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11.
Douglas W. Cooper 《Journal of the Air & Waste Management Association (1995)》2013,63(2):205-208
Factors which help minimize pressure drop at a given level of collection efficiency for a bed packed with roughly spherical collectors are studied here by using the quality factor, the ratio of the single collector collection efficiency to the force per unit area on the single collector. This analysis indicates that energy-efficient designs can be obtained as follows: choose a representative particle size; if impaction predominates, design for an impaction parameter near one; if interception predominates, design for the smallest packing diameters feasible; if gravitational settling predominates, design for the largest packing diameters possible; if diffusion predominates, design for collector Reynolds numbers near 102. Some more general cases are also discussed. 相似文献
12.
J. S. Evans P. L. Kinney J. L. Koehler D. W. Cooper 《Journal of the Air & Waste Management Association (1995)》2013,63(5):551-553
Abstract There is a dearth of information on dust emissions from sources that are unique to the U.S. Department of Defense testing and training activities. However, accurate emissions factors are needed for these sources so that military installations can prepare accurate particulate matter (PM) emission inventories. One such source, coarse and fine PM (PM10 and PM2.5) emissions from artillery backblast testing on improved gun positions, was characterized at the Yuma Proving Ground near Yuma, AZ, in October 2005. Fugitive emissions are created by the shockwave from artillery pieces, which ejects dust from the surface on which the artillery is resting. Other contributions of PM can be attributed to the combustion of the propellants. For a 155–mm howitzer firing a range of propellant charges or zones, amounts of emitted PM10 ranged from ~19 g of PM10 per firing event for a zone 1 charge to 92 g of PM10 per firing event for a zone 5. The corresponding rates for PM2.5 were ~9 g of PM2.5 and 49 g of PM2.5 per firing. The average measured emission rates for PM10 and PM2.5 appear to scale with the zone charge value. The measurements show that the estimated annual contributions of PM10 (52.2 t) and PM2.5 (28.5 t) from artillery backblast are insignificant in the context of the 2002 U.S. Environment Protection Agency (EPA) PM emission inventory. Using national–level activity data for artillery fire, the most conservative estimate is that backblast would contribute the equivalent of 5 x 10–4% and 1.6 x 10–3% of the annual total PM10 and PM2.5 fugitive dust contributions, respectively, based on 2002 EPA inventory data. 相似文献
13.
J. A. Sousa J. E. Houck J. A. Cooper J. M. Daisey 《Journal of the Air & Waste Management Association (1995)》2013,63(12):1439-1444
The Deep Creek Lake Study of 1983 provided an opportunity to obtain emission samples from coal-fired power plants with a dilution sampler for mutagenicity testing. Stack and ambient samples of particulate matter were collected with a dilution sampler at three coal-fired power plants in West Virginia. Samples were sequentially extracted with cyclohexane (CX), dichloromethane (DCM) and acetone (ACE) and tested for mutagenicity in the Ames Salmonella/microsome assay using TA98 (-S9). For the stack samples, the CX, DCM and ACE fractions constituted 1.0, 0.7 and 98.1 percent of the total extractable organic material (EOM), respectively, compared to 28.5, 7.4 and 64.1 percent for the ambient samples. In contrast, the mutagenic activity of the organic fractions was concentrated in the CX and DCM fractions. The cyclohexane- and dichloromethane-soluble fractions of the stack samples from all locations exhibited mutagenicity when tested in the plate incorporation assay. No significant response was observed with the acetone fraction. When tested with Kado's modification of the preincubation assay, the acetone-soluble fraction did exhibit mutagenic activity comparable to that of the other fractions when expressed in units of revertants per milligram of particular matter. Chemical analyses of one of the acetone-soluble fractions indicated that half of the mass was sulfuric acid while the remainder consisted of C, H and O. More than 30 peaks were detected in the high pressure liquid chromatogram of this fraction. Although little mutagenic activity was detected in the polar ACE fraction of the diluted stack emissions samples with this single bioassay, in view of the large mass of this fraction, further investigation of the chemical composition and genotoxic activity of this fraction would be prudent. 相似文献
14.
de Nazelle A Nieuwenhuijsen MJ Antó JM Brauer M Briggs D Braun-Fahrlander C Cavill N Cooper AR Desqueyroux H Fruin S Hoek G Panis LI Janssen N Jerrett M Joffe M Andersen ZJ van Kempen E Kingham S Kubesch N Leyden KM Marshall JD Matamala J Mellios G Mendez M Nassif H Ogilvie D Peiró R Pérez K Rabl A Ragettli M Rodríguez D Rojas D Ruiz P Sallis JF Terwoert J Toussaint JF Tuomisto J Zuurbier M Lebret E 《Environment international》2011,37(4):766-777
15.
Sensitized photodechlorination of polychlorinated biphenyl, PCB 138, in three different surfactant solutions was studied. The sensitizer of choice was leuco-methylene blue, which was produced in situ from methylene blue using either triethylamine or sodium borohydride. Three types of surfactants, anionic (SDS), neutral (TWEEN 80), and cationic (CTAB) at different concentrations were investigated. The neutral and cationic surfactants were found to be more effective than anionic. In each case the surfactant concentration was found to play a significant role in the rate of dechlorination. For different sensitized systems (triethylamine or sodium borohydride), a different product distribution and a different pathway of dechlorination was observed. 相似文献
16.
