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Water Quality Assessment in the Bamoun Plateau, Western-Cameroon: Hydrogeochemical Modelling and Multivariate Statistical Analysis Approach 认领
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作者 Zakari Mfonka Amidou Kpoumié +7 位作者 Abdou Nasser Ngouh Oumar Farouk Mouncherou Daouda Nsangou Felaniaina Rakotondrabe Alain Fouépé Takounjou Mounira Zammouri Jules Rémy Ndam Ngoupayou Paul-Désiré Ndjigui 《水资源与保护(英文)》 2021年第2期112-138,共27页
This study focuses on the geochemical and bacteriological investigation of surface and ground water in the Bamoun plateau (Western-Cameroon). During the period from September 2013 to August 2014, 71 samples were colle... This study focuses on the geochemical and bacteriological investigation of surface and ground water in the Bamoun plateau (Western-Cameroon). During the period from September 2013 to August 2014, 71 samples were collected from two springs, one borehole, four wells and the Nchi stream for analysis of major elements. In order to obtain the characteristics of the various species of bacteria, 7 samples were selected. The analytical method adopted for this study is the conventional hydrochemical technic and multivariate statistical analysis, coupled with the hydrogeochemical modelling. The results revealed that, water from the zone under study are acidic to basic, very weakly to weakly mineralized. Four types of water were identified: 1) CaMg-HCO<sub>3</sub>;2) CaMg-Cl-SO<sub>4</sub>;3) NaCl-SO<sub>4</sub> and 4) NaK-HCO<sub>3</sub>. The major elements were all listed in the World Health Organization guidelines for drinking water quality, except for nitrates which was found at a concentration > 50 mg /l <span style="white-space:nowrap;">NO<sup>-</sup><sub style="margin-left:-7px;">3</sub> </span>in the borehole F401. As for the hydrobiological aspect, the entire sample contained all the bacteriological species except for spring S301 and well P401. According to the hydrogeochemical modelling, the Gibbs model and multivariate statistical tests, the quality of surface and ground water of the Foumban locality is influenced by two important factors: 1) the natural factors characterized by the water-rock interaction, evapotranspiration/crystallization, 2) the anthropogenic factors such as: uncontrolled discharges of liquid and solid effluents of all kinds and without any prior treatment within the ground and the strong urbanization accompanied by lack of sanitation and insufficient care. 展开更多
关键词 Foumban Surface and Ground Water Water-Rock Interaction Bacteriological Parameters Hierarchical Clustering Analysis Principal Component Analysis
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High Plant Species Distributed in and around Dengizkul, Bukhara Region 认领
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作者 Husniddin Kurbonovich Esanov Feruz Qamariddinovich Shodmonov Aziz Mukhtorovich Kobilov 《美国植物学期刊(英文)》 2021年第2期266-273,共8页
The article presents the results of research conducted in Dengizkul and around this area. It identifies plant species in and around the lake and analyzes species composition. As a result of the analysis, 70 species of... The article presents the results of research conducted in Dengizkul and around this area. It identifies plant species in and around the lake and analyzes species composition. As a result of the analysis, 70 species of tall plants belonging to 24 families were identified in the lake. The identified species are divided into aquatic and riparian plants. Of these, 18 species are found in lake water and 52 species in its vicinity. The low number of high plant species in the lake water is due to the salinity of the water. The protection of this area is based on the natural conservation of the surrounding plant <span style="font-family:Verdana;">population.</span> 展开更多
关键词 Dengizkul BUKHARA Zarafshan River Water Basin High Plants WATER
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Water Dynamics under Drip Irrigation to Proper Manage Water Use in Arid Zone 认领
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作者 Siguibnoma Kevin Landry Ouédraogo Marcel Bawindsom Kébré Francois Zougmoré 《农业化学和环境(英文)》 2021年第1期57-68,共12页
The water resources reduction due to climate changes and also population increase, have contributed to increas<span style="font-family:Verdana;">ing</span><span style="font-family:Verdana... The water resources reduction due to climate changes and also population increase, have contributed to increas<span style="font-family:Verdana;">ing</span><span style="font-family:Verdana;"> the constraint on water disponibility and accessibility. In the agricultural field, we need moderate soil and water resources management. This work aims to simulate water dynamics in soil under drip irrigation system in arid regions to better manage irrigation water. Simulations are done with soil physical properties of Burkina Faso. We assess maize plant water requirements for the whole growing season. With Hydrus 2D, we simulate water supply in the soil column. We assign atmospheric conditions on the top of the domain, zero flux of water on the lateral sides, and free drainage on the bottom boundary domain. We perform many irrigation events to analyze wetting pattern distribution around the em</span><span style="font-family:Verdana;">i</span><span style="font-family:Verdana;">tter</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> which allowed us to contain the amount of irrigation water applied, only around the area dominated by roots</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> and then reduce water losses that roots cannot uptake. According to the different growing stages of the maize crop, we choose proper irrigation duration and frequency, and suggest irrigation schedule for the whole growing season.</span> 展开更多
