bluuebunny/crossref_metadata_2025 huggingface dataset:
Stock Returns and Implied Volatility: A New VAR Approach
Authors: Lee Bong Soo , Ryu Doojin
Published: February 2013

The authors re-examine the return-volatility relationship and its dynamics under a new vector autoregression (VAR) identification framework. By analyzing two model-free impliedvolatility indices – the well-established VIX (in the United States) and the recently published VKOSPI (in Korea) – and their stock market indices, the authors find an asymmetric volatility phenomenon in both the developed and emerging markets. However, the VKOSPI shows impulse response dynamics that are quite different from those of the VIX. This finding can be attributed to the unique characteristics of the KOSPI200 options market, which determine the dynamics of the VKOSPI.
Effect of atmospheric organic complexation on iron-bearing dust solubility
Authors: Paris R. , Desboeufs K. V.
Published: February 2013

Abstract. Recent studies reported that the effect of organic complexation may be a potentially important process to be considered in models to estimate atmospheric iron flux to the ocean. In this study, we investigated this effect by a series of dissolution experiments on iron-bearing dust in presence or absence of various organic compounds typically found in the atmospheric waters (acetate, formate, oxalate, malonate, succinate, glutarate, glycolate, lactate, tartrate and humic acid as an analogue of humic like substances (HULIS)). Only 4 of tested organic ligands (oxalate, malonate, tartrate and humic acid) caused an enhancement of iron solubility which was associated with an increase of dissolved Fe(II) concentrations. For all of these organic ligands, a positive linear dependence of iron solubility to organic concentrations was observed and showed that the extent of organic complexation on iron solubility decreased in order oxalate > malonate = tartrate > humic acid. This was attributed to the ability of electron donors of organic ligands and implied a reductive ligand-promoted dissolution. This study confirmed that oxalate is the most effective ligand playing on dust iron solubility and showed, for the first time, the potential effect of HULIS on iron dissolution in atmospheric conditions.
Validation of XCO2 derived from SWIR spectra of GOSAT TANSO-FTS with aircraft measurement data
Authors: Inoue M. , Morino I. , Uchino O. , Miyamoto Y. , Yoshida Y. , Yokota T. , Machida T. , Sawa Y. , Matsueda H. , Sweeney C. , Tans P. P. , Andrews A. E. , Patra P. K.
Published: February 2013

Abstract. Column-averaged volume mixing ratios of carbon dioxide (XCO2) retrieved from Greenhouse gases Observing SATellite (GOSAT) Short-Wavelength InfraRed (SWIR) observations were compared with aircraft measurements by the Comprehensive Observation Network for TRace gases by AIrLiner (CONTRAIL) project, the National Oceanic and Atmospheric Administration (NOAA), and the National Institute for Environmental Studies (NIES). Before validation, we investigated the impacts of GOSAT SWIR column averaging kernels (CAK) and the shape of a priori profiles on the calculation of XCO2 based on aircraft measurements (aircraft-based XCO2). The differences between aircraft-based XCO2 with and without the application of GOSAT CAK were evaluated to be less than ±0.4 ppm at most, and less than 0.1 ppm on average. Therefore, we concluded that the GOSAT CAK produces only a minor effect on the aircraft-based XCO2 calculation in terms of the overall uncertainty of GOSAT XCO2. In this study, two approaches were used to validate GOSAT products (Ver. 02.00). First, we performed a comparison of GOSAT data retrieved within ±2-degree or ±5-degree latitude/longitude boxes centered at each aircraft measurement site and aircraft-based data measured on a GOSAT overpass day (i.e. extraction of temporally matched cases). As this method resulted in no matched data for observation sites where no aircraft measurement was made on the GOSAT overpass day, we also attempted to validate GOSAT products by gap-filling the aircraft-based XCO2 time series through curve fitting. Both methods indicated that GOSAT XCO2 agreed well with aircraft-based XCO2, except that the former is negatively biased by 1–2 ppm with a standard deviation of 1–3 ppm.
Application of ground-based hyperspectral imaging to retrieve ice crystal shape and fields of cirrus optical thickness
Authors: Schäfer M. , Bierwirth E. , Ehrlich A. , Heyner F. , Wendisch M.
Published: February 2013

Abstract. A ground-based hyperspectral imaging spectrometer (AisaEAGLE) is applied to measure downward spectral radiance fields with high spatial (1024 spatial pixels within 36.7° field of view), spectral (488 spectral pixels, 400–970 nm, 1.25 nm full width at half maximum) and temporal (4–30 Hz) resolution. The calibration, measurement, and data evaluation procedures are introduced. A method is presented to retrieve the cirrus optical thickness τci using ground-based spectral radiance data collected by AisaEAGLE. On the basis of four measurement cases during the second campaign of the Cloud Aerosol Radiation and tuRbulence of trade wInd cumuli over BArbados (CARRIBA) project in 2011 the spatial inhomogeneity of the investigated cirrus is characterized by the standard deviation of the retrieved τci, as well as the width of the frequency distribution of the retrieved τci. By comparing measured and simulated downward solar radiance as a function of scattering angle, a first estimation of the detected cirrus ice crystal shape is given and used in the retrieval of the τci. The sensitivity of the retrieval method with respect to surface albedo, effective radius reff, cloud height, and ice crystal shape was characterized. Significant sensitivities of the retrieval method were found for the assumed surface albedo (up to 30%) and ice crystal shape (up to 90%). The sensitivity with regard to the effective radius (≤ 5%) and the cloud height (≤ 0.5%) is rather small and can be neglected.
Biogeography of planktonic microbial communities across the whole Mediterranean Sea
Authors: Mapelli F. , Varela M. M. , Barbato M. , Alvariño R. , Fusi M. , Álvarez M. , Merlino G. , Daffonchio D. , Borin S.
Published: February 2013

