bluuebunny/crossref_metadata_2025_split huggingface dataset:
Internal tides and tidal cycles of vertical mixing in western Long Island Sound
Authors: McCardell Grant , O'Donnell James , Souza Alejandro J. , Palmer Matthew R. 
Published: January 2016

AbstractIn estuaries, tidal period variations in the rate of vertical mixing have been observed to result from various causes: in Liverpool Bay and the York River, they have been attributed to tidal straining of the along‐channel density gradient modulating stratification; in the Hudson River they arise from tidal modulation of the height of the tidal current bottom boundary layer (BBL). Along continental shelves, tidal period fluctuations in mixing have been observed to result from the dissipation of internal waves (IWs). Western Long Island Sound (WLIS) moored instrument records indicate that large near‐bottom increases in dissolved oxygen (DO) and heat and a decrease in salt occur during the middle of the flood tide: an analysis of water mass signatures indicates that the transport involved is vertical and not horizontal. Temperature data from a vertical thermistor array deployed in the WLIS for 16 days in August 2009 clearly show a tidal cycle of IW activity creating a mean thermocline depression at midflood of approximately 25% of the water depth with individual IW thermocline depressions of as much as 50% of the water depth. Contemporaneous ADCP measurements show increases in shear due to IWs during the flood. Near‐bottom internal wave activity is maximal at and after midflood and is correlated with near‐bottom temperature and DO tendencies at both tidal and subtidal scales. We conclude that internal tides are an important vertical mixing mechanism in the WLIS through both increased shear from IWs and displacement of the pycnocline into the region of high shear in the BBL.
A nudged chemistry‐climate model simulation of chemical constituent distribution at northern high‐latitude stratosphere observed by SMILES and MLS during the 2009/2010 stratospheric sudden warming
Authors: Akiyoshi H. , Nakamura T. , Miyasaka T. , Shiotani M. , Suzuki M. 
Published: January 2016

AbstractStratospheric sudden warming (SSW) is a dramatic phenomenon of the winter stratosphere in which the distribution of chemical constituents, associated chemical tendency, and transport of chemical constituents differ significantly inside and outside of the polar vortex. In this study, the chemical constituent distributions in the major SSW of 2009/2010 were simulated by the Model for Interdisciplinary Research on Climate 3.2‐Chemistry‐Climate Model (CCM) nudged toward the European Center for Medium‐Range Weather Forecasts‐Interim Re‐Analysis data. The results were compared with Superconducting Submillimeter‐Wave Limb‐Emission Sounder (SMILES) and Microwave Limb Sounder (MLS) observations. In addition, ozone tendency due to ozone transport and chemical ozone loss in the high‐latitude lower stratosphere before and after the SSW was analyzed for the period from 1 January 2010 to 11 February 2010. The evolution and distribution of ozone and HCl inside/outside the polar vortex associated with the vortex shift to the midlatitudes in January are quite similar between SMILES and MLS. Those of ClO are also similar, considering the difference in the local time for the measurement. Analyses of the nudged CCM run indicate that inside the polar vortex at 50 hPa, the ozone concentration increased moderately owing to partial cancelation between the large negative ozone tendency due to chemical ozone destruction and large positive ozone tendency due to horizontal ozone influx from outside of the vortex as well as downward advection. In the region of a high ozone concentration with the same area as that of the polar vortex at 50 hPa, the large increase in ozone was primarily due to a downward advection of ozone. SMILES and MLS observations, nudged CCM simulations, and ozone tendency analyses revealed a highly longitudinal dependent ozone tendency at high latitudes during the SSW.
Carbon emissions from decomposition of fire‐killed trees following a large wildfire in Oregon, United States
Authors: Campbell John L. , Fontaine Joseph B. , Donato Daniel C. 
Published: January 2016

