Financing for wind energy

This paper outlines the method used in Northern Ireland to finance the generation of electricity from renewable sources in general and wind power in particular.     

TRANSIENT THERMOELASTIC FRACTURE OF INTERFACE CRACKS

Abstract

The transient behavior of an interface crack at the center and edge of two finite dissimilar materials free to bend and subjected to a transient thermal load was studied. It was first assumed that the crack was insulated. The effect of allowing heat to conduct through the crack upon closing was also investigated. The effects of the mechanical and thermal material property ratios as well as the thickness ratio on the crack deformations and the transient strain energy release rate were calculated.     

Antimicrobial-resistant Salmonella serovars isolated from imported foods

A total of 187 Salmonella isolates representing 82 serotypes recovered from 4072 imported foods in the year 2000 by the U.S. Food and Drug Administration field laboratories were tested for their susceptibility to 17 antimicrobials of human and veterinary importance. Fifteen (8%) isolates were resistant to at least one antimicrobial, and five (2.7%) were resistant to three or more antimicrobials. Most of the isolates (n=9) exhibited resistance to tetracycline. Four isolates from catfish or tilapia from Taiwan or Thailand also demonstrated resistance to nalidixic acid. These nalidixic acid-resistant Salmonella isolates possessed a point mutation at the Ser83 or Asp87 position in DNA gryase, resulting in amino acid substitutions to phenylalanine, tyrosine, or asparagine. One Salmonella Derby isolated from frozen anchovies imported from Cambodia was resistant to six antimicrobials including ampicillin, amoxicillin/clavulanic acid, chloramphenicol, sulfamethoxazole, tetracycline, and trimethoprim/sulfamethoxazole. Of seven isolates displaying resistance to sulfonamides, only one S. Derby and one Salmonella Agona contained class 1 integrons that were further shown to possess the aadA and pse-1 genes conferring resistance to streptomycin and ampicillin, respectively. This study indicates that antimicrobial-resistant Salmonella are present in imported foods, primarily of seafood origin, and stresses the need for continued surveillance of foodborne zoonotic bacterial pathogens from imported foods entering the United States.     

Comparison of eight phenotypic methods for subspecies characterization of thermophilic Campylobacter spp. isolated from pig liver

Four hundred pork livers from bacon pigs (37 herds) obtained at six pig-processing plants were studied to assess the Campylobacter contamination rate. Deep tissue areas were sampled immediately after evisceration. Approximately 6% of livers were infected with Campylobacter spp., including Campylobacter coli (67%), Campylobacter jejuni (30%), and Campylobacter lari (3%). The 60 resulting isolates (39 C. coli isolates, 19 C. jejuni isolates, and 2 C. lari isolates) employed in this study were characterized at the subspecies level in a comparison of eight phenotyping schemes, including four biotyping, two serotyping, and two phage-typing schemes. The Skirrow-Benjamin biotyping scheme produced two biotypes for C. jejuni, i.e., biotype 2 (95%) and biotype 1 (5%). The Lior biotyping scheme subdivided C. coli into biotype 1 (41%) and biotype 2 (59%), while biotype 4 was the dominant type (95%) for C. jejuni. The Roop scheme allowed further differentiation of C. coli into three biovars, i.e., biovar 1 (57%), biovar 2 (40%), and biovar 3 (3%), and it subdivided C. jejuni into two biotypes, i.e., biovar 1 (95%) and biovar 2 (5%). Preston biotyping produced the largest degree of subspecies differentiation, with 18 C. coli biotypes and 7 C. jejuni biotypes being identified. The most common were biotypes 2650 and 6030, representing 18 and 42% of all C. coli and C. jejuni isolates, respectively. The Penner-Hennessy serotyping scheme successfully serotyped 89% of the isolates, with 10 serotypes being identified; 30% of the serotypeable isolates were accounted for by Penner 23, followed by Penner 20 (16%) and Penner 39 (14%). The Lior serotyping scheme successfully serotyped only 45% of the strains, and eight serogroups were identified, with Lior 36 (31%), Lior 20 (23%), and Lior 5 being the most frequent. The Preston scheme and the Khakhria-Lior phage-typing scheme were able to type 16 and 25% of the isolates, respectively. The Preston scheme produced three phage groups, i.e., 69 (56%), 90 (22%), and 116 (22%), and the Khakhria-Lior scheme also produced three phage types, i.e., 44 (40%), 27 (33%), and 37 (20%), as well as atypical lysis patterns (7%). The results of this study demonstrate the role of Preston biotyping in the phenotyping of isolates, particularly in diagnostic laboratories that have no access or limited access to molecular typing equipment.     

Effects of chilling rate on outgrowth of Clostridium perfringens spores in vacuum-packaged cooked beef and pork

Cooked, chilled beef and cooked, chilled pork were inoculated with three strains of Clostridium perfringens (NCTC 8238 [Hobbs serotype 2], NCTC 8239 [Hobbs serotype 3], and NCTC 10240). Inoculated products were heated to 75 degrees C, held for 10 min in a circulating water bath to heat activate the spores, and then chilled by circulating chilled brine through the water bath. Samples were chilled from 54.4 to 26.6 degrees C in 2 h and from 26.6 to 4.4 degrees C in 5 h. Differences in initial C. perfringens log counts and log counts after chilling were determined and compared with the U.S. Department of Agriculture (USDA) stabilization guidelines requiring that the chilling process allow no more than 1 log total growth of C. perfringens in the finished product. This chilling method resulted in average C. perfringens increases of 0.52 and 0.68 log units in cooked beef and cooked pork, respectively. These log increases were well within the maximum 1-log increase permitted by the USDA, thus meeting the USDA compliance guidelines for the cooling of heat-treated meat and poultry products.     

