bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evapotranspiration and water use efficiency in relation to climate and canopy nitrogen in U.S. forests
Authors: Guerrieri Rossella , Lepine Lucie , Asbjornsen Heidi , Xiao Jingfeng , Ollinger Scott V. 
Published: September 2016

AbstractUnderstanding relations among forest carbon (C) uptake and water use is critical for predicting forest‐climate interactions. Although the basic properties of tree‐water relations have long been known, our understanding of broader‐scale patterns is limited by several factors including (1) incomplete understanding of drivers of change in coupled C and water fluxes and water use efficiency (WUE), (2) difficulty in reconciling WUE estimates obtained at different scales, and (3) uncertainty in how evapotranspiration (ET) and WUE vary with other important resources such as nitrogen (N). To address these issues, we examined ET, gross primary production (GPP), and WUE at 11 AmeriFlux sites across North America. Our analysis spanned leaf and ecosystem scales and included foliar δ13C, δ18O, and %N measurements; eddy covariance estimates of GPP and ET; and remotely sensed estimates of canopy %N. We used flux data to derive ecosystem WUE (WUEe) and foliar δ13C to infer intrinsic WUE. We found that GPP, ET, and WUEe scaled with canopy %N, even when environmental variables were considered, and discuss the implications of these relationships for forest‐atmosphere‐climate interactions. We observed opposing patterns of WUE at leaf and ecosystem scales and examined uncertainties to help explain these opposing patterns. Nevertheless, significant relationship between C isotope‐derived ci/ca and GPP indicates that δ13C can be an effective predictor of forest GPP. Finally, we show that incorporating species functional traits—wood anatomy, hydraulic strategy, and foliar %N—into a conceptual model improved the interpretation of Δ13C and δ18O vis‐à‐vis leaf to canopy water‐carbon fluxes.
Coupled radiative convective equilibrium simulations with explicit and parameterized convection
Authors: Hohenegger Cathy , Stevens Bjorn 
Published: September 2016

AbstractRadiative convective equilibrium has been applied in past studies to various models given its simplicity and analogy to the tropical climate. At convection‐permitting resolution, the focus has been on the organization of convection that appears when using fixed sea surface temperature (SST). Here the SST is allowed to freely respond to the surface energy. The goals are to examine and understand the resulting transient behavior, equilibrium state, and perturbations thereof, as well as to compare these results to a simulation integrated with parameterized cloud and convection. Analysis shows that the coupling between the SST and the net surface energy acts to delay the onset of self‐aggregation and may prevent it, in our case, for a slab ocean of less than 1 m. This is so because SST gradients tend to oppose the shallow low‐level circulation that is associated with the self‐aggregation of convection. Furthermore, the occurrence of self‐aggregation is found to be necessary for reaching an equilibrium state and avoiding a greenhouse‐like climate. In analogy to the present climate, the self‐aggregation generates the dry and clear subtropics that allow the system to efficiently cool. In contrast, strong shortwave cloud radiative effects, much stronger than at convection‐permitting resolution, prevent the simulation with parameterized cloud and convection to fall into a greenhouse state. The convection‐permitting simulations also suggest that cloud feedbacks, as arising when perturbing the equilibrium state, may be very different, and in our case less negative, than what emerges from general circulation models.
Cryoseismology
Authors: Podolskiy Evgeny A. , Walter Fabian 
Published: September 2016

AbstractThe last decade witnessed an explosion in yearly number of publications on passive glacier seismology. The seismic signals from a wide range of glacier‐related processes fill a broad band of frequencies (from 10−3to 102 Hz) and moment magnitudes (fromM–3 toM7) providing a fresh and unprecedented view on fundamental processes in the cryosphere. New insights into basal motion, iceberg calving, glacier, iceberg, and sea ice dynamics, and precursory signs of unstable glaciers and ice structural changes are being discovered with seismological techniques. These observations offer an invaluable foundation for understanding ongoing environmental changes and for future monitoring of ice bodies worldwide. In this review we discuss seismic sources in the cryosphere as well as research challenges for the near future. The field of glacier seismology is evolving so rapidly that some parts of this review will likely soon be outdated. Nevertheless, given an overwhelming number of recent publications and rapidly growing seismic data volumes provided by modern seismic installations in polar and mountain regions, this introduction to cryosphere seismicity aims to serve as a timely and comprehensive reference for glaciologists and seismologists.
Bayesian analysis of stage‐fall‐discharge rating curves and their uncertainties
Authors: Mansanarez V. , Le Coz J. , Renard B. , Lang M. , Pierrefeu G. , Vauchel P. 
Published: September 2016

