ABSTRACT: Most forest lands are managed for multiple purposes, among them timber production and water supply. Conflicts often arise in such cases because logging is perceived as a threat to water quality. These conflicts can result from uncertain factual information, from differences in underlying social values, or from imbalances in the incidence of costs and benefits. Resulting conificts may go unresolved because existing institutional structures fail to address the real roots of the dispute. When such conificts go unresolved, benefits are often lost, and social, political, and managerial costs are high. This study found that the roots of conifict may lie in value differences or in interest impacts, but attention may be focused inappropriately and unproductively on factual issues. It suggests that at least some long-standing disputes in the management of forested watersheds may be resolved by identifying the root causes of these disputes and choosing those actions, whether they be changes in management guidelines or altered institutional structures, which are appropriate to those causes. 相似文献
Carrier agent as one of the synthetic persistent molecules present in textile effluents considered as one of the most highly toxic, carcinogenic and serious inhibitor of the microbial respirometric activity. This chemical is used as accelerants in the dyeing or printing the hydrophobic fibers by dispersed dyes. Hydrophobic polypropylene (PP) fibers cannot be dyed by conventional dyeing process due to the absence of dye sites in the molecular chain and their high crystallinity. This study presents a carrier-free exhaust dyeing as an environmentally friendlier and cleaner process. In order to produce dyeable PP fibers, the PP was blended and melt spun with poly(butylene terephthalate) (PBT) at various ratios. First PP and PBT granules at blend ratios of 5, 10, 20, 30, 40 percent of PBT dispersed phase were physically mixed then the melt spinning of blended samples was carried out by a Maddock mixing zone extruder. The results showed that suitable exhaust dyeing process without using any carrier agents was possible for all PP/PBT alloy fiber samples. The dye uptake of samples significantly increased by increasing the PBT dispersed phase content. By increasing the PBT dispersed phase content decrease in the crystallinity percent resulting in significant enhancement in dye uptake of the alloy fiber samples was observed. A degree of four polynomial equation for dye uptake against blend ratio was obtained by which the optimum blend ratio was 72/28 percent of PP/PBT alloy fiber composition. In all alloy fiber dyed samples uniform coloration was observed. No considerable changes in the mechanical properties for dyed samples against undyed samples were observed. Interestingly, the best mechanical property among alloy fiber samples was observed in the sample containing 30 percent PBT dispersed phase which approximately corresponds to optimum blend ratio gained from mathematical calculations. In all PP/PBT alloy fiber samples strong fastness to soaping and very good to excellent fastness to light were achieved. 相似文献
Since the last decade, the application of natural dyes on textile materials is gaining popularity all over the world, possibly because of increasing awareness of environment, ecology, and pollution control. In this research, extraction of dyes from weld using soxhlet apparatus has been studied. The color components extracted and isolated from weld plant were characterized by Column Chromatography, Thin Layer Chromatography (TLC), NMR, mass, IR techniques. The natural dye extract obtained from the weld was used for the dyeing of wool fiber. The results indicated that the exhaustion rate for the extracted dye increases by 49% compared to the raw dye. This, in turn, leads to a considerable decrease in the amount of the extracted dye used to reach the same desired results. Finally, for comparative studies between synthetic and this natural dye, all dyed specimens were tested for wash and light fastness properties, making weld a viable alternative to synthetic acid dyes. 相似文献
A new solid state fermentation reactor (SSFR) for solid substrate was used for the production of lipopeptide antibiotic iturin A using Bacillus subtilis RB14-CS. Solid state fermentation (SSF) is the technique of cultivation of microorganisms on solid and moist substrates in the absence of free water. SSF has shown much promise in the development of several bioprocesses and products because of their several advantages like absence of free water that allows simplified downstream processing and low cost. SSFR allows agitation of the SSF culture with improved temperature control and air supply. Interestingly, when okara, the widely available waste product from the tofu industries, was used as the solid substrate for the SSFR, no iturin A production was observed. However, without agitation, production of iturin A was observed in the SSFR but the production level remained low. The low production of iturin A was found to be due to the heat generation and excess temperature rise inside the reactor system during the fermentation process. Maintaining the temperature within a range of 25–30°C, production of iturin A was significantly improved in the SSFR. This was comparable to the laboratory scale production, and signifies the potential application of the SSFR for SSF. 相似文献
For policy decisions with respect to CO2-mitigation measures in the agricultural sector, national and regional estimations of the efficiency of such measures are required. The conversion of ploughed cropland to zero-tillage is discussed as an option to reduce CO2 emissions and promises at the same time effective soil and water conservation. Based on the upscaling of simulation results with the soil and land resources information system SLISYS-BW, estimations of CO2-mitigation rates in relation to crop rotations and soil type have been made for the state of Baden-Württemberg (Germany). The results indicate considerable differences in the CO2-mitigation rates between crop rotations ranging from 0.48 to 0.03 Mg C ha−1 a−1 for winter cereals–spring cereals–rape rotations and winter cereals–spring cereals–corn silage rotations, respectively. The efficiency of the crop rotations is strongly related to the total carbon input and in particular the amount of crop residues. Among the considered soil types, highest CO2-mitigation rates are associated with Cumulic Anthrosols (0.62 Mg C ha−1 a−1) and the lowest with Gleysols (−0.01 Mg C ha−1 a−1). An agricultural extensification scenario with conventional plowing but conversion of the presently applied intensive crop rotations to a clover–clover–winter cereals rotation indicated a CO2-mitigation potential of 466 Gg C a−1. However, the present high market prices for cereals and increasing demand for energy production from biomass encourages an intensification of the agricultural production and an excessive removal of biomass which in future will seriously reduce the potential for carbon sequestration on cropland. 相似文献
Journal of Material Cycles and Waste Management - This study was done to evaluate the suitability of biochar-based mixtures for growth media. Biochars from agricultural wastes were produced by slow... 相似文献
In this study, a novel and facile route for the synthesis of cyclodextrin-conjugated graphene oxide (CDs–GO) nanocomposites by esterification reaction in the presence of EDC/DMAP as catalyst, was developed. The formation of CDs–GO was successfully approved by FT-IR, SEM, TEM, TGA and BET analyses. Then competitive adsorption capacity of cadmium ion by CDs–GO composites and the impact of different empirical parameters like contact time, initial metal ion concentration, and initial pH on the adsorption process were studied. The results showed that β-CD–GO at pH 7 is suitable for removing Cd(II) with 90?% removal efficiency. Also, the adsorption capacity experiment at constant concentration of 50 ppm of Cd(II) showed that more than 50?% of Cd(II) ions could be adsorbed by γ-CD–GO reaching an equilibrium within 2 h. Therefore, the γ-CD–GO and α-CD–GO showed high adsorption capacity toward Cd2+ (222.22 mg/g) which were pointedly more than that of β-CD–GO (208.33 mg/g). Furthermore, adsorption kinetics, isotherm studies, and thermodynamic analyses were evaluated. The adsorption data exhibited excellent fit to the pseudo-second-order (R2?>?0.99) and Freundlich isotherm models.