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481.
Ketwalee Kositkanawuth Roja Haritha Gangupomu Brian H. Dennis Frederick M. MacDonnell Richard Billo 《Journal of the Air & Waste Management Association (1995)》2013,63(10):1182-1195
To increase U.S. petroleum energy independence, the University of Texas at Arlington (UT Arlington) has developed a direct coal liquefaction process which uses a hydrogenated solvent and a proprietary catalyst to convert lignite coal to crude oil. This sweet crude can be refined to form JP-8 military jet fuel, as well as other end products like gasoline and diesel. This paper presents an analysis of air pollutants resulting from using UT Arlington's liquefaction process to produce crude and then JP-8, compared with 2 alternative processes: conventional crude extraction and refining (CCER), and the Fischer-Tropsch process. For each of the 3 processes, air pollutant emissions through production of JP-8 fuel were considered, including emissions from upstream extraction/production, transportation, and conversion/refining. Air pollutants from the direct liquefaction process were measured using a LandTEC GEM2000 Plus, Draeger color detector tubes, OhioLumex RA-915 Light Hg Analyzer, and SRI 8610 gas chromatograph with thermal conductivity detector. According to the screening analysis presented here, producing jet fuel from UT Arlington crude results in lower levels of pollutants compared to international conventional crude extraction/refining. Compared to US domestic CCER, the UTA process emits lower levels of CO2-e, NOx, and Hg, and higher levels of CO and SO2. Emissions from the UT Arlington process for producing JP-8 are estimated to be lower than for the Fischer-Tropsch process for all pollutants, with the exception of CO2-e, which were high for the UT Arlington process due to nitrous oxide emissions from crude refining. When comparing emissions from conventional lignite combustion to produce electricity, versus UT Arlington coal liquefaction to make JP-8 and subsequent JP-8 transport, emissions from the UT Arlington process are estimated to be lower for all air pollutants, per MJ of power delivered to the end user.
Implications: The United States currently imports two-thirds of its crude oil, leaving its transportation system especially vulnerable to disruptions in international crude supplies. At current use rates, U.S. coal reserves (262 billion short tons, including 23 billion short tons lignite) would last 236 years. Accordingly, the University of Texas at Arlington (UT Arlington) has developed a process that converts lignite to crude oil, at about half the cost of regular crude. According to the screening analysis presented here, producing jet fuel from UT Arlington crude generates lower levels of pollutants compared to international conventional crude extraction/refining (CCER). 相似文献
482.
Aerostat-lofted instrument and sampling method for determination of emissions from open area sources
An aerostat-borne instrument and sampling method was developed to characterize air samples from area sources, such as emissions from open burning. The 10 kg battery-powered instrument system, termed “the Flyer”, is lofted with a helium-filled aerostat of 4 m nominal diameter and maneuvered by means of one or two tethers. The Flyer can be configured variously for continuous CO2 monitoring, batch sampling of semi-volatile organic compounds (SVOCs), volatile organic compounds (VOCs), black carbon, metals, and PM by size. The samplers are controlled by a trigger circuit to avoid unnecessary dilution from background sampling when not within the source plume. The aerostat/Flyer method was demonstrated by sampling emissions from open burning (OB) and open detonation (OD) of military ordnance. A carbon balance approach was used to derive emission factors that showed excellent agreement with published values. 相似文献
483.
International pharmaceutical companies are becoming increasingly proactive in their approach to environmental management, and the results so far are impressive. The forces that affect the global pharmaceutical industry will most likely push these companies toward even greater commitments to environmental improvement and, ultimately, sustainability. © 2000 John Wiley & Sons, Inc. 相似文献
484.
In an era of increasing stakeholder scrutiny, virtually any company or industry is vulnerable to exaggerated claims of environmental harm against its products. When these claims are picked up by the media, the company can suddenly have a full‐fledged crisis on its hands. That's exactly the position the carpet industry found itself in a few years ago. But, as this article explains, carpet makers were able to fight back effectively using sound science and diplomacy. The carpet industry's experience offers valuable lessons for the entire business community. © 2000 John Wiley & Sons, Inc. 相似文献
485.
