bluuebunny/crossref_metadata_2025 huggingface dataset:
Continental microseismic intensity delineates oceanic upwelling timing along the west coast of North America
Authors: Thomson Richard E. , Heesemann Martin , Davis Earl E. , Hourston Roy A. S.
Published: August 2014

The biological productivity of coastal upwelling regions undergoes marked interannual variability as marine ecosystems respond to changes in the prevailing winds. Determination of the principal metrics that define the upwelling cycle—the spring transition, when ocean conditions switch from downwelling‐ to upwelling‐favorable, and the Fall Transition, when conditions return to downwelling‐favorable—is essential for understanding changes in coastal productivity. Here we demonstrate that upwelling in the northern California Current System may be delineated by changes in microseismic activity recorded at a broadband seismological station in southwestern British Columbia. Observed high correlation between microseismic intensity and offshore bottom pressure fluctuations at ~0.2 Hz confirms a direct link to regional wind‐wave generation. Comparison of transition times derived from coincident 20 year records of microseismic intensity and alongshore wind stress for the British Columbia‐Oregon coast suggests that seismically derived times may be more representative of coastal upwelling than times derived using traditional methods.
Calculating the velocity of a fast‐moving snow avalanche using an infrasound array
Authors: Havens Scott , Marshall Hans‐Peter , Johnson Jeffrey B. , Nicholson Bill
Published: August 2014

On 19 January 2012, a large D3 avalanche (approximately 103 t) was recorded with an infrasound array ideally situated for observing the avalanche velocity. The avalanche crossed Highway 21 in Central Idaho during the largest avalanche cycle in the 15 years of recorded history and deposited approximately 8 m of snow on the roadway. Possible source locations along the avalanche path were estimated at 0.5 s intervals and were used to calculate the avalanche velocity during the 64 s event. Approximately 10 s prior to the main avalanche signal, a small infrasound signal originated from the direction of the start zone. We infer this to be the initial snow pack failure, a precursory signal to the impending avalanche. The avalanche accelerated to a maximum velocity of 35.9 ± 7.6m s−1 within 30 s before impacting the highway. We present a new technique to obtain high spatial and temporal resolution velocity estimates not previously demonstrated with infrasound for avalanches and other mass wasting events.
Inertial Alfvén wave localization and turbulent spectrum
Authors: Sharma R. P. , Kumari Anju , Yadav Nitin
Published: August 2014

The localization of pump inertial Alfvén wave (IAW) in low β plasmas (β ≪ me/ mi) has been investigated by developing a model based on weak IAW and finite amplitude background density fluctuations. When IAW is perturbed by these fluctuations which are in the form of magnetosonic and ion acoustic waves, its phase velocity gets modified and IAW breaks up into localized structures of very high intensity. Numerical simulation has been carried out to analyze the localized structures and magnetic fluctuation spectrum of pump IAW. We have also developed a simplified model to understand the physical insight into evolution pattern of IAW. Results obtained from simulation reveal that turbulent spectrum up to k⊥λe ≈ 1 follows Kolmogorov power law. Furthermore, at shorter wavelengths, dispersion starts and spectrum steepens with power law index ∼ − 3.8. Energy transport to smaller length scales through this mechanism may be accountable for the observed parallel electron heating in low β plasmas. Results obtained from the numerical simulation are consistent with the observations of various spacecraft like FAST and Hawkeye.
Distribution of vertical velocity inferred from secondary flow in a curved tidal channel
Authors: Russell P. , Vennell R.
Published: August 2014

High‐resolution observations from the curved tidal channel of the Otago Harbour shows secondary flows up to 20% of the primary flow and vertical velocity inferred from secondary flow up to 1% of the primary flow. This vertical velocity is inferred on a much finer scale than previous works. The spatial pattern of this vertical velocity is upward on the inside and downward on the outside of the bend, consistent with previous laboratory flume measurements. Linear regression, rp = 0.95, shows the cross‐channel distribution of the observed secondary flow can be resolved from the horizontal ADCP measurements well enough to be consistent with the cross‐channel distribution of secondary flow derived from the observed primary flow using the model of Kalkwijk and Booij (1986). Linear regression, rp = 0.80, shows the vertical velocity inferred from observed secondary flow is consistent with vertical velocity derived from the observed primary flow using the model of Kalkwijk and Booij (1986). This also shows the cross‐channel distribution of the observed secondary flow is resolved well enough from the horizontal ADCP measurements to be able to infer the vertical velocity from mass continuity. The required horizontal resolution is made possible by Radial Basis Function (RBF) smoothing and spatial interpolation that allows for continuity of the spatial derivatives. Modeling trajectories using channel dimensions and velocity field values equivalent to the observations show that 3‐dimensional secondary circulation forms a loose helical flow pattern.
Humidity variability revealed by a sounding array and its implications for cloud representation in GCMs
Authors: Lin Yanluan
Published: August 2014

Subgrid‐scale humidity variability is critical for statistical cloud schemes. The Atmospheric Radiation Measurement (ARM) sounding array, covering a comparable size to a grid box of current global climate models (GCMs), provides estimates of subgrid‐scale humidity variability. Using radiosonde measurements from ARM sounding arrays, humidity variabilities at a tropical and a midlatitude site are analyzed. Normalized moisture variance is small in the lower troposphere but tends to be large in the middle troposphere. Moisture variability dominates relative humidity (RH) variability at the tropical site, but the contribution by temperature variability cannot be ignored at the midlatitude site. Based on the analysis, a simple linear relationship between RH variance and mean is proposed. Cloud schemes assuming Gaussian distributions give comparable cloudiness as those assuming a beta distribution considering both moisture variance and skewness. A probability distribution function scheme assuming a Gaussian distribution of RH has more flexibility than a RH threshold scheme, which tends to overestimate cloudiness in the moist boundary layer over the tropics. Supersaturation with respect to ice needs to be allowed in the upper troposphere over the tropics to reduce the persistent overestimated cloudiness there. Similar comparison results are found from analysis of cloud resolving model simulations. The study suggests that measurements from sounding arrays would be valuable for statistical cloud scheme evaluation and development.
Electrochemical Cathodic Protection Powered by Triboelectric Nanogenerator
Authors: Guo Wenxi , Li Xiaoyi , Chen Mengxiao , Xu Lu , Dong Lin , Cao Xia , Tang Wei , Zhu Jing , Lin Changjian , Pan Caofeng , Wang Zhong Lin
Published: August 2014

