Functionally graded materials (FGMs), with ceramic –ceramic constituents are fabricated using powder technology techniques. In this work three different sets of FGMs samples were designed in to 3 layers, 5 layers and 7 layers. The ceramic constituents were represented by hard ferrite (Barium ferrite) and soft ferrite (lithium ferrite). All samples sintered at constant temperature at 1100^oC for 2 hrs. and characterized by FESEM. Some physical properties were measured for fabricated FGMs include apparent density, bulk density, porosity, shrinkage and hardness. The results indicated that the density increase with the increase the number of layer. Lateral shrinkage is one of the important parameter f

In this research, a novel thin film Si-GO10 and nanopowders Si-GO30 of silica-graphene oxide (GO) composite were prepared via the sol–gel method and deposited on glass substrates using spray pyrolysis. X-ray diffraction (XRD) results showed a relatively strong peak in the graphite layer that corresponds to the (002) plane. Transmission electron microscope (TEM) images showed that SiO₂ nanoparticles were randomly distributed on the surface of GO plates, and the particle size in these nanopowders was below 50 nm. Field emission scanning electron microscopy (FESEM) analysis demonstrated that silica nanoparticles on the surface of GO plates exhibited almost spherical and rod-like nanoparticle shape, which in tur

Background: Surface treatment of machined dental zirconia for enhancement of the adhesion to resin cement, using Er,Cr:YSGG  Laser. Materials and Methods: Total number of 42 zirconia disc specimens (9 mm diameter, and 2 mm height) was sintered according to the manufacturer instruction. They are divided into six groups, each group of seven samples. Laser groups (Experiment parameters) were depend on laser total irradiation time, pulse duration, and power. Group (A): 20 sec., 60 µs pulse duration. Group (B): 30 sec., 60 µs pulse duration. Group (C): 40 sec., 60 µs pulse duration. Group (D): 20 sec., 700 µs pulse duration. Group (E): 30 sec., 700 µs pulse duration, with different powers used (1, 1

Magneto-rheological (MR) valve is one of the devices generally used to control the speed of Hydraulic actuator of MR fluid. The performance of valve depends on the magnetic circuit design. Present study deals with a new design of MR valve. A mathematical model for the MR valve is developed and the simulation is carried out to evaluate the newly developed MR valve. The design of the magnetic circuit is accomplished by magnetic finite element software such as Finite Element Method Magnetic (FEMMR). The model dimensions of MR valve, material properties are taken into account. The results of analysis are presented in terms of magnetic strength H and magnetic flux density B. The simulation results based on the proposed model indicate that the ef

Abstract

Paraffin wax is utilized for the heat storage applications taking advantage from the high stored latent heat during the phase change (from solid to fluid) period. What isn't right with this procedure is that the wax has a little heat transfer rate because of its low thermal conductivity. The thermal conductivity improvement of the paraffin wax has been examined utilizing nano-material with high thermal conductivity. In the recent study, (Al₂O₃) nanoparticles with weights of 1, 2, and 3% of the paraffin wax were added to the paraffin wax. The Iraqi paraffin wax accessible at the local markets was utilized as a phase change material (PCM).

Many properties of the

Ibuprofen is one of the most important members of NSAIDs, named aryl propionic acid derivative. Isatin (1H-indole-2,3-dione) is an important molecule of heterocyclic compounds that have many biological activities. This work illustrates the synthesis of new ibuprofen-isatin derivatives by connecting ibuprofen hydrazide with different isatin derivatives by a condensation reaction, followed by characterization by fourier-transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (1H-NMR) spectroscopy. The anti-inflammatory activity was evaluated by using the egg-white induce edema method for all the synthesized compounds (5-8), the compounds 5 and 6 showed better anti-inflammatory activity than ibuprofen as a standard

this work, a simple method was used to prepare the MnO2 nanoparticles. These nanoparticles then were characterized by several techniques, such as X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy (SEM) and atomic force microscope (AFM). The results showed that the diffraction peak of MnO2 nanoparticles was similar to that of standard data. The images of AFM and SEM indicated that the MnO2 nanorods were growing from the MnO2 nano spherical shape. PVA-pentaerythritol/MnO2 nanocomposite films were fabricated by evaporating casting method. The dielectric constant and loss tangent of P-Ery/MnO2 films were measured between 10 kHz and 1 MHz using LCR. As the content of MnO2 increased, the dielectric constant

Computational study of three-dimensional laminar and turbulent flows around electronic chip (heat source) located on a printed circuit board are presented. Computational field involves the solution of elliptic partial differential equations for conservation of mass, momentum, energy, turbulent energy, and its dissipation rate in finite volume form. The k-ε turbulent model was used with the wall function concept near the walls to treat of turbulence effects. The SIMPLE algorithm was selected in this work. The chip is cooled by an external flow of air. The goals of this investigation are to investigate the heat transfer phenomena of electronic chip located in enclosure and how we arrive to optimum level for cooling of this chip. These par

In the present study, a low cost adsorbent is developed from the naturally available sawdust
which is biodegradable. The removal capacity of chromium(VI) from the synthetically prepared
industrial effluent of electroplating and tannery industrial is obtained.
Two modes of operation are used, batch mode and fixed bed mode. In batch experiment the
effect of Sawdust dose (4- 24g/L) with constant initial chromium(VI) concentration of 50 mg/L and
constant particle size less than1.8 mm were studied.
Batch kinetics experiments showed that the adsorption rate of chromium(VI) ion by Sawdust
was rapid and reached equilibrium within 120 min. The three models (Freundlich, Langmuir and
Freundlich-Langmuir) were fitted to exper