bluuebunny/crossref_metadata_2025_split huggingface dataset:
An analytical approach for calculating energy spectra of relativistic runaway electron avalanches in air
Authors: Cramer E. S. , Dwyer J. R. , Arabshahi S. , Vodopiyanov I. B. , Liu N. , Rassoul H. K. 
Published: August 2014

AbstractSimplified equations describing the transport and energy spectrum of runaway electrons are derived from the basic kinematics of the continuity equations. These equations are useful in modeling the energy distribution of energetic electrons in strong electric fields, such as those found inside thunderstorms. Dwyer and Babich (2011) investigated the generation of low‐energy electrons in relativistic runaway electron avalanches. The paper also developed simple analytical expressions to describe the detailed physics of Monte Carlo simulations of relativistic runaway electrons in air. In the current work, the energy spectra of the runaway electron population are studied in detail. Dependence of electron avalanche development on properties such as the avalanche length, radiation length, and the effective Møller scattering efficiency factor are discussed in detail. To describe the shapes of the electron energy spectra for a wide range of electric field strengths, the diffusion term responsible for random deviation of electron energy ionization loss from the mean value is added to the kinetic equation. We find that the diffusion in energy space helps maintain an exponential energy spectrum for electric fields that approach the runaway electron threshold field.
Drivers of variability in Arctic sea‐ice drift speed
Authors: Olason Einar , Notz Dirk 
Published: August 2014

AbstractWe explore the main drivers of seasonal and long‐term variations in basin‐scale Arctic sea‐ice drift speed. To do so, we examine the relationship between the observed time‐varying area‐mean ice drift speed in the central Arctic and observed thickness and concentration as well as surface wind stress. Drift speeds are calculated from the positions of drifting buoys, thickness is based on submarine observations, concentration on satellite observations, and the wind stress comes from a global reanalysis. We find that seasonal changes in drift speed are correlated primarily with changes in concentration when concentration is low and with changes in thickness otherwise. The correlation between drift speed and concentration occurs because changing concentration changes how readily the ice responds to the synoptic‐scale forcing of the atmosphere. Drift speed is correlated with neither concentration nor thickness in April and May. We show this behavior to be correlated with a decrease in the localization of deformation. This indicates that the increase in drift speed is caused by newly formed fractures not refreezing, leading to an overall reduced ice‐cover strength without a detectable change in ice concentration. We show that a strong long‐term trend exists in months of relatively low ice concentration. Using our analysis of the seasonal cycle, we show that the trend in concentration drives a significant portion of the drift‐speed trend, possibly reinforced by a trend in cyclone activity. Hence, the trend in drift speed in this period is primarily caused by increased synoptic‐scale movement of the ice pack.
Further development of a parameterization for convective turbulent dust emission and evaluation based on field observations
Authors: Klose Martina , Shao Yaping , Li Xiaolan , Zhang Hongsheng , Ishizuka Masahide , Mikami Masao , Leys John F. 
Published: August 2014

AbstractFurther developments of a parameterization scheme for convective turbulent dust emission (CTDE) are presented. The scheme is advanced by including (1) a new statistical description of instantaneous momentum flux, (2) a correction function for cohesive force to account for the effect of soil moisture, and (3) a correction function for lifting force to consider the effect of vegetation roughness elements. The probability density function describing instantaneous momentum flux is now derived from large‐eddy simulations for different atmospheric stabilities. The vegetation correction function is based on a drag partition theory. Additional improvements on the representations of interparticle cohesive force and particle size distribution are introduced. The new CTDE scheme is tested against the field data obtained at a sand storm monitoring station in the Horqin Sandy Land in China in 2011 and during the Japan‐Australia Dust Experiment in Australia in 2006.
Hydrogen implantation in silicates: The role of solar wind in SiOH bond formation on the surfaces of airless bodies in space
Authors: Schaible Micah J. , Baragiola Raúl A. 
Published: August 2014

