bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evolution of gas saturation and relative permeability during gas production from hydrate‐bearing sediments: Gas invasion vs. gas nucleation
Authors: Jang Jaewon , Santamarina J. Carlos 
Published: December 2013

AbstractCapillarity and both gas and water permeabilities change as a function of gas saturation. Typical trends established in the discipline of unsaturated soil behavior are used when simulating gas production from hydrate‐bearing sediments. However, the evolution of gas saturation and water drainage in gas invasion (i.e., classical soil behavior) and gas nucleation (i.e., gas production) is inherently different: micromodel experimental results show that gas invasion forms a continuous flow path while gas nucleation forms isolated gas clusters. Complementary simulations conducted using tube networks explore the implications of the two different desaturation processes. In spite of their distinct morphological differences in fluid displacement, numerical results show that the computed capillarity‐saturation curves are very similar in gas invasion and nucleation (the gas‐water interface confronts similar pore throat size distribution in both cases); the relative water permeability trends are similar (the mean free path for water flow is not affected by the topology of the gas phase); and the relative gas permeability is slightly lower in nucleation (delayed percolation of initially isolated gas‐filled pores that do not contribute to gas conductivity). Models developed for unsaturated sediments can be used for reservoir simulation in the context of gas production from hydrate‐bearing sediments, with minor adjustments to accommodate a lower gas invasion pressure Po and a higher gas percolation threshold.
Nonlinear effective pressure law for permeability
Authors: Li M. , Xiao W.‐L. , Bernabé Y. , Zhao J.‐Z. 
Published: December 2013

AbstractThe permeability k of porous rocks is known to vary with confining pressure pc and pore fluid pressure pf. But it is, in principle, possible to replace the two‐variable function k(pf, pc) by a function k(peff) of a single variable, peff(pf, pc), called the effective pressure. Our goal in this paper is to establish an experimental method for determining a possibly nonlinear, effective pressure law (EPL) for permeability, i.e., find the function κs(pf, pc) such that the effective pressure is given by peff = pc − κs(pf, pc) pf. We applied this method to a set of 26 sandstone cores from various hydrocarbon reservoirs in China. We found that κs greatly varied, from sample to sample, in magnitude and range, sometimes even reaching theoretically prohibited values (i.e., greater than 1 or lower than porosity). One interesting feature of κs(pf, pc) is that it could be approximately described in all rocks but one as a decreasing function κs(pc − pf) of Terzaghi's differential pressure. We also investigated the dependence of permeability on peff for each of our samples. Three models from the literature, i.e., exponential (E), power law (P), and the Walsh model (W), were tested. The (W) model was more likely to fit the experimental data of cores with a high pressure dependence of permeability whereas (E) occurred more frequently in low‐pressure‐sensitive rocks. Finally, we made various types of two‐ and three‐dimensional microstructural observations that generally supported the trend mentioned above.
Reply to comment by Denyszyn and Halls (this volume) on “Geological and geophysical observations in the Kane Basin preclude the presence of a major plate boundary in southwestern Nares Strait”
Authors: Oakey Gordon N. , Chalmers James A. 
Published: December 2013

AbstractThe Paleogene movement of the Greenland Plate relative to North America took place in two stages. The movement of the Eocene stage is highly constrained by the known geometry of magnetic lineations and fracture zones in Labrador Sea and Baffin Bay. This geometry requires that the link from Baffin Bay to the Eurekan Orogeny must have been distributed deformation in the Canadian Archipelago, effectively forming an “Ellesmerian” microplate. Geophysical/geological observation in southwestern Nares Strait means that the strike‐slip movement of Greenland relative to North America during the Paleocene cannot have been through the Kane Basin but must have taken place farther northwest, probably within the Eurekan Fold Belt.
Transport of fine sediment over a coarse, immobile riverbed
Authors: Grams Paul E. , Wilcock Peter R. 
Published: December 2013

