检索结果-南通市图书馆

Reconstructing the neutrally-buoyant particle flow near a singular corner

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta mechanica Sinica 2022年第8期38卷 41-48页

作者： Francesco Romanò Univ.Lille CNRSONERAArts et Métiers Institute of TechnologyCentrale LilleUMR 9014-LMFL-Laboratoire de Mécanique des Fluides de Lille-Kampéde FérietUniv.LilleCNRSONERAF-59000LilleFrance

The correction of buoyancy effects is tackled for particles moving close to a singular corner in creeping flow conditions.A few density-mismatched particle trajectories are used to reconstruct the dynamics of a neutrally-buoyant particle all over the target *** propose to take advantage of the dissipative dynamics of density-mismatched particles in order to probe the target ***,we retrieve the neutrally-buoyant particle flow all over the domain by reconstructing the phase space of the density-mismatched particulate flow and taking the limit of the particle-to-fluid density ratio tending to *** robustness of such an approach is demonstrated by deliberately ill-conditioning the reconstruction *** fact,we show that our algorithm well performs even when we rely on qualitatively-different density-mismatched orbit topologies or on bundles of close trajectories rather than homogeneously distributed *** applications to microfluidics and improvements of the proposed algorithm are finally discussed.

关键词： Stokesian dynamics microfluidics Particle/fluid flow

evolution of the deflection According to Truck Overloading—Comparison between Benkelman Beam method and Fem of Lateritic Pavements

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Civil engineering 2018年第4期8卷 478-488页

作者： Fatou Samb Ndiassé Diop Baye Birane Thiam makhaly Ba laboratoire de mécanique et de modélisation UFR Sciences de l’Ingénieur Université de Thiès Thiès Sénégal

The study of the deflection due to the passage of an axle on a pavement structure has the advantage to make possible to pronounce on the portance, the rigidity and the homogeneity of this one. In the case where the allowed axle load is not respected, surface deflection leads to premature deterioration of the roadway. In order to study the evolution of these deformations, deflection measurements were made by using the Benkelman method in the Fatick-Kaolack road in Senegal by varying the axle load with the following values: 10, 13 and 16 tons on three different zones. The results show a linear evolution of the deflection as a function of the axle load. Also, the impact of truck overloading was studied by considering different values of the axle load with comparison to the allowed axle load by using frequent types of vehicle. A numerical simulation of the Cast3m pavement was done first, in the case of an isolated single wheel with a radius of 12.5 cm, then in the case of an equivalent dual wheel with a radius of 18.1 cm for loads of 10 to 19 tons. In the same way, the pavement design software (ALIZe) is used to analyse the variation of the axle load. The results show a linear evolution of the deflection, which corroborates the measurements made in the field and those obtained by Samb (2014) with a slope coefficient equal to 1.7. Nevertheless, the case of an isolated single wheel of 12.5 cm radius is closest to the measurements with a straight line of slope coefficient equal to 1.9.

关键词： deflection Axle Overload Truck Overloading Cast3m ALIZe Fem Lateritic Gravel

Railway Traffic Vibration Impact Analysis on Surrounding Buildings by Fem—Case Study: TeR (Regional express Train) Dakar—AIBD

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geomaterials 2019年第1期9卷 17-28页

作者： Fatou Samb Fortunée A. Fanoukoe Ariel Joselyne Nzontheu Keno moussa Diop laboratoire de mécanique et de modélisation UFR Sciences de l’Ingénieur Université de Thiès Thiès Sénégal

The vibrations induced by railway traffic can affect the stability of structures, buildings and buried structures. To evaluate this impact, this study was carried out considering the case of the Regional express Train which will connect Dakar to Blaise Diagne International Airport. For that, the modeling software Plaxis dynamic [1], able to generate harmonic loads, is used and permitted to have a dynamic analysis and comparison between static and dynamic load for one passage of the train for 2.56 s. In the modeling, two behavior laws were used those of mohr Coulomb for the layers of soil, embankments and the form layer, and then the linear elastic model for the rest of the elements. The results obtained showed extreme vertical displacements 40.18 mm for the building and when no load is applied on the track, there was 40.24 mm for a static load, and 40.17 mm for a dynamic load. Also, it was observed for the track a displacement of 33.73 mm for a static load and 19.83 mm for a dynamic load. However, further studies are necessary to take into account the permanent deformation after an accurate cycle of train passage in order to better evaluate the railway traffic impact.

