bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparative assessment of three‐phase oil relative permeability models
Authors: Ranaee Ehsan , Riva Monica , Porta Giovanni M. , Guadagnini Alberto 
Published: June 2016

AbstractWe assess the ability of 11 models to reproduce three‐phase oil relative permeability (
) laboratory data obtained in a water‐wet sandstone sample. We do so by considering model performance when (i) solely two‐phase data are employed to render predictions of
and (ii) two and three‐phase data are jointly used for model calibration. In the latter case, a Maximum Likelihood (ML) approach is used to estimate model parameters. The tested models are selected among (i) classical models routinely employed in practical applications and implemented in commercial reservoir software and (ii) relatively recent models which are considered to allow overcoming some drawbacks of the classical formulations. Among others, the latter set of models includes the formulation recently proposed by Ranaee et al. (), which has been shown to embed the critical effects of hysteresis, including the reproduction of oil remobilization induced by gas injection in water‐wet media. We employ formal model discrimination criteria to rank models according to their skill to reproduce the observed data and use ML Bayesian model averaging to provide model‐averaged estimates (and associated uncertainty bounds) of
by taking advantage of the diverse interpretive abilities of all models analyzed. The occurrence of elliptic regions is also analyzed for selected models in the framework of the classical fractional flow theory of displacement. Our study confirms that model outcomes based on channel flow theory and classical saturation‐weighted interpolation models do not generally yield accurate reproduction of
data, especially in the regime associated with low oil saturations, where water alternating gas injection (WAG) techniques are usually employed for enhanced oil recovery. This negative feature is not observed in the model of Ranaee et al. (2015) due to its ability to embed key effects of pore‐scale phase distributions, such as hysteresis effects and cycle dependency, for modeling
observed during WAG.
Attribution of regional flood changes based on scaling fingerprints
Authors: Viglione Alberto , Merz Bruno , Viet Dung Nguyen , Parajka Juraj , Nester Thomas , Blöschl Günter 
Published: June 2016

AbstractChanges in the river flood regime may be due to atmospheric processes (e.g., increasing precipitation), catchment processes (e.g., soil compaction associated with land use change), and river system processes (e.g., loss of retention volume in the floodplains). This paper proposes a new framework for attributing flood changes to these drivers based on a regional analysis. We exploit the scaling characteristics (i.e., fingerprints) with catchment area of the effects of the drivers on flood changes. The estimation of their relative contributions is framed in Bayesian terms. Analysis of a synthetic, controlled case suggests that the accuracy of the regional attribution increases with increasing number of sites and record lengths, decreases with increasing regional heterogeneity, increases with increasing difference of the scaling fingerprints, and decreases with an increase of their prior uncertainty. The applicability of the framework is illustrated for a case study set in Austria, where positive flood trends have been observed at many sites in the past decades. The individual scaling fingerprints related to the atmospheric, catchment, and river system processes are estimated from rainfall data and simple hydrological modeling. Although the distributions of the contributions are rather wide, the attribution identifies precipitation change as the main driver of flood change in the study region. Overall, it is suggested that the extension from local attribution to a regional framework, including multiple drivers and explicit estimation of uncertainty, could constitute a similar shift in flood change attribution as the extension from local to regional flood frequency analysis.
Capillary Electrochromatography
Authors: Yan Chao , Wang Yan , Xue Yun 
Published: June 2016

Abstract
Capillary electrochromatography (CEC) is a hybrid separation technique of capillary high‐performance liquid chromatography (cHPLC) and capillary electrophoresis (CE). The mobile phase in a capillary column of CEC is driven by electroosmotic flow (EOF), giving advantages such as high efficiency, high resolution, high selectivity, and low sample and solvent consumption. However, the formation of air bubbles hinders the CEC to become a mainstream separation technique. In order to solve this problem, pressurized capillary electrochromatography (pCEC), with EOF combining hydraulic pressure as its driving force, has been developed and gained more attention. In this article, we introduce the development of CEC and pCEC on their theory, instrumentation, sample introduction, column technology, and applications. Besides, gradient elution and two‐dimensional separation based on CEC and pCEC will also be illustrated.
Neutron Diffraction in Studies of Protein Dynamics and Functions, Application of
Authors: Niimura Nobuo , Takimoto‐Kamimura Midori , Tanaka Ichiro 
Published: June 2016

