bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phase sorting wave‐particle correlator
Authors: Kletzing C. A. , LaBelle J. , Bounds S. R. , Dolan J. , Kaeppler S. R. , Dombrowski M. 
Published: December 2016

AbstractWave‐particle correlations, particularly of Langmuir waves and electrons, have been the subject of significant interest extending back to the 1970s. Often, these correlations have been simply observing modulation of the electrons at the plasma frequency with no phase resolution. The first phase‐resolving correlators were developed at UC Berkeley in the late 1980s and reported by Ergun in the early 1990s. A design is presented which further improves on phase resolution in correlations of Langmuir waves and electrons with phase resolution of 22.5°. In this technique, a phase‐locked loop (PLL) is used to lock onto the wave and subdivide the phase. Electrons are sorted on‐the‐fly as they arrive into the phase bins. Discussed are details of accurate timing, testing, and calibration of this system as well as results from rocket flights in which statistically significant phase correlations have been observed.
Hydrodynamic influences on acoustical and optical backscatter in a fringing reef environment
Authors: Pawlak Geno , Moline Mark A. , Terrill Eric J. , Colin Patrick L. 
Published: December 2016

AbstractObservations of hydrodynamics along with optical and acoustical water characteristics in a tropical fringing reef environment reveal a distinct signature associated with flow characteristics and tidal conditions. Flow conditions are dominated by tidal forcing with an offshore component from the reef flat during ebb. Measurements span variable wave conditions enabling identification of wave effects on optical and acoustical water properties. High‐frequency acoustic backscatter (6 MHz) is strongly correlated with tidal forcing increasing with offshore directed flow and modulated by wave height, indicating dominant hydrodynamic influence. Backscatter at 300 and 1200 kHz is predominantly diurnal suggesting a biological component. Optical backscatter is closely correlated with high‐frequency acoustic backscatter across the range of study conditions. Acoustic backscatter frequency dependence is used along with changes in optical properties to interpret particle‐size variations. Changes across wave heights suggest shifts in particle‐size distributions with increases in relative concentrations of smaller particles for larger wave conditions. Establishing a connection between the physical processes of a fringing tropical reef and the resulting acoustical and optical signals allows for interpretation and forecasting of the remote sensing response of these phenomena over larger scales.
A calibration‐free formulation of the complementary relationship of evaporation for continental‐scale hydrology
Authors: Szilagyi Jozsef , Crago Richard , Qualls Russell 
Published: December 2016

AbstractAn important scaling consideration is introduced into the formulation of the complementary relationship (CR) of land surface evapotranspiration (ET) by specifying the maximum possible evaporation rate (Epmax) of a small water body (or wet patch) as a result of adiabatic drying from the prevailing near‐neutral atmospheric conditions. In dimensionless form the CR therefore becomes yB = f(
xB) = f(X) = 2X2 − X3, where yB = ET/Ep, xB = Ew/Ep. Ew is the wet‐environment evaporation rate as given by the Priestley‐Taylor equation, Ep is the evaporation rate of the same small wet surface for which Epmax is specified and estimated by the Penman equation. With the help of North American Regional Reanalysis data, the CR this way yields better continental‐scale performance than earlier, calibrated versions of it and is on par with current land surface model results, the latter requiring vegetation, soil information and soil moisture bookkeeping. Validation has been performed by Parameter‐Elevation Regressions on Independent Slopes Model precipitation and United States Geological Survey runoff data. A novel approach is also introduced to calculate the value of the Priestley‐Taylor parameter to be used with continental‐scale data, making the new formulation of the CR completely calibration free.
Flood type specific construction of synthetic design hydrographs
Authors: Brunner Manuela I. , Viviroli Daniel , Sikorska Anna E. , Vannier Olivier , Favre Anne‐Catherine , Seibert Jan 
Published: December 2016

