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Scatterhoarding rodents favor higher predation risks for cache sites:The potential for predators to influence the seed dispersal process

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Integrative Zoology 2015年第3期10卷 257-266页

作者： Michael A.STEELE ghislain rompré Jeffrey A.STRATFORD Hongmao ZHANG Matthew SUCHOCKI Shealyn MARINO Department of Biology Wilkes UniversityWilkes-BarrePAUSA The Scotts Company MarysvilleOHUSA School of Life Science Central China Normal UniversityWuhanChina

Scatterhoarding rodents often place caches in the open where pilferage rates are reduced,suggesting that they tradeoff higher risks of predation for more secure cache *** tested this hypothesis in two study systems by measuring predation risks inferred from measures of giving-up densities(GUDs)at known cache sites and other sites for *** GUDs were measured with small trays containing 3 L of fine sand mixed with sunflower *** the first experiment,we relied on a 2-year seed dispersal study in a natural forest to identify caches of eastern gray squirrels(Sciurus carolinensis)and then measured GUDs at:(i)these caches;(ii)comparable points along logs and rocks where rodent activity was assumed highest;and(iii)a set of random *** found that GUDs and,presumably,predation risks,were higher at both cache and random points than those with *** the second site,we measured GUDs of eastern gray squirrels in an open park system and found that GUDs were consistently lowest at the base of the tree compared to more open sites,where previous studies show caching by squirrels to be highest and pilferage rates by naïve competitors to be *** results confirm that predation risks can influence scatterhoarding decisions but that they are also highly context dependent,and that the landscape of fear,now so well documented in the literature,could potentially shape the temporal and spatial patterns of seedling establishment and forest regeneration in systems where scatterhoarding is common.

关键词： giving-up densities predation risk scatterhoarding Sciurus seed dispersal

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Numerical simulation of multi-dimensional inviscid compressible flows by using TV-HLL scheme

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Chinese Journal of Aeronautics 2016年第6期29卷 1553-1562页

作者： Pascalin Tiam Kapen ghislain Tchuen University of Dschang IUT-FVLISIE/L2MSPP.O.Box 134BandjounCameroon Universite des Montagnes ISSTP.O.Box 208BangangteCameroon

This paper deals with the numerical solution of inviscid compressible flows. The threedimensional Euler equations describing the mentioned problem are presented and solved numerically with the finite volume method. The evaluation of the numerical flux at the interfaces is performed by using the Toro Vazquez-Harten Lax Leer(TV-HLL) scheme. An essential feature of the proposed scheme is to associate two systems of differential equations, called the advection system and the pressure system. It can be implemented with a very simple manner in the standard finite volume Euler and Navier–Stokes codes as extremely simple task. The scheme is applied to some test problems covering a wide spectrum of Mach numbers, including hypersonic, low speed flow and three-dimensional aerodynamics applications.

关键词： Euler equations Finite volume method Hypersonic Low speed flows Three-dimensional aerodynamics applications Toro Vazquez-Harten Lax Leer(TV-HLL)

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In-situ formation of Ni-Al intermetallics-coated graphite/Al composite in a cold-sprayed coating and its high temperature tribological behaviors

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Journal of Materials Science & Technology 2017年第6期33卷 507-515页

作者： Chunjie Huang Wenya Li Marie-Pierre Planche Hanlin Liao ghislain Montavon ICB UMR 6303 CNRS Univ.Bourgogne Franche-ComtéUTBM State Key Laboratory of Solidification Processing Shaanxi Key Laboratory of Friction Welding Technologies Northwestern Polytechnical University

In this study, cold spraying（CS） was used to deposit a mixture of nickel-coated graphite and 40 vol.% Al powder（Ni-Gr/Al） on a steel substrate aiming to effectively preserve a certain volume fraction of graphite in the deposited Ni-Gr/Al composite coating. The microstructure of the as-sprayed coating and the effect of post-spray heat-treatment（PSHT） temperatures on the in-situ formation of Ni-Al intermetallic phases in coating were studied. The tribological behaviors of the as-sprayed coating and the PSHTed coating under 450？C were tested at 25？C, while the as-sprayed coating was tested at 450？C for *** a result, the Ni-Gr particles showed a homogenous distribution in the coating. The multilayer Ni-Al intermetallics-coated graphite/Al composite coating was achieved in situ after the PSHT of 450？C, where the graphite did decompose at 550？C leaving big pores in the coating. The coefficients of friction（COF）of the CSed coating and the PSHTed coating were measured at 450？C as well as 25？C, which showed a similar tendency, much higher than that of the CSed coating tested at 25？C. The lubrication phase（graphite） improved the formation of a graphite film during sliding friction and decreased the COF, while the hard Ni-Al intermetallic phases contributed to the increase of COF.

