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Adequacy of Water Use Resources for Drinking and Irrigation, Study Case of Sarh City, Capital of Moyen-Chari Province, CHAD

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Open Journal of Modern Hydrology 2023年第1期13卷 1-21页

作者： edith kadjangaba Djimako Bongo Mekila Le Bandoumel Faculty of Science and Technology University of Doba Daba Chad Normal School Superior of the Technical Education of Sarh Sarh Chad Water and Environment Laboratory (LABEEN) Faculty of Exact and Applied Sciences University of N’djamena N’djamena Chad

Our objective is to evaluate adequacy of water for consumption and irrigation. We collected nineteen water samples from 21 to 26, May 2017. Twenty-two physico-chemical and bacteriological parameters were taken into account, electrical conductivity, pH, total hardness, bicarbonate, nitrates, sulfates, chlorides, calcium, sodium, magnesium, potassium, dissolved oxygen and biochemical oxygen demand, chemical oxygen demand, total coliforms, Escherichia Coli, and fecal coliforms. To evaluate water intended for consumption, average values measured parameters were compared to [1] for quality water drinking and we evaluated overall quality of water by means of simplified SEQ-Water grid. Concerning irrigation water, evaluation is based on interpretation of quality parameters of irrigation water that we have calculated;among these parameters we can mention the percentage of sodium, rate of sodium absorption, ratio of magnesium adsorption, residual sodium carbonate. Kelly ratio, Corrosivity ratio and Permeability Index. Results show that surface water is weakly mineralized compared to groundwater and presents a good chemical quality;however, it is slightly altered by presence of organic pollutants. The overall assessment of groundwater quality shows that about 47% of water sampled varies between average quality and very poor quality for consumption. This poor quality is mainly due to presence of nitrates in water, whose content sometimes exceeds the limit authorized by [1]. From a bacteriological point of view, germs of faecal origin such as Total Coliforms, Escherichia Coli and Faecal Coliforms contaminate all groundwater points sampled. They are of poor quality and unfit for human consumption without prior treatment. We also evaluated the quality of water used for irrigation using 6 parameters. The results show that all of our water points are suitable for irrigation, according to the values of CSR and Kelly ratio. The same is true for the permeability index, which shows tha

关键词： SEQ-Eau Water Quality Consumption Irrigation Physico-Chemical and Bacteriological Parameters

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Recharge and Groundwater Quality of an Alluvial Aquifer： Case of the City of N＇djamena （Chad）

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Journal of Environmental Science and Engineering(B) 2017年第10期6卷 493-505页

作者： edith kadjangaba Frederic Huneau Yves Travi Daira Djoret . Laboratory of Water and Environment Faculty of Exact and Applied Sciences University of N'djamena N'djamena 1027 Chad Laboratory of Hydrogeology University of Corsica Pascal PaolL Grimadi Campus Corte 52 F-20250 France Laboratory of Hydrogeology University of Avignon and the Countries of Vaucluse Jean Henry FABRE Campus Baruch de Spinoza 31239 84916 France

Isotopic tracers and water quality indicators （TDS （Total Dissolved Solid）, Cl^- and NO3^-contents） were used to characterize the recharge and control of the quality of groundwater in the alluvial aquifer beneath of the N＇djamena city. For this study, a total of 92 waters samples were taken and this included 67 wells, 21 pumps and 4 surface waters. Some groundwater has 6180 and 62H values close to those of the city of N＇djamena and/or the Chad river rains. However, all sampled points are below the Global Meteoric Water Line reflecting their evaporated characters. The interpretation of the isotopic tracers highlights that the recharge of the analyzed ground waters may result from two major mechanisms：（1） direct infiltration of local precipitation; （2） lateral inflow of river waters. The upper aquifer is the most vulnerable to pollution, especially during the recharge period. This pollution is due to the leaching of soils during the rainy season and the rise of the groundwater level which accompanies the overflowing of the Chad and causes the leaching of the polluted horizons of the unsaturated zone. In contrast, the lower aquifer has acceptable concentrations of solutes.

