bluuebunny/crossref_metadata_2025_split huggingface dataset:
Groundwater Hydrology and Stable Isotope Analysis of an Open‐System Pingo in Northwestern Mongolia
Authors: Yoshikawa Kenji , Sharkhuu Natsagdorj , Sharkhuu Anarmaa 
Published: April 2013

ABSTRACTThe first record of stable isotopes through a complete sequence of ice within an open‐system pingo in northwestern Mongolia indicates a complex history of ice formation and pingo growth. A continuous section of ice 32 m long was cored through the centre of Mongot Pingo, and ice cores were analysed for stable isotopes and chemical composition. Two different stable isotope patterns in separate ice sections are identified: 1 open‐system freezing and 2 semi‐closed system (or closed system) freezing. Discharge measurements were observed in 2009 after drilling through pingo ice to artesian sub‐pingo water and compared with data collected from the same pingo in 1968. Approximately 850–950 m3 of sub‐pingo water discharged within 120 h during drilling in both 1968 and 2009, a volume equivalent to about 10 per cent of the current pingo ice volume. Between 1968 and 2009, permafrost (pingo ice) thickened by about 60 cm (1.46 cm per year), from 32.0 to 32.6 m, due to the decrease in sub‐pingo artesian water pressure after water release from the 1968 drilling. The major mechanism for ice formation at this pingo is groundwater artesian pressure, though not continuously. Four major stages of pingo growth after 8790 yr BP are inferred. Copyright © 2013 John Wiley & Sons, Ltd.
Local N environment in the dilute nitrides Ga(N,P), Ga(N,As), and Ga(N,Sb)
Authors: Güngerich M. , Sander T. , Heiliger C. , Czerner M. , Klar P. J. 
Published: April 2013

AbstractWe study the hydrostatic pressure response of the local environment of N in the ternary dilute nitride alloys, i.e., GaN0.021P0.979, GaN0.085As0.915, and GaN0.015Sb0.985 by Raman spectroscopy and density functional theory (DFT) of the local vibrational mode (LVM) of N. In all samples studied N is surrounded by four Ga atoms. To a first approximation the N vibrational mode can be described by the N‐atom vibrating in a rigid cage formed by the four Ga nearest neighbors. However, our careful experimental and theoretical analysis reveals that, despite the same nearest neighbor environment of N in the three dilute nitride hosts under study, distinct differences between the pressure dependence of the corresponding local N‐vibrational modes remain. These differences are rather due to the different chemical identities of the anions of the host than due to differences in N content and strain. Furthermore, it is shown that the LVM of N in the three alloys behaves differently under hydrostatic pressure than the optical extended phonon modes of zincblende GaN.
Iron in magnesium oxide at high pressures: a first principles theoretical investigation
Authors: Larico Rolando , Justo João F. , Assali Lucy V. C. 
Published: April 2013

AbstractAn iron‐related high‐to‐low spin transition in ferropericlase, (MgFe)O, has been identified at high pressures. Since this is one of the major minerals of Earth's lower mantle, and the respective transition occurs at mantle pressure and temperature conditions, this transition could have important geophysical implications. Here, we performed a theoretical investigation on the properties of a substitutional iron impurity in magnesium oxide, (MgO: FeMg), and the respective changes with increasing isotropic pressure. This microscopic configuration represents the limiting case of absent iron–iron interactions in ferropericlase, which allowed us to explore the magnetic properties of the isolated iron center. The calculations were performed using the WIEN2k package, within the density functional theory plus a Hubbard potential correction. The structural, electronic, and magnetic properties of those centers at several charge states and pressures (up to 100 GPa) were compared. We also discussed the possibility of an iron‐related intermediate spin (IS) state in ferropericlase. Our results on the quadrupole splitting indicate that such IS state should have properties similar to the respective spin state in ferrosilicate perovskite.
Pressure effect on the anomalies of the electric and magnetic properties of diluted magnetic semiconductor CdGeAs2 doped with Mn
Authors: Arslanov Rasul , Mollaev Akhmedbek , Kamilov Ibragimkhan , Arslanov Temirlan , Zalibekov Ullubiy , Novotortsev Vladimir , Marenkin Sergey , Troyanchuk Igor 
Published: April 2013

