Enhancement of the Activities of γ-Ga<Subscript>2</Subscript>O<Subscript>3</Subscript>–Al<Subscript>2</Subscript>O<Subscript>3</Subscript> Catalysts for Methane-SCR of NO by Treatment with NH<Subscript>3</Subscript>

Abstract  

The precursor particles for γ-Ga₂O₃–Al₂O₃ solid solutions were prepared by the coprecipitation method from aqueous solutions of Ga(NO₃)₃ and Al(NO₃)₃ with (NH₄)₂CO₃ as a precipitant. The γ-Ga₂O₃–Al₂O₃ solid solutions were obtained by calcination of the precursor at 700 °C. In this paper, the performance of the catalysts treated with NH₃ was investigated for the selective catalytic reduction (SCR) of NO with methane as a reducing agent, and it was found that γ-Ga₂O₃–Al₂O₃ catalysts treated with NH₃ and subsequently annealed in air showed higher activities than the γ-Ga₂O₃–Al₂O₃ catalysts without NH₃ treatment. NH₃ treatment of the catalyst caused partial rearrangement of Ga³⁺ and Al³⁺ ions and increased the population of tetrahedral Ga³⁺ ions in the defective spinel structure.     

Permeability of synthetic poly(α-amino acid) membranes to oxygen dissolved in water

Membranes of synthetic poly(α-amino acids), namely, poly(γ-methyl L -glutamate) (PMLG), poly(γ-benzyl L -glutamate) (PBLG), poly(L -glutamic acid) (PLGA), poly(L -methionine) (PLM), and poly(N^?-carbobenzoxy-L -lysine) (PCLL), were prepared and their permeabilities of oxygen dissolved in water were measured in the 8–50°C temperature range using an oxygen electrode. Permeation curves for the poly(α-amino acid) membranes did not approach steady-state currents because of membrane degradation. To eliminate this, the membranes were laminated between polystyrene membranes; thus, the poly(α-amino acid) membranes came in direct contact with neither cathode surface nor electrolyte solution. No effect of membrane thickness on the permeability was observed. The Arrhenius plots of permeability coefficients for PCLL appear to change slope at about 22°C. This is consistent with the diffusion of oxygen in PCLL through the side-chain regions between helices. Comparisons between the permeability of oxygen dissolved in water and permeability of gaseous oxygen obtained by the high-vacuum method and between the activation energy of permeation of dissolved oxygen and that of gaseous oxygen were made in order to elucidate the effect of water on the oxygen permeation of each polymer. The permeability of the poly(α-amino acid) membranes to dissolved oxygen appears to depend on the properties of the side chains of the polymers.     

Isolation of a serotype G6P11 bovine rotavirus showing two-way cross-neutralization with the serotype G10P11 virus

Four stains designated as OB94-1 to OB94-4 of group A bovine rotavirus (BRV) were isolated from 35 fecal samples of calves with diarrhea in sporadic outbreaks. In VP7 (G) and VP4 (P) serotyping of these isolates, OB94-1 to OB94-3 were determined as G6P5, G6P5 and G10P5, respectively, by cross neutralization (NT) test and the G- and P- serotyping polymerase chain reaction (PCR) analysis. OB94-4 showed a one-way antigenic relation with the Lincoln stain (G6P1) and a weak antigenic relationship with the KK3 strain (G10P11), and was determined as G6P11 by the PCR method. Thus, OB94-4 was shown to be a new G6 BRV with different antigenic properties from the others in the NT test.     

Decision-Making Deficits of Korsakoff Patients in a New Gambling Task With Explicit Rules: Associations With Executive Functions.

Decision-making deficits reflected by risky decisions in gambling tasks have been associated with frontal lobe dysfunctions in various neurologic and psychiatric populations. The question remains whether decision-making impairments are related to executive functions. The authors developed a new gambling task, the Game of Dice Task, with explicit and stable rules for reinforcement and punishment, to investigate relations between executive functions and risk-taking behavior in an explicit decision-making situation. A sample of 35 alcoholic Korsakoff patients and 35 healthy controls was examined with the Game of Dice Task and a neuropsychological test battery. Results show that Korsakoff patients are strongly impaired in this explicit decision-making task and that these disturbances are correlated with specific executive functions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Automatic 3-D grayscale volume matching and shape analysis.