关键词： Groundwater stable isotope water quality recharge N'djamena city.

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Influence of Fresh Water on Microbubble Generation in an Airlift Column Applied to Aquaculture: Extraction Capacity

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Open Journal of Applied Sciences 2022年第11期12卷 1809-1823页

作者： Djimako Bongo Nekoulnang Djetounako Clarisse edith kadjangaba Salif Gaye Jean-Yves Champagne Higher Normal School of Technology of Sarh Sarh Chad Paleontology Department National Research Center for Development of N’djamena N’djamena Chad Faculty of Sciences and Techniques University of Doba Doba Chad LME Materials and Energetics Laboratory University Institute of Technology Thiès Senegal Laboratory of Fluid Mechanics and Acoustics INSA-Lyon Lyon France

Bubble flows consist a liquid phase and a gaseous phase dispersed as bubbles. They occur in nature and in many industrial applications, such as oil transportation in pipelines and steam generators for power generation. Due to large difference in density between gas and liquid, the flottability force causes bubbles to rise, which in turn can generate overall motion and agitation in liquid. This use of gravity as a flow driver, which is specific to disperse phase systems, is used in process engineering (bubble columns and gasosiphon) to sparingly promote mixing and exchange between gas and liquid. In many applications, bubbles are used to agitate a liquid in order to promote mixing and transfers. This work is devoted to study of hydrodynamics of a bubble column. Experimentally, we have determined properties fluctuations of velocities inside the aquarium of rising homogeneous bubbles for different bubble sizes and vacuum rates. The interfacial area between gas and liquid phase is a crucial factor for mass transfer in bubble columns. The molecular exchange between a given volume of gas and water can be enhanced by formation of smaller bubbles, leading to a larger gas-liquid interface. This work presents the various physical phenomena that apply to bubbles, as well as associated dimensionless numbers. A state art of Micro-Bubble Generators (MBG) is then presented, presenting systems using various phenomena such as cavitation, electrolysis, or shear.

关键词： Vacuum Airlift Column MIBC Casein Turbidity Surfactant Coalescence

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Vulnerability Evaluation of Groundwater of N’Djamena City: Contribution of the Parametric Methods GOD and SI

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Journal of Environmental Protection 2021年第7期12卷 472-489页

作者： David Deubalbe edith kadjangaba Djimako Bongo Sabine Djimouko Jean Claude Doumnang Mbaigane Yaya Mahmout Geology Department Faculty of Exact and Applied Sciences University of N’djamena N’djamena Chad Faculty of Sciences and Techniques University of Doba Doba Chad Higher Normal School of Technology of Sarh Sarh Chad Letters Arts and Human Sciences Faculty University of Moundou Moundou Chad Natural Substances Laboratory Exact and Applied Sciences Faculty University of N’Djamena N’Djamena Chad

The purpose of this work is to study the vulnerability of the Quaternary aquifer that lies beneath the N’Djamena city Chad. The subsoil of N’Djamena city Chad is made up of a multilayered aquifer in which there are two main aquifers located respectively at a depth of about 10 and 60 m, between the two there is an intermediate aquifer at about 30 m depth. It is this latter water table, generally captured by human-powered pumps, that is the subject of this study. Because of anarchic garbage dumping, wastewater discharge, latrines scattered throughout the city, chemical fertilizers and herbicides used on the banks of Chari River and its tributary the Logone for market gardening, the quality of the water in this aquifer is highly threatened. Moreover, it has been noting that the sources of pollution are constantly increasing in conjunction with the growth of the population, so the knowledge and protection of groundwater are necessary. We have therefore carried out a study of intrinsic vulnerability using two mapping methods (GOD and SI), as mapping is recognized as an effective tool for decision support in the case of safeguarding water resources. The results obtained by the GOD method show that 38% of the study area is covered by high vulnerability, 29% by moderate vulnerability, 21% by low vulnerability and 21% by the very low vulnerability. With the SI method, 54% of the study area is covering by low vulnerability and 46% by the low and moderate vulnerability. The coincidence rate of low nitrate values in groundwater with areas of very low and low vulnerability is 91% and 76% for the GOD and SI methods, respectively. Although these observations validated the different maps obtained, the SI approach seems to be the most adequate for vulnerability tracing in our study area.