关键词 Drip Irrigation Water Dynamics Hydrus (2D/3D) WATER
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Water in coesite: Incorporation mechanism and operation condition,solubility and P-T dependence, and contribution to water transport and coesite preservation 认领
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作者 Wei Yan Yanyao Zhang +5 位作者 Yunlu Ma Mingyue He Lifei Zhang Weidong Sun Christina Yan Wang Xi Liu 《地学前缘:英文版》 SCIE CAS 2021年第1期313-326,共14页
A series of coesite,coexisting with or without a liquid phase,was synthesized in the nominal system SiO2-H2O at800-1450℃and 5 GPa.Micro-Raman spectroscopy was used to identity the crystalline phase,electron microprob... A series of coesite,coexisting with or without a liquid phase,was synthesized in the nominal system SiO2-H2O at800-1450℃and 5 GPa.Micro-Raman spectroscopy was used to identity the crystalline phase,electron microprobe and LA-ICP-MS were employed to quantity some major and trace elements,and unpolarized FTIR spectroscopy was applied to probe the different types of hydrogen defects,explore water-incorporation mechanisms and quantify water contents.Trace amounts of A1 and B were detected in the coesite.Combining our results with the results in the literatures,we have found no positive correlation between the Al contents and the"Al"-based hydrogen concentrations,suggesting that previously proposed hydrogen-incorporation mechanism H^++Al^3+■Si^4+does not function in coesite.In contrast,we have confirmed the positive correlation between the B contents and the B-based hydrogen concentrations.The hydrogen-incorporation mechanism H^++B3^+■Si^4+readily takes place in coesite at different P-T conditions,and significantly increases the water content at both liquid-saturated and liquid-undersaturated conditions.For the SiO2-H2O system,we have found that type-Ⅰhydrogarnet substitution plays a dictating role in incorporating water into coesite at liquid-saturated condition,type-II hydrogarnet substitution contributes significantly at nearly dry condition,and both operate at conditions in between.The water solubility of coesite,as dictated by the type-Ⅰhydrogarnet substitution,positively correlates with both P and T,cH2O=-105(30)+5.2(32)×P+0.112(26)×T,with cH2O in wt ppm,P in GPa and T in℃.Due to its low water solubility and small fraction in subducted slabs,coesite may contribute insignificantly to the vertical water transport in subduction zones.Furthermore,the water solubility of any coesite in exhuming ultra-high pressure metamorphic rocks should be virtually zero as coesite becomes metastable.With an adequately fast waterdiffusion rate,this metastable coesite should be completely dry,which may have been the ke 展开更多
关键词 Coesite preservation FTIR New IR experimental Protocol Anhydrous minerals P-T dependence of water solubility Water-incorporation mechanism
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A study of water curtain parameters of underground oil storage caverns using time series monitoring and numerical simulation 认领
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作者 Yi-guo XUE Ze-xu NING +5 位作者 Dao-hong QIU Mao-xin SU Zhi-qiang LI Fan-meng KONG Guang-kun LI Peng WANG 《浙江大学学报:A卷英文版》 SCIE EI CAS 2021年第3期165-181,共17页
Water curtain systems(WCSs)are key components for the operation of underground oil storage caverns(UOSCs)and their optimization and design are important areas of research.Based on the time series monitoring of the fir... Water curtain systems(WCSs)are key components for the operation of underground oil storage caverns(UOSCs)and their optimization and design are important areas of research.Based on the time series monitoring of the first large-scale underground water-sealed storage cavern project in China,and on finite element analysis,this study explores the optimum design criteria for WCSs in water-sealed oil caverns.It shows that the optimal hole spacing of the WCS for this underground storage cavern is 10 m in order to ensure seal effectiveness.When the WCS is designed with a 10-m horizontal hole spacing and a water curtain pressure(WCP)of 80 kPa,a water curtain hole(WCH)has an influence radius of approximately 25 m.The smaller the vertical distance is between a WCH and the main cavern,the greater the water inflow into the main cavern.The vertical hydraulic gradient criterion can be satisfied when this distance is 25 m.It shows that the optimal WCP is 70 kPa,which meets sealing requirements. 展开更多
