ORCID Profile
0000-0003-0948-784X
Current Organisation
Shenzhen MSU-BIT University
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In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Numerical Modelling and Mechanical Characterisation | Biomaterials | Manufacturing Processes and Technologies (excl. Textiles) | Biomechanics | Automotive Engineering Materials | Biomedical Engineering | Automotive Engineering | Biomechanical Engineering | Structural Engineering | Manufacturing Engineering not elsewhere classified | Composite Materials | Manufacturing Engineering | Human Movement and Sports Science | Ship and Platform Structures | Solid Mechanics | Mechanical Engineering | Materials Engineering | Mechanical Engineering | Composite and Hybrid Materials |
Biological sciences | Fabricated Metal Products not elsewhere classified | Other | Emerging Defence Technologies | Environmentally Sustainable Manufacturing not elsewhere classified | Expanding Knowledge in Technology | Construction Materials Performance and Processes not elsewhere classified | Sheet Metal Products | Structural Metal Products | Expanding Knowledge in Engineering | Skeletal system and disorders (incl. arthritis)
Publisher: Elsevier BV
Date: 11-2018
Publisher: Springer Science and Business Media LLC
Date: 24-01-2012
Publisher: Elsevier BV
Date: 05-2011
Publisher: Springer Science and Business Media LLC
Date: 08-2012
Publisher: Springer Science and Business Media LLC
Date: 11-03-2016
DOI: 10.1038/LSA.2016.46
Publisher: Hindawi Limited
Date: 2015
DOI: 10.1155/2015/916029
Abstract: An overview on the development of hybrid fundamental solution based finite element method (HFS-FEM) and its application in engineering problems is presented in this paper. The framework and formulations of HFS-FEM for potential problem, plane elasticity, three-dimensional elasticity, thermoelasticity, anisotropic elasticity, and plane piezoelectricity are presented. In this method, two independent assumed fields (intraelement filed and auxiliary frame field) are employed. The formulations for all cases are derived from the modified variational functionals and the fundamental solutions to a given problem. Generation of elemental stiffness equations from the modified variational principle is also described. Typical numerical ex les are given to demonstrate the validity and performance of the HFS-FEM. Finally, a brief summary of the approach is provided and future trends in this field are identified.
Publisher: MDPI AG
Date: 08-11-2018
DOI: 10.3390/IJMS19113513
Abstract: By bending a straight carbon nanotube and bonding both ends of the nanotube, a nanoring (or nano-wheel) is produced. The nanoring system can be driven to rotate by fixed outer nanotubes at room temperature. When placing some atoms at the edge of each outer tube (the stator here) with inwardly radial deviation (IRD), the IRD atoms will repulse the nanoring in their thermally vibration-induced collision and drive the nanoring to rotate when the repulsion due to IRD and the friction with stators induce a non-zero moment about the axis of rotational symmetry of the ring. As such, the nanoring can act as a wheel in a nanovehicle. When the repulsion is balanced with the intertubular friction, a stable rotational frequency (SRF) of the rotor is achieved. The results from the molecular dynamics simulation demonstrate that the nanowheel can work at extremely low temperature and its rotational speed can be adjusted by tuning temperature.
Publisher: Trans Tech Publications, Ltd.
Date: 2013
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMR.634-638.883
Abstract: A new damage-adaptive bone remodeling model, in which an algorithm incorporating both strain and damage stimuli, is developed in this paper. Typically, a human proximal femur model is established to predict the bone mass distribution during bone remodeling process. And human physiology damage-repair cycle is considered in the model. The governing equations of the mathematical model, digesting the predecessors’ ideas, are numerically solved and implemented into ANSYS software via the user interface of finite element algorithm. With the aid of this novel model, the whole healing behavior of human proximal femur is elucidated properly.
Publisher: Science China Press., Co. Ltd.
Date: 2004
DOI: 10.1360/04YE0119
Publisher: Springer Science and Business Media LLC
Date: 12-08-2016
Publisher: Informa UK Limited
Date: 11-01-2007
Publisher: Springer Science and Business Media LLC
Date: 13-04-2016
Publisher: American Scientific Publishers
Date: 02-2011
Publisher: Trans Tech Publications, Ltd.
Date: 2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.462-463.639
Abstract: Structural response of pin-supported metallic foam core sandwich beam is theoretically investigated. Effects of local denting and core strength and interaction of bending and axial stretching are considered in analysis. A rigid-plastic beam-on-foundation is employed to consider local denting deformation. The local denting continues during the overall deformation of sandwich beam. It is shown that upon neglecting the effect of local denting, the load-carrying capacity and energy absorption of sandwich beam may be overestimated, and the normal axial (membrane) force associated with plastic stretching substantially stiffens the sandwich beams.
Publisher: SAGE Publications
Date: 21-11-2018
Abstract: An analytical solution is developed for a simply supported multilayer magneto-electro-elastic plate, which is adhesively bonded by viscoelastic interlayer and subjected to transverse loading. The three-dimensional equations of magneto-electro-elasticity are used to describe the mechanical behavior in each layer of the plate, while the mechanical property of the viscoelastic interlayer is simulated by the standard linear solid model with strain memory effect. The imperfect electric conditions between adjacent layers are considered. Making use of the Fourier series expansion as well as the state-space method, a linear equation system to the solution of the problem considered is derived. By means of the Laplace transformation, the undetermined coefficients contained in the equation system are obtained analytically. The present solution can be used as the benchmark to assess the other numerical solutions. The comparison study shows a trend that the finite element solution converges to the proposed theoretical results as the mesh density increases in contrast to the theoretical solution, the finite element solution is, however, time-consuming, in terms of mesh ision and calculation. In this study, the effects of the time interlayer thickness and interlayer electric coefficient on the mechanical, electric, and magnetic fields are also investigated.
Publisher: Wiley
Date: 2007
DOI: 10.1002/NUM.20221
Publisher: Trans Tech Publications Ltd.
Date: 15-06-2006
Publisher: Springer Science and Business Media LLC
Date: 07-04-2012
Publisher: IOP Publishing
Date: 23-05-2016
DOI: 10.1088/0957-4484/27/27/275701
Abstract: Few-layered black phosphorus materials currently attract much attention due to their special electronic properties. As a consequence, a single-layer black phosphorus (SLBP) nanotube has been theoretically built. The corresponding electronic properties of such a black phosphorus nanotube (BPNT) were also evaluated numerically. However, unlike graphene formed with 2sp(2) covalent carbon atoms, SLBP is formed with 3sp(3) bonded atoms. It means that the structure from SLBP will possess lower Young's modulus and mechanical strength than those of carbon nanotubes. In this study, molecular dynamics simulation is performed to investigate the strength and stability of BPNTs affected by the factors of diameter, length, loading speed and temperature. Results are fundamental for investigating the other physical properties of a BPNT acting as a component in a nanodevice. For ex le, buckling of the BPNT happens earlier than fracture, before which the nanostructure has very small axial strain. For the same BPNT, a higher load speed results in lower critical axial strain and a nanotube with lower axial strain can still be stable at a higher temperature.
Publisher: Elsevier BV
Date: 05-2016
Publisher: Elsevier BV
Date: 10-2006
Publisher: AIP Publishing
Date: 22-04-2015
DOI: 10.1063/1.4918899
Abstract: In this paper, the interfacial mechanical properties of large-sized monolayer graphene attached to a flexible polyethylene terephthalate (PET) substrate are investigated. Using a micro-tensile test and Raman spectroscopy, in situ measurements are taken to obtain the full-field deformation of graphene subjected to a uniaxial tensile loading and unloading cycle. The results of the full-field deformation are subsequently used to identify the status of the interface between the graphene and the substrate as one of perfect adhesion, one showing slide or partial debonding, and one that is fully debonded. The interfacial stress/strain transfer and the evolution of the interface from one status to another during the loading and unloading processes are discussed and the mechanical parameters, such as interfacial strength and interfacial shear strength, are obtained quantitatively demonstrating a relatively weak interface between large-sized graphene and PET.
Publisher: MDPI AG
Date: 11-12-2021
DOI: 10.3390/MD19120702
Abstract: Fucoidans are sulfated, complex, fucose-rich polymers found in brown seaweeds. Fucoidans have been shown to have multiple bioactivities, including anti-inflammatory effects, and are known to inhibit inflammatory processes via a number of pathways such as selectin blockade and enzyme inhibition, and have demonstrated inhibition of inflammatory pathologies in vivo. In this current investigation, fucoidan extracts from Undaria pinnatifida, Fucus vesiculosus, Macrocystis pyrifera, Ascophyllum nodosum, and Laminaria japonica were assessed for modulation of pro-inflammatory cytokine production (TNF-α, IL-1β, and IL-6) by human peripheral blood mononuclear cells (PBMCs) and in a human macrophage line (THP-1). Fucoidan extracts exhibited no signs of cytotoxicity in THP-1 cells after incubation of 48 h. Additionally, all fucoidan extracts reduced cytokine production in LPS stimulated PBMCs and human THP-1 cells in a dose-dependent fashion. Notably, the 5–30 kDa subfraction from Macrocystis pyrifera was a highly effective inhibitor at lower concentrations. Fucoidan extracts from all species had significant anti-inflammatory effects, but the lowest molecular weight subfractions had maximal effects at low concentrations. These observations on various fucoidan extracts offer insight into strategies that improve their efficacy against inflammation-related pathology. Further studies should be conducted to elucidate the mechanism of action of these extracts.
Publisher: Elsevier BV
Date: 2005
Publisher: Elsevier BV
Date: 12-2001
Publisher: Elsevier BV
Date: 07-2007
Publisher: Elsevier BV
Date: 12-1996
Publisher: Elsevier BV
Date: 11-1995
Publisher: SAGE Publications
Date: 05-11-2021
Abstract: As a promising technology to revolutionize traditional manufacturing processes, additive manufacturing has received great attention by virtue of its cost savings, minimum material waste, and tool-less production of complex geometries. The development of fiber-reinforced composites via this technique that exhibits superior strength is thus becoming a hot spot in recent years. This paper focused on the 3 D printing of polylactic acid (PLA) composites with the incorporation of chopped long carbon fiber (CF) with an average length of 4.6 mm via FDM fabrication. By varying its loading quantity, the effect of CF contents on the mechanical, thermal, and morphological properties of these 3 D printed composites was thoroughly investigated. The results showed that with the increase of CF contents, all assessed properties of CF/PLA composites including tensile properties, flexural properties, hardness, and thermal conductivity were effectively improved compared to the neat PLA. Their performance exhibited the same upward-downward-upward trend with the addition of CF. It can be attributed to the mutual influence generated from inter-/intra filament porosities and the high stiffness of CF. Meanwhile, a machine learning technique, Gaussian Process modeling was also introduced in this study for the property prediction of the composites. In comparison with the experimental analysis, the optimal CF content of 6.7 wt% with the best overall performance was predicted using this model, which was very close to the best experimental results at 5 wt% CF.
Publisher: Elsevier BV
Date: 03-2010
Publisher: Wiley
Date: 06-11-2015
Abstract: The control of exciton and triondynamics in bilayer MoS2 is demonstrated, via the comodulations by both temperature and electric field. The calculations here show that the band structure of bilayer MoS2 changes from indirect at room temperature toward direct nature as temperature decreases, which enables the electrical tunability of the K-K direct PL transition in bilayer MoS2 at low temperature.
Publisher: American Chemical Society (ACS)
Date: 10-07-2017
Abstract: The tightly bound biexcitons found in atomically thin semiconductors have very promising applications for optoelectronic and quantum devices. However, there is a discrepancy between theory and experiment regarding the fundamental structure of these biexcitons. Therefore, the exploration of a biexciton formation mechanism by further experiments is of great importance. Here, we successfully triggered the emission of biexcitons in atomically thin MoSe
Publisher: Springer Berlin Heidelberg
Date: 2013
Publisher: Elsevier BV
Date: 11-2003
Publisher: MDPI AG
Date: 16-01-2019
Abstract: As a heterogeneous material, functionally graded material (FGM) behaves as continuously changed material properties in certain directions from one composition to another, and hence it has received much more attention for biomedical applications and thermal protections to achieve innovative functions that conventional homogeneous material cannot accomplish. However, due to the particularly small thickness ratio of coating to substrate in practice, the conventional mesh discretization of the coating region is inefficient. To simplify the meshing procedure and increase the efficiency of analysis, the approximated transfer algorithm based on the concept of finite difference is developed for transferring boundary conditions applied on the coating surface to the interface of coating and substrate. As a result, only the substrate with transferred convection boundary conditions needs to be solved numerically, i.e., by the fundamental-solution based hybrid finite element method (HFS-FEM) with high accuracy and feasible polygonal element construction, in which only integrals along the element boundary are evaluated because of the application of fundamental solutions of the problem as kernel functions of interior approximated fields. Finally, numerical experiments including the single-layered, multi-layered and functionally graded coatings are carried out to verify the accuracy and applicability of the present method.
