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101.
Like many governmental actors in recent decades, the U.S. National Park Service (NPS) has operated increasingly through partnerships with other state and federal agencies, non-governmental organizations (NGOs), community groups, and private sector corporations. Perhaps the most salient example of this trend toward partnerships is the rapid growth and development of national heritage areas (NHAs). Since the first NHA received congressional designation in 1984, NHAs have become an increasingly popular strategy for protecting and managing landscapes. To date, congressional designation has been granted to 49 NHAs, making them one of the fastest growing initiatives involving the NPS. Despite this growth, no prior research has examined the efficacy or effectiveness of the NHA model. This article introduces the NHA concept, while reviewing the literature on evaluation research and its application to protected area management. We then offer an NHA program theory model for evaluating NHAs. The model was developed using a theory-based, process evaluation approach, along with 90 qualitative interviews conducted at three study sites: Blackstone River Valley National Heritage Corridor, MA-RI (BLAC); Delaware and Lehigh National Heritage Corridor, PA (DELE); and Cane River National Heritage Area, LA (CANE). We conclude by discussing the key challenges and implications associated with developing a long-term research agenda for evaluating NHAs.  相似文献   
102.
Biomonitors are organisms that provide quantitative information on environmental quality. There are some constraints and limitations for the use of plants as biomonitors of soil pollution, as pointed out recently by some authors in this journal. However, we defend the use of plants as biomonitors, and argue that they have important advantages over soil analyses as indicators of soil quality, particularly when investigations are made on a large scale.  相似文献   
103.
Current occupant protection assessment for side impact is focused on struck side occupants sitting alone. In a representative sample of tow-away side collisions from the UK, only one-third of front seat occupants in side collisions were alone, on the struck side of the car. The other two-thirds were either a non-struck side occupant alone or a situation where the adjacent seat was also occupied. In terms of restraint protection for non-struck side occupants, belts appeared to be less effective in perpendicular compared to oblique side crashes. Front seat occupancy had bearing on injury outcome. With both front seats occupied, there was a reduction in AIS 27+ injury to belted non-struck side occupants due to a reduction in chest and lower limb injuries. Struck side occupants sustained increased injury rates to the extremities when accompanied by a belted non-struck side occupant but no notable increases in moderate to serious injury to the head, chest, abdomen or pelvis.  相似文献   
104.
Open-top chambers (OTCs) and corresponding ambient air plots (AA) were used to assess the impact of ambient ozone on growth of newly planted apple trees at the Montague Field research center in Amherst, MA. Two-year-old apple trees (Malus domestica Borkh 'Rogers Red McIntosh') were planted in the ground in circular plots. Four of the plots were enclosed with OTCs where incoming air was charcoal-filtered (CF); four were enclosed with OTCs where incoming air was not charcoal-filtered (NF) and four were not enclosed, allowing access to ambient air conditions (AA). Conditions in both CF and NF OTCs resulted in increased tree growth and changed incidence of disease and arthropod pests, compared to trees in AA. As a result, we were not able to use the OTC method to assess the impact of ambient ozone on growth of young apple trees in Amherst, MA.  相似文献   
105.
106.
Evaluation of modified clay coagulant for sewage treatment   总被引:1,自引:0,他引:1  
Jiang JQ  Zeng Z  Pearce P 《Chemosphere》2004,56(2):181-185
The use of modified clays as coagulants for sewage treatment was investigated in this study. The raw clays were montmorillonites K10 and KSF, and were modified by polymeric Al or Fe and/or Al/Fe mixing polymeric species. The comparative performance of modified clays and aluminium sulphate and ferric sulphate were evaluated in terms of the removal of turbidity, suspended solids, UV(254)-abs, colour, and total and soluble CODs. The results demonstrated that after being modified with mixing polymeric Al/Fe species, two montmorillonite clays possess greater properties to remove the particles (as suspended solids) and organic pollutants (as COD and UV(254)-abs) from the sewage and to enhance the particle settling rate significantly.  相似文献   
107.