Metal corrosion is universal in the nature and the corrosion prevention for metals plays an important role everywhere in national economic development and daily life. Here a disk triboelectric nanogenerator (TENG) with segmental structures is introduced as power source to achieve a special cathodic protection effect for steels. The output transferred charges and short‐circuit current density of the TENG achieve 1.41 mC/min and 10.1 mA/m2, respectively, when the rotating speed is 1000 revolutions per minute (rpm). The cathodic protection potential, Tafel polarization curves and electrochemical impedance spectra (EIS) measurements are measured to evaluate the corrosion protection effect for the 403 stainless steel (403SS). The cathodic protection potential range from –320 mV to –5320 mV is achieved by changing rotation speeds and external resistance when the steel is coupled in a 0.5 m NaCl solution to the negative pole of the disk TENG. The corrosion tests results indicate that the TENG can produce 59.1% degree of protection for Q235 steels in 0.5 m NaCl solution. Furthermore, an application of marine corrosion prevention is presented by mounting the TENG onto a buoy. This work demonstrates a versatile, cost‐effect and self‐powered system to scavenging mechanical energy from environment, leading to effectively protect the metal corrosion without additional power sources.
Understanding How Processing Additives Tune the Nanoscale Morphology of High Efficiency Organic Photovoltaic Blends: From Casting Solution to Spun‐Cast Thin Film
Authors: Shao Ming , Keum Jong Kahk , Kumar Rajeev , Chen Jihua , Browning James F. , Das Sanjib , Chen Wei , Hou Jianhui , Do Changwoo , Littrell Kenneth C. , Rondinone Adam , Geohegan David B. , Sumpter Bobby G. , Xiao Kai
Published: August 2014

Adding a small amount of a processing additive to the casting solution of photoactive organic blends has been demonstrated to be an effective method for achieving improved power conversion efficiency (PCE) in organic photovoltaics (OPVs). However, an understanding of the nano‐structural evolution occurring in the transformation from casting solution to thin photoactive films is still lacking. In this report, the effects of the processing additive diiodooctane (DIO) on the morphology of the established blend of PBDTTT‐C‐T polymer and the fullerene derivative PC71BM used for OPVs are investigated, starting in the casting solution and tracing the effects in spun‐cast thin films by using neutron/X‐ray scattering, neutron reflectometry, and other characterization techniques. The results reveal that DIO has no observable effect on the structures of PBDTTT‐C‐T and PC71BM in solution; however, in the spun‐cast films, it significantly promotes their molecular ordering and phase segregation, resulting in improved PCE. Thermodynamic analysis based on Flory‐Huggins theory provides a rationale for the effects of DIO on different characteristics of phase segregation due to changes in concentration resulting from evaporation of the solvent and additive during film formation. Such information may help improve the rational design of ternary blends to more consistently achieve improved PCE for OPVs.
Tailoring the Plasmonic Modes of a Grating‐Nanocube Assembly to Achieve Broadband Absorption in the Visible Spectrum
Authors: Geldmeier Jeffrey , König Tobias , Mahmoud Mahmoud A. , El‐Sayed Mostafa A. , Tsukruk Vladimir V.
Published: August 2014

Engineered metal‐dielectric‐metal nanostructures with broadband absorbing properties in the visible spectral range are fabricated by combining the plasmonic resonances of different noble metal nanostructures. Silver nanocubes and gold nanogratings couple to each other using a dielectric polymer spacer with controllable thickness, resulting in a large multiplicative enhancement of absorption properties across a broad spectral range. Narrow, long nanogrooves in a gold film are first fabricated using electron beam lithography, after which a polymer spacer layer with a controllable thickness ranging from 4 to 12 nm is assembled by spin‐assisted layer‐by‐layer assembly. Finally, silver nanocubes with different surface coverages ranging from 12% to 22% are deposited using the Langmuir–Blodgett technique. The individual plasmon resonances of these different nanostructures are located at significantly different optical frequencies and are tuned in this study to allow a significant increase of light absorbance of the original gratings to an average value of 84% across the broad wavelength range of 450–850 nm.
Extraordinary Macroscale Wear Resistance of One Atom Thick Graphene Layer
Authors: Berman Diana , Deshmukh Sanket A. , Sankaranarayanan Subramanian K. R. S. , Erdemir Ali , Sumant Anirudha V.
Published: August 2014

