Scientia Iranica
Volume:29 Issue: 6, Nov-Dec 2022

The present work aims to investigate the effect of the parameters of the laser machining process and laser line angle to injection direction of sample plastics on the electrical resistance of Polymethyl Methyl Methacrylate (PMMA)/Multi-Wall Carbon Nanotubes (MWCNT) Nano-composite. The laser machining process was performed on the samples considering a combination of power, feed rate, and laser line angle with respect to to the direction of melted flow parameters. According to the obtained results from electrical resistance and magnetic properties measurements, this was demonstrated that the laser line angle to the direction of melted flow does not statistically, and physically affect the electrical resistance of the composite. And increasing laser machining power leads to electrical resistance reduction. On another hand, feed rate enhancement (with fixed lasering power) causes increasing the electrical resistance. Moreover, this is found out that laser machining does not significantly affect the magnetic properties of the samples.

HA and FA are classified as precious compounds in the agricultural and biomedical industries. The production of these compounds from SB, using SSF and SmF systems compared in a 220-liter bioreactor over 70 days. Initially, fourteen treatments examined to determine the best treatment with a proper C/N ratio. Among examined treatments, BFFU characterized as the most effective mixture (C/N ratio 32.5). The results obtained via SSF using BFFU treatment were 3.96 and 2.36% DM for HA and FA, respectively. The most efficient treatment and fermentation system implemented via two different bioreactor volumes (60 and 1000 liter) to compare the appropriate condition for higher yield. In contrast with SSF, production yield via the SmF system resulted in a higher yield in half of the processing time. These results were almost 3 times more than the SSF results that scaled up to 12.84 and 7.91% DM over a period of 36 days. Whereas, these results were slightly higher applying 1000 liter CSTR that was 14.25 and 8.39% DM over 35 days. The FTIR analysis has shown structural similarities between SB-derived HA and FA in the present study with the commercial counterpart with highly strong and strong peaks for functional groups.

In the present study, MHD Casson nanofluid under the influence of exponential temperature dependent thermal conductivity and variable viscosity past a stretching surface has been scrutinize. After the application of the similarity transformations, the governing partial differential equations of the modelled problem are converted into ordinary differential equations and solution is achieved with the assistance of the shooting method. The solution obtained with the help of shooting technique is used to analyze the distribution of mass and heat flux over sheet. The influence of various governing parameters on the dimensionless velocity, temperature and concentration distribution have been analyzed and discussed in detail. The simulations of the presented model show that the surface drag is upsurged as each of the Casson parameter and temperature dependent thermal conductivity parameter is boosted whereas the rate of heat transfer is diminished. It is also observed that an increment in the temperature near the surface is noted against the thermal conductivity parameter whereas an opposite trend is observed away from the surface.

The Graetz-Nusselt problem is addressed with non-Newtonian power-law nanofluid with slip boundary conditions. In the said fluid model, the power-law coefficient m and flow index n depend on the nanoparticles concentration φ. The Al_2 O_3-water nanofluid is considered and results are obtained for typical values of nanoparticle concentration i.e., φ=1%,2%,3%,4% and 5%. First of all, we calculate the analytical solution of fully developed velocity field for power-law nanofluid via Navier linear slip law. Next, the temperature profile is obtained by utilizing the condition of specified surface temperature. The longitudinal conduction (realizable for small Peclet number) is also considered. The graphical results of mean temperature and local Nusselt number are presented for various values of slip length, nanoparticle concentration, power-law index and Peclet number. As expected, the concentration of nanoparticles boosts the heat transfer rate while the slippery boundaries always provide larger flow rates of nanofluid. The analysis reveals that local Nusselt number and mean temperature are enhanced in the presence of nanoparticles concentration. Furthermore, the thermal entry length is considerably enhanced upon raising the nanoparticle concentration and slip length. Moreover, the impact of slip length on local Nusselt number is opposite to the effect of Péclet number.

In this investigation, the combined effects of magnetohydrodynamic and Arrhenius activation energy on Carreau nanofluid past a nonlinear stretching sheet have been examined. Buongiorno nanofluid model is considered to study the impact of nanoparticles with porous medium. For the analysis of the modelled problem convective heating mode and heat source/sink has also been incorporated. With the help of appropriate similarity transformations, formulated PDEs are transmuted into nonlinear ODEs. The solution of the resulting ODEs is achieved via shooting technique. For the limiting case, the results are numerically computed and compared with the already reported results for the validity of the MATLAB code and found splendid agreement. The variations in fluid motion, the temperature and concentration due to changes in different parameters are analyzed graphically and discussed in detail. Our simulations show that temperature profile is hiked as each of the Biot number, Arrhenius energy parameter and magnetic number are increased. It is also observed that the skin friction coefficient is enhanced for the increasing values of stretching parameter. Moreover, the enhancement in the skin friction is more fluid is shear thickening behaviour.

The current model represents the construction of entropy generation, heat transport and flow characteristics of /blood flow in a Darcy-Forchheimer stretching cylinder under the impact of Cattaneo-Christov heat flux and thermal radiation. The basic PDEs are turned into ODEs by using the correct similarity transformations. The 4th order Runge–Kutta shooting system is used to solve these ODEs. Homotopy perturbation method (HPM) for the nonlinear system is developed for the comparison purpose and more accurate and reliable outcomes is illustrated through graphs and tables. The effects of various factors on velocity, temperature, and entropy production are analysed visually. The velocity profile improves with larger magnetic field values, whereas the temperature profile has the reverse effect. Higher values of the Darcy-Forchheimer number enhance skin friction and heat transfer rates. In the present analysis, are nanoparticles blood is considered as base fluid. This investigation is helpful in biomedical engineering, including medicine and electronics. They play an essential role in nano biotechnology, particularly in cancer therapy and nano medicine, because these metal nanoparticles are thought to improve photo catalytic operation in the presence of titanium dioxide-drug delivery systems, particularly when drugs are injected into the blood stream.

It has been long known that Silibinin, a naturally derived herbal phytochemical, is an effective drug for the treatment of toxic thyroid damage; however, its role in cancer treatment is still not approved and is under investigation. Besides, due to the poor water solubility and bioavailability of Silibinin and the side effects that drug payloads cause, its delivery to the point of care with a controlled release rate is challenging. In this work, we propose a protocol to prepare liposome-encapsulated Silibinin (LES) with the ability to produce reactive oxygen species (ROS) for the treatment of MCF-7 breast cancer cells. Spherical-shaped LES nanoparticles with an average size of 60 nm and narrow size distribution (PDI=0.11) were synthesized by the thin film hydration method. Studies of the pharmacokinetics showed that a burst release occurred during the first 12 h that was followed by a sustained release over the next 12 days. MTT assays and the analysis of the drug effect determined that LES nanoparticles displayed a significant cytotoxic effect to kill breast cancer cells. IC50 values for LES nanoparticles were experimentally determined to be 20 μМ which was significantly lower than that of the pristine drug (38 μМ).....