The IIASA Data Communication Network

This paper presents IIASA Computer Science Project plans for the construction of a computer-computer network connecting centers in National Member Countries

The Upper Kotlin clays of the Saint Petersburg region as a foundation and medium for unique facilities: an engineering-geological and geotechnical analysis

The article reviews the issues concerned with correctness of the engineering-geological and hydrogeological assessment of the Upper Kotlin clays, which serve as the foundation or host medium for facilities of various applications. It is claimed that the Upper Kotlin clays should be regarded as a fissured-block medium and, consequently, their assessment as an absolutely impermeablestratum should be totally excluded. Presence of a high-pressure Vendian aquifer in the lower part of the geological profile of the Vendian sediments causes inflow of these saline waters through the fissured clay strata, which promotes upheaval of tunnels as well as corrosion of their lining. The nature of the corrosion processes is defined not only by the chemical composition and physical and chemical features of these waters, but also by the biochemical factor, i.e. the availability of a rich microbial community. For the first time ever, the effect of saline water inflow into the Vendian complex on negative transformation of the clay blocks was studied. Experimental results revealed a decrease in the clay shear resistance caused by transformation of the structural bonds and microbial activity with the clay’s physical state being unchanged. Typification of the Upper Kotlin clay section has been performed for the region of Saint Petersburg in terms of the complexity of surface and underground building conditions. Fissuring of the bedclays, the possibility of confined groundwater inflow through the fissured strata and the consequent reduction of the block strength as well as the active corrosion of underground load-bearing structures must be taken into account in designing unique and typical surface and underground facilities and have to be incorporated into the normative documents

Original Russian Text ©

905 This Letter is devoted to the optical anisotropy arising in a moving medium, where the velocity of light propagation depends on the velocity and direction of motion of the medium. In a rotating medium, the light trajectory is curved The transverse entrainment can be observed for radiation propagating in a rotating optical disk (OD). In 1977, Bilger and Stowell [2] performed an experiment with light propagating in a rotating OD arranged in a laser ring interferometer. The results were interpreted in terms of the Fizeau effect. However, since the rotating disk features a tangential discontinuity of the light propagation velocity on the flat surface, the phase shift in circulating electromagnetic waves was related to both longitudinal and transverse entrainment of the wave. This is confirmed by calculations based on a solution to the dispersion equation, which show that an additional shift of the interference pattern in such experiments can amount to about 20% of the value due to the longitudinal Fizeau effect Below, we consider the results of interferometric experiments in which the optical anisotropy of light propagating in a rotating transparent medium has been studied as a function of the rotation speed. Here, by the optical anisotropy we imply the dependence of the velocity of light on the velocity and direction of motion of the medium where it propagates. The entrainment of light in a moving medium was studied using an interferometer, in which the light was introduced via a flat surface of a rotating OD In the proposed scheme, the beam of laser L is divided by beam splitter BS into two beams. These beams are directed by mirrors M 1 and M 2 so as to pass via the OD in opposite directions. As a result of the OD rotation, one beam acquires a positive, and the other beam, a negative phase shift. Then, the two beams are mixed in the BS, and the mixed beam directed by mirror M 3 passes through optical system OS and strikes photodetector PD. Reversal of the direction of OD rotation leads to a change in the direction of the shift of interference fringes observed in the aperture plane of the PD. The optical path length in the OD was increased due to the multiple reflection of beams from mirror flat surfaces (the front flat surface was mirror coated in the central part, and the rear surface was entirely mirror coated). To the first approximation, the proposed scheme is equivalent to a one-pass Fizeau interferometer. Let us Abstract -We consider the first results of measurements of the effect of a velocity vector field in a rotating transparent medium on the light propagation velocity c in this medium. Laser radiation with a wavelength of λ = 0.632991 µ m passed through a rotating optical disk with n = 1.7125 in an interferometer, where the beam path length projected on the flat disk surface was l = 30.4 mm, the disk thickness was d = 20 mm, and the angle of light incidence on the flat disk surface was ϑ 0 = 50.7 ° . The disk rotation speed was varied up to 380 Hz, which corresponded to a projection of V 2 n = 36 m/s of the medium velocity onto the wave vector of the electromagnetic wave. The experimental data confirmed to the first approximation the classical linear dependence of the shift of interference fringes on the velocity of a rotating medium

