bluuebunny/crossref_metadata_2025_split huggingface dataset:
Postseismic GRACE and GPS observations indicate a rheology contrast above and below the Sumatra slab
Authors: Broerse Taco , Riva Riccardo , Simons Wim , Govers Rob , Vermeersen Bert 
Published: June 2015

AbstractMore than 7 years of observations of postseismic relaxation after the 2004 Sumatra‐Andaman earthquake provide an improving view on the deformation in the wide vicinity of the 2004 rupture. We include both Gravity Recovery and Climate Experiment (GRACE) gravity field data that show a large postseismic signal over the rupture area and GPS observations in the back arc region. With increasing time GPS and GRACE show contrasting relaxation styles that were not easily discernible on shorter time series. We investigate whether mantle creep can simultaneously explain the far‐field surface displacements and the long‐wavelength gravity changes. We interpret contrasts in the temporal behavior of the GPS‐GRACE observations in terms of lateral variations in rheological properties of the asthenosphere below and above the slab. Based on 1‐D viscoelastic models, our results support an (almost) order of magnitude contrast between oceanic lithosphere viscosity and continental viscosity, which likely means that the low viscosities frequently found from postseismic deformation after subduction earthquakes are valid only for the mantle wedge. Next to mantle creep, we also consider afterslip as an alternative mechanism for postseismic deformation. We investigate how the combination of GRACE and GPS data can better discriminate between different mechanisms of postseismic relaxation: distributed deformation (mantle creep) versus localized deformation (afterslip). We conclude that the GRACE‐observed gravity changes rule out afterslip as the dominant mechanism explaining long‐wavelength deformation even over the first year after the event.
Equilibrium, kinetics, and thermodynamics of Pd(II) adsorption onto poly(m‐aminobenzoic acid) chelating polymer
Authors: Mildan Elif , Gülfen Mustafa 
Published: June 2015

ABSTRACTThis study describes the equilibrium, kinetics, and thermodynamics of the palladium(II) (Pd(II)) adsorption onto poly(m‐aminobenzoic acid) (p‐mABA) chelating polymer. The p‐mABA was synthesized by the oxidation reaction of m‐aminobenzoic acid monomer with ammonium peroxydisulfate (APS). The synthesized p‐mABA chelating polymer was characterized by FTIR spectroscopy, gel permeation chromatography (GPC), thermal analysis, potentiometric titration, and scanning electron microscopy (SEM) analysis methods. The effects of the acidity, temperature, and initial Pd(II) concentration on the adsorption were examined by using batch adsorption technique. The optimum acidity for the Pd(II) adsorption was determined as pH 2. In the equilibrium studies, it was found that the Pd(II) adsorption capacity of the polymer was to be 24.21 mg/g and the adsorption data fitted better to the Langmuir isotherm than the Freundlich isotherm. The kinetics of the adsorption fitted to pseudo‐second‐order kinetic model. In the thermodynamic evaluation of the adsorption, the ΔG° values were calculated as −16.98 and −22.26 kJ/mol at 25–55°C temperatures. The enthalpy (ΔH°), entropy (ΔS°), and the activation energy (Ea) were found as 35.40 kJ/mol, 176.05 J/mol K, and 61.71 kJ/mol, respectively. The adsorption of Pd(II) ions onto p‐mABA was a spontaneous, endothermic, and chemical adsorption process which is governed by both ionic interaction and chelating mechanisms. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42533.
Novel magnetic polyamic hydrazide nanocomposite: Preparation, characterization, and application for the removal of cd2+ and pb2+ from industrial wastes
Authors: Zargoosh Kiomars , Habibi Hossein , Abdolmaleki Amir , Firouz Kourosh 
Published: June 2015

