bluuebunny/crossref_metadata_2025_split huggingface dataset:
Italian seismicity and Vesuvius' eruptions synchronize on a quasi 60 year oscillation
Authors: Bragato Pier Luigi 
Published: April 2015

AbstractThe analysis of the time distribution of the major earthquakes that occurred in Italy since 1600 reveals that seismicity alternates periods of higher and lower activities over cycles of about 60 years. The same rhythm is present in the eruptive history of the Vesuvius. The large spatial scale of synchronization leads to suppose an external forcing. A hint on its possible origin comes from climatology, where a quasi 60 year cycle is found for various parameters and processes. A hypothesis, also supported by other studies, is that seismicity and volcanism are controlled by cycles of sea level rise. The mechanism could justify similar regularities observed for seismicity in other areas (e.g., cycles of earthquakes in the southern San Andreas Fault, in California) or for strong earthquakes at the global level. The increasing oceanic load of the last century could be coresponsible of the current long‐lasting rest of the Vesuvius.
Basalt volatile fluctuations during continental rifting: An example from the Rio Grande Rift, USA
Authors: Rowe Michael C. , Lassiter John C. , Goff Kathleen 
Published: April 2015

AbstractHydration and metasomatism of the lithospheric mantle potentially influences both the magmatic and tectonic evolution of southwestern North America. Prior studies have suggested that volatile enrichments to the mantle underlying western North America resulted from shallow subduction of the Farallon Plate during the Laramide (∼74–40 Ma). This study examines temporal and spatial variations in volatile elements (H2O, Cl, F, and S) determined from olivine and orthopyroxene‐hosted melt inclusions along and across the Rio Grande Rift, the easternmost extent of Laramide shallow subduction. Maximum chlorine enrichments are observed in the southern rift with a Cl/Nb of ∼210 and reduce with time to MORB‐OIB levels (∼5–17). Measured water abundances are <0.8 wt % in rehomogenized inclusions; however, calculated H2O, based on Cl/Nb systematics, primarily varies from 0.5 to 2 wt % H2O. Sulfur abundances (<0.61 wt %), and calculated sulfide saturation, indicate magmas with high Cl/Nb also contain oxidized sulfur. The abundance of fluorine in melt inclusions (up to 0.2 wt %) is not correlated to other volatile elements. Temporal variations in melt inclusion volatile abundances coupled with varying isotopic (Sr‐Nd‐Pb) whole‐rock systematics suggest a transition from lithospheric to asthenospheric melt generation in the southern RGR and potential lithosphere‐asthenosphere melt mixing in the central RGR. East to west decrease in volatile enrichment likely reflects a combination of varying mantle sources and early removal of metasomatized lithospheric mantle underlying regional extension. Results indicate, from multiple causes, subduction‐related volatile enrichment to the lithospheric mantle is ephemeral, and strong enrichments in volatiles are not preserved in active magmatic‐tectonic provenances.
Radar observations of simultaneous traveling ionospheric disturbances and atmospheric gravity waves
Authors: Nygrén T. , Aikio A. T. , Voiculescu M. , Cai L. 
Published: April 2015

AbstractSimultaneous observations of atmospheric gravity waves (AGWs) and traveling ionospheric disturbances (TIDs) measured by an incoherent scatter radar at high latitudes are shown. The measurements were made using a beam swing experiment of the EISCAT UHF radar. The F region TID is seen as wavefronts in electron density, whereas the E region AGW is seen in the oscillations of the neutral wind. The wave vector of the TID has a downward component indicating that energy propagates upward. The periods of AGWs and TIDs are approximately the same (52–57min), so it is concluded that the observed gravity wave in the E region propagates to the F region causing the TID there. Two interesting properties of the waves are observed. First, the neutral wind oscillations have an amplitude minimum at about 115km. It is suggested that this could be related to the minimum of the vertical refractive index around 120km. Second, in the course of time, the wave vector of the TID turns more in the downward direction, which leads to an increase in the horizontal wave length from 400 to 1450km. A possible explanation is that the background wind increases with altitude and turns the wavefronts more horizontal when distance from a stationary source increases. We suggest that the source is the sunrise terminator, since the horizontal direction of propagation of the TID in the morning hours is from the west, where both the auroral and thunderstorm activity are low.
New insights into the generation of the 2013 Lushan Earthquake (Ms 7.0), China
Authors: Wang Zhi , Su Jinrong , Liu Cunxi , Cai Xuelin 
Published: April 2015

