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231.
The U.S. Department of Defense approved activities conducted at the Utah Test and Training Range (UTTR) include both operational readiness test firing of intercontinental ballistic missile motors as well as the destruction of obsolete or otherwise unusable intercontinental ballistic missile motors through open burn/open detonation (OB/ OD). Within the Utah Division of Air Quality, these activities have been identified as having the potential to generate unacceptable noise levels, as well as significant amounts of hazardous air pollutants. Hill Air Force Base, UT, has completed a series of field tests at the UTTR in which sound-monitoring surveillance of OB/OD activities was conducted to validate the Sound Intensity Prediction System (SIPS) model. Using results generated by the SIPS model to support the decision to detonate, the UTTR successfully disposed of missile motors having an aggregate net explosive weight (NEW) of 56,500 lbs without generating adverse noise levels within populated areas. These results suggest that, under appropriate conditions, missile motors of even larger NEW may be detonated without exceeding regulatory noise limits. In conjunction with collecting noise monitoring data, air quality data was collected to support the development of air emission factors for both static missile motor firings and OB/OD activities. Through the installation of 15 ground-based air samplers, the generation of combustion fixed gases, hazardous air pollutants, and chlorides were monitored during the 56,500-lb NEW detonation event. Comparison of field measurements to predictions generated from the U.S. Navy's energetic combustion pollutant formation model, POLU4WN, indicated that, as the detonation fireball expanded from ground zero, organic compounds as well as carbon monoxide continued to oxidize as the hot gases reacted with ambient air. Hazardous air pollutant analysis of air samplers confirmed the presence of chloromethane, benzene, toluene, 1,2-propadiene, and 2-methyl-l-propene, whereas the absence of hydrogen chloride gas suggested that free chlorine is not generated during the combustion process.  相似文献   
232.
Stabilized Coal Ash Artificial Reef Studies   总被引:1,自引:0,他引:1  
In 1989, an experimental stabilized coal ash reef was deployed in Poole Bay off the southern coast of the UK. Three different mixtures of pulverised fuel ash, gypsum, flue gas desulphurisation sludge and cement were used along with concrete controls. the aim was to study the environmental compatibility of the reef materials through heavy metal analyses of the blocks to determine if any leaching or changes were occurring. at the same time, reef encrusting and associated biota have been analyzed together with material from concrete control and natural reefs to determine if there was any evidence for excess bioaccumulation.

This paper presents the results from studies of sectioned reef blocks immersed for 3 and 4 years. No significant change in levels of heavy metals (Cd, Cr, Cu, Mn, Ni, Pb, Zn) has been detected. Surface loss of calcium, presumably associated with the gypsum component, is confirmed with evidence of replacement by magnesium. Trends in data suggest initial surface changes which slow with time.

Epibiota have been analyzed for heavy metal content. the variety of reef-associated organisms has been extended to include mobile, resident species which are higher in the food chain: molluscs, crustaceans and territorial fish. No consistent evidence of bioaccumulation of a range of heavy metals (above those levels found in organisms associated with control reefs) has been detected. Monitoring of the encrusting species range and densities shows little difference between colonisation of the concrete and ash mixture blocks.  相似文献   
233.
A method that can be used for the monitoring of exposure to alkylating agents in the environment is presented. It is based on the quantification of alkylated N‐terminal valines in hemoglobin, using a modified Edman degradation procedure. The detection limit (GC/electron capture detector or GC/MS) is increased by two magnitudes of ten when using pentafluorophenyl isothiocyanate instead of phenyl isothiocyanate in the derivatization step. As little as one nmole N‐(—2 hydroxyethyl)valine per gram hemoglobin can be detected under practical conditions.  相似文献   
234.
235.
Patterns of ozone concentration ([O(3)]), O(3) deposition velocity (v(d)) and O(3) flux (F(c)) over an evergreen forest canopy are shown in relation to measuring method, physiological activity of the trees, and time of year. The gradient and eddy correlation methods were compared and showed similar diel v(d) patterns. Daytime F(c) was correlated with CO(2) and water vapour fluxes, while no correlation between [O(3)] in the range 10-70 ppb (nl l(-1)) and F(c) was seen in this study. F(c) was primarily driven by stomatal conductance, reactions with surfaces, particles and gases, and not by [O(3)]. On a monthly basis, [O(3)] was always highest in the afternoon while v(d) was typically higher in the morning, resulting in an equal F(c) over the day. Night-time F(c) was more than half of the daytime O(3) flux. The data reveal the importance of emissions of nitric oxide and terpenes as O(3) removal factors in evergreen forest dominated by Norway spruce.  相似文献   
236.
