bluuebunny/crossref_metadata_2025_split huggingface dataset:
Degradation of imidazolium‐based ionic liquids in aqueous solution by Fenton oxidation
Authors: Domínguez Carmen M. , Munoz Macarena , Quintanilla Asunción , de Pedro Zahara M. , Ventura Sonia P.M. , Coutinho João A.P. , Casas Jose A. , Rodriguez Juan J. 
Published: March 2014

AbstractBACKGROUNDThe breakdown of imidazolium ionic liquids (ILs) by Fenton oxidation has been demonstrated, but using unaffordable doses of hydrogen peroxide (H2O2). The literature studies so far do not report on the evolution of total organic carbon (TOC) and ecotoxicity. Therefore, the potential application of the process for the degradation of ILs still remains an open question. This work investigates the feasibility of the Fenton process for the treatment of aqueous effluents containing imidazolium‐based ILs of different structures, represented by the length of the alkyl chain and the nature of the anion. Special attention is paid to the evolution of the ecotoxicity and the consumption of H2O2 as a critical issue for the economy of the process. The experiments were performed at 70 °C.RESULTSWith the stoichiometric H2O2 dose, the complete conversion of the starting imidazolium‐based ILs was achieved in less than 5 min, at 70°C, with 60% of TOC reduction after 4 h, except in the [C4mim][CH3CO2] case, where iron precipitation was observed, thus inhibiting its catalytic action. Low ecotoxicity effluents were obtained at the stoichiometric H2O2 dose, even in the cases of the highly ecotoxic ILs of long alkyl chain with chloride anion.CONCLUSIONFenton oxidation is shown to be a promising solution for the degradation of imidazolium‐based ILs in water, allowing deep detoxification with the stoichiometric H2O2 dose. © 2014 Society of Chemical Industry
REVIEW ARTICLE: RESILIENCE, POVERTY AND DEVELOPMENT
Authors: Béné Christophe , Newsham Andrew , Davies Mark , Ulrichs Martina , Godfrey‐Wood Rachel 
Published: March 2014

AbstractResilience has become prominent in academia where it is used as a central framework in disciplines such as ecology, climate change adaptation or urban planning. Policy makers and international development agencies also increasingly refer to it. The objective of this paper is to assess the advantages and limits of resilience in the context of development. Although the review highlights some positive elements—for example, the ability to foster an integrated approach—it also shows that resilience has important limitations. In particular, it is not a pro‐poor concept, in the sense that it does not exclusively apply to, or benefit, the poor. As such, resilience building cannot replace poverty reduction. Copyright © 2014 John Wiley & Sons, Ltd.
Modeling the memristor with piecewise linear function
Authors: Mu Xiaomu , Yu Juntang , Wang Shuning 
Published: March 2014

SUMMARYMemristor is introduced as the fourth basic circuit element. In this paper, we show that piecewise linear function can be used to model memristor. Piecewise linear function is used as a window function to model the memristor device. The piecewise linear window function is linear at each subregion of the domain. Because of this good character, explicit relation between the thickness of the doped region and the charge can be delivered, together with the explicit memristance expression. Models using a general nonlinear window function may not have these explicit results. The piecewise linear window function is also more flexible than the existing window functions. Piecewise linear function can also be used to model the more general memristive systems. Copyright © 2014 John Wiley & Sons, Ltd.
Atlantic warm and cold water events and impact on African west coast precipitation
Authors: Lutz K. , Jacobeit J. , Rathmann J. 
Published: March 2014

ABSTRACTVariability of sea surface temperatures (SSTs) in the tropical southeast Atlantic Ocean has previously been shown to significantly contribute to changes in summer rainfall along the West African as well as the Angolan coast. This study examines links between southeast Atlantic SST and African west coast precipitation variability for an extended 60‐year period from 1951 to 2010. In contrast to earlier studies, our analyses cover the whole Atlantic coast from Guinea to South Africa and are not limited to specific seasons. In addition to the analyses of the total variability, pronounced anomalies in terms of warm and cold water events and their impact on African west coast precipitation are analyzed. By using for the first time a new comprehensive classification of Atlantic Niño and Niña events, consistent results are achieved for a larger region of Africa, also considering Atlantic cold water events which have rather been neglected so far.Results show that, depending on the particular region, southeast Atlantic SSTs play an important role for coastal rainfall variability throughout the year. Furthermore, the rainfall response to Atlantic cold and warm water events appears to be asymmetric in season and magnitude. Atlantic cold events can cause a stronger decrease in rainfall along the West African and Gabon coast than the increase is in warm events. In addition, not all seasons show a significant rainfall response to both warm and cold water events.
A single blunt impact on cartilage promotes fibronectin fragmentation and upregulates cartilage degrading stromelysin‐1/matrix metalloproteinase‐3 in a bovine ex vivo model
Authors: Ding Lei , Guo Danping , Homandberg Gene A. , Buckwalter Joseph A. , Martin James A. 
Published: March 2014

