bluuebunny/crossref_metadata_2025 huggingface dataset:
L’apport d’internet aux petites entreprises (PE) touristiques dans la construction de leur positionnement stratégique : le cas des hébergeurs
Authors: Favre-Bonté Véronique , Tran Sébastien
Published: June 2014

La diffusion des TIC chez les PE demeure faible (Eurostat 2010) et pourtant, parmi les applications IT, Internet est pour les PE une source d’opportunités de développement de leurs affaires (Scaglione, Schegg et Murphy, 2009). L’un des enjeux est donc de savoir si Internet peut être utilisé efficacement par ces petites structures et comment sa mise en oeuvre peut contribuer à améliorer leur positionnement stratégique. Nous avons étudié quatre cas d’entreprises dans l’hébergement touristique qui est un secteur très en avance dans l’utilisation des TIC en général et d’Internet en particulier (Kalika et Rival, 2009 ; Aldebert et Loufrani-Fedida, 2010). Notre recherche montre que les PE peuvent utiliser Internet comme un outil de différenciation, notamment sur les dimensions liées à la relation client (marketing, distribution). La réussite, quant à l’utilisation d’un site Internet, repose sur un choix très judicieux de la technologie par rapport au positionnement de l’entreprise. La mise en place d’une stratégie doit donc se faire à partir d’une véritable réflexion quant au métier de la PE, car cela conditionne les services et les fonctionnalités proposées à partir des technologies. Enfin, ce n’est pas tant le profil technophile qui importe que le profil innovant et preneur de risques du dirigeant et son aptitude à percevoir l’utilité des technologies.
Comment développer l’éveil à la création d’entreprise par la simulation ?
Authors: Lepers Pascale , Vaesken Philippe
Published: June 2014

Parmi les initiatives portées par les grandes écoles et les universités en matière de sensibilisation des étudiants à la création d’entreprise, il existe notamment le Challenge « Projets d’entreprendre », d’abord initié à Évry, puis transposé à Villeneuve d’Ascq. D’autres études destinées à mesurer les intentions et/ou les capacités entrepreneuriales des étudiants ont été réalisées, notamment celles conduites par Boissin, Chollet et Emin (2005), depuis 2005 sur des populations identiques à l’INT d’Évry et à Grenoble, mais aussi Arlotto et Bourcieu (2002), Arlotto et Jourdan (2003), Fayolle, Gailly et Lassas-Clerc. (2006), Léger-Jarniou (2008), dans des contextes similaires.

À partir de l’expérience du Challenge menée à Villeneuve d’Ascq, l’objectif est de faire un retour sur les ambitions et sur les résultats obtenus en matière d’apprentissage, ainsi que sur la manière dont les élèves ingénieurs et les étudiants concernés vivent cette ouverture d’esprit à la création d’entreprise. Cet article insiste surtout sur les capitalisations d’expériences et de connaissances entrepreneuriales qui peuvent être acquises au terme d’une semaine fondée sur une simulation à but, adaptée à la création d’entreprise. Par rapport à ce public composite d’étudiants, celle-ci permet de proposer un modèle pédagogique basé sur les grands thèmes inhérents au développement des capacités entrepreneuriales, à savoir : comprendre, construire, apprendre.
L’influence du profil éthique du propriétaire-dirigeant sur le contenu informatif1 des nombres comptables
Authors: Ngantchou Alexis
Published: June 2014

Depuis les travaux pionniers de Beaver, Ball et Brown en 1968, une abondante littérature s’est développée autour de la problématique du contenu informatif des nombres comptables. Les scandales financiers survenus au début de ce siècle ont eu comme portée, le renouvellement de ce débat. Dans la plupart des cas, la perspective d’analyse retenue par différents travaux empiriques a été celle des entreprises managériales cotées. Dans la mesure où cette perspective d’analyse ne permet pas de saisir l’influence directe des acteurs sur la qualité des chiffres publiés, cet article propose une extension de la problématique des nombres comptables en contexte PME, la question principale étant de savoir si le profil éthique du propriétaire-dirigeant influence le contenu informatif de ces nombres. L’étude empirique porte sur les données comptables d’un échantillon de 93 PME candidates au financement bancaire. Le principal résultat mis en évidence est que les PME rationnées sur le marché du crédit bancaire sont paradoxalement celles dont la valeur comptable des actifs nets est relativement plus élevée. L’analyse permet d’établir que le profil éthique des propriétaires-dirigeants justifie ce résultat.
TIC et performance
Authors: Aldebert Bénédicte , Gueguen Gaël
Published: June 2014

Les recherches sur le lien entre TIC et performance ne permettent pas de trancher sur la nature de ce lien : une relation directe et positive n’est pas systématique. Il semble que c’est au travers de processus organisationnels que les TIC auront un impact sur les performances. En raison du rôle du propriétaire-dirigeant au sein d’une PME, son intérêt pour les TIC ne s’avérera pas neutre. Dès lors, l’objectif de cette recherche est de mieux comprendre le rôle du dirigeant de PME dans les pratiques en matière de technologies de l’information de son entreprise et d’observer les conséquences sur la performance. Plus précisément, nous cherchons à répondre à la question suivante : est-ce que l’intérêt du dirigeant favorise une plus grande utilisation des TIC et par-delà, une meilleure performance ou intervient-il sur l’utilisation des TIC en agissant comme un amplificateur de la qualité de leur utilisation par le personnel ? L’intérêt de cette recherche est d’éclairer la théorie sur le lien entre les TIC et la performance en prenant appui sur un secteur où le management de l’information est crucial. Pour ce faire, nous utiliserons les résultats d’une enquête menée auprès de 123 PME touristiques des Alpes-Maritimes.
Evaluation of an immunoassay for determination of plasma efavirenz concentrations in resource‐limited settings
Authors: Abdissa Alemseged , Wiesner Lubbe , McIlleron Helen , Friis Henrik , Andersen Åse Bengård , Kæstel Pernille
Published: June 2014

