Boiling heat transfer characteristics of a sulfuric-acid flow in thermochemical iodine–sulfur cycle

The Japan Atomic Energy Agency has been conducting research and development on the thermo-chemical iodine–sulfur (IS) process, which is one of the most attractive water-splitting hydrogen production methods that uses nuclear thermal energy. The sulfuric acid decomposer is one of the key components of the IS process. The boiling heat transfer coefficients of sulfuric acid solutions are required to design the sulfuric acid decomposer. These coefficients were measured in aqueous solutions where the mole fraction of H₂O ranged from 0.17 to 0.37 (heat flux range from 16.9 kW/m² to 5.6 kW/m²) and compared with the empirical correlations formulated for binary mixtures. A combination of the Stephan–Körner correlation, using the empirical constant A₀ = 2.00, and the Nishikawa–Fujita correlation was used to predict the experimental results with an accuracy of ±10%.     

Simulation research on monomer agglomeration of nonmetallic inclusions in steel with a diffusion limited aggregation model

The monomer agglomeration of nonmetallic inclusions was simulated with a diffusion limited aggregation （DLA） model of the fractal theory. The simulation study with a random two-dimensional diffusion was carried out. The results indicate that the DLA model can be used for the simulation of agglomeration behavior of the cluster-type inclusions. The morphology of clusters was observed with SEM and compared with the simulated agglomerates. The modelling procedure of the DLA model is applicable for the agglomeration process. The uncertainty of agglomeration process and the persuasive average agglomerative ratio was analyzed. The factors about the agglomerative ratio with the collision path distance and the size of particles or seed were discussed. The adherence of the nonmetallic inclusions on the dam, the weir and the walls of a tundish, and the absorption of inclusions by stopper or nozzle were also discussed.     

VHL gene and TSC 2 gene

Hereditary cancer is rare, but it has served as a useful model in the understanding of carcinogenesis. A number of cancer genes have been identified by the study of hereditary human cancers and implicated in sporadic forms of the some tumors. In this article, I reviewed von Hippel-Lindau disease (VHL) gene and tuberous sclerosis 2 (TSC 2) gene.     

Observation of the solid-state formation of a TTF–CA complex by terahertz spectroscopy

The solid-state synthesis of a tetrathiafulvalene–chloranil (TTF–CA) complex was demonstrated, and progress in the formation of the complex was monitored using a GaP Raman terahertz (THz) spectrometer. Clear transitions in the THz absorption spectra indicated that the mixture of TTF and CA became the black phase TTF–CA complex. The results of X-ray diffraction, Raman scattering, and FTIR spectra are presented as supporting evidence.     

Evidence for Altered Phosphoinositide Signaling-Associated Molecules in the Postmortem Prefrontal Cortex of Patients with Schizophrenia

Phosphoinositides (PIs) play important roles in the structure and function of the brain. Associations between PIs and the pathophysiology of schizophrenia have been studied. However, the significance of the PI metabolic pathway in the pathology of schizophrenia is unknown. We examined the expression of PI signaling-associated proteins in the postmortem brain of schizophrenia patients. Protein expression levels of phosphatidylinositol 4-phosphate 5-kinase type-1 gamma (PIP5K1C), phosphatidylinositol 4-kinase alpha (PIK4CA, also known as PIK4A), phosphatase and tensin homolog deleted from chromosome 10 (PTEN), protein kinase B (Akt), and glycogen synthase kinase 3β (GSK3β) were measured using enzyme-linked immunosorbent assays and multiplex fluorescent bead-based immunoassays of the prefrontal cortex (PFC) of postmortem samples from 23 schizophrenia patients and 47 normal controls. We also examined the association between PIK4CA expression and its genetic variants in the same brain samples. PIK4CA expression was lower, whereas Akt expression was higher, in the PFC of schizophrenia patients than in that of controls; PIP5K1C, PTEN, and GSK3β expression was not different. No single-nucleotide polymorphism significantly affected protein expression. We identified molecules involved in the pathology of schizophrenia via this lipid metabolic pathway. These results suggest that PIK4CA is involved in the mechanism underlying the pathogenesis of schizophrenia and is a potential novel therapeutic target.     

