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Hydro-geochemistry of groundwater and surface water in Dschang town(West Cameroon):Alkali and alkaline-earth elements ascertain lithological and anthropogenic constraints

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Journal of Groundwater Science and Engineering 2021年第3期9卷 212-224页

作者： Yemeli Elida Joelle Temgoua Emile Kengni Lucas Ambrosi Jean-Paul Momo-nouazi Mathieu silatsa-tedou francis brice Wamba Franck Robean Tchakam-Kamtchueng brice University of Dschang Department of Earth SciencesDschangCameroon. University of Dschang Faculty of Agronomy and Agricultural SciencesDschangCameroon. Aix Marseille University CNRSIRDINRAECollege de FranceCEREGEAix En ProvenceFrance. Institute of Geological and Mining Research YaoundeCameroon.

The study aims to identify a suitable site for open and bore well in a farmhouseusing ground magnetic survey in south *** also aims to define depth to granitoid and structural elements which traverse the selected *** data(n=84)measured,processed and interpreted as qualitative and *** results of total magnetic intensities indicate that the area is composed of linear magnetic lows trending NE-SW direction and circular to semi-circular causative *** magnetic values ranged from-137 nT to 2345 nT with a mean of 465 *** to equator shows significant shifting of causative bodies in the southern and northern *** signal map shows exact boundary of granitic *** directional filter has brought out structural element trending NE-SW *** of individual profile brought to light structurally weak zone between 90 m and 100 m in all the profile *** decrease of magnetic values from 2042 nT to 126 nT noticed in profile line 6 between 20 m and 30 m indicates fault *** breaks obtained from these maps were visualized,interpreted and identified two suitable sites for open and bore *** averaged power spectrum estimates depth of shallow and deep sources in 5 m and 50 m,*** method has also been applied to estimate depth of granitoid and structural elements using structural indexes 0,1,2,and 3 and found depth ranges from90 *** indicates magnetic method is one of the geophysical methods suitable for groundwater exploration and site selection for open and borewells.

关键词： Alkali/alkaline-earth elements Groundwater and surface water Geochemical anomaly Anthropogenic impact Dschang-Cameroon

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Extensive Pineapple Production Constraints and Land Suitability in the Centre Region of Cameroon

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Agricultural Sciences 2023年第2期14卷 240-255页

作者： Georges Marius Etame Kossi Honoré Beyegue Djonko Alexis Boukong francis brice silatsa tedou Department of Agriculture Faculty of Agronomy and Agricultural Sciences University of Dschang Dschang Cameroon Department of Soil Science Faculty of Agronomy and Agricultural Sciences University of Dschang Dschang Cameroon Sustainable Tropical Action Yaoundé Cameroon

The low level of productivity observed in pineapple fields in Centre Came-roon must be sustainably reduced in order to increase producers’ income while using the same resources. The identification and control of production constraints are key steps in optimizing the use of limited resources. To this end, the FAO land assessment methodology following the Fuzzy-MCDM pro-tocol was used for the two pineapple production basins in the Centre, namely Awae and Bokito. It was found that the land in Awae Basin is moderately suitable S2sf with constraints imposed by texture, pH and base saturation. In the Bokito Basin, 25% of the land is suitable S1wf and 75% is moderately suitable S2wsf with constraints imposed by soil texture (27%), temporary soil water saturation (99%), pH, base saturation and exchangeable sodium. Constraint correction improves the land index (potential suitability) and re-mains limited by permanent constraints that cannot be corrected. Improve-ment of the technical itinerary through modification of plant densities, selec-tion of improved cultivars and balanced fertilization must be undertaken to optimize pineapple production in Centre Cameroon.

关键词： Land Suitability Constraints Pineapple Centre Cameroon

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Land Suitability Evaluation for Oil Palm (<i>Elaeis guineensis</i>Jacq.) in Coastal Plains of Southwest Cameroon

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Open Journal of Soil Science 2020年第7期10卷 257-273页

作者： Georges Kogge Kome Fritz Oben Tabi Roger Kogge Enang francis brice tedou silatsa Department of Soil Science Faculty of Agronomy and Agricultural Sciences (FASA) University of Dschang Dschang Republic of Cameroon

