Method For Different Values Research Articles

Solution of the Fractional Form of Unsteady Squeezing Flow through Porous Medium

We propose two friendly analytical techniques called Adomian decomposition and Picard methods to analyze an unsteady axisymmetric flow of nonconducting, Newtonian fluid. This fluid is assumed to be squeezed between two circular plates passing through porous medium channel with slip and no-slip boundary conditions. A single fractional order nonlinear ordinary differential equation is obtained by means of similarity transformation with the help of the fractional calculus definitions. The resulting fractional boundary value problems are solved by the proposed methods. Convergence of the two methods’ solutions is confirmed by obtaining various approximate solutions and various absolute residuals for different values of the fractional order. Comparison of the results of the two methods for different values of the fractional order confirms that the proposed methods are in a well agreement and therefore they can be used in a simple manner for solving this kind of problems. Finally, graphical study for the longitudinal and normal velocity profiles is obtained for various values of some dimensionless parameters and fractional orders.

Unsteady MHD Free Convective Flow Past an Inclined Parabolic Accelerated Plate with Hall Current, Radiation Effects and Variable Temperature in a Porous Medium

We analyze the effects of hall current and radiation on unsteady hydromagnetic free convection flow of a viscous incompressible electrically conducting fluid past an inclined parabolic accelerated plate in a porous medium by applying a transverse magnetic field which makes an angle α to the inclined plate.The fluid is assumed to be viscous, incompressible and electrically conducting with a strong magnetic field. Using the modified Ohm’s law and the Bossinesq approximation the governing equations of the problem are reduced to local non-similarity boundary layer equations using suitable transformation.The dimensionless governing equations of flow field are solved numerically by Crank-Nicolson finite difference method for different values of governing flow parameters. The velocity and temperature profiles are shown through graphs.

Digital Watermarking Approach Based on Edge Based Sorted Pixel Value Difference (ESPVD)

Objectives: The major challenge in Imaging applications, particularly Digital Multimedia data transfer over the internet is data authentication with copyright protection to ensure ownership of identification. This paper aims to propose a new digital watermarking approach based on Edgebased sorted pixel value difference (ESPVD) to protect copyrights. Method: The hypothesis behind the proposed method is mainly composed of two phases: Watermark inserting phase, detection and extraction phase. In the inserting phase, first of all motif pattern approach is used to generate the mixed Image and then, identify the edge pixel locations using morphological edge (ME) operator to embed the watermark. Now, sorted pixel value difference method is used to insert the watermark. The watermark extraction phase also uses the same procedure which is stated earlier to retrieve the watermark image. To evaluate and match the ground truth images with the proposed watermarked images, peak signal to noise ratio (PSNR) and normalized cross correlation (NCC) are employed as quantitative measures. Findings: The proposed algorithm is tested with two logo images inserted over 30 different popular images and the outcomes indicates that the proposed approach is consistently performing well in terms of PSNR and NCC. Application/Improvements: The present approach provides high level of authentication, robustness, security and copyright protection against several attacks by using motif patterns while changing the order of pattern sequence in the formation of mixed image.

The allele combinations of three loci based on, liver, stomach cancers, hematencephalon, COPD and normal population: A preliminary study

The purpose of this study was to examine the specific allele combinations of three loci connected with the liver cancers, stomach cancers, hematencephalon and patients with chronic obstructive pulmonary disease (COPD) and to explore the feasibility of the research methods. We explored different mathematical methods for statistical analyses to assess the association between the genotype and phenotype. At the same time we still analyses the statistical results of allele combinations of three loci by difference value method and ratio method. All the DNA blood samples were collected from patients with 50 liver cancers, 75 stomach cancers, 50 hematencephalon, 72 COPD and 200 normal populations. All the samples were from Chinese. Alleles from short tandem repeat (STR) loci were determined using the STR Profiler plus PCR amplification kit (15 STR loci). Previous research was based on combinations of single-locus alleles, and combinations of cross-loci (two loci) alleles. Allele combinations of three loci were obtained by computer counting and stronger genetic signal was obtained. The methods of allele combinations of three loci can help to identify the statistically significant differences of allele combinations between liver cancers, stomach cancers, patients with hematencephalon, COPD and the normal population. The probability of illness followed different rules and had apparent specificity. This method can be extended to other diseases and provide reference for early clinical diagnosis.