AbstractA key uncertainty concerning the effect of wildfire on carbon dynamics is the rate at which fire‐killed biomass (e.g., dead trees) decays and emits carbon to the atmosphere. We used a ground‐based approach to compute decomposition of forest biomass killed, but not combusted, in the Biscuit Fire of 2002, an exceptionally large wildfire that burned over 200,000 ha of mixed conifer forest in southwestern Oregon, USA. A combination of federal inventory data and supplementary ground measurements afforded the estimation of fire‐caused mortality and subsequent 10 year decomposition for several functionally distinct carbon pools at 180 independent locations in the burn area. Decomposition was highest for fire‐killed leaves and fine roots and lowest for large‐diameter wood. Decomposition rates varied somewhat among tree species and were only 35% lower for trees still standing than for trees fallen at the time of the fire. We estimate a total of 4.7 Tg C was killed but not combusted in the Biscuit Fire, 85% of which remains 10 years after. Biogenic carbon emissions from fire‐killed necromass were estimated to be 1.0, 0.6, and 0.4 Mg C ha−1 yr−1 at 1, 10, and 50 years after the fire, respectively; compared to the one‐time pyrogenic emission of nearly 17 Mg C ha−1.
Glacier crevasses: Observations, models, and mass balance implications
Authors: Colgan William , Rajaram Harihar , Abdalati Waleed , McCutchan Cheryl , Mottram Ruth , Moussavi Mahsa S. , Grigsby Shane 
Published: January 2016

AbstractWe review the findings of approximately 60 years of in situ and remote sensing studies of glacier crevasses, as well as the three broad classes of numerical models now employed to simulate crevasse fracture. The relatively new insight that mixed‐mode fracture in local stress equilibrium, rather than downstream advection alone, can introduce nontrivial curvature to crevasse geometry may merit the reinterpretation of some key historical observation studies. In the past three decades, there have been tremendous advances in the spatial resolution of satellite imagery, as well as fully automated algorithms capable of tracking crevasse displacements between repeat images. Despite considerable advances in developing fully transient three‐dimensional ice flow models over the past two decades, both the zero stress and linear elastic fracture mechanics crevasse models have remained fundamentally unchanged over this time. In the past decade, however, multidimensional and transient formulations of the continuum damage mechanics approach to simulating ice fracture have emerged. The combination of employing damage mechanics to represent slow upstream deterioration of ice strength and fracture mechanics to represent rapid failure at downstream termini holds promise for implementation in large‐scale ice sheet models. Finally, given the broad interest in the sea level rise implications of recent and future cryospheric change, we provide a synthesis of 10 mechanisms by which crevasses can influence glacier mass balance.
Cooperative adaptive guidance and control paradigm for marine robots in an emergency ship towing scenario
Authors: Bruzzone G. , Bibuli M. , Zereik E. , Ranieri A. , Caccia M. 
Published: January 2016

SummaryThis paper focuses on the control strategy needed by marine robots to be able to follow moving paths within a cooperative framework. This control aspect is essential in order to effectively perform emergency ship towing operations. In particular, these robots coordinate their motion, with the aim of performing an autonomous tying operation, linking the messenger line of a distressed ship to a salvage tugboat. Automatic guidance algorithms are developed in order to provide cooperation and coordination of robots' motion, in such a way to perform the knotting maneuver between the two employed vehicles. In particular, the major contribution of the present work in terms of adaptive control methodology consists in extending a well‐known path following strategy for multi‐vehicle cooperation to cope with moving reference paths. Extensive experimental testing validates the proposed concept, also pointing out the feasibility and effectiveness of the developed system in real‐case scenarios. Copyright © 2016 John Wiley & Sons, Ltd.
Catalytic Aerobic Photo‐oxidation of a Methyl Group on a Heterocycle to Produce an Aldehyde via Homolytic CI Bond Cleavage caused by Irradiation with Visible Light
Authors: Nagasawa Y. , Tachikawa Y. , Yamaguchi E. , Tada N. , Miura T. , Itoh A. 
Published: January 2016

AbstractA new catalytic method was developed for photo‐oxidizing the methyl group on aromatic heterocycles such as benzothiazole, benzoxazole, and quinoline to produce the corresponding aldehyde. This is the first report of the metal‐free catalytic synthesis of benzothiazole‐2‐carboxaldehydes using molecular oxygen as the terminal oxidant.magnified image
Iridium(III)‐Catalyzed Direct CH Sulfonamidation of 2‐Aryl‐1,2,3‐triazole N‐Oxides with Sulfonyl Azides
Authors: Zhu Bingfeng , Cui Xiuling , Pi Chao , Chen Dong , Wu Yangjie 
Published: January 2016