Publisher: Springer Science and Business Media LLC
Date: 03-2007
Publisher: Elsevier BV
Date: 04-2000
Publisher: Emerald
Date: 15-11-2011
DOI: 10.1108/02644401111179045
Abstract: The purpose of this paper is to present a new special element model for thermal analysis of composites. A hybrid finite element formulation taking the fundamental solution as kernel function is presented in this work for analyzing the thermal behavior and predicting the effective thermal conductivity of fiber‐reinforced composites. A representative volume cell containing single or multiple fibers (or inclusions) is considered to investigate the overall temperature distribution affected by the inclusions and the interactions among them, and to evaluate the effective thermal conductivity of the composites using the presented algorithm with special‐purpose inclusion elements. Numerical ex les are presented to demonstrate the accuracy and applicability of the proposed method in analyzing fiber‐reinforced composites. The independent intra‐element field and frame field, as well as the newly‐developed hybrid functional, make the algorithm versatile in terms of element construction, with the result that the related variational functional involves the element boundary integral only. All numerical results are compared with the solutions from ABAQUS and good agreement is observed for all cases, clearly demonstrating the potential applications of the proposed approach to large‐scale modeling of fiber‐reinforced composites. The usage of special inclusion element can significantly reduce model meshing effort and computing cost, and simultaneously avoid mesh regeneration when the fiber volume fraction is changed. Due to the fact that the established special elements exactly satisfy the interaction of matrix and fiber within the element, only element boundary integrals are involved, thus the algorithm can significantly reduce modeling effort and computing cost with less elements, and simultaneously avoid mesh regeneration when the fiber volume fraction is changed. Based on the special fundamental solution, a newly‐constructed inclusion element is applied to a number of test problems involving unit RVCs with multiple fibers to access the accuracy of the model. The effective thermal conductivity of the composites is evaluated for cases of single and multiple fibers using the average temperatures at certain points on a data‐collection surface. A new algorithm for evaluating effective properties with special elements is presented.
Publisher: Elsevier BV
Date: 10-1996
Publisher: SAGE Publications
Date: 06-07-2015
Abstract: This paper investigates the effects of clustering on the effective transverse thermal conductivity of unidirectional cement composites filled with natural hemp fibers. A typical clustering pattern with four hemp fibers embedded into cement matrix is designed as the representative two-dimensional unit cell, which is taken from the periodic cement composite under consideration, and a clustering degree parameter is introduced to adjust the distance between clustered fibers. For this heterogeneous two-component composite model, distributions of the heat flux component are obtained using finite element simulation for various clustering cases involving different global fiber volume concentrations, clustering degree parameters, and thermal conductivity of both fiber and matrix, to evaluate the effective thermal conductivity of the composite. To further reveal the effects caused by clustered fibers, a random cluster pattern of hemp fibers in the unit cell is considered for comparison with the present regular clustering pattern. Further, a simple theoretical model with specified flexible factor f is developed by matching the theoretical and numerical predictions.
Publisher: Elsevier BV
Date: 07-2014
Publisher: Elsevier BV
Date: 2012
Publisher: Elsevier BV
Date: 2012
Publisher: Elsevier BV
Date: 10-2010
Publisher: IOP Publishing
Date: 06-07-2020
Publisher: Springer Science and Business Media LLC
Date: 29-04-2016
Publisher: Elsevier BV
Date: 10-1990
Publisher: Elsevier BV
Date: 2015
DOI: 10.1016/J.JMBBM.2014.10.009
Abstract: It is important to determine the litude and variation characteristics of piezovoltage in wet bone, which can, in turn, be taken as a basis for studying whether electrical signals induced by external forces can affect the growth of bone cells. This work measured the characteristics of piezoelectric effects under dynamic and static loading. The results show that the variations of piezovoltage in wet bone in both loading and load holding periods follow a stretched exponential relaxation law, and the relaxation time constants of the piezovoltages are much larger than those of dry bone. This finding means that the active time of piezovoltage in wet bone is much longer than that of dry bone. Regardless of the loading and load holding processes, continuously increasing deformation in wet bone caused piezoelectric charges to be continuously induced and increased the dielectric constant of wet bone along with the deformation process. In general, compared with piezovoltage in dry bone, that in wet bone had lower litude and could exist for a longer duration. It can be inferred, therefore, that piezoelectricity might create coupling with the streaming potential in bone by changing the thickness of the double electrode layer.
Publisher: Elsevier BV
Date: 12-2018
Publisher: Springer Science and Business Media LLC
Date: 22-02-2014
Publisher: Elsevier BV
Date: 02-2016
Publisher: Elsevier BV
Date: 06-2019
Publisher: Springer Science and Business Media LLC
Date: 21-05-1999
Publisher: Elsevier BV
Date: 03-2005
Publisher: Elsevier BV
Date: 08-2020
Publisher: IOP Publishing
Date: 26-04-2021
Abstract: Graphene, as a typical two-dimensional material, is popular in the design of nanodevices. The interlayer relative sliding of graphene sheets can significantly affect the effective bending stiffness of the few-layered graphene. For restricting the relative sliding, we adopted the atomic shot peening method to bond the graphene sheets together by ballistic C60 fullerenes from its two surfaces. Collision effects are evaluated via molecular dynamics simulations. Results obtained indicate that the fullerenes’ incident velocity has an interval, in which the graphene sheet can be bonded after collision while no atoms on the fullerenes escaping from the graphene ribbon after collision. The limits of the interval increase with the layer number. Within a few picoseconds of collision, a stable carbon network is produced at an impacted area. The graphene sheets are bonded via the network and cannot slide relatively anymore. Conclusions are drawn to show the way of potential applications of the method in manufacturing a new graphene-based two-dimensional material that has a high out-of-plane bending stiffness.
Publisher: Elsevier BV
Date: 10-2006
Publisher: Elsevier BV
Date: 05-2014
DOI: 10.1016/J.COLSURFB.2013.12.003
Abstract: Synthesis of magnetic Fe3O4/SiO2/graphene-CdTe QDs/chitosan nanocomposites (FGQCs) is investigated with respect to their potential of improving the drug loading content above that of magnetic/fluorescent bifunctional nanocomposites. To evaluate the performance of the FGQCs, their surface morphology was thoroughly assessed. The in vitro interaction between the FGQCs and heptoma cell line smmc-7721 cells was observed for the first time by TEM ultrathin section imaging. At an excitation wavelength of 365 nm, the graphene-QDs exhibit a strong luminescence in aqueous environments. The loading content and entrapment efficiency of the FGQCs were 70% and 50%, respectively. The cytotoxicity of this novel drug delivery system was evaluated in vitro using heptoma cell line smmc-7721 and quantified by the 3-(4,5-dimethylthiazol-z-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The results show that FGQCs are a promising new multifunctional material for drug delivery in biological and medical applications.
Publisher: Elsevier BV
Date: 05-2017
Publisher: IOP Publishing
Date: 29-04-2016
DOI: 10.1088/0957-4484/27/23/235703
Abstract: Similar to a carbon nanotube fabricated from a graphene sheet, a black phosphorus nanotube (BPNT) can also be theoretically produced by curling rectangular single-layer black phosphorus (SLBP). In the present study, the effect of the thermal vibration of atoms on the failure of a BPNT is investigated using molecular dynamics simulations. Two types of double-shell BPNTs obtained by curling the SLBP along its armchair ucker and zigzag directions respectively are involved in simulation. At finite temperature, a bond on the outer shell of the tube is under tension due to both the curvature of the tube and the serious thermal vibration of the atoms. As the length of a bond with such elongation approaches its critical value, i.e. 0.279 nm, or the smallest distance between two nonbonding phosphorus atoms is over 0.389 nm caused by a great variation of the bond angle, the tube fails quickly. The critical stable states of either an armchair or a zigzag BPNT at finite temperature are calculated and compared. To achieve a stable BPNT with high robustness, the tube should have a higher radius or should work at a lower temperature. Only when the BPNT has structural stability does it have the potential application as a nanowire in a future nano electro-mechanical system.
Publisher: Elsevier BV
Date: 09-2009
Publisher: Elsevier BV
Date: 09-2001
Publisher: Springer Science and Business Media LLC
Date: 08-2003
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7CP01274H
Abstract: Due to weak interactions among phosphorus atoms in black phosphorene, a nanotube obtained by curling single-layer black phosphorus is not as stable as a carbon nanotube (CNT) under uniaxial compression.
Publisher: MDPI AG
Date: 19-08-2016
DOI: 10.3390/NANO6080153
Publisher: Elsevier BV
Date: 06-1994
Publisher: American Chemical Society (ACS)
Date: 28-07-2017
Publisher: Elsevier BV
Date: 03-2007
Publisher: Elsevier BV
Date: 05-2010
Publisher: Trans Tech Publications, Ltd.
Date: 2013
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.535-536.405
Abstract: The objective of this work is to study the large deflection of a pin-supported slender geometrically asymmetric metal foam core sandwich beam under transverse loading by a flat punch. Based on the yield criterion for geometrically asymmetric metal foam core sandwich structure, analytical solution for the large deflection of a pin-supported slender sandwich beam is obtained, in which the interaction of bending and stretching induced by large deflection is considered. The finite element results confirm the accuracy of the analytical solutions. The effects of asymmetric factor and boundary condition on the structural response of the asymmetric sandwich beam are discussed in detail. It is shown that the axial stretching induced by large deflection plays an important role in the load-carrying and energy absorption capacities of geometrically asymmetric sandwich structure.
Publisher: Elsevier BV
Date: 02-2016
Publisher: Informa UK Limited
Date: 04-2012
Publisher: Elsevier BV
Date: 07-2012
Publisher: Elsevier BV
Date: 07-2016
Publisher: Springer Science and Business Media LLC
Date: 28-07-2017
DOI: 10.1038/S41598-017-07184-X
Abstract: In a short nanobearing system made from carbon nanotubes, the rotor with high rotational frequency may escape from the stator, which may cause a stability problem to the system of a nanodevice with such a nanobearing. In the present work, nanobearings with tri-walled nanotubes are investigated to reveal the conditions for the moving away of the free inner tube from the high-speed rotating middle tube. Experimental results show that the escape happens when the radii difference between the two rotors is larger than 0.34 nm and the rotational frequency of the middle tube is higher than a critical value. And before the escape occurs, the rotational frequency of the inner tube is lower than this critical value. Due to the radii difference being larger than 0.34 nm, the two rotors are non-coaxial, and the centrifugal force of the inner tube results in strong radial and axial interactions between the edges of the two rotors. When the relative sliding speed is relatively high, an edge of the inner rotor will pass through the potential barrier at the adjacent edge of the middle rotor, and further escape from the middle rotor occurs. The selection of a longer middle rotor with smaller radius can increase the critical rotational frequency of the middle rotor.
Publisher: Elsevier BV
Date: 08-2021
Publisher: Elsevier BV
Date: 1991
Publisher: Elsevier BV
Date: 11-1992
Publisher: Elsevier BV
Date: 02-2011
Publisher: ASME International
Date: 09-2005
DOI: 10.1115/1.1995716
Abstract: This paper presents an overview of the Trefftz finite element and its application in various engineering problems. Basic concepts of the Trefftz method are discussed, such as T-complete functions, special purpose elements, modified variational functionals, rank conditions, intraelement fields, and frame fields. The hybrid-Trefftz finite element formulation and numerical solutions of potential flow problems, plane elasticity, linear thin and thick plate bending, transient heat conduction, and geometrically nonlinear plate bending are described. Formulations for all cases are derived by means of a modified variational functional and T-complete solutions. In the case of geometrically nonlinear plate bending, exact solutions of the Lamé-Navier equations are used for the in-plane intraelement displacement field, and an incremental form of the basic equations is adopted. Generation of elemental stiffness equations from the modified variational principle is also discussed. Some typical numerical results are presented to show the application of the finite element approach. Finally, a brief summary of the approach is provided and future trends in this field are identified. There are 151 references cited in this revised article.
Publisher: Trans Tech Publications, Ltd.
Date: 10-2010
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMR.152-153.73
Abstract: Damage initiation and propagation in unidirectional glass fibre reinforced epoxy matrix composites under tension load were simulated in this study. Cell models with either single fibre or multiple fibres were modelled by extended finite element method (XFEM). The damage progress in the cells was investigated and then the nominal stress-strain curves as well as stress distributions in the fibre and matrix were obtained. Results presented here indicate that the extended finite element method is an effective modelling technique to study the initiation and propagation of a crack along an arbitrary, mesh-independent, solution-dependent path.
Publisher: Springer Science and Business Media LLC
Date: 21-03-2007
Publisher: AIP Publishing
Date: 15-06-2015
DOI: 10.1063/1.4922916
Abstract: A nano universal joint is constructed from curved double-wall carbon nanotubes with a short outer tube as stator and a long inner tube as a rotor. When one end of the rotor is driven (by a rotary motor) to rotate, the same rotational speed but with different rotational direction will be induced at the other end of the rotor. This mechanism makes the joint useful for designing a flexible nanodevice with an adjustable output rotational signal. The motion transmission effect of the universal joint is analyzed using a molecular dynamics simulation approach. In particular, the effects of three factors are investigated. The first factor is the curvature of the stator, which produces a different rotational direction of the rotor at the output end. The second is the bonding conditions of carbon atoms on the adjacent tube ends of the motor and the rotor, sp1 or sp2 atoms, which create different attraction between the motor and the rotor. The third is the rotational speed of the motor, which can be considered as the input signal of the universal joint. It is noted that the rotor's rotational speed is usually the same as that of the motor when the carbon atoms on the adjacent ends of the motor and the rotor are sp1 carbon atoms. When they become the new sp2 atoms, the rotor experiences a jump in rotational speed from a lower value to that of the motor. The mechanism of drops in potential of the motor is revealed. If the carbon atoms on the adjacent ends are sp2 atoms, the rotor rotates more slowly than the motor, whereas the rotational speed is stable when driven by a higher speed motor.
