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161.
A national Baumol–Oates tax on waste in Denmark helped achieve a reduction of 26% in net solid waste from 1987 to 1998. The
tax, which is levied per ton of waste, was particularly effective as regards the heavier waste streams such as construction
waste and garden waste. When it comes to industrial and commercial waste, there are indications that the waste tax is not
sufficiently significant to induce changes in behavior, and that except for very waste-intensive enterprises, companies do
not seem to be very price sensitive. For household waste, the impact of the tax can be improved where tariffs for garbage
collection are weight based, rather than per unit. However, the waste sector is an area in which the price signals are modified
and filtered by institutionalized practices in municipal administration, and in which true-cost pricing is not easy to achieve.
Hence, the rational choice assumption of environmental economics needs to be supplemented by an institutional dimension to
interpret responses to environmental taxes correctly.
Received: July 13, 2001 / Accepted: October 2, 2001 相似文献
162.
本文通过大量查阅灾害史料,对解放前灾民的食物进行了归类总结,其中有:植物类、动物类、土石类及其它,从一个方面反映了社会的落后与不平等. 相似文献
163.
Green RH 《Disasters》1986,10(4):288-302
Frustrations and failures will continue to mount if we do not immediately summon the courage to revise the ways we think and take action-as well as maintaining essential services to support life and health … Saving hundreds of thousands … who are at risk of dying from malnutrition or infection is an immediate imperative. But it must be only one stage in the progress toward other activities, and one element in the truly comprehensive approach… The main intent of this paper is to explore aspects of the nature and evolution of poverty in Sub-Saharan Africa with special reference to food and hunger and their interaction with macro-economic policy. An attempt is made to outline the overall context within which food aid needs to be used in order to have a greater developmental impact. Following an Introductory Section I, Section II provides a sketch map of how recession and lagging food production - with cyclical weather crises superimposed - affect the human condition of poor people. Section III reviews die interaction between "standard" IMF stabilization and World Bank structural adjustment strategies and poverty/hunger. Improvements in the design of stabilization and adjustment programmes, and of the inter-relationship with them of emergency programmes, can be identified. A number turn on the broadened and more innovative or catalytic use of food aid. Section IV reviews aspects of facing a continuing series of emergencies and of designing life support programmes to facilitate rehabilitation of the households directly affected as well as of the national economies. From this base it explores a series of elements in achieving renewed development. The concluding Section seeks to explore the strengths, limitations and potentials of food aid in the context set by the previous sections. The standard criticisms of food aid appear to be overstated and/or to relate to particular modalities or approaches rather than to anything intrinsic. A number of criteria for improving the effectiveness of food aid - especially in respect to rehabilitation, recovery and renewed development - are set out. 相似文献
164.
利用回转窑焚烧废物简述 总被引:2,自引:0,他引:2
本文介绍了回转窑的类型、结构和及其工艺特点,并对国内外利用回转窑焚烧危险废物的实验情况进行了综述,为我国废物焚烧领域的工作者提供借鉴。 相似文献
165.
Jingyang Luo Shiyu Fang Wenxuan Huang Feng Wang Le Zhang Fang Fang Jiashun Cao Yang Wu Dongbo Wang 《Frontiers of Environmental Science & Engineering》2022,16(8):106
166.
In the present work we investigate whether the distribution of energy flows in ecosystems responds to criteria of trophic organization. We analyzed weighted and unweighted food webs estimating, for each node, trophic position (TP), Shannon's index of inflow diversity (H) and individual contribution to the whole average mutual information (AMI). Finally, we performed the same analysis on simulated webs that were constructed using the following criteria: (a) preserving topology and varying link strength; (b) modifying position of links and their intensities. 相似文献
167.
