Hydraulic characteristics of open-channel flow with partially-placed double layer rigid vegetation

Environmental Fluid Mechanics - Vegetation in watercourses can influence different aspects of flow structure, subsequently affecting many processes of flow, such as pollutant transportation,...     

Impacts of land use and land cover change on the interactions among multiple soil-dependent ecosystem services (case study: Jiroft plain,Iran)

The spatial and temporal distribution pattern is an outstanding feature of the relationship among ecosystem services (ESs) that explains links between human activities and disturbed chemical composition of ecosystems. This study investigated the spatiotemporal variation of land use/cover changes (LUCC) and quantifies the change in four essential ecosystem services with an emphasis on soil (nutrient delivery ratio, carbon storage, crop production, and water yield) and their relationships in the Jiroft plain, Iran, during 1996–2016 through analytical tools including Land Change Modeler, and the Integrated Valuation of Ecosystem Services and Tradeoff. During the 20-year concentrate period, there was a considerable overall gain in cropland (5396 km²) and urban (1787 km²), loss of unused land (5692 km²), water (2088 km²), and forest (1083 km²). As a result of LUCC, while crop production and nutrient delivery ratio showed a rising trend, overall carbon storage and water yield decreased. The spatiotemporal trade-off between carbon storage and crop production, the temporal trade-off between crop production and water yield, and synergy between water yield and crop production were widespread in Jiroft plain. These results showed that the interaction among ESs mutates over time and can be changed under planning and policies. This study will enrich the research of the geographical distribution of ESs interaction in dryland ecosystems to provide practical ecosystem management under local conditions.

     

Determination of first-order landfill gas modeling parameters and uncertainties

Using first-order kinetic empirical models to estimate landfill gas (LFG) generation and collection rates is well recognized in the literature. The uncertainty in the estimated LFG generation rates is a major challenge in evaluating performance of LFG collection and LFG to energy facilities. In this investigation, four methods for quantifying first-order LFG generation model parameters, methane generation potential, L₀, and methane generation rate constant, k, were evaluated. It was found that the model is insensitive to the approach taken in quantifying the parameters. However, considering the recognition of using the model in the literature, the optimum method to estimate L₀ and k is to determine L₀ using disposed municipal solid waste composition and laboratory component specific methane potential values. The k value can be selected by model fitting and regression using the first-order model if LFG collection data are available. When such data are not available, k can be selected from technical literature, based on site conditions. For five Florida case-study landfills L₀ varied from 56 to 77 m³ Mg⁻¹, and k varied from 0.04 to 0.13 yr⁻¹ for the traditional landfills and was 0.10 yr⁻¹ for the wet cell. Model predictions of LFG collection rates were on average lower than actual collection. The uncertainty (coefficient of variation) in modeled LFG generation rates varied from ±11% to ±17% while landfills were open, ±9% to ±18% at the end of waste placement, and ±16% to ±203% 50 years after waste placement ended.     

Pathogenicity of Aeromonas hydrophila isolated from the Malaysian Sea against coral (Turbinaria sp.) and sea bass (Lates calcarifer)

Environmental Science and Pollution Research - A study was carried out to determine the pathogenicity (hemolytic activity) on corals (Turbinaria sp.) and sea bass (Lates calcarifer) of Aeromonas...     

North–South Investment Flows and Optimal Environmental Policies

In the context of a simple North–South model that focuses on the international movement of capital, we show how neglect of pollution-generating effects of foreign investment may lead to distorted and misleading policy recommendations. Such a neglect has recently received emphasis in the empirical literature on East Asian economies, as in Bello and Rosenfeld (1990, “Dragons in Distress: Asia's Miracle Economics in Crisis,” Food First, San Francisco), and was shown to overlook resulting tendencies in these economies toward specialization, away from agriculture and toward manufacturing. Our simple model formalizes this observation and allows us to show that even for an unspecialized capital-poor, resource-rich South, such pollution-generating effects provide incentives for the North to encourage, rather than to discourage, foreign investment abroad and strengthen Southern incentives to restrict foreign investment more sharply than is conventionally assumed. In a nutshell, it brings out the implications of Northern capital “creating its own demand” as a consequence of its adverse impact on the Southern resource base. Despite its simplicity, the model thus sheds light on three interrelated aspects of international trading relations: production asymmetry, incomplete markets, and monopolistic advantage.     