AbstractThis paper presents the results of the high pressure (up to 7 GPa) effect on the diluted magnetic semiconductor (DMS) CdGeAs2: Mn with x = 0.06–030. The normal R0 and anomalous RS portions of the Hall coefficients have been determined from the magnetic field dependencies of the Hall resistance. Pressure ranges related to the anomalies of the electric and magnetic properties have been found and studied. It has been shown that structural phase transitions are observed on the baric dependencies and their transition point shifts depending on the Mn content.The first‐ and second‐order phase transitions (ferromagnetic–paramagnetic and paramagnetic–paramagnetic) have been identified on the magnetic susceptibility dependence in the pressure areas of P > 1.3 GPa and P ≈ 4 GPa which can be explained by occurrence of the second phase of MnAs in the basic structure of CdGeAs2. Positive (PMR) and negative magnetoresistance (NMR) induced by high pressure also takes place in all the compounds studied.
High‐pressure study of the thermoelectric properties of various oxides (ZnO, Ti2O3, FexOy) and FeAs‐based compounds
Authors: Morozova Natalia V. , Khmeleva Iuliia A. , Ovsyannikov Sergey V. , Karkin Alexander E. , Shchennikov Vladimir V. 
Published: April 2013

AbstractIn the present work the results of investigation of the thermoelectric (TE) properties of some Zn, Ti and Fe oxides and FeAs‐based compounds under compression up to 20 GPa are reported. The data obtained of thermoelectric power S dependence on pressure P for the materials under consideration revealed some new features of the electron properties of both initial and high‐pressure phases (RS‐ZnO). For FeAs‐based compounds the complex behavior of S on P was found depending probably on the contribution of d‐states in the conductivity. The decreasing of the semiconductors gap has been established under pressure for the narrow‐gap semiconductors Ti2O3 and Fe2O3; the sign inversion being observed in the first oxide pointing to the change of dominant type of the charge carries. Pressure cycling of Fe2O3 led to a nanostructured state with the modified electronic properties. TE data at high pressure allowed the electronic properties of the materials with the different type of the electron structure to be detailed.
Rashba spin–orbit interaction effect on multiphoton optical transitions in a quantum dot
Authors: Kumar Manoj , Lahon Siddhartha , Kumar Jha Pradip , Mohan Man 
Published: April 2013

AbstractWe demonstrate in this work the effect of Rashba spin–orbit interaction (SOI) on multiphoton optical transitions of a quantum dot (QD) in the presence of a terahertz (THz) laser field and external static magnetic field. This combination is solved by accurate nonperturbative Floquet theory. Investigations are made for the optical response of intraband transitions between the various states of the conduction band with spin flipping. It is found that spin‐flip transitions and corresponding multiphoton transitions are strongly affected by Rashba spin orbit coupling and THz laser fields. This aspect will enhance the ongoing efforts for making ultrasensitive optospintronics devices.
Magnetic phase transition and relaxation effects in lithium iron phosphate
Authors: Sundarayya Y. , Mishra Ajay Kumar , Brand Richard A. , Hahn Horst , Bansal C. , Sunandana C. S. 
Published: April 2013

