Hydrogen degradation of steels in gas mains after long periods of operation

We study the degradation of the mechanical and corrosion properties of 17G1S steel in gas mains as a result of operation for 28–40 yr. We reveal the simultaneous decrease in its strength and hardness, on the one hand, and impact toughness and crack resistance, on the other hand. The indicated parameters prove to be most sensitive to the in-service degradation of the metal. The degradation of steel leads to the increase in the strain-hardening coefficient and the appearance of the yield plateau in the tensile stress-strain diagram and causes the appearance of sensitivity to hydrogen embrittlement increasing in the process of operation. We analyze the role of absorbed hydrogen affecting the mechanism of strain aging and responsible for the appearance of defects. It is shown that the polarization resistance can be used not only for monitoring of the corrosion state of gas pipelines but also for the prediction of changes in their mechanical properties in the process of operation. __________ Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 43, No. 5, pp. 97–104, September–October, 2007.     

Learning about tools in infancy.

These experiments explored the role of prior experience in 12- to 18-month-old infants' tool-directed actions. In Experiment 1, infants' use of a familiar tool (spoon) to accomplish a novel task (turning on lights inside a box) was examined. Infants tended to grasp the spoon by its handle even when doing so made solving the task impossible (the bowl did not fit through the hole in the box, but the handle did) and even though the experimenter demonstrated a bowl-grasp. In contrast, infants used a novel tool flexibly and grasped both sides equally often. In Experiment 2, infants received training using the novel tool for a particular function; 3 groups of infants were trained to use the tool differently. Later, infants' performance was facilitated on tasks that required infants to grasp the part of the tool they were trained to grasp. The results suggest that (a) infants' prior experiences with tools are important to understanding subsequent tool use, and (b) rather than learning about tool function (e.g., hammering), infants learn about which part of the tool is meant to be held, at least early in their exposure to a novel tool. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A 322 MHz random-cycle embedded DRAM with high-accuracy sensing and tuning

A 16 Mb embedded DRAM macro in a fully CMOS logic compatible 90 nm process with a low noise core architecture and a high-accuracy post-fabrication tuning scheme has been developed. Based on the proposed techniques, 61% improvement of the sensing accuracy is realized. Even with the smallest 5 fF/cell capacitance, a 322 MHz random-cycle access while 32 ms data retention time which contributes to save the data retention power down to 60 /spl mu/W are achieved.     

Structure and Certain Properties of Hot-Pressed Boron Carbide-Based Ceramic with Calcium-Silicon Additive

The influence which the composition of powder mixtures, the treatment conditions which the mixtures are subjected to, and the conditions under which the hot-pressed composite materials B₄C – (5-10 mass%) calcium-silicon are fabricated exert on the structure, nature of failure, and mechanical properties of these materials is investigated. Optimum properties are possessed by material containing 10 mass% of addition. It is shown that the structure, morphology, and dispersivity, as well as the nature of the distribution of the components that are added to the composite material (secondary phase) vary as the temperature of hot pressing changes. Maximal mechanical characteristics of the composite material (σ_bend = 560 MPa, K _1c = 4.7 MPa·m^1/2, HV = 37 GPa) are attained at hot-pressing temperatures in the range 2000-2100°C.     

Labor-Management Cooperation and Customer Satisfaction

The satisfaction that a customer has with the construction product and construction services provided by a contractor has a direct influence on the customer’s willingness to select that contractor for future work. Labor and management working together have the opportunity to influence customer satisfaction. Activities at the contractor/craft worker level, the contractor/local union level, and the contractor association/local union level have the greatest potential to influence customer satisfaction. A precisely defined plan incorporating labor-management activities targeted at specific satisfaction factors will have the greatest likelihood of creating high customer satisfaction.     

Study of phase equilibria in the Al - Pd - Re system

Scanning and transmission electron microscopy have been combined with x-ray diffraction to examine the phase equilibria in the Al - Pd - Re system at 1000°C for compositions from 50 to 100 at.% Al, and the corresponding isothermal section has been constructed. The binary monoclinic Al₃ Re phase has been observed for the first time. It is confirmed that there is a stable icosahedral phase in this system. The boundaries to its homogeneity region have been determined and the phase equilibria in which it participates.     

Fundamental aspects of excitation and propagation of on-line partial discharge signals in three-phase medium voltage cable systems

On-line partial discharge (PD) detection of three-phase belted medium voltage cable connections results in a number of interpretation differences as compared to off-line measurements where only one phase is energized. The induced currents and charges in the phase conductors and earth screen upon a PD not only depend on the discharge site, but also become phase angle dependent. Furthermore, simulations show that the PD distribution itself varies with the amount of eccentricity of the rotating electric field and may differ from the off-line distributions obtained with a linear field. Finally, the PD propagation in a multi-conductor cable also alters the signals measured at the cable terminals. In this paper, induced charges and PD distributions are studied by means of computer simulation. The cable propagation characteristics are verified by measurements.     

Alcohol tolerance in humans is enhanced by prior caffeine antagonism of alcohol-induced impairment.

The author tested the hypothesis that a history of drug-induced antagonism of alcohol impairment would enhance alcohol tolerance in humans. Groups of participants (N = 21) repeatedly performed a psychomotor task under different drug treatments: 0.65 g/kg alcohol, 4 mg/kg caffeine, or both drugs combined. Tolerance to a 0.65 g/kg alcohol dose challenge was then tested. Results showed that a history of combined alcohol and caffeine administrations increased alcohol tolerance compared with an exposure history to either drug alone. The findings contribute to the understanding of the complexities of polydrug use history and provide a useful model to examine how alcohol tolerance might be affected by a history of coadministration with other drugs (e.g., cocaine and nicotine). (PsycINFO Database Record (c) 2010 APA, all rights reserved)