Shape Of Cylinder Research Articles

αTAT1-induced tubulin acetylation promotes ameloblastoma migration and invasion

AbstractAmeloblastoma (AB) is the most common benign epithelial odontogenic tumor occurring in the jawbone. AB is a slowly growing tumor but sometimes shows a locally invasive and an aggressive growth pattern with a marked bone resorption. In addition, the local recurrence and distant metastasis of AB also sometimes occurs, which resembles one of the typical malignant potentials. From these points of view, to understand better the mechanisms of AB cell migration or invasion is necessary for the better clinical therapy and improvements of the patients' quality of life. Microtubules in eukaryotic cells reveal the shape of hollow cylinders made up of polymerized alpha (α)- and beta (β)-tubulin dimers and form the cytoskeleton together with microfilaments and intermediate filaments. Microtubules play important roles in cell migration by undergoing assembly and disassembly with post-translational modifications. Stability of microtubules caused by their acetylation is involved in cell migration. In this study, we investigated the expression and distribution of acetylated α-tubulin and alpha-tubulin N-acetyltransferase 1 (αTAT1), an enzyme which acetylates Lys-40 in α-tubulin, in AB specimens, and analyzed how tubulin was acetylated by αTAT1 activation in a human AB cell line, AM-1. Finally, we clarified that TGF-β-activated kinase1 (TAK1) was phosphorylated by TGF-β stimulation, then, induced tubulin acetylation via αTAT1 activation, which subsequently activated the migration and invasion of AB cells.

Влияние пространственной неоднородности подложек и электрического поля на динамику зажатой капли

This article investigates the forced oscillations of an incompressible liquid drop under the action of an inhomogeneous alternating electric field. The drop is surrounded by an incompressible fluid of a different density and is clamped between two inhomogeneous parallel plates. In equilibrium, the drop has the shape of a round cylinder bounded in the axial direction by these plates. The external electric field acts as an external force causing the contact line to move. To describe the motion of the contact line, a modified Hocking boundary condition is used: the velocity of the contact line is proportional to the deviation of the contact angle from its equilibrium value and the rate of fast relaxation processes, the frequency of which is proportional to the doubled frequency of the electric field. The use of this equation makes it possible to qualitatively describe the experimental dependence of the contact angle as a function of stress, in contrast to the Young-Lippmann equation. The solution of the problem is represented as a Fourier series in terms of eigenfunctions of the Laplace operator. The resulting system of inhomogeneous equations for unknown amplitudes is solved numerically. Graphs of the amplitude-frequency characteristics and the dynamic shape of the drop are plotted for various values of the problem parameters. The wetting parameter depends on the polar angle  , i.e. the coefficient of interaction between the plate and the fluid (contact line) is a function of the coordinates.

Punching shear performance of steel-fiber reinforced concrete-steel sandwich plates under different patch loading heads

Steel-concrete-steel sandwich structure is gradually applied to the containment of nuclear power plants for its good behaviors in sealing performance and mechanical properties. Concentrated loads are possible loading cases of the nuclear power plants in practical engineering, such as fuel channels and auxiliary buildings striking on containment walls. In this paper, four steel-concrete-steel sandwich plates with headed studs and tie bars were designed. The inner core used fiber reinforced self-compacting high strength concrete, which was a material innovation in the noval steel-concrete-steel composite structure. Static concentrated loads acted on sandwich plates through three different shapes of patch loads, i.e., square, cylinder and hemisphere loading heads. Punching shear failure mode and mechanism of four specimens were revealed and analyzed. Besides, refined finite element models were established by Abaqus software. The influence of the concrete strength and loading heads with different widths was parametrically studied. Finally, calculation methods of bearing capacity at two peak points were proposed, which provided some reference for the applicability of steel-concrete-steel sandwich plates in engineering.