Boundary layer flow and heat transfer past a permeable shrinking surface embedded in a porous medium with a second-order slip: A stability analysis

The fluid flow and heat transfer over a permeable shrinking sheet embedded in a porous medium with a second-order slip is studied. Using appropriate similarity variables, the governing partial differential equations are reduced to ordinary differential equations before being solved numerically by a shooting method for different values of the selected governing parameters. The numerical results reveal that two (dual) solutions are possible for a certain range of these parameters. A stability analysis is performed to determine which solution is stable and which one is not. The effects of suction and the second order slip parameters on the skin friction coefficient and the local Nusselt number as well as on the velocity and temperature profiles are plotted and discussed. It is found that applying the slip condition increases the range of solutions. Also, the skin friction coefficient is higher for the no slip condition compared to that of with slip condition.

Mixed convection squeezing three-dimensional flow in a rotating channel filled with nanofluid

Purpose – The purpose of this paper is to numerically solve the problem of an unsteady squeezing three-dimensional flow and heat transfer of a nanofluid in rotating vertical channel of stretching left plane. The fluid is assumed to be Newtonian, incompressible and electrically conducting embedded with nanoparticles. Effect of internal heat generation/ absorption is also considered in energy equation. Four different types of nanoparticles are considered, namely, copper (Cu), alumina (Al2O3), silver (Ag) and titanium oxide (TiO2) with the base fluid as water. Maxwell-Garnetts and Brinkman models are, respectively, employed to calculate the effective thermal conductivity and viscosity of the nanofluid. Design/methodology/approach – Using suitable similarity transformations, the governing partial differential equations are transformed into set of ordinary differential equations. Resultant equations have been solved numerically using Runge-Kutta-Fehlberg fourth fifth order method for different values of the governing parameters. Effects of pertinent parameters on normal, axial and tangential components of velocity and temperature distributions are presented through graphs and discussed in detail. Further, effects of nanoparticle volume fraction, squeezing parameter, suction/injection parameter and heat source/sink parameter on skin friction and local Nusselt number profiles for different nanoparticles are presented in tables and analyzed. Findings – Squeezing effect enhances the temperature field and consequently reduces the heat transfer rate. Large values of mixed convection parameter showed a significant effect on velocity components. Also, in many heat transfer applications, nanofluids are potentially useful because of their novel properties. They exhibit high-thermal conductivity compared to the base fluids. Further, squeezing and rotation effects are desirable in control the heat transfer. Originality/value – Three-dimensional mixed convection flows over in rotating vertical channel filled with nanofluid are very rare in the literature. Mixed convection squeezing three-dimensional flow in a rotating channel filled with nanofluid is first time investigated.

Homotopy analysis transform algorithm to solve time-fractional foam drainage equation

AbstractThis paper emphasizes on finding the solution for a foam drainageequation using the technique of modified homotopy analysis transform method (MHATM). MHATM is a new amalgamation of the homotopy analysis method and Laplace transform method with homotopy polynomial. Comparisons are made between the results of the proposed method for different values of fractional derivative α and exact solutions. Then, we analyze the results by numerical simulations, which demonstrate the simplicity and effectiveness of the present method.

Similarity Solution for High Weissenberg Number Flow of Upper-Convected Maxwell Fluid on a Linearly Stretching Sheet

High Weissenberg boundary layer flow of viscoelastic fluids on a stretching surface has been studied. The flow is considered to be steady, low inertial, and two-dimensional. Upon proper scaling and by means of an exact similarity transformation, the nonlinear momentum and constitutive equations of each layer transform into the respective system of highly nonlinear and coupled ordinary differential equations. Numerical solutions to the resulting boundary value problem are obtained using an efficient shooting technique in conjunction with a variable stepping method for different values of pressure gradients. It is observed that, unlike the Newtonian flows, in order to maintain a potential flow, normal stresses must inevitably develop. The velocity field and stresses distributions over plate are presented for difference values of pressure gradient and Weissenberg numbers.

Effects of Thermophoresis, Dufour, Hall and Radiation on an Unsteady MHD Flow past an Inclined Plate with Viscous Dissipation, Chemical Reaction and Heat Absorption and Generation

This paper investigates study of MHD(Magnetohydrodynamics) flow of viscous incompressible fluid past an inclined porous plate embedded in porous medium with the effects of Thermophoresis, Dufour, Hall, radiation, viscous dissipation, chemical reaction and heat generation or absorption. Non dimensional partial differential equations of governing equations of flow are solved numerically by applying Crank-Nicolson finite difference method for different values of parameters. Velocity, temperature, concentration profiles are discussed through graphs for different values of parameters and skin friction coefficients, Nusselt number and Sherwood number are discussed through tables.