Abstract

Neutron protein crystallography (NPC) provides the unique information for the study of protein dynamics and functions. After the specific features of the interactions between neutrons and biomacromolecules, and the neutron diffractometers in the world were briefly introduced, the following topics relevant to the protonation states of the polar amino acid residues of several proteins are discussed in detail: they are the pH dependence, proton transfer derived from enzyme reaction, serine protease, the drug design, and charge balance. The proteins described herein are met‐myoglobin, lysozyme, HIV‐1 protease, endothiapepsin, transthyretin (TTR), dihydrofolate reductase (DHFR), insulin, RNase A,
d
‐xylose isomerase, human C carbonic anhydrase II (HCAII), c‐GMP‐dependent protein kinase, urate oxidase, ferredoxin oxidoreductase, cellulase, peroxidase, several serine proteases (such as trypsin, elastase, thrombin, and achromobacter protease (AP‐I)), toho‐1 β‐lactamase, and farnesyl pyrophosphate synthase (FPPS).
The Di‐Iron OxygenasePhnZ
Authors: Séguin Jacqueline P , Zechel David L 
Published: June 2016

AbstractPhnZ is a di‐iron‐dependent monooxygenase from the HD superfamily of metal ion‐dependent phosphohydrolases. These enzymes utilize a conserved histidine‐aspartate motif in the active site for metal ion binding. PhnZ is commonly found in marine bacteria where it works in tandem with the α‐ketoglutarate‐dependent dioxygenase PhnY to extract inorganic phosphate from the organophosphonate natural product 2‐aminoethylphosphonic acid. PhnY hydroxylates 2‐aminoethylphosphonic acid stereospecifically to generate (R)‐2‐amino‐1‐hydroxyethylphosphonic acid, whereupon PhnZ catalyzes the oxidative cleavage of the carbon–phosphorus bond yielding glycine and inorganic phosphate. Analysis of the metal ion dependence of PhnZ through activity assays, ICP‐MS, Mössbauer spectroscopy, and EPR spectroscopy have shown that this enzyme utilizes a mixed‐valence Fe(II)/Fe(III) di‐iron cofactor for catalysis. The X‐ray crystal structures of PhnZ have revealed that one Fe ion (Fe2) is used to bind the substrate in a bidentate manner, while the other Fe ion (Fe1) is likely used to reduce dioxygen. Two conserved active site residues, Y24 and E27, are observed to migrate in and out of the active site in response to substrate binding. Y24 is observed to bind Fe2, occupying the putative dioxygen binding site, but is expelled upon recognition of the substrate amino group by the residue E27. This is proposed to allow dioxygen to bind to Fe1, placing it well within proximity of the substrate bound at Fe2. A mechanism for oxidative carbon–phosphorus bond cleavage by PhnZ has been proposed based on these results. PhnZ not only represents the third known mechanism for enzymatic cleavage of CP‐bonds but also provides a window into the evolution of new functions within an enzyme superfamily.
Zinc‐Catalyzed Tandem Diels–Alder Reactions of Enynals with Alkenes: Generation and Trapping of Cyclic o‐Quinodimethanes (o‐QDMs)
Authors: Zhang Jiantao , Xiao Yelin , Chen Kai , Wu Wanqing , Jiang Huanfeng , Zhu Shifa 
Published: June 2016

AbstractA systematic investigation of ZnCl2‐catalyzed reactions of enynals with alkenes has been undertaken. Structurally unique propeller‐like products could be obtained under mild conditions. Cyclic o‐quinodimethanes (o‐QDMs) are generated through [4+2] cycloaddition between enynals and alkenes. Both electron‐poor and electron‐rich dienophiles could be used to trap the active intermediate through [4+2] cycloaddition. But [1,5]‐H shift products could also be observed when electron‐rich alkenes were used as dienophile. DFT calculations were performed to understand the reaction mechanism. A competition between the [4+2] cycloaddition and [1,5]‐H shift was proposed for the transformation of cyclic o‐QDMs. The selectivity could be affected by the properties of the substrates.magnified image
Continuous‐Flow Synthesis and Derivatization of Aziridines through Palladium‐Catalyzed C(sp3)−H Activation
Authors: Zakrzewski Jacek , Smalley Adam P. , Kabeshov Mikhail A. , Gaunt Matthew J. , Lapkin Alexei A. 
Published: June 2016

