14 research outputs found

    Enhancement of electrochemical activity of Raney-type NiZn coatings by modifying with PtRu binary deposits: Application for alkaline water electrolysis

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    This study presents electrochemical preparation and characterization of PtRu-modified Cu/Ni/NiZn electrodes (Cu/Ni/NiZn-PtRu) as cathode materials for alkaline water electrolysis. The electrodes were characterized using energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. Their electrochemical activities as cathode materials for alkaline water electrolysis were evaluated with the help of current potential curves. The results showed that the PtRu-modified layers have porous structures with relatively low Pt and Ru chemical compositions. The modification of the alkaline leached Cu/Ni/NiZn surface by Pt and/or Ru enhances the electrochemical activity of the electrode. Their catalytic activity depends on the molar ratios of Pt and Ru; the PtRu binary deposit with the percentage weight ratio of approximately 56:44 exhibits the highest hydrogen evolution activity among the studied electrodes. The enhanced hydrogen evolution activity of the PtRu-modified electrodes was related to the porous surface and/or a possible synergistic effect between the metals. Copyright (c) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved

    The Sariçiçek Howardite Fall in Turkey: Source Crater of HED Meteorites on Vesta and İmpact Risk of Vestoids

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    The Sariçiçek howardite meteorite shower consisting of 343 documented stones occurred on 2 September 2015 in Turkey and is the first documented howardite fall. Cosmogenic isotopes show that Sariçiçek experienced a complex cosmic ray exposure history, exposed during ~12–14 Ma in a regolith near the surface of a parent asteroid, and that an ~1 m sized meteoroid was launched by an impact 22 ± 2 Ma ago to Earth (as did one third of all HED meteorites). SIMS dating of zircon and baddeleyite yielded 4550.4 ± 2.5 Ma and 4553 ± 8.8 Ma crystallization ages for the basaltic magma clasts. The apatite U-Pb age of 4525 ± 17 Ma, K-Ar age of ~3.9 Ga, and the U,Th-He ages of 1.8 ± 0.7 and 2.6 ± 0.3 Ga are interpreted to represent thermal metamorphic and impact-related resetting ages, respectively. Petrographic, geochemical and O-, Cr- and Tiisotopic studies confirm that Sariçiçek belongs to the normal clan of HED meteorites. Petrographic observations and analysis of organic material indicate a small portion of carbonaceous chondrite material in the Sariçiçek regolith and organic contamination of the meteorite after a few days on soil. Video observations of the fall show an atmospheric entry at 17.3 ± 0.8 kms-1 from NW, fragmentations at 37, 33, 31 and 27 km altitude, and provide a pre-atmospheric orbit that is the first dynamical link between the normal HED meteorite clan and the inner Main Belt. Spectral data indicate the similarity of Sariçiçek with the Vesta asteroid family (V-class) spectra, a group of asteroids stretching to delivery resonances, which includes (4) Vesta. Dynamical modeling of meteoroid delivery to Earth shows that the complete disruption of a ~1 km sized Vesta family asteroid or a ~10 km sized impact crater on Vesta is required to provide sufficient meteoroids ≤4 m in size to account for the influx of meteorites from this HED clan. The 16.7 km diameter Antonia impact crater on Vesta was formed on terrain of the same age as given by the 4He retention age of Sariçiçek. Lunar scaling for crater production to crater counts of its ejecta blanket show it was formed ~22 Ma ago

