http://blogs.najah.edu/author/sjodeh An-Najah Blogs :: Shehdeh W. Jodeh en-us Sat, 27 Jul 2024 14:48:37 IDT Sat, 27 Jul 2024 14:48:37 IDT [email protected] [email protected] http://blogs.najah.edu/staff/sjodeh/article/Physical-Vapor-Deposition-of-Hydrogen-Storage-Alloys-and-Their-Charecterestics-as-Metal-Hydrides-ElectrodesPublished ArticlesA new method of preparing thin film metal-hydride electrodes for metal-hydride batteries is described The method consists of simultaneous deposition of multi-component metallic species onto a substrate while bombarding the growing deposited thin film electrode with a low energy hydrogen ion beam An amorphous LaNi4 hydride thin film electrode has been prepared by this Hydrogen Ion Beam Assisted Deposition HIBAD technique The electrochemical discharge capacity and cycle life of this electrode in a 6 M KOH solution surpass previously reported values for La-Ni thin film electrodes prepared by other deposition methodshttp://blogs.najah.edu/staff/sjodeh/article/Characteristics-of-Removal-of-Hydrophobic-Organic-Carbons-from-SandMulch-Using-Nonionic-SurfactantsPublished ArticlesIn this study a nonionic surfactant Triton X-100 was used to study the sorption characteristics of organic contents in soil The surface tension is used for calculating this kind of sorption The results indicated that when the concentration of surfactant was lower than the CMC the amount of surfactant sorbed on soil increased with the increasing surfactant concentration and the surfactant sorption characteristics of the uncontaminated soil could be modeled by the Freundlich isotherm For the contaminated soils the amount of surfactant sorbed was higher than those for the uncontaminated soils Capsule: Relation between CMC and surfactant sorbed on soil Number of words = 100http://blogs.najah.edu/staff/sjodeh/article/Electrical-properties-study-accompanying-pyrolysis-and-ion-implantation-for-prestine-and-polyacrylonitrilePublished ArticlesHeat treatment of polyacrylonitrile PAN leads to products with semiconductor to metal-like conductivities The electrical properties of these-materials are further modified by ion implantation It is noted that the conductivity 107cm1 of heat treated PAN at 435C PAN435 increases upon ion implantation with arsenic reaching a maximum value of 14101 cm1 at a dose of 51016 ioncm2 and energy of 200KeV On the other hand ion implantation of the more conducting heat treated PAN at 750C PAN750 leads to a decrease in the electrical conductivity of the material The data also indicate that the decrease in conductivity observed after implantation of PAN750 is due to the breakup of the graphite-like extended electronic states The temperature dependence of conductivity provided further information on the structures of the pyrolyzed and of the ion implanted samples Whereas the conductivity-temperature behavior of PAN750 is consistent with the Cohen-Jortner model for transport in inhomogeneous and disordered solids the ion implanted sample PAN750I displays a behavior which can be described most adequately in terms of a variable range hopping conduction mechanism http://blogs.najah.edu/staff/sjodeh/article/Chemical-structural-characterization-of-pyrolyzed-and-subsequently-ion-implanted-polyacrylonitrilePublished ArticlesInfrared IR Auger electron spectroscopy AES and X-ray photoelectron spectra XPS of pristine pyrolyzed and ion-implanted polyacrylonitrite PAN samples were obtained in order to correlate the structural changes accompanying pyrolysis and implantation with the electrical properties of the respective PAN products The results show that PAN is first converted to a polyconjugated heterocyclic ladder structure at a temperature of 435C and then to a graphite-like structure at temperature above 750C Pyrolysis studies took place in a temperature range of 350750C IR studies showed that upon heat treatment at 435C major structural changes occur as indicated by the complete disappearance of the nitrile and methylene absorption bands and the formation of new bands The degree of conjugation in pyrolyzed PAN can be selectively controlled by the proper choice of the heat treatment temperature From the studies ion implantation causes extensive nitrogen depletion and the nitrogen chemical state in the implanted sample is different from that found in the pyrolyzed materials Upon ion implantation the component assigned to the nitrogen in a sigma bonding state 40127eV increased in intensity 46 relative to the intensity 27 of the component for which nitrogen is in a hetroaromatic structure Both AES and XPS analysis showed the variation of C:N ratio as a function of heat treatment http://blogs.najah.edu/staff/sjodeh/article/Sorption-characteristics-of-a-non-ionic-surfactant-in-soil-contaminated-with-decanePublished ArticlesHydrophobic and non-polar organic carbon compounds have low aqueous solubilities and the biodegradation of such compounds may be restricted because of their low solubility coupled with strong bindingsorption on to solids The main goal of this research is to study the factors affecting the sorption of surfactants on to soil such as the surfactant concentration and the soil organic content and the removal of organic contaminants like decane from the soil using a non-ionic surfactant Triton X-100 The results indicated that when the concentration of surfactant was lower than the critical micelle concentration CMC the amount of surfactant sorbed on to soil increased with