Combined effects of various strategies to curtail exhaust emissions in a biomass waste fueled CI engine coupled with SCR system

This study is an exhaustive investigation on engine performance and combustion features of a conventional diesel engine charged with biodiesel produced from biomass waste. Grapeseed oil methyl ester resulted in poor thermal efficiency with enormous quantity of harmful emissions. As an effort to reduce the engine pollutants, Grapeseed oil methyl ester was doped with zinc oxide nano particles, engine cylinder shape modification and exhaust gas recirculation method was used. Hydrocarbons, carbon monoxide and smoke emissions reduced considerably, whereas reduction in nitrogen oxide emissions was low. Selective catalytic reduction technique at optimized mass flow rate of aqueous urea solution minimized the nitrogen oxide emissions by 76.9% compared to grapeseed oil methyl ester without compromise in brake thermal efficiency.

On the behavior of nonlinear hydrodynamic coefficients of a submerged cylinder beneath the water surface

This study aims at numerically exploring the behavior of flow fields and nonlinear hydrodynamic coefficients of a horizontal cylinder beneath the free surface flow considering the effects of nonlinear surface waves and various cylinder shapes. The computational model is based on two-dimensional incompressible Navier-Stokes solvers along with the treatment of the free surface flow using the volume of fluid method. The effect of the turbulent flow is also considered by using the shear stress transport turbulence model. The simulation result of a benchmark case study of the submerged cylinder is first validated with available experiment data, where a mesh convergence analysis is also performed. Afterward, the flow fields and hydrodynamic force coefficients around the cylinder surface are analyzed, and the influences of various cylinder shapes and Reynolds numbers on the hydrodynamic coefficients are investigated. A state diagram representing the hydrodynamic behavior including stable and unstable stages is finally proposed; this is an important criterion for the practice design of submerged civil structures under the free surface flow.

The analogy of nanoparticle shapes on the theory of convective heat transfer of Au–Fe3O4 Casson hybrid nanofluid

AbstractIn recent times, Au nanoparticles have been commonly used for delivering the drug especially in the case of hypothermia of tumors, but low absorption of IR light does not solve destruction of tumor cells. However, nanoparticles such as Fe3O4 coated with Au could be used to deliver the drug to a specific spot due to applied external magnetic field. Due to these applications, boundary layer approximation is invoked to simplify the mathematical model. This paper presents the nanoparticle shape analysis and heat transfer features of the Au–Fe3O4–blood hybrid nanofluid flowing past a stretching surface on a magnetohydrodynamic medium. Numerical solutions of nonlinear differential equations are obtained by RKF‐45 method with the help of shooting technique. The behavior of emerging parameters is described graphically for velocity and temperature profiles. It is found that the blade‐shaped Au and Fe3O4 nanoparticles have better thermal conductance than brick, sphere, cylinder, needle, and platelet shapes. It is also observed that the Lorentz force generated due to magnetic field helps in controlling the flow and enhance the thermal conductivity of hybrid nanofluid.

Effects of Soret and Dufour numbers on MHD thermosolutal convection of a nanofluid in a finned cavity including rotating circular cylinder and cross shapes

This study considers a more complex problem by introducing magnetohydrodynamic (MHD) thermosolutal convection of a nanofluid in a square cavity including dual rotation amongst an outer circular cylinder and an inner cross shape. The influences of the length of a cross shape LCros, a dimensionless time parameter τ, Hartmann number Ha, Soret number Sr, Dufour number Du, solid volume fraction ϕ, an inclination angle of a magnetic field γ, and Rayleigh number Ra on the heat/mass transfer and nanofluid movements within a cavity are examined. Three different thermal/solutal boundary conditions of an outer circular cylinder carrying (Tc & Cc) (case 1), (Th & Ch) (case 2), and adiabatic conditions (case 3) are conducted. The inner cross shape is kept at Th and Ch. The obtained numerical simulations revealed that the changes in the thermal/solutal boundary conditions have a good role in controlling the thermosolutal convection and nanofluid speed within a cavity. Increasing the length of a cross shape LCros enhances the nanofluid speed and intensity of temperature and concentration within a cavity in cases 1 and 3. Case 2 gives the highest values of mean Nusselt number Nu¯ and Sherwood number Sh¯. The Rayleigh number is performing well in enhancing the nanofluid movements and heat/mass transfer within a cavity.

