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51.
Ovarian macroscopical analysis, histological validation and field sampling procedures were used to evaluate the variability
in reproductive traits of the mole crab Emerita brasiliensis Schmitt, 1935 (Decapoda: Hippidae) in two exposed sandy beaches of Uruguay with contrasting morphodynamics. All developmental
stages involved in the complex life cycle exhibited lower abundance, individual size and temporal occurrence in a harsh reflective
beach, compared with a more benign dissipative environment. In addition, this population showed more compressed events of
the reproductive cycle (e.g oogenesis, encounter of potential mate and female parental care) and recruitment period. However,
the beginning of the vitellogenesis, ovary maturity, male sexual differentiation and ending of spermatogenesis occurred at
smaller sizes under dissipative conditions. These results disagree with the recent findings of delayed sexual maturity in
dissipative beaches. We postulate that, in dissipative conditions, high food availability might allow an overlapping of reproductive
and moulting processes, and thus females may reach optimum size and sexual maturity with fewer moults than in reflective beaches.
Hence, reproductive responses must be considered not only in relation to environmental harshness, but also in the context
of life history traits and their phylogenetic and allometric constraints.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
52.
Indicator-Based Approach for Assessing the Vulnerability of Freshwater Resources in the Bagmati River Basin,Nepal 总被引:3,自引:0,他引:3
To assess the vulnerability of water resources in the Bagmati River Basin in Nepal, this paper adopts an indicator-based approach
wherein vulnerability is expressed as a function of water stress and adaptive capacity. Water stress encompasses indicators
of water resources variation, scarcity, and exploitation and water pollution, whereas adaptive capacity covers indicators
of natural, physical, human resource, and economic capacities. Based on the evaluation of eleven indicators, which were aggregated
into eight vulnerability parameters, an increasingly stressful situation and lack of adaptive capacity became evident. Considerable
spatial variation in indicator values suggests differential policy options. While the northern parts need attention to reduce
pollution loading and conserve vegetation cover, the southern parts need improvements in physical capacity, i.e. water infrastructures.
The comprehensive and easily interpretable findings of the study are expected to help decision makers reach sound solutions
to reduce freshwater resources vulnerability in the Bagmati River Basin, Nepal. With its inherent flexibility, the approach
has demonstrated its potential for application in different times and areas for monitoring and comparison purposes. 相似文献
53.
Luc Véchot Tomasz Olewski Carmen Osorio Omar Basha Yi Liu Sam Mannan 《Journal of Loss Prevention in the Process Industries》2013,26(3):398-409
The prediction of the potential hazards associated to accidental liquefied natural gas (LNG) spills has motivated a number of different studies including experimental and numerical approaches. Most of these studies focus on dispersion predictions, however there is limited information regarding source term of it: liquid spill and vaporization. There is a need of further improvements on the understanding of these phenomena and the quantification of the most important parameters that can affect them.The vaporization of cryogenic liquids is governed by the heat transfer phenomena including conduction, convection and thermal radiation mechanisms. The present work investigates the contribution of each of these heat transfer modes to the vaporization rate of cryogenic liquid nitrogen (LN2) contained in a Dewar flask using well controlled and instrumented laboratory scale experiments. LN2 vaporization rate was measured with individually controllable contributions from convective (generated by an electric fan) and thermal radiative (generated by light bulb) heat transfer in the presence of a baseline conductive heat transfer rate.In both cases of convection and radiation analysis the experimental study showed that they can play a significant role in the vaporization rate of LN2. It was observed that the radiative heat absorbed by the LN2 during the vaporization experiment represents only 50%–65% of the incident radiation that would reach the LN2 pool surface if no vapour was present. Convective heat transfer generated by the fan was shown to have had the most significant contribution to the total heat transfer. As expected, this contribution was significantly higher than the one from bulb radiation. The experimental data also showed that the liquid level in the Dewar play a key role in the resulting amount of convective heat transfer. This could be attributed to the fact that lower liquid level the side walls of the Dewar were high enough to hold a layer of vapour and limit air motion directly above the liquid surface, thus limiting the heat transfer by convection. 相似文献
54.
Alhazza Ibrahim M. Ebaid Hossam Omar Mohamed S. Hassan Iftekhar Habila Mohamed A. Al-Tamimi Jameel Sheikh Mohamed 《Environmental science and pollution research international》2022,29(4):5517-5525
Environmental Science and Pollution Research - The bioactivity of nanoparticles has engendered a promise in scientific communities for developing novel therapeutic strategies. This study... 相似文献
55.
Romshoo Shakil Ahmad Murtaza Khalid Omar Shah Waheed Ramzan Tawseef Ameen Ummer Bhat Mustafa Hameed 《Environmental science and pollution research international》2022,29(35):52732-52751
Environmental Science and Pollution Research - The Himalayan glaciers provide water to a large population in south Asia for a variety of purposes and ecosystem services. As a result, regional... 相似文献
56.
