6,706 research outputs found

    A Review on the Progress of Ion-Engineered Water Flooding

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    BMP treatment technologies, monitoring needs, and knowledge gaps: status of the knowledge and relevance within the Tahoe Basin

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    This Technical memorandum fulfills Task 2 for Agreement 03-495 between El Dorado County and the Office of Water Programs at California State University Sacramento and their co-authors, Bachand & Associates and the University of California Tahoe Research Group: 1) a review of current stormwater treatment Best Management Practices (BMP) in the Tahoe Basin and their potential effectiveness in removing fine particles and reducing nutrient concentrations; 2) an assessment of the potential for improving the performance of different types of existing BMPs through retrofitting or better maintenance practices; 3) a review of additional promising treatment technologies not currently in use in the Tahoe Basin; and 4) a list of recommendations to help address the knowledge gaps in BMP design and performance. ... (PDF contains 67 pages

    A Short Review on the Development of Salt Tolerant Cultivars in Rice

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    Rice is staple food for half of the world. With a population of almost 9.6 billion by the year 2050, there is a dire need of developing techniques to improve the crop plants, not only in terms of better yield but also to withstand harsh environmental conditions and stresses like drought, temperature, flood and salinity. Salinity is second to drought stress and hence it is very important to develop crops tolerant to salinity stress. This review discusses the mechanisms of salt tolerance and the recent developments in understanding the complex tolerance phenomena. One way to address the salinity issue is to develop tolerant rice varieties using conventional and modern breeding techniques for which screening the rice germplasm for the varieties with desired traits is critical. Conventional methods to develop tolerant rice varieties are discussed along with modern biotechnology techniques are also discussed. Quantitative Trait Loci (QTL) and Marker Assisted Selection (MAS) are promising techniques. In addition to these modern techniques, some recent developments in the fields of transgenic plants, haploid breeding and Somaclonal variations have also been discussed. The limited knowledge about molecular and genetic mechanisms to tolerate abiotic stresses, however is a barrier to efficiently develop tolerant cultivars. A combination of conventional and modern biotechnology techniques could possibly open up the new ways

    More Than a Green Roof: An Analysis of Low Impact Development Policies and Practices

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    While the concept of green infrastructure is becoming increasingly popular, practitioners and institutions that implement it have varying perspectives on its meaning. This case study aimed to understand how a medium-sized municipality defines green infrastructure as a concept and incorporates it into official policies and related development plans to encourage green stormwater management strategies. It further sought to understand how the analyzed policies and related plans stimulate low impact development implementation in response to climate change adaptation efforts. A content analysis of eight official documents was conducted to determine how the City of St. Catharines, Ontario defines green infrastructure and includes it in its policies and plans. NVivo 12 was used to gather the meaning of green infrastructure and related terms qualitatively. The findings discuss how green infrastructure was defined and incorporated, as well as the consistency of its usage and meaning across the sampled official documents

    Visible light assisted organosilane assembly on mesoporous silicon films and particles

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    Porous silicon (PSi) is a versatile matrix with tailorable surface reactivity, which allows the processing of a range of multifunctional films and particles. The biomedical applications of PSi often require a surface capping with organic functionalities. This work shows that visible light can be used to catalyze the assembly of organosilanes on the PSi, as demonstrated with two organosilanes: aminopropyl-triethoxy-silane and perfluorodecyl-triethoxy-silane. We studied the process related to PSi films (PSiFs), which were characterized by X-ray photoelectron spectroscopy (XPS), time of flight secondary ion mass spectroscopy (ToF-SIMS) and field emission scanning electron microscopy (FESEM) before and after a plasma patterning process. The analyses confirmed the surface oxidation and the anchorage of the organosilane backbone. We further highlighted the surface analytical potential of 13 C, 19 F and 29 Si solid-state NMR (SS-NMR) as compared to Fourier transformed infrared spectroscopy (FTIR) in the characterization of functionalized PSi particles (PSiPs). The reduced invasiveness of the organosilanization regarding the PSiPs morphology was confirmed using transmission electron microscopy (TEM) and FESEM. Relevantly, the results obtained on PSiPs complemented those obtained on PSiFs. SS-NMR suggests a number of siloxane bonds between the organosilane and the PSiPs, which does not reach levels of maximum heterogeneous condensation, while ToF-SIMS suggested a certain degree of organosilane polymerization. Additionally, differences among the carbons in the organic (non-hydrolyzable) functionalizing groups are identified, especially in the case of the perfluorodecyl group. The spectroscopic characterization was used to propose a mechanism for the visible light activation of the organosilane assembly, which is based on the initial photoactivated oxidation of the PSi matrixWe acknowledge MSC funding provided by the European Commission through FP7 grant THINFACE (ITN GA 607232) and by Ministerio de EconomĂ­a y Competitividad through grant NANOPROST (RTC-2016-4776-1

    Advancing disaster risk reduction through the integration of science, design, and policy into eco-engineering and several global resource frames

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    By the later part of the 21st Century, our planet will be faced with compelling climatic circumstances requiring tradeoffs to maintain viable environmental conditions and standards of living. The prognosis for people near coastlines and waterways is particularly dire without decisive actions that capitalize on shared strengths such as ecosystems. One clear opportunity is the regenerative services and co-benefits of natural infrastructure that reduce the impacts of environmental disasters as magnified by climatic change. Certainly, nature-based solutions are increasingly being viewed as critical actions to reduce societal risk. However, to advance the use of natural infrastructure through eco-engineering, there is a need to clarify the science regarding risk reduction effectiveness, develop agreeable principles, standards, and designs, and grow a demonstration site network responsive to circumstances faced by communities around the globe. In addition, there is a need to consider the legal, policy, and regulatory obstacles and opportunities for natural infrastructure within local to national contexts (i.e., science-based building codes, architectural design criteria, incentive policies, etc.). Ultimately, the integration of science, designs, and policy coupled with installation within several globally recognized resource frames (IWRM, ICZM, etc.) will help establish eco-engineering standards. Supportive coastal, river, and urban examples from around the world are used to illustrate the current state of knowledge, model this integration of science, design, and policy, serve as initial “benchmark site”, and finally help define guiding principles for the emerging field of eco-engineering
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