Evaluation of Bone Marrow Texture and Trabecular Changes With Quantitative DCE-MRI and QCT in Alloxan-Induced Diabetic Rabbit Models

PurposeTo investigate whether the microvascular permeability of lumbar marrow and bone trabecular changes in early-stage diabetic rabbits can be quantitatively evaluated using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), quantitative computed tomography, and texture-analyzed permeability parameter Ktrans map of DCE-MRI.Materials and MethodsThis prospective study included 24 rabbits that were randomly assigned to diabetic (n = 14) and control (n = 10) groups. All rabbits underwent sagittal MRI of the lumbar region at 0, 4, 8, 12, and 16 weeks after alloxan injection. Pearson correlation coefficient was performed to determine the correlation between permeability parameter and bone mineral density (BMD). Repeated-measures ANOVA was used to analyze the changes in lumbar BMD over time in each group and the texture parameters of diabetic rabbit lumbar marrow at different time points. Mann–Whitney U rank sum test was used to compare the differences of each index between the two groups and calculate the area under the curve (AUC).ResultsBMD was correlated with Ktrans, Kep, and Ve but not with Vp. At weeks 0–16, the BMD of the rabbits in the diabetic and normal groups was not statistically significant, but the change in BMD showed an overall downward trend. For texture analysis, entropy, energy, and Uniformized positive pixel (UPP) parameters extracted from the Ktrans map showed significant differences from week 0 to 16 between the two groups. The identification ability at 8–12 weeks was higher than that at 12–16 weeks, and the AUCs were 0.734, 0.766, and 0.734, respectively (P < 0.05 for all).ConclusionsThe changes in BMD measured using quantitative computed tomography occurred later than those measured using bone trabecular morphometry. Texture analysis parameters based on DCE-MRI quantitative parameter Ktrans map are feasible to identify early changes in lumbar marrow structure in diabetic rabbits.

Physical aspects of magnetized Jeffrey nanomaterial flow with irreversibility analysis

This analysis presents the applications of entropy generation phenomenon in incompressible flow of Jeffrey nanofluid in presence of distinct thermal features. The novel aspects of various features like Joule heating, porous medium, dissipation features and radiative mechanism is addressed. In order to improve the thermal transportation systems based on nanomaterials, the convective boundary conditions are introduced. The thermal viscoelastic nanofluid model is expressed in term of differential equations. The problem is presented via nonlinear differential equations for which analytical expressions are obtained by using homotopy analysis method(HAM). The accuracy of solution is ensured. The effective outcomes of all physical parameters associated with the flow model are carefully examined and underlined through various curves. The observations summarized from current analysis reveal that presence of permeability parameter offers resistance to the flow. A monotonic decrement in local Nusselt number is noted with Hartmann number and Prandtl number. Moreover, entropy generation and Bejan number increases with radiation parameter and fluid parameter.

Oscillatory flow of casson fluid between parallel plates with an inclined magnetic field

The study of heat and mass transfer of oscillatory casson flow inporous medium subject to an inclined magnetic field, radiative heatflux and heat source is presented. It is supposed that Casson fluid islittle conductive and produced emf is insignificant. The solutions ofcoupled partial differential equations of velocity, temperature and con-centration profiles are found using Galerkins technique of finite elementmethod. The effect of various parameters such as Reynolds number Re,Grashoff number Gr, Solute Grashoff number Gc, Peclet number Pe,Hartman number Ha, Scmidth number Sc, Permeability parameter K,Radiative parameter R, Heat generation parameter S, Chemical reactionparameter Kr and frequency parameter w on velocity, temperature andconcentration are shown graphically and skin friction, Nusselts numberand Sherwood number are discussed by tables.

Mathematical Modeling of Treatment Effect on Tumor Growth and Blood Flow through a Channel with Magnetic Field

In this research, we investigated the effect of tumor growth on blood flow through a micro channel by formulated the governing model with the assumption that blood is an incompressible, eclectrially conducting fluid which flow is caused by the pumping action of the heart and suction. The governing model was scaled using some dimensionless variables and the region of the tumor was obtained from Dominguez [1] which was incorporated in our model. The model is further reduced to an ordinary differential equation using a perturbation condition. However, the ordinary differential equation was solved using method of undermined coefficients, and the constants coefficients obtained via matrix method. Furthermore, the simulation to study the effect of the pertinent parameters was done suing computation software called Mathematica. It is seen in our investigation that the entering parameters such as magnetic field parameter, the Reynolds number, womersley number, oscillatory frequency parameter, and permeability parameter affect the blood velocity profile in decreasing and increasing fashion.

Assessment of oil-producing wells by means of stimulation approach through matrix acidizing: a case study in the Azraq region

The acidizing approach belongs to the well workover operations, where acid mixtures are initially implemented to treat damage near the wellbore area after drilling operations have been completed. Acidizing treatment is characterized by removal of fine particles and debris from the porous media of the damaged zone, hence leading to improve oil production from wells. This study evaluates the assessment of the acidizing treatment in vertical oil-producing wells. Gradually, the damage formation was reduced and then eliminated, and to a great extent, was compensated with the better performance of oil production from reservoirs. Target candidate wells were enriched by environmentally friendly additives and special chemicals, in predefined amounts, to achieve enhanced oil production rates from wells. A semi-analytical model was formulated for extrapolating the skin magnitude, depending on the damage formation’s permeability parameter as well as on the physical characteristics and reservoir depth. The figures of skin magnitude for all target wells were decreased, and oil production rates were enhanced after performing the matrix acidizing process. These findings are valid for diverse geological settings of different formations, as all treated intervals within the investigated wells have shown an objective response to the matrix acidizing approach. Eventually, productivity rates are imperative to increase potential economic outcomes.

