bluuebunny/crossref_metadata_2025_split huggingface dataset:
New data on the magnetostratigraphy of the Jurassic–Cretaceous boundary interval, Nordvik Peninsula (northern East Siberia)
Authors: Bragin V.Yu. , Dzyuba O.S. , Kazansky A.Yu. , Shurygin B.N. 
Published: March 2013

AbstractThe results of this study were used to identify a reversed polarity magnetozone, referred to as M17r, in Berriasian sections of the Nordvik Peninsula (northern East Siberia) within the normal polarity magnetozone (M18n) from previous studies. The new magnetozone embraces the Volgian–Ryazanian boundary (Chetaites chetae/C. sibiricus zonal boundary). It was also found that the former magnetozone M17r at Nordvik, which includes the C. sibiricus/Hectoroceras kochi zonal boundary should correspond to magnetozone M16r. Using magnetostratigraphic and biostratigraphic criteria proves that the Boreal C. sibiricus Zone is correlated with at least the major part of the Tethyan Tirnovella occitanica Zone, and the Boreal H. kