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Removal of Copper from Acid Mine Drainage (AMD) or Acid Rock Drainage (ARD)

Journal of Water Resource and Protection 2021年第7期13卷 435-454页

作者： Agabu Shane Xinyang Xu John Siame Alick Nguvulu Tewodros Mitiku Tena Musango Lungu Sydney Chinyanta Jackson Kawala victor mwango bowa Brian Chirambo Department of Mining Engineering School of Mines and Mineral Sciences Copperbelt University Kitwe Zambia Department of Environmental Engineering College of Natural Resources and Civil Engineering Northeastern University Shenyang China Department of Chemical Engineering School of Mines and Mineral Sciences Copperbelt University Kitwe Zambia Department of Geomatics Engineering School of Mines and Mineral Sciences Copperbelt University Kitwe Zambia Department of Environmental Engineering School of Mines and Mineral Sciences Copperbelt University Kitwe Zambia

Acid mine drainage is wastewater from a mine having a low pH and an elevated level of dissolved heavy metals. These metals are harmful to aquatic, animal and human life. This paper looks at the removal of copper from acid mine drainage using ion exchange to less than 1 mg/l. A weak acidic cation resin was used. Spectrophotometric determination of copper with sodium diethyldithiocarbamate was used to determine the copper concentrations in the treated water. Using regression analysis, the experimental results gave a correlation coefficient of 0.977 and a coefficient of determination of 99.5%. Results indicated that the higher the flows rate the shorter the period after which the copper concentration in the treated water reaches 1 mg/l. At pH 3.85 and 5.09, the resin performed better and at pH above 6.62 and between pH 3.0 and below the resin’s does not perform well. The higher the resin height the greater is the resin exchange capacity and the longer it takes for the copper concentration to reach 1 mg/l in the treated water. The higher the wastewater copper concentration the shorter the time it takes the resin to reach 1 mg/l. The results for this experiment indicated that acid mine drainage can be treated well by ion exchange resins, but it is also very important to establish suitable operating conditions.

关键词： Acid Mine Drainage Copper Ion Exchange Resin and Spectrophotometry

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Surface Water Quality Response to Land Use Land Cover Change in an Urbanizing Catchment: A Case of Upper Chongwe River Catchment, Zambia

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Journal of Geographic Information System 2021年第5期13卷 578-602页

作者： Alick Nguvulu Agabu Shane Claude S. Mwale Tewodros M. Tena Phenny Mwaanga John Siame Brian Chirambo Musango Lungu Frank Mudenda Dickson Mwelwa Sydney Chinyanta Jackson Kawala victor mwango bowa Levi S. Mutambo Nicholas Okello Charles Musonda Department of Geomatics Engineering Copperbelt University Kitwe Zambia Department of Mining Engineering Copperbelt University Kitwe Zambia Department of Environmental Engineering Copperbelt University Kitwe Zambia Department of Chemical Engineering Copperbelt University Kitwe Zambia Department of Civil Engineering University of Pretoria Pretoria South Africa Department of Civil and Environmental Engineering University of Zambia Lusaka Zambia Business and Information Technology Department Cavendish University Lusaka Zambia

The Upper Chongwe River Catchment has recently been overexploited for water resources with increased complaints by various water users about the deteriorating quality of surface water within the sub-catchment. This study was motivated by the need to investigate and understand the response of surface water quality to land use land cover (LULC) change due to urbanization. Water samples, collected at 9 sampling sites from 2006 to 2017, were analyzed for water quality using the weighted arithmetic water quality index and trend using the Mann-Kendall statistics. LULC change is detected and analyzed in ERDAS Imagine 2014 and ArcGIS 10.4 using 2006 Landsat 5 TM and 2017 Landsat 8 OLI imageries. The relationship between LULC change and water quality was performed with multiple regression analysis and Pearson correlation. The results reveal that Built-up area, Grassland and surface water increased by 5.48%, 13.34% and 0.03% respectively while Agricultural land and Forest Land decreased by −13.41% and −5.42% respectively. The water quality index ranged from 43.04 to 110.40 in 2006 and from 170 to 430 in 2017 indicating a deterioration in the quality of surface water from good to unsuitable for drinking at all the sampled sites. Built-up/bare lands exhibited a significant positive correlation with EC (R2 = 0.61, p ≤ 0.05), turbidity (R2 = 0.69, p ≤ 0.05), TDS (R2 = 0.61, p ≤ 0.05), Cl (R2 = 0.62, p ≤ 0.05) and a significant negative correlation with NH4 (R2 = −0.729, p ≤ 0.05). Agriculture exhibited a significant positive correlation with turbidity (R2 = 0.71, p ≤ 0.01) and Fe (R2 = 0.75, p ≤ 0.01. Forest cover correlated negatively with most of the water quality parameters apart

关键词： Water Quality LULC Change Water Quality Index River Catchment Watershed

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Cortical hem signaling center: functions, development, and potential implications for evolution and brain disorders

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Neural Regeneration Research 2025年第4期20卷 1079-1080页