The Influence of Glucose Concentration to Resonant Wavelength Shift of Polymer-Based Microring Resonators

Microring resonators (MRRs) is a compact and multi-functioned device which is mainly characterized by free spectral range (FSR) and quality factor (Q-factor). In this paper, the influence of glucose concentration to the resonant wavelength shift of MRRs is presented. The calculation was carried out using semi-numerical method for different values of FSR and Q-factor. The parameters used in the calculation including incident wavelength, ring radii of circular waveguide, gap sizes between circular and straight waveguides, the dimension of both waveguides, and refractive index of polymer, SiO2 and glucoce solution. The results show that glucose affects the resonant wavelength shift for each values of FSR and Q-factor. The increase of the glucose concentration causes the increase of the resonant wavelength shift, therefore this polymer-based MRR’s can be used for glucose sensing application.

Automatic Change Detection Method of Multitemporal Remote Sensing Images Based on 2D-Otsu Algorithm Improved by Firefly Algorithm

This paper presents a new automatic change detection method of multitemporal remote sensing images based on 2D-Otsu algorithm improved by Firefly algorithm. The proposed method is designed to automatically extract the changing area between two temporal remote sensing images. First, two different temporal remote sensing images were acquired through difference value method of remote sensing images; then, the 2D-Otsu threshold segmentation principles are analyzed and the optimal threshold of 2D-Otsu threshold segmentation method is figured out by using the Firefly algorithm, where the difference images are conducted with binary classification to obtain the changing category and the nonchanging category; finally, the proposed method is used to carry out change detection experiments on the two selected areas, where a variety of methods are compared. Experimental results show that the proposed method can effectively and quickly extract the changing area between the two temporal remote sensing images; thus, it is an effective method of change detection for remote sensing images.

<b>Thermodynamic properties of water desorption of forage turnip seeds

The purpose of this study was to determine the thermodynamic properties of the process of water sorption in forage turnip seeds. The equilibrium moisture content of forage turnip seeds was determined by the gravimetric-dynamic method for different values of temperature and water activity. According to the results, increasing the moisture content increases the energy required for the evaporation of water in forage turnip seeds, and the values of integral isosteric heat of desorption, within the moisture content range of 3.33 to 11.30 (% d.b.), varies from 4,222.70 to 2,870.34 kJ kg-1. With the elevation in the equilibrium moisture content, there is an increase in differential entropy and Gibbs free energy, which has positive values, demonstrating non-spontaneity in the process of desorption in the seeds. The theory of enthalpy-entropy compensation can be satisfactorily applied to the sorption phenomenon, and the process of water desorption of forage turnip seeds is controlled by enthalpy.

Space-frequency analysis with parallel computing in a phase-sensitive optical time-domain reflectometer distributed sensor.

For a phase-sensitive optical time-domain reflectometer (ϕ-OTDR) distributed sensor system, space-frequency analysis can reduce the false alarm by analyzing the frequency distribution compared with the traditional difference value method. We propose a graphics processing unit (GPU)-based parallel computing method to perform multichannel fast Fourier transform (FFT) and realize the real-time space-frequency analysis. The experiment results show that the time taken by the multichannel FFT decreased considerably based on this GPU parallel computing. The method can be completed with a sensing fiber up to 16 km long and an entry-level GPU. Meanwhile, the GPU can reduce the computing load of the central processing unit from 70% down to less than 20%. We carried out an experiment on a two-point space-frequency analysis, and the results clearly and simultaneously show the vibration point locations and frequency components. The sensor system outputs the real-time space-frequency spectra continuously with a spatial resolution of 16.3 m and frequency resolution of 2.25 Hz.

Bladder volume estimation from electrical impedance tomography

Non-invasive estimation of bladder volume is required to progress from scheduled voiding to a demand-driven emptying scheme for patients with impaired bladder volume sensation. Electrical impedance tomography (EIT) is a promising candidate for the non-invasive monitoring of bladder volume. This article focuses on four estimation algorithms used to map recorded EIT data to a volume estimate. Two different approaches are presented: the tomographic algorithms (one based on global impedance, the other on equivalent circular diameter) rely on the reconstruction of a tomographic image and then extract a volume estimate, whereas the parametric algorithms (one based on neural networks, the other on the singular value difference method) directly map the raw data to a volume estimate. The four algorithms presented here are evaluated for volume estimation error, noise tolerance and suppression of varying urine conductivity based on finite element simulation data.

A Gray Scale High Quality Digital Image Watermarking using Equal Pixel Value difference Method (EPVD)

Due to growth of Internet and multimedia technologies in today’s life, it made easy to copy and distribution of any document without any owner’s consent. Watermarking is a process of concealing the digital information in a document for providing the ownership on his/her document. To increase security of ownership of a document and to improve quality of indistinguishable watermarked image from host image, a new watermarking approach equal pixel value difference method is proposed in this paper during embedding and extraction process. This method provides equal differences between pixels of watermarked image and host image placed at same pixel position which improves the quality of watermarked image. The experimental results show watermarked images with good robustness and Imperceptibility. General Terms Security, Watermarking, Embedding, Extraction.

