http://blogs.najah.edu/author/s-musameh An-Najah Blogs :: Sharif M.Sh. Musameh en-us Fri, 19 Apr 2024 20:25:44 IDT Fri, 19 Apr 2024 20:25:44 IDT [email protected] [email protected] http://blogs.najah.edu/staff/s-musameh/article/Tribological-behavior-of-chromium-nitride-coating-by-unbalanced-magnetron-sputteringPublished ArticlesThe possibility of improving tribological properties of aluminum alloys using a chrome nitride coating is exploded Thin films of CrxN1xwere deposited on aluminum 6061 using a reactive sputtering technique in an unbalanced magnetron deposition system The structure composition and morphology of the deposited thin films were characterized by using x-ray diffraction XRD scanning electron microscopy SEM electron probe microanalysis EPMA and x-ray photoelectron spectroscopy XPS http://blogs.najah.edu/staff/s-musameh/article/Characterization-Analysis-of-Chromium-Nitride-Reactively-Sputtered-Deposited-Coating-on-Aluminum-AlloyPublished ArticlesThe possibility of significantly improving the wear resistance corrosion and friction behavior of aluminum alloys for automobile engine applications is demonstrated by using a chrome nitride CrN coating Thin films of CrxN1x were deposited on aluminum 6061 using a reactive sputtering technique in an unbalanced magnetron deposition system The hardness and elastic modulus of the films were measured using a nanoindentation technique A CrN film of a few micrometers thick was shown to significantly improve the wear resistance of aluminum alloy The reduction of adhesive wear by the presence of a CrxN1x coating on the surface of the aluminum alloy is believed to be responsible http://blogs.najah.edu/staff/s-musameh/article/The-Use-of-Thermal-Analysis-System-as-a-Tool-for-the-On-line-MeasurementsPublished ArticlesThermal analysis TA that incorporates image analysis can be a powerful online tool for estimating degree of silicon modification in cast test samples This work is a review of different articles that elaborate this subject from different perspectives The goal of the study outlined in the one of the article was on-line quantitative control of aluminum-silicon modification level using thermal analysis The other articles examined the effect of strontium fading on the size and shape of silicon particles in the 319 aluminum alloys Measurements of the size of silicon particles formed during solidification were used to quantity strontium fading In the other article the influences of strontium on the silicon modification and aluminum-copper eutectic microstructures in the 319-aluminum alloy were examined The strontium levels considered were between 8 and 96 ppm The goal of work discussed in the fourth article is to demonstrate the possibility to quantify and to characterize the development of Cu enriched phases in the 3xx series and aluminum alloys using the thermal analysis While the analysis of the effects of the elements on eutectic nucleation and growth temperatures and the decalescence shows two different trends Addition of Ba and Yb both causes linear changes with increased concentration while addition of Ca and Y result in an instantaneous effect with the first addition and no farther significant with increased concentration http://blogs.najah.edu/staff/s-musameh/article/X--Ray-Diffraction-of-Ferroelectric-PZT-Thin-FilmsPublished ArticlesIn this paper the x- ray diffraction were taken for different ratios of Ferroelectric Lead Zirconate Titanate PZT thin films From this method the PZT locations were defined and the 11 1 orientations were found for each filmhttp://blogs.najah.edu/staff/s-musameh/article/Effect-of-Pressure-and-Temperature-on-Preparing-PZT-FilmsPublished ArticlesFerroelectrics lead zirconate titanate PZT thin films were fabricated by pulsed laser deposition on Pt coated Si substrate The effect of oxygen partial pressure substrate temperature and time of ablation on the film orientation and composition will be presented It was found that highly 111 textured PZT films could be grown with careful selection of ablation conditions which are: the oxygen pressure is 300 mT substrate temperature is 605 C and the ablation time is 16 minutes http://blogs.najah.edu/staff/s-musameh/article/The-effects-of-shear-rate-and-capillary-length-to-diameter-ratio-on-isothermal-extrudate-swell-of-polymer-meltsPublished ArticlesThe objective in this article is to establish useful composition-processing structure-property relationships for predicting the rheological properties of automotive type multi-component polymer liquids and to determine the effects of shear rate and capillary length-to-diameter ratio on isothermal extrudate swell of polymer melts