bluuebunny/crossref_metadata_2025_split huggingface dataset:
Paleolongitudinal estimates for paleocontinents derived from interplate distances based on Late Ordovician bivalves
Authors: Schmachtenberg William F. 
Published: June 2011

The geographic distribution of 293 Modern bivalve genera has been analyzed and found to be statistically correlated with distance. In particular, a least-squares regression analysis of the data indicates that the distance between faunal realms (D) in kilometers can be estimated using the equation D = (ln(d) + 0.4233)/−0.00013, where d is the Dice coefficient of faunal similarity. Analysis of 59 genera of Late Ordovician bivalves indicates that the above equation also describes their biogeographic distribution.Using this formula, the distance between Laurentia and Scotland/Northwest Ireland was estimated to be 5500 kilometers. This is consistent with the reconstruction of a connection among these areas during the Late Ordovician based on brachiopod and graptolite biogeographic data.Paleomagnetic and paleoclimatic data also suggest that Avalonia, Baltica, and Laurentia were at tropical latitudes. Distances between these paleocontinents can therefore be used to estimate paleolongitudes. If the location of England on the eastern side of Avalonia is used as zero degrees paleolongitude for the Late Ordovician as it is today, the paleolongitude for South America, Laurentia, Scotland and northwest Ireland, and Baltica would be 125°W, 45°W, 10°W, and 15°E, respectively. Because of drifting of the Avalonia plate, these paleolongitudes probably do not coincide with the longitudinal grid used today. The paleolongitudes indicate only the relative spacing between continents in the past. The methodology in this study should be useful for improving the accuracy of paleogeographic reconstructions for the Late Ordovician throughout the Cenozoic, and especially the Paleozoic periods for which magnetic seafloor anomaly data are not available.
The Wage Impact of Immigration in Germany - New Evidence for Skill Groups and Occupations
Authors: Steinhardt Max Friedrich 
Published: June 2011

Abstract
This paper contributes to the ongoing debate regarding the appropriate approach to use in identifying the impact of immigration on native workers’ labor market outcomes. The initial regression analysis makes use of German administrative data and is based on the variation of foreign workers’ shares within education-experience cells over time. It confirms previous findings suggesting that immigration in Germany had no adverse impact on native wages. However, the paper highlights that in Germany immigrants and natives with similar education and experience are likely to work in different occupations. The subsequent analysis based on occupational clustering uses the same data and finds significant adverse wage effects for natives, particularly for those in basic service occupations. The paper argues, therefore, that an identification strategy based on formal education characteristics might lead to biased estimates if a country’s labor market is characterized by occupational segmentation of immigrants.
Impact on force decrease at the end of actuator plunger motion
Authors: Zagirnyak Mykhaylo , Branspiz Yurii , Pshenychnyi Andrii , Miljavec Damijan 
Published: June 2011

Impact on force decrease at the end of actuator plunger motion
It is shown that decrease and damping of the traction force at the end of the plunger move is possible not only due to application of a special keeper design, but also due to change of the plunger shank geometric form. The computer modeling with the use of finite element method is used to analyze the influence of system geometry on force distribution along plunger movement. The damping effect is confirmed when special shape plunger shanks are used.
Steady-state modelling method for matrix-reactance frequency converter with boost topology
Authors: Korotyeyev Igor , Zięba Beata 
Published: June 2011

Steady-state modelling method for matrix-reactance frequency converter with boost topologyThis paper presents a method intended for calculation of steady-state processes in AC/AC three-phase converters that are described by nonstationary periodical differential equations. The method is based on the extension of nonstationary differential equations and the use of Galerkin's method. The results of calculations are presented in the form of a double Fourier series. As an example, a three-phase matrix-reactance frequency converter (MRFC) with boost topology is considered and the results of computation are compared with a numerical method.
Application of optimal current driver for the torque control of BLDC motor
Authors: Bernat Jakub , Stępień Sławomir 
Published: June 2011