Regulation of lactate production in Streptococcus bovis: A spiraling effect that contributes to rumen acidosis

When Streptococcus bovis was grown in batch culture with 6 g/L glucose at pH 6.7, maximum specific growth rate was 1.47 h(-1), and lactate was the primary fermentation product. In continuous culture at pH 6.7 and growth rate equal to .10 h(-1), little lactate was formed, and formate, acetate, and ethanol accounted for most of the product. When extra-cellular pH decreased to 4.7, intra-cellular pH declined to 5.4, and organisms switched back to lactate production. Intracellular concentration of fructose 1,6-diphosphate of batch culture cells was greater than 12 mM, a concentration that allowed maximal lactate dehydrogenase activity. When Streptococcus bovis was grown in continuous culture at pH 6.7, intracellular fructose-l,6-diphosphate declined to .4 mM, a concentration which gave little lactate dehydrogenase activity at pH 6.5 or greater. Decreasing pH of continuous culture to 4.7 increased intracellular fructose-1,6-diphosphate concentration to .8 mM. This concentration was still limiting if lactate dehydrogenase was assayed at pH 6.5, but nearly maximal activity was obtained when enzyme was assayed at pH 5.5. The small increase in fructose-l,6-diphosphate and decreased requirement of lactate dehydrogenase for fructose-l,6-diphosphate under acidic assay conditions, accounted for increased lactate production during low pH (4.7) continuous culture. These and other aspects of lactate regulation by Streptococcus bovis are discussed as factors leading to rumen acidosis. This pattern of regulation also helps to explain why rumen acidosis is difficult to reverse.     

Three-dimensional shape recognition method using ultrasonics for manipulator control system

This article describes a three-dimensional shape recognition method that employs an ultrasonic distance sensor mounted on a manipulator, and its application to a manipulator control system. The principle of the method is to reconstruct an object surface numerically using both distance and orientation informations of an object. The method makes it possible to control the manipulator, to set the sensor in any position and orientation employing freedom of the manipulator, and to measure the object. The method is available for manipulator control because it can precisely assess the distance from the manipulator to the object, as well as reconstruct the object shape. Experimental results show that the newly developed method make object shape recognition easy and inexpensive. Application experiment proved that the method is effective for manipulator work due to its provision of distance information.     

Hydrogen storage properties of lithium silicon alloy synthesized by mechanical alloying

A lithium silicon alloy was synthesized by mechanical alloying method. Hydrogen storage properties of this Li-Si-H system were studied. During hydrogenation of the lithium silicon alloy, lithium atom was extracted from the alloy and lithium hydride was generated. Equilibrium hydrogen pressures for desorption and absorption reactions were measured in a temperature range from 400 to 500 °C to investigate the thermodynamic characteristics of the system, which can reversibly store 5.4 mass% hydrogen with smaller reaction enthalpy than simple metal Li. Li absorbing alloys, which have been widely studied as a negative electrode material for Li ion rechargeable batteries, can be used as hydrogen storage materials with high hydrogen capacity.     

Performance tests of catalysts for the safe conversion of hydrogen inside the nuclear waste containers in Fukushima Daiichi

The safe decommissioning as well as decontamination of the radioactive waste resulting from the nuclear accident in Fukushima Daiichi represents a huge task for the next decade. At present, research and development on long-term safe storage containers has become an urgent task with international cooperation in Japan. One challenge is the generation of hydrogen and oxygen in significant amounts by means of radiolysis inside the containers, as the nuclear waste contains a large portion of sea water. The generation of radiolysis gases may lead to a significant pressure build-up inside the containers and to the formation of flammable gases with the risk of ignition and the loss of integrity.In the framework of the project “R&D on technology for reducing concentration of flammable gases generated in long-term waste storage containers” funded by the Japanese Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT), the potential application of catalytic recombiner devices inside the storage containers is investigated. In this context, a suitable catalyst based on the so-called intelligent automotive catalyst for use in a recombiner is under consideration. The catalyst is originally developed and mass-produced for automotive exhaust gas purification, and is characterized by having a self-healing function of precious metals (Pd, Pt and Rh) dissolved as a solid solution in the perovskite type oxides. The basic features of this catalyst have been tested in an experimental program. The test series in the REKO-4 facility has revealed the basic characteristics of the catalyst required for designing the recombiner system.     

Estimation method for the light extraction efficiency of light-emitting elements with a rigorous grating diffraction theory

The light extraction efficiency of a light-emitting element with microstructured surface is analyzed with a rigorous grating diffraction theory. The grating theory reveals an improvement of extraction efficiency due to diffraction of light by the surface microstructure. The simulation results show that the improvement of extraction efficiency is due mainly to the reflected diffraction rather than to the transmitted diffraction. A part of total-internal-reflection light is diffracted into directions at less than the critical angle. Extraction efficiency is improved by multiple reflection and diffraction of light in a high-refractive-index layer. We propose a simple design method for an efficient surface microstructure from the viewpoint of reflected diffraction.