bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geomagnetic paleointensity in historical pyroclastic density currents: Testing the effects of emplacement temperature and postemplacement alteration
Authors: Bowles Julie A. , Gee Jeffrey S. , Jackson Mike J. , Avery Margaret S. 
Published: October 2015

AbstractThellier‐type paleointensity experiments were conducted on welded ash matrix or pumice from the 1912 Novarupta (NV) and 1980 Mt. St. Helens (MSH) pyroclastic density currents (PDCs) with the intention of evaluating their suitability for geomagnetic paleointensity studies. PDCs are common worldwide, but can have complicated thermal and alteration histories. We attempt to address the role that emplacement temperature and postemplacement hydrothermal alteration may play in nonideal paleointensity behavior of PDCs. Results demonstrate two types of nonideal behavior: unstable remanence in multidomain (MD) titanomagnetite, and nonideal behavior linked to fumarolic and vapor phase alteration. Emplacement temperature indirectly influences MSH results by controlling the fraction of homogenous MD versus oxyexsolved pseudo‐single domain titanomagnetite. NV samples are more directly influenced by vapor phase alteration. The majority of NV samples show distinct two‐slope behavior in the natural remanent magnetization—partial thermal remanent magnetization plots. We interpret this to arise from a (thermo)chemical remanent magnetization associated with vapor phase alteration, and samples with high water content (>0.75% loss on ignition) generate paleointensities that deviate most strongly from the true value. We find that PDCs can be productively used for paleointensity, but that—as with all paleointensity studies—care should be taken in identifying potential postemplacement alteration below the Curie temperature, and that large, welded flows may be more alteration‐prone. One advantage in using PDCs is that they typically have greater areal (spatial) exposure than a basalt flow, allowing for more extensive sampling and better assessment of errors and uncertainty.
Impacts of tides on tsunami propagation due to potential Nankai Trough earthquakes in the Seto Inland Sea, Japan
Authors: Lee Han Soo , Shimoyama Tomohisa , Popinet Stéphane 
Published: October 2015

AbstractThe impacts of tides on extreme tsunami propagation due to potential Nankai Trough earthquakes in the Seto Inland Sea (SIS), Japan, are investigated through numerical experiments. Tsunami experiments are conducted based on five scenarios that consider tides at four different phases, such as flood, high, ebb, and low tides. The probes that were selected arbitrarily in the Bungo and Kii Channels show less significant effects of tides on tsunami heights and the arrival times of the first waves than those that experience large tidal ranges in inner basins and bays of the SIS. For instance, the maximum tsunami height and the arrival time at Toyomaesi differ by more than 0.5 m and nearly 1 h, respectively, depending on the tidal phase. The uncertainties defined in terms of calculated maximum tsunami heights due to tides illustrate that the calculated maximum tsunami heights in the inner SIS with standing tides have much larger uncertainties than those of two channels with propagating tides. Particularly in Harima Nada, the uncertainties due to the impacts of tides are greater than 50% of the tsunami heights without tidal interaction. The results recommend simulate tsunamis together with tides in shallow water environments to reduce the uncertainties involved with tsunami modeling and predictions for tsunami hazards preparedness.
The source of the Leeuwin Current seasonality
Authors: Ridgway K. R. , Godfrey J. S. 
Published: October 2015

AbstractThe seasonal circulation around the southwestern boundary of Australia is documented using sea level anomalies from satellite altimetry. Results extrapolated to the coast agree closely with tide gauge observations indicating that seasonal altimeter fields are realistic. Monthly sea level maps identify an annual propagating wave along a waveguide extending along the shelf edge, from the Gulf of Carpentaria to southern Tasmania. The annual sea level pulse does not originate from the Pacific Ocean, as annual Pacific sea level variations are completely out of phase with signals south of the Indonesian archipelago. The presence of a phase discontinuity is demonstrated in annual sea level, temperature, and salinity observations. The origin of the Leeuwin Current seasonality is in the Gulf of Carpentaria where monsoonal winds drive a massive buildup of sea level from November to December. During December–February, a sea level “pulse” emerges from the region, and rapidly propagates poleward along the western and southern Australian boundary. In the broad shelf region centered at 19°S, an independent process forms a high sea level feature when a positive heat flux anomaly induces an annual increase in sea surface temperature which is rapidly mixed through the water column by the strong regional tides. In March, the winds relax and switch to a downwelling favorable alongshore component. In this period, the sea level pulse is essentially in a quasi‐static equilibrium with the annual propagating wind systems. The change in cross‐shelf sea level gradient along the 8000 km path length at the western and southern boundaries, drives the seasonal changes in the Leeuwin Current flow.
Improved Thermal Conductivity of Poly(trimethylene terephthalate‐block‐poly(tetramethylene oxide) Based Nanocomposites Containing Hybrid Single‐Walled Carbon Nanotubes/Graphene Nanoplatelets Fillers
Authors: Paszkiewicz Sandra , Szymczyk Anna , Pilawka Ryszard , Przybyszewski Bartlomiej , Czulak Andrzej , RosŁaniec Zbigniew 
Published: October 2015