AbstractSediment transport in cobble‐boulder rivers consists mostly of fine sediment moving over a coarse, immobile bed. Transport rate depends on several interrelated factors: boundary shear stress, the grain size and volume of fine sediment, and the configuration of fine sediment into interstitial deposits and bed forms. Existing models do not incorporate all of these factors. Approaches that partition stress face a daunting challenge because most of the boundary shear is exerted on immobile grains. We present an alternative approach that divides the bed into sand patches and interstitial deposits and is well constrained by two clear end‐member cases: full sand cover and absence of sand. Entrainment from sand patches is a function of their aerial coverage. Entrainment from interstices among immobile grains is a function of sand elevation relative to the size of the immobile grains. The bed‐sand coverage function is used to predict the ratio of the rate of entrainment from a partially covered bed to the rate of entrainment from a completely sand‐covered bed, which is determined using a standard sand transport model. We implement the bed‐sand coverage function in a morphodynamic routing model and test it against observations of sand bed elevation and suspended sand concentration for conditions of nonuniform fine sediment transport in a large flume with steady uniform flow over immobile hemispheres. The results suggest that this approach may provide a simple and robust method for predicting the transport and migration of fine sediment through rivers with coarse, immobile beds.
Cenozoic deformation and exhumation history of the Central Kyrgyz Tien Shan
Authors: Macaulay Euan A. , Sobel Edward R. , Mikolaichuk Alexander , Kohn Barry , Stuart Finlay M. 
Published: December 2013

AbstractNew low‐temperature thermochronological data from 80 samples in eastern Kyrgyzstan are combined with previously published data from 61 samples to constrain exhumation in a number of mountain ranges in the Central Kyrgyz Tien Shan. All sampled ranges are found to have a broadly consistent Cenozoic exhumation history, characterized by initially low cooling rates (<1°C/Myr) followed by a series of increases in exhumation that occurred diachronously across the region in the late Cenozoic that are interpreted to record the onset of deformation in different mountain ranges. Combined with geological estimates for the onset of proximal deformation, our data suggest that the Central Kyrgyz Tien Shan started deforming in the late Oligocene‐early Miocene, leading to the development of several, widely spaced mountain ranges separated by large intermontane basins. Subsequently, more ranges have been constructed in response to significant shortening increases across the Central Kyrgyz Tien Shan, notably in the late Miocene. The order of range construction is interpreted to reflect variations in the susceptibility of inherited structures to reactivation. Reactivated structures are also shown to have significance along strike variations in fault vergence and displacement, which have influenced the development and growth of individual mountain ranges. Moreover, the timing of deformation allows the former extent of many intermontane basins that have since been partitioned to be inferred; this can be linked to the highly time‐transgressive onset of late Cenozoic coarse clastic sedimentation.
Investigation of the Thin‐Film Phase Diagram of the Cr–Ni–Re System by High‐Throughput Experimentation
Authors: Janghorban Amin , Pfetzing‐Micklich Janine , Frenzel Jan , Ludwig Alfred 
Published: December 2013

AbstractThe Cr–Ni–Re system was investigated over the whole composition range using combinatorial fabrication methods combined with high‐throughput characterization techniques in order to establish its thin film phase diagram. After annealing at 940 and 1100 °C, the phase equilibrium was reached in the Ni‐rich part of the ternary in agreement with the published bulk phase diagram. Annealing the materials library at 940 °C is not sufficient to achieve the equilibrium state in the Re‐rich part of the system, however by annealing the materials library at 1100 °C the formation of expected phases (three solid‐solutions and a topologically close packed compound) could be observed. As a result of this study, a thin film phase diagram of the complete Cr–Ni–Re at 1100 °C was established, which is well comparable to the bulk phase diagram. This shows that the combinatorial thin film phase diagram approach is feasible and especially promising for materials systems with expensive and/or high melting point constituents.
Hydroxyphenyl‐Substituted Benzophosphole Oxides: Impact of the Intramolecular Hydrogen Bond on the Fluorescence Properties
Authors: Fukazawa Aiko , Osaki Hiroshi , Yamaguchi Shigehiro 
Published: December 2013

