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101.
Ruth Offermann Thilo Seidenberger Daniela Thrän Martin Kaltschmitt Sergey Zinoviev Stanislav Miertus 《Mitigation and Adaptation Strategies for Global Change》2011,16(1):103-115
So far, various studies assessed global biomass potentials and came up with widely varying results. Existing potential estimates
range from 0 EJ/a up to more than 1,550 EJ/a which corresponds to about three times the current global primary energy consumption.
This paper provides an overview of the available research on bioenergy potentials and reviews the different assessments qualitative
way with the objective to interpret previous research in an integrated way. In the context of this paper we understand bioenergy
as energy from biomass sources including energy crops, residues, byproducts and wastes from agriculture, forestry, food production
and waste management. In this review special attention was paid to the difference between residue and energy potentials, land
availability estimates, and the geographical resolution of existing potential estimates. The majority of studies concentrate
on energy crop potentials retrieved from surplus agricultural land and only few publications assess global potentials separated
by different world regions. It results that land allocated to the exclusive production of energy crops varies from 0 to 7,000 ha,
depending on land category and scenario assumptions. Only a small number of available potential assessments consider residue
potentials as well as energy crop potentials from degraded land. Future energy crop potentials are assumed to vary in the
mean from 200 to 600 EJ/yr. In contrast residue potentials are expected to contribute between 62 and 325 EJ/yr. The highest
potentials are assigned to Asia, Africa and South America while Europe, North America and the Pacific region contribute minor
parts to the global potential. 相似文献
102.
Maie Bachmann Ruth Tomson Jaan Kalda Maksim Säkki Jaanus Lass Viiu Tuulik Hiie Hinrikus 《The Environmentalist》2007,27(4):511-517
This study was aimed to investigate the changes in the human electroencephalographic (EEG) signal caused by modulated low-level
microwaves. The 450 MHz microwave exposure modulated at 40 Hz and 70 Hz frequencies was applied to a group of 15 volunteers.
The field power density at the scalp was 0.16 mW/cm2. Ten cycles of the exposure (1 min on and 1 min off) at both modulation frequencies were applied. Analysis of the EEG signal
was performed using three different methods: nonlinear method of scaling analysis for length distribution of low variability
periods (LDLVP), relative changes in EEG energy (S-parameter) and beta ratio (H-parameter). The analysis revealed significant changes caused by microwave for the whole group (H-parameter method). The exposure caused increase of the EEG beta power (S-parameter method). Statistically significant changes in EEG were detected for four subjects (26.7%) at 40 Hz modulation frequency
(LDLVP method). 相似文献
103.
This paper describes a series of tests carried out with a comprehensive transportation, land use and air quality simulation system, which has been designed for planning application at the metropolitan or regional scale, within the framework of the U.S. Government's Clean Air legislation. The urban location portion of the system was developed at the University of Pennsylvania under the direction of S. H. Putman. The air quality sections incorporate models formulated in earlier studies. The system was tested with data from the San Francisco Bay area, for the period 1975–1980. The test policies included changes in regional transportation costs and population totals; local interventions in the transportation network; and controls on pollutant emissions from mobile and stationary sources. To assess net impacts, the outcomes predicted for each policy were compared with the outcomes predicted in a “benchmark”, or base run of the system. The tests showed that the system is sensitive to a broad range of air quality policies, and that it is capable of predicting important air quality consequences of transportation and land use policies. Some further development will be needed before the system can be used in practical planning situations, but there is little doubt as to the soundness of its central theoretical constructs and logical structure. 相似文献
104.
105.
106.
Shults RA Jones BH Kresnow MJ Langlois JA Guerrero JL 《Journal of Safety Research》2004,35(4):447-452
INTRODUCTION: Little population-based information exists about the long-term effects of motor-vehicle crash-related injuries. METHOD: We analyzed data from the 1995 National Health Interview Survey Disability (NHIS-D) Supplement to estimate the prevalence of crash-related disability among noninstitutionalized U.S. adults aged 18 years and older. RESULTS: More than 1.2 million adults were living in their homes with the disabling effects of motor-vehicle crash-related injuries in 1995. The prevalence of crash-related disability was highest for persons in their mid-life years, ages 35-64. Half of the respondents had sustained the injuries more than 5 years before the interview. Forty-one percent of working-aged individuals reported being unable to work because of their disability. CONCLUSIONS: Because crash-related disability is most prevalent during the mid-life years, quality of life and productivity may be affected for decades. These findings highlight the personal and societal burden associated with motor-vehicle crash-related disability in the United States. 相似文献
107.