AbstractAccurate estimates of flood peaks, corresponding volumes, and hydrographs are required to design safe and cost‐effective hydraulic structures. In this paper, we propose a statistical approach for the estimation of the design variables peak and volume by constructing synthetic design hydrographs for different flood types such as flash‐floods, short‐rain floods, long‐rain floods, and rain‐on‐snow floods. Our approach relies on the fitting of probability density functions to observed flood hydrographs of a certain flood type and accounts for the dependence between peak discharge and flood volume. It makes use of the statistical information contained in the data and retains the process information of the flood type. The method was tested based on data from 39 mesoscale catchments in Switzerland and provides catchment specific and flood type specific synthetic design hydrographs for all of these catchments. We demonstrate that flood type specific synthetic design hydrographs are meaningful in flood‐risk management when combined with knowledge on the seasonality and the frequency of different flood types.
Nutrient processes at the stream‐lake interface for a channelized versus unmodified stream mouth
Authors: Niswonger Richard , Naranjo Ramon , Smith David , Constantz Jim , Allander Kip , Rosenberry Donald , Neilson Bethany , Rosen Michael R. , Stonestrom David 
Published: December 2016

AbstractInorganic forms of nitrogen and phosphorous impact freshwater lakes by stimulating primary production and affecting water quality and ecosystem health. Communities around the world are motivated to sustain and restore freshwater resources and are interested in processes controlling nutrient inputs. We studied the environment where streams flow into lakes, referred to as the stream‐lake interface (SLI), for a channelized and unmodified stream outlet. Channelization is done to protect infrastructure or recreational beach areas. We collected hydraulic and nutrient data for surface water and shallow groundwater in two SLIs to develop conceptual models that describe characteristics that are representative of these hydrologic features. Water, heat, and solute transport models were used to evaluate hydrologic conceptualizations and estimate mean residence times of water in the sediment. A nutrient mass balance model is developed to estimate net rates of adsorption and desorption, mineralization, and nitrification along subsurface flow paths. Results indicate that SLIs are dynamic sources of nutrients to lakes and that the common practice of channelizing the stream at the SLI decreases nutrient concentrations in pore water discharging along the lakeshore. This is in contrast to the unmodified SLI that forms a barrier beach that disconnects the stream from the lake and results in higher nutrient concentrations in pore water discharging to the lake. These results are significant because nutrient delivery through pore water seepage at the lakebed from the natural SLI contributes to nearshore algal communities and produces elevated concentrations of inorganic nutrients in the benthic zone where attached algae grow.
Impact of evapotranspiration process representation on runoff projections from conceptual rainfall‐runoff models
Authors: Guo Danlu , Westra Seth , Maier Holger R. 
Published: December 2016

AbstractConceptual rainfall‐runoff models are commonly used to estimate potential changes in runoff due to climate change. The development of these models has generally focused on reproducing runoff characteristics, with less scrutiny on other important processes such as the conversion from potential evapotranspiration (PET) to actual evapotranspiration (AET). This study uses three conceptual rainfall‐runoff models (GR4J, AWBM, and IHACRES_CMD) and five catchments in climatologically different regions of Australia to explore the role of ET process representation on the sensitivity of runoff to plausible future changes in PET. The changes in PET were simulated using the Penman‐Monteith model and by perturbing each of the driving variables (temperature, solar radiation, humidity, and wind) separately. Surprisingly, the results showed the potential of a more than sevenfold difference in runoff sensitivity per unit change in annual average PET, depending on both the rainfall‐runoff model and the climate variable used to perturb PET. These differences were largely due to different ways used to convert PET to AET in the conceptual rainfall‐runoff models, with particular dependencies on the daily wet/dry status, as well as the seasonal variations in store levels. By comparing the temporal patterns in simulated AET with eddy‐covariance‐based observations at two of the study locations, we highlighted some unrealistic behavior in the simulated AET from AWBM. Such process‐based evaluations are useful for scrutinizing the representation of physical processes in alternative conceptual rainfall‐runoff models, which can be particularly useful for selecting models for projecting runoff under a changing climate.
The influence of mixing on stable isotope ratios in porous media: A revised Rayleigh model
Authors: Druhan Jennifer L. , Maher Kate 
Published: December 2016