The U.S. Environmental Protection Agency (EPA) implemented a program to identify tailpipe emissions of criteria and air-toxic contaminants from in-use, light-duty low-emission vehicles (LEVs). EPA recruited 25 LEVs in 2002 and measured emissions on a chassis dynamometer using the cold-start urban dynamometer driving schedule of the Federal Test Procedure. The emissions measured included regulated pollutants, particulate matter, speciated hydrocarbon compounds, and carbonyl compounds. The results provided a comparison of emissions from real-world LEVs with emission standards for criteria and air-toxic compounds. Emission measurements indicated that a portion of the in-use fleet tested exceeded standards for the criteria gases. Real-time regulated and speciated hydrocarbon measurements demonstrated that the majority of emissions occurred during the initial phases of the cold-start portion of the urban dynamometer driving schedule. Overall, the study provided updated emission factor data for real-world, in-use operation of LEVs for improved emissions modeling and mobile source inventory development.  相似文献   
108.
Public visits to parks and protected areas continue to increase and may threaten the integrity of natural and cultural resources and the quality of the visitor experience. Scientists and managers have adopted the concept of carrying capacity to address the impacts of visitor use. In the context of outdoor recreation, the social component of carrying capacity refers to the level of visitor use that can be accommodated in parks and protected areas without diminishing the quality of the visitor experience to an unacceptable degree. This study expands and illustrates the use of computer simulation modeling as a tool for proactive monitoring and adaptive management of social carrying capacity at Arches National Park. A travel simulation model of daily visitor use throughout the Park's road and trail network and at selected attraction sites was developed, and simulations were conducted to estimate a daily social carrying capacity for Delicate Arch, an attraction site in Arches National Park, and for the Park as a whole. Further, a series of simulations were conducted to estimate the effect of a mandatory shuttle bus system on daily social carrying capacity of Delicate Arch to illustrate how computer simulation modeling can be used as a tool to facilitate adaptive management of social carrying capacity.  相似文献   
109.
Airborne particulate matter has been collected from within,and proximal to, an opencast coal mine in south Wales. Thiswork forms the first part of a three year project to collectand characterise, then determine the possible toxicology ofairborne particles in the south Wales region. High-resolutionField Emission SEM has shown that the coal mine dusts consistlargely of an assemblage of mineral grains and vehicle exhaustparticles. SEM-EDX has shown that the mineralogical make-up ofthe PM10 is complex, heterogeneous, and constantly changing.These findings are supported by analytical TEM-EPXMA.However, patterns can be determined relating the mineralogicalcomposition of the airborne particles to collection locationsand mining activities within the opencast. At our studyopencast, Park Slip West, quartz, which has known healtheffects, never exceeded 30% of the total collection mass, andaverage levels were much less. Vehicle exhaust emissions wasthe largest source in terms of particle numbers. The mass ofairborne particulate matter within the pit averagedapproximately twice that of outside the pit: importantlyhowever, this higher mass was due to relatively large, andnon-respirable, mineral grains. This study demonstrates that the physicochemical andmineralogical characterisation of airborne particles frommining and quarrying is essential to quantify the respirablefraction, and to identify potentially hazardous componentswithin the PM10.  相似文献   
110.
Four-week-old paper birch (Betula papyrifera Marsh.) seedlings, inoculated or non-inoculated with the ectomycorrhizal fungus Pisolithus tinctorius (Pers.) Coker & Couch and grown in steamed or non-steamed soil, were exposed to ozone (O(3)) and/or simulated acid rain (SAR). Plants were exposed to O(3) for 7 h per day on 5 days per week for 12 weeks. O(3) concentrations were maintained between 0.06 and 0.08 ppm. SAR was applied 10 min per day on 2 days per week. O(3), SAR, soil regime and mycorrhizal treatment did not significantly affect any of the measured variables. Interactions between O(3) and SAR, SAR and mycorrhizal treatment, soil regime and mycorrhizal treatment and ozone and soil regime had significant effects. Treatment of seedlings with pH 3.5 SAR caused increases in growth which were more apparent in birch exposed to O(3). Mucorrhizal treatment caused increased growth in non-steamed soil, while growth appeared to decrease in steamed soil. Birch seedlings grew much better in steamed soil. The implications of increased growth in steamed soil may demonstrate the importance of looking at the secondary effects of pollutants on soil-borne organisms.  相似文献   
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