Melting Effect on Mixed Convection Boundary Layer Flow About a Vertical Surface Embedded in a Porous Medium: Opposing Flows Case

The effect of melting phenomenon on the steady mixed convection boundary layer flow about a vertical surface embedded in a fluid-saturated porous medium is numerically studied. The boundary layer partial differential equations are transformed into a set of nonlinear ordinary differential equations by using similarity transformation and then are solved using the shooting method for different values of the mixed convection and melting parameters. Results show that dual solutions exist for a certain range of these parameters. The results also indicate that the melting phenomenon reduces the heat transfer rate and expedites the boundary layer separation.

Post-buckling longterm dynamics of a forced nonlinear beam: A perturbation approach

The aim of this paper is to determine by a singular perturbation approach the dynamic response of a harmonically forced system experiencing a pitchfork bifurcation. The model of an extensible beam forced by a harmonic excitation and subject to an axial static buckling is space-discretized by a Galerkin approach and studied by the Normal Form Method for different values of equation parameters influencing the nonlinear dynamic behavior like damping coefficient, load amplitude and frequency. A relevant issue in the perturbation methods is the concept of small and zero divisors which are related to the possibility to build a transformation that simplifies the original studied problem, i.e. to obtain the Normal Form, by eliminating as much as possible nonlinearities in the equations. For nonconservative systems, like structural damped systems, there are no conditions in the prior literature that define what “small” means relatively to a divisor. In the present paper some conditions about the order of magnitude of the divisors with respect to the perturbation entity are given and related to some physical parameters in the governing equations in order to estimate the relevance of some nonlinear effects.

MHD Natural Convection with Convective Surface Boundary Condition over a Flat Plate

We apply the one parameter continuous group method to investigate similarity solutions of magnetohydrodynamic (MHD) heat and mass transfer flow of a steady viscous incompressible fluid over a flat plate. By using the one parameter group method, similarity transformations and corresponding similarity representations are presented. A convective boundary condition is applied instead of the usual boundary conditions of constant surface temperature or constant heat flux. In addition it is assumed that viscosity, thermal conductivity, and concentration diffusivity vary linearly. Our study indicates that a similarity solution is possible if the convective heat transfer related to the hot fluid on the lower surface of the plate is directly proportional to(x-)-1/2wherex-is the distance from the leading edge of the solid surface. Numerical solutions of the ordinary differential equations are obtained by the Keller Box method for different values of the controlling parameters associated with the problem.

Mixed convection flow of second grade fluid with variable heat flux past a vertically stretching flat surface

In the present investigation, a numerical study of the flow and heat transfer analysis of viscoelastic second grade fluid due to heated, continuous stretching of a vertical sheet has been carried out. The stretching velocity is assumed to vary linearly with the distance measured from the leading edge. The surface heat flux is assumed to be varied in power of distance measured from the leading edge. The governing differential equations are transformed by introducing proper non-similarity variables and solved numerically using two different methods, namely, the local non-similarity method with second level of truncation and the implicit finite difference method for values of ξ (=Grx/Rex2) ranging from 0 to 10. The comparisons of the results obtained by the aforementioned methods are found in excellent agreement. Effects of the viscoelastic parameter, λ (Deborah number) on the skin-friction and the heat transfer coefficients have been shown graphically for the fluid with Prandtl number equal to 0.7, 7.03 and 15.0. Keywords: Mixed convection, second grade fluid, stretching flat surface and variable surface heat flux.

X-ray powder diffraction investigation of the faulted crystal structure of MnH2P3O10· 2H2O

The crystal structure of manganese(III) dihydrogen triphosphate dihydrate, MnH2P3O10 · 2H2O, has been studied by means of X-ray powder diffraction data using the Rietveld method. The compound crystallizes in the monoclinic space group P2/c, with unit cell dimensions a = 7.8286(2), b = 4.9503(2), c = 12.25415(18) Å, β = 95.7922(11)°, V = 472.47(2) Å3, Z = 2. It has a layered structure, with manganese-triphosphate polymeric layers, parallel to the bc plane, and water molecules located in the interlayer space. Powder pattern of the compound exhibits anisotropic peak broadening, which cannot be explained by crystallite size effects. The reflections with k = 2n remain narrow, whereas those with k = 2n + 1 and h ≠ 0 are widened substantially. These features have been assigned to stacking faults with a b/2 translation. Simulated diffraction patterns, calculated with the program DIFFaX by recursion method for different values of stacking faults probability, reproduced the experimental X-ray powder pattern. A phenomenological treatment of anisotropic peak broadening was used to complete the Rietveld refinement.