AbstractA continuous‐flow synthesis of aziridines by palladium‐catalyzed C(sp3)−H activation is described. The new flow reaction could be combined with an aziridine‐ring‐opening reaction to give highly functionalized aliphatic amines through a consecutive process. A predictive mechanistic model was developed and used to design the C−H activation flow process and illustrates an approach towards first‐principles design based on novel catalytic reactions.
Direct Synthesis of Phospholyl Lithium from White Phosphorus
Authors: Xu Ling , Chi Yue , Du Shanshan , Zhang Wen‐Xiong , Xi Zhenfeng 
Published: June 2016

AbstractThe selective construction of P−C bonds directly from P4 and nucleophiles is an ideal and step‐economical approach to utilizing elemental P4 for the straightforward synthesis of organophosphorus compounds. In this work, a highly efficient one‐pot reaction between P4 and 1,4‐dilithio‐1,3‐butadienes was realized, which quantitatively affords phospholyl lithium derivatives. DFT calculations indicate that the mechanism is significantly different from that of the well‐known stepwise cleavage of P−P bond in P4 activation. Instead, a cooperative nucleophilic attack of two C
Li bonds on P4, leading to simultaneous cleavage of two P−P bonds, is favorable. This mechanistic information offers a new view on the mechanism of P4 activation, as well as a reasonable explanation for the excellent yields and selectivity. This method could prove to be a useful route to P4 activation and the subsequent production of organophosphorus compounds.
Safe and Selective Nitro Group Reductions Catalyzed by Sustainable and Recyclable Fe/ppm Pd Nanoparticles in Water at Room Temperature
Authors: Feng Jie , Handa Sachin , Gallou Fabrice , Lipshutz Bruce H. 
Published: June 2016

AbstractAs a result of a unique synergy between ligand‐free Fe/ppm Pd nanoparticles and PEG‐containing designer surfactants, a facile and selective reduction of nitro‐containing aromatics and heteroaromatics can be effected in water at room temperature in the presence of NaBH4. This new nanotechnology involves low catalyst loadings, is highly chemoselective, and tolerates a wide variety of functional groups. The process, which includes recycling of the entire aqueous medium, offers a general, environmentally responsible, and notably safe approach to highly valued reductions of nitro‐containing compounds.
Two‐Coordinate Magnesium(I) Dimers Stabilized by Super Bulky Amido Ligands
Authors: Boutland Aaron J. , Dange Deepak , Stasch Andreas , Maron Laurent , Jones Cameron 
Published: June 2016

AbstractA variety of very bulky amido magnesium iodide complexes, LMgI(solvent)0/1 and [LMg(μ‐I)(solvent)0/1]2 (L=‐N(Ar)(SiR3); Ar=C6H2{C(H)Ph2}2R′‐2,6,4; R=Me, Pri, Ph, or OBut; R′=Pri or Me) have been prepared by three synthetic routes. Structurally characterized examples of these materials include the first unsolvated amido magnesium halide complexes, such as [LMg(μ‐I)]2 (R=Me, R′=Pri). Reductions of several such complexes with KC8 in the absence of coordinating solvents have afforded the first two‐coordinate magnesium(I) dimers, LMg−MgL (R=Me, Pri or Ph; R′=Pri, or Me), in low to good yields. Reductions of two of the precursor complexes in the presence of THF have given the related THF adduct complexes, L(THF)Mg−Mg(THF)L (R=Me; R′=Pri) and LMg−Mg(THF)L (R=Pri; R′=Me) in trace yields. The X‐ray crystal structures of all magnesium(I) complexes were obtained. DFT calculations on the unsolvated examples reveal their Mg−Mg bonds to be covalent and of high s‐character, while Ph⋅⋅⋅Mg bonding interactions in the compounds were found to be weak at best.
Controlling the Stealth Effect of Nanocarriers through Understanding the Protein Corona
Authors: Schöttler Susanne , Landfester Katharina , Mailänder Volker 
Published: June 2016