Complex marine ecosystems contain multiple feedback cycles that can cause unexpected responses to perturbations. To better predict these responses, complicated models are increasingly being developed to enable the study of feedback cycles. However, the sparseness of ecological data often limits the direct empirical parameterization of all model parameters. Here we use a Bayesian inverse analysis approach to synthesize empirical data and ecological theory derived from published studies of a coral atoll's enclosed pelagic ecosystem (Takapoto Atoll, French Polynesia). We then use the estimates of flux magnitudes to parameterize probabilistic compartment models with two forms of heterotrophic consumption: (1) “bottom-up” donor-controlled heterotrophic consumption and (2) “top-down” mass-action heterotrophic consumption. We explore how the flux magnitudes affect the ecosystem's stability properties of resilience, reactivity, and resistance under both assumptions for heterotrophic consumption. The models suggest that the microbial uptake of dissolved organic carbon (DOC) regulates the long term rate of return to steady state following a temporary or pulse perturbation (resilience), and the cycling of carbon between abiotic pools and heterotrophic compartments regulates the short-term response (reactivity). In the bottom-up process model, the sensitivity of steady state masses following a sustained or press perturbation (resistance) is highest for the DOC pool following a sustained change to the microbial uptake rate of DOC. Further, a change in the microbial uptake of DOC propagates through the ecosystem and affects the steady state values of zooplankton. The analysis suggests that the food web is highly dependent on the recycling between the abiotic and biotic carbon pools, particularly as mediated by the microbial consumption of DOC, and this recycling determines how the ecosystem responds to perturbations. 相似文献
168.
In planktonic food webs, the conversion rate of plant material to herbivore biomass is determined by a variety of factors such as seston biochemical/elemental composition, phytoplankton cell morphology, and colony architecture. Despite the overwhelming heterogeneity characterizing the plant–animal interface, plankton population models usually misrepresent the food quality constraints imposed on zooplankton growth. In this study, we reformulate the zooplankton grazing term to include seston food quality effects on zooplankton assimilation efficiency and examine its ramifications on system stability. Using different phytoplankton parameterizations with regards to growth strategies, light requirements, sinking rates, and food quality, we examined the dynamics induced in planktonic systems under varying zooplankton mortality/fish predation, light conditions, nutrient availability, and detritus food quality levels. In general, our analysis suggests that high food quality tends to stabilize the planktonic systems, whereas unforced oscillations (limit cycles) emerge with lower seston food quality. For a given phytoplankton specification and resource availability, the amplitude of the plankton oscillations is primarily modulated from zooplankton mortality and secondarily from the nutritional quality of the alternative food source (i.e., detritus). When the phytoplankton community is parameterized as a cyanobacterium-like species, conditions of high nutrient availability combined with high zooplankton mortality led to phytoplankton biomass accumulation, whereas a diatom-like parameterization resulted in relatively low phytoplankton to zooplankton biomass ratios highlighting the notion that high phytoplankton food quality allows the zooplankton community to sustain relatively high biomass and to suppress phytoplankton biomass to low levels. During nutrient and light enrichment conditions, both phytoplankton and detritus food quality determine the extent of the limit cycle region, whereas high algal food quality increases system resilience by shifting the oscillatory region towards lower light attenuation levels. Detritus food quality seems to regulate the amplitude of the dynamic oscillations following enrichment, when algal food quality is low. These results highlight the profitability of the alternative food sources for the grazer as an important predictor for the dynamic behavior of primary producer–grazer interactions in nature. 相似文献
169.
Waste plastics recycling by an entrained-flow gasifier 总被引:1,自引:0,他引:1
Takatoshi Shoji Kenjiro Shindoh Hironori Ozaki Atsushi Sodeyama 《Journal of Material Cycles and Waste Management》2001,3(2):75-81
We studied an entrained-flow gasification process which efficiently converts waste plastics to energy at a high energy recovery
rate. Waste plastics, after being shredded to <8 mm or <14 mm, were fed into an entrained-flow gasifier with air and oxygen.
In the gasifier, organic substances were pyrolyzed, partially combusted, and then converted into synthetic gas (CO, H2) at a high temperature (over 1600 K). The clarified gasification characteristics were that the lower heat value (LHV) of
the product gas was over 4.2 MJ/Nm3 and the cold gas efficiency was approximately 60%. Other inert substances in the wastes such as ashes and metals were melted
into slag and condensed on bag filters. The bag filters and a water scrubber removed impurities such as dusts, heavy metals,
and hydrogen halides from the product gases. Solid hydrocarbons, which include char and soot, were removed at a hot cyclone
and on the bag filters.
Received: July 19, 2000 / Accepted: October 3, 2000 相似文献
170.
This paper discusses a method by which individuals working in government, private business, not-for-profit and educational organizations developed a collaborative statewide program involving the exchange of materials from manufacturers, commercial business and not-for-profit organizations in Ohio. 相似文献