НОВЫЕ ТЕХНОЛОГИИ ВОССТАНОВЛЕНИЯ И ЗАЩИТЫ ЭНЕРГЕТИЧЕСКОГО ОБОРУДОВАНИЯ КОМПОЗИТНЫМИ МАТЕРИАЛАМИ

The analysis of possible variants of reconstruction of the power equipment is fulfilled and the conclusion concerning the prospects of such work with the use of composite materials is reached. The data on the technical characteristics of composite repair materials for various purposes are presented, the results of repairs of power equipment, in particular the technology for the recovery of the boarding surfaces of the diffuser rings and protection of the pumps D1250 casings are provided. The technology of the recovery pneumatic cylinder, hydraulic cylinder rod, as well as the unique technology of restoration of working surfaces of the impeller vanes of transfer pump, that had been destroyed by corrosion in conjunction with the cavitation processes and were considered as not restorable is described. The restored impeller was in operation during a year and only thereafter it was removed for restoration. Another composite material discussed in the article – diagum – makes it possible to perform a series of repairs associated with restoration of the rubber-covered surfaces of pump casings as well as with restoration of various surfaces of the conveyor belts. Taking the excellent adhesive properties of this composite into account, restoration of worn stainless steel sieve screens to remove abrasive material was fulfilled with the aid of it. The restoration was accomplished via the use of the conveyor belt which application time had expired, that was glued to a metal sieve with diagum. The use of the composites is economically justified, because the application of them in repairs reduces, firstly, terms of restoration work and, secondly, the price of repairs. Third, equipment that was damaged beyond repair is being commissioned by the use of the mentioned composites. Проведен анализ возможных вариантов восстановления энергетического оборудования и сделан вывод о перспективности выполнения таких работ с помощью композитных материалов. Изложены сведения о технических характеристиках композитных ремонтных материалов различного назначения, приведены результаты ремонтов энергетического оборудования, в частности отработана технология восстановления посадочных поверхностей под диффузорными кольцами и защиты корпусов насосов Д1250. Описана технология восстановления пневмоцилиндра, штока гидроцилиндра, а также уникальная технология восстановления рабочих поверхностей лопаток колеса перекачивающего насоса, которые были полностью сведены коррозией в совокупности с кавитационными процессами и восстановлению традиционными способами не подлежали. Восстановленное колесо отработало один год, и лишь после этого было снято на повторное восстановление. Еще один композитный материал из рассмотренных в статье – диагум – позволил выполнить целую серию ремонтных работ, связанных как с восстановлением обрезиненных поверхностей корпусов насосов, так и с ремонтом различного вида поверхностей транспортерных лент. Учитывая отличные адгезионные свойства данного композита, с его помощью выполнено восстановление изношенных нержавеющих сит грохотов для отсева абразивного материала. Это восстановление выполняли за счет использования отслужившей свой срок транспортерной ленты, которую приклеивали к металлическому ситу с помощью диагума. Применение композитов экономически оправдано, поскольку благодаря им сроки восстановительных работ сокращаются, снижается себестоимость ремонтов и вводится в строй оборудование, которое восстановлению не подлежало

Pichia pastoris regulates its gene-specific response to different carbon sources at the transcriptional, rather than the translational, level

Background: The methylotrophic, Crabtree-negative yeast Pichia pastoris is widely used as a heterologous protein production host. Strong inducible promoters derived from methanol utilization genes or constitutive glycolytic promoters are typically used to drive gene expression. Notably, genes involved in methanol utilization are not only repressed by the presence of glucose, but also by glycerol. This unusual regulatory behavior prompted us to study the regulation of carbon substrate utilization in different bioprocess conditions on a genome wide scale. Results: We performed microarray analysis on the total mRNA population as well as mRNA that had been fractionated according to ribosome occupancy. Translationally quiescent mRNAs were defined as being associated with single ribosomes (monosomes) and highly-translated mRNAs with multiple ribosomes (polysomes). We found that despite their lower growth rates, global translation was most active in methanol-grown P. pastoris cells, followed by excess glycerol- or glucose-grown cells. Transcript-specific translational responses were found to be minimal, while extensive transcriptional regulation was observed for cells grown on different carbon sources. Due to their respiratory metabolism, cells grown in excess glucose or glycerol had very similar expression profiles. Genes subject to glucose repression were mainly involved in the metabolism of alternative carbon sources including the control of glycerol uptake and metabolism. Peroxisomal and methanol utilization genes were confirmed to be subject to carbon substrate repression in excess glucose or glycerol, but were found to be strongly de-repressed in limiting glucose-conditions (as are often applied in fed batch cultivations) in addition to induction by methanol. Conclusions: P. pastoris cells grown in excess glycerol or glucose have similar transcript profiles in contrast to S. cerevisiae cells, in which the transcriptional response to these carbon sources is very different. The main response to different growth conditions in P. pastoris is transcriptional; translational regulation was not transcript-specific. The high proportion of mRNAs associated with polysomes in methanol-grown cells is a major finding of this study; it reveals that high productivity during methanol induction is directly linked to the growth condition and not only to promoter strength

Impact of COVID-19 and other viral infections of male fertility (Preliminary data)

Objective. To study the parameters of the hormonal status, hemostasis parameters, biochemical blood test and semen analysis in men of reproductive age who have undergone a new coronavirus infection (COVID-19). Material and methods. The study included 50 men who had a new coronavirus infection (COVID-19) and received treatment in hospital setting. The study was conducted 3 months later in the presence of positive IgG antibodies to COVID-19. All patients underwent a comprehensive examination, including the study of the hormonal profile, hemostasis parameters, biochemical blood test, identification of concomitant urological diseases, as well as semen analysis (concentration, mobility, morphology, MAR-test), according to WHO 2010 criteria. Results. The examination revealed a decrease in the level of total testosterone in 19 (38%) patients. The values ranged from 6.41 to 10 nmol/l (reference values 10.50—35.40 nmol/l). The biochemical blood analysis revealed the following changes: an increase in creatinine levels to 117—180 μM / L (reference values 80—115 μM/L) in 15 (30%) patients, total bilirubin (22—42.7 μM/L (refer-ence values 1.7—21.0 μMol/L) in 9 (18%) patients, alanine aminotransferase 43-109 U/L (reference values 0.0—41 U/L) in 19 (38%) patients, the level of aspartate aminotransferase was 45—82 U/L (with a norm of 0.0—40 U/L) in 10 (20%) patients Analysis of the hemo-stasis revealed hypercoagulation in 11 (22%) patients, and hypocoagulation in 6 (12%) patients. Abnormalities in the semen analysis were found in 10 (20%) patients with teratozoospermia in all the samples. In 8 (16%) patients, leukospermia was determined. There was a statistically significant decrease in the serum total testosterone level in 38% of patients (