Cylinder Of Material Research Articles

Towards the exact solutions of Burger’s fluid flow through arteries with fractional time derivative magnetic field and thermal radiation effects

We consider the unsteady flow of Burger fluid within a circular cylindrical tube, driven by a time-dependent pressure gradient, a body acceleration and a magnetic field acting normal to the flow direction. The solutions of the fractional constitutive equations governing the unsteady Burger’s fluid flow through arterial walls were obtained via the Laplace transform and the finite Hankel transform. The effects of magnetic field on parameters such as blood temperature and velocity were studied by Caputo time-fractional derivatives. We note that the solutions of many particular models such as fractional Oldroyd-B fluid, fractional Maxwell fluid, fractional second grade fluid and fractional Newtonian fluid models can be recovered from the solutions of the fractional constitutive equations governing the unsteady Burger’s fluid flow by particularizing the material coefficients (i.e. special and limiting cases of the earlier Burger’s fluid model). The numerical computations have been carried out to analyze the effects of fractional parameter α, similarity parameter β, relaxation time λ1, retardation time λ3, radius of the circular cylinder R0 and material parameter λ2 on the blood velocity and temperature. Some interesting flow and temperature characteristics are presented graphically and discussed. The study reveals that blood velocity, temperature and fractional parameters are reduced in the presence of magnetic field. The importance of this study can be found in the application fields of magnetic field control of biotechnological processes, bio magnetic device technology, biomedical engineering, medicine, etc.

Van der Waals Interactions of Moving Particles with Surfaces of Cylindrical Geometry

General nonrelativistic theory has been developed and the expressions obtained for the tangential (dissipative) and radial (conservative) image forces and van der Waals forces (vdW) acting on charged and neutral particles when they move parallel to the axis of a cylinder with circular cross-section, or in the space between coaxial cylinders. Numerical calculations of vdW forces have been performed for metal (Au) and dielectric (Si) materials of cylinders (filaments) and Cs atoms at velocities ~107m/s. A remarkable result is that in the case of metal cylinders (atomic filaments and chains) the dynamic vdW potential can be repulsive for certain values of the velocity–distance parameter and the characteristic atomic frequency. In the case of a Si material, the dynamic vdW potential increases relative to the static one (by modulus) when the velocity–distance parameter Vω0/R changes from zero to ~1.3 and then tends to zero.

Elastic fields of a wedge disclination in a functionally graded cylinder

In this paper, the elastic fields of a wedge disclination in a functionally graded cylinder are obtained in closed-form by directly solving the equilibrium equations. The cylinder material is graded radially according to a power law characterized by a gradient index. The disclination has a small fixed core of nanometer dimension. The results show that: (1) the displacement, radial and transverse stresses vary with the radial coordinate according to a sum of power laws, (2) the gradient index changes the elastic fields through modification of the elastic parameters, and modification of the power law indices of the field dependence on (i) the radial coordinate and (ii) the cylinder dimensions, (3) the stresses at and near the disclination core are generally reduced by both positive and negative gradients, (4) the transverse stress at the disclination core can be reduced to zero and even compressive for small negative gradients, (5) a significant size effect exists for the disclination stresses, and the effect is influenced strongly by the gradient index, (6) the energy of the disclination is a strong, non-monotonic function of the gradient. These results suggest that various relaxation phenomena such as crack nucleation and disclination splitting may be controlled by selecting a suitable gradient for the material variation.

Design and Fabrication of Faulty Product Detection and Separation System

With recent advances in industrial technologies, automation has become an indispensable part in the manufacturing world. Industrial environments are adopting more and more aspects of automation to increase product quality, accuracy, and reduce product costs. Conveyor systems are used wildly in manufacturing industries. This automated conveyor system works by detecting the size of the material in the conveyor using ultrasonic sensors. The microcontroller analyses this data from the ultrasonic sensor and then directs the pneumatic cylinder material to different directions, height-wise, depending on the height of the material. The position of the conveyor is indicated by a 16X2 liquid crystal display and LED. This project thus automates the material separation process in the conveyor to improve efficiency and increase productivity.