increasing surfactant concentration and the surfactant sorption characteristics of the uncontaminated soils could be modelled using the Freundlich isotherm For the contaminated soils the amount of surfactant sorbed was higher than that for the uncontaminated soils The amount of surfactant sorbed on to soils also depends on the organic content of the soils When the concentration of surfactant is higher than the CMC the amount of surfactant added to the soil-aqueous system will increase the number of micelles and also increase the solubilization of organic contaminants from the soils Measurements of surface tension were used for our analysis in order to collect the data and draw conclusionshttp://blogs.najah.edu/staff/sjodeh/article/Sorption-Charactarestics-of-Nonionic-Surfactant-Remediated-with-DecanePublished ArticlesHydrophobic and non-polar organic carbon compounds have low aquous solubilities and the biodegradation of such compounds may be restricted because of the low solubility coupled with strong bindingsorption onto solids There is interest in evaluating whether the biotreatment hydrophobic organic carbons may be facilitated through surfactant addition since surfactant can increase the amount of sparingly soluble hydrophobic organic carbons present in the liquid phase by incorporation in surfactant micelles or aggregates The main goal of this research is to study the factors affecting the surfactant sorption on soil such as surfactant concentration soil organic content and removing organic contaminant like decane from soil using nonionic surfactant Triton X-100 The results indicated that when the concentration of surfactant was lower than the CMC the amount of surfactant sorbed on soil increased with the increasing surfactant concentration and surfactant sorption characteristics of the uncontaminated soils could be modeled by Freundlich isotherm For the contaminated soils the amount of surfactant sorbed was higher than those for the uncontaminated soils The amount of surfactant sorbed on soils also depends on the organic content in the soils When the concentration of surfactant was higher than the CMC the amount of surfactant added into the soilaqueous system will increase the number of micelle and it increase the solubilization of organic contaminant from the soils Measurements of surface tension were used for our analysis to gain the data and conclusion from this studyhttp://blogs.najah.edu/staff/sjodeh/article/Physical-Vapor-Deposition-Techniques-in-Electrical-Contacts-in-AutomotivePublished Articles Today there are about 1500 electrical terminals in each automobile As the electrical content in the automobile increases at a rate of 10 to 15 a year the demand for reliable economical and environmentally benign electrical connectors is expected to grow To ensure reliable electrical contacts various coatings are applied to the connectors Presently most connectors used in automobiles are electroplated with tin as the under-hood space becomes more compact and an increasing number of sensors are mounted close to the engine the coatings are required to function at 150 C to 200 C in the under hood environment Electroplated tin coatings fail at these temperatures because of inter diffusion which causes bonding between mating contact surfaces alloy formation at the Sn-substrate interface and oxidation of mating surfaces On the other hand a gold layer of 1 to 3 um thickness which has been used successfully in military vehicles for high temperature applications is considered too expensive for civilian vehicles Furthermore the friction coefficient of tin coatings is high which can cause difficulties during the assembly of multipin connectors In contrast to the large amount of work for electrical contacts in electronics and computers research and development efforts for automotive electrical contacts have been few The growing demands and the harsh environment encountered by electrical connectors in automobiles call for new coating compositions structures and perhaps new processing techniques Although electroplating is used for mass production of tin coated connectors vapor deposition has been suggested as an alternative method for coating electrical contacts The advantages of vapor deposition over electroplating are numerous From a research point of view vapor deposition can be used to create coating structures and composition which are often either difficult or impossible to make by electroplating including multilayers composites and amorphous alloys of metals and ceramics In the microelectronics industry vapor deposition techniques are standard industrial processes In non-electronic applications vapor deposition techniques have been integrated into continuous process lines for coating metal strips window glass plastic foils and automobile parts Using vapor deposition as a tool novel coating structures have been developed for low friction coefficient fretting wear resistant and high temperature stable electrical contacts Thin films of Ag and Ag-Ni nanocrystalline composites between 100- and 500 nm thick were deposited by electron beam evaporation onto sputter cleaned 301 stainless steel substrates The structure and composition of the films were studied in details using x-ray diffraction XRD scattering electron microscopy SEM electron probe microanalysis EPMA and Auger depth profiling The contact properties such as contact resistance friction coefficient fretting wears resistance and thermal