Omar El‐Anwar 《Disasters》2013,37(3):489-515
The widespread destruction that follows large‐scale natural disasters, such as Hurricane Katrina in August 2005, challenges the efficacy of traditional temporary housing methods in providing adequate solutions to housing needs. Recognising these housing challenges, the Congress of the United States allocated, in 2006, USD 400 million to the Department of Homeland Security to support Alternative Housing Pilot Programs, which are intended to explore the possibilities of providing permanent and affordable housing to displaced families instead of traditional temporary housing. This paper presents a new methodology and optimisation model to identify the optimal configurations of post‐shelter housing arrangements to maximise the overall net socioeconomic benefit. The model is capable of quantifying and optimising the impacts of substituting temporary housing with alternative housing on the social and economic welfare of displaced families as well as the required additional costs of doing so. An application example is presented to illustrate the use of the model and its capabilities. 相似文献
57.
Mohamed Hanine Omar Boutkhoum Abderrafie El Maknissi Abdessadek Tikniouine Tarik Agouti 《The Environmentalist》2016,36(4):351-367
The location selection for landfill municipal solid waste is an important issue in waste management. Selection of the optimal location requires consideration of multiple alternative solutions and evaluation factors because of system complexity. Further, ranking of the alternative locations and selection of the most optimal and efficient locations for landfill waste are an important multi-criteria decision-making problem. In this study, the candidate locations for landfill are determined based on Political, Economical, Environmental and Social factors are assessed through decision-makers’ opinion and by the methodology that incorporates fuzzy analytic hierarchy process (fuzzy AHP) and fuzzy technique for order preference by similarity to ideal solution (fuzzy TOPSIS). Specifically, the fuzzy AHP technique is applied to determine the weights of selected criteria impacting the location selection process, and the fuzzy AHP is adapted to model the linguistic vagueness and ambiguity, which can also be expressed as triangular fuzzy numbers. Furthermore, fuzzy TOPSIS technique is employed to rank the alternative locations. The applicability of this methodology is demonstrated by a case study of landfill waste location selection in the region of Casablanca, Morocco, and the results are compared with other techniques. Finally, to complete the treatment, a sensitivity analysis is performed to examine the impact of the preferences given by decision-makers to choose the best location. 相似文献
58.
Neil H. Carter José Vicente López-Bao Jeremy T. Bruskotter Meredith Gore Guillaume Chapron Arlyne Johnson Yaffa Epstein Mahendra Shrestha Jens Frank Omar Ohrens Adrian Treves 《Ambio》2017,46(3):251-264
The growing complexity and global nature of wildlife poaching threaten the survival of many species worldwide and are outpacing conservation efforts. Here, we reviewed proximal and distal factors, both social and ecological, driving illegal killing or poaching of large carnivores at sites where it can potentially occur. Through this review, we developed a conceptual social–ecological system framework that ties together many of the factors influencing large carnivore poaching. Unlike most conservation action models, an important attribute of our framework is the integration of multiple factors related to both human motivations and animal vulnerability into feedbacks. We apply our framework to two case studies, tigers in Laos and wolverines in northern Sweden, to demonstrate its utility in disentangling some of the complex features of carnivore poaching that may have hindered effective responses to the current poaching crisis. Our framework offers a common platform to help guide future research on wildlife poaching feedbacks, which has hitherto been lacking, in order to effectively inform policy making and enforcement. 相似文献
59.
Omar?A.?KhondkerEmail author Umaru?S.?Ishiaku Asami?Nakai Hiroyuki?Hamada 《Journal of Polymers and the Environment》2005,13(2):115-126
This paper mainly focuses on the fabrication process of long fibre reinforced unidirectional thermoplastic composites made using both natural (untreated) treated jute yarns. Jute yarns were wound in layers onto a metallic frame. Polypropylene films were inserted between these layers and compression moulded to fabricate unidirectional jute/PP composite specimens. Static mechanical properties were evaluated from tensile three point bending tests. Pre- post-failure examination were carried out on the test specimens using optical scanning electron microscopy to analyse the test results and investigate the correlations between their impregnation state, processing conditions, mechanical performances and fracture morphologies. For the unidirectional jute/PP film-stacked composites, the results indicated that the processing condition at the moulding temperature of 160°C and moulding pressure of 2.0 MPa for 15 min was ideally suited to obtain optimized properties. Improved wettability of resin melts due to complete matrix fusion at this processing condition facilitated thorough impregnation with minimum microstructural imperfections (microvoids) being generated. Jute/PP composites that contained treated jute yarns have shown superiority in tensile bending properties. Jute yarns polished or coated with PVA/PP (polyvinyl alcohol/polypropylene) must have contributed positively to fibre/matrix interfacial interactions leading to matrix to fibre effective stress transfer, thereby improving their reinforcing effects. Tensile strength and modulus of PP resin increased by approximately 285% and 388%, respectively, due to 50 wt% reinforcement by natural jute yarns. Further improvements in strength and modulus were achieved by approximately 14% and 10%, respectively, when treated yarns were used . The maximum bending stress modulus of jute/PP composites containing untreated yarns were approximately 190% and 460% higher than those of the virgin PP materials, and bending properties were improved by further 11% and 23%, respectively, due to coating treatments on the yarn surface. 相似文献
60.
Despite being based on the premise of a dynamic interpersonal process, studies on leader–member exchange theory often fail to acknowledge its dyadic and dynamic nature. We discuss how the interpersonal affect dynamics literature—and particularly its focus on the emergence of relationship patterns—may advance research on leader–follower interactions. 相似文献