Biogeochemistry of nonylphenol ethoxylates in urban estuarine sediments

We have examined the concentrations and distributions of nonylphenol ethoxylate (NPEO) surfactants and their primary neutral metabolites in two dated sediment cores collected in 1988 and 1996 from a depositional area proximal to a wastewater treatment plant within Jamaica Bay, NY. Total NPEO concentrations ranged from >50 microg/g near the surface (4-6 cm, deposited ca. 1990) to below detection limits (<0.1 microg/g) at 50 cm depth (deposited ca. 1940). The general decrease in NPEO concentrations with increasing depth in sediment reflected increased commercial use of these compounds over the last 50 yr. NPEO ethoxymer distributions in recent sediments were dominated by NP(0-3)EO, consistent with the increased relative input of these particular ethoxymers to the estuary following the upgrade of local biological sewage treatment processes to full activated sludge in the late 1970s. NPEO ethoxymer profiles in deeper sediments were characterized by relatively higher proportions of unmetabolized, highly ethoxylated NPEOs. Depth profiles of NP1EO and NP in the upper portion of the sediment core showed evidence for in situ diagenetic conversion of NP1EO to NP. However, comparison of NPEO concentrations in selected strata from the core collected in 1996 with those in matched strata from a core collected from the same location in 1988 provided no evidence for in situ degradation of total NPEOs during the elapsed 8 yr between collection dates.     

Construction and preliminary evaluation of an Aspergillus flavus reporter gene construct as a potential tool for screening aflatoxin resistance

Effective preharvest strategies to eliminate aflatoxin accumulation in crops are not presently available. The molecular biology of aflatoxin biosynthesis has been extensively studied, and genetic and molecular tools such as reporter gene systems for the measurement of fungal growth have been developed. A reporter construct containing the Aspergillus flavus beta-tubulin gene promoter fused to Escherichia coli beta-glucuronidase (GUS) has been shown to be a reliable tool for the indirect measurement of fungal growth in maize kernels. Since cost-saving alternative methods for the direct measurement of aflatoxin levels are needed to facilitate more widespread field and laboratory screening of maize lines, a new reporter gene construct involving the promoter region of the omtA gene of the aflatoxin biosynthetic pathway was constructed and tested. Expression of GUS activity by this construct (omtA::GUS) was correlated with aflatoxin accumulation in culture. In the fungal transformant GAP26-1, which harbors this construct, aflatoxin production and GUS expression on sucrose-containing medium showed the same temporal pattern of toxin induction. Furthermore, GUS expression by GAP26-1 was shown to be associated with aflatoxin accumulation in maize kernels inoculated with this strain. Our results suggest that this and other reporter gene pathway promoter constructs may provide superior alternatives to direct aflatoxin quantification with respect to time, labor, and materials for the screening of maize lines for resistance to aflatoxin accumulation.     

Lithium bis(fluorosulfonyl)imide-PYR14TFSI ionic liquid electrolyte compatible with graphite

Lithium bis(fluorosulfonyl)imide (LiFSI) in 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR₁₄TFSI) was successfully tested as an electrolyte for graphite composite anodes at elevated temperature of 55 °C. The graphite anode showed a good cyclability during the galvanostatic testing at C/10 rate and 55 °C with the capacity close to theoretical. The formation of SEI in different electrolytes was the subject of study using impedance spectroscopy on symmetrical cells containing two lithium electrodes. The 0.7 m LiFSI in PYR₁₄TFSI exhibits a good ionic conductivity (5.9 mS cm⁻¹ at 55 °C) along with high electrochemical stability and high thermal stability. These properties allow their potential application in large-scale lithium ion batteries with improved safety.     

Environmental Risks Associated with Beneficial End Uses of Mine Lakes in Southwestern Australia

Abstract  Lakes develop when pits from open cut mines are left to fill with groundwater. In recent years, mining companies, mining communities, and regulatory agencies have begun to consider potential beneficial end uses for mine lakes. Beneficial end uses are unlikely to be without environmental impacts, however, and a proper consideration of the total benefit to the community should consider them. This paper briefly reviews potential beneficial end uses and possible environmental impacts that might arise with them for mine lakes in the Collie Basin, a coal mining region in Western Australia. We identified eight distinct, but not necessarily incompatible, end uses from a search of the literature on mine lakes throughout the world: recreation and tourism, wildlife conservation, aquaculture, irrigation, livestock water, potable water, industrial water, and chemical extraction. Recreation, conservation, and possibly aquaculture use the mine lake directly, whereas the other end uses utilise extracted water. All end uses have the potential to have environmental effects, with the most common being an actual or perceived impact on human health and safety. A semi-quantitative risk assessment, using published literature sources, identified wildlife conservation as the end use with the least environmental risk, and irrigation as the end use with the greatest environmental risk. Such risks need to be balanced against economic and social benefits. There is an urgent need for a regulatory framework to address mine lake options.