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21.
In this report, the development of an online, noninvasive, measurement method of the biofilm thickness in a liquid phase is presented. The method is based in the analysis of the ultrasound wave pulse-echo behavior in a liquid phase reproducing the real reactor conditions. It does not imply the removal of the biomass from the support or any kind of intervention in the support (pipes) to detect and perform the measurements (non-invasiveness). The developed method allows for its sensor to be easily and quickly mounted and unmounted in any location along a pipe or reactor wall. Finally, this method is an important innovation because it allows the thickness measurement of a biofilm, in liquid phase conditions that can be used in monitoring programs, to help in scheduling cleaning actions to remove the unwanted biofilm, in several application areas, namely in potable water supply pipes.  相似文献   
22.
Risk assessment constitutes a critical phase of the safety management process. It basically consists of evaluating the risks involved in the execution of working activities, so as to provide the managers with information suitable to address intervention measures. The most important activity in risk assessment is the risk evaluation task but, despite its importance, national and international regulations have never formalized a standard methodology for addressing it, leaving companies complete freedom to adopt the approach they consider appropriate. As a consequence, companies generally settle on the use of simple methodologies which frequently are not able to emphasize all the main aspects affecting risk in the workplace and to produce a precise ranking of hazardous activities. In this paper, a new methodology for risk evaluation is then proposed with the aim to overcome limitations of the classical approaches. In particular, new factors are introduced to take into account effects of human behavior and environment on risk level, other than the classical injury magnitude and occurrence probability of an accident. The proposed methodology also integrates an estimative approach based on the fuzzy logic theory, which permits more coherence in the evaluation process, producing a very suitable final rank of hazardous activities. Finally, an actual case study is reported to show the capabilities of the new risk evaluation model.  相似文献   
23.
The aim of this study was to determine and quantify effects of copper and lithium in tissues of early juveniles of the ramshorn snail, Marisa cornuarietis. For this purpose, hatchlings of M. cornuarietis were exposed for 7 days to a range of five different sublethal concentrations of copper (5, 10, 25, 50, and 75 μg Cu2+ L−1) and lithium (50, 100, 200, 1000, and 5000 μg Li+ L−1). Both metals changed the tissue structure of epidermis, hepatopancreas, and gills, varying between slight and strong reactions, depending on the copper and lithium concentration. The histopathological changes included alterations in epithelial and mucous cells of the epidermis, swelling of hepatopancreatic digestive cells, alterations in the number of basophilic cells, abnormal apices of digestive cells, irregularly shaped cilia and changes in the amount of mucus in the gills. The most sensible organ in M. cornuarietis indicating Cu or Li pollution is the hepatopancreas (LOECs were 10 μg Cu2+ L−1, or 200 μg Li+ L−1). In epidermis, mantle and gills relevant effects occurred with higher LOECs (50 μg Cu2+ L−1, or 1000 μg Li+ L−1). Base on LOECs, our results indicated that histopathological endpoints are high sensitivity to copper and lithium compared to endpoints for embryonic developmental toxicity.  相似文献   
24.
Through the years, mining and beneficiation processes produces large amounts of As-rich mine wastes laid up in huge tailings and open-air impoundments (Barroca Grande and Rio tailings) that are the main source of pollution in the surrounding area once they are exposed to the weathering conditions leading to the formation of AMD and consequently to the contamination of the surrounding environments, in particularly soils. In order to investigate the environmental contamination impact on S. Francisco de Assis (village located between the two major impoundments and tailings) agricultural soils, a geochemical survey was undertaken to assess toxic metals associations, related levels and their spatial distribution, and to identify the possible contamination sources. According to the calculated contamination factor, As and Zn have a very high contamination factor giving rise to 65.4 % of samples with a moderate to high pollution degree; 34.6 % have been classified as nil to very low pollution degree. The contamination factor spatial distribution put in evidence the fact that As, Cd, Cu, Pb, and Zn soils contents, downstream Barroca Grande tailing, are increased when compared with the local Bk soils. The mechanical dispersion, due to erosion, is the main contamination source. The chemical extraction demonstrates that the trace metals distribution and accumulation in S. Francisco de Assis soils is related to sulfides, but also to amorphous or poorly crystalline iron oxide phases. The partitioning study allowed understanding the local chemical elements mobility and precipitation processes, giving rise to the contamination dispersion model of the study area. The wind and hydrological factors are responsible for the chemical elements transport mechanisms, the water being the main transporter medium and soils as one of the possible retention media.  相似文献   
25.