stability of these coating s have been measured The friction coefficient of the Ag-coated contacts decreased with decreasing film thickness A low friction coefficient of 02 was achieved for the 100-nm thick Ag on 301 steel This Ag coated contact lasted about 200000 cycles during fretting wear test Both then Ag and Ag81Ni19 composite coatings about 500 nm thick passed the 1000000-cycle fretting wear test These coatings also showed good high temperature stability during heat aging at 150 C in air especially the Ag81Ni19 composite coating This study shows that vapor deposition is a very powerful technique which can be used to discover new coating compositions and structures for electrical contact applications The advantages of vapor deposition over tradition plating processes are also discussed http://blogs.najah.edu/staff/sjodeh/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/sjodeh/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 J of Active and Passive Electronic Devices Vol 2 pp 305314http://blogs.najah.edu/staff/sjodeh/article/The-Study-of-the-Effects-of-Ion-Chemical-Activity-on-Conductivity-of-PolyDimethylsilylene-Co--Methylphenylsilylene-1Published ArticlesThe effects of ion implantation on the electrical and structural properties of polydimethylsilylene-co-methylphenylsilylene DMMPS thin films have been investigated Ionic species of krypton arsenic fluorine ch1orine and sulfur were implanted at energies ranging from 35 to 200 keV and with doses of up to 1 x 1016 ioncm2 The conductivity of the polymer increased upon implantation reaching a maximum value of 96 x 10-6 cm-l for the case of arsenic ion at a dose of 1 x 1016 ioncm2 and energy of 100 keV The results showed that ion implantation induced conduction in DMMPS was primarily due to structural modifications of the material brought about by the energetic ions Infrared analysis and Auger electron spectroscopy showed evidence for the formation of a silicon carbide-like structure upon implantationhttp://blogs.najah.edu/staff/sjodeh/article/Environmentally-Friendly-and-Inexpensive-Dielectric-Coolant-for-Fuel-Cell-StacksPublished ArticlesAn environmentally friendly and inexpensive dielectric coolant for fuel cell stacks The present invention is directed to a fuel cell 1 a system and a method of cooling a fuel cell 16 The fuel cell is configured to react fuel with oxygen 52 to generate an electric current and at least one reaction product and comprises an electrochemical catalytic reaction cell 1 configured to include a fuel flowpath 26 an oxygen flowpath 58 and a coolant flowpath 16 fluidly decoupled from the fuel flowpath and the oxygen flowpath The coolant flowpath defines a coolant isolation manifold 20 that includes a fluid dielectric coolant comprising a vegetable oil-based dielectric fluidhttp://blogs.najah.edu/staff/sjodeh/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/sjodeh/article/Thermal-properties-of-automotive-polymers-III-ndash-Thermal-characteristics-and-flammability-of-fire-retardant-polymersPublished ArticlesThermal properties and flammability behavior of two grades of fire retardant polypropylene and nylon 66 and their base resins were determined A nylon 6 base polymer and a nano-composite based on that polymer were also analyzed Thermal gravimetric analysis showed more complex degradation patterns for the fire retardant grades as compared to the base resin This was attributed to decomposition of ingredients present in the fire retardant Degradation of polypropylene in air started at about 100C lower temperature than degradation in nitrogen For nylon the degradation in both atmospheres occurred at approximately the same temperature Modulated Differential Scanning Calorimetry MDSC measurements were used to determine melting and glass transition temperatures heats of fusion heat capacity and thermal conductivity Both phosphorus-based and halogen-based fire retardants modified the ignition propagation and melt-dripping behavior of nylon and polypropylene during burning Incorporation of a nano-filler was found to be ineffective in imparting fire retardancy to nylon 6 Performance of these materials will have to be evaluated in actual vehicle applications and fire exposures before use on a broad scale basis http://blogs.najah.edu/staff/sjodeh/article/Electrically-conducting-thin-films-obtained-by-ion-implantation-in-pyrolyzed-polyacrylonitrilePublished ArticlesHeat treatment of polyacrylonitrile PAN leads to products with semiconductor-to-metal range of conductivities The electrical properties of these materials are further modified by ion implantation The conductivity 1107 cm1 of heat treated PAN at 435C PAN435 increases upon ion implantation with As Kr Cl or F reaching the maximum value of 89101 cm1 at a dose of 51016 ioncm2 and an energy of 200 KeV for the case of F implantation On the other hand ion implantation in the more conducting heat-treated PAN at 750 C PAN750 leads to a decrease in the electrical conductivity It is shown that the conductivity modifications are primarily due to structural rearrangements induced by the energetic ions Specific chemical doping contribution to conductivity is noted for halogen implantation in PAN435 The temperature dependence of conductivity of PAN heat treated at 750C suggests a two path conduction namely a three dimensional variable range hopping conduction and a metallic conduction After ion implantation the conductivity-temperature dependence is interpreted in terms