作者： victor V.Chizhikov Igor Y.Iskusnykh Department of Anatomy and Neurobiology University of Tennessee Health Science CenterMemphisTNUSA

Development of the telencephalon relies upon several signaling centers-localized cellular populations that supply secreted factors to pattern the cortical *** such signaling center is the cortical hem,which arises during embryonic development at the telencephalic dorsal midline,adjacent to the choroid plexus and hippocampal primordium(Figure 1A).While the cortical hem has also been described in reptiles and birds,most of our knowledge about the developmental roles of the cortical hem is derived from the analysis in *** cortical hem produces several types of secreted molecules,including wingless-related integration site(Wnt)and bone morphogenetic(Bmp)*** cortical hem is particularly important for the development of the hippocampus,which is involved in learning and memory,and the neocortex,which is the most complex brain region that mediates multiple types of behavior and higher cognitive functions(Mangale et al.,2008;Dal-Valle-Anton and Borrell,2022).

关键词： epithelium Figure center

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“What is a Sociologist Doing Here?”An Unconventional People-Centered Approach to Improve Warning Implementation in the Sendai Framework for Disaster Risk Reduction

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International Journal of Disaster Risk Science 2020年第2期11卷 218-229页

作者： victor Marchezini Cemaden–National Early Warning and Monitoring Center of Natural Disasters Distrito de Eug8nio de Melo 12.247-016Sao Jose dos CamposSPBrazil Doctorate Program on Earth System Science National Institute for Space ResearchSao Jose dos CamposBrazil Programa de Pós-Gradua??o em Desastres Naturais ICT/Unesp-CemadenSao Jose dos Campos.Brazil

The Sendai Framework for Disaster Risk Reduction 2015–2030 recommends several actions for early warning systems(EWSs). However, there is a lack of information about their means of implementation. This article used institutional ethnography to analyze the 2012–2018 implementation of a national warning system in Brazil. The challenges related to daily activities, and the interdisciplinary works in the four axes of EWSs towards multi-hazard and people-centered approaches are discussed. This national experience is then discussed in the light of the global challenges of EWSs considering two main issues:(1) experiences of implementation and barriers related to people-centered warning systems;and(2)types of national/regional warning systems and hazards/threats that are being monitored as an important input for multi-hazard approaches. There are few multi-hazard warning systems in place and EWSs are focused on hydrometeorological hazards, mainly related to floods. The Sendai Framework needs to improve access to data and information, identify views from the frontline, consider political threats and vulnerabilities, and find ways to talk about disaster risk creation processes at a larger scale.

关键词： Risk governance Interdisciplinary research People-centered warning systems

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Cryotic climate conditions and their eventual implication in the high-mountain surface of the Nevado de Toluca volcano, Mexico

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Journal of Mountain Science 2021年第9期18卷 2273-2286页

作者： SOTO victor Facultad de Ciencias Biológicas y Agropecuarias Universidad VeracruzanaPoza Rica-Tuxpan 92870México

The state of the cryosphere in tropical regions is of great importance because the temperature around the glaciers, permafrost and snow cover always fluctuates near the melting point. These thermal conditions and their high sensitivity to climate change cause the accelerated disappearance of these elements;therefore, it is important to know the climatic factors that regulate them, as well as the physical characteristics of each cryospheric element. Unlike glaciers, permafrost and snow cover have not been widely studied. In recent decades, the study of the glacial and periglacial environment has been carried out in intertropical mountains. However, despite the altitude of their relief and the frequent occurrence of snowfall in tropical high mountains, the conditions that determine such events have been barely analyzed;and in the case of Mexico, the volume of snowfall and its thickness have not been quantified either, as well as their corresponding duration. Consequently, this work is aimed to analyze the temperature and precipitation conditions that determine the snowfall at the higher part of the Nevado de Toluca volcano;at the same time, the conditions of the cryotic climate and their possible implication on the surface are studied. The analysis of data from 1965 to 2016, using frequency statistics, allowed to realize that snowfall occurs with low intensity, its accumulation being less than 10 cm thick and 10 mm of snow water equivalent, which causes the snowpack to stay only a few weeks on average. At the same time, it was determined that there is a significant increase in the number of freeze-thaw cycles. Therefore, due to the climate conditions and their influence on the mountain surface, it is probable that the bedrock is subject to a greater gelifraction dynamics, and the unconsolidated soil surface increases;the combination of the above could cause a greater geomorphological dynamic over time, particularly due to debris flows, and by water and wind erosion of

关键词： Air temperature Cryotic conditions High-mountain climatology Periglacial geomorphology Snow precipitation

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Transnational Dialogues on Interdisciplinary Approaches for Advancing People-Centered Warning Systems

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International Journal of Disaster Risk Science 2023年第5期14卷 868-872页

作者： victor Marchezini Cemaden–National Early Warning and Monitoring Centre of Natural Disasters São Josédos Campos12.247-016Brazil Natural Hazards Center Institute of Behavioral ScienceUniversity of Colorado BoulderBoulderCO80309USA

