Dynamic behaviour of sulfur forms in rapid pyrolysis of coals with alkali treatment

Three kinds of subbituminous and bituminous coals with added potassium hydroxide were heated at 523 K in a nitrogen stream to transform thermally stable organic sulfur to reactive species. Extents of total sulfur removal were 27–52% during the course of alkali treatment, while weight loss was 8–13%. The extent of total sulfur removal was linearly proportional to the internal surface area of the parent coal. The parent coals and alkali-treated samples were pyrolysed rapidly in a free-fall reactor in a nitrogen stream at 1233 K. Under these conditions the alkali-treated samples lost more organic sulfur than did the parent coals. The observed changes in the content of sulfur forms were successfully simulated kinetically. The combined process of rapid pyrolysis with alkali leaching was effective for reduction of organic sulfur, except for a high-rank coal of small internal surface area.     

Estimation of surface properties of grafted layers formed on low- and high-density polyethylene plates by photografting of methacrylic acid and acrylic acid at different monomer concentrations and temperatures

An investigation was carried out on estimation of hydrophilicity, wettability and water-absorptivity, and surface analysis by X-ray photoelectron spectroscopy of the low- and high-density polyethylene (LDPE and HDPE) plates photografted with methacrylic acid (MAA) and acrylic acid (AA) at different monomer concentrations or temperatures. Wettability of the MAA-grafted LDPE and HDPE plates increased with grafted amounts, and became constant when the substrate surfaces were fully covered with the grafted polymer chains. On the other hand, for the AA-grafted LDPE and HDPE plates, wettability had the maximum value, and then gradually decreased against the grafted amount probably due to aggregation of grafted PAA chains, although the surfaces were covered with grafted PAA chains at lower grafted amounts compared with grafted PMAA chains. Water-absorptivity sharply increased at lower grafted amounts due to formation of shorter grafted polymer chains for photografting at lower monomer concentrations or due to restriction of the location of grafting to the outer surface region for photografting at lower temperatures. Therefore, for photograftings of AA or onto the HDPE plates, the substrate surfaces were covered with grafted polymer chains and the grafted layers formed possessed higher water-absorptivity at lower grafted amounts. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Decomposition of GAP Single Droplets Used as Liquid Monopropellants

Hydrazine monopropellant thrusters are used as propulsion system for trajectory corrections and other operations of satellites or unmanned spacecrafts. But hydrazine is difficult to handle, therefore the design and the synthesis of next generation monopropellants that could be able to supersede hydrazine is currently studied by scientists around the world. In this study, we focus on liquid glycidyl azide polymer (GAP) as next generation monopropellant. GAP is a liquid and stable substance at standard temperature and pressure. GAP is self‐reacting with exothermic decomposition, however, the decomposition of GAP single droplets when heated was not investigated. To clarify the decomposition of GAP single droplets, we examined their decomposition behavior. It was found that GAP single droplets changed their status at certain temperatures in a furnace. Bubbles were generated at temperatures over 493 K, and micro explosions occurred at temperatures above 603 K. The temperature in GAP single droplets rapidly rose when micro explosions occurred. Moreover, the activation energy was obtained from the results of micro explosion delay time and of DTA. It was found that GAP is able to easily generate micro explosions by a small amount of energy.     

Enhanced detection efficiency of genetically encoded tag allows the visualization of monomeric proteins by electron microscopy

A cadmium-binding, genetically encoded protein tag, consisting of three repeats of metallothionein (3MT), can be used in electron microscopy for the visualization of multimeric- but not monomeric-tagged proteins due to insufficient electron density in monomeric proteins. Here, we present a technique for detecting monomeric 3MT-tagged green fluorescent protein (GFP-3MT) using a platinum compound to intensify the electron density. Substitution of cadmium by platinum as a result of incubating purified cadmium-binding 3MT-tagged GFP (GFP-Cd-3MT) with cis-diamminedichloroplatinum(II) (cisDDP) was assessed by a UV absorption band centered at 284?nm thereby indicating platinum-sulfhydryl bonds. The incubation time and the concentration of cisDDP to reach maximal absorption were 2?h and 36-fold molar equivalent of cisDDP, respectively. GFP-Pt-3MT isolated by gel filtration chromatography contained 29 platinum atoms per single GFP-3MT molecule. Electron-dense particles were observed in a GFP-Pt-3MT sample by electron microscopy without negative staining. Further image processing and image analysis demonstrated that particles with higher density relative to their surroundings were detectable in both GFP-Cd-3MT and GFP-Pt-3MT samples. These results demonstrate that replacement of cadmium with platinum, together with proper image analyses, improve detection efficiency and enable the visualization of 3MT-tagged monomeric protein by electron microscopy.     