ABSTRACTPost‐traumatic osteoarthritis (PTOA) is characterized by progressive cartilage degeneration in injured joints. Since fibronectin‐fragments (Fn‐fs) degrade cartilage mainly through up‐regulating matrix metalloproteinases (MMPs) and pro‐inflammatory cytokines, we hypothesized that Fn‐fs play a key role in PTOA by promoting chondrolysis in and around injured cartilage. To test this hypothesis, we profiled the catabolic events focusing on fibronectin fragmentation and proteinase expression in bovine osteochondral explants following a single blunt impact on cartilage with a drop tower device which created partial‐thickness tissue damage. Injured and control explants were cultured for up to 14 days. The presence of Fn‐fs, MMPs (‐1, ‐3, ‐13), ADAMTS‐5 in culture media and in cartilage was determined with immunoblotting. The daily proteoglycan (PG) depletion of cartilage matrix was assessed with DMMB assay. The effect of explant‐conditioned media on chondrocytes was also examined with immunoblotting. Impacted cartilage released significantly higher amount of native Fn, three chondrolytic Fn‐fs and PG than non‐impacted controls did. Those increases coincided with up‐regulation of MMP‐3 both in culture media and in impacted cartilage. These findings support our hypothesis that PTOA may be propelled by Fn‐fs which act as catabolic mediators through up‐regulating cartilage‐damaging proteinases. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:811–818, 2014.
How the root zone modifies soil wettability: Model experiments with alfalfa and wheat
Authors: Hassan Magda , Woche Susanne K. , Bachmann Jörg 
Published: March 2014

AbstractTo investigate the effect of plants on soil water repellency (SWR), two column experiments with wheat (Triticum aestivum) and alfalfa (Medicago sativa) with a growing period of three months had been carried out under constant and near‐natural climatic conditions. Model soils with defined wettability were created by mixing a natural sandy loam subsoil with different proportions of a wettable and a hydrophobized pure quartz sand, resulting in a wettable model soil and three model soils with increasing level of subcritical SWR (initial contact angle CA > 0° and < 90°). Results showed a significant decrease of the mean CA after the experiments compared to the initial CA while the mean CA was constant for plant free columns used as a reference. CA as a function of depth in some cases showed a depth dependent variation with decreased CA at the bottom or as well at top and bottom. The deviation from the initial CA was most pronounced for wheat under constant climatic conditions. Changes in CA could be related to changes in pH, i.e., CA was decreased and pH increased. Subcritical WR at the beginning of the growth period affected significantly the moisture content profiles during the entire growing season as well as plant dry mass production. We expect that plant root exudates of plants widely used for foot production cause directly or indirectly pH‐related modifications of the WR level in the root zone dependent on plant species and the ambient climatic conditions.
Nitrogen‐fertilizer forms affect the nitrogen‐use efficiency in fertigated citrus groves
Authors: Quaggio José Antônio , Souza Thais Regina , Bachiega Zambrosi Fernando César , Marcelli Boaretto Rodrigo , Mattos Dirceu 
Published: March 2014