Publisher: World Scientific Pub Co Pte Lt
Date: 12-2013
DOI: 10.1142/S1758825113500373
Abstract: A yield criterion for physically asymmetric sandwich cross-sections is proposed in this paper. Using the yield criterion, analytical solutions for the large deflections of fully cl ed asymmetric slender sandwich beams transversely loaded by a flat punch at the midspan are derived considering the core strength effect and interaction of bending and axial stretching. Finite element (FE) method is employed to predict the large deflection behavior of the sandwich beams. Good agreement is achieved between the analytical predictions and FE results. Effects of asymmetric factor, core strength and loading punch size are also discussed. It is demonstrated that core strength and loading punch size have significant influences on the load-carrying and energy absorption capacities of physically asymmetric metal sandwich beams while the asymmetry effect could be neglected when the deflection exceeds sandwich beam depth.
Publisher: Elsevier BV
Date: 11-2007
Publisher: Elsevier BV
Date: 12-2015
Publisher: Springer Science and Business Media LLC
Date: 02-06-2016
DOI: 10.1038/SREP27338
Abstract: A thermal nanomotor is relatively easy to fabricate and regulate as it contains just a few or even no accessory devices. Since the double-wall carbon nanotube (CNT)-based rotary nanomotor was established in a thermostat, assessment of the rotation of the rotor (inner tube) in the stator (outer tube) of the nanomotor has been critical, but remains challenging due to two factors: the small size of the rotor (only a few nanometers) and the high rotational frequency (»1 GHz). To measure the rotation of the nanomotor, in the present study, a probe test method is proposed. Briefly, the rotor is connected to an end-tube (CNT) through a graphene (GN) nanoribbon. As the CNT-probe is on the trajectory of the end-tube which rotates with the rotor, it will collide with the end-tube. The sharp fluctuation indicating the probe tip deflection can be observed and recorded. As a curly GN by hydrogenation is adopted for connecting the rotor and the end-tube, collision between the end-tube and the probe tip occurs only when the centrifugal force is higher than a threshold which can be considered as the rotational frequency of the rotor being measured by the present method.
Publisher: Elsevier BV
Date: 12-2016
Publisher: IOP Publishing
Date: 21-02-2020
Abstract: Graphene exhibits excellent mechanical properties under atomically thin thickness, which made it very suitable for nanoelectromechanical systems that had high requirements for the thickness of coatings. The epitaxial bilayer graphene on the 4H-SiC (0001) surface presents high stiffness and hardness comparable to diamond. However, due to structural transition occurring at the nanoscale, it is difficult to elucidate reinforcement mechanisms using experimental methods. Here, we applied molecular dynamics simulations to study nanoindentation of epitaxial carbon-film-covered 4H-SiC (0001) surfaces. Because a weak interaction potential existed between graphene layers at indentation depth (h < 0.8 Å) that far smaller than interlayer distance, the epitaxial bilayer graphene does not allow the 4H-SiC to exceed its intrinsic stiffness. When the indentation depth h ≥6.45 Å, the sp
Publisher: Elsevier BV
Date: 03-2004
Publisher: Elsevier BV
Date: 1993
Publisher: Elsevier BV
Date: 09-2007
Publisher: Informa UK Limited
Date: 08-2012
DOI: 10.1080/10255842.2011.565752
Abstract: Pulsed electromagnetic field (PEMF) devices have been used clinically to slow down osteoporosis and accelerate the healing of bone fractures for many years. However, the underlying mechanism by which bone remodelling under PEMF is regulated remains poorly understood. In this paper, a mathematical model of bone cell population of bone remodelling under PEMF at cellular level is developed to address this issue for the first time. On the basis of this model and control theory, parametric study of control mechanisms is carried out and a number of possible control mechanisms are identified. These findings will help further the understanding of bone remodelling under PEMF and advance therapies and pharmacological developments in clinical trials.
Publisher: Elsevier BV
Date: 12-2007
Publisher: Trans Tech Publications, Ltd.
Date: 2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.462-463.720
Abstract: Metallic sandwich plates have been widely used in blast-resistance structures due to the excellent capacity of energy absorption. In this work, dynamic response of square honeycomb sandwich plates is investigated using LS-DYNA. The effect of mass of TNT charge on the deformation and on internal energy of square honeycomb sandwich plate is numerically analyzed. The relationship of deflection, as well as internal energy and the mass of TNT charge is obtained. The performance of square honeycomb sandwich plate is compared with monolithic solid plate with the same mass and blast loading. During the response of sandwich plate, the deformation includes local dent of upper face sheet, overall bending and stretching of both face sheets and buckling of square honeycomb core while the deformation of monolithic solid plate is involved in overall bending and stretching. It denotes that square honeycomb sandwich plate has better capacity of resistance-deformation and energy absorption than that of monolithic solid plate with the same mass and the same blast loading.
Publisher: Elsevier BV
Date: 09-2006
Publisher: Springer Science and Business Media LLC
Date: 10-2009
Publisher: Elsevier BV
Date: 07-2014
Publisher: IOP Publishing
Date: 18-05-2011
DOI: 10.1088/0957-4484/22/26/265714
Abstract: Using the theory of surface elasticity, we investigate the mechanical properties of nanoporous materials. The classical theory of porous materials is modified to account for surface effects, which become increasingly important as the characteristic sizes of microstructures shrink to nanometers. First, a refined Timoshenko beam model is presented to predict the effective elastic modulus of nanoporous materials. Then the surface effects on the elastic microstructural buckling behavior of nanoporous materials are examined. In particular, nanoporous gold is taken as an ex le to illustrate the application of the proposed model. The results reveal that both the elastic modulus and the critical buckling behavior of nanoporous materials exhibit a distinct dependence on the characteristic sizes of microstructures, e.g. the average ligament width.
Publisher: Elsevier BV
Date: 1996
Publisher: SAGE Publications
Date: 08-05-2014
Abstract: The post-buckling problem of a large deformed beam is analyzed using the canonical dual finite element method (CD-FEM). The feature of this method is to choose correctly the canonical dual stress so that the original non-convex potential energy functional is reformulated in a mixed complementary energy form with both displacement and stress fields, and a pure complementary energy is explicitly formulated in finite dimensional space. Based on the canonical duality theory and the associated triality theorem, a primal–dual algorithm is proposed, which can be used to find all possible solutions of this non-convex post-buckling problem. Numerical results show that the global maximum of the pure-complementary energy leads to a stable buckled configuration of the beam, while the local extrema of the pure-complementary energy present unstable deformation states. We discovered that the unstable buckled state is very sensitive to the number of total elements and the external loads. Theoretical results are verified through numerical ex les and some interesting phenomena in post-bifurcation of this large deformed beam are observed.
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1CP03481B
Abstract: A method is proposed for designing tunable chiral nano-networks using partly hydrogenated graphene ribbons and carbon nanotubes (CNTs).
Publisher: Elsevier BV
Date: 10-2008
Publisher: SPIE
Date: 09-08-2013
DOI: 10.1117/12.2029520
Publisher: Elsevier BV
Date: 10-2003
Publisher: Emerald
Date: 30-09-2014
Abstract: – The purpose of this paper is to develop a heuristic method for topology optimization of a continuum with bi-modulus material which is frequently occurred in practical engineering. – The essentials of this model are as follows: First, the original bi-modulus is replaced with two isotropic materials to simplify structural analysis. Second, the stress filed is adopted to calculate the effective strain energy densities (SED) of elements. Third, a floating reference interval of SED is defined and updated by active constraint. Fourth, the elastic modulus of an element is updated according to its principal stresses. Final, the design variables are updated by comparing the local effective SEDs and the current reference interval of SED. – Numerical ex les show that the ratio between the tension modulus and the compression modulus of the bi-modulus material in a structure has a significant effect on the final topology design, which is different from that in the same structure with isotropic material. In the optimal structure, it can be found that the material points with the higher modulus are reserved as much as possible. When the ratio is far more than unity, the material can be considered as tension-only material. If the ratio is far less than unity, the material can be considered as compression-only material. As a result, the topology optimization of continuum structures with tension-only or compression-only materials can also be solved by the proposed method. – The value of this paper is twofold: the bi-modulus material layout optimization in a continuum can be solved by the method proposed in this paper, and the layout difference between the structure with bi-modulus material and the same structure but with isotropic material shows that traditional topology optimization result could not be suitable for a real bi-modulus layout design project.
Publisher: IOP Publishing
Date: 18-12-2019
Abstract: By curving a rectangular diamondene, an sp
Publisher: Elsevier BV
Date: 12-2017
DOI: 10.1016/J.SCITOTENV.2017.05.074
Abstract: The cation exchange capacity (CEC) is one of the most important soil properties as it influences soil's ability to hold essential nutrients. It also acts as an index of structural resilience. In this study, we demonstrate a method for 3-dimensional mapping of CEC across a study field in south-west Spain. We do this by establishing a linear regression (LR) between the calculated true electrical conductivity (σ - mS/m) and measured CEC (cmol(+)/kg) at various depths. We estimate σ by inverting Veris-3100 data (EC
Publisher: Elsevier BV
Date: 2017
Publisher: Elsevier BV
Date: 12-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5NR00877H
Abstract: The self-assembly of nanomaterials into three-dimensional hierarchical structures is a fundamental step impacting a large number of synthetic and natural processes. These range from the scalable fabrication of nano-devices such as batteries, sensors and third generation solar cells to the uptake and accumulation of particulate pollution in the lung alveoli. Here, we show that the Dynamic behavior of ultra-fine particles (UFP < 100 nm) erges significantly from that of sub- and micro equivalents. For freely diffusing bodies, this leads to the formation of stochastically reproducible films that approach the morphology and density of ballistically deposited ones. A novel deposition mechanism and regime are proposed that successfully capture the full spectrum of size-dependent self-assembly dynamics. These findings are a significant step toward the engineering of scalable parallel nano-fabrication approaches, and the understanding of the interaction of unbound nanostructures with their surrounding.
Publisher: Elsevier BV
Date: 08-2021
Publisher: Elsevier BV
Date: 2005
Publisher: Elsevier BV
Date: 06-2006
Publisher: Elsevier BV
Date: 10-2011
Publisher: IOP Publishing
Date: 11-11-2022
Abstract: Graphyne nanotube (GNT), as a promising one-dimensional carbon material, attracts extensive attention in recent years. However, the synthesis of GNT is still challenging even in the laboratory. This study reveals the feasibility of fabricating a GNT by self-assembling a monolayer graphyne (GY) ribbon on a carbon nanotube (CNT) via theoretical and numerical analysis. Triggered by the van der Waals force from the CNT, a GY ribbon near the tube first winds upon the tube and then conditionally self-assembles to form a GNT. The self-assembly process and result are heavily influenced by the ambient temperature, which indicates the thermal vibration of the nanosystem. Molecular dynamic simulation results address the temperature range conducive to successful self-assembly. Different types of GNTs, e.g. α -, β -, and γ -GNTs with specified chirality (armchair, zigzag, and chiral), length, and radius, can be obtained via self-assembly by controlling the geometry of the GY ribbons and temperature. The present theoretical understanding is helpful for fabricating GNTs with predefined morphology.
Publisher: Elsevier BV
Date: 12-2018
Publisher: The Optical Society
Date: 09-2006
DOI: 10.1364/AO.45.006551
Abstract: We present a new method of regional identification, partition, and integral (RIPI) phase unwrapping for processing images, especially those with low quality, obtained from moiré interferometry experiments. By introducing the principle of preorder traversal of a general tree in data structures and then by applying the idea of a regional integral, the proposed method makes regional partition and phase evaluation much easier and more accurate, and it also overcomes the common faults that can occur when conventional approaches, such as line defects, are used. Ex les are given to demonstrate the advantage and applicability of the proposed RIPI method when processing experimental images. It is shown that the proposed method works well for global phase distribution, and, at the same time, local mutational information is preserved and limited to its vicinity without affecting other parts.
Publisher: Elsevier BV
Date: 11-1992
Publisher: Elsevier BV
Date: 08-2004
Publisher: MDPI AG
Date: 10-08-2022
Abstract: Polyethylene terephthalate (PET) is one of the most commonly used substrate materials in the field of flexible electronics, and its stress-induced birefringence often has a detrimental effect on the optical properties of the device. Therefore, a deep and systematic understanding of the stress-optical properties of PET films is crucial for device design and manufacture. The photoelastic method is a direct optical measurement technique based on the stress-induced birefringence effect of materials, which has the advantages of being nondestructive and noncontact. In this work, the photoelastic method was used to quantitatively characterize the anisotropy of the stress-optical properties of PET films under the uniaxial stress state. First, a self-built reflection-transmission coaxial bidirectional photoelasticity measurement system was developed by means of a combination of transmission and reflection photoelasticity. Then, the stress-optical coefficients and isoclinic angles of PET films with different stretching angles were measured. Finally, the linear combinations of the photoelastic tensor components and refractive-index-related parameters were determined by fitting the analytical relationship between the stress-optical coefficients and isoclinic angles.
Publisher: Elsevier BV
Date: 04-2020
Publisher: Elsevier BV
Date: 12-2012
Publisher: American Chemical Society (ACS)
Date: 07-11-2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8CP06013D
Abstract: A nano rotation–translation convertor with a deformable rotor is presented, and the dynamic responses of the system are investigated considering the coupling among the van der Waals (vdW), centrifugal and frictional forces.