Introduction

Therapeutic drug monitoring (TDM) may improve antiretroviral efficacy through adjustment of individual drug administration. This could result in reduced toxicity, prevent drug resistance, and aid management of drug–drug interactions. However, most measurement methods are too costly to be implemented in resource‐limited settings. This study evaluated a commercially available immunoassay for measurement of plasma efavirenz.

Methods

The immunoassay‐based method was applied to measure efavirenz using a readily available Humastar 80 chemistry analyzer. We compared plasma efavirenz concentrations measured by the immunoassay with liquid chromatography tandem mass spectrometry (LC‐MS/MS) (reference method) in 315 plasma samples collected from HIV patients on treatment. Concentrations were categorized as suboptimal<1 µg/ml, normal 1–4 µg/ml or high>4 µg/ml. Agreement between results of the methods was assessed via Bland‐Altman plot and κ statistic values.

Results

The median Interquartile range (IQR) efavirenz concentration was 2.8 (1.9; 4.5) µg/ml measured by the LC–MS/MS method and 2.5 (1.8; 3.9) µg/ml by the immunoassay and the results were well correlated (ρ=0.94). The limits of agreement assessed by Bland–Altman plots were −2.54; 1.70 µg/ml. Although immunoassay underestimated high concentrations, it had good agreement for classification into low, normal or high concentrations (K=0.74).

Conclusions

The immunoassay is a feasible alternative to determine efavirenz in areas with limited resources. The assay provides a reasonable approximation of efavirenz concentration in the majority of samples with a tendency to underestimate high concentrations. Agreement between tests evaluated in this study was clinically satisfactory for identification of low, normal and high efavirenz concentrations.
A comparison of mantle convection models featuring plates
Authors: Stein C. , Lowman J. P. , Hansen U.
Published: June 2014

Oceanic plates are an integral part of the Earth's mantle and thus play an important role in its dynamics and evolution. To allow plate behavior to arise naturally in numerical mantle convection models, self‐consistent plate generation methods apply a fully rheological approach (featuring a temperature‐, pressure‐ and stress‐dependent viscosity). However, due to the extreme local viscosity changes that the self‐generation of model plates entails, their computational requirements are demanding. Alternative plate modeling methods specify the existence of plates explicitly but can also obtain dynamically determined velocities (e.g., by employing a force‐balance method). Here we present modifications to a force‐balance model by utilizing a rheology‐dependent viscosity profile. Accordingly, plate viscosity and plate thickness are no longer prescribed by the modeler but now follow as a dynamic consequence of the temperature and stress dependence of the viscosity and the model's evolution. We describe the new method and present benchmark results for a rheologically self‐consistent mantle convection model and the modified force‐balance plate model. Our results show that both plate modeling methods lead to the same system behavior for a wide range of system parameters making the new method a powerful tool to also achieve plate‐like surface motion naturally.
Evidence for a nitrous acid (HONO) reservoir at the ground surface in Bakersfield, CA, during CalNex 2010
Authors: VandenBoer T. C. , Markovic M. Z. , Sanders J. E. , Ren X. , Pusede S. E. , Browne E. C. , Cohen R. C. , Zhang L. , Thomas J. , Brune W. H. , Murphy J. G.
Published: June 2014

Measurements of HONO(g) and particulate nitrite (NO2−(p)) were made with a modified Ambient Ion Monitor–Ion Chromatography (AIM‐IC) instrument during California at the Nexus of Air Quality and Climate 2010 in Bakersfield, CA (CalNex‐San Joaquin Valley (SJV)). Observations of gas and particulate matter (PM2.5) water‐soluble composition showed accumulation of both species at night, followed by loss the next day. Intercomparison with a Stripping Coil‐UV/Vis Absorption Photometer (SC‐AP) demonstrated excellent agreement with the AIM‐IC HONO(g) measurement (slope = 0.957, R2 = 0.86), and the particulate nitrite observations were validated to be free of known interferences for wet chemical instrumentation. The accumulation of nitrite into particulate matter was found to be enhanced when gaseous mixing ratios of HONO(g) were highest. Reactive uptake of HONO(g) on to lofted dust and the ground surface, forming a reservoir, is a potential mechanism to explain these observations. The AIM‐IC HONO(g) measurements were parameterized in a chemical model to calculate the ground surface daytime HONO(g) source strength at 4.5 m above the surface, found to be on the order of 1.27 ppb h−1, to determine the relative importance of a surface reservoir. If all deposited nighttime HONO(g) is reemitted the following day, up to 30% of the daytime HONO(g) source at CalNex‐SJV may be accounted for. The observations of HONO(g) and NO2−(p) in Bakersfield, during CalNex, suggest a surface sink and source of HONO(g). Extension of currently accepted unknown daytime HONO(g) source reactions to include a potential surface HONO(g) reservoir should therefore be sound, but quantitation of the relative contributions of each surface source toward daytime HONO(g) production remains to be resolved.
Combining regional moist static energy and ENSO for forecasting of early and late season Indian monsoon rainfall and its extremes
Authors: Rajagopalan Balaji , Molnar Peter
Published: June 2014