AbstractWe report the observation of a para‐antiferromagnetic transition at ∼50 K in lithium iron phosphate, LiFePO4 through DC magnetic susceptibility and Mössbauer spectroscopy. The ferrous ion Fe2+ (3d6, 5D) in LiFePO4 exhibits relaxation effects with a relaxation frequency ∼1.076 × 107 s−1 at 300 K. The temperature dependence of the frequency suggests the origin of the relaxation is of the spin–lattice type. The quadrupole splitting at low temperatures indicates that the excited orbital states mix strongly to the orbital doublet ground state via spin–orbit coupling. Modified molecular field model analysis yields a saturation value for hyperfine field Bhf ∼ 125 kOe. The anomaly in susceptibility and Mössbauer parameters below 27 K may be ascribed to a contribution of orbital angular momentum. The high value of the asymmetry parameter η (∼0.8) of the electric field gradient obtained in the antiferromagnetic regime indicates a strongly distorted octahedral oxygen neighborhood for the ferrous sites.
WATER TEMPERATURE PATTERNS BELOW LARGE GROUNDWATER SPRINGS: MANAGEMENT IMPLICATIONS FOR COHO SALMON IN THE SHASTA RIVER, CALIFORNIA
Authors: Nichols A. L. , Willis A. D. , Jeffres C. A. , Deas M. L. 
Published: April 2013

ABSTRACTElevated stream temperature is a primary factor limiting the coho salmon (Oncorhynchus kisutch) population in California's Shasta River Basin. Understanding the mechanisms driving spatial and temporal trends in water temperature throughout the Shasta River is critical to prioritising river restoration efforts aimed at protecting this threatened species. During the summer, the majority of streamflow in the Shasta River comes from large‐volume, cold‐water springs at the head of the tributary Big Springs Creek. In this study, we evaluated the initial character of this spring water, as well as the downstream fate and transport of these groundwater inflows during July and August 2008. Our results indicated that Big Springs Creek paradoxically provided both cool and warm waters to the Shasta River. During this period, cool groundwater inflows heated rapidly in the downstream direction in response to thermal loads from incoming solar radiation. During the night time, groundwater inflows did not appreciably heat in transit through Big Springs Creek. These diurnally varying water temperature conditions were inherited by the Shasta River, producing longitudinal temperature patterns that were out of phase with ambient meteorological conditions up to 23 km downstream. Findings from this study suggest that large, constant temperature spring sources and spring‐fed rivers impart unique stream temperature patterns on downstream river reaches that can determine reach‐scale habitat suitability for cold‐water fishes such as coho salmon. Recognising and quantifying the spatiotemporal patterns of water temperature downstream from large spring inflows can help identify and prioritize river restoration actions in locations where temperature patterns will allow rearing of cold‐water fishes. Copyright © 2013 John Wiley & Sons, Ltd.
Graphene in Light: Design, Synthesis and Applications of Photo‐active Graphene and Graphene‐Like Materials
Authors: Wang Hang‐Xing , Wang Qiang , Zhou Kai‐Ge , Zhang Hao‐Li 
Published: April 2013

AbstractGraphene functionalized with photo‐active units has become one of the most exciting topics of research in the last few years, which remarkably sustains and expands the graphene boom. The rise of photo‐active graphene in photonics and optoelectronics is evidenced by a spate of recent reports on topics ranging from photodetectors, photovoltaics, and optoelectronics to photocatalysis. For these applications, the fabrication of photo‐active graphene through appropriate chemical functionalization strategies is essential as pristine graphene has zero bandgap and only weak absorption of photons. Written from the chemists' point of view, up‐to‐date chemical functionalization of graphene with various small organic molecules, conjugated polymers, rare‐earth components, and inorganic semiconductors is reviewed. Particular attention is paid to the development of graphene functionalized with light‐harvesting moieties, including materials synthesis, characterization, energy/charge‐transfer processes, and applications in photovoltaics. Challenges currently faced by researchers and future perspectives in this field are also discussed.
Interdigitated Multicolored Bioink Micropatterns by Multiplexed Polymer Pen Lithography
Authors: Brinkmann Falko , Hirtz Michael , Greiner Alexandra M. , Weschenfelder Markus , Waterkotte Björn , Bastmeyer Martin , Fuchs Harald 
Published: April 2013