AbstractThe past decade has seen a significant increase in interest in the use of polymeric nanocarriers in medical applications. In particular, when used as drug vectors in targeted delivery, nanocarriers could overcome many obstacles for drug therapy. Nevertheless, their application is still impeded by the complex composition of the blood proteins covering the particle surface, termed the protein corona. The protein corona complicates any prediction of cell interactions, biodistribution, and toxicity. In particular, the unspecific uptake of nanocarriers is a major obstacle in clinical studies. This Minireview provides an overview of what we currently know about the characteristics of the protein corona of nanocarriers, with a focus on surface functionalization that reduces unspecific uptake (the stealth effect). The ongoing improvement of nanocarriers to allow them to meet all the requirements necessary for successful application, including targeted delivery and stealth, are further discussed.
Functionalized silica nanoparticles for trapping Pb2+ ions via diazo‐azomethine scaffolds
Authors: Narula Priyanka , Mutneja Ruchi , Singh Raghubir , Kaur Varinder 
Published: June 2016

Diazo‐azomethine coated silica sorbent for the adsorption of Pb2+ ions has been fabricated. The sorbent was obtained by one‐pot synthesis of silica nanoparticles in the presence of diazo‐azomethine molecules possessing silatranyl side chains for grafting via covalent bond formation. The functionalized silica nanoparticles exhibited characteristic physicochemical properties of diazo‐azomethine scaffolds as determined using Fourier transform infrared spectroscopy, scanning and transmission electron microscopies and thermogravimetric analysis. Various adsorption parameters such as pH, weight of adsorbent, time taken for equilibration and recovery of lead ions were optimized using a batch method. The sorbent showed high adsorption capacity for lead ions of 460.4 mg g−1 at pH = 4. The effect of various competing ions on the adsorption of lead ions was studied and interference was removed by using a masking agent. The sorbent can be regenerated and reused, and is compatible for the adsorption of Pb2+ ions from green leafy vegetables. Copyright © 2016 John Wiley & Sons, Ltd.
Development of lignin carbon fibers: Evaluation of the carbonization process
Authors: Kleinhans Henrik , Salmén Lennart 
Published: June 2016

ABSTRACTThe use of lignin as a renewable resource for the production of less‐expensive carbon fibers has in recent years attracted great interest. In order to develop the strength properties, the stabilization and carbonization processes have to be optimized. For this reason, the process parameters during carbonization have here been studied on stabilized lignin fibers in the temperature interval from 300 to 1300 °C. The effects of temperature, heating rate, and straining of fibers during carbonization on the strength properties of carbon fibers were investigated. The heating rate, in the range from 1 to 40 °C/min, was shown to have no effect on the property development of the fibers. During carbonization with no load applied to the fibers, a shrinkage of 20% was noted. Counteracting the shrinkage by imposing a load on the fibers during the carbonization resulted in fibers with a greater stiffness. The tensile strength was not, however, affected by this loading. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43965.
Novel polyurea polymers with enhanced mechanical properties
Authors: Toader Gabriela , Rusen Edina , Teodorescu Mircea , Diacon Aurel , Stanescu Paul O. , Rotariu Traian , Rotariu Adrian 
Published: June 2016

ABSTRACTThe present work describes the preparation of a set of new polyurea polymers suitable for ballistic protection applications by employing different aromatic diamines derivatives with different flexibility degrees. This modification would allow the synthesis of polymers with both enhanced and controllable mechanical properties through the combination of aliphatic and aromatic molecules. Besides the classical methylene diphenyl diisocyanate and polypropylene glycol bis(2‐aminopropyl ether) (PPG), benzidine, 4,4′‐diaminodiphenylmethane and 3,6‐diamino carbazole were chosen as the third monomer and used in different ratios toward PPG, in order to optimize the polymer properties. The proportions between the polyurea components were selected as such to achieve the total consumption of the monomers. The different types of polyurea obtained have been characterized by Fourier transform infrared spectroscopy, thermal measurements (differential scanning calorimetry and thermogravimetric analysis), tensile tests, and scanning electron microscope. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43967.
Conducting epoxy networks modified with non‐covalently functionalized multi‐walled carbon nanotube with imidazolium‐based ionic liquid
Authors: Lopes Pereira Elaine C. , Soares Bluma G. 
Published: June 2016

