bluuebunny/crossref_metadata_2025_split huggingface dataset:
Debris flow runup on vertical barriers and adverse slopes
Authors: Iverson Richard M. , George David L. , Logan Matthew 
Published: November 2016

AbstractRunup of debris flows against obstacles in their paths is a complex process that involves profound flow deceleration and redirection. We investigate the dynamics and predictability of runup by comparing results from large‐scale laboratory experiments, four simple analytical models, and a depth‐integrated numerical model (D‐Claw). The experiments and numerical simulations reveal the important influence of unsteady, multidimensional flow on runup, and the analytical models highlight key aspects of the underlying physics. Runup against a vertical barrier normal to the flow path is dominated by rapid development of a shock, or jump in flow height, associated with abrupt deceleration of the flow front. By contrast, runup on sloping obstacles is initially dominated by a smooth flux of mass and momentum from the flow body to the flow front, which precedes shock development and commonly increases the runup height. D‐Claw simulations that account for the emergence of shocks show that predicted runup heights vary systematically with the adverse slope angle and also with the Froude number and degree of liquefaction (or effective basal friction) of incoming flows. They additionally clarify the strengths and limitations of simplified analytical models. Numerical simulations based on a priori knowledge of the evolving dynamics of incoming flows yield quite accurate runup predictions. Less predictive accuracy is attained in ab initio simulations that compute runup based solely on knowledge of static debris properties in a distant debris flow source area. Nevertheless, the paucity of inputs required in ab initio simulations enhances their prospective value in runup forecasting.
Push‐pull tracer tests: Their information content and use for characterizing non‐Fickian, mobile‐immobile behavior
Authors: Hansen Scott K. , Berkowitz Brian , Vesselinov Velimir V. , O'Malley Daniel , Karra Satish 
Published: November 2016

AbstractPath reversibility and radial symmetry are often assumed in push‐pull tracer test analysis. In reality, heterogeneous flow fields mean that both assumptions are idealizations. To understand their impact, we perform a parametric study which quantifies the scattering effects of ambient flow, local‐scale dispersion, and velocity field heterogeneity on push‐pull breakthrough curves and compares them to the effects of mobile‐immobile mass transfer (MIMT) processes including sorption and diffusion into secondary porosity. We identify specific circumstances in which MIMT overwhelmingly determines the breakthrough curve, which may then be considered uninformative about drift and local‐scale dispersion. Assuming path reversibility, we develop a continuous‐time‐random‐walk‐based interpretation framework which is flow‐field‐agnostic and well suited to quantifying MIMT. Adopting this perspective, we show that the radial flow assumption is often harmless: to the extent that solute paths are reversible, the breakthrough curve is uninformative about velocity field heterogeneity. Our interpretation method determines a mapping function (i.e., subordinator) from travel time in the absence of MIMT to travel time in its presence. A mathematical theory allowing this function to be directly “plugged into” an existing Laplace‐domain transport model to incorporate MIMT is presented and demonstrated. Algorithms implementing the calibration are presented and applied to interpretation of data from a push‐pull test performed in a heterogeneous environment. A successful four‐parameter fit is obtained, of comparable fidelity to one obtained using a million‐node 3‐D numerical model. Finally, we demonstrate analytically and numerically how push‐pull tests quantifying MIMT are sensitive to remobilization, but not immobilization, kinetics.
A generalized non‐Darcian radial flow model for constant rate test
Authors: Liu Ming‐Ming , Chen Yi‐Feng , Hong Jia‐Min , Zhou Chuang‐Bing 
Published: November 2016

AbstractModels used for data interpretation of constant rate tests (CRTs) are commonly derived with the assumption of Darcian flow in an idealized geometry, hence disregarding the non‐Darcian nature of fluid flow and the complexity of flow geometry. In this study, an Izbash's law‐based analytical model is proposed by means of Laplace transform and linearization approximation for interpretation of non‐Darcian flow in a generalized radial formation where the flow dimension may become fractional between 1 and 3. The source storage and skin effects are also considered in the model development. The proposed model immediately reduces to Barker's (1988) model for Darcian flow in the generalized radial formation and to Wen et al.'s (2008a) model for non‐Darcian flow in a two‐dimensional confined aquifer. A comparison with numerical simulations shows that the proposed model behaves well in low non‐Darcian flow condition or at late times. The proposed model is finally applied for data interpretation of the constant rate pumping tests performed at Ploemeur, showing that the estimated hydraulic properties (i.e., hydraulic conductivity, specific storage coefficient, non‐Darcy exponent, and the dimension of flow geometry) are well representative of the hydrogeologic conditions on the field scale at the test site after the exploitation of groundwater. The proposed model is an extension of the generalized radial flow (GRF) model, which would be of significance in the problem of choosing an appropriate dimension of flow geometry in which non‐Darcian flow occurs.
Climate Change Impacts: Birds
Authors: Tomotani Barbara M , Ramakers Jip JC , Gienapp Phillip 
Published: November 2016

