bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of an entropy‐based metric in multiobjective calibration to improve model performance
Authors: Pechlivanidis I. G. , Jackson B. , McMillan H. , Gupta H. 
Published: September 2014

AbstractParameter estimation for hydrological models is complicated for many reasons, one of which is the arbitrary emphasis placed, by most traditional measures of fit, on various magnitudes of the model residuals. Recent research has called for the development of robust diagnostic measures that provide insights into which model structural components and/or data may be inadequate. In this regard, the flow duration curve (FDC) represents the historical variability of flow and is considered to be an informative signature of catchment behavior. Here we investigate the potential of using the recently developed conditioned entropy difference metric (CED) in combination with the Kling‐Gupta efficiency (KGE). The CED respects the static information contained in the flow frequency distribution (and hence the FDC), but does not explicitly characterize temporal dynamics. The KGE reweights the importance of various hydrograph components (correlation, bias, variability) in a way that has been demonstrated to provide better model calibrations than the commonly used Nash‐Sutcliffe efficiency, while being explicitly time sensitive. We employ both measures within a multiobjective calibration framework and achieve better performance over the full range of flows than obtained by single‐criteria approaches, or by the common multiobjective approach that uses log‐transformed and untransformed data to balance fitting of low and high flow periods. The investigation highlights the potential of CED to complement KGE (and vice versa) during model identification. It is possible that some of the complementarity is due to CED representing more information from moments >2 than KGE or other common metrics. We therefore suggest that an interesting way forward would be to extend KGE to include higher moments, i.e., use different moments as multiple criteria.
Nonlinear time‐series modeling of unconfined groundwater head
Authors: Peterson T. J. , Western A. W. 
Published: September 2014

AbstractThis paper presents a nonlinear transfer function noise model for time‐series modeling of unconfined groundwater hydrographs. The motivation for its development was that existing groundwater time‐series models were unable to simulate large recharge events and multiyear droughts. This was because existing methods do not partition rainfall to runoff and do not account for nonlinear soil water drainage. To account for these nonlinear processes, a vertically integrated soil moisture module was added to an existing transfer function noise model. The soil moisture module has a highly flexible structure that allowed 84 different forms to be built. Application of the time‐series model requires numerical calibration of parameters for the transfer functions, noise model and, for the nonlinear models, the soil moisture module. This was undertaken using the Covariance Matrix Adaptation Evolutionary Strategy (CMA‐ES) global calibration scheme. However, reproducible calibration to the global optima was challenging and a number of modifications were required to the transfer function noise model. In trialing the 84 nonlinear models and 2 linear models, each was applied to eleven observation bores within a paired catchment study area in Great Western, Victoria, Australia. In comparison with existing groundwater hydrograph time‐series models, the proposed nonlinear time‐series model performed significantly better at all observation bores during calibration and evaluation periods. Both the linear and nonlinear models were also used to quantify the impact of revegetation within the paired catchment; however, results were inconclusive, which is likely due to time‐series data for the state of the revegetation being unavailable. By analyzing the application of 84 nonlinear models to each bore, an optimal structure for the soil moisture module was identified. It is unlikely, however, that this model structure would be appropriate for all climates and geologies. To encourage further investigations, open‐source code for the highly flexible groundwater time‐series modeling framework is available and we invite others to develop new models.
Regional acceleration in ice mass loss from Greenland and Antarctica using GRACE time‐variable gravity data
Authors: Velicogna I. , Sutterley T. C. , van den Broeke M. R. 
Published: September 2014

AbstractWe use Gravity Recovery and Climate Experiment (GRACE) monthly gravity fields to determine the regional acceleration in ice mass loss in Greenland and Antarctica for 2003–2013. We find that the total mass loss is controlled by only a few regions. In Greenland, the southeast and northwest generate 70% of the loss (280±58 Gt/yr) mostly from ice dynamics, the southwest accounts for 54% of the total acceleration in loss (25.4±1.2 Gt/yr2) from a decrease in surface mass balance (SMB), followed by the northwest (34%), and we find no significant acceleration in the northeast. In Antarctica, the Amundsen Sea (AS) sector and the Antarctic Peninsula account for 64% and 17%, respectively, of the total loss (180±10 Gt/yr) mainly from ice dynamics. The AS sector contributes most of the acceleration in loss (11±4 Gt/yr2), and Queen Maud Land, East Antarctica, is the only sector with a significant mass gain due to a local increase in SMB (63±5 Gt/yr).
Seismic reflectivity effects from seasonal seafloor temperature variation
Authors: Wood Warren T. , Martin Kylara M. , Jung Wooyeol , Sample John 
Published: September 2014