Recently, shape matching in three dimensions (3-D) has been gaining importance in a wide variety of fields such as computer graphics, computer vision, medicine, and biology, with applications such as object recognition, medical diagnosis, and quantitative morphological analysis of biological operations. Automatic shape matching techniques developed in the field of computer graphics handle object surfaces, but ignore intensities of inner voxels. In biology and medical imaging, voxel intensities obtained by computed tomography (CT), magnetic resonance imagery (MRI), and confocal microscopes are important to determine point correspondences. Nevertheless, most biomedical volume matching techniques require human interactions, and automatic methods assume matched objects to have very similar shapes so as to avoid combinatorial explosions of point. This article is aimed at decreasing the gap between the two fields. The proposed method automatically finds dense point correspondences between two grayscale volumes; i.e., finds a correspondent in the second volume for every voxel in the first volume, based on the voxel intensities. Mutiresolutional pyramids are introduced to reduce computational load and handle highly plastic objects. We calculate the average shape of a set of similar objects and give a measure of plasticity to compare them. Matching results can also be used to generate intermediate volumes for morphing. We use various data to validate the effectiveness of our method: we calculate the average shape and plasticity of a set of fly brain cells, and we also match a human skull and an orangutan skull.     

Sunlight mutagenesis: changes in mutational specificity during the irradiation of phage M13mp2

BACKGROUND: The accumulation of fibrillar deposits of amyloid beta-peptide (Abeta) in brain parenchyma and cerebromeningeal blood vessels is a key step in the pathogenesis of Alzheimer's disease. In this report, polymerization of Abeta was studied using fluorescence correlation spectroscopy (FCS), a technique capable of detecting small molecules and large aggregates simultaneously in solution. RESULTS: The polymerization of Abeta dissolved in Tris-buffered saline, pH 7.4, occurred above a critical concentration of 50 microM and proceeded from monomers/dimers into two discrete populations of large aggregates, without any detectable amount of oligomers. The aggregation showed very high cooperativity and reached a maximum after 40 min, followed by an increase in the amount of monomers/dimers and a decrease in the size of the large aggregates. Electron micrographs of samples prepared at the time for maximum aggregation showed a mixture of an amorphous network and short diffuse fibrils, whereas only mature amyloid fibrils were detected after one day of incubation. The aggregation was reduced when Abeta was incubated in the presence of Abeta ligands, oligopeptides previously shown to inhibit fibril formation, and aggregates were partly dissociated after the addition of the ligands. CONCLUSIONS: The polymerization of Abeta is a highly cooperative process in which the formation of very large aggregates precedes the formation of fibrils. The entire process can be inhibited and, at least in early stages, partly reversed by Abeta ligands.     

Double-island single-electron devices. A useful unit device forsingle-electron logic LSI's

We fabricated a single-electron device that is useful as a unit device for single-electron logic circuits. The device is a three-current-terminal device fabricated on a silicon-on-insulator (SOI) wafer, which includes two Si islands whose electric potential can be controlled by gates. Sub-50-nm Si islands were integrated in an area smaller than 0.02 μm² through self-aligned formation of the islands by pattern-dependent oxidation (PADOX) of a T-shaped wire. By PADOX, each island was embedded in one branch of the T-shaped wire. We show two electrical characteristics which demonstrate the usefulness of this device as a circuit element. First, current switching between two branches was performed at 30 K by using gate voltage to control the Coulomb blockade in each island. Second, a correlation between the two currents was observed because the two islands were integrated close to each other. The latter indicates a capacitive coupling between the islands, which opens up the possibility of one-by-one transfer of electrons in this device. These findings show that the proposed island-integration technique is applicable to making ultra-low-power and highly integrated single-electron circuits     

Depression of proton conductivity in recast Nafion film measured on flat substrate

The proton conductivity of recast Nafion^® thin films in the lateral direction (parallel to the interface) was measured in humidified atmospheres. The conductivity decreased with a decrease in the thickness of the film: e.g., the conductivity of a film with a thickness of about 100 nm was about an order of magnitude less than that of the bulk material. The dependence of the conductivity on temperature was also measured, and a thinner film showed a higher apparent activation energy for conduction. Since both the conductivity and the apparent activation energy for conduction were affected by the thickness, these phenomena may be due to an intrinsic change in the material. Based on the fact that the apparent activation energy for conduction in the bulk membrane under dry conditions is high, the high apparent activation energy for conduction in thin films may be due to the hindrance of water adsorption.     

Estimating Hg emissions from coal-fired power stations in China

Mercury emissions from Chinese power stations are subject to large uncertainties because Hg speciation data have only been reported for a few stations. This communication presents an evaluation of predicted Hg removals at five Chinese plants based on reaction mechanisms developed and validated for the coals and gas cleaning conditions in the American utility industry. Whereas the reported speciation data represent considerable ranges of coal quality, furnace rating, firing configuration, and flyash collection with both ESPs and fabric filters, mercury removals are predicted within the measurement uncertainties in four of five cases.