AbstractHydroxyl on the lunar surface revealed by remote measurements has been thought to originate from solar wind hydrogen implantation in the regolith. The hypothesis is tested here through experimental studies of the rate and mechanisms of OH bond formation due to H+ implantation of amorphous SiO2 and olivine in ultrahigh vacuum. The samples were implanted with 2–10 keV H+, in the range of solar wind energies, and the OH absorption band at ~2.8 µm measured by transmission Fourier transform infrared spectroscopy. For 2 keV protons in SiO2, the OH band depth saturated at fluences F ~5 × 1016 H+/cm2 to a maximum 0.0032 absorption band depth, corresponding to a column density ηs = 1.1 × 1016 OH/cm2. The corresponding values for 5 keV protons in olivine are >2 × 1017/cm2, 0.0067, and 4.0 × 1016 OH/cm2. The initial conversion rate of implanted H+ into hydroxyl species was found to be ~90% and decreased exponentially with fluence. There was no evidence for molecular water formation due to proton irradiation. Translating the laboratory measurements in thin plate samples to the granular lunar regolith, it is estimated that the measurements can account for a maximum of 17% relative OH absorption in reflectance spectroscopy of mature soils, consistent with spacecraft observations in the infrared of the Moon.
The WFDEI meteorological forcing data set: WATCH Forcing Data methodology applied to ERA‐Interim reanalysis data
Authors: Weedon Graham P. , Balsamo Gianpaolo , Bellouin Nicolas , Gomes Sandra , Best Martin J. , Viterbo Pedro 
Published: August 2014

AbstractThe WFDEI meteorological forcing data set has been generated using the same methodology as the widely used WATCH Forcing Data (WFD) by making use of the ERA‐Interim reanalysis data. We discuss the specifics of how changes in the reanalysis and processing have led to improvement over the WFD. We attribute improvements in precipitation and wind speed to the latest reanalysis basis data and improved downward shortwave fluxes to the changes in the aerosol corrections. Covering 1979–2012, the WFDEI will allow more thorough comparisons of hydrological and Earth System model outputs with hydrologically and phenologically relevant satellite products than using the WFD.
Brain diabetic neurodegeneration segregates with low intrinsic aerobic capacity
Authors: Choi Joungil , Chandrasekaran Krish , Demarest Tyler G. , Kristian Tibor , Xu Su , Vijaykumar Kadambari , Dsouza Kevin Geoffrey , Qi Nathan R. , Yarowsky Paul J. , Gallipoli Rao , Koch Lauren G. , Fiskum Gary M. , Britton Steven L. , Russell James W. 
Published: August 2014

AbstractObjectivesDiabetes leads to cognitive impairment and is associated with age‐related neurodegenerative diseases including Alzheimer's disease (AD). Thus, understanding diabetes‐induced alterations in brain function is important for developing early interventions for neurodegeneration. Low‐capacity runner (LCR) rats are obese and manifest metabolic risk factors resembling human “impaired glucose tolerance” or metabolic syndrome. We examined hippocampal function in aged LCR rats compared to their high‐capacity runner (HCR) rat counterparts.MethodsHippocampal function was examined using proton magnetic resonance spectroscopy and imaging, unbiased stereology analysis, and a Y maze. Changes in the mitochondrial respiratory chain function and levels of hyperphosphorylated tau and mitochondrial transcriptional regulators were examined.ResultsThe levels of glutamate, myo‐inositol, taurine, and choline‐containing compounds were significantly increased in the aged LCR rats. We observed a significant loss of hippocampal neurons and impaired cognitive function in aged LCR rats. Respiratory chain function and activity were significantly decreased in the aged LCR rats. Hyperphosphorylated tau was accumulated within mitochondria and peroxisome proliferator‐activated receptor‐gamma coactivator 1α, the NAD+‐dependent protein deacetylase sirtuin 1, and mitochondrial transcription factor A were downregulated in the aged LCR rat hippocampus.InterpretationThese data provide evidence of a neurodegenerative process in the hippocampus of aged LCR rats, consistent with those seen in aged‐related dementing illnesses such as AD in humans. The metabolic and mitochondrial abnormalities observed in LCR rat hippocampus are similar to well‐described mechanisms that lead to diabetic neuropathy and may provide an important link between cognitive and metabolic dysfunction.
Observation of Interstitial Molecular Hydrogen in Clathrate Hydrates
Authors: Grim R. Gary , Barnes Brian C. , Lafond Patrick G. , Kockelmann Winfred A. , Keen David A. , Soper Alan K. , Hiratsuka Masaki , Yasuoka Kenji , Koh Carolyn A. , Sum Amadeu K. 
Published: August 2014

AbstractThe current knowledge and description of guest molecules within clathrate hydrates only accounts for occupancy within regular polyhedral water cages. Experimental measurements and simulations, examining the tert‐butylamine+H2+H2O hydrate system, now suggest that H2 can also be incorporated within hydrate crystal structures by occupying interstitial sites, that is, locations other than the interior of regular polyhedral water cages. Specifically, H2 is found within the shared heptagonal faces of the large (43596273) cage and in cavities formed from the disruption of smaller (4454) water cages. The ability of H2 to occupy these interstitial sites and fluctuate position in the crystal lattice demonstrates the dynamic behavior of H2 in solids and reveals new insight into guest–guest and guest–host interactions in clathrate hydrates, with potential implications in increasing overall energy storage properties.
Planet–Satellite Nanostructures Made To Order by RAFT Star Polymers
Authors: Rossner Christian , Vana Philipp 
Published: August 2014