We exploit El Niño–Southern Oscillation (ENSO) indices and moist static energy of surface air over the Indian subcontinent and surroundings as predictors of monsoon rainfall over India during early and late seasons, defined here as 20 May to 15 June and 20 September to 15 October, respectively. Although these seasons contribute only ~22% of the entire seasonal rainfall, they clearly affect planning of agriculture and water resources. A simple, nonlinear, statistical model applied to these predictors accounts for ~40% and 45% of the observed variance of early and late season rainfall, respectively, and similar fractions for 3 day maximum rainfall intensity. Forecasted average and 3 day maximum rainfall at grid points covering India show greatest success over central India during the early season and over west central, northwestern, and northern India during the late season, regions where agriculture dominates land use. These predictors, however, offer virtually no predictability of peak season rainfall.
Long‐ and short‐term postseismic gravity changes of megathrust earthquakes from satellite gravimetry
Authors: Tanaka Yusaku , Heki Kosuke
Published: June 2014

Using monthly satellite gravimetry data, we studied time‐variable gravity field after three M9 class earthquakes, the 2004 Sumatra‐Andaman, 2010 Chile (Maule), and 2011 Tohoku‐oki earthquakes. The observations showed that the gravity typically (1) decreases coseismically, (2) continues to decrease for a few months, and (3) increases over a longer period. Therefore, postseismic gravity changes have two components with different time constants and polarities. The mechanisms of short‐ and long‐term postseismic gravity changes are not as clear as coseismic changes at the moment, but might be explained to some extent with afterslip and the Maxwell viscoelasticity, respectively. These two components are difficult to discriminate with surface velocity measurements because the forearc area moves trenchward at both stages. They appear in different polarities in gravity, making satellite gravimetry a unique tool to separate them.
Modeling strain and pore pressure associated with fluid extraction: The Pathfinder Ranch experiment
Authors: Barbour Andrew J. , Wyatt Frank K.
Published: June 2014

Strainmeters can be subject to hydrologic effects from pumping of nearby water wells, depending on the state of the local rock. Strain signals associated with hydrology are generally not used and regarded as troublesome because they are much larger than most tectonic signals (e.g., tides or slow slip episodes in Cascadia), but here we show that fluid extraction leads to detectable strain and pore pressure signals, which we use to constrain valuable material properties of the rock, namely the hydraulic diffusivity and elastic shear modulus. We collected multiple years of pump activity at two active water wells near a pair of Plate Boundary Observatory borehole strainmeters in southern California. These data demonstrate clearly the connection between fluid extraction and deformation: the onset of transient strains and pore pressures is strongly correlated with both the onset of fluid extraction, and the sizes of the transient signals are strongly correlated with cumulative extraction volumes. These data also suggest that the instruments are a possible tool for remote monitoring of fluid injection and withdrawal. Based on poroelastic modeling, we find estimates of hydraulic diffusivity (0.061 m2s−1 to 0.126 m2s−1) which are consistent with data for fractured igneous rock, and estimates of shear modulus (39.7 MPa to 101 MPa) which are comparable to data for shallow granodiorite—expected to be weak from weathering, and other sources of damage (e.g., faulting). We infer that crustal rock in this region is drained at shallow depths by pervasive, hydraulically conductive fractures: as a result of changes in applied stress, fluid flow will occur rather than a sustained change in pore fluid pressure.
Current status of CME/shock arrival time prediction
Authors: Zhao Xinhua , Dryer Murray
Published: June 2014

One of the major solar transients, coronal mass ejections (CMEs) and their related interplanetary shocks have severe space weather effects and become the focus of study for both solar and space scientists. Predicting their evolutions in the heliosphere and arrival times at Earth is an important component of the space weather predictions. Various kinds of models in this aspect have been developed during the past decades. In this paper, we will present a view of the present status (during Solar Cycle 24 in 2014) of the space weather's objective to predict the arrival of coronal mass ejections and their interplanetary shock waves at Earth. This status, by implication, is relevant to their arrival elsewhere in the solar system. Application of this prediction status is clearly appropriate for operational magnetospheric and ionospheric situations including A − > B − > C…solar system missions. We review current empirical models, expansion speed model, drag‐based models, physics‐based models (and their real‐time prediction's statistical experience in Solar Cycle 23), and MHD models. New observations in Solar Cycle 24, including techniques/models, are introduced as they could be incorporated to form new prediction models. The limitations of the present models and the direction of further development are also suggested.
Specification of > 2 MeV electron flux as a function of local time and geomagnetic activity at geosynchronous orbit
Authors: Su Yi‐Jiun , Quinn Jack M. , Johnston W. Robert , McCollough James P. , Starks Michael J.
Published: June 2014