Stress Analysis of Thick-Wall Hollow Functionally Graded Material Based on Plane Strain Problem

In this study, the mechanical behaviours of thick-walled hollow functionally graded material (FGM) cylinder subjected to uniform pressures at inner and outer surfaces are proposed. The hollow FGM cylinder has variable geometric profile, thickness and material properties like elastic modulus and mass density are all assumed to vary radially according to exponentially-varying functions in radial direction. With the help of the infinitesimal elasticity theory and plane strain assumption, analytic solutions of stress and deformation are proposed. Numerical example is given to show the performance between FEM and homogeneous cylinder. Finally, summary and the future work are presented at the end of the paper.

Tunable nearly perfect light absorber consisted of gold cylinder and phase changing material in the near-infrared regime

In this paper, we design and investigate a dual-band nearly perfect light absorber by simulation method. It consists of a three-layered structure with a gold (Au) cylinder array layer and a Ge2Sb2Te2 (GST) spacer on the metal aluminum (Al) substrate. The absorber exhibits nearly perfect light absorbance in the infrared regime. The dependency of the light absorption performance on various geometric parameters is explored. Dynamically tunable of the light absorption peak in the range of 1050–1550 nm is achieved by changing the crystallization fraction of the GST material. The absorption performance is independent with the polarization angle of incidence light and the incident light direction. Furthermore, we demonstrate a high sensitivity refractive index (RI) sensor based on this structure. This tunable absorber exhibits great potential application in high-performance optoelectronic devices and sensors.

Achievements of the department for development of new products, related technologies and materials of JSC RosNITI

The latest achievements of the department for new products, related technologies and materials are presented in the following areas: creation of anti-corrosion and conservation coatings; development of cylinders; development and testing of rolling tools, technological lubricants and coatings. Based on the results of the activities of the department employees, high-tech science-intensive types of new products with high added value, which are in demand in the market, have been developed and implemented, such as heat-insulated lift pipes, oil and gas pipes with a metal coating of the welded joint zone, pipes with threaded casing connections with GW coatings, pipes with deoxidized inner and outer surfaces, cylinders of new designs, original lubricants and deoxidizing materials.

Research on the variation of resistance of granular system with different sizes under compressive stress

Titanium diboride (TiB2) is a granular material with good electrical conductivity. Its electrical resistance changes significantly under the action of force. Therefore, it can be used as a variable resistor in the power field. In order to achieve this goal, TiB2 particles with a diameter of 30 μm are selected. Through experiments, the resistance of a granular system under a different material height, a different cylinder diameter, and a different force is measured. The relationship between resistance and force is analyzed. Based on the force chain network, a model of the resistance network of the granular system under constant force is established. The effect of cylinder diameter and material height on electrical resistance can be described by this model. The experimental results show the accuracy of the model. The research results of this paper can provide a basis for the application of granular material in the field of power equipment.

ON AUTOMATIC SEGMENTATION METHOD USING IN SOLVING NONLINEAR INITIAL BOUNDARY VALUE PROBLEMS OF MECHANICS OF SOFT-SHELL STRUCTURES

An approach to improving nonlinear initial boundary value problems of thin-walled structures solution algorithm is represented in the work. The algorithm is based on using line method and parameter differentiation method and is oriented to analysis of composite structures behavior at arbitrary physical and geometrical nonlinearity. Obviously, the less restrictions the calculation algorithm imposes on problem statement, the more features of its realization must be taken into account when developing corresponding software module. The drawback of universality of the algorithm represented is that its direct implementation in some cases can lead either to wrong results, or to loss of calculation stability. To avoid these problems we suggest automatic segmentation method using as a step of the algorithm developed. The essence of the method lies in testing fulfillment of the condition of normalized integral matrices of initial and conjugate differential equation systems orthogonality at the step of problem preprocessing. In the points of integration interval where orthogonality condition is not fulfilled segmentation of the interval is carried out. For testing this approach we select nonlinear problems of dynamic inflation of an infinite cylinder of Mooney-Rivlin material and a sphere of Neo-Hookean material by suddenly applied pressure. It is shown that automatic segmentation method allows improving period and amplitude calculation accuracy, as well as increasing iteration process convergence rate. A problem of dynamic inflation of a hinged hemisphere of Neo-Hookean material by suddenly applied pressure is considered. On the basis of its solution results we suggest the approach to determining parameters of calculation algorithm which allow obtaining correct solution.

