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991.
The Jackfish Bay Remedial Action Plan is the first of Lake Superior's Areas of Concern (AOCs) to consider recognition as an Area in Recovery (AiR). As a result of a high degree of complexity and uncertainty, ecosystem recovery in Jackfish Bay has been determined using a combination of regulatory policies and scientific evidence and extensive public and expert-based decision making. As a result, the conceptualization of the AiR status in Jackfish Bay has been developed with the adaptive management and the ecosystem approach, which provide the basic principles of assessing, monitoring, and managing the Area of Concern. To determine the status of beneficial use impairments caused by effluent from the Terrace Bay Pulp Inc., three public advisory committees—an academic panel of experts, a government technical review committee, and the Jackfish Bay Public Area in Recovery Review Committee (PARRC)—reviewed relevant scientific data and documents, including peer-reviewed publications, to assess changes in pollution levels in Jackfish Bay and improvements to aquatic, biotic, and benthic environments of the bay. The public decision-making process concluded with recommendations by the PARRC to develop a systematic monitoring program so that the ecosystem recovery process in the bay could be assessed on a continued basis, leading to its eventual delisting as an AOC. The entire process provides an example of blending science and public policies for remediation of a degraded ecosystem on the Great Lakes. 相似文献
992.
Every electrical system component must have recognizable predictable characteristics in order to be usable in today's modern electrical distribution system. The use of busways for power distribution in commercial and industrial buildings has become very popular in recent years due, in part, to the fact that it offers the requisite proven predictable electrical and mechanical characteristics. This allows the distribution system designer to use busway with confidence that it will perform as he intends. Of the many electrical and mechanical characteristics which must be evaluated, the busway short circuit rating has become one of the most important. This increased importance is the result of larger electrical services and lower loss supply equipment creating significant increases in available short circuit current levels. In addition, the present cost of equipment failure is at an all-time high. It is certainly better to spend a little extra (whether time or money) in the design and construction stages to provide maximum system performance under all conditions including possible short circuits. 相似文献
993.
In the testing of mine monitoring systems, a software package was developed for the mine monitoring test facility designed at West Virginia University. The software establishes delay times of sensor input to annunciation for single alarms and multiple simultaneous alarms. The alarm measurement techniques for the test fixture are described, as is the software developed to analyze and graph monitoring system response data. Also included is the analysis capability of the facility, the criteria for evaluating mine monitoring systems, and typical test data from a sample system. 相似文献
994.
Bose Bimal K. Szczesny Paul M. Steigerwald Robert L. 《Industry Applications, IEEE Transactions on》1985,(5):1182-1191
Microcomputer-based control of a residential photovoltaic power conditioning system is described. The microcomputer is responsible for array current feedback control, maximum power tracking control, array safe zone steering control, phase-locked reference wave synthesis, sequencing control, and some diagnostics. The control functions are implemented using Intel 8751 single-chip microcomputer-based hardware and software. The controller has been tested in the laboratory with the prototype power conditioner and shows excellent performance. 相似文献
995.
Joos F. Miguel Snaddon Robert W. L. Johnson Neil A. 《Industry Applications, IEEE Transactions on》1985,(6):1366-1372
Droplet growth is examined in a water-in-oil type emulsion where the droplets are subjected exclusively to viscous and dielectrophoretic forces. The latter are produced by the interaction of the droplets with an otherwise uniformly imposed electric field. Theoretical considerations are presented as a basis for understanding and interpreting the experiments. An emulsion consisting of deionized water droplets in a silicone oil of specific gravity I is subjected to a uniform 60 Hz, ac electrostatic field. Initially, the droplets are fairly monodisperse with mean diameters of approximately 25 , sm. The changes in droplet size distributions with time are examined with a laser diffraction system for water volume fractions ranging from 0.001 to 0.1 and applied fields ranging from 52 to 520 kVm-1. The average droplet size increases exponentially with time; we examine the exponent's dependence on average field strength and droplet volume fraction. 相似文献
996.
Erin E. Gnass Giese Robert W. Howe Amy T. Wolf Gerald J. Niemi 《Journal of Great Lakes research》2018,44(5):950-959
Breeding birds and anurans (frogs and toads) in coastal wetlands of Green Bay, Lake Michigan vary dynamically with changing water levels, habitat type, and geography. We describe species assemblages over a seven-year period (2011–2017) beginning with historic low water levels followed by an increase in average lake level of 0.85?m. In general, species richness and abundance of marsh-obligate species responded positively to increasing water levels, although several species of shallow wetlands (sandhill crane, sedge wren, swamp sparrow, and American toad) showed the opposite trend. Anuran assemblages were more diverse in the middle and upper bay, coinciding with a well-established nutrient gradient from the hypereutrophic lower bay to more oligotrophic waters of the upper bay. Three marsh-obligate bird species (black tern, sandhill crane, and sedge wren) were significantly more abundant in the middle or upper bay while sora, American coot, and common gallinule were more abundant in the eutrophic lower bay. Our findings have several important implications for conservation. Inland wetlands near the coast (including diked wetlands) might play a key ecological role by providing refugia for some species during low water years. However, the importance of shallow coastal wetlands and nearshore gradients of wetland habitat might be overlooked during low water years; when high water returns, these areas can become extremely productive and species-rich. 相似文献
997.