Tilt-angle measurement of a sample stage using a capacitive liquid-based inclinometer

Alignment of projection images in tomographic reconstruction is a critical process that governs the quality of the reconstructed three-dimensional (3D) image. The most popular alignment method is the marker-based alignment, which typically uses colloidal gold particles added to the specimen (called fiducial markers) to calculate the coordinates of each projection image in the tilt series. This method, however, is not effective when each image contains only a small number of fiducial markers. Therefore, of all the parameters required for alignment, we focussed on the tilt angle and attempted to gage it directly in order to examine whether the acquired angle is accurate enough to perform tomographic reconstruction. We showed that the tilt angle measured using a commercially available capacitive liquid-based inclinometer is more precise than the reading from the monitor of the electron microscope and that it can lead to 3D reconstructions of quality similar to those obtained by the marker-based alignment method.     

Association analysis of the SmaI polymorphism of the dopamine D4 receptor in Japanese schizophrenics

Capture of rats by digging their cavities, identification of rat strains, sex and age, examination of their skin cut or damage, and detection of antigen and antibody of epidemic hemorrhagic fever virus (EHFV) were conducted in epidemic areas of epidemic hemorrhagic fever (EHF) in Jinaghan Plain, Hubei Province, to study prevalence of EHFV infection in rats. Results showed that Apodemus agarius and Rattus norvegius accounted for 69.7% and 23.6% of the total rats captured, respectively, their infection rates of EHFV were 21.8% and 30.9%, respectively. Infection rate of EHFV was significantly higher in adult rats than in sub-adult and young ones, with prevalence of 40.8%, 17.0% and 12.4%, respectively. Infection rate of EHFV was 45.9% in rats with skin cut, significantly higher than in those without it (13.9%). There was an obvious litter-clustering phenomenon in infected rats, but their litters distributed in space randomly. Serotyping of infected rats showed that Apodemus agarius mainly was in a wild rat pattern, Rattus norvegius in a domestic rat pattern, and a small number of rats were in undefined patterns. It indicated that Jinaghan Plain was a mixed epidemic area of EHF with domestic and wild rat patterns and with Apodemus agarius and Rattus norvegius as main reservoir host, and age, skin cut, and close contact with them were important factors contributing to transmit it.     

Complete amino acid sequence of chitinase-a from bulbs of gladiolus (Gladiolus gandavensis)

The complete amino acid sequence of gladiolus bulb chitinase-a (GBC-a) was determined. First the tryptic peptides from GBC-a after it was reduced and S-carboxymethylated were sequenced and then the peptides were further studied by chemical cleavage of the enzyme. GBC-a consisted of 274 amino acid residues and had a molecular mass of 30,714 Da. Two consensus sequences essential for chitinase activity by plant class III chitinases were conserved in GBC-a, although its sequence similarity with plant class III chitinases was less than 20%. Sequence comparison of GBC-a with sequences of other proteins in a protein identification resource (PIR) showed that the GBC-a sequence was 33% similar to that of narbonin, a seed storage 2S globulin from narbon beans.     

Identification of the aspartic acid residue located at or near substrate-binding site of rye seed chitinase-c

Two children with acquired immunodeficiency syndrome (AIDS) and progressive encephalopathy underwent MR spectroscopy before and after antiretroviral therapy. Initial MR spectroscopy of the basal ganglia region showed decreased N-acetylaspartate (NAA)/creatine (Cr) and a lactate peak. After therapy, there was improvement in NAA/Cr and an absence of the abnormal lactate peak. We suggest that decreased NAA/Cr in AIDS is reversible, that brain lactate might correlate with inflammation, and that MR spectroscopy can be useful in treatment trials.     

Novel materials for high-efficiency III–V multi-junction solar cells

As a result of developing wide bandgap InGaP double hetero structure tunnel junction for sub-cell interconnection, InGaAs middle cell lattice-matched to Ge substrate, and InGaP-Ge heteroface structure bottom cell, we have demonstrated 38.9% efficiency at 489-suns AM1.5 with InGaP/InGaP/Ge 3-junction solar cells by in-house measurements. In addition, as a result of developing a non-imaging Fresnel lens as primary optics, a glass-rod kaleidoscope homogenizer as secondary optics and heat conductive concentrator solar cell modules, we have demonstrated 28.9% efficiency with 550-suns concentrator cell modules with an area of 5445 cm². In order to realize 40% and 50% efficiency, new approaches for novel materials and structures are being studied. We have obtained the following results: (1) improvements of lattice-mismatched InGaP/InGaAs/Ge 3-junction solar cell property as a result of dislocation density reduction by using thermal cycle annealing, (2) high quality (In)GaAsN material for 4- and 5-junction applications by chemical beam epitaxy, (3) 11.27% efficiency InGaAsN single-junction cells, (4) 18.27% efficiency InGaAs/GaAs potentially modulated quantum well cells, and (5) 7.65% efficiency InAs quantum dot cells.