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661.
Saulo R Bragan?a Juliane Vicenzi Kareline Guerino Carlos P Bergmann 《Waste management & research》2006,24(1):60-66
The purpose of this study was to evaluate the production feasibility of triaxial whiteware using sand from cast iron moulds as a raw material instead of silica, and recycled glass in place of feldspar. Formulations were prepared using sand, glass waste, and white-firing clay such that only 50% of the composition was virgin material (clay). The ceramic bodies were formed by pressing and fired at different temperatures (between 1100 and 1300 degrees C). Specimens were characterized in terms of green density prior to firing; and their flexural strength, linear shrinkage, and water absorption were measured after firing. The microstructure was determined by scanning electron microscopy. Possible environmental impacts of this recycling process were also evaluated, through solubility and leaching tests, according to Brazilian standards. Gaseous emissions during the firing process were also analysed. The results showed that it is possible to produce triaxial ceramics by using such alternative raw materials. 相似文献
662.
663.
Calcium carbonate transfer was experimentally examined in hydrothermal mussels Bathymodiolus azoricus, which were collected from 850 m depth at Menez Gwen hydrothermal vent site (31°31′W, 37°50′N) on the Mid Atlantic Ridge in
May 2007. In each of four 10-day experiments, groups of mussels were maintained at atmospheric pressure or re-pressurised
to depths relevant to their site of occurrence, i.e. 850 m depth at Menez Gwen, 1,750 m at Lucky Strike (31°31′W, 37°18′N)
and 2,300 m at Rainbow (31°31′W, 36°13′N). The shells of experimental mussels were perforated and mantle tissue was fixed
for light and TEM studies at days 7 and 10 following the injury. Simultaneously, haemocytes from the extrapallial fluid (EPF)
at the site of induction were studied. At day 7 the response was most intense in the middle fold of the mantle margin and
possibly proportional to hydrostatic pressure. At day 10 the epithelial cells on the mantle surface facing the body cavity
produced copious organic secretions that avidly bound calcium. Haemocyte migration was noted within the mantle tissue, and
the haemocytes at the mantle surface facing the shell had a Ca-positive granular content. Large haemocytes were detected in
the EPF at the injury site, and some showed evidence of an immune reaction while others showed Ca-positive granular content.
These results suggest that haemocytes are involved in shell repair in these deep-sea mussels just as in some freshwater and
shallow marine molluscs. 相似文献
664.
665.
José Carlos Parada-Fabián Patricia Juárez-García Iván Natividad-Bonifacio Carlos Vázquez-Salinas Elsa Irma Quiñones-Ramírez 《Food and environmental virology》2016,8(3):215-220
Foodborne viruses are a common and, probably, the most under-recognized cause of outbreaks of gastroenteritis. Among the main foods involved in the transmission of human enteric viruses are mollusks, and fruits and vegetables irrigated with wastewater and/or washed with non-potable water or contaminated by contact with surfaces or hands of the infected personnel during its preparation. In this study, 134 food samples were analyzed for the detection of Norovirus, Rotavirus, and Hepatitis A virus (HAV) by amplification of conserved regions of these viruses. From the 134 analyzed samples, 14 were positive for HAV, 6 for Norovirus, and 11 for Rotavirus. This is the first report in Mexico where emphasis is given to the presence of HAV and Norovirus on perishable foods and food from fisheries, as well as Rotavirus on frozen vegetables, confirming the role of vegetables and bivalve mollusks as transmitting vehicles of enteric viruses. 相似文献
666.
