bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inelastic Compaction in High‐Porosity Limestone Monitored Using Acoustic Emissions
Authors: Baud Patrick , Schubnel Alexandre , Heap Michael , Rolland Alexandra 
Published: December 2017

AbstractWe performed a systematic investigation of mechanical compaction and strain localization in Saint‐Maximin limestone, a quartz‐rich, high‐porosity (37%) limestone from France. Our new data show that the presence of a significant proportion of secondary mineral (i.e., quartz) did not impact the mechanical strength of the limestone in both the brittle faulting and cataclastic flow regimes, but that the presence of water exerted a significant weakening effect. In contrast to previously published studies on deformation in limestones, inelastic compaction in Saint‐Maximin limestone was accompanied by abundant acoustic emission (AE) activity. The location of AE hypocenters during triaxial experiments revealed the presence of compaction localization. Two failure modes were identified in agreement with microstructural analysis and X‐ray computed tomography imaging: compactive shear bands developed at low confinement and complex diffuse compaction bands formed at higher confinement. Microstructural observations on deformed samples suggest that the recorded AE activity associated with inelastic compaction, unusual for a porous limestone, could have been due to microcracking at the quartz grain interfaces. Similar to published data on high‐porosity macroporous limestones, the crushing of calcite grains was the dominant micromechanism of inelastic compaction in Saint‐Maximin limestone. New P wave velocity data show that the effect of microcracking was dominant near the yield point and resulted in a decrease in P wave velocity, while porosity reduction resulted in a significant increase in P wave velocity beyond a few percent of plastic volumetric strain. These new data highlight the complex interplay between mineralogy, rock microstructure, and strain localization in porous rocks.
A New Southern North Atlantic Isochron Map: Insights Into the Drift of the Iberian Plate Since the Late Cretaceous
Authors: Macchiavelli Chiara , Vergés Jaume , Schettino Antonio , Fernàndez Manel , Turco Eugenio , Casciello Emilio , Torne Montserrat , Pierantoni Pietro Paolo , Tunini Lavinia 
Published: December 2017

AbstractThis paper presents a new southern North Atlantic plate model from Late Cretaceous to present, with the aim of constraining the kinematics of the Iberian plate during the last 83.5 Myr. This model is presented along with a detailed isochron map generated through the analysis of 3 aeromagnetic tracks and ~400 ship tracks from the National Centers for Environmental Information database. We present a new technique to obtain well‐constrained estimates of the Iberia‐North America plate motions from magnetic anomalies, overcoming the scarcity of large‐offset fracture zones and transform faults. We build an integrated kinematic model for NW Africa, Morocco, Iberia, Europe, and North America, which shows that the deformation is partitioned between Pyrenees and Betic‐Rif orogenic domain during the Late Cretaceous‐Oligocene time interval. In the Eastern Betics domain, the calculated amount of NW Africa‐Iberia convergence is ~80 km between 83.5 and 34 Ma, followed by ~150 km since the Oligocene. The motion of Iberia relative to Europe in the Central Pyrenees is characterized by overall NE directed transpressional motion during the Campanian and the Paleocene, followed by NW directed transpressional movement until the Lutetian and overall NNW directed convergence from Bartonian to Chattian. This motion occurs along the axis of the Bay of Biscay from the Santonian–Campanian boundary to the middle Priabonian, subsequently jumping to King's Trough at Anomaly 17 (36.62 Ma).
Seismicity in the Vicinity of the Tristan Da Cunha Hot Spot: Particular Plate Tectonics and Mantle Plume Presence
Authors: Schlömer Antje , Geissler Wolfram H. , Jokat Wilfried , Jegen Marion 
Published: December 2017

AbstractEarthquake locations along the southern Mid‐Atlantic Ridge have large uncertainties due to the sparse distribution of permanent seismological stations in and around the South Atlantic Ocean. Most of the earthquakes are associated with plate tectonic processes related to the formation of new oceanic lithosphere, as they are located close to the ridge axis or in the immediate vicinity of transform faults. A local seismological network of ocean‐bottom seismometers and land stations on and around the archipelago of Tristan da Cunha allowed for the first time a local earthquake survey for 1 year. We relate intraplate seismicity within the African oceanic plate segment north of the island partly to extensional stresses induced by a bordering large transform fault and to the existence of the Tristan mantle plume. The temporal propagation of earthquakes within the segment reflects the prevailing stress field. The strong extensional stresses in addition with the plume weaken the lithosphere and might hint at an incipient ridge jump. An apparently aseismic zone coincides with the proposed location of the Tristan conduit in the upper mantle southwest of the islands. The margins of this zone describe the transition between the ductile and the surrounding brittle regime. Moreover, we observe seismicity close to the islands of Tristan da Cunha and nearby seamounts, which we relate to ongoing tectono‐magmatic activity.
Non‐Redfieldian Dynamics Explain Seasonal pCO2Drawdown in the Gulf of Bothnia
Authors: Fransner Filippa , Gustafsson Erik , Tedesco Letizia , Vichi Marcello , Hordoir Robinson , Roquet Fabien , Spilling Kristian , Kuznetsov Ivan , Eilola Kari , Mörth Carl‐Magnus , Humborg Christoph , Nycander Jonas 
Published: December 2017

