bluuebunny/crossref_metadata_2025_split huggingface dataset:
Very low frequency earthquakes in Cascadia migrate with tremor
Authors: Ghosh Abhijit , Huesca‐Pérez Eduardo , Brodsky Emily , Ito Yoshihiro 
Published: April 2015

AbstractWe find very low frequency earthquakes (VLFEs) in Cascadia under northern Washington during 2011 episodic tremor and slip event. VLFEs are rich in low‐frequency energy (20–50 s) and depleted in higher frequencies (higher than 1 Hz) compared to local earthquakes. Based on a grid search centroid moment tensor inversion, we find that VLFEs are located near the plate interface in the zone where tremor and slow slip are observed. In addition, they migrate along strike with tremor activity. Their moment tensor solutions show double‐couple sources with shallow thrust mechanisms, consistent with shear slip at the plate interface. Their magnitude ranges between Mw 3.3 and 3.7. Seismic moment released by a single VLFE is comparable to the total cumulative moment released by tremor activity during an entire episodic tremor and slip event. The VLFEs contribute more seismic moment to this episodic tremor and slip event than cumulative tremor activity and indicate a higher seismic efficiency of slow earthquakes in Cascadia than previously thought. Spatiotemporal correlation of VLFE and tremor activity suggests that they are the results of the same physical processes governing slow earthquakes.
Nonlocal impacts of the Loop Current on cross‐slope near‐bottom flow in the northeastern Gulf of Mexico
Authors: Nguyen Thanh‐Tam , Morey Steven L. , Dukhovskoy Dmitry S. , Chassignet Eric P. 
Published: April 2015

AbstractCross‐slope near‐bottom motions near De Soto Canyon in the northeastern Gulf of Mexico are analyzed from a multidecadal ocean model simulation to characterize upwelling and downwelling, important mechanisms for exchange between the deep ocean and shelf in the vicinity of the 2010 BP Macondo well oil spill. Across the continental slope, large‐scale depression and offshore movement of isopycnals (downwelling) occur more frequently when the Loop Current impinges upon the West Florida Shelf slope farther south. Upwelling and onshore movement of isopycnals occurs with roughly the same likelihood regardless of Loop Current impingement on the slope. The remote influence of Loop Current on the De Soto Canyon region downwelling is a consequence of a high‐pressure anomaly that extends along the continental slope emanating from the location of Loop Current impact.
Potential for larger earthquakes in the East San Francisco Bay Area due to the direct connection between the Hayward and Calaveras Faults
Authors: Chaussard E. , Bürgmann R. , Fattahi H. , Nadeau R. M. , Taira T. , Johnson C. W. , Johanson I. 
Published: April 2015

AbstractThe Hayward and Calaveras Faults, two strike‐slip faults of the San Andreas System located in the East San Francisco Bay Area, are commonly considered independent structures for seismic hazard assessment. We use Interferometric Synthetic Aperture RADAR to show that surface creep on the Hayward Fault continues 15 km farther south than previously known, revealing new potential for rupture and damage south of Fremont. The extended trace of the Hayward Fault, also illuminated by shallow repeating micro‐earthquakes, documents a surface connection with the Calaveras Fault. At depths greater than 3–5 km, repeating micro‐earthquakes located 10 km north of the surface connection highlight the 3‐D wedge geometry of the junction. Our new model of the Hayward and Calaveras Faults argues that they should be treated as a single system with potential for earthquake ruptures generating events with magnitudes greater than 7, posing a higher seismic hazard to the East San Francisco Bay Area than previously considered.
Northern Adriatic meteorological tsunamis: Assessment of their potential through ocean modeling experiments
Authors: Šepić Jadranka , Vilibić Ivica , Fine Isaac 
Published: April 2015