Evaluation and Analysis of RT Suspected Defects on Reactor Pressure Boundary Weld

The control rod driving mechanism (CRDM) is one of the important equipments in the nuclear reactor, and its sealing shell is part of the pressure boundary of the nuclear reactor. The sealing shell is a pressure vessel made of two different material (austenitic stainless steel and nickel base alloy) cylinders welded by dissimilar metal welds. Product production process, in this dissimilar metal weld ray detection found suspected defects show. In this paper, the mechanism and process of the suspected defects are expounded through experimental verification, and it is proved that the suspected defects do not affect the quality of the weld.

Влияние режима литья под давлением на свойства аппретированных и функционализированных нанокомпозитов на основе полиэтилена низкой плотности

The results of a study of the effect of injection molding on the physicomechanical and technological properties of nanocomposites based on functionalized low-density polyethylene by maleic anhydride and dressed with talc γ-aminopropyltriethoxysilane are presented. As the object of study, nanocomposites with 5.0 and 30 mass. % of dressed talc were used. Properties such as breaking stress, elongation at break, flexural strength, and volumetric shrinkage were investigated. It was found that the introduction of dressed talc in the composition of chemically modified low density polyethylene contributes to some increase in the breaking stress and the flexural modulus of the nanocomposite. Experimental studies were carried out in a wide range of temperatures of the material cylinder and casting pressure. It was found that comparatively high physical and mechanical properties are achieved in samples obtained at higher temperatures in the zones of the material cylinder. Casting pressure ranged from 50 to 150 MPa. It was found that relatively high physicomechanical and technological properties for nanocomposites with 5.0 and 30 mass. % talc content are achieved at a temperature of the material cylinder in the zones 110 – 130 – 160 – 180 °C and a casting pressure of 150 MPa. A significant reduction in volumetric shrinkage is achieved in samples with 30%mass. talc content. The influence of mold temperature and holding time under pressure on the change in the properties of nanocomposites is considered. It is shown that the most optimal mode in the cooling mold for samples with 5.0 mass. % talc content is 50 °C and the exposure time under pressure is 20 s, and for a nanocomposite with 30%mass. talc content — 50 °C and holding time 10 s. The influence of the location of the gate device relative to the surface of the sample on the change in the properties of composite materials is studied. The scientific substantiation of the discovered patterns in changing the properties of nanocomposites is given.

Реакционная экструзия нанокомпозитов на основе этиленовых сополимеров и минеральных наполнителей

The paper presents the results of a study of the influence of the temperature regime of reaction extrusion on the main physicomechanical characteristics of nanocomposites based on copolymers of ethylene with butylene and ethylene with hexene and natural minerals - clinoptilolite and vesuvian. The optimal temperature regime of extrusion of nanocomposites based on copolymers of ethylene and natural minerals was established. At a maximum extrusion temperature of 230 °C in the dosing zone, counterflow increases, which contributes to an increase in the residence time of the nanocomposite melt and, accordingly, to a decrease in extruder productivity. The possibility of mechanochemical synthesis of nanocomposites vulcanized with dicumyl peroxide on an extruder using monotreme technology has been proved. It was found that as a result of vulcanization of nanocomposites based on ethylene copolymers, a significant increase in the ultimate tensile stress and a decrease in the elongation at break are observed. With an increase in the maximum extrusion temperature in the extruder head to 230 °C, it does not lead to the appearance of a counterflow. At the same time, it was shown that with an increase in the temperature regime of extrusion of vulcanized nanocomposites over 200 °C, the time spent by the melt in the material cylinder practically does not undergo changes. A fundamental feature of the effect of chemical crosslinking with dicumyl peroxide on the processing process and the regularity of changes in the properties of nanocomposites are established. The probable mechanism of the vulcanization process in the melt of the polymer matrix and its selective effect on the reaction extrusion process, structural features and properties of nanocomposites are presented.