This paper describes new environmental policies and expanded administrative agencies which in recent years have been adopted by many governments faced with a continuing decline in the quality of their environments. In a number of developed and developing countries, devising a far reaching environmental policy for sustainable development of the natural resources sector is a national priority. Specific environmental policies may be classified according to objectives, timeframe, mechanisms for implementation, whether or not they are binding, and the nature of sanction. This paper provides some generalizations about certain features common to most environmental policies. In the first section an examination is made of some of the most pressing problems which environmental policies relating to natural resources seek to address. The second section discusses environmental policies themselves. The third section, which makes up the main body of the paper, assesses the strengths and weaknesses of a variety of mechanisms available for implementing environmental policies to promote sustainable development in the natural resources sector.  相似文献   
26.
We describe a 4-year-old female child with severe global mental retardation, myoclonic epilepsy, proximal hypotonia and dysmorphisms, whose prenatal diagnosis following amniocentesis revealed a constitutional female karyotype carrying a t(1;15)(q10;p11) familial reciprocal translocation. Post-natal high-resolution karyotype, Fluorescence in situ hybridization (FISH) screening for subtelomeric rearrangements, VNTR search for UPD15 in the blood and fibroblast, and WCP1 and 15 in the mother, failed to provide an explanation for the complex clinical phenotype of the proband. Since the pachytene configuration of the translocated chromosomes defines a high probability of 3:1 segregation, an extensive workup was undertaken to look for a possibly cryptic mosaicism. Four percent of the cells with trisomy 15 was found in the peripheral blood lymphocytes examined by classical cytogenetic technique and interphase FISH analysis. The clinical features associated with cryptic trisomy 15 mosaicism and the problems concerning prenatal diagnosis and genetic counselling for carriers of translocations at high risk of 3:1 segregation are discussed. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
27.
Jalali R 《Disasters》2002,26(2):120-139
On 17 August 1999 Turkey was hit by a massive earthquake. Over 17,000 lives were lost and there was extensive damage to Turkey's heartland. This paper examines how various public and private institutions, including state and civil society institutions such as NGOs and the media responded to the needs of earthquake survivors. It documents the extensive involvement of NGOs in the relief efforts immediately after the disaster and examines the impact of such participation on state-civil society relations in the country. The data show that state response to the disaster went through several phases from a period of ineptitude to effective management. The paper credits the media and the NGOs for acting as advocates for survivors and forcing changes at the state level. The paper argues that an ideal response system, which fully addresses the needs of victims, can only be based on state-civil society relations that are both collaborative and adversarial.  相似文献   
28.
29.
In this work, 24-h PM10 samples were collected in Rio de Janeiro, Brazil, and analysed for trace elements (Cd, Ce, Cu, La, Mo, Ni, Pb, Pd, Rh, Sb and Sn). The sampling was carried out at five locations (Bonsucesso; Centro, downtown city; Copacabana; Nova Igua?u and Sumaré) with different traffic densities and anthropogenic activities. An analytical method based on the EPA method for the determination of trace elements in airborne particulate matter (PM), using ultrasonic-assisted extraction and inductively coupled plasma mass spectrometry (ICP-MS) was applied. Our results suggest that vehicular traffic is the most important source of environmental pollution at the studied sites. The presence of Mo, Pd and Rh in the analysed filters reflects an additional source of pollution caused by the erosion and deterioration of automotive catalytic converters.  相似文献   
30.
A number of microorganisms were isolated from sewage. Biochemical Oxygen Demand (BOD-5 day) analysis was carried out by individual pure cultures. The cultures giving higher or equal BOD values as compared to reference GGA solution were selected for the formulation of a defined mixed microbial consortium. This microbial consortium was co-immobilized on calcium-alginate beads. Four synthetic and six industrial samples were tested for BOD by using immobilized beads as well as sewage as source of seeding materials. BOD values obtained with beads for all the synthetic as well as industrial samples were fairly comparable with those obtained with sewage. Reusability of prepared microbial beads was also checked with different synthetic and industrial samples and was compared with reference GGA solution. The same microbial beads can be reused three times for different BOD-5 day estimations. It is recommended that immobilized microbial beads can be used as a ready-to-use seeding material for BOD analysis.  相似文献   
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