Damping Steels for Sheet Stacker Components During Sheet Rolling

Metallurgist - Steels alloyed with chromium are used for the first time for manufacturing sheet stacker components. Steel with a high chromium content (45X), exhibiting good damping properties,...     

Structure and Properties of an Ni3Al Intermetallic Compound Formed as a Result of Spark Plasma Sintering of the Powder Mixtures Prepared by Various Methods

Metallurgist - The paper described the structure and mechanical properties of nickel aluminide (Ni3Al) obtained by spark plasma sintering of the two compositions of nickel and aluminum powder...     

Effectiveness of dietary non-starch polysaccharides in experimental toxic hepatitis

The efficiency of some polysaccharides was investigated in mice with an experimental toxic hepatitis. Hepatitis was induced by the oral administration of 10% solution CCl4 in olive oil at a dosage of 3 ml/kg body weight every day during 7 days. After that tested substances were administrated every day 30-40 min before a feeding at a dosage of 150 mg/kg body weight during 14-21 days. Results showed that a calcium alginate, two low-methoxyl pectins (one with the degree of esterification about 50% and other with the degree of esterification less 5%), fucoidan, and chitozan, but not lambda-carrageenan and kappa-carrageenan, have beneficial affects on liver total lipid, glycogen, malondialdehyde, and diene conjugates as well as on blood total lipid and alanine aminotransferase activity in animals with experimental toxic hepatitis.     

Stability of Liquid Bridges Between Coaxial Equidimensional Disks to Axisymmetric Finite Perturbations: A Review

This paper reviews the dynamics of breaking or oscillating axisymmetric liquid bridges, and estimates of the energy which is needed to break a liquid bridge. We consider a liquid bridge spanning two coaxial equal disks with sharp edges and held by surface-tension forces. The liquid volume is assumed to be conserved under perturbations, and the contact lines are pinned to the disk edges. The perturbations are finite and axisymmetric. An analysis is based on the one-dimensional models previously used in capillary jet theory and last several decades for study a liquid bridge dynamics. According to the scientific project JEREMI (Japanese and European Research Experiment on Marangoni Instabilities), the first stage of the space experiment on ISS will involve an isothermal liquid bridge with a gas blowing parallel to the axial direction of the bridge. The geometry corresponds to a cylindrical volume liquid bridge coaxially placed into an outer cylinder with solid walls. The gas enters the annular duct bounded by the outer cylinder and the internal system consisting of supporting vertical rods and the liquid bridge. Considering that the bridge is small (the rod’s radii are 3 mm) and the gas velocity is typically (0.25 ÷ 0.37) m/s, the perturbations cannot be considered small. Thus, one may assume that the amplitude of the liquid bridge perturbations is sufficiently large that departures from linearity must be considered.     

The study of weak oscillatory flows in space experiments

The effects of residual accelerations have been studied by using three-dimensional modeling of the flow in a rectangular cell filled with a liquid, Pr=20, the walls of which were kept at different temperatures. The system was subjected to an acceleration field, which can be decomposed into two parts: a steady component and another one which varies slowly with time, the frequency is about f₀≈10⁻³ Hz. The convective heat transport and flow characteristics are discussed for different parameters of g-jitter. The high and low frequency modulation of a sinusoidal g-jitter is discussed. To capture many of the essential characteristics of buoyancy-induced convection a new approach is suggested, which was developed based on the observation of the trajectories of tracer particles. On the one hand, it is a typical way to record the flow in experiments. On the other hand, creating database of different types of trajectories gives the possibility to solve the inverse problem. The shape of the trajectory depends on the g-jitter parameters. It is shown that for slow convective motions the tracer particles perform loops along trajectory due to g-jitter with low frequencies, and the additional high frequencies only cause trembling of the shape of these loops. Taking the experimentally recorded trajectories of tracer particles and comparing with those in the database, one can draw a conclusion about the amplitude and direction of the resulting gravity vector during the experiment.     

The Stability of a Thermocapillary-Buoyant Flow in a Liquid Bridge with Heat Transfer Through the Interface

An experimental investigation has been performed to study a supercritical flow driven by the combined effects of buoyancy and thermocapillary forces, in a non-isothermal liquid cylindrical column heated from above (liquid bridge). The liquid zone was of 3mm in radius and 2.58mm in height made of n-decane. Changing temperature of air in the experimental chamber via controlling the temperature at its external wall, the conditions at the onset of instability of the flow, as characterized by the critical value of the imposed temperature difference, were determined for several values of the liquid volume. Performing ”chaos analysis” of the obtained data, different regimes of the supercritical flow were identified. The experimental observations are supported by a computer modeling of the thermoconvective flow made for the experimental conditions neglecting deformations of the liquid-gas interface. It is shown that the spatial structure of the flow may change with external conditions in the ambient gas.     

Changes in the chemotherapy sensitivity of leukemia L1210 cells during the development of diazan resistance

L 1210 leukemia strain resistant to diazan (L 1210/D1) was studied for its drug sensitivity in comparison with the parent strain. The resistant strain exhibited significantly higher sensitivity to nine drugs: dopan, sarcolysine, apirazidin, cyclophosphane, 6-mercaptopurine, thiophosphamide, rubomycin, vinblastine and vincristine. L 1210/D1 gained cross resistance to four drugs: 1-(2-chloroethyl)-3-(2, 6-dioxy-3-piperidyl)-1-nitrosourea, methotrexate, 5-fluorouracil and ftorafur. The resistant strain sensitivity remained unchanged (in comparison with the parent strain) to seven drugs: degranol, prospidin, nitrosomethylurea, chlorozotocin, deazauridine, bleomycin and L-asparaginase (crasnitine).     

Correction to: “Damping Steels for Sheet Stacker Components During Sheet Rolling”

Metallurgist - The affiliation of V. S. Shevtsova and R. Zh. Abuova should read