bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fe/Mn Oxide Catalysts for Fischer‐Tropsch Synthesis Part VIII: Surface Characterization of Fe/Mn‐Fischer‐Tropsch Catalysts by Auger‐Electron‐Spectroscopy
Authors: Hess D. , Papp H. , Baerns M. 
Published: March 2014

AbstractSurface compositions of Fe/Mn‐oxide Fischer‐Tropsch catalysts were determined by AES. Bulk compositions of the samples varied from pure iron oxide to pure manganese oxide. A method for quantification of Auger spectra was developed. The iron content in the surfaces of the samples after calcination and reduction is larger than in the bulk. The surface composition after FT synthesis depends on the temperature of reduction before synthesis. The results of surface analysis of the calcined and reduced samples are compared with those of adsorption measurements described elsewhere.
Zur Wirkungsweise amphiphiler Korrosionsinhibitoren in Rostschutzemulsionen
Authors: Förster Th. , von Rybinski W. , Schwuger M. J. 
Published: March 2014

AbstractA prerequisite for the protection of metallic materials against atmospheric corrosion is to prevent the deposition of water on the metal surface. If present in sufficient concentration, amphiphilic corrosion inhibitors are adsorbed on metallic surfaces as closely packed hydrophobic films which form a barrier against the ambient air. As a consequence, the metal surface is no longer exposed to the humidity so that the atmospheric corrosion is strongly reduced. Good corrosion protection is achieved if the metal surface is covered by a strongly hydrophobic and irreversibly adsorbed inhibitor film. For ecological reasons rust‐preventive oils are increasingly substituted by anticorrosion emulsions. Unlike corrosion‐inhibiting oils, the performance of an anticorrosion emulsion is influenced not only by the choice of the corrosion inhibitor but also by the choice of the emulsifier. A synergistic reinforcement of the hydrophobic action was obtained by using an emulsifier that matched the corrosion inhibitor. In addition, the distribution equilibrium of corrosion inhibitors capable of ionizing at the oil‐water interface, like fatty acids at the proper pH, influences the performance of the anticorrosion emulsion.
Vapour Liquid Equilibria for Pure Fluids from the Perturbation Theory of the Kihara Molecule Systems
Authors: Kantor R. , Bonblík T. 
Published: March 2014

AbstractThe second‐order perturbation theory of the Kihara fluids is employed for the description of the vapour‐liquid equilibria of pure compounds. On the basis of vapour pressures and liquid volumes the Kihara potential parameters of 48 models for 28 pure fluids were adjusted. Good agreement between the theoretical and experimental values of orthobaric properties up to temperature T/Tc = 0.9 was observed.
Intermediates and Products of Ethanol Oxidation on Platinum in Acid Solution
Authors: Bittins‐Cattaneo B. , Wilhelm S. , Cattaneo E. , Buschmann H. W. , Vielstich W. 
Published: March 2014

AbstractThe adsorbate formed during ethanol oxidation in acidic solutions is studied by Fourier transform infrared reflection‐absorption spectroscopy (FTIR) at constant potential, on‐line (DEMS) and thermal desorption mass spectroscopy (ECTDMS). – As in the case of methanol adsorbate COad was identified by FTIR and in addition COHad by ECTDMS. On‐line MS experiments showed the formation of methane during the cathodic sweep of the voltammogram. Main products of ethanol oxidation from the bulk are carbon dioxide and acetaldehyde.
Electrochemically Induced Structural Changes in Conducting Polymers
Authors: Heinze Jürgen , Bilger Ralf , Meerholz Klaus 
Published: March 2014

AbstractThe cis/trans isomerization of cis‐PA upon cathodic reduction can be detected voltammetrically. The analysis of the redox data reveals that the trans‐form is thermodynamically more favourable in the charged than in the neutral state. Cyclic voltammetry also reflects geometric relaxation processes which occur in conjugated materials such as PPy or PTh during charging and discharging. The results are in good agreement with quantummechanical predictions based on the bipolaron model. Additional spectroelectrochemical studies unambiguously show that the charging process in the whole accessible potential range is faradaic.
(Na, Sr) Beta″ Aluminas – Herstellung und Charakterisierung neuer polykristalliner Festelektrolyte mit gemischter Leitfähigkeit
Authors: Allitsch G. , Linhardt P. , Breiter M. W. 
Published: March 2014