Abstract. The M84/3 cruise recently held onboard of R/V Meteor represented a great and rare opportunity for the scientific community to realize a multidisciplinary survey on the whole Mediterranean Sea. In this context, molecular microbiology investigation, realized by applying Automated Ribosomal Intergenic Sequence Analysis (ARISA) and microscope evaluation of prokaryotic abundance, were performed on seawater samples aiming to identify the environmental factors driving planktonic bacterial community composition across both vertical and longitudinal transects. Prokaryotic abundance decreased along with depth in all the stations and presented similar values in sub-surface, meso- and bathypelagic layers across the whole Mediterranean basin. On the contrary, peculiar bacterial assemblages were selected along a longitudinal transect in the surface layers of the eastern and western sub-basins. Sharp vertical profiling of the bacterial communities was observed only considering the boundary of the water column, while the study of bacterial β-diversity at finer scale across the water column displayed higher variability at the intermediate layers. Nonetheless, different physico-chemical factors were significantly related to microbial zonation both according to geographic position and across the water column in the whole Mediterranean Sea. These results demonstrated that bacterial diversity is putatively correlated to different water masses across the water column of the complex hydrographical systems of the eastern and western Mediterranean sub-basins.
Observation of Lithium Isotope Effects Accompanying Electrochemical Release from Lithium Cobalt Oxide
Authors: Takami Yuta , Yanase Satoshi , Oi Takao
Published: February 2013

Change in the lithium isotope composition in a lithium cobalt oxide (LiCoO2) cathode for lithium ion secondary batteries accompanying the electrochemical lithium release from the cathode into an organic electrolyte solution was observed. The 7Li/6Li isotopic ratios of the electrodes after the release of 37.2 to 55:4% lithium were 1.018 to 1.033 times smaller than that before the release. This means that the heavier isotope, 7Li, is preferentially transferred to the electrolyte solution.
Triple Spin Interaction and Entanglement
Authors: Steeb Willi-Hans
Published: February 2013

We study a Hamilton operator Ĥ for spin-1/2 with triple spin interactions. The eigenvalues and eigenvectors are determined and the unitary matrices exp(-iHt/ħ) are found. Entanglement of the eigenvectors is investigated. A Hamilton operator K̂ for spin-1 and triple spin interaction is also discussed.
Ion Hydration Under Pressure: A Molecular Dynamics Study
Authors: Druchok Maksym , Holovko Myroslav
Published: February 2013

This study is intended to elucidate the role of pressure on the hydration behaviour of ions in aqueous solutions. Molecular dynamics simulations were performed for systems modelling CsF, CsCl, CsBr, and CsI aqueous solutions under ‘normal’ (105 Pa, 298 K) and ‘high pressure’ (4 ·109 Pa, 500 K) conditions. Structural details are discussed in terms of radial distributions functions, coordination numbers, and instantaneous configurations of the ionic hydration shells. The dynamic properties studied include the velocity autocorrelation functions and self-diffusion coefficients of the ions for both pressure regimes. The results indicate strong changes in the hydration behaviour and mobility of the ions.
The Local Structure of Liquid TiCl4 Analyzed by X-Ray Diffraction and Raman Spectroscopy
Authors: Iwadate Yasuhiko , Ohkubo Takahiro
Published: February 2013

Structural analyses were performed to determine the local structure of liquid TiCl4 using laboratory-scale X-ray diffraction and Raman spectroscopy from which the existence of tetrahedral TiCl4 molecules in the liquid was definitely confirmed. Conventionally, in molten salts, the valence increase of the central metal ion, for example in the range from 1 to 3, leads to more complicated liquid structures, yet a further increase in valence is usually accompanied by an enhanced covalency, forming stable tetrahedral molecules like e. g. CCl4.We discuss the intermolecular structure of TiCl4 liquid as well as the intramolecular one.
Optimization of a Molten Salt Electrolytic Bath Geometry for Rare Earth Metal Recovery using a Finite Element Method
Authors: Numata Hiroo , Akatsuka Hiroshi , Matsuura Haruaki
Published: February 2013

For a recycling procedure for rare earths from spent hydrogen absorbing alloys by rare earths electrodeposition in a molten salt, the electrolytic bath and the cathode accessories have been optimized by evaluating the appropriate secondary current distribution using finite element method (FEM) computer simulation. The desirable cathode dish as an accessory was designed to prevent drops of less adherent electrodeposits, which improved the current density distribution compared with an a priori determined one. In the bath optimization, a reciprocal proportionality of the difference between the maximum and minimum current densities vs. the ratio of volume to surface area (or electrolyte volume) was found. It was found by FEM that if a resistive floating mass is assumed on the electrolyte surface, the observed necking in the electrodeposit near the electrolyte surface can be analyzed.
Aharony–Bergman–Jafferis–Maldacena Wilson Loops in the Fermi Gas Approach
Authors: Klemm Albrecht , Mariño Marcos , Soroush Masoud
Published: February 2013

The matrix model of the Aharony-Bergman-Jafferis-Maldacena theory can be formulated in terms of an ideal Fermi gas with a non-trivial one-particle Hamiltonian. We show that, in this formalism, vacuum expectation values (vevs) of Wilson loops correspond to averages of operators in the statistical-mechanical problem. This makes it possible to calculate these vevs at all orders in 1/N, up to exponentially small corrections, and for arbitrary Chern-Simons coupling, by using the Wentzel- Kramer-Brillouin expansion.We present explicit results for the vevs of 1/6 and the 1/2 Bogomolnyi- Prasad-Sommerfield Wilson loops, at any winding number, in terms of Airy functions. Our expressions are shown to reproduce the low genus results obtained previously in the ’t Hooft expansion.
Robots Bring Math-Powered Ideas to Life
Authors: Allen Kasi C.
Published: February 2013