An algorithm has been developed for specifying > 2 MeV electron flux everywhere along geosynchronous orbit for use in operational products. The statistics of integrated electron fluxes from four GOESs for more than a solar cycle clearly indicate that the local time variation can be represented by a Gaussian distribution as a function of geomagnetic Kp index, which empirically determines the center and the half width of the Gaussian distribution. Using the most current estimated 3 h Kp value as an input, the prediction scheme requires the most recent electron flux measurements from available GOES(s) to determine the maximum and minimum for a Gaussian fit and to provide estimated electron fluxes at geosynchronous orbit with the time resolution of the instrument. In balancing between sufficient data for statistics and the change of geomagnetic configuration, the optimal length of data accumulation time for nowcasting is 6 h when one or two satellites are available. The prediction efficiency (PE) is independent of local time and solar cycle. We found that the PE values are greater than 0.5 when Kp < 5 and independent of Kp at low and moderate values; however, PE decreases dramatically with increasing Kp when Kp ≥ 5. Although the PE varies from year to year and with the choice of the test satellite, our finding resulted in a PE > 0.6 in 67.6% of the cases and PE > 0.8 more than 23.5% of the time based on our analysis from four GOESs between 1998 and 2009. Moreover, skill scores from our newly developed algorithm are ~90% of the time better than those resulting from a simpler algorithm based on a table provided by O'Brien (2009), indicating a dramatic improvement in predictive capability.
The Metallic Nature of Epitaxial Silicene Monolayers on Ag(111)
Authors: Johnson Neil W. , Vogt Patrick , Resta Andrea , De Padova Paola , Perez Israel , Muir David , Kurmaev Ernst Z. , Le Lay Guy , Moewes Alexander
Published: June 2014

Silicene is a two‐dimensional structure composed of a buckled hexagonal honeycomb lattice of silicon atoms. Freestanding silicene is yet to be synthesized, but epitaxial silicene monolayers have been directly observed or predicted to exist on a number of supporting substrates. Herein the atomic and electronic structures of five distinct epitaxial silicene morphologies on Ag(111) are examined through the complementary techniques of density functional theory and soft X‐ray spectroscopy at the Si L2,3 edge. Hybridization with the Ag(111) substrate is shown to cause these silicene monolayers to become strongly metallic, and the specific electronic interactions that are responsible for this metallic nature are determined. The results imply that epitaxial silicene on Ag(111) does not possess the Dirac cone electronic structure that is characteristic of freestanding silicene and graphene sheets.
Highly Conductive Stretchable and Biocompatible Electrode–Hydrogel Hybrids for Advanced Tissue Engineering
Authors: Sasaki Masato , Karikkineth Bijoy Chandapillai , Nagamine Kuniaki , Kaji Hirokazu , Torimitsu Keiichi , Nishizawa Matsuhiko
Published: June 2014

Hydrogel‐based, molecular permeable electronic devices are considered to be promising for electrical stimulation and recording of living tissues, either in vivo or in vitro. This study reports the fabrication of the first hydrogel‐based devices that remain highly electrically conductive under substantial stretch and bending. Using a simple technique involving a combination of chemical polymerization and electropolymerization of poly (3,4‐ethylenedioxythiophene) (PEDOT), a tight bonding of a conductive composite of PEDOT and polyurethane (PU) to an elastic double‐network hydrogel is achieved to make fully organic PEDOT/PU–hydrogel hybrids. Their response to repeated bending, mechanical stretching, hydration‐dessication cycles, storage in aqueous condition for up to 6 months, and autoclaving is assessed, demonstrating excellent stability, without any mechanical or electrical damage. The hybrids exhibit a high electrical conductivity of up to 120 S cm−1 at 100% elongation. The adhesion, proliferation, and differentiation of neural and muscle cells cultured on these hybrids are demonstrated, as well as the fabrication of 3D hybrids, advancing the field of tissue engineering with integrated electronics.
Structural Distortion and Compositional Gradients Adjacent to Epitaxial LiMn2O4 Thin Film Interfaces
Authors: Gao Xiang , Ikuhara Yumi H. , Fisher Craig A. J. , Moriwake Hiroki , Kuwabara Akihide , Oki Hideki , Kohama Keiichi , Yoshida Ryuji , Huang Rong , Ikuhara Yuichi
Published: June 2014

Thin film electrode materials are key components in the development of high rate, high capacity solid‐state Li‐ion batteries. Detailed knowledge of the epitaxial film/substrate(current‐collector) interface structures, which provides insights into epitaxial growth mechanisms and the effects of microstructure on electrochemical properties, is essential for efficient materials and device design. Here we report the epitaxial growth mechanism of a typical cathodic LiMn2O4 thin film by exploring the detailed structural and compositional variations in the vicinity of a film/substrate interface using state‐of‐the‐art scanning transmission electron microscopy. Direct observation of atom columns shows the epitaxial film forms an atomically flat and coherent heterointerface with the substrate, but that the crystal lattice is tetragonally distorted with a measurable compositional gradient from the interface to the crystal bulk. The growth mechanism is interpreted in terms of a combination of chemical and physicomechanical effects, namely a complex interplay between the internal Jahn‐Teller distortions induced by oxygen non‐stoichiometry and the lattice misfit strain.
High Performance Na0.5[Ni0.23Fe0.13Mn0.63]O2 Cathode for Sodium‐Ion Batteries
Authors: Hasa Ivana , Buchholz Daniel , Passerini Stefano , Scrosati Bruno , Hassoun Jusef
Published: June 2014

The synthesis of a new layered cathode material, Na0.5[Ni0.23Fe0.13Mn0.63]O2, and its characterization in terms of crystalline structure and electrochemical performance in a sodium cell is reported. X‐ray diffraction studies and high resolution scanning electron microscopy images reveal a well‐defined P2‐type layered structure, while the electrochemical tests demonstrate excellent characteristics in terms of high capacity and cycle life. This performance, the low cost, and the environmental compatibility of its component poses Na0.5[Ni0.23Fe0.13Mn0.63]O2 to be among the most promising materials for the next generation of sodium‐ion batteries.
Cranial radiation for pediatric T‐lineage acute lymphoblastic leukemia: A systematic review and meta‐analysis
Authors: Kelly Michael J. , Trikalinos Thomas A. , Dahabreh Issa J. , Gianferante Matthew , Parsons Susan K.
Published: June 2014

