Magnesium-Based Materials for Hydrogen Storage: Microstructural Properties

Magnesium (Mg) is hydrogenated as core-shell-type hydride. Therefore, increase of absorption capacity to the theoretical hydrogen capacity is still one of the most important issues for the hydrogen storage materials. In this study, the procedure of the core-shell structure as well as effect of Al concentration in Mg on the growth MgH2 in Mg were investigated. MgH2 was formed on the surface as well as inside of unreacted Mg core. The inside MgH2 was formed in a granular form on Mg grain boundary and its size increased by applying plastic deformation. Thickness of the surface MgH2 and size of the internal MgH2 increased with an increase in hydrogenation time until the hydride surface was completely covered with MgH2. However, the growth of the surface and internal MgH2 came to a halt after the surface was covered with MgH2. From these results, supplying H from metal side was dominantly contributed for growth of the surface and internal MgH2 because diffusion rate of H in Mg was much higher than that in MgH2. In addition, the growth of internal MgH2 as well as control of surface MgH2 can contribute to the promotion of the complete hydrogenation of Mg-based hydrogen storage materials

Studies on the System Sulphuric Acid-Water-Tri-n-Butyl Phosphate

It is intended in this study on the system H₂SO₄-H₂O-TBP to determine the species formed in the equilibrated organic phase and to clarify the extracting mechanism of aqueous sulphuric acid into organic phase. As in the previous report published in this Memoir, physico-chemical measurements of volumeswelling, density, viscosity and electrical conductivity were carried out with the equlibrated organic phase in addition to the conventional distribution measurement of sulphuric acid and water. It was found that the extracting species is [TBP·Hᴏ] at the equilibrated acid concentration in aqueos phase below 2.0M and that three other species were found to exist above 2.0M ; the one formed at lower acid concentration has the general formula [(TBP)₃·H₃O⁺(x+2)H₂O···HSO₄⁻], (x was determined as 2.5), the one formed at medium acid concentration is [TBP·H₃O+(x+2y/3)H₂O···HSO₄-] (y was determined as 0.25), and the one formed at higher acid concentration is [TBP·2{H₃O+(x+5y-3/6)H₂O···HSO₄}] They dissociate partly. The activities and activity coefficients of the two species [TBP·H₂O] and [(TBP)₃·H₃O⁺4.5H₂O···HSO₄⁻] stable at lower acid concentration and the equilibrium constant between them were determined with Redlich-Kister equations

Improving the Cycle-life of Naphthoquinone-based Active Materials by Their Polymerization for Rechargeable Organic Batteries

AbstractTo increase the cycle-stability of rechargeable batteries using an organic positive-electrode material, we synthesized a polymer from a 5,8-dihydroxy-1,4-naphthoquinone (DHNQ) skeleton, which potentially undergoes a four-electron transfer redox reaction. The polymeric material (PDHNQ) was synthesized by the condensation reaction between DHNQ and formaldehyde under acidic media conditions. The initial capacity of the electrode using the monomer (DHNQ), 193 mAh/g, quickly decayed to 56 mAh/g after 100 cycles. On the other hand, the electrode incorporating the prepared PDHNQ showed the higher initial discharge capacity of 256 mAh/g and a longer cycle-life, retaining about 133 mAh/g after 100 cycles

Ti–Pd Alloys as Heterogeneous Catalysts for Hydrogen Autotransfer Reaction and Catalytic Improvement by Hydrogenation Effects

Ti−Pd alloys were investigated as heterogeneous catalysts for hydrogen autotransfer reactions. This is the first reported study of alloys as catalysts for hydrogen‐borrowing reactions using alcohols. We improved the catalytic activities of alloys by increasing their specific surface areas via a hydrogenation−powdering process. The reactivities and selectivities of hydrogenated Ti−Pd alloys [Ti−Pd (Hy) ] were higher than those of non‐hydrogenated alloy catalysts in N‐alkylation by hydrogen autotransfer using alcohols. A plausible catalytic cycle is proposed based on control studies and deuterium labelling experiments

Sexual Experience Induces the Expression of Gastrin-Releasing Peptide and Oxytocin Receptors in the Spinal Ejaculation Generator in Rats

Male sexual function in mammals is controlled by the brain neural circuits and the spinal cord centers located in the lamina X of the lumbar spinal cord (L3-L4). Recently, we reported that hypothalamic oxytocin neurons project to the lumbar spinal cord to activate the neurons located in the dorsal lamina X of the lumbar spinal cord (dXL) via oxytocin receptors, thereby facilitating male sexual activity. Sexual experiences can influence male sexual activity in rats. However, how this experience affects the brain-spinal cord neural circuits underlying male sexual activity remains unknown. Focusing on dXL neurons that are innervated by hypothalamic oxytocinergic neurons controlling male sexual function, we examined whether sexual experience affects such neural circuits. We found that >50% of dXL neurons were activated in the first ejaculation group and similar to 30% in the control and intromission groups in sexually naive males. In contrast, in sexually experienced males, similar to 50% of dXL neurons were activated in both the intromission and ejaculation groups, compared to similar to 30% in the control group. Furthermore, sexual experience induced expressions of gastrin-releasing peptide and oxytocin receptors in the lumbar spinal cord. This is the first demonstration of the effects of sexual experience on molecular expressions in the neural circuits controlling male sexual activity in the spinal cord

Investigating body perception of multiple virtual hands in synchronized and asynchronized conditions

As part of research on human augmentation, multiple bodies are used in a virtual environment. For example, a study on multiple partial body parts has been conducted using up to 64 hands and showed that multiple hands reduced the distance traveled by one hand. However, body perception has yet to be verified. In this study, we investigated how body perception changes when nine hands, partial bodies, are moved synchronously in a virtual environment, compared to a single hand. In addition, we examined whether the sense of body ownership for all nine hands was elicited simultaneously or whether it was elicited for some of the hands while switching between them. Participants performed a reaching task using one or nine hands presented in a virtual environment. After the reaching task, a threat stimulus was given, and hand movements in response to the threat were measured. After completion of each condition, the subjective sense of body ownership and sense of agency was investigated using a Likert scale. The results indicated that users felt the sense of body ownership of several hands for the nine hands and manipulated them by switching their attention to multiple bodies