AbstractThe investigation and application of complex nanostructures requires the hierarchical arrangement of distinct domains on a small scale. Herein, we report a method to prepare planet–satellite arrangements using RAFT polymers. Our approach is based on star polymers decorated with trithiocarbonate groups on their outer periphery that attach to gold surfaces and thus provide the polymer with the ability to connect (larger) gold nanoparticle planets with (smaller) gold nanoparticle satellites. By adjusting the molecular weight of the polymeric linker, nanostructures with tailored planet–satellite distances, as evidenced by transmission electron microscopy, are obtained. This strategy offers a straightforward way to prepare gold nanoparticle scaffolds with multiple reactive functionalities at defined distances from the central core.
Structural and dielectric studies of amorphous and semicrystalline polymers blend‐based nanocomposite electrolytes
Authors: Choudhary Shobhna , Sengwa Ram Jeewan 
Published: August 2014

ABSTRACTThe solid polymeric nanocomposite electrolyte (SPNE) films based on the blend of amorphous poly(methyl methacrylate) (PMMA) and semicrystalline poly(ethylene oxide) (PEO) (PMMA:PEO = 80:20 wt %) doped with lithium perchlorate (LiClO4) salt and montmorillonite (MMT) clay nanofiller were prepared by classical solution cast, ultrasonic assisted solution cast and ultrasonication along with microwave irradiated solution cast followed by melt‐pressing methods. The X‐ray diffraction study of these electrolytes revealed the amorphous behavior with intercalated MMT structures. The suppressed crystallinity of PEO in the blend electrolyte complexes confirmed the existence of single discrete PEO chains confined within the PMMA domains. The dielectric relaxation spectroscopy of these materials was performed over the frequency range 20 Hz to 1 MHz, at ambient temperature. The presence of a singular relaxation peak in the loss tangent and electric modulus spectra of these electrolytes confirms a coupled cooperative chain segmental dynamics of the blend polymer owing to their miscible amorphous morphology. The behavior of transient complexes formed between the polymers functional groups, lithium cations and the intercalated MMT nanoplatelets was explored. The ambient temperature ionic conductivity of these electrolytes depends on the structural dynamics and the sample preparation methods. It is revealed that the presence of PEO in the PMMA matrix mainly governs the structural, dielectric, and ionic properties of these SPNE films. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2015,132, 41311.
Synthesis, PL characterizations and concentration quenching effect in Dy3+ and Eu3+ activated LiCaBO3 phosphor
Authors: Kharabe V. R. , Oza Abha H. , Dhoble S. J. 
Published: August 2014

AbstractLiCaBO3:Dy3+/Eu3+ phosphors were synthesized by a solid‐state reaction. The synthesized materials were characterized using powder X‐ray diffraction pattern (XRD) for confirmation. All the structural parameters were calculated from the XRD data. Scanning electron microscopy (SEM) images showed rod‐like morphology. Photoluminescence (PL) emission spectra showed two emissions (484 and 577 nm) in Dy3+‐doped LiCaBO3:Dy3+phosphors with the concentration quenching effect and the critical distance was calculated to be about 22.76 Å. LiCaBO3:Eu3+ phosphor was effectively excited by a near‐UV light of 392 nm. The emission spectra exhibited the transition from 5D0 level to 7FJ (J = 0–2) with main emission at 614 nm, which comes from the electrodipole transition because of the asymmetric point group. The quenching concentration of Eu3+ is about 0.2 mol%, and the critical distance was calculated to be about 38.93 Å. Copyright © 2014 John Wiley & Sons, Ltd.
A simple validated RP‐HPLC bioanalytical method for the quantitative determination of a novel valproic acid arylamide derivative in rat hepatic microsomes
Authors: Silva‐Trujillo Arianna , Correa‐Basurto José , Romero‐Castro Aurelio , Albores Arnulfo , Mendieta‐Wejebe Jessica Elena 
Published: August 2014