AbstractFor an irreversible reaction, the Rayleigh or distillation‐type relationship between stable isotope enrichment and reactant concentration is compromised if fluid samples are characterized by a range of water ages or different extents of reaction progress. Such mixed samples are rarely avoided in the standard methods of sampling fluid from natural porous media. As a result, application of a Rayleigh model to stable isotope ratios measured in aquifers commonly requires a diminished or effective fractionation factor relative to the intrinsic value obtained in the absence of transport effects. Thus, quantitative application of intrinsic parameter values to a fractionating reaction occurring in porous media flow requires revision to the functional form of the relationship between reactant concentration and isotope fractionation. Here we derive a series of analytical solutions for the relationship between fractionation and flow subject to nonuniform fluid travel time distributions. These solutions are unique from previous approaches in that they avoid the use of a dispersion coefficient. The results are demonstrated against multicomponent reactive transport simulations of stable isotope fractionation in homogeneous and spatially correlated heterogeneous flow fields, and applied to a data set of stable chromium (Cr) isotope enrichment obtained from a contaminated aquifer. We show that the flux‐weighted isotope ratio of a solute is more sensitive to the effects of physical heterogeneity than solute concentrations. Our results support an updated functional form of the traditional Rayleigh model that describes the relationship between reactant concentration and isotope fractionation and is valid for a mixed‐fluid sample.
Interband Absorption Enhanced Optical Activity in Discrete Au@Ag Core–Shell Nanocuboids: Probing Extended Helical Conformation of Chemisorbed Cysteine Molecules
Authors: Bao Zhi Yong , Zhang Wei , Zhang Yong‐Liang , He Jijun , Dai Jiyan , Yeung Chi‐Tung , Law Ga‐Lai , Lei Dang Yuan 
Published: December 2016

AbstractDetailed understanding of the interaction between a chiral molecule and a noble metal surface is essential to rationalize and advance interfacial self‐assembly of amino acids and metal‐mediated anchoring of proteins. Here we demonstrate that individual Au@Ag core–shell nanocuboids can serve as a plasmonic reporter of an extended helical network formed among chemisorbed cysteine molecules, through generating an interband absorption enhanced, Ag‐surface‐exclusive circular dichroism (CD) band in the UV region. The observed unusual, strong CD response in the hybrid Au@Ag–cysteine system can be used to probe in real time conformational evolution and structural rearrangement of biomolecules in general and also monitor the interfacial interaction between a metal surface and an adsorbed molecule, opening up the possibility of using Ag nanostructures as promising stereochemically attuned nanosensors.
Development and Cycloaddition Reactivity of a New Class of Pyridine‐Based Mesoionic 1,3‐Dipole
Authors: Erguven Huseyin , Leitch David C. , Keyzer Evan N. , Arndtsen Bruce A. 
Published: December 2016

AbstractWe describe here the development and structural characterization of a new type of mesoionic 1,3‐dipole, which can be generated in the one‐step reaction of imines with pyridine‐ or quinoline‐based acid chlorides. Coupling the formation of these dipoles with alkyne cycloaddition can open a general and modular route to synthesize indolizines from combinations of available and diversifiable building blocks.
A Leaf‐Inspired Luminescent Solar Concentrator for Energy‐Efficient Continuous‐Flow Photochemistry
Authors: Cambié Dario , Zhao Fang , Hessel Volker , Debije Michael G. , Noël Timothy 
Published: December 2016

AbstractThe use of solar light to promote chemical reactions holds significant potential with regard to sustainable energy solutions. While the number of visible light‐induced transformations has increased significantly, the use of abundant solar light has been extremely limited. We report a leaf‐inspired photomicroreactor that constitutes a merger between luminescent solar concentrators (LSCs) and flow photochemistry to enable green and efficient reactions powered by solar irradiation. This device based on fluorescent dye‐doped polydimethylsiloxane collects sunlight, focuses the energy to a narrow wavelength region, and then transports that energy to embedded microchannels where the flowing reactants are converted.
Chemical Bonding Analysis as a Guide for the Preparation of New Compounds: The Case of VIrGe and HfPtGe
Authors: Bende David , Wagner Frank R. , Sichevych Olga , Grin Yuri 
Published: December 2016

AbstractThe chemical bonding of transition metal compounds with a MgAgAs‐type of crystal structure is analyzed with quantum chemical position‐space techniques. The observed trends in QTAIM Madelung energy and nearest neighbor electron sharing explain the occurrence of recently synthesized MgAgAs‐type compounds, TiPtGe and TaIrGe, at the boundary to the TiNiSi‐type crystal structure. These bonding indicators are used to identify favorable element combinations for new MgAgAs‐type compounds. The new phases—the high‐temperature VIrGe and the low‐temperature HfPtGe—showing this type of crystal structure are prepared and characterized by powder X‐ray diffraction and differential thermal analysis.
Oxygen Activation at the Active Site of a Fungal Lytic Polysaccharide Monooxygenase
Authors: O'Dell William B. , Agarwal Pratul K. , Meilleur Flora 
Published: December 2016

