Degradation of photovoltaic backsheets: Comparison of the aging induced changes on module and component level

In reliability testing of components for PV modules an always remaining question is about material (in)compatibilities and synergistic effects and thus, how results of singly tested materials correlate with materials aged within PV modules. Testing of single materials would simplify sample preparation, reduce costs and offer more testing options. Therefore the main objective of this study was to compare the aging behavior of single backsheets with that of backsheets incorporated within PV modules. Four different types of backsheets were chosen, all of them comprising of polyethylene terephthalate (PET) core layers, but differing outer protection layers. Test modules using identical components, varying only in the type of backsheet used were produced and damp heat aged (85°C/85% RH ≤2000 h). The results revealed no influence of the PV module lamination on the thermal characteristics of the polymeric backsheets. Even after DH aging, differences between single and module laminated backsheets were negligible. Degradation effects of PET could be detected for all aged sheets by thermal analysis and were confirmed by tensile tests and rheological measurements. Thus, it can be stated that testing of single PET based backsheets under DH aging conditions is a practicable way to investigate the applicability of a new backsheet. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42093.     

Surveillance of Enteric Viruses and Microbial Indicators in the Eastern Oysters (Crassostrea virginica) and Harvest Waters along Louisiana Gulf Coast

Noroviruses are the most common causative agent of viral gastroenteritis in humans, and are responsible for major foodborne illnesses in the United States. Filter‐feeding molluscan shellfish exposed to sewage‐contaminated waters bioaccumulate viruses, and if consumed raw, transmit the viruses to humans and cause illness. We investigated the occurrence of norovirus GI and GII and microbial indicators of fecal contamination in the eastern oysters (Crassostrea virginica) and water from commercial harvesting areas along the Louisiana Gulf Coast (January to November of 2013). Microbial indicators (aerobic plate count, enterococci, fecal coliforms, Escherichia coli, male‐specific coliphages, and somatic coliphages) were detected at the densities lower than public health concerns. Only one oyster sample was positive for norovirus GII at 3.5 ± 0.2 log₁₀ genomic equivalent copies/g digestive tissues. A stool specimen obtained from an infected individual associated with a norovirus outbreak and the suspected oysters (Cameron Parish, La., area 30, January 2013) were also analyzed. The norovirus strain in the stool belonged to GII.4 Sydney; however, the oysters were negative and could not be linked. In general, no temporal trend was observed in the microbial indicators. Low correlation among bacterial indicators was observed in oysters. Strongest correlations among microbial indicators were observed between enterococci and fecal coliforms (r = 0.63) and between enterococci and E. coli (r = 0.64) in water (P < 0.05); however, weak correlations were found in oysters (r < 0.45) and between oysters and harvest water (r ≤ 0.36, P > 0.05). Our results emphasize the need for regular monitoring of pathogenic viruses in commercial oyster harvesting areas to reduce the risks of viral gastroenteritis incidences.     

Effectiveness of icing as a postharvest treatment for control of Vibrio vulnificus and Vibrio parahaemolyticus in the eastern oyster (Crassostrea virginica)

The focus of this research was to investigate the efficacy of icing as a postharvest treatment for reduction of the levels of Vibrio vulnificus and Vibrio parahaemolyticus in commercial quantities of shellstock oysters. The experiments were conducted in June and August of 2006 and consisted of the following treatments: (i) on-board icing immediately after harvest; (ii) dockside icing approximately 1 to 2 h prior to shipment; and (iii) no icing (control). Changes in the levels of pathogenic Vibrio spp. during wholesale and retail handling for 2 weeks postharvest were also monitored. On-board icing achieved temperature reductions in all sacks in accordance with the National Shellfish Sanitation Program standard, but dockside icing did not meet this standard. Based on one-way analysis of variance, the only statistically significant relationship between Vibrio levels and treatment occurred for samples harvested in August; in this case, the levels of V. vulnificus in the noniced oysters were significantly higher (P < 0.05) than were the levels in the samples iced on-board. When analyzing counts over the 14-day storage period, using factorial analysis, there were statistically significant differences in V. vulnificus and V. parahaemolyticus levels by sample date and/or treatment (P < 0.05), but these relationships were not consistent. Treated (iced) oysters had significantly higher gaping (approximately 20%) after 1 week in cold storage than did noniced oysters (approximately 10%) and gaping increased significantly by day 14 of commercial storage. On-board and dockside icing did not predictably reduce the levels of V. vulnificus or V. parahaemolyticus in oysters, and icing negatively impacted oyster survival during subsequent cold storage.     