Abstract

Climate change can affect populations and species in various ways. Rising temperatures can shift geographical distributions and lead to (phenotypic or genetic) changes in traits, mostly phenology, which may affect demography. Most of these effects are well documented in birds. For example, the distribution of species has shifted polewards, and birds are nowadays breeding or migrating earlier. An important aspect of the observed phenological changes is whether species are thereby able to maintain synchrony with phenological changes in their environment, for example the phenology of their prey species. Disrupted synchrony, for example between predator and prey, can lead to reduced reproductive success or survival, which can negatively affect demography. Evidence for this happening in birds is – so far – limited but theoretical models predict that extinction risks could arise through insufficient adaptation to such phenological mismatches.

Key Concepts

Climate change will alter the optimal value of traits.

Populations can track a changing environment by phenotypic plasticity.

If phenotypic plasticity is not sufficient to track the environment, selection arises and an evolutionary change becomes necessary.

Maladaptation can lead to extinction due to reduced reproductive success or survival.

Genetic variation is important for evolutionary change and hence adaptation to climate change.
Metapopulation Ecology
Authors: van Nouhuys Saskya 
Published: November 2016

Abstract

A metapopulation is a spatially structured population that persists over time as a set of local populations with limited dispersal between them. At equilibrium, the frequencies of local extinctions and colonisations are in balance. Starting in 1969, and accelerating in the early 1990s, mathematical models of metapopulations have shown the importance of landscape connectivity and dispersal for persistence of a species in fragmented landscapes. Metapopulation ecology is a key concept in conservation ecology. Although pure metapopulations may be rare, there are many empirical studies in which metapopulation processes, primarily local colonisation and extinction, have been useful in explaining dynamics of natural, managed and experimental systems. Metapopulation structure also affects population genetics, the rate of evolution, and the evolution of traits related to habitat use. Finally, just as a population can be structured as a metapopulation, communities inhabiting a heterogeneous landscape can form a metacommunity.

Key Concepts

A metapopulation is made up of semi‐independent local populations, with interplay between local and regional population dynamics.

While few species may live as metapopulations in the strict sense, many species depend on metapopulation processes. That is, a species regional persistence depends on asynchronous local dynamics and dispersal.

Models of the persistence of species in fragmented landscapes become more realistic if the metapopulation dynamics of the species is taken into account.

Closely interacting species, such as a predator and its prey or strong competitors, may persist on a landscape scale owing to metapopulation dynamics of the species involved.

Metapopulation structure imposes genetic structure on a population, influencing its genetic viability, rate of evolution and what traits evolve.

Communities of species that are distributed in a landscape form a metacommunity. This concept shares important characteristics with metapopulations.
Development of new equipment for intra‐arrest brain cooling that uses cooled oxygen in the lungs: volunteer study
Authors: Sakurai Atsushi , Tagami Rumi , Ihara Shingo , Yamaguchi Junko , Sugita Atsunori , Sawada Nami , Komatsu Tomohide , Hori Satoshi , Kinoshita Kosaku 
Published: November 2016

AimsMany experimental studies have reported that intra‐arrest cooling during cardiac arrest is a promising treatment to mitigate brain injury. However, there is no clinically established method for cooling the brain during cardiac arrest. We hypothesized that, as blood flow in the lungs must be very slow during cardiopulmonary resuscitation, the blood could be cooled by ventilating the lungs with cooled oxygen like a radiator, and that this cooled blood would in turn cool the brain. The aim of this study was to develop equipment to cool oxygen for this purpose and to confirm its safety on a group of volunteers.MethodsWe developed new equipment that cools oxygen by running it through a vinyl chloride coil submerged in a bottle of water and frozen at −80°C. Using this equipment, seven volunteers were given oxygen by mask, and their blood pressure, heart rate, and peripheral saturation of oxygen were measured. The temperature in the mask was also measured.ResultsThis equipment was able to decrease the temperature in the mask to −5°C at the Jackson Rees circuit for an oxygen flow of 10 L/min. Among the volunteer group, vital signs were unchanged and the temperature in the mask decreased from 30.1 ± 2.6°C (mean ± standard deviation) to 15.9 ± 9.6°C. No adverse effects were observed in the volunteers after experimentation.ConclusionWe successfully developed new equipment to cool oxygen and established its safety in a volunteer study.
Synthesis of Atisine, Ajaconine, Denudatine, and Hetidine Diterpenoid Alkaloids by a Bioinspired Approach
Authors: Li Xiao‐Huan , Zhu Min , Wang Zhi‐Xiu , Liu Xiao‐Yu , Song Hao , Zhang Dan , Wang Feng‐Peng , Qin Yong 
Published: November 2016