ABSTRACTThe thermal conductivity of poly(trimethylene terephthalate‐block‐poly(tetramethylene oxide) copolymer (PTT‐PTMO)–based nanocomposites filled with the hybrid system of nanofillers, including single‐walled carbon nanotubes (SWCNT) and graphene nanoplatelets (GNP) is studied. At the same loading, SWCNT provided greater thermal conductivity enhancement when added to thermoplastic elastomer matrix when compared to GNP. Moreover, SEM images showed that SWCNT and GNP were well dispersed in PTT‐PTMO, suggesting that in situ polymerization is a highly efficient method for preparing hybrid nanocomposites with low loading of carbon nanofillers. To further improve thermal conductivity of PTT‐PTMO–based nanocomposites, a hybrid SWCNT/GNP was used. When the ratio of SWCNT to GNP was 5:1, i.e. 0.5 wt% of SWCNT and 0.1 wt% of GNP, the PTT‐PTMO–based nanocomposites exhibited the highest thermal conductivity of 0.30 W/m·K, higher than that filled with SWCNT and GNP alone. This suggests that the combination of two types of nanofillers, which differ in shape, allows obtaining the synergistic effect for the thermal conductivity enhancement of PTT‐PTMO.
Single‐Molecule Spin Switch Based on Voltage‐Triggered Distortion of the Coordination Sphere
Authors: Harzmann Gero D. , Frisenda Riccardo , van der Zant Herre S. J. , Mayor Marcel 
Published: October 2015

AbstractHere, we report on a new single‐molecule‐switching concept based on the coordination‐sphere‐dependent spin state of FeII species. The perpendicular arrangement of two terpyridine (tpy) ligands within heteroleptic complexes is distorted by the applied electric field. Whereas one ligand fixes the complex in the junction, the second one exhibits an intrinsic dipole moment which senses the E field and causes the distortion of the FeII coordination sphere triggering the alteration of its spin state. A series of complexes with different dipole moments have been synthesized and their transport features were investigated via mechanically controlled break‐junctions. Statistical analyses support the hypothesized switching mechanism with increasing numbers of junctions displaying voltage‐dependent bistabilities upon increasing the FeII complexes’ intrinsic dipole moments. A constant threshold value of the E field required for switching corroborates the mechanism.
The Synthesis of B2(SIDip)2 and its Reactivity Between the Diboracumulenic and Diborynic Extremes
Authors: Böhnke Julian , Braunschweig Holger , Dellermann Theresa , Ewing William C. , Hammond Kai , Jimenez‐Halla J. Oscar C. , Kramer Thomas , Mies Jan 
Published: October 2015

AbstractA new compound with the formula L‐B2‐L wherein the stabilizing ligand (L) is 1,3‐bis[diisopropylphenyl]‐4,5‐dihydroimidazol‐2‐ylidene (SIDip) has been synthesized, isolated, and characterized. The π‐acidity of the SIDip ligand, intermediate between the relatively non‐acidic IDip (1,3‐bis[diisopropylphenyl]imidazol‐2‐ylidene) ligand and the much more highly acidic CAAC (1‐[2,6‐diisopropylphenyl]‐3,3,5,5‐tetramethylpyrrolidin‐2‐ylidene) ligand, gives rise to a compound with spectroscopic, electrochemical, and structural properties between those of L‐B2‐L compounds stabilized by CAAC and IDip. Reactions of all three L‐B2‐L compounds with CO demonstrate the differences caused by their respective ligands, as the π‐acidities of the CAAC and SIDip carbenes enabled the isolation of bis(boraketene) compounds (L(OC)B‐B(CO)L), which could not be isolated from reactions with B2(IDip)2. However, only B2(IDip)2 and B2(SIDip)2 could be converted into bicyclic bis(boralactone) compounds.
Synthesis of a cellulose‐based hydrogel network: Characterization and study of urea fertilizer slow release
Authors: Mohammadi‐Khoo Shahin , Moghadam Peyman Najafi , Fareghi Amir Reza , Movagharnezhad Nasim 
Published: October 2015

