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Biothermomechanical behavior of skin tissue

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Acta Mechanica Sinica 2008年第1期24卷 1-23页

作者： F.Xu t.j.Lu K.A.Seffen Engineering Department Cambridge University Cambridge CB2 1PZ UK MOE Key Laboratory of Strength and Vibration School of Aerospace Xi'an Jiaotong University 710049 Xi'an China

Advances in laser, microwave and similar technologies have led to recent developments of thermal treatments involving skin tissue. the effectiveness of these treatments is governed by the coupled thermal, mechanical, biological and neural responses of the affected tissue： a favorable interaction results in a procedure with relatively little pain and no lasting side effects. Currently, even though each behavioral facet is to a certain extent established and understood, none exists to date in the interdisciplinary area. A highly interdisciplinary approach is required for studying the biothermomechanical behavior of skin, involving bioheat transfer, biomechanics and physiology. A comprehensive literature review pertinent to the subject is presented in this paper, covering four subject areas：（a） skin structure, （b） skin bioheat transfer and thermal damage, （c） skin biomechanics, and （d） skin biothermomechanics. the major problems, issues, and topics for further studies are also outlined. this review finds that significant advances in each of these aspects have been achieved in recent years. Although focus is placed upon the biothermomechanical behavior of skin tissue, the fundamental concepts and methodologies reviewed in this paper may also be applicable for studying other soft tissues.

关键词： Review Skin tissue Bioheat transfer Biomechanics Biothermomechanics

Drying of suspensions and solutions on inert particle surface in mechanically spouted bed dryer

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China Particuology 2007年第5期5卷 337-344页

作者： Elisabeth Pallai-Varsányi judit tóth jános Gyenis University of Pannonia Faculty of Information TechnologyResearch Institute of Chemical and Process Engineering Egyetem u. 2H-8200 VeszprémHungary Hungarian Academy of Sciences Chemical Research CentreInstitute of Materials and Environmental ChemistryPusztaszeri u. 59-67H-1025 BudapestHungary

to eliminate some disadvantages of the conventional spouted bed dryers the mechanically spouted bed （MSB） system was developed. this dryer type is convenient to use inert particles providing an increased surface area for drying of materials of high-moisture content and heat sensitive materials. On three different drying tasks are demonstrated the experimental optimization of process parameters to obtain products of demanded quality. the main object was at drying of AIO（OH） suspension to preserve the particle size under 2.5μm and to obtain product with a moisture content of about 0.05 kg/kg （d.b.）. For this reason a very thin particle coating and intensive abrasion had to be assured. At drying of tomato concentrates the thermoplasticity makes the process very difficult. to jump over the deliquescent and sticky state developed at the critical temperature-moisture content values a very short drying time （8-10 s） must be provided. the third task was to form powder-like product from bovine serum albumin （BSA） solution having very low solid content （2-4%）. the selected process parameters given in this paper resulted in a mean particle size of less than 20 μm while the soluble oreserved orotein content was higher than 90%.

关键词： Mechanically spouted bed Film-like drying Inert particles Heat sensitive material

Mathematical modelling of ball and plate system with experimental and correlation function-based model validation

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Control theory and technology 2024年第2期22卷 326-341页

作者： t.R.Dil Kumar S.j.Mija Department of Electrical Engineering National Institute of Technology CalicutKozhikode673601KeralaIndia

the ball and plate system is an inherently nonlinear under actuated benchmark system used for validating the performance of various control schemes. A mathematical model depicting the dynamics close to that of the system is very much required for such a test bed. In this correspondence, the complete nonlinear model, a simplified nonlinear model, and a linearized model of the ball and plate system are developed. the system comprises a ball and plate mechanism and a rotary servo unit. the ball and plate mechanism is modelled using the Euler–Lagrange method, whereas the rotary servo subsystem is modelled from the first principles. the nonlinear model of the combined system is developed by including the dynamics of the servo motor with gear and rolling resistance between the ball and the plate. the simplified nonlinear model of the system is obtained with suitable assumptions. the model is linearized around the operating point using the jacobian. the validity of the developed models is investigated through correlation function analysis. the open-loop response of the three models, viz., nonlinear, simplified nonlinear, and linearized models, is analyzed in the MAtLAB/Simulink platform. Since the open-loop system is unstable, the experimental validation of the model is performed with a double-loop PSO (particle swarm optimization) PID control scheme.

