Plane Of Plate Research Articles

Computational study of consequence of effect of velocity slip on nanofluids with suspended CNTs

In this article, we have discussed two-dimensional steady, incompressible, and laminar hydromagnetic flow along with the transfer of heat above a plane plate that contains water and ethylene glycol-based nanofluids with multi- and single-wall CNTs. The velocity slip boundary condition is included in this research article to evaluate the nature of flow. The plate surface is subjected to variable wall temperature. The transfer of heat has been contemplated in the company of suspended CNTs above a flat plate. Navier–Stokes and the concept of the Prandtl boundary layer have been used to determine the governing equations of heat transfer and flow. Since the attained governing equations representing energy and flow are nonlinear PDEs, they are altered into nonlinear ODEs accompanied by analogous boundary limitations by applying some appropriate similarity transformations. Hence the "RK45" function is used to solve them numerically. The influence of governing parameters on the dimensionless flow and heat transfer profiles are studied and discussed thorough graphical plots .

Design and fabrication of composite current collector used in 2-cell stacks for portable power generator

This study designed a planar carbon fiber composite collector plate with excellent conductivity and mechanical strength for use in the proton exchange membrane fuel cell (PEMFC). The collector plate is made of phenolic resin mixed with conductive particles such as graphite powder, and coated onto carbon fiber cloth. After the solvent is allowed to evaporate, the prepreg is cut and stacked layer by layer into a mold for the heat pressing process at 150 °C. The resin in the carbon fiber prepreg cloth is cured into a carbon fiber composite board. A computer numerical control (CNC) engraving machine was used to engrave the carbon fiber composite board into the current collector shape. The carbon fiber composite current collectors were placed into a high temperature furnace for the carbonization process. The resin between the carbon fibers is removed by the high temperature to increase conductivity. The carbon fiber composite collectors were assessed for conductivity, mechanical strength, and performance. Afterwards, a planar two cell fuel cell stack was assembled for testing performance and stability. A printed circuit board (PCB) was used to design the circuit and the planar two cell fuel cell module made using the heat pressing process. The planar two cell module was combined with a small hydrogen storage tank to form a portable power generation device.

Thermal Performance on Radiative and Ohmic Dissipative Magneto-Nanoliquid Over Moving Flat Porous Plate Suspended by Single Wall Carbon Nanotubes and Multi Wall Carbon Nanotubes

This investigation examines heat transport in the flow of magnetized Blasius flow suspended by carbon nanotubes (CNTs) on an accelerated by moving flat porous plate that contains water and ethylene glycol as base fluids. The transfer of heat has been contemplated in the company of suspended CNTs above a plane plate. The flow simulations are carried by utilizing the impact of magnetic field and uniform porous medium. The transport of thermal is controlled by the significant influence of thermal radiation, heat source, heat and Joule dissipation. Utilizing scaling analysis flow governing problem is converted into a set of higher order nonlinear ordinary differential equations which afterwards are tackled numerically by employing Runge-Kutta Fehlberg 45 method with shooting quadrature. Quantities of flow physical significance are portrayed through graphically. Verification of attained numerical results with available literature under certain limitations are presented and found excellent agreement. With elevation in convective term flow profiles of SWCNTs and MWCNTs are reduced. A reduction of flow characteristic dimensions is observed with increasing magnetic field and porosity terms. Finally, SWCNTs and MWCNTs are positively influenced by Joule dissipation and negatively by thermal radiation.

A Technique for Planar Integration of Components of W-Band Backward-Wave Oscillator to Eliminate Misalignment

The alignment within the required tolerance between components like electron beam source, beam-wave interaction structure and spent beam collector is a major challenge in the realization of the high-power vacuum-tube sub-THz source. To overcome this major issue, a novel integrated W-band beam-wave interaction circuit along with spent beam collector and beam adapter region has been designed and developed on two planar metallic plates itself for the first time. It accomplished the level of required alignment of different components of a sub-THz source. This interaction circuit along with beam adapter region and spent beam collector has been developed on a single plate. These structures have been developed using optimized micro-milling techniques with achieved dimensional deviation less than <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$ &lt; 7~\mu \text{m}$ </tex-math></inline-formula> . The average surface roughness is found to be around 100 nm, which is much less than the skin depth in the W band.

Food volume estimation by multi-layer superpixel.