AbstractA unified approach to four different (atisine, ajaconine, denudatine, and hetidine) diterpenoid alkaloid skeletons was developed and applied to the total synthesis of the natural products dihydroajaconine (2, atisine type) and gymnandine (4, denudatine type). The synthesis features a biogenetically inspired strategy that relies on C−H oxidation, aza‐pinacol coupling, and aza‐Prins cyclization as key steps.
Synergic Effect of Active Sites in Zinc‐Modified ZSM‐5 Zeolites as Revealed by High‐Field Solid‐State NMR Spectroscopy
Authors: Qi Guodong , Wang Qiang , Xu Jun , Trébosc Julien , Lafon Olivier , Wang Chao , Amoureux Jean‐Paul , Deng Feng 
Published: November 2016

AbstractUnderstanding the nature of active sites in metal‐supported catalysts is of great importance towards establishing their structure–property relationships. The outstanding catalytic performance of metal‐supported catalysts is frequently ascribed to the synergic effect of different active sites, which is however not well spectroscopically characterized. Herein, we report the direct detection of surface Zn species and 1H–67Zn internuclear interaction between Zn2+ ions and Brønsted acid sites on Zn‐modified ZSM‐5 zeolites by high‐field solid‐state NMR spectroscopy. The observed promotion of C−H bond activation of methane is rationalized by the enhanced Brønsted acidity generated by synergic effects arising from the spatial proximity/interaction between Zn2+ ions and Brønsted acidic protons. The concentration of synergic active sites is determined by 1H–67Zn double‐resonance solid‐state NMR spectroscopy.
Microsecond Timescale Dynamics of GDP‐Bound Ras Underlies the Formation of Novel Inhibitor‐Binding Pockets
Authors: Mao Yunyun , Yao Haijie , Wang Hui , Cheng Peng , Long Dong 
Published: November 2016

AbstractThe recent discovery of inhibitory compounds binding to distinct pockets on GDP‐bound Ras has renewed the view on the druggability of this crucial cancer driver. However, the origin of these pockets, which are not readily formed in the crystal structure in the absence of the compounds, is yet unclear. Herein, we explored the intrinsic flexibility of Ras⋅GDP on microsecond to millisecond timescales using relaxation‐based NMR experiments, and identified substantial slow dynamics with τex of 34 μs at 5 °C, which maps to the regions showing a high level of correlation with those displaying conformational differences between the inhibitor‐bound and free states. These findings, which have been demonstrated in both wild‐type Ras and the oncogenic mutant (G12V), support the mechanism of extended conformational selection for Ras–inhibitor interactions where the small molecules redistribute the protein conformational ensemble favoring the final bound states.
Numerical simulation of the behavior of high‐viscosity fluids falling film flow down the vertical wavy wall
Authors: Chen Shichang , Ma Jianping , Zhang Xianming , Chen Wenxing 
Published: November 2016

AbstractFalling film flow with high‐viscosity fluid is used throughout in the process intensification of industry production. However, analysis of wave characteristics based on operational conditions and independent of the geometrical wall is seriously restricted to low‐fluid viscosity. A general predictability of dynamic flow behavior of highly viscous fluid falling film flow is lacking. Our work has been motivated by such a challenge. Numerical simulations of gravity‐driven two‐dimensional steady falling film flow on vertical wall with wavy pattern were performed by using high‐viscosity fluids. Changes of falling film hydrodynamics with the increase of flow rate and fluid viscosity, including local and overall film thickness characteristics and its distribution, as well as the comparison velocity distribution with typical parabolic profiles, were presented to understand the film flow behavior. Furthermore, the effect of structural parameters of wavy wall on the flow behaviors both in crest and in trough of wall was also discussed. It was found that the flow behavior of falling film with high‐viscosity fluids was partly different from the film flow with very low fluids, and the film in trough was particularly sensitive to the changes either of the amplitude of wall or of the interval between two wave nodes. © 2016 Curtin University of Technology and John Wiley & Sons, Ltd. © 2016 Curtin University of Technology and John Wiley & Sons, Ltd.
Neues BAW‐Merkblatt zur Bewertung der Tragfähigkeit bestehender massiver Verkehrswasserbauten
Authors: Fleischer Helmut , Kunz Claus , Ehmann Rainer , Spörel Frank 
Published: November 2016