Shui-Yan?Tang Pansy?Honying?Li Gerald?E.?Fryxell Carlos?Wing-Hung?LoEmail author 《Environmental management》2015,56(3):777-790
This study examines the effects of internal motivations and external pressures on the integration of environmental management (EM) practices within manufacturing operations in China. The moderating role of perceptions toward the regulatory process is also considered along with comparisons between wholly Chinese-owned and foreign-owned enterprises. From a sample of 131 manufacturing companies in the Guangzhou area, it was found that the salience of fees and fines has a strong positive influence on perceptions toward the regulator (the local Environmental Protection Bureau, EPB). This also has a positive effect on perceptions toward regulations themselves for foreign-owned enterprises. Business-case motivations for EM positively shape enterprise perceptions toward regulations, whereas risk-reduction motivations have a negative effect on perceptions toward regulations in foreign-owned enterprises. Enterprise perceptions toward the regulatory process have direct effects on the integration of EM practices in wholly Chinese-owned enterprises, but in opposite directions. While positive perceptions toward regulations have positive influence, positive perceptions toward regulators (i.e., the EPB) negatively affect it. Overall, these results indicated that promoting the adoption of EM practices depends on convincing business leaders that EM practices contribute to profit making. The regulatory process can potentially promote these practices, but measures need to be taken to ensure that the regulator is not co-opted by the regulated, especially in wholly Chinese-owned enterprises. 相似文献
667.
Juan Carlos Valdivieso Paul F.J. Eagles Joan Carles Gil 《Journal of Environmental Planning and Management》2015,58(9):1544-1561
Despite the increasing number of protected areas around the world and their importance in the conservation of species and ecosystems, protected areas management capacity remains difficult to evaluate. A standard is needed to help policy makers compare the goals with the results obtained. This empirical research builds a tool to analyze the management efficiency and predicts the new touristic outcomes in case of a policy change. Using as example the state parks agencies in the USA, this paper develops a technological frontier using data envelopment analysis based on the Protected Areas Management Approach. After that, a prediction of the outcomes is analyzed with a budget change for any state park agency. Data suggest that many of them need to improve their performance to be more efficient. Another result obtained shows how budget changes will affect each agency's performance in different degrees and, therefore, budget reductions should be modeled separately. 相似文献
668.
The Prestige oil spill in November 2002 is considered the biggest large-scale catastrophe of its type in Europe, thousands of seabirds dying in the subsequent months. Here, the total concentration of 16 polycyclic aromatic hydrocarbons (TPAH) was measured in the blood cell fraction of adult and chick yellow-legged gulls (Larus michahellis) from unoiled and oiled coastal areas in North Western Spain. In addition, hematocrit, plasma metabolites, electrolytes and enzymes, as well as body mass were determined in the same individuals. Our results strongly suggest the presence of health damages of sublethal nature in adult gulls breeding in oiled colonies 17 months after the Prestige oil spill. This is supported by the following evidences: (1) gulls sampled in unoiled and oiled colonies differed in blood TPAH levels, (2) gulls sampled in unoiled and oiled colonies differed in several blood parameters indicative of physiological disorders, and (3) TPAH in blood was significantly related to several of these parameters. Differences in the level of asparatate aminotransferase (AST), gamma-glutamyl transferase (GGT), total protein, glucose and inorganic phosphorus suggest damages on some vital organs (i.e. liver and kidney) in adult birds from oiled areas. Meanwhile, chicks presented weaker effects than adults, showing only between-area differences in hematocrit. Since TPAH levels in blood did not differ between both age-groups, the stronger effects on adults should be due to their longer exposure to these pollutants and/or to severe exposure in the months following the spill. The presence of PAHs in chicks indicates that these pollutants were incorporated into the food chain because nestlings would have been only exposed to contaminated organisms in the diet (e.g. fishes and crustaceans). Our findings support the view that PAHs may deeply alter the physiology of seabirds, and emphasize the necessity of quantifying the circulating levels of these compounds in order to evaluate the sublethal effects associated to large oil spills. 相似文献
669.
Carlos Cardelino 《Journal of the Air & Waste Management Association (1995)》2013,63(7):637-645
ABSTRACT This work studied the daily variability of mobile sources in rural and urban areas, in and around the Atlanta Metropolitan Area. Traffic counter data collected during the 1992 Southern Oxidants Study Atlanta Intensive Study were used to analyze the spatial and temporal distribution of traffic volume. A simple method to study the daily variability of mobile emissions from the different types of urban and rural roads is presented. The method is based on hourly traffic volume data and emission factors and it has been generalized to describe the daily variability of mobile emissions for urban and rural areas and for the whole modeling domain. Implications of this study for improving mobile emission inventories are also discussed. 相似文献