AbstractWe have developed a method for the direct sulfonamidation of 2‐aryl‐1,2,3‐triazole N‐oxides using sulfonyl azides as the amino source to release molecular nitrogen as the sole by‐product. This protocol exhibits excellent functional group tolerance and proceeds efficiently under external oxidant‐free conditions. Various 2‐(2‐sulfonamidoaryl)‐1,2,3‐triazoles were prepared in up to 97% yields for 25 examples with excellent regioselectivity.magnified image
Propylene Polymerization over MgCl2‐Supported Ziegler–Natta Catalysts Containing Tri‐Ether as the Internal Donor
Authors: Zahedi Roya , Afshar Taromi Faramarz , Mirjahanmardi Seyed Heidar , Nekoomanesh Haghighi Mehdi , Jadidi Khosrow , Jamjah Roghayeh 
Published: January 2016

ABSTRACT1‐Methoxy‐2,2‐bis(methoxymethyl)butane as a new internal donor was synthesized by the reaction of 1,1,1‐tris(hydroxymethyl)propane with sodium hydride as the base and methyl iodide as the alkyl halide. The tri‐ether compound was characterized by NMR and FTIR techniques. The MgCl2‐supported titanium catalysts were incorporated with varying amounts of 1‐methoxy‐2,2‐bis(methoxymethyl)butane as the internal donor (ID) and also without the internal donor were synthesized, and then the prepared catalysts were characterized. The concentration of titanium, magnesium, and chloride were determined by spectrophotometry and by complexometric and argentometric titration, respectively. The polymerization of propylene was carried out with the prepared catalysts in conjunction with triethylaluminum as a cocatalyst and hydrogen as a chain transfer agent, with and without cyclohexylmethyldimethoxysilane as the external donor. The effects of a new internal donor on MgCl2‐supported Ziegler–Natta catalysts for propylene polymerization were investigated, and then these results were compared to the obtained polypropylenes results, which were obtained using the conventional Ziegler–Natta catalyst containing diisobutyl phthalate as the internal donor. The highest isotacticity, melting temperature, and crystallinity degree of polypropylene were obtained using Cat‐D with an ID/Mg molar ratio equal to 0.44, and the highest catalytic activity is related to Cat‐B with an ID/Mg molar ratio equal to 0.22.The Ziegler–Natta catalysts incorporated with various ID/Mg molar ratios of 1‐methoxy‐2,2‐bis(methoxymethyl)butane were synthesized. The polymerization of propylene was carried out with the prepared catalysts. The highest catalytic activity is related to Cat‐B with an ID/Mg molar ratio equal to 0.22. The catalyst with an optimum ID/Mg molar ratio equal to 0.44 is a favorable catalyst for polymerization of propylene.
Construction of Hetero‐Four‐Layered Tripalladium(II) Cyclophanes by Transannular π⋅⋅⋅π Interactions
Authors: Lee Haeri , Noh Tae Hwan , Jung Ok‐Sang 
Published: January 2016

AbstractA synthetic strategy for the generation of new molecular species utilizing a provision of nature is presented. Nano‐dimensional (23(2)×21(1)×16(1) Å3) hetero‐four‐layered trimetallacyclophanes were constructed by proof‐of‐concept experiments that utilize a suitable combination of π⋅⋅⋅π interactions between the central aromatic rings, tailor‐made short/long spacer tridentate donors, and the combined helicity. The behavior of the unprecedented four‐layered metallacyclophane system offers a landmark in the development of new molecular systems.
Palladium‐Catalyzed Asymmetric Allylic Alkylations with Toluene Derivatives as Pronucleophiles
Authors: Mao Jianyou , Zhang Jiadi , Jiang Hui , Bellomo Ana , Zhang Mengnan , Gao Zidong , Dreher Spencer D. , Walsh Patrick J. 
Published: January 2016

AbstractThe first two highly enantioselective palladium‐catalyzed allylic alkylations with benzylic nucleophiles, activated with Cr(CO)3, have been developed. These methods enable the enantioselective synthesis of α‐2‐propenyl benzyl motifs, which are important scaffolds in natural products and pharmaceuticals. A variety of cyclic and acyclic allylic carbonates are competent electrophilic partners furnishing the products in excellent enantioselectivity (up to 99 % ee and 92 % yield). This approach was employed to prepare a nonsteroidal anti‐inflammatory drug analogue.
Solid‐State NMR of PEGylated Proteins
Authors: Ravera Enrico , Ciambellotti Silvia , Cerofolini Linda , Martelli Tommaso , Kozyreva Tatiana , Bernacchioni Caterina , Giuntini Stefano , Fragai Marco , Turano Paola , Luchinat Claudio 
Published: January 2016