    Optical and structural properties of CuO nanofilm: Its diode application

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    The high crystalline CuO nanofilms have been prepared by spin coating and annealing combined with a simple chemical method. The obtained films have been characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, ultraviolet-vis (UV-vis) spectroscopy and photoluminescence (PL) spectroscopy. Structural analysis results demonstrate that the single phase CuO on Si (1 0 0) substrate is of high a crystalline structure with a dominant in monoclinic (1 1 1) orientation. FT-IR results confirm the formation of pure CuO phase. UV-vis absorption measurements indicate that the band gap of the CuO films is 2.64eV. The PL spectrum of the CuO films shows a broad emission band centered at 467 nm, which is consistent with absorption measurement. Also, Au/CuO/p-Si metal/interlayer/semiconductor (MIS) diodes have been fabricated. Electronic properties (current-voltage) of these structures were investigated. In addition, the interfacial state properties of the MIS diode were obtained. The interface-state density of the MIS diode was found to vary from 6.21 x 10(12) to 1.62 x 10(12) eV(-1) cm(-2)

    Hydrophobic AEROSIL®R972 Fumed Silica Nanoparticles Incorporated Monolithic Nano-Columns for Small Molecule and Protein Separation by Nano-Liquid Chromatography

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    A new feature of hydrophobic fumed silica nanoparticles (HFSNPs) when they apply to the preparation of monolithic nano-columns using narrow monolithic fused silica capillary columns (e.g., 50-µm inner diameter) was presented. The monolithic nano-columns were synthesized by an in-situ polymerization using butyl methacrylate (BMA) and ethylene dimethacrylate (EDMA) at various concentrations of AEROSIL®R972, called HFSNPs. Dimethyl formamide (DMF) and water were used as the porogenic solvents. These columns (referred to as HFSNP monoliths) were successfully characterized by using scanning electron microscopy (SEM) and reversed-phase nano-LC using alkylbenzenes and polyaromatic hydrocarbons as solute probes. The reproducibility values based on run-to-run, column-to-column and batch-to-batch were found as 2.3%, 2.48% and 2.99% (n = 3), respectively. The optimized column also indicated promising hydrophobic interactions under reversed-phase conditions, while the feasibility of the column allowed high efficiency and high throughput nano-LC separations. The potential of the final HFSNP monolith in relation to intact protein separation was successfully demonstrated using six intact proteins, including ribonuclease A, cytochrome C, carbonic anhydrase isozyme II, lysozyme, myoglobin, and α-chymotrypsinogen A in nano-LC. The results showed that HFSNP-based monolithic nanocolumns are promising materials and are powerful tools for sensitive separations

    Fetus in fetu: A report of two cases

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    Fetus in fetu is a rare condition that has been defined as the presence of one of the twins in the body of the other. It is most frequently located in retroperitoneal area; however, it has been reported in other locations as well. This report presents two cases of “fetus in fetu” cases: one located in the retroperitoneal area and the other in the sacrococcygeal area

    Effect of interleukin-10 on pancreatic damage caused by organophosphate poisoning

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    Organophosphate poisoning is a common cause of severe morbidity and mortality in emergency departments. Acute pancreatitis is a frequently reported consequence of organophosphate poisoning, but preventing this potentially severe complication has not been the subject of much research. We tested whether interleukin-10, a cytoprotective agent, could prevent or diminish pathological signs of acute pancreatitis caused by organophosphate poisoning. Thirty rats were divided into three equal groups. Group 1 did not receive any agent during the experiment. Group 2 received 0.8 g/kg fenthion intraperitoneally, followed by 6 ml/kg intraperitoneal normal saline 30 min and 3 h later. Group 3 received 0.8 g/kg fenthion intraperitoneally, followed by 2 mu g/kg of interleukin-10 intraperitoneally 30 min and 3 h later. All rats underwent laparotomy and thoracotomy while still under anesthesia at 6 h, and tissue samples were obtained from the pancreas. After blood samples were taken by cardiac puncture, the animals were sacrificed. Organophosphate poisoning resulted in significant elevations of serum amylase and glucose. Interleukin-10 significantly reduced pancreatic damage as determined by pathologic scoring, but not by enzyme elevations. Interleukin-10 should be considered for larger studies in other animal models to confirm its ability to decrease pancreatic damage after organophosphate poisoning treatment with interleukin-10. (C) 2005 Elsevier Inc. All rights reserved
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