Increase In Power-law Exponent Research Articles

Effect of little millet ( Panicum miliare ) on physical, rheological, nutritional and microstructural properties of bread

The present study aims to use little millet for development of composite bread based on its functional, rheological, physical, textural, sensory, microstructural and nutritional characteristics. Composite flours were formulated with various proportions (10%, 25% and 40% w/w) of little millet flour (LMF) in refined wheat flour (RWF). The water holding capacity (WHC), water absorption index (WAI), and water solubility index (WSI) of the dough were affected with LMF incorporation. The decrease in storage modulus (G′) and increase in power law exponent (0.081 to 0.203) with rise in LMF percent in flour indicated the less elastic nature of composite dough. The loaf weight, height, and volume of the developed bread were found as 4.9%, 17.3%, and 10.1% less than the control bread, respectively. Physical, textural, and sensory analysis revealed that 25% LMF incorporated bread was found to be acceptable, and it showed a significant (p ≤ 0.05) increase in fiber content (25.5%). Practical applications An attempt is made to develop a functional bread using underutilized LMF for the health-conscious group of people. The current research characterized the physical, rheological, textural, and microstructural changes imparted in bread through millet flour incorporation, which could be successfully referred during composite bread production. A substitute of 25% LMF was acceptable, and the developed bread was found to have a significant increase in fiber content, which can prove to be highly beneficial for individuals suffering from heart disease, diabetes, and obesity. This study can act as a support for the milling industry to produce composite flour blends, and it may also be helpful to bring out convenient bakery products into the market, which can replace the wheat-based products.

The Method of Lines Analysis of Heat Transfer of Ostwald-de Waele Fluid Generated by a Non-uniform Rotating Disk with a Variable Thickness

In this article, it is aimed to address one of Ostwald-de Waele fluid problems that either, has not been addressed or very little focused on. Considering the impacts of heat involving in the Non-Newtonian flow, a variant thickness of the disk is additionally considered which is governed by the relation z = a (r/RO+1)-m. The rotating Non-Newtonian flow dynamics are represented by the system of highly nonlinear coupled partial differential equations. To seek a formidable solution of this nonlinear phenomenon, the application of the method of lines using von Karman’s transformation is implemented to reduce the given PDEs into a system of nonlinear coupled ordinary differential equations. A numerical solution is considered as the ultimate option, for such nonlinear flow problems, both closed-form solution and an analytical solution are hard to come by. The method of lines scheme is preferred to obtain the desired solution which is found to be more reliable and in accordance with the required physical expectation. Eventually, some new marvels are found. Results indicate that, unlike the flat rotating disk, the local radial skin friction coefficients and tangential decrease with the fluid physical power-law exponent increases, the peak in the radial velocity rises which is significantly distinct from the results of a power-law fluid over a flat rotating disk. The local radial skin friction coefficient increases as the disk thickness index increases, while local tangential skin friction coefficient decreases, the local Nusselt number decrease, both the thickness of the velocity and temperature boundary layer increase.

Scintillation and BER analysis of the partially coherent flat-topped array laser beam in the non-Kolmogorov atmospheric turbulence on slant path

Using the extended Huygens–Fresnel principle in this paper, a semi analytical expression for describing the on-axis scintillation index of a partially coherent flat-topped array laser beam through slant path of non-Kolmogorov atmospheric turbulence is derived; consequently, with the help of the log-normal intensity probability density function, the bit error rate (BER) is evaluated. The main aims of this paper are exploring the effects of source factors (such as wavelength, order of flatness, and beam width) and the non-Kolmogorov turbulent atmosphere parameters (such as Kolmogorov inner scale, general spectral power-law exponent, the turbulence structure constant) on propagation behaviour of scintillation index, and, hence, on BER. Results indicate that, when the average SNR increases, BER is more affected while the power-law exponent increases. Consequently, it can be deduced that the mean bit error rate increases while the power-law exponent decreases. In addition, the scintillation index and BER as communication link parameters represent the fact that increasing the atmospheric refractive-index structure parameter on the ground and decreasing the inner scale of turbulence eddies, which expresses the conditions of strong turbulence, causes an increase in theses link parameters.