The concept of lifestyle is rather difficult to pin down. It is used in a variety of disciplines and related to many different problems. In our highly modern society, lifestyle is more often mentioned as something we need to change in order to achieve a sustainable development. Our main interest then is how we create and change a lifestyle. How can we understand why it is sometimes difficult to achieve change? In relation to terms like beliefs, desires, intentions, habits and artefacts six factors will be suggested. Within these factors we may have a foundation for a mechanism underlying the creation and change of lifestyle. A definition of the concept of lifestyle from a cognitive science perspective will also be suggested, as derived from the same foundation and terms related to it.  相似文献   
237.
Odor emission from livestock production systems is a major nuisance in many rural areas. This study aimed at determining the major airborne chemical compounds responsible for the unpleasant odor perceived in swine facilities during slurry handling, and at proposing predictive models of odor concentration (OC) based on the concentrations of specific odorants in the air. A multivariate data analysis strategy involving principal components analysis and multiple linear regressions was implemented to analyze the relationships between concentration of 35 gases (measured by GC/MS or gas detection tubes), and the overall OC perceived by sensory analysis. The study compiled data on the concentration of odor and odorants, measured in the headspace of 24 unstored and stored slurry samples collected from three different types of production units on 8 commercial swine farms. Among all the measured constituents, OC was found to have the highest correlation with the sulfur containing compounds (i.e. hydrogen sulfide, dimethylsulfide, dimethyldisulfide, dimethyltrisulfide). The concentration of hydrogen sulfide accounted for 68% of the variation in OC above the stirred slurry samples. The highest concentrations of volatile organic compounds were observed for phenols and indoles, which made a significant contribution to the overall OC when the slurry was fresh. The contribution of ammonia to the OC was only significant in the absence of hydrogen sulfide. The precision of predictive models of OC based on the concentration of specific odorants in the air was satisfactory (R2 between 0.66 and 0.89). Hence, this study suggests that monitoring of specific odor compounds released from agitated swine slurry can be used to predict the concentration of odor perceived close to the source (e.g. at storage units), allowing the assessment of odor nuisance potentials.  相似文献   
238.
In recent years, cities have been portrayed as important loci for transformations of large-scale systems. This paper contributes to scholarship on urban transitions by exploring why the boundaries, functions and challenges of large-scale systems typically are framed differently at the urban level of governance than at more aggregated levels of governance. Empirically, we examine the wastewater system in Denmark by contrasting framings at the urban and national levels over the last 20 years and the transition dynamics that emerged as a consequence of their juxtaposition. The findings illustrate that urban governance of the wastewater system was influenced by a particular concern with developing attractive and competitive urban spaces. The wastewater system emerged as a ‘place-bound’ and even ‘place-making’ governance concern; as such, the boundaries and functions of the system were subject to continuous redefinition at the city level. This urban framing conflicted with the national-level, efficiency-oriented framing of the wastewater system as homogenous, without regard to place-specific differences. The research findings suggest that a distinct characteristic of urban-level governance is concern for place-specific development; this concern can be transformative because it leads to ongoing reinterpretation of traditional boundaries and dependencies between large-scale systems and local contexts.  相似文献   
239.
The effect of atmospheric nitrogen deposition on the species richness of acid grasslands was investigated by combining data from a large Danish monitoring program with a large European data set, where a significant non-linear negative effect of nitrogen deposition had been demonstrated (Stevens et al., 2010). The nitrogen deposition range in Denmark is relatively small and when only considering the Danish data a non-significant decrease in the species richness with nitrogen deposition was observed. However, when both data sets were combined, then the conclusion of the European survey was further corroborated by the results of the Danish monitoring. Furthermore, by combining the two data sets a more comprehensive picture of the threats to the biodiversity of acid grasslands emerge; i.e., species richness in remnant patches of acid grassland in intensively cultivated agricultural landscapes is under influence not only from nitrogen deposition, but also from current and historical land use.  相似文献   
240.
This paper presents results from laboratory studies to measure the methane yield and rate of digestion of reject bananas. These parameters were determined in experiments that took into account the likely configuration of a full-scale plant in the banana growing region of north Queensland. The digestion was conducted in a 200-l reactor using fed-batch operation, relying entirely on the natural microbial consortia on the reject bananas to avoid reliance on external inocula such as sludge, an undesirable material around food packaging facilities. An enrichment culture was first established in a highly buffered 200-l batch digestion unit. The fed-batch digester was then started by exchanging leachate with the mature batch reactor. Under loading conditions of 0.6 kg VS m(-3)d(-1) over 70 days where the average working volume was 160 l, the digester produced 398+/-20 l CH4 kg VS(-1). Increasing the loading rate to 1.6 kg VS m(-3)d(-1) resulted in a reduced methane yield of 210 l CH4 kg VS(-1) over 23 days of operation, with a concomitant accumulation of banana waste in the digester. The leachate at the end of digestion contained over 4000 mg l(-1)K, 200 mg l(-1) N and 75 mg l(-1), levels that exceed acceptable limits for general agricultural irrigation.  相似文献   
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