The role of drug and alcohol use and the risk of motor vehicle crashes in Shiraz,Iran, 2014: A case–crossover study

Background: Traffic accidents and traffic-related injuries and mortality have become a major public health concern in Iran. This study aimed to examine the role of drug and alcohol use in motor vehicle accidents in Iran.

Methods: This case–crossover study was conducted on 441 drivers who survived a road traffic crash and were taken to the emergency department of Shahid Rajaee trauma hospital in Shiraz, southern Iran. Data were collected using checklists that included demographic characteristics and drug and alcohol use prior to driving. Alcohol and drug use was identified through self-report, and cannabis, morphine, and methamphetamine urine tests were used to confirm drug abuse among drivers.

Results: In total 17.9% of drivers reported using drugs (cannabis, opium, or metamphetamine) and 8.84% of drivers reported consuming alcohol prior to the collision. The crude odds ratios (ORs) for having a crash for opium, cannabis, and metamphetamine were 1.94 (95% interval confidence [CI], 1.11–3.38), 2.37 (95% CI, 1.03–5.42), 5.5 (95% CI, 1.21–24.81), respectively, and for all drugs was 3.83 (95% CI, 2.28–6.43). The OR for alcohol was 3.5 (95% CI, 1.73–7.06) based on self-report.

Conclusion: Drug and alcohol use are increasing the risk of traffic crashes in Iran. Risk-reducing programs must be designed and implemented.     

Optimal sizing and siting of renewable energy resources in distribution systems considering time varying electrical/heating/cooling loads using PSO algorithm

Distributed Generation (DG) sources based on Renewable Energy (RE) can be the fastest growing power resources in distribution systems due to their environmental friendliness and also the limited sources of fossil fuels. In general, the optimal location and size of DG units have profoundly impacted on the system losses in a distribution network. In the present article, the Particle Swarm Optimization (PSO) algorithm is employed to find the optimal location and size of DG units in a distribution system. The optimal location and size of DG units are determined on the basis of a multi-objective strategy as follows: (i) the minimization of network power losses, (ii) the minimization of the total costs of Distributed Energy Resources (DERs), (iii) the improvement of voltage stability, and (iv) the minimization of greenhouse gas emissions. The related distribution system was assumed to be composed of the fuel cells, wind turbines, photovoltaic arrays, and battery storages. The electrical, cooling, and heating loads were also considered in this article. The heating and cooling requirements of the system consist of time varying water heating load, space heating load, and space cooling load. In this study, the waste and fuel cell were used to produce the required heating and cooling loads in the distribution system. In addition, the absorption chiller was used to supply the required space cooling loads. A detailed performance analysis was carried out on 13 bus radial distribution system to demonstrate the effectiveness of the proposed methodology.     

Government management and overexploitation of groundwater resources: absence of local community initiatives in Ardabil plain-Iran

Although mismanagement of groundwater resources has resulted in their destruction over centuries, climate change is speeding up this process more than ever. On the one hand, urgent action by government bodies is needed to address the challenge. On the other hand, a vast body of literature proves that bottom-up collective action, although requiring a longer time period, is a better solution to manage such resources. This research aims to address this dilemma. The groundwater resource in Ardabil plain in Iran, which has long been managed solely through government intervention, has been chosen as a case study to explore the opportunities and limitations of managing a critically endangered area from a common pool resource perspective. Our study suggests that managing Ardabil groundwater resources should be conducted on two scales. The bottom-up institutional agreements should take place at village scale while the government should stay in charge of the overall organization at plain scale.     

Reliable method for prediction of the flash point of various classes of amines on the basis of some molecular moieties for safety measures in industrial processes

This work presents a novel, reliable and simple method of estimating the flash point of various types of flammable amines, which are important for safety measures in industrial processes. Different amines include aliphatic amines such as primary, secondary, tertiary and cyclic amines as well as aromatic amines and hetero arenes containing nitrogen heteroatom. The proposed correlation is based on the contribution of some specific molecular moieties and functional groups, which can easily be used for any types of amines. Intermolecular forces are important in the new method, which are counted by two increasing and decreasing parameters. The root mean square (rms) deviation is 18 K for different classes of amines including 133 diverse compounds. The estimated flash points have been compared with one of the best available predictive methods, which gives much lower value of the rms deviation.