Homotopy Perturbation Method for Creeping Flow of Non-Newtonian Power-Law Nanofluid in a Nonuniform Inclined Channel with Peristalsis

AbstractThis article is an analytic discussion for the motion of power-law nanofluid with heat transfer under the effect of viscous dissipation, radiation, and internal heat generation. The governing equations are discussed under the assumptions of long wavelength and low Reynolds number. The solutions for temperature and nanoparticle profiles are obtained by using homotopy perturbation method. Results for the behaviours of the axial velocity, temperature, and nanoparticles as well as the skin friction coefficient, reduced Nusselt number, and Sherwood number with other physical parameters are obtained graphically and analytically. It is found that as the power-law exponent increases, both the axial velocity and temperature increase, whereas nanoparticles decreases. These results may have applicable importance in the research discussions of nanofluid flow in channels with small diameters under the effect of different temperature distributions.

Controllability robustness for scale-free networks based on nonlinear load-capacity

In this paper, we propose a general nonlinear load-capacity model to investigate the controllability robustness of scale-free networks under the cascading failure triggered by removing the highest-load edge. Based on the nonlinear model, the effect of the capacity distribution is studied to enlighten how to reduce network cost by adjusting capacity distribution for controllability robustness against cascading failures. By performing numerical simulations on Barabási–Albert (BA) scale-free networks and some real networks, we find that the unoccupied capacities of nearly highest-load edges make little impact on controllability robustness, and the high-load edges become more important to controllability robustness as the power law exponent increases. In particular, for scale-free networks with small-degree power law exponents or small out-in degree correlation coefficients, by properly reducing the unoccupied capacities of high-load edges, we can effectively cut down the network cost without reducing the controllability robustness.

Flow and heat transfer of Ostwald-de Waele fluid over a variable thickness rotating disk with index decreasing

This paper investigates the flow and heat transfer of Ostwald-de Waele fluid over a variable thickness rotating disk with style of z=a (r/R0+1)−m. Boundary layer governing partial equations are reduced to a set of semi-similarity ordinary differential equations by modified local von Kármán’s transformation and then solved by Runge–Kutta method coupled with multi-shooting technique. The effects of involved parameters (Ostwald-de Waele fluid physical power law exponent, disk thickness index, Prandtl number) on velocity and temperature fields, local skin friction coefficient and Nusselt number are presented graphically. Some new phenomena are found. Results indicate that, unlike the flat rotating disk, the local radial skin friction coefficients and tangential decrease with the fluid physical power law exponent increases, the peak in the radial velocity rises which is significantly distinct from the results of a power-law fluid over a flat rotating disk. As disk thickness index m increases, the local radial skin friction coefficient increases while local tangential skin friction coefficient decreases, the local Nusselt number decrease, both the thickness of velocity and temperature boundary layer increase.

Fiber coupling efficiency in non-Kolmogorov satellite links

Behavior of the fiber coupling efficiency in non-Kolmogorov satellite links is investigated. Examining the fiber coupling efficiency of downlink versus the non-Kolmogorov power law exponent for different rms wind speeds, zenith angles, receiver lens diameters, structure constants and the wavelengths, the fiber coupling efficiency is found to decrease when the non-Kolmogorov power law exponent increases. At a fixed non-Kolmogorov power law exponent, the fiber coupling efficiency of downlink is found to decrease as the rms wind speed, the zenith angle, the receiver lens diameter or the structure constant increases and the wavelength decreases. For any non-Kolmogorov satellite downlink, the reduction of coherence length will make the optimum design parameter larger. And when the fiber coupling efficiency is considered in the satellite uplinks, the effect of non-Kolmogorov turbulence can be neglected.