During the last few years, graphene's unusual friction and wear properties have been demonstrated at nano to micro scales but its industrial tribological potential has not been fully realized. The macroscopic wear resistance of one atom thick graphene coating is reported by subjecting it to pin‐on‐disc type wear testing against most commonly used steel against steel tribo‐pair. It is shown that when tested in hydrogen, a single layer of graphene on steel can last for 6400 sliding cycles, while few‐layer graphene (3–4 layers) lasts for 47 000 cycles. Furthermore, these graphene layers are shown to completely cease wear despite the severe sliding conditions including high contact pressures (≈0.5 GPa) observed typically in macroscale wear tests. The computational simulations show that the extraordinary wear performance originates from hydrogen passivation of the dangling bonds in a ruptured graphene, leading to significant stability and longer lifetime of the graphene protection layer. Also, the electronic properties of these graphene sheets are theoretically evaluated and the improved wear resistance is demonstrated to preserve the electronic properties of graphene and to have significant potential for flexible electronics. The findings demonstrate that tuning the atomistic scale chemical interactions holds the promise of realizing extraordinary tribological properties of monolayer graphene coatings.
Surface Polarization Matters: Enhancing the Hydrogen‐Evolution Reaction by Shrinking Pt Shells in Pt–Pd–Graphene Stack Structures
Authors: Bai Song , Wang Chengming , Deng Mingsen , Gong Ming , Bai Yu , Jiang Jun , Xiong Yujie
Published: August 2014

Surface charge state plays an important role in tuning the catalytic performance of nanocrystals in various reactions. Herein, we report a synthetic approach to unique Pt–Pd–graphene stack structures with controllable Pt shell thickness. These unique hybrid structures allow us to correlate the Pt thickness with performance in the hydrogen‐evolution reaction (HER). The HER activity increases with a decrease in the Pt thickness, which is well explained by surface polarization mechanism as suggested by first‐principles simulations. In this hybrid system, the difference in work functions of Pt and Pd results in surface polarization on the Pt surface, tuning its charge state for hydrogen reduction. Meanwhile, the supporting graphene provides two‐dimensional channels for efficient charge transport, improving the HER activities. This work opens up possibilities of reducing Pt usage while achieving high HER performance.
A Lightweight Polymer Solar Cell Textile that Functions when Illuminated from Either Side
Authors: Zhang Zhitao , Li Xueyi , Guan Guozhen , Pan Shaowu , Zhu Zhengju , Ren Dayong , Peng Huisheng
Published: August 2014

An all‐solid‐state, lightweight, flexible, and wearable polymer solar cell (PSC) textile with reasonable photovoltaic performance has been developed. A metal textile electrode made from micrometer‐sized metal wires is used as the cathode, and the surfaces of the metal wires are dip‐coated with the photoactive layers. Two ultrathin, transparent, and aligned carbon nanotube sheets that exhibit remarkable electronic and mechanical properties were coated onto the modified metal textile at both sides as the anode to produce the desired PSC textile. Because of the designed sandwich structure, the PSC textile displays the same energy conversion efficiencies regardless of which side it is irradiated from. As expected, the PSC textiles are highly flexible, and their energy conversion efficiencies varied by less than 3 % after bending for more than 200 cycles. The PSC textile shows an areal density (5.9 mg cm−2) that is lower than that of flexible film‐based PSCs (31.3 mg cm−2).
A Universal Procedure for the [18F]Trifluoromethylation of Aryl Iodides and Aryl Boronic Acids with Highly Improved Specific Activity
Authors: van der Born Dion , Sewing Claudia , Herscheid J. (Koos) D. M. , Windhorst Albert D. , Orru Romano V. A. , Vugts Danielle J.
Published: August 2014

Herein, we describe a valuable method for the introduction of the [18F]CF3 group into arenes with highly improved specific activity by the reaction of [18F]trifluoromethane with aryl iodides or aryl boronic acids. This [18F]trifluoromethylation reaction is the first to be described in which the [18F]CF3 products are generated in actual trace amounts and can therefore effectively be used as PET tracers. The method shows broad scope with respect to possible aryl iodide and aryl boronic acid substrates, as well as good to excellent conversion. In particular, the [18F]trifluoromethylation of boronic acids was found to outperform [18F]trifluoromethylation reactions of halogenated aryl precursors with regard to conversion, reaction conditions, and kinetics.
Successful percutaneous retrieval of a dislodged left atrial appendage occlusion device with double transseptal sheaths and biopsy bioptome
Authors: Chan Ngai‐Yin , Choy Chi‐Chung , Lau Chun‐Leung
Published: August 2014

A 64‐year‐old woman underwent left atrial appendage occlusion with an Amplatzer Cardiac Plug device. Displacement of the device was detected on day 1 with transesophageal echocardiographic checking. The device became dislodged and flitted in the left atrium after unsuccessful retrieval with a snare and 12 Fr steerable transseptal sheath. A double transseptal sheath technique was then attempted. The flitting device was stabilized by one 12 Fr steerable transseptal sheath and successfully retrieved with a biopsy bioptome through another similar transseptal sheath. The patient suffered from no long‐term sequelae. © 2014 Wiley Periodicals, Inc.
Energy Dissipation Rates of Newtonian and Non‐Newtonian Fluids in a Stirred Vessel
Authors: Wang Xu , Feng Xin , Yang Chao , Mao Zai‐Sha
Published: August 2014

Energy dissipation rates of water and glycerol as Newtonian fluids and carboxyl methyl carbonate solution as non‐Newtonian fluid in a stirred vessel are investigated by 2D particle image velocimetry and compared. Mean velocity profiles reflect the Reynolds (Re) number similarity of two flow fields with different rheological properties, but the root mean square velocity profiles differ in rheology at the same Re‐number. Energy dissipation rates are estimated by direct calculation of fluctuating velocity gradients. The varying energy dissipation rates of Newtonian and non‐Newtonian fluids result from the difference in fluid rheology and apparent viscosity distribution which decides largely the flow pattern, circulation intensity, and rate of turbulence generation.
Reactivity of Metal Catalysts in Glucose–Fructose Conversion
Authors: Loerbroks Claudia , van Rijn Jeaphianne , Ruby Marc‐Philipp , Tong Qiong , Schüth Ferdi , Thiel Walter
Published: August 2014