AbstractTechnical applications of isomorphs of the beta″ alumina family are described in the beginning of the paper. The production and characterization of new polycrystalline solid electrolytes, obtained by partial replacement of the monovalent sodium cation by the bivalent strontium cation in the starting material, sodium beta″ alumina from Ceramatec Inc., is reported next. The equilibrium distribution curve and the conductivities are discussed.
Simultaneous Photoacoustic and Photoelectrochemical Studies at Semiconductor Electrodes. Internal Quantum Efficiency, Peltier Heat, and Energy Conversion Efficiency for Photoanodic Water Oxidation at Flame‐Oxidized Titanium in 0.5 M H2SO4
Authors: Rappich Jörg , Dohrmann Jürgen K. 
Published: March 2014

AbstractAt an n‐TiO2 (rutile) thin‐film electrode made by flame‐oxidation of Ti foil, photoacoustic and photocurrent spectra have been measured simultaneously in 0.5 M H2SO4 at various electrode potentials. The potential dependence of the photoacoustic signal at constant light energy has been analyzed in terms of a simple model of the heat producing processes at the electrode. The internal quantum efficiency of the photocurrent, the Peltier heat and the energy conversion efficiency for photoanodic water oxidation have been determined from the photoacoustic measurement without the necessity to calibrate the intensity of the light source.
Properties of Slurry Electrodes from Activated Carbon Powder
Authors: Kastening Bertel 
Published: March 2014

AbstractSlurry electrodes (suspensions of particulate electrode material) are suitable for carrying out electrochemical processes outside an electrochemical cell while removing the required charge from one electrode of such a cell. The suspended material must be stable against electrochemical attack within a certain range of potentials and must exhibit a sufficient capacity. Properly pretreated activated carbon powder can be polarized in acidic aqueous solution within potentials between about −0.2 and +1.0 V (vs. standard hydrogen electrode). In alkaline solutions, the limit towards positive potentials in considerably lower, about +0.3 V. Within these ranges, an almost constant capacity of about 100 … 120 F/g is observed, and there are no primary indications for Faradaic processes. While the capacity can essentially be attributed to a double‐layer behaviour, electrochemical surface reactions without a distinct redox potential may well be present; this presumption is supported by an examination of the ion exchange between the electrolyte within the pores of the particles and the external electrolyte. Frequent contacts with the “feeder” electrode are required for charging the capacity of the particles because, for particles with diameters between 0.2 and 0.5 mm, typically less than 0.01% of the charge necessary for complete adaptation to the feeder electrode potential is transferred during a single contact. This is due to the short duration of a collision (2 to 7 μs at liquid flow rates about 1 m/s towards the electrode) and to the sum of electrolyte and contact resistances. In 4 M H2SO4, the electrolyte resistance ranges from 5 to 2 Ω. The values of the contact resistance (15 to 5 Ω) are compatible with the behaviour expected from the theory of an elastic collision.
Kinetics of Ketyl Radical Reactions Occurring in the Photoreduction of Benzophenone by Isopropyl Alcohol
Authors: Demeter A. , László B. , Bérces T. 
Published: March 2014

AbstractBenzophenone – isopropyl alcohol – acetonitrile, benzophenone – benzhydrol – acetonitrile and acetone – isopropyl alcohol – acetonitrile systems were studied by laser flash photolysis transient absorption technique and by steady‐state quantum yield determinations. Kinetic parameters were derived for reactions of the ketyl radicals formed in the primary photoreduction steps. The room temperature overall rate coefficients at 0.001 mol dm−3 benzophenone and 2.6 mol dm−3 isopropyl alcohol in acetonitrile are in 108 dm3 mol−1 s−1 units: 12.8 ± 0.6, 8.0 ± 0.4 and 0.59 ± 0.01 for Mc2ĊOH + Me2ĊOH, Me2ĊOH + Ph2ĊOH and Ph2ĊOH + Ph2ĊOH, respectively. (The error limits represent 2 standard deviations.) Combination was shown to be the only significant reaction in the interaction of two Ph2ĊOH radicals, while disproportionation is the dominating path in the reactions inolving Me2ĊOH radicals. Evidences are presented for the existence of four reaction channels in the cross reaction of the two ketyl radicals. These are combination (4a), disproportionations (4b) and (4c) and formation of a “light absorbing transient” (4d), with branching ratios k4a/k4 = 0.18 ± 0.08, k4b/k4 = 0.61 ± 0.11, k4c/k4 = 0.05 ± 0.02 and k4d/k4 = 0.18 ± 0.03, respectively. – The radical transfer reaction Me2ĊOH + Ph2CO → Me2CO + Ph2ĊOH, which may change considerably the product distribution and quantum yields in the photoreduction of benzophenone by isopropyl alcohol at medium and low light intensities, was investigated by quantum yield determinations and a room temperature rate coefficient of k5 = (7.3 ± 1.2) · 104 dm3 mol−1 s−1 was extracted through computer model simulation. This rate coefficient is considerably lower than the values reported previously.
Influence of Substituents and Functional Groups on the Surface Composition of Ionic Liquids
Authors: Kolbeck Claudia , Niedermaier Inga , Deyko Alexey , Lovelock Kevin R. J. , Taccardi Nicola , Wei Wei , Wasserscheid Peter , Maier Florian , Steinrück Hans‐Peter 
Published: March 2014