An adjoint method was used to investigate the sensitivity of peak ozone at selected sites in Southern California to nearly 900 model inputs including surface emissions, reaction rate coefficients, dry deposition velocities, boundary conditions, and initial conditions. Simulations showed large changes in ozone and ozone sensitivities at three sites investigated between summers 1987 and 1997 due to emission reductions. However, only small changes in ozone and ozone sensitivities were predicted between 1997 and 2010. Sensitivities of the differences in ozone between simulations with different emission scenarios were calculated and compared to sensitivities of ozone in each simulation. In some cases, the sensitivities of ozone differences were smaller than those of ozone itself, but in other cases, such as when the sensitivityto NOx emissions changed sign, sensitivities of differences were larger. The adjoint method was most useful for determining when and where model inputs affect, or have the potential to affect, an ozone response. For example, the method was used to plot the spatial distribution of important emission source regions to 1-hour versus 8-hour peak ozone. Changes in the distribution and sign of the adjoint function for emitted species revealed changes in the area of influence of pollutant emissions on peak ozone due to emission controls. The adjoint method provides useful information complementary to that obtained from forward sensitivity analysis methods. 相似文献
998.
Government agencies have recently emphasized the importance of food safety. Reducing the risk of foodborne illnesses within the home requires American consumers to put government refrigeration and freezer recommendations into practice; however, little research has been conducted regarding the use of proper refrigeration and freezer storage practices by consumers. A random sample survey was conducted to examine attitudes and practices of proper refrigeration and storage techniques of consumers in Peoria County, Illinois, and to determine whether gender, age, education, and income level have an effect on these variables. Eighty-one of 500 random sample surveys mailed were returned between 10 January and 15 February 2005. The majority of the participants were female (56, 69.1%), were 50 to 59 years old (18, 22.2%), had a bachelor's degree (33, 40.7%), and had a reported total household income of 60,000 dollars or greater (39, 91.4%). Average attitudinal scores indicated that participants thought it was important to take proper steps to prevent foodborne illnesses in the home; however, 68.8% of participants scored poorly on the practice portion of the survey. Only 12.3% of participants stated that they had a thermometer in their freezer, and 24.7% had one in their refrigerator. Eighty-four percent of respondents did not store eggs correctly in the refrigerator. No significant relationships (P < 0.05) were found within this sample population. These results suggest that further evaluation of consumer practices and attitudes is needed to better understand consumers so that they can be effectively educated about the prevention of foodborne illnesses at home. 相似文献
999.
Sonne C Leifsson PS Dietz R Born EW Letcher RJ Hyldstrup L Riget FF Kirkegaard M Muir DC 《Environmental science & technology》2006,40(18):5668-5674
Reproductive organs from 55 male and 44 female East Greenland polar bears were examined to investigate the potential negative impact from organohalogen pollutants (OHCs). Multiple regressions normalizing for age showed a significant inverse relationship between OHCs and testis length and baculum length and weight, respectively, and was found in both subadults (dichlorodiphenyl trichloroethanes, dieldrin, chlordanes, hexacyclohexanes, polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs)) and adults (hexachlorobenzene [HCB]) (all p < 0.05). Baculum bone mineral densities decreased with increasing chlordanes, DDTs, and HCB in subadults and adults, respectively (all p < 0.05). In females, a significant inverse relationship was found between ovary length and sigma PCB (p = 0.03) and sigma CHL (p < 0.01), respectively, and between ovary weight and sigma PBDE (p < 0.01) and uterine horn length and HCB (p = 0.02). The study suggests thatthere is an impact from xenoendocrine pollutants on the size of East Greenland polar bear genitalia. This may pose a riskto this polar bear subpopulation in the future because of reduced sperm and egg quality/quantity and uterus and penis size/robustness. 相似文献
1000.
Muniz JJ Joyce MM Taylor JD Burghardt JR Burghardt RC Johnson GA 《Reproduction (Cambridge, England)》2006,131(4):751-761
Glycosylation dependent cell adhesion molecule 1 (GlyCAM-1), a mucin component of sheep histotroph produced by glandular epithelium (GE) during early pregnancy, is hypothesized to function in implantation. However, GlyCAM-1 is present in uterine tissues subsequent to implantation suggesting additional functions of this l-selectin-binding ligand. This study focused on uterine GlyCAM-1 expression during placentome development in sheep. Western blot analysis of day 50 pregnant sheep identified 45, 40, and 25 kDa bands in interplacentomal endometrium, 40 and 25 kDa bands in placentomes, and 80 and 40 kDa bands in chorioallantois. The GlyCAM-1 proteins in interplacentomal regions were comparable to those detected in day 15-19 pregnant sheep, however, the 80 kDa form was unique to chorioallantois, and the absence of the 45 kDa GlyCAM-1 in placentomes indicated differences between interplacentomal and placentomal endometrium. Immunofluorescence identified GlyCAM-1 in lumenal epithelium (LE), stromal fibroblasts, and vascular smooth muscle cells. To better define its cellular distribution, GlyCAM-1 was co-localized with either epithelium-specific cytokeratin, smooth muscle-specific alpha-smooth muscle actin (alpha SMA), or stromal-specific vimentin. In interplacentomal endometrium, GlyCAM-1 co-localized with cytokeratin in LE but not in GE. GlyCAM-1 did not co-localize with alpha SMA, and was localized in the extracellular matrix of vimentin-positive stroma. In placentomes, GlyCAM-1 did not co-localize with cytokeratin, but did co-localize with alpha SMA and vimentin. Thus, in contrast to interplacentomal regions, GlyCAM-1 in placentomes was predominantly localized in vasculature rather than epithelial cells. Further, leukocytes expressing L-selectin were localized to the endothelial surface of GlyCAM-1-expressing vessels within placentomes. These data suggest that GlyCAM-1 assumes distinct functions in compartment-specific regions of the sheep uterus. 相似文献