RHEOLOGY OF POWER LAW FLUID FLOW AROUND A STAGNATION POINT IN POROUS MEDIUM WITH ENERGY DISSIPATION

An investigation on two-dimensional stagnation point flow past a stretching or shrinking surface in a porous medium with energy dissipation using power law model is carried out in this paper. By applying some similarity transformations, the governing partial differential equations are converted to non-linear ordinary differential equations. Consequently, numerical calculations of these equations are done by using MATLAB built- in bvp4c method. Impact of various parameters such as Prandtl number, permeability parameter and magnetic parameter are depicted graphically on velocity and temperature distributions. Also, the numerical values for velocity gradient and shear stress are shown in tabular form. From the analysis, it is noted that Prandtl number helps in reducing the shear stress, Also, as the power law parameter increases, a decrease in velocity is observed.

Porous medium on unsteady Helical flows of Generalized Oldroyd-B with two infinite coaxial circular cylinders

This article deals with the influence of porous media on Helical flows of Generalized Oldroyd-B between two infinite coaxial circular cylinders .The fractional derivative are modeled for this problem and studied by using finite Hankel and Laplace transforms .The velocity fields founded by using the fundamentals of the series form in terms of Mittag-leffler equation . The research focused on the parameters like (permeability parameter z ,fractional parameters(𝛼 , 𝛽) , relaxation 𝜆1 , retardation 𝜆2 , kinematic viscosity v , magnetic parameter M and time t) which effected on the velocity field u and w. MATHEMATICA package used to study and analyze the above variables by drawing many graphs .

Entropy generation of peristaltic Eyring–Powell nanofluid flow in a vertical divergent channel for biomedical applications

Exploring the movement of blood in a blood vessel has been fascinated by clinicians and biomedical researchers because it is predominant in cell tissue engineering, drug targeting and various treatments like hypothermia, hyperthermia, and cancer. It is noticed that numerous non-Newtonian rheological fluids like Carreau fluid, tangent hyperbolic fluid, Eyring–Powell fluid and viscoelastic fluid manifest the characteristics of blood flow. Further, the investigation of entropy generation can be used to raise the performance of medical equipments. Consequently, the present mathematical model scrutinizes the transport characteristics and entropy generation of the peristaltic Eyring–Powell nanofluid in a permeable vertical divergent channel in the presence of dissipation and linear radiation. The non-similar variables are employed to convert the dimensional partial differential equations into dimensionless form which are tackled by the Homotopy perturbation method. The impacts of emerging parameters like Eyring–Powell parameters, left and right wall amplitudes, thermophoresis, mean flow rate, radiation, permeability parameter, Brownian motion, Eckert number, Hartman number on Eyring–Powell nanofluid axial velocity, temperature, and concentration are manifested. Present results disclose that the thermal Grashof number highly inflates the pressure rise. Eyring–Powell nanofluid temperature reduces for uplifting the linear radiation parameter. Growing values of the non-uniform parameter lead to move the trapping bolus towards the left and right wall. The total entropy generation diminishes for magnifying the temperature difference parameter.

Investigation of Effects of Thermal Radiation, Magnetic Field, Eckert Number, and Thermal Slip on MHD Hiemenz Flow by Optimal Homotopy Asymptotic Method

Analytical investigation of thermal radiation, Prandtl number, Eckert number, permeability parameter, magnetic field, velocity, and thermal slip effects on magnetohydrodynamic Hiemenz flow over a permeable plate with forced convection has been presented. Similarity variable conversion method has been applied to transmute the fundamental governing equations of the fluid dynamics in flow into a pair of nonlinear third-order ordinary differential equations and is analytically solved by the optimal homotopy asymptotic method (OHAM). The influences of several relevant physical parameters in the model on velocity and temperature of the fluid have been studied and analysed profoundly by use of graphs and tables. It is detected that, with mounting value of suction/blowing parameter and magnetic field parameter, the skin friction coefficient enhances. Likewise, it is seen that the Nusselt number increases with enhancing value of magnetic parameter. It is also witnessed that the velocity increases as the Eckert number, blowing/suction parameter, and permeability parameter increase, but it decays against magnetic field and velocity slip parameter. Moreover, the result reveals that the fluid temperature upsurges along with snowballing the radiant heat, magnetic field parameter, and the Eckert number. However, it descends against thermal slip parameter, Prandtl number, wall temperature exponent, and velocity slip parameter. A comparison with previous studies has been made, and the result shows an excellent agreement.

Mobilities of a Spherical Particle Straddling the Interface of a Semi-Infinite Brinkman Flow

The motion of a spherical particle straddling the flat interface of a semi-infinite Brinkman flow is considered under conditions of low Reynolds number and low capillary number regime. The analysis is applied in the case of 90° contact angle and when the viscosity of the constituent fluid in the Brinkman region is much more than that of the adjacent fluid. Analytical expressions for the hydrodynamic scalar resistance coefficients are obtained and represented graphically as a function of the slip parameter at the surface of the particle and the permeability parameter of the porous region. The hydrodynamic mobilities are also obtained and represented in tables. The limiting cases of Stokes clear fluid and Darcy's flow are recovered.