AbstractThe fertigated area of the Brazilian citrus industry has grown rapidly during recent years, and an efficient management of nitrogen (N) application at these sites is required for sustainable citrus production. Therefore, a field trial with Valencia orange trees [Citrus sinensis (L.) Osbeck] on Swingle citrumelo rootstock (Citrus paradise Macfad. x Poncirus trifoliata L. Raf.) was conducted for 8 years to evaluate the effects of N rates (80, 160, 240 and 320 kg ha–1 y–1) applied by fertigation, either as ammonium nitrate (AN) or calcium nitrate (CN), on soil solution dynamics, fruit yield, nutritional status, and N‐use efficiency (NUE) of trees. The maximum fruit yield was reached with 240 kg N ha–1 for AN, whereas a linear response and greater fruit yield was observed for N supplied as CN. The NUE was reduced for both N forms with increasing N rates. However, the NUE for CN was 14 to 38% greater than the NUE for AN. The lower fruit yield and NUE for AN compared to CN‐treated trees was associated with the increased acidification of the soil solution with increased AN rates (pH ≤ 4.0). This limited nitrification resulted in a high ammonium (NH$ _4^+ $) concentration in the soil solution and a reduction in the net absorption of cations by the trees, particularly calcium (Ca). Due to the improved ion balance as well as the higher pH of the soil solution (pH ≥ 6.3) and diminished NH$ _4^+ $ availability, gains in both fruit yield and NUE in fertigated citrus groves in tropical soils can be obtained with the use of CN as a source of N.
Thermal effects of endoscopy in a human temporal bone model: Implications for endoscopic ear surgery
Authors: Kozin Elliott D. , Lehmann Ashton , Carter Margaret , Hight Ed , Cohen Michael , Nakajima Hideko H. , Lee Daniel J. 
Published: March 2014

Objectives/HypothesisAlthough the theoretical risk of elevated temperatures during endoscopic ear surgery has been reported previously, neither temperature change nor heat distribution associated with the endoscope has been quantified. In this study, we measure temperature changes during rigid middle ear endoscopy in a human temporal bone model and investigate whether suction can act as a significant cooling mechanism.Study DesignHuman temporal bone model of endoscopic middle ear surgery.MethodsFresh human temporal bones were maintained at body temperature (∼36°C). Temperature fluctuations were measured as a function of 1) distance between the tip of a 3‐mm 0° Hopkins rod and round window membrane, and 2) intensity of the light source. Infrared imaging determined the thermal gradient. For suction, a 20‐Fr suction catheter was utilized.ResultsWe found: 1) an endoscope maximally powered by a xenon or light‐emitting diode light source resulted in a rapid temperature elevation up to 46°C within 0.5 to 1 mm from the tip of the endoscope within 30 to 124 seconds, 2) elevated temperatures occurred up to 8 mm from the endoscope tip; and 3) temperature decreased rapidly within 20 to 88 seconds of turning off the light source or applying suction.ConclusionsOur findings have direct implications for avoiding excessive temperature elevation in endoscopic ear surgery. We recommend: 1) using submaximal light intensity, 2) frequent repositioning of the endoscope, and 3) removing the endoscope to allow tissue cooling. Use of suction provides rapid cooling of the middle ear space and may be incorporated in the design of new instrumentation for prolonged dissection.Level of EvidenceNA Laryngoscope, 124:E332–E339, 2014
Controlling the radiation direction of propagating surface plasmons on silver nanowires
Authors: Wang Zhuoxian , Wei Hong , Pan Deng , Xu Hongxing 
Published: March 2014

AbstractMetal nanowires supporting propagating surface plasmons (SPs) can be used as nanowaveguides and nanoantennas for light manipulation beyond the diffraction limit. Here the control of the propagation and radiation of SPs on silver nanowires is investigated. By covering an Al2O3 layer onto a silver nanowire to change the local dielectric environment, the wave vector of the propagating SPs is increased. Thus, the radiation direction of SPs into the substrate is changed according to the phase matching condition, which is experimentally shown by Fourier imaging method. The radiation angle is sensitively dependent on the Al2O3 thickness. By depositing 1 nm Al2O3, the increase of the radiation angle can be close to 1 degree. These results show that dielectric‐layer‐coating provides a simple and effective method to control the propagation and radiation of SPs, which will be of great importance for designing plasmonic circuits, antennas and sensors based on silver nanowires.
Nanofibrillar Peptide Hydrogels for the Immobilization of Biocatalysts for Chemical Transformations
Authors: Hickling Christopher , Toogood Helen S. , Saiani Alberto , Scrutton Nigel S. , Miller Aline F. 
Published: March 2014