AbstractLytic polysaccharide monooxygenases have attracted vast attention owing to their abilities to disrupt glycosidic bonds via oxidation instead of hydrolysis and to enhance enzymatic digestion of recalcitrant substrates including chitin and cellulose. We have determined high‐resolution X‐ray crystal structures of an enzyme from Neurospora crassa in the resting state and of a copper(II) dioxo intermediate complex formed in the absence of substrate. X‐ray crystal structures also revealed “pre‐bound” molecular oxygen adjacent to the active site. An examination of protonation states enabled by neutron crystallography and density functional theory calculations identified a role for a conserved histidine in promoting oxygen activation. These results provide a new structural description of oxygen activation by substrate free lytic polysaccharide monooxygenases and provide insights that can be extended to reactivity in the enzyme–substrate complex.
Beryllium Phosphine Complexes: Synthesis, Properties, and Reactivity of (PMe3)2BeCl2 and (Ph2PC3H6PPh2)BeCl2
Authors: Buchner Magnus R. , Müller Matthias , Rudel Stefan S. 
Published: December 2016

AbstractThe directed synthesis, spectroscopic properties, and reactivity of bis(trimethylphosphine) beryllium dichloride (1) and bis(diphenylphosphino)propane beryllium dichloride (2) are reported, including the crystal structure of (PMe3)2BeCl2 (1). These four‐coordinate beryllium compounds can be alkylated with n‐butyllithium (nBuLi) to give three‐coordinate (Ph2PC3H6PPh2)BenBu2 (3) and (PMe3)BenBu2 (4). PMe3 can be removed from (PMe3)BenBu2 (4) in vacuo to yield [nBu2Be]2 (5). For the first time, the presence of [nBu2Be]2 as a dimer in solution, which has been postulated for decades, could be observed spectroscopically. This novel, ether‐free pathway provides access to beryllium dialkyl compounds that have never been in contact with oxygen‐atom‐containing reagents or solvents. This “freeness from oxygen” is crucial for semiconductor applications where oxygen is often unwanted and must be avoided at all costs.
Asymmetric Strecker Reaction Arising from the Molecular Orientation of an Achiral Imine at the Single‐Crystal Face: Enantioenriched l‐ and d‐Amino Acids
Authors: Miyagawa Shinobu , Yoshimura Koji , Yamazaki Yusuke , Takamatsu Naoya , Kuraishi Tetsuya , Aiba Shohei , Tokunaga Yuji , Kawasaki Tsuneomi 
Published: December 2016

AbstractStrecker synthesis has long been considered one of the prebiotic reactions for the synthesis of α‐amino acids. However, the correlation between the origin of chirality and highly enantioenriched α‐amino acids through this method remains a puzzle. In the reaction, it may be conceivable that the handedness of amino acids has been determined at the formation stage of the chiral intermediate α‐aminonitrile, that is, the enantioselective addition of hydrogen cyanide to an imine. Herein, an enantiotopic crystal surface of an achiral imine acted as an origin of chirality for the enantioselective formation of α‐aminonitriles by the addition of HCN. In conjunction with the amplification of the enantiomeric excess and multiplication of enantioenriched aminonitrile, a large amount of near enantiopure α‐amino acids, with the l‐ and d‐handedness corresponding to the molecular orientation of the imine, is reported.
Malachite green adsorption by potassium salts‐activated carbons derived from textile sludge: Equilibrium, kinetics and thermodynamics studies
Authors: Tang S.H. , Zaini M.A.A. 
Published: December 2016