17.
Joseph C. Cooper Giovanni Signorello 《Journal of Environmental Planning and Management》2008,51(1):1-14
Programs that reimburse farmers for the cost of implementing more environmentally benign management practices are becoming increasingly popular in both the US and the EU. Utilizing the random utility and random profit difference approaches, the paper develops a theoretical model that explains why farmers may require a premium in excess of the decrease in profits to adopt a conservation plan, and may even require a premium in the case where adoption of the plan is associated with a mean increase in profits. This premium is estimated using a survey of farmers in conjunction with predictions of changes in production costs. 相似文献
18.
Fungicidal values of bio-oils and their lignin-rich fractions obtained from wood/bark fast pyrolysis 总被引:2,自引:0,他引:2
Pine wood, pine bark, oak wood and oak bark were pyrolyzed in an auger reactor. A total of 16 bio-oils or pyrolytic oils were generated at different temperatures and residence times. Two additional pine bio-oils were produced at the National Renewable Energy Laboratory in a fluidized-bed reactor at different temperatures. All these bio-oils were fractionated to obtain lignin-rich fractions which consist mainly of phenols and neutrals. The pyrolytic lignin-rich fractions were obtained by liquid-liquid extraction. Whole bio-oils and their lignin-rich fractions were studied as potential environmentally benign wood preservatives to replace metal-based CCA and copper systems that have raised environmental concerns. Each bio-oil and several lignin-rich fractions were tested for antifungal properties. Soil block tests were conducted using one brown-rot fungus (Gloeophyllum trabeum) and one white-rot fungus (Trametes versicolor). The lignin-rich fractions showed greater fungal inhibition than whole bio-oils for a impregnation solution 10% concentration level. Water repellence tests were also performed to study wood wafer swelling behavior before and after bio-oil and lignin-rich fraction treatments. In this case, bio-oil fractions did not exhibit higher water repellency than whole bio-oils. Comparison of raw bio-oils in soil block tests, with unleached wafers, at 10% and 25% bio-oil impregnation solution concentration levels showed excellent wood preservation properties at the 25% level. The good performance of raw bio-oils at higher loading levels suggests that fractionation to generate lignin-rich fractions is unnecessary. At this more effective 25% loading level in general, the raw bio-oils performed similarly. Prevention of leaching is critically important for both raw bio-oils and their fractions to provide decay resistance. Initial tests of a polymerization chemical to prevent leaching showed some success. 相似文献
19.
R. Wilson G. Peters J. Regel D. Grémillet K. Pütz M. Kierspel H. Weimerskirch J. Cooper 《Marine Biology》1998,130(4):559-566
Stomach temperature loggers have proved useful for the study of feeding activity in free-living seabirds, but their usage
has been restricted because they are frequently dislodged and lost during the seabirds' regular regurgitation of indigestible
prey remains. In the present study we examine the incidence of spontaneous regurgitation (pellet production) in free-living
seabirds, consider the effect this has on the likely retrieval of stomach temperature loggers and present a structural modification
of the logger housings which leads to a much lower incidence of regurgitation. Systems were tested on albatrosses, cormorants,
gannets and penguins.
Received: 15 July 1997 / Accepted: 31 October 1997 相似文献
20.
Sara P. Bombaci Cooper M. Farr H. Travis Gallo Anna M. Mangan Lani T. Stinson Monica Kaushik Liba Pejchar 《Conservation biology》2016,30(1):216-225
Scientists are increasingly using Twitter as a tool for communicating science. Twitter can promote scholarly discussion, disseminate research rapidly, and extend and diversify the scope of audiences reached. However, scientists also caution that if Twitter does not accurately convey science due to the inherent brevity of this media, misinformation could cascade quickly through social media. Data on whether Twitter effectively communicates conservation science and the types of user groups receiving these tweets are lacking. To address these knowledge gaps, we examined live tweeting as a means of communicating conservation science at the 2013 International Congress for Conservation Biology (ICCB). We quantified and compared the user groups sending and reading live tweets. We also surveyed presenters to determine their intended audiences, which we compared with the actual audiences reached through live tweeting. We also asked presenters how effectively tweets conveyed their research findings. Twitter reached 14 more professional audience categories relative to those attending and live tweeting at ICCB. However, the groups often reached through live tweeting were not the presenters’ intended audiences. Policy makers and government and non‐governmental organizations were rarely reached (0%, 4%, and 6% of audience, respectively), despite the intent of the presenters. Plenary talks were tweeted about 6.9 times more than all other oral or poster presentations combined. Over half the presenters believed the tweets about their talks were effective. Ineffective tweets were perceived as vague or missing the presenters’ main message. We recommend that presenters who want their science to be communicated accurately and broadly through Twitter should provide Twitter‐friendly summaries that incorporate relevant hashtags and usernames. Our results suggest that Twitter can be used to effectively communicate speakers’ findings to diverse audiences beyond conference walls. 相似文献