A joint experimental and computational study on the glucose–fructose conversion in water is reported. The reactivity of different metal catalysts (CrCl3, AlCl3, CuCl2, FeCl3, and MgCl2) was analyzed. Experimentally, CrCl3 and AlCl3 achieved the best glucose conversion rates, CuCl2 and FeCl3 were only mediocre catalysts, and MgCl2 was inactive. To explain these differences in reactivity, DFT calculations were performed for various metal complexes. The computed mechanism consists of two proton transfers and a hydrogen‐atom transfer; the latter was the rate‐determining step for all catalysts. The computational results were consistent with the experimental findings and rationalized the observed differences in the behavior of the metal catalysts. To be an efficient catalyst, a metal complex should satisfy the following criteria: moderate Brønsted and Lewis acidity (pKa=4–6), coordination with either water or weaker σ donors, energetically low‐lying unoccupied orbitals, compact transition‐state structures, and the ability for complexation of glucose. Thus, the reactivity of the metal catalysts in water is governed by many factors, not just the Lewis acidity.
Absorption of carbon dioxide into sterically hindered amines: Kinetics analysis and the influence of promoters
Authors: Vaidya Prakash D. , Jadhav Santosh G.
Published: August 2014

The sterically hindered amines 2‐amino‐2‐methyl‐1‐propanol (AMP) and 2‐piperidineethanol (PE) are promising candidate absorbents for CO2 capture. Although reaction kinetics of the CO2‐AMP system is extensively studied, there exists some deviations in the reported kinetic parameters and there is some uncertainty about the reaction mechanism. Contrarily, kinetic data on the CO2‐PE reaction system is scarce. In this work, these reaction systems were revisited to set right the discrepancy of previous works and facilitate and deepen fundamental understanding of these reaction systems. Kinetic data were obtained experimentally at 298, 303, and 308 K by using a stirred‐cell reactor. The molarities of AMP and PE in the aqueous solutions were varied from 1 to 3 M and 0.05 to 0.25 M. Second order rate constants for the reactions with AMP and PE were equal to 809 and 899 m3/(kmol s) at 303 K. The increase in temperature and amine concentration caused the expected increase in the values of the observed pseudo‐first order reaction rate constants. Finally, it was found that the investigated reactions were accelerated by the addition of two sterically hindered secondary amines comprising an alkyl group, viz., N‐methyl‐ and N‐ethyl‐monoethanolamine, even at low additive concentrations (0.05–0.1 M).
Nucleophilic Difluoro(phenylsulfonimidoyl)methylation of Unactivated Alkyl Bromides with PhSO(NTBS)CF2H: Facile Entry into gem‐Difluoroalkenes
Authors: Shen Xiao , Liu Qinghe , Ni Chuanfa , Hu Jinbo
Published: August 2014

An efficient nucleophilic difluoro(phenylsulfonimidoyl)methylation of unactivated primary alkyl bromides with PhSO(NTBS)CF2H has been developed. It is particularly remarkable that, when 1.5 equiv. of alkyl bromides are used, the substitution products are obtained in moderate to excellent yields. The prepared difluoro(phenylsulfonimidoyl)methylated alkanes can be readily transformed to gem‐difluoroalkenes via base‐mediated β‐elimination reaction.
On Desilylation of 13‐Vertex Carborane 1,2‐Me2Si(CH2)2‐1,2‐C2B11H11
Authors: Zhang Jian , Xie Zuowei
Published: August 2014

The reasons for facile double desilylation of 13‐vertex carborane 1,2‐Me2Si(CH2)2‐1,2‐C2B11H11 (2) are discussed in this article. New 13‐ and 14‐vertex ruthenacarboranes bearing the same ‐CH2SiMe2CH2‐ linkage have been prepared and structurally characterized for comparison. Structural analyses of 13‐ and 14‐vertex heteroboranes as well as control experiments suggest that the facile double desilylation of 2 on silica gel can be attributed to the joint actions of several factors involving the high ring‐strain of exo five‐membered C4Si ring, Lewis acidity of Si atom and Br⊘nsted acidity of silica surface.
Markov chain order estimation based on the chi‐square divergence
Authors: Baigorri Angel Rodolfo , Gonçalves Cátia Regina , Resende Paulo Angelo Alves
Published: August 2014

In the selection model context, several alternatives for estimating the order of a Markov chain have been proposed. The Akaike's information criterion, AIC, is the best known and most used alternative, in spite of its inconsistency. The Bayesian information criterion (BIC) and the efficient determination criterion (EDC) have been stated as strong consistent approaches. The success of the AIC is mainly a result of its better performance when compared with the widely known consistent alternatives. In this work, we define a few objects which capture relevant information from the sample of a finite Markov chain and we use the chi‐square divergence to define a new estimator for the Markov chain order, named GDL. Finally, we show numerical simulations and a simple application to compare the proposed alternative with AIC, BIC and EDC.The Canadian Journal of Statistics42: 563–578; 2014 © 2014 Statistical Society of Canada
Outcome in Patients With Left‐Sided Native‐Valve Infective Endocarditis and Isolated Large Vegetations
Authors: Desch Steffen , Freund Anne , de Waha Suzanne , Eitel Ingo , Lurz Philipp , Stiermaier Thomas , Fuernau Georg , Schuler Gerhard , Thiele Holger
Published: August 2014

Background

In patients with left‐sided native‐valve infective endocarditis (IE), the risk of embolism is increased with a vegetation size ≥10 mm. For this reason—according to guidelines—surgery may be considered in patients with isolated large vegetations (without any other indication for surgery). However, the value of surgery in this patient subset has never been systematically studied.