The United Nations Office for Disaster Risk Reduction and the World Meteorological Organization launched in 2022 the executive plan of the world program "Early Warning Systems for All" to be implemented from 2023 to *** program champions an investment of USD 3.1 billion into the four pillars of warning systems and calls for multi-hazard and peoplecentered warning systems(PCWS).However,there is a scientific gap concerning interdisciplinary approaches to promoting *** by the call for action of "Early Warning Systems for All" and warning research gaps on the lack of interdisciplinarity,a workshop series "Interdisciplinary Approaches for Advancing People-Centered Warning Systems" was held in early *** short article shares the preliminary findings and recommendations of this research,which involved a transnational virtual dialogue between one scientific organization in Brazil and one from the United *** findings and recommendations discussed in three virtual sessions and one collective working paper were centered on three aspects:promoting interdisciplinary integration in research;the need to discuss the characteristics of a PCWS;and promoting problem-and solution-based programs with people to integrate them at all phases of the warning system.

关键词： Capacity building Cooperation Interdisciplinary methods Warning implementation Warning research

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Miscellaneous Rotating Solitary Waves to a Coupled Dispersionless System

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Chinese Physics Letters 2009年第9期26卷 61-64页

作者： Kuetche Kamgang victor Ecole Nationale Superieure Polyteehnique University of Yaounde I PO Box 8390 Cameroon Department of Physics Faculty of Science University of Yaounde I PO Box. 812 Cameroon Higher Teacher's Training College of Maroua University of Maroua P.O. Box. 46 Cameroon The A bdus Salam International Centre for Theoretical Physics P.O. Box 586 Strada Costiera II-34014 Trieste Italy

We investigate the soliton structure of a coupled dispersionless system describing a current-conducting string with infinite length within a magnetic field. Thus, following Hirota＇s method, we unwrap three typical localized waves with nonzero angular momentum depending strongly upon their angular velocities. Illustrating the soliton behavior of these waves, we focus our interests on breather-like waves and depict the elastic scattering amongst such waves.

关键词： sea surface nonliear interaction numerical method

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Mathematics of microRNAs: stabilizing gene regulatory networks

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National Science Review 2019年第6期6卷 1189-1190页

作者： victor Ambros Program in Molecular Medicine University of Massachusetts Medical School

Micro RNAs(miRNAs) are fascinating in their versatility. Animal cells express hundreds of distinct micro RNAs, and each micro RNA can regulate hundreds of distinct m RNA ***, in aggregate, the micro RNA compliment of a cell can exert pervasive effects on gene expression. Individual micro RNAs can also be potent determinants of phenotype: The

关键词： RNA stabilizing gene regulatory networks Mathematics of microRNAs

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Processing stages of Gd_2Sr(Al_(1-x)Fe_x)_2O_7 series

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Rare Metals 2014年第1期33卷 47-53页

作者： Ekaterina Tugova victor Gusarov Laboratory of New Inorganic Materials Ioffe Physical Technical Institute of RAS Department of Physical Chemistry St. Petersburg State Institute of Technology Technical University

The continuous series of perovskite-related oxides with the general formula GdzSr（Al1-xFex）207 0 〈 x 〈 1 were prepared by conventional ceramic technology in air. The pro- cessing stages of Gd2Sr（Al1-xFex）207 0 〈 x 〈 1 phases were investigated by means of X-ray powder diffraction （XRD） and scanning electron microscopy （SEM） with the element phase analysis. The three main stages of GdeSr（All_~Fex）aO7 for- marion are pointed out. The analysis of the mutual influence of intermediate compounds on the synthesis of the target solid solutions of complex composition, in particular for Gd2Sr（All-xFex）207 was carried out. It is determined that the closeness of the reactive mixture composition to the composition of individual compounds Gd2SrA1207 or GdaSrFeaO7 is of importance for the realization of a partic- ular way of GdESr（Al1-xFex）207 solid solutions formation. It is shown that at x ,= 0.2 the reversing in scheme of Gd2Sr（Al1-Fex）207 series formation is observed. The formation of the Gd2Sr（Al1-xFex）207 continuous series is indicated by the monotonic dependence of molar unit cell volume on the iron content x.

关键词： Rare-earth metals Oxide materials Solid-state reactions Ceramics X-ray diffraction (XRD) Scanning electron microscopy (SEM)

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Finite Element Analysis of Residual Stress and Distortion in an Eccentric Ring Induced by Quenching

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材料热处理学报 2004年第05B期25卷 746-751页

作者： LI M. victor Portland State University PO Box 751-ME Portland OR 97207-075J USA

The residual stresses and distortion induced by quenching in an eccentric ring were investigated in this study with finite element method. The ring was made of AISI 52100 steel. A fully coupled 3D temperature-displacement analysis was performed to simulate heat transfer, phase transformations, and mechanical stresses and strains during the heating and subsequent quenching processes. Commercial FEA package ABAQUS/Standard 6.4 was used for the analyses along with user subroutines developed by the authors to model the thermal and mechanical constitutive behavior. The simulation results show that transformation plasticity plays an important role on the residual stress distribution.

关键词：残余应力有限元分析变形偏心环相变塑性

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