AbstractPotential for generation of meteotsunami waves via open ocean resonance has been documented for the shallow northern Adriatic, based on a set of barotropic numerical modeling experiments. Model simulations were forced by a bell‐shaped traveling atmospheric (air pressure, wind) disturbance, with shape and propagation parameters chosen in accordance with measurements done during several observed northern Adriatic meteotsunamis. Air pressure disturbances were found to generate much larger meteotsunami waves than wind disturbances, with wind disturbances having a limited influence in the very coastal and shallow areas only. Numerical simulations reveal that the most important factor for generation of large meteotsunami waves is matching between the speed of the atmospheric disturbance and the speed of long‐ocean waves. Already a small (∼10%) deviation from resonant conditions stops the wave growth and dramatically decreases height of predicted waves. A train of atmospheric disturbances can significantly increase maximum wave heights at selected locations at which multiple reflections and superimpositions of meteotsunami waves occur. Sensitivity of model simulations to resonant conditions and limited cross‐propagation width of atmospheric disturbance explain the localization of destructive meteotsunami waves in a limited area during destructive historic events. Mapping of maximum predicted wave heights indicates places with large meteotsunami hazard potential, matching the locations where real events were observed, and may be a useful tool for assessing vulnerability and risks in coastal areas during extreme sea level events.
The Development of Alternative Brake Systems
Authors: Gombert Bernd D.M. , Schautt Martin , Roberts Richard P. 
Published: April 2015

ABSTRACTOver the past 15 years or so, there has been considerable interest within the automobile industry in dry electrically powered brake systems. This has been driven by a variety of different reasons, including the inherent compatibility with electronic higher level vehicle systems, a desire to remove hydraulic components and so simplify assembly and maintenance, improved passive safety (pedal), more flexibility in pedal design and feel, and simpler tuning of systems by means of software. While there is still no production system on the mass market, the trend toward more electric vehicles will only strengthen the motivation to introduce them.In this chapter, we explain some of the benefits of dry brake‐by‐wire (BBW) systems in the context of current developments. We then introduce a selection of alternative approaches to the problem, both in terms of brake actuator construction and vehicle concepts. Next, we address the challenges facing any supplier orOEMwho intends to introduce such a system. These help explain why there is still no such system on the market, despite many optimistic forecasts at the turn of the millennium. Some of the issues addressed during the development of the SiemensVDOelectronic wedge brake (EWB) are then briefly discussed. Finally, we summarize the situation in some brief conclusions.
Exhaust Emissions
Authors: Matti Maricq M. 
Published: April 2015

AbstractEmissions regulations present a growing challenge in the design of new vehicles. The necessity to lower pollutants to ultra low levels requires careful tuning of the engine with progressively more elaborate aftertreatment systems. At the same time, engines must be made more efficient and vehicles lighter to meet requirements for reduced greenhouse gas emissions. The brunt of engine calibration and aftertreatment development is conducted with engine and chassis dynamometer systems coupled to sensitive instrumentation that can detect parts per million levels of pollutants in vehicle exhaust. This chapter reviews the current state of the art in this area. It examines the sampling systems used to probe the myriads of constituents present in combustion exhaust. The chemical compounds and particulate matter are analyzed by a wide array of instrumentation. These are increasingly evolving in capability, both in terms of sensitivity and time response. This chapter describes the traditional methods for the detection of hydrocarbons,NOx,CO, andPM. It further details advances inFTIRmethods aimed at detectingNO,NO2,N2O,NH3, non‐methane organics, and other species, and new developments in aerosol instrumentation used for real‐time measurement of particle size distributions and number and mass emissions.
Drive Cycles
Authors: Case Mark E. , Tomazic Dean 
Published: April 2015

Abstract
Increased public focus on environmental issues as well as the continuously rising use of fossil fuels and the associated decline in reserves on top of global warming issues have resulted in a series of actions to minimize the exhaust emissions of automobiles and increase their fuel economy. In order to accurately monitor and control these, the corresponding legislation agencies have introduced exhaust emission and testing standards to which all vehicle manufacturers have to adhere to. All of these standards are highly market dependent and therefore differ substantially among each other. Therefore, it is inevitable in a global economy to be familiar with the variety of different standards and testing procedures and their implications on powertrain and vehicle design as well as calibration. This chapter provides insight into the exhaust emission standards, test cycles applied, and the corresponding procedures required worldwide including some examples.
Fuel Economy Optimization
Authors: Bowyer Stephen F. , Tomazic Dean , Rogers Gary W. 
Published: April 2015

Abstract
High fuel prices and government regulations are putting more effort on automakers to provide fuel‐efficient vehicles. However, customer expectations limit the amount of reduction in performance and refinement that is commonly accompanied with improved fuel economy. As such, it is critical that the automotive manufacturers utilize new technologies and strategies to achieve significant reductions in fuel consumption with minimal impact to vehicle behavior. In order to do so, further optimization of the internal combustion engine must be explored. This chapter outlines several potential strategies and new technologies that enable better fuel consumption for future automotive vehicles.
Driver Assistance
Authors: Wisselmann Dirk , Huber Werner 
Published: April 2015