Publisher: Elsevier BV
Date: 05-1995
Publisher: Springer Science and Business Media LLC
Date: 11-10-2017
DOI: 10.1038/S41598-017-13328-W
Abstract: A nanotube from single-layer black phosphorus (BP) has never been discovered in experiments. The present study proposed a method for the fabrication of a BP nanotube (BPNT) from a parallelogram nanoribbon self-assembled on a carbon nanotube (CNT). The nanoribbon has a pair of opposite sides along the third principal direction. According to the numerical simulation via molecular dynamics approach, we discover that a wider BP nanoribbon can form into a series of chiral nanotube by self-assembly upon CNTs with different radii. The radius of a BPNT from the same ribbon has a wide range, and depends on both geometry of the ribbon and the CNT. One can obtain a BPNT with the specified radius by placing the ribbon nearby a given CNT. The method provides a clue for potential fabrication of BPNTs.
Publisher: Elsevier BV
Date: 09-2010
Publisher: Wiley
Date: 2005
DOI: 10.1002/NME.1333
Publisher: Springer Science and Business Media LLC
Date: 2000
Publisher: Elsevier BV
Date: 10-2015
Publisher: Elsevier BV
Date: 10-2004
Publisher: Elsevier BV
Date: 08-1995
Publisher: IOP Publishing
Date: 25-11-2014
DOI: 10.1088/0957-4484/25/50/505701
Abstract: Rotation of the inner tube in a double-walled carbon nanotube (DWCNT) system with a fixed outer tube is investigated and found to be inducible by a relatively high uniform temperature (say, 300 K). We also found the mechanism of a gradientless temperature-driven rotating motor lies in the inner tube losing its geometric symmetry in a high-temperature field. This mechanism can be taken as a guide for designing a motor from such a bi-tube system. Using a computational molecular dynamics (CMD) approach and the adaptive intermolecular reactive empirical bond order (AIREBO) potential, the dynamic behavior of a bi-tube system subjected to uniformly distributed temperature is studied. In particular, the effects of environmental temperature, boundary conditions of the outer tube, and intertube gap on the dynamic behavior of the bi-tube system are investigated. Numerical ex les show that a bi-tube system with the inner tube having 0.335 nm of interlayer gap produces the highest rotational speed.
Publisher: Elsevier BV
Date: 11-2015
Publisher: Wiley
Date: 12-01-2007
DOI: 10.1002/CNM.978
Publisher: Elsevier BV
Date: 03-1993
Publisher: Informa UK Limited
Date: 02-2006
Publisher: Springer Science and Business Media LLC
Date: 12-08-2010
Publisher: Elsevier BV
Date: 07-2002
Publisher: Elsevier BV
Date: 12-2002
Publisher: Springer Science and Business Media LLC
Date: 10-2003
Publisher: Elsevier BV
Date: 10-1999
Publisher: Elsevier BV
Date: 09-2004
Publisher: Research Square Platform LLC
Date: 17-04-2023
Publisher: American Chemical Society (ACS)
Date: 08-09-2014
DOI: 10.1021/NN503893J
Abstract: Phosphorene is a new family member of two-dimensional materials. We observed strong and highly layer-dependent photoluminescence in few-layer phosphorene (two to five layers). The results confirmed the theoretical prediction that few-layer phosphorene has a direct and layer-sensitive band gap. We also demonstrated that few-layer phosphorene is more sensitive to temperature modulation than graphene and MoS2 in Raman scattering. The anisotropic Raman response in few-layer phosphorene has enabled us to use an optical method to quickly determine the crystalline orientation without tunneling electron microscopy or scanning tunneling microscopy. Our results provide much needed experimental information about the band structures and exciton nature in few-layer phosphorene.
Publisher: Elsevier BV
Date: 10-2018
Publisher: Springer Science and Business Media LLC
Date: 06-2016
Publisher: Springer Science and Business Media LLC
Date: 10-2009
Publisher: MDPI AG
Date: 16-12-2014
Publisher: Elsevier BV
Date: 02-1996
Publisher: MDPI AG
Date: 21-01-2019
DOI: 10.3390/MA12020321
Abstract: This article investigated the microstructure of Ti6Al4V that was fabricated via selective laser melting specifically, the mechanism of martensitic transformation and relationship among parent β phase, martensite (α’) and newly generated β phase that formed in the present experiments were elucidated. The primary X-ray diffraction (XRD), transmission electron microscopy (TEM) and tensile test were combined to discuss the relationship between α’, β phase and mechanical properties. The average width of each coarse β columnar grain is 80–160 μm, which is in agreement with the width of a laser scanning track. The result revealed a further relationship between β columnar grain and laser scanning track. Additionally, the high dislocation density, stacking faults and the typical ( 10 1 ¯ 1 ) twinning were identified in the as-built s le. The twinning was filled with many dislocation lines that exhibited apparent slip systems of climbing and cross-slip. Moreover, the α + β phase with fine dislocation lines and residual twinning were observed in the stress relieving s le. Furthermore, both as-built and stress-relieved s les had a better homogeneous density and finer grains in the center area than in the edge area, displaying good mechanical properties by Feature-Scan. The α’ phase resulted in the improvement of tensile strength and hardness and decrease of plasticity, while the newly generated β phase resulted in a decrease of strength and enhancement of plasticity. The poor plasticity was ascribed to the different print mode, remained support structures and large thermal stresses.
Publisher: American Chemical Society (ACS)
Date: 04-09-2019
Abstract: Advances in cardiovascular materials have brought us improved artificial vessels with larger diameters for reducing adverse responses that drive acute thrombosis and the associated complications. Nonetheless, the challenge is still considerable when applying these materials in small-diameter blood vessels. Here we report the biomimetic design of an acellular small-diameter vascular graft with specifically lamellar nanotopography on the luminal surface via a modified freeze-cast technique. The experimental findings verify that the well-designed nanolamellar structure is able to inhibit the adherence and activation of platelets, induce oriented growth of endothelial cells, and eventually remodel a neovessel to maintain long-term patency
Publisher: Springer Science and Business Media LLC
Date: 04-03-2017
Publisher: MDPI AG
Date: 27-10-2021
DOI: 10.3390/PH14111091
Abstract: Opioids are widely used as therapeutic agents against moderate to severe acute and chronic pain. Still, these classes of analgesic drugs have many potential limitations as they induce analgesic tolerance, addiction and numerous behavioural adverse effects that often result in patient non-compliance. As opium and opioids have been traditionally used as painkillers, the exact mechanisms of their adverse reactions over repeated use are multifactorial and not fully understood. Older adults suffer from cancer and non-cancer chronic pain more than younger adults, due to the physiological changes related to ageing and their reduced metabolic capabilities and thus show an increased number of adverse reactions to opioid drugs. All clinically used opioids are μ-opioid receptor agonists, and the major adverse effects are directly or potentially connected to this receptor. Multifunctional opioid ligands or peripherally restricted opioids may elicit fewer adverse effects, as shown in preclinical studies, but these results need reproducibility from further extensive clinical trials. The current review aims to overview various mechanisms involved in the adverse effects induced by opioids, to provide a better understanding of the underlying pathophysiology and, ultimately, to help develop an effective therapeutic strategy to better manage pain.
Publisher: Elsevier BV
Date: 10-2004
Publisher: Springer Science and Business Media LLC
Date: 09-2005
Publisher: Elsevier BV
Date: 07-2021
Publisher: AIP Publishing
Date: 16-06-2015
DOI: 10.1063/1.4922713
Abstract: A rotational transmission system from coaxial carbon nanotubes (CNTs) is investigated using a computational molecular dynamics approach. The system consists of a motor from a single-walled carbon nanotube and a bearing from a double-walled carbon nanotube. The motor has a high fixed rotational frequency and the two ends of the outer tube in the bearing are fixed. The inner tube in the bearing works as a rotor. Because of the interlayer friction in the bearing, configurations of the joint between the adjacent ends of motor and rotor have significant effects on rotational transmission properties. Four factors are considered in simulation, i.e., the bonding types of atoms (sp1 and sp2) on the ends of motor and rotor, the difference between motor and rotor radii, the rotational speed of motor, and the environmental temperature. It is found that the synchronous transmission happens if the sp1 atoms on the jointed ends of motor and rotor are bonded each other and become new sp2 atoms. Therefore, the lower difference between radii of motor and rotor, higher temperature of environment leads to synchronous rotational transmission easily. If the environmental temperature is too low (e.g., & K), the end of motor adjacent to rotor is easily under buckling and new sp2 atoms appear, too. With capped CNTs or higher radii difference between rotor and motor at an appropriate temperature, a stable asynchronous rotation of rotor can be generated, and the rotor's frequency varying linearly with motor's frequency between 230 and 270 GHz. A multi-signal transmission device combined with oscillating and rotational motion is proposed for motor and stator shares a same size in radius.
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5RA10470J
Abstract: Temperature effects on a motion transmission system made from coaxial carbon nanotubes ((5, 5) motor and (5, 5)/(10, 10)/(1, 15) converter) is studied. Changing the environmental temperature can induce mode conversion of the rotation of (5, 5) rotor.
Publisher: IOP Publishing
Date: 10-2010
Publisher: Elsevier BV
Date: 10-2006
Publisher: Springer Science and Business Media LLC
Date: 12-10-2016
DOI: 10.1038/SREP35157
Abstract: Graphene is an active element used in the design of nano-electro-mechanical systems (NEMS) owing to its excellent in-plane physical properties on mechanical, electric and thermal aspects. Considering a component requiring negative Poisson’s ratio in NEMS, a graphene kirigami (GK) containing periodic re-entrant honeycombs is a natural option. This study demonstrates that a GK with specific auxetic property can be obtained by adjusting the sizes of its honeycombs. Using molecular dynamics experiments, the size effects on the auxetic behaviour of GK are investigated. In some cases, the auxetic difference between the hydrogenated GK and continuum kirigami (CK) is negligible, in which the results from macro CK can be used to predict auxetic behaviour of nano kirigami. Surface effect of GK is demonstrated from two aspects. One is to identify the difference of mechanical responses between the pure carbon GK and the hydrogenated GK at same geometry and loading condition. Another is from the difference of mechanical responses between the GK model and the CK model under same loading condition and geometric configuration. Generally, surface energy makes the GK possess higher variation of auxetic behaviour. It also results in higher modulus for the GK as comparing with that of the CK.
Publisher: Springer Science and Business Media LLC
Date: 17-10-2009
Publisher: Elsevier BV
Date: 05-1995
Publisher: Elsevier BV
Date: 2018
Publisher: Springer Science and Business Media LLC
Date: 17-01-2018
DOI: 10.1038/S41598-017-18789-7
Abstract: For a resonator-based nano-balance, the capability of capturing a nanoparticle is essential for it to measure the mass of the particle. In the present study, a cl ed-cl ed nanobeam from a Boron-Nitride and Carbon (BNC) nanotube acts as the nano-balance, and a fullerene, e.g., C 60 , is chosen as the particle, and the capturing capability is quantitatively estimated by the minimal escape velocity (MEV) of the fullerene from the nanobeam after collision. When centrally colliding with the nanobeam, the escape of fullerene depends on both incidence of fullerene and temperature of the system. When the colliding in the Boron-Nitride (BN) area of the beam surface, the nanoball escapes easier than that at the carbon area. The MEV of the nanoball is lower at higher temperature. As the nanoball sometimes slides for a few pica-seconds on the beam surface before being bounced out, the nanoball can escape only when the beam surface can provide the nanoball enough kinetic energy to overcome the van der Waals interaction between them. The capturing capability of the nano-balance can, thus, be improved by reducing the initial kinetic energy of the system.
Publisher: Elsevier BV
Date: 05-2009
Publisher: Informa UK Limited
Date: 2012
Publisher: Springer Science and Business Media LLC
Date: 31-10-2013
DOI: 10.1038/SREP03102
Publisher: Springer Science and Business Media LLC
Date: 08-04-2015
DOI: 10.1038/SREP09568
Abstract: It is well known that when coarse-grained metals undergo severe plastic deformation to be transformed into nano-grained metals, their ductility is reduced. However, there are no ductile fracture criteria developed based on grain refinement. In this paper, we propose a new relationship between ductile fracture and grain refinement during deformation, considering factors besides void nucleation and growth. Ultrafine-grained Al-Mg alloy sheets were fabricated using different rolling techniques at room and cryogenic temperatures. It is proposed for the first time that features of the microstructure near the fracture surface can be used to explain the ductile fracture post necking directly. We found that as grains are refined to a nano size which approaches the theoretical minimum achievable value, the material becomes brittle at the shear band zone. This may explain the tendency for ductile fracture in metals under plastic deformation.
Publisher: Elsevier BV
Date: 07-2004
Publisher: WIT Press
Date: 22-10-2014
DOI: 10.2495/BEM360061
Publisher: Elsevier BV
Date: 04-2013
Publisher: MDPI AG
Date: 27-08-2021
DOI: 10.3390/MOLECULES26175199
Abstract: The molecular dynamics (MD) method is used to investigate the influence of the shielding gas on the dynamic behavior of the heterogeneous rotation transmission nano-system (RTS) built on carbon nanotubes (CNTs) and boron nitride nanotube (BNNT) in a helium environment. In the heterogeneous RTS, the inner CNT acts as a rotor, the middle BNNT serves as a motor, and the outer CNT functions as a stator. The rotor will be actuated to rotate by the motor due to the interlayer van der Waals effects and the end effects. The MD simulation results show that, when the gas density is lower than a critical range, a stable signal of the rotor will arise on the output and the rotation transmission ratio (RRT) of RTS can reach 1.0, but as the gas density is higher than the critical range, the output signal of the rotor cannot be stable due to the sharp drop of the RRT caused by the large friction between helium and the RTS. The greater the motor input signal of RTS, the lower the critical working helium density range. The results also show that the system temperature and gas density are the two main factors affecting the RTS transmission behavior regardless of the size of the simulation box. Our MD results clearly indicate that in the working temperature range of the RTS from 100 K to 600 K, the higher the temperature and the lower the motor input rotation frequency, the higher the critical working helium density range allows.