AbstractA simple and specific bioanalytical method based on reversed‐phase high‐performance liquid chromatography (RP‐HPLC) coupled with ultraviolet detection was developed and validated for the determination of a novel valproic acid arylamide, N‐(2‐hydroxyphenyl)‐2‐propylpentanamide (HO‐AAVPA) in rat hepatic microsomes (a subcellular fraction containing phase I enzymes, especially cytochrome P450). The chromatographic separation was achieved using a reversed‐phase Zorbax SB‐C18 column and a mobile phase of acetic acid in water (0.2% v/v) and acetonitrile (40:60 v/v) with a flow rate of 0.5 mL/min. The calibration curve was linear over the range of 882–7060 ng/mL (r2 = 0.9987), and the lower limit of quantification and the lower limit of determination were found to be 882 and 127.99 ng/mL, respectively. The method was validated with excellent sensitivity, and intra‐day accuracy and precision varied from 93.79 to 93.12%, and from 2.12 to 4.36%, respectively. The inter‐day accuracy and precision ranged from 93.29 to 97.30% and from 0.68 to 3.60%, respectively. The recovery of HO‐AAVPA was measured between 91.36 and 97.98%. The assay was successfully applied to the analysis of kinetic metabolism and pharmacokinetic parameters in vitro by a substrate depletion approach. Copyright © 2014 John Wiley & Sons, Ltd.
HPLC‐UV method for quantifying etoposide in plasma and tumor interstitial fluid by microdialysis: application to pharmacokinetic studies
Authors: Pigatto Maiara Cássia , Mossmann Daniele Lenz , Dalla Costa Teresa 
Published: August 2014

AbstractA simple and sensitive bioanalytical method was developed and validated for determination of etoposide in plasma and microdialysis samples of Walker‐256 tumor‐bearing rats. A microdialysis probe was implanted in the center of a subcutaneous tumor and Ringer's solution was used as perfusion medium. Chromatographic separation was conducted on a Shimadzu CLC‐C8 column using a mobile phase consisting of water–acetonitrile (70:30; v/v) adjusted to pH 4.0 ± 0.1 with formic acid at a gradient flow rate of 1.0–0.6 mL/min, an injection volume of 30 μL and UV detection at 210 nm. Microdialysate samples were analyzed without processing and plasma samples (100 μL) were spiked with phenytoin as internal standard (IS) (1 µg/mL) followed by extraction with tert‐butyl methyl ether. The organic layer was evaporated and reconstituted with 100 μL of mobile phase before injection. The methods for plasma and microdialysate were linear in the ranges of 25–10,000 ng/mL and of 10–1500 ng/mL, respectively. All the validation parameters such as intra‐ and inter‐day precision and accuracy and stability were within the limits established by international guidelines. The present method was successfully applied in the investigation of etoposide pharmacokinetics in rat plasma and microdialysate tumor samples following a single 15 mg/kg intravenous dose. Copyright © 2014 John Wiley & Sons, Ltd.
Efficacy and tolerability of treatment with azacitidine for 5 days in elderly patients with acute myeloid leukemia
Authors: Sadashiv Santhosh K. , Hilton Christie , Khan Cyrus , Rossetti James M. , Benjamin Heather L. , Fazal Salman , Sahovic Entezam , Shadduck Richard K. , Lister John 
Published: August 2014

AbstractAcute myeloid leukemia (AML) patients aged ≥60 years tolerate standard induction chemotherapy poorly. Therapy with azacitidine at a dose of 75 mg/m2/day for 7 days appears to be better tolerated, and is approved by the Food and Drug Administration (FDA) for the treatment of elderly AML patients with bone marrow (BM) blast counts of 20–30%. Here, we report the results of a prospective, phase 2, open‐label study that evaluated the tolerability and efficacy of a 5‐day regimen of single‐agent subcutaneous azacitidine 100 mg/m2/day administered every 28 days in 15 elderly patients with newly diagnosed AML, 14 of whom had BM blast counts >30%. The overall response rate was 47%. Complete remission, partial remission, and hematologic improvement were achieved by 20, 13, and 13% of patients, respectively. Median overall survival was 355 days for the entire cohort, and 532 days for responders. Median time to best response was 95 days, and median treatment duration was 198 days (range = 13–724 days). Grade 3–4 hematologic toxicities comprised predominantly febrile neutropenia (40%) and thrombocytopenia (20%). Febrile neutropenia was the most common cause of hospitalization. Nonhematologic toxicities, consisting of injection‐site skin reactions and fatigue (Grades 1–2), occurred in 73% (n = 11) of patients. No treatment‐related deaths occurred during the study. The dose and schedule of therapy remained constant in all but four patients. The findings of this study suggest that administration of subcutaneous azacitidine 100 mg/m2/day for 5 days every 28 days is a feasible, well‐tolerated, and effective alternative to standard induction chemotherapy in elderly patients with AML.
Lactose‐Functionalized Dendrimers Arbitrate the Interaction of Galectin‐3/MUC1 Mediated Cancer Cellular Aggregation
Authors: Michel Anna K. , Nangia‐Makker Pratima , Raz Avraham , Cloninger Mary J. 
Published: August 2014