On November 13-14, 2003, a symposium on high-visibility safety belt use enforcement in Raleigh, NC: (a) celebrated the 10th anniversary of North Carolina's Click It or Ticket program; (b) documented current knowledge regarding safety belt use; (c) proposed strategies to increase use further; and (d) discussed research to support these strategies. 相似文献
108.
Woodard KR French EC Sweat LA Graetz DA Sollenberger LE Macoon B Portier KM Wade BL Rymph SJ Prine GM Van Horn HH 《Journal of environmental quality》2002,31(6):1980-1992
Florida dairies need year-round forage systems that prevent loss of N to ground water from waste effluent sprayfields. Our purpose was to quantify forage N removal and monitor nitrate N (NO3(-)-N) concentrations in soil water below the rooting zone for two forage systems during four 12-mo cycles (1996-2000). Soil in the sprayfield is an excessively drained Kershaw sand (thermic, uncoated Typic Quartzipsamment). Over four cycles, average loading rates of effluent N were 500, 690, and 910 kg ha(-1) per cycle. Nitrogen removed by the bermudagrass (Cynodon spp.)-rye (Secale cereale L.) system (BR) during the first three cycles was 465 kg ha(-1) per cycle for the low loading rate, 528 kg ha(-1) for the medium rate, and 585 kg ha(-1) for the high. For the corn (Zea mays L.)-forage sorghum [Sorghum bicolor (L.) Moench]-rye system (CSR), N removals were 320 kg ha(-1) per cycle for the low rate, 327 kg ha(-1) for the medium, and 378 kg ha(-1) for the high. The higher N removals for BR were attributed to higher N concentration in bermudagrass (18.1-24.2 g kg(-1)) than in corn and forage sorghum (10.3-14.7 g kg(-1)). Dry matter yield declined in the fourth cycle for bermudagrass but N removal continued to be higher for BR than CSR. The BR system was much more effective at preventing NO3(-)-N leaching. For CSR, NO3(-)-N levels in soil water (1.5 m below surface) increased steeply during the period between the harvest of one forage and canopy dosure of the next. Overall, the BR system was better than CSR at removing N from the soil and maintaining low NO3(-)-N concentrations below the rooting zone. 相似文献
109.
110.
Direct and interactive effects of enemies and mutualists on plant performance: a meta-analysis 总被引:5,自引:0,他引:5
Morris WF Hufbauer RA Agrawal AA Bever JD Borowicz VA Gilbert GS Maron JL Mitchell CE Parker IM Power AG Torchin ME Vázquez DP 《Ecology》2007,88(4):1021-1029
Plants engage in multiple, simultaneous interactions with other species; some (enemies) reduce and others (mutualists) enhance plant performance. Moreover, effects of different species may not be independent of one another; for example, enemies may compete, reducing their negative impact on a plant. The magnitudes of positive and negative effects, as well as the frequency of interactive effects and whether they tend to enhance or depress plant performance, have never been comprehensively assessed across the many published studies on plant-enemy and plant-mutualist interactions. We performed a meta-analysis of experiments in which two enemies, two mutualists, or an enemy and a mutualist were manipulated factorially. Specifically, we performed a factorial meta-analysis using the log response ratio. We found that the magnitude of (negative) enemy effects was greater than that of (positive) mutualist effects in isolation, but in the presence of other species, the two effects were of comparable magnitude. Hence studies evaluating single-species effects of mutualists may underestimate the true effects found in natural settings, where multiple interactions are the norm and indirect effects are possible. Enemies did not on average influence the effects on plant performance of other enemies, nor did mutualists influence the effects of mutualists. However, these averages mask significant and large, but positive or negative, interactions in individual studies. In contrast, mutualists ameliorated the negative effects of enemies in a manner that benefited plants; this overall effect was driven by interactions between pathogens and belowground mutualists (bacteria and mycorrhizal fungi). The high frequency of significant interactive effects suggests a widespread potential for diffuse rather than pairwise coevolutionary interactions between plants and their enemies and mutualists. Pollinators and mycorrhizal fungi enhanced plant performance more than did bacterial mutualists. In the greenhouse (but not the field), pathogens reduced plant performance more than did herbivores, pathogens were more damaging to herbaceous than to woody plants, and herbivores were more damaging to crop than to non-crop plants (suggesting evolutionary change in plants or herbivores following crop domestication). We discuss how observed differences in effect size might be confounded with methodological differences among studies. 相似文献