Application of optimal current driver for the torque control of BLDC motorThis research presents the novel control strategy of the brushless DC motor. The optimal current driver is designed using Linear Quadratic Regulator and feedback linearization. Additionally, the current reshaping strategy is applied to control the motor torque. Thus, the torque controller is built based on the optimal current driver. The motor is simulated using the FEM analysis.
Energy conversion in small water plants with variable speed PM generator
Authors: Sobczyk Tadeusz , Mazgaj Witold , Szular Zbigniew , Węgiel Tomasz 
Published: June 2011

Energy conversion in small water plants with variable speed PM generatorThe Small Hydro Power Plants allow to increase the energy amount from renewable sources, especially from small rivers in mountainous areas. This paper presents a new concept of a energy conversion system for application in a Small Hydropower Plant (SHP) which is based on a permanent magnet generator (PM generator) with a propeller turbine integrated with the generator rotor. The PM generator can work at a variable speed and therefore energy produced by the PM generator has to be converted by means of a power electronic unit to fit to the three-phase power grid parameters. For this concept, dimensions and parameters of the PM generator were specially designed on account of integration with water turbine. The paper precisely describes elements of energy conversion system and also presents the results of numerical tests for chosen working conditions. An original algorithm of control strategy for power electronic unit was used to adjust generated energy to the required parameters of the three-phase grid.
Drive optimisation of a pulsatile Total Artificial Heart
Authors: Pohlmann André , Lessmann Marc , Finocchiaro Thomas , Fritschi Andreas , Steinseifer Ulrich , Schmitz-rode Thomas , Hameyer Kay 
Published: June 2011

Drive optimisation of a pulsatile Total Artificial HeartTotal Artificial Hearts (TAHs) are required for the therapy of terminal heart diseases as heart transplants are only a limited option due to the available number of donor hearts. For implantation TAHs have to meet constraints regarding its dimensions, weight, perfusions and electrical losses. An innovative linear driven TAH is presented, which meets all constraints except weight. Therefore the geometry of the linear drive is optimised to reduce its weights while simultaneously limiting the electrical losses as much as possible. In order to calculate the losses, this paper introduced a combined calculation chain consisting of FEM simulations and analytical equations. Based on this chain the linear drive is optmised by the method of parameter variations. The results yield a hierachic order of parameters which are most suitable for the weight reduction of the drive for low losses. By this the weight of the linear drive is reduced by 25%. As the allowable loss limit is not exceeded yet, room for further weight reduction achieved by an optimisation of the axial geomtry parameters is given.
Metainformation infrastructure for geospatial information
Authors: Kliment T. 
Published: June 2011

Metainformation infrastructure for geospatial informationThe Infrastructure for Geospatial Information consists of an information component, where the bearers of geoinformation are geospatial data, and a metainformation component. The bearers of metainformation are metadata, which describe these geospatial data. Metadata serve as a tool for discovery, retrieve and evaluation of geospatial data within the Infrastructure of Geospatial Information. In order to acquire metadata from a metadata producer to a metadata consumer, the implementation of various tools - components of Metainformation Infrastructure for Geospatial Information is required. This paper describes the main principles and components of Metainformation infrastructure and the possibility of using open source tools for their implementation in practice.
Diversité des carrières d'auteur de l'audiovisuel et du spectacle vivant. Les auteurs de la SACD, 1997-2008
Authors: Gouyon Marie 
Published: June 2011

R éSUMé En 2008, la Société des auteurs et compositeurs dramatiques (SACD) a versé 136 millions d’euros de droits à 17 700 auteurs et compositeurs dramatiques. Entre 1997 et 2008, les répertoires gérés par la SACD ont beaucoup évolué, en particulier celui de l’audiovisuel, du fait des mutations technologiques intervenues depuis la fin des années 1990 dans ce secteur : apparition puis généralisation de la télévision numérique terrestre (TNT), développement des chaînes thématiques, etc. Les auteurs se distinguent nettement les uns des autres selon le répertoire (audiovisuel ou spectacle vivant) auquel ils participent, leur durée et leur volume de production, leur niveau de contributions aux diffusions et aux représentations, ainsi par les montants de droits perçus. La population des auteurs et compositeurs dramatiques reste âgée et très masculine, bien que les femmes y soient de plus en plus nombreuses.
First Variation Formula in Wasserstein Spaces over Compact Alexandrov Spaces
Authors: Gigli Nicola , Ohta Shin-Ichi 
Published: June 2011