关键词： Fem modelling Impact Vibrations Railway Traffic Harmonic Loads

Finite-temperature ductility-brittleness and electronic structures of Al_(n)Sc(n=1,2 and 3)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare metals 2024年第8期43卷 3974-3989页

作者： Xue-Qian Wang Ying Zhao Hao-Xuan Liu Shu-Chen Sun Hong-Bo Yang Jia-min Zhong Gan-Feng Tu Song Li Yu-Dong Zhang Claude esling Hai-Le Yan Liang Zuo Key Laboratory for Anisotropy and Texture of materials(ministry of education) School of Material Science and EngineeringNortheastern UniversityShenyang 110819China School of metallurgy Northeastern UniversityShenyang 110819China Rare earth Functional materials(Xiong'an)Innovation Center Co. Ltd.Xiong'an 071700China laboratoire d'étude des microstructures et de mécanique des matériaux(Lem3) Unikersitéde Lorraine57045MetzFrance

Finite-temperature ductility-brittleness and electronic structures of Al_(3)Sc,Al_(2)Sc and AlSc are studied comparatively by first-principles calculations and ab initio molecular *** show that Al_(3)Sc and Al_(2)Sc are brittle at both ground state and finite temperatures,while AlSc possesses a significantly superior *** ground state,AlSc is ductile from Pugh's and Poisson's criteria,while it is brittle in Pettifor's *** ductility of all Al_(3)Sc,Al_(2)Sc and AISc improves greatly with the elevated ***,the Cauchy pressure of AlSc undergoes a transition from negative to *** T>600 K,AlSc is unequivocally classified as ductile from all criteria *** all compounds,the Al-Al bond originated from s-p and p-p orbital hybridizations,and the Al-Sc bond dominated by p-d covalent hybridization,are the first and second strongest chemical bonds,*** explain the difference in mechanical properties,the mean bond strength(mBS)is introduced in this *** weaker Al-Al bond in AlSc,leading to a smaller mBS,could be the origin of the softer elastic stiffness and superior intrinsic *** longer length of the Al-Al bond in AlSc is responsible for its weaker bond ***,the enhanced metallicity of the Al-Al bond in AlSc would also contribute to its exceptional *** longer length of the Al-Al bond in AISc is responsible for its weaker bond ***,the enhanced metallicity of the Al-Al bond in AlSc would also contribute to its exceptional ductility.

关键词： Al-Sc Target materials Intrinsic ductility Finite-temperature elastic constant First-principles calculation

Geomagnetic Investigation method Using Iphone®Integrated magnetic Sensor

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

International Journal of Geosciences 2014年第1期5卷 1-4页

作者： mapathe Ndiaye Ababacar Diagne laboratoire de mécanique et modélisation UFR Sciences de l’Ingénieur University of Thies Thies Senegal

We carried out a geomagnetic investigation using Iphone 4S? integrated magnetic sensor. The investigated area is a faulted sedimentary terrain crossed by basaltic volcanic veins. The obtained magnetic anomaly map shows the limits between the sedimentary rocks and a magnetic body at a given depth. These results are compared to the geometry of the magnetic body as shown by geological maps. The results seem to be accurate for the determination of geometry and the depth of the magnetic body.

关键词： Geomagnetic magnetic Anomaly Iphone 4S Vein Basalt

A first-principle assisted framework for designing high elastocaloric Ni-mn-based magnetic shape memory alloy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of materials Science & Technology 2023年第3期134卷 151-162页

作者： Xiao-ming Huang Ying Zhao Hai-Le Yan Shuai Tang Yiqiao Yang Nan Jia Bo Yang Zongbin Li Yudong Zhang Claude esling Xiang Zhao Liang Zuo Key Laboratory for Anisotropy and Texture of materials(ministry of education) School of Material Science and EngineeringNortheastern UniversityShenyang110819China State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang110819China Analytical and Testing Center Northeastern UniversityShenyang110819China laboratoire d’Étude des microstructures et de mécanique des matériaux(Lem3) CNRS UMR 7239Universitéde Lorraine57045 MetzFrance

A large adiabatic temperature change(△T_(ad))is a prerequisite for the application of elastocaloric ***,a large volume change ratio(△V/V_(0))during martensitic transformation is favorable to enhance△T_(ad).However,the design or prediction of△V/V_(0)in experiments is a complex task because the structure of martensite changes simultaneously when the lattice parameter of austenite is tuned by mod-ifying chemical *** far,the solid strategy to tailor△V/V_(0)is still urgently *** this work,a first-principles-based method was proposed to estimate△V/V_(0)for Ni-mn-based *** this method,the substitution of Ga for In is found to be an effective method to increase the value of△V/V_(0)for Ni-mn-In *** with the strategies of reducing the negative contribution of magnetic en-tropy change(via the substitution of Cu for mn)and introducing strong crystallographic texture(through directional solidification),an outstanding elastocaloric prototype alloy of Ni_(50)(mn_(28.5)Cu_(4.5))(In_(14)Ga_(3))was fabricated *** room temperature,a huge△T_(ad)of-19 K and a large specific adiabatic temperature change of 67.8 K/GPa are *** proposed first-principle-assisted framework opens up the possibility of efficiently tailoring△V/V_(0)to promote the design of advanced elastocaloric refrigerants.