Publisher: Elsevier BV
Date: 11-2000
Publisher: Elsevier BV
Date: 02-2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D3NR01116J
Abstract: Reducing the external size to the nanoscale enables ZIF-62 glass to achieve theoretical strength and large deformability.
Publisher: Elsevier BV
Date: 04-2007
Publisher: Elsevier BV
Date: 03-1996
Publisher: Elsevier BV
Date: 05-2004
Publisher: Elsevier BV
Date: 06-2014
Publisher: Elsevier BV
Date: 12-2022
Publisher: MDPI AG
Date: 08-2022
DOI: 10.3390/MA15155298
Abstract: Determining the quality of Ti-6Al-4V parts fabricated by selective laser melting (SLM) remains a challenge due to the high cost of SLM and the need for expertise in processes and materials. In order to understand the correspondence of the relative density of SLMed Ti-6Al-4V parts with process parameters, an optimized extreme gradient boosting (XGBoost) decision tree model was developed in the present paper using hyperparameter optimization with the GridsearchCV method. In particular, the effect of the size of the dataset for model training and testing on model prediction accuracy was examined. The results show that with the reduction in dataset size, the prediction accuracy of the proposed model decreases, but the overall accuracy can be maintained within a relatively high accuracy range, showing good agreement with the experimental results. Based on a small dataset, the prediction accuracy of the optimized XGBoost model was also compared with that of artificial neural network (ANN) and support vector regression (SVR) models, and it was found that the optimized XGBoost model has better evaluation indicators such as mean absolute error, root mean square error, and the coefficient of determination. In addition, the optimized XGBoost model can be easily extended to the prediction of mechanical properties of more metal materials manufactured by SLM processes.
Publisher: Elsevier BV
Date: 08-2004
Publisher: Springer Science and Business Media LLC
Date: 28-10-2015
Publisher: Elsevier BV
Date: 03-2013
Publisher: Hindawi Limited
Date: 2014
DOI: 10.1155/2014/947205
Abstract: Aiming at the large scale numerical simulation of particle reinforced materials, the concept of local Eshelby matrix has been introduced into the computational model of the eigenstrain boundary integral equation (BIE) to solve the problem of interactions among particles. The local Eshelby matrix can be considered as an extension of the concepts of Eshelby tensor and the equivalent inclusion in numerical form. Taking the subdomain boundary element method as the control, three-dimensional stress analyses are carried out for some ellipsoidal particles in full space with the proposed computational model. Through the numerical ex les, it is verified not only the correctness and feasibility but also the high efficiency of the present model with the corresponding solution procedure, showing the potential of solving the problem of large scale numerical simulation of particle reinforced materials.
Publisher: IOP Publishing
Date: 04-2016
Publisher: World Scientific Pub Co Pte Lt
Date: 08-2015
DOI: 10.1142/S0219876215400125
Abstract: In this paper, unidirectional fiber reinforced composites with periodic square array of circular and hexagonal fibers is studied by a novel fundamental-solution-based hybrid finite element model. Due to the periodicity of composites, a representative unit cell containing a single fiber with circular or hexagonal cross section is taken into consideration and analyzed using the proposed hybrid finite element model. In the present numerical model, special polygonal fiber elements with arbitrary number of sides are developed by coupling the independent element interior and frame displacement fields. The element interior displacement fields are approximated by the combination of fundamental solutions to prior satisfy the governing equation of the problem, so that the domain integral appeared in the weak-form hybrid functional in terms of dual variables is converted into boundary integrals. Independently the element frame displacement fields are approximated by the conventional shape functions to guarantee the continuity of adjacent elements. Following this, special polygonal fiber elements are constructed to reduce mesh effort in the fiber region and achieve good accuracy with fewer elements. Finally, numerical tests are carried out for assessing the performance of the present special elements.
Publisher: Springer Science and Business Media LLC
Date: 15-05-2012
Publisher: Springer Science and Business Media LLC
Date: 13-10-2013
Publisher: Elsevier BV
Date: 11-1996
Publisher: Trans Tech Publications, Ltd.
Date: 05-2014
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMM.553.745
Abstract: A finite element model is developed in this paper to simulate the perforation of aluminium foam sandwich panels subjected to high velocity impact using the commercial finite element analysis software LS-DYNA. The aluminum foam core is governed by the material model of crushable foam materials, while both aluminium alloy face sheets are modeled with the simplified Johnson-Cook material model. A non-linear cohesive contact model is employed to simulate failure between adjacent layers, and an erosion contact model is used to define contact between bullets and panels. All components in the model are meshed with 3D solid element SOLID 164. The developed finite element model is used to simulate the dynamic response of an aluminium foam sandwich panel subjected to projectile impact at velocity ranging from 76 m/s to 187m/s. The relationship between initial velocity and exit velocity of the projectile obtained from numerical modelling agrees well with that obtained from experimental study, demonstrating the effectiveness of the developed finite element model in simulating perforation of sandwich panels subjected to high velocity impact.
Publisher: Public Library of Science (PLoS)
Date: 10-10-2016
Publisher: Springer Science and Business Media LLC
Date: 05-2011
Publisher: Informa UK Limited
Date: 10-2012
Publisher: Elsevier BV
Date: 03-2003
Publisher: Trans Tech Publications, Ltd.
Date: 2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.462-463.349
Abstract: The resistance of metallic sandwich plates to blast loading is studied in this work. Two typical cores, i.e. trapezoidal plate core and metallic foam core are considered in the analysis. The normal and longitudinal compressive stresses of the trapezoidal plate core are analytically and numerically obtained. Large deflection and resistance of metallic sandwich plates to blast loading are numerically analyzed. The results are compared with that of monolithic solid plates made of the same material and having equivalent weight. It is shown that the well-designed sandwich plates possess higher resistance to blast loading than monolithic solid plates.
Publisher: Elsevier BV
Date: 11-2016
Publisher: World Scientific Pub Co Pte Lt
Date: 12-2012
DOI: 10.1142/S0219519412500273
Abstract: To understand the physiology of tissue burns for successful clinical treatment, it is important to investigate the thermal behavior of human skin tissue subjected to heat injury. In this paper, a fundamental solution-based hybrid finite element formulation is proposed for numerically simulating steady-state temperature distribution inside a multilayer human skin tissue during burning. In the present approach, since only element boundary integrals are involved, the computational dimension is reduced by one as the fundamental solutions used analytically satisfies the bioheat governing equation. Further, in multi-layer skin modeling, the burn is applied via a heating disk at constant temperature on a part of the epidermal surface of the skin tissue. Numerical results from the proposed approach are firstly verified by comparing them with exact solutions of a simple single-layered model or the results from conventional finite element method. Thereafter, a sensitivity analysis is carried out to reveal the effect of biological and environmental parameters on temperature distribution inside the skin tissue subjected to heat injury.
Publisher: Elsevier BV
Date: 1993
Publisher: Wiley
Date: 2007
DOI: 10.1002/NME.1810
Publisher: Elsevier BV
Date: 11-2009
Publisher: EDP Sciences
Date: 20-10-2015
DOI: 10.1051/MECA/2014069
Publisher: American Chemical Society (ACS)
Date: 04-02-2016
Abstract: We report a trion (charged exciton) binding energy of ∼162 meV in few-layer phosphorene at room temperature, which is nearly 1-2 orders of magnitude larger than those in two-dimensional (2D) transition metal dichalcogenide semiconductors (20-30 meV) and quasi-2D quantum wells (∼1-5 meV). Such a large binding energy has only been observed in truly one-dimensional (1D) materials such as carbon nanotubes, whose optoelectronic applications have been severely hindered by their intrinsically small optical cross sections. Phosphorene offers an elegant way to overcome this hurdle by enabling quasi-1D excitonic and trionic behaviors in a large 2D area, allowing optoelectronic integration. We experimentally validated the quasi-1D nature of excitonic and trionic dynamics in phospherene by demonstrating completely linearly polarized light emission from excitons and trions in few-layer phosphorene. The implications of the extraordinarily large trion binding energy in a higher-than-one-dimensional material are far-reaching. It provides a room-temperature 2D platform to observe the fundamental many-body interactions in the quasi-1D region.
Publisher: Authorea, Inc.
Date: 05-10-2023
Publisher: MDPI AG
Date: 18-10-2022
DOI: 10.3390/ENDOCRINES3040055
Abstract: Obesity produces a systemic low-grade inflammation associated with many adverse health conditions and, as we recently learned, with complications of COVID-19. Functional studies in animal models have demonstrated that asperuloside, an iridoid glycoside found in many medicinal plants, has produced promising anti-obesity results. However, the safety profile and the anti-inflammatory properties of asperuloside remain unknown. Here, we confirmed the previously reported anti-obesity properties of asperuloside, and, importantly, we performed toxicity studies assessing cell viability providing a dose reference for future animal experiments. Asperuloside significantly reduced blood levels of leptin and the mRNA levels of orexigenic peptides, such as NPY and AgRP in mice consuming HFD, with no effect on mice eating a standard chow diet. In addition, our results indicate that ASP reduced both hypothalamic and hepatic mRNA levels of pro-inflammatory cytokines such as IL-1, IL-6 and TNF-α as well as the blood levels of plasminogen activator inhibitor-1 (PAI-1), which are known to play a major role in the development of insulin resistance and cardiovascular complications. Collectively, our findings suggest that asperuloside is a safe compound for long-term use in animal models and that it reduces the elevated levels of pro-inflammatory cytokines occurring in obesity.
Publisher: Elsevier BV
Date: 03-2020
Publisher: Springer Science and Business Media LLC
Date: 29-12-2011
Publisher: Elsevier BV
Date: 12-1995
Publisher: Elsevier BV
Date: 05-2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7CP04427E
Abstract: A string of fullerenes is used for generating a nanotube by self-assembly of a black phosphorus (BP) nanoribbon at a temperature of 8 K.
Publisher: Elsevier BV
Date: 06-2004
Publisher: Elsevier BV
Date: 05-2007
Publisher: Elsevier BV
Date: 02-2010
Publisher: IOP Publishing
Date: 04-2011
Publisher: American Chemical Society (ACS)
Date: 26-04-2017
Publisher: Elsevier BV
Date: 07-2001
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6CP04359C
Abstract: The mechanism of the rotation measurement of the nanomotor according to the deflection of a probe tip.
Publisher: MDPI AG
Date: 16-01-2015
DOI: 10.3390/IJMS16012001
Publisher: Springer Science and Business Media LLC
Date: 03-2014
Publisher: Elsevier BV
Date: 12-1999
Publisher: Emerald
Date: 19-07-2011
DOI: 10.1108/02644401111141028
Abstract: The purpose of this paper is to develop a hybrid‐Trefftz (HT) finite element model (FEM) for simulating heat conduction in nonlinear functionally graded materials (FGMs) which can effectively handle continuously varying properties within an element. In the proposed model, a T‐complete set of homogeneous solutions is first derived and used to represent the intra‐element temperature fields. As a result, the graded properties of the FGMs are naturally reflected by using the newly developed Trefftz functions (T‐complete functions in some literature) to model the intra‐element fields. The derivation of the Trefftz functions is carried out by means of the well‐known Kirchhoff transformation in conjunction with various variable transformations. The study shows that, in contrast to the conventional FEM, the HT‐FEM is an accurate numerical scheme for FGMs in terms of the number of unknowns and is insensitive to mesh distortion. The method also performs very well in terms of numerical accuracy and can converge to the analytical solution when the number of elements is increased. The value of this paper is twofold: a T‐complete set of homogeneous solutions for nonlinear FMGs has been derived and used to represent the intra‐element temperature and the corresponding variational functional and the associated algorithm has been constructed.
Publisher: Springer Science and Business Media LLC
Date: 15-02-2006
Publisher: American Chemical Society (ACS)
Date: 21-04-2014
DOI: 10.1021/NL5003608
Abstract: The oscillatory behavior of a double-walled carbon nanotubes with a rotating inner tube is investigated using molecular dynamics simulation. In the simulation, one end of the outer tube is assumed to be fixed and the other is free. Without any prepullout of the rotating inner tube, it is interesting to observe that self-excited oscillation can be triggered by nonequilibrium attraction of the ends of two tubes. The oscillation litude increases until it reaches its maximum with decrease of the rotating speed of the inner tube. The oscillation of a bitube is sensitive to the gap between two walls. Numerical results also indicate that the zigzag/zigzag commensurate model with a larger gap of >0.335 nm can act as a terahertz oscillator, and the armchair/zigzag incommensurate model plays the role of a high litude oscillator with the frequency of 1 GHz. An oblique chiral model with a smaller gap of <0.335 nm is unsuitable for the oscillator because of the steep d ing of oscillation.