According to the definition worked out in the European research projectRESPONSE, the so‐called advanced driver assistance systems (ADAS) monitor vehicle surroundings and can (autonomously) take over control of the lateral and/or longitudinal movement of a vehicle under defined circumstances, as long as the driver does not intervene.ADASare generally characterized by the following features. Theysupport the driver in his or her primary driving task;provide active support for lateral and/or longitudinal control;detect and evaluate the vehicle environment;use complex signal processing;enable direct interaction between the driver and the system.ADASaim to improve driving safety, efficiency, and comfort and are specifically designed for different driving situations, so that a “symbiotic” relationship between the driving task and the controller functionality of theADASis established. Nowadays, a large number of differentADASare available on the market. The roadmap of introduction is presented in this chapter. Different importantADASfrom the areas such as comfort (e.g., adaptive cruise control) and safety (e.g., protection of vulnerable road users) are discussed exemplary. A view to futureADAS, where three main trends can be identified, closes the chapter:increased degree of automation inADASdesigned for increased comfort;introduction of novelADASfor traffic safety;introduction ofADASfor improved efficiency.
Battery Charging Standards
Authors: Van den Bossche Peter 
Published: April 2015

AbstractIn urban traffic, due to their beneficial effect on environment, electrically propelled vehicles are an important factor for improvement of traffic and more particularly for a healthier living environment. One of the main benefits of the electric vehicle is its use of mains electricity as energy source, allowing on one hand to displace finite fossil fuel sources with renewables, and on the other hand a zero‐emission operation at point of use, with reduced or zero indirect emissions at generation level.On board the vehicle, the electric energy is stored in traction batteries which are the key critical components of the vehicle. The transfer of the energy from the grid to the vehicle creates the need for charging infrastructures. The transfer can be done conductively, the most widely used system, or wirelessly by induction, eliminating the need for cables and connectors.To allow a wide deployment of electric vehicles, they should have universal access to charging infrastructures, which highlights the need for drafting comprehensive standards on the matter. This article will give an overview of global developments in the field.
Silver Hexafluoroantimonate‐Catalyzed Direct α‐Alkylation of Unactivated Ketones
Authors: Naveen Naganaboina , Koppolu Srinivasa Rao , Balamurugan Rengarajan 
Published: April 2015

AbstractA practically simple and direct α‐alkylation of unactivated ketones using benzylic alcohols has been achieved. The in situ formed acetals are the key for the success of the reaction. The catalyst, silver hexafluoroantimonate(V) (AgSbF6) provides double activation by converting the ketone into an enol ether via acetal and generation of carbocationic center at the benzylic position of the benzylic alcohol. The alcohols include benzylic propargyl alcohols, cinnamyl alcohols, and diarylmethanols.magnified image
Metabolic Profiling of Bacteria by Unnatural C‐terminated D‐Amino Acids
Authors: Pidgeon Sean E. , Fura Jonathan M. , Leon William , Birabaharan Morgan , Vezenov Dmitri , Pires Marcos M. 
Published: April 2015

AbstractBacterial peptidoglycan is a mesh‐like network comprised of sugars and oligopeptides. Transpeptidases cross‐link peptidoglycan oligopeptides to provide vital cell wall rigidity and structural support. It was recently discovered that the same transpeptidases catalyze the metabolic incorporation of exogenous D‐amino acids onto bacterial cell surfaces with vast promiscuity for the side‐chain identity. It is now shown that this enzymatic promiscuity is not exclusive to side chains, but that C‐terminus variations can also be accommodated across a diverse range of bacteria. Atomic force microscopy analysis revealed that the incorporation of C‐terminus amidated D‐amino acids onto bacterial surfaces substantially reduced the cell wall stiffness. We exploited the promiscuity of bacterial transpeptidases to develop a novel assay for profiling different bacterial species.
Orthogonal Insertion of Lanthanide and Transition‐Metal Atoms in Metal–Organic Networks on Surfaces
Authors: Urgel José I. , Ecija David , Auwärter Willi , Stassen Daphné , Bonifazi Davide , Barth Johannes V. 
Published: April 2015