Darcy–Forchheimer up/downflow of entropy optimized radiative nanofluids with second‐order slip, nonuniform source/sink, and shape effects

AbstractThis article examines the influence of single‐walled carbon nanotube (SWCNT)/multi‐walled carbon nanotube (MWCNT) nanoparticles shapes on the radiative up and down flow of nanofluids past a thin needle. This nanofluid flow is considered in the presence of Darcy‐Forchheimer effects, thermal radiation, Wu's slip, and non‐uniform heat source/sink. Brick, cylinder, platelet, and blade shapes of nanoparticles are considered. Numerical solutions are attained by a well‐known shooting technique. A comprehensive discussion regarding the effects of physical parameters on velocity, temperature, skin friction coefficient, and local Nusselt number is carried out. Outcomes reveal that fluid velocities of SWCNT/MWCNT‐Water nanofluids behave in the opposite manner in up and down flows of nanofluids in the order of brick, cylinder, platelet and blade‐shaped nanoparticles. The porosity parameter regulates the heat transfer rate efficaciously. The surface viscous drag intensifies for the nanofluids involving the nanoparticles in the order of their shapes as brick, blade, cylinder, and platelet.

Justification of the geometric dimensions of drum sorting machine

This article presents the results of research to determine the basic geometric dimensions of a drum sorting machine designed for potato sorting. A critical analysis of the current situation in this area has been carried out. A number of research works have been studied aimed at developing special methods to reduce manual labour and improve the quality of sizing and sorting potatoes. At the same time, it is important to sort by size with a low level of product damage, with high productivity. Known mechanical and robotic machines used for sorting potatoes: roller, drum, conveyor (belt) and combined. And also, with the help of machine and computer vision, laser backscattering of light, ultrasonic, visual and spectral analysis systems, optical, acoustic intelligent sorting systems. Among the mechanical ones, the drum sorting machine is the simplest in design. The disadvantage of this machine is that during operation the product to be sorted is only in the lower part of the drum, i.e. only part of the work surface is used. To eliminate the abovementioned disadvantage, a new design of the machine is recommended. Where the sorting surface is made of elastic mesh, the size of the holes increased in the direction of movement of the ends along the sorting surface. The ends are connected and pulled together on two drums. The holes of the elastic mesh material vary in size, the size of the holes increases from the beginning to the end of the sorting surface. The drum can be in a truncated cone or a cylinder shape. To ensure the efficient operation of the proposed machine, mathematical calculations are derived, including geometric and kinematic parameters.

Wind tunnel tests of aerodynamic interference effects on two iced vertical circular cylinders in a tandem arrangement

The aerodynamic characteristics of the two iced vertical circular cylinders in a tandem arrangement, due to the shape change by icing, are complex, and lack systematical investigation. Therefore, a set of wind tunnel tests were carried out to study the aerodynamic characteristics of the leeward vertical cylinder, with ice shape, icing thickness, cylinder spacing, and icing relative position of cylinders varied in the subcritical Reynolds number range in this study. Results show that the icing thicknesses had a greater impact on the lift coefficients of D-shaped ice leeward cylinder at the same angle of attack. The aerodynamic characteristics of the iced leeward cylinder were stable when the ratio (L/D) of cylinder spacing was within the range of 4.8–6.2. The change of flow field should be considered in the stability analysis of two circular vertical cylinders. The drag coefficients of the iced leeward cylinder varied significantly due to the shielding effects, especially within the range of 9° attack angle and L< 6.2D. The results of this work can provide an experimental reference for future research on wind resistance of two circular cylindrical structures in engineering practice.

Impact of Turbulence Models of Wind Pressure on two Buildings with Atypical Cross-Sections