关键词： magnetic shape memory alloy elastocaloric effect First-principles calculation martensitic transformation Volume change ratio

Geomechanical Characterization of Sandstones Cliffs of Segou (Senegal, West Africa) in the madina Kouta Basin

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Geosciences 2012年第1期3卷 166-174页

作者： Déthié Sarr meissa Fall Papa malick Ngom mapathé Ndiaye Cheikh H. Kane makhaly Ba laboratoire de mécanique et modélisation-UFR Sciences de l’Ingénieur Université de Thiès Thiès Sénégal

This work presents the behavior of Segou sandstones in the laboratory and in the field conditions. Four types of sandstone are collected in the northern part of the madina Kouta basin (eastern Senegal). These types of specimens are the white sandstones, the red sandstones, the purple sandstones and the sandstones with intercalation of pelites. Uniaxial tests are carried out on these specimens of sandstones. The Young moduli (e) and the Uniaxial Compression Strengths (Rc) are higher for the white sandstone. Values of the mechanical parameters decrease slightly for red sandstones due to an increase of the amount of pelites in the composition of the rock. decrease of mechanical parameters is more important for the purple facies due to an important network of fractures. The facies with weaker characteristics corresponds to the sandstones with intercalation of pelites. This is due to the soft nature of the pelites. The slope stability of the Cliff sides depends also on to these characteristics.

关键词： Unconfined Compression Test-Uniaxial Compression Strength (UCT Rc) JRC (Joint Roughness Coefficient) Young modulus (e) Roughness Segou-madina Kouta Basin Discontinuities Dihedral Slope Cliff

effects of Unstable Footwear on Stance Pattern

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Biosciences and medicines 2014年第3期2卷 20-24页

作者： m. A. Choukou S. Ghouli F. C. Boyer R. Taiar laboratoire de Biomécanique GRESPI Université de Reims-Champagne Ardenne Reims France

Inadequate safety shoe wearing is thought to be responsible of many musculoskeletal disorders. A new concept of unstable footwear is proposed to reduce mechanical stresses during work. major expectations argue for a better ankle dynamic behavior leading to an increased muscular activity. The aim of this study was to evaluate the variation of stance characteristics while walking on level ground as a function of the models of safety shoes. Twenty healthy males (aged 23.6 ± 7) were asked to make six gait cycles on a walking track while barefoot, shod with low cost safety footwear, high cost one, and equipped by masa? Barefoot Technology shoes (the most unstable footwear). Stance phases (heel strike, flat foot and toe-off) have been normalized as percentages of the maximum value of ground reaction force recorded during each step. The highest significant percentages have been observed in masa? Barefoot Technology shoes condition and only during heel strike (8% to 10.1% higher) and toe-off (10% to 11.3% higher). In contrast, the temporal durations of the three stance phases were not significantly different between the four conditions. The convexity of safety shoe induces less stability increasing the adaptation of the muscle activity of the wearer at heel-strike and toe-off in order to regain stable gait pattern.

关键词： Gait Barefoot Convex Shoes Pain

effect of Water Content and Grains Size Distribution on the Characteristic Resilient Young’s modulus (ec) Obtained Using Anisotropic Boyce model on Gravelly Lateritic Soils from Tropical Africa (Burkina Faso and Senegal)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Civil engineering 2021年第1期11卷 134-152页

作者： Bibalo Ida Josiane Ki makhaly Ba Rokhaya Gueye Pierre Hornych Ali Sana laboratoire de mécanique et modélisation (L2m) UFR Sciences de l’Ingénieur Université de Thiès Thiès Sénégal

This research was carried out to determine the rheological parameters of lateritic soils in order to contribute to the improvement of the technical documents used for pavement design in tropical Africa. The study is based on the loading repeated of cyclic triaxial tests (LRT) performed at University Gustave Eiffel (formerly Institut Français des Sciences et Technologies des Transports de l’Aménagement et des Réseaux (IFSTTAR)) in Nantes with the application of the European standard EN 13286-7: 2004 [1]. The tests were performed at constant confinement stress and using the stepwise method to determine the resilient axial () and radial () deformation as a function of the axial and radial stresses. Four gravel lateritic soilse="font-family:;" "="">e="font-family:Verdana;"> from different sites selected in Burkina Faso and Senegal were the subject of this research for the triaxial tests. These materials have a maximum diameter of 20 mm a

关键词： Lateritic Soil Cyclic Triaxial with Repeated Loading (LRT) Characteristic Resilient Young’s modulus Anisotropic Boyce model Water Content Grains Size Distribution