STATISTICAL ANALYSIS OF ORGANOSULFUR EXTRACTION DATA OF OHIO 5/6 COAL USING THE PERCHLOROETHYLENE COAL CLEANING PROCESS

ABSTRACT

The perchloroethylene coal cleaning process removes both organic and pyritic forms of sulfur using perchloroethylene as the solvent medium. The effect of process variables including temperature, extraction time, solvent to coal ratio and particle size of coal has been studied by a systematic 2⁴ full factorial experimental design with a single replicate. The process was found to be strongly dependent on the type of coal. Hence, this variable was controlled by choosing one single type of coal, i.e., Ohio 5/6 (1:1 mixture of Ohio 5 and Ohio 6 coals) throughout this entire investigation. The significant effects and interactions have been quantified by F-tests. The estimates of significant effects have been obtained by Yates algorithm. Residual probability and normal probability plots have been obtained to test model adequacy. Finally, a computational model has been developed to predict the organosulfur extraction efficiency of this coal at various values of process variables. The parity plots conclude that the model has a good interpolational predictive capability.     

Inhibitory tagging in inhibition of return is affected in schizophrenia: Evidence from the Stroop task.

L. J. Fuentes, A. B. Vivas, and G. W. Humphreys (see record 1999-10305-007) showed that stimulus processing is affected when stimuli are presented to locations subject to inhibition of return. They argued that activated representations of stimuli presented at inhibited locations are disconnected from their associated responses through an "inhibitory tagging" mechanism occurring in inhibition of return. In the present research, the authors asked whether such a mechanism is affected in people with schizophrenia. Healthy adults and patients with schizophrenia performed a Stroop task in an inhibition of return paradigm. Healthy adults showed a reduction in the Stroop interference when stimuli were presented at inhibited locations, a result that agrees with the inhibitory tagging mechanism hypothesis and replicates previous findings. However, patients with schizophrenia did not show such a reduction, a result suggesting that they have a deficit in inhibitory processing occurring in inhibition of return. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of DMBA Preparation on DMBA-Induced Rat Mammary Carcinogenesis

We compared two protocols for 7,12-dimethylbenz[ a ]anthracene (DMBA)-induced mammary carcinogenesis. DMBA (20 mg/ml) was prepared at room temperature or at 60°C and administered by gavage to 50-day-old Sprague-Dawley rats. Two days post-DMBA, mammary epithelial DNA was 32 P-postlabeled. At 12 weeks post-DMBA, tumor DNA was screened for H- ras codon 61 mutations using an enriched polymerase chain reaction (EPCR). The number of in situ carcinomas (3.0 - 2.7 vs. 2.5 - 2.7), invasive carcinomas (1.1 - 1.6 vs. 0.6 - 0.8), and H- ras codon 61 mutations (34 - 13% vs. 23 - 13%) were statistically not different ( p = 0.05) between the groups. The relative adduct levels in mammary organoids were significantly ( p h 0.001) greater in the 60°C (568 - 158) than the room temperature (150 - 130) group. While DMBA-DNA adduct levels differed significantly between these protocols, this did not correlate with significant differences in tumor pathologies or H- ras codon 61 mutations.     

The Discovery of Potent Nonstructural Protein 5A (NS5A) Inhibitors with a Unique Resistance Profile—Part 2

In ongoing studies towards novel hepatitis C virus (HCV) therapeutics, inhibitors of nonstructural protein 5A (NS5A) were evaluated. Specifically, starting from previously reported lead compounds, peripheral substitution patterns of a series of biaryl‐linked pyrrolidine NS5A replication complex inhibitors were probed and structure–activity relationships were elucidated. Using molecular modelling and a supercritical fluid chromatographic (SFC) technique, intramolecular H‐bonding and peripheral functional group topology were evaluated as key determinants of activity and membrane permeability. The novel compounds exhibited retained potency as compared with the lead compounds, and also showed promising results against a panel of resistance viruses. Together, the results of the study take us a step closer towards understanding the potency of daclatasvir, a clinical candidate upon which the compounds were based, and to designing improved analogues as second‐generation antiviral agents targeting NS5A.     

Measurement and analysis of angle-resolved scatter from small particles in a cylindrical microchannel

Scatter of a two-dimensional Gaussian beam of a rectangular cross section by individual particles suspended in a fluid in a cylindrical channel is modeled by using a full-wave approach. First, the internal and scattered fields associated with the cylindrical channel and the two-dimensional Gaussian beam are computed. The spatial variations of the computed electromagnetic field inside the channel indicate that particles and cells of sizes relevant to flow cytometry are subjected to essentially plane-wave illumination, and hence Lorenz-Mie theory is applicable for spherical particles. Further, it is assumed that the perturbation of the electromagnetic field in the channel that is due to the presence of a particle is negligible, allowing us to ignore the interactive scatter of the particle and the channel (they are electromagnetically uncoupled). This approximation is valid when the particle intercepts a small fraction of the total energy inside the channel and when the particle or cell has a low relative refractive index. Measurements of scatter from the channel agree with the analytical model and are used to determine the location of detectors to measure scatter from particles in the channel. Experimental results of accumulated scatter from single latex spheres flowing in the channel show good agreement with computed results, thereby validating the internal field and uncoupled scatter models.     

