粉尘在巷道中的紊流传递分析

建立的粉尘在巷道中的传递方程是一个二维平流扩散输运方程。在巷道顶底板为吸收壁的条件下，导出了粉尘浓度分布函数。传统的工业沉降室沉降效率公式（横向混合模型）只是论文所列方程的一个特例。降低紊流强度和减小紊流扩散系数和纵向弥散系数均可提高沉降效率     

Influence of coal ash on the concrete properties and its performance under sulphate and chloride conditions

Environmental Science and Pollution Research - This study investigated the influence of coal bottom ash (CBA) on the concrete properties and evaluate the effects of combined exposure of sulphate...     

重力作用下尘粒运动的数值解法

提出了重力作用下尘粒运动的数值解法。依据尘粒的重力、浮力及所受到的阻力推出了尘粒自然沉降时的运动方程。当尘粒的运动在斯托克斯领域内时采用理论公式求解其运动轨迹,当尘粒的运动进入非斯托克斯领域内时,提出了修正斯托克斯公式的方法以达到用理论公式来近似模拟该领域内的尘粒自然沉降运动     

Financial comparisons of fishing gear used in Kenya's coral reef lagoons

The cost of fishing and the income earned by fishers using small and large traps, gill nets, beach seines, hand lines, and spearguns were assessed in the multigear fishery of southern Kenya to establish a financial rationale for fishing gear use. Direct observations and key-informant interviews with fish leaders and boat captains were used to gather data on fish catch, cost of fishing gear, boats, and the price of fish. Among the fishing gear used, spearguns had the lowest monthly cost (USD 1 mo(-1)) while big traps had the highest (USD 13 mo(-1)). Income was highest among capital cost beach seine fishers (USD 183 mo(-1)) and lowest among noncapital cost beach seine fishers (USD 20 mo(-1)). There was a direct positive correlation between income earned and profitability of gear. Correlation of the financial measure for each gear to four categories of damage to fish and habitats showed that low cost fishing gear were associated with the highest environmental damage indicating a trade-off between cost of gear and environmental health.     

Factors affecting farmers’ use of organic and inorganic fertilizers in South Asia

Environmental Science and Pollution Research - Fertilizer, though one of the most essential inputs for increasing agricultural production, is a leading cause of nitrous oxide emissions from...     

Valuing Recreational Benefits of Coral Reefs: The Case of Mombasa Marine National Park and Reserve, Kenya

A contingent valuation study was conducted with adult Kenyan citizens and foreign tourists to estimate the value of recreational benefits arising from coral reefs at Mombasa Marine National Park and Reserve (MMNPR), and to assess the implications for local reef management. Citizen and foreign visitors to MMNPR were willing to pay an extra $2.2 (median = $2.2 (median = 1.6) and $8 (median = $8 (median = 6.7) per visit respectively, in addition to current park entrance fees, to support reef quality improvements. By aggregating visitors’ willingness to pay bids over the number of visitors to MMNPR in 2006–2007 the value of benefits was estimated at 346,733, which was more than twice the total annual operational expenditure of346,733, which was more than twice the total annual operational expenditure of 152,383 for MMNPR. The findings indicate that annual revenues from citizen and foreign visitors may be increased by 60% to 261,932 through the implementation of proposed higher park fees of261,932 through the implementation of proposed higher park fees of 3.10 for citizens and $15 for foreign visitors. However, any fee increase would serve to intensify concerns among citizens that only relatively affluent Kenyans can afford to visit MMNPR. Park managers need to demonstrate that the extra revenue would be used to fund the proposed conservation activities. This valuation study demonstrates that visitors are prepared to pay higher user fees for access to the marine protected area revealing considerable untapped resource to finance reef quality improvements.     

Assessing the Impacts of Establishing MPAs on Fishermen and Fish Merchants: The Case of Lyme Bay,UK

Shortly after the implementation of a marine protected area (MPA) in Lyme Bay in 2008, inside which scallop dredging and bottom trawling is prohibited, a socio-economic impact assessment was initiated. This article presents the initial findings from this study. The aim was to understand the costs and benefits to fishermen and fish merchants of establishing the MPA. These were assessed using a combination of primary and secondary data. The results indicate that the impacts of the closure differ according to the gear type and the fishing location used by the fishermen. Static gear fishermen who fish inside the closed area have seen changes in terms of increased fishing effort, mostly because they have been able to increase the number of crab and whelk pots they deploy. The effects of the closure on static gear fishermen who fish outside the closed area has been reported in terms of increased conflicts with towed gear fishermen who now fish regularly in their traditional grounds. Fishermen using towed gear on the other hand have been impacted through displacement effects as they have been forced to look for other fishing grounds outside the closed area. Most fish merchants and processors initially claimed that they were heavily impacted by the closure but when they were interviewed 1 year after the closure they suggested a more stable picture. Preliminary analyses of landings data indicate that the introduction of the MPA has so far had minimal impacts on the average incomes and financial profits of fishermen and fish merchants. This conclusion, however, reflects a short-term view as the impacts of the closure of Lyme Bay are likely to be felt for a long time to come.     

Window on the Pentagon: EIA and defense decision making

Two sources of difficulty complicate tying EIA to decision making at the Department of Defense: the nature of the federal EIA process and the DOD decision-making process. Several steps, focused on each of the problem sources, are suggested that would enable DOD to enhance its existing leadership in doing EIA for its projects.