AbstractThe effects of seasonal temperature variation on sound speed contrasts at the seafloor are usually considered negligible in the analysis of seismic data but may be significant at large incidence angles (offsets) important for inversion of sediment elastic properties, or long‐range acoustic transmission. In coastal areas, the maximum annual seafloor temperature variation can be several degrees Celsius or more, corresponding to a sound speed variation of 30 m/s or more. Thermal pulses propagate via conduction several meters into the seafloor resulting in a damped quasi‐sinusoidal temperature profile with predictable wave number characteristics. The oscillating seasonal and spatial character of this signal creates a time‐ and frequency‐dependent effect on the elastic seafloor reflectivity. Results of numerical simulations show that the expected temperature profile for most sediment types and porosities will have the strongest affect on frequencies between about 60 and 600 Hz, at incidence angles greater than about 50°.
Subglacial Lake Vostok not expected to discharge water
Authors: Richter Andreas , Popov Sergey V. , Schröder Ludwig , Schwabe Joachim , Ewert Heiko , Scheinert Mirko , Horwath Martin , Dietrich Reinhard 
Published: September 2014

AbstractThe question whether Antarctica's largest lake, subglacial Lake Vostok, exchanges water is of interdisciplinary relevance but has been undecided so far. We present the potential pathway, outlet location, and threshold height of subglacial water discharge from this lake based on a quantitative evaluation of the fluid potential. If water left Lake Vostok, it would flow toward Ross Ice Shelf. Discharge would occur first to the east of the southern tip of the lake. At this location the bedrock threshold is 91 ± 23 m higher than the hydrostatic equipotential level of Lake Vostok. It is concluded that Lake Vostok is not likely to reach this level within climatic timescales and that no discharge of liquid water is to be expected. We show that in absence of the ice sheet the Lake Vostok depression would harbor a lake significantly deeper and larger than the present aquifer.
Observed decline in Titan's thermospheric methane due to solar cycle drivers
Authors: Westlake J. H. , Waite J. H. , Bell J. M. , Perryman R. 
Published: September 2014

AbstractWe present Cassini Ion and Neutral Mass Spectrometer observations of Titan's N2 and CH4 from Cassini flybys of Titan spanning the time period from 2004 to 2013 representing 9 years of in situ neutral density observations. This data reveal an upward trend in CH4 mixing ratios during the extended solar minimum encountered prior to 2011 followed by a downward trend in the mixing ratios of CH4 after the onset of solar maximum conditions in 2011. Through modeling studies using the time‐dependent Titan Global Ionosphere‐Thermosphere Model we show that this trend is due to enhanced photodestruction of CH4 in Titan's thermosphere from the increased solar EUV/UV flux during solar maximum times. The enhanced photodestruction of the methane leads to an increase in production of large hydrocarbons as observed in the enhanced production of large hydrocarbon ions and a twofold increase in the downward flux of C2 and larger hydrocarbons during solar maximum. Methane in the thermosphere is resupplied through upward flux from the lower thermosphere and stratosphere resulting in a refilling of the thermospheric methane on timescales of three Earth years. From this calculation it is expected that Titan's thermospheric methane will recover in the 2015 timeframe.
Paleomagnetism and U‐Pb zircon geochronology of Lower Cretaceous lava flows from the western Lhasa terrane: New constraints on the India‐Asia collision process and intracontinental deformation within Asia
Authors: Ma Yiming , Yang Tianshui , Yang Zhenyu , Zhang Shihong , Wu Huaichun , Li Haiyan , Li Huaikun , Chen Weiwei , Zhang Junhong , Ding Jikai 
Published: September 2014