ABSTRACTIn the present study, we synthesized a low‐cost biodegradable hydrogel based on cellulose in order to perform controlled release of fertilizer. For this purpose, the cellulose was modified and crosslinked with urea. Then the prepared hydrogel underwent loading with the fertilizer in order to study the controlled release. Characterization of the samples was carried out by Fourier Transform Infrared (FT‐IR) spectroscopy, elemental analysis, thermal gravimetric analysis (TGA), and scanning electron microscopy (SEM). The hydrogel showed a good swelling behavior in distilled water, tap water, and 0.9% NaCl solution. Besides, water holding and water retention behavior of the hydrogel was investigated. Finally, the release of fertilizer from the loaded hydrogel was studied and showed excellent controlled release. According to the results, this hydrogel can be employed as a suitable moisture‐holding additive in the soil for agricultural purposes. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42935.
Näherungsverfahren für das Torsionsmoment aus Kippstabilisierung bei Brettschichtholzträgern
Authors: Hofmann Reiner , Kuhlmann Ulrike 
Published: October 2015

AbstractWährend es für die Bemessung von Horizontalverbänden bekannte Ansätze für die Stabilisierungslasten gibt, wird das infolge Kippen im Trägerquerschnitt an der Gabellagerung entstehende Torsionsmoment, wenn überhaupt, nur sehr grob abgeschätzt. Zu dieser Thematik wurden umfangreiche numerische Untersuchungen an parallelgurtigen geraden Trägern, an parallelgurtigen Trägern mit angehobenem Untergurt und an Satteldach‐ und Fischbauchträgern mit und ohne seitliche Stützung des Druckgurts durch Horizontalverbände durchgeführt. Auf der Grundlage der durchgeführten Untersuchungen konnte ein Näherungsansatz für die Bestimmung des Torsionsmoments aus Kippstabilisierung erarbeitet werden. Der Schubspannungsnachweis kippgefährdeter Träger kann damit unter Berücksichtigung des Torsionsmoments aus Kippstabilisierung geführt werden, ohne dass die Schnittgrößen nach Biegetorsionstheorie II. Ordnung dafür bestimmt werden müssen.A simplified design method for the torsional moment caused by stability effects of glued laminated timber beamsIn contrast to stabilizing forces on horizontal bracing for the torsional moment caused by lateral torsional buckling of glued laminated timber beams in the cross section next to the support only a very rough estimation exists. Therefore a considerable number of numerical calculations have been realized for straight single span girders with parallel chords, for single span girders with raised lower chords and for saddle roof and fish‐bellied girders with or without considering horizontal bracings supporting the upper chords of the girders. On the basis of the results of these studies a simplified design method for the torsional moment could be derived. Thereby the verification of shear considering the torsional moment caused by stability effects may be realized without using a calculation according to second order theory.
Using simulators for teaching computer organization and architecture
Authors: Prasad P. W. C. , Alsadoon Abeer , Beg Azam , Chan Anthony 
Published: October 2015

ABSTRACTAn important problem in teaching the subjects of Computer Architecture and Organization (CO&CA) is the linking of the theoretical knowledge with the practical experience. Visualization of different computer hardware architectures with the use of the simulators enhances the learning process among students. Many useful computer simulators can help address this issue by covering various aspects of CO&CA. The programs range from simple simulators to specific teaching tools to advanced and specialized software. We assessed several simulators and selected one that was freely available and that enabled the students to learn the concepts to the fullest. This paper describes our experience of incorporating simulation tools into teaching the CO&CA to information technology and computing students. We demonstrate that the use of simulators helped students understand better how a computer was constructed and how it functioned internally. © 2015 Wiley Periodicals, Inc. Comput Appl Eng Educ 24:215–224, 2016; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21699
Introducing the super consumer
Authors: Flynn Leisa Reinecke , Goldsmith Ronald Earl 
Published: October 2015