AbstractMultiplexing, i.e., the application and integration of more than one ink in an interdigitated microscale pattern, is still a challenge for microcontact printing (μCP) and similar techniques. On the other hand there is a strong demand for interdigitated patterns of more than one protein on subcellular to cellular length scales in the lower micrometer range in biological experiments. Here, a new integrative approach is presented for the fabrication of bioactive microarrays and complex multi‐ink patterns by polymer pen lithography (PPL). By taking advantage of the strength of microcontact printing (μCP) combined with the spatial control and capability of precise repetition of PPL in an innovative way, a new inking and writing strategy is introduced for PPL that enables true multiplexing within each repetitive subpattern. Furthermore, a specific ink/substrate platform is demonstrated that can be used to immobilize functional proteins and other bioactive compounds over a biotin–streptavidin approach. This patterning strategy aims specifically at application by cell biologists and biochemists addressing a wide range of relevant pattern sizes, easy pattern generation and adjustment, the use of only biofriendly, nontoxic chemicals, and mild processing conditions during the patterning steps. The retained bioactivity of the fabricated cm2 area filling multiprotein patterns is demonstrated by showing the interaction of fibroblasts and neurons with multiplexed structures of fibronectin and laminin or laminin and ephrin, respectively.
XRD In Situ Observation of Carbothermic Reduction of Magnetite Powder in Microwave Electric and Magnetic Fields
Authors: Sabelström Nils , Hayashi Miyuki , Yokoyama Yuki , Watanabe Takashi , Nagata Kazuhiro 
Published: April 2013

AbstractRecently, microwave energy is expected to be a heat source for high temperature process aiming at CO2 reduction and energy conservation owing to the possibility of volumetric and selective heating. In order to examine the applicability of microwave heating to ironmaking, a basic research may be required with respect to the heating mechanism of raw and product materials of ironmaking as well as the carbothermic reduction mechanism of iron ore. To carry out this research, the authors have developed a single mode microwave furnace combined with X‐ray diffraction analysis. By using this, the authors have elucidated the effects of electric and magnetic fields of microwave on carbothermic reduction of magnetite powders, and have observed the selective heating of materials. It has been found that the Fe3O4–C mixed powders are more rapidly heated by the magnetic field than by the electric field just after the onset of heating. The rapid heating owing to the magnetic field is associated with the magnetic loss of Fe3O4 powders. With respect to the magnetic field heating, once the temperature increases up to 800–1000°C, the temperature does not increase and the reduction hardly progresses, which may stem from the decrement in the microwave absorption of the sample. The main heat source is C at this stage. On the other hand, temperature monotonically increases up to around 1000°C and reaction gradually progresses for the electric field heating. It is considered that the main energy absorber is C at the beginning, and then is possibly changed to FeO at elevated temperatures.
Anwendung des Innsbrucker Komponentenmodells bei der Optimierung eines modernen Deckenschaltischs
Authors: Fink J. , Rubin D. , Hollmann K. 
Published: April 2013

AbstractDie Überarbeitung einer momententragfähigen Riegel‐Stützen‐Verbindung eines Rüstturms erforderte neben der konstruktiven Ausarbeitung eines möglichst bedienungsfreundlichen Anschlusses eine exakte statische Untersuchung dessen Tragverhaltens. Hierzu kam das Innsbrucker Komponentenmodell zum Einsatz, anhand dessen alle benötigten Optimierungsmaßnahmen nachrechenbar wurden, um schlußendlich einem völlig neuartigen Rotationskeil‐Anschluß die nötige Steifigkeit und Tragfähigkeit zu verleihen. Im folgenden werden die einzelnen Schritte des Entwicklungsprozesses beschrieben.
Anwendung des Realbrand‐Bemessungskonzeptes bei der Tirol‐Therme Längenfeld
Authors: Huber G. , Aste Ch. , Trauner T. , Mathieu J. , Klein C. 
Published: April 2013