A compelling contest motivates students and makes mathematics and STEM relevant.
Exploring Slope with Stairs & Steps
Authors: Smith Toni M. , Seshaiyer Padmanabhan , Peixoto Nathalia , Suh Jennifer M. , Bagshaw Graham , Collins Laurena K.
Published: February 2013

Two activities help develop students' understandings of rate of change and slope within STEM contexts.
Surviving an Avalanche of Data
Authors: English Lyn D.
Published: February 2013

Help first-grade students learn to competently generate, test, revise, and represent data before being formally taught to do so.
La traduction de la phénoménologie husserlienne en espagnol : une perspective socio-traductologique
Authors: Castro Nayelli
Published: February 2013

Cette étude montre la complexité de la construction du corpus husserlien en espagnol en suivant les traces traductives de deux ouvrages : Meditaciones cartesianas et Ideas. À l’aide des outils de la sociologie de la culture et de la sociologie de la traduction, la réflexion proposée met au jour le rôle des philosophes-traducteurs appartenant au réseau intellectuel hispanophone ainsi que la production discursive par laquelle ils gèrent l’importation des idées phénoménologiques. Sur la base d’un continuum textuel comprenant aussi bien les oeuvres originales, que les traductions et les paratextes écrits par les traducteurs de ces oeuvres, il est possible de dessiner un réseau intellectuel, au sein duquel les rapports entre « philosopher » et « traduire » sont mis à jour.
Des philosophies de la traduction à la théorie non-philosophique de la traduction
Authors: Rao Sathya
Published: February 2013

L’objet de cet article est de proposer une critique de la praxéologie de Jean-René Ladmiral et de l’éthique de la traduction d’Antoine Berman du point de vue de la non-philosophie de François Laruelle. Plus exactement, il s’agira de voir comment les élaborations des deux traductologues demeurent sous l’emprise de la philosophie et, à ce titre, ne peuvent proposer une théorie pleinement satisfaisante de la traduction. Dans un second temps, nous formulerons les principes d’une théorie non-philosophique de la traduction.
Catherine Malabou’s Plasticity in Translation
Authors: Shread Carolyn
Published: February 2013

Translating Catherine Malabou’sLa Plasticité au soir de l’écriture: Dialectique, destruction, déconstruction(2005) for its 2009 English publication, I was struck by how suggestive Malabou’s concept of plasticity is for a reworking of conventional notions of translation. In this philosophical autobiography of her encounters with Hegel, Heidegger, and Derrida, Malabou introduces “plasticity,” suggesting that the more contemporary notion of plasticity supersede Derrida’s proposal of writing as motor scheme. Reviewing and developing Derrida’s innovative discussions of translation, this article argues that the giving, receiving, exploding, and regenerating of form described by plasticity changes change, and therefore alters the transformation that is translation. Adapting Malabou’s philosophical concept to the field of translation studies, I make a distinction between elastic translation and plastic translation, which allows us to break free of paradigms of equivalence that have for so long constrained translation theories and practice. While plasticity drives Malabou’s philosophical intervention in relation to identity and gender, it also enables a productive reconceptualization of translation, one which not only privileges seriality and generativity over narratives of nostalgia for a lost original, but which also forges connections across different identity discourses on translation.
La recherche traductologique : méthodes ou approche?
Authors: Gile Daniel
Published: February 2013

Les approches prévalentes dans la recherche traductologique sous sa forme universitaire peuvent être classées en deux grandes catégories, l’une relevant des sciences humaines (ASH) et l’autre s’inspirant de la recherche scientifique canonique (ASC). Les méthodes employées dans cette dernière se distinguent souvent par leur complexité relative, mais aussi par leur caractère plus ou moins intrusif. Les traductologues non formés aux méthodes de recherche sont parfois attirés par la puissance potentielle des méthodes avancées et des nouvelles technologies, mais leur emploi peut s’avérer contre-productif quand elles n’ont qu’une faible valeur ajoutée pour un gros coût en ressources et quand elles menacent la validité écologique de l’étude.
Where is the “History” in Translation Histories?
Authors: Malena Anne
Published: February 2013

This paper explores two interrelated problems of method of concern to translation historians and that are part of the overarching issue of interdisciplinarity. The first has to do with conflicting methods used in history and the second with deciding whether or not it is necessary for a translation scholar to define her or his philosophical position with regards to history. This article is part of a book project on the history of translation in Louisiana, which has been understudied. The writing of a translation history implies the act of rendering visible what has been obscured by the official grand narrative of History, or what Nietzsche called “monumental” history. To look for translation where officially there was none, or very little, amounts to search for multiple histories of people who do not necessarily fit into the dominant definition of what it means to be American, because they spoke languages other than English and adhered to cultural practices that resisted melting into the common pot. From this perspective history is viewed as discourse because, very much like translation, it is made up of language, seen as living matter shaped and manipulated by power relations. The focus of the study is two local 19th-century historians from Louisiana who repeatedly doubled up as translators—from French to English and back into French—to produce histories of Louisiana. The conclusion states that translation historians are first historiographers, imbued with all the disciplinary and ethical responsibilities that entails. Since historiography forms a nexus for history and translation, it is not only necessary to theorize both but also to develop methods that can be integral to both.
Contribution de l’étude de la traduction des contextes minorisés à la méthodologie de la recherche en traductologie : le cas basque
Authors: Jaka Aiora
Published: February 2013