Hypothesis

We hypothesized that surgery may be superior to medical therapy in terms of clinical outcome in the aforementioned patients.

Methods

All patients who presented at our institution between January 2000 and July 2012 with isolated left‐sided native‐valve IE and large vegetations (≥10 mm) were examined. Patients with conventional indications for surgical treatment were excluded. Follow‐up for clinical events was performed according to predefined definitions.

Results

A total of 71 patients with left‐sided native‐valve IE and isolated large vegetations qualified for inclusion into the study cohort. Mean vegetation length was 17 ± 5 mm. A total of 59 patients underwent surgery after a mean of 5 ± 6 days following the initiation of antibiotic treatment. Mean follow‐up duration was 6.0 ± 2.9 years. Surgical compared to purely medical treatment was associated with a significant increase in long‐term all‐cause mortality (P = 0.03 by log‐rank test, unadjusted analysis). Upon multivariable Cox regression analysis, surgical treatment, affection of mitral valve, blood cultures positive for Staphylococcus aureus, and increasing age showed trends as independent predictors of long‐term mortality.

Conclusions

Surgical treatment in patients with left‐sided native‐valve IE and isolated large vegetations without any other indication for surgery seems to be associated with excess mortality. A randomized controlled trial of surgery vs conservative treatment in this subset of patients is justified.
The Nature of the Active Site in Ziegler–Natta Olefin Polymerization Catalysis Systems – A Computational Investigation
Authors: Kumawat Jugal , Kumar Gupta Virendra , Vanka Kumar
Published: August 2014

Full quantum chemical calculations with density functional theory (DFT) show that a principal role of donors in Ziegler–Natta (ZN) olefin polymerization catalysts is to coordinate to the metal center at the active sites on the MgCl2 surface. Thereby, the behavior of the catalyst is modulated to favor insertion over termination and, thus, polymerization occurs. This is shown to be true for a range of different donors. The calculations indicate that active sites that feature anionic chloride ligands at the titanium center (the conventional model for the active site) would lead to lower‐molecular‐weight polymers. If an –OC2H5 group were present instead of a chloride ligand, the active site would much more effectively produce long chain polymers. Therefore, the current work provides important new insights into the nature of the ZN polymerization process.
Chiral MnIII–salalen and –salan Complexes Derived from (S)‐Pyrrolidin‐2‐ylmethanamine and Their Catalytic Activity in the Asymmetric Strecker Reaction
Authors: Kumar Pramod , Saravanan S. , Khan Noor‐ul Hasan , Hussain Firasat , Singh Surendra
Published: August 2014

The salalen and salan ligands have been synthesized by the reactions of (S)‐pyrrolidin‐2‐ylmethanamine and salicylaldehyde derivatives. These ligands were treated with Mn(CH3COO)2·4H2O followed by air oxidation to give (S,R)‐MnIII–salalen and –salan complexes in yields of 84–88 %. The absolute configuration of (S,R)‐MnIII–salalen was determined by single‐crystal X‐ray diffraction and CD analysis of the ligands and complexes showed similiar Cotton effects. The MnIII–salalen and –salan complexes were screened for their catalytic activity in the asymmetric Strecker reaction. (S,R)‐2,4‐Di‐tert‐butyl‐6‐({[1‐(3,5‐di‐tert‐butyl‐2‐hydroxybenzyl)pyrrolidin‐2‐yl]methylimino}methyl)phenolatomanganese(III) chloride (5 mol‐%) was found to be a suitable catalyst for the asymmetric Strecker reaction of N‐(4‐methoxybenzylidene)diphenylmethanamine with ethyl cyanoformate, which gave 89 % yield and 55 % ee of 2‐(benzhydrylamino)‐2‐(4‐methoxyphenyl)acetonitrile at –15 °C after 24 h.
Unprecedented Borylene Insertion into a C–N Bond
Authors: Ghadwal Rajendra S. , Schürmann Christian J. , Engelhardt Felix , Steinmetzger Christian
Published: August 2014

Carbenes are well established reactive intermediates and play an important role in organic synthesis, whereas the scope of borylenes is rather limited. Selective borylene insertion into a C–N bond to yield boryl‐functionalized N‐heterocyclic olefins (NHOs), [{N(Dipp)N(DippBH)CHCH}CCH2]2 (6) and [{N(Dipp)N(DippBPh)CHCH}CCH2][{N(Dipp)N(2‐iPr‐6‐CHMeCH2BC6H3)CHCH}CCH2] (8) (Dipp = 2,6‐iPr2C6H3) is reported for the first time. KC8 reduction of (IPrCH2)BRX2 adducts (IPrCH2 = {N(Dipp)CH}2CCH2; R = X = I (2); R = Ph, X = Cl (4)) affords compounds 6 and 8. Surprisingly, treatment of (IPrCH2)BHCl2 (3) with KC8 yields completely unexpected diborane compound (IPr)BH2BH2(IPr) (7). Compound 2 is unstable in THF and induces ring opening reaction to form the borenium ion [(IPrCH2)B{O(CH2)4I}2]I (5).
Syntheses of 4‐Substituted 2‐(Trichloromethyl)quinazolines under Mild Conditions by Benzyne [4+2] Cycloaddition
Authors: Lechuga‐Eduardo Harim , Olivo Horacio F. , Romero‐Ortega Moises
Published: August 2014