AbstractStage‐fall‐discharge (SFD) rating curves are traditionally used to compute streamflow records at sites where the energy slope of the flow is variable due to variable backwater effects. We introduce a model with hydraulically interpretable parameters for estimating SFD rating curves and their uncertainties. Conventional power functions for channel and section controls are used. The transition to a backwater‐affected channel control is computed based on a continuity condition, solved either analytically or numerically. The practical use of the method is demonstrated with two real twin‐gauge stations, the Rhône River at Valence, France, and the Guthusbekken stream at station 0003⋅0033, Norway. Those stations are typical of a channel control and a section control, respectively, when backwater‐unaffected conditions apply. The performance of the method is investigated through sensitivity analysis to prior information on controls and to observations (i.e., available gaugings) for the station of Valence. These analyses suggest that precisely identifying SFD rating curves requires adapted gauging strategy and/or informative priors. The Madeira River, one of the largest tributaries of the Amazon, provides a challenging case typical of large, flat, tropical river networks where bed roughness can also be variable in addition to slope. In this case, the difference in staff gauge reference levels must be estimated as another uncertain parameter of the SFD model. The proposed Bayesian method is a valuable alternative solution to the graphical and empirical techniques still proposed in hydrometry guidance and standards.
The Effects of Iron, Silicon, Chromium, and Aluminum Additions on the Physical and Mechanical Properties of Recycled 3D Printing Filaments
Authors: Pan Guan‐Ting , Chong Siewhui , Tsai Hsuan‐Ju , Lu Wei‐Hua , Yang Thomas C.‐K. 
Published: September 2016

AbstractWith the increasing use of 3D printers especially the fused filament fabrication type in the industries and general public, there is indeed a need to consider the after‐use treatment for the products. The use of recycled filaments as the feedstock for 3D printers is a feasible alternative, but its application is limited to rather poor product quality. This study, thus, evaluates the effects of adding iron (Fe), silicon (Si), chromium (Cr), and aluminum (Al) nano‐crystalline powders into the recycled polypropylene/high‐density polyethylene plastics feedstock for filament extrusion. Physical and mechanical analysis tests revealed that the addition of 1% Fe–Si–Cr or Fe–Si–Al resulted in better thermal stability, and up to 37% and 17% improvement, respectively, in yield strength and Young modulus compared with the original recycled filaments, possibly due to the enhancement of interfacial adhesion between the nano‐metal powders and the polymer, leading to reduced crack formation.
The Patterning Cascade Model and Carabelli's trait expression in metameres of the mixed human dentition: exploring a morphogenetic model
Authors: Paul Kathleen S. , Astorino Claudia M. , Bailey Shara E. 
Published: September 2016

AbstractObjectivesThe Patterning Cascade Model (PCM) provides an evolutionary developmental framework for exploring diversity in tooth crown form. According to the model, proximity of secondary enamel knots and tooth germ size track underlying developmental processes that dictate ultimate crown morphology (i.e., cusp number, accessory cusp presence/size). Previous research has shown the model to successfully predict variation in Carabelli's trait expression between antimeric and metameric pairs of human permanent molars. In this study, we quantify Carabelli's trait expression for metameres of the mixed dentition (dm2 and M1) and assess the PCM's potential for explaining differences in expression between the two elements.Materials and methodsCrown dimensions, intercusp distances, and Carabelli's trait expression were collected from 49 subadults possessing observable dm2/M1 pairs. Wilcoxon signed‐rank tests and paired t‐tests were performed to assess whether metameres differ significantly in morphometric variables. We explored the relationships between relative intercusp distances (RICDs) and Carabelli's trait expression using proportional odds logistic regression.ResultsIntra‐individual dm2/M1 pairs differed significantly in Carabelli's trait expression (p = 0.01), with dm2 exhibiting higher grades of expression more commonly despite its smaller crown size. Paired molars differed in only one statistically significant RICD: metacone‐hypocone (p < 0.01). Most RICDs shared the predicted negative relationship with Carabelli's trait expression, but this relationship was only statistically significant for three RICDs in the dm2 (mean, protocone‐paracone, metacone‐hypocone).ConclusionsWe found mixed support for the PCM's ability to explain differences in Carabelli's trait expression between metameres of the mixed molar row. Results suggest that protocone‐paracone enamel knot spacing has the greatest influence on Carabelli's trait expression. Lack of statistical significance for many of the relationships explored may reflect limitations related to sample composition and sample size.
Harnessing the Dual Properties of Thiol‐Grafted Cellulose Paper for Click Reactions: A Powerful Reducing Agent and Adsorbent for Cu
Authors: Rull‐Barrull Jordi , d'Halluin Martin , Le Grognec Erwan , Felpin François‐Xavier 
Published: September 2016

