bluuebunny/crossref_metadata_2025_split huggingface dataset:
Resonant photoemission shake‐up satellites from semiconductors with shallow 3d and 4d core levels
Authors: Klein Andreas , Siepchen Bastian , Späth Bettina , Mankel Eric , Mayer Thomas , Jaegermann Wolfram 
Published: December 2010

AbstractPhotoemission spectra from shallow 3d and 4d levels of ZnTe, ZnSe, CdTe, CdS, and tin‐doped In2O3 (ITO) using synchrotron radiation from the BESSY II storage ring are presented. All compounds show pronounced resonant shake‐up satellites at the excitation threshold of the 3p and 4p‐levels. The resonance intensity profiles are compared to 3p and 4p photoemission. Electron correlation energies U of 10.15, 10.75, 6.15, and 7.3 eV are derived for ZnTe, ZnSe, CdTe, and ITO, respectively.
Calculations for the linear and nonlinear optical coefficients of ZCTC crystals
Authors: Feng Chao , Lu Guiwu , Wang Xinqiang , Zhang Peng , Zhou Guanggang , Yang Hongwang , Jiao Yuqiu 
Published: December 2010

AbstractThe structural, electronic, linear and nonlinear optical properties of ZnCd(SCN)4 (ZCTC) single crystal were studied by using quantum‐mechanical calculations based on the density functional theory (DFT) and pseudopotential method. The optimized lattice constant can be compared with the experimental values when the effects of temperature are considered. Combining with partial density of states of ZCTC crystal, it was found that C2p, N2p and S3p orbitals occur obvious hybrid, which is the main source of the second‐order nonlinear optical effect of ZCTC crystal. Then DFT has been used to calculate the hyperpolarizability of ZCTC single crystal, from which the second harmonic generation (SHG) coefficients was calculated using ionic group theory. The calculated SHG coefficients are d14 = 1.08 ∼ 1.93 pm/V and d15 = 4.01 ∼ 4.79 pm/V. Both of them are in agreement with the tendencies shown by the experimental results (d14 = 3.2 pm/V and d15 = 7.6 pm/V). It was also found that the greatest contribution for SHG of ZCTC crystal is from SCN anionic group.
Triplet exciton in polymeric electroluminescence
Authors: Gu Lei , Li Sheng , George Thomas F. , Sun Xin 
Published: December 2010

AbstractDue to self‐trapping in polymer, a triplet exciton can be combined with a polaron to form a charged exciton with spin S = 1/2 or 3/2. The former one is emissive. This combination opens a charged exciton channel to make the triplet exciton emissive, enabling the electroluminescence efficiency to increase from 25 to 50%. A precondition is determined for opening this new channel, namely that the injected current density should exceed a certain threshold which depends on the lifetime of the triplet exciton.
A surgical navigation system for oral and maxillofacial surgery and its application in the treatment of old zygomatic fractures
Authors: Chen Xiaojun , Lin Yanping , Wang Chengtao , Shen Guofang , Zhang Shilei , Wang Xudong 
Published: December 2010

AbstractBackgroundNowadays, there is a trend towards computer‐aided oral and maxillofacial surgery. However, due to complicated preoperative planning, traditional neurosurgery‐orientated navigation systems are not suitable and have to be adapted.MethodsA surgical navigation system is presented for oral and maxillofacial surgery, named AccuNavi, which integrates 3D medical modelling, preoperative surgical planning and intraoperative tracking. Various algorithms were introduced, for each of which a set of dynamic link libraries (DLLs) were developed using C++, as well as the VTK and ITK, via object‐orientated programming methodology, allowing for expandability, accessibility and maintainability in our system.ResultsThe advantage of AccuNavi is validated through clinical applications, especially in a case report about the planning and subsequent precise treatment of old zygomatic fractures. The postoperative 3D‐reconstructed CT image demonstrated that the fractured zygoma was fixed in the appropriate position and orientation.ConclusionsThe clinical application demonstrates tyhe feasibility and reliability of AccuNavi, and it can be extended to various areas in oral and maxillofacial surgery. Copyright © 2010 John Wiley & Sons, Ltd.
Differences in managerial discretion across countries: how nation‐level institutions affect the degree to which ceos matter
Authors: Crossland Craig , Hambrick Donald C. 
Published: December 2010