http://blogs.najah.edu/staff/s-musameh/article/Ferromagnetic-Resonance-of-Hematin-Langmuir-Blodgett-FilmsPublished ArticlesThis paper reports measurements of ferromagnetic resonance FMR in hematin films grown on glass substrates as a function of orientation of external magnetic field From these measurements it has been observed that the anisotropy for the sample without an acid is much more than that of the sample with the acid http://blogs.najah.edu/staff/s-musameh/article/The-PRIME-Lab-biomedical-programPublished ArticlesThe biomedical accelerator mass spectrometry AMS initiative at PRIME Lab including the status of equipment and sample preparation is described Several biomedical projects are underway involving one or more of the nuclides: 14C 26Al and 41Ca Routine production of CaF2 and graphite is taking place Finally the future direction and plans for improvement of the biomedical program at PRIME Lab are discussed http://blogs.najah.edu/staff/s-musameh/article/A-Rheological-Equation-of-State-for-the-Steady-Shear-Viscosity-Properties-of-Multi-Component-Polmer-LiquidsPublished ArticlesBased on thermodynamic principles a rheological equation of state for multi-component polymer liquids has been derived http://blogs.najah.edu/staff/s-musameh/article/Anomalous-Effect-of-DC-High-Electric-Field-on-the-Dielectric-Dispersion-of-Hg12-CrystalsPublished ArticlesA study of the dielectric dispersion and loss of Hg12single crystal is reported as a function of an applied dc field at different frequencies and temperature Anomalous behavior of both the dielectric constant and loss tangent under dc biasing is observed This is attributed to the bulk characteristics of the crystal http://blogs.najah.edu/staff/s-musameh/article/Shielding-Effectivnes-of-Carbon-Fiber--Epoxy-Composite-at-Microwave-FrequenciesPublished Articles6This paper reports results of measurements performed on carbon fiber-epoxy composite unidirectional sample at microwave frequencies in the X-band 8-12 GHz These measurements were performed on pure epoxy and 50 wt composites using one and two specimens with different separating distances between them The measurements included the insertion loss IL the return loss RL where the shielding effectiveness SE was deduced from both the IL and RL as a function of the frequency The return loss insertion loss and shielding effectiveness show relatively low frequency dependence It was found that the SE value reaches around 12dB for one specimen and 15 dB for two specimens in contact at 8 GHz The SE increases to 28 dB when the spacing between the two specimens exceeds 50 mm at 8 GHz The two specimen arrangements enhances the SE of this unidirectional composite material compared with one layer case The results suggest that this carbon fiber-epoxy composite could be used in some micro-wave applicationshttp://blogs.najah.edu/staff/s-musameh/article/Numerical-calculation-of-the-magnetodielectric-anisotropy-effect-in-magnetic-fluidsPublished ArticlesThe magnetodielectric anisotropy effect in Fe3O4 particle magnetic fluid has been numerically calculated Our results in agreement with previously reported results show that the dielectric constant in the direction parallel to the field increases with the applied field while that normal to the field decreases The results also in agreement with previous results show that the dielectric constant in the field direction increases with temperature above a given temperature Ts reaching a maximum at Tm then decreases for higher temperatures; while in the direction normal to the field it decreases with temperature for temperatures above Ts reaching a minimum at Tm then increases for higher temperatures Furthermore our results show the important role that dimensionality plays on the magnetodielectric anisotropy effect http://blogs.najah.edu/staff/s-musameh/article/A-Fifth-order-Multiperturbation-Derivation-of-the-Energy-Coefficients-of-Polyatomic-MoleculesPublished ArticlesA multiperturbation theory has been developed for molecular systems In the present paper we extend this theory to fifth order in the energy The bare-nucleus hydrogenic function is chosen as the zero-order wave function rather than the more customary hartree-fock function With this choice the multiperturbation wave functions are independent of the nuclear charges and of the total number of nuclear centers and electrons for the molecule and are thus completely transferable to other systems Making the simplest possible choice we describe an n-electron m-center polyatomic molecule as n hydrogenic electrons on a single center perturbed by electron-electron and electron-nucleus coulomb interactions With this choice of zero-order Hamiltonian