Enzymes are attractive, “green” alternatives to chemical catalysts within the industrial sector, but their robustness to environmental conditions needs optimizing. Here, an enzyme is tagged chemically and recombinantly with a self‐assembling peptide that allows the conjugate to spontaneously assemble with pure peptide to form β‐sheet‐rich nanofibers decorated with tethered enzyme. Above a critical concentration, these fibers entangle and form a 3D hydrogel. The immobilized enzyme catalyzes chemical transformations and critically its stability is increased significantly where it retains activity after exposure to high temperatures (90 °C) and long storage times (up to 12 months).
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Simultaneous R2*, R2, and R2′ quantification by combining S0 estimation of the free induction decay with a single spin echo: A single acquisition method for R2 insensitive quantification of holmium‐166–loaded microspheres
Authors: van de Maat G. H. , de Leeuw H. , Seevinck P. R. , van den Bosch M. A. A. J. , Nijsen J. F. W. , Bakker C. J. G. 
Published: March 2014

PurposeTo present a new method, S0 estimation of the free induction decay combined with a single spin echo measurement (SOFIDSE), that enables simultaneous measurements of R2*, R2, and R2′ in order to quantify the local concentration of holmium microspheres (Ho‐MS) for radioembolization.Theory and MethodsSOFIDSE estimates R2* and the signal magnitude at time point 0, S0, from a multigradient echo readout of the free induction decay and subsequently estimates R2 using S0 and a single spin echo, from which R2′ is deducted. The method was evaluated by comparing SOFIDSE R2 values with values obtained from shifted spin echo (SSE) measurements on a phantom setup containing Ho‐MS and from dual spin echo measurements on a healthy volunteer.ResultsOn average, SOFIDSE showed a small overestimation of R2 values compared with SSE independent of the microsphere concentration. R2′ values determined by subtraction of either SOFIDSE R2 or SSE R2 from R2* showed excellent agreement (correlation coefficient = 1; P = 9 · 10−11). The Ho‐MS–induced R2′ values obtained by SOFIDSE were insensitive to the R2 value of the tissue in which they resided.ConclusionSOFIDSE enables quantification of Ho‐MS, in media with spatially or temporally varying R2 values, in a single acquisition. Magn Reson Med 73:273–283, 2015. © 2014 Wiley Periodicals, Inc.
Efficient DG‐like formulation equipped with curved boundary edges for solving elasto‐acoustic scattering problems
Authors: Barucq Hélène , Djellouli Rabia , Estecahandy Elodie 
Published: March 2014

SUMMARYA Discontinuous Galerkin (DG)‐based approach is proposed for computing the scattered field from an elastic bounded object immersed in an infinite homogeneous fluid medium. The proposed method possesses two distinctive features. First, it employs higher‐order polynomial‐shape functions needed to address the high‐frequency propagation regime. Second, it is equipped with curved boundary edges to provide an accurate representation of the fluid–structure interface. The most salient benefits resulting from the latter feature, as demonstrated by the numerical investigation, are the following: (i) an improvement by—at least—two orders of magnitude on the relative error and (ii) the disappearance of spurious resonance frequencies in the surrounding fluid medium. In addition, the reported numerical results reveal that when using cubic polynomials with less than three elements per wavelength, the proposed DG method computes the scattered field with a relative error below 1% for an elastic scatterer of about 30 wavelengths. This observation highlights the potential of the proposed solution methodology for efficiently solving mid‐frequency to high‐frequency elasto‐acoustic scattering problems. Copyright © 2014 John Wiley & Sons, Ltd.
Preparation and characterization of bottle‐brush polymer via host−guest self‐assembly between β‐cyclodextrin and adamantane
Authors: Liu Sa , Wang Yanyan , Cai Jie , Ren Li , Wang Lin , Wang Yingjun 
Published: March 2014