Magnetophotothermal interaction in a rotating solid cylinder of semiconductor silicone material with time dependent heat flow

A mathematical model linking thermoelasticity to photothermal experiments is proposed with the consideration of the photothermal effect. The system equations for coupled plasma, heat conduction with phase-lags (PLs), and motion equations are introduced and solved by using the Laplace transform technique. The photothermal, thermal, and elastic waves in a rotating solid cylinder of semiconductor material are analyzed with the proposed model. The cylinder surface is constrained and subjected to a time-dependent pulse heat flux. The sensitivity of the physical fields for the angular velocity, PLs, and thermal vibration parameters is investigated. In addition, the effects of the effective parameters on the physical quantities are graphically illustrated and discussed in detail.

The Poynting effect

Intuition suggests that twisting a cylinder will shorten it, but here it is shown that for a cylinder of an incompressible material, like rubber, twisting will always produce elongation.

Permeability properties of a pressure induced compacted polymer liner in gas cylinder

AbstractThe permeability properties of composite gas cylinders for breathing gas with polymer inner‐liner are investigated. The cylinder wall can be described as a composite membrane consisting of two layers. The permeability properties of the cylinder are presented as permeability coefficient and permselectivity. Deviation from the expected gas components might lead to incidents and potentially harmful situations when breathing gas from a compressed gas cylinder. Hence, gas permeability and potential changes in gas composition, must be considered when choosing cylinder materials. Cases of decompression sickness initiated this study. Experimental data show that pressure and oxygen fraction in the gas cylinder drops and that the permeability coefficient varies depending on the inner pressure. Permeability coefficients of 0.62–0.90 Barrer for oxygen and 0.44–0.56 Barrer for nitrogen are measured. Cracks in the inner‐liner have caused an accentuated drop in of oxygen fraction and pressure.

Transient Response in a Bi-material Cylinder of Soft Ferromagnetic Material Subjected to Magnetic Shock

The transient response in a bi-material cylinder of soft ferromagnetic material under magnetic shock is investigated in this study. The analytical solutions for displacement and stress have been derived using the finite Hankel transform and the Laplace transform. The numerical examples show that the displacement and stress fields respond dynamically in the bi-material cylinder under magnetic shock. The derived displacement at the center and radial stress on the surface of the cylinder satisfy the boundary conditions, showing the correctness of calculation. The displacement and stress waves propagate from the surface to the center of the cylinder when the magnetic field is loaded. The stress fields increase from the center to the surface of the cylinder and are much larger than the quasi-static state since the waves reflect, collide and concentrate in the body of the cylinder. The method of this paper can be used in the design of soft ferromagnetic structures.

Melting process modeling of Carreau non-Newtonian phase change material in dual porous vertical concentric cylinders

In this paper a numerical simulation of the melting process of Carreau non-Newtonian phase change material inside two porous vertical concentric cylinders included constant temperatures of the inner and outer walls, represented by Th and Tc, respectively. Half of the void between the two pipes is filled with copper porous media and paraffin wax as a phase change material. The governing equations are converted into a dimensionless form and are solved using the finite element method. The enthalpy porosity theory is applied to simulate the phase change of phase change material while the porous media follow to the Darcy law. Outcomes are shown and compared in terms of the streamline, isotherm, melting fraction and mean Nusselt numbers. The solid liquid interface location and the temperature distribution are predicted to describe the melting process. The effects of the Carreau index, porosity and non-dimensional parameters such as Stefan number, Darcy number, and Rayleigh number are analyzed. Our results indicate a good agreement between this study and the previous investigations. The results show that an increase in Rayleigh number, Stefan number, and Darcy number, increases the melting volume fraction and reduces the melting time. Also, the time of melting non-Newtonian phase change material decreases when Carreau index and porosity decrease.

Dynamic oscillatory powers, cross sections, and energy efficiencies in coherent optical heterodyning.

