Engineering and Technology Journal

The third-order optical nonlinearities of polyurethane open cell (PUOC)/MgO nanocomposites, dissolved in dimethylformamide are characterized by Z-scan technique with continuous-wave (CW) Nd:YAG laser at its second harmonic frequency of 532 nm with TEM00 Gaussian profile. The synthesized samples are also characterized by scanning electron microscopy imaging. The nonlinear refractive indices and nonlinear absorption coefficients of the synthesized samples are obtained in the order of 10-8 cm2/W with negative sign and 10-5 cm2/W, respectively. The origin of optical nonlinearity in this case may be attributed due to the presence of strong saturable absorption effect. All the results suggest that the nonlinear coefficients of the synthesized samples can be controlled by the nanoparticles contents into PUOC. Furthermore, the results show that PUOC/MgO may be helpful candidate for the application in nonlinear optical field in the visible region

In present work alumina with grain size (50 nm ) and titanium dioxide with grain size (20nm ) are used to thermal conductivity is tested separately when mixed with water at different percent concentrations (0.05%, 0.1 %, 0.3%, and 0.5 W %), in order to investigate their effects on enhancement of heat transfer of pool boiling water and enhancement thermal conductivity of nanofluid.
The experimental results of thermal conductivity of water before and after adding of nanoparticles have been presented in this work. The results of a theoretical study of thermal conductivity of nanofluids with Al2O3 and TiO2 nanoparticles are also presented and compared with the experimental results. Both results showed an increment of 1.5% -1.8% enhancements have been obtained when a small amount of nanoparticles is added to the pure water. The theoretical calculation is based on the mechanism of Brownian motion which is the reason for improvement of thermal conductivity

In this work attempt was made to formulate water based boehmite (AlOOH) nanofluid in one and two steps methods. Boehmite is the first born alumina phase as prepared by sol gel route using aluminum isopropoxide precursor, exhibit a combination of excellent consistency and dispersibility in water. Plain nanofluids containing boehmite at different concentrations were investigated for colloidal, suspensions and/or dispersions stability and thermal conductivity enhancement. X-ray diffraction analysis, laser diffraction particle size analysis, viscosity, thermal conductivity measurements, TG/DSC thermal analysis and sedimentation balance were used as characterization tools. The results show promising long-term fluid stability and thermal conductivity enhancement relative to starting based fluid following non-linear dependence on particles concentration. The maximum 2.7 times enhancement in thermal conductivity occurred at narrow boehmite concentration range as a result of achieving optimum nanoparticles aggregation level where neither the case of nanoparticles homogenous dispersion nor the case of fully aggregated clusters could retain these enhancements values. This far beyond behavior from Maxwell's model was explained on the basis of the known mechanisms of thermal conductivity enhancement of nanofluids

The use of a laser to modified the surfaces of various materials engineering is a important topics in the present time. Two types of alloys were used in this investigation; 6063Al and C11000 alloys. Samples were prepared by cutting into disc shape of radius 12 mm and then cleaning and polishing process to produce same surface roughness for all samples . Surface roughness and micro hardness were measured for all samples before and after laser shock wave treatment . different laser parameters effect on alloys surface properties were studied such as laser energy , confinement layer( different depth of DDDW) ,and number of laser pulses . The results reveal that the surface roughness are increased by 200% for 6063Al alloy and by 120% for C11000 alloy when we used laser energy of 400mj , number of laser pulses of 100 and confinement layer 5mm . While the microhardness increase by 80% for the two kinds of alloys and at the same conditions . Different measurements were carried out for all samples such as XRF, EDX, SEM , and different mechanical tests For precise and accurate results

Polyaniline (PANI) in Emeraldine salt form was prepared by chemical oxidative polymerization of the appropriate monomeric aniline using two different acid doping (Hydrochloric acid (HCL) and P-Toluene sulfonic Acid (PTSA)) respectively. The prepared samples were characterized by Fourier transform- infrared (FT-IR) spectroscopy; Ultraviolet- Visible (UV-VIS) spectroscopy and X-ray diffraction technique (XRD). The FT-IR and UV-VIS spectroscopy results indicate the doping state of PANi (HCL and PTSA). The crystallinity of the samples was studied in detail by X-ray diffraction technique. The (I-V) characteristic of (PANI) at room temperature, it was showed linear curve close to zero bias indicates that the charge transfer is a straight forward consequence of ohmic behavior, indicating that the measurement was performed in a field independent conductivity region. The scanning electron microscopy (SEM) was used to determine the morphology of the as-prepared nanomaterials