AbstractIm Tiroler Ötztal in Österreich entsteht derzeit unter Nutzung einer natürlichen Heilwasserquelle ein großzügiges Thermenprojekt mit diversen Wasserlandschaften, einem Luxushotel und Parkmöglichkeit für etwa 500 Fahrzeuge. Aus der Forderung einer autofreien Landschaftsgestaltung und dem hoch liegenden Grundwasserspiegel ergab sich die Notwendigkeit einer eingeschossigen Tiefgarage mit einer Dachfläche von ca. 12000 m�. Die hohen Lasten aus der massigen Erdeinschüttung und der für diesen Bereich typischen Schneelast in Kombination mit möglichst großzügigen Parkverhältnissen ohne störende Stützen an den Fahrgassenrändern stellte eine Herausforderung für die Tragwerksplaner dar. Eine Stahl‐Beton‐Verbundkonstruktion stellte sich sowohl in Hinblick auf Ästhetik, Rohbaukosten und Baugeschwindigkeit als Optimum heraus. Dem Wunsch nach einer möglichst wirtschaftlichen Lösung ohne aufwendige Brandschutzmaßnahmen konnte hierbei nur durch eine objektbezogene Realbrandnachweisführung nachgekommen werden. Die Überzeugung der örtlichen Behörden von diesem zeitgemäßen Berechnungsverfahren anstelle der oft unwirtschaftlichen Standardnachweise war dabei von besonderer Bedeutung.
Verglastes Hängedach für die Römertherme in Baden bei Wien
Authors: Schober H. , Gugeler J. 
Published: April 2013

AbstractDurch eine komplett verglaste Überdachung des ehemaligen Außenbeckens der Römertherme in Baden bei Wien wurde eine großzügige, transparente Schwimmhalle als Kernstück eines modernen Kurbades geschaffen.Einfache stählerne Hängebänder im Abstand von 1,50 m spannen frei über knapp 30 m und bilden das minimierte und filigrane Tragwerk des Schwimmhallendaches. Über schrägstehende Baumstützen werden die zugbeanspruchten Hängebänder in die Fassadenrichtung umgelenkt und bilden hier die Fassadenprofile, welche über Spannanker im massiven Kellergeschoß rückverankert sind. So entstand eine äußerst transparente Gebäudehülle mit deutlich ablesbarem Kraftfluß.
Lehrter Bahnhof Berlin ‐ Zustimmung im Einzelfall der Glasanwendungen
Authors: Wellershoff F. , Stief U. 
Published: April 2013

AbstractZur Erlangung der Zustimmung im Einzelfall für die Verglasung des Lehrter Bahnhofs durch das Eisenbahn‐Bundesamt (EBA) wurden zahlreiche Bauteilversuche durchgeführt. In diesem Beitrag wird auf die Besonderheiten der zustimmungspflichtigen Glasbauteile eingegangen. Neben Belastungs‐ und Resttragfähigkeitsversuche wurden qualitätssichernde Maßnahmen für die Anwendung von Structural Glazing Silicon‐Klebstoffen durchgeführt.
Talbrücke Korntal‐Münchingen ‐ innovativer Brückenentwurf als Rohrfachwerk‐Verbundbrücke, Teil 1‐ Entwurf
Authors: Bernhardt K. , Mohr B. , Seifried G. , Angelmaier V. 
Published: April 2013

AbstractDie Rohrfachwerk‐Verbundbrücke Korntal‐Münchingen wird als Beispiel für den modernen Brückenbau in Deutschland vorgestellt, bei dem durch werkstoffübergreifendes Ingenieurdenken innerhalb der Straßenbauverwaltungen, Planungsbüros und Baufirmen innovative Lösungen möglich werden.Der erste Teil des Aufsatzes befaßt sich mit dem Entwurf, im zweiten Teil werden Ausschreibung, Vergabe und Bauausführung behandelt.
Einflußlinien für Ausnutzungsgrade in Stabwerken
Authors: Schade D. 
Published: April 2013

AbstractWenn in Querschnittsnachweisen von Stabwerken Kombinationen von Schnittgrößen eingehen und Einflußlinien zur ungünstigen Anordnung von Verkehrslasten benutzt werden, sind Einflußlinien für Ausnutzungsgrade wie die bisher in einfachen Fällen benutzten Einflußlinien für Kernmomente nützlich.
Der Einfluß von Schweißeigenspannungen und Schweißverformungen auf das Beulverhalten von axialgedrückten Zylinderschalen
Authors: Banke F. , Schmied J. , Schulz U. 
Published: April 2013

