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101.
Among the difficulties found in the implementation of ISO 14001 systems, resistance to change can always be found. It is mainly a consequence of the hurry to change, loss of focus, concentration of decision making at the level of top management, arbitrary imposition of objectives and results, faulty communication, and the absence of motivational and financial incentive for change.Therefore, the main objective of this paper is to present best practices with respect to the management of organizational change due to the implementation of ISO 14001 norms in two industrial companies in the Midwest region of the State of São Paulo – Brazil.  相似文献   
102.
A laboratory-scale reactor system is built and operated to measure the kinetic of formation for single and mixed carbon dioxide–tetrahydrofuran hydrates. The T-cycle method, which is used to collect the kinetic data, is briefly discussed. For single carbon dioxide hydrate, the induction time decreases with the increase of the initial carbon dioxide pressure up to 2.96 MPa. Beyond this pressure, the induction time is becoming relatively constant with the increase of initial carbon dioxide pressure indicating that the liquid phase is completely supersaturated with carbon dioxide. Experimental results show that the inclusion of tetrahydrofuran reduces the induction time required for hydrate formation. These observations indicate hydrate nucleation process and onset growth are more readily to occur in the presence of tetrahydrofuran. In contrast, the presence of sodium chloride prolongs the induction time due to clustering of water molecules with the ions and the salting-out effects. It is also shown that the degree of subcooling required for hydrate formation is affected by the presence of tetrahydrofuran and sodium chloride in the hydrate forming system. The presence of tetrahydrofuran in the hydrate system significantly reduces the amount of carbon dioxide uptake. The apparent rate constant, k, for those systems are reported.  相似文献   
103.
In this paper we compute the genuine savings indicators for the Republic of Ireland over the period 1995-2005. We expand and improve existing World Bank's estimates by: a) using data collected from official Irish sources; b) employing the net present value method to assess resource depreciation; c) including external costs from SO(2) and NOx emissions; and d) estimating human capital accumulation using the returns to education. We also perform a sensitivity analysis to check the robustness of our estimates to different assumptions and parameters. Our estimates are consistently smaller than the World Bank's and negative in the first years of the period considered.  相似文献   
104.
    
ABSTRACT: A survey of 31 Florida spring-runs was conducted to estimate their submerged macrophyte standing crop and primary productivity. The standing crops of submerged vegetation were not significantly (p > 0.05) correlated to either total nitrogen (r = 0) or total phosphorus (r =?0.20) concentrations, but standing crops were significantly (p < 0.01) correlated to the percentage of the spring-run's water surface shaded by marginal vegetation (r =?0.76). Maximum daily rates of primary productivity were positively correlated with average submerged macrophyte standing crops (r = 0.81; p < 0.001) and inversely correlated with the degree of shading by marginal vegetation (r =? 0.43; p < 0.05).  相似文献   
105.
106.
Environment, Development and Sustainability - Although sustainability assessment is widely discussed at Brazil, in Brazilian Amazon its use is still little applied, considering this territory is...  相似文献   
107.
The main objectives of this work focus, firstly, on a review of the current existent methodologies to estimate air quality modelling uncertainty, and, secondly, in the preparation of guidelines for modelling uncertainty estimation, which can be used by local and regional authorities responsible for air quality management. From the application exercise, it was concluded that it is possible to define a subset of statistical parameters able to reproduce the general uncertainties estimation. Concerning the quality indicators defined by EU directives, the results show that the legislated uncertainty estimation measures are ambiguous and inadequate in several aspects, mainly in what concerns the error measures for hourly and daily indicators based on the highest observed concentration. A relative error at the percentile correspondent to the allowed number of exceedances of the limit value was suggested and tested, showing that is a more robust and appropriate parameter for model performance evaluation.  相似文献   
108.
Forest fires represent a serious threat to public security in Europe due to the large burned area. Moreover, smoke pollution due to forest fire events is an important public health issue for the communities directly affected, and particularly for the personnel involved in firefighting operations. Aiming to contribute to the scientific knowledge concerning firefighters exposure to forest fires smoke, data of individual exposure to carbon monoxide, nitrogen dioxide, volatile organic compounds, and particulate matter were obtained during experimental field fires for a group of 10 firefighters equipped with portable “in continuum” measuring devices. Measured values are very high exceeding the Occupational Exposure Standard limits, in particular for peak limit thresholds. These are the first measurements and analysis of firefighter's individual exposure to toxic gases and particles in fire smoke experiments in Europe. However, they already indicate that urgent measures to avoid these levels of exposure are needed.  相似文献   
109.