AbstractWe extend results proved by the second author (Amer. J. Math., 2009) for nonnegatively curved Alexandrov spaces to general compact Alexandrov spaces X with curvature bounded below. The gradient flow of a geodesically convex functional on the quadratic Wasserstein space ((X),W2) satisfies the evolution variational inequality. Moreover, the gradient flow enjoys uniqueness and contractivity. These results are obtained by proving a first variation formula for the Wasserstein distance.
On Zindler Curves in Normed Planes
Authors: Martini Horst , Wu Senlin 
Published: June 2011

AbstractWe extend the notion of Zindler curve from the Euclidean plane to normed planes. A characterization of Zindler curves for general normed planes is given, and the relation between Zindler curves and curves of constant area-halving distances in such planes is discussed.
Sharp Inequalities for Differentially Subordinate Harmonic Functions and Martingales
Authors: Osękowski Adam 
Published: June 2011

AbstractWe determine the best constants Cp,∞ and C1,p, 1 < p < ∞, for which the following holds. If u, v are orthogonal harmonic functions on a Euclidean domain such that v is differentially subordinate to u, thenIn particular, the inequalities are still sharp for the conjugate harmonic functions on the unit disc of ℝ2. Sharp probabilistic versions of these estimates are also studied. As an application, we establish a sharp version of the classical logarithmic inequality of Zygmund.
Evaluation of Highly Alloyed Stainless Materials for CO2/H2S Environments
Authors: Asphahani A. I. 
Published: June 2011

Abstract
Martensitic, autstenitic, ferritic-austenitic, and high-nickel stainless steels and high-iron, nickel-base alloys are tested for their resistance to localized corrosive attack and to stress corrosion cracking in media containing chloride, saturated with CO2/H2S gas. Several testing environments are used in order to simulate service applications in deep H2S wells, deep CO2 wells, and enhanced recovery by CO2 injection. The alloys' performances are compared at different strength levels (0, 20, and 50% cold work), and the effects of temperature and CO2/H2S content are examined. The overall resistance of each class of alloys is outlined. Furthermore, within the same class of alloys, the differences are described with respect to localized corrosion and to stress corrosion cracking resistance.
Breakdown of Oxide Films on Steel Exposed to Chloride Solutions
Authors: Townsend H. E. , Cleary H. J. , Allegra L. 
Published: June 2011

Abstract
Breakdown of the thin air-formed oxide film is the first step in the corrosion of steel exposed to aqueous chloride environments. We studied oxide-film breakdown by observing changes, with time, of appearance, weight loss, and corrosion potential while varying the three components of the system: environment, substrate, and film. Environment was varied by changes in chloride and hydrogen peroxide concentrations. Low carbon steel, stainless steel, aluminum, and titanium substrates were studied. Various types of crystalline oxide film were applied to steel substrates by RF sputtering. The results of this work demonstrated that the chemical and electronic properties of the oxide film on steel are inconsequential in determining whether film-breakdown will occur. We interpret these results in terms of a film-breakdown mechanism in which substrate dissolution begins at film defects and spreads, thus causing removal of the film by undercutting. According to this model, the ability of the substrate to spontaneously reform a stable oxide and repair the film determines resistance to film-breakdown.
An Auger Electron Spectroscopic Study of Phosphorus Segregation in the Grain Boundaries of Nickel Base Alloy 600
Authors: Guttmann M. , Dumoulin Ph. , Tan-Tai Nguyen , Fontaine P. 
Published: June 2011

Abstract
The grain boundary composition of nickel base alloy 600 has been studied by means of Auger electron spectroscopy. After being cathodically charged with hydrogen in a water saturated salt bath at 200 C, all the specimens could be intergranularly fractured in the Auger chamber. Phosphorus was the only element found to segregate at the grain boundaries of the two materials studied in all conditions of heat treatment considered; sulfur appeared essentially as a contaminant, which built up on the surfaces after fracture. The segregation of P was shown to be of the equilibrium (McLean) type, whereas Si did not segregate appreciably to the grain boundaries. The results, discussed in connection with published corrosion and stress corrosion data, explain the influence of P and the virtual absence of influence of Si on the sensitivity of alloy 600 to intergranular corrosion in HNO3 + Cr6+ solutions. They also indicate that the segregation of P is not the cause of intergranular stress corrosion cracking of this alloy in pure water and caustic environment, and that hydrogen embrittlement is very unlikely to be the mechanism of this phenomenon.
Dependence of Corrosion Fatigue Crack Initiation Mechanisms on the Corrosion Behavior of Two Stainless Chromium Steels
Authors: Mueller Matthias P. 
Published: June 2011