Simulation du retrait thermique à basse température et de la fissuration transversale d'une chaussée recyclée par Retraitement à Haute Performance (RHP)

Résumé Au Canada, les refroidissements hivemaux et les contractions thermiques qu'ils génèrent dans les couches des chaussées sont souvent à l'origine d'une fissuration transversale sévère. Cet article définit un modèle numérique destiné à simuler la fissuration transversale d'origine thermique de chaussées semi-rigides. Il s'intéresse en particulier à l'analyse de la fissuration transversale de chaussées semi-rigides recyclées par Retraitement à Haute Performance (RHP). Le modèle permet une analyse globale de la fissuration d'origine thermique. Les simulations qu'il permet de réaliser montrent l'importance des propriétés mécaniques et thermiques de la couche de base et du sol lorqu'ils sont gelés. Elles montrent par ailleurs l'existence d'une relation entre le pas, la profondeur et l'ouverture des fissures.

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Simulation of thermal shrinkage at low temperature and of transverse cracking of a high performance recycled pavement

In Canada, thermal contraction in pavement layers during winters often lead to severe transverse cracking. This article describes a numerical model intended to simulate the thermal cracking of semi-rigid pavements. Analyses were conducted on High Performance Recycled (HPR) pavements. The model allows to conduct a global analysis of the thermal cracking phenomena. Simulations show the importance of mechanical and thermal properties of the base course materials and of subgrade soils when they are frozen. The model also shows that there is a relationship between crack depth, crack opening and crack spacing.

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Note éditoriale Le CERIB et l'Université Laval sont Membres Titulaires de la RILEM.     

Seal glass compatibility with bare and (Mn,Co)3O4 coated AISI 441 alloy in solid oxide fuel/electrolyzer cell atmospheres

To understand seal glass compatibility with interconnect materials in solid oxide fuel/electrolyzer cell environments, a SrO–La₂O₃–Al₂O₃–SiO₂ (SABS-0) seal glass is bonded with bare AISI 441 alloy and (Mn,Co)₃O₄ coated AISI 441 alloy; the bonded samples are thermally treated in air and H₂/H₂O atmospheres at 800 °C for 1000 h. Alloy oxidation, diffusion of the AISI 441/SABS-0 sample elements, chemical reaction, (Mn,Co)₃O₄ coating stability, and SABS-0 glass devitrification contribute to the interfacial interaction. The interfacial compatibility with the bare AISI 441 alloy is better than with the (Mn,Co)₃O₄ coated AISI 441 alloy. The thermal treatment atmospheres have no significant effect on the interfacial stability for the bare AISI 441alloy. For the (Mn,Co)₃O₄ coated AISI 441 alloy, the interfacial stability is better in the H₂/H₂O atmosphere.     

Rheological behavior of carbon nanotube-alumina nanoparticle dispersion systems

In this work, Al₂O₃ nanoparticle and CNT-Al₂O₃ nanoparticle suspensions were studied. Both Al₂O₃ nanoparticle and CNT-Al₂O₃ nanoparticle systems exhibit shear-thinning behavior. The viscosities increase monotonically with the suspension solids loading. For the 40 vol.% solids loading suspension, CNT effect on the viscosity is not substantial until the content is ≥ 1.3 vol.%. The suspension yield stress to flow provides a measure of the particle-particle networking in the suspension. With the adsorbed poly(acrylic acid) (PAA) layer on the particle surface, substantial colloidal interactions are observed when the solids loading is > 35 vol.% and the CNT content is > 1.3 vol.%. Storage modulus and loss modulus can be used to understand the relative magnitude of the viscoplastic behavior and the elastic behavior of the suspension as well as the transition between the two. The relative magnitude of the dynamic modulii is a strong function of the solids loading and the CNT content.     

1000BASE-T千兆以太网双绞线收发技术

目前,1000BASE-T双绞线收发模块已被广泛应用在千兆以太网中,它能在现有5类双绞线中实现千兆位传输,将传统10/100M以太网连接平滑升级到千兆以太网,大大降低了以太网升级成本。光通信模块制造商飞博创公司已在国内领先推出具有自动协商功能的1000BASE-T双绞线收发模块,该收发模块采用世界流行的SFP迷你封装,能广泛应用于国内外著名厂商提供的千兆以太网通信产品中。千兆以太网传输技术IEEE802.3协议族规范了4种媒质可以承载千兆以太网的传输(图1),表1则列出了信号在这4种媒质中的传输距离。1000BASE-T技术以其简单和低廉的升级方…     

Polymer-Derived High-Temperature Nonoxide Materials: A Review

This review is focused on an attractive class of polymer-derived high-temperature ceramics, namely, polymer-derived nonoxide materials. With a brief introduction of high-temperature nonoxides, the origin of using polycarbosilane (PCS) polymer melt spinning to synthesize silicon carbide (SiC) fibers is traced back. For SiC formation, the four stages for the conversion from polymer precursors to microcrystalline ceramics are examined first: crosslinking, polymer decomposition, ceramic formation, and crystallization. Also, the important parameters related to PCS pyrolysis are explained, and polymer-derived SiC microstructures and compositions are evaluated. Solid-solution carbides and transition metal carbides are further reviewed. For boride materials, the discussion is focused on transition metal borides and boride composites. Similar to PCS conversion to SiC, nitride materials mostly start with polycarbosilazane (PSZ) precursors and form into the final materials through pyrolysis. With different carbide and nitride precursors mixed and pyrolyzed together, high-temperature nonoxide composites are formed. Such molecular-level intermixing and versatile capability of forming different shapes enable many exciting properties. Among these are mechanical and thermal properties, along with electrical conductivity, electromagnetic shielding, and charge storage capability. An overview of applications of polymer-derived nonoxides is provided, followed by a summary and outlook.