AbstractTo better understand the India‐Asia collisional process and intracontinental deformation within Asia, a paleomagnetic study has been conducted on the Qushenla Formation lava flows dated at ~132–120 Ma from the Yanhu area in the western Lhasa terrane. Stepwise thermal demagnetization isolates stable characteristic remanent magnetizations, which include dual polarity and pass fold tests at a 99% confidence level, indicating primary magnetizations. The tilt‐corrected site‐mean direction for 51 sites is D = 28.2°, I = 34.5°, and k = 74.3° with α95 = 2.3°, corresponding to a paleopole at 61.4°N, 192.9°E (A95 = 2.1°). Our new paleomagnetic data, combined with previous Cretaceous volcanic paleomagnetic data from the Lhasa terrane, show that the precollisional southern margin of Asia was at ~16.8°N with a relatively E‐W alignment and that the Lhasa terrane did not experience significantly discrepant north‐south movement although local vertical axis rotations did take place after the Cretaceous. Comparison with the apparent polar wander paths (APWPs) of India and the Cretaceous‐Paleocene paleopoles of the Tethyan Himalaya shows that the India‐Asia collision was at ~54.3 Ma and the Greater India during the Paleocene had a large northern extent of ~2000 km (~18.1°) beyond its present northern margin. Comparison with the Cretaceous Eurasian APWP indicates that a latitudinal convergence of ~1000 km has taken place between the Lhasa terrane and Eurasia since the India‐Asia collision. The amount of north‐south shortening deduced from Cretaceous paleomagnetic data is consistent with that accommodated by the Cenozoic fold and thrust belts between the Lhasa terrane and the Hexi corridor.
Willingness to pay and willingness to work for improvements of municipal and community‐managed water services
Authors: Vásquez William F. 
Published: September 2014

AbstractThis study investigates household preferences, in labor time and monetary terms, for improved water services in Guatemala using sequential contingent valuation questions. The household survey was implemented in areas served by municipal and community‐managed systems, which allows for comparing household preferences under those governance approaches. Results show that respondents with municipal services are willing to pay a substantial increase (more than 200%) in their water bills for reliable supplies of safe drinking water. They are also willing to work approximately 19 h per month for such improved services when labor hours are proposed as the payment vehicle. In contrast, households with community‐managed services are not willing to pay or work for service improvements, even though they report to be quite dissatisfied with current services. Policy implications are discussed.
Amine‐Responsive Adaptable Nanospaces: Fluorescent Porous Coordination Polymer for Molecular Recognition
Authors: Haldar Ritesh , Matsuda Ryotaro , Kitagawa Susumu , George Subi J. , Maji Tapas Kumar 
Published: September 2014

AbstractFlexible and dynamic porous coordination polymers (PCPs) with well‐defined nanospaces composed of chromophoric organic linkers provide a scaffold for encapsulation of versatile guest molecules through noncovalent interactions. PCPs thus provide a potential platform for molecular recognition. Herein, we report a flexible 3D supramolecular framework {[Zn(ndc)(o‐phen)]⋅DMF}n (o‐phen=1,10‐phenanthroline, ndc=2,6‐napthalenedicarboxylate) with confined nanospaces that can accommodate different electron‐donating aromatic amine guests with selective turn‐on emission signaling. This system serves as a molecular recognition platform through an emission‐readout process. Such unprecedented tunable emission with different amines is attributed to its emissive charge‐transfer (CT) complexation with o‐phen linkers. In certain cases this CT emission is further amplified by energy transfer from the chromophoric linker unit ndc, as evidenced by single‐crystal X‐ray structural characterization.
An Organocatalytic Azide–Aldehyde [3+2] Cycloaddition: High‐Yielding Regioselective Synthesis of 1,4‐Disubstituted 1,2,3‐Triazoles
Authors: Ramachary Dhevalapally B. , Shashank Adluri B. , Karthik S. 
Published: September 2014

AbstractAn organocatalytic azide–aldehyde [3+2] cycloaddition (organo‐click) reaction of a variety of enolizable aldehydes is reported. The organo‐click reaction is characterized by a high rate and regioselectivity, mild reaction conditions, easily available substrates with simple operation, and excellent yields with a broad spectrum of substrates. It constitutes an alternative to the previously known CuAAC, RuAAC, and IrAAC click reactions.
Hydrogels from dextran and soybean oil by UV photo‐polymerization
Authors: Omer Rebaz A. , Hughes Alan , Hama Jawameer Rasool , Wang Wenxin , Tai Hongyun 
Published: September 2014