Abstract
Corrosion fatigue experiments have been carried out in a 0.5N and 4N sodium chloride solution with pH of 6.5 at 80 C. The solution has been air saturated. Two different chromium steels were examined, a tempered martensitic steel with 12% chromium and a pure ferritic steel with 18% chromium and 2% molybdenum. The results of this investigation showed that the corrosion fatigue crack initiation mechanisms are directly related to the type of corrosion attack. Under pitting corrosion conditions, a pronounced decrease in fatigue limit has been measured. Under passive corrosion conditions, a corrosion fatigue limit exists, which could be related to the thickness of the passive surface film and the surface slip characteristics of the alloy. It has been shown that under passive corrosion conditions, the corrosion fatigue limit cannot be lower than the cyclic yield strength of the material. Nonmetallic inclusions were found to play an important role in corrosion fatigue crack initiation. In the 12% chromium steel, sulfide inclusions acted as pit initiation sites. Chemically inert niobiumcarbonitrides in the 18% chromium steel induced local corrosion attack, but only under corrosion fatigue conditions in the 4N sodium chloride solution.
Hydrogen Embrittlement Behavior of the Amorphous Alloy Fe32Ni36Cr14P12B6
Authors: Tong H. S. , Macur J. E. 
Published: June 2011

Abstract
Room temperature hydrogen embrittlement behavior of the amorphous alloy Fe32Ni36Cr14P12B6 was studied under various conditions. Hydrogen charging was performed in a 1N H2SO4 solution at a current density of 10 mA/cm2 and hydrogen embrittlement susceptibility was determined using the constant extension rate technique at an extension rate of 5.0×10−4 cm/S. The fracture stress decreased significantly on the hydrogenized specimen. However, recovery of this fracture stress was observed as a function of degassing time at room temperature. The fracture morphology of the specimens with/without hydrogen charging was also studied.
Evaluation of Corrosion Behavior of Coated Metals with AC Impedance Measurements
Authors: Mansfeld F. , Kendig M. W. , Tsai S. 
Published: June 2011

Abstract
AC impedance measurements have been performed in 0.5 N NaCl for coated steel and aluminum alloys which had been subjected to different surface treatment procedures. These procedures included phosphating for steel and exposure to a conversion coating for the Al alloys. A polybutadiene coating of 8 ± 2 μm thichness was applied by spin coating. The AC impedance measurements made it possible to follow the penetration of electrolyte into the coating and to detect the initiation of corrosion at the metal/coating interface. A general model has been used to analyze the impedance data in terms of reactions occurring during the interaction of the coated metals with the environment. Based on this analysis the different pretreatment procedures have been ranked in terms of their efficiency in providing corrosion protection by the organic coating. A comparison between impedance results and visual observation over several days of the corroded and the delaminated areas under the coating confirm that AC impedance data can be used to characterize organic coating/metal systems.
Permeation of Hydrogen, Trapping, and Damage in Spheroidized AISI 1090 Steel
Authors: Xie S. X. , Hirth J. P. 
Published: June 2011

Abstract
Spheroidized AISI 1090 steel was electrolytically charged with hydrogen from a 1 normal sulfuric acid solution containing a recombination poison. Permeation, trapping and damage effects were studied as a function of cold work, charging current density, and time. Irreversible damage, manifested as void formation, was found to occur at a critical charging current density which decreased with increasing cold work. Voids formed when the hydrogen fugacity was sufficient to cause void growth by plastic deformation. Effects of microstructure were found to be similar to those in prior work using gas phase permeation techniques.
Erosive Wear of Advanced Ceramics in Coal-Slurry Streams
Authors: Shetty D. K. , Wright I. G. , Clauer A. H. , Peterson J. H. , Merz W. E. 
Published: June 2011