In this paper the effect ofaddition 0.2,0.4,0.6,0.8,1gof Titanium oxide (TiO2) Nanoparticles inwater absorption, dimensions change and thickness for Polyvinyl alcohol (PVA)/Corn Starch(CS)10g/10g blend and PVA/CS/TiO2 thick films have been studied. Films were prepared using solution casting method. Films were immersing in water for 60 days. The results show that, the water absorption and dimensions change decrease with increasing nanoparticles content, but thickness increase with increasing nanoparticles after immersion, also weightlosing, dimensions change and thickness were found after drying. The results show that the weightlosing, dimensions change decrease with increasing nanoparticles, reducing in thickness increase with increasing nanoparticles

Silver nanowire grow on FTO coated quartz substrate by using hydrothermal method, it can be observed that the morphology of the product is wire-like and nearly uniform in width (60 ± 10 nm), while the length is in a relatively broad range (from 0.2 to 4 μm) with an average at 2.5 μm. The calculated lattice constant according to the (111) peak is 4.08 Å which is closely consistent with the standard value (4.086 Å).

Nano-SiO2 with different weight percentage (1,2 ,3, 4 and 5) % wt. , and 3% MWCNT were usedto fabricate nano-SiO2/MWNT/epoxy composite samples by hand layup method. Ultrasonic mixing processwas used to disperse the nano additives into the resin system. scanning electron microscopy (SEM)where usedto carry out the characteristic of fracture surface. By both the high aspect ratio and the very high modulus ofnano fillers. The mechanical properties of the composite with different weight percentages of nano-SiO2 havebeen investigated and After examine, the Scanning Electron Microscopy (SEM) explains well dispersednanotubes and SiO2 nano particles in the matrix. No evidence of agglomeration of the nanotubes can be foundin this micrographs. By adding SiO2 nano particles to epoxy/MWCNT composite, this would dramaticallyimprove the bending properties and The Young’s modulus has been doubled and quadrupled for compositeswith respectively 2 and 4 wt.% nano SiO2, compared to the pure resin matrix samples (3.36 ,4.06 ,and 1.59 )GPa respectively .While flexural strength has been increased in random manner with maximum value for 2 wt%(111 MPa). The hardness of nano composite increased with increase of SiO2 filler loading, it can be seen thatthe SiO2 filler greatly increased the hardness, which can be attributed to the higher hardness and moreuniform dispersion of SiO2 filler. The higher hardness is exhibited by the 5 wt% SiO2 filled compared to othernanocomposites. The results show that at 5wt% nano SiO2 content there is 11% increase in hardness

Abstract
In The present work has been prepare samples of polymer and the formation of composite material at different rates (20%, 50% &70%) of nano lead to clarify the difference in the spectrum absorption bremsstrahlung rays through the process of exponential equations graphic representation of the rate correction as a function of energy within the range (0.1 –1.7) MeV using NaI(Tl) energy selective scintillation counter with 90Sr/90Y negative beta source. It was getting also attenuation coefficient of the prepared samples to the same range of energy through graphic representation of natural allegartm count rate as a function of the thickness of absorbent material as the gradient relationship diagrams represents absorption coefficient. The result shows a directly relationship, between the thickness of the absorbent material and the absorption factor. The result, also show that, a reversal relationship, between the absorption factor and the energy of beta particle. The results shows that , the samples prepared of good absorption for beta particles and absorb bremsstrahlung rays and this efficiency is relatively unchanged according to the proportion of nano lead additives which shows a positive impact of the materials prepared in the process of radiation shielding

Nanocrystalline zinc cadmium sulfide (ZnxCd1-xS) thin films were deposited on glass substrate by chemical bath deposition (CBD) technique using the mixed aqueous solution of zinc chloride ((ZnCl2), cadmium chloride (CdCl2), thiourea (CS(NH2)2) and ammonia solution (NH4OH). The as deposited films were characterized by high quality instrument type (HMS-3000). The results show that all the prepared films have n-type conductivity; this is concluded from the Hall measurements. The electrical conductivity is found to decrease with increasing x, while the activation energies are found to be increasing from (0.458 to 0.860 eV) as x increase from ( 0.1 to 0.9).