ABSTRACTIn this work, hydrogels were synthesized by UV photo‐polymerization of hydrophilic dextran functionalized with acrylate groups (Dex‐A) and hydrophobic acrylate epoxidized soybean oil (AESO). The acrylation of dextran was accomplished by reacting dextran (Mw 70,000 g mol−1) with acryloyl chloride and pyridine. The Dex‐A was characterized by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). Five rigid hydrogels were prepared using the weight ratios of Dex‐A and AESO as 10/90, 20/80, 30/70, 40/60, and 50/50. The hydrogels were characterized by FTIR, thermal gravimetric analyses (TGA) and scanning electronic microscopy (SEM). The experimental results demonstrated that the swelling and release profiles of the Dex‐A/AESO hydrogels can be tailored by varying the ratio of Dex‐A and AESO thus varying the balance of hydrophilicity and hydrophobicity of the network structures and the crosslinking density. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41446.
Polymerization reactions of epoxidized soybean oil and maleate esters of oil‐soluble resoles
Authors: Cavusoglu Jesmi , Çaylı Gökhan 
Published: September 2014

ABSTRACTIn this study, the polymerization reactions of epoxidized soybean oil (ESO) with the maleate half‐esters of oil‐soluble resoles and the properties of the final products were demonstrated. The maleate half‐esters of the dimeric oil‐soluble resoles were obtained by the esterification reaction of maleic anhydride with a p‐tertiary butyl phenol (p‐TBP) resole and p‐nonyl phenol resole resins in the first step. The monomers were characterized by IR and 1H‐NMR techniques. Then, the oil‐soluble resole maleates were polymerized with ESO to obtain tough and load‐bearing thermoset materials. The thermal and mechanical properties of the materials were determined by dynamic mechanical analysis, differential scanning calorimetry, thermogravimetric analysis, and tensile strength testing. The tensile strengths and storage moduli of the crosslinked polymers varied between 0.17 and 13 MPa and 10 and 1088 MPa, respectively. The elongation percentages of the materials were between 1 and 128%. The thermal resistance of the thermosets was measured as the 5% weight loss temperature. The reaction product of the ESO and maleate ester of p‐TBP showed the highest 5% weight loss at 247°C. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41457.
A novel polymer chain growing mode and styrene copolymer prepared with low molecular weight copolymer of α‐methylstyrene and styrene as macroinitiator
Authors: Liu Qian , Liu Lianying , Ma Yuhong , Zhao Changwen , Yang Wantai 
Published: September 2014

ABSTRACTA new polymer chain growth mode, having multiple potential chain propagation sites, initiated by oligomer of α‐methylstyrene (AMS) and styrene (St) (PAS) is presented in this article. The effects of PAS content, AMS fraction in PAS and reaction temperature on bulk polymerization of St have been investigated. It is demonstrated that the PAS performed as macroinitiator in the polymerization of St. The average molecular weights of products increase significantly with the evolution of the polymerization, which is different from conventional free radical polymerization. With 20 wt % macroinitiator, the molecular weights increase from 1.21 × 105 to 3.00 × 105 with the monomer conversion increasing from 15.3 to 83.0%. This unique feature is tentatively attributed to both the reversible polymerization–depolymerization of AMS segments at high temperature which could generate more than one propagation sites in a polymer chain and the combination termination of St free radical polymerization. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41460.
Structural studies of “aggregation‐prone” peptide‐analogues of teleostean egg chorion ZPB proteins
Authors: Louros Nikolaos N. , Petronikolou Nektaria , Karamanos Theodoros , Cordopatis Paul , Iconomidou Vassiliki A. , Hamodrakas Stavros J. 
Published: September 2014