AbstractPEGylated proteins are widely used in biomedicine but, in spite of their importance, no atomic‐level information is available since they are generally resistant to structural characterization approaches. PEGylated proteins are shown here to yield highly resolved solid‐state NMR spectra, which allows assessment of the structural integrity of proteins when PEGylated for therapeutic or diagnostic use.
Apparent First‐Order Liquid–Liquid Transition with Pre‐transition Density Anomaly, in Water‐Rich Ideal Solutions
Authors: Zhao Zuofeng , Angell C. Austen 
Published: January 2016

AbstractThe striking increases in response functions observed during supercooling of pure water have been the source of much interest and controversy. Imminent divergences of compressibility etc. unfortunately cannot be confirmed due to pre‐emption by ice crystallization. Crystallization can be repressed by addition of second components, but these usually destroy the anomalies of interest. Here we study systems in which protic ionic liquid second components dissolve ideally in water, and ice formation is avoided without destroying the anomalies. We observe a major heat capacity spike during cooling, which is reversed during heating, and is apparently of first order. It occurs just before the glassy state is reached and is preceded by water‐like density anomalies. We propose that it is the much‐discussed liquid–liquid transition previously hidden by crystallization. Fast cooling should allow the important fluctuations/structures to be preserved in the glassy state for leisurely investigation.
Diastereodivergent Catalysis Using Modularly Designed Organocatalysts: Synthesis of both cis‐ and trans‐Fused Pyrano[2,3‐b]pyrans
Authors: Huang Huicai , Konda Swapna , Zhao John C.‐G. 
Published: January 2016

AbstractBoth enantiomers of cis‐ and trans‐fused 3,4,4a,8a‐tetrahydro‐2H,5H‐pyrano[2,3‐b]pyran‐7‐carboxylates have been obtained in high diastereoselectivities and enantioselectivities from the same starting materials using a tandem inverse‐electron‐demand hetero‐Diels–Alder/oxa‐Michael reaction catalyzed by modularly designed organocatalysts (MDOs). Diastereodivergence was achieved in these reactions through the direct control of the stereochemistry of the bridgehead atoms of the fused ring using new MDOs self‐assembled from both enantiomers of proline and cinchona alkaloid thiourea derivatives.
Fluorescent Detection of 2,4‐DNT and 2,4,6‐TNT in Aqueous Media by Using Simple Water‐Soluble Pyrene Derivatives
Authors: Kovalev Igor S. , Taniya Olga S. , Slovesnova Nataliya V. , Kim Grigory A. , Santra Sougata , Zyryanov Grigory V. , Kopchuk Dmitry S. , Majee Adinath , Charushin Valery N. , Chupakhin Oleg N. 
Published: January 2016

AbstractPyrene‐containing water‐soluble probes for the fluorescent detection of nitroaromatic compounds (NACs), such as explosive components (2,4‐DNT and 2,4,6‐TNT) and herbicides (2,4‐dinitrocresol, 2,4‐DNOC), in aqueous media are reported. In the probes, the introduction of surface‐active hydrophilic “heads” at the periphery of lipophilic (i.e., hydrophobic) pyrene “tails” resulted in the formation of highly fluorescent micelle‐like aggregates/pre‐associates in aqueous solutions at concentrations of ≤10−5 m. The enhanced fluorescence quenching of the herein reported architectures is achieved in the presence of ultra‐trace amounts of TNT or 2,4‐DNT with values of Stern–Volmer quenching constant close to 1×105 m−1 and a detection limit as low as 182 ppb. The most hydrophilic probes demonstrated higher response to 2,4‐DNT over TNT. Filter paper test strips impregnated with 1×10−5 m solutions of the probes were able to detect TNT, 2,4‐DNT, and other NACs at levels as low as 50 ppb in water.
Construction and evaluation of PHP‐based management and training system for electrical power laboratory
Authors: Yu Hongpeng , Xu He , Xu Yan , Li Zhen , Wang Peng , Wang Peiyuan 
Published: January 2016