AbstractBy using lactose‐functionalized poly(amidoamine) dendrimers as a tunable multivalent platform, we studied cancer cell aggregation in three different cell lines (A549, DU‐145, and HT‐1080) with galectin‐3. We found that small lactose‐functionalized G(2)‐dendrimer 1 inhibited galectin‐3‐induced aggregation of the cancer cells. In contrast, dendrimer 4 (a larger, generation 6 dendrimer with 100 carbohydrate end groups) caused cancer cells to aggregate through a galectin‐3 pathway. This study indicates that inhibition of cellular aggregation occurred because 1 provided competitive binding sites for galectin‐3 (compared to its putative cancer cell ligand, TF‐antigen on MUC1). Dendrimer 4, in contrast, provided an excess of ligands for galectin‐3 binding; this caused crosslinking and aggregation of cells to be increased.
Bimetallic Nickel–Rhodium Nanoparticles Supported on ZIF‐8 as Highly Efficient Catalysts for Hydrogen Generation from Hydrazine in Alkaline Solution
Authors: Xia Bingquan , Cao Nan , Dai Hongmei , Su Jun , Wu Xiaojun , Luo Wei , Cheng Gongzhen 
Published: August 2014

AbstractHighly dispersed bimetallic Ni–Rh nanoparticles with an average diameter of (1.2±0.2) nm were successfully deposited on the metal–organic framework (MOF) ZIF‐8 by using a simple liquid impregnation method. These catalysts were composition dependent toward the dehydrogenation of hydrazine in alkaline solution, whereas Ni66Rh34@ZIF‐8 exhibited the highest catalytic activity among all the catalysts tested with a turnover frequency value of 140 h−1 and 100 % hydrogen selectivity at 50 °C. The excellent catalytic performance may be caused by the synergistic molecular‐scale alloying effect of the bimetallic Ni–Rh nanoparticles on ZIF‐8 and the promotion effect of ZIF‐8. The development of high‐performance catalysts by utilizing MOFs as a novel porous catalyst support to control the limited growth of metal nanoparticles may promote the application of hydrous hydrazine as a promising chemical hydrogen‐storage material and open up new opportunities to use MOF‐supported metal nanoparticles for more applications.
Societal Acceptance of Coal and the Future of Coal Research in Germany
Authors: Nippa Michael , Lee Roh Pin 
Published: August 2014

AbstractIn Deutschland formiert sich seit längerem Widerstand gegen die Kohleverstromung und die Nutzung von Kohle. Dies hat auch Auswirkungen auf die Kohleforschung, was zu einem unwiederbringlichen Know‐how‐Verlust führen könnte. Letztlich ergeben sich daraus gravierende Konsequenzen für die nachhaltige Effizienzsteigerung bei Kohletechnologien. Die Akzeptanzforschung zur Kohle am Deutschen EnergieRohstoff‐Zentrum hat eine Reihe von kontraintuitiven Ergebnissen zutage gefördert. Im Beitrag wird das Forschungsprogramm vorgestellt, ausgewählte Ergebnisse beleuchtet und erste Implikationen abgeleitet.
Modelling development for ultrafiltration membrane fouling of heterogeneous membranes with non‐uniform pore size
Authors: Abdelrasoul Amira , Doan Huu , Lohi Ali , Cheng Chil‐Hung 
Published: August 2014

AbstractThe aim of the present study is to develop a mathematical model for a better understanding and prediction of the Ultrafiltration membrane fouling, which can be applied to the heterogeneous membrane with non‐uniform pore size. Polysulfone flat membrane with a molecular weight cut‐off (MWCO) of 60 000 (nominal size of 0.05 µm) was used with a constant feed flow rate and a cross‐flow mode in ultrafiltration of a latex paint solution. The pore size distribution of the heterogeneous membrane was estimated using ImageJ software. The model was developed based on analyses of particle attachments. All possible depositional and coagulation fouling attachments were included in the model with the evidence derived from the SEM images. Monodisperse particles with sizes of 50 nm and 100 nm, as well as the latex effluent with a wide range of particle size distribution, were utilized in order to test the validity of the model. The transmembrane pressure estimated from the mathematical model agreed with the transmembrane pressure experimentally measured mostly within 3.3–10.0 % error and up to 13.0 % error, using the monodisperse particles and latex effluent, respectively.