Abstract
Erosive wear of advanced ceramics and cemented carbides was evaluated in a coal-slurry jet test that simulates the conditions in letdown valves in liquefaction plants. The results indicate that some ceramics, notably those based on SiC, possess superior wear resistance as compared to the cemented carbides. The paper discusses the influence of the microstructures and the physical properties of the target materials on their relative susceptibility to erosive wear.
A Study of Zircaloy-2 Corrosion in High Temperature Water Using Ion Beam Methods
Authors: Woolsey I. S. , Morris J. R. 
Published: June 2011

Abstract
Corrosion experiments have been carried out on Zircaloy-2 specimens in water at 355 C to study the transport of oxygen and hydrogen (as deuterium) in growing corrosion films. The transport behavior was studied by using O18 and deuterium labelled water, and analyzing the corrosion films for these isotopes by the use of ion beam induced nuclear reactions. Analysis for O18 was performed by means of the O18 (p,α)N15 reaction, using incident 850 and 950 keV protons. The analyses for deuterium were made using the D(He3,d)p reaction employing incident 850 and 1300 keV He3 ions, and detecting the scattered α-particles. The composition of the corrosion films was also examined in 2.9 MeV and 3.9 MeV α-particle backscattering experiments. From these studies, it was concluded that the corrosion of Zircaloy-2 in high temperature water occurs predominantly by oxygen diffusion through the corrosion film via grain boundary or similar short circuit diffusion paths, to form fresh oxide at the oxide metal interface. The diffusivity of oxygen through the pre-breakaway films decreased with time as a result of a decrease in the available easy diffusion paths as the oxide aged. This was interpreted as the primary cause of the subparabolic kinetics normally observed prior to the rate transition during high temperature aqueous corrosion of Zircaloy-2. There was also evidence that increasing grain size deeper within thick pre-breakaway films contributes to the decrease in oxygen diffusivity. The oxygen transport behavior in post-breakaway corrosion films indicates that the rate transition results from the generation of new diffusion pathways in previously protective oxide. Unexpectedly high concentrations of deuterium were observed in the corrosion films. These were about 4.5% atomic at the oxide surface, falling to 1 % atomic at depths between 1 and 1.5 μm. The deuterium was also found to be highly mobile within the oxide, much more so than oxygen.
Effect of Steam Impurities on Corrosion Fatigue Crack Growth Rates of a Turbine Disc Steel
Authors: Rungta R. , Begley J. A. , Staehle R. W. 
Published: June 2011

Abstract
Corrosion fatigue crack growth studies have been conducted on a Ni-Cr-Mo-V turbine disc steel in saturated sodium chloride and sodium sulfate environments at 100C. The results show that crack growth rate is accelerated in both the environments at open circuit potential, compared to the rate in air environment. Crack growth rate is further accelerated in both environments with the application of a large cathodic potential. Anodic potential has no effect on crack growth rate relative to that at open circiut potential. Cracking occurred transgranularly around the open circuit potential and intergranularly under severe cathodic charging conditions. The amount of intergranular cracking increased with decreasing frequency in the Cl− environment and occurred predominantly at low ΔK levels. It is suggested that the material cracks by two mechanisms: hydrogen embrittlement at very cathodic potentials, and film rupture and anodic dissolution at relatively noble potentials around the open circuit potential. Finally, comparison of the results with those for concentrated sodium hydroxide (100 C) and double distilled water (97 C) shows that although sodium hydroxide (which is another impurity present in the steam) is the most aggressive specie, distilled water inhances cracking as well. It is recommended that further work be done in high purity water.
Oxide Scale Formation on Iron-Chromium Alloys in Elevated Temperature Air Environments
Authors: Fabis P. , Heidersbach R. , Brown C. , Rockett T. 
Published: June 2011

Abstract
Oxide scales formed on metals at elevated temperatures may be different, both chemically and structurally, from the scales on the metal once it has cooled to room temperature. This paper discusses Raman spectroscopy instrumentation for the in-situ identification of scales formed on metal surfaces exposed to gaseous environments. The results of an experimental program to characterize scales formed on two commercial iron-chromium alloys, AISI 446 and 502, in air and oxygen environments are also presented.