AbstractGlobal seismic waveform inversion can provide information on where the 2013 Ms 7.0 Lushan earthquake occurred in Sichuan Province, China, and how its aftershock sequence expanded. To investigate the generation mechanism of the Lushan earthquake and its relation to the 2008 Wenchuan earthquake (Ms 8.0), 50 temporary seismic stations were installed in the source area following the Lushan earthquake. Crustal stress data were also collected along the Longmen‐Shan Fault zone (LMFZ) to reveal its influence on the generation of the Lushan earthquake. Seismic imaging and crustal stress analysis have revealed that the Lushan earthquake occurred in a distinct area with high velocity (Vp, Vs), low Poisson's ratio (σ), and high crustal stress. The high‐velocity zone at the Lushan source may reflect Precambrian metasedimentary or igneous rock in the seismogenic layer, which enables the accumulation of high crustal stress to generate large earthquakes. However, a sharply contrasting gap zone with low‐velocity, high‐σ anomalies is clearly imaged in the upper crust under the concatenated area between the Lushan and Wenchuan earthquakes. Seismic images indicate that the low‐velocity gap zone is associated with fluid‐bearing ductile flow from the lower crustal materials of Tibet being pushed into a weakened segment of the LMFZ. This study suggests that the 2013 Lushan earthquake may have been triggered by high crustal stress accumulation together with high coseismic stress further increased by the Wenchuan earthquake in the metamafic seismogenic layer. Contrasting rheological variations in the crust and crustal stress changes along the LMFZ control the rupture processes that generated the Lushan and Wenchuan earthquakes, as well as the generation of new earthquakes in the future.
A framework to identify Pareto‐efficient subdaily environmental flow constraints on hydropower reservoirs using a grid‐wide power dispatch model
Authors: Olivares Marcelo A. , Haas Jannik , Palma‐Behnke Rodrigo , Benavides Carlos 
Published: April 2015

AbstractHydrologic alteration due to hydropeaking reservoir operations is a main concern worldwide. Subdaily environmental flow constraints (ECs) on operations can be promising alternatives for mitigating negative impacts. However, those constraints reduce the flexibility of hydropower plants, potentially with higher costs for the power system. To study the economic and environmental efficiency of ECs, this work proposes a novel framework comprising four steps: (i) assessment of the current subdaily hydrologic alteration; (ii) formulation and implementation of a short‐term, grid‐wide hydrothermal coordination model; (iii) design of ECs in the form of maximum ramping rates (MRRs) and minimum flows (MIFs) for selected hydropower reservoirs; and (iv) identification of Pareto‐efficient solutions in terms of grid‐wide costs and the Richard‐Baker flashiness index for subdaily hydrologic alteration (SDHA). The framework was applied to Chile's main power grid, assessing 25 EC cases, involving five MIFs and five MRRs. Each case was run for a dry, normal, and wet water year type. Three Pareto‐efficient ECs are found, with remarkably small cost increase below 2% and a SDHA improvement between 28% and 90%. While the case involving the highest MIF worsens the flashiness of another basin, the other two have no negative effect on other basins and can be recommended for implementation.
Chute cutoff as a morphological response to stream reconstruction: The possible role of backwater
Authors: Eekhout J. P. C. , Hoitink A. J. F. 
Published: April 2015