Publisher: Informa UK Limited
Date: 02-2011
Publisher: Springer Science and Business Media LLC
Date: 12-05-2011
Publisher: Springer Science and Business Media LLC
Date: 04-2014
Publisher: Elsevier BV
Date: 05-2011
Publisher: Elsevier BV
Date: 2020
Publisher: Elsevier BV
Date: 10-2013
Publisher: Springer Science and Business Media LLC
Date: 10-12-2004
Publisher: Elsevier BV
Date: 03-2009
Publisher: AIP Publishing
Date: 03-10-2022
DOI: 10.1063/5.0107552
Abstract: Nanotwined (nt) copper is attractive in applications such as microbumps in the microelectronics industry because nt-copper presents sound mechanical and physical properties. To date, most studies of the mechanical properties of nt-copper have been performed at macroscales. However, different stories are told at micro/nanoscales, e.g., smaller size leads to higher strength. Understanding the mechanical properties of nt-copper at micro/nanoscales is crucial for improving the reliability and endurability of microdevices. In this paper, we fabricated nt-copper film with tailored microstructures, i.e., twin boundaries (TBs) with different spacings and orientations (parallel or slanted to loading direction). Then, we applied micro-compression testing, atomistic simulation, and theoretical analysis to investigate the influence of vertical twin-boundary spacing λ and orientation on the deformation behavior of nt-micropillars. Results show that the yield stress is increased with decreasing vertical λ. Micropillars with slanted λ = 15.5 nm TBs present the greatest strength, which may be attributed to a finer λ. The phenomenon, strength increasing with decreasing λ, was well explained by the Hall–Petch and confined layer slip models. Large-scale molecular dynamics simulations were used to uncover the atomistic and real-time deformation mechanisms. This microscale research on nt-micropillars may provide insights on designing advanced microelectronics.
Publisher: IOP Publishing
Date: 08-02-2016
DOI: 10.1088/0957-4484/27/9/095705
Abstract: A novel approach is presented to improve the oscillatory behavior of oscillators based on double-walled carbon nanotubes containing rotating inner tubes applied with different helical rises. The influence of the helical rise on the oscillatory litude, frequency, and stability of inner tubes with different helical rises in armchair@zigzag bitubes is investigated using the molecular dynamics method. Our simulated results show that the oscillatory behavior is very sensitive to the applied helical rise. The inner tube with h = 10 Å has the most ideal hexagon after the energy minimization and NVT process in the armchair@zigzag bitubes, superior even to the inner tube without a helical rise, and thus it exhibits better oscillatory behavior compared with other modes. Therefore, we can apply an appropriate helical rise on the inner tube to produce a stable and smooth oscillator based on double-walled carbon nanotubes.
Publisher: Elsevier BV
Date: 09-2008
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5RA02124C
Abstract: Molecular dynamics simulation is adopted to study the dynamic behavior of an oscillator from curved double-walled carbon nanotubes with rotating inner tube. Effects of curvature and temperature on its dynamic response are investigated.
Publisher: AIP Publishing
Date: 28-01-2008
DOI: 10.1063/1.2838716
Abstract: The evolution of real-time stress in porous silicon (PS) during drying is investigated using micro-Raman spectroscopy. The results show that the PS s le underwent non-negligible stress when immersed in liquid and suffered a stress impulsion during drying. Such nonlinear transformation and nonhomogeneneous distribution of stress are regarded as the coupling effects of several physical phenomena attributable to the intricate topological structure of PS. The effect of dynamic capillarity can induce microcracks and even collapse in PS structures during manufacture and storage.
Publisher: American Physical Society (APS)
Date: 11-05-2021
Publisher: IEEE
Date: 2016
Publisher: Informa UK Limited
Date: 02-2011
Publisher: Elsevier BV
Date: 03-2005
Publisher: Elsevier BV
Date: 04-2019
Publisher: Elsevier BV
Date: 06-2005
Publisher: WIT Press
Date: 28-06-2011
DOI: 10.2495/BE110171
Publisher: Springer Science and Business Media LLC
Date: 31-08-2005
Publisher: The Royal Society
Date: 26-10-2011
Abstract: Nanomaterials with chiral morphologies hold promise for a wide ersity of technologically important applications in such fields as micro/nano-electromechanical systems and medical engineering. Understanding the mechanisms underlying the formation of chiral morphologies of natural and synthesized materials remains an issue of crucial significance. In this study, a refined Kirchhoff rod model taking into account anisotropic surface effects is employed to describe quasi-one-dimensional nanomaterials with complicated spatial morphologies. It is shown that anisotropic surface stresses can induce the formation of rich morphologies of nanomaterials. A general shape equation of nanowires is derived by the variational method of energy. Thereby, the effects of anisotropic surface properties, bulk elastic properties and cross-sectional sizes on the chiral morphologies of nanomaterials are quantitatively investigated, and the conditions for the formation of binormal nanohelices are given. The physical mechanism addressed in this study is verified by our recent experiments on tuning the twisting chirality of polymer lamellae via surface treatments. Our analysis suggests that one can design and adjust the morphology of synthesized nanohelices by tailoring or functionalizing their surfaces during fabrication. This study is also helpful in interpreting the formation of such artificial and biological chiral materials as the flagella of bacterial and self-assembled helical ribbons.
Publisher: IOP Publishing
Date: 08-2009
Publisher: Elsevier BV
Date: 02-2003
Publisher: World Scientific Pub Co Pte Lt
Date: 12-2007
DOI: 10.1142/S0219455407002460
Abstract: Buckling and postbuckling behaviors of multi-walled carbon nanotubes (MWCNTs) under a compressive force are studied. MWCNTs are modeled by Donnell's shallow shell nonlinear theory with the allowance of van der Waals (vdW) interaction between the walls. It is shown herein that the buckling load decreases while the buckling strain increases as the innermost radius of MWCNT increases. For the postbuckling behavior, the shortening-load curves show an initial steep gradient that gradually level up when the radius of the innermost tube changes from a small value to a large value. However, the deflection-load curves are almost level for various radii of MWCNTs. In addition, the analytical results showed that the shortening-load curves are almost linear but the deflection-load curves are nonlinear and the stability of MWCNTs can be enhanced by adding tubes.
Publisher: American Chemical Society (ACS)
Date: 04-03-2016
Publisher: Elsevier BV
Date: 04-2015
Publisher: Springer Science and Business Media LLC
Date: 23-05-2014
DOI: 10.1038/SREP05017
Publisher: Springer Science and Business Media LLC
Date: 05-09-2007
Publisher: American Scientific Publishers
Date: 07-2011
Publisher: MDPI AG
Date: 06-2018
DOI: 10.3390/APP8060905
Publisher: FapUNIFESP (SciELO)
Date: 10-2015
Publisher: Springer-Verlag
Date: 2006
Publisher: Springer Science and Business Media LLC
Date: 06-2005
Publisher: Springer Science and Business Media LLC
Date: 04-2002
Publisher: Elsevier BV
Date: 07-2006
DOI: 10.1016/J.BIOMATERIALS.2006.03.015
Abstract: A hypothetical regulation mechanism for bone modeling and remodeling under electromagnetic field is proposed. In this hypothesis, the bone modeling and remodeling mechanism is described as follows: the circular loads that we bear during ordinary daily activities generate micro-damage in cortical bone and these micro-cracks are removed by osteoclasts. Then growth factors, which are in latent forms in osteocytes, are activated by osteoclasts and released into bone fluid. These growth factors stimulate osteoblasts to refill the cavities. An electromagnetic field can stimulate the multiplication of growth factors and accelerate the bone remodeling process indirectly. It can be seen that many features reported in adaptive bone modeling and remodeling are explained by the proposed hypothesis. Further, a computational model is established based on the hypothesis, which can simulate the bone modeling and remodeling process under multi-field loads.
Publisher: Elsevier BV
Date: 02-1996
Publisher: Elsevier BV
Date: 11-1994
Publisher: Springer Science and Business Media LLC
Date: 07-03-2019
Publisher: Tsinghua University Press
Date: 02-2005
Publisher: Springer Science and Business Media LLC
Date: 2001
Publisher: Cold Spring Harbor Laboratory
Date: 17-09-2022
DOI: 10.1101/2022.09.15.508124
Abstract: New medicines are urgently required to treat the fatal neuromuscular disease, Duchenne muscular dystrophy (DMD). DMD involves progressive muscle damage and weakness, which are preceded by oxidative stress, inflammation, and mitochondrial dysfunction. Dimethyl fumarate (DMF) is a potent small molecule nuclear erythroid 2-related factor 2 (Nrf2) activator with current clinical utility in the treatment of multiple sclerosis and psoriasis. Pharmaceutical targeting of Nrf2 by DMF has strong translational potential for DMD, given it: (1) promotes antioxidant defence systems (2) has a potent immuno-modulatory profile and (3) can be rapidly re-purposed into clinical care strategies for DMD patients. Here, we tested two weeks of daily 100mg/kg DMF versus 5mg/kg standard care prednisone (PRED) treatment during the peak muscle degeneration period in juvenile mdx mice, the gold standard murine DMD model. Both drugs modulated seed genes driving the DMD disease program and improved muscle force production in fast-twitch muscle. However, only DMF showed pro-mitochondrial effects that protected contracting muscles from fatigue, improved histopathology and augmented clinically compatible muscle function tests. In contrast, PRED treatment stunted mouse growth, worsened histopathology and modulated many normally expressed inflammatory and extracellular matrix (ECM) genes consistent with pan immunosuppression. These findings suggest DMF could be a more selective modulator of the DMD disease program with better efficacy and fewer side effects than standard care PRED therapy warranting follow-up studies to progress clinical translation.
Publisher: IOP Publishing
Date: 12-04-2019
Publisher: Elsevier BV
Date: 11-1996
Publisher: MDPI AG
Date: 14-01-2018
DOI: 10.3390/MA11010133
Publisher: Springer Science and Business Media LLC
Date: 26-03-1999
Publisher: Elsevier BV
Date: 03-2003
Publisher: World Scientific Pub Co Pte Lt
Date: 03-07-2014
DOI: 10.1142/S0219519414500602
Abstract: In this paper, the method of fundamental solution (MFS) coupling with the dual reciprocity method (DRM) is developed to solve nonlinear steady state bioheat transfer problems. A two-dimensional nonlinear skin model with temperature-dependent blood perfusion rate is studied. Firstly, the original bioheat transfer governing equation with nonlinear term induced by temperature-dependent blood perfusion rate is linearized with the Taylor's expansion technique. Then, the linearized governing equation with specified boundary conditions is solved using a meshless approach, in which the DRM and the MFS are employed to obtain particular and homogeneous solutions, respectively. Several numerical ex les involving linear, quadratic and exponential relations between temperature and blood perfusion rate are tested to verify the efficiency and accuracy of the proposed meshless model in solving nonlinear steady state bioheat transfer problems, and also the sensitivity of coefficients in the expression of temperature-dependent blood perfusion rate is analyzed for investigating the influence of blood perfusion rate to temperature distribution in skin tissues.
Publisher: Elsevier BV
Date: 05-2004
Publisher: IOP Publishing
Date: 12-01-2016
DOI: 10.1088/0957-4484/27/5/055706
Abstract: Since a double-walled carbon nanotube (DWCNT)-based rotary motor driven by a uniform temperature field was proposed in 2014, how to control quantitatively the rotation of the rotor is still an open question. In this work, we present a mathematical relationship between the rotor's speed and interaction energy. Essentially, the increment of interaction energy between the rotor and the stator(s) determines the rotor's rotational speed, whereas the type of radial deviation of an end carbon atom on the stator determines the rotational direction. The rotational speed of the rotor can be specified by adjusting temperature and radial deviation of an end carbon atom on the stator. It is promising for designing a controllable temperature-driven rotary motor based on DWCNTs with length of few nanometers only.
Publisher: Elsevier BV
Date: 11-2003
Publisher: IOP Publishing
Date: 06-2014
Publisher: Oxford University Press (OUP)
Date: 08-08-2013
Abstract: In this paper, a new algorithm is developed based on the homogenization method integrating with the newly developed Hybrid Treffe FEM (HT-FEM) and Hybrid Fundamental Solution based FEM (HFS-FEM). The algorithm can be used to evaluate effective elastic properties of heterogeneous composites. The representative volume element (RVE) of fiber reinforced composites with periodic boundary conditions is introduced and used in our numerical analysis. The proposed algorithm is assessed through two numerical ex les with different mesh density and element geometry and used to investigate the effect of fiber volume fraction, fiber shape and configuration on the effective properties of composites. It is found that the proposed algorithm is insensitive to element geometry and mesh density compared with the traditional FEM ( e.g. ABAQUS). The numerical results indicate that the HT-FEM and HFS-FEM are promising in micromechanical modeling of heterogeneous materials containing inclusions of various shapes and distributions. They are potential to be used for future application in multiscale simulation.
Publisher: World Scientific Pub Co Pte Lt
Date: 23-04-2013
DOI: 10.1142/S021987621350014X
Abstract: In this paper, a three-dimensional material point human head model is constructed from the computed tomography (CT) scanned images of an adult male volunteer, and used to study the dynamic response of human head under the impact of a three-dimensional cylindrical lead projectile with a speed of 6.4 m/s. The model consists of skull bone, brain tissue and membrane of human head, which is close to the real one. The skull and membrane are modeled by an elastic constitutive model, and the brain tissue is modeled by an anisotropic viscoelastic constitutive model. These constitutive models have been implemented in our three-dimensional explicit material point method code, MPM3D, and is verified by comparing its numerical results for a ball impact problem with those obtained by LS-DYNA. The simulation results help illustrate the response of skull bone, membrane and brain tissues subjected to impact, which contributes to the understanding of the biomechanics and mechanisms of head injury.