AbstractAiming at a molecule that has distinct fluorescence properties dependent on the environment of the sample, we designed and synthesized 2‐(o‐hydroxyphenyl)‐substituted benzophosphole oxides, which can form an intramolecular hydrogen bond between the hydroxy group and the phosphine oxide moiety. A 3‐phenylated derivative fluoresces in several specific solvents that have hydrogen‐bond‐accepting abilities, whereas it is virtually non‐emissive in toluene, CH2Cl2, and MeCN. Experimental and theoretical studies indicate that this trend likely results from the switching of the excited‐state character. When in weak hydrogen‐bonding solvents, the compound forms a non‐emissive excited state that results from excited‐state intramolecular proton transfer (ESIPT). In hydrogen‐bonding solvents the compound forms an emissive excited state with an intermolecular hydrogen bond between the hydroxy group and the solvent. Switching between the intramolecular and intermolecular hydrogen bonds can be a mechanism for controlling the fluorescence properties of the phosphole‐oxide‐based π‐electron systems.
Post‐Synthesis Treatment gives Highly Stable Siliceous Zeolites through the Isomorphous Substitution of Silicon for Germanium in Germanosilicates
Authors: Xu Hao , Jiang Jin‐gang , Yang Boting , Zhang Lin , He Mingyuan , Wu Peng 
Published: December 2013

AbstractGermanosilicates, an important family of zeolites with increasing number of members and attractive porosities, but containing a large quantity of unstable Ge atoms in the framework, meet with great obstacles in terms of limited thermal and hydrothermal stability when it comes to practical use. A facile stabilization method thus has been developed to substitute isomorphously Ge atoms for Si atoms, giving rise to ultrastable siliceous analogues of the pristine germanosilicates.
Translocation of Platinum Anticancer Drugs by Human Copper ATPases ATP7A and ATP7B
Authors: Tadini‐Buoninsegni Francesco , Bartolommei Gianluca , Moncelli Maria Rosa , Inesi Giuseppe , Galliani Angela , Sinisi Marilù , Losacco Maurizio , Natile Giovanni , Arnesano Fabio 
Published: December 2013

AbstractCisplatin, carboplatin, and oxaliplatin are widely used anticancer drugs. Their efficacy is strongly reduced by development of cell resistance. Down‐regulation of CTR1 and up‐regulation of the Cu‐ATPases, ATP7A and ATP7B, have been associated to augmented drug resistance. To gain information on translocation of Pt drugs by human Cu‐ATPases, we performed electrical measurements on the COS‐1 cell microsomal fraction, enriched with recombinant ATP7A, ATP7B, and selected mutants, and adsorbed on a solid supported membrane. The experimental results indicate that Pt drugs activate Cu‐ATPases and undergo ATP‐dependent translocation in a fashion similar to that of Cu. We then used NMR spectroscopy and ESI‐MS to determine the binding mode of these drugs to the first N‐terminal metal‐binding domain of ATP7A (Mnk1).
Aqueous Anion Receptors through Reduction of Subcomponent Self‐Assembled Structures
Authors: Mosquera Jesús , Zarra Salvatore , Nitschke Jonathan R. 
Published: December 2013

AbstractTo prepare new functional covalent architectures that are difficult to synthesize using conventional organic methods, we developed a strategy that employs metal–organic assemblies as precursors, which are then reduced and demetalated. The host–guest chemistry of the larger receptor thus prepared was studied using NMR spectroscopy and fluorescence experiments. This host was observed to strongly bind aromatic polyanions in water, including the fluorescent dye molecule pyranine with nanomolar affinity, thus allowing for the design of an indicator‐displacement assay.
Stimuli‐Responsive Self‐Assembly of a Naphthalene Diimide by Orthogonal Hydrogen Bonding and Its Coassembly with a Pyrene Derivative by a Pseudo‐Intramolecular Charge‐Transfer Interaction
Authors: Das Anindita , Ghosh Suhrit 
Published: December 2013

AbstractA naphthalene diimide (NDI) building block containing hydrazide (H1) and hydroxy (H2) groups self‐assembled into a reverse‐vesicular structure in methylcyclohexane by orthogonal H‐bonding and π‐stacking. At an elevated temperature (LCST=43 °C), destruction of the assembled structure owing to selective dissociation of H2–H2 H bonding led to macroscopic precipitation. Further heating resulted in homogeneous redispersion of the sample at 70 °C (UCST) and the formation of a reverse‐micellar structure. In the presence of a pyridine (H3)‐functionalized pyrene (PY) donor, a supramolecular dyad (NDI–PY) was formed by H2–H3 H‐bonding. Slow transformation into an alternate NDI–PY stack occurred by a folding process due to the charge‐transfer interaction between NDI and PY. The mixed NDI–PY assembly exhibited a morphology transition from a reverse micelle (with a NDI–PY mixed‐stack core) below the LCST to another reverse micelle (with a NDI core) above the UCST via a “denatured” intermediate.
On the Molecular Structure and Bonding in a Lithium Bismuth Porphyrin Complex: LiBi(TPP)2
Authors: Balasanthiran Vagulejan , Chisholm Malcolm H. , Durr Christopher B. 
Published: December 2013