Brian Gullett Lukas Oudejans Abderrahmane Touati Shawn Ryan Dennis Tabor 《Journal of Material Cycles and Waste Management》2008,10(1):32-37
A jet resonance-enhanced multiphoton ionization (REMPI) monitor was tested on a hazardous-waste-fired boiler for its ability
to determine concentrations of polychlorinated dibenzodioxins and dibenzofurans (PCDDs/Fs). Jet REMPI is a real-time instrument
capable of highly selective and sensitive (from parts per billion to parts per trillion) detection of a broad range of aromatic
compounds, including a number of air toxic compounds. The PCDD/F toxic equivalency (TEQ) value was derived from a predetermined
correlation (R
2 = 0.74) with monochlorobenzene (MClBz). This relationship was applied to nine subsequent jet REMPI on-line measurements of
MClBz and parallel, standard extractive sampling for PCDD/F TEQ. For high waste-firing rates, with a range of PCDD/F TEQ values
between 3.9 and 6.0 ng TEQ/m3, the TEQ values predicted by jet REMPI had a relative difference of 26% with the standard EPA Method 23 results. At low waste-firing
rates (0.9–1.6 ng TEQ/m3), the relative difference increased to 219%. This limited testing shows that jet REMPI has promise as an on-line diagnostic
monitor, providing feedback on the effects on PCDD/F emissions of operating parameter changes such as fuel feed interruptions
or air pollution control failures. 相似文献
486.
F. Dennis Thomas Author Vitae Richard D. Blomberg Author Vitae Author Vitae Linda A. Cosgrove Author Vitae Author Vitae 《Journal of Safety Research》2008,39(5):459-468
Introduction
In 2004, Washington State applied NHTSA's High Visibility Enforcement model used in the Click It or Ticket seat belt campaign in an attempt to reduce unsafe driving behaviors around commercial motor vehicles (CMVs). The program was called Ticketing Aggressive Cars and Trucks (TACT). This paper details the methods used to evaluate the program's effectiveness and the results of the evaluation.Method
Four high-crash interstate highway corridors, each approximately 25 miles in length, were selected. Two of these corridors received TACT media messages and increased enforcement over an 18-month period while two comparison corridors did not receive any increased media or enforcement.Results
A total of 4,737 contacts were made with drivers during the two enforcement waves, and 72% of these contacts led to a citation. Drivers at the intervention sites who said they saw or heard any of the TACT messages increased from 17.7% in the pre period to a high of 67.3% in the post periods. Drivers at the intervention sites also reported increased exposure to the core message of leaving more space when passing trucks (14% pre to 40% post period). The percentage of drivers who said they leave more room when passing trucks than when passing cars rose from 16% in the pre period to 24% in the post period at the intervention sites, while comparison sites showed no change. Over 150 hours of video recorded by law enforcement officers in unmarked vehicles were utilized to examine violation rates and severity of violations before and after the intervention campaigns. Statistical analyses showed that violation rates were reduced significantly at the intervention sites (between 23% and 46%), while remaining constant at the comparison sites. Analyses of the video data also showed that the seriousness of the residual violations at the intervention sites decreased.Conclusions
Overall, the evaluation results provide a consistent picture of the effectiveness of the TACT pilot project. Success was demonstrated at every step - messages were received and understood, knowledge was changed in the intended direction, self reported driving behavior around large trucks improved, and observed driving behaviors confirmed the self reports.Impact on Industry
After this initial success in Washington State, the TACT model will continue to be implemented and evaluated by FMCSA in an attempt to validate the program. Based on the results of this study and the consistent positive results found for other sTEP projects, it is likely that TACT will show continued success in a variety of settings and will help reduce the number and severity of crashes involving CMVs. Future research should attempt to use many of the methods described here to further validate the methods for not only evaluations of TACT programs, but also for any other highway safety programs that require measurements of the program's effectiveness. 相似文献487.
A.L. Stephenson J.S. Dennis S.A. Scott 《Process Safety and Environmental Protection》2008,86(6):427-440
Owing to concerns about energy security and because of increased environmental awareness, the biofuel industry is expanding worldwide. It is therefore extremely important to be able to quantify the sustainability of biofuels in order to determine their benefits over using conventional fossil fuel derived transport fuels. This study investigates the total energy requirement and global warming potential (GWP) of the production of biodiesel from oilseed rape in the UK, using life cycle analyses. Large- and small-scale productions are compared and the sensitivity of these environmental impacts to production variables investigated. Possible changes to the processes are considered, with a view to reduce the energy requirement and global warming potential.This research shows that the scale of the production of biodiesel from oilseed rape in the UK, and the transport involved in the various stages of manufacture, has little effect on its global warming potential. It is also shown that if the rape meal and glycerol were combusted in combined heat and power plants, and the rate of application of nitrogenous fertiliser were reduced from 211 kg/ha to 100 kg/ha, the energy requirement and global warming potential savings from using biodiesel rather than ultra low sulphur diesel would increase dramatically, to 170% and 120%, respectively, on a basis of equivalent net energy content. 相似文献
488.