Abstract The article deals with the numerical analysis of the wind pressure distribution on a group of two high-rise buildings of different shape for different wind directions. The first building has the shape of a circular cylinder and the second was created by a combination of semicircles and a longitudinal member. The floor plan of the second building was similar to the letter S. The simulations were realized as 3D steady RANS. CFD results were compared with experimental measurements in the wind tunnel of the Slovak University of Technology in Bratislava. The results were processed using statistical methods such as correlation coefficient, fractional bias and fraction of data within a factor of 1.3, which determined the most suitable CFD model. The purpose of the present article was to verify the distribution of the external pressure coefficient on scale models at a scale of 1:350, which are located in the Atmospheric Surface Layer (ASL). In numerical modeling, the most important thing was to ensure similarity with the flow in the experimental Atmospheric Boundary Layer (ABL) and with the flow around the models. SST k–ω was evaluated as the most suitable turbulent model for the given type of problem. Turbulent models had a decisive influence on the overall distribution of external wind pressures on objects. The results showed that the most suitable orientation of the objects in terms of the external wind pressure coefficient is 0°, when the cylinder produced a shielding effect, with min mean cpe = −0.786. The most unfavorable wind effects were shown by the wind direction of 90° and 135° with the value min mean cpe = −1.361.

Abrasive-Wheel-Wear Abrasion Resistance Test for Hard Anodic Oxide Coating on the Nonplanar Cylinder Shape Sample

Abrasive-Wheel-Wear Abrasion Resistance Test for Hard Anodic Oxide Coating on the Nonplanar Cylinder Shape Sample

Transport Calculation of the Multiplicity Moments for Cylinders

In a previous paper by Pázsit and Pál [“Multiplicity Theory Beyond the Point Model,” Ann. Nucl. Energy, Vol. 154 (2021)], a general transport theory calculation of the factorial moments of the number of neutrons emitted spontaneously from a sample was elaborated. In contrast to the original derivations by Hage and Cifarelli [“On the Factorial Moments of the Neutron Multiplicity Distribution of Fission Cascades,” Nucl. Instrum. Meth. Phys. Res. A, Vol. 236 (1985)] and Böhnel [“The Effect of Multiplication on the Quantitative Determination of Spontaneously Fissioning Isotopes by Neutron Correlation Analysis,” Nucl. Sci. Eng., Vol. 90 (1985)], also referred to as the point model, in the transport model the spatial and angular dependence of the internal fission chain is taken into account with a one-speed transport theory treatment. Quantitative results were given for a spherical item, and the bias of the point model regarding the estimation of the fission rate as compared to the more exact space-dependent model was estimated as a function of the size of the sphere and the factor. In the present paper the formalism and the quantitative work are extended to the treatment of items with cylindrical shapes, which are more relevant in many practical applications. Results are presented for both square cylinders () and for tall () and flat () cylinders. This way the differences between the cylinder and the sphere on one hand and those between the various cylinder shapes on the other hand can be estimated. The results show that the bias depends on the geometry of the cylinder quite moderately, but similarly to the case of the sphere, the bias of the point model is quite significant for larger item sizes and values, and it is nonconservative (underestimates the fissile mass) as well.

Quantum states of hydrogen cations confined into spherical and nanotube-like potential wells: , (C 2h and C 2v ) and (D 3h )

In this work, the potential energy surfaces (PESs) of hydrogen-based cations and placed inside infinite potential wells, in the shape of an infinite cylinder and a sphere, are investigated. The calculations are performed using the diffusion Monte Carlo (DMC) technique. Different symmetries are studied, some of them for the first time. The PESs trends are rationalized. The Raman shift of mode of spherically confined is also calculated.

The effect of nanoparticle shape on alumina/EG-water (50:50) nanofluids flow within a solar collector: Entropy and exergy investigation

In this paper, the entropy generation (EGen) and exergy of a solar collector (SC) with alumina/ethylene glycol-water (50:50) nanofluid (NFs) flow are calculated. The tubes and the absorber plate of the collector are made of copper and steel, and the results of both materials are compared. Tubes with hexagonal cross section are considered. Nanoparticles (NPs) with four different shapes of platelet, brick, blade, and cylinder are considered, and their effect is evaluated. Volume fraction (ϕ) changes in the range of 0–4%, and mass flow rate varies from 0.25 to 1 kg/s. These parameters as well as the material of collector tubes and the shape of NPs are the variables of this study and their effect on fluid frictional entropy generation (Sg,ff), thermal entropy generation (Sg,th), total entropy generation (Sg,tot), exergy output (Exout), and exergy loss (Exloss) is examined. Proposed relationships and an in-house code in MATLAB software are used for analysis. The results demonstrated that the use of copper tube leads to smaller amounts of Sg,ff, and Sg,tot than steel tube. Besides, the Exout for cooper tubes is higher than that for steel ones. An increment in the flow rate enhances Sg,tot. Increasing the fluid mass flow rate from 0.25 to 1 kg/s increases the values of Sg,tot 7.9 and 8.4 times for the steel and copper collectors, respectively. The addition of NPs reduces Sg,th but enhances Sg,ff at high values of ϕ. The addition of 4% of all shapes NPs intensifies the magnitudes of Exout and Exloss.