Estimating the volume of food plays an important role in diet monitoring. However, it is difficult to perform this estimation automatically and accurately. A new method based on the multi-layer superpixel technique is proposed in this paper to avoid tedious human-computer interaction and improve estimation accuracy. Our method includes the following steps: 1) obtain a pair of food images along with the depth information using a stereo camera; 2) reconstruct the plate plane from the disparity map; 3) warp the input image and the disparity map to form a new direction of view parallel to the plate plane; 4) cut the warped image into a series of slices according to the depth information and estimate the occluded part of the food; and 5) rescale superpixels for each slice and estimate the food volume by accumulating all available slices in the segmented food region. Through a combination of image data and disparity map, the influences of noise and visual error in existing interactive food volume estimation methods are reduced, and the estimation accuracy is improved. Our experiments show that our method is effective, accurate and convenient, providing a new tool for promoting a balanced diet and maintaining health.

Boundary plate influence on tie bars axial force demands in composite plate shear walls‒concrete filled

In composite plate shear walls–concrete filled (C-PSW/CF), there is an indeterminate flow of force between concrete, steel plate and tie bars. Finite element methods (FEM) are frequently used to verify this force flow. The theoretical models available in the literature to predict the tie bar maximum axial force demands were based on walls without boundary plates. The finding in this study is intended to help understand whether current theoretical approaches are conservative and can be applied to boundary plate walls as well. Within the scope of this study, tie bar axial force demands for walls with boundary plates consisting of planar and round shapes and without boundary plates were investigated and compared. For this, a previously benchmarked finite element (FE) wall model was considered and configured to have no boundary plate and have planar and round boundary plates. FE models were analyzed under monotonic lateral displacement up to 4% drift ratio. Passive lateral pressures and transverse force variations on the planar and round boundary plates were investigated.

Comparative folding/unfolding performance of notch-type compliant joints

Origami design has been a popular research field for decades, generating inspiration for various structural applications. The shift from paper to more practical materials such as plate-like metals is materialized by surrogate folds such as compliant hinges. Therefore, it is critical to explore the kinematic and dynamic characteristics of these joints. In this paper, a comparative numerical study of the folding/unfolding performance of three notch-type compliant joints, namely groove, elliptical holes, and rectangular holes is presented. Indicators including stress contour, load-deformation, moment-angle, and stiffness-angle are selected to evaluate the performance of joints with different geometric parameters, especially the hysteretic behaviors of the joints. The results illustrate that the geometric parameters of the plate and joint are well correlated with these performance indicators. The transition behaviors of the folding/unfolding stiffness of all joints are associated with a certain regime of rotational angles. Besides, the performances of all studied joints are benchmarked against the much-popularized outside LET joint, from which their deformation modes are recognized. Finally, considering various performance aspects, the groove joint is recognized as the most suitable for the folding of a planar plate.

Structure of Shock Wave in Nanoscale Porous Nickel at Pressures up to 7 GPa

The structure of shock waves in pressed porous samples of nickel nanoparticles was investigated in a series of uniaxial planar plate impact experiments in the pressure range of 1.6-7.1 GPa. The initial porosity of the samples was about 50%. Wave profiles were obtained using laser velocimetry techniques. The nanomaterial demonstrated a complex response to shock loading including the development of a two-wave structure associated with precursor and compaction waves. The effect on profiles and measurements of the observed precursor reverberations propagating between the front of a compaction wave and a monitored sample surface was described. The obtained wave profiles were used to estimate the thicknesses of precursor and compaction wave fronts.

Corrosion effects on the fatigue performance of high-strength bolted friction connections

In this paper, the corrosion effects on the fatigue performance of the friction connections are experimentally and numerically investigated. Fatigue test was conducted on the connections with four corrosion levels, and the failure mode and fracture surfaces were analyzed. Based on the finite element modeling of the connection, the crack initiation life caused by the fretting fatigue was calculated based on several multiaxial fatigue criteria, and the crack propagation life in the complex stress field was predicted using the AFGROW software. The results show that the fatigue life of the friction connections could be significantly reduced by corrosion, and the fatigue failure occurred near the minimum cross-section plane of the inner plates. It was also observed that the fatigue cracks initiated at the fretting wear scar and the corrosion pits at the hole edge for the uncorroded and corroded connections, respectively. The predictions show that the fatigue life prediction method in which the crack initiation and propagation lives are both considered can accurately predict the fatigue behavior of the uncorroded connections under different stress ranges. The fatigue life of the corroded friction connections with a mass loss ratio>7.8% can be estimated by assuming an initial crack at the hole edge in the minimum cross-section plane and ignoring the crack initiation life induced by fretting damage.

