High-intensity laser-accelerated ion beam produced from cryogenic micro-jet target

We report on the successful operation of a newly developed cryogenic jet target at high intensity laser-irradiation. Using the frequency-doubled Titan short pulse laser system at Jupiter Laser Fa- cility, Lawrence Livermore National Laboratory, we demonstrate the generation of a pure proton beam a with maximum energy of 2 MeV. Furthermore, we record a quasi-monoenergetic peak at 1.1 MeV in the proton spectrum emitted in the laser forward direction suggesting an alternative acceleration mechanism. Using a solid-density mixed hydrogen-deuterium target, we are also able to produce pure proton-deuteron ion beams. With its high purity, limited size, near-critical density, and high-repetition rate capability, this target is promising for future applications

Kinetic, Isotherm and Thermodynamic Analysis on Adsorption of Cr(VI) Ions from Aqueous Solutions by Synthesis and Characterization of Magnetic-Poly(divinylbenzene-vinylimidazole) Microbeads

The magnetic-poly(divinylbenzene-1-vinylimidazole) [m-poly(DVB-VIM)] microbeads (average diameter 53–212 μm) were synthesized and characterized; their use as adsorbent in removal of Cr(VI) ions from aqueous solutions was investigated. The m-poly(DVB-VIM) microbeads were prepared by copolymerizing of divinylbenzene (DVB) with 1-vinylimidazole (VIM). The m-poly(DVB-VIM) microbeads were characterized by N2 adsorption/desorption isotherms, ESR, elemental analysis, scanning electron microscope (SEM) and swelling studies. At fixed solid/solution ratio the various factors affecting adsorption of Cr(VI) ions from aqueous solutions such as pH, initial concentration, contact time and temperature were analyzed. Langmuir, Freundlich and Dubinin–Radushkvich isotherms were used as the model adsorption equilibrium data. Langmuir isotherm model was the most adequate. The pseudo-first-order, pseudo-second-order, Ritch-second-order and intraparticle diffusion models were used to describe the adsorption kinetics. The apparent activation energy was found to be 5.024 kJ mol−1, which is characteristic of a chemically controlled reaction. The experimental data fitted to pseudo-second-order kinetic. The study of temperature effect was quantified by calculating various thermodynamic parameters such as Gibbs free energy, enthalpy and entropy changes. The thermodynamic parameters obtained indicated the endothermic nature of adsorption of Cr(VI) ions. Morever, after the use in adsorption, the m-poly(DVB-VIM) microbeads with paramagnetic property were separeted via the applied magnetic force. The magnetic beads could be desorbed up to about 97% by treating with 1.0 M NaOH. These features make the m-poly(DVB-VIM) microbeads a potential candidate for support of Cr(VI) ions removal under magnetic field

Influences of copper and manganese concentrations on the properties of polycrystalline ZnS:Cu and ZnS:Mn thin films

Copper and manganese doped zinc sulfide (ZnS:Cu and ZnS:Mn) thin films are deposited on glass substrates using chemical bath deposition (CBD) method, with the both copper and manganese concentration varying from 0.5 to 4 mol%. All films were annealed in the temperature range of 100-500 °C and characterized by X-ray diffraction (XRD) and optical absorption. All samples are shown to be crystallized in the hexagonal phase of ZnS with a preferential orientation in the (008) direction. The XRD analysis showed that after annealing process, ZnS:Cu and ZnS:Mn films can be converted to ZnO:Cu and ZnO:Mn films at annealing temperature of 300 °C. The electrical conductivity measurments were taken in the dark before and after annealing temperature of 400 °C for 1 h. The electrical conductivity of ZnS:Cu films decreased after annealing process. However, it increased for ZnS:Mn thin films. The activation energy values were obtained using the temperature-dependent current measurements in the range of 300-623 K

Influence of the thickness on physical properties of chemical bath deposited hexagonal ZnS thin films

Hexagonal ZnS thin films of thicknesses ranging between 454 to 750 nm are deposited on a glass substrate by chemical bath deposition at 80 °C. The ZnS thin films are characterized by X-ray diffraction (XRD) and optical absorption spectroscopy. The films are shown to be crystallized in the hexagonal phase and present a preferential orientation along the c-axis by XRD measurements . Only one peak, corresponding to the (008) phase (29=29.5°), appears on the diffractograms. The ZnS films show a high transmission. The optical constants such as refractive index n, extinction coefficient k, real ?1 and imaginary ?2 part of dielectric constant are calculated in the visible region. A reduction in refractive index (n) and the extinction coefficient (k) is observed as film thickness decreases. The electrical conductivity decreased from 1.62×10-9to 1.32×10 -10 (?.cm)-1 when the films are annealed at 400 °C for 1 hour. The temperature-dependent current was measured in the range 27-400 °C and the activation energy values were obtained using the temperature-dependent current measurements