AbstractHigh inputs of nutrients and organic matter make coastal seas places of intense air‐sea CO2exchange. Due to their complexity, the role of coastal seas in the global air‐sea CO2exchange is, however, still uncertain. Here, we investigate the role of phytoplankton stoichiometric flexibility and extracellular DOC production for the seasonal nutrient and CO2partial pressure (pCO2) dynamics in the Gulf of Bothnia, Northern Baltic Sea. A 3‐D ocean biogeochemical‐physical model with variable phytoplankton stoichiometry is for the first time implemented in the area and validated against observations. By simulating non‐Redfieldian internal phytoplankton stoichiometry, and a relatively large production of extracellular dissolved organic carbon (DOC), the model adequately reproduces observed seasonal cycles in macronutrients and pCO2. The uptake of atmospheric CO2is underestimated by 50% if instead using the Redfield ratio to determine the carbon assimilation, as in other Baltic Sea models currently in use. The model further suggests, based on the observed drawdown of pCO2, that observational estimates of organic carbon production in the Gulf of Bothnia, derived with themethod, may be heavily underestimated. We conclude that stoichiometric variability and uncoupling of carbon and nutrient assimilation have to be considered in order to better understand the carbon cycle in coastal seas.
Variability of Phytoplankton Size Structure in Response to Changes in Coastal Upwelling Intensity in the Southwestern East Sea
Authors: Shin Jung‐Wook , Park Jinku , Choi Jang‐Geun , Jo Young‐Heon , Kang Jae Joong , Joo HuiTae , Lee Sang Heon 
Published: December 2017

AbstractThe aim of this study was to examine the size structure of phytoplankton under varying coastal upwelling intensities and to determine the resulting primary productivity in the southwestern East Sea. Samples of phytoplankton assemblages were collected on five occasions from the Hupo Bank, off the east coast of Korea, during 2012–2013. Because two major surface currents have a large effect on water mass transport in this region, we first performed a Backward Particle Tracking Experiment (BPTE) to determine the coastal sea from which the collected samples originated according to advection time of BPTE particles, following which we used upwelling age (UA) to determine the intensity of coastal upwelling in the region of origin for each sample. Only samples that were affected by coastal upwelling in the region of origin were included in subsequent analyses. We found that as UA increased, there was a decreasing trend in the concentration of picophytoplankton, and increasing trends in the concentration of nanophytoplankton and microphytoplankton. We also examined the relationship between the size structure of phytoplankton and primary productivity in the Ulleung Basin (UB), which has experienced significant variation over the past decade. We found that primary productivity in UB was closely related to the strength of the southerly wind, which is the most important mechanism for coastal upwelling in the southwestern East Sea. Thus, the size structure of phytoplankton is determined by the intensity of coastal upwelling, which is regulated by the southerly wind, and makes an important contribution to primary productivity.
Excitation Location and Seasonal Variation of Transoceanic Infragravity Waves Observed at an Absolute Pressure Gauge Array
Authors: Tonegawa T. , Fukao Y. , Shiobara H. , Sugioka H. , Ito A. , Yamashita M. 
Published: December 2017