关键词： Ball and plate system Correlation function Model validation Particle swarm optimization(PSO) PSO PID controller

Analysis of Surface Integrity in Drilling Metal Matrix and Hybrid Metal Matrix Composites

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journal of Materials Science & technology 2012年第8期28卷 761-768页

作者： t.Rajmohan K.Palanikumar j.Paulo Davim Department of Mechanical Engineering Sri Chandrasekharendra Saraswathi Viswa Maha Vidyalaya University Department of Mechanical Engineering Sri Sai Ram Institute of Technology Department of Mechanical Engineering University of AveiroCampus Santiago3810-193 AveiroPortugal

Hybrid metal matrix composites consist of at least three constituents-a metal or an alloy matrix and two reinforcements in various forms, bonded together at the atomic level in the composite. Despite their higher specific properties of strength and stiffness, the non homogeneous and anisotropic nature combined with the abrasive reinforcements render their machining difficult. In this paper, the surface integrity of machining in drilling hybrid composites has been discussed. Drilling tests are carried out at different spindle speed, feed rates, and different drill tool materials to investigate the effect of the various cutting parameters on the surface quality and the extent of the deformation of drilled surface due to drilling. Materials used for the present investigation are A1356/IOSIC （wt%） metal matrix and A1356/10SiC-3mica （wt%） hybrid composites. the composites are fabricated using stir casting route. the drilling tests are conducted on vertical computer numeric control （CNC） machining center using carbide, coated carbide and polycrystalline diamond （PCD） drills. the surface roughness decreases with increasing spindle speed and increases with increasing feed rate. the machined surface is analyzed by scanning electron microscopy （SEM）. SEM images of the machined surfaces indicate the presence of grooves and pits. Microhardness depth profiles indicate that the subsurface damage is limited to the top of 100-250 μm.

关键词： Hybrid composites Scanning electron microscopy (SEM) Subsurface Drilling

A new four-dimensional hyperjerk system with stable equilibrium point, circuit implementation, and its synchronization by using an adaptive integrator backstepping control

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Chinese Physics B 2018年第10期27卷 231-239页

作者： j P Singh V t Pham t Hayat S jafari F E Alsaadi B K Roy Department of Electrical Engineering National Institute of Technology Silchar 788010 India School of Electronics and telecommunications Hanoi University of Science and Technology 01 Dai Co Viet Hanoi Viet Nam Department of Mathematics Faculty of Science King Abdulaziz University Jeddah 21589 Saudi Arabia Department of Mathematics Quaid-I-Azam University Islamabad 44000 Pakistan Ambikar University of technology Tehran 15875-4413Iran Department of Information technology Faculty of Computing and IT King Abdulaziz University Jeddah Saudi Arabia

this paper reports a new simple four-dimensional（4 D） hyperjerk chaotic system. the proposed system has only one stable equilibrium point. Hence, its strange attractor belongs to the category of hidden attractors. the proposed system exhibits various dynamical behaviors including chaotic, periodic, stable nature, and coexistence of various attractors. Numerous theoretical and numerical methods are used for the analyses of this system. the chaotic behavior of the new system is validated using circuit implementation. Further, the synchronization of the proposed systems is shown by designing an adaptive integrator backstepping controller. Numerical simulation validates the synchronization strategy.

关键词： new hyperjerk chaotic system stable equilibrium hidden attractors adaptive backstepping control synchronization

Dynamic mechanical relaxation behavior of Zr_(35)Hf_(17.5)ti_(5.5)Al_(12.5)Co_(7.5)Ni_(12)Cu_(10)high entropy bulk metallic glass

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journal of Materials Science & technology 2021年第24期83卷 248-255页

作者： L.t.Zhang Y.j.Duan t.Wada H.Kato j.M.Pelletier D.Crespo E.Pineda j.C.Qiao School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi’an710072China Institute for Materials Research Tohoku UniversitySendai980-8577Japan Universitéde Lyon MATEISUMR CNRS5510Bat.B.PascalINSA-LyonF-69621Villeurbanne CedexFrance Department of Physics Barcelona Research Center in Multiscale Science and TechnologyInstitute of Energy TechnologiesUniversitat Politècnica de Catalunya08019BarcelonaSpain

Non-equiatomic high entropy bulk metallic glasses were reported recently and show unique mechanical and physical *** mechanical relaxation behavior of Zr_(35)Hf_(17.5)ti_(5.5)Al_(12.5)Co_(7.5)Ni_(12)Cu_(10)high entropy bulk metallic glass was investigated by dynamic mechanical analysis(DMA)and the mechanical spectra could be well described by the quasi-point defects(QPD)*** to typical metallic glasses,the intensity of theβrelaxation of Zr_(35)Hf_(17.5)ti_(5.5)Al_(12.5)Co_(7.5)Ni_(12)Cu_(10)high entropy bulk metallic glass is lower due to the sluggish *** the same time,the correlation factor is higher than that of conventional metallic glasses and this is ascribed to the high configuration *** parallel,physical aging below the glass transition temperature leads to a decrease of atomic mobility,caused by a decrease of the concentration of defects.

