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191.
192.
The initial chicken manure and the three fractions derived from it by fast pyrolysis, that is, the two biooils Fractions I and II as well as the residual char were analyzed by Curie-point pyrolysis-gas chromatography/mass spectrometry (Cp Py-GC/MS). The individual compounds identified were grouped into the following six compound classes: (a) N-heterocyclics; (b) substituted furans; (c) phenol and substituted phenols; (d) benzene and substituted benzenes; (e) carbocyclics; and (f) aliphatics. Of special interest were the relatively high concentrations of N-heterocyclics in biooil Fraction II which was obtained in the highest yield and had the highest calorific value. Prominent N-heterocyclics in biooil Fraction II were methyl-and ethyl-substituted pyrroles, pyridines, pyrimidine, pyrazines, and pteridine. Also noteworthy was the high abundance of aliphatics in biooil Fraction I and the char. The alkanes and alkenes in biooil Fraction I ranged from n-C7 to n-C18 and C7:1 to C18:1, respectively, and those in the char from n-C7 to n-C19 and C7:1 to C19:1, respectively. The N-heterocyclics in the two biooil Fractions came from the chicken manure, from proteinaceous materials during fast pyrolysis or were formed during the fast pyrolysis manure conversion by the Maillard reaction which involved the formation of N-heterocyclics by amino acids interacting with sugars.  相似文献   
193.
Noncrop areas such as hedgerows in agricultural landscapes can perform several ecological and agronomic functions (e.g., habitat, movement corridors, windbreak, etc.), but their dynamics and drivers of changes are often poorly known. We conducted a study in three agricultural landscapes of southern Quebec, Canada, to assess and compare the spatial and temporal (1958–1997) dynamics of three hedgerow networks in relation to geomorphic conditions (marine, glacial, and mixed deposit) and land-use changes. Hedgerow networks were mapped and described in terms of their structure (density, degree of connectivity, and presence of trees or shrubs) and their relationship to other components of the landscape (connection to woodland). Relationships were assessed in time and space using nonparametric correlation, Mantel test, and principal components analysis (PCA). Results show significant differences between hedgerow structure for the three landscapes and distinct temporal and spatial dynamics that can be related to changes in management practices and agricultural policies. On marine deposits, increases in hedgerow density did not always correspond to an increase in their degree of connectivity, suggesting a possible reduction in network quality. On glacial deposits, hedgerow density declined following abandonment of agricultural land, but rather than disappearing, these linear structures were integrated into adjacent brush or forested areas. Our analysis reveals the complex spatial and temporal dynamics of the hedgerow networks and highlights the need to take into account spatial attributes such as connectivity and connection to woodland to evaluate more accurately overall network quality.  相似文献   
194.
This study proposes a model linking firm motivations for seeking ISO 14001 certification to the effectiveness of three major components of an environmental management system (EMS)--environmental policy, the assessment of environmental aspect and impacts, and management review. The relationship of these EMS components with a self-reported measure of environmental performance is also examined. From a sample of 29 ISO 14001 certified facilities in Hong Kong (of 71 total certifications at the time the data was collected), it was found that motivations to enhance firm reputation are positively related to perceptions of the effectiveness of the policy statement. Motivations for reputation enhancement and cost reduction were positively related to perceptions of EMS effectiveness in assessing environmental aspects and impacts. The effectiveness of the methodology for identifying environmental aspects and impacts was also found to be positively related to improved environmental performance.  相似文献   
195.
This study examines managerial preferences for various policy mechanisms commonly used to address environmental problems using a sample of 653 Chinese managers from firms in Beijing, Dalian and Guangzhou. Overall, these managers appeared to favor regulatory instruments, placing somewhat less faith in market and communicative instruments. However, all measures appear to have ample support within each subgroup. In addition, the influence of two situational factors on these preferences was investigated--the immediacy of environmental impact and diffusion of responsibility. The results of the study indicate that these two factors interact in explaining managerial preferences, but only for the use of market mechanisms.  相似文献   
196.
ABSTRACT: Alum and sodium aluminate were injected into the hypolimnion of eutrophic Kezar Lake, New Hampshire, with a specially designed applicator mechanism. This new method of applying aluminum salts to achieve phosphorus inactivation included two separate chemical distribution systems mounted on a hydraulic weed harvester. The design of the applicator system is described, and its cost-effectiveness is compared with other aluminum salt injections.  相似文献   
197.