AbstractThe orthogonal coordinative properties of tetrapyrrole macrocycles and nitrile ligands have been used in a multistep procedure towards interfacial d‐f hetero‐bimetallic nanoarchitectures based on a free‐base porphyrin derivative functionalized with meso‐cyanobiphenylene substituents. Molecular‐level scanning tunneling microscopy studies reveal that the porphyrin module alone self‐assembles on Ag(111) in a close‐packed layer with a square unit cell. Upon co‐deposition of Gd atoms, a square‐planar motif is formed that reflects the fourfold coordination of CN ligands to the rare‐earth centers. The resulting nanoporous network morphology is retained following exposure to a beam of Co atoms, which induces selective porphyrin metalation and ultimately yields a gridlike 2D metallosupramolecular architecture.
Catalytic Asymmetric Total Synthesis of (−)‐Galanthamine and (−)‐Lycoramine
Authors: Li Lei , Yang Qiao , Wang Yuan , Jia Yanxing 
Published: April 2015

AbstractThe catalytic asymmetric total syntheses of (−)‐galanthamine (1) and (−)‐lycoramine (2) have been achieved by using a conceptually new strategy featuring two metal‐catalyzed reactions as the key steps. A new method for the construction of 3,4‐fused benzofurans has been developed through a palladium‐catalyzed intramolecular Larock annulation reaction, which was successfully applied to the construction of the ABD tricyclic skeleton of 1 and 2. To achieve the asymmetric synthesis of 1 and 2, a ScIII/N,N′‐dioxide complex was used to catalyze the enantioselective conjugate addition of 3‐alkyl‐substituted benzofuranone to methyl vinyl ketone for the construction of a chiral quaternary carbon center.
Cytochrom‐c‐Calixaren‐Kristalle auf Elektroden: intermolekularer Elektronentransfer zwischen definiert lokalisierten Redoxzentren
Authors: McGovern Róise E. , Feifel Sven C. , Lisdat Fred , Crowley Peter B. 
Published: April 2015

AbstractDie Assemblierung von Redoxproteinen auf Elektrodenoberflächen ist ein entscheidender Schritt für die Entwicklung von biohybriden Systemen. Kürzlich konnte gezeigt werden, dass p‐sulfoniertes Calix[4]aren als “molekularer Klebstoff” für die Assemblierung und Kristallbildung von Cytochrom c (Cyt c) dient. Hier präsentieren wir die ersten elektrochemischen Daten für Calixaren‐Cyt‐c‐Kristalle im Mikromaßstab auf SAM‐modifizierten Goldelektroden. Die Elektrochemie der Kristalle wurde mittels Zyklovoltammetrie charakterisiert. Hierbei konnten enorme Konzentrationen an elektroaktivem Cyt c nachgewiesen werden. Die erhaltenen Peakströme nahmen linear mit der Quadratwurzel der Vorschubgeschwindigkeit zu. Dadurch war es möglich, die Selbstaustauschrate (kex) der Cyt‐c‐Moleküle zu bestimmen. Durch diese Studie kann nachgewiesen werden, dass auch Proteinkristalle eine hohe Elektroaktivität und einen schnellen intermolekularen Elektronentransfer aufweisen können. Es kann erwartet werden, dass diese Beobachtungen auch einen signifikanten Einfluss auf die Entwicklung neuer bioelektronischer Bauelemente haben.
An Unusually Small Singlet–Triplet Gap in a Quinoidal 1,6‐Methano[10]annulene Resulting from Baird’s 4n π‐Electron Triplet Stabilization
Authors: Streifel Benjamin C. , Zafra José L. , Espejo Guzmán L. , Gómez‐García Carlos J. , Casado Juan , Tovar John D. 
Published: April 2015

