Emergence paths of cracks on a free surface during wedging

Mining Institute, Siberian Division, Russian Academy of Sciences, 630091 Novosibirsk. Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 36, No. 6, pp. 142–152, November–December, 1995.     

Excitation of surface wave beams at the interface between linear and nonlinear media

The spatial evolution of quasi-optical electromagnetic-wave beams propagating in the vicinity of an interface between linear and nonlinear media is studied. It is demonstrated that three-dimensional nonlinear surface beams can efficiently be excited by Gaussian beams of optimal shape, incident onto the nonlinear interface at angles exceeding the total internal reflection angle, and that giant nonlinear Goos-Hänchen effect can result from this process.     

Electron transfer and catalytic control by the iron-sulfur clusters in a respiratory enzyme, E. coli fumarate reductase

Factors governing the efficacy of long-range electron relays in enzymes have been examined using protein film voltammetry in conjunction with site-directed mutagenesis. Investigations of the fumarate reductase from Escherichia coli, in which three Fe-S clusters relay electrons over more than 30 A, lead to the conclusion that varying the medial [4Fe-4S] cluster potential over a 100 mV range does not have a significant effect on the inherent kinetics of electron transfer to and from the active-site flavin. The results support a proposal that the reduction potential of an individual electron relay site in a multicentered enzyme is not a strong determinant of activity; instead, as deduced from the potential dependence of catalytic electron transfer, electron flow through the intramolecular relay is rapid and reversible, and even uphill steps do not limit the catalytic rate.     

Synthesis of 4,5-diaryl-1,2,3-benzenetricarboxylates by reaction of 4-hydroxycyclopent-2-en-1-one-2-carboxylates with dimethyl acetylenedicarboxylate

4,5-Diaryl-1,2,3-benzenetricarboxylates were prepared by cycloaddition of 4-hydroxycyclo-2-penten-1-one-2-carboxylates with dimethyl acetylenedicarboxylate.     

TD-ERCS map-based confusion and diffusion of autocorrelated data

In this article, we proposed a new scheme to encrypt highly autocorrelated image pixel data. In existing literature, single substitution was used to break autocorrelation in images. To get better results, instead of single substitution box, some researchers are minimizing the autocorrelation via utilizing multiple substitution boxes. However, we found that multiple substitution boxes cannot solve the problem of autocorrelation independently. Therefore, we added chaotic confusion and diffusion to the existing substitution scheme in order to remove the correlation completely. Initially, we break the autocorrelation of data by permuting the pixels via TD-ERCS chaotic map. Bitwise XOR is carried out for diffusion using logistic map followed by the existing substitution scheme. Experimental analysis shows that the proposed scheme has greater resistance to brute force attack and statistical attack. Further analyses such as statistical analysis, peak signal-to-noise ratio, contrast analysis, key space analysis, entropy analysis, correlation analysis, key sensitivity analysis, and encryption quality analysis proved the high robustness of the proposed scheme.