An experimentally simple and convenient synthesis of 4‐susbstituted 2‐(trichloromethyl)quinazolines by cycloaddition of benzyne with 2‐(trichloromethyl)‐1,3‐diazabutadienes was developed. The 2‐(trichloromethyl)‐1,3‐diazabutadienes (R1 = H and Me) were prepared from trichloroacetamidine and the appropriate N,N‐dimethylamide dimethyl acetal or from trichloroacetamidine and a Vilsmeier–Haack reagent containing an aryl group.
Study of the Complexation of Pb(II) with meso‐2,3‐ Dimercaptosuccinic Acid (DMSA) and 2,3‐Dimercapto‐1‐propanesulfonic acid (DMPS) Using a Bismuth‐Bulk Rotating Disk Electrode
Authors: de la Gala Morales María , Ariño Cristina , Díaz‐Cruz José Manuel , Esteban Miquel
Published: August 2014

For the first time, the suitability of bismuth bulk rotating disk electrode (BiB‐RDE) for the study of metal complexation has been tested. Cyclic (CV) and differential pulse (DPV) voltammetry have been used to study the complexation of Pb(II) with two of the most effective chelating agents for the treatment of Pb(II) poisoning (meso‐2,3‐dimercaptosuccinic acid, DMSA, and 2,3‐dimercapto‐1‐propanesulfonic acid, DMPS). Multivariate curve resolution has been applied to voltammetric data to obtain the stoichiometries and stability constants of the complexes formed. In both systems, the ML2 complex was predominant, with log β2 values of 10.13 and 8.80 for DMSA‐Pb(II) and DMPS‐Pb(II), respectively.
Topographic stress and rock fracture: a two‐dimensional numerical model for arbitrary topography and preliminary comparison with borehole observations
Authors: Slim Mirna , Perron J. Taylor , Martel Stephen J. , Singha Kamini
Published: August 2014

Theoretical calculations indicate that elastic stresses induced by surface topography may be large enough in some landscapes to fracture rocks, which in turn could influence slope stability, erosion rates, and bedrock hydrologic properties. These calculations typically have involved idealized topographic profiles, with few direct comparisons of predicted topographic stresses and observed fractures at specific field sites. We use a numerical model to calculate the stresses induced by measured topographic profiles and compare the calculated stress field with fractures observed in shallow boreholes. The model uses a boundary element method to calculate the stress distribution beneath an arbitrary topographic profile in the presence of ambient tectonic stress. When applied to a topographic profile across the Susquehanna Shale Hills Critical Zone Observatory in central Pennsylvania, the model predicts where shear fractures would occur based on a Mohr–Coulomb criterion, with considerable differences in profiles of stresses with depth beneath ridgetops and valley floors. We calculate the minimum cohesion required to prevent shear failure, Cmin, as a proxy for the potential for fracturing or reactivation of existing fractures. We compare depth profiles of Cmin with structural analyses of image logs from four boreholes located on the valley floor, and find that fracture abundance declines sharply with depth in the uppermost 15 m of the bedrock, consistent with the modeled profile of Cmin. In contrast, Cmin increases with depth at comparable depths below ridgetops, suggesting that ridgetop fracture abundance patterns may differ if topographic stresses are indeed important. Thus, the present results are consistent with the hypothesis that topography can influence subsurface rock fracture patterns and provide a basis for further observational tests. Copyright © 2014 John Wiley & Sons, Ltd.
Endoscopic ultrasound‐guided pelvic abscess drainage (with video)
Authors: Holt Bronte , Varadarajulu Shyam
Published: August 2014

Pelvic abscesses present a serious and challenging management problem. Endoscopic ultrasound (EUS)‐guided drainage provides a safe and effective minimally invasive treatment option. The likelihood of a successful outcome is dependent on appropriate patient selection, drainage technique and postoperative management. This review outlines the evidence behind and procedural steps required for EUS‐guided pelvic abscess drainage.
Delivering Loyalty Via Customer Experience Management at DHL Freight
Authors: MacGillavry Kim , Wilson Alan
Published: August 2014

Creating a positive customer experience enables a company to differentiate itself from the competition. This is particularly true in the highly fragmented road freight business, where the offering has become highly commoditized and price driven. DHL Freight, a leading provider of international road transportation solutions, set out to enhance the customer experience by bringing the voice of the customer into the organization, improving customer interactions, and developing an organization‐wide customer‐driven vision, common purpose, and value proposition. The need to engage the whole organization, across multiple locations and countries, in delivering an excellent customer experience was critical to the success of the initiative. Within 12 months of implementation, DHL Freight is seeing a major change in the culture and operations of the company. Encouraged by this success, each country in which DHL Freight operates is taking steps to appoint a dedicated customer experience leader in their respective senior management teams. The company's experiences point the way for implementing an effective customer management approach in other operations‐driven businesses. © 2014 Wiley Periodicals, Inc.
Organizational Culture, IT Competence, and Supply Chain Agility in Small and Medium‐Size Enterprises
Authors: Malekifar Shaghayegh , Taghizadeh Seyedeh Khadijeh , Rahman Syed Abidur , Khan Saif Ur Rehman
Published: August 2014

The ability to manage a supply chain flexibly and responsively is essential to competitive advantage, particularly for small and medium‐sizes enterprises (SMEs) that lack the economies of scale of larger firms. An examination of the relationship among organizational culture, information technology (IT) competence, and supply chain agility leads to a conceptual framework that can help SMEs structure their business strategies and practices to keep them aligned with market changes. © 2014 Wiley Periodicals, Inc.
Correlation of structure and spin–phonon coupling in (La, Nd) doped BiFeO3 films
Authors: Ahlawat Anju , Satapathy S. , Maan Satish , Sathe V. G. , Gupta P. K.
Published: August 2014