Coherence length in non-Kolmogorov satellite links

Behavior of the coherence length in non-Kolmogorov satellite links is investigated. Equivalent structure constants for non-Kolmogorov spectra are employed in order to make relevant comparisons for different non-Kolmogorov power law exponents. Examining the coherence length versus the non-Kolmogorov power law exponent for different rms wind speeds, zenith angles, link lengths, structure constants and the wavelengths, the coherence length is found to decrease when the non-Kolmogorov power law exponent increases. At a fixed non-Kolmogorov power law exponent, the coherence length is found to decrease as the rms wind speed, the zenith angle or the structure constant increases and the wavelength decreases. As the link length increases, the coherence length decreases for power law exponent values smaller than that for the Kolmogorov case. However, an increase in the link length seems not to cause the coherence length to vary appreciably at power law exponent values larger than the Kolmogorov case power law exponent.

Simulation of two generalised Newtonian fluids flow in micropore with dead end

This research deals with the numerical simulation of Carreau and power-law fluids flow in an open capillary of a reservoir. The capillary is connected to a dead end. The finite volume method (FVM) on a structured and co-located grid has been used. The numerical method has been validated through the comparison of numerical results against the analytical solutions of power-law fluid flow in a planar channel. The effects of fluids, the operating conditions and the aspect ratio of dead end at the low Reynolds (Re) numbers on the oil sweeping from the dead end are investigated. The simulation results show that by increasing the power-law exponent in the case of power-law fluids, the swept depth in the dead end increases. However, according to the results, the effect of Re number on the flow pattern and the oil sweeping from the dead end is insignificant at the investigated conditions. In the case of Carreau model, at the conditions investigated, the swept area increases as the power-law exponent increases, but the Reynolds number has still minor effects on the flow pattern. Also, as the aspect ratio of dead end increases, the sweep efficiency increases.

Natural convection heat and mass transfer of non-Newtonian power law fluids with yield stress in porous media from a vertical plate with variable wall heat and mass fluxes

This work studies the heat and mass transfer by natural convection from a vertical plate with variable wall heat and mass fluxes in a porous medium saturated with a non-Newtonian power law fluid with yield stress for the general case of power law variations in wall heat and mass fluxes. The governing equations are transformed into a dimensionless form by the similarity transformation and then solved by a cubic spline collocation method. Results are presented for velocity, temperature, and concentration profiles, as well as the Nusselt and Sherwood numbers for various parameters of the power law fluid with yield stress in porous media. The existence of threshold pressure gradient in the power law fluids tends to decrease the fluid velocity and the local Nusselt and Sherwood numbers. An increase in the power law exponent increases the local Nusselt and Sherwood numbers.

Emergence of a band‐limited power law in the aftershock decay rate of a slider‐block model

In order to elucidate how structural heterogeneities affect the aftershock decay rate, we examine the aftershock sequences produced by a slider‐block model of seismicity. In this model, the geometry of the seismic zone is the only free parameter and all aspects of the system are known. The power law aftershock decay rate holds only for smooth faults. A band‐limited power law emerges at intermediate fault complexity. For rough faults, only a transient regime toward an exponential decay is observed. In all fault geometries examined, a band‐limited power law model fits the synthetic aftershock decay rate better than the Modified Omori Law. Then, as the connected seismic elements form a simpler localised surface, we show that the power law aftershock decay rate extends over longer time, and that the power law exponent increases. These results support the inference that the correlation time of the power law aftershock decay rate increases as the deformation localises along dominant major faults.

Creep behavior of a closed-cell aluminum foam

The results of creep tests on a closed-cell aluminum foam (Alporas) are reported. At low stresses and temperatures, the behavior is well described by existing models for foams. At high stresses and temperatures, the power law creep exponent increases from about 4 to 15 and the activation energy increases from about 100 to 450 kJ/mol. The increase in power law exponent may be related to damage; a finite element damage model of a two-dimensional honeycomb gives consistent results with the measured foam behavior.