AbstractWe have performed a systematic study addressing the surface behavior of a variety of functionalized and non‐functionalized ionic liquids (ILs). From angle‐resolved X‐ray photoelectron spectroscopy, detailed conclusions on the surface enrichment of the functional groups and the molecular orientation of the cations and anions is derived. The systems include imidazolium‐based ILs methylated at the C2 position, a phenyl‐functionalized IL, an alkoxysilane‐functionalized IL, halo‐functionalized ILs, thioether‐functionalized ILs, and amine‐functionalized ILs. The results are compared with the results for corresponding non‐functionalized ILs where available. Generally, enrichment of the functional group at the surface is only observed for systems that have very weak interaction between the functional group and the ionic head groups.
Reactivity of Hydroxy‐ and Aquo(hydroxy)‐λ3‐iodane–Crown Ether Complexes
Authors: Miyamoto Kazunori , Yokota Yukie , Suefuji Takashi , Yamaguchi Kentaro , Ozawa Tomoyuki , Ochiai Masahito 
Published: March 2014

AbstractWe have designed a series of hydroxy(aryl)‐λ3‐iodane–[18]crown‐6 complexes, prepared from the corresponding iodosylbenzene derivatives and superacids in the presence of [18]crown‐6, and have investigated their reactivities in aqueous media. These activated iodosylbenzene monomers are all non‐hygroscopic shelf‐storable reagents, but they maintain high oxidizing ability in water. The complexes are effective for the oxidation of phenols, sulfides, olefins, silyl enol ethers, and alkyl(trifluoro)borates under mild conditions. Furthermore, hydroxy‐λ3‐iodane–[18]crown‐6 complexes serve as efficient progenitors for the synthesis of diaryl‐, vinyl‐, and alkynyl‐λ3‐iodanes in water. Other less polar organic solvents, such as methanol, acetonitrile, and dichloromethane, are also usable in some cases.
Arthrospira (Spirulina) Species as Bioadsorbents for Lead, Chromium, and Cadmium – a Comparative Study
Authors: Balaji Sundaramoorthy , Kalaivani Thiagarajan , Rajasekaran Chandrasekaran , Shalini Mohan , Siva Ramamoorthy , Singh Rajan Kumar , Akthar Mohammed Asif 
Published: March 2014

AbstractArthrospira (Spirulina) belongs to the cyanobacterial family has been reported as a potential bioremediation agent. The bioadsorption potential of Arthrospira species, namely A. indica, A. maxima, and A. platensis, was tested against lead, chromium, and cadmium toxicity under laboratory conditions. Arthrospira species were cultured in Zarrouk's medium containing lead, chromium, and cadmium with two varying concentrations (0.01 and 0.05 mM) and in river water contaminated with tannery effluent containing these heavy metals. Parameters like specific growth rate, total chlorophyll, and total protein contents were analyzed and compared. Specific growth rate, total chlorophyll, and total protein contents possess dose dependent decrease with increase in concentrations of metals and also in heavy metal contaminated tannery effluent when compared with control. Statistical analysis revealed that there is a good correlation between the specific growth rate and protein content in all the species. Atomic absorption spectrometry analysis also revealed that there is a maximum bioadsorption potential of the Arthrospira species. Results indicated that the three Arthrospira species used in this experiment were found to be potential candidates for bioadsorption against lead, chromium, and cadmium.
Spent Mushroom Compost as Biosorbent for Dye Biosorption
Authors: Toptas Aslı , Demierege Salih , Mavioglu Ayan Ebru , Yanik Jale 
Published: March 2014

AbstractIn this study, spent mushroom compost was investigated as a biosorbent for the removal of textile dyes from aqueous solution. Batch adsorption method was implemented for the study and analysis of the pH function, biosorbent amount, and contact time of the biosorption process. Biosorption kinetics followed the pseudo‐second‐order kinetic model for Acid Red 111 (AR111) and Basic Red 18 (BR18), whilst biosorption of Levafix Braun E‐RN (LB) was well described by pseudo‐first‐order and intra‐particle diffusion models. The biosorption process was found to be spontaneous and exothermic. The biosorption data conformed best with the Langmuir model. The maximum adsorption capacities were found as 140.9, 400.0, and 169.5 mg g−1 for AR111, BR 18 and LB, respectively. The results showed that spent mushroom compost can be utilized as low‐cost biosorbent in treating colored dye effluents.
Ruthenium Halide Complexes as N‐Alkylation Catalysts
Authors: Rodríguez‐Bárzano Andrea , Fonseca Joel D. A. , Blacker A. John , McGowan Patrick C. 
Published: March 2014