Effects of a magnetic field on double-diffusive convection of a nanofluid in a cavity saturated by wavy layers of porous media: ISPH analysis

PurposeThe purpose of this study is to use the incompressible smoothed particle hydrodynamics method to examine the influences of a magnetic field on the double-diffusive convection caused by a rotating circular cylinder with paddles within a square cavity filled by a nanofluid.Design/methodology/approachThe cavity is saturated by two wavy layers of non-Darcy porous media with a variable amplitude parameter. The embedded circular cylinder with paddles carrying T_h and C_h is rotating around the cavity center by a uniform circular velocity.FindingsThe lineaments of nanofluid velocity and convective flow, as well as the mean of Nusselt and Sherwood numbers, are represented below the variations on the frequency parameter, amplitude parameter of the wavy porous layers, Darcy parameter, nanoparticles parameter, Hartmann number and Ryleigh number. The performed simulations showed the role of paddles mounted on circular cylinders for enhancing the transmission of heat and mass within a cavity. The wavy porous layers at the lower Darcy parameter are playing as a blockage for the nanofluid flow within the porous area. Increasing the concentration of the nanoparticles to 6% reduces the maximum flow speed by 8.97% and maximum streamlines |ψ|max by 10.76%. Increasing Hartmann number to 100 reduces the maximum flow speed by 65.83% and |ψ|max by 75.54%.Originality/valueThe novelty of this work is to examine the effects of an inclined magnetic field and rotating novel shape of a circular cylinder with paddles on the transmission of heat/mass in the interior of a nanofluid-filled cavity saturated by undulating porous medium layers.

Designing artificial neural network of nanoparticle diameter and solid–fluid interfacial layer on single‐walled carbon nanotubes/ethylene glycol nanofluid flow on thin slendering needles

AbstractIn this study, an artificial neural network (ANN) has been developed to predict the boundary layer flow of a single‐walled carbon nanotubes nanofluid toward three different nonlinear thin isothermal needles of paraboloid, cone, and cylinder shapes with convective boundary conditions. Different effects of particle diameter and solid–fluid interface coating have been taken into account in the thermal conductivity model of nanofluid in which ethylene glycol has been used as the base fluid. Single and dual phase approach is used to establish the management model under the phenomenon of zero heat and mass flux. A dataset has been developed for different scenarios of the fluid model by changing the relevant parameters with the Runge–Kutta based shooting technique. Two different ANN models have been developed to predict Nusselt number and skin friction coefficient (SFC) values. The values obtained from ANN models have been compared with the numerical data, which are the target values. In addition, mean square error and R values have also been examined in order to analyze the prediction performance of ANN models more comprehensively. The calculated R values for Nusselt number and SFC were obtained as 0.9999. The results obtained showed that ANN can predict Nusselt number and SFC values with high accuracy.

First and Second Law Thermodynamic Analyses of Hybrid Nanofluid with Different Particle Shapes in a Microplate Heat Exchanger