AbstractStream restoration efforts often aim at creating new unconstrained meandering channels without weirs and bank revetments. In reconstructed streams, the initial morphological response of the new streams is often rapid, until a dynamic equilibrium is reached. Here we report on a chute cutoff that occurred within 3 months after realization of a stream restoration project, caused by a plug bar that formed in response to a backwater effect. The temporal evolution of the morphology of both the new and the old channels was monitored over a period of nearly 8 months, including precutoff conditions. The observations can be separated into three stages. Stage 1 is the initial period leading to cutoff vulnerability, stage 2 is the actual cutoff, and stage 3 is the morphological adjustment in response to the cutoff. In stage 1, a plug bar was deposited in one of the channel bends. Hydrodynamic model results show the location of the plug bar coincides with a region where bed shear stress decreased in downstream direction due to backwater. Longitudinal channel bed profiles show that the channel slope decreased soon after channel reconstruction. Hence, sediment from upstream was available to form the plug bar. After the plug bar was deposited, an embayment formed in the floodplain at a location where the former channel was located (stage 2). The former channel was filled with sediment prior to channel construction. It is likely that the sediment at this location was less consolidated, and therefore, prone to erosion. The chute channel continued to incise and widen into the floodplain and, after 6 months, acted as the main channel, conveying the discharge during the majority of time (stage 3). The cutoff channel gradually continued to fill with sediment, from the moment the plug bar formed until the chute channel incised into the floodplain. Sedimentary successions of the deposited material show upward fining, which is in agreement with observations of chute cutoffs in rivers. Although the artificial setting limits the degree in which the observed processes can be projected on natural rivers, the observations prompt to investigate the role of backwater effects in natural chute cutoff initiation.
Assessment of flow regime alterations over a spectrum of temporal scales using wavelet‐based approaches
Authors: Wu Fu‐Chun , Chang Ching‐Fu , Shiau Jenq‐Tzong 
Published: April 2015

AbstractThe full range of natural flow regime is essential for sustaining the riverine ecosystems and biodiversity, yet there are still limited tools available for assessment of flow regime alterations over a spectrum of temporal scales. Wavelet analysis has proven useful for detecting hydrologic alterations at multiple scales via the wavelet power spectrum (WPS) series. The existing approach based on the global WPS (GWPS) ratio tends to be dominated by the rare high‐power flows so that alterations of the more frequent low‐power flows are often underrepresented. We devise a new approach based on individual deviations between WPS (DWPS) that are root‐mean‐squared to yield the global DWPS (GDWPS). We test these two approaches on the three reaches of the Feitsui Reservoir system (Taiwan) that are subjected to different classes of anthropogenic interventions. The GDWPS reveal unique features that are not detected with the GWPS ratios. We also segregate the effects of individual subflow components on the overall flow regime alterations using the subflow GDWPS. The results show that the daily hydropeaking waves below the reservoir not only intensified the flow oscillations at daily scale but most significantly eliminated subweekly flow variability. Alterations of flow regime were most severe below the diversion weir, where the residual hydropeaking resulted in a maximum impact at daily scale while the postdiversion null flows led to large hydrologic alterations over submonthly scales. The smallest impacts below the confluence reveal that the hydrologic alterations at scales longer than 2 days were substantially mitigated with the joining of the unregulated tributary flows, whereas the daily‐scale hydrologic alteration was retained because of the hydropeaking inherited from the reservoir releases. The proposed DWPS approach unravels for the first time the details of flow regime alterations at these intermediate scales that are overridden by the low‐frequency high‐power flows when the long‐term averaged GWPS are used.
Comparison of the Modeling Techniques for Chassis Applications. An Advice for the User
Authors: Heßeler Frank , Katriniok Alexander , Reiter Matthias , Maschuw Jan , Abel Dirk 
Published: April 2015

AbstractExamination of the developments in the automotive industry during the past decade shows that the number of mechatronic systems in a vehicle grows steadily and will continue to grow in the future. This trend is particularly encouraged by the increase in safety and comfort that has been enabled by the use of mechatronic systems. To a great extent, these functions are realized by software that is integrated into a vehicle as an embedded system. A further trend is a stronger interconnection of separate functions in the vehicle, which makes the functional development of new systems even more difficult and time‐consuming. Therefore, in this context, the need for a modern control design via Rapid Control Prototyping is growing. Many challenges in this development process can be solved by simulation models. This chapter focuses on the use of simple and real‐time capable simulation models that can be used for controller development. The chapter gives the reader some assistance to choose the right type of model for different applications. Besides the description of the basic dynamic physical equations of a chassis system, two different possibilities (signal‐oriented and object‐oriented) are shown to implement these equations in simulation programs.
Dual Mass Flywheel
Authors: Kroll Jürgen , Kooy Ad 
Published: April 2015