Acidified sodium chlorite treatment for inhibition of Listeria monocytogenes growth on the surface of cooked roast beef

The effects of acidified sodium chlorite (ASC) against Listeria monocytogenes on the surface of cooked roast beef were investigated. L. monocytogenes, strain V7, serotype 1/2a, was inoculated at numbers of 6.0 log CFU/g onto 5-g cubes of cooked regular or spicy roast beef. The samples were allowed to air dry for 1 h. The cooked roast beef samples were dipped into ASC or sprayed with ASC solutions of 250, 500, 750, or 1,000 ppm, then placed in bags with or without a vacuum and refrigerated at 4 degrees C. L. monocytogenes counts were determined after 0, 7, 14, 21, and 28 days of storage by spread plating roast beef samples onto Oxford agar plates that were incubated at 37 degrees C for 48 h. At day 28, the number of L. monocytogenes on the > or = 500 ppm ASC-treated spicy roast beef samples had count reductions that were >4.0 log CFU/g, whereas the same concentrations of ASC-treated regular roast beef samples had approximately a 2.5 log CFU/g reduction in L. monocytogenes counts when compared with the untreated samples. No significant differences (P > 0.05) were observed in L. monocytogenes counts between the vacuum- or nonvacuum-packaged ASC-treated cooked roast beef samples. Sensory evaluation showed no significant differences (P > 0.05) between ASC-treated and untreated roast beef. ASC can be used as a processing aid in the form of a dip or spray treatment to control L. monocytogenes on the surface of cooked roast beef.     

Hyperbranched polymer/montmorillonite clay nanocomposites

Two to four pseudo-generation aliphatic hyperbranched polymers (HBPs) with -OH end-groups have been solution processed with various types of montmorillonite (MMT) layered alumino-silicate clays, and carefully dried to produce solid HBP/MMT nanocomposites. Exfoliated nanocomposites were obtained by processing the polyester HBPs with up to 20 wt% Na⁺ MMT in water, and intercalation only became dominant at higher loadings, for which the MMT layer spacing was directly dependent on the HBP pseudo-generation number. Intercalation was observed at much lower MMT contents in HBPs processed with different organically modified MMTs in THF. In this case, the absolute MMT layer spacings in the nanocomposites showed little apparent dependence on the nature of the organic modifier and the pseudo-generation number of the HBP, although the difference between the final layer spacing and its value prior to mixing increased significantly with the polarity of the organic modifier. The various HBP/MMT nanocomposites were incorporated into polyurethane formulations by melt processing in the presence of a low molar mass polyol or solution processing in THF. Na⁺MMT contents as low as 1.2 wt% led to an increase in the rubbery plateau modulus by about 60% with respect to that of the corresponding unfilled matrix, whereas much smaller relative increases were observed with unexfoliated or partly exfoliated MMT.     

Biocompatible/bioabsorbable silver nanocomposite coatings

A novel biomass‐mediated method to synthesize cellulose‐stabilized silver nanoparticles (SNPs) and incorporate them into biocompatible/bioabsorbable poly‐L ‐lactic acid (PLLA) for producing SNP–PLLA nanocomposite thin films was developed and the antimicrobial efficacy and biocompatibility of the SNP–PLLA films were studied. The formation and coating morphology of SNPs were characterized with UV–visible spectrophotometry and transmission electron microscopy (TEM), and the release rate of silver ion from the SNP–PLLA films was determined by inductively coupled plasma‐optical emission spectrometry. Antimicrobial testing of the SNP–PLLA films performed with Staphylococcus aureus and Escherichia coli according to ISO 22196 standards demonstrated that the SNP–PLLA nanocomposite films with a SNP concentration of 700 ppm reduced colonies forming unit (CFU) counts by 99.8 and 99.99%, respectively. Despite the significant antimicrobial activity, the nanocomposite films with the same SNP concentration had little effect on the viability of human HeLa cells. This strategy that has been developed for the synthesis of nanoparticles and the formation of composite films demonstrates promise for reducing perioperative surgical site infections associated with indwelling devices. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Alcoholism and judgments of affective stimuli.

