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1.
This paper describes a novel technology for the removal of solidified radioactive waste from underground storage tanks at the DOE Hanford site in southeast Washington. The process involves the use of a unique high pressure system which pulverizes the hardened saltcake with stainless steel pellets to a powder for easy vacuum removal. The steel pellets can be magnetically separated from the waste material for re-use. Specifically this study analyzes the effects of various steel abrasives, pressure of the air stream, and stand-off distance on removal rates and penetration depth on simulated saltcake samples using the high pressure technique. A full-scale test set-up and protocol were implemented to allow for comprehensive testing. To insure reproducibility of the method, tests were then run for the optimum removal parameters. A time-dependent test was also conducted to determine the relationship of removal rates to length of pressure blasts. The results of these tests revealed that stand-off distance and pressure could be positively correlated to removal volumes. Additionally, a statistical analysis confirmed that nozzle angle is independent of removal rate. This study demonstrated that the pellet ‘blaster’ technique is a safe, effective method for removal of radioactive wastes without any increase in either waste mass or volume.  相似文献   
2.
Motor vehicle crashes killed almost 5,000 pedestrians in 2005 in the United States. Pedestrian risk may be higher in areas characterized by urban sprawl. From 2000 to 2004, pedestrian fatality rates declined in the United States, but the Atlanta metropolitan statistical area did not experience the same decline. Pedestrian fatality rates for males, Hispanics, and the 15–34 and 35–54 year age groups were higher in Atlanta than in the United States overall. Pedestrian safety interventions should be targeted to high-risk populations and localized pedestrian settings.  相似文献   
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Ramalina maciformis and Ramalina lacera were exposed to different solutions and UV-B to seek for alterations in the PSII photosynthetic quantum yield (F(v)/F(m)), in response to chemicals and radiation. For R. maciformis, significant alterations of the F(v)/F(m) ratio occurred only in response to different bisulphite solutions. The F(v)/F(m) ratio decreased most in R. maciformis and R. lacera following exposure to 5 and 1 mM bisulphite, respectively. Significant differences in F(v)/F(m) ratios were observed for R. lacera in response to different solutions and light at different wavelengths, this being synergistic. The PSII system was unaffected by simulated acid rain in both lichens. R. maciformis, in particular, may survive limited acid rain exposure owing to high Ca oxalate accumulation. The F(v)/F(m) ratio decreased most in R. lacera following short-term exposures to CuSO(4), suggesting that this species is more sensitive to Cu ions under acidic conditions.  相似文献   
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Ecosystem restoration in south Florida is a state and national priority centered on the Everglades wetlands. However, urban development pressures affect the restoration potential and remaining habitat functions of the natural undeveloped areas. Land use (LU) planning often focuses at the local level, but a better understanding of the cumulative effects of small projects at the landscape level is needed to support ecosystem restoration and preservation. The South Florida Ecosystem Portfolio Model (SFL EPM) is a regional LU planning tool developed to help stakeholders visualize LU scenario evaluation and improve communication about regional effects of LU decisions. One component of the SFL EPM is ecological value (EV), which is evaluated through modeled ecological criteria related to ecosystem services using metrics for (1) biodiversity potential, (2) threatened and endangered species, (3) rare and unique habitats, (4) landscape pattern and fragmentation, (5) water quality buffer potential, and (6) ecological restoration potential. In this article, we demonstrate the calculation of EV using two case studies: (1) assessing altered EV in the Biscayne Gateway area by comparing 2004 LU to potential LU in 2025 and 2050, and (2) the cumulative impact of adding limestone mines south of Miami. Our analyses spatially convey changing regional EV resulting from conversion of local natural and agricultural areas to urban, industrial, or extractive use. Different simulated local LU scenarios may result in different alterations in calculated regional EV. These case studies demonstrate methods that may facilitate evaluation of potential future LU patterns and incorporate EV into decision making.  相似文献   
7.
A sampling procedure for 2,4- and 2,6-toluenediisocyanate (TDI) and 4,4′-diphenylmethane diisocyanate (MDI) in the range 0.007-0.7 mg/m3 in a 15 L air sample is described. The sampling is performed with 9-(N-methylaminomethyl)-anthracene (MAMA) adsorbed on a solid sorbent, Amberlite XAD-2. The recoveries are 80–100% in this chemosorption reaction. The urea derivatives are desorbed with N,N-dimethylformamide and analysed by high performance liquid chromatography (HPLC). Samples and prepared chemosorption tubes are stable for at least two weeks if stored in the dark. To complete the investigation, field measurements of TDI were performed in an industrial atmosphere.  相似文献   
8.
The porous polymers Amberlite XAD-2 and XAD-7 were evaluated for the sampling of ethylene glycol, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol and 2-ethoxyethyl acetate in work-room air. Using diethyl ether desorption, these adsorbents were found excellent for the compounds studied.  相似文献   
9.
Previous attempts to measure heavy metals in air are discussed with particular reference to lead. A polarographic method was developed for lead in air samples taken on glass fiber sheet. Using this method, the distribution of lead across the glass fiber sheet was investigated, and within experimental error, found to be uniform. Air samples from 18 Ontario cities, previously analyzed for benzo [a]pyrene content were analyzed.  相似文献   
10.
Information processing style, often termed cognitive style, has gained prominence in the organizational behavior literature as researchers use it as a basis for studying decision making behavior, conflict, strategy development, and group processes. However, the many operational definitions and measures of cognitive style have produced inconsistent and confusing results. This study tested the interrelationship among four measures of this construct: the Myers–Briggs Type Indicator, the Group Embedded Figures Test, the Learning Styles Inventory, and the Decision Style Inventory. Measures that appeared to be conceptually linked through their underlying theories were compared. Results indicate that the various measures are not strongly interrelated and appear to be measuring different aspects of information processing and decision making. Copyright © 1999 John Wiley & Sons, Ltd.  相似文献   
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