The improvement in the quantitative and qualitative heat transfer performances of working fluids is trending research in the present time for heat transfer applications. In the present work, the first and second law analyses of a microplate heat exchanger with single-particle and hybrid nanofluids are conducted. The microplate heat exchanger with single-particle and hybrid nanofluids is analyzed using the computational fluid dynamics approach with symmetrical heat transfer and fluid flow analyses. The single-particle Al2O3 nanofluid and the hybrid Al2O3/Cu nanofluid are investigated for different nanoparticles shapes of sphere (Sp), oblate spheroid (OS), prolate spheroid (PS), blade (BL), platelet (PL), cylinder (CY) and brick (BR). The first law characteristics of NTU, effectiveness and performance index and the second characteristics of thermal, friction and total entropy generation rates and Bejan number are compared for Al2O3 and Al2O3/Cu nanofluids with considered different-shaped nanoparticles. The OS- and PL-shaped nanoparticles show superior and worse first and second law characteristics, respectively, for Al2O3 and Al2O3/Cu nanofluids. The hybrid nanofluid presents better first and second law characteristics compared to single-particle nanofluid for all nanoparticle shapes. The Al2O3/Cu nanofluid with OS-shaped nanoparticles depicts maximum values of performance index and Bejan number as 4.07 and 0.913, respectively. The first and second law characteristics of the best combination of the Al2O3/Cu nanofluid with OS-shaped nanoparticles are investigated for various volume fractions, different temperature and mass flow rate conditions of hot and cold fluids. The first and second law characteristics are optimum at higher hot fluid temperature, lower cold fluid temperature, lower hot and cold fluid mass flow rates. In addition, the first and second law characteristics have improved with increase in volume fraction.

Influence of cylinder breadth and shape on the onset of flow unsteadiness and the aeolian tone level

The Reynolds number for the onset of flow unsteadiness is determined for several canonical geometries (triangles, rectangles, ellipses and lozenges) at different sectional breadth (L) to height (d) ratios (aspect ratio AR=L∕d), for more than 70 shapes. The flow is modeled using a direct Navier–Stokes incompressible two-dimensional solver and the shape is defined by an Immersed Boundary Method. The employed procedure takes the fluctuation of the velocity in the wake as the criterion to define the unsteadiness and a binary search to find the transition. This procedure yields critical Reynolds number Rec values in agreement with available data in the literature. When AR approaches zero, the five shapes lead to almost the same value of 31, which corresponds to Rec for a flat plate normal to the flow. It is then found that Rec grows exponentially with the aspect ratio, the influence of the cross section shape being accounted for by a single regression parameter. For all aspect ratios, the ellipse exhibits the highest Rec, and the front-pointing triangle the lowest, the three other geometries laying in between those two. The physics of the influence of cross-section shape on Rec is analyzed, considering its link with recirculation length in particular. An exploitation of the results is outlined for the analysis of recent aeroacoustic shape optimizations at fixed Re=150, through correlation between the lift fluctuation at this regime with the distance to the onset of unsteadiness it corresponds to.

Broadband multimodal THz waveguides for efficient transfer of high-power radiation in space-confined conditions

Terahertz (THz) range, which lies between the microwave and infrared regions of the electromagnetic spectrum, presents a new frontier containing an abundance of technical applications and fundamental research problems. There are several challenges limiting the progress in the THz science and technology. One of them is the limited range ofthe guided-wave propagation of THz radiation, owing to the high loss from the finite conductivity of metals and the high absorption coefficient of dielectric materials in the THz range. In this work, we discuss the design and fabrication of multimodal hollow THz waveguides used at the X-band Electron Paramagnetic Resonance (EPR) endstation located at the Novosibirsk Free Electron Laser facility (NovoFEL). Experiments carried out at the EPR endstation are aimed to investigate the impact of THz and far infrared radiation on the spin system of different inorganic complexes and organic radicals. The EPR probehead and cryostat impose strict constraints on the possible ways of transferring the THz radiation to the sample, requiring the development, manufacturing, and characterization of specific waveguides. The proposed waveguides for X-band EPR measurements under THz radiation resemble hollow metal/dielectric waveguides. They have the shape of ahollow cylinder, tapering towards the end, with a silver-coated inner surface, and allow THz radiation to be transmitted over a distance of about 60 cm in a wide frequency range from THz to middle infrared. The waveguides performance was characterized at different frequencies of NovoFEL radiation and compared with numerical simulations. Following the requirements ofpolarization-sensitive EPR experiments, the waveguides were further modified by a miniature attachment, consisting of a polarizer, a semiconductor mirror, and a quarter-wave plate. The attachment allows preserving the initial polarization properties of THz radiation, turns its propagation vector, and creates the circular-polarized light irradiating the sample – all inside the limited volume of the EPR probehead.