AbstractThe purpose of this study is to propose a new perspective on classifying or segmenting consumers by describing a minority of them who are uniquely motivated by high levels of status seeking, brand identification, and materialism. We term this segment of individuals “super consumers.” The data came from an online survey of 351 adult US consumers. A cluster analysis using these three variables as criteria produced a two‐cluster solution. Comparing mean scores between these two groups of consumers on measures of market mavenism, shopping frequency, amount of spending, age, and gender showed that the super consumers were significantly more likely to be market mavens, to shop more frequently, and to spend more than the other consumers were. The super consumers were younger in age as well, but there were no gender differences between the two groups. Copyright © 2015 John Wiley & Sons, Ltd.
Learning curves for transfemoral transcatheter aortic valve replacement in the PARTNER‐I trial: Success and safety
Authors: Minha Sa'ar , Waksman Ron , Satler Lowell P. , Torguson Rebecca , Alli Oluseun , Rihal Charanjit S. , Mack Michael , Svensson Lars G. , Rajeswaran Jeevanantham , Blackstone Eugene H. , Tuzcu E. Murat , Thourani Vinod H. , Makkar Raj , Ehrlinger John , Lowry Ashley M. , Suri Rakesh M. , Greason Kevin L. , Leon Martin B. , Holmes David R. , Pichard Augusto D. 
Published: October 2015

ObjectivesTo identify number of cases needed to maximize device success and minimize adverse events after transfemoral transcatheter aortic valve replacement (TF‐TAVR), and determine if adverse events were linked to the technical performance learning curve.BackgroundTF‐TAVR is a complex procedure with an incompletely characterized learning curve for clinical outcomes.MethodsFrom 4/2007–2/2012, 1521 patients underwent TF‐TAVR in the PARTNER‐I trial. Outcomes learning curves were defined as number of cases needed to reach a plateau for device success, adverse events, and post‐procedure length of stay. Institutional variation was accounted for by mixed‐model non‐linear techniques, which were also used to identify contribution of the procedure time learning curve to 30‐day major adverse events and length of stay.ResultsEighty percent device success was achieved after 22 cases; major vascular complications fell below 5% after 70 cases and major bleeding below 10% after 25 cases. It took an average of 28 cases to achieve a consistent low risk of 30‐day major adverse events, but institutions entering in the middle of the trial achieved it after about 26. The most significant correlate of 30‐day major adverse events and post‐procedure length of stay was procedure time (P < 0.0001). However, this association was related to patient and unmeasured variables, not the procedure time learning curve (P = 0.6).ConclusionsBy end of trial, a consistent low risk of adverse events was achieved after ∼26 cases. However, these improved results were due to change in patient risk profile; outcomes were not linked to the technical performance learning curve. © 2015 Wiley Periodicals, Inc.
Recanalization of chronic total coronary occlusions—high success rate despite a restrictive use of the retrograde approach
Authors: Bijuklic Klaudija , Schwencke Carsten , Schofer Joachim 
Published: October 2015

AimThe retrograde approach in chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is increasingly being used as a first‐line intervention despite a higher radiation exposure, contrast volume, and a higher major adverse cardiac event (MACE) rate compared with the antegrade approach.It was aimed to evaluate the overall success rate of CTO‐PCI over time when the retrograde approach was restrictively used only after a failed antegrade attempt.Methods and ResultsIn a prospective single operator registry from January 2008 to December 2012 about 436 consecutive patients underwent a CTO‐PCI.Mean age was 63.4 ± 10.3 years, and 86% were male. The overall success rate improved significantly over time [68% (first quartile) to 91% (fourth quartile), P < 0.001] due to a significant increase of the antegrade success rate. This could be achieved by a retrograde approach of less than 20% with no change over time. The overall in‐hospital MACE rate was 0.69% with no difference between antegrade and retrograde procedures.ConclusionsA high CTO‐PCI success rate of above 90% could be achieved with a restrictive use of the retrograde technique. © 2015 Wiley Periodicals, Inc.
Fractional flow reserve‐guided paclitaxel‐coated balloon treatment for de novo coronary lesions
Authors: Shin Eun‐Seok , Ann Soe Hee , Balbir Singh Gillian , Lim Kyung Hun , Kleber Franz X. , Koo Bon‐Kwon 
Published: October 2015

