A stain may be something quite ordinary: the ink stain on my index finger; the mark of your fingers on this book. A stain may also be embarrassing: lipstick on a cheek; sweat rings under the arms; a bloody discharge. A stain may be forensically incriminating. A stain may be kept for sentimental reasons. Moreover, every stain has its own particular texture. Texture denotes the consistency of a surface and the sensory, often tactile imprint that is left on it. The stain may be absorbed in the thing that supports it; then again, it may stay on the surface, something separate. Every stain is unique.

In this article the author deals with seven factors that make the stain into a powerful model for rethinking the visual: the stain as prototype and prefiguration; the stain as relic; the stain of Veronica; the stain as a psycho-energetic symptom; the stain as pars pro toto for the womb; the stain and le désir mimétique; and finally, the stain as an image paradigm of the residue.