排序方式: 共有28条查询结果,搜索用时 281 毫秒
11.
12.
13.
Sapna Kaul Kevin J. Boyle Nicolai V. Kuminoff Christopher F. Parmeter Jaren C. Pope 《Journal of Environmental Economics and Management》2013
We develop a nonparametric approach to meta-analysis and use it to identify modeling decisions that affect benefit transfer errors. The meta-data describe the results from 31 empirical studies testing the convergent validity of benefit transfers. They evaluated numerous methodological procedures, collectively reporting 1071 transfer errors. Our meta-regressions identify several important findings, including: (1) the median absolute error is 39%; (2) function transfers outperform value transfers; (3) transfers describing environmental quantity generate lower transfer errors than transfers describing quality changes; (4) geographic site similarity is important for value transfers; (5) contingent valuation generates lower transfer errors than other valuation methods; and (6) combining data from multiple studies tends to reduce transfer errors. 相似文献
14.
15.
Waste management involving bioresource recovery in a cane molasses-based distillery engaged in the manufacture of rectified spirit (alcohol) is described. The spentwash generated from the distillation of fermenter wash is highly acidic (pH 4.0-4.3) with high rates of biochemical and chemical oxygen demand (BOD: 52-58, COD: 92-100 kg/m3) and suspended solids (2.0-2.5 kg/m3). Biogas is recovered from high strength raw spentwash through the full-scale application of a biomethanation system as pretreatment option, comprising anaerobic fixed film reactors. This, combined with subsequent concentration through multiple effect evaporators (MEE), and utilization of concentrated effluent for biocomposting of pressmud (another by-product of the industry) for production of biomanure contributes to the elimination of effluent discharges. 相似文献
16.
The Science of Nature - 相似文献
17.
Meenakshi Kaul G. M. J. Mohren V. K. Dadhwal 《Mitigation and Adaptation Strategies for Global Change》2010,15(5):489-510
A dynamic growth model (CO2FIX) was used for estimating the carbon sequestration potential of sal (Shorea Robusta Gaertn. f.), Eucalyptus (Eucalyptus Tereticornis Sm.), poplar (Populus Deltoides Marsh), and teak (Tectona Grandis Linn. f.) forests in India. The results indicate that long-term total carbon storage ranges from 101 to 156 Mg C?ha?1, with the largest carbon stock in the living biomass of long rotation sal forests (82 Mg C?ha?1). The net annual carbon sequestration rates were achieved for fast growing short rotation poplar (8 Mg C?ha?1?yr?1) and Eucalyptus (6 Mg C?ha?1?yr?1) plantations followed by moderate growing teak forests (2 Mg C?ha?1?yr?1) and slow growing long rotation sal forests (1 Mg C?ha?1?yr?1). Due to fast growth rate and adaptability to a range of environments, short rotation plantations, in addition to carbon storage rapidly produce biomass for energy and contribute to reduced greenhouse gas emissions. We also used the model to evaluate the effect of changing rotation length and thinning regime on carbon stocks of forest ecosystem (trees?+?soil) and wood products, respectively for sal and teak forests. The carbon stock in soil and products was less sensitive than carbon stock of trees to the change in rotation length. Extending rotation length from the recommended 120 to 150 years increased the average carbon stock of forest ecosystem (trees?+?soil) by 12%. The net primary productivity was highest (3.7 Mg ha?1?yr?1) when a 60-year rotation length was applied but decreased with increasing rotation length (e.g., 1.7 Mg ha?1?yr?1) at 150 years. Goal of maximum carbon storage and production of more valuable saw logs can be achieved from longer rotation lengths. ‘No thinning’ has the largest biomass, but from an economical perspective, there will be no wood available from thinning operations to replace fossil fuel for bioenergy and to the pulp industry and such patches have high risks of forest fires, insects etc. Extended rotation lengths and reduced thinning intensity could enhance the long-term capacity of forest ecosystems to sequester carbon. While accounting for effects of climate change, a combination of bioenergy and carbon sequestration will be best to mitigation of CO2 emission in the long term. 相似文献
18.
Aatmeeyata D.S. Kaul Mukesh Sharma 《Atmospheric environment (Oxford, England : 1994)》2009,43(35):5691-5697
This study aimed to understand the non-exhaust (NE) emission of particles from wear of summer tire and concrete pavement, especially for two wheelers and small cars. A fully enclosed laboratory-scale model was fabricated to simulate road tire interaction with a facility to collect particles in different sizes. A road was cast using the M-45 concrete mixture and the centrifugal casting method. It was observed that emission of large particle non exhaust emission (LPNE) as well as PM10 and PM2.5 increased with increasing load. The LPNE was 3.5 mg tire−1 km−1 for a two wheeler and 6.4 mg tire−1 km−1 for a small car. The LPNE can lead to water pollution through water run-off from the roads. The contribution of the PM10 and PM2.5 was smaller compared to the LPNE particles (less than 0.1%). About 32 percent of particle mass of PM10 was present below 1 μm. The number as well as mass size distribution for PM10 was observed to be bi-modal with peaks at 0.3 μm and 4–5 μm. The NE emissions did not show any significant trend with change in tire pressure. 相似文献
19.
Application of riverbed sand for the adsorptive separation of cadmium(II) from aqueous solutions has been investigated. Removal increased from 26.8 to 56.4% by decreasing the initial concentration of cadmium from 7.5 x 10(-5) to 1.0 x 10(-5)M at pH 6.5, 25 degrees C temperature, agitation speed of 100 rpm, 100 microm particle size and 1.0 x 10(-2) NaClO4 ionic strength. Process of separation is governed by first order rate kinetics. The value of rate constant of adsorption, k(ad), was found to be 2.30 x 10(-2)per min at 25 degrees C. Values of coefficient of mass transfer, beta L, were calculated and its value at 25 degrees C was found to be 1.92 x 10(-2)cm/s. Values of Langmuir constant were calculated. Values of thermodynamic parameters delta G0, delta H0 and delta S0 were also calculated and were recorded as -0.81 kcal/mol, -9.31 kcal/mol and -28.10 cal/mol at 25 degrees C. pH has been found to affect the removal of cadmium significantly and maximum removal, 58.4%, has been found at pH 8.5. Process can be used for treatment of cadmium(II) rich wastewaters. 相似文献
20.
The major metabolite of 1-propyl-3,5-diethyl-6-chlorouracil has been identified as 6,8-diethyl-2-methyl-tetrahydrooxazolo[3,2-c]pyrimidine-5,7(4H,6H)-dione. The biotransformation to this bicyclic barbituric acid derivative takes place via substitution of the chlorine by ß- and not by α-hydroxy group of the intermediate hydroxypropane. 相似文献