AbstractA new BiLi porphyrin sandwich compound, LiBi(TPP)2 has been synthesized and characterized (TPP=tetraphenylporphyrin). The unique molecular structure of LiBi(TPP)2 is such that the Bi sits between the porphyrins and is directed towards the Li. This complex was shown to remain intact in solution by temperature‐dependent 2D NMR spectroscopy. In order to investigate the potential interaction between these two metals, DFT calculations were used and showed a Bi 6s orbital polarized towards Li which could be indicative of a BiLi dative bond. This bond is remarkably short, 2.87 Å, and is among the shortest BiLi distances seen in a small molecule.
Class III Delocalization in a Cyanide‐Bridged Trimetallic Mixed‐Valence Complex
Authors: Pieslinger German E. , Alborés Pablo , Slep Leonardo D. , Baraldo Luis M. 
Published: December 2013

AbstractThe NIR and IR spectroscopic properties of the cyanide‐bridged complex, trans‐[Ru(dmap)4{(μ‐CN)Ru(py)4Cl}2]3+ (py=pyridine, dmap=4‐dimethylaminopyridine) provide strong evidence that this trimetallic ion behaves as a Class III mixed‐valence species, the first example reported of a cyanide‐bridged system. This has been accomplished by tuning the energy of the fragments in the trimetallic complex to compensate for the intrinsic asymmetry of the cyanide bridge. Moreover, (TD)DFT calculations accurately predict the spectra of the trans‐[Ru(dmap)4{(μ‐CN)Ru(py)4Cl}2]3+ ion and confirms its delocalized nature.
Use of a Phosphonate Methyltransferase in the Identification of the Fosfazinomycin Biosynthetic Gene Cluster
Authors: Gao Jiangtao , Ju Kou‐San , Yu Xiaomin , Velásquez Juan E. , Mukherjee Subha , Lee Jaeheon , Zhao Changming , Evans Bradley S. , Doroghazi James R. , Metcalf William W. , van der Donk Wilfred A. 
Published: December 2013

AbstractNatural product discovery has been boosted by genome mining approaches, but compound purification is often still challenging. We report an enzymatic strategy for “stable isotope labeling of phosphonates in extract” (SILPE) that facilitates their purification. We used the phosphonate methyltransferase DhpI involved in dehydrophos biosynthesis to methylate a variety of phosphonate natural products in crude spent medium with a mixture of labeled and unlabeled S‐adenosyl methionine. Mass‐guided fractionation then allowed straightforward purification. We illustrate its utility by purifying a phosphonate that led to the identification of the fosfazinomycin biosynthetic gene cluster. This unusual natural product contains a hydrazide linker between a carboxylic acid and a phosphonic acid. Bioinformatic analysis of the gene cluster provides insights into how such a structure might be assembled.
Copper‐Doped CdSe/ZnS Quantum Dots: Controllable Photoactivated Copper(I) Cation Storage and Release Vectors for Catalysis
Authors: Bear Joseph C. , Hollingsworth Nathan , McNaughter Paul D. , Mayes Andrew G. , Ward Michael B. , Nann Thomas , Hogarth Graeme , Parkin Ivan P. 
Published: December 2013