关键词 Underground oil storage Water curtain system(WCS) Water-sealed cavern Optimum design criteria Monitoring data Finite element method(FEM)
Altering membrane structure to enhance water permeability and performance of anion exchange membrane fuel cell 认领
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作者 YANG Yue GAO XueQiang +7 位作者 SONG Wei YU HongMei LI WenBin QI ManMan HUANG He WANG PengHao FAN ZhiXuan SHAO ZhiGang 《中国科学:技术科学英文版》 SCIE EI CAS 2021年第2期414-422,共9页
Water management has been proven significant for enhancing both performance and durability of anion exchange membrane fuel cell. Besides searching new material, decreasing membrane thickness and modifying operation pa... Water management has been proven significant for enhancing both performance and durability of anion exchange membrane fuel cell. Besides searching new material, decreasing membrane thickness and modifying operation parameters, a simple and universal method of altering membrane structure is proposed in this work. Composite membranes made by unique processing method that includes both casting and electrospinning processes were compared with traditional casting membrane, all with the same thickness of 40 μm. Comparing to traditional casting membrane, the composite membrane put at proper position shows a higher water permeability, thus even more than 50% enhancement of the peak performance. 展开更多
关键词 AEMFC water management membrane structure ELECTROSPINNING water permeation
Numerical Simulation of Water Entry of Wedges in Waves Using A CIPBased Model 认领
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作者 HU Zi-jun ZHAO Xi-zeng +3 位作者 LI Meng-yu ZHAO Xin YAO Wen-wei SHAO Jie 《中国海洋工程:英文版》 SCIE EI 2021年第1期48-60,共13页
In this study,the water entry of wedges in regular waves is numerically investigated by a two-dimensional in-house numerical code.The numerical model based on the viscous Navier−Stokes(N−S)equations employs a high-ord... In this study,the water entry of wedges in regular waves is numerically investigated by a two-dimensional in-house numerical code.The numerical model based on the viscous Navier−Stokes(N−S)equations employs a high-order different method—the constrained interpolation profile(CIP)method to discretize the convection term.A Volume of Fluid(VOF)-type method,the tangent of hyperbola for interface capturing/slope weighting(THINC/SW)is employed to capture the free surface/interface,and an immersed boundary method is adopted to treat the motion of wedges.The momentum source function derived from the Boussinesq equation is applied as an internal wavemaker to generate regular waves.The accuracy of the numerical model is validated in comparison with experimental results in the literature.The results of water entry in waves are provided in terms of the impact force of wedge,velocity and pressure distributions of fluid.Considerable attention is paid to the effects of wave parameters and the position of wedge impacting the water surface.It is found that the existence of waves significantly influences the velocity and pressure field of fluid and impact force on the wedges. 展开更多
关键词 Water entry water wave WEDGE internal wave maker CIP method VOF method
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Simple Measurement of Carbon Films on Copper Tubes and Their Effects on Corrosion 认领
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作者 Takashi Iyasu Motoki Kuratani +3 位作者 Itaru Ikeda Noriyuki Tanaka Yutaka Yamada Osamu Sakurada 《复合材料期刊(英文)》 2021年第1期12-22,共11页
It has been reported that pitting corrosion in copper tubes occurs due to the effect of a carbon film produced by the influence of undergoing an oil and heat treatment. As a quantitative method for determining the res... It has been reported that pitting corrosion in copper tubes occurs due to the effect of a carbon film produced by the influence of undergoing an oil and heat treatment. As a quantitative method for determining the residual carbon amount, it has been reported that the inner surface of a copper tube can be dissolved with a mixed acid to collect and analyze the adhering carbon;however, this method is dangerous and difficult. Therefore, two methods were examined as a simple quantitative method for obtaining the residual carbon amount using copper tubes with known residual carbon amounts. One method utilizes X-ray photoelectron spectroscopy (XPS), and the other method utilizes the potential difference between the carbon film-adhered surface and carbon film-removed surface. In regard to XPS measurement, a linear correlation was found between the spectral intensity of C and the residual carbon amount;therefore, XPS measurements were considered to be effective as a simple measurement method for the carbon film on the inner surface of a copper tube. In the evaluation method by measuring the corrosion potential, a correlation was observed between the potential difference ΔE and the residual carbon amount of the inner surface of the tube and the outer surface of the polished tube. It is considered possible to estimate the residual carbon amount from the prepared calibration curve. Through these studies, it is suggested that the carbon film was non-uniformly present on the surface of the copper tube. Therefore, the galvanic current was measured, and the effect of a non-uniform carbon film on corrosion behavior was investigated. As a result, in the measurement of galvanic current, the current flowed from the copper tube with a large amount of residual carbon (cathode) to the copper tube with a small amount of residual carbon (anode). In addition, the higher the area ratio of the carbon film was, the larger the galvanic current tended to be. 展开更多