Le présent article vise à mettre en lumière la contribution que l’étude de la traduction dans les contextes minorisés peut apporter à la méthodologie de la recherche en traductologie. En analysant des exemples tirés de l’histoire de la traduction basque, l’article montre que la traduction dans ce type de système marginal n’est souvent qu’un autre moyen de réécriture, qui ne diffère guère d’autres procédés littéraires tels que l’adaptation ou la transformation. Une méthodologie de recherche pouvant servir à expliquer tous ces phénomènes de traduction devrait donc surmonter la définition trop restreinte tenue par le discours traditionnel de la traduction, et adopter une perspective interdisciplinaire permettant d’élargir la définition de la traduction. Dans ce sens, les théories postcoloniales ainsi que d’autres approches issues du « power turn » en traductologie offrent d’excellents outils pour l’étude de la traduction dans les systèmes littéraires minorisés en général et dans le contexte basque en particulier.
Expatriation et traduction : Chester Himes traduit dans le champ français du roman policier (1957-1960)
Authors: Gouanvic Jean-Marc
Published: February 2013

L’oeuvre de l’écrivain américain Chester Himes comporte sept romans policiers qui ont la particularité d’avoir été d’abord écrits en anglo-américain, puis traduits et publiés en français, enfin publiés pour la première fois en anglo-américain aux États-Unis dans une version différente de la version originale, source de la traduction. Le présent article tente d’analyser les déterminations qui sont à l’origine du fort intérêt de Himes pour le roman policier, en resituant les conditions qui l’ont amené à se tourner vers le genre. Nous examinons l’habitus de Himes, le rôle essentiel joué par Marcel Duhamel (directeur de la Série Noire), par le champ français du roman policier et par la traduction (en la personne de la traductrice Minnie Danzas), ainsi que l’illusio spécifique de ses romans policiers et tout spécialement The Five-Cornered Square et sa traduction, La reine des pommes. Nous voyons, pour finir, comment le succès rencontré par La reine des pommes en 1958 a élargi considérablement la gamme des possibles narratifs dans le champ français du roman policier.
L’addiction à l’adolescence : entre affect et cognition. Symbolisation, inhibition cognitive et alexithymie
Authors: Karray Khemiri Amira , Derivois Daniel
Published: February 2013

Les conduites addictives sont fréquentes chez les adolescents. La littérature montre chez cette population des distorsions cognitives expliquant les tendances impulsives, l’intolérance à la frustration, l’incapacité à contenir son ressenti. La psychologie cognitive pointe la défaillance du contrôle cognitif, à l’image de la défaillance du contrôle de l’action, de l’impulsion et de tout ce qui est en dehors du contrôle mental. La psychopathologie psychodynamique considère ces mêmes conduites comme modalités privilégiées de l’agir, reflétant un fonctionnement d’anti-représentation, de défaillance dans la symbolisation. Cette dernière s’associe aux difficultés d’élaboration des affects et duplique ainsi en termes cognitivistes les caractéristiques de l’alexithymie. Le fonctionnement cognitivo-émotionnel et affectif de l’adolescent et du jeune adulte toxicomane sera étudié. À travers une revue synthétique de la littérature, les auteurs se pencheront sur l’adjonction d’un déficit de l’inhibition cognitive à une défaillance symbolique dans la pathologie addictive de l’adolescence et du jeune adulte.
De la broue dans l’toupet ou Non, les parents boivent moins !
Authors: Paradis Catherine , Demers Andrée , Nadeau Louise , Picard Élyse
Published: February 2013

Objectif : L’objectif de cette étude est d’évaluer si les stresseurs du conflit travail-famille modèrent l’association entre la parentalité et la consommation d’alcool parmi les adultes canadiens en emploi. Méthode : En s’appuyant sur le pendant canadien de l’étude GENACIS internationale (GENder Alcohol and Culture: an International Study), l’échantillon est composé de 3 403 femmes et 3 295 hommes en emploi, âgés de 18 à 55 ans et qui ont indiqué avoir consommé de l’alcool au moins une fois au cours des 12 mois précédant l’enquête. Des analyses de régression hiérarchique ont été effectuées afin de tester l’hypothèse de modération. Résultats : Les principales conclusions peuvent être résumées comme suit : i) le rôle parental est négativement associée à la consommation d’alcool ; ii) les stresseurs du conflit travail-famille ne sont pas associés à la consommation d’alcool chez les hommes et ils ne sont que marginalement associés à la consommation d’alcool chez les femmes ; iii) les stresseurs du conflit travail-famille ne modèrent pas l’association entre le rôle parental et la consommation d’alcool. Conclusion : Les futures recherches devraient porter sur les processus spécifiques selon lesquels la parentalité structure la consommation d’alcool. Il serait aussi pertinent de vérifier si l’effet du rôle parental sur la consommation d’alcool est plus marqué dans des contextes de consommation qui favorisent la consommation abusive d’alcool.
Children's role in the community response to HIV in Zimbabwe
Authors: Skovdal Morten , Magutshwa‐Zitha Sitholubuhle , Campbell Catherine , Nyamukapa Constance , Gregson Simon
Published: February 2013

Introduction

Recent debates on how to achieve an optimal HIV response are dominated by intervention strategies that fail to recognize children's role in the community response to HIV. Whilst formal responses are key to the HIV response, they must recognize and build on indigenous community resources. This study examines adult's perspectives on the role of children in the HIV response in the Matobo District of southern Zimbabwe.

Methods

Through a mix of individual interviews (n=19) and focus group discussions (n=9), 90 community members who were active in social groups spoke about their community response to HIV. Transcripts were subjected to a thematic analysis and coding to generate key concepts and representations.