AbstractViele massive Verkehrswasserbauwerke, also Bauwerke aus Beton, Stahlbeton oder Mauerwerk, sind in Deutschland überdurchschnittlich alt. So ist beispielsweise rund ein Drittel aller Schleusen im Bereich der Wasserstraßen‐ und Schifffahrtsverwaltung des Bundes älter als 100 Jahre, überschreitet also die heute für solche Anlagen anzusetzende planmäßige Nutzungsdauer. Wie Schleusen weisen auch etliche Wehre und Kanalbrücken statische Besonderheiten auf, darunter heute nicht mehr gebräuchliche Bauweisen und sehr mächtige Querschnittsabmessungen. Werden Änderungen an den Bauwerken vorgenommen oder Schäden sichtbar, besteht die Notwendigkeit, das Tragwerk erneut statisch zu bemessen und im Rahmen einer Nachrechnung die erforderliche Standsicherheit rechnerisch nachzuweisen. Diese Untersuchungen können mit einem neuen BAW‐Merkblatt „TbW” [1] vorgenommen werden. Im Gegensatz zum Brücken‐ und Hochbau war bisher für statische Bewertungen bestehender massiver Wasserbauwerke kein angepasstes Regelwerk verfügbar.
DPPH·–luminol chemiluminescence system and its application in the determination of scutellarin in pharmaceutical injections and rat plasma with flow injection analysis
Authors: Yao Hong , Huang Xiaomei , Shi Peiying , Lin Zhen , Zhu Meilan , Liu Ailin , Lin Xinhua , Tang Yuhai 
Published: November 2016

AbstractIn this article, a DPPH·–luminol chemiluminescence (CL) system was reported and the CL mechanism was discussed according to the CL kinetic properties after sequence injecting DPPH· into the DPPH·–luminol reaction mixture. It was observed that scutellarin could inhibit the CL response of the DPPH·–luminol system. Based on this observation, a simple and rapid flow injection CL method was developed for the determination of scutellarin using the inhibition effect in alkaline medium. The optimized chemical conditions for the CL reaction were 5 × 10−6 mol/L DPPH· and 1.0 × 10−4 mol/L luminol in 0.01 mol/L NaOH. Under optimized conditions, the CL intensity was inversely proportional to the concentration of scutellarin over the ranges 5–2000 and 40–3200 ng/ml in pharmaceutical injection and rat plasma, respectively. The limits of detection (S/N = 3) were 5 and 40 ng/ml in preparations and rat plasma, respectively. Furthermore, the precision, recovery and stability of the validated method were acceptable for the determination of scutellarin in both pharmaceutical injections and rat plasma. The presented method was successfully applied in the determination of scutellarin in pharmaceutical injections and real rat plasma samples.
Simultaneous conversion of free fatty acids and triglycerides to biodiesel by immobilized Aspergillus oryzae expressing Fusarium heterosporum lipase
Authors: Amoah Jerome , Quayson Emmanuel , Hama Shinji , Yoshida Ayumi , Hasunuma Tomohisa , Ogino Chiaki , Kondo Akihiko 
Published: November 2016

AbstractThe presence of high levels of free fatty acids (FFA) in oil is a barrier to one‐step biodiesel production. Undesirable soaps are formed during conventional chemical methods, and enzyme deactivation occurs when enzymatic methods are used. This work investigates an efficient technique to simultaneously convert a mixture of free fatty acids and triglycerides (TAG). A partial soybean hydrolysate containing 73.04% free fatty acids and 24.81% triglycerides was used as a substrate for the enzymatic production of fatty acid methyl ester (FAME). Whole‐cell Candida antarctica lipase B‐expressing Aspergillus oryzae, and Novozym 435 produced only 75.2 and 73.5% FAME, respectively. Fusarium heterosporum lipase‐expressing A. oryzae produced more than 93% FAME in 72 h using three molar equivalents of methanol. FFA and TAG were converted simultaneously in the presence of increasing water content that resulted from esterification. Therefore, F. heterosporum lipase with a noted high level of tolerance of water could be useful in the industrial production of biodiesel from feedstock that has high proportion of free fatty acids.
Effects of the Functionalization of the Ordered Mesoporous Carbon Support Surface on Iron Catalysts for the Fischer–Tropsch Synthesis of Lower Olefins
Authors: Oschatz Martin , Hofmann Jan P. , van Deelen Tom W. , Lamme Wouter S. , Krans Nynke A. , Hensen Emiel J. M. , de Jong Krijn P. 
Published: November 2016