关键词 Copper Tube Residual Carbon Pitting Corrosion Cooling Water System Re-frigerator XPS
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An Experimental Study on Bio-Clogging in Porous Media during Geothermal Water Reinjection 认领
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作者 Jianguo Feng Yao Zhao +1 位作者 Deshuai Ji Zongjun Gao 《水资源与保护(英文)》 2021年第2期139-153,共15页
To study the mechanism of bio-clogging in a porous medium during the reinjection of geothermal water and to improve reinjection efficiency, an indoor one-dimensional reinjection experiment was conducted based on the g... To study the mechanism of bio-clogging in a porous medium during the reinjection of geothermal water and to improve reinjection efficiency, an indoor one-dimensional reinjection experiment was conducted based on the geological model of the geothermal reinjection demonstration project in Dezhou City. The biological process of porous media clogging was investigated by analyzing the variation of permeability within the medium, the main indexes of nutrient salts, and the content of extracellular polymeric substances (EPS). High-throughput sequencing, based on 16S rRNA, was used to analyze the characteristics and succession of microbial communities during the reinjection of geothermal water. The results of the study show that significant bio-clogging occurs during the reinjection of geothermal water, with an increase in the heterogeneity of the thermal reservoir medium, and a decrease in permeability. The extent of clogging gradually reduces with an increase in seepage path. Thus, thermal reservoir clogging is more serious closer to the water inlet. With an increase in the duration of reinjection, the permeability of the porous medium undergoes three stages: “rapid”, “decline-slow”, and “decrease-stable”. The results show that the richness and diversity of the bacterial community increase and decrease, respectively, during the reinjection process. Bacterial community succession occurs, and the bacterial communities mainly include the Proteobacteria and Bacteroidetes phyla. <em>Pseudomonas</em> and <em>Devosia</em> are respectively the dominant bacteria in the early and late stages of geothermal water reinjection. 展开更多
关键词 Geothermal Water Reinjection Bio-Clogging Indoor Experiment High-Throughput Sequencing
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Effects of Industrial Agriculture and Urbanization on Structure and Functional Organization of Macroinvertebrate of Coastal Streams in Cameroon 认领
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作者 Fils Mamert Onana Antoine Arfao Tamsa +4 位作者 Siméon Tchakonte Ernest Koji Nectaire Lié Nyamsi Tchatcho Yannick Nkouefuth Nfongmo Serge Hubet Zebaze Togouet 《水资源与保护(英文)》 2021年第2期154-171,共18页
The impact of land use changes on watercourses is poorly documented in Cameroon. Therefore, this study examines the effects of agriculture and urbanization on water quality, the structure and functional organization o... The impact of land use changes on watercourses is poorly documented in Cameroon. Therefore, this study examines the effects of agriculture and urbanization on water quality, the structure and functional organization of macroinvertebrates of streams in the coastal zone of Cameroon. Nine sampling stations including three per catchment area with different land occupations (agricultural, urban and forest) were selected. Benthic macroinvertebrates were sampled monthly from February to July 2018 and the physicochemical variables were measured simultaneously. The urban and agricultural streams showed highly polluted waters with high nutrient and suspended matter content, whereas the forest stream waters are moderately polluted. In addition, the hierarchical ascending classification indicated a proximity in water quality between the agricultural and forest streams for which the main physicochemical variables did not vary significantly. With regards to macroinvertebrates, the forest watercourse is characterized by the proliferation of pollution-sensitive taxa, high diversity indices and complex trophic structuring, indicating its good ecological status. In contrast the urban watercourse, heavily polluted is characterized by low diversity indices reflecting a simplification of the structure of stands dominated by the pollution-tolerant collector-gatherer stands. The majority of biological indices and functional feeding groups were not significantly different between the agricultural and forest streams, suggesting a less pronounced impact of agriculture on macroinvertebrates. Our results showed that, riparian vegetation even though constituted of perennial crops, reduces the effects of agricultural inputs on streams and promotes the establishment of diversified macroinvertebrate communities. 展开更多