Findings

In the wake of the HIV epidemic, traditional views of children's social value as domestic “helpers” have evolved into them being regarded as capable and competent actors in the care and support of people living with HIV or AIDS, and as integral to household survival. Yet concurrent representations of children with excessive caregiving responsibilities as potentially vulnerable and at risk suggest that there is a limit to the role of children in the HIV response.

Conclusion

Community volunteers and health staff delivering HIV services need to recognize the “behind the scene” role of children in the HIV response and ensure that children are incorporated into their modus operandi – both as social actors and as individuals in need of support.
Money devaluation
Authors: Ratliff Melissa
Published: February 2013

“Money” has a multitude of meanings, but here our discussion will be limited to coinage. In antiquity coins originally had intrinsic value – the earliest Greek and Roman coins had worth equivalent to the quantity of metal they contained. Over time they lost value as rulers reduced the amount (fineness and weight) of gold and silver in the precious metal coinage. This eventually led to a system where the coins' values were completely unrelated to their metal content, creating fiduciary coinage, requiring trust between the people and the issuing state.
Aristobulus II
Authors: Atkinson Kenneth
Published: February 2013

Aristobulus II was the youngest son of the Judaean monarch Alexander Jannaeus and his spouse, queen Alexandra Salome.
Investigation of the Thermal Shock Behavior of Ceramic Using a Combination of Experimental Testing and FE‐Simulation Methods
Authors: Zhang Wei , Doynov Nikolay , Wolf Matthias , Dreibati Ossama , Ossenbrink Ralf , Michailov Vesselin
Published: February 2013

Thermal shock behavior of ceramics plays a decisive role in their broad industrial applications. For enhanced understanding of damage and failure mechanism under thermal shock loading, in the present work, a combination of experimental testing and numerical simulation methods has been used. The thermal shock behavior of the alumina (99.7%) disk samples has been investigated by using a plasma test stand: the bottom of the ceramic disks were locally heated in the center by plasma beam; during the heat treatment the temperature distribution at the top of the sample was recorded with a thermographic system. To characterize the thermal shock resistance, a thermomechanical simulation was subsequently carried out. It calculates the temperature and stress distribution within the ceramic disks. The calculated critical thermal tension stresses are reported, which led to the failure of the ceramic disks under thermal shock loading. The effect of the sample thickness on the temperature and stress distribution is presented. Compared with the experimental results the simulated results show excellent agreement. As conclusion, it is possible to determine the thermal shock behavior of ceramic materials by the combination of experimental testing and numerical simulation.
Modeling scale formation in flat‐sheet membrane modules during water desalination
Authors: Kostoglou Margaritis , Karabelas Anastasios J.
Published: February 2013

Modeling the operation of spiral‐wound membrane modules is essential for their successful design and optimization. Such models must include the main types of membrane fouling, degrading desalination plant performance, including scaling due to sparingly soluble salts. Unfortunately, the complexity of underlying physicochemical processes and the coexistence of several spatial and temporal scales render intractable modeling of membrane scaling based on first principles. Therefore, a suitable (albeit simplified) framework is developed for incorporating scaling dynamics into a fluid flow model formulated at an intermediate (i.e., mesoscopic) length scale of membrane operation. The general mesoscopic approach involves integration of spatially distributed submodels, thereby allowing predictions at the large (entire membrane sheet) scale; these submodels comprise constitutive laws and kinetic rate expressions derived at fine scales. A submodel for the effect of pre‐existing bulk particles on scale formation is developed herein. Several numerical results are presented to exemplify the potential of the proposed framework. © 2013 American Institute of Chemical Engineers AIChE J, 59: 2917–2927, 2013
Computational screening of porous carbons, zeolites, and metal organic frameworks for desulfurization and decarburization of biogas, natural gas, and flue gas
Authors: Peng Xuan , Cao Dapeng
Published: February 2013

Eighteen kinds of porous materials from carbons, zeolites, and metal organic frameworks (MOFs) have been extensively investigated for desulfurization and decarburization of the biogas, natural gas, and flue gas by using a molecular modeling approach. By considering not only the selectivity but also capacity, Na‐5A, zeolite‐like MOF (zMOF), and Na‐13X, MIL‐47 are screened as the most promising candidates for removal of sulfide in the CH4CO2H2S and N2CO2SO2 systems, respectively. However, for simultaneous removal of sulfide and CO2, the best candidates are zMOF for the natural gas and biogas (i.e., CH4CO2H2S system) and MOF‐74‐Zn for the flue gas (i.e., N2CO2SO2 system). Moreover, the regeneration ability of the recommended adsorbents is further assessed by studying the effect of temperature on adsorption. It is found that compared to the zMOF and MIL‐47 MOFs, the Na‐5A and Na‐13X zeolites are not easily regenerated due to the difficulty in desorption of sulfide at high temperature, which results from the stronger adsorbent–adsorbate interactions in zeolites. The effect of sulfide concentration on the adsorption properties of the recommended adsorbents is also explored. We observe that the zMOF and MIL‐47 are also superior to the Na‐5A and Na‐13X for desulfurization of gas mixtures containing high sulfide concentration. This is because MOFs with larger pore volume lead to a greater sulfide uptake. The effects of porosity, framework density, pore volume, and accessible surface area on the separation performance are analyzed. The optimum porosity is about 0.5–0.6, to meet the requirements of both high selectivity and uptake. It is expected this work provides a useful guidance for the practical applications of desulfurization and decarburization. © 2013 American Institute of Chemical Engineers AIChE J, 59: 2928–2942, 2013
Ionic liquids: Solubility parameters and selectivities for organic solutes
Authors: Wang Li‐Sheng , Wang Xin‐Xin , Li Yi , Jiang Kan , Shao Xian‐Zhao , Du Chao‐Jun
Published: February 2013