关键词： Cold spraying Ni-coated graphite powder Post-spray heat-treatment Intermetallics Tribological performance

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Evaluation of Mixture Performance Recycled Asphalt Pavement Materials as Base Layer with or without Rejuvenator into the Asphalt

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Journal of Wuhan University of Technology(Materials Science) 2020年第3期35卷 579-597页

作者： Alaye Quirin Engelbert Ayeditan LING XianZhang DONG Zejiao Bambou ghislain Department of Civil Engineering Harbin Institute of TechnologyHarbin 150001China Department of Civil Engineering University of Abomey-Calavi01 BP 2009 Cotonou.Benin Department of Road and Railway Engineer-ing Harbin Institute of TechnologyHarbin 150001China

The binder properties were determined in accordance with Chinese standard such as ductility test, which allowed to measure the distance in centimeters that a standard briquette of asphalt had been stretched before breaking. Then, penetration test was carried out in order to know some properties of the asphalt, which are the hardness and the softness. Finally, softening point test was carried out in order to determine the temperature at which the bitumen attains a particular degree of softening under the specification of the test. According to Chinese standard for performance tests, firstly, Marshall test was carried out in order to measure the theoretical density, air voids, voids filled with asphalt, stability, flow, and voids in mineral aggregate of asphalt specimens. Secondly, Freeze-thaw splitting test was carried out in order to determine Splitting strength ratio. Finally, dynamic stability (rutting) test was carried out to determine average dynamic stability. Beside the tests carried out, the gradation of the extracted aggregate in accordance with American Association of State Highway and Transportation Officials was carried out to determine the dimensions of the particles weight distribution. Furthermore, both the percentage of recycled asphalt pavement materials and binder in mixture were determined to know how much of the new material during the mixture was needed. However, two specimens were used to evaluate the performance of recycled asphalt pavement materials. One specimen of recycled asphalt pavement materials was ten years old, and another one of recycled asphalt pavement materials was five years old. The results show that the conditions of the environment such as moisture, temperature, and age, decrease the ductility and penetration properties of binder when increase the softening point property of binder. Then the gradation of recycled asphalt pavement aggregate is of the required values to reuse in the mixture, while the flow ratio, the splitting s

关键词： recycled asphalt pavement rejuvenator asphalt rutting performance

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Effect of Substrate Type on Deposition Behavior and Wear Performance of Ni-Coated Graphite/Al Composite Coatings Deposited by Cold Spraying

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Journal of Materials Science & Technology 2017年第4期33卷 338-346页

作者： Chunjie Huang Wenya Li Yingchun Xie Marie-Pierre Planche Hanlin Liao ghislain Montavon ICB UMR 6303 CNRSUniversite Bourgogne Franche-ComteUTBMF-90100 BelfortFrance State Key Laboratory of Solidification Processing Shaanxi Key Laboratory of Friction Welding TechnologiesNorthwestern Polytechnical UniversityXi'an 710072China

This work focused on the deposition characteristics and wear behavior of Ni-coated graphite mixed with40 vol.% Al（Ni-Gr/Al） composite coatings sprayed on an Al alloy and a steel substrate by cold spraying（CS）. The morphology of the flattened Ni-Gr particles was examined by single-impact tests. Crosssectional microstructure and wear performance of the Ni-Gr/Al composite coatings were studied. Results showed that a larger number of Ni-Gr particles were finally bonded with the steel substrate, whereas many craters existed on the Al alloy substrate after the single-impact tests. The coating on the steel substrate had a high thickness, high graphite content and low coeficient of friction（COF） compared to those on the Al alloy substrate. In addition, the CS coatings presented a homogeneous distribution and uniform morphology of graphite, and a comparative COF to that of conventional thermal sprayed coatings. It was shown that CS could avoid the decomposition and transformation of graphite phase.