AbstractWithin the continuum of π‐extended quinoidal electronic structures exist molecules that by design can support open‐shell diradical structures. The prevailing molecular design criteria for such structures involve proaromatic nature that evolves aromaticity in open‐shell diradical resonance structures. A new diradical species built upon a quinoidal methano[10]annulene unit is synthesized and spectroscopically evaluated. The requisite intersystem crossing in the open‐shell structure is accompanied by structural reorganization from a contorted Möbius aromatic‐like shape in S0 to a more planar shape in the Hückel aromatic‐like T1. This stability was attributed to Baird’s Rule which dictates the aromaticity of 4n π‐electron triplet excited states.
Enantioselective Palladium(0)‐Catalyzed Nazarov‐Type Cyclization
Authors: Kitamura Kei , Shimada Naoyuki , Stewart Craig , Atesin Abdurrahman C. , Ateşin Tülay A. , Tius Marcus A. 
Published: April 2015

AbstractA Pd0‐catalyzed asymmetric Nazarov‐type cyclization is described. The optimized ligand for the reaction incorporates a weakly coordinating pyridine ring into a TADDOL‐derived phosphoramidite (TADDOL=α,α,α,α‐tetraaryl‐1,3‐dioxolane‐4,5‐dimethanol). The reaction leads to the formation of cyclopentenones as single diastereoisomers that incorporate two contiguous asymmetric centers, one tertiary and one an all‐carbon‐atom quaternary stereocenter, in high yield and optical purity. It is noteworthy that the reaction does not require that substrates should be activated by aryl substituents.
Large Optical Nonlinearity Induced by Singlet Fission in Pentacene Films
Authors: Liu Yunlong , Zhang Chunfeng , Wang Rui , Zhang Bo , Tan Zhanao , Wang Xiaoyong , Xiao Min 
Published: April 2015

AbstractBy creating two triplet excitons from one photo‐excited singlet exciton, singlet fission in organic semiconductors has drawn tremendous attention for its potential applications in boosting the efficiency of solar conversion. Here, we show that this carrier‐multiplication effect can also be used to dramatically improve the nonlinear optical response in organic materials. We have observed large optical nonlinearity with a magnitude of χ(3) up to 10−9 esu in pentacene films, which is further shown to be a result of singlet fission by monitoring the temporal dynamics. The potential application of such efficient nonlinear optical response has been demonstrated with a singlet‐fission‐induced polarization rotation.
Reconstitution of Biosynthetic Machinery for the Synthesis of the Highly Elaborated Indole Diterpene Penitrem
Authors: Liu Chengwei , Tagami Koichi , Minami Atsushi , Matsumoto Tomoyuki , Frisvad Jens Christian , Suzuki Hideyuki , Ishikawa Jun , Gomi Katsuya , Oikawa Hideaki 
Published: April 2015

AbstractPenitrem A is one of the most elaborated members of the fungal indole diterpenes. Two separate penitrem gene clusters were identified using genomic and RNA sequencing data, and 13 out of 17 transformations in the penitrem biosynthesis were elucidated by heterologous reconstitution of the relevant genes. These reactions involve 1) a prenylation‐initiated cationic cyclization to install the bicyclo[3.2.0]heptane skeleton (PtmE), 2) a two‐step P450‐catalyzed oxidative processes forming the unique tricyclic penitrem skeleton (PtmK and PtmU), and 3) five sequential oxidative transformations (PtmKULNJ). Importantly, without conventional gene disruption, reconstitution of the biosynthetic machinery provided sufficient data to determine the pathway. It was thus demonstrated that the Aspergillus oryzae reconstitution system is a powerful method for studying the biosynthesis of complex natural products.
A Chemically Triggered and Thermally Switched Dielectric Constant Transition in a Metal Cyanide Based Crystal
Authors: Shi Chao , Zhang Xi , Cai Ying , Yao Ye‐Feng , Zhang Wen 
Published: April 2015

AbstractA dielectric constant transition is chemically triggered and thermally switched in (HPy)2[Na(H2O)Co(CN)6] (2, HPy=pyridinium cation) by single‐crystal‐to‐single‐crystal transformation and structural phase transition, respectively. Upon dehydration, (HPy)2[Na(H2O)2Co(CN)6] (1) transforms to its semi‐hydrated form 2, accompanying a transition from a low‐dielectric state to a high‐dielectric state, and vice versa. This dielectric switch is also realized by a structural phase transition in 2 that occurs between room‐ and low‐temperature phases, and which corresponds to high‐ and low‐dielectric states, respectively. The switching property is due to the variation in the environment surrounding the HPy cation, that is, the hydrogen‐bonding interactions and the crystal packing, which exert predominant influences on the dynamics of the cations that transit between the static and motional states.