AbstractThe concept of managerial discretion provides a theoretical fulcrum for resolving the debate about whether chief executive officers (CEOs) have much influence over company outcomes. In this paper, we operationalize and further develop the construct of managerial discretion at the national level. In an empirical examination of 15 countries, we find that certain informal and formal national institutions—individualism, tolerance of uncertainty, cultural looseness, dispersed firm ownership, a common‐law legal origin, and employer flexibility—are associated with the degree of managerial discretion available to CEOs of public firms in a country. In turn, we show that country‐level managerial discretion is associated with how much impact CEOs have on the performance of their firms. We also find that discretion mediates the relationship between national institutions and CEO effects on firm performance. Finally, we discuss two inductively derived institutional themes: autonomy orientation and risk orientation. Copyright © 2011 John Wiley & Sons, Ltd.
Metallurgical and Mechanical Characterization of Laser Spot Welded Low Carbon Steel Sheets
Authors: Masoumi M. , Marashi S.P.H. , Pouranvari M. 
Published: December 2010

AbstractThis paper aims at investigating metallurgical and mechanical characterization of low carbon steel laser spot welds. Microstructural examinations, microhardness tests and quasi‐static tensile‐shear tests were preformed. Mechanical properties of the welds were described in terms of peak load and failure mode. The effects of laser spot welding parameters including pulse frequency, laser energy, welding speed, pulse width and welded circle diameter, on low carbon steel laser spot weld performance were studied using the Taguchi design of experiment method. It was found that the effective laser pulse energy is the controlling factor in the determination of mechanical strength of laser spot welds.
Effect of Cooling Rate on the Microstructure of Proeutectoid Ferrite under a High Magnetic Field in Fe‐0.52C
Authors: Wang S. J. , Zhao X. , Xiao N. , Zuo L. 
Published: December 2010

AbstractFor steels, cooling rate is a key factor affecting and deciding the morphology, amount, size and distribution of proeutectoid phase during cooling after austenitizing. In this study, the influence of cooling rate on the formation of proeutectoid ferrite in a high purity Fe‐0.52C alloy during transformation from austenite to ferrite under a high magnetic field was investigated. Results showed that the high magnetic field of 12 T can significantly change the morphology and distribution of proeutectoid ferrite. As compared with the specimens transformed without applying a magnetic field, the proeutectoid ferrite grains were elongated and aligned along the field direction, and only small amounts of acicular proeutectoid Widmanstätten ferrite were observed. The amount of acicular proeutectoid Widmanstätten ferrite in the specimens transformed under the magnetic field increased with increasing cooling rate. The reasons for the observed phenomena were discussed on the basis of free energy, interfacial energy and elastic strain energy of the involved phases transformed under the high magnetic field.
Update on the Equilibrium between Liquid Fe‐Ti‐O Slags and Metallic Iron
Authors: Seim S. , Kolbeinsen L. 
Published: December 2010

AbstractThe current work is an update on the equilibrium between a synthetic high titania slag and metallic iron at temperatures above the slag melting point. The experimental setup is essentially the same as previously shown in the literature, thus employing a cold crucible in a high frequency induction furnace. A new addition to the experimental setup is the temperature measurement by a spectropyrometer. The temperature measurements will give the liquidus temperature for the slags. This temperature shows a decreasing trend as the FeO content in the slag increases. 24 slags have been successfully produced with iron saturation with a FeO content ranging from 6 to 33 wt%. The slags show a clear trend and provide a solid foundation to the location of the slag‐metal equilibrium line in the investigated area. The experiments are in agreement with previously published experimental data but not with previously calculated results using thermodynamical software.
Influence of Sequential Contact with Two Melts on the Wetting Angle of the Ladle Slag and Different Steel Grades on Magnesia‐Carbon Refractories
Authors: Heikkinen E.‐P. , Kokkonen T. , Mattila R. , Fabritius T. 
Published: December 2010

AbstractThe chemical wear mechanism in the slagline of a steel ladle has been investigated by measuring the wetting between molten steels and slags and MgO‐C‐refractories using an optical dilatometer and SEM‐analysis. The results support the wear mechanism in which the graphite is dissolved in steel while the oxide part is destroyed due to dissolution of MgO grains into the slag.
Influence of the Cold Rolling and Annealing Sequence on the Ridging Behaviour of Ti‐Stabilized 18% Cr Ferritic Stainless Steel
Authors: Jung I. , Mola J. , Chae D. , De Cooman B. C. 
Published: December 2010