There are heterogeneous approaches to cranial radiation therapy (CRT) for T‐lineage acute lymphoblastic leukemia (T‐ALL). We performed a systematic review of studies that specified a radiation strategy and reported survival for pediatric T‐ALL. Our analysis included 62 publications reporting 78 treatment groups (patient n = 5844). The average event‐free survival (EFS) was higher by 6% per 5 years (P < 0.001). Adjusting for year, EFS differed by radiation strategy. Compared to the reference group (CRT for all) which had a year‐adjusted EFS of 65% (95% confidence interval, CI: 61–69%) the adjusted EFS was significantly worse (rate difference (RD) = −9%, 95% CI: −15 to −2%) among studies that used a risk‐directed approach to CRT (P = 0.004). The adjusted EFS for the other strategies were not significantly different compared to the reference group: CRT for central nervous system positive patients only (RD = −3%, 95% CI: −14 to 7%, P = 0.49); CRT omitted for all patients (RD = 5%, 95% CI: −4 to 15%, P = 0.33). CRT may not be necessary with current chemotherapy for T‐ALL. These findings, however, are susceptible to bias and caution should be applied in drawing conclusions on the comparative effectiveness of alternative CRT strategies. Am. J. Hematol. 89:992–997, 2014. © 2014 Wiley Periodicals, Inc.
Autoimmune cytopenias in chronic lymphocytic leukemia
Authors: Visco Carlo , Barcellini Wilma , Maura Francesco , Neri Antonino , Cortelezzi Agostino , Rodeghiero Francesco
Published: June 2014

Chronic lymphocytic leukemia (CLL) is frequently complicated by secondary autoimmune cytopenias (AIC) represented by autoimmune hemolytic anemia (AIHA), immune thrombocytopenia (ITP), pure red cell aplasia, and autoimmune granulocytopenia. The distinction of immune cytopenias from cytopenias due to bone marrow infiltration, usually associated with a worse outcome and often requiring a different treatment, is mandatory. AIHA and ITP are more frequently found in patients with unfavorable biological risk factors for CLL. AIC secondary to CLL respond less favorably to standard treatments than their primary forms, and treating the underlying CLL with chemotherapy or monoclonal antibodies may ultimately be necessary. Am. J. Hematol. 89:1055–1062, 2014. © 2014 Wiley Periodicals, Inc.
Material models of dark energy
Authors: Pearson Jonathan A.
Published: June 2014

A new class of “dark energy” models is reviewed and developed, in which the relativistic theory of solids is used to construct material models of dark energy. These are models which include the effects of a continuous medium with well defined physical properties at the level of linearized perturbations. The formalism is constructed for a medium with arbitrary symmetry, and then specialised to isotropic media (which will be the case of interest for the majority of cosmological applications). The theory of relativistic isotropic viscoelastic media is developed whilst keeping in mind that we ultimately want to observationally constrain the allowed properties of the material model. This is done by obtaining the viscoelastic equations of state for perturbations (the entropy and anisotropic stress), as well as identifying the consistent corner of the theory which has constant equation of state parameter . A connection to the non‐relativistic theory of solids is obtained by identifying the two quadratic invariants that are needed to construct the energy‐momentum tensor, namely the Rayleigh dissipation function and Lagrangian for perturbations. Finally, the notion is developed that the viscoelastic behavior of the medium can be thought of as a non‐minimally coupled massive gravity theory. This also provides a tool‐kit for constructing consistent generalizations of coupled dark energy theories.
Isolierung eines neutralen, Bor‐haltigen Radikals, stabilisiert durch ein cyclisches (Alkyl)(amino)carben
Authors: Bissinger Philipp , Braunschweig Holger , Damme Alexander , Krummenacher Ivo , Phukan Ashwini K. , Radacki Krzysztof , Sugawara Shun
Published: June 2014

Unter Verwendung eines cyclischen (Alkyl)(amino)carben(CAAC)‐Liganden konnten neutrale, CAAC‐stabilisierte Radikale mit einer Borylfunktion durch Reduktion der entsprechenden Halogenboranaddukte erhalten werden. Die Duryl‐substituierte Radikalspezies wurde vollständig mithilfe von Röntgenstrukturanalyse, EPR‐Spektroskopie und DFT‐Rechnungen charakterisiert. Die hier isolierten Spezies weisen eine größere Spindichte auf dem Borzentrum als bekannte Borylradikale auf. Weiterhin erwies sich die Titelverbindung unter inerten Bedingungen in Lösung wie auch im Feststoff als überaus temperaturstabil. Elektrochemische Untersuchungen lassen auf die Erzeugung eines stabilen formalen Borylanions schließen.
Chemical Kinetic Resolution of Unprotected β‐Substituted β‐Amino Acids Using Recyclable Chiral Ligands
Authors: Zhou Shengbin , Wang Jiang , Chen Xia , Aceña José Luis , Soloshonok Vadim A. , Liu Hong
Published: June 2014