关键词： Vulnerability GOD SI Groundwater Nitrate N’Djamena City

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The evolution of sexual imprinting in socially monogamous populations

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Current Zoology 2015年第6期61卷 1043-1061页

作者： edith INVERNIZZI R. Tucker GILMAN Faculty of Life Sciences University of Manchester C. 1249a Michael Smith Building Dover Street Manchester M 13 9PL UK

Sexual imprinting is a common mechanism of mate preference learning. It is thought to influence how traits evolve and in some cases to promote speciation. Recently there has been increasing interest in how sexual imprinting itself evolves. Theoretical work on polygynous mating systems predicts that females will evolve paternal imprinting, which means they learn to prefer phenotypes expressed by their fathers. In nature however, females of some species learn to prefer phenotypes expressed by their mothers instead. We used a dynamical systems model and tools from adaptive dynamics to study how sexual imprinting evolves in species with socially monogamous mating systems. We considered cases in which the target trait for imprinting is un- der viability selection but is not a reliable signal of paternal investment. Thus, the target trait signals the genetic benefits rather than the parental care benefits of mate choice. When mating is socially monogamous and there is some extra-pair patemity, we show that maternal imprinting can be favored over paternal imprinting. Counterintuitively, females often become choosier when selecting social partners in systems where extra-pair mating is more frequent. That is, females may be more selective when choosing social partners that will sire a smaller percentage of their offspring. Our results offer new testable hypotheses, and ad- vance our understanding of the mechanisms that drive the evolution of mate choice strategies in nature .

关键词： Sexual imprinting Mate preference learning Monogamy Extra-pair mating Evolution Model

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Treatment of Helicobacter pylori infection in atrophic gastritis

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World Journal of Gastroenterology 2018年第22期24卷 2373-2380页

作者： edith Lahner Marilia Carabotti Bruno Annibale Medical-Surgical Department of Clinical Sciences and Translational Medicine Sant'Andrea Hospital University Sapienza

Helicobacter pylori(Hp) is a major human pathogen causing chronic, progressive gastric mucosal damage and is linked to gastric atrophy and cancer. Hp-positive individuals constitute the major reservoir for transmission of infection. There is no ideal treatment for Hp. Hp infection is not cured by a single antibiotic, and sometimes, a combined treatment with three or more antibiotics is ineffective. Atrophic gastritis(AG) is a chronic disease whose main features are atrophy and/or intestinal metaplasia of the gastric glands, which arise from long-standing Hp infection. AG is reportedly linked to an increased risk for gastric cancer, particularly when extensive intestinal metaplasia is present. Active or past Hp infection may be detected by conventional methods in about two-thirds of AG patients. By immunoblotting of sera against Hp whole-cell protein lysates, a previous exposure to Hp infection is detected in all AG patients. According to guidelines, AG patients with Hp positivity should receive eradication treatment. The goals of treatment are as follows:(1) Cure of infection, resolution of inflammation and normalization of gastric functions;(2) possible reversal of atrophic and metaplastic changes of the gastric mucosa; and(3) prevention of gastric cancer. An ideal antibiotic regimen for Hp should achieve eradication rates of approximately 90%, and complex multidrug regimens are required to reach this goal. Amongst the factors associated with treatment failure are high bacterial load, high gastric acidity, Hp strain, smoking, low compliance, overweight, and increasing antibiotic resistance. AG, when involving the corporal mucosa, is linked to reduced gastric acid secretion. At a non-acidic intra-gastric p H, the efficacy of the common treatment regimens combining proton pump inhibitors with one or more antibiotics may not be the same as that observed in patients with Hp gastritis in an acid-producing stomach. Although the efficacy of these therapeutic regimens has