AbstractA range of ruthenium‐arene compounds with chloride, bromide or iodide ligands were prepared and tested as catalysts for the homogeneous redox neutral alkylation of tert‐butylamine with phenethyl alcohol, and compared to the previously reported catalyst [RuCl2(p‐cymene)]2, in the presence of the diphosphine 1,1′‐bis(diphenylphosphino)ferrocene (dppf). The best catalytic activities were obtained with ruthenium iodide compounds. The formation of either [RuX(p‐cymene)(dppf)][X] or [(RuX2(p‐cymene))2(dppf)] (X = halide) under the catalytic conditions employed was investigated.
Phosphane‐ and Amine‐Catalyzed Ring‐Opening Reactions of Cyclopropenones with Isatin Derivatives: Synthesis of Carboxylated 1H‐Indoles and Multisubstituted 2H‐Pyran‐2‐ones
Authors: Zhao Wen‐Tao , Tang Xiang‐Ying , Shi Min 
Published: March 2014

AbstractThe phosphane‐ and amine‐catalyzed ring‐opening reactions of cyclopropenones with isatin derivatives give different reaction outcomes. Under phosphane catalysis, carboxylated 1H‐indoles are afforded in good yields, and under amine catalysis, multisubstituted 2H‐pyran‐2‐ones are provided in moderate yields. The mechanistic aspects of these reactions are discussed on the basis of control experiments.
Sol–Gel‐Derived Lithium Superionic Conductor Li1.5Al0.5Ge1.5(PO4)3 Electrolyte for Solid‐State Lithium–Oxygen Batteries
Authors: Kichambare Padmakar D. , Howell Thomas , Rodrigues Stanley 
Published: March 2014

AbstractLithium aluminium germanium phosphate (LAGP) is attracting a great deal of attention as a solid electrolyte for lithium–oxygen (Li–O2) batteries due to its high ionic conductivity. In this study, LAGP is prepared by a sol–gel process using comparatively low‐cost GeCl2 as one of the reactants. The final product (LAGP) is obtained by sintering the dry precursor gel at 900 °C for 6 h. The influence of the duration of water evaporation during polymerization on the microstructure of LAGP has been examined. The structure, morphology, and electrochemical properties of LAGP are investigated by employing X‐ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption–desorption analysis, and electrochemical impedance spectroscopy. XRD studies confirm the formation of Li1.5Al0.5Ge1.5(PO4)3 as a primary phase along with small amounts of AlPO4 and Li2O as impurity phases. LAGP specimens have ionic conductivities in the range of 10−4 to 10−5 S cm−1 at room temperature. In addition, LAGP also exhibits electrocatalytic activity towards the oxygen‐reduction and evolution reactions. These results demonstrate the potential of LAGP prepared by sol–gel processes as a solid electrolyte for lithium‐ion conduction in solid‐state lithium–oxygen batteries.
Controlled Growth of CoSx Nanostrip Arrays (CoSx‐NSA) on Nickel Foam for Asymmetric Supercapacitors
Authors: Dubal Deepak P. , Gund Girish S. , Lokhande Chandrakant D. , Holze Rudolf 
Published: March 2014

AbstractA high‐energy‐density asymmetric supercapacitor based on cobalt sulfide nanostrip arrays (CoSx‐NSA) as the cathode and reduced graphene oxide as the anode has been prepared; the CoSx‐NSA was synthesized on three‐dimensional (3D) nickel (Ni) foam by using a simple and scalable chemical bath deposition (CBD) method. The reduced graphene oxide sheets were deposited on the Ni foam by hydrothermal treatment of the foam in a graphene oxide solution. Novel and unique nanostructured architectures of the CoSx electrode provide a large effective surface area. In addition, both of the electrode materials are directly grown on the substrate without any conductive additives or binders, avoiding unnecessary materials. The asymmetric supercapacitor device operates in a wider potential window, achieving a remarkably high energy density, excellent rate capability, and long‐term cycling stability. These attractive results make CoSx‐NSA a promising material for asymmetric supercapacitors of high energy and power density, utilizing an aqueous electrolyte solution.
Hybrid simulation testing of a self‐centering rocking steel braced frame system
Authors: Eatherton Matthew R. , Hajjar Jerome F. 
Published: March 2014