The first chemical method for resolution of N,C‐unprotected β‐amino acids was developed through enantioselective formation and disassembly of nickel(II) complexes under operationally convenient conditions. The specially designed chiral ligands are inexpensive and can be quantitatively recycled along with isolation of the target β‐substituted‐β‐amino acids in good yields and excellent enantioselectivity. The method features a broad synthetic generality including β‐aryl, β‐heteroaryl, and β‐alkyl‐derived β‐amino acids. The procedure is easily scaled up, and was used for the synthetically and economically advanced preparation of the anti‐diabetic drug sitagliptin.
Riboswitches Based on Kissing Complexes for the Detection of Small Ligands
Authors: Durand Guillaume , Lisi Samuele , Ravelet Corinne , Dausse Eric , Peyrin Eric , Toulmé Jean‐Jacques
Published: June 2014

Biosensors derived from aptamers were designed for which folding into a hairpin shape is triggered by binding of the cognate ligand. These aptamers (termed aptaswitches) thus switch between folded and unfolded states in the presence and absence of the ligand, respectively. The apical loop of the folded aptaswitch is recognized by a second hairpin called the aptakiss through loop–loop or kissing interactions, whereas the aptakiss does not bind the unfolded aptaswitch. Therefore, the formation of a kissing complex signals the presence of the ligand. Aptaswitches were designed that enable the detection of GTP and adenosine in a specific and quantitative manner by surface plasmon resonance when using a grafted aptakiss or in solution by anisotropy measurement with a fluorescently labeled aptakiss. This approach is generic and can potentially be extended to the detection of any molecule for which hairpin aptamers have been identified, as long as the apical loop is not involved in ligand binding.
Separating Xylene Isomers by Commensurate Stacking of p‐Xylene within Channels of MAF‐X8
Authors: Torres‐Knoop Ariana , Krishna Rajamani , Dubbeldam David
Published: June 2014

The development of energy‐efficient processes for selective separation of p‐xylene from mixtures with its isomers is of vital importance in the petrochemical industries. Current industrial practice uses BaX zeolite that has high adsorption selectivity for p‐xylene. Finding para‐selective structures is challenging. With state‐of‐the‐art simulation methodologies we systematically screened a wide variety of zeolites and metal–organic frameworks (MOFs). Our investigations highlight the crucial importance of the channel dimension on the separation. MAF‐X8 is particularly noteworthy because the channel dimensions and geometry allow “commensurate stacking” which we exploit as a separation mechanism at saturation conditions. Due to a significantly improved capacity compared to BaX, the cycle times for p‐xylene with MAF‐X8 are found to be about a factor of 4.5 longer. This is expected to result in significant process improvements.
Control of Three‐Dimensional Cell Adhesion by the Chirality of Nanofibers in Hydrogels
Authors: Liu Guo‐Feng , Zhang Di , Feng Chuan‐Liang
Published: June 2014

In the three‐dimensional (3D) extracellular matrix (ECM), the influence of nanofiber chirality on cell behavior is very important; the helical nanofibrous structure is closely related to the relevant biological events. Herein, we describe the use of the two enantiomers of a 1,4‐benzenedicarboxamide phenylalanine derivative as supramolecular gelators to investigate the influence of the chirality of nanofibers on cell adhesion and proliferation in three dimensions. It was found that left‐handed helical nanofibers can increase cell adhesion and proliferation, whereas right‐handed nanofibers have the opposite effect. These effects are ascribed to the mediation of the stereospecific interaction between chiral nanofibers and fibronectin. The results stress the crucial role of the chirality of nanofibers on cell‐adhesion and cell‐proliferation behavior in 3D environments.
Effects of rare earth samarium oxide on the properties of polypropylene‐graft‐cardanol grafted by reactive extrusion
Authors: Mao Xinggong , Deng Yi , Lin Jinhuo , Chen Qinhui
Published: June 2014

Rare earth elements can improve the performance of polymers because of their special 4f orbitals. The nucleation and stabilization of radical groups of rare earth particles can affect the structure of polypropylene (PP) and its properties. In this study, samarium oxide (Sm2O3) particles were used as a cocatalyst and nucleating agent in polypropylene‐graft‐cardanol (CAPP) grafted by reactive extrusion. The properties of polypropylene‐graft‐cardanol containing modified Sm2O3 with a titanate coupling agent (CAPPMS) were investigated by ultraviolet–visible spectrometry, polarizing microscopy, differential scanning calorimetry, scanning electron microscopy, universal testing, and capillary rheometry with the reference of CAPP containing unmodified Sm2O3 particles. The results show that the titanate coupling agent (TCA‐401) coated on the surface of the Sm2O3 particles improved the dispersion of the Sm2O3 particles and the adhesion between the Sm2O3 particles and CAPP matrix. The Sm2O3 particles promoted more cardanol to graft onto PP. Acting as nucleator for CAPP, the Sm2O3 particles increased the crystallization rate, increased the melting temperature, and decreased the spherulite size of CAPP. The modified Sm2O3 particles showed a greater effect on the mechanical and rheological properties than the unmodified Sm2O3 particles did. The tensile strength, impact strength and flexural strength of CAPPMS increased by 10 MPa, 0.64 kJ/m2, and 6.5 MPa, respectively, compared to those of CAPP when we used 4.5 mol % modified Sm2O3 particles. The viscosity of CAPPMS increased to a certain extent in the presence of the modified Sm2O3. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41012.
Synthesis and characterization of novel twin‐tailed hydrophobically associated copolymers and their applications to Cr(III) removal from aqueous solutions
Authors: Kuang Wei , Gao Chuanwei
Published: June 2014