This article deals with the development and application of a cartographic database for a synoptic Geographic Information System (GIS). Its purpose is the storage and evaluation of the heterogeneous datasets of the interdisciplinary scientific research program MADAM (Mangrove Dynamics and Management), which aims to develop recommendations for a tailored integrated coastal management scheme for the mangrove ecosystem at Bragança (North Brazil). The article describes the integration of remote sensing data, aerial photographs, as well as point data provided by fieldwork from different scientific fields. Using various innovative processing techniques and different scale-resolution levels, an assessment of temporal–spatial changes of the mangrove peninsula and the adjacent rural socioeconomic impact area, the type of mangrove structure, as well as a land-use cover analyses was undertaken. The definition of the spatial level of detail was found to be a major issue in the development of the GIS, as well as during the processing and analysis procedures. A division between strong and weak patterns in the mangrove ecosystem could be made, which implies different management measures and sets of specific interdisciplinary studies and monitoring at hierarchical scales.  相似文献   
198.
Representative duplicate fly ash samples were obtained from the stacks of 400- and 385-MW utility boilers (Unit A and Unit B, respectively) using a modified U.S. Environmental Protection Agency (EPA) Method 17 sampling train assembly as they burned 0.9 and 0.3 wt % S residual (No. 6 fuel) oils, respectively, during routine power plant operations. Residual oil fly ash (ROFA) samples were analyzed for Ni concentrations and speciation using inductively coupled plasma-atomic emission spectroscopy, X-ray absorption fine structure (XAFS) spectroscopy, and X-ray diffraction (XRD). ROFA deionized H2O extraction residues were also analyzed for Ni speciation using XAFS and XRD. Total Ni concentrations in the ROFAs were similar, ranging from 1.3-1.5 wt%; however, stack gas Ni concentrations in the Unit A were 0.990 microg/Nm3 compared with 0.620 microg/Nm3 for Unit B because of the greater residual oil feed rates employed at Unit A to attain higher 400-MW load conditions with a lower heating value oil. Ni speciation analysis results indicated that ROFAs from Unit A contain approximately 3 wt % NiSO4 x xH2O (where x is assumed to be 6 for calculation purposes) and appoximately 4.5 wt% of a Ni-containing spinel compound, similar in composition to (Mg,Ni)(Al,Fe)2O4. ROFAs from Unit B contain on average 2 wt% NiSO4 x 6 H20 and 1.1 wt% NiO. XAFS and XRD analyses did not detect any nickel sulfide compounds, including carcinogenic nickel subsulfide (Ni3S2) (XAFS detection limit is 5% of the total Ni concentration). In addition, XAFS measurements indicated that inorganic sulfate and organic thiophene species accounted for > 97% of the total S in the ROFAs. Unit A ROFAs contained much lower thiophene proportions because cyclone-separated ROFA reinjection is employed on this unit to collect and reburn the larger carbonaceous particles.  相似文献   
199.
For decades, industry has been the main source of pollution in China. Determined to make changes, the mainland Chinese authorities have decided to promote mechanisms that incorporate environmental concerns into the internal management of enterprises. This is manifested in the rapid adoption of the ISO14000 standards, including a significant increase in ISO14001 registrations in China. Thus, this study examined the environmental policy statements of 106 certified facilities in mainland China against a strict interpretation of the mandatory requirements of the ISO 14001:1996 standard and the nonmandatory ISO14004 requirements in order to shed some light on the implementation of environmental management systems in an emerging economic giant. It was decided to analyze the environmental policy statement because such a statement is a core element in the ISO system of environmental management of each facility and there are relatively clear and specific requirements on what an environmental policy statement shall include. An analysis of the contents of the environmental policy statements shows that conformance to the relevant requirements of both the mandatory ISO14001 standard and the nonmandatory ISO14004 standard is far from impressive and that the facilities in our sample seldom went beyond the minimum requirements. By using ISO14001 and ISO14004 conformance scores as the dependent variables, we found that conformity to ISO14001 and overall conformance to ISO14000 series can be explained to some extent by the degree of top management commitment, the experience with informal environmental management systems, and the form of ownership of the facilities.  相似文献   
200.
ABSTRACT: Integrated water resources management is important, especially in watersheds where substantial interactions exist between the ground and surface water sources. This management warrants the need for reliable estimates of both an overall basin water budget and hydrologic fluctuations between ground water and surface water sources. The objectives of this study were to estimate the total water budget and to simulate the effects of the management of water in the Big Lost River Basin in Idaho. The study used the FIPR Hydrological Model (FHM), a hydrological model developed by the University of South Florida for the Florida Institute of Phosphate Research (FIPR). The FHM is an integrated model that simulates the full water budget of the surface and ground water systems. It has two public domain components: Hydrological Simulation Program ‐ FORTRAN (HSPF) and Modular Three‐Dimensional Finite‐Difference Ground Water Flow Model (MODFLOW). This study quantified the hydrologic fluxes between ground water and surface water and determined a comprehensive and accurate water budget for the Big Lost River. The study showed an annual amount of 10.44 m3/sec leaves the basin and never to return to the system. The study is useful in developing and calculating the annual water budget in the Big Lost River, and this process should be applicable to estimating water budgets in other basins.  相似文献   
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