ObjectivesTo assess the safety and efficacy of fractional flow reserve (FFR) guided paclitaxel‐coated balloon (PCB) treatment for de novo coronary artery lesions. Background: There is limited data on PCB treatment for de novo lesions especially of major epicardial coronary arteries.MethodsSixty‐six patients with 67 de novo lesions who underwent successful plain old balloon angioplasty (POBA) were included. If POBA‐FFR was favorable (≥ 0.85), PCB was applied and if POBA‐FFR was <0.85, stent implantation was preferred over PCB.ResultsForty‐five lesions were treated with PCB (67.2%) and 22 lesions with stents (32.8%). Dual antiplatelet therapy duration was 6 weeks. Late luminal loss with PCB was significantly less than stent (0.05 ± 0.27 mm vs. 0.40 ± 0.54 mm, P = 0.022). The baseline FFR of target lesions was 0.69 ± 0.16 in PCB and 0.60 ± 0.11 in stent group (P = 0.015), however, the FFR at 9 months was not different between groups (0.85 ± 0.08 in PCB vs. 0.85 ± 0.05 in stent group, P = 0.973). At 1 year, one myocardial infarction and one target lesion revascularization related to in‐stent restenosis were detected, both in the stent group.ConclusionPOBA‐FFR‐guided PCB treatment is safe and effective for de novo coronary lesions with good anatomical and physiological patency at mid‐term follow‐up. © 2015 Wiley Periodicals, Inc.
Production of Methyl Oleate in Reactive‐Separation Systems
Authors: López‐Ramírez María Dolores , García‐Ventura Ulises Miguel , Barroso‐Muñoz Fabricio Omar , Segovia‐Hernández Juan Gabriel , Hernández Salvador 
Published: October 2015

AbstractThe esterification of oleic acid and methanol using sulfuric acid as a homogeneous catalyst is studied in reactive‐separation systems. The conversion of the free fatty acid was investigated in two different experiments with the molar ratio of methanol/oleic acid, amount of catalyst, temperature, and reaction time as variables. The conversion of the free fatty acid was found to depend strongly on the molar ratio of methanol/oleic acid. The reaction time had a direct effect on the conversion of the free fatty acid, and this conversion decreased with higher temperature. These results were valuable for a preliminary study on biodiesel production, using an acid homogeneous catalyst in a reactive dividing‐wall distillation column.
Sulfur‐Based Catholyte Solution with a Glass‐Ceramic Membrane for Li–S Batteries
Authors: Wang Lina , Zhao Yu , Thomas Morgan L. , Dutta Arghya , Byon Hye Ryung 
Published: October 2015

AbstractShuttling of soluble polysulfide species within electrodes is one of the most challenging issues in lithium–sulfur (Li–S) batteries. The resulting deposition of polysulfide species reduces the conductivity of the metallic Li electrode and the quantity of active material. Here, we demonstrate pronounced suppression of polysulfide shuttle using a sulfide‐impermeable glass‐ceramic membrane, which is employed as separator between the positive and negative electrodes. As a result, highly stable Li–S electrochemistry occurs in the sulfur‐dissolving tetrahydrofuran catholyte solution, which provides good capacity retention and Coulombic efficiency for cycling. This demonstration holds promise for practical next‐generation batteries with marked reversibility and the possibility to increase the energy density when equipped with a catholyte flow‐through mode.
Total Synthesis and Configurational Assignment of Ascospiroketal A
Authors: Chang Stanley , Hur Soo , Britton Robert 
Published: October 2015

AbstractThe total synthesis of the marine fungus‐derived natural product ascospiroketal is described. This concise synthesis relies on a unique AgI‐promoted tandem cascade cyclization that provides direct access to the correctly configured tricyclic core of the natural product from a linear precursor. The synthesis of candidate stereostructures of ascospiroketal A allowed for the confident assignment of both the relative and absolute stereochemistry of this unusual octaketide.
Minimizing Aryloxy Elimination in RhI‐Catalyzed Asymmetric Hydrogenation of β‐Aryloxyacrylic Acids using a Mixed‐Ligand Strategy
Authors: Li Yang , Wang Zheng , Ding Kuiling 
Published: October 2015

AbstractThe first example of efficient asymmetric hydrogenation of challenging β‐aryloxyacrylic acids was realized using a RhI‐complex based on the heterocombination of a readily available chiral monodentate secondary phosphine oxide (SPO) and an achiral monodentate phosphine ligand as the catalyst. Excellent enantioselectivities (92–>99 % ee) were achieved for a wide variety of chiral β‐aryloxypropionic acids with minor aryloxy elimination in most cases. The resultant products were readily transformed into biologically active compounds through simple synthetic manipulations.
Total Synthesis of (−)‐Isoschizogamine
Authors: Takada Akihiro , Fujiwara Hiroaki , Sugimoto Kenji , Ueda Hirofumi , Tokuyama Hidetoshi 
Published: October 2015

AbstractThe total synthesis of (−)‐isoschizogamine was accomplished, featuring the construction of the quaternary carbon center by the modified Johnson–Claisen rearrangement in basic media and the facile assembly of the key tetracyclic quinolone intermediate through a cascade cyclization. The characteristic cyclic aminal was constructed by late‐stage CH functionalization at the position adjacent to the lactam nitrogen using a combination of CrO3 and nBu4NIO4 and subsequent Bi(OTf)3‐mediated cyclization.