Water pollution is one of the most serious environmental problems facing society. The objective of this study was to provide an efficient and inexpensive way of removing Cr(III) from polluted water. Novel twin‐tailed hydrophobically associating copolymers (PAAD) were prepared by micellar copolymerization of acrylamide (AM) and sodium 2‐acrylamido‐2‐methylpropane sulfonate with N,N‐dibutylmethacrylamide in an aqueous solution. The PAAD series, comprising copolymers of different molecular weights (ranged from 1.42 to 1.78 × 106 g/mol) and compositions was characterized by gel permeation chromatography–multiangle laser light scattering, 1H NMR and FTIR spectroscopy, and elemental analysis. The surface activity, morphology, and aggregation properties of PAAD samples were measured by surface tension and dynamic light scattering. A schematic representation of the formation of Cr(OH)3 and its precipitation using PAAD samples as coagulant aid is discussed in the article. In addition, the Cr(OH)3–copolymer interaction, as investigated by precipitation experiments, demonstrated that these copolymers have good Cr(OH)3 binding capacity and potential as coagulant aid for the removal of Cr(III) from polluted water. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41028.
Ethanol‐responsive characteristics of polyethersulfone composite membranes blended with poly(N‐isopropylacrylamide) nanogels
Authors: Song Xiao‐Lu , Xie Rui , Luo Tao , Ju Xiao‐Jie , Wang Wei , Chu Liang‐Yin
Published: June 2014

Ethanol‐responsive smart membranes with different microstructures are prepared from blends of polyethersulfone (PES) and poly(N‐isopropylacrylamide) (PNIPAM) nanogels by immersion precipitation phase inversion method in a convenient and controllable manner. The introduction of PNIPAM nanogels forms the microporous structures on the surface of the top skin layer and on the pore walls of the finger‐like porous sublayer of membranes. The ethanol‐responsive characteristics of the proposed PES composite membranes are systematically investigated. With increasing ethanol concentration in the range from 0 to 15 wt %, the trans‐membrane flux of ethanol solution increases. The microstructures and the resultant ethanol‐responsive characteristics of the composite membranes can be regulated by the content of PNIPAM nanogels blended in the membranes. The more the content of PNIPAM nanogels blended in the membranes, the more the number of the submicron pores is, and thus the better the ethanol‐responsive characteristics of the composite membranes. The proposed ethanol‐responsive smart membranes are expected to be combined with the traditional pervaporation membranes as a smart vavle to achieve continuous and highly efficient ethanol production during the biological fermentation. The preparation technique and results in this study provide valuable guidance for further design and the industrial‐scale fabrication of novel composite membranes for application in ethanol separation systems. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41032.
Compatibilization of kraft lignin‐polyethylene composites using unreactive compatibilizers
Authors: Hu Lei , Stevanovic Tatjana , Rodrigue Denis
Published: June 2014

This article presents a novel approach to compatibilize Kraft lignin with polyethylene that involves the use of modified poly (styrene‐co‐ethylene‐co‐butylene‐co‐styrene) (SEBS) as unreactive compatibilizers. As SEBS shows no compatibilizing effect on Kraft lignin‐polyethylene composites, SEBS was functionalized via nitration followed by amination to obtain nitrated (SEBS‐NO2) and aminated (SEBS‐NH2) SEBS. The compatibilizing effects of SEBS derivatives were studied by means of morphological and mechanical analyses. The results show that SEBS‐NO2 is less effective than SEBS‐NH2, the later displaying comparable compatibilizing efficiency to a commercial reactive compatibilizer based on maleated polyethylene. Overall, compatibilization was found to decrease lignin particle size. Addition of SEBS‐NH2 varying between 1% and 10% improved the tensile strength of composites by up to 96%, elongation at break by up to 64%, and impact strength by up to 48%. Finally, the crystallinity and density of the resulting composites were also studied. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41040.
Graphene oxide reinforced chitosan/polyvinylpyrrolidone polymer bio‐nanocomposites
Authors: El Achaby Mounir , Essamlali Youness , El Miri Nassima , Snik Asmae , Abdelouahdi Karima , Fihri Aziz , Zahouily Mohamed , Solhy Abderrahim
Published: June 2014

Bio‐nanocomposite films based on chitosan/polyvinylpyrrolidone (CS/PVP) and graphene oxide (GO) were processed using the casting/evaporation technique. It has been found that the three components of bio‐nanocomposites can be easily mixed in controlled conditions enabling the formation of thick films with high quality, smooth surface and good flexibility. Structural and morphological characterizations showed that the GO sheets are well dispersed in the CS/PVP blend forming strong interfacial interactions that provide an enhanced load transfer between polymer chains and GO sheets thus improving their properties. It has been found that the water resistance of the CS/PVP blend is improved, and the hydrolytic degradation is limited by addition of 0.75 and 2 wt % GO. The modulus, strength, elongation and toughness of the bio‐nanocomposites are together increased. Herein, the steps to form new bio‐nanocomposite films have been described, taking the advantage of the combination of CS, PVP and GO to design the aforementioned bio‐nanocomposite films, which allow to have extraordinary properties that would have promising applications as eventual packaging materials. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41042.
Timor‐Leste's Pursuit of Inclusive Opportunity
Authors: Sugden Craig
Published: June 2014