AbstractThis work is aimed at evaluating the adsorption of malachite green (MG) on potassium salts‐activated carbons derived from textile sludge. Potassium hydroxide (KOH), potassium iodide (KI), and the potassium salts (KOH + KI) composite were used in chemical activation. The physicochemical properties of the activated carbons were characterized according to textural and surface chemistry. The specific surface area of activated carbon is in the range of 66 to 584 m2/g. The KOH and KI + KOH composite series exhibit a higher surface area. The maximum MG adsorption are between 167 and 113 mg/g. Langmuir model shows the best conformity to the equilibrium data, while the kinetics data were best fitted to the pseudo‐second‐order model, suggesting the chemisorption process. The intraparticle diffusion maybe involved, but it is not the sole rate‐limiting step, while the film diffusion could be the controlling mechanism. Thermodynamics data revealed that the MG adsorption is spontaneous and endothermic. Copyright © 2016 Curtin University of Technology and John Wiley & Sons, Ltd.
Human behavioural ecology and Pacific archaeology
Authors: DINAPOLI ROBERT J. , MORRISON ALEX E. 
Published: December 2016

ABSTRACTThe diverse islands of Oceania are ideal locations for the study of human ecology. Here, we argue that human behavioural ecology (HBE) provides a useful theoretical framework to approach a range of topics in Pacific prehistory, including, but not limited to, subsistence, territoriality, and monumentality. We further stress that the strength of this approach lies in the use of models as heuristic devices, and that HBE is not mutually exclusive from other explanatory frameworks, but complements larger research agendas in Pacific archaeology.
The absorption kinetics of ketoconazole plays a major role in explaining the reported variability in the level of interaction with midazolam: Interplay between formulation and inhibition of gut wall and liver metabolism
Authors: Liu Bo , Crewe H. Kim , Ozdemir Mahmut , Rowland Yeo Karen , Tucker Geoffrey , Rostami‐Hodjegan Amin 
Published: December 2016

AbstractThe impact of different single oral doses of ketoconazole (KTZ) (100, 200 and 400 mg) and of staggering its dosage (400 mg at −12, −2, 0, 2 and 4 h), with respect to the administration of a single 5 mg oral dose of midazolam (MDZ) on the extent of inhibition of the metabolism of the latter, was evaluated in healthy subjects in two separate studies. Escalation of the ketoconazole dosage resulted in 2.3 (1.9), 2.7 (1.7) and 4.2 (2.5) ‐fold increases in the mean AUC(0,12h) (and Cmax) values of midazolam. Dose‐staggering was associated with 3.9 (2.5), 4.9 (2.9), 5.4 (2.8), 2.0 (1.3) and 1.2 (0.9) ‐fold increases in the mean AUC(0,12h) (and Cmax) of midazolam. These findings could be predicted by physiologically based pharmacokinetic (PBPK) modelling using the ADAM (advanced dissolution absorption and metabolism) model within the Simcyp Simulator (Version 12 Release 2) to characterize the absorption kinetics of ketoconazole with respect to disintegration time, supersaturation ratio and precipitation rate. This study also emphasizes a need to account for inter‐individual variability in the gut wall and systemic exposure of inhibitors with physicochemical properties similar to ketoconazole, in particular in their rate of oral absorption and when using different pharmaceutical formulations, in designing and evaluating the extent of drug–drug interactions. Copyright © 2016 John Wiley & Sons, Ltd.
Skin‐mimetic chromatography for prediction of human percutaneous absorption of biologically active compounds occurring in medicinal plant extracts
Authors: Stepnik Katarzyna , Malinowska Irena 
Published: December 2016

AbstractThe main aim of this study was to predict quantitatively human percutaneous absorption of chosen compounds commonly occurring in plants which can be used as medicinal extracts in the drug and beauty industries. The most important human percutaneous descriptors, i.e. logKp (logarithm of the water/skin partition coefficient) and logJmax (logarithm of the maximum flux of solutes penetrating the skin), of fatty acids and polyphenols were determined using both in vitro and in silico methods. For in vitro determination of human percutaneous absorption, micellar liquid chromatography based on hexadecyltrimethylammonium bromide, sodium dodecyl sulfate and polyoxyethylene (23) lauryl ether (Brij35) was used. Human percutaneous absorption was characterized by entirely new QSAR/QRAR models based on retention, lipophilic, steric and electronic data as well as on the linear free energy relationship parameters. Many different correlations between human skin absorption and different physicochemical parameters were performed, e.g. the in silico estimated logKp value was correlated with the retention parameter logkw (logarithm of the retention factor extrapolated to pure water) from the systems imitating a cutaneous environment (R2 = 0.92). Moreover, the influence of lipophilicity on percutaneous absorption was examined. The obtained correlation was excellent (R2 = 0.95).