Thixomolded magnesium alloys: Strategic product innovation in automobiles

The research on magnesium alloys for structural lightweight applications is today at an embryonic stage, but these alloys offer great potential. Thixomolding of magnesium alloys for automotive applications is promising since the process can be used to manufacture net-shape parts cost-effectively and with high reliability and repeatability.     

Upgrading of a reliable water supply system at the Kola nuclear power plant for service life extension

Measures taken to develop and put into operation three new exterior channels for emergency process water with two additional 60VTs pumping units, which remain operational even during an earthquake and were installed in the second block pumping station, are described. In addition, the three existing 12NDS horizontal pumping units were used as a basis to develop a third channel for the emergency process water. Above-ground water ducts with thermal insulation and heating systems to prevent freezing during the anticipation state, which is the constant state of the emergency system, were laid. As a result of upgrading with the development of three channels, the emergency process water feeding reached an adequately safe level of reliability. __________ Translated from Atomnaya énergiya, Vol. 100, No. 3, pp. 173–177, March, 2006.     

Increasing the nominal safety of the no. 5 unit of the Kursk nuclear power plant

The main technical measures for increasing the nominal safety of the No. 5 unit of the Kursk nuclear power plant are presented: optimization of the neutron-physical characteristics of the core, adoption of a comprehensive monitoring, control, and protection system, switching to cluster-type control rods, adoption of a system for limiting radioactive emissions during anticipated accidents with pipeline rupture outside the containment system. __________ Translated from Atomnaya énergiya, Vol. 100, No. 4, pp. 320–327, April, 2006.     

Degradation of steels in the hulls of river ships

The surface corrosion of skin plates of the hulls of river ships is caused by the interaction of oxygen and hydrogen with the iron surface at the sites of damage to the protective lacquer coatings on the outer surface of the hull. The inner surface of the hull is subjected to the action of the condensates of water vapor with different degrees of acidity. Furthermore, near the fuel tanks, hydrogen-containing media (mainly, the hydrocarbon fuel) also affect the inner surface of the hull. As a result of hydrogenation, the plasticity of the skin plates of the fuel tanks sharply decreases, which is confirmed by the data of measurements of their impact toughness and microhardness, as well as by the results of microfractographic examinations. The contemporary hull plates subjected to thermomechanical treatment reveal a significant improvement of their plastic characteristics as compared with the requirements of the existing standard specifications. __________ Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 43, No. 3, pp. 117–120, May–June, 2007.     

Thermodesorption of samarium from oxidized tungsten surface

Thermodesorption of samarium (Sm) atoms and samarium oxide (SmO) molecules from samarium films deposited in vacuum onto tungsten substrates covered with thin (<1 nm thick) layers of tungsten oxides has been studied. It is established that samarium reduces tungsten from its oxides. The parameters of Sm and SmO desorption from an oxidized tungsten surface are determined.     

Certain regularities of the kinetics of drying of moist materials

A method for calculating the kinetics of drying under the conditions of continuous variation in the Rehbinder number in the period of decreasing drying rate is considered. __________ Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 80, No. 4, pp. 143–146, July–August, 2007.     

Forming n-p junctions based on p-CdHgTe with low charge carrier density

The first results on the formation of n ⁺-p photodiodes with a long-wavelength boundary at λ_0.5 = 10.6 μm based on p-CdHgTe epilayers with a hole density of 3.3 × 10¹⁴ cm^?3 are presented. The CdHgTe layers were obtained by molecular beam epitaxy and exhibited p-type conduction in the as-grown state. The hole density and mobility were determined by means of the mobility spectrum technique. The photodiode structures were prepared by B⁺ ion implantation into as-grown p-CdHgTe epilayers without additional annealing. The R ₀ A product for the n ⁺-p photodiodes obtained is about 20 Θ cm² at 77 K.     

Reflection of electrons during tunneling and an intersubband polaron in the 2D electron system of a delta-layer in GaAs

Al-δ-GaAs structures are studied where tunneling to one or more subbands of the 2D electron system of a near-surface delta-doped layer is observed. Reflection of electrons at the threshold of the emission of an LO-phonon is observed. This phenomenon occurs when a new subband is involved in the tunneling process and when intersubband transitions of the electrons in a 2D-system with the emission of an LO-phonon are added to the inelastic tunneling within a single subband. It is shown that, under the conditions of an intersubband polaron resonance, the reflection processes dominate during tunneling into the delta-layer. If, however, tunneling from the delta-layer occurs, the reflection processes are observed when two subbands are occupied.