关键词 Industrial Agriculture URBANIZATION MACROINVERTEBRATES Water Quality Riparian Vegetation Perennial Crops
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How precipitation and grazing influence the ecological functions of drought-prone grasslands on the northern slopes of the Tianshan Mountains, China? 认领
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作者 HUANG Xiaotao LUO Geping +6 位作者 CHEN Chunbo PENG Jian ZHANG Chujie ZHOU Huakun YAO Buqing MA Zhen XI Xiaoyan 《干旱区科学:英文版》 SCIE 2021年第1期88-97,共10页
Drought-prone grasslands provide a critical resource for the millions of people who are dependent on livestock for food security.However,this ecosystem is potentially vulnerable to climate change(e.g.,precipitation)an... Drought-prone grasslands provide a critical resource for the millions of people who are dependent on livestock for food security.However,this ecosystem is potentially vulnerable to climate change(e.g.,precipitation)and human activity(e.g.,grazing).Despite this,the influences of precipitation and grazing on ecological functions of drought-prone grasslands in the Tianshan Mountains remain relatively unexplored.Therefore,we conducted a systematic field investigation and a clipping experiment(simulating different intensities of grazing)in a drought-prone grassland on the northern slopes of the Tianshan Mountains in China to examine the influences of precipitation and grazing on aboveground biomass(AGB),soil volumetric water content(SVWC),and precipitation use efficiency(PUE)during the period of 2014–2017.We obtained the meteorological and SVWC data using an HL20 Bowen ratio system and a PR2 soil profile hydrometer,respectively.We found that AGB was clearly affected by both the amount and seasonal pattern of precipitation,and that PUE may be relatively low in years with either low or excessive precipitation.The PUE values were generally higher in the rapid growing season(April–July)than in the entire growing season(April–October).Overall,moderate grazing can promote plant growth under water stress conditions.The SVWC value was higher in the clipped plots than in the unclipped plots in the rapid growing season(April–July),but it was lower in the clipped plots than in the unclipped plots in the slow growing season(August–October).Our findings can enhance the understanding of the ecological effects of precipitation and grazing in drought-prone grasslands and provide data that will support the effective local grassland management. 展开更多
关键词 climate change human activity aboveground biomass precipitation use efficiency soil volumetric water content water stress
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Dosimetric Characteristics of 6 MV Medical Linac at BAEC 认领
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作者 Sudeb Kumar Roy Pretam Kumar Das +4 位作者 Rajada Khatun Md. Ashikur Rahman Shirin Akter Tushar Kumar Mohammad Monjur Ahasan 《医学物理学、临床工程、放射肿瘤学(英文)》 2021年第1期38-46,共9页
Dosimetric characteristic is one of the essential parameters of a medical linear accelerator (LINAC), which must be obtained before clinical use. The dosimetric characteristics for 6 MV photon beam were measured and c... Dosimetric characteristic is one of the essential parameters of a medical linear accelerator (LINAC), which must be obtained before clinical use. The dosimetric characteristics for 6 MV photon beam were measured and compared with the corresponding published data. The study was done using a Varian linear accelerator (Model Clinac-iX) at the Institute of Nuclear Medical Physics (INMP), AERE, Savar, Dhaka, under the Bangladesh Atomic Energy Commission (BAEC). The data is taken for 10 field sizes (2 × 2, 3 × 3, 5 × 5, 7 × 7, 10 × 10, 15 × 15, 20 × 20, 25 × 25, 30 × 30 and 40 × 40 cm<sup>2</sup>) at same conditions. The measured Percent Depth Dose (PDD) curves were obtained for 6 MV photon beams with the field as mentioned above and compared with the calculated PDD curves. The measured depth dose (D<sub>max</sub>) for reference field size (FS) 10 × 10 cm<sup>2</sup> is 15.99 mm, and the PDD at 10 cm depth (D<sub>10</sub>) is 66.87% for 6 MV photon energies that are found to be compatible with the published report BJR supplement 25. The measured PDD curves for photon energies show a good agreement with the standard PDD curves. The photon beam dosimetry data found in the current study are compatible and all the tolerances are within the clinically acceptable tolerance limit. 展开更多
关键词 Linac Machines 3D Water Phantom Ionization Chamber ELECTROMETER
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Development and Forecasting Drought Indices Using SPI (Standardized Precipitation Index) for Local Level Agricultural Water Management 认领