The aim of this work was to determine the concentrations and isotopic compositions of plutonium and uranium in environmental samples for safeguards purposes. An analytical method was developed with a plutonium and uranium separation procedure based on extraction chromatography (using 2 mL TEVA and UTEVA columns) and detection with a quadrupole ICP-MS applying an ultra-sonic nebulizer coupled with a membrane desolvation system. Starting from blank swipes, the background equivalent concentration (BEC) was 8 fg for 239Pu and 1 ng 238U. The method was successfully applied to certified reference materials as well as to round robin samples obtained in the framework of the inter-laboratory exercise program, promoted by the Brazilian–Argentine Agency for Accounting and Control of Nuclear Materials (ABACC), together with the US Department of Energy (USDOE). After the introduction of an additional ion-exchange separation step, the methodology was applied to the IAEA-384 sediment reference sample with precise and accurate total plutonium and uranium, 240Pu/239Pu, 241Pu/239Pu, 234U/238U and 235U/238U atomic ratio results.  相似文献   
110.
The use of organic waste and compost as a source of organic matter and nutrients is a common practice to improve soil physico-chemical properties, meanwhile reducing the need for inorganic fertilisers. Official guidelines to assess sewage sludge and compost quality are mostly based on total metal content of these residues. Measurement of the total concentration of metals may be useful as a general index of contamination, but provides inadequate or little information about their bioavailability, mobility or toxicity when the organic residue is applied to the soil. However, ecotoxicity tests provide an integrated measure of bioavailability and detrimental effects of contaminants in the ecosystem. In the present study, three different types of biodegradable organic residues (BORs) have been considered: sewage sludge from municipal wastewater treatment (SS), compost from the organic fraction of unsorted municipal solid waste (MSWC), and garden waste compost (GWC). The BORs were subjected to chemical characterisation and total metal quantification (Cd, Cr, Cu, Ni, Pb and Zn), in order to verify their suitability for land application. Water leachability was determined through the DIN 38414-S4 method, while the modified BCR sequential extraction procedure was used for metal speciation. Ecotoxicity of the BORs was studied by direct and indirect bioassays. Direct toxicity bioassays were: plant growth tests with cress (Lepidium sativum L.) and barley (Hordeum vulgare L.), and earthworm (Eisenia fetida) mortality. On the other hand, indirect exposure bioassays, with leachate from the residues, took into account: luminescent bacteria (Vibrio fischeri), seed germination (L. sativum and H. vulgare) and Daphnia magna immobilization. As far as total metal concentration is concerned, with particular reference to Zn, SS resulted neither suitable for the use in agriculture nor compatible to be disposed of as an inert material into landfill, according to the Directive 1999/31/EC. Zinc in SS was mainly present in exchangeable form (28.5%), appearing as highly bioavailable. As a consequence, SS exhibited either high ecotoxicity effects with the indirect exposure bioassays or significant mortality with the earthworm bioassay. Total content of metals in MSWC allowed its classification as "stabilised biowaste", according to 2nd draft [DG Env.A.2. Working document of Biological treatment of biowaste - 2nd draft. Directorate-General Environment, Brussels, 12th February; 2001. accessed in:http://europa.eu.int/comm/environment/waste/facts_en.htm, at 10/09/2002] while leachate, on the basis of the concentration of these contaminants, could be classified as "inert waste". This residue showed significant ecotoxicity effects with direct exposure bioassays as well as with the luminescent bacteria bioassay. However, it resulted less toxic than SS. Finally, GWC could be classified as a Class 2 compost, with no detectable toxic effects on the organisms used in the bioassays, except for the luminescent bacteria. In this case, an EC(50) of 73.0% was observed. Considering the results, the use of a battery of toxicity test in conjunction with chemical analysis should be suggested, in order to correctly assess possible environmental risks deriving from disposal or land application of biodegradable organic residues.  相似文献   
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