Synthesis and characterization of molybdenum trioxide with an orthorhombic crystal structure for supercritical water gasification application

Supercritical water (SCW) catalytic gasification is promising for the production of synthetic gas from biomass. However, maintaining the activity of heterogeneous catalysts under high pressure and hydrothermal conditions is the most important. Therefore, this study investigates the activity and stability of molybdenum trioxide (MoO3) for the gasification of formaldehyde in SCW. MoO3 with an orthorhombic crystal structure was synthesized by the sol-gel method and tested in the gasification of formaldehyde in SCW. Structural and morphological changes of MoO3 with supercritical water gasification were studied by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), a scanning electron microscope (SEM), N2 adsorption-desorption, thermogravimetric analysis (TGA), temperature-programmed desorption of oxygen (O2-TPD), temperature-programmed desorption with ammonia (TPD-NH3), and temperature-programmed reaction of hydrogen (H2-TPR). The XRD results show that MoO3 has an orthorhombic crystal structure. Its structure changed to a monoclinic structure upon gasification with supercritical water. SEM images showed that the rod-shaped catalyst particles transformed into thin planar plates at high pressure and temperature conditions in the presence of carbonaceous compounds. H2-TPR and XRD results showed that MoO3 was reduced to MoO2 during SCW gasification with hydrogen and carbonaceous compounds. Moreover, the oxygen stability of the catalyst changed during SCW gasification, and active oxygen species formed on the surface of the catalyst. Compared with homogeneous gasification, in the presence of the MoO3 catalyst, the fractions of CO2 and CH4 increased to 50% and 8.4%, respectively, and the fractions of H2 and CO decreased from 37.8% and 11.8% to 32.2% and 3.9%, respectively, due to the changed decomposition mechanism. Orthorhombic molybdenum oxide can be proposed as a promising catalyst for methane production.

Research on Skeleton Plate Flatness Detection Method Based on Laser Sensor

The flatness of the seismic isolation support skeleton plate determines the seismic isolation performance of the seismic isolation support, and in view of the limitations of the traditional measurement method in the engineering field, the use of laser sensor and computer-related processing technology is proposed to solve the problem of flatness measurement of the seismic isolation support skeleton plate. The laser sensor measurement can obtain the data of the skeleton plate plane, and use the relevant tools to calculate the difference between the maximum offset value and the minimum offset value from each measurement point to the ideal plane to obtain the flatness value. The experimental results show that the flatness measurement method of seismic isolation support skeleton plate based on laser sensor can quickly and accurately complete the measurement of skeleton plate flatness, with low requirements for engineering application environment and good measurement stability.

Fast numerical estimation of residual stresses induced by laser shock peening

The aim of this paper is to develop a model allowing a fast first approximate estimation of the elastic–plastic stress wave propagation caused by a laser impact and the resulting residual stress field. We start by modeling the stress wave propagation, adopting a 1D uniaxial modeling, reducing the behavior of the specimen to the axis of the laser impact, excluding any edge effects caused by the edges of the laser spot. The plastic strain field resulting from this propagation can in turn be used to compute the residual stresses, by making use of an analytic modeling in the case of an infinite planar plate. The accuracy of the 1D model is assessed by comparing it to finite elements simulations, acting as a reference solution, for several materials and laser spot diameters. The results show that the stress wave propagation from the 1D model is close to identical to the reference solution. The residual plastic and stress fields from the finite elements model present a uniaxial distribution on a large portion of the laser spot, except for the very edge and spot center. The comparison between the 1D model and the reference solution shows a good match, indicating that the 1D model can be used for a fast approximation the mechanical fields created by a laser impact for laser spot diameters larger than 2 mm.