Declining yields in oil palm fresh fruit bunch (FFB) have been recorded over the past years in the coastal lowlands of southwest Cameroon and current actual yields are very low (−1•yr−1) compared to the potential yields (25 t FFB ha−1•yr−1). One of the problems limiting optimum oil palm production is lack of detailed pedological information to guide plantation establishment and management. A land suitability evaluation was carried out for some major oil palm producing areas of southwest Cameroon to identify land qualities limiting optimal production. Thirteen sites (9 with sedimentary parent materials and 4 with volcanic parent material) were evaluated using a parametric method. Results indicate that climate was not a major limiting factor for oil palm production in coastal plains of southwest Cameroon. However, soil physical characteristics (mainly clayey texture and poor drainage) and soil fertility constitute limitations to oil palm production. Specifically, limitations in cation exchange capacity (CEC), base saturation (BS), organic carbon (OC) and pH were slight to moderate while K mole fraction was the most severe and the most limiting in all the sites. The fertility limitations were more pronounced in soils derived from sedimentary parent materials where 33% had limitations caused by soil pH and OC compared to none for volcanic soils. In addition, 77.8% of sedimentary soils had limitations caused by CEC compared to 25% for volcanic soils. Considering the overall suitability, soils derived from volcanic parent materials were potentially more suitable for oil palm cultivation ((S3)—50%, (S2)—50%) compared to sedimentary soils ((N)—

关键词： Land Evaluation Oil Palm K Mole Fraction Soil Parent Material Coastal Plain Soils

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Determination of contact parameters for discrete element method simulations of granular systems

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Particuology 2008年第6期6卷 521-528页

作者： Kevin francis Malone Institute of Particle Science and Engineering University of Leeds

Both linear-spring-dashpot （LSD） and non-linear Hertzian-spring-dashpot （HSD） contact models are commonly used for the calculation of contact forces in Discrete Element Method （DEM） simulations of granular systems. Despite the popularity of these models, determination of suitable values for the contact parameters of the simulated particles such as stiffness, damping coefficient, coefficient of restitution, and simulation time step, is not altogether obvious. In this work the relationships between these contact parameters for a model system where a particle impacts on a flat base are examined. Recommendations are made concerning the determination of these contact parameters for use in DEM simulations.

关键词： Discrete Element Method (DEM) Linear-spring--dashpot model Non-linear Hertzian-spring-dashpot model Contact parameters

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Neutrino astronomy： An update

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Frontiers of physics 2013年第6期8卷 759-770页

作者： francis Halzen Wisconsin IceCube Particle Astrophysics Center (WIPAC) and Department of Physics University of Wisconsin Madison WI 53706 USA

Detecting neutrinos associated with the still enigmatic sources of cosmic rays has reached a new watershed with the completion of IceCube, the first detector with sensitivity to the anticipated fluxes. In this review, we will briefly revisit the rationale for constructing kilometer-scale neutrino detectors and summarize the status of the field.

关键词： neutrinos cosmic rays astrophysics

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No country is an island in regulating food safety:How the WTO monitors Chinese food safety laws through the Trade Policy Review Mechanism(TPRM)

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Journal of Integrative Agriculture 2015年第11期14卷 2142-2156页

作者： francis Snyder Northwest A&F University School of Transnational Law Peking University Shenzhen Graduate School College of Europe

Established within the framework of the World Trade Organization （WTO）, the Trade Policy Review Mechanism （TPRM） reviews periodically the trade policies of all WTO Members. The review includes many aspects of food safety regulation. China＇s trade policy is reviewed every two years. This paper analyses in detail the reviews of China＇s trade policy in 2006, 2008, 2010, 2012 and 2014. It focuses in particular on food safety laws and types of standards, alignment of domestic standards with international standards, the role of different domestic institutions, transparency and notification of food safety measures under the WTO agreements on Sanitary and Phytosanitary Measures （SPS） and on Technical Barriers to Trade （TBTAgreement）, import and export, and geographical indications （GIs）. It concludes that the WTO TPRM can contribute, within its mandate, to reform of Chinese food safety laws and improvement of food safety in China. it notes that China has already undertaken substantial reforms of its system for regulating food safety. It recommends that China should continue to participate actively in the TPRM, follow its own path with regard to alignment and learn selectively from other WTO Members.