Silver Poly (methyl methacrylate) PMMA nanocomposite thin films deposited on glass substrates by in-situ aerosol assisted plasma polymerization at atmospheric pressure and room temperature, from methyl methacrylate monomer in the presence of different concentrations of Ag nanoparticles (3%, 5%, 7%, and 9wt%). The average particles size for the silver nanoparticles was within 50nm. Metal polymer nanocomposite thin films were characterized by UV-VIS, XRD, and SEM the optical studies show that the energy band gap will be different according to the silver PMMA concentration. The XRD pattern indicates that the pure PMMA is amorphous where The XRD pattern of Ag nanoparticles in PMMA, all the refractions corresponded to the pure silver metal with cubic symmetry. SEM and the XRD reveal the presence of silver nanoparticle embedded into PMMA. It can be concluded that it can be prepared Ag\ PMMA nanocomposite thin films by aerosol assisted dielectric barrier discharge DBD plasma jet polymerization and control the optical energy band gap irregulars by controlling the experiment variables

AgSbSe2thin films with different thicknesses (100,300,500, and 700nm) have been deposited by single source vacuum thermal evaporation onto glass substrates at ambient temperature to study the effect of thickness on its structural morphology, and electrical properties. The X–ray diffraction patterns of AgSbSe2thin film show that with low thickness (t=100,300 and 500nm) have amorphous structure convert to polycrystalline structure with increase thickness to 700 nm..AFM measurements show that the average grain size increases while the average surface roughness decreases with the increase of thickness. The DC conductivity of the vacuum evaporated AgSbSe2thin films was measured in the temperature range (298-473)K and was found to increase on order of magnitude with increase of thickness. The plot of conductivity with reciprocal temperature suggests, there are two activation energies Ea1, andEa2 for AgSbSe2for all and thicknesses which decrease with increasing thickness. The electric carrier concentration and mobility show opposite dependence upon thickness.

In this study, friction stir method (FSP) was used for include walled (Al2O3) Nano-sized particles into the matrix of Al 5083 alloy by electrophoretic deposition (EPD). The impact of these reinforcements on microstructural modification, mechanical properties and corrosion resistance of FSP Al 5083 surface composites were studied. A rib cylindrical hardened steel tool was used with the rotation speeds of 800, 1000 and 1200 rpm and travel speeds 50 mm/min. Mechanical properties and corrosion resistance of FSP samples were evaluated and compared with the basis alloy. The corrosion behavior of the samples was investigated by potentiostatic polarization tests. Microstructural analysis accomplished by optical and SEM microscopes showed that reinforcements are well distributed within the stir zone, and grain refinement is gained. The reinforcement incremented the hardness from Hv80.083 metric weight unit for as castings to a most of Hv135.413 for friction stir. Although friction stir parameter has attenuated the corrosion current density (7.15μA/cm2) compared to the results of the as-cast samples.

Synthesis of titanium dioxide (TiO2) Thin film on three microscope glasses using sol-gel method has been studied intensively. The starting materials were titanium(III)chloride, Ammonium Hydroxide. The components were mixed together to form the sol. Then, at 50 heating and ageing was applied to form stable sol-gel . Every glass substrate dipping in sol-gel beaker for period time (1,3,5)min respectively, for obtaining different thickness films. To evaluate the performance of films, After annealing at 500 the crystallinity of the films was determined by using the x-ray diffractometer (XRD). The change on the surface morphology was observed using Atomic Force Microscope(AFM). Finally, Optical properties measurements Absorbance (A) and transmittance(T)) for (TiO2) films were studied by UV-Visible spectrometer.
analysis on the films. It has been successfully shown that the anatase crystalline phase was observed when the TiO2 thin film was annealing at 500°C. The roughness and the crystalline size of TiO2 thin film changed with the thickness. The minimum grain size( 6.92) nm for thickness 1.2μm UV-visible studying that absorption is maximum at UV spectrum (opaque) and the transmittance is maximum at the visible spectrum