AbstractAn array of 10 absolute pressure gauges (APGs) deployed in deep water 50 km east of Aogashima, an island in southern Japan, observed several isolated signals in the infragravity wave (IGW) frequency band (0.002–0.03 Hz) during boreal summer, whereas relatively high IGW energy persisted during boreal winter. The isolated IGW shows dispersion with a delay time of 4–5 days as a function of frequency. Here we estimate the excitation locations of IGWs for the two seasons with estimated incoming direction of IGW, calculation of transoceanic IGW trajectories and propagation times, and spatiotemporal variations of significant wave heights from WAVEWATCH III. In boreal summer, the isolated IGWs are primarily caused by IGW energies excited at the shoreline of South America, based on the following three observations: IGWs observed at the array originated from the east: the easterly ray path from the array reaches South America: and an event‐like IGWs were observed at the array when a storm approaches eastward to the shoreline of South America, in which the observed delay time of 4–5 days was also supported by the frequency‐dependent calculation of IGW propagation times. In boreal winter, the incessant IGWs consist of transoceanic IGW energies leaked from the shoreline, primarily from North America, and secondly from South America and the western Aleutian Islands.
Mitigating Satellite‐Based Fire Sampling Limitations in Deriving Biomass Burning Emission Rates: Application to WRF‐Chem Model Over the Northern sub‐Saharan African Region
Authors: Wang Jun , Yue Yun , Wang Yi , Ichoku Charles , Ellison Luke , Zeng Jing 
Published: December 2017

AbstractLargely used in several independent estimates of fire emissions, fire products based on MODIS sensors aboard the Terra and Aqua polar‐orbiting satellites have a number of inherent limitations, including (a) inability to detect fires below clouds, (b) significant decrease of detection sensitivity at the edge of scan where pixel sizes are much larger than at nadir, and (c) gaps between adjacent swaths in tropical regions. To remedy these limitations, an empirical method is developed here and applied to correct fire emission estimates based on MODIS pixel level fire radiative power measurements and emission coefficients from the Fire Energetics and Emissions Research (FEER) biomass burning emission inventory. The analysis was performed for January 2010 over the northern sub‐Saharan African region. Simulations from WRF‐Chem model using original and adjusted emissions are compared with the aerosol optical depth (AOD) products from MODIS and AERONET as well as aerosol vertical profile from CALIOP data. The comparison confirmed an 30–50% improvement in the model simulation performance (in terms of correlation, bias, and spatial pattern of AOD with respect to observations) by the adjusted emissions that not only increases the original emission amount by a factor of two but also results in the spatially continuous estimates of instantaneous fire emissions at daily time scales. Such improvement cannot be achieved by simply scaling the original emission across the study domain. Even with this improvement, a factor of two underestimations still exists in the modeled AOD, which is within the current global fire emissions uncertainty envelope.
Thermochronometry Across the Austroalpine‐Pennine Boundary, Central Alps, Switzerland: Orogen‐Perpendicular Normal Fault Slip on a Major “Overthrust” and Its Implications for Orogenesis
Authors: Price Jason B. , Wernicke Brian P. , Cosca Michael A. , Farley Kenneth A. 
Published: December 2017

AbstractFifty‐one new and 309 published thermochronometric ages (nine systems with closure temperatures ranging from ~450 to 70°C) from the Graubünden region of the Central Alps demonstrate that a pronounced thermal mismatch between the Austroalpine allochthon (Alpine “orogenic lid”) and the Pennine zone persisted until at least 29 Ma and, allowably, until circa 18 Ma. The observed mismatch supports previous suggestions that the famous “overthrust” between the Austroalpine allochthon and the Pennine zone, historically regarded as primarily an Eocene top‐north thrust fault, is in fact primarily an Oligocene‐Miocene normal fault that has a minimum of 60 km of displacement with top‐south or top‐southeast sense of shear. Two hallmarks of Alpine geology, deposition of the foredeep Molasse and emplacement of the Helvetic nappes, appear to be coeval, peripheral manifestations of crustal thickening via the interposition of the Pennine zone as a northward intruding wedge between the Austroalpine “lid” and the European cratonic margin, with the Helvetic system (European margin) acting as the “floor” of the wedge. We presume the Penninic wedge is driven by the buoyant rise of subducted crust no longer able to remain attached to the descending slab. If so, emplacement of the Pennine wedge could have occurred mainly after Adria was juxtaposed against cratonic Europe.
Adaptation to Sea Level Rise: A Multidisciplinary Analysis for Ho Chi Minh City, Vietnam
Authors: Scussolini Paolo , Tran Thi Van Thu , Koks Elco , Diaz‐Loaiza Andres , Ho Phi Long , Lasage Ralph 
Published: December 2017