AbstractThe most effective measure for optimum vibration isolation of petrol and diesel engines with a high specific power rating and a high specific torque is the use of a dual mass flywheel (DMF). In this component, a spring mass damper is activated before the clutch. Its resonance frequency is below the excitation frequency of the engine at idle speed and thus outside the operating range. The spring mass damper filters the torsional vibrations introduced by the engine and thus calms the downstream drive line.This contribution provides an introductory analysis of the relationship between the trend for downsizing on the one hand and greater torsional vibrations and their noise development on the other. The function and structure of theDMFbasic concept and the further models derived from this basic concept are described later. The speed‐adaptive absorbing function of theDMFwith centrifugal pendulum‐type absorber (CPA) is presented in detail. A separate chapter describes a procedure for vibration simulation that looks in detail at all elements and excitation objects that come under consideration for the power transfer. This chapter looks not only at theDMFand the clutch system but also the entire powertrain, including engine and engine management. It also discusses the selection of suitable target factors that can be used to assess the quality of the design.
Open Differentials
Authors: Palazzolo Joseph 
Published: April 2015

Abstract
Open differentials have been installed in automotive applications for over 100 years. This chapter reviews the primary need and basic function of a differential for automotive applications. The mechanical power flow and construction of an open differential are presented along with the shortcomings of such a device. From the basic construction, one of many analytical approaches that is applied to explain the behavior of the differential and torque bias ratios from the internal friction within the device is reviewed. The elements of the differential are reviewed; specifically, the differential carrier, pin, pinion gears, and side gears. The general configuration and differences between two‐ and four‐pinion differentials are presented and explained.
Control Systems and Strategies for Automated Manual and Double Clutch Transmissions
Authors: Müller Bruno , Rathke Götz , Reuschel Michael , Wagner Uwe , Winkelmann Stefan , Grethel Marco , Gerhart Jürgen 
Published: April 2015

AbstractAutomated manual transmissions (AMT) and double clutch transmissions (DCT) can increase comfort while simultaneously reducing fuel consumption and emissions. To implementAMTandDCTinto a vehicle powertrain, numerous hardware components have to work together. These include several design variants of electric motors, control units, sensors, and, depending on the design, an electrohydraulic, electromechanical, or hydrostatic actuating mechanism. Depending on the combination and design of these components, various concepts can be considered and transmission types developed that satisfy not only the specific requirements of theOEMsbut also the individual applications. From a software perspective, the higher level functional logic is particularly important. Through appropriate control logic and adaption routines, this functional logic must ensure a consistently high level of comfort over the entire life.Irrespective of the specific design, an automatic transmission is only part of the overall vehicle system. The high complexity and the strong interaction between the subsystems require intensive alignment and testing of the subsystems as well as the overall system. If the automated forms of manual transmission are also to expand in other markets and compete with classic automatic transmissions, however, further improvements must be implemented in terms of efficiency (including weight and mounting space), comfort, and cost.
Emission Control Systems—Oxides of Nitrogen
Authors: Song Soonho 
Published: April 2015

AbstractFacing the strict emission regulations for oxides of nitrogen (NOX), many approaches have been proposed and applied to controlNOXemissions from current engine systems. Representative de‐NOXtechnologies inSIandCIengines are introduced in terms of in‐cylinder control and aftertreatment system. In‐cylinder control such as the spark timing, fuel injection strategies, exhaust gas recirculation (EGR), and induction system (boosted engine with charge air cooling) provides means ofNOXreduction before and during the combustion process by decreasing the gas temperature and controlling the chemical reactions of combustion. On the contrary, the aftertreatment systems such as the three‐way catalytic converter (TWC), selective catalytic reduction (SCR), andNOXadsorber provide the means to reduce already formedNOXafter combustion process via chemical reactions between the exhaust gas and other chemical components such as the reductant, oxidizer, and catalysts. In this section, the basic principles of operation are discussed. Then, applications of integrated de‐NOXtechnologies are introduced in the commercial engine systems.
Multidimensional Simulation
Authors: Reitz Rolf D. , Rutland Christopher J. 
Published: April 2015

