Calorimetric study of ytterbium orthovanadate YbVO4 polycrystalline ceramics

The heat capacity of ytterbium orthovanadate was first measured by adiabatic calorimetry in the temperature range T?=?12.28–344.06?K. No obvious anomalies were observed on the curve obtained. The values of standard thermodynamic functions in the temperature range T?=?0–400 K were calculated. Based on low-temperature calorimetry data obtained, previously published data on the high-temperature heat capacity of ytterbium orthovanadate were corrected. The anomalous contribution to heat capacity for YbVO₄ was compared with the data known for YbPO₄.     

Experimental investigation of systems for synchronizing time scales by means of the Quasar satellite communication system network

Experiments conducted at ground stations of the Quasar satellite communication network using both a null base as well as a base of around 2000 km is described. In experiments with a null base, the time scale transmission error was 1 nsec. Comparison of the results of collocation with data cbtained by the GLONASS system in the course of experiments using a 2100-km base demonstrated a divergence of the results of from 5 to 25 nsec. Translated from Izmeritel'naya Tekhnika, No. 4, pp. 35–38, April, 1996.     

Ultrasonic logging as a method of evaluating the static deformation characteristics of real media

Conclusions The physical causes promoting a difference in the values of the moduli of elasticity determined by static and dynamic (ultrasonic and resonance) methods of investigation were examined. On the basis of analyzing these causes formulas were proposed for calculating longitudinal wave velocities in mutually perpendicular directions for loaded and unloaded states of the object of investigation. The possibility of estimating the static parameters of deformability of a real (not idealized) medium directly from the data of ultrasonic investigations, in particular, from ultrasonic logging data, was shown. Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 7, pp. 36–42, July, 1998.     

Relation between the level of E. coli gene expression and the structure of translation initiation region (TIR). III. Sites of complementary interaction of TIR with 16S rRNA

The addition of vertebral disc degeneration to the job-related disease register raises the question of vertebral disc degeneration patterns according to loading strain. The readings of the lumbar vertebra of construction workers and nurses were compared with those of a group without workload. In the groups examined, aged 35 to 50, monosegmental damage was found in only 17% of the patients with high workload, as opposed to 29% of those with no workload, mostly with monosegmental damage at level L5/S1. Damage to the upper segments of the lumbar spine with intact discs in between was found exclusively in patients with high workload. Multiple segment damage in the age range examined was found in subjects with activities that add to the load of the spinal column. The value of MRI in assessing and evaluating illness originating from the vertebral discs is currently being discussed.     

Effect of composition and porosity on the hardenability and hardness penetration of structural powder steels

Conclusions The effect of porosity ( > 10%) on the hardenability of the powder steels is stronger than the effect of carbon content. The role of these factors changes with the reduction of porosity ( < 10%) and the carbon content exerts a stronger effect on the hardenability of the steel. After hot pressing, the hardenability of the powder steels approaches the hard-enability of the dense steels of a similar chemical composition.The hardenability of the alloy powder steels at a constant carbon content and porosity is independent of the degree of alloying of the steel.The strength of the effect of complex alloying on the hardness penetration of the powder steels increases with decreasing porosity, especially after hot pressing and annealing as a result of the more efficient homogenizing of the structure with respect to carbon and alloying elements.Translated from Poroshkovaya Metallurgiya, No. 1(277), pp. 82–86, January, 1986.     

Properties of titanium alloy AT2 and weldments of the alloy

Conclusions Alloy AT2 and weldments of the alloy have high strength and ductility at temperatures from 500 to –253°. The deformability of the weld seam is approximately the same as that of the alloy. The corrosion resistance in hydrochloric and phosphoric acids is the same for the weld seam and the base metal. Alloy AT2 and weldments of the alloy are more resistant to hydrochloric and phosphoric acids than alloy VT1.E. O. Paton Institute of Electric Welding of the Academy of Sciences, Ukrainian SSR. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 1, pp. 66–68, January, 1976.