Abstract: The investigation on the thermogravimetric analysis of unsaturated polyester matrix composites reinforced with untreated saccharum fibers and other treated by alkaline solution of NaOH with four weight percent include 0.5, 1, 2 and 2.5% was involved in this work. Generally the incorporation of saccharum fibers slightly change the thermal stability of the unsaturated polyester matrix by the weight loss value and only for reinforcement by unsaturated sacchrum fibers and that treated in 2.5% NaOH.

Abstract: The present research, studies the effect of adding two different types of reinforcing powders, which included: Bamboo (Ba) and Rice Husk (RH), that added with different weight fractions (2, 4, 6 and 8 wt. %), and with the selected size particles of (25µm and 75µm) on thermal behavior of heat Cure Poly (Methyl Methacrylate) such as thermal conductivity and thermal diffusivity in addition to the differential scanning calorimetry (DSC) analysis and these tests were accomplished at temperature of laboratory. The poly Methyl Methacrylate properties which reinforced by (Bamboo and Rice Husk) powders are mainly influenced by the interfacial adhesion strength between the powders and the matrix, and in order to get better correlation between the natural powder and PMMA matrix, so the powders were treated with alkali (sodium hydroxide NaoH) solution prior to use as reinforcement materials. The results showed that the values of the thermal conductivity and thermal diffusivity increased with increasing of the weight fraction for both particle sizes (25 µm and 75 µm) of natural powders.

Abstract: In this paper the effect of surface roughness on the performance of counter flow microchannel heat exchanger has been numerically investigated. The studied Microchannel heat exchanger is a square shape and made of aluminum as substrate material with different values of hydraulic diameters (20, 50, 110, 150 ) μm. The working fluid used is water at constant properties. Roughness- viscosity model has been used to study the roughness effect with 0.14 ratio of roughness to hydraulic diameter. The results obtained indicate that pressure drop of (CFMCHX) increased with increasing surface roughness and decrease hydraulic diameter also the results showed that there is a slight increasing in thermal performance with increasing the surface roughness.

Abstract: In this research stir casting technique is used to produce (ZA-27)alloy hybrid composites reinforced by nano particles (BN and Si3N4) with various weight percentage.The wear test were used pin on disk for both (ZA-27) alloy and all composites.The results indicate that the value of hardness increased with increasing the additives of nano (BN and Si3N4) percentage for ZA-27 hybrid metal matrix composites. It was found that the nano particles play an important role in improving the wear properties of alloys. Since nano particles impede dislocations movement, causing enhancement in the mechanical properties.