In this research, the study effect of additive titanium dioxide powder (TiO2) as a lone composite ( Ep+TiO2) and a mixture of (TiO2) and silicon oxide (SiO2), ( Ep+ TiO2+SiO2)as a hybrid composite on the mechanical and physical properties for epoxy coating. Thescompsiteswere prepared by (Hand Lay- the molding) method. The samples were tested for compressive strength, surface hardness, modulus of elasticity, thermal conductivity and diffusion coefficient, from the results obtained showed improvement in mechanical properties after adding ceramic powders, as the alone composite (EP+ TiO2) had the highest compressive strength ( 53.738 ) ᴍPa, the hybrid composite ( EP+TiO2 +SiO2 ) had the highest surface hardness (79.65), modulus of elasticity (1166.66 ) ᴍPa, impact strength ( 8.48) ᴍPa, thermal conductivity (0.4961 )watt/ m.c◦. As for the diffusion coefficient in the acidic solution ( HCL), the epoxy without adding the highest diffusion coefficient ( 31.3x 10-10) m2/ sec while for immersion in ordinary water, the one composite material (Ep+ TiO2) had the highest value of the diffusion coefficient (7.56x10-10)m2/sec.
This paper presents the Taguchi approach for optimization of hardness for shape memory alloy (Cu-Al-Ni) . The influence of powder metallurgy parameters on hardness has been investigated. Taguchi technique and ANOVA were used for analysis. Nine experimental runs based on Taguchi’s L9 orthogonal array were performed (OA),for two parameters was study (Pressure and sintering temperature) for three different levels (300 ,500 and 700) MPa ,(700 ,800 and 900)oC respectively . Main effect, signal-to-noise (S/N) ratio was study, and analysis of variance (ANOVA) using to investigate the micro-hardness characteristics of the shape memory alloy .after application the result of study shown the hei
... Show MoreIn this research we solved numerically Boltzmann transport equation in order to calculate the transport parameters, such as, drift velocity, W, D/? (ratio of diffusion coefficient to the mobility) and momentum transfer collision frequency ?m, for purpose of determination of magnetic drift velocity WM and magnetic deflection coefficient ? for low energy electrons, that moves in the electric field E, crossed with magnetic field B, i.e; E×B, in the nitrogen, Argon, Helium and it's gases mixtures as a function of: E/N (ratio of electric field strength to the number density of gas), E/P300 (ratio of electric field strength to the gas pressure) and D/? which covered a different ranges for E/P300 at temperatures 300°k (Kelvin). The results show
... Show MoreMagnesium oxide nanoparticles (MgO NPs) were synthesized by a green method using the peels of Persimmon extract as the reducing agent , magnesium nitrate, and NaOH. This method is eco-friendly and non-toxic. In this study, an ultrasound device was used to reduce the particle size, with the impact on the energy gap was set at the beginning at 5.39 eV and then turned to 4.10 eV. The morphological analysis using atomic force microscopy (AFM) showed that the grain size for MgO NPs was 67.70 nm which became 42.33 nm after the use of the ultrasound. The shape of the particles was almost spherical and became cylindrical. In addition the Field-Emission Scanning Electron Microscopy (FESEM) analysis sh
... Show MoreFlame thermal spray technique has been used to produce a cermets composite coating based on powders of ceramic oxides (
AhOJ) reinforced by mineral powders as bonding material ( Ni - AI ) at different rates on Inconel substrates , after preparing it by grit blasting.
After completing the best parameters of coating such as distance of spraying , surface roughness and angle of spraying , the tests of porosity , hardness , microstructure and thermal cycling have been made.
The experimental results show that all properties of coating were effected after heat treatment. The best value of heat treatmen t is at (I 000°C) for (l.Shr) in which the &
... Show MoreJurisprudential rules, a broad section to lower the legitimacy of the ruling on the developments of politics, which is increasing day by day, and developments of complex judicial issues, provided that the rule derived from the texts of the legitimate or verbal significance.
And the introduction of jurisprudence rules in the provisions concerning the legitimate policy, the first to take from the provisions of the situation; because the rules of jurisprudence is a summary of the provisions reached by the scholars of the nation after study and scrutiny, which is qualified and largely to cover the need of the owners of public mandates.
The 2011 Iraqi Measles Control Campaign had as its aim to improve immunization coverage among young adults' 17-24years and, in the longer term, prevention of measles epidemics. The aim of the study is estimation measles vaccination and revaccination efficacy by evaluate the seroprevalence of antibody and response to reimmunization in young adults. A previously vaccinated 189 young adult medical students were tested for measles specific IgG &IgM pre and post catch-up revaccination by using commercially available ELISA. To assess the seroprevalence of antibody response pre measles reimmunization in previously vaccinated young adults; 45 were found to be seronegative. To differentiate between primary and secondary vaccine failure, anti- mea
... Show MoreThe Caputo definition of fractional derivatives introduces solution to the difficulties appears in the numerical treatment of differential equations due its consistency in differentiating constant functions. In the same time the memory and hereditary behaviors of the time fractional order derivatives (TFODE) still common in all definitions of fractional derivatives. The use of properties of companion matrices appears in reformulating multilevel schemes as generalized two level schemes is employed with the Gerschgorin disc theorems to prove stability condition. Caputo fractional derivatives with finite difference representations is considered. Moreover the effect of using the inverse operator which tr
In this work, some of new 2-benzylidenehydrazinecarbothioamide derivatives have been prepared by condensation of thiosemicarbazide and different substituted aromatic benzaldehydes in presence of glacial acetic acid to give compounds (1-6), these compounds have characterized by its physical properties and spectroscopic methods. This work also included theoretical study to prove the ability of these compounds as corrosion inhibitors; The program package of Gaussian 09W with its graphical user interface GaussView 5.0 had used for this purpose; the methods of Density Functional Theory (DFT) with basis set of 6-311G (d,p) / hybrid function of B3LYP and semiempirical method of PM3 have been used, the study included theoretical simulation
... Show MoreIn this work, some of new 2-benzylidenehydrazinecarbothioamide derivatives
have been prepared by condensation of thiosemicarbazide and different substituted
aromatic benzaldehydes in presence of glacial acetic acid to give compounds (1-6),
these compounds have characterized by its physical properties and spectroscopic
methods. This work also included theoretical study to prove the ability of these
compounds as corrosion inhibitors; The program package of Gaussian 09W with its
graphical user interface GaussView 5.0 had used for this purpose; the methods of
Density Functional Theory (DFT) with basis set of 6-311G (d,p) / hybrid function of
B3LYP and semiempirical method of PM3 have been used, the study included
t