AbstractThe influence of the cold rolling and annealing sequence on the ridging resistance and the crystallographic texture distribution of AISI 439 type ferritic stainless steel was studied in order to determine optimal processing conditions for surface quality improvement. In the present study, the effect of two sequences of cold rolling and annealing were analysed: a single cold rolling and annealing, and an interrupted cold rolling with an intermediate and a final anneal. In the conventional single step cold rolling, the ridging resistance was found to deteriorate with increasing cold reduction ratio. For a fixed total cold reduction ratio in the two stage cold rolling, ridging was less pronounced when a higher reduction was applied in the second step. Band‐like clusters of grains with similar crystallographic orientations were observed in the mid‐thickness of sheets with severe ridging. The results show that severe ridging is related to the presence of band‐like clusters of 〈111〉//ND oriented grains. The two stage cold rolling was found to result in less band‐like clusters and an improved surface quality.
Relaxation and Stability of Welding Residual Stresses in High Strength Steel under Mechanical Loading
Authors: Farajian M. , Wimpory Robert C. , Nitschke‐Pagel Th. 
Published: December 2010

AbstractThe relaxation of near surface welding residual stresses in S1100QL under static and cyclic mechanical loadings was studied. By increasing static loads the residual stress relaxes continuously. Under cyclic loading the residual stresses behave depending on the initial status, local yield strength and maximum applied load. If the von Mises stress as a function of residual stress, load and mean stresses, exceeds the local yield strength, plastic deformation and thus relaxation occurs. The first load cycle is of importance in which a considerable portion of the initial residual stress field relaxes. Afterwards regardless of whether in high or low cycle fatigue conditions, the relaxation rates were the same and comparatively smaller than the first relaxation. When no relaxation in the first load cycle occurred, the number of cycles did not change the residual stress. The specimens were loaded until failure or a maximum of 2x106 numbers of cycles.
Tragverhalten von Scher‐Lochleibungsverbindungen mit dem Beginn des Gewindes in der Nähe der Scherfuge
Authors: Friede Roland , Lange Jörg , Nicolay Thorsten 
Published: December 2010

AbstractIm Nachweisverfahren einer Scher‐Lochleibungsverbindung wird unterschieden, ob der Schaft oder das Gewinde in der Scherfuge liegt. Mit der Umstellung der Schraubennorm von der DIN 6914 auf die DIN EN 14399‐4 haben sich die Schraubengeometrien teilweise geändert. Dies führt dazu, dass das Gewinde in vielen Fällen näher an bzw. häufiger in der Scherfuge liegt. In der aktuellen Normung wird nicht näher definiert, bei welchen Bedingungen der Schaftquerschnitt angesetzt werden darf und bis zu welcher Position der Scherfuge der ungünstigere Gewindequerschnitt angesetzt werden muss. Es wurden Versuche mit dem Ziel durchgeführt, das Tragverhalten von scherbelasteten Schraubengarnituren zu untersuchen, insbesondere im Übergangsbereich zum Gewinde. Dabei wurde die Position der Scherfuge verändert. Der Einfluss der neuen Schraubengeometrien und die Ergebnisse der Abscherversuche werden nachfolgend genauer beschrieben.Shear bearing of bolted connections with the beginning of the thread near the shear plane. In bolted connections the shear load is calculated with the cross section of the bolt. It is important whether the shank or the thread is in the shear plane. In the new code for bolts DIN EN 14399‐4 the dimension of the bolts are modified. Compared to the previous code, the DIN 6914, in many situations the thread is closer to the shear plane or even in the shear plane. In the current standards there is no requirement about how long the shank has to protrude into the shear plane. Tests were performed to assess the ultimate load of bolts in shear connections with different positions of the shear plane. In the paper the differences of the codes DIN 6914 and DIN EN 14399‐4 are shown and the results of the tests are presented.
Flughafen Sheremetyevo, Moskau – Planung und Fertigung der Stahldächer und Brücke
Authors: Drawer Oliver , Fahlbusch Mark , Thiel Matthias 
Published: December 2010