Active shape control for flexible space structures using an optimal gyricity distribution

An active shape control approach for a circular flexible space structure is studied. The shape of these flexible structures may need active shape control due to some particular mission objectives. For example, antenna reflectors may have requirements for their shape accuracy to guarantee communication performance; and some solar sails may change their shape to realize different commissions during interplanetary flight. This paper investigates an active shape control process executed by the gyricity (stored angular momentum) distribution existing in the circular flexible space structure. The shape of the circular flexible space structure is expected to be reformed from a plane plate to a paraboloidal plate. An optimal gyricity distribution is derived based on the optimal control theory for systems described by partial differential equations. Distributed forces can be generated by the optimal gyricity distribution in a rotating field to implement the active shape control. The dynamic model of the circular flexible space structure is established for the active shape control through the finite element method. Numerical simulation validates the functionality of the shape control method, and illustrates the shape-adjusting process of the circular flexible space structure.

Regarding at the Circular Plates Rigidity with Radial Ribs, Neglecting the Welding Seams Influence. Ribs with Constant Thickness and Lineal Variable Heighness on Length, Placed Just on a Face

Abstract On base of obtained results in working [1], in a certain case one should take account the lineal chamfering of ribs upon the neutral fiber position and of the circular and plane plate bending rigiditybwith radial ribs. The illustration of the theoretical resultss is achieved on a given case.

Двойственная вариационная модель стационарного процесса теплопроводности, учитывающая пространственную нелокальность

Microcontinuum theories boast a great potential for simulating structurally sensitive materials. There exists a sufficiently large number of works delineating the basics of non-local mechanics using the theory of elasticity as an example. Estimating the investigative capacity of non-local mechanics is at present particularly relevant to simulating nanodevices, nanoelectromechanical systems (NEMS), and media featuring complex internal micro- and nanostructures. Typically, analysing these simulations involves overcoming certain difficulties caused by the necessity to solve integro-differential equations numerically. Variational methods may be successfully applied to analysing mathematical models of continuous media as an additional tool. The paper describes plotting an alternative functional for the problem of steady-state thermal conductivity in a homogeneous body, taking into account non-locality effects and featuring a temperature-independent thermal conductivity coefficient. We show that the stationary conditions for this functional do not differ from those in the absence of non-locality. The alternative functional combined with the fundamental functional presented previously constitute a dual variational model. We quantitatively analyse the problem of an infinite planar plate featuring constantly active internal heat sources. The dual variational formulation of the problem allows us not only to obtain an approximate solution to the problem under consideration, but also to estimate its error, as well as to reduce this error by selecting other approximating functions if necessary

A simplified formula to estimate the load history due to ballistic impacts with bullet splash. Development and validation for finite element simulation of 9x21mm full metal jacket bullets

An original simplified formula is proposed to estimate the load history caused by ballistic impacts characterized by the so-called bullet splash phenomenon, consisting in the complete bullet fragmentation with no penetration of the target. The formula is based on the progressive momentum variation of the mass of the bullet impacting on a planar plate normal to the impact direction. The method aims at creating a simplified approach to assess the response of structures by means of explicit finite element simulations without the need of modelling the interaction between impactor and target. The results demonstrate that the proposed method can be used to estimate the forces generated by bullet-splash phenomena of 9x21mm full metal jacket bullets and effectively applied to finite element simulations allowing significant reductions in computational cost.

Research on bearing capacity of honeycomb plate box-type hollow roof structure

• A new type of honeycomb plate box-type hollow roof structure is prepared with good ductility. • The validity of the numerical analysis model was verified by comparing the results of experiment with the results of the coupling model. • Influential factors on the bearing capacity of honeycomb plate box-type hollow roof structure obtained by parametric analysis. In this paper, a new type of honeycomb plate box-type hollow roof structure was prepared. The failure modes and mechanical properties of the box-type hollow roof structure were analyzed by bearing capacity test and numerical simulation. The validity of the numerical analysis model was verified by comparing the results of experiment with the results of the coupling model. The influence of specification of honeycomb plate, height of the side plate, rise-span ratio of the structure, configuration of box-type hollow roof structure, and initial geometric defect on the bearing capacity of the honeycomb plate box-type hollow roof structure were analyzed. The results show that the failure mode of the specimen is tensile failure of the surface plane of the honeycomb plate with strengthened frame and buckling instability of the plate near the joint. The results of coupling model are in good agreement with the results of experiment. The stiffness of honeycomb plate box-type hollow roof structure can be improved by the thickness of plate and the height of core layer of honeycomb plate. The ultimate bearing capacity of the honeycomb plate box-type hollow roof structure increases with the increase of the height and rise-span ratio. The bottom plate of box-type hollow roof structure can make the force transmission path of the structure more reasonable and effectively reduce the phenomenon of stress concentration. Compared with the structure without initial geometric defect, the stable bearing capacity of the structure is reduced by 18.6 % and the ultimate bearing capacity is reduced by 28 % when the initial geometric defect of 80 mm is applied to the structure.