ABSTRACTIn this work, a novel polymer polyamic hydrazide (PAH) was synthesized via the reaction of terephthalohydrazide with pyromelitic dianhydride. The obtained PAH was characterized with nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared (FT‐IR) spectroscopy and elemental analysis. Finally, a novel magnetic nanocomposite was prepared by immobilization of PAH on the Fe3O4 nanoparticles in water. The prepared magnetic nanocomposite was successfully used for selective removal of Pb2+ and Cd2+ ions from industrial wastes and the effects of affecting parameters on the adsorption capacity of the magnetic nanocomposite adsorbent for the removal of Pb2+ and Cd2+ from model aqueous solutions were investigated. The maximum adsorption capacities of Pb2+ and Cd2+ were found to be 138.9 and 103.1 mg g−1, respectively. The kinetics and mechanism of the adsorption of Pb2+ and Cd2+ on the surface of the prepared nanocomposite were studied and it was found that complex formation between active sites of the surface of the nanocomposite and metal ions is the possible mechanism for adsorption of metal cations. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42538.
Preparation and characterization of octadecane/polyurea nanocapsule‐embedded poly(ethylene oxide) nanofibers
Authors: Kook Jun‐Won , Cho Wonseok , Koh Won‐Gun , Cheong In Woo , Kim Jung Hyun 
Published: June 2015

ABSTRACTThis article describes the preparation and characterization of latent heat storage poly(ethylene oxide) nanofibers (LHS‐PEO nanofibers) with octadecane/polyurea (PCM/PU) nanocapsules. PCM/PU nanocapsules were prepared by interfacial polycondensation from toluene 2,4‐diisocyanate and ethylene diamine in a resin‐fortified emulsion system. LHS‐PEO nanofibers were prepared using an electrospinning procedure with varying PCM/PU nanocapsules content, i.e., from 0 to 8 wt %. The PCM/PU nanocapsules were polydisperse with an average diameter of 200 nm. The melting and freezing temperatures were determined as 23.7 and 28.2°C, respectively, and the corresponding latent heats were determined as 123.4 and 124.1 kJ kg−1, respectively. The encapsulation efficiency of the PCM/PU nanocapsules was 78.1%. The latent heat capacity of the LHS‐PEO nanofibers increased as the PCM/PU nanocapsules content increased. Defects, such as holes and disconnection of the nanofibers, were observed, particularly inside the LHS‐PEO nanofibers. For packaging applications, mats were fabricated from the nanocapsules‐embedded nanofibers with varying nanocapsule content and the mats’ surface temperatures were monitored with a thermal imaging camera. The results proved the feasibility of using the LHS‐PEO nanofibers for thermal energy storage and functional packaging materials. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42539.
Crystallization and melting behavior of partially miscible six‐armed poly(l‐lactic acid)/poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) blends
Authors: Jiang Ni , Abe Hideki 
Published: June 2015

ABSTRACTThe crystallization kinetics and spherulitic morphology of six‐armed poly(L‐lactic acid) (6a‐PLLA)/poly(3‐hydroxybutyrate‐co−3‐hydroxyvalerate) (PHBV) crystalline/crystalline partially miscible blends were investigated with differential scanning calorimetry and polarized optical microscopy in this study. Avrami analysis was used to describe the isothermal crystallization process of the neat polymers and their blends. The results suggest that blending had a complex influence on the crystallization rate of the two components during the isothermal crystallization process. Also, the crystallization mechanism of these blends was different from that of the neat polymers. The melting behavior of these blends was also studied after crystallization at various crystallization temperatures. The crystallization of PHBV at 125°C was difficult, so no melting peaks were found. However, it was interesting to find a weak melting peak, which arose from the PHBV component for the 20/80 6a‐PLLA/PHBV blend after crystallization at 125°C, and it is discussed in detail. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42548.
Influence of new thermoplastic sizing agents on the mechanical behavior of poly(ether ketone ketone)/carbon fiber composites
Authors: Giraud Isabelle , Franceschi Sophie , Perez Emile , Lacabanne Colette , Dantras Eric 
Published: June 2015

