Dehydrogenation activities of coal liquefaction catalysts on various ranks of coals

The amount of hydrogen evolved from a coal during pyrolysis at atmospheric pressure in the presence of coal hydroliquefaction catalysts can be used to compare the activity of different catalysts for the highpressure hydrogenation of coals. This technique has now been used to compare the variation in the effectiveness of MoO₃-TiO₂, and Fe₂O₃-SO^2?₄, as hydroliquefaction catalysts with change in coal rank. It is indicated that coals with carbon contents of ≈ 82 wt% are the most amenable to hydroliquefaction at high pressure.     

Analysis of stress due to shrinkage in a hardening process of liquid epoxy resin

At present, epoxy resin is applied during the manufacturing of more compact and thinner components for the packaging of electronic and other devices. Epoxy resin has superior properties in terms of heat resistance, insulation, and strength; however, defects such as deformations and cracks often occur because of stress concentration. It is important to determine the inner stress of resin solidification for molding processes. Through a combination of numerical analyses of heat generated due to chemical reactions and experiments on shrinkage and strain that occur during hardening of epoxy resin, it becomes possible to analyze the stress generated due to hardening shrinkage. The developed analytical method can contribute to the realization of highly reliable components made of epoxy resin. © 2002 Wiley Periodicals, Inc. Heat Trans Asian Res, 31(3): 194–211, 2002; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.10028     

The magnetic properties of ytterbium trihydride

Ytterbium trihydrides (2.02 < H/Yb < 2.96) were synthesized at high hydrogen gas pressures by thermally decomposing.aluminium hydride under high pressure. The magnetic susceptibility of ytterbium trihydrides was measured by the Faraday method at temperatures 78 to 300 K. The gram magnetic susceptibility of YbH_2.96 in the temperature range 78 to 295 K obeys the Curie-Weiss law withP _eff = 4.37 µ_B andT _gq = –62.7 K. The electrical resistance of ytterbium dihydrides were measured by the d.c. method at temperatures of 78 to 273 K. YbH showed a metallic resistivity in the temperature range 78 to 273 K, but YbH_1.2 and YbH_1.5 showed semiconducting characteristics at temperatures of 241 to 273 K and at 163 to 273 K, respectively. The band gap energy of YbH_1.2 which appeared to show semiconducting behaviour was 0.241 eV, and of YbH_1.5 was 0.294 eV.     

Delayed figure reconstruction by a chimpanzee (Pan troglodytes) and humans (Homo sapiens).

A chimpanzee (Pan troglodytes) was trained to construct a copy of 3-element compound figures from a set of 9 elements. Delay intervals between sample offset and element presentation varied. The chimpanzee maintained accuracy at about 80% correct for a delay of 32 s, which was slightly higher than the mean of 4 human (Homo sapiens) Ss. Excellent visual reproductive memory in the chimpanzee as compared with that in humans was demonstrated. However, the nature of the reproductive memory was different in the 2 species in that humans better constructed meaningful figures, which represented food items, than meaningless ones, whereas the chimpanzee constructed these 2 types of figures with the same accuracy. This outcome suggests that the reproductive memory for meaningful figures of the chimpanzee may have been processed separately from symbolic processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Control system for the Khepera robot by a neural network with competition and cooperation

This article describes a new approach to control systems for a mobile robot Khepera by using a neural network with competition and cooperation as the processing unit for the robot sensors. Competition makes only one neuron active, while cooperation keeps them all active. In our research, we find that the Khepera controlled by this neural network can maintain a smoother trajectory than when it is controlled by the output values of its own sensors, especially in noisy environments. This work was presented in part at the Fifth International Symposium on Artificial Life and Robotics, Oita, Japan, January 26–28, 2000     

Memory Conscious Scheduling for Cluster-based NUMA Multiprocessors

For Non-Uniform Memory Access (NUMA) multiprocessors, memory access overhead is crucial to system performance. Processor scheduling and page placement schemes, dominant factors of memory access overhead, are closely related. In particular, if the processor scheduling scheme is dynamic space-sharing, it should be considered together with the page placement scheme for efficient process execution. Most research in this area, however, has focused exclusively on either the processor scheduling scheme or the page placement scheme alone without considering the interaction between the two. This paper proposes several policies for cluster-based NUMA multiprocessors that are combinations of a processor scheduling scheme and a page placement scheme and investigates the interaction between them. The simulation results show that policies that cooperate to employ the home-cluster concept achieve the best performance. The paper also compares the best of the proposed policies with other existing dynamic processor scheduling policies. Based on our study reported here, the best policy is found to perform better than other existing policies.     

Sensory regulation of stance-to-swing transition in generation of adaptive human walking: A simulation study

In this paper, we investigated sensory mechanisms to regulate the transition from the stance to swing phases in the generation of adaptive human bipedal walking based on a neuromusculoskeletal model. We examined the contributions of the sensory information from the force-sensitive afferents in the ankle extensor muscle and from the position-sensitive afferents from the hip, inspired by a neuro-mechanical simulation for the stepping of the hind legs of cats. Our simulation results showed that the sensory signals related to the force in the ankle extensor muscle make a larger contribution than sensory signals related to the joint angle at the hip to produce robust walking against disturbances, as observed in the simulation results of cat locomotion. This suggests that such a sensorimotor mechanism is a general property and is also embedded in the neuro-control system of human bipedal walking.     

Progress Report on NMIJ Acoustic Gas Thermometry at the Triple Point of Water

Herein, progress in the development of an acoustic gas thermometry (AGT) system at the National Metrology Institute of Japan is reported. This AGT system is an initial low-cost version that uses a 1-l quasi-spherical resonator (QSR) made of oxygen-free copper. The system was tested by measuring the speed of sound in argon at the temperature of triple point of water. Measurements were conducted at ten different pressures, ranging from 60 kPa to 420 kPa. The ideal gas limit of the squared speed of sound was obtained through extrapolation, and a preliminary calculation of the Boltzmann constant, which was 12 ppm below the CODATA2014 value, was made. Large inconsistencies among microwave and acoustic modes were observed, which are dominant sources of uncertainty in speed of sound measurements. The system will be improved by replacing the present QSR with another one that is more precisely fabricated.     

Daily oscillation of gene expression associated with nacreous layer formation

Three major organic matrix components, nacrein, MSI60 and N16 have been reported from the nacreous layer of Japanese pearl oyster, Pinctada fucata. Though several in vitro experiments have been carried out to elucidate the functions of these molecules details have not yet been clarified. In this report, we tempt to clarify the gene expression levels encoding the above three proteins between samples of 1) summer and winter seasons and 2) ocean and aquarium environments by using real-time polymerase chain reaction (PCR). It was confirmed that the biomineralization process of P. fucata is mainly influenced by the circatidal rhythm of the ocean environment. The gene expressions coding for N16 and MSI60 increased at the time of high tide, while that of nacrein increased at the time of low tide. The similar tendency observed in N16 and MSI60 showed the possibility that both components are secreted simultaneously, supporting a hypothesis that N16 forms cross-linkage with MSI60 to form the membrane. The expressions of MSI60, N16 and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes were remarkable in winter season, while no variation was found in the expression level of the nacrein gene in summer and winter season. The study is the first attempt regarding the seasonal and circadian rhythms observed on gene expressions incorporated into molluscan shell formation. The results will give a new insight into the relationship between molluscan physiology and the mechanism of shell formation.