AbstractA new approach exploiting the dual properties of thiol‐grafted cellulose paper for promoting copper‐catalyzed [3+2]‐cycloadditions of organic azides with alkynes and adsorbing residual copper species in solution was developed. The thiol‐grafted cellulose paper, used as a paper strip, effects the reduction of CuII to catalytically active CuI and acts as a powerful adsorbent for copper, thereby facilitating the work‐up process and leaving the crude mixture almost free of copper residues after a single filtration.
Crosslinking of poly(vinyl alcohol) and poly(vinyl acetate) using poly(maleic anhydride‐alt−2,4‐dimethyl‐1,3‐pentadiene) as polyfunctional crosslinker and decrosslinking by ozone degradation
Authors: Lou Limin , Okamura Haruyuki , Matsumoto Akikazu 
Published: September 2016

ABSTRACTCrosslinking and decrosslinking reactions of poly(vinyl alcohol) (PVA) and poly(vinyl acetate) (PVAc) using an alternating copolymer of maleic anhydride and 2,4‐dimethyl‐1,3‐pentadiene (PMAD) as the polyfunctional crosslinker and subsequent ozone degradation are reported. PVA and PVAc are heated at 200 °C for 0.5 to 3 h in the presence of 5 to 30 wt % of PMAD in the solid state to obtain the corresponding crosslinked polymers. The reactions of a hydroxy group of PVA and an acetate group of PVAc with an anhydride group of PMAD slowly proceed to give insoluble polymers with a loose crosslinking structure. Almost no change in the thermal decomposition temperatures and the IR spectra is observed during the crosslinking reactions. The crosslinked PVA produces hydrogels with a high swelling ratio of 500 to 1700%, which are readily degradable during a reaction with ozone in water at 0 °C. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44229.
Highly effective adsorption performance of carboxymethyl cellulose microspheres crosslinked with epichlorohydrin
Authors: Lin Qingwen , Gao Mengfan , Chang Jiali , Ma Hongzhu 
Published: September 2016

ABSTRACTDifferent sizes of epichlorohydrin‐crosslinked carboxymethyl cellulose (E/CMC) microspheres were successfully prepared by an inverse suspension method. With further modification by monochloroacetic acid (MCA), MCA–E/CMC microspheres were successfully synthesized. The structures and morphologies of these microspheres were analyzed with polarizing microscopy, scanning electron microscopy, ultraviolet–visible spectroscopy, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller analysis, and laser particle ζ‐potential recording. The adsorption properties of the microspheres were investigated with methylene blue (MB) as a model pollutant. The highest adsorption amount of MB (998.2 mg/g) onto MCA–E0.7/CMC which was the samples which treated with 0.7 mL of C4H9OH was obtained. Meanwhile, the effect of the operating parameters, such as the contact time, initial pH of the solution, temperature, and initial dye concentration, on the adsorption amount and MB removal were systematically studied. The results show that pseudo‐second‐order kinetic model provided the best correlation with the experimental data for the adsorption of MB onto the MCA–E0.7/CMC microspheres. Both the physical and chemical adsorption played the main role in the adsorption process. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44363.
The flammability of expandable polystyrene foams coated with melamine modified urea formaldehyde resin
Authors: Cao Bo , Gu Xiaoyu , Song Xiaohui , Jin Xiaodong , Liu Xinyu , Liu Xiaodong , Sun Jun , Zhang Sheng 
Published: September 2016