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作者 Motaleb Hossain Sarker Shamsuddin Ahmed +5 位作者 Md. Shadekul Alam Dilruba Begum Tariful Newaz Kabir Rifat Jahan Md. Monwar-Ul Haq Syeda Tasbiha Dewan Kabir 《大气和气候科学(英文)》 2021年第1期32-52,共21页
Drought is primarily an agricultural phenomenon that refers to conditions where plants are responsive to certain levels of moisture stress that affect both the vegetative growth and yield of crops. It occurs when supp... Drought is primarily an agricultural phenomenon that refers to conditions where plants are responsive to certain levels of moisture stress that affect both the vegetative growth and yield of crops. It occurs when supply of moisture stored in the soil is insufficient to meet the optimum need of a particular type of crop. Causes of drought in Bangladesh are related to climate variability and non-availability of surface water resources. While it may be possible to indicate the immediate cause of a drought in a particular location, it often is not possible to identify an underlying cause. Therefore, to improve all these services in favour of enhancing agricultural production and reducing food insecurity in Bangladesh, it is mandatory to develop an effective way for disseminating the SPI data indicating drought indices to farmers, and enhance drought and climate resilience. To develop future plan and policy in agricultural sector of Bangladesh, it is vital to understand the previous droughts events with accurate indicators. Since this study will contribute to the agricultural development of Bangladesh therefore there is an obvious need to understand the change of drought frequency all over Bangladesh using a standardized drought index. The main intention of this project is to prepare a proper baseline for forecasting drought indices using SPI data. So, the final outcome of this project would be a knowledge base where a proper forecasting tools and dissemination networks can be updated/developed for farmers. 展开更多
关键词 SPI DROUGHT Water Management Climate Adaptation
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Climate Influenced Challenges of Accessibility to Water by Households Downstream of the Upper Benue River Basin-Nigeria 认领
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作者 Vincent Nduka Ojeh Shadrach Terlumun Semaka 《大气和气候科学(英文)》 2021年第1期53-72,共20页
The study examined climate influenced challenges of accessibility to water by households downstream of the Upper Benue River Basin, Nigeria. Literatures related to the topic being investigated were reviewed. The study... The study examined climate influenced challenges of accessibility to water by households downstream of the Upper Benue River Basin, Nigeria. Literatures related to the topic being investigated were reviewed. The study adopted a descriptive survey design. The population of the study consisted of communities in Adamawa, Gombe, Bauchi and Taraba states. Eight different communities, two in each local government were sampled for the study. Simple random and purposive samplings were used for the study. A total of 351 respondents were selected for the study using Krejcie and Morgan sample size determination. Data analysis was done using frequency tables percentages and mean statistics. The findings of the study showed that climate variability has great impact on water stress and threats to households’ downstream in Upper Benue River basin represented with a mean 3.85 (decrease in the quality and quantity of surface water) as well as 3.43 (drying up of rivers and lakes). The study also revealed that water stress induced by climate variability has a significant effect on household livelihoods represented by 87% of the respondents in the study area. It was also revealed that that households downstream the basin are vulnerable to climate change and households in the study area have development strategies to contend with water stress so as to better their livelihood among which is surface water harvesting (2.78), reducing the number of times dishes are washed (2.96), reducing the quantity of water used for bathing (3.0) among others. The study recommended that stakeholders and the government should make proactive efforts to ensuring that alternative water sources are established in the study area to reduce water stress among the rural populace. 展开更多
关键词 Upper Benue River Basin ACCESSIBILITY Households Water Challenges
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Ecology and Species Composition of Fresh Water Snails in Amassoma Community and Niger Delta University Campuses, Bayelsa State, Nigeria 认领
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作者 Ebenezer Amawulu Ndubuisi Uchechi Assumpta 《生态学期刊(英文)》 2021年第1期86-93,共8页