Ionic liquids (ILs) are innovative solvents for chemical processing. In this work, a database on activity coefficients of organic solutes at infinite dilution in ILs was collected from literature sources. The activity coefficients have been correlated by activity coefficient model for the regular solution and have been used to estimate the solubility parameter of ILs. The solubility parameters of ILs have been further correlated based on a concept of the group contribution method. Through the analysis of the database and the prediction results of selectivities, it was shown here that as compared with conventional organic solvents, higher selectivity can be achieved by using ILs as working solvents for separation of alkane/aromatic, aromatic/aromatic hydrocarbon mixtures via extraction or supported liquid membrane. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3034–3041, 2013
Simulation study on the liquid‐crystalline ordering and fluidity of energetic diblock copolymers based on poly[3,3‐bis(azidomethyl) oxetane]
Authors: Yang Zhou , Xin‐Ping Long , Qing‐Xuan Zeng
Published: February 2013

The liquid‐crystalline ordering and fluidity of energetic diblock copolymers based on poly[3,3‐bis(azidomethyl) oxetane] (BAMO) and 3‐nitratomethyl‐3′‐methyloxetane (NMMO) were investigated by the dissipative particle dynamics method. The results show that these copolymers, with moderate BAMO block lengths (x's), experienced the disorder, nematic, and smectic phases with decreasing temperature. The nematic phase was suppressed when the rod length was too long or short. After the formation of the smectic phase, the fluidity had a sharp decline. The temperature forming the smectic phase was defined as the order–disorder transition temperature (TODT) and depended strongly on x. A simple scaling rule, TODT ≈ e−x, between TODT and x was constructed. The effect of the soft NMMO block fraction on the fluidity emerged before the formation of the smectic phase. These results can help researchers design and synthesize new energetic copolymers with an appropriate melting temperature range for use as binders of solid propellants. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Improving weathering resistance of flame‐retarded polymers
Authors: Wilén Carl‐Eric , Pfaendner Rudolf
Published: February 2013

Most flame‐retarded polymer products need to be highly durable throughout their service lifetime in many demanding applications areas such as construction, transportation, electric equipment, and textiles, where low flammability in combination with high resistance toward oxidative deterioration triggered by the action of light, heat, and/or mechanical stress is a mandatory quality. To achieve this, it is essential to better understand the overall interplay (both physical and chemical processes) between different components such as different flame retardant structures in their respective polymers and in the presence of coadditives such as processing stabilizers, antioxidants, light stabilizers, metal deactivators, filler deactivators, ultraviolet absorbers, and so on, in the flame‐retarded polymer product. In this article, the key difficulties in improving weathering resistance of flame‐retarded polymers are reviewed. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Improved conductivity and thermal stability by the formation of a charge‐transfer complex in β‐nucleation‐agent‐nucleated and MWCNT‐filled iPP composites
Authors: Zhang Yu , Liu Hong , Zhang Lei , Li Xinpeng , Du Hainan , Zhang Jie
Published: February 2013

In this study, the influence of β‐nucleation agent (β‐NA) on the morphology and properties of multi‐walled carbon nanotube (MWCNT) filled isotactic polypropylene (iPP) composites was explored in details. The results show that the incorporation of β‐NA has promoted the dispersion of MWCNT in the iPP matrix, which is profitable for improving the thermal stability and conductivity properties of MWCNT‐iPP composites. Besides, the 0.05 wt % β‐NA nucleated samples exhibit higher impact toughness than that of un‐β‐NA‐nucleated ones. Further SEM observations show that the morphology of MWCNT changes from large agglomerations to small clusters with doping of β‐NA. The main reason is that the incorporation of β‐NA (TMB‐5) in MWCNT filled iPP matrix has led to the formation of a charge‐transfer complex. Some of these clusters act as nucleation sites for inducing crystallization of α spherulites, which have a compete growth with β‐NA induced β crystals. Meanwhile, other clusters exist in the inter‐lamella amorphous phase of β crystals, some of them even combine two adjacent β spherulites. Accordingly, a large conductive network comes into being. Based on the investigated results, a mechanism model is proposed. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Clasaurertobelviadukt – Integrale Instandsetzung eines Mauerwerksviadukts
Authors: Jäger Thomas
Published: February 2013

Der Clasaurertobelviadukt der Rhätischen Bahn liegt auf der Strecke Chur – Arosa und wurde im Jahr 1914 als Natursteinmauerwerksviadukt mit sechs Bogenöffnungen erstellt. Aufgrund andauernder Geländeverschiebungen wurde das Bauwerk seit der Inbetriebnahme stark beschädigt. Zur Sicherstellung der Betriebssicherheit war eine umfangreiche Instandsetzung unumgänglich.

Mit dem umfangreichen Umbau des Brückentragwerks resultierte eine signifikante Änderung des Kraftflusses. Dieser Beitrag zeigt die Problemstellung auf und behandelt anschließend die konzeptionellen Überlegungen bei der Entwicklung des Tragwerksmodells sowie ausgewählte Resultate der Tragwerksanalyse. Die komplexen Randbedingungen erforderten im Weiteren eine Abstimmung der einzelnen Bauphasen.

Clasaurer Valley Bridge – Integral Structural Repair of a Masonry Bridge

The Clasauerer Valley Bridge of the Rhaetian Railway is located on the track Coire – Arosa. It was built as a masonry arch bridge with six openings in 1914. Due to significant ground movements, the structure suffered heavy damage. To ensure the operating safety an extensive overhaul was necessary.