ABSTRACTIn this study, unidirectional poly(ether ether ketone)/carbon fiber (CF) composite sheets were elaborated with unsized, epoxy‐sized, and thermoplastic‐sized CFs by hot‐press molding. The thermoplastic sizings that we used were poly(ether imide) (PEI) and poly(ether ketone ketone) oligomer aqueous dispersions. Scanning electron microscopy observation of the composites freeze fractures showed that unlike unsized or epoxy‐sized CFs, the thermoplastic sizings improved the interaction between the fibers and the matrix. A comparative study of the mechanical relaxations by dynamic mechanical analysis was carried out on the different composites before and after immersion in kerosene. At low temperature, the PEI sizing had a significant influence on the β relaxation, particularly after kerosene immersion. The thermoplastic sizings did not modify the glass‐transition temperature but improved the kerosene resistance on the composites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2015,132, 42550.
Association of long‐term tacrolimus (FK506) therapy with abnormal megakaryocytosis, bone marrow fibrosis, and dyserythropoiesis
Authors: Yang Zhongbo , Loew Thomas , Hammer Richard D. 
Published: June 2015

Key Clinical MessageHaematopoietic abnormalities associated with tacrolimus are relatively rare with reversible pure red cell aplasia being the most common. We report for the first time, to our best knowledge, tacrolimus therapy associated with bone marrow fibrosis, abnormal megakaryocytosis, and dyserythopoiesis in a 17‐year‐old male treated with tacrolimus for nephrotic syndrome.
Selective Aromatic Hydroxylation with Dioxygen and Simple Copper Imine Complexes
Authors: Becker Jonathan , Gupta Puneet , Angersbach Friedrich , Tuczek Felix , Näther Christian , Holthausen Max C. , Schindler Siegfried 
Published: June 2015

AbstractThe formation of a bis(μ‐oxido)dicopper complex with the ligand 2‐(diethylaminoethyl)‐6‐phenylpyridine (PPN) and its subsequent hydroxylation of the pendant phenyl group (studied earlier by Holland et al., Angew. Chem. Int. Ed.­ 1999, 38, 1139–1142) has been reinvestigated to gain a better understanding of such systems in view of the development of new synthetic applications. To this end, we prepared a simple copper imine complex system that also affords selective o‐hydroxylation of aromatic aldehydes by using dioxygen as the oxidant: Applying the ligand N′‐benzylidene‐N,N‐diethylethylenediamine (BDED), salicylaldehyde was prepared in good yields and we show that this reaction also occurs through an intermediate bis‐μ‐oxido copper complex. The underlying reaction mechanism for the PPN‐supported complex was studied at the BLYP‐D/TZVP level of density functional theory and the results for representative stationary points along reaction paths of the BDED‐supported complex reveal a closely related mechanistic scenario. The results demonstrate a new facile synthetic way to introduce OH groups into aromatic aldehydes.
Green and Straightforward Modification of Graphite Electrode via In Situ Synthesis of Graphene Nanosheets for Quantifying Prazosin Hydrochloride in Urine Samples and Pharmaceutical Formulations
Authors: Rabieh Sasan , Koushanpour Ashkan , Tajabadi Fariba 
Published: June 2015

AbstractA sensitive electrochemical sensor based on in situ modification of graphite electrode via graphene nanosheets (GNs) was developed as a green method for prazosin hydrochloride (PRA) analyses. In this study, GNs were electrochemically synthesized on the surface of graphite electrode via in situ approach and used for the analyses. The proposed sensor showed several advantages such as high sensitivity, low LOD, and excellent repeatability. The oxidation peak current at the optimum analytical conditions using a GNs/graphite electrode at pH 6.0 was linearly dependent on PRA concentration in the range of 0.09–100 µM. A LOD of 0.02 µM and RSD of 3.8 % for 10 µM solution of PRA with a great recovery were obtained.
The Early Millennium Slowdown: Replicating the Peersman (2005) Results
Authors: Grant Angelia L. 
Published: June 2015

SummaryThis paper undertakes both a narrow and wide replication of the constant coefficients vector autoregression (VAR) identified with sign restrictions considered by Peersman (Journal of Applied Econometrics2005;20(2): 185–207. His results for the US are robust to an increase in the sample period from 2002:Q2 to 2014:Q2, but the extension to time‐varying parameters highlights the importance of testing the robustness of results against time variation. In particular, there are differences across models regarding the role of individual shocks during the 2001 US slowdown. Copyright © 2015 John Wiley & Sons, Ltd.
3D nonlinear transient field‐circuit modeling of inductive fault current limiters
Authors: Cvoric Dalibor , Lahaye Domenico , de Haan Sjoerd , Ferreira Braham 
Published: June 2015

