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Recent progress on bimetallic NiCo and CoFe based electrocatalysts for alkaline oxygen evolution reaction: A review

Journal of Energy Chemistry 2022年第4期31卷 101-137页

作者： gebrehiwet abrham gebresl.se Maria Victoria Martínez-Huerta Maria Jesus Lázaro Instituto de Carboquímica CSIC.Miguel LuesmaCastán 450018ZaragozaSpain Instituto de Catálisis y Petroleoquímica CSIC.Marie Curie 228049MadridSpain

The deployment of hydrogen as an energy carrier is found to be a vital alternative fuel for the future. It is expected that water electrolysis, powered by renewable energy sources, be able to scale-up hydrogen production. However, the reaction kinetic of oxygen evolution reaction(OER) is a sluggish process, which predominantly limits the efficiency of water electrolysis. This review recapitulates the recent progress and efforts made in the design and development of two selected earth-abundant bimetallic electrocatalysts(Ni Co and Co Fe) for alkaline OER. Each bimetal electrocatalyst is thoroughly outlined and discussed in five sub-sections, including bimetal(oxy) hydroxides, Layered double hydroxides(LDHs) structures,oxides, composites, alloy and nanostructured electrocatalysts, and assembled with ***, a brief introduction to an in situ/operando characterization techniques and advantages for monitoring the structure of the electrocatalysts is provided. Finally, a summary outlining the challenges and conceivable approaches to advance OER performance is highlighted and discussed.

关键词： Water electrolysis Oxygen evolution reaction Bimetallic electrocatalyst Nickel Cobalt and iron

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Detection of schedule delay risk of empirical construction projects

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Frontiers of Engineering Management 2018年第2期5卷 251-267页

作者： Tsegay gebrehiwet Hanbin LUO Department of Construction Management School of Civil Engineering and Mechanics Huazhong University of Science and Technology

In Ethiopian construction projects, schedule delay risk is a predominant issue because it is not properly addressed. Although several studies have been focused on the various effects of risk in construction projects, limited efforts have been made to investigate the typical and the overall schedule delay risk. In this study, our aim is to detect the typical and overall schedule delay risk throughout the construction project lifecycle, which consists of the pre-construction, construction, and post-construction stages, and compare the stages with each other. Common criteria, sub-criteria, and attributes were developed for all alternatives for the purpose of making a risk decision. The methodology that was followed integrated the multiplecriteria decision-making(MCDM) model of fuzzy analytic hierarchy process comprehensive evaluation(FAHPCE)and the relative important index(RII). Data were collected from 77 participants, who were selected through purposive sampling from different contracting organizations in Ethiopian construction projects by means of questionnaires that were distributed to experienced experts. The findings showed that there is a typical delay risk either in the type or in the level of the different construction ***, the most influenced alternative is the construction stage because of the high-risk responsibility,resource, and contract condition related criteria. The postconstruction stage was the second most influenced stage because of the high-risk responsibility-related criteria. The pre-constructed stage was the least influenced stage that consist high-risk criteria of responsibility, resource, and contract condition related. These differences provided noteworthy information about risk mitigation in construction projects by identifying the exact risk level on specific activity to make appropriate decision.

关键词： fuzzy analytic hierarchy process comprehensive evaluation construction project detection of delay risk relative important index

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影响厄立特里亚国际旅游流入因素的研究

影响厄立特里亚国际旅游流入因素的研究

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作者： Mehari Gebremeskel gebrehiwet 江西财经大学

学位级别：硕士

旅游业是当今世界上最具经济活力的行业之一。它正在成为各国的主要的收入来源并不断地给各国创造就业机会。厄立特里亚具有自然、历史和文化所赋予的巨大旅游潜力。尽管具有这些潜力,厄立特里亚也无法充分开发旅游业并从中获益。在厄... 详细信息