An extensive modification of the structure was executed, resulting in a significant change of the flow of forces. This paper presents the problems and treats conceptual considerations as well as the development of the structural model including a discussion of selected results, respectively. Furthermore, the complex boundary conditions required a detailed planning of the construction work.
Influence of outer membrane c‐type cytochromes on particle size and activity of extracellular nanoparticles produced by Shewanella oneidensis
Authors: Ng Chun Kiat , Sivakumar Krishnakumar , Liu Xin , Madhaiyan Munusamy , Ji Lianghui , Yang Liang , Tang Chuyang , Song Hao , Kjelleberg Staffan , Cao Bin
Published: February 2013

The metal‐reducing bacterium Shewanella oneidensis is capable of reducing various metal(loid)s and produces nanoparticles (NPs) extracellularly, in which outer membrane c‐type cytochromes (OMCs) have been suggested to play important roles. The objective of this study was to investigate the influence of the OMCs, that is, MtrC and OmcA, on the size and activity of the extracellular silver NPs (AgNPs) and silver sulfide NPs (Ag2S NPs) produced by S. oneidensis MR‐1. We found that (i) the lack of OMCs on S. oneidensis cell surface decreased the particle size of the extracellular biogenic AgNPs and Ag2S NPs; (ii) the biogenic AgNPs from the mutant lacking OMCs showed higher antibacterial activity; and (iii) the biogenic Ag2S NPs from the mutant lacking OMCs exhibited higher catalytic activity in methylviologen reduction. The results suggest that it may be possible to control particle size and activity of the extracellular biogenic NPs via controlled expression of the genes encoding surface proteins. In addition, we also reveal that in extracellular biosynthesis of NPs the usually neglected non‐cell‐associated NPs could have high catalytic activity, highlighting the need of novel methods that can efficiently retain extracellular NPs in the biosynthesis processes. Biotechnol. Bioeng. 2013; 110: 1831–1837. © 2013 Wiley Periodicals, Inc.
Engineering of a bacterial tyrosinase for improved catalytic efficiency towards D‐tyrosine using random and site directed mutagenesis approaches
Authors: Molloy Susan , Nikodinovic‐Runic Jasmina , Martin Leona B. , Hartmann Hermann , Solano Francisco , Decker Heinz , O'Connor Kevin E.
Published: February 2013

The tyrosinase gene from Ralstonia solanacearum (GenBank NP518458) was subjected to random mutagenesis resulting in tyrosinase variants (RVC10 and RV145) with up to 3.2‐fold improvement in kcat, 5.2‐fold lower Km and 16‐fold improvement in catalytic efficiency for D‐tyrosine. Based on RVC10 and RV145 mutated sequences, single mutation variants were generated with all variants showing increased kcat for D‐tyrosine compared to the wild type (WT). All single mutation variants based on RV145 had a higher kcat and Km value compared to the RV145 and thus the combination of four mutations in RV145 was antagonistic for turnover, but synergistic for affinity of the enzyme for D‐tyrosine. Single mutation variant 145_V153A exhibited the highest (6.9‐fold) improvement in kcat and a 2.4‐fold increase in Km compared to the WT. Two single mutation variants, C10_N322S and C10_T183I reduced the Km up to 2.6‐fold for D‐tyrosine but one variant 145_V153A increased the Km 2.4‐fold compared to the WT. Homology based modeling of R. solanacearum tyrosinase showed that mutation V153A disrupts the van der Waals interactions with an α‐helix providing one of the conserved histidine residues of the active site. The kcat and Km values for L‐tyrosine decreased for RV145 and RVC10 compared to the WT. RV145 exhibited a 2.1‐fold high catalytic efficiency compared to the WT which is a 7.6‐fold lower improvement compared to D‐tyrosine. RV145 exhibited a threefold higher monophenolase:diphenolase activity ratio for D‐tyrosine:D‐DOPA and a 1.4‐fold higher L‐tyrosine:L‐DOPA activity ratio compared to the WT. Biotechnol. Bioeng. 2013; 110: 1849–1857. © 2013 Wiley Periodicals, Inc.
Randomized clinical trial on the effect of coffee on postoperative ileus following elective colectomy (Br J Surg 2012; 99: 1530–1538)
Authors: Griffiths S N , Bailey J , Kenefick N J
Published: February 2013

The Editors welcome topical correspondence from readers relating to articles published in the Journal. Responses should be sent electronically via the BJS website (www.bjs.co.uk). All letters will be reviewed and, if approved, appear on the website. A selection of these will be edited and published in the Journal. Letters must be no more than 250 words in length.
Double bifurcation lesion treated with double tryton sidebranch stent: First case report
Authors: Unzué Leire , García Eulogio , Almería Carlos
Published: February 2013

The optimal percutaneous treatment strategy for coronary bifurcation lesions is still unknown. Several dedicated coronary bifurcation stents, such as the Tryton Side Branch StentTM (Tryton Medical, Durham, NC) have been developed to improve clinical outcomes. We presented a double bifurcation lesion case treated with two Tryton sidebranch stents, with a single drug eluting stent covering the main vessel and both bifurcations. © 2013 Wiley Periodicals, Inc.
Die Verfügbarkeit von Hochtechnologie‐Rohstoffen
Authors: Melcher Frank , Wilken Hildegard
Published: February 2013

Die deutsche Industrie ist in hohem Maße von einer sicheren Rohstoffversorgung abhängig. Vierzehn mineralische Rohstoffe werden von der Europäischen Union als kritisch bewertet. Obwohl die Rohstoffsicherung primär als Aufgabe der Industrie anzusehen ist, geben die Bundesregierung und die EU wesentliche Impulse für eine nachhaltige und zukunftsorientierte Rohstoffstrategie. Teil dieser Strategie ist die Gründung der DERA als zentrale deutsche Beratungsstelle für die Wirtschaft.