ABSTRACTUrea formaldehyde resin (UF) was modified by introducing melamine during the condensation in order to reduce the amount of free formaldehyde and increase the solid content. The melamine modified UF (MUF) was firstly mixed with intumescent flame retardant (IFR) and then coated on the surface of pre‐expanded polystyrene (PS) particles to prepare flame retardant expandable PS (EPS) foams. The flammability of EPS foam samples was characterized by limiting oxygen index (LOI), UL‐94 vertical burning and cone calorimeter tests, and the results indicated that the peak heat release rate was significantly reduced from 406 to 49 kW/m2 and LOI value could reach 36.3 with V‐0 rating in UL‐94 test after coated with IFR. The smoke density test indicated that the maximum smoke density was decreased by the addition of IFR. Thermal analysis suggested that the thermal stability and char formation were significantly improved by the presence of coated flame retardants. The residual char observation revealed that MUF and IFR were beneficial to form integrated char layers with hollow stents, which could be the main reason for the improvement of flame retardant properties. The mechanical properties of flame retardant EPS foams can still meet the standard requirements for industrial applications. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44423.
Clinical outcomes associated with per‐operative discontinuation of aspirin in patients with coronary artery disease: A systematic review and meta‐analysis
Authors: Luni Faraz Khan , Riaz Haris , Khan Abdur Rahman , Riaz Talha , Husnain Muhammad , Riaz Irbaz Bin , Khan Muhammad Shahzeb , Taleb Mohammed , Kanjwal Yusuf , Cooper Christopher J. , Khuder Sadik A. 
Published: September 2016

Background: Postoperative state is characterized by increased thrombotic risk by virtue of platelet activation. Whether aspirin ameliorates this risk in patients with established coronary artery disease undergoing cardiac or noncardiac surgery is unknown. We conducted a systematic review and meta‐analysis to compare the risk of major adverse cardiac events (MACE) and the risk of bleeding in patients with early (3–5 or more days before surgery) vs. late discontinuation(<3–5 days)/no discontinuation of aspirin.Methods: Multiple databases were searched from inception of these databases until March 2015 to identify studies that reported discontinuation of aspirin in patients undergoing surgery. The outcomes measured were all cause mortality, nonfatal myocardial infarction and other relevant thrombotic events (MACE) which also may include, fatal and nonfatal MI, stent thrombosis and restenosis, stroke, perioperative cardiovascular complications (heart failure, MI, VTE, acute stroke) and perioperative bleeding during the perioperative period to up to 30 days after surgery.Results: A total of 1,018 titles were screened, after which six observational studies met the inclusion criteria. Our analysis suggests that there is no difference in MACE with planned discontinuation of aspirin (OR = 1.17, 95% CI = 0.76–1.81; P = 0.05; I2 = 55%). Early discontinuation of aspirin showed a decreased risk of peri‐operative bleeding (OR 0.82, 95% CI = 0.67–0.99; P = 0.04; I2 = 42%).Conclusion: Our analysis suggests that planned short‐term discontinuation in the appropriate clinical setting appears to be safe in the correct clinical setting with no increased risk of thrombotic events and with a decreased risk of bleeding. © 2016 Wiley Periodicals, Inc.
Hydrogen Peroxide used as a Solar Fuel in One‐Compartment Fuel Cells
Authors: Fukuzumi Shunichi , Yamada Yusuke 
Published: September 2016

AbstractClean and highly efficient production of solar fuels as well as effective methods to store solar fuels have long been sought to solve global energy and environmental issues. Among solar fuels such as gaseous hydrogen and carbon monoxide, aqueous hydrogen peroxide (H2O2) is an ideal chemical for energy storage, because endothermic H2O2 decomposition produces only water and oxygen. In addition, H2O2 can be transported in plastic containers with a high energy density. H2O2 can be converted into electricity by using H2O2 fuel cells without a membrane and composed of an anode and a cathode, and they can selectively catalyze H2O2 oxidation or reduction. The one‐compartment structure without a membrane is more promising to develop low‐costing fuel cells than a two‐compartment structure with expensive membranes. This article provides a focused review of recent developments and future perspectives of H2O2 fuel cells without membranes, combined with H2O2 production from seawater and dioxygen in the air by utilizing solar energy.
Outstanding Low‐Temperature Capacitance of an AC–AC Supercapacitor in Acid Redox Electrolyte
Authors: Su Linghao , Gong Liangyu , Ma Chuanli , Wang Xiuxia , Sun Zongdong 
Published: September 2016