关键词： Cold spraying Ni-coated graphite Deposition behavior Microstructure Wear performance

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Granitic inselbergs of Lara(Panafrican Chain,Far-North Cameroon):Assets for the implementation of geotourism in Mountainous region

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Journal of Mountain Science 2022年第11期19卷 3192-3212页

作者： ZANGMO TEFOGOUM ghislain NOUHOU DAMA Zouyane Hyacinthe GOUNTIÉDEDZO Merlin MAFO DONGMO Irène Department of Earth Sciences de la Terre Faculty of ScienceUniversity of MarouaP.O.Box 814 MarouaCameroon Department of Life and Earth Sciences High Teacher Training CollegeUniversity of MarouaP.O.Box 55MarouaCameroon

The locality of Lara(Far-North Region,Cameroon)is made up of a pediplain strewn with coalescent *** interaction of internal and external geological processes has contributed to transform the latter into inselbergs,whose geotouristic values are yet to be *** and laboratory work enabled us to select the geomorphosites through their aesthetic value(particular size and shape)and,geomorphological and geological ***,it permitted to study and map the geomorphosites using Optic Microscope,Google Earth,GIS software and many other ***,four inselbergs have been selected and studied in the locality of *** petrographic study of these inselbergs shows that granites are the main components of inselbergs and they present a fine to coarse-grained texture,materialized by quartz,micas,plagioclases and alkali feldspars(white and pink in colour).Inselbergs exhibit vertical and parallel networks of diaclases giving them a stratified appearance in some *** addition,on some inselberg limbs and piedmonts,are built tors which contribute to their *** tops of inselbergs,are embellished by several alluring pedestal *** their flanks,shelters of various shapes and sizes(about 12 m length)have developed through the heaps of blocks *** the ten shelters selected,some have a fairly high cultural value as they are sacred places for the local ***,Lara's granitic inselbergs include enclaves(cognate enclaves and xenocrysts)that also significantly improve their geoheritage *** are landforms with high education and aesthetic value that attracted a larger local and foreign population of about 863 visitors between *** constitute an exceptional geoheritage that could attract more tourists in the locality of Lara;but the promotion of geotourism is needed through interpretative panels,marketing of geomorphosites through leaflets,web,media,and geotours,to mention a few.

关键词： Lara Inselbergs Granite geoheritage Geotouristic activities

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Typology of Natural Hazards and Assessment of Associated Risks in the Mount Bambouto Caldera(Cameroon Line,West Cameroon)

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Acta Geologica Sinica(English Edition) 2009年第5期83卷 1008-1016页

作者： ghislain T.ZANGMO Armand D.KAGOU David G.NKOUATHIO Pierre WANDJI Department of Earth Science Faculty of ScienceUniversity of DschangCameroon Laboratory of Geology High Teacher Training SchoolUniversity of Yaounde ICameroon

Mount Bambouto is a polygenic stratovolcano of the Cameroon Volcanic Line, built between 21 Ma and 4.5 Ma. It is situated approximately 200 km NE of Mount Cameroon, between 09° 55＇ and 10°15＇ longitude east and, 05°25＇ and 05°50＇ latitude north. The volcano covers an area of 500 km^2 and culminates at 2740 m at Meletan dome and bears a collapsed caldera at the summit （13 × 8 km）. Mount Bambouto is characterized by several natural hazards of different origins： meteorological, such as landslides and rock falls; anthropogenic, such as bushfires, tribal wars and deforestation; and volcanological, such as volcanic eruption. The thematic map shows that 55-60% of the caldera has high probability of occurrence of mass movement. The caldera has a high population density （3000 inhabitants）, which increases the level of risk, evaluated at approximately $US3.8 million for patrimony, 3000 civilian deaths and destruction of biodiversity.

关键词： caldera hazard risk assessment Mount Bambouto Cameroon Line

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Neurostimulation for fecal incontinence after correction of repair of imperforate anus

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World Journal of Clinical Cases 2017年第3期5卷 124-127页

作者： Alexandre Bougie Nathalie McFadden Sandeep Mayer Michel Lebel ghislain Devroede Surgery Department Centre Hospitalier Universitaire de SherbrookeFaculté de MédecineUniversité de Sherbrooke Medicine Department NeurologyCentre Hospitalier Universitaire de SherbrookeFaculté de MédecineUniversité de Sherbrooke

We are reporting the case of a 32-year-old female who had suffered from fecal incontinence(FI). She was born with an imperforate anus and a recto-vaginal fistula; she underwent repair at 6 mo of age. At 29 years of age, she was still fecally incontinent despite extensive pelvic floor reeducation. A magnetic resonance imaging and an anal electromyography were performed. Because her symptoms were considered to be probably due to extra-sphincteric implantation of the neo-anus, a redo was performed of the recto-neo-anal intra-sphincteric anastomosis. A neurostimulator device was subsequently implanted for persistent incontinence. Solid and liquid FI resolved, and her quality of life improved markedly. Combining surgery to correct the position of the neo-anus within the anal sphincter complex and neurostimulation could thus become a new approach in cases of refractory FI for patients with imperforate anus as a newborn. Follow-up into adulthood after pediatric imperforate anus surgery should be recommended for adult patients with persistent FI.