Is a Complete Anatomical Fit of the Tomofix Plate Biomechanically Favorable? A Parametric Study Using the Finite Element Method.

The opening wedge high tibial osteotomy (HTO) fixation using the Tomofix system is at the risk of mechanical failure due to unstable fixation, lateral hinge fracture, and hardware breakage. This study aimed to investigate the effect of the level of anatomical fit (LOF) of the plate on the failure mechanisms of fixation. A finite element model of the HTO with a correction angle of 12 degrees was developed. The LOF of the TomoFix plate was changed parametrically by altering the curvature of the plate in the sagittal plane. The effect of the LOF on the fixation performance was studied in terms of the factor of safety (FOS) against failure mechanisms. The FOSs were found by 1) dividing the actual stiffness of the plate-bone construct by the minimum allowable one for unstable fixation, 2) dividing the compressive strength of the cortical bone by the actual maximum pressure at the lateral hinge for the lateral hinge fracture, and 3) the Soderberg criterion for fatigue fracture of the plate and screws. The increase of the LOF by applying a larger bent to the plate changed the fixation stiffness slightly. However, it reduced the lateral hinge pressure substantially (from 182 MPa to 71 MPa) and increased the maximum equivalent stresses in screws considerably (from 187 MPa to 258 MPa). Based on the FOS-LOF diagram, a gap smaller than 2.3 mm was safe, with the highest biomechanical performance associated with a 0.5 mm gap size. Although a high LOF is necessary for the Tomofix plate fixation to avoid mechanical failure, a gap size of 0.5mm is favored biomechanically over complete anatomical fit.

Energy selectivity in electron absorptive heating methods: does the angular momentum trap matter? An experimental investigation

Comparison between the Maxwell demon and a planar electrode has been revisited with an in-depth analysis of whether the angular momentum trap of the Maxwell demon indeed provides better energy selectivity than a small planar electrode that absorbs electrons indiscriminately. The evolutions of the EEDF under the influence of these heating techniques is directly analyzed, as well as the resultant plasma parameters. Experimental results show that the Maxwell demon indeed provides better energy selectivity as shown by its better retention of hot electrons than an indiscriminative absorption surface, which in turn results in smaller disturbance to the plasma potential a smaller reduction of the plasma density in the heating process. Experimental result also shows no electron heating when the demon is replaced by an ion-sheath forming large electrode, this is consistent with Mackenzie’s original results (MacKenzie et al 1971 App. Phys. Lett. 18 529). While it is possible to obtain the exact same plasma parameters replacing the Maxwell demon with a suitably sized planar plate and additional plasma parameters control, for experiments sensitive to the exact processes from which plasma parameters are formed, one should not overlook the physical differences of these heating methods.

Resummation for quantum propagators in bounded spaces.

We outline an approach to calculating the quantum mechanical propagator in the presence of geometrically nontrivial Dirichlet boundary conditions. The method is based on a generalization of an integral transform of the propagator studied in previous work (the so-called "hit function") and a convergent sequence of Padé approximants that exposes the limit of perfectly reflecting boundaries. In this paper the generalized hit function is defined as a many-point propagator, and we describe its relation to the sum over trajectories in the Feynman path integral. We then show how it can be used to calculate the Feynman propagator. We calculate analytically all such hit functions in D=1 and D=3 dimensions, giving recursion relations between them in the same or different dimensions and apply the results to the simple cases of propagation in the presence of perfectly conducting planar and spherical plates. We use these results to conjecture a general analytical formula for the propagator when Dirichlet boundary conditions are present in a given geometry, also explaining how it can be extended for application for more general, nonlocalized potentials. Our work has resonance with previous results obtained by Grosche in the study of path integrals in the presence of delta potentials. We indicate the eventual application in a relativistic context to determining Casimir energies using this technique.