AbstractOne of the most critical impacts of sea level rise is that flooding suffered by ever larger settlements in tropical deltas will increase. Here we look at Ho Chi Minh City, Vietnam, and quantify the threats that coastal floods pose to safety and to the economy. For this, we produce flood maps through hydrodynamic modeling and, by combining these with data sets of exposure and vulnerability, we estimate two indicators of risk: the damage to assets and the number of potential casualties. We simulate current and future (2050 and 2100) flood risk using IPCC scenarios of sea level rise and socioeconomic change. We find that annual damage may grow by more than 1 order of magnitude, and potential casualties may grow 5–20‐fold until the end of the century, in the absence of adaptation. Impacts depend strongly on the climate and socioeconomic scenarios considered. Next, we simulate the implementation of adaptation measures and calculate their effectiveness in reducing impacts. We find that a ring dike would protect the inner city but increase risk in more rural districts, whereas elevating areas at risk and dryproofing buildings will reduce impacts to the city as a whole. Most measures perform well from an economic standpoint. Combinations of measures seem to be the optimal solution and may address potential equity conflicts. Based on our results, we design possible adaptation pathways for Ho Chi Minh City for the coming decades; these can inform policy‐making and strategic thinking.
Relationship Between Institutional Standardized Letter of Evaluation Global Assessment Ranking Practices, Interviewing Practices, and Medical Student Outcomes
Authors: Pelletier‐Bui Alexis , Van Meter Michael , Pasirstein Michael , Jones Christopher , Rimple Diane 
Published: December 2017

AbstractBackgroundEmergency medicine (EM) program directors rely largely on the standardized letter of evaluation (SLOE) to help determine which applicants to interview in the face of an increasing number of applications. To further characterize the SLOE's role in the EM application process, particularly the global assessment (GA) ranking and its effect on interviewing practices and medical student outcomes, the leaders of EM programs were surveyed regarding their experiences in both generating and utilizing the SLOE.MethodsIndividuals on the Council of Emergency Medicine Residency Directors (CORD) and Clerkship Directors in Emergency Medicine (CDEM) Academy listservs were anonymously surveyed from March 21–30, 2015, with 18 questions in multiple‐choice and fill‐in‐the‐blank formats.ResultsThere were 99 respondents. Only 39 respondents (39%) reported adhering strictly to SLOE guidelines by evenly placing their students into thirds (top, middle, lower) on the SLOE GA. Most respondents interviewed individuals ranked in the lower third. Programs adhering strictly to ranking guidelines were more likely to interview students in the lower third than those adhering loosely or not at all. There was no relationship between a program's self‐reported adherence to the SLOE ranking guidelines and the number of unmatched students in EM during the 2014 and 2015 academic years.ConclusionMany SLOE writers do not strictly adhere to CORD's SLOE writing guidelines when using the GA ranking, due to the fear of adversely impacting an applicant's ability to successfully match into EM. This calls into question the validity of the SLOE as it is currently used. However, this study suggests that adhering to recommended SLOE ranking guidelines is unlikely to substantially increase the risk that students will fail to match. If more evaluators were to adhere to the guidelines, the SLOE could become the valid evaluation instrument that graduate medical education has long been pursuing.
Iron‐Catalyzed Aminative Cyclization/Intermolecular Homolytic Aromatic Substitution Using Oxime Esters and Simple Arenes
Authors: Shimbayashi Takuya , Okamoto Kazuhiro , Ohe Kouichi 
Published: December 2017

AbstractIntermolecular C−H alkylation of simple arenes in the presence of an iron catalyst has been achieved in a cascade manner with an aminative cyclization triggered by N−O bond cleavage of an alkene‐tethered oxime ester. Various arenes, including electron‐rich and electron‐poor arenes, and heteroarenes can be employed in the reaction system. Regioselectivity and radical trapping experiments support the involvement of alkyl radical species, which undergo a homolytic aromatic substitution (HAS) to afford the arylation products.
Planung und Realisierung einer innerstädtischen tiefen Trogbaugrube bei komplexen Randbedingungen
Authors: Stahlhut Olaf , Borchert Kurt.‐M. , Voigt Robert E. 
Published: December 2017