Publisher: World Scientific Pub Co Pte Ltd
Date: 16-06-2023
DOI: 10.1142/S1758825123500588
Abstract: The engineered topological structures of the unit cell endow elastic metamaterials (EMMs) with the extraordinary capability to attenuate elastic waves. In real-life scenarios, a practical EMM (i.e., metastructure), consisting of a limited number of unit cells, is the truncation of the infinite EMM, which may detriment seriously the attenuation capability. To understand the mechanism behind the detriment, an efficient way to evaluate and analyze the stopbands for metastructures is essential. Instead of relying on the commonly adopted frequency response analysis to characterize stopbands for metastructures, which are sensitive to frequency sweeping steps and short of information of truncated resonance affecting wave attenuation performance, a novel modal-based method (MM) is proposed to assess the wave attenuation of 3D metastructures. Specifically, the modal-based analysis scheme incorporating the modal superposition principle and a freshly developed layer-based strain energy ratio (SER) measurement method is proposed. Through employing the MM, the opening and ceasing of the stopbands are evaluated by characterizing dominant eigenmodes developed in metastructures. Accordingly, the influences of eigenmodes induced by different mechanisms on wave attenuation performance are investigated, and the stopband formation mechanisms are elaborated. Furthermore, under the guidance of a freshly proposed modal-based design framework, metastructures with modified geometrical parameter settings (GPSs) are demonstrated with enlarged normalized bandwidths (NBs) at lower frequencies, which show improved applicability in multiple engineering disciplines.
Publisher: Springer Science and Business Media LLC
Date: 08-2012
Publisher: IOP Publishing
Date: 22-12-2018
Abstract: The rotation transmission system (RTS) made from co-axial multi-walled nanotubes (MWNTs) has the function of regulating the input rotation from a nanomotor. The mechanism for the regulation is that the friction among the tubes during rotation governs the rotation of the rotors in the nanosystem. By integrating a rotary nanomotor and a nanobearing into an MWNT-based RTS, it is discovered that the stator (outer tube) provides relatively greater friction on the rotors by penetrating the motor tube, which has a higher stable rotational frequency. And the output rotation of the rotors in the system depends significantly on the temperature of the system, as the rotor tubes are slightly longer than the motor tube. Briefly, at low temperatures, say 8 K, the rotors rotate synchronously with the motor. However, at high temperatures, the rotors rotate slower than the motor with a bigger difference between their rotational frequencies. Hence, the output rotational frequencies can be adjusted by changing the temperature as well as the input rotational frequency.
Publisher: MDPI AG
Date: 21-01-2019
DOI: 10.3390/APP9020352
Abstract: The mechanical behavior of nanocomposites consisting of highly ordered nanoporous nickel (HONN) and its carbon nanotube (CNT)-reinforced composites (CNHONNs) subjected to a high temperature of 900 K is investigated via molecular dynamics (MD) simulations. The study indicates that, out-of-plane mechanical properties of the HONNs are generally superior to its in-plane mechanical properties. Whereas the CNT shows a significant strengthening effect on the out-of-plane mechanical properties of the CNHONN composites. Compared to pure HONNs, through the addition of CNTs from 1.28 wt‰ to 5.22 wt‰, the weight of the composite can be reduced by 5.83‰ to 2.33% while the tensile modulus, tensile strength, compressive modulus and compressive strength can be increased by 2.2% to 8.8%, 1% to 5.1%, 3.6% to 10.2% and 4.9% to 10.7%, respectively. The energy absorption capacity can also be improved due to the existence of CNTs. Furthermore, the MD simulations provide further insights into the deformation mechanism at the atomic scale, including fracture in tension, pore collapse in compression and local changes in lattice structures due to stacking faults.
Publisher: Springer Science and Business Media LLC
Date: 12-06-2007
Publisher: SPIE
Date: 09-08-2013
DOI: 10.1117/12.2027957
Publisher: Elsevier BV
Date: 09-2006
Publisher: Elsevier BV
Date: 02-2013
Publisher: Elsevier BV
Date: 03-2002
Publisher: Elsevier BV
Date: 08-2003
Publisher: Elsevier BV
Date: 11-2005
DOI: 10.1016/J.BIOMATERIALS.2005.03.042
Abstract: Theoretical prediction of surface bone remodeling in the diaphysis of the long bone under various external loads are made within the framework of adaptive elastic theory. These loads include external lateral pressure, electric and thermal loads. Two solutions are presented for analyzing thermoelectroelastic problems of surface bone remodeling. The analytical solution that gives explicit formulation is capable of modeling homogeneous bone materials, while the semi-analytical solution is suitable for analyzing inhomogeneous cases. Numerical results are presented to verify the proposed formulation and to show the effects of mechanical, thermal and electric loads on surface bone remodeling process.
Publisher: Elsevier BV
Date: 05-2019
Publisher: Springer Science and Business Media LLC
Date: 28-11-2012
Publisher: Springer Science and Business Media LLC
Date: 06-2008
Publisher: Springer Science and Business Media LLC
Date: 22-02-2018
DOI: 10.1038/S41598-018-21694-2
Abstract: When argon is used as a protecting gas in the fabrication or working environment of a nanodevice, absorption of some argon atoms onto the surface of the device lead to different responses. In this work, the rotation of the rotor in a carbon nanotube (CNT)-based rotary nanomotor in argon environment is investigated. In the rotary nanomotor, two outer CNTs act as the stator and are used to constrain the inner CNT (i.e., the rotor). The rotor is driven to rotate by the stator due to their collision during thermal vibration of their atoms. A stable rotational frequency (SRF) of the rotor occurs when the rotor reaches a dynamic equilibrium state. The value of the SRF decreases exponentially with an increase in the initial argon density. At dynamic equilibrium date, some of the argon atoms rotate synchronously with the rotor when they are absorbed onto either internal or external surface of the rotor. The interaction between the rest of the argon atoms and the rotor is stronger at higher densities of argon, resulting in lower values of the SRF. These principles provide insight for future experimentation and fabrication of such rotary nanomotor.
Publisher: BMJ
Date: 22-06-2022
Abstract: To examine the associations of infertility, recurrent miscarriage, and stillbirth with the risk of first non-fatal and fatal stroke, further stratified by stroke subtypes. In idual participant pooled analysis of eight prospective cohort studies. Cohort studies across seven countries (Australia, China, Japan, Netherlands, Sweden, the United Kingdom, and the United States) participating in the InterLACE (International Collaboration for a Life Course Approach to Reproductive Health and Chronic Disease Events) consortium, which was established in June 2012. 618 851 women aged 32.0-73.0 years at baseline with data on infertility, miscarriage, or stillbirth, at least one outcome event (non-fatal or fatal stroke), and information on covariates were included 93 119 women were excluded. Of the participants, 275 863 had data on non-fatal and fatal stroke, 54 716 only had data on non-fatal stroke, and 288 272 only had data on fatal stroke. Non-fatal strokes were identified through self-reported questionnaires, linked hospital data, or national patient registers. Fatal strokes were identified through death registry data. The median follow-up for non-fatal stroke and fatal stroke was 13.0 years (interquartile range 12.0-14.0) and 9.4 years (7.6-13.0), respectively. A first non-fatal stroke was experienced by 9265 (2.8%) women and 4003 (0.7%) experienced a fatal stroke. Hazard ratios for non-fatal or fatal stroke were stratified by hypertension and adjusted for race or ethnicity, body mass index, smoking status, education level, and study. Infertility was associated with an increased risk of non-fatal stroke (hazard ratio 1.14, 95% confidence interval 1.08 to 1.20). Recurrent miscarriage (at least three) was associated with higher risk of non-fatal and fatal stroke (1.35, 1.27 to 1.44, and 1.82, 1.58 to 2.10, respectively). Women with stillbirth were at 31% higher risk of non-fatal stroke (1.31, 1.10 to 1.57) and women with recurrent stillbirth were at 26% higher risk of fatal stroke (1.26, 1.15 to 1.39). The increased risk of stroke (non-fatal or fatal) associated with infertility or recurrent stillbirths was mainly driven by a single stroke subtype (non-fatal ischaemic stroke and fatal haemorrhagic stroke), while the increased risk of stroke (non-fatal or fatal) associated with recurrent miscarriages was driven by both subtypes. A history of recurrent miscarriages and death or loss of a baby before or during birth could be considered a female specific risk factor for stroke, with differences in risk according to stroke subtypes. These findings could contribute to improved monitoring and stroke prevention for women with such a history.
Publisher: Trans Tech Publications, Ltd.
Date: 05-2014
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMM.553.356
Abstract: Simulation of transient bioheat transfer in a two dimensional (2D) human eye model is conducted using a newly developed hybrid fundamental solution-finite element method (HFS-FEM) coupling with the radial basis function (RBF) approximation. Firstly, a time stepping scheme based on the finite difference method (FDM) is used to handle time variable in the transient Pennes bioheat equation. Secondly, the particular solution of the governing equation is approximated by a RBF approach. Then, the homogeneous solution is calculated by means of HFS-FEM. The obtained results are compared with those from ABAQUS and a good agreement between them is observed.
Publisher: Informa UK Limited
Date: 12-2004
Publisher: Wiley
Date: 18-01-2010
DOI: 10.1002/JRS.2584
Publisher: World Scientific Pub Co Pte Lt
Date: 04-2016
DOI: 10.1142/S1758825116500381
Abstract: The optimal layouts of multiple bi-modulus materials in a continuum under ill-loaded cases are found using the scheme of fractional-norm ([Formula: see text]-norm and [Formula: see text] is in (0, 1)) weighting objective function. The major ideas of the present study are as follows. First, the bi-modulus material topology optimization is solved using material replacement approach. Second, the power-law scheme is adopted to express the equivalent stiffness of multiple materials. Third, the ill-loaded topology optimization is solved by changing the value of [Formula: see text]. Combining the three techniques, a feasible solution for the ill-loaded structural optimization can be found even when there are many bi-modulus materials. Numerical tests are presented to show the characters of the materials layout in the structure.
Publisher: Springer Science and Business Media LLC
Date: 12-2006
Publisher: Elsevier BV
Date: 06-2007
Publisher: SPIE
Date: 09-08-2013
DOI: 10.1117/12.2030203
Publisher: ASME International
Date: 09-05-2012
DOI: 10.1115/1.4005561
Abstract: The objective of this work is to investigate the quasi-static plastic behavior of a fully cl ed metal foam core sandwich beam transversely loaded by a flat punch. A rigid-plastic beam-on-foundation model is extended to study the local denting deformation of a metal foam core sandwich beam. The effects of local denting and core strength on the overall deformation are incorporated in the analysis. Analytical solutions are derived for three different regimes of post-yield deformation mechanisms. Additionally, finite element results are obtained. Comparisons of the present analytical predictions with numerical, previous experimental, and analytical results are presented, respectively. It is shown that local denting has a significant effect on the finite deflection response of the metal foam core sandwich structure. The load-carrying and energy absorption capacities of sandwich beams may be overestimated if the effect of local denting is neglected in analysis. It is demonstrated that the present analytial model can reasonably predict the behaviors of post-yield deformation of sandwich beams. Moreover, the present analytical method can be extended to predict the low velocity/energy impact problems of sandwich structures.
Publisher: Wiley
Date: 17-01-2023
DOI: 10.1002/JCP.30946
Abstract: Medulloblastoma (MB) is the most common malignant pediatric brain tumor. Current treatment modalities are not completely effective and can lead to severe neurological and cognitive adverse effects. In addition to urgently needing better treatment approaches, new diagnostic and prognostic biomarkers are required to improve the therapy outcomes of MB patients. The RNA‐binding proteins, LIN28A and LIN28B, are known to regulate invasive phenotypes in many different cancer types. However, the expression and function of these proteins in MB had not been studied to date. This study identified the expression of LIN28A and LIN28B in MB patient s les and cell lines and assessed the effect of LIN28 inhibition on MB cell growth, metabolism and stemness. LIN28B expression was significantly upregulated in MB tissues compared to normal brain tissues. This upregulation, which was not observed in other brain tumors, was specific for the aggressive MB subgroups and correlated with patient survival and metastasis rates. Functionally, pharmacological inhibition of LIN28 activity concentration‐dependently reduced LIN28B expression, as well as the growth of D283 MB cells. While LIN28 inhibition did not affect the levels of intracellular ATP, it reduced the expression of the stemness marker CD133 in D283 cells and the sphere formation of CHLA‐01R cells. LIN28B , which is highly expressed in the human cerebellum during the first few months after birth, subsequently decreased with age. The results of this study highlight the potential of LIN28B as a diagnostic and prognostic marker for MB and open the possibility to utilize LIN28 as a pharmacological target to suppress MB cell growth and stemness.
