The preparation of Ln2MX5 where Ln = rare earths,M = Zr and Hf,and X = S,Se

Compounds of the title formula were prepared by reactions of the elements in evacuated silica tubes in the presence of iodine. The compounds formed for the following combinations: When M = Zr or Hf and X = S, all rare earths except Eu and Yb. When M = Zr and X = Se, rare earths between La and Tb, except Eu. When M = Hf and X = Se, rare earths La and Ce. X-Ray powder patterns were indexed on the basis of orthorhombic cells analogous to that of U₃S₅. Electrical measurements show high-resistivity semiconduction for La₂ZrS₅ and Ce₂HfS₅ but lower resistivity for Sm₂HfS₅, perhaps indicative of the presence of some Sm⁺².     

An experimental investigation of Lewis acid-base interactions of liquid carbon dioxide using Fourier Transform Infrared (FT-IR) spectroscopy

Presented here is an investigation into the solvent properties of liquid carbon dioxide by means of FT-IR spectroscopy. A high-pressure, circulation-type apparatus was designed and built specifically for this study. The spectra for the combination bands for carbon dioxide show that there are interactions between methanol and carbon dioxide. However, the spectra of the fundamental O-D vibration of deuterated methanol in liquid carbon dioxide indicate that there is no hydrogen bonding. Therefore. we conclude that the interactions between carbon dioxide and methanol are Lewis acid-base interactions rather than hydrogen bonding. This conclusion is supported by experiments where acetone is introduced into the CO₂/methanol-d binary system. FT-IR measurements show that acetone hydrogen bonds with deuterated methanol.Paper presented at the Twelfth Symposium on Thermophysical Properties, June 19–24, 1994, Boulder, Colorado, U.S.A.     

Cognitive ergonomics of a mail order filling company: Part 2--influence of shelf coding and address information on acquisition time

This is the second part of a study on a mail order picking task. In the first part of the study, recognition time was addressed by varying colour, position and highlighting cues in a computer-simulated version of the picking task. This study addresses the product acquisition time. Shelf coding and continuous presentation of the address information were varied in a factorial experiment in which 14 subjects (seven experts and seven novices) had participated. Experts were slower but more accurate than the novices. Continuous display of address information appears to be a good training aid for implementing new shelf coding systems, and for new operators. Shelf coding effect appears to disappear with practice. A summary of the recommendations is given.     

Heterogeneity of coronary flow reserve in the examination of multiple individual allograft coronary arteries

BACKGROUND: Epicardial and resistance vessel function in the transplanted heart has been evaluated primarily in regions supplied by a single vessel. Heterogeneity of flow among multiple perfusion fields as a marker of early endothelial dysfunction in the microcirculation has not been evaluated previously. This study tested the hypothesis that increased variability of coronary flow reserve (CFR) among multiple vascular regions would be associated with allograft coronary vasculopathy. METHODS AND RESULTS: One hundred six posttransplant patients undergoing cardiac catheterization had measurement of CFR in at least 3 major epicardial vessels. Patients were divided into those with minimal angiographic abnormalities (n=37) and those with no angiographic abnormalities (n=69). The ranges, coefficients of variation, and univariate and multivariate regression analyses of CFR were computed to determine the major clinical factors influencing the degree of variability. The abnormal angiographic group was older (54+/-11 versus 47+/-13 years; P<0.003), had older hearts (35+/-11 versus 27+/-10 years; P<0.005), and were further posttransplant (1626+/-1022 versus 931+/-984 days; P<0.0009). There was no difference in global CFR between groups (normal, 3.4+/-0.8 versus abnormal, 3.4+/-0.7; P=NS). The coefficient of variation of CFR was higher for the abnormal group (16.3+/-8.6% versus 11.0+/-5.5%; P<0. 0006). Univariate and multivariate predictors of increased variability in CFR included angiographic abnormalities, patient age, and body mass index. Both angiographic abnormalities and an elevated CV of CFR were predictive of a combined end point of death, congestive heart failure, or subsequent development of >/=50% coronary stenosis. CONCLUSIONS: These data demonstrate that increased variability of CFR is associated with discernible allograft coronary arteriopathy and is predictive of outcome in patients after heart transplantation.     

Comparative discrete element modelling of a vibratory sieving process with spherical and rounded polyhedron particles

Current spherical particle usage in discrete element modelling (DEM) is not able to accurately reflect the particle shape effect in some specific industrial applications. This study specifically investigated the effect of particle shape in discrete element modelling of a vibratory sieving process, with the focus on comparing results from spherical and non-spherical modelling methods. The particle size distribution of an iron ore material was initially obtained experimentally through vibratory sieving tests. An identical process was replicated in DEM with both spheres and non-spherical particles, and resulting particle size distributions were subsequently compared against the experimental results. A rounded polyhedron shape was utilised to calibrate and generate non-spherical particles based on a 2D particle shape characterisation process. Modelling results suggested that the rounded polyhedron method was able to accurately reflect the particle-sieve contacts without excessive rolling resistance tuning, which was required by the spheres.     

WISC-IV profiles in children with traumatic brain injury: Similarities to and differences from the WISC-III.

The Wechsler Intelligence Scale for Children—Fourth Edition (WISC–IV; D. Wechsler, 2003a) is often utilized to assess children with traumatic brain injury (TBI), although little information is available regarding its psychometric properties in these children. The current study examined WISC–IV performance in a sample of 61 children with TBI. As compared to the standardization sample, results indicated that the TBI group exhibited relative deficits on all subtest and index scores, with the greatest deficits on the Processing Speed Index (PSI) and Coding subtest scores. However, the Perceptual Reasoning Index score was not uniquely sensitive to brain injury, and the Cognitive Processing Index score was less sensitive to TBI than the PSI score. Also, the PSI did not uniquely predict learning and memory abilities, as had been reported in previous studies of the Wechsler Intelligence Scale for Children—Third Edition (WISC–III; D. Wechsler, 1991). The present findings indicate substantive differences between the WISC–III and WISC–IV profiles of children with TBI. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Atmospheric plasma‐aided biocidal finishes for nonwoven polypropylene fabrics. II. Functionality of synthesized fabrics

Atmospheric plasma‐aided graft copolymerization of textile materials provides single or multiple functionality polypropylene (PP) modified fabrics. Biocidal PP's are modified ones to kill or inhibit the growth of microorganisms such as bacteria, molds, and fungi, and insect and tick repelling action. Novel PP biocidal fabrics synthesized by graft copolymerization using plasma‐aided technique (see part I of this study) using antibacterial and insect repellent agents have been tested and evaluated and proved to be antimicrobial, tick repellent, and antistatic. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1911–1917, 2007     

The Uses and Challenges of Zeolites in Automotive Applications

This study gives an overview of zeolites used for hydrocarbon trapping, selective catalytic reduction of nitrogen oxides (NO_x) with NH₃ (NH₃-SCR) and hydrocarbon NO_x reduction applications. We also discuss challenges for the use of zeolites in these applications and the material properties that require improvement.