AbstractOrdered mesoporous carbon (CMK‐3) with different surface modifications is applied as a support for Fe‐based catalysts in the Fischer–Tropsch to olefins synthesis (FTO) with and without sodium and sulfur promoters. Different concentrations of functional groups do not affect the size (3–5 nm) of Fe particles in the fresh catalysts but iron (carbide) supported on N‐enriched CMK‐3 and a support with a lower concentration of functional groups show higher catalytic activity under industrially relevant FTO conditions (340 °C, 10 bar, H2/CO=2) compared to a support with an O‐enriched surface. The addition of promoters leads to more noticeable enhancements of the catalytic activity (3–5 times higher) and the selectivity to C2–C4 olefins (≈2 times higher) than surface functionalization of the support. Nitrogen surface functionalization and removal of surface groups before impregnation and calcination, however, further increase the activity of the catalysts in the presence of promoters. The confinement of the Fe nanoparticles in the mesopores of CMK‐3 restricts but does not fully prevent particle growth and, consequently, the decrease of activity under FTO conditions.
ChemInform Abstract: Near‐Zero Thermal Expansion and High Ultraviolet Transparency in a Borate Crystal of Zn4B6O13.
Authors: Xing Xianran , et al.  
Published: November 2016

AbstractPolycrystalline Zn4B6O13 is prepared by calcination of a stoichiometric mixture of Zn(O‐Ac)2 and B2O3 in air (800 °C, 3 d).
ChemInform Abstract: Honeycomb‐Like S = 5/2 Spin—Lattices in Manganese(II) Vanadates.
Authors: Sanjeewa Liurukara. D. , McGuire Michael A. , McMillen Colin D. , Willett Daniel , Chumanov George , Kolis Joseph W. 
Published: November 2016

AbstractSingle crystals of new complex manganese vanadate materials are hydrothermally synthesized and characterized by single crystal XRD and magnetic measurements.
ChemInform Abstract: Copper‐Mediated 1,2‐Difunctionalization of Styrenes with Sodium Arylsulfinates and tert‐Butyl Nitrite: Facile Access to α‐Sulfonylethanone Oximes.
Authors: Yang Ji , Liu Yan‐Yun , Song Ren‐Jie , Peng Zhi‐Hong , Li Jin‐Heng 
Published: November 2016

AbstractFunctionalized target compounds, required as synthons of natural products, pharmaceutical agents or in material science, are available in moderate to good yields in the presence of CuBr.
ChemInform Abstract: A General Method for Synthesis of cis‐Dicarbonyl Epoxides Through DBU/LiBr‐Cocatalyzed Cyclization of α,β‐Dicarbonyl Peroxides.
Authors: Zong Zhenzhen , Bai Xiaohui , Lu Shenglin , Li Zhiping 
Published: November 2016

AbstractInterestingly, substrate (VII) affords trans‐isomers as single or major products.
ChemInform Abstract: Ga(OTf)3‐Mediated Synthesis of Substituted Benzofurans.
Authors: Wang Heui‐Sin , Chan Chieh‐Kai , Chang Meng‐Yang 
Published: November 2016

AbstractStarting from potassium oxygenated phenoxides and α‐bromoaryl ketones various 2‐ and 3‐substituted benzofurans are prepared.
ChemInform Abstract: Enantioselective Synthesis of 2,3‐Disubstituted trans‐2,3‐Dihydrobenzofurans Using a Broensted Base/Thiourea Bifunctional Catalyst.
Authors: Barrios Antunez Diego‐Javier , Greenhalgh Mark D. , Fallan Charlene , Slawin Alexandra M. Z. , Smith Andrew D. 
Published: November 2016

AbstractThe title products are obtained in high yields and with high diastereo and enantioselectivities.
ChemInform Abstract: Spiroanthraceneoxazolidine as a Synthetic Equivalent of Methanimine in the Reaction with Donor—Acceptor Cyclopropanes. Synthesis of Diethyl 5‐Arylpyrrolidine‐3,3‐dicarboxylates.
Authors: Buev Evgeny M. , Moshkin Vladimir S. , Sosnovskikh Vyacheslav Y. 
Published: November 2016

AbstractYield and ease of the title transformation are well correlated with the electron‐donating nature of the aryl substituent at the cyclopropane ring.