AbstractThe capacitive behavior of AC–AC supercapacitor (AC=activated carbon) at −18 °C are greatly improved by using an acid redox electrolyte comprising p‐phenylenediamine. By introducing p‐phenylenediamine into 38 % H2SO4 solution, the energy density at −18 °C is remarkably elevated to the level achievable at 23 °C in 38 % H2SO4.
Tuning Pickering Emulsions for Optimal Reaction and Filtration Conditions
Authors: Skale Tina , Stehl Dmitrij , Hohl Lena , Kraume Matthias , von Klitzing Regine , Drews Anja 
Published: September 2016

AbstractThe use of Pickering emulsions has recently received increased attention in catalyzed multiphase reactions. Here, the ultrafiltration of Pickering emulsions is studied for product separation and to retain the catalyst in the reactor. To find the optimum between a high specific surface area for high reaction rates and a suited drop size distribution for high permeate fluxes, the preparation method of Pickering emulsion was investigated. It was found that the stability of the emulsion during filtration does not only depend on the solid particle content, but also on the drop size distribution.
Sound settlement: noise surpasses land cover in explaining breeding habitat selection of secondary cavity‐nesting birds
Authors: Kleist Nathan J. , Guralnick Robert P. , Cruz Alexander , Francis Clinton D. 
Published: September 2016

AbstractBirds breeding in heterogeneous landscapes select nest sites by cueing in on a variety of factors from landscape features and social information to the presence of natural enemies. We focus on determining the relative impact of anthropogenic noise on nest site occupancy, compared to amount of forest cover, which is known to strongly influence the selection process. We examine chronic, industrial noise from natural gas wells directly measured at the nest box as well as site‐averaged noise, using a well‐established field experimental system in northwestern New Mexico. We hypothesized that high levels of noise, both at the nest site and in the environment, would decrease nest box occupancy. We set up nest boxes using a geospatially paired control and experimental site design and analyzed four years of occupancy data from four secondary cavity‐nesting birds common to the Colorado Plateau. We found different effects of noise and landscape features depending on species, with strong effects of noise observed in breeding habitat selection of Myiarchus cinerascens, the Ash‐throated Flycatcher, and Sialia currucoides, the Mountain Bluebird. In contrast, the amount of forest cover less frequently explained habitat selection for those species or had a smaller standardized effect than the acoustic environment. Although forest cover characterization and management is commonly employed by natural resource managers, our results show that characterizing and managing the acoustic environment should be an important tool in protected area management.
Effects of food abundance and early clutch predation on reproductive timing in a high Arctic shorebird exposed to advancements in arthropod abundance
Authors: Reneerkens Jeroen , Schmidt Niels Martin , Gilg Olivier , Hansen Jannik , Hansen Lars Holst , Moreau Jérôme , Piersma Theunis 
Published: September 2016

SummaryClimate change may influence the phenology of organisms unequally across trophic levels and thus lead to phenological mismatches between predators and prey. In cases where prey availability peaks before reproducing predators reach maximal prey demand, any negative fitness consequences would selectively favor resynchronization by earlier starts of the reproductive activities of the predators. At a study site in northeast Greenland, over a period of 17 years, the median emergence of the invertebrate prey of SanderlingCalidris albaadvanced with 1.27 days per year. Yet, over the same period Sanderling did not advance hatching date. Thus, Sanderlings increasingly hatched after their prey was maximally abundant. Surprisingly, the phenological mismatches did not affect chick growth, but the interaction of the annual width and height of the peak in food abundance did. Chicks grew especially better in years when the food peak was broad. Sanderling clutches were most likely to be depredated early in the season, which should delay reproduction. We propose that high early clutch predation may favor a later reproductive timing. Additionally, our data suggest that in most years food was still abundant after the median date of emergence, which may explain why Sanderlings did not advance breeding along with the advances in arthropod phenology.