关键词： Atrophic gastritis Preneoplastic condition Intestinal metaplasia Helicobacter pylori Eradication treatment

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Real-time air pollution monitoring with sensors on city bus

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Digital Communications and Networks 2020年第1期6卷 23-30页

作者： Sami Kaivonen edith C.-H.Ngai Department of Information Technology Uppsala UniversitySweden

This paper presents an experimental study on real-time air pollution monitoring using wireless sensors on public transport *** study is part of the GreenIoT project in Sweden,which utilizes Internet-of-Things to measure air pollution level in the city center of *** deploying low-cost wireless sensors,it is possible to obtain more fine-grained and real-time air pollution levels at different *** sensors on public transport vehicles complement the readings from stationary sensors and the only ground level monitoring station in *** paper describes the deployment of wireless sensors on Uppsala buses and the integration of the mobile sensor network with the GreenIoT *** experiments have been conducted to evaluate the communication quality and data quality of the system.

关键词： Smart city Internet-of-Things Mobile sensor network Air pollution monitoring

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Toluene degradation by a water/silicone oil mixture for the design of two phase partitioning bioreactors

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Chinese Journal of Chemical Engineering 2017年第10期25卷 1512-1518页

作者： Maxime Guillerm Annabelle Couvert Abdeltif Amrane edith Norrant Audrey Breton éric Dumont Erole Nationale Supérieure de Chimie de Rennes UMR CNRS 6226 11 allee de Beaulieu CS 5083K 35708 Rennes Cedex 7 France UCB BioPharma sprl Avenue de l'Industrie B 1420 Braine l'Alleud Belgum Total S.A CSTJF Avenue Larribau CA 374 64018 Pau Cedex France UMR CNRS 6144 GEPEA IMT-Atlantique La Chantrerie 4 rue Alfred Kastler B.P. 20722 44307 Nantes Cedex 3 France

Toluene degradation performances were studied in a 10 L Two-Phase Partitioning Bioreactor(TPPB).The liquid phase consisted of a mixture of water and PDMS 50(Poly Di Methyl Siloxane,*** oil,viscosity of 46 m Pa·s) in the volume ratio of 75%/25%.Two series of experiments were carried out:in the first,the reactor was sequentially supplied with toluene whereas in the second,toluene was continuously *** sludge from the wastewater treatment plant of Beaurade(Rennes,France) was used at an initial concentration of 0.5 dry mass g·(mixture L)^(-1).The elimination capacity(EC) was investigated as well as the change in biomass concentration over *** biodegradation was very ef ficient(removal ef ficiency,RE=100%) for toluene flows ranging from 0.2 to 1.2 ml·h^(-1),corresponding to elimination capacities of up to 104 g·m^(-3)·h^(-1).For a toluene flow of 1.2 ml·h^(-1),the biomass concentration measured at the end of the experiment was 4.7 dry mass g·(mixture L)^(-1).The oxygen concentration in the liquid phase was clearly not a limiting factor in these operating *** on these results,an extrapolation leading to the design of a large-scale pilot TPPB can now be considered to study toluene degradation performances in industrial conditions.

关键词： Degradation Toluene Silicone oil Multiphase reactor Biomass

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Using Location based Augmented Reality to Improve Destination Image of China-Beijing:Role of Immersive Experience,User Engagement,Perceived Service Quality and Authenticity

Using Location based Augmented Reality to Improve Destinatio...