AbstractIn Fortsetzung der vielen in Karlsruhe entstandenen Arbeiten zur Frage der Stabilität von Schalen wird im vorliegendem Beitrag auf den Einfluß von Ringschweißnähten auf das Beulverhalten von axialgedrückten Zylinderschalen numerisch und experimentell eingegangen. Bei den numerisch durchgeführten Untersuchungen werden dabei zunächst die beim Schweißen entstehenden Temperaturfelder und die aus ihnen resultierenden Schweißverformungen und Schweißeigenspannungen ermittelt. Nach experimenteller Verifikation der Verformungswerte werden dann für die verschiedenen Schalenschlankheiten und Schweißparameter die Beullasten bestimmt.
Die neuen Regelungen in der europäischen Norm EN 1993‐1‐1 für Stäbe unter Druck und Biegung
Authors: Greiner R. , Lindner J. 
Published: April 2013

AbstractIm Hinblick auf das Erscheinen der kommenden europäischen Stahlbaunorm EN 1993‐1‐1 werden die neuen Regelungen für Stäbe unter Druck und Biegung beschrieben, die Hintergründe für ihre Herleitung erläutert und Zahlenbeispiele zur Verdeutlichung ihrer Anwendung gegeben. Behandelt werden die sogenannten vereinfachten Regelungen mittels Interaktionsgleichungen ähnlich jener der bestehenden DIN 18800 oder der Vornorm des Eurocode 3. Es werden jeweils zwei Nachweisgleichungen für verdrehsteife bzw. verdrehweiche Stäbe vorgegeben, welche auf die Ausweichformen des Biegeknickens bzw. Biegedrillknickens in und aus der Ebene ausgerichtet sind. Die wesentlichen Weiterentwicklungen der "neuen" Regelungen betreffen die Interaktionsfaktoren sowie die Abminderungsfaktoren für Biegedrillknicken. Die Arbeiten gehen auf die Zusammenarbeit in der Technischen Kommission 8 der Europäischen Konvention für Stahlbau (ECCS/EKS) zurück und bewirken in verschiedenen Anwendungsbereichen verbesserte und teils wirtschaftlichere Ergebnisse.
Erweiterung der Traglastuntersuchungen an Stäben unter Druck und Biegung auf einfach‐symmetrische Querschnitte
Authors: Greiner R. , Kaim P. 
Published: April 2013

AbstractAusgehend von der Entwicklung der Bemessungsregeln für Stäbe unter Druck und Biegung für die Endfassung der EN 1993‐1‐1 werden weiterführende Untersuchungen für einfach‐symmetrische Querschnittsformen dargestellt. Sie umfassen Traglastberechnungen für die relevanten Formen des Stabilitätsversagens durch Biegeknicken und Biegedrillknicken für Stäbe mit plastischer sowie elastischer Querschnittstragfähigkeit. Sie beschränken sich auf Druck und einachsige Biegung in der Symmetrieebene sowie auf Einzelstäbe mit gabelgelagerten Enden.Neben den numerischen Untersuchungen wurden Vergleiche mit den Ergebnissen der bestehenden Bemessungsregeln angestellt, welche jedoch für doppelt‐symmetrische Querschnitte hergeleitet worden waren. Das Ergebnis zeigt, daß die Formeln das Tragverhalten trotzdem in großen Bereichen durchaus ausreichend beschreiben, daß es aber auch Teilbereiche mit sehr konservativer Annäherung gibt. Für praktische Zwecke wäre eine Anwendung der bestehenden Formeln auf einfach‐symmetrische Querschnitte mit einigen einfachen Zusatzregeln möglich, bevor gesonderte Regeln direkt für solche Querschnittsformen entwickelt werden.