In this work a hybrid composite materials were prepared containing matrix of polymer blend (Novolac 80% + Epoxy 20%) reinforced by different reinforcing materials (Alumina Powder + Silica Powder + Asbestos short fiber ) with two values of volume fraction (30, 40) %.
The hybrid composite materials prepared are:
H1 = Blend + Al2O3 + AS (30) %
H2 = Blend + SiO2 + AS (30) %
H3 = Blend + Al2O3 + SiO2+ AS (30) %
H4 = Blend + Al2O3 + AS (40) %
H5 = Blend + SiO2 + AS (40) %
H6 = Blend + Al2O3 + SiO2+ AS (40) %
Oxy - Acetylene was used to examine erosion .
The sample (H6) of the volume fraction (40%) showed higher erosion resistance values whereas the sample (H1) was less in value to resist erosion, the highest rates of erosion. For the (H1) sample there was high tendency to weight loss with high temperature and less as to the sample (H6

The enhancements of heat transfer coefficient and Nusselt number in a heat exchanger system were achieved by using Titanium-dioxide (TiO2) nanoparticles with an average diameter of 10 nm. TiO2 nanoparticles/water has a better thermal conductivity compared to conventional working fluids (water). The heat transfer rate in a vertical shell and tube heat exchanger counter flow under laminar and turbulent flow conditions were investigated. The liquid flow rate has been varied in the range of 50-300 l/h while the inlet temperature was between 20 to 60 ºC. The effects of factors such as the Reynolds number and the peclet number on the heat transfer and flow characteristics were carried out and investigated. It was observed that the convection heat transfer increased remarkably with the increment of the temperature under various values of the Reynolds number. As well as, the Nusselt number increased about 17% as compared to pure water; at a nanofluid velocity of 0.0192 m/s at inlet temperature of 600C.

In this work a hybrid composite materials were prepared containing matrix of polymer blend (Novolac 80% + Epoxy 20%) reinforced by different reinforcing materials (Alumina Powder (type α) + Silica Powder + Asbestos short fiber) with two values of volume fraction (30, 40) %.

The water absorption of high density polyethylene filled with micro hybrid (titanium dioxide and alumina), alumina and titanium dioxide with weight ratio of 15%, 20%, 25% and 30% , are measured in order to study the effect of these particles on water absorption of this polymer. The result shows that the increase of content of filler particles increasing water absorption, because of filler particles which have a higher water absorption percentage than the matrix material, and the filler will take up the free volume within the polymer matrix and create a tortuous path for the water permeating through the sample

This research covers reinforcement of unsaturated polyester resin by metal powders, and studying some of their mechanical properties. The samples were prepared by hand lay-out technique. The unsaturated polyester resin was reinforced by two types of metal powders Copper (15.598 μm) and aluminum (21.533μm) at selected volume fraction of (0, 5, 10. 15, 20 and 25 %). The study of mechanical properties includes tensile properties (strength at fracture point, elastic modulus and elongation at at break), flexural strength and flexural modulus, impact properties and hardness. The results show a noticeable increase in values of tensile strength at fracture point and tensile modules of elasticity, as the volume fraction of metal powder increase and reach to maximum value at 15 % volume ratio for both types, where as flexural strength, flexural modulus and fracture toughness reach to maximum value at 10 %volume ratio for both types composites, however elongation at break shows decrement as the volume fraction of metal powder is increased for both types composites

In this present study, we present a method for the preparation of electrochemical silver nanoparticles .we employed two electrodes of pure silver with length 8-12 cm, thickness of 0.4 mm and width 8-10 mm inside a container full of DDDW with distance 10 mm between them and with potential difference about 27 volt.
For the purpose of analyzing of optical, structural and morphological properties of the surface that describe the nature, the charging and the voltages of these materials by using the UV-VIS, X-ray, Z-potential, SEM, AFM, and TEM were employed.Size and properties were controlled in high concentrations with good stability for long period without aggregation. Colloidal silver-NPs with grain size of 30-50 nm had been produced at optimum conditions