Effects of microwave heating on the thermal states of biological tissues

A mathematical analysis of microwave heating equations in one-dimensional multi-layer model has been discussed. Maxwell's equations and transient bioheat transfer equation were numerically calculated by using finite difference method to predict the effects of thermal physical properties on the transient temperature of biological tissues. This prediction of the temperature evolution in biological bodies can be used as an effective tool for thermal diagnostics in medical practices. Key words: Microwave heating, Maxwell's equations, bioheat, multi layer. African Journal of Biotechnology Vol.2(11) 2003: 453-45

Hall current and joule heating effects on peristaltic flow of a sisko fluid with mild stenosis through a porous medium in a tapered artery with slip and convective boundary conditions

This work is arranged to investigate the Hall current and Joule heating effects on peristaltic flow of a Sisko fluid through a porous medium. The streaming is through tapered artery with mild stenosis. The influences of radiative heat transfer and chemical reactions are taken in consideration. Convective conditions are considered for heat and mass transfer. However, the slip conditions are adopted for the velocity distribution. The combined effects of viscous dissipation and radiation in energy expression are presented. Soret and Dufour features produce the coupled differential systems. The presumptions of the long wavelength and low Reynolds number are adopted to examine the governing equations of motion. The analytical solutions of these equations are given by two methods. The first one uses regular perturbation technique, which based on small wave number for small artery. The second one is based on utilizing the Homotopy perturbation technique. The approximate analytical solutions of the pressure rise and friction force are predestined along a numerical integration. The influences of various physical parameters of the problem are debated and depicted graphically through a set of figures. It is found that the axial velocity increases with the increase of Hall current parameter and with the decrease of Hartmann number. Also, it can be observed that the Brickmann number and Dufour number give rise to the fluid temperature. Meanwhile, reverse effect is observed towards concentration for both Schmidt number and chemical reaction number. Furthermore, the stream lines are graphically shown

Magnetohydrodynamic Peristaltic motion with heat and mass transfer of a Jeffery fluid in a tube through porous medium

The effects of radiation on the unsteady flow of an incompressible non-Newtonian (Jeffrey) fluid through porous medium have been discussed. The thermal diffusion and diffusion thermo effect are taken to our consideration. The non-linear partial differential equations which govern this problem are simplified by making the assumptions of long wave length approximation. The analytical formula of the velocity, temperature and concentration have been obtained. In addition, it has been illustrated graphically for significant various parameters such as, magnetic parameter, permeability parameter, and thermal parameters

Hazards of Radioactive Mineralization Associated with Pegmatites Used as Decorative and Building Material

The present study aimed to assess the radiological hazards associated with applying the investigated granite in the building materials and the infrastructures applications. The investigated granites are classified into four categories: El-Urf, barren, colourful and opaque. El Urf monzogran-ite intrudes metagabbro diorite complex with sharp contacts. Based on the activity concentrations, the environmental parameters such as absorbed dose rate (Dair), annual effective dose (AED), ra-dium equivalent activity (Raeq), external (Hex) and internal (Hin) hazard indices were measured. The mineralized pegmatite is located in the southwestern foothill of the Gabal El Urf younger granite. It displays well-defined zonation of three zones: outer, middle and inner zones represented by potash feldspar, quartz and mica, respectively. The isorad map showed that El Urf monzogranite is barren (Up to 100 cps) surrounding an excavation of the studied pegmatite that exhibits moderate colorful mineralization (phase-I = 500–1500 cps) and anomalous opaque mineralization (phase-II = 1500– 3500 cps) pegmatites. The obtained results of radionuclides activity concentrations illustrated that the Opaque granites have the highest values of238U (561 ± 127 Bq kg−1),232Th (4289 ± 891 Bq kg−1) and40K (3002 ± 446 Bq kg−1) in the granites, which are higher than the recommended worldwide average. Many of the radiological hazard parameters were lesser than the international limits in the younger granites and barren pegmatites. All of these parameters were higher in the colorful and opaque mineralized pegmatites. The high activity and the elevated radiological hazard parameters in the mineralized pegmatites are revised to the presence of radioactive and radioelements bearing minerals, such as thorite, meta-autunite, kasolite, phurcalite, columbite, fergusonite, Xenotime and fluorapatite. Other instances of mineralization were also recorded as cassiterite, atacamite, galena, pyrite and iron oxide minerals. Thus, the granites with high radioactivity concentration cannot be applied in the different applications of building materials and ornamental stones. © 2022 by the authors. Li-censee MDPI, Basel, Switzerland.Funding: This research was funded by the Nuclear Materials Authority, Egypt. The APC was covered by “Dunarea de Jos” University of Galati, Romania, through grant no. RF3621/2021