The knowledge about the population dynamics of freshwater snail intermediate host and their roles in disease transmission is little known in Bayelsa State. This study investigated the species composition of fresh wate... The knowledge about the population dynamics of freshwater snail intermediate host and their roles in disease transmission is little known in Bayelsa State. This study investigated the species composition of fresh water snail intermediate host in Amassoma community and the Niger Delta University Campuses during August 2019-October 2019 across five locations (Main campus Hostel, E.T.F Building, Ogboebi-Ama, Efeke-Ama, Ogbopina). Snails were collected from the water bodies with the aid of a scooping net and hand picking. The morphological identification of the snail intermediate host followed standard procedures. From the result, five hundred and seventy-one freshwater snails belonging to four genera and five species were recorded. The presence of <em>Lymnae</em> and <em>Bulinus</em> in the locations highlights foci for fascioliasis and schistosomiasis. The presence of <em>Melanoides</em> spp. is novel in Bayelsa State. The public health implications of these snails have called for timely control intervention. 展开更多
关键词 Species Composition Fresh Water Snail Melanoides spp. SCHISTOSOMIASIS FASCIOLIASIS Bayelsa State
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Assessment of the Effectiveness of Potassium Polyacrylate on Crop Production 认领
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作者 Yélézouomin Stéphane Corentin Somé Diakalya Traoré +2 位作者 Malicki Zoromé Pounyala Awa Ouoba Dapola Evariste Constant Da 《农业化学和环境(英文)》 2021年第1期113-123,共11页
Water control is a major problem in crop production, particularly in fragile ecosystems such as the Sahel. Water is the most important factor in plant productivity. Many initiatives have been developed in this directi... Water control is a major problem in crop production, particularly in fragile ecosystems such as the Sahel. Water is the most important factor in plant productivity. Many initiatives have been developed in this direction, including all methods of irrigation and water and soil conservation. The objective of this work is to assess the effectiveness of this amendment in crop production in the context of climate variability. The methodology is based on experi<span>mentation to statistically compare the natural biomass on a soil of sil</span><span>ty-clay-sandy texture, divided into two blocks, one of which is amended with potassium polyacrylate and the other is not. This study showed that the wet and dry biomasses produced on soils with potassium polyacrylate are significantly higher than those produced on unamended soils at the 5% threshold. Based on these results, potassium polyacrylate may be a solution to recurrent dryness pockets. However, uncontrolled environmental testing is necessary to confirm these results.</span> 展开更多
关键词 Water Management Plant Production Potassium Polyacrylate OUAGADOUGOU
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Water Resources, Infrastructure Restoration, and Protection of the Upper Mississippi River Basin 认领
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作者 Kenneth R. Olson Samuel J. Indorante Gerald A. Miller 《土壤科学期刊(英文)》 2021年第1期13-38,共26页
The Upper Mississippi River flows approximately 2000 km from Lake Itasca, Minnesota to Cairo, Illinois where it is confluences with the Ohio River to form the Lower Mississippi River. North of the confluence, numerous... The Upper Mississippi River flows approximately 2000 km from Lake Itasca, Minnesota to Cairo, Illinois where it is confluences with the Ohio River to form the Lower Mississippi River. North of the confluence, numerous snags, sand bars, rapids, and other obstructions made the Upper Mississippi River travel difficult. This paper highlights how the geological and landscape resources of the Upper Mississippi River and tributary watershed were responsible for the successful economic development of this historically rich region of North America. Environmental challenges include an attempt to keep invasive species such as the Asian carp out of the rivers and lakes north of the Twin Cities. In an attempt to protect the Mississippi River resource, Environmental and Conservation groups have opposed continued navigation through Minneapolis and St. Paul and the planned Upper Mississippi River navigation infrastructure restoration by the United States Corps of Engineers including the upper and lower St. Anthony locks and dams. These Environmental, Conservation and Save the River groups are attempting to mitigate the historic highest and best use of the Mississippi River and adjacent watershed, navigation, and economic development, by having the urban river restored to the natural state. 展开更多
关键词 Falls of St. Anthony LOCKS DAMS Minneapolis St. Paul Navigation Water Pollution
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Role of interfacial water in adhesion,friction,and wear--A critical review 认领
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作者 Lei CHEN Linmao QIAN 《摩擦:英文版》 SCIE EI 2021年第1期1-28,共28页