AbstractIm Zuge einer deutlichen Erweiterung der Fluggastkapazitäten und Modernisierung ist in Moskau das dritte Terminal am Flughafen Sheremetyevo entstanden (Bild 1). Unter der Leitung der Arnold AG übernahm das Büro B+G Ingenieure Bollinger und Grohmann GmbH (B+G) die Planung mehrerer Vordächer und einer Fußgängerbrücke zwischen Parkhaus und Terminal. In der weiteren Entstehung wurden die Firmen Müller Offenburg GmbH & Co. KG (MOG), Heinrich Lamparter Stahlbau GmbH & Co. KG (StaLA) und Radabau GmbH für die Fertigung verpflichtet. Der folgende Beitrag befasst sich mit den Besonderheiten der Planung sowie der Fertigung der einzelnen Bauteile in diesem speziellen Projekt.Sheremetyevo Airport, Moscow, Russia – Structural design and fabrication of steel roofing and bridge. The new Terminal 3 was built as part of the significant expansion and modernization to increase passenger capacities at Sheremetyevo Airport in Moscow (Figure 1). Bollinger + Grohmann Ingenieure carried out the structural design for various canopies and a footbridge between parking garage and terminal building under the supervision of the Arnold AG. In the later stage of the project Müller Offenburg GmbH & Co. KG (MOG), Heinrich Lamparter Stahlbau GmbH & Co. KG (StaLA) and the Radabau GmbH were assigned the manufacturing contract. The following article deals with the peculiarities during the design stage and fabrication of individual structural elements of this particular project.
Die Instandsetzung der Old White Nile Bridge in Khartoum/Sudan
Authors: Haumer Wolfram , Gebert Gregor , Ehrlicher Frank , El‐Dawi Khalid 
Published: December 2010

AbstractDie Old White Nile und die Old Blue Nile Bridge waren die ersten beiden Brücken überhaupt, die in Khartoum, der Hauptstadt des Sudan über den Nil führten. Sie wurden von der Britischen Baufirma Dorman Long Ltd. in den Jahren 1908 und 1928 gebaut und erfüllen bis heute in nahezu unveränderter Form ihren Dienst. Sie stellen damit funktionstüchtige, ingenieurtechnische Denkmale dar und zeugen von der außergewöhnlichen Ingenieurleistung, die hier unter schwierigen klimatischen und technologischen Bedingung erbracht wurde.Der folgende Beitrag befasst sich mit der Instandsetzung der Old White Nile Bridge, welche im Zeitraum von 2004 bis 2007 durchgeführt wurde. Die Schüßler‐Plan Ingenieurgesellschaft wurde von der Brückenbauverwaltung der Stadt Khartoum mit verschiedenen Untersuchungen im Zusammenhang mit dem Sanierungskonzept betraut. Der Aufsatz befasst sich neben einem historischen Rückblick mit der Entscheidung, ob ein Auswechseln der 80 Jahre alten, in ihrer Funktion stark eingeschränkten Brückenlager aus statischer Sicht notwendig ist oder diese am Bauwerk belassen werden können. Auch für die Old Blue Nile Bridge ist in den kommenden Jahren eine grundlegende Instandsetzung vorgesehen. Da die Konstruktion vergleichbar ist, können die bei der Old White Nile Bridge gewonnenen Erkenntnisse hierbei einen wertvollen Beitrag leisten.Rehabilitation of old steel bridges over the Nile in Khartoum/Sudan. The Old White Nile Bridge and the Old Blue Nile Bridge were the first bridges ever to cross the Nile at Khartoum – Capital of the Sudan. They were build In 1928 and 1908 by the British Company Dorman Long Ltd. and till today service the traffic in Khartoum in their since then unchanged form. They represent as such a functional technical monument and an attest of the unusual engineering achievement, which was realised under the most extreme climatic and technological conditions.The following report is about the rehabilitation of the Old White Nile Bridge, which was carried out from 2004 till 2007. The Schüßler‐Plan Ingenieurgesellschaft was contracted by the Bridge Department of the State of Khartoum with several analysis related with the rehabilitation concept. The report starts with an historic review of the bridge and continuous with the decision weather it is statically necessary to exchange the nearly 80 year old bearings that are strongly hindered in their function, or weather they could be left unchanged. For the Blue Nile Bridge also, a complete rehabilitation is planned in the near future. Since the two bridge structures are comparable, the knowledge collected at the Old White Nile Bridge could be of great advantage for the Blue Nile rehabilitation.
Schlüssiges Nachweisformat biegesteifer Verbindungen geschweißter Kastenprofile
Authors: Strehl Christian 
Published: December 2010