H0 the first-order wave function for any polyatomic molecule will consist entirely of two-electron one-center and one-electron two-center first-order wave functions These are exactly transferable from calculations on He-like and H2-like systems To calculate the first-order and second order correction for the wave function of any polyatomic molecule we need the first-order and second-order correction for a two-electron atomic wave function the first-order and second-order correction for a one-electron diatomic molecular wave function and some additional mixed second-order corrections The wave functions necessary will be two-center one-electron at most The second-order wave function for a polyatomic molecule contains additional contributions which cannot be obtained from the simple subsystems but represent multiple perturbation contributions which are two electron diatomic and one-electron triatomic in character The expressions for the multiperturbation energy-expansion coefficients through fifth order are derivedhttp://blogs.najah.edu/staff/s-musameh/article/Electrical-and-electromagnetic-shielding-behavior-of-laminated-epoxy-carbon-fiber-compositePublished ArticlesThis paper reports results on the electrical properties of laminated epoxy composite containing 25 layers of carbon fibers in the form of mats The dependence of the activation energy calculated from DC resistivity measurements on temperature reveals two independent conduction processes The AC impedance is independent of the applied frequency below 75C and the real componet of the dielectric constant is also independent of temperature at high frequencies The determined shielding effectiveness is dominated by the insertion loss The observed optimum shielding effectiveness occurs at 30 mm spacing and applied frequency 9 GHz http://blogs.najah.edu/staff/s-musameh/article/Characteristics-of-double-layers-of-aluminium-epoxy-composite-in-the-X-bandPublished ArticlesResults of measurements performed on spaced layers of aluminium-epoxy composite at microwave frequencies in the X-band 812 GHz are reported These measurements were performed on pure epoxy and on 55 and 90 wt composites using pairs of specimens with different spacings These measurements include the insertion and return losses as functions of frequency An evaluation of the shielding effectiveness SE of these composites in different geometrical arrangements is also included It is observed that the SE is enhanced substantially in specimens with high concentrations of aluminium flakes and it reaches more than 55 dB for double specimens with zero spacing Furthermore the SE value reaches around 80 dB when the spacing between the two specimens exceeds 50 mm This observed level of SE may be applied successfully in the use of the composites for shielding purposes http://blogs.najah.edu/staff/s-musameh/article/Some-electrical-properties-of-aluminum-epoxy-compositePublished ArticlesThe dependence of some electrical properties of aluminum flake-epoxy composites on frequency and filler content is studied The insertion loss as well as the shielding effectiveness SE show great dependence on filler concentration The SE for the composites varies linearly with the microwave frequency and reaches up to 50 dB for a 90 wt composite specimen The dependence of the electrical conductivity on the filler content shows that the composite changes from an insulating to a conductive behavior The composite structure revealed by scanning electron microscopy supports the observed variations of the electrical conductivity http://blogs.najah.edu/staff/s-musameh/article/Microwave-assessment-of-two-layer-composite-systemsPublished ArticlesApplied physics communications 1990 vol 10 no1-2 pp 15-27http://blogs.najah.edu/staff/s-musameh/article/Electrical-behavior-of-aluminum-glass-fiber-polypropylene-composite-in-the-X-bandPublished ArticlesWe reports results of the measurements performed on aluminum glass fiber-polypropylene composites in the X-band 8-12 GHz Results are obtained from two specimens with different fiber concentrations and different separating distances The data cover the insertion loss IL return loss RL and the equivalent input impedance Z The results indicate some dependency on the frequency and separating distancehttp://blogs.najah.edu/staff/s-musameh/article/Reversible-metastable-configurations-in-amorphous-siliconPublished ArticlesWe present experimental evidence for reversible metastable alloy atom configurations in amorphous silicon In a-Si:F we identify reversible transitions between samples with Si---F---Si bridging configurations and samples containing only conventional silicon-fluorine bonding structures