of a variable range hopping conduction mechanism http://blogs.najah.edu/staff/sjodeh/article/Properties-of-blends-of-sulfonic-acids-doped-polyaniline-and-polyester-polyether-block-copolymerPublished ArticlesBlends of polyaniline protonated with functionalized sulfonic acids dopant and various block copolymers of poly 14-butylene terephthalate-co-polytetramethylene oxide having variable proportion of hard to soft segment can be cast as freestanding films from hexafluoro-2-propanol solution The electrical conductivity of these blends showed percolation threshold values below 1 a behavior which is indicative of a fibrillar network phase-separated morphology A significant effect of the counter-ion of the functionalized acid dopant was noted Polyaniline doped with camphor sulfonic acid or with methane sulfonic acid produced higher conductivity values than polyaniline doped with dodecylbenzene sulfonic acid The hard segment in the insulating copolymer was found to suppress the electrical conductivity of the resulting compositions The phase-separated morphology in these blends was confirmed from the observed approximate linear relation of the specific volume on the composition of the blend http://blogs.najah.edu/staff/sjodeh/article/Dependence-of-electrical-properties-on-copolymer-composition-in-polyanilinepolybutylene-terephthalate-co-polytetramethylene-oxide-blendsPublished ArticlesABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY Volume: 219 Pages: U416-U417 Part: Part 2 Meeting Abstract: 407-POLY Published: MAR 26 2000http://blogs.najah.edu/staff/sjodeh/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/sjodeh/article/Thermal-Properties-of-Automotive-Polymers-IV-Thermal-Gravimetric-Analysis-and-Differential-Scanning-Calorimetry-of-Selected-Parts-from-a-Chevrolet-CamaroPublished ArticlesThermal properties of polymeric materials were measured to identify phase changes and decomposition characteristics as the materials are heated through their decomposition temperatures Fifty-seven polymeric components used on the 1997 Chevrolet Camaro were studied Consideration was also given to parts different from those analyzed previously for the Dodge Caravan investigation The base polymers in these parts were identified by Fourier transform infrared spectroscopy and pyrolysisgas chromatographymass spectroscopy Filler content and type were determined by thermogravimetric analysis TGA High-resolution TGA was used to determine thermal decomposition temperatures and rates of decomposition These analyses were conducted in nitrogen and air atmospheres Decomposition temperature and rate of decomposition were found to be a function of the chemical structure of the polymer For the polymeric materials examined in this study we observed thermal decomposition temperatures in the range of 270 to 500C when the samples were heated in air and in the range of 284 to 450C when the samples were heated in nitrogen We also used TGA to determine the amounts of organic residues including carbon black and the amounts of inorganic fillers in the different components Differential scanning calorimetry DSC measurements were conducted using a modulated differential scanning calorimeter Melting points glass transition temperatures heat capacities heats of fusion and thermal conductivity values were calculated from the DSC data These variables measure the amount of heat absorbed or evolved during heating of the samplehttp://blogs.najah.edu/staff/sjodeh/article/Internal-state-populations-and-the-time-of-flight-of-ground-state-species-ejected-after-the-193-nm-excimer-laser-ablation-of-CuO-BaO2-and-Y2O3Published ArticlesLaser-induced fluorescence is used to measure time-of-flight TOF and internal state distributions of atoms ions and diatomics ejected after the 193 nm ablation of Y2O3 BaO2 and CuO These measurements indicate that the bulk of material is ejected with speeds in the range of 104105 cms while particle speeds in the emitting component of the plume exceed 106 cms The TOF profiles of all the species were non-Maxwellian containing extended low-velocity ``tails It is postulated that these tails arise from the evaporation andor sputtering of target material that occurs after the laser ablation pulse This particle emission is caused either by residual energy deposited in the target after the explosive vaporizationablation pulse or from radiation exchange andor ion bombardment from the expanding plasma plume The extent of these ``tails increases with increasing fluence generating oscillations in the TOF distributions of Cu atoms from CuO at high fluence Rotational and vibrational temperatures were estimated for YO and BaO molecules in the plume and no CuO was detectedhttp://blogs.najah.edu/staff/sjodeh/article/Dynamics-of-laser-sputtering-of-the-hydroxyl-radical-from-CaOH2-SrOH2-and-sucrose-samplesPublished ArticlesThe ArF laser sputtering of calcium hydroxide strontium hydroxide and sucrose crystals is studied by laser induced fluorescnce LIF and LIF time of flight TOF techniques under vacuum conditions Studied using LIF for these three materials at several fluences 083 17 and 22 J cm2 and probe distance 04 08 12 15 and 21 cm yield an average rotational temperature of 56016 K from the first six rotational states for the Q1 R1 R2 and Q2 lines No rotational cooling was observed as a function of distance The translational temperature analysis by LIF-TOF indicates that the process can be represented by a fast and slow component