AbstractThe combustion process inICengines is characterized by complex multiphase, turbulent reacting flows that span multiple regimes, including premixed flame propagation, mixing‐controlled burning, and chemical kinetics‐controlled processes. For predictive modeling, these processes must be represented with accurate mathematical models and numerical schemes, and this chapter reviews the current state of the art. Zero‐dimensional models based on thermodynamic cycle analysis can require extensive model constant tuning. Multidimensional computational fluid dynamics (CFD) modeling reduces the amount of model calibration required. However, submodels must still be used to describe processes that occur on time and length scales too small to be resolved in a simulation, but the inclusion of more and more detail has been made possible by recent dramatic increases in computer power. It is now widely recognized that engineCFDsimulations can offer significant advantages in the engine development process, including being able to provide detailed in‐cylinder information, which is often inaccessible in experiments. Other advantages over engine experiments include lower cost, the ability to explore wider ranges of parameter variation, and the ability to separate and monitor individual processes. In addition, when coupled with optimization tools, new design concepts can be discovered using multidimensional modeling, as described with examples in this chapter.
Lubrication and Friction
Authors: Wong Victor W. 
Published: April 2015

AbstractThis chapter describes in brief the basic lubrication and friction processes at the major engine components. It starts with a clarification of the common descriptors of mechanical losses and friction in the engine, followed by the topic of lubrication fundamentals such as lubrication regimes. Then the lubrication of the contacting surfaces in each of the major engine subsystems is discussed in turn. These subsystems include the piston assembly: ring‐pack/liner, piston‐skirt/liner, piston‐pin/connecting‐rod contacts; connecting rod and crankshaft bearings; and the valvetrain subsystem. The relative contributions to total friction from the various subsystems are discussed, with the piston‐assembly contributing to about half of the total friction. The remainder of the friction comes from the crankshaft, connecting rod, and camshaft bearings, and the valvetrain oscillating parts. The bearings are in predominantly hydrodynamic lubrication, in contrast to the valvetrain oscillating components, which are characterized to be mostly in the mixed/boundary lubrication regimes. Lubricating oil composition is discussed in the final section. It is generally believed that the bulk oil viscosity, with proper viscosity and (boundary) friction modification, could be controlled to lower component friction, in conjunction with antiwear additives. Effects of lubricant‐derived ash on diesel particulate filter (DPF) restriction are significant, with large differences observed among lubricant‐derived ash originating from different metallic‐based additives—such as among calcium, magnesium, or zinc compounds—at the same mass accumulation.
EV Auxiliaries
Authors: Jin Gang , Liao Yuefeng 
Published: April 2015

Abstract

This chapter presents an overview of the auxiliary subsystems of an electric vehicle. The phrase
engine auxiliaries
in a conventional vehicle equipped with an internal combustion engine often refers to the components driven by the engine
auxiliary belt
, for example, the alternator, the
AC
compressor, the hydraulic power‐assisted steering pump, and sometimes to the components driven by the engine vacuum circuits, for example, the brake booster. Owing to the absence of the internal combustion engine in an electric vehicle, the aforementioned components and the corresponding subsystems at large must be redesigned with different power source and possibly different operation mechanisms. The core of the design challenge is to maximize energy usage efficiency to ensure adequate driving range of the electric vehicle. Many of the technologies employed by this redesign for electric vehicles have been under development for conventional vehicles to improve fuel efficiencies and other performance measures. This trend is popularly referred to as
electrification
where energy is increasingly stored and delivered in the form of electricity. The progress toward electric vehicles only helps intensify this development by demanding maximum energy usage efficiency and by offering a naturally available high voltage power net that can further enhance efficiency over the 12V system.