Compositional dependence of structural and thermal properties of AsTe amorphous alloys

Structural and thermal properties have been examined as a function of composition throughout the glass forming region of the AsTe binary system. The techniques of neutron activation analysis and thermogravimetric analysis were employed to quantitate the chemical composition. Density, x-ray diffraction, and bulk magnetic susceptibility were used to structurally characterize the glasses; the latter property was determined as a function of temperature from 4 to 300°K. The thermal transition temperatures and associated changes in enthalpy have been examined as a function of concentration by differential scanning calorimetry. Thermogravimetry and mass spectroscopy were used to determine the vaporization characteristics. Finally, evidence is presented to support the conclusion that a new face-centered cubic crystalline structure has the binary stoichiometry AsTe.     

An analysis of accuracy experiments carried out over of a multi-faceted model of trust

Trust models in internet environments today are single-faceted. A single-faceted approach to modelling trust can suit some, or many, individuals but we believe that such a single-faceted approach cannot capture the wide and varied range of subjective views of trust found across a large and broad population. In response, we have designed, developed and evaluated a rich, semantic, human-centric model of trust that can handle the myriad of terms and intertwined meanings of trust. This multi-faceted model of trust can be Personalised on a per user basis and specialized on per domain basis. In this paper we briefly present an overview of this model and explain how it can be Personalised and specialized. However, the primary focus of this paper is on the experimental evaluation that has been carried out to evaluate the accuracy of recommendations based on this multi-faceted, Personalised model of trust for internet environments.     

Comparison of bioactive peptides prepared from sheep cheese whey using a food‐grade bacterial and a fungal protease preparation

Novel bacterial (HT) and fungal (FPII) food‐grade protease preparations were evaluated for their ability to hydrolyse sheep cheese whey (SCW) and the generation of bioactive peptides. Both protease preparations hydrolysed the whey proteins to small peptides over 24‐h hydrolysis time, but the time course hydrolysis profiles were different as evaluated by SDS‐PAGE. The HT whey hydrolysate had considerably higher antioxidant and angiotensin‐I converting enzyme (ACE)‐inhibitor activity than the FPII hydrolysate. Neither hydrolysate was cytotoxic towards Vero cells. OFFGEL electrophoresis of the small peptide pool fraction (<15 amino acids) of each hydrolysate indicated differences in the pI distribution of the bioactive peptides. This likely reflects the diverse hydrolytic specificity of the proteases. Although the antioxidant activity of both hydrolysates was not significantly affected by simulated gastrointestinal digestion, the loss of ACE‐inhibitor activity was greater with the FPII hydrolysate.     

Influence of the concentration of CO2 and SO2 on the absorption of CO2 by a lithium orthosilicate-based absorbent

A novel, high temperature solid absorbent based on lithium orthosilicate (Li(4)SiO(4)) has shown promise for postcombustion CO(2) capture. Previous studies utilizing a clean, synthetic flue gas have shown that the absorbent has a high CO(2) capacity, >25 wt %, along with high absorption rates, lower heat of absorption and lower regeneration temperature than other solids such as calcium oxide. The current effort was aimed at evaluating the Li(4)SiO(4) based absorbent in the presence of contaminants found in typical flue gas, specifically SO(2), by cyclic exposure to gas mixtures containing CO(2), H(2)O (up to 25 vol. %), and SO(2) (up to 0.95 vol. %). In the absence of SO(2), a stable CO(2) capacity of ～ 25 wt % over 25 cycles at 550 °C was achieved. The presence of SO(2), even at concentrations as low as 0.002 vol. %, resulted in an irreversible reaction with the absorbent and a decrease in CO(2) capacity. Analysis of SO(2)-exposed samples revealed that the absorbent reacted chemically and irreversibly with SO(2) at 550 °C forming Li(2)SO(4). Thus, industrial application would require desulfurization of flue gas prior to contacting the absorbent. Reactivity with SO(2) is not unique to the lithium orthosilicate material, so similar steps would be required for other absorbents that chemically react with SO(2).     

A simple and efficient synthesis of fatty thioacids

A rapid and high-yielding two-step synthesis of fatty thioacids from readily available staring materials has been devised. In the first step, an acid chloride is reacted with thioacetic acid at room temperature to produce a mixed thioanhydride, which in the second step is nucleophilically deacetylated with propylamine or butylamine at 5°C. Each step is complete in five minutes and proceeds in quantitative yield. The versatility of the procedure is demonstrated by the synthesis of fatty thioacids from six to sixteen carbons in length.     

