Features of the structure with static strain aging of an austenitic corrosion-resistant steel

Conclusion The data provided clearly point to the complex nature of static strain aging for steel type Kh16N15 which depends significantly on the degree of prior deformation. The shape of carbides formed is determined by the degree of prior deformation and it changes from acicular (in austenitized specimens) to lamellar (in lightly worked specimens) and a circular shape (in strongly worked specimens).Novopolotsk Polytechnic Institute. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 7, pp. 39–40, July, 1988.     

The positive effect of pretreatment with serotonin and gangliosides on the development of early mouse embryos after cryopreservation

Blood pressure (BP) during siesta declines to levels similar to those of night time sleep. The objective of the study was to assess the effect of siesta on 24-h ambulatory BP (ABP) data. Two different approaches were employed for the definition of day and night periods: (1) actual patient reported day and night intervals (ACT) with siesta period analysed as a third time period; and (2) arbitrary day and night time intervals (ARB) with the presence of siesta being ignored. A total of 203 24-h ABP recordings were analysed, with a siesta during ABP monitoring reported in 154 of them. Mean siesta BP was very close to ACT night time BP. Among recordings with a siesta, ACT daytime BP was higher and night time BP lower than the corresponding ARB BPs (P < 0.001). The magnitude of night time BP drop was greater with ACT intervals, resulting in a lower percentage of non-dippers (P < 0.001). Among 49 recordings without a siesta, differences between ACT and ARB BPs were less pronounced for daytime but not for night time. Differences in the magnitude of nocturnal BP drop between ACT and ARB periods, although statistically significant, did not affect the prevalence of non-dippers. In conclusion, analysis of 24-h BP profiles by using ARB instead of ACT day and night intervals results in underestimation of the nocturnal BP drop and overestimation of the proportion of non-dippers. This bias is more pronounced in patients who take a siesta during ABP monitoring.     

Molybdenum disulfide and graphite — fillers for polyorganosiloxanes

Conclusions Molybdenum disulfide and graphite catalytically accelerate the oxidation and depolymerization of polyorganosiloxanes at high temperatures.Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 11, pp. 50–51, November, 1966.     

Software package for solving hyperbolic-type equations

The TURBO1 software package for solving the hyperbolic systems of differential equations on multiprocessor computing systems with distributed memory is described. The package is a standard-oriented and extensible software package. Within a single formalism, it is possible to solve several problems describing different physical processes. For their solution the package provides the user with numerical procedures and software blocks containing initial and boundary conditions, as well as mass forces specific to the problem. The potential of this package is demonstrated on an example from numerical simulation of classical problems of gas dynamics, i.e., the Rayleigh-Taylor instability (RTI) and the shear layer problems.     

Improvement of Mode Selectivity of High-Harmonic Gyrotrons by Using Operating Cavities with Short Output Reflectors

An important problem in realization of gyrotrons operating at high cyclotron harmonics is discrimination of parasitic oscillations excited at lower harmonics. In this paper, we propose to use an operating cavity with a short output irregularity providing a partial reflection of the operating wave. This allows decreasing the length of the cavity with no considerable change in both the operating electron current and the efficiency of the gyrotron operation. At the same time, since the output irregularity weakly reflects parasitic low-frequency waves, the reduction in the length of the cavity leads to a significant increase in the starting currents of the parasitic near-cutoff waves.     

Fractal analysis of fracture in aluminum alloy 01450T

The fractal dimensions of rupture surfaces of specimens of aluminum alloy 01450T tested for cyclic and static tension are evaluated. The relationship between the fatigue curve and the fractal dimension as a function of stress is established. The dependence of the maximum coefficient of stress intensity on the fractal dimension is determined.Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 8, pp. 20–25, August, 1995.     

New nucleoside conjugates with phospholipids: synthesis of anti-HIV activity of rac-1-hexadecyl-2-acyl-sn-glycero-3-phosphonucleosides

New nucleoside-phospholipid conjugates were synthesized based on 1,2-disubstituted glycerides and nucleosides. These contain rac-1-hexadecyl-2-palmitoyl(or 2-methylcarbamoyl)-sn-glycero-3-phosphate as the phospholipid component and 2',3'-didehydro-3'-deoxythymidine, 1-(Z-5-hydroxypentene-2-yl)thymine, or 2',3'-isopropylideneuridine as a nucleoside component. The conjugates were synthesized by three different ways: from rac-1-hexadecyl-2-acyl-sn-glycero-3-phospodichlorides, -3-phosphatidic acids, or -3-H-phosphonates. When subjected to mild alkaline hydrolysis, conjugates containing a 2-palmitoyl group formed conjugates with the lysophospholipid component that had not yet been described. All the conjugates obtained were amorphous compounds stable at room temperature. Their hemolytic and anti-HIV activities were determined. Some conjugates were found to completely inhibit in vitro HIV-1 reproduction in lower doses than the corresponding nucleosides.     

Dynamics of lipid peroxidation and antioxidant system in patients with severe combined trauma

The objective of the study was to determine the influence of blood loss volume on lipid peroxidation (LP) process and antioxidant system (AOS) state in the patients with a heavy combined trauma. The studies were proceeded in 36 patients with a heavy combined trauma. The mean age of the patients was 40 +/- 2. A craniocerebral trauma was associated with trauma of both thorax and abdominal cavities and locomotor system. Blood loss reached 75% of circulating blood volume (CBV), mean value was 28 +/- 3%. Blood samples for the studies were obtained at admission of the patients by emergency medical service teams, and--after 4; 24 hours, 3 and 7 days after the trauma. CBV determination was made by dradioisotope method. LP and AOS state was judged from serum level of primary (conjugated dienes), secondary (malonic dialdehyde, MDA) LP products and extracellular antioxidant enzyme ceruloplasmin (CP). K coefficient, an integral indicator was used for LP-AOS system imbalance assessment. According to the obtained data, in the studied patients intensification of the LP processes manifesting in CD and MDA contents increase was most expressed from 1 to 3 days after trauma (2.0-2.6-fold, p < 0.05) and rise of TP content maximally in the 3 day 2.28-fold (p < 0.05) was observed in the there patients. At the admission of decrease (1.6-fold, p < 0.05) was registered which normalized to the 3 day. K coefficient time course study permitted to establish that as early as at the admission of the patients into the clinic its value was substantially higher than the normal one, and to the 4 hour the imbalance in the LP-AOS system increased 5.0-fold (p < 0.05). An expression of LP processes and AOS disturbances in the patients with heavy combined trauma depended on the blood loss volume. The revealed imbalance in the LP-AOS system is indicative of a necessity of inclusion antioxidants into the complex therapy.     

Kinetics of damage cumulation in materials of flexible vacuum elements

An analysis is made of the process of damage cumulation in flexible elements of a wave transmission in cyclic loading used in vacuum technology systems. A kinetic diagram of cyclic damage is proposed and their relationship is determined within the rate of damage, the stress, and the specific flow. New parameters characterizing the individual stages of damage cumulation are evaluated. The results show that defects in the form of pores or microcracks build up along the grain boundaries of flexible elements of the wave transmission.Translated from Problemy Proehnosti, No. 1, pp. 14–18, January, 1990.