AbstractSupramolecular assemblies with a bottle‐brush structure are obtained by inclusion complexation between β‐cyclodextrin and adamantane. β‐cyclodextrin‐modified chitosan is synthesized via the aldimine condensation reaction between β‐cyclodextrin monoaldehyde and chitosan as the host. The guest is prepared through the esterification reaction between methoxypoly(ethylene glycol) and 1‐adamantanecarboxylic acid chloride. The supramolecular assemblies are formed through the inclusion of adamantane‐modified methoxypoly(ethylene glycol) into the β‐cyclodextrin cavity on the chitosan chain. Fourier transform infrared and 1H NMR spectra were used to prove that the host, guest and assemblies were successfully obtained. UV−visible spectra were employed to confirm the formation of assemblies. Furthermore, the size of the particles in the assembled solution, the change before and after self‐assembly, and the effect of the addition of competitive molecules were studied by dynamic light scattering measurements. The results indicate that supramolecular assemblies have formed successfully which might be used to realize the biomimetic structure of the articular cartilage proteoglycan. © 2014 Society of Chemical Industry
Reduction of the TiO2–x melting temperature induced by oxygen deficiency with implications on experimental data accuracy and structural transition processes
Authors: Knaup J. M. , Marx J. , Frauenheim T. 
Published: March 2014

Abstractmagnified imageMolecular dynamics simulations show a clear reduction of the melting temperature of rutile TiO2 induced by O deficiency. The observed effect is considerably stronger than reported in the experimental literature. This difference may be caused by a lack of knowledge of the O content at the melting point during experiments. In combination with temperature induced reduction, the melting temperature reduction poses questions about the process of Magnéli phase formation in TiO2 memristor devices. Using TiO2 as a model for transition metal oxide ceramics, we propose a mechanism for the flash sintering process.magnified imageTime evolution of the Ti–Ti g (r) at 2500 K at 6.9% and 9,3% O deficiency during MD simulation at the 0 K volume.(© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Double‐layer channel structure based ZnO thin‐film transistor grown by atomic layer deposition
Authors: Ahn Cheol Hyoun , Kim So Hee , Cho Sung Woon , Yun Myeong Gu , Cho Hyung Koun 
Published: March 2014

AbstractA double channel structure has been used by depositing a thin amorphous‐AlZnO (a‐AZO) layer grown by atomic layer deposition between a ZnO channel and a gate dielectric to enhance the electrical stability. The effect of the a‐AZO layer on the electrical stability of a‐AZO/ZnO thin‐film transistors (TFTs) has been investigated under positive gate bias and temperature stress test. The use of the a‐AZO layer with 5 nm thickness resulted in enhanced subthreshold swing and decreased Vth shift under positive gate bias/temperature stress. In addition, the falling rate of the oxide TFT using a‐AZO/ ZnO double channel had a larger value (0.35 eV/V) than that of pure ZnO TFT (0.24 eV/V). These results suggest that the interface trap density between dielectric and channel was reduced by inserting a‐AZO layer at the interface between the channel and the gate insulator, compared with pure ZnO channel. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
TaON surface energetics and optical spectra
Authors: Esch Tobit R. , Vidic Jandro , Bredow Thomas 
Published: March 2014

Abstractmagnified imageThe stabilities and electronic structures of the bulk and several low‐index surfaces of β‐TaON were studied quantum‐chemically at semi‐empirical and hybrid density‐functional level. Excitation spectra of the bulk and surfaces were calculated by using an iterative CIS approach (MSINDO‐CIS). The calculated structure parameters, atomic positions and band gaps for the bulk are compared with experimental data. For comparison we also studied a hypothetical configuration of TaON where the anion ordering is changed. The O/N distribution has a significant effect on the optical spectra and may effect the photocatalytic efficiency of the material. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Perceived Influence and Friendship as Antecedents of Cooperation in Top Management Teams: A Network Approach
Authors: Rank Olaf N. , Tuschke Anja 
Published: March 2014

AbstractUsing the relational dyad as unit of analysis this study examines the effects of perceived influence and friendship ties on the formation and maintenance of cooperative relationships between corporate top executives. Specifically, it is argued that perceived influence as well as friendship ties between any two managers will enhance the likelihood that these managers collaborate with each other. Additionally, a negative interaction effect between perceived influence and friendship on cooperation is proposed. The empirical analyses draw on network data that have been collected among all members of the top two organizational levels for the strategy-making process in two multinational firms headquartered in Germany. Applying logistic regression based on QAP the empirical results support our hypotheses on the direct effects between perceived influence, friendship ties, and cooperative relationships in both companies. In addition, we find at least partial support for our assumption that perceived influence and friendship interact negatively with respect to their effect on cooperation. Seemingly, perceived influence is partially substituted by managerial friendship ties.