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作者： Vikih edith Vefemsi 山西大学

学位级别：硕士

旅游业正蓬勃发展,过去七年中全球旅游业保持持续增长。中国旅游业现已发展成为国内经济最重要的支柱产业之一。“旅游目的地形象”这一概念表示游客对特定目的地的综合感知和印象。如今,人们认为良好的旅游目的地形象是带动旅游业发展... 详细信息

旅游业正蓬勃发展,过去七年中全球旅游业保持持续增长。中国旅游业现已发展成为国内经济最重要的支柱产业之一。“旅游目的地形象”这一概念表示游客对特定目的地的综合感知和印象。如今,人们认为良好的旅游目的地形象是带动旅游业发展的重要因素。因此,在旅游业中,旅游目的地形象和沉浸式体验这两个概念获得广泛关注。本研究运用实证主义哲学,基于演绎方法的定量研究,旨在探讨通过提升沉浸体验给旅游目的地形象所带来的影响,并分析通过提升游客的实际用户体验、感知服务质量和感知真实性给旅游目的地形象所带来的间接影响。本研究针对422位旅客通过在线问卷调查的方式收集了与上述变量相关的数据,所有旅客均为到访北京并在旅行期间使用基于地理位置的增强现实技术（LBAR）的人。样本采集针对性强,采样技术便捷。分析结果表明,提升旅客的沉浸式体验不仅对旅游目的地形象影响显著,而且对于旅客的用户体验、感知服务质量和感知真实性给旅游目的地形象所带来的间接影响,影响也较为显著。基于SEM假设检验,证实本研究中提出的所有假设都是正确的。故本研究对于未来旅游业发展以及增强现实技术在旅游业中的应用具有重要意义。

关键词：增强现实技术沉浸式体验旅游目的地形象用户体验感知服务质量感知真实性

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Rare earth element geochemistry in soils along arid and semiarid grasslands in northern China

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Ecological Processes 2022年第1期11卷 386-399页

作者： Yi‑Wen Cao Xiao‑Ming Liu Chao Wang edith Bai Nanping Wu CAS Key Laboratory of Forest Ecology and Management Institute of Applied EcologyChinese Academy of SciencesShenyang 110016China University of Chinese Academy of Sciences Beijing 100049China Department of Earth Marine and Environmental SciencesUniversity of North Carolina‑Chapel HillChapel HillNC 27515USA Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains School of Geographical SciencesNortheast Normal UniversityChangchun 130024China Institute of Deep‑Sea Science and Engineering Chinese Academy of SciencesSanya 572000China

Background:Rare earth elements(REE)are a group of trace elements that behave geochemically *** fractionation patterns normalized to reference materials provide a powerful tool for documenting *** processes are particularly difficult to illustrate with respect to contemporary and past climate *** this study,we characterize the rare earth element(REE)contents in bulk soils and respective geochemical fractions(e.g.,exchangeable,carbonate‑bound,reducible,and oxidizable fractions)and to decipher the relationships between REE geochemistry components and climatic factors across a large‑scale northern China transect(NCT).Results:Across the NCT,bulk REE concentrations ranged from 55.2 to 241.1μg g^(−1)with a main portion in the residual fraction(49–79%),followed by oxidizable fraction(2–40%),reducible fraction(3–22%),carbonate‑bound fraction(0.1–16%),and negligible exchangeable *** REE contents of geochemical components(carbonate‑bound,reducible,and oxidizable)in topsoils correlated to climate factors(mean annual precipitation,mean annual temperature,potential evaporation,and aridity index(AI)).The normalized abundances to the upper continental crust(UCC)composition show that the middle REE was generally enriched than the light REE and heavy REE in topsoils along the *** overall UCC‑normalized bulk REE patterns in topsoils and subsoils were similar,characterized by weak negative Ce anomalies and positive Eu ***:Our data in topsoils and depth profiles collectively suggest that cycling of REE was primarily regulated by abiotic processes in area with AI*** similar UCC normalized patterns in topsoils suggest that the REE was originated from a common source with limited influences from other sources(e.g.,atmospheric dusts and anthropogenic contribu‑tions).Our results to some extent provide evidence for

关键词： Rare earth elements Soil Grassland Northern China Aridity index

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