ABSTRACTEgg envelopes of vertebrates are composed of a family of proteins called zona pellucida (ZP) proteins, which are distinguished by the presence of a common structural polymerizing motif, known as ZP domain. Teleostean fish chorion is a fibrous structure, consisting of protein members of the ZPB/ZP1 and the ZPC/ZP3 families, which are incorporated as tandemly repeating heterodimers inside chorion fibers. Computational analysis of multiple ZPB/ZP1 proteins from several teleostean species, reveals two potential “aggregation‐prone” sequence segments, forming a specific polymerization interface (AG interface). These two peptides were synthesized and results are presented in this work from transmission electron microscopy, Congo red staining, X‐ray fiber diffraction and ATR FT‐IR, which clearly display the ability of these peptides to self‐aggregate, forming amyloid‐like fibrils. This, most probably implies that the AG interface of ZPB/ZP1 proteins plays an important role for the formation of the repeating ZPB‐ZPC heterodimers, which constitute teleostean chorion fibrils. © 2014 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 102: 427–436, 2014.
Foam stability: The importance of film size and the micellar structuring phenomenon
Authors: Lee Jongju , Nikolov Alex , Wasan Darsh 
Published: September 2014

AbstractThe kinetic stability of SDS foam was probed using Bartsch method at concentrations above CMC (0.03 M and 0.06 M) and below CMC (0.006 M). The foam created from the higher concentration (0.06 M) of micellar solution was more kinetically stable than that produced from the 0.03 M SDS solution and showed a stepwise decrease. On the other hand, the foam produced from SDS surfactant concentration below CMC (0.006 M) did not show such a behaviour and the height remained more or less constant. The effect of the foam lamella size on the bulk foam stability was also investigated. It was found that the critical lamella area is independent of the hydrostatic pressure. And, it took longer to reach the critical lamella area in the 0.06 M SDS system than to reach the critical lamella area in the 0.03 M SDS system. We probed the foam stability by studying the stability of a single foam lamella and observed the micellar layering phenomenon. We found 5 film thickness transitions in the case of 0.06 M SDS system and 3 thickness transitions for 0.03 M SDS system. Therefore, the foam lamella formed from the 0.06 M SDS solution is kinetically more stable than that formed from the 0.03 M SDS solution because the better layering structure in the former case slows down the liquid film drainage. Therefore, this study clearly demonstrates that both the size of the foam lamella and the micellar concentration are important factors in controlling the bulk foam stability.
Development of a thermodynamic model of aqueous solution suited for foods and biological media. Part B: Prediction of standard formation properties
Authors: Toure Oumar , Audonnet Fabrice , Lebert André , Dussap Claude‐Gilles 
Published: September 2014

AbstractIn food and biological processes, aqueous complexes cover a wide diversity of species and the presence of several phases. The modelling of such processes must take into account these specificities, which require a generalization of the existing thermodynamic models of aqueous solutions.The chemical potential (the molar Gibbs free energy) of a given compound is an important variable to characterize the physical‐chemical properties at equilibrium. Its value depends on two parameters: the Gibbs free energy of formation and the activity coefficient. Both are linked to a chosen reference state. Then, the main thermodynamic modelling task consists in the prediction and/or the collection of formation properties data and in the development of a predictive model of activity coefficients.In this study, a method of prediction of the gas phase formation properties of several organic molecules of interest in foods and biological media using the same input data as those of the COSMO‐RS model (i.e., results of quantum DFT/COSMO calculations) is introduced. This kind of fully predictive approach allows the treatment of conformations. This is its main advantage compared to classical group contribution methods.For fifteen of the studied molecules, the Gibbs free energies of formation predicted at infinite dilution in water are also calculated and compared to experimental data.
Modelling of pyrolysis in a high capacity thermo balance
Authors: Marias Frederic , Santacreu Stephanie Delage 
Published: September 2014

AbstractThis paper deals with the two dimensional modelling of transient pyrolysis of biomass in a fixed bed. The model that is developed mainly relies on the theory of volume averaging. This model includes heat and mass transfer and pyrolysis reaction. It allows the prediction of temperature, moisture content organic material content, and char content, as well as the prediction of internal evolution of the composition of the gas held and released from the sample under investigation.This model is used in order to describe pine wood pyrolysis taking place in a macro thermobalance which is also presented in the paper. Comparison of the numerical results with the experimental ones, in terms of mass loss of the sample, shows good agreement and validates the model. A deeper analysis of the results allows a better understanding of the processes involved in the thermal degradation.