AbstractThe first photoactivated doped quantum dot vector for metal‐ion release has been developed. A facile method for doping copper(I) cations within ZnS quantum dot shells was achieved through the use of metal‐dithiocarbamates, with Cu+ ions elucidated by X‐ray photoelectron spectroscopy. Photoexcitation of the quantum dots has been shown to release Cu+ ions, which was employed as an effective catalyst for the Huisgen [3+2] cycloaddition reaction. The relationship between the extent of doping, catalytic activity, and the fluorescence quenching was also explored.
Synthesis of Quinazolines and Tetrahydroquinazolines: Copper‐Catalyzed Tandem Reactions of 2‐Bromobenzyl Bromides with Aldehydes and Aqueous Ammonia or Amines
Authors: Fan Xuesen , Li Bin , Guo Shenghai , Wang Yuanyuan , Zhang Xinying 
Published: December 2013

AbstractAn efficient synthesis of diversely substituted quinazolines and 1,2,3,4‐tetrahydroquinazolines through copper‐catalyzed tandem reactions of the readily available 2‐bromobenzyl bromides, aldehydes, and aqueous ammonia or amines has been developed. By using ammonia and simple aliphatic amines as the nitrogen source, the present method provides a versatile and practical protocol for the synthesis of quinazolines and 1,2,3,4‐tetrahydroquinazolines.
Alkali‐Metal Trichloroacetates for Dichloromethylenation of Fullerenes: Nucleophilic Addition‐Substitution Route
Authors: Apenova Marina G. , Akhmetov Vladimir A. , Belov Nikita M. , Goryunkov Alexey A. , Ioffe Ilya N. , Lukonina Natalia S. , Markov Vitaliy Yu. , Sidorov Lev N. 
Published: December 2013

AbstractThe first experimental evidence that fullerenes react with alkali‐metal trichloroacetates through a nucleophilic addition‐substitution route, yielding dichloromethylenefullerenes as the final products, is reported. The intermediates, C60(CCl3)− and C70(CCl3)− anions, have been isolated in their protonated forms as ortho‐C60(CCl3)H, as well as three ortho and one para isomer of C70(CCl3)H. The structures were unambiguously determined by means of 1H, 13C, and 1H–13C HMBC NMR spectroscopy along with UV/Vis spectroscopy. The observed regiochemistry was analyzed with the aid of quantum chemical calculations. Conversion of the protonated compounds into the [6,6]‐closed C60/70(CCl2) cycloadducts under basic conditions can be effected only for the ortho isomers, whereas para‐C70(CCl3)H decomposes back into pristine C70.
Extensive frequency selective measurements of radiofrequency fields in outdoor environments performed with a novel mobile monitoring system
Authors: Estenberg Jimmy , Augustsson Torsten 
Published: December 2013

AbstractA novel, car based, measuring system for estimation of general public outdoor exposure to radiofrequency fields (RF) has been developed. The system enables fast, large area, isotropic spectral measurements with a bandwidth covering the frequency range of 30 MHz to 3 GHz. Measurements have shown that complete mapping of a town with 15000 inhabitants and a path length of 115 km is possible to perform within 1 day. The measured areas were chosen to represent typical rural, urban and city areas of Sweden. The data sets consist of more than 70000 measurements. All measurements were performed during the daytime. The median power density was 16 µW/m2 in rural areas, 270 µW/m2 in urban areas, and 2400 µW/m2 in city areas. In urban and city areas, base stations for mobile phones were clearly the dominating sources of exposure. Bioelectromagnetics. 35:227–230, 2014. © 2013 Wiley Periodicals, Inc.
Networks of lexical borrowing and lateral gene transfer in language and genome evolution
Authors: List Johann‐Mattis , Nelson‐Sathi Shijulal , Geisler Hans , Martin William 
Published: December 2013

Like biological species, languages change over time. As noted by Darwin, there are many parallels between language evolution and biological evolution. Insights into these parallels have also undergone change in the past 150 years. Just like genes, words change over time, and language evolution can be likened to genome evolution accordingly, but what kind of evolution? There are fundamental differences between eukaryotic and prokaryotic evolution. In the former, natural variation entails the gradual accumulation of minor mutations in alleles. In the latter, lateral gene transfer is an integral mechanism of natural variation. The study of language evolution using biological methods has attracted much interest of late, most approaches focusing on language tree construction. These approaches may underestimate the important role that borrowing plays in language evolution. Network approaches that were originally designed to study lateral gene transfer may provide more realistic insights into the complexities of language evolution.Editor's suggested further reading in BioEssaysLinguistic evidence supports date for Homeric epics Abstract