关键词： food safety food standards public health consumer welfare China Chinese food safety laws World Trade Organization WTO law Trade Policy Review Mechanism (TPRM) SPS Agreement TBT Agreement

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Topological Studies of Three-dimensional Flows in a High Pressure Compressor Stator Blade Row without and with Boundary Layer Aspiration

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Chinese Journal of Aeronautics 2011年第5期24卷 541-549页

作者： Ankit SACHDEVA francis LEBOEUF Laboratoire de Mécanique des Fluides et d'Acoustique Ecole Centrale de Lyon

This paper presents a numerical study of the flow topologies of three-dimensional （3D） flows in a high pressure compressor stator blade row without and with boundary layer aspiration on the hub wall. The stator blade is representative of the first stage operating under transonic inlet conditions and the blade design encourages development of highly complex 3D flows. The blade has a small tip clearance. The computational fluid dynamics （CFD） studies show progressive increase of hub corner stall with the increase in incidence. Aspiration is implemented on the hub wall via a slot in the comer between the hub wall and the suction surface. The CFD studies show aspiration to be sensitive to the suction flow rate; lower rate leads to very complex flow struc- tures and increased level of losses whereas higher rate renders aspiration effective for control of hub comer separation. The flow topologies are studied by trace of skin friction lines on the walls. The nature of flow can be explained by the topological rules of closed separation. Furthermore, a deeper analysis is done for a particular case with advanced criterion to test the non-degeneracy of critical points in the flow field.

关键词： high pressure compressor flow topologies three-dimensional flows boundary layer aspiration tip clearance

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Metamodeling and multicriteria analysis for sustainable and passive residential building refurbishment: A case study of French housing stock

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Building Simulation 2022年第3期15卷 453-472页

作者： Zaid Romani Abdeslam Draoui francis Allard LaRAT National School of Architecture of TetouanMorocco Team of Heat Transfer&Energetic FST of Tangier(UAE/U10FST) Abdelmalek Essaâdi UniversityMorocco LaSIE La Rochelle UniversityFrance

For the energy-related issues that the world is facing nowadays,the renovation of the building stock is one of the major *** objective of this study is to present an approach that helps to develop a multi-criteria decision support tool dedicated to the rehabilitation of sustainable and passive energy housing by integrating heating energy needs,economic,social and environmental criteria throughout the life cycle stages of the *** methodology consists of developing metamodels to predict heating energy needs from polynomial regression,design of experiments method and thermo-aeraulic simulations of building *** metamodel is used to carry out a combinatorial study of real technical *** methodology was applied to a real-life existing building located in La Rochelle city(France)based on an in-situ energy *** multicriteria analysis methods were studied and compared:weighted sum,Min-Max and Pareto ***,technical constraints as well as owner preferences and performance constraints have been *** technical solutions have been obtained in order to meet the various criteria *** addition,window shading and natural ventilation have been proposed to reduce the thermal discomfort rate in *** study was extended to all French ***,this method can be transformed into a decision support tool which will be useful for architects,engineers and stockholders.

关键词： metamodeling building refurbishment multi-criteria decision support sustainable building passive building

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Climate Optimum rejuvenates the Mediterranean marine world

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Integrative Zoology 2010年第2期5卷 112-121页

作者： francis D.POR Department of Evolution Systematics and Ecology the National Collections of Natural HistoryHebrew University of JerusalemJerusalemIsrael

The Mediterranean,a sea with an already eventful history,is again undergoing an extreme change.A combination of general warming of the Mediterranean Sea and contact with the Indopacific world through the Suez Canal has set the stage for massive changes in the biota that inhabit this *** over a century,tropical species of all taxa have been migrating back into the Mediterranean,suggesting a duplication or restoration of a mid-Pliocene Piacenzian or late Miocene Tortonian *** cases are presented in three major *** is not a serial invasion by individual rogue exotic and damaging species,as often wrongly assumed and *** its unique biogeographic magnitude being recognized,an opportunity to study the progress of this phenomenon is being *** is because of the changed priorities in research,the acute taxonomic impediment and to the geopolitical difficulties in ***,the limitations of the restoration process are defined and a careful future outlook is presented.

关键词： climate optimum Lessepsian migration Mediterranean biota Tethys tropical restoration

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Uncertainty, certainty, and relativity(Invited Paper)

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Chinese Optics Letters 2016年第1期14卷 2-6页

作者： francis T.S.Yu Department of Electrical Engineering Penn State University

One of the most fascinating principles in quantum mechanics must be Heisenberg＇s uncertainty principle, which can be briefly stated as follows： every physicM observation cannot be precisely determined without some degree of error or uncertainty. And it is by no means can one use the principle within the limit of certainty region, as will be shown in this Letter. Two of the most important pillars in modern physics must be Einstein＇s relativity theory and SchrSdinger＇s contribution to quantum mechanics. Yet, there is a profound connection between these discoveries by means of the uncertainty relationship, in which we shown that the observation of a high-speed object is conceivable if the speed of the observer keeps up with object＇s speed.

关键词： and relativity certainty Uncertainty

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