Die Reservensituation für die kritischen Rohstoffe ist in den allermeisten Fällen unbedenklich, und es gibt genügend Möglichkeiten, Rohstoffe aus bisher nicht genutzten Vorkommen zu gewinnen, zu substituieren oder zu recyceln. Es sind vielmehr Faktoren wie die technische Verfügbarkeit, geostrategische Risiken und Marktmacht, die bei allen diesen Metallen kritisch bewertet werden. Darauf müssen sich Firmen einstellen und reagieren. Ein wichtiger Punkt ist die Entwicklung der BRIC‐Staaten, allen voran Chinas; zum einen haben diese Länder durch den Aufbau ihrer Wirtschaften einen sehr hohen Rohstoffbedarf, zum anderen entwickeln sie zunehmend Technologien zur Rohstoffveredelung im eigenen Land. Dies verringert – vor allem in einem sehr rohstoffreichen Land mit niedrigem Lohnniveau wie China – die Kapazitäten der für den Export vorgesehenen Rohstoffe, was sich wiederum in höheren Preisen auswirkt. Der Bedarf an Rohstoffen, die nicht aus Ländern mit hohem Eigenbedarf oder Exportquoten kommen, steigt. Dies führt wiederum dazu, dass die Rohstoffversorgung auch auf Länder zugreift, in denen keine gesicherten Standards im Bergbau, Umweltmanagement, oder sozialer Sicherheit gelten oder in denen der Rohstoffabbau mit der Finanzierung von Konflikten einhergeht. Zukünftig werden Weltwirtschaft und Verbraucher für diese artisanal geförderten Rohstoffe die Umsetzung von Mindeststandards verlangen.
A General Strategy for the Synthesis of Functionalised UiO‐66 Frameworks: Characterisation, Stability and CO2 Adsorption Properties
Authors: Biswas Shyam , Van Der Voort Pascal
Published: February 2013

A general synthetic strategy has been developed, which can be used for the preparation of all the known as well as five new functionalised UiO‐66‐X compounds [X = H, F, F2, Cl, Cl2, Br, Br2, I, CH3, (CH3)2, CF3, (CF3)2, NO2, NH2, OH, (OH)2, OCH3, (CO2H)2, SO3H, C6H4]. Starting from a reaction mixture of ZrOCl2·8H2O, H2BDC‐X (BDC: 1,4‐benzenedicarboxylate), formic acid and N,N‐dimethylacetamide (DMA) having a molar ratio of 1:1:100:104.44, all the UiO‐66‐X compounds, except UiO‐66‐CO2H, were obtained under solvothermal conditions (150 °C, 24 h). The phase purity of all the compounds was ascertained by X‐ray powder diffraction (XRPD) analysis, DRIFT spectroscopy and elemental analysis. Determination of lattice parameters from the XRPD patterns of the new thermally activated UiO‐66‐X {X = CF3 (1‐CF3), (CO2H)2 [2‐(CO2H)2], F2 (3‐F2), Cl2 (4‐Cl2), Br2 (5‐Br2)} compounds revealed their structural similarity with the unfunctionalised UiO‐66. Thermogravimetric analyses (TGA) indicate that the five new compounds are stable in the range 290–390 °C in air. Except for 3‐F2, the new compounds maintain their structural integrity in water, acetic acid and 1 M HCl, as verified by XRPD analysis of the samples recovered after suspending them in the respective liquids. As confirmed by N2 and CO2 sorption analyses, all of the new thermally activated compounds exhibit significant microporosity values (SLangmuir = 217–836 m2 g–1), which are lower than that of the parent UiO‐66. Comparative CO2 sorption studies reveal that the UiO‐66‐X compounds with X = NO2, NH2, OH, CH3 and (CH3)2 show enhanced CO2 uptake compared to that of the parent compound at 1 bar and 0 °C.
Enantioselective Reduction of 3‐Aryl‐2‐oxo‐propanoic Acids: A Comparison of Enzymatic and Transition‐Metal‐Catalyzed Methods
Authors: Lüttenberg Sebastian , Ta Tien Dat , von der Heyden Jan , Scherkenbeck Jürgen
Published: February 2013

Phenyllactic acids are important constituents of depsipeptides, which are a large class of natural products expressing a wide range of biological activities. Despite there being several methods for the enantioselective synthesis of α‐hydroxy acids, almost no studies are available addressing the substrate selectivity of transition‐metal and enzyme‐catalyzed methods for the preparation of substituted phenyllactic or more general aryllactic acids. We report herein comparative results for Rh‐DiPAMP (DiPAMP = 1,2‐ethandiylbis[(o‐methoxyphenyl)phenylphosphane]) and lactate dehydrogenase catalyzed enantioselective reductions of several 3‐aryl‐2‐oxopropanoic acids.
A General Synthesis of Bis‐α‐acyloxy‐1,4‐ and ‐1,5‐diketones Through Catalytic Oxidative Opening of Acylated THF and THP Diols
Authors: Piccialli Vincenzo , D'Errico Stefano , Borbone Nicola , Oliviero Giorgia , Centore Roberto , Zaccaria Sabrina
Published: February 2013

The first general synthesis of bis‐α‐acyloxy‐1,4‐ and ‐1,5‐diketones has been accomplished in a catalytic oxidative opening of bis‐acylated THF and THP (tetrahydropyran) diols, which were synthesised by osmium‐ or ruthenium‐catalysed oxidative cyclisation of 1,5‐ and 1,6‐dienes. The overall sequence corresponds to the regioselective double ketoacyloxylation of the starting diene. The synthesised bis‐α‐acyloxy‐1,5‐dicarbonyl compounds have been transformed into pyridine‐based oxido pincer ligands or pyrazinedimethanol substances, leading to the discovery of unprecedented aromatisation routes.