AbstractFür Knotenverbindungen mit großen geschweißten Kastenprofilen – wie im Kesselgerüstbau erforderlich – wird im vorliegenden Beitrag ein Nachweisformat vorgestellt. Als Beispiel dient ein Knoten an einer Stütze mit Anschluss zu zwei Riegeln und vier Diagonalen. Die Annahmen für die Aufteilungen der Schnittgrößen im Knotenbereich sind in Bildern und Formeldarstellungen für ein Tabellenkalkulationsprogramm dargelegt. Zusätzliche tabellarisch aufgeführte Zahlenwerte ermöglichen anhand des fiktiven Beispiels eine Kontrolle des Berechnungsalgorithmus. Der komprimierte Berechnungsgang leitet zu einer ausführlichen praktischen Anwendung an.Conclusive calculation algorithm for rigid connections with welded box sections. For the construction of nodes with large welded plates in kind of rectangular profiles, as for example required for racks in power plants, a calculation algorithm is presented. The geometry of a node is determined by a column with two girders and four struts. The assumptions for the distribution of the internal forces in the region of the nodes are shown in kind of figures and formulas for a table calculation program. The calculation algorithm can be checked by given values for a fictitious example. For a practical application it is recommended to distribute the calculation over several sheets in the table calculation program by supplementing this with explaining text. Furthermore, it is also recommended to check the complex geometry of the schemes as shown in figures 1 and 2 after input of the parameters by a plot.
Ein Konzept für den Traglastnachweis gurtgelagerter doppeltsymmetrischer I‐Träger unter Berücksichtigung der Profilverformung
Authors: Geldmacher Georg , Lange Jörg 
Published: December 2010

AbstractBiegeträger aus I‐Profilen werden aus verschiedenen Gründen ohne Auflagersteifen, also nur an den Gurten gelagert, ausgeführt. Dabei wird die Stabilität gegen das Biegedrillknicken dieser Träger durch Profilverformung in den Auflagerbereichen vermindert, was die gängigen Nachweisformeln und Hilfsmittel in der Regel nicht berücksichtigen. In diesem Aufsatz werden die Ergebnisse einer Dissertation vorgestellt, in der durch analytische Betrachtungen ein Ersatzmodell zur Ermittlung der Verzweigungslast abgeleitet wurde. Durch experimentelle und numerische Traglastuntersuchungen wurden Traglastkurven entwickelt, so dass ein praxisnahes Nachweiskonzept für gurtgelagerte Träger vorgestellt werden kann.A model for the determination of the ultimate load of doublesymmetric I‐shaped beams on seats considering distortional effects. For several reasons, I‐shaped beams are built without stiffeners at the bearings, and because of this they are seated on one flange only. The stability against lateral torsional buckling of these beams is therefore reduced by distortional effects that occur close to the bearings, but this is normally not taken into account by the common design‐formulae and guidelines. This article presents the results of a doctoral thesis where an analogous model for the determination of buckling‐loads has been derived. By experimental and numerical investigations buckling curves for the determination of ultimate loads have been developed, in order to provide a design concept for beams on seats.
Crystal Structure of Iron(II) Acetate
Authors: Weber Birgit , Betz Richard , Bauer Wolfgang , Schlamp Stephan 
Published: December 2010

AbstractIn this paper the X‐ray structure and magnetic properties of iron(II) acetate – starting material for the synthesis of a wide range of iron complexes – are presented. The compound crystallises in the space group Pbcn and was identified as 2D coordination polymer consisting of iron atoms and acetate moieties with all the iron atoms hexacoordinate and different coordination modes for the acetate moieties. Additional hydrogen bond contacts lead to a porous coordination polymer with 1D channels in the size of mesopores. Temperature dependent magnetic measurements confirm that the complex is a high‐spin compound in the entire temperature range investigated with a room temperature magnetic moment of 5.4 μB. Field‐dependent magnetisation measurements reveal a slightly sigmoidal curve progression typical for metamagnetism.