We studied the effect of structural change on the spin–phonon coupling in doped BiFeO3 (BFO) films (Bi0.8La0.1Nd0.1FeO3) grown on SrTiO3 (001) substrate. The temperature‐dependent Raman studies show phonon anomalies in the vicinity of magnetic ordering temperature TN owing to the spin–phonon coupling. Doped films exhibit strong anomalies in the line widths of Raman bands around TN revealing the presence of strong spin–lattice coupling. The modification in structure as a result of A‐site doping in BFO films plays an important role in controlling the nature of spin–phonon coupling. Copyright © 2014 John Wiley & Sons, Ltd.
Psychotropic Drug Use in a Cohort of Workers 4 Years After an Industrial Disaster in France
Authors: Diène Eloi , Geoffroy‐Perez Béatrice , Cohidon Christine , Gauvin Stéphanie , Carton Matthieu , Fouquet Aurélie , Fatras Jean‐Yves , Imbernon Ellen
Published: August 2014

Two years after the 2001 Toulouse industrial disaster, a longitudinal study was set up to evaluate the impact of the disaster. The current substudy examines the medium‐term impact (5 years) the incident had on the mental health of 3,004 participants. As part of the monitoring, data relating to the psychotropic drug use of 2,494 participants were collected from administrative databases 4 years after the disaster. Use of psychotropics was higher among women for anxiolytics (10.4% for men and 15.0% for women), hypnotics (10.5% and 17.0%), and antidepressants (7.6% and 11.2%). Exposure to the disaster, especially proximity to the exposure, was significantly associated with the use of antidepressants in men, OR = 3.22, 95% CI[1.57, 6.61]. This was also the case for other exposure factors (saw dead or injury, injured, home damage, death or injury loved one, psychological disorders, exposure toxic fumes): range of OR 1.75 to 2.52 in men, 1.48 to 1.62 in women. In conclusion, this study highlights the medium‐term psychological impact of an industrial disaster on psychotropic drug use and the potential for using medical records data as a means for tracking postdisaster mental health.
Reported Barriers to Mental Health Care in Three Samples of U.S. Army National Guard Soldiers at Three Time Points
Authors: Valenstein Marcia , Gorman Lisa , Blow Adrian J. , Ganoczy Dara , Walters Heather , Kees Michelle , Pfeiffer Paul N. , Kim H. Myra , Lagrou Robert , Wadsworth Shelley MacDermid , Rauch Sheila A. M. , Dalack Gregory W.
Published: August 2014

The military community and its partners have made vigorous efforts to address treatment barriers and increase appropriate mental health services use among returning National Guard soldiers. We assessed whether there were differences in reports of treatment barriers in 3 categories (stigma, logistics, or negative beliefs about treatment) in sequential cross‐sectional samples of U.S. soldiers from a Midwestern Army National Guard Organization who were returning from overseas deployments. Data were collected during 3 time periods: September 2007–August 2008 (n = 333), March 2009–March 2010 (n = 884), and August 2011–August 2012 (n = 737). In analyses using discretized time periods and in trend analyses, the percentages of soldiers endorsing negative beliefs about treatment declined significantly across the 3 sequential samples (19.1%, 13.9%, and 11.1%). The percentages endorsing stigma barriers (37.8%, 35.2%, 31.8%) decreased significantly only in trend analyses. Within the stigma category, endorsement of individual barriers regarding negative reactions to a soldier seeking treatment declined, but barriers related to concerns about career advancement did not. Negative treatment beliefs were associated with reduced services use (OR = 0.57; 95% CI [0.33, 0.97]).
Melt Processing and Characterization of Bionanocomposites Made from Poly(butylene succinate) Bioplastic and Carbon Black
Authors: Snowdon Michael , Mohanty Amar Kumar , Misra Manjusri
Published: August 2014

Melt processing was used to prepare poly(butylene succinate), PBS, bionanocomposites containing carbon black. Filler loadings of 1, 3, and 5 wt% carbon black were added in order to improve the mechanical, thermal and electrical properties. The bionanocomposite with the highest content of nanofiller tested showed an overall enhancement in properties. The mechanical performance of the material improved in impact strength, 131%, max flexural stress, 17%, tensile stress at yield, 5%, and storage modulus, 19%. The thermal and electrical conductivity of the bionanocomposite increased 50 and 102%, respectively. Good dispersion of the filler was confirmed by SEM and optical microscope images.
Effect of Ionic Liquid Modified Synthetic Layered Silicates on Thermal and Mechanical Properties of High Density Polyethylene Nanocomposites
Authors: Livi Sébastien , Duchet‐Rumeau Jannick , Gérard Jean‐François
Published: August 2014

In this work, synthetic layered silicates denoted Somasif ME‐100 and Laponite® RD were modified with dialkyl imidazolium and alkyl phosphonium ionic liquids by cationic exchange reaction. In both cases, the phosphonium (P‐ME, P‐RD) or imidazolium ion (I‐ME, I‐RD)‐treated micas and laponites display an excellent thermal stability compared to commonly used quaternary ammonium salts. To highlight the effect of these ionic liquids, the modified layered silicates were introduced in a high density polyethylene (HDPE). Thus, polyethylene nanocomposites filled with a low amount of nanoparticles (2 wt%) were prepared by twin screw extrusion. Then, transmission electronic microscopy (TEM) analysis has been used to investigate the effect of ILs on the different morphologies of these nanocomposites. In addition, the use or not of compatibilizer such as PEgMA (20% by weight) has been also studied on the mechanical behaviour of these polymer nanocomposites. Even though the thermal stability of polyethylene matrix remains unchanged, a good stiffness‐thoughness compromise has been observed.
Improving the Ionic Conductivity of Carboxylated Nitrile Rubber/LDH Composites by Adding Imidazolium Bis(trifluoromethylsulfonyl)imide Ionic Liquids
Authors: Laskowska Anna , Marzec Anna , Boiteux Gisele , Zaborski Marian , Gain Olivier , Serghei Anatoli , Maniukiewicz Waldemar
Published: August 2014