Vehicle-induced loads on traffic sign panels

The determination of the loads on traffic sign panels in the current standards does not, in general, take into account the vehicle-induced loads, as explained by Quinn, Baker and Wright (QBW in what follows) (J. Wind Eng. Ind. Aerodyn. 89 (2001) 831). On the other hand, a report from Cali and Covert (CC) (J. Wind Eng. Ind. Aerodyn. 84 (2000) 87) indicates that in highway sign support structures, vehicle-induced loads have led to premature failures in some cases. The aim of this paper is to present a mathematical model for the vehicle-induced load on a flat sign panel, simple enough to give analytical results, but able to explain the main characteristics of the phenomenon. The results of the theoretical model help to explain the behaviour observed in the experiments performed in previous studies.     

Vehicle induced loads on pedestrian barriers

This paper is a continuation of a previous one, Sanz-Andrés, Santiago-Prowald, Baker and Quinn (J. Wind Eng. Ind. Aerodyn. 91 (2003) 925) concerning the loads generated on a structural panel (traffic sign) by vehicle running along the road, although obviously, the results are also applicable to the effects of other moving vehicles such as trains. The structural panel was modelized as a large plate whose largest dimension is perpendicular to the vehicle motion direction. In this paper a similar approach is used to develop a mathematical model for the vehicle-induced load on pedestrian barriers, modelized as a large plate whose largest dimension is parallel to the vehicle motion direction. The purpose of the work is to develop a model simple enough to give analytical results, although with the physical phenomena correctly accounted for, such as to be able to explain, at least qualitatively, the main characteristics of the phenomenon, as observed in the experiments performed by Quinn et al. (J. Wind Eng. Ind. Aerodyn. 89 (2001) 831).Actually, in spite of the model simplicity, results of the theoretical model show a reasonable good quantitative agreement with the experimental results. The aim of this and previous publications is to provide to the transport infrastructure community with some simple tools that can help to explain, and in some cases also to compute, the unsteady loading produced by moving vehicles on persons and installations placed close to the roads or tracks.     

Relationship between blood lead concentrations and dietary lead intake in infants: the Glasgow Duplicate Diet Study 1979-1980

In 1979-1980 a duplicate diet study of 131 infants was carried out in Glasgow where the water was plumbosolvent and water lead levels were known to be often above 100 micrograms/l. The main aim of the study was to establish the form of the relationship between water lead, dietary lead and blood lead in infants. The study was designed so that there was a balanced number of measurements over a wide range of lead intakes. Blood lead concentrations of the mothers were measured as well as those of the infants. Results from the study showed that high values of lead in water, diet and blood were closely associated with each other. Blood lead concentrations appeared to have non-linear (cube root) relationships with water lead concentrations and dietary intakes of lead, with steadily smaller increases in blood lead as amounts or concentrations of ingested lead increased. However, infants who were wholly breast fed showed a much weaker effect of water lead on blood lead. Some diets had much higher lead concentrations than the water lead concentration would have suggested because they had been made up with water from the hot tap (rather than the kitchen cold water tap).     

Dechlorination of polychlorinated biphenyls using magnesium and acidified alcohols

Polychlorinated biphenyls (PCBs) were widely used in industry until their regulation in the 1970s. However, due to their inherent stability, they are still a widespread environmental contaminant. A novel method of degradation of PCBs (via hydrodehalogenation) has been observed using magnesium powder, a carboxylic acid, and alcohol solvents and is described in this paper. The rates of degradation were determined while varying the type of acid (formic, acetic, propionic, butyric, valeric, benzoic, ascorbic, and phosphoric), the amount of magnesium from 0.05 to 0.25 g, the amount of acetic acid from 0.5 to 50 μL and the concentration of PCB-151 from 0.1 to 50 μg/mL, as well as the alcohol solvent (methanol, ethanol, propanol, butanol, octanol, and decanol). The results of these studies indicate that the most rapid PCB dechlorination is achieved using a matrix consisting of at least 0.02 g Mg/mL ethanol, and 10 μL acetic acid/mL ethanol in which case 50 ng/μL of PCB-151 is dechlorinated in approximately 40 min.