A numerical study of laminar magnetohydrodynamic mixed convection in an inclined lid-driven squarecavity with opposing temperature gradients is presented. The vertical sidewalls are assumed to havenon-uniform temperature variation while the top and bottom walls are kept insulated with the topsurface moving at a constant speed. The transport equations are given in terms of the stream functions-vorticity formulation and are non-dimensionalized and then solved numerically by an accurate finite-volume method. The computation is carried out for wide ranges of the inclination angle (0 ≤  ≤ /2), theRichardson number (0.01 ≤ Ri ≤ 100), the Hartmann number (0 ≤ Ha ≤ 100), the amplitude ratio (0 ≤ ε ≤ 1)and the phase deviation (0 ≤  ≤ ). The results indicate that the rate of heat transfer along the heatedwalls is enhanced on increasing either Hartmann number or inclination angle. Average Nusselt numberis also, increased with increasing of the amplitude ratio for all values of the phase deviation. The non-uniform heating on both walls provides higher heat transfer rate than non-uniform heating of one wall.

A numerical investigation is performed into the natural convection heat transfer characteristics within an enclosed cavity filled with nanofluid. The left and right walls of the cavity have a complex-wavy geometry and are maintained at a low and high temperature, respectively. Meanwhile, the upper and lower walls of the cavity are both flat and insulated. The nanofluid is composed of Al2O3 nanoparticles suspended in pure water. In performing the analysis, the governing equations are formulated using the Smoothed Particle Hydrodynamics and the complex-wavy-surface is modeled as the superimposition of two sinusoidal functions. The simulations examine the effects of the volume fraction of nanoparticles, the Rayleigh number and the complex-wavy-surface geometry parameters on the flowstreamlines, isotherm distribution and Nusselt number within the cavity. The results show that for all values of the Rayleigh number, the Nusselt number, increases as the volume fraction of nanoparticles increases. In addition, it is shown that the heat transfer performance can be optimized by tuning the wavy-surface geometry parameters in accordance with the Rayleigh number. Overall, the results presented in this study provide a useful insight into potential strategies for enhancing the convection heat transfer performance within enclosed cavities with complex-wavy-wall surfaces.

A numerical investigation is performed into the natural convection heat transfer characteristics within an enclosed cavity filled with nanofluid. The left and right walls of the cavity have a complex-wavy geometry and are maintained at a low and high temperature, respectively. Meanwhile, the upper and lower walls of the cavity are both flat and insulated. The nanofluid is composed of Al2O3 nanoparticles suspended in pure water. In performing the analysis, the governing equations are formulated using the Smoothed Particle Hydrodynamics and the complex-wavy-surface is modeled as the superimposition of two sinusoidal functions. The simulations examine the effects of the volume fraction of nanoparticles, the Rayleigh number and the complex-wavy-surface geometry parameters on the flowstreamlines, isotherm distribution and Nusselt number within the cavity. The results show that for all values of the Rayleigh number, the Nusselt number, increases as the volume fraction of nanoparticles increases. In addition, it is shown that the heat transfer performance can be optimized by tuning the wavy-surface geometry parameters in accordance with the Rayleigh number. Overall, the results presented in this study provide a useful insight into potential strategies for enhancing the convection heat transfer performance within enclosed cavities with complex-wavy-wall surfaces.

In this paper, the buoyancy-driven fluid flow and heat transfer in a square cavity with partially active side walls are investigated numerically. The top and vertical walls of the cavity are maintained at the relatively low temperature. The governing partial differential equations have been described in smoothed particle hydrodynamics formulations. The transport equations for a Newtonian fluid are solved numerically using smoothed particle hydrodynamics (SPH) method. The results indicate the relation among changes taking part in the heat source length, heat source location, Rayleigh number, maximum temperature and maximum value of stream function and velocities.

Three interesting thermoresponsive branched oligoethylene glycol dendrimers based on tetrabromohydroquinone were efficiently synthesized from tetrabromohydroquinone and three different oligoethylene glycol derivatives. By visual inspection, all these dendrimers are water-soluble at room temperature. The thermoresponsive behaviors were investigated by using UV/vis turbidity measurement at different temperatures for 0.25 wt% of aqueous solutions from D1, D2 and D3. The cytotoxicity of the prepared dendrimers was tested against MCF-7 breast cancer cells. All tested dendrimers showed considerable results, where D2 dendrimer gave the best result; it showed cytotoxicity against MCF-7 cell line with IC50 of 1.07 mg/mL and resistant fraction equals 1.97%, the other two dendrimers showed a modest cytotoxic profile.