We investigated the ability of three imidazolium ionic liquids (ILs) (1‐ethyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIM TFSI), 1‐butyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide (BMIM TFSI), 1‐hexyl‐methylimidazolium bis(trifluoromethylsulfonyl)imide (HMIM TFSI)) that have the same anion but different alkyl chain lengths of cation in amounts of 2.5, 5, 10 and 15 phr (parts per hundred rubber)to improve the ionic conductivity of carboxylated nitrile butadiene rubber (XNBR)/layered double hydroxide (MgAl‐LDH) composites. The presence of these ionic liquids modified the relaxation behavior of the XNBR matrix. Increasing the length of the cation side‐chain (from ethyl‐ to hexyl‐) impactsthe glass transition temperature of the rubber matrix, the crosslink density, the mechanical properties and the ionic conductivity of the resulting XNBR/IL‐LDH composites. Among this group of ionic liquids, 1‐ethyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIM TFSI)or alternatively 1‐butyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide (BMIM TFSI)proved most suitable for enhancingthe ionic conductivity of rubber composites without substantial deterioration of their mechanical properties.
Discovery of rare protein‐coding genes in model methylotroph Methylobacterium extorquens AM1
Authors: Kumar Dhirendra , Mondal Anupam Kumar , Yadav Amit Kumar , Dash Debasis
Published: August 2014

Proteogenomics involves the use of MS to refine annotation of protein‐coding genes and discover genes in a genome. We carried out comprehensive proteogenomic analysis of Methylobacterium extorquens AM1 (ME‐AM1) from publicly available proteomics data with a motive to improve annotation for methylotrophs; organisms capable of surviving in reduced carbon compounds such as methanol. Besides identifying 2482(50%) proteins, 29 new genes were discovered and 66 annotated gene models were revised in ME‐AM1 genome. One such novel gene is identified with 75 peptides, lacks homolog in other methylobacteria but has glycosyl transferase and lipopolysaccharide biosynthesis protein domains, indicating its potential role in outer membrane synthesis. Many novel genes are present only in ME‐AM1 among methylobacteria. Distant homologs of these genes in unrelated taxonomic classes and low GC‐content of few genes suggest lateral gene transfer as a potential mode of their origin. Annotations of methylotrophy related genes were also improved by the discovery of a short gene in methylotrophy gene island and redefining a gene important for pyrroquinoline quinone synthesis, essential for methylotrophy. The combined use of proteogenomics and rigorous bioinformatics analysis greatly enhanced the annotation of protein‐coding genes in model methylotroph ME‐AM1 genome.
Controllable Fabrication of CuO/Ammonium Perchlorate (AP) Nanocomposites through Ceramic Membrane Anti‐Solvent Recrystallization
Authors: Qin Hong , Zha Mingxia , Ma Zhenye , Zhao Fengqi , Xu Siyu , Xu Huixiang
Published: August 2014

To improve the dispersion of CuO nanoparticles in ammonium perchlorate (AP), CuO/AP nanocomposites are designed and the novel ceramic membrane anti‐solvent crystallization (CMASC) method is applied to the nanocomposites synthesis. Typical experimental results demonstrate that nanocomposites with a size of less than 20 μm exhibit well‐defined hexahedral‐like structure and that the CuO nanoparticles are physically coated by AP crystals. The well‐dispersion of CuO nanoparticles and preparation of superfine AP crystals can be achieved at one step. The nucleation and growth mechanism of nanocomposites is discussed. To explore the actual formation process of the nanocomposites, relevant experiments are designed and carried out. The results are well consistent with previous assumptions and verify that several parameters, including feeding rate, volume ratio of matched solvent and anti‐solvent, can be employed to manipulate the size and morphology of the nanocomposites. The catalytic activity of CuO nanoparticles in the nanocomposites exhibits superior performance.
Intracellular Implantation of Enzymes in Hollow Silica Nanospheres for Protein Therapy: Cascade System of Superoxide Dismutase and Catalase
Authors: Chang Feng‐Peng , Chen Yi‐Ping , Mou Chung‐Yuan
Published: August 2014

An approach for enzyme therapeutics is elaborated with cell‐implanted nanoreactors that are based on multiple enzymes encapsulated in hollow silica nanospheres (HSNs). The synthesis of HSNs is carried out by silica sol–gel templating of water‐in‐oil microemulsions so that polyethyleneimine (PEI) modified enzymes in aqueous phase are encapsulated inside the HSNs. PEI‐grafted superoxide dismutase (PEI‐SOD) and catalase (PEI‐CAT) encapsulated in HSNs are prepared with quantitative control of the enzyme loadings. Excellent activities of superoxide dismutation by PEI‐SOD@HSN are found and transformation of H2O2 to water by PEI‐CAT@HSN. When PEI‐SOD and PEI‐CAT are co‐encapsulated, cascade transformation of superoxide through hydrogen peroxide to water was facile. Substantial fractions of HSNs exhibit endosome escape to cytosol after their delivery to cells. The production of downstream reactive oxygen species (ROS) and COX‐2/p‐p38 expression show that co‐encapsulated SOD/CAT inside the HSNs renders the highest cell protection against the toxicant N,N′‐dimethyl‐4,4′‐bipyridinium dichloride (paraquat). The rapid cell uptake and strong detoxification effect on superoxide radicals by the SOD/CAT‐encapsulated hollow mesoporous silica nanoparticles demonstrate the general concept of implanting catalytic nanoreactors in biological cells with designed functions.