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411.
The purpose of this study was to examine the factor structure of the transformational leadership model in human service teams. As the nature of this work environment mandates certain management‐by‐exception practices, patterns of correlations between perceptions of active and passive management‐by‐exception behaviors and transformational, transactional, and laissez‐faire leadership were of interest. 236 leaders and 620 subordinates from 54 mental health teams completed the Multifactor Leadership Questionnaire, form 8Y. Results suggest that active and passive management‐by‐exception factors are independent constructs. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   
412.
 The effect of the soil solids concentration in batch tests on the measured values of the partition coefficient (K p) of organic pollutants in landfill liner-soil material was investigated. Since this study was based on the results of batch and column tests conducted independently, there were limitations to the conclusions derived. The organic compounds tested were benzene, methylene chloride, toluene, trichloroethylene, and p-xylene. The results of this study showed that as soil solids concentrations increased, the measured K p values of these organic compounds strongly decreased. The observed values of K p stabilized when the soil solids concentration was above a certain value. Typical K p values obtained from batch tests conducted under high soil solids concentrations were close to those obtained from column tests. It was concluded that the K p values of organic compounds measured under low soil solids concentrations, i.e., less than 100 g/l, may not correctly simulate the field situation. Consequently, the values of K p obtained with low soil solids concentrations can result in an overestimation of the retardation factor of the landfill liner material. Received: March 14, 2002 / Accepted: August 25, 2002  相似文献   
413.
The UK National Air Quality Strategy has required local authorities to review and assess air quality in their area of jurisdiction and determine locations in their areas where concentrations of specific air quality pollutants are predicted to exceed national air quality objectives in the future. Statutory air quality management areas (AQMAs) are designated where air quality is predicted to be above specified objective concentrations by specific target dates, and statutory air quality action plans will be necessary to improve the local air quality within these areas. Over 124 local authorities in England (including London), Wales and Scotland anticipate declaring AQMAs following the conclusion of the statutory air quality review and assessment process. However, other influences are being exerted on the local air quality management process and AQMA decision-making processes. Such influences include regional and sub- regional collaborative working between local authorities and government agencies and wider political decision-making processes. Some regions of Great Britain (encompassing England (including London), Scotland and Wales) anticipate many AQMA designations, whilst other regions are not anticipating any such designations despite apparently similar air quality circumstances. Evidence for regional or sub-regional variations in the locations of anticipated AQMAs are examined through an evaluation of the outcomes of the scientific review and assessment process undertaken by local authorities declaring AQMAs, and through a local authority survey to identify influences on decision-making processes at a level above that of the local authority. Regional variation is reported in the type of pollutant causing AQMAs to be declared, in the numbers of AQMAs in regions and in the spatial distribution of AQMAs across Great Britain.  相似文献   
414.
ABSTRACT: A grid based daily hydrologic model for a watershed with paddy fields was developed to predict the stream discharge. ASCII formatted elevation, soil, and land use data supported by the GRASS Geographic Information System are used to generate distributed results such as surface runoff and subsurface flow, soil water content, and evapotranspiration. The model uses a single flow path algorithm and simulates a water balance at each grid element. A linear reservoir assumption was used to predict subsurface runoff components. The model was applied to a 75.6 km2 watershed located in the middle of South Korea, and observed stream flow hydrographs from 1995 and 1996 were compared to model predictions. The stream flow predictions of 1995 and 1996 generally agreed with the observed flow, resulting in a Nash‐Sutcliffe efficiency R2 of 0.60 and 0.62, respectively. The hydraulic conductivity for percolating water through the saturated layer affected baseflow generation. The levee height of the paddy influenced the time and magnitude of the surface runoff, depending on irrigation management. The model will be used for making low flow management decisions by evaluating the role of each land use to stream flow, especially in case of paddy decrease by gradual urbanization of a watershed.  相似文献   
415.
ABSTRACT: Ground water contamination by excess nitrate leaching in row‐crop fields is an important issue in intensive agricultural areas of the United States and abroad. Giant cane and forest riparian buffer zones were monitored to determine each cover type's ability to reduce ground water nitrate concentrations. Ground water was sampled at varying distances from the field edge to determine an effective width for maximum nitrate attenuation. Ground water samples were analyzed for nitrate concentrations as well as chloride concentrations, which were used as a conservative ion to assess dilution or concentration effects within the riparian zone. Significant nitrate reductions occurred in both the cane and the forest riparian buffer zones within the first 3.3 m, a relatively narrow width. In this first 3.3 m, the cane and forest buffer reduced ground water nitrate levels by 90 percent and 61 percent, respectively. Approximately 40 percent of the observed 99 percent nitrate reduction over the 10 m cane buffer could be attributed to dilution by upwelling ground water. Neither ground water dilution nor concentration was observed in the forest buffer. The ground water nitrate attenuation capabilities of the cane and forest riparian zones were not statistically different. During the spring, both plant assimilation and denitrification were probably important nitrate loss mechanisms, while in the summer nitrate was more likely lost via denitrification since the water table dropped below the rooting zone.  相似文献   
416.