In a recent analysis [J. Quant. Spectrosc. Radiat. Transfer250, 106994 (2020)JQSRAE0022-407310.1016/j.jqsrt.2020.106994], the emergence of a dynamic oscillatory radiation force in coherent optical/electromagnetic (EM) heterodyning has been demonstrated for TM- and TE-polarized amplitude-modulated (AM) plane waves interacting with a lossless dielectric circular cylinder. A dynamic oscillatory component of the EM radiation force emerged at the beat frequency of two interfering fully correlated wave fields driven at slightly different frequencies. This work extends the scope of that analysis to examine the oscillatory behavior of energy-related physical observables from the standpoint of energy conservation applied to scattering. Partial-wave series for the oscillatory scattering, extinction and absorption powers, cross sections, and energy efficiencies are derived in cylindrical coordinates for a circular homogeneous cylinder material using the short-term time averaging (STTA) procedure and Poynting's theorem. AM plane progressive waves incident upon a lossless dielectric cylinder with arbitrary radius are considered. Numerical computations of the oscillatory scattering and extinction energy efficiencies illustrate the theory. A criterion based on computing and quantifying accurately the percentage (or relative) error between the dynamic (oscillatory) extinction and scattering efficiencies is developed and numerically evaluated. This benchmark tool provides physical validation and verification of the results from the standpoint of energy conservation. The results show that the percent (relative) error increases at the resonances of the dielectric cylinder as its refractive index increases. Far from the resonances, the oscillatory component of the STTA remains appropriate because the percent (relative) error does not exceed 0.05%, provided the beating difference frequency is much smaller than that of the primary waves. The case of an absorptive dielectric cylinder is also illustrated and discussed. The present analysis is of fundamental importance in order to validate dynamic radiation force computational results from the standpoint of energy conservation in the development, design, and optimization of oscillatory optical heterodyne tweezers and tractor beams in related applications in particle manipulation.

Wear of uncoated and PVD coated cemented carbide tools for processing of copper based materials part I: Lab test verification in dry and lubricated sliding

In the manufacturing of metal zippers, including several complicated forming and shearing process steps, the tool wear is a limiting factor, since it deteriorates the quality of the zipper elements. Hence, an increased understanding of the tool wear mechanisms occurring in the zipper production is important to prolong the tool life.To gain deeper insights into the tool wear mechanisms active in the process of shearing Cu alloy wire into separate zipper elements, the present study utilizes a simplified sliding test rig. The rig comprises a small tool material cylinder sliding against a large rotating work material cylinder, in a crossed cylinders configuration. One uncoated and two PVD-coated cemented carbide cylinders were tested under contact conditions similar to those of the actual shearing. The tool material cylinder was analyzed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) at selected intervals during the test. The surface appearance was investigated and compared with observations on tools used in actual zipper production. The degradation was found to include gradual wear against the Cu alloy, transfer of the Cu alloy and characteristic modifications of the topography, indicative of wear mechanisms operating at a very small scale, confirming that the wear of the shearing tools can be mimicked by the test.

Temperature and solvent facilitated extrusion based 3D printing for pharmaceuticals

On demand manufacturing of patient-specific oral doses provides significant advantages to patients and healthcare staff. Several 3D printing (3DP) technologies have been proposed as a potential digital alternative to conventional manufacturing of oral tablets. For an additive manufacturing approach to be successful for on-demand preparation, a facile process with minimal preparation steps and training requirements is needed. A novel hybrid approach to the 3D printing process is demonstrated here based on combining both a solvent and heating to facilitate extrusion. The system employed a moderate elevated temperature range (65-100 °C), a brief drying period, and a simple set-up. In this approach, a compact material cylinder is used as a pharmaceutical ink to be extruded in a temperature-controlled metal syringe. The process proved compatible with hygroscopic polymers [Poly(vinyl alcohol (PVA) and polyvinylpyrrolidone (PVP)] and a number of pharmaceutical fillers (lactose, sorbitol and D-mannitol). The fabricated tablets demonstrated acceptable compendial weight and content uniformity as well as mechanical resistance. In vitro drug release of theophylline from 3D printed tablets was dependent on the nature of the polymer and its molecular weight. This reported approach offers significant advantages compared to other 3DP technologies: simplification of pre-product, the use of a moderate temperature range, a minimal drying period, and avoiding the use of mechanically complicated machinery. In the future, we envisage the use of this low-cost and facile approach to fabricate small batches of bespoke tablets.