Thin microwire with negative magnetostriction in a zero magnetic field

The effect of residual mechanical stresses on the distribution of magnetization in thin metal microwires with negative magnetostriction has been studied in a zero magnetic field. It is established that the microwire has a nonzero residual magnetization in the absence of twisting and bulging rotational modes.     

The spatial scales of heterogeneities in the direct-current discharge stream

The results of a calculational-experimental investigation of spatial scale heterogeneities in a gas stream with direct-current discharge are presented. The numerical modeling was made within the framework of the Navier-Stokes equations with a distributed source of input energy density in a gas. The experimental study was conducted by the Talbot-interferometry method. The Shtrel number was used as the criterion of the optical homogeneity of the stream.St. Petersburg Institute of Mechanics. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 62, No. 6, pp. 820–824, June, 1992.     

Telomere Length in Metaphase Chromosomes of Human Triploid Zygotes

The human lifespan is strongly influenced by telomere length (TL) which is defined in a zygote—when two highly specialised haploid cells form a new diploid organism. Although TL is a variable parameter, it fluctuates in a limited range. We aimed to establish the determining factors of TL in chromosomes of maternal and paternal origin in human triploid zygotes. Using Q-FISH, we examined TL in the metaphase chromosomes of 28 human triploid zygotes obtained from 22 couples. The chromosomes’ parental origin was identified immunocytochemically through weak DNA methylation and strong hydroxymethylation in the sperm-derived (paternal) chromosomes versus strong DNA methylation and weak hydroxymethylation in the oocyte-derived (maternal) ones. In 24 zygotes, one maternal and two paternal chromosome sets were identified, while the four remaining zygotes contained one paternal and two maternal sets. For each zygote, we compared mean relative TLs between parental chromosomes, identifying a significant difference in favour of the paternal chromosomes, which attests to a certain “imprinting” of these regions. Mean relative TLs in paternal or maternal chromosomes did not correlate with the respective parent’s age. Similarly, no correlation was observed between the mean relative TL and sperm quality parameters: concentration, progressive motility and normal morphology. Based on the comparison of TLs in chromosomes inherited from a single individual’s gametes with those in chromosomes inherited from different individuals’ gametes, we compared intraindividual (intercellular) and interindividual variability, obtaining significance in favour of the latter and thus validating the role of heredity in determining TL in zygotes. A comparison of the interchromatid TL differences across the chromosomes from sets of different parental origin with those from PHA-stimulated lymphocytes showed an absence of a significant difference between the maternal and paternal sets but a significant excess over the lymphocytes. Therefore, interchromatid TL differences are more pronounced in zygotes than in lymphocytes. To summarise, TL in human zygotes is determined both by heredity and parental origin; the input of other factors is possible within the individual’s reaction norm.     

Study on the Influence of Different Energy Sources on the Structure and Mechanical Properties of a Welded Joint from an EP693 Nickel Alloy

Russian Journal of Non-Ferrous Metals - The results of a study on the influence of types of welding (laser, electron beam, and argon arc) on the properties of a permanent joint made of an EP693...     

Making better use of refractory scrap

Refractories and Industrial Ceramics -     

Alkali Cellulose as a Regulator of the Rheological Behavior of Solutions of Dyes

The characteristics of the rheological properties of dispersions of alkali cellulose are investigated and the possibility of using it as an effective regulator of the rheological properties of printing inks is demonstrated. Power- and resource-saving technology for printing textiles with active dyes based on the use of mixed alkali cellulose—starch as the printing ink thickener are proposed.     

Early soot formation stages in low-pressure diffusional counterflow hydrocarbon flames

Early soot formation stages were investigated in low-pressure counterflow hydrocarbon flames. A mechanism is proposed for the formation of aggregates and discrete spherical soot particles. It is proposed that the formation of the physical surface is preceded by the emergence of a skeleton structure consisting of carbon molecule chains as a result of their polarizing and dipole interaction with the charged soot nuclei.Kiev. Translated from Fizika Goreniya i Vzryva, Vol. 29, No. 3, pp. 97–100, May–June, 1993.