ABSTRACTMulti‐walled carbon nanotube (MWCNT) was non‐covalently functionalized with room‐temperature ionic liquid (IL), 1‐butyl‐3‐methyl‐imidazolium tetrafluoroborate and blended with epoxy pre‐polymer (ER) with the assistance of ultrasonication in the presence of acetone as a diluting medium. The ability of IL in improving the dispersion of MWCNT in epoxy pre‐polymer was evidenced by transmission optical microscopy. The corresponding epoxy/MWCNT networks cured with anhydride displayed an increase of the electrical conductivity of around three orders of magnitude with the addition of IL in a proportion of MWCNT/IL = 1:5 mass ratio. The effect of IL on dynamic mechanical properties and thermal conductivity was also evaluated. The improved thermal and electrical properties was attributed to the better dispersion of MWCNT within the epoxy matrix by IL, evidenced by transmission electron microscopy of the ER/MWCNT networks cured with anhydride. Raman spectroscopy was also used to confirm the interaction between MWCNT and IL. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43976.
Geological subsidence and sinking islands: the case of Manono (Samoa)
Authors: SAND CHRISTOPHE , BOLÉ JACQUES , BARET DAVID , OUETCHO ANDRÉ‐JOHN , PETCHEY FIONA , HOGG ALAN , ASAUA TAUTALA 
Published: June 2016

ABSTRACTW.R. Dickinson, as part of his wide study of the geological history of the Pacific islands, has linked the unique case of the deeply submerged Lapita site of Mulifanua in western Upolu (Samoa) to the slow subsidence of Upolu island. Recent archaeological research on the neighbouring small island of Manono has yielded new and detailed data on this geological process. A series of new dates has allowed us to define the speed of the subsidence and demonstrate the massive environmental changes to which the local population has had to adapt over the past 2000 years.
Preparation of Ru/Graphene using Glucose as Carbon Source and Hydrogenation of Levulinic Acid to γ‐Valerolactone
Authors: Wu Lingqiao , Song Jinliang , Zhou Baowen , Wu Tianbin , Jiang Tao , Han Buxing 
Published: June 2016

AbstractThe preparation of functional materials and value‐added chemicals using biomass‐derived feedstocks is an interesting topic. Herein, we propose a method to prepare Ru/graphene catalyst using glucose as the carbon source. The catalyst was characterized by scanning and transmission electron microscopies, Raman and X‐ray photoelectron spectroscopies, and X‐ray diffraction. It was found that Ru particles of 2–6 nm were supported uniformly on high‐quality graphene. The performance of the Ru/graphene for hydrogenation of levulinic acid to γ‐valerolactone was studied. The Ru/graphene had much higher activity for the hydrogenation reaction than commercial Ru/C, and was active even at room temperature. The high activity was partially due to the unique structure of graphene, which resulted in an electron‐enriched Ru nanocatalyst. In addition, the Ru/graphene could be reused at least four times without considerable decrease in activity, indicating the excellent stability of the catalyst under our conditions.
Direct Observation of the Collision of Single Pt Nanoparticles onto Single‐Crystalline Gold Nanowire Electrodes
Authors: Shin Changhwan , Bae Hyeonhu , Kang Mijeong , Kim Bongsoo , Kwon Seong Jung 
Published: June 2016

AbstractWe observed the collision of single Pt nanoparticles (NPs) onto an Au nanowire (NW) electrode by using electrocatalytic amplification. Previously, such observations had typically been performed by using a microscale disk‐type ultramicroelectrode (UME). The use of a NW electrode decreased the background noise current and provided a shielding effect, owing to adsorption of the NPs onto the insulating sheath. Therefore, the transient current signal that was caused by the collision of single NPs could be more clearly distinguished from the background current by using a NW electrode instead of a UME. Furthermore, the use of a NW electrode increased the collisional frequency and the magnitude of the transient current signal. The experimental data were analyzed by using a theoretical model and a random walk simulation model.
Ion‐Free and Ion‐Pairing Assemblies of Anion‐Responsive π‐Electronic Systems Possessing Directly Linked Alkyl Chains
Authors: Haketa Yohei , Katayama Daisuke , Fukunaga Shinya , Bando Yuya , Sakurai Tsuneaki , Matsuda Wakana , Seki Shu , Maeda Hiromitsu 
Published: June 2016

AbstractAlkyl‐substituted pyrrole‐based anion‐responsive π‐electronic systems formed supramolecular gels and liquid crystals through effective π–π stacking and van der Waals interactions. The addition of chloride as a planar cation salt afforded ion‐pairing assemblies as soft materials comprising planar receptor‐Cl− complexes and the cation.