Publisher: Wiley
Date: 24-04-2015
DOI: 10.1111/JACE.13595
Publisher: SAGE Publications
Date: 07-2016
Abstract: The following article has been included in a multiple retraction: Triality Theory and Complete Post-buckling Solutions of Large Deformed Beam by Canonical Dual Finite Element Method Kun Cai, David Y Gao, Qinghua Qin. ontent/early/2015/06/28/1081286515591085.abstract In 2015 SAGE were made aware of concerns regarding the Special Issue of Mathematics & Mechanics of Solids on Advances in Canonical Duality Theory, guest-edited by Professor David Gao. At the request of the Guest Editor, the Special Issue has been retracted, due to conflict of interest regarding Professor Gao’s role as Guest Editor and co-author on a number of submitted papers. In addition the peer review process was less rigorous than the journal requires. The Guest Editor takes full responsibility for the retraction. The following articles that were due to appear in the Special Issue have therefore been retracted: Canonical Duality-Triality: Bridge between Nonconvex Analysis/Mechanics and Global Optimization in complex systems David Y Gao, Ning Ruan, and Vittorio Latorre. ontent/early/2015/02/24/1081286514566533.abstract Canonical Dual Approach for Contact Mechanics Problems with Friction Vittorio Latorre, Simone Sagratella, David Y Gao. ontent/early/2015/01/20/1081286514566534.abstract Canonical Duality Theory for Solving Non-Monotone Variational Inequality Problems Guoshan Liu, David Y Gao, Shouyang Wang. ontent/early/2015/02/04/1081286514566535.abstract Double Well Potential Function and Its Optimization in The n-dimensional Real Space. Part I Shu-Cherng Fang, David Y Gao, Gang-Xuan Lin, Ruey-Lin Sheu, Wen-Xun Xing. ontent/early/2015/02/24/1081286514566704.abstract Double Well Potential Function and Its Optimization in The n-dimensional Real Space. Part II Yong Xia, Ruey-Lin Sheu, Shu-Cherng Fang, Wenxun Xing. ontent/early/2015/02/09/1081286514566723.abstract Analytic Solutions to 3-D Finite Deformation Problems Governed by St Venant-Kirchhoff Material David Y Gao and E. Hajilarov. ontent/early/2015/07/06/1081286515591084.abstract Triality Theory and Complete Post-buckling Solutions of Large Deformed Beam by Canonical Dual Finite Element Method Kun Cai, David Y Gao, Qinghua Qin. ontent/early/2015/06/28/1081286515591085.abstract Global Solutions to Spherically Constrained Quadratic Minimization via Canonical Duality Theory Yi Chen, David Y Gao. ontent/early/2015/04/08/1081286515577122.abstract Unified Canonical Duality Methodology for Global Optimization Vittorio Latorre, David Y Gao and N. Ruan. ontent/early/2015/07/06/1081286515591305.abstract A Framework of Canonical Dual Algorithms for Global Optimization Xiaojun Zhou, David Y Gao, Chunhua Yang. ontent/early/2015/07/22/1081286515592190.abstract Canonical Duality Theory for Solving Nonconvex/Discrete Constrained Global Optimization Problems Ning Ruan, David Y Gao. ontent/early/2015/07/08/1081286515591087.abstract Global Optimization Solutions to a Class of Non-convex Quadratic Minimization Problems with Quadratic Constraints Yubo Yuan. ontent/early/2015/07/06/1081286515591086.abstract On Minimal Distance between Two Non-Convex Surfaces Daniel Morales-Silva, David Y Gao. ontent/early/2015/07/27/1081286515592949.abstract The Editor-in-Chief and SAGE strive to uphold the very highest standards of publication ethics and are committed to supporting the high standards of integrity of Mathematics & Mechanics of Solids. Authors, reviewers, editors and interested readers are encouraged to consult SAGE’s ethics statements and the Committee on Publication Ethics (COPE) website for guidelines on publication ethics.
Publisher: Global Science Press
Date: 10-2012
Abstract: This paper presents three boundary meshless methods for solving problems of steady-state and transient heat conduction in nonlinear functionally graded materials (FGMs). The three methods are, respectively, the method of fundamental solution (MFS), the boundary knot method (BKM), and the collocation Trefftz method (CTM) in conjunction with Kirchhoff transformation and various variable transformations. In the analysis, Laplace transform technique is employed to handle the time variable in transient heat conduction problem and the Stehfest numerical Laplace inversion is applied to retrieve the corresponding time-dependent solutions. The proposed MFS, BKM and CTM are mathematically simple, easy-to-programming, meshless, highly accurate and integration-free. Three numerical ex les of steady state and transient heat conduction in nonlinear FGMs are considered, and the results are compared with those from meshless local boundary integral equation method (LBIEM) and analytical solutions to demonstrate the efficiency of the present schemes.
Publisher: IOP Publishing
Date: 15-01-2018
Abstract: A nano continuous variable transmission (nano-CVT) system is proposed by means of carbon nanotubes (CNTs). The dynamic behavior of the CNT-based nanosystem is assessed using molecular dynamics simulations. The system contains a rotary CNT-motor and a CNT-bearing. The tube axes of the nanomotor and the rotor in the bearing are laid in parallel, and the distance between them is known as the eccentricity of the rotor with a diameter of d. By changing the eccentricity (e) of the rotor from 0 to d, some interesting rotation transmission phenomena are discovered, whose procedures can be used to design various nanodevices. This might include the failure of rotation transmission-i.e. the rotor has no rotation-when e ≥ d at an extremely low temperature, or when the edges of the two tubes are orthogonal at their intersections in any condition. This hints that the state of the nanosystem can be used as an on/off switch or breaker. For a system with e = d and a high temperature, the rotor rotates in the reverse direction of the motor. This means that the output signal (rotation) is the reverse of the input signal. When changing the eccentricity from 0 to d continuously, the output signal gradually decreases from a positive value to a negative value as a result a nano-CVT system is obtained.
Publisher: Elsevier BV
Date: 09-2006
Publisher: Informa UK Limited
Date: 04-2019
Publisher: Springer Science and Business Media LLC
Date: 28-10-2015
Publisher: MDPI AG
Date: 24-06-2022
DOI: 10.3390/PH15070789
Abstract: Analgesic tolerance is a major problem in the clinic for the maintenance of opioid-induced long-term pain relief. Opioids with mixed activity on multiple opioid receptors promise reduced antinociceptive tolerance in preclinical studies, but these compounds typically show poor bioavailability upon oral, subcutaneous, intraperitoneal, or intravenous administration. We designed UTA1003 as a novel opioid that acts as a mu (MOP) and kappa (KOP) opioid receptor agonist and a partial agonist for delta (DOP) opioid receptor. In the present study, its antinociceptive effects, as well as its effects on antinociceptive tolerance and motor behaviour, were investigated in male rats. Acute antinociception was measured before (basal) and at different time points after subcutaneous injection of UTA1003 or morphine using the tail flick and hot plate assays. Various motor behavioural activities, including horizontal locomotion, rearing, and turning, were automatically measured in an open-field arena. The antinociceptive and behavioural effects of repeated administration of UTA1003 and morphine were determined over eight days. UTA1003 induced mild antinociceptive effects after acute administration but induced no tolerance after repeated treatment. Importantly, UTA1003 co-treatment with morphine prevented antinociceptive tolerance compared to morphine alone. UTA1003 showed less motor suppression than morphine in both acute and sub-chronic treatment regimens, while it did not affect morphine-induced motor suppression or hyper-excitation. Based on these activities, we speculate that UTA1003 crosses the blood-brain barrier after subcutaneous administration and, therefore, could be developed as a lead molecule to avoid opioid-induced antinociceptive tolerance and motor suppression. Further structural modifications to improve its antinociceptive effects, toxicity profile, and ADME parameters are nevertheless required.
Publisher: Institution of Engineering and Technology (IET)
Date: 2007
DOI: 10.1049/EL:20073668
Publisher: IOP Publishing
Date: 13-02-2015
DOI: 10.1088/0957-4484/26/9/095702
Abstract: In a thermally driven rotary motor made from double-walled carbon nanotubes, the rotor (inner tube) can be actuated to rotate within the stator (outer tube) when the environmental temperature is high enough. A sudden stoppage of the rotor can occur when the inner tube has been actuated to rotate at a stable high speed. To find the mechanisms of such sudden stoppages, eight motor models with the same rotor but different stators are built and simulated in the canonical NVT ensembles. Numerical results demonstrate that the sudden stoppage of the rotor occurs when the difference between radii is near 0.34 nm at a high environmental temperature. A smaller difference between radii does not imply easier activation of the sudden rotor stoppage. During rotation, the positions and electron density distribution of atoms at the ends of the motor show that a sp(1) bonded atom on the rotor is attracted by the sp(1) atom with the biggest deviation of radial position on the stator, after which they become two sp(2) atoms. The strong bond interaction between the two atoms leads to the loss of rotational speed of the rotor within 1 ps. Hence, the sudden stoppage is attributed to two factors: the deviation of radial position of atoms at the stator's ends and the drastic thermal vibration of atoms on the rotor in rotation. For a stable motor, sudden stoppage could be avoided by reducing deviation of the radial position of atoms at the stator's ends. A nanobrake can be, thus, achieved by adjusting a sp1 atom at the ends of stator to stop the rotation of rotor quickly.
Publisher: Elsevier BV
Date: 10-2022
Publisher: Elsevier BV
Date: 2016
Publisher: Proceedings of the National Academy of Sciences
Date: 08-09-2014
Abstract: Given the extensive use of lipid bilayer reconstitution for the study of mechanosensitive channels, it is imperative to understand the biophysical properties of lipid bilayers. We have theoretically and experimentally proven that the traditional micropipette aspiration method fails to accurately describe these properties. Herein we introduce a superior framework, which combines computational modeling with patch fluorometry for the assessment of bilayer properties. Our results show the limitations of Laplace’s law for estimation of tension within a patch membrane. We also demonstrate, in contrast to the cell-attached configuration, there is a significant difference between the stress developed in the outer and in the inner monolayers of the bilayer in the excised patch configuration. These results are of critical importance for patch-cl electrophysiology in general.
Publisher: Springer Science and Business Media LLC
Date: 19-04-2014
Publisher: Elsevier BV
Date: 05-2012
Publisher: Informa UK Limited
Date: 12-2012
Publisher: Springer Science and Business Media LLC
Date: 27-07-1999
Publisher: Elsevier BV
Date: 02-2013
Publisher: Springer Science and Business Media LLC
Date: 08-01-2011
DOI: 10.1007/S10856-010-4225-Z
Abstract: In this paper, a calcium zinc iron silicon oxide composite (CZIS) was prepared using the sol-gel method. X-ray diffraction (XRD) was then employed to test the CZIS composite. The results from the test showed that the CZIS had three prominent crystalline phases: Ca(2)Fe(1.7)Zn(0.15)Si(0.15)O(5), Ca(2)SiO(4), and ZnFe(2)O(4). Calorimetric measurements were then performed using a magnetic induction furnace. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analysis were conducted to confirm the growth of a precipitated hydroxyapatite phase after immersion in simulated body fluid (SBF). Cell culture experiments were also carried out, showing that the CZIS composite more visibly promoted osteoblast proliferation than ZnFe(2)O(4) glass ceramic and HA, and osteoblasts adhered and spread well on the surfaces of composite s les.
Publisher: Springer Science and Business Media LLC
Date: 20-11-2015
Publisher: Springer Science and Business Media LLC
Date: 25-11-2009
Publisher: Elsevier BV
Date: 03-2010
Publisher: Cold Spring Harbor Laboratory
Date: 29-08-2023
DOI: 10.1101/2023.08.28.555025
Abstract: The loss of upper and lower motor neurons, and their axons is central to the loss of motor function and death in amyotrophic lateral sclerosis (ALS). Due to the erse range of genetic and environmental factors that contribute to the pathogenesis of ALS, there have been difficulties in developing effective therapies for ALS. One dichotomy emerging in the field is that protection of the neuronal cell soma itself does not prevent axonal vulnerability and degeneration, suggesting the need for targeted therapeutics to prevent axon degeneration. Post-translational modifications of protein acetylation can alter the function, stability and half-life of in idual proteins, and can be enzymatically modified by histone acetyltransferases (HATs) and histone deacetyltransferases (HDACs), which add, or remove acetyl groups, respectively. Maintenance of post-translational microtubule acetylation has been suggested as a potential mechanism to stabilise axons and prevent axonal loss and neurodegeneration in ALS. This study has utilized an orally dosed HDAC6 specific inhibitor, ACY-738, prevent deacetylation and stabilize microtubules in the mSOD1G93A mouse model of ALS. Furthermore, co-treatment with riluzole was performed to determine any effects or drug interactions and potentially enhance preclinical research translation. This study shows ACY-738 treatment increased acetylation of microtubules in the spinal cord of mSOD1G93A mice, reduced lower motor neuron degeneration in the lumbar spinal cord of female mice, ameliorated reduction in peripheral nerve axon puncta size, but did not prevent overt motor function decline. The current study also shows peripheral nerve axon puncta size to be partially restored after treatment with riluzole and highlights the importance of co-treatment to measure the potential effects of therapeutics in ALS.
Publisher: Elsevier BV
Date: 10-2008
Publisher: Elsevier BV
Date: 05-2012
Publisher: Springer Science and Business Media LLC
Date: 06-12-2012
Publisher: Elsevier BV
Date: 11-1996
Publisher: Elsevier BV
Date: 05-1995
Start Date: 03-2014
End Date: 12-2017
Amount: $310,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 01-2014
End Date: 12-2017
Amount: $380,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 02-2002
End Date: 01-2007
Amount: $686,825.00
Funder: Australian Research Council
View Funded ActivityStart Date: 04-2016
End Date: 12-2021
Amount: $340,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2006
End Date: 02-2010
Amount: $260,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 07-2014
End Date: 11-2015
Amount: $500,000.00
Funder: Australian Research Council
View Funded Activity