Implementation of the moving particle semi-implicit method on GPU

The Moving Particle Semi-implicit (MPS) method performs well in simulating violent free surface flow and hence becomes popular in the area of fluid flow simulation. However, the implementations of searching neighbouring particles and solving the large sparse matrix equations (Poisson-type equation) are very time-consuming. In order to utilize the tremendous power of parallel computation of Graphics Processing Units (GPU), this study has developed a GPU-based MPS model employing the Compute Unified Device Ar...     

An adeno-associated viral vector transduces the rat hypothalamus and amygdala more efficient than a lentiviral vector

Background  

This study compared the transduction efficiencies of an adeno-associated viral (AAV) vector, which was pseudotyped with an AAV1 capsid and encoded the green fluorescent protein (GFP), with a lentiviral (LV) vector, which was pseudotyped with a VSV-G envelop and encoded the discosoma red fluorescent protein (dsRed), to investigate which viral vector transduced the lateral hypothalamus or the amygdala more efficiently. The LV-dsRed and AAV1-GFP vector were mixed and injected into the lateral hypothalamus or into the amygdala of adult rats. The titers that were injected were 1 × 10⁸ or 1 × 10⁹ genomic copies of AAV1-GFP and 1 × 10⁵ transducing units of LV-dsRed.     

Heat characteristics of chemical warfare agents

The heat characteristics of sulfur mustard (H), Lewisite (L), LI, LII, LIII, yellow agent (1:1 mass/mass H and L) and H heels were investigated by thermogravimetric - differential thermal analysis (TG-DTA). The object of this study was to provide details of the effectiveness of elevated temperature on the decomposition of these agents in both an active atmosphere (air) and an inert atmosphere (nitrogen). TG-DTA measured object mass change and heat radiation/absorption corresponding to regulated temperature changes of the test materials. All agents, with the exception of one of the H heels, exhibited an endotherm suggesting evaporation of the agents rather than oxidation.     

Indirect Photo-Induced Phosphorylation Via a C-Ester Caged Troika Acid

Abstract

Use of a photoremovable “caging” group allows the generation of reactive molecules under mild conditions. Photo-induced phosphorylations typically have involved attachment of the photosensitive group at phosphorus.[1] We now have investigated indirect photolytic activation of an unmodified phosphonic acid group using broad band UV (Hg lamp), 308 nm XeCl excimer laser or 355 nm YAC laser irradiation of the o-nitrobenzyl C-ester of “troika acid” [(E)-1²]. In alcohols or neutral buffer, irradiation of (E)-2 gave phosphorylation of the solvent plus phosphorocyanidate, the expected 2-isomer product.²All thrce UV sources gave -1:2 E:Z product distribution in MeOH. In the (E)-1 methyl C-ester, the oxime functionality absorbed strongly near 205 nm (E_max 5200), weakly at 308 nm and negligibly above 355 nm, and no photoisomerization was seen using the 355 nm source. Thus, oxime isomerization in (E)-2 at least using 355 nm irradiation. requires the o-nitrobenzyl group, and possibly involves an energy- or charge-wansfer effect. Phosphorylation of EtOH/t-BuOH mixtures by photolysis of (E)-2 showed little alkyl selectivity. consistent with photoinduced formation of an intermediate. plausibly (E)-1, which undergoes spontaneous dissociative fragmentation via a monomeric metaphosphate-like species.     

Carbon dioxide conversion to valuable chemical products over composite catalytic systems

This paper reports an experimental study on catalytic conversion of carbon dioxide to methanol,ethanol and acetic acid.Catalysts having different catalytic functions were synthesized and combined in different ways to enhance the selectivity to desired products.The combined catalyst system possessed the following functions:methanol synthesis,Fischer-Tropsch synthesis,water-gas-shift and hydrogenation.Results showed that the methods of integrating these catalytic functions played an important role in achieving the desired product selectivity.We speculate that if methanol synthesis sites were located adjacent to the C-C chain growth sites,the formation rate of C₂ oxygenates would be enhanced.The advantage of using a high temperature methanol catalyst PdZnAl in the combined catalyst system was demonstrated.In the presence of PdZnAl catalyst,the combined catalyst system was stable at 380°C.It was observed that,at high temperature,kinetics favored oxygenate formation.The results implied that the process can be intensified by operating at high temperature using Pd-based methanol synthesis catalyst.Steam reforming of the byproduct organics was demonstrated as a means to provide supplemental hydrogen.Preliminary process design,simulation,and economic analysis of the proposed CO₂ conversion process were carried out.Economic analysis indicates how ethanol production cost was affected by the price of CO₂ and hydrogen.     

The near-ground structure of the nocturnal sound field

The near-ground behavior of the low-frequency (100 Hz to 500 Hz) sound field in the nocturnal sound duct is studied theoretically and experimentally. In the first few meters of the atmosphere, narrow-band sound fields are found to have a characteristic vertical structure. The sound field is the superposition of a "surface mode," whose magnitude decreases monotonically with altitude, with a sum of "higher modes," each of whose magnitudes has a pronounced minimum a few meters from the ground at approximately the same height. The surface mode attenuates to negligible levels after a few hundred meters from the source. Consequently, more than a few hundred meters from a narrow-band source, there is a "quiet height" at which the sound level is reduced by 10 to 15 dB relative to its value on the ground. The narrow-band quiet height is shown to be a robust feature of nocturnal sound propagation.     

Search for disoriented chiral condensate in 158<Emphasis Type="Italic">A</Emphasis> GeV Pb+Pb collisions in WA98 experiment

The current status of the search for localized domains of disoriented chiral condensates (DCC) in Pb+Pb collisions at 158A GeV/c are presented. A new method based on the discrete wavelet transformation (DWT) technique along with an analysis of correlation between charged and neutral particles has been used for the search of localized DCC domains. We show that both the methods indicate the presence of non-statistical fluctuations in data.     

Simple Amides and Amines for the Synergistic Recovery of Rhodium from Hydrochloric Acid by Solvent Extraction

The separation and isolation of many of the platinum group metals (PGMs) is currently achieved commercially using solvent extraction processes. The extraction of rhodium is problematic however, as a variety of complexes of the form [RhCl_n(H₂O)_6-n]⁽ⁿ⁻³⁾⁻ are found in hydrochloric acid, making it difficult to design a reagent that can extract all the rhodium. In this work, the synergistic combination of a primary amine (2-ethylhexylamine, L^A) with a primary amide (3,5,5-trimethylhexanamide, L¹) is shown to extract over 85 % of rhodium from 4 M hydrochloric acid. Two rhodium complexes are shown to reside in the organic phase, the ion-pair [HL^A]₃[RhCl₆] and the amide complex [HL^A]₂[RhCl₅(L¹)]; in the latter complex, the amide is tautomerized to its enol form and coordinated to the rhodium centre through the nitrogen atom. This insight highlights the need for ligands that target specific metal complexes in the aqueous phase and provides an efficient synergistic solution for the solvent extraction of rhodium.