Investigations on the physical properties of the polycrystalline ZnS thin films deposited by the chemical bath deposition method

Transparent and polycrystalline zinc sulfide (ZnS) thin films were prepared by the chemical bath deposition (CBD) technique onto glass substrates deposited at 80 °C using aqueous solution of zinc acetate, thiourea, triethanolamine and tri-sodium citrate at a pH of about 10.55. Triethanolamine and tri-sodium citrate were used as complexing agents. The thickness of the films, which were calculated from the interference patterns around 400-800 nm maxima and minima wavelengths, varied from 403 to 934 nm in the visible range. UV-visible spectrophotometric measurement showed transperancy from 66% to 87% of the films with a direct allowed energy band gap in the range of 3.79-3.93 eV. X-ray diffraction (XRD) patterns prove crystallinity of deposited films that crystallize in the hexagonal phase of ZnS. The ZnS thin films were characterized by XRD, energy dispersive X-ray analysis (EDX) and optical absorption spectra. The current-voltage characteristic of polycrystalline ZnS films grown by CBD are reported. © 2006 Elsevier B.V. All rights reserved

Using of the advanced technologies in Turkish automotive industry

Nowadays, technological change exists as the most important organization dynamics. It is possible that the organizations may make the development and benefit strategies insurable in the global competition circumstance by keeping an harmony with this technological change. The organizations, therefore, need to use very different management and production technologies. One of the sectors in which these technologies are mostly used is the automotive industry. In the world, it is estimated as the development rate coming from the past is observed that it will continue its development rate in the future. The existence of this industry becomes as an important economical power for the countries as it is considered with main production industry and supply industries that it affects. The automotive industry is a sector that is developing each year with the increasing importance in Turkish economy. The country is preferred by a lot of global Arms as a production and a marketing base for because of the reasons as like cheaper manpower, being close location, the encouraging, and the economical stabilization in recent years. In this study, the present usage levels and the estimated levels of the technologies of the organizations operating in automotive production industry in Turkey are considered and realized. The effects of the management and the production technologies on the business criteria are also investigated. And the relation between these criteria and the estimated levels that the organizations want to reach is studied. © 2008 PICMET

Effect of pH on the physical properties of CdS thin films deposited by CBD

CdS thin films with different pH values changing from 9 to 12 were deposited on glass substrates using chemical bath deposition technique (CBD). The effect of pH on the structural, optical and electrical properties of CdS thin films is investigated. X-ray diffraction, Ultraviolet-visible absorption spectroscopy, Scanning electron microscopy, Energy dispersive X-ray analysis, and Raman spectroscopy were used to characterize the thin films. X-ray diffraction data reveal growth of the cubic phase with preferential orientation along (1 1 1) direction. Raman peaks appearing at 296 cm -1 and 593 cm -1 for all samples were attributed to 1LO and 2LO phonons of CdS, and they shifted to the blue region with increase in pH values. The band gap of the films increased from 2.29 to 2.40 eV with increasing pH values. Resistivity, carrier density and mobility of the films were determined using Hall effect measurements. After all investigations, it was concluded that the pH value of 11 is suitable for producing CdS thin films by chemical bath deposition technique. The formed film was transparent, uniform and with good adherence to the substrate. These results indicate that films obtained at pH 11 by CBD are good candidates for applications in different optoelectronic devices

Comparative study of the properties of CuS thin films deposited using different bath processes

In this work, we present the influence of the reaction time of a complex substance (trisodium citrate) with a copper source (Cu2SO4·5H2O) on the structural, morphological and optical properties of CuS thin films deposited at 55-70 min. using chemical bath deposition onto glass substrate. In the first process, trisodium citrate and Cu2SO4·5H2O were mixed for 1 min, while the substances were mixed for 1 h. in the second process. The hexagonal structure of the deposited polycrystalline thin films with a preferred orientation along (130) was determined by the XRD technique except for the thin films deposited at 70 min. The surface roughnesses of the thin films were different from each other. The direct optical band gaps of CuS thin films obtained from the first process were found to be 2.39-2.45, whereas those of the second process were found to be 2.34-2.48 eV