Adsorption of heavy metal cations from aqueous solutions by wool fibers

Adsorption of metal cations by kivircik wool from aqueous NiCl₂, CuCl₂, ZnCl₂, CdCl₂, HgCl₂ and Pb(NO₃)₂ solutions at 25°C and 50°C was investigated using atomic absorption spectroscopy. A fiber diffusion controlled adsorption rate model was used to predict the effective diffusion coefficients of metal ions in wool. It has been shown that wool is a potential adsorbent for removing toxic metal ions from contaminated water.     

Transition from single- to multi-layered structures in nanoporous gold-palladium ultrathin films

The transition from single- to multi-layered structures in nanoporous films was investigated in nanoporous gold-palladium (np-AuPd) ultrathin films. Configuration and contact behavior of AuPd ligaments in porous layers were characterized with patterned or curved np-AuPd films. In a multi-layered structure, AuPd ligaments in the layer closest to the substrate exhibit a different configuration than in a single-layered structure. This transition is discussed in relation to film thickness, volume contraction and bonding with the substrate.     

Morphology,order, light transmittance,and water vapor permeability of aluminum‐coated polypropylene zeolite composite films

In this study, the polypropylene–zeolite composite films having 2–6 wt % natural zeolite were coated with a thin film of aluminum (Al) by magnetron sputtering, and the contribution of the Al coating on film properties was investigated. The samples were characterized by EDX, X‐ray diffraction, SEM, AFM, UV–visible spectroscopy, and water vapor permeation analyses. The surface of the films coated with a smooth Al film having 98–131 nm thickness. EDX revealed that Al percentage on the surface appeared to be as 8–10 wt % indicating contribution of polymer surface under Al film to analysis. XRD analysis showed that the grain size of Al at the surface was 22–29 nm. The surface roughness increased after Al‐coating process. The transmission of coated films was very low for both UV and visible regions of the light spectrum. Permeation analysis indicated that water vapor permeation was lower for Al‐coated material. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Engineering Defect-Free Nanoporous Pd from Optimized Pd-Ni Precursor Alloy by Understanding Palladium-Hydrogen Interactions During Dealloying

Thin films of nanoporous palladium (np-Pd) were produced from binary palladium-nickel (Pd-Ni) precursor alloys. A suitable precursor alloy and a method of dealloying to yield optimum nanoporosity (average pore/ligament size of 7 nm) were developed by studying the effects of various processing parameters on final microstructure. To obtain crack-free np-Pd, a 100 nm thin film of 20 at. pct Pd (80 at. pct Ni) can be dealloyed for ~5 hours in a 1 M solution of sulfuric acid, with oleic acid and oleylamine added as surfactants. Both shorter and longer dealloying times, as well as heating, inhibit the formation of crack-free np-Pd. Stress measurements at different stages of dealloying revealed that the necessary dealloying time is determined by the diffusion-controlled corrosion reaction occurring within the thin film during dealloying. Strong interaction between hydrogen and np-Pd was reflected in the stress evolution during dealloying. A mechanism is proposed for the formation of a Ni-rich dense top layer that results from H-induced swelling during initial dealloying and permits the development of defect-free np-Pd beneath, by limiting the speed of dealloying.     

Design and simulation of the PV/PEM fuel cell based hybrid energy system using MATLAB/Simulink for greenhouse application

In this study, design and optimization of the hybrid renewable energy system consisting of Photovoltaic (PV)/Electrolyzer/Proton Exchange Membrane Fuel Cell (PEMFC) was investigated to provide electricity and heat for Greenhouse in ?anl?urfa (Turkey). The coupling of a photovoltaic system with PEMFC was preferred to supply continuous production of electric energy throughout the year. Additionally, produced heat from PEMFC was used to heating of the greenhouse by micro cogeneration application. The MATLAB/Simulink was applied to the design and optimization of the proposed hybrid system. In the designed system, solar energy was selected to produce the Hydrogen (H₂) required to run the electrolyzer. In cases where the solar energy is not sufficient and cannot meet the electricity requirement for the electrolyzer; the H₂ requirement for the operation of the PEMFC was met from the H₂ storage tanks and energy continuity was ensured. The electrolyzer was designed for H₂ demand of the 3 kW PEMFC which were met the greenhouse energy requirement. PEMFC based hybrid system has 48% electrical and 45% thermal efficiencies. According to optimization results obtained for the proposed hybrid system, the levelized cost of energy was found 0.117 $/kWh. The obtained results show the proposed PV/Electrolyzer/PEMFC hybrid power system provides an applicable option for powering stand-alone application in a self-sustainable expedient.     

DRYING OF AIR IN SILICA GEL PACKED COLUMNS

Silica gels that were made humidity indicating by impregnation of CoCl₂ were used for air drying in isothermal packed column. The effects of type of silica gel, packing height, particle size and air flow rate on breakthrough curves were studied. The breakthrough curves predicted by Rasmuson and Neretniek's analytical solution were in good agreement with experimental data.     

Deep learning based automatic grading of bi-colored apples using multispectral images

Multimedia Tools and Applications - Grading of apple fruits involves their inspection, assessment and sorting by quality. Machine vision has been the industry’s choice as it is fast, reliable...     

Oxidation behaviour of double layers of TiSi2 on polycrystalline silicon

The oxidation of TiSi₂ on Si(100) and on polycrystalline silicon films in H₂O-O₂ and dry O₂ was studied in the temperature range 700–1050°C. The same mechanism was found for both types of structures. As in the case of the oxidation of silicon the reaction may be described by a linear-parabolic two-step model. In the initial phase of the process the rate is limited by the reaction at the TiSi₂-oxide interface, and later by the diffusion of the oxidant to the interface. Only during the first stage may small amounts of TiO₂ be formed. Contamination of the starting surface by TiO₂ is most probably responsible for the conflicting results reported in the literature.     

Effect of total pressure on the uniformity of epitaxial GaAs films grown in the Ga-HCl-AsH3-H2 system

The effect of total system pressure on the uniformity of epitaxial GaAs layers grown at 1023 K in the LP-VPE system has been studied with respect to layer thickness and dopant uptake. It was found that the uniformity of both of these quantities is distinctly improved when the hydrogen pressure is lowered from 3.3×10⁴ to 6.5×l0³ Pa. This behaviour is explained by the increase in gas phase diffusivity and the reduction in depletion of the gas phase during GaAs growth at reduced total pressure.