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431.
Hybrid zones are often found in areas where the environmental characteristics of native habitat of both parental species meet. One of the plausible mechanisms that maintain species distinctiveness, or limit hybridization, is the existence of local species-specific preferences for the natal habitat type. We evaluated this hypothesis for two passerine bird species, the pied Ficedula hypoleuca and collared flycatcher F. albicollis, in their narrow hybrid zone in Central Europe. Both species have quite distinct habitat distributions, and they have also been reported to differ in their foraging niches. In a series of aviary experiments, we demonstrated that both species show distinct preferences for trees from their native area. The pied flycatcher preferred coniferous vegetation, while the collared flycatcher favored deciduous vegetation. In addition, both species differed in foraging substrate preferences. The pied flycatcher preferred to forage in the lower strata on the ground than the canopy, whereas the collared flycatcher foraged more at the canopy level. Both males and females of each species were highly consistent in their preference patterns. Due to the widespread nature of hybrid zones as places with transitional habitat features and the well-known habitat tight associations of various animal taxa with particular habitat types, we propose that habitat preferences might be an important and common mechanism that enhances the formation of conspecific pairs.  相似文献   
432.

Due to current water stress, there is a problem with hygiene and sanitation in many parts of the world. According to predictions from the United Nations, more than 2.7 billion people will be challenged by water scarcity by the middle of the century. The water industry is increasingly interested in desalination of the sea, ocean, and brackish water. Desalination processes are widely classified as thermal or membrane technologies. In the Middle East, thermal desalination remains the primary technology of choice, but membrane processes, for example reverse osmosis (RO), have evolved rapidly and in many other parts of the world are currently even surpassing thermal processes. The purpose of this paper is to review the renewable energy source, the technology, desalination systems, and their possible integration with renewable energy resources and their cost. This article suggests that the most practical renewable desalination techniques to be used are the solar photovoltaic integrated RO desalination process, the hybrid solar photovoltaic-wind integrated RO desalination process, the hybrid solar photovoltaic-thermal (PVT) integrated RO desalination process, and the hybrid solar photovoltaic-thermal effect distillation (PVT-MED) desalination process. However, intensive research is still required to minimize the cost, reduce the heat loss, enhance the performance, and increase the productivity.

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433.

In this study, modified polyacrylamide (PAAm) cryogels with high dye holding capacity were synthesized with an easily and cheaply process and adsorption of Remazol Black B (RBB) with the synthesized materials was investigated. Firstly, PAAm cryogels were synthesized with free radical cryo-copolymerization method and they were modified with Hofmann reaction to form amine groups in the structure of the cyrogels. Then, to increase the removal efficiency of cryogels, polyethylenimine (PEI) molecules were crosslinked onto the cryogels via NH2 groups present in the PAAm gels modified by the Hofmann reaction. The original and modified cryogels were characterized with fourier transformed infrared spectroscopy, 13C nuclear magnetic resonance spectroscopy, scanning electron microscopy and thermogravimetric analysis. The point of zero charge (pHpzc) of the modified cryogels was found to be 7.13 and RBB removing capabilities of PEI-modified PAAm cryogels were investigated at pH between 2 and 7. In addition, the adsorption treatments were performed at different process time, incubation temperature, initial dye concentration and adsorbent amount to find maximum removal capacity of the adsorbent. The modified cryogels adsorbed maximum amount of RBB at pH 2 and the sorption process reached equilibrium in 6 h. It was observed that the adsorption efficiency did not change much with the increase in temperature. The maximum RBB removal capacity of the modified cyrogels was determined to be 201 mg/g when the initial RBB concentration was 200 mg/L, treatment time was 6 h at pH 2. Moreover, the adsorption of RBB dye with the modified cryogels takes place with a second order kinetic and RBB dye adsorption data showed compliance with the Langmuir isotherm. The findings of the study expose that the obtained PEI-modified PAAm cryogels are a hopeful material for RBB removal in aqueous environment.

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434.
435.

Latin America experiences an increasing urban primacy index and a rapid expansion of the financial system, putting direct pressure on the demand for resources to satisfy the consumption of large cities. We investigate the convergence of per capita biocapacity in 16 Latin America countries and evaluate the factors that influence its evolution over time. Specifically, we analyze the impact of the urban primacy index, economic progress, and the financial globalization index on the convergence of per capita biocapacity. We use the methodological framework developed by Phillips and Sul Econometrica 75:1771-1855, (2007) to analyze the convergence and the formation of convergence clubs of biocapacity during 1970–2017. The findings indicate that the countries of the region do not share a common trend of biocapacity, although they are grouped into five converging clubs. Biocapacity transition analysis reveals that countries have heterogeneous transition pathways between them. Using marginal effects, we find that the urban primacy index and economic progress reduce the biocapacity. The effect of the financial globalization index on biocapacity is not conclusive. The quantile regressions reveal that quantiles’ impact of the urban primacy index and financial globalization on per capita biocapacity is heterogeneous. However, the effect of economic progress on biocapacity that predominates among quantiles is positive. The adoption of common policies among the countries that form the converging clubs could improve the effectiveness of pro-environmental policies and promote the achievement of the Sustainable Development Goals related to environmental quality.

  相似文献   
436.
Environmental Science and Pollution Research - We investigate the validity of the environmental Kuznets curve (EKC) hypothesis for the NAFTA countries. In this investigation, we approach this...  相似文献   
437.
Environmental Science and Pollution Research - We aim at analyzing the influence of incentive policies on renewable energy deployment in European Union countries and Turkey over the 2000–2018...  相似文献   
438.
Journal of Material Cycles and Waste Management - Estimation of mixed municipal waste composition is important for the option of suitable waste treatment. Many studies have presented their...  相似文献   
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