Nanoparticles exhibit unique physical properties that are not found in their bulk counterpart. The synthesis structure which contains Au or Ag core metallic particles and a shell of CdSe semiconductor has the combined properties of quantum dots and the metallic particles. A new method has been developed to grow plasmonic semiconductor nanocomposites of Au/CdSe and Ag/CdSe nanostructure. The method based on preparing seed of metal nanoparticles which used as a seed using organometllic pyrolysis followed by adding the semiconductor precursors. Their chemical composition crystal structure is determined via X-Ray Diffraction. The collective optical properties of the plasmonic semiconductor nanohybrid has been measured using spectrophotometer techniques and compared to those individual components. The main features which observed in the hybrid nanostructure is broodning of Plasmonic band and decrease in its amplitude in addition to shifting excitonic energy band to higher wave length.The quenching of the emission of Au/CdSe has been observed due to photoinduced electron injection into metallic seed. The electron transfer processes from CdSe to the gold is more faster than that of the silver. For this reason, we can consider the CdSe/Au is strong plasmonic - exitonic coupling but CdSe/Ag is week plasmonic-excitonic coupling.

Nanoparticles exhibit unique physical properties that are not found in their bulk counterpart. The synthesis structure which contains Au or Ag core metallic particles and a shell of CdSe semiconductor has the combined properties of quantum dots and the metallic particles. A new method has been developed to grow plasmonic semiconductor nanocomposites of Au/CdSe and Ag/CdSe nanostructure. The method based on preparing seed of metal nanoparticles which used as a seed using organometllic pyrolysis followed by adding the semiconductor precursors. Their chemical composition crystal structure is determined via X-Ray Diffraction. The collective optical properties of the plasmonic semiconductor nanohybrid has been measured using spectrophotometer techniques and compared to those individual components. The main features which observed in the hybrid nanostructure is broodning of Plasmonic band and decrease in its amplitude in addition to shifting excitonic energy band to higher wave length.The quenching of the emission of Au/CdSe has been observed due to photoinduced electron injection into metallic seed. The electron transfer processes from CdSe to the gold is more faster than that of the silver. For this reason, we can consider the CdSe/Au is strong plasmonic - exitonic coupling but CdSe/Ag is week plasmonic-excitonic coupling.

Heavy fuel oil and ash samples were collected from the Assiut thermal power plant in Egypt and subjected to gamma spectrometry analysis for natural radioactivity contents. Considerable results were observed where the ash contains nearly 1,000 times natural radionuclides more than raw oil. The results were confirmed by measuring the samples via using different devices in different institutions. All ash samples had radium equivalent activities and external hazard index values more than 370 Bq/kg and unity respectively. The mean absorbed dose rate was10,650 nGy/h which is nearly 190 times higher than the global average value of 55 nGy/h. The corresponding annual external effective dose is estimated to be 13 mSv/year, which is nearly 30 times higher than that in areas of natural background radiation (0.46 mSv/year).

Heavy fuel oil and ash samples were collected from the Assiut thermal power plant in Egypt and subjected to gamma spectrometry analysis for natural radioactivity contents. Considerable results were observed where the ash contains nearly 1,000 times natural radionuclides more than raw oil. The results were confirmed by measuring the samples via using different devices in different institutions. All ash samples had radium equivalent activities and external hazard index values more than 370 Bq/kg and unity respectively. The mean absorbed dose rate was10,650 nGy/h which is nearly 190 times higher than the global average value of 55 nGy/h. The corresponding annual external effective dose is estimated to be 13 mSv/year, which is nearly 30 times higher than that in areas of natural background radiation (0.46 mSv/year).

Heavy fuel oil and ash samples were collected from the Assiut thermal power plant in Egypt and subjected to gamma spectrometry analysis for natural radioactivity contents. Considerable results were observed where the ash contains nearly 1,000 times natural radionuclides more than raw oil. The results were confirmed by measuring the samples via using different devices in different institutions. All ash samples had radium equivalent activities and external hazard index values more than 370 Bq/kg and unity respectively. The mean absorbed dose rate was10,650 nGy/h which is nearly 190 times higher than the global average value of 55 nGy/h. The corresponding annual external effective dose is estimated to be 13 mSv/year, which is nearly 30 times higher than that in areas of natural background radiation (0.46 mSv/year).