The article asks if Timor‐Leste's high rate of economic growth has been matched by progress in reaching the young nation's goal of inclusive opportunity. The answer is ‘yes’. Opportunity is defined as a function of circumstances and policy, and is represented by usage of basic public services. It is concluded that opportunity generally improved for both poorer and richer groups during the first decade of formal independence, and the distribution of opportunity typically moved in favour of the poorer Timorese. A similar pattern of opportunity becoming more inclusive is found in other developing Asian and Pacific economies. Comparisons with these economies suggest that Timor‐Leste is a mid‐range performer. The findings provide encouragement that public policy is heading in the right direction in Timor‐Leste. The findings do, however, suggest that extra effort is needed to target the needs of the poorest Timorese and to raise the quality of government expenditure.
Integriertes Virtuelles Energielabor zur Planung nachhaltiger Projekte
Authors: Bort Bastian , Geißler Marie‐Christine
Published: June 2014

In Zukunft müssen – nach den Anforderungen der europäischen Richtlinie über die Gesamtenergieeffizienz von Gebäuden 2010/31/EU [1] – alle neuen öffentlichen Gebäude ab 2018 und alle anderen neuen Gebäude ab 2020 dem Niedrigstenergiestandard entsprechen. Des Weiteren wird von Bauherren immer häufiger eine nachhaltige Planung und Zertifizierung nach gängigen Zertifizierungssystemen wie dem Deutschen Gütesiegel für Nachhaltiges Bauen (DGNB), dem Leadership in Energy and Environmental Design (LEED) oder der Building Research Establishment Environmental Assessment Method (BREEAM) für Gebäude sowie für ganze Stadtquartiere gefordert. Um diesen Anforderungen gerecht zu werden und eine hohe Nutzungsqualität und einen hohen Qualitätsstandard zu gewährleisten, verfolgen Projektteams einen lebenszyklusorientierten Ansatz zur Optimierung von Gebäuden und Quartieren. Hierfür wurde im Rahmen des EU‐Forschungsprojektes Holistic Energy Efficiency Simulation and Life Cycle Management Of Public Use Facilities (HESMOS; 09/2010‐12/2013) ein Integriertes Virtuelles Energielabor (IVEL) entwickelt, welches derzeit im EU‐Forschungsprojekt Collaborative Holistic Design Laboratory and Methodology for energy‐efficient Embedded Buildings (eeEmbedded 10/2013‐09/2017) weiterentwickelt wird.

Integrated Virtual Energy Laboratory for the design of sustainable projects. According to the European Buildings Directive for the Energy Performance of Buildings 2010/31/EU [1] all new public buildings must correspond to the nearly zero energy standard from 2018 and all other new buildings from 2020. Furthermore, sustainable design and evaluation according to established certification systems such as the German Sustainable Building Certificate (DGNB), the Leadership in Energy and Environmental Design (LEED) or the Building Research Establishment Environmental Assessment Method (BREEAM) is more and more requested by investors for buildings and entire neighbourhood developments. In order, to meet these requirements and to ensure a high quality of the building, project teams pursue a holistic life‐cycle approach to optimize buildings and neighbourhoods. In order to support this optimization process, an Integrated Virtual Energy Laboratory (IVEL) was developed during the EU research project Holistic Energy Efficiency Simulation and Lifecycle Management Of Public Use Facilities (09/2010‐12/2013 HESMOS) and will be further developed in the EU research project Collaborative Holistic Design Laboratory and Methodology for energy‐efficient Embedded Buildings (eeEmbedded 10/2013‐09/2017).
Optimierung des Eigenverbrauchs, der Eigendeckungsrate und der Netzbelastung von einem Mehrfamiliengebäude mit Elektromobilität
Authors: Hall Monika , Dorusch Falk , Geissler Achim
Published: June 2014

An einem kleinen, gut gedämmten Mehrfamilienhaus mit Elektromobilität und einer großen Photovoltaikanlage wird untersucht, welche Verbraucher sich für die Steigerung des Eigenverbrauchs eignen. Das detaillierte Monitoring weist aus, dass hierzu die Wärmepumpe der größte geeignete Einzelverbraucher ist. Mit der Limitierung der Laufzeit der Wärmepumpe auf die Tagesstunden kann gezeigt werden, dass die Gleichzeitigkeit von Elektrizitätsbezug und Photovoltaikertrag erhöht und damit nicht nur die Netzbelastung reduziert, sondern auch die Einspeisespitze zur Mittagszeit geglättet werden. Der thermische Komfort wird dabei nicht beeinflusst. Für die Gesamtbilanzierung des Gebäudes wird anhand der Messdaten die Eigendeckungs‐ und Eigenverbrauchsrate detailliert betrachtet. Verschiedene Bilanzzeiträume und Bilanzierungszeitschritte werden gegenübergestellt. Je kürzer der Bilanzzeitraum und die Zeitschritte gewählt werden, desto geringer sind die Eigendeckungs‐ und Eigenverbrauchsraten. Dies ist ein wichtiger Aspekt bei der Diskussion über die Anforderungen an die Gleichzeitigkeit in Gebäudestandards und normativen Berechnungsvorschriften der Gesamtenergiebilanzierung von Gebäuden.

Optimization of self‐consumption, self‐cover rate and net interaction of an apartment building with electromobility. Based on a small, well insulated multi‐family dwelling with included e‐car and large PV installation the load with the highest potential for increasing self‐consumption is evaluated. The monitoring shows that the heat pump has the highest potential for increasing self‐consumption. The run‐time schedule of the heat pump is limited to daytime hours as a proof of concept. This increases the self‐consumption and decreases the net interaction and also shaves the peak electricity export at noon. The thermal comfort does not decrease, hereby. The self‐consumption rate and self‐cover rate both depend on the balancing time period and the time‐step chosen. This is an important aspect in regard to defining self‐consumption requirements for building labels or energy codes.