Is avian humoral immunocompetence suppressed by testosterone? 总被引:2,自引:2,他引:0
Dennis Hasselquist James A. Marsh Paul W. Sherman John C. Wingfield 《Behavioral ecology and sociobiology》1999,45(3-4):167-175
A key issue in sexual selection theory is how a correlation between male secondary sexual characters and male genetic quality
can be maintained. The immunocompetence-handicap hypothesis proposes that testosterone-dependent male characters remain honest
signals because of the immunosuppressive effect of elevated steroid hormone levels. The hypothesis requires that physiological
levels of testosterone depress immune system function. We quantified testosterone titers and humoral immunocompetence of captive
male and female red-winged blackbirds (Agelaius phoeniceus) at three points in the annual cycle (autumn, prebreeding, and breeding). We also conducted an implant experiment on the
males to assess the effects of prolonged, above-normal testosterone titers on humoral immune responses. Humoral immunocompetence
was measured as secondary antibody production to a non-pathogenic protein antigen, keyhole limpet hemocyanin, using an enzyme-linked
immunosorbent assay we developed for A. phoeniceus. Secondary antibody responses of individuals were highly repeatable between sampling periods. Neither physiological nor above-normal
levels of plasma testosterone suppressed secondary antibody production. In paired tests of the same individuals between prebreeding
and breeding, and between breeding and implant, plasma testosterone increased significantly but secondary antibody responses
were unaffected. We are confident in these results because with 80% power, an 11–14% difference in antibody titers would have
been detected. There was no relationship between plasma testosterone levels and humoral immunocompetence in free-ranging males
tested at the peak of breeding. These results cast doubt on a key assumption of the immunocompetence-handicap hypothesis.
Received: 13 April 1998 / Accepted after revision: 7 October 1998 相似文献
489.
Dennis A. Wentz Ian R. Waite Frank A. Rinella 《Environmental monitoring and assessment》1998,51(3):673-693
During 1992–93, 27 organochlorine compounds (pesticides plus total PCB) and 17 trace elements were analyzed in bed sediment and aquatic biota from 20 stream sites in the Willamette Basin as part of the U.S. Geological Survey's National Water-Quality Assessment Program. Data from each medium were compared to evaluate their relative effectiveness for assessing occurrence (broadly defined as documentation of important concentrations) of these constituents. Except for Cd, Hg, Se, and Ag, trace element concentrations generally were higher in bed sediment than in biota. Conversely, although frequencies of detection for organochlorine compounds in biota were only slightly greater than in bed sediment, actual concentrations in biota (normalized to lipid) were as much as 19 times those in sediment (normalized to organic carbon). Sculpin (Cottus spp.) and Asiatic clams (Corbicula fluminea), found at 14 and 7 sites, respectively, were the most widespread taxa collected during the study. Concentrations of trace elements, particularly As and Cu, were typically greater in Asiatic clams than in sculpin. In contrast, almost half of the organochlorine compounds analyzed were found in sculpin, but only DDT and its degradation products were detected in Asiatic clams; this may be related to the lipid content of sculpin, which was about three times higher than for clams. Thus, the medium of choice for assessing occurrence depends largely on the constituent(s) of interest. 相似文献
490.
This study of 402 professional and administrative employees of a VA hospital addressed the question of whether certain dispositional factors (Agreeableness, Conscientiousness, and Equity Sensitivity) could account for the relationship between contextual work attitudes and organizational citizenship behavior (OCB). Findings indicate this not to be the case. Fairness/satisfaction had independent effects on OCB. Additionally, Conscientiousness predicted some forms of OCB. Neither Agreeableness nor Equity Sensitivity affected OCB. Implications are noted for further inquiry into OCB. 相似文献