关键词： High entropy bulk metallic glass Mechanical relaxation Quasi-point defects Physical aging

Primary beneficiation of tantalite using magnetic separation and acid leaching

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International journal of Minerals,Metallurgy and Materials 2014年第12期21卷 1153-1159页

作者： M.Nete F.Koko t.theron W.Purcell j.t.Nel Department of Chemistry University of the Free State the South African Nuclear Energy Corporation SOC Ltd.(Necsa) P.O.Box 582Pretoria 0001 South Africa

Primary beneficiation was successfully performed prior to dissolution of manganotantalite （sample A） and ferrotantalite （sample C） samples obtained from two different mines in the Naquissupa area, Mozambique. Magnetic separation removed the majority of iron and titanium, whereas H2SO4 leaching removed a large portion of thorium and uranium in these samples. Analytical results indicated that 64.14wt% and 72.04wt% of the total Fe and ti, respectively, and -2wt% each of Nb205 and ta205 were removed from sample C （ferrotantalite） using the magnetic separation method, whereas only 9.64wt% and 8.66wt% of total Fe203 and tiO2, respectively, and -2wt% each of NbEOs and ta2O5 were removed from sample A （manganotantalite）. A temperature of 50℃ and a leaching time of 3 h in the presence of concentrated HESOa were observed to be the most appropriate leaching conditions for removal of radioactive elements from the tantalite ores. the results obtained for sample A under these conditions indicated that 64.14wt% U3O8 and 60.77wt% thO2 were leached into the acidic solution, along with 4.45wt% and 0.99wt% of Nb2O5 and ta2O5, respectively.

关键词： tantalite beneficiation magnetic separation acid leaching

Analysis of the anelastic deformation of high-entropy Pd_(20)Pt_(20)Cu_(20)Ni_(20)P_(20) metallic glass under stress relaxation and recovery

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journal of Materials Science & technology 2022年第12期107卷 82-91页

作者： Y.j.Duan L.t.Zhang t.Wada H.Kato E.Pineda D.Crespo j.M.Pelletier j.C.Qiao School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi’an 710072China Department of Physics Institute of Energy TechnologiesUniversitat Politècnica de CatalunyaBarcelona 08019Spain Institute for Materials Research Tohoku UniversitySendai 980-8577Japan Universitéde Lyon MATEISUMR CNRS5510Bat.B.PascalINSA-LyonF-69621 Villeurbanne CedexFrance

the anelastic deformation behavior of Pd_(20)Pt_(20)Cu_(20)Ni_(20)P_(20) high-entropy metallic glass was probed by monitoring the stress relaxation and recovery processes. the stress relaxation under consecutive strain steps can be described by the Kohlrausch-Williams-Watts(KWW) function. In addition, considering a hierarchy of relaxation processes related to the structural heterogeneity, a constitutive model is proposed in order to describe the whole process of stress relaxation and determine the contribution of different time scales. Moreover, a crossover from stochastic activation to percolation of flow defects with the ultimate strain can be observed during stress relaxation process. the anelastic recovery process after a strain step is studied as a function of the initial strain level and characterized by means of a direct spectrum analysis. the peaks in the recovery time-spectra revealed the evolution of flow defects in Pd_(20)Pt_(20)Cu_(20)Ni_(20)P_(20) high-entropy metallic glass. the understanding of the atomic free-volume zones effect and the anelastic deformation provides important insight into how atomic structural features affect the deformation behavior of high-entropy metallic glasses, and may provide a new avenue into the improvement of their mechanical properties.

关键词： High-entropy metallic glass Stress relaxation Anelastic deformation Flow defects Free-volume zones

tHE INtERFACIAL BEHAVIORS OF ALUMINUM MAtRIX COMPOSItE IN DIFFERENt WELDING MEtHODS

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Acta Metallurgica Sinica(English Letters) 2004年第1期17卷 55-60页

作者： W.Guo j.t.Niu j.F.Zhai G.t.Zhou M.Z.Wang State Key Laboratory of Advanced Welding Production technology Harbin Institute of Technology(HIT)Harbin150001China State Key Laboratory of Metal Matrix Composite Shanghai Jiaotong University.Shanghai 200030.China

Non-interlayer liquid phase diffusion welding (China Patent) and laser welding methods for aluminum matrix composite are mainly described in this paper. In the non-interlayer liquid phase diffusion welding, the key processing parameters affecting the strength of joint is welding temperature. When temperature rises beyond solidus temperature, the bonded line vanishes. the strength of joint reaches the maximum and becomes constant when welding temperature is close to liquid phase temperature. Oxide film in the interface is no longer detected by SEM in the welded joint. With this kind of technique, particle reinforced aluminum matrix composite Al2 O3p/6061Al is welded successfully, and the joint strength is about 80% of the strength of composite (as-casted). In the laser welding, results indicate that because of the huge specific surface area of the reinforcement, the interfacial reaction between the matrix and the reinforcement is restrained intensively at certain laser power and pulsed laser beam. the laser pulse frequency directly affects the reinforcement segregation and the reinforcement distribution in the weld, so that the weldability of the composite could be improved by increasing the laser pulse frequency. the maximum strength of the weld can reach 70% of the strength of the parent.

关键词： non-interlayer liquid phase diffusion welding Al2O3p/6061 Alaluminum matrix composite laser welding interface behavior reinforcement