旅游业是当今世界上最具经济活力的行业之一。它正在成为各国的主要的收入来源并不断地给各国创造就业机会。厄立特里亚具有自然、历史和文化所赋予的巨大旅游潜力。尽管具有这些潜力,厄立特里亚也无法充分开发旅游业并从中获益。在厄立特里亚,旅游业的收入微不足道,而其业绩不佳的原因并未被全面地研究探讨过。各种国内和国际的研究将其归因于该行业的低绩效。本文将通过探索,介绍和调查厄立特里亚的旅游潜力来分析目的地旅游流入的决定因素。利用目的地竞争力分析模型,重点考察了决定厄立特里亚旅游客源流入的变量。该研究基于与该模型相关的指标结果分析,以确定影响厄立特里亚作为旅游目的地的旅游流入的因素。研究者采用描述性和经验性研究设计,通过采用均值、标准差、曲线图等方法对结果进行分析。在本研究中,一手数据和二手数据都被用于分析。一手数据收集了从分发提问者到旅游服务提供者(利益相关者)和文化事务局以及与旅游官员部的访谈。二手数据来自厄立特里亚旅游局的书面文件、不同的相关研究、书籍、出版和未出版的文件。研究分析表明,政治稳定性差(与埃塞俄比亚的边境战争)和不适当的旅游投资环境是影响厄立特里亚旅游流入的主要决定因素。西方国家对厄立特里亚的不良形象以及联合国安理会和美国对厄立特里亚实施的不公正制裁也阻碍了该国旅游业的发展。该调查还显示,除在旅游资源,管理和情境条件等方面评价较高外,厄立特里亚可继承的旅游资源禀赋优于创建的资源。但是大多数因素的评级低于非洲标准,因此为了促进旅游业的发展,政府需要为此做出很大的改进并且给予特别的关注。

关键词：文化禀赋目的地竞争力旅游目的地管理

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基于神经网络的黄柏河东支流域水质遥感估算

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环境科学与技术 2022年第6期45卷 195-202页

作者：赵程铭董晓华李中华薄会娟张庆玉章程焱 gebrehiwet Legese Reta 三峡大学水利与环境学院湖北宜昌443002 宜昌市流域水生态保护综合执法支队湖北宜昌443000

水质安全是水环境中的关键因素,流域中复杂的空间差异一直是水质估算精度不高的主要原因。文章提出采用一阶微分算法提高遥感影像数据与实测水质参数之间的相关性,利用遥感影像数据与流域库区空间划分条件作为BP神经网络的输入模拟流域... 详细信息

水质安全是水环境中的关键因素,流域中复杂的空间差异一直是水质估算精度不高的主要原因。文章提出采用一阶微分算法提高遥感影像数据与实测水质参数之间的相关性,利用遥感影像数据与流域库区空间划分条件作为BP神经网络的输入模拟流域空间结构建立高精度水质反演模型。以黄柏河东支流域尚家河水库坝址以上流域为研究对象,基于Landsat-8遥感影像数据,选取主要水质参数:氨氮、总磷、高锰酸盐指数。经验证模型达到“优”精度等级,估算值与实测值最小决定系数为0.85、最小纳什效率系数为0.82、最小百分比偏差值为-9.51%、最大均方根误差与标准值比值为0.42。从水质参数估算结果空间分布图确定流域中玄庙观水库以氨氮浓度为代表污染最为严重。

关键词：黄柏河东支流域 BP神经网络水质反演 Landsat-8

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<i>Acacia etbaica</i>as a Potential Low-Cost Adsorbent for Removal of Organochlorine Pesticides from Water

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Journal of Water Resource and Protection 2015年第3期7卷 278-291页

作者： Abraha Gebrekidan Mekonen Teferi Tsehaye Asmelash Kindeya gebrehiwet Amanual Hadera Kassa Amare Jozef Deckers Bart Van Der Bruggen Department of Chemistry Mekelle University Mekelle Ethiopia Department of Biology Mekelle University Mekelle Ethiopia Department of Microbiology Mekelle University Mekelle Ethiopia Department of Land Resource Management & Environmental Protection Mekelle University Mekelle Ethiopia Department of Earth Science Mekelle University Mekelle Ethiopia Department for Earth and Environmental Science KU Leuven Leuven Belgium Department of Chemical Engineering Process Engineering for Sustainable Systems (ProcESS) KU Leuven Leuven Belgium

The presence of pesticides in the environment is of great concern due to their persistent nature and chronic adverse effect on human health and the environment. Water bodies are subject to pollution by organochlorine pesticides, especially in developing countries, where water pollution is a key sustainability challenge. Hence, activated carbon is considered a universal adsorbent for the removal of organochlorine pollutants from water. Activated carbon from Acatia etbaica was prepared using traditional kilns with low investment costs. Pesticides such as aldrin, dieldrin and DDT were selected for adsorption because of their common usage in agricultural and malaria control activities and may occur in high concentrations in surface waters that are used as drinking water sources. The effect of the adsorbent dose and initial concentration were investigated. To describe the equilibrium isotherms the experimental data were analyzed by the Langmuir and Freundlich isotherm models. The Freundlich model gave the best correlation with the experimental data. Activated carbon prepared from Acacia etbaica was found to be an effective and low-cost alternative for the removal of organochlorine pesticides from aqueous solutions. The preparation method allows the use of this material by local communities for effective remediation of pollution by pesticides.

关键词： Acacia etbaica Activated Carbon Organochlorine Pesticides Adsorption Water Purification

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