关键词： Fecal incontinence Congenital malformation Neuromodulation Neurostimulation Imperforate anus

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Optimum insulation thickness and exergy savings of building walls in Bamenda: a comparative analysis

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Energy Storage and Saving 2024年第1期3卷 60-70页

作者： Fodoup Cyrille Vincelas Fohagui Yemeli Wenceslas Kohole Njimboh Henry Alombah Derek Ajesam Asoh ghislain Tchuen Department of Electrical and Electronics Engineering College of TechnologyThe University of BamendaP.O.Box 39BambiliCameroon Department of Energetic Environment and Thermal EngineeringIUT-FV BandjounUR-ISIEUniversity of DschangP.O.Box 134BandjounCameroon National Higher Polytechnic Institute and Higher Technical Teacher Training College The University of BamendaP.O.Box 39BambiliCameroon

The goal of this study is to examine the energetic,entransy,and exergetic methodologies employed to estimate the ideal insulation thickness for construction walls in terms of cost and ecological *** achieve these goals,the life cycle cost analysis-based insulating thicknesses of the various methods are evaluated along with the overall costs,yearly cost reductions,and total *** fuel consumption,CO_(2) emissions,and ecological effects are then compared using an environmental analysis based on the three *** savings of hollow concrete brick(HCB),compressed stabilized earth brick(CSEB),and sundried earth brick(SEB)walls are evaluated along with the insulation thicknesses in terms of cost and ecological *** a result,it is determined that the exergetic technique is better suited for optimizing insulating *** CSEB,SEB,and HCB walls,the economic ideal insulation thicknesses are 0.01 m,0.016 m,and 0.02 m,with yearly financial savings of 5$⋅m^(-2),7.5$⋅m^(-2),and 9$⋅m^(-2).For CSEB,SEB,and HCB walls,accordingly,the ecological optimal insulation thicknesses are 0.023 m,0.032 m,and 0.040 m,with net savings of exergetic ecological impact equal to 59 mPts⋅m^(-2),55 mPts⋅m^(-2),and 51 mPts⋅m^(-2).

关键词： Insulation thickness Environmental impact Entransy Exergy Exergoeconomic

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Evaluation of Groundwater Suitability for Domestic and Irrigational Purposes:A Case Study from Mingoa River Basin,Yaounde,Cameroon

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Journal of Water Resource and Protection 2012年第5期4卷 285-293页

作者： Tabue Youmbi Jean ghislain Feumba Roger Wethe Joseph Ekodeck Georges Emmanuel De Marsily ghislain Department of Earth Sciences University of Yaounde IYaoundeCameroon Centre Regional pour l’Eau Potable et l’Assainissement a Moindre cout OuagadougouBurkina Faso Universite Pierre Marie Curie de Paris 6 et Ecole des Mines de Paris ParisFrance

A baseline study involving analyses of subsurface water samples from the Mingoa river basin (longitude: 11°30′E;latitude: 3°52′N) in migmatitic complex in Yaounde Cameroon (central Africa) was carried out to assess their suitability for drinking, domestic and agricultural purposes. Study results show that pH is ranged between 5.1≤ pH ≤ 5.8 and then, induces acidic waters. Groundwater samples are generally characterized by low conductivity values, of which 100% are within the range (55 ≤ EC ≤ 1500 μS/cm). The mean values of the major cations (Ca2+, Mg2+, Na+, K+) and anions (SO42– , Cl–, HCO3– ) are all within the World Health Organization (WHO) standards. Two of the springs sampled have nitrate (NO3– ) contamination. Even though contamination and acidic waters exist in some of the springs, the majority of the springs are excellent for agricultural and domestic purposes. Assessment of the groundwater for agricultural irrigation revealed two main categories. These are low salinity-low sodicity (C1-S1) and medium salinity-low sodicity (C2-S1), using the US Salinity Laboratory (USSL) classification scheme. As much as all of the samples plotted in the “excellent to good” and “good to permissible” categories on the Wilcox diagram. The groundwater in the study area may therefore be regarded as good for irrigation activities. The major identifiable geochemical processes responsible for the evolution of the various ions are mineral weathering, chemical reactions and anthropogenic activities.

关键词： Groundwater Suitability Mingoa Watershed Yaounde Cameroon Central Africa

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