SummaryDue to increasing levels of fault currents, fault current limiters (FCLs) are expected to play an important role in the protection of future power grids. Inductive saturable FCLs are particularly interesting due to their inherent reaction on the fault. Many different configurations have been proposed in literature. Being difficult or impossible to create accurate analytical models of some FCL configurations, the development of finite element (FE) models for inductive FCLs is required. This paper presents a 3D nonlinear transient FE modeling technique applied to two inductive FCLs, namely the so‐called open‐core and three‐leg single‐core FCLs. The models have been validated by comparing simulation results with lab measurements. Results show excellent agreement. The models constitute a valuable tool for design, optimization, and verification of inductive FCLs. Copyright © 2015 John Wiley & Sons, Ltd.
Algorithmically imposed thermodynamic compliance for material models in mechanical simulations using the AIM method
Authors: Dunant C. F. , Bentz E. C. 
Published: June 2015

SummaryThermodynamic irreversibility can be imposed on empirical material behaviour by using an appropriate algorithm which takes the path‐dependence of the degradation process into account. This new algorithm, Algorithmically Imposed Mechanics (AIM), for algorithmically irreversible mechanics, is described, and the convergence and unicity of the solutions obtained are proven. AIM is applicable to a range of mechanical behaviour and is demonstrated to work in conjunction with non‐local damage with rotating cracks as well as a mixed plastic and damage behaviour. Copyright © 2015 John Wiley & Sons, Ltd.
On image gradients in digital image correlation
Authors: Neggers J. , Blaysat B. , Hoefnagels J. P. M. , Geers M. G. D. 
Published: June 2015

SummaryIn digital image correlation (DIC), the unknown displacement field is typically identified by minimizing the linearized form of the brightness conservation equation, while the minimization scheme also involves a linearization, yielding a two‐step linearization with four implicit assumptions. These assumptions become apparent by minimizing the non‐linear brightness conservation equation in a consistent mathematical setting, yielding a one‐step linearization allowing a thorough study of the DIC tangent operator. Through this analysis, eight different image gradient operators are defined, and the impact of these alternative image gradients on the accuracy, efficiency, and initial guess robustness is discussed on the basis of a number of academic examples and representative test cases. The main conclusion is that for most cases, the image gradient most common in literature is recommended, except for cases with: (1) large rotations; (2) initial guess instabilities; and (3) costly iterations due to other reasons (e.g., integrated DIC), where a large deformation corrected mixed gradient is recommended instead. Copyright © 2015 John Wiley & Sons, Ltd.
Adaptation of micro‐diffusion method for the analysis of15N natural abundance of ammonium in samples with small volume
Authors: Zhang Shasha , Fang Yunting , Xi Dan 
Published: June 2015

RationaleThere are several preparation methods for the measurement of the nitrogen (N) isotopic composition of ammonium (NH4+) in different types of samples (freshwater, saltwater and soil extracts). The diffusion method is the most popular and it involves NH4+in solutions being released under alkaline conditions and then immediately trapped by an acidified filter. However, the traditional preparation is designed for samples with large volume and relatively high N concentrations. The performance of diffusion for small‐volume samples (e.g., a few milliliters) remains unknown.MethodsWe examined the overall performance of micro‐diffusion on 5 mL samples on varying the incubation time, temperature and initial NH4+concentration. The trapped ammonia was chemically converted into nitrous oxide (N2O) with hypobromite and hydroxylamine in sequence. The produced N2O was analyzed by a commercially available purge and cryogenic trap system coupled to an isotope ratio mass spectrometer.ResultsWe found that diffusion can be complete with no more than 7 days of treatment at 37 °C. Increasing the temperature to 50 °C and the incubation time to 11 days did not improve the overall performance. There were no significant differences in the overall performance during diffusion with NH4+concentrations from 15 to 60 μM. The blank size was relatively large, and the N contamination might come from the reagents especially KCl salts.ConclusionsThe method presented here combines micro‐diffusion and hypobromite oxidation and hydroxylamine reduction. It is suitable for samples with small volume and low NH4+concentrations. Our study demonstrates that the NH4+concentrations in samples can be as low as 15 μM, and a volume of 5 mL is sufficient for this method. We suggest that this method can be used for the routine determination of15N/14N for either natural abundance or15N‐enriched NH4+. Copyright © 2015 John Wiley & Sons, Ltd.
On the formation of SFn– (n = 1–6) anions via a novel route and their properties
Authors: Mane Rupali , Mehrotra Nitin , Maity Dilip K. , Gupta Anit K. 
Published: June 2015