This study sought to differentiate alcoholism-related changes in judgments of emotional stimuli from those of other populations in which such changes have been documented. Two sets of visual stimuli, one containing words and the other containing drawings of faces (representing a range of emotional content), were presented to abstinent alcoholic adults with and without Korsakoff's syndrome, as well as to a healthy control group and four groups of patients with other neurobehavioral disorders: Parkinson's disease, schizophrenia, depression, and posttraumatic stress disorder. Participants rated the stimuli according to emotional valence and intensity of emotion. Results implicated bi-hemispheric frontal and subcortical involvement in the abnormalities of emotion identification associated with alcoholism, and they also support the notion of age-related vulnerabilities in conjunction with alcoholism. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relational self-regulation: Gender differences in risk for dysphoria.

Examined gender differences in the level and psychological significance of discrepancy with own ideal standards (ISs) vs ideal standards held by parents and close others. 190 undergraduates completed the Selves Questionnaire, an interpersonal contingency beliefs measure, and the Beck Depression Inventory. Women showed higher levels of discrepancy with their own ISs than with the inferred ISs of parents and close others, suggesting that women may seek congruency with others' hopes and wishes at the price of failing to attain their own aspirations. Men showed equal levels of discrepancy with their own and significant-other ISs. Discrepancy with own ISs was associated with increased dysphoria in both men and women, but discrepancy with others' ISs was associated with significantly elevated levels of dysphoria only in women. Beliefs that failing to meet others' standards would result in abandonment and rejection contributed independently from discrepancy in predicting dysphoria. The findings suggest that the tendency to modulate affect, self-esteem and behavior from a relational perspective may increase risk for psychological distress. Women may be more likely to adopt this regulatory style as a function of their socialization experiences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparative Release of Phenylpropanolamine HC1 from Long-Acting Appetite Suppressant Products: Acutrim Vs. Dexatrim

The release of phenylpropanolamine HC1 from two commercially available long-acting appetite suppressant products, Acutrim and Dexatrim, was evaluated by using a dissolution apparatus modified from the well-calibrated Ghannam-Chien diffusion cells. The solubility profile of phenylpropanolamine showed extreme dependency on pH. The release of phenylpropanolamine from Acutrim tablets was observed to be fairly independent of pH and fluid dynamics, but is affected by the osmotic pressure in the dissolution medium. The release profiles of phenylpropanolamine from both Dexatrim and Acutrim were observed to consist of two stages: an initial, fast-release phase and a sustained-release phase at steady state. While both products achieve 100% release of the loading dose, the sustained-release portion of the phenylpropanolamine dose was observed to release from Acutrim tablets at zero-order kinetics over a 8-hr period, but showed a gradual dissolution from Dexatrim granules for over a 4-hr duration. Therefore, a prolonged release of phenylpropanolamine over the target 16-hr period was achieved by Acutrim tablets, but not by Dexatrim capsules.     

The use of olive mill wastewater by wild type Yarrowia lipolytica strains: medium supplementation and surfactant presence effect

BACKGROUND: The aim of this work was to study the ability of two different wild type strains of the yeast Yarrowia lipolytica to grow on olive mill wastewater (OMW) and their potential to produce high‐value products such as lipases. Factors that affect cellular growth and OMW degradation were studied, such as nitrogen supplementation, cells concentration and surfactant addition. RESULTS: Both strains, W29 and IMUFRJ 50682, were able to grow in OMW with 19 g L^?1 of COD and approximately 800 mg L^?1 of total phenols concentration. The strain W29 presented the highest potential for extracellular lipase production in OMW medium. Lipase productivity was improved by the medium supplementation with ammonium sulphate up to 6 g L^?1, leading to 80% of COD degradation and 70% of total phenols reduction. The surfactant Tween 80 enhanced cell growth and COD degradation, but had a negative effect on lipase activity. CONCLUSIONS Y. lipolytica has a great potential for OMW valorisation by its use as culture medium for biomass and enzymes production. The operating conditions that favoured lipase production differ from the conditions that improve COD reduction. Copyright © 2008 Society of Chemical Industry