/ Land use/land cover classifications for 1973 and 1991, derived from the interpretation of satellite imagery, are quantified on the basis of biophysical land units in a study area in southeastern Australia. Nutrient export potentials are estimated for each land unit based on their composition of land use/land cover classes. Spatial and temporal comparisons are made of the land units based on the calculated pollution hazard indicators to provide an insight into changes in the state of the environment and the regional significance of land use changes. For example, one ecosystem, unique to the study, showed a large increase in pollution hazard over the study period as a manifestation of an 11-fold rise in cleared area and an expansion of cropping activities. The benefits to environmental management in general are discussed.KEY WORDS: Land cover change; Nutrient export; Environmental condition; Pollution hazard; Agricultural pollution; Nonpoint source pollution; Diffuse pollution; Environmental degradation  相似文献   
417.
Sciurus carolinensis ) have been labor intensive and costly, I demonstrate the use of line transect surveys to estimate gray squirrel density and determine the costs of conducting surveys to achieve precise estimates. Density estimates are based on four transects that were surveyed five times from 30 June to 9 July 1994. Using the program DISTANCE, I estimated there were 4.7 (95% CI = 1.86–11.92) gray squirrels/ha on the Clemson University campus. Eleven additional surveys would have decreased the percent coefficient of variation from 30% to 20% and would have cost approximately $114. Estimating urban gray squirrel density using line transect surveys is cost effective and can provide unbiased estimates of density, provided that none of the assumptions of distance sampling theory are violated.  相似文献   
418.
Economic interpretations of sustainable development have concentrated on the need to maintain the aggregate capital stock intact, so as to ensure a constant stream of welfare through time. A sectoral approach to sustainability, in terms of this model, will be justified if substitution possibilities between that sector and the rest of the economy are limited. This assumption is examined in relation to the water sector, and it is found that further assumptions about substitution possibilities need to be made within the sector itself. Suggestions are offered as to how such substitutions might be made to advantage, which is contrasted to recent water management practices in England and Wales. It is argued that assumptions about substitution possibilities are in general overly restrictive, with the result that sustainability objectives fall short of optimum levels that could be achieved.  相似文献   
419.
ABSTRACT: Accurate data about nutrient concentrations in wastewater treatment plant effluents are needed for river basin water-quality studies. As part of the U.S. Geological Survey's National Water-Quality Assessment Program in the South Platte River Basin, nutrient data were requested from 31 wastewater-treatment plants located in the basin. This article describes the types of nutrient data available from the plants, examines the variability of effluent nutrient concentrations, and discusses methods for estimation of nutrient concentrations where data are lacking. Ammonia was monitored at 88 percent of the plants, nitrite plus nitrate was monitored at 40 percent of the plants, and organic nitrogen and phosphorus were monitored at less than 25 percent of the plants. Median total nitrogen concentrations and median total phosphorus concentrations were small compared to typical literature estimates for wastewater-treatment plants with secondary treatment. Nutrient concentrations in effluent from wastewater-treatment plants varied widely between and within plants. For example, ammonia concentrations varied as much as 5 mg/L during a day, as much as 10 mg/L from day to day, and as much as 30 mg/L from summer to winter within a plant. In the South Platte River Basin, estimates of median annual ammonia and nitrite plus nitrate concentrations can be improved based on plant processes; and nitrite plus nitrate and organic nitrogen concentrations can be estimated based on ammonia concentrations. However, to avoid large estimation errors, more complete nutrient data from wastewater-treatment plants are needed for integration into river basin water quality studies. The paucity of data hinders attempts to evaluate the relative importance of point source and nonpoint source nutrient loadings to rivers.  相似文献   
420.
ABSTRACT: A study was conducted to determine the effects of mining and reclaiming originally undisturbed watersheds on surface-water hydrology in three small experimental watersheds in Ohio. Approximately six years of data were collected at each site, with differing lengths of premining (Phase 1), mining and reclamation (Phase 2), and post-reclamation (Phase 3) periods. Mining and reclamation activities showed no consistent pattern iii base-flow, and caused slightly more frequent higher daily flow volumes. Phase 2 activities can cause reductions in seasonal variation in double mass curves compared with Phase 1. Restoration of seasonal variations was noticeably apparent at one site during Phase 3. The responses of the watersheds to rainfall intensities causing larger peak flow rates generally decreased due to mining and reclamation, but tended to exceed responses observed in Phase 1 during Phase 3. Natural Resources Conservation Service (NRCS) curve numbers increased due to mining and reclamation (Phase 2), ranging from 83 to 91. During Phase 3, curve numbers remained approximately constant from Phase 2, ranging from 87 to 91.  相似文献   
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