ABSTRACTThe online management and training of information for laboratories has rarely been discussed in the traditional education system design. However, it plays a vital role in informatization and automation of electrical power laboratory. Using PHP: Hypertext Preprocessor (PHP), we have designed and developed an online management and training environment targeted for electrical power laboratory. In this article, the Model‐View‐Controller (MVC) architecture cooperative designed for the management and training system modules was provided, and key steps of developing such modules using PHP were described. A questionnaire survey was conducted for students to use the system, and their attitudes toward the system were calculated and analyzed. Results showed that management and training system for electrical power laboratory can lead to preferable learning interest and outcome. © 2016 Wiley Periodicals, Inc. Comput Appl Eng Educ 24:371–381, 2016; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21715
Goose‐neck snare‐assisted transcatheter ASD closure: A safety procedure for large and complex ASDs
Authors: Butera Gianfranco , Lovin Nicusor , Paola Basile Domenica , Carminati Mario 
Published: January 2016

ObjectiveTo report on a new technique that increases the safety of percutaneous atrial septal defect (ASD) closure using a goose‐neck snare system.BackgroundASD transcatheter closure is a widespread procedure. However, in some cases, ASDs may be large and with soft rims. In these situation, a potential risk exists for device malposition or embolization.MethodsWhen transesophageal echocardiography (TEE) evaluation and balloon sizing showed large defects with floppy rims the chosen Amplatzer device was implanted in a standard way. In large defects with floppy rims, before release a 5‐mm goose‐neck snare with its 4 Fr catheter was placed across the delivery cable and fixed to catch the screwing mechanism of implanted Amplatzer device. The delivery cable was unscrewed and the device reached its final position without any tension. If the position was considered satisfactory the device was released from the goose‐neck snare.ResultsThirteen patients had a snare‐assisted ASD transcatheter closure. Median device size was 24 mm (range 14‐38 mm). Retrieval or repositioning of the device using the goose‐neck snare was performed in four cases: in three patients, because of device malposition after delivery cable release and in one patient, because of unsuitability of closure of a second significant defect. Furthermore, in two subjects with multiple ASDs, a second fenestration looked quite significant with the device still attached to the delivery cable while it appeared smaller after release.ConclusionsSnare‐assisted Amplatzer ASD device placement is a new method for ASD percutaneous closure and adds safety to the procedure. © 2016 Wiley Periodicals, Inc.
Microvascular dysfunction in the immediate aftermath of chronic total coronary occlusion recanalization
Authors: Ladwiniec Andrew , Cunnington Michael S. , Rossington Jennifer , Thackray Simon , Alamgir Farquad , Hoye Angela 
Published: January 2016

ObjectivesThe aim of this study was to compare microvascular resistance under both baseline and hyperemic conditions immediately after percutaneous coronary intervention (PCI) of a chronic total occlusion (CTO) with an unobstructed reference vessel in the same patientBackgroundMicrovascular dysfunction has been reported to be prevalent immediately after CTO PCI. However, previous studies have not made comparison with a reference vessel. Patients with a CTO may have global microvascular and/or endothelial dysfunction, making comparison with established normal values misleading.MethodsAfter successful CTO PCI in 21 consecutive patients, coronary pressure and flow velocity were measured at baseline and hyperemia in distal segments of the CTO/target vessel and an unobstructed reference vessel. Hemodynamics including hyperemic microvascular resistance (HMR), basal microvascular resistance (BMR), and instantaneous minimal microvascular resistance at baseline and hyperemia were calculated and compared between reference and target/CTO vessels.ResultsAfter CTO PCI, BMR was reduced in the target/CTO vessel compared with the reference vessel: 3.58 mm Hg/cm/s vs 4.94 mm Hg/cm/s, difference −1.36 mm Hg/cm/s (−2.33 to −0.39, p = 0.008). We did not detect a difference in HMR: 1.82 mm Hg/cm/s vs 2.01 mm Hg/cm/s, difference −0.20 (−0.78 to 0.39, p = 0.49). Instantaneous minimal microvascular resistance correlated strongly with the length of stented segment at baseline (r = 0.63, p = 0.005) and hyperemia (r = 0.68, p = 0.002).ConclusionsBMR is reduced in a recanalized CTO in the immediate aftermath of PCI compared to an unobstructed reference vessel; however, HMR appears to be preserved. A longer stented segment is associated with increased microvascular resistance. © 2016 Wiley Periodicals, Inc.