AbstractBeim BV Alter Wall wird die Erschaffung hochwertiger Büro‐ und Einzelhandelsflächen im Herzen der Hamburger Innenstadt realisiert. In Zusammenarbeit mit dem BID Nikolai‐Quartier (Business‐Improvement‐District) wird der Alte Wall in einen hochwertigen innerstädtischen Boulevard umgestaltet. Dazu werden in unmittelbarer Nähe des Rathauses in Hamburg vorhandene Gebäude bis auf die straßenseitige Fassade rückgebaut und eine Tiefgarage mit fünf Untergeschossen errichtet. In diesem Bereich liegen sehr inhomogene geologische Verhältnisse, bestehend aus Auffüllungen, organischen Weichschichten sowie Wechsellagerungen aus Sanden, Geschiebemergeln und Tonen, vor. Auf Grundlage der Ergebnisse der im Vorfeld außerhalb des Baufelds durchgeführten Baugrunduntersuchungen wurde die Baugrube als Trogbaugrube geplant. Als Baugrubenumschließung wurde eine Schlitzwand mit Tiefen von 43–50 m bis in die erkundeten natürlichen Dichtschichten ausgeführt. Die Baugrube wurde zweifach ausgesteift und zusätzlich zur Sicherung des ca. 7 m hohen Geländesprungs von der Seite Alter Wall zum Fleet mittels Ankern einseitig rückverankert. Bevor die Abbrucharbeiten des Gebäudes begonnen wurden, war die Durchführung von Baugrunduntersuchungen direkt im Baufeld nicht möglich. Die nach Abbruch durchgeführten Baugrunduntersuchungen im Baufeld haben ergeben, dass in einem Bereich der Baugrube eine vermutete tiefe glaziale Sandrinne vorhanden ist, sodass die Schlitzwand nicht in der natürlichen Dichtschicht abgesetzt werden konnte, da diese erst in einer Tiefe von ca. 70 m unter Gelände ansteht. Als Abdichtungsmaßnahme wurde ein vertikaler Dichtschleier mit Weichgel, der von Unterkante der Schlitzwand bis in die natürliche Dichtschicht reicht, realisiert. Aufgrund während der Herstellung der Baugrubenumschließung neu gewonnener Erkenntnisse musste die Planung aktualisiert und unmittelbar auf der Baustelle umgesetzt werden. Die Entwicklung und die dynamische Fortschreibung der Baugrubenplanung, die Ergebnisse der Verformungs‐ und Grundwasserstandsmessungen, die Sicherstellung der verträglichen Verformung der historischen Bebauung sowie der abgestützten Fassade und der Funktionsfähigkeit der Holzpfahlgründung des Hamburger Rathauses werden erläutert.
A low‐cost multimodal head‐mounted display system for neuroendoscopic surgery
Authors: Xu Xinghua , Zheng Yi , Yao Shujing , Sun Guochen , Xu Bainan , Chen Xiaolei 
Published: December 2017

AbstractBackgroundWith rapid advances in technology, wearable devices as head‐mounted display (HMD) have been adopted for various uses in medical science, ranging from simply aiding in fitness to assisting surgery. We aimed to investigate the feasibility and practicability of a low‐cost multimodal HMD system in neuroendoscopic surgery.MethodsA multimodal HMD system, mainly consisted of a HMD with two built‐in displays, an action camera, and a laptop computer displaying reconstructed medical images, was developed to assist neuroendoscopic surgery. With this intensively integrated system, the neurosurgeon could freely switch between endoscopic image, three‐dimensional (3D) reconstructed virtual endoscopy images, and surrounding environment images. Using a leap motion controller, the neurosurgeon could adjust or rotate the 3D virtual endoscopic images at a distance to better understand the positional relation between lesions and normal tissues at will.ResultsA total of 21 consecutive patients with ventricular system diseases underwent neuroendoscopic surgery with the aid of this system. All operations were accomplished successfully, and no system‐related complications occurred. The HMD was comfortable to wear and easy to operate. Screen resolution of the HMD was high enough for the neurosurgeon to operate carefully. With the system, the neurosurgeon might get a better comprehension on lesions by freely switching among images of different modalities. The system had a steep learning curve, which meant a quick increment of skill with it. Compared with commercially available surgical assistant instruments, this system was relatively low‐cost.ConclusionsThe multimodal HMD system is feasible, practical, helpful, and relatively cost efficient in neuroendoscopic surgery.
The Dynamic Equilibrium of Hexakis(pentafluoroethyl)distannane Adducts [XSn(C2F5)3{Sn(C2F5)3}]− (X=Cl, Br, I, Sn(C2F5)3)
Authors: Wiesemann Markus , Klösener Johannes , Neumann Beate , Stammler Hans‐Georg , Hoge Berthold 
Published: December 2017

AbstractThe tin–tin bond cleavage of hexaorganodistannanes by nucleophiles is a long‐known reaction and widely used for stannate formation or stannyl group transfer. Herein, we detail our experiments to provide analytical evidence for the existence of the reasonably stable anionic complexes [XSn(C2F5)3{Sn(C2F5)3}]− (X=Cl, Br, I, Sn(C2F5)3) derived from hexakis(pentafluoroethyl)distannane. NMR investigations at low temperature lend further mechanistic insights. Thus, by detection of the imposing ion [Sn(C2F5)3{Sn(C2F5)3}2]−, one can surmise that the chemistry of Sn2(C2F5)6 has more in common with the isolobal iodine than with classical distannanes.