SUMMARYThe self‐centering rocking steel frame is a seismic force resisting system in which a gap is allowed to form between a concentrically braced steel frame and the foundation. Downward vertical force applied to the rocking frame by post‐tensioning acts to close the uplifting gap and thus produces a restoring force. A key feature of the system is replaceable energy‐dissipating devices that act as structural fuses by producing high initial system stiffness and then yielding to dissipate energy from the input loading and protect the remaining portions of the structure from damage. In this research, a series of large‐scale hybrid simulation tests were performed to investigate the seismic performance of the self‐centering rocking steel frame and in particular, the ability of the controlled rocking system to self‐center the entire building. The hybrid simulation experiments were conducted in conjunction with computational modules, one that simulated the destabilizing P‐Δ effect and another module that simulated the hysteretic behavior of the rest of the building including simple composite steel/concrete shear beam‐to‐column connections and partition walls. These tests complement a series of quasi‐static cyclic and dynamic shake table tests that have been conducted on this system in prior work. The hybrid simulation tests validated the expected seismic performance as the system was subjected to ground motions in excess of the maximum considered earthquake, produced virtually no residual drift after every ground motion, did not produce inelasticity in the steel frame or post‐tensioning, and concentrated the inelasticity in fuse elements that were easily replaced. Copyright © 2014 John Wiley & Sons, Ltd.
Silver nanoparticles induced accumulation of reactive oxygen species and alteration of antioxidant systems in the aquatic plant Spirodela polyrhiza
Authors: Jiang Hong-Sheng , Qiu Xiao-Ni , Li Gen-Bao , Li Wei , Yin Li-Yan 
Published: March 2014

Abstract

Silver nanoparticles (AgNPs) are widely used commercially because of their antibacterial properties. Oxidative stress is known to be involved in the toxicity of AgNPs to bacteria, animals, and algae. The authors used Spirodela polyrhiza to investigate whether AgNPs can induce oxidative stress in higher plants. Results showed that there was a dose-dependent increase in levels of reactive oxygen species, superoxide dismutase and peroxidase activity, and the antioxidant glutathione content in 6-nm AgNP treatments. Catalase activity and malondialdehyde content in 6-nm AgNP treatments was significantly higher than the control at silver concentrations of 5 mg L−1. Superoxide dismutase and catalase activity and antioxidant glutathione and malondialdehyde content were not significantly different at 10 mg L−1 of AgNPs (6 nm and 20 nm). Treatment with 20 µg L−1 Ag+ (the amount almost equal to 10 mg L−1 AgNPs released) did not change the reactive oxygen species level or antioxidant enzymes activity. Micron-sized Ag particles had no effect on S. polyrhiza. Transmission electron microscopy showed that, compared with the control, chloroplasts in S. polyrhiza treated with 6-nm and 20-nm AgNPs accumulated starch grains and had reduced intergranal thylakoids. These results clearly indicate that AgNPs are able to cause oxidative stress and affect the chloroplast structure and function of S. polyrhiza, and this effect was not caused by Ag+ released from particles. Environ Toxicol Chem 2014;33:1398–1405. © 2014 SETAC
Oncologic outcomes of total laryngectomy: Impact of margins and preoperative tracheostomy
Authors: Basheeth Naveed , O'Leary Gerard , Khan Habib , Sheahan Patrick 
Published: March 2014

AbstractBackgroundThe purpose of this present study was to investigate risk factors for local recurrence and death after total laryngectomy, with particular emphasis on pattern of local recurrence (stomal vs pharyngeal/base of tongue) and impact of preceding tracheostomy.MethodsWe conducted a retrospective review of 75 consecutive total laryngectomies for cancer of the larynx.ResultsNineteen patients underwent preoperative tracheostomy, which was a significant risk factor for local recurrence (p = .04). With regard to pattern of local recurrence, preoperative tracheostomy (p = .03) and pathological nodal status (pN+; p = .04) were significant for stomal, but not pharyngeal recurrence; whereas positive margins (p = .01) was significant for pharyngeal, but not stomal recurrence. Preoperative tracheostomy, pN+, lymphovascular invasion, and positive margins were all significant for survival.ConclusionPreoperative tracheostomy continues to be a significant adverse prognosticator in patients undergoing total laryngectomy. Our findings also suggest distinct causative factors for different patterns of postlaryngectomy local recurrence. © 2014 Wiley Periodicals, Inc. Head Neck 37: 862–869, 2015