Surficial water adsorption and interfacial water condensation as natural phenomena that can alter the contact status of the solid interface and tribological performances are crucial in all length scales,i.e.,from eart... Surficial water adsorption and interfacial water condensation as natural phenomena that can alter the contact status of the solid interface and tribological performances are crucial in all length scales,i.e.,from earthquakes to skating at the macroscale level and even to micro/nano-electromechanical systems(M/NEMS)at the microscale/nanoscale level.Interfacial water exhibits diverse structure and properties from bulk water because of its further interaction with solid surfaces.In this paper,the evolutions of the molecular configuration of the adsorbed water layer depending on solid surface chemistry(wettability)and structure,environmental conditions(i.e.,relative humidity and temperature),and experimental parameters(i.e.,sliding speed and normal load)and their impacts on tribological performances,such as adhesion,friction,and wear,are systematically reviewed.Based on these factors,interfacial water can increase or reduce adhesion and friction as well as facilitate or suppress the tribochemical wear depending on the water condensation kinetics at the interface as well as the thickness and structure of the involved interfacial water. 展开更多
关键词 water adsorption water condensation ADHESION FRICTION tribochemical wear
Removal of the Methylene Blue Dye (MB) with Catalysts of Au-TiO<sub>2</sub>: Kinetic and Degradation Pathway 认领
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作者 María-Cruz Arias Claudia Aguilar +6 位作者 Mohamad Piza Elvira Zarazua Francisco Anguebes Francisco Anguebes Francisco Anguebes Francisco Anguebes Víctor Cordova 《催化剂现代研究(英文)》 2021年第1期1-14,共14页
Au-TiO<sub>2</sub> catalysts were used in the photocatalytic degradation of the methylene blue dye (MB). The synthesis of titanium oxide (TiO<sub>2</sub>) was carried out by sol-gel method. Sub... Au-TiO<sub>2</sub> catalysts were used in the photocatalytic degradation of the methylene blue dye (MB). The synthesis of titanium oxide (TiO<sub>2</sub>) was carried out by sol-gel method. Subsequently, particles of Au were deposited on the surface of the semiconductor by photo-deposition, thus modifying the surface of the semiconductor. For the characterization of the catalyst obtained, the techniques of X-ray Diffraction (DRX), Scanning Electron Microscopy (SEM), Spectroscopy with Diffuse Reflectance (DR) and Surface Area by the BET (Brunauer, Emmett y Teller) were used. The solid obtained was tested experimentally as a catalyst in the photocatalytic degradation of a solution of MB. The data obtained were analyzed by UV-vis Spectroscopy and Total Organic Carbon (TOC) and the results indicated conversions were greater than 80%. The intermediate products were evaluated by mass coupled gas chromatography (GC-MS) and the MB decomposition route was by hydroxylation, obtaining aromatic intermediates, esters and products of the chemical degradation of the molecule. 展开更多
关键词 Titanium Oxide Water Pollution Methylene Blue Dye Heterogeneous Photocatalysis
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Investigation of the Relationship among Water and Crop Production under Bounded Irrigation Conditions 认领
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作者 Tawheed Mohammed Elheesin Shareef Zhongming Ma +1 位作者 Juan Chen Xiaoxia Niu 《水能与环境工程(英文)》 2021年第1期18-35,共18页
Water scarcity is relative and variable concept that can occur at any level of supply and demand. It is also a social construct, which is linked to the intervention in the water cycle and changes over time as a result... Water scarcity is relative and variable concept that can occur at any level of supply and demand. It is also a social construct, which is linked to the intervention in the water cycle and changes over time as a result of natural hydrological change. It is more severe when water acts as a backbone in economic policies, planning and management methods. Water scarcity can be expected to increase with most forms of economic development, but, if properly identified, many of its causes can be expected and avoided or mitigated. However, the limited irrigation management is considered a very important issue in the agricultural scope. Therefore, in this study</span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> the relationship between water, crop production, photosynthesis, crop transpiration, crop growth, crop yields and water use efficiency have been discussed under limited irrigation conditions. However, the crops have some ability to adapt and resist against limited irrigation. Hence, under high temperate conditions, this is a shortage of water and photosynthesis is decreased with a pore (stoma) restraining. At the same time</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> the evapotranspiration reaches to the utmost value and the water use efficiency rises because of optimal monitoring of leaf pore (stoma). Therefore, the modality which is the reduction of the risks and improving industrial control in incomplete irrigation are the chief constraints of providing irrigation water in the future, which leads to increased crop production and ultimately providing a provision of food security. 展开更多
关键词 Freshwater Consumption Insufficient Irrigation Water Use Efficiency Yield Formation
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