Exome-wide association study to identify rare variants influencing COVID-19 outcomes : Results from the Host Genetics Initiative

Publisher Copyright: Copyright: © 2022 Butler-Laporte et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Host genetics is a key determinant of COVID-19 outcomes. Previously, the COVID-19 Host Genetics Initiative genome-wide association study used common variants to identify multiple loci associated with COVID-19 outcomes. However, variants with the largest impact on COVID-19 outcomes are expected to be rare in the population. Hence, studying rare variants may provide additional insights into disease susceptibility and pathogenesis, thereby informing therapeutics development. Here, we combined whole-exome and whole-genome sequencing from 21 cohorts across 12 countries and performed rare variant exome-wide burden analyses for COVID-19 outcomes. In an analysis of 5,085 severe disease cases and 571,737 controls, we observed that carrying a rare deleterious variant in the SARS-CoV-2 sensor toll-like receptor TLR7 (on chromosome X) was associated with a 5.3-fold increase in severe disease (95% CI: 2.75–10.05, p = 5.41x10-7). This association was consistent across sexes. These results further support TLR7 as a genetic determinant of severe disease and suggest that larger studies on rare variants influencing COVID-19 outcomes could provide additional insights.Peer reviewe

Non-Linear Heat and Mass Transfer of Second Grade Fluid Flow with Hall Currents and Thermophoresis Effects

A mathematical model analysis has been developed to investigate the effect of thermophoresis on unsteady flow of non- Newtonian fluid with heat and mass transfer through a porous medium over a permeable infinite vertical plate. The considered non- Newtonian fluid follows a second grade model and is stressed by a uniform strong magnetic field; so the Hall currents are taken into consideration. The problem is modulated mathematically by a system of coupled non-linear partial differential equations which pertaining to describe the continuity, momentum, energy and concentration. These equations involve the effects of thermal radiation, heat generation, thermal diffusion(Soret), viscous dissipation and chemical reaction. The numerical solutions of the dimensionless equations are found as a functions of the physical parameters of this problem. The numerical formulas of the velocity components (u) and (w), temperature (q ) and concentration (C) as well as Nusselt number(Nu) and Sherwood number(Sh) are computed. The physical parameters effects of the problem on these formulas are described and illustrated graphically through some figures and tables

Effects of microwave heating on the thermal states of biological tissues

A mathematical analysis of microwave heating equations in one-dimensional multi-layer model has been discussed. Maxwell's equations and transient bioheat transfer equation were numerically calculated by using finite difference method to predict the effects of thermal physical properties on the transient temperature of biological tissues. This prediction of the temperature evolution in biological bodies can be used as an effective tool for thermal diagnostics in medical practice

Magnetohydrodynamic Peristaltic Flow of Jeffry Nanofluid with Heat Transfer Through a Porous Medium in a Vertical Tube

The present paper deals with the peristaltic motion of a non-Newtonian nanofluid with heat transfer through a porous medium inside a vertical tube. The system is stressed by a uniform magnetic field. The viscous dissipation, internal heat generation with radiation effects are considered. A Rung-Kutta-Merson method and a Newton iteration in a shooting and matching technique are used to find the solutions of the momentum, temperature and nanoparticles equations. The numerical formula of the axial velocity, temperature and nanoparticles are obtained as functions of the physical parameters of the problem. Numerical calculations are carried out for these formula. The effects of physical parameters of the problem on this formula are discussed numerically and illustrated graphically througth a set of figures