RationaleSulfur hexafluoride (SF6) being a potential greenhouse gas, coupled with its numerous applications, makes the study of the formation and fragmentation of SF6‐based species important. The formation of SF6‐based anionic species has been studied using the gas feed‐sputtering route and the mechanisms at play during the sputter‐ejection of guest molecule‐derived particles have also been probed.MethodsStudies of the formation of SFn– (n = 1–6) anions were conducted from various surfaces (metal and compound) that were subjected to Cs+ ion sputtering in the presence of SF6 gas employing the gas feed‐cesium sputter technique. The anions generated were mass analyzed using a double‐focusing magnetic sector mass spectrometer. Quantum mechanical computations were performed to study the ground state structure and stability of neutral and negatively charged SFn (n = 1–6) systems applying density functional theory (DFT) and ab initio methods (MP2 and CC).ResultsThis technique readily generated 32SFn– (n = 1–6) anions for all sizes of 'n' with practicable yields. Mass spectrometric measurements of the yield of sputter‐ejected 32SFn– (n = 1–6) anions reveal an oscillatory pattern as a function of 'n', with odd values of 'n' being relatively more abundant. The relative yield of 34SFn– (n = 1–6) anions with respect to size was also measured albeit with low signal intensity. Also observed were F–, S–, F2–, 33SF5– and 33SF6– anionic species. The relevant electron affinity and bond dissociation energy (BDE) values were also computed.ConclusionsGas‐phase SFn– (n = 1–6) anions can be effectively generated by using the gas spray‐cesium sputter technique. Both experimental measurements and calculations indicate the existence of odd–even oscillations in the stability and electronic structure of the SFn (n = 1–6) systems. The highest yield recorded was for the sputter‐ejected SF5– species and this may be attributed to its 'superhalogen' anionic character coupled with the relatively favorable F0 fragmentation pathway of sputtered SF6–. A signature pertaining to intact SF6– anion ejection is also observed. Copyright © 2015 John Wiley & Sons, Ltd.
The prevalence of mental health morbidity and its associated factors among women attending a prenatal clinic in Tanzania
Authors: Mahenge Bathsheba , Stöckl Heidi , Likindikoki Samuel , Kaaya Sylvia , Mbwambo Jessie 
Published: June 2015

AbstractObjectiveTo establish the prevalence of symptoms of anxiety, depression, and post‐traumatic stress disorder (PTSD) among women attending prenatal care in Tanzania, and identify associated factors.MethodsA cross‐sectional study was conducted of one in five physically well women attending a prenatal‐care clinic in Muhimbili National Hospital, Dar es Salaam, between December 2011 and April 2012. Trained research assistants carried out face‐to‐face interviews using a structured questionnaire. The Hopkins Symptoms Checklist and the PTSD Diagnostic Scale were used to establish levels of depression and anxiety symptoms.ResultsAmong the 1180 women interviewed, 905 (76.7%) had symptoms of anxiety, 923 (78.2%) had symptoms of depression, and 58 (4.9%) had moderate/severe PTSD symptoms. After adjustment for women's sociodemographic characteristics, age of the woman and their partner, educational level of the woman and their partner, relationship duration, employment, and marital status were associated with symptoms of at least one of the three mental disorders (P< 0.05 for all).ConclusionMany pregnant women had symptoms of mental health disorders. Screening of mental health disorders during prenatal care and training of healthcare providers are needed.