Nanocrystallinity in RuO2 coatings—Influence of precursor and preparation temperature

The effects of precursor and calcination temperature on the nano morphology of ruthenium dioxide on titanium, prepared from thermal decomposition of aqueous salt solutions were investigated. Transmission electron microscopy, X-ray diffraction, gas porosimetry and cyclic voltammetry showed that lower calcination temperature yielded smaller crystallites. The crystallites were between 6 and 22 nm in diameter. When using ruthenium nitrosyl nitrate the firing temperature had a large impact on the grain size, but for chloride there was only a minor effect in the temperature range 350-550 °C.     

Reliability performance of safety instrumented systems: A common approach for both low- and high-demand mode of operation

Safety instrumented systems (SISs) are usually divided into two modes of operation, low-demand and high-demand. Unfortunately, this classification is not easy to justify and the available formulas that are used to quantify the reliability performance in these two modes of operation are unable to capture combined effects of functional testing, spurious activations, and successful responses to demands. This article discusses some important modeling issues for SIS reliability performance quantification, and demonstrates their implementation in a Markov model. The accuracy of the Markov model for a simple case study of a pressure transmitter is verified through comparison with a scenario-based formula, and it is shown that the Markov approach gives a sufficiently accurate result for all demand rates, covering both low- and high-demand modes of operation.     

Designing spaces for every listener

Inclusive design aims at objects and environments that are accessible, usable and comfortable for all people throughout their entire lifespan. In architecture, this aim is usually associated with physical accessibility. Yet acoustic qualities may considerably impact usability and comfort as well, especially in spaces for listening. This case study explores the notion of acoustic comfort for all in the context of university education. One auditorium, situated in a historic building and subject to renovation in the near future, is studied in detail: acoustic obstacles are identified in collaboration with user/experts and are measured in situ; specific interventions are proposed in consultation with building professionals, technicians and conservation specialists and are tested using dedicated acoustic simulation software. The study draws attention to the importance of acoustic comfort for all and offers a first view of which solutions are possible and desirable and how these can be obtained.     

Validity and reliability of the Lesbian, Gay, Bisexual Working Alliance Self-Efficacy Scales.

In this paper, the authors report on the development and initial psychometric evaluation of the Lesbian, Gay, and Bisexual Working Alliance Self-Efficacy Scales (LGB-WASES) with data collected from two studies and 534 counseling trainees. Exploratory factor analysis results yielded a 32-item scale with a three-factor model (a) Emotional Bond, (b) Establishing Tasks, and (c) Setting Goals. LGB-WASES scores were internally consistent and remained stable over a 3-week period. Construct validity evidence suggests the LGB-WASES scores were (a) positively related to general perceptions of counseling self-efficacy and multicultural counseling competency, (b) negatively related to attitudes toward lesbians and gay men, and (d) unrelated to social desirability. Recommendations for future research are also discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A study of diffusion in poly(ethyleneglycol)-gelatin based semi-interpenetrating networks for use in wound healing

Semi-interpenetrating networks (sIPNs) designed to mimic extracellular matrix via covalent crosslinking of poly(ethylene glycol) diacrylate in the presence of gelatin have been shown to aid in wound healing, particularly when loaded with soluble factors. Ideal systems for tissue repair permit an effective release of therapeutic agents and flow of nutrients to proliferating cells. Appropriate network characterization can, consequently, be used to convey an understanding of the mass transfer kinetics necessary for materials to aid in the wound healing process. Solute transport from and through sIPNs has not yet been thoroughly evaluated. In the current study, the diffusivity of growth factors and nutrients through the polymeric system was determined. Transport of keratinocyte growth factor was modeled by treating the sIPN as a plane sheet into which the protein was loaded. The diffusion coefficient was determined to be 4.86 × 10⁻⁹ ± 1.86 × 10⁻¹² cm²/s. Glucose transport was modeled as flow through a semi-permeable membrane. Using lag-time analysis, the diffusion coefficient was calculated to be 2.25 × 10⁻⁶ ± 1.98 × 10⁻⁷ cm²/s. The results were evaluated in conjunction with previous studies on controlled drug release from sIPNs. As expected from Einstein-Stokes equation, diffusivity decreased as molecular size increased. The results offer insight into the structure-function design paradigm and show that release from the polymeric system is diffusion controlled, rather than dissolution controlled.     

Effect of high-pressure/high-temperature processing on chemical pectin conversions in relation to fruit and vegetable texture

Heat sterilization of plant derived food products entails considerable organoleptic and nutritional quality losses. For instance, texture loss of fruits and vegetables occurs, next to turgor pressure losses, mainly due to chemical changes in the cell-wall pectic polysaccharides. High-pressure sterilization, i.e. the combination of high temperature (?90 °C) with high pressure (?500 MPa), could present a positive alternative assuring safety while minimizing quality losses. In this study, the potential of high-pressure sterilization in preserving fruit and vegetable texture was evaluated by investigating the effect of combined high-pressure/high-temperature (HP/HT) treatments on two texture related chemical pectin conversions in model sytems. First, a protocol was developed to perform reproducible kinetic studies at HP/HT under constant processing conditions. Subsequently, apple pectin solutions at pH 6.5 were subjected to different HP/HT combinations (500, 600 and 700 MPa/90, 110 and 115 °C) and the extent of chemical demethoxylation and β-eliminative depolymerization was determined. At atmospheric pressure, both zero-order reaction rate constants increased with increasing temperature. At all temperatures, demethoxylation showed a higher rate constant than β-elimination. However, a temperature rise resulted in a stronger acceleration of β-elimination than of demethoxylation. When combining high temperature with high pressure, β-elimination was retarded or even stopped, whereas demethoxylation was stimulated. These results are very promising in the context of the texture preservation of high-pressure sterilized fruits and vegetables, as β-elimination is accepted to be one of the main causes of thermal softening and low methoxylated pectin can enhance tissue strength by forming cross-links with calcium ions present.     

High Dietary Fat Exacerbates Weight Gain and Obesity in Female Liver Fatty Acid Binding Protein Gene-Ablated Mice

Since liver fatty acid binding protein (L-FABP) facilitates uptake/oxidation of long-chain fatty acids in cultured transfected cells and primary hepatocytes, loss of L-FABP was expected to exacerbate weight gain and/or obesity in response to high dietary fat. Male and female wild-type (WT) and L-FABP gene-ablated mice, pair-fed a defined isocaloric control or high fat diet for 12 weeks, consumed equal amounts of food by weight and kcal. Male WT mice gained weight faster than their female WT counterparts regardless of diet. L-FABP gene ablation enhanced weight gain more in female than male mice—an effect exacerbated by high fat diet. Dual emission X-ray absorptiometry revealed high-fat fed male and female WT mice gained mostly fat tissue mass (FTM). L-FABP gene ablation increased FTM in female, but not male, mice—an effect also exacerbated by high fat diet. Concomitantly, L-FABP gene ablation decreased serum β-hydroxybutyrate in male and female mice fed the control diet and, even more so, on the high-fat diet. Thus, L-FABP gene ablation decreased fat oxidation and sensitized all mice to weight gain as whole body FTM and LTM—with the most gain observed in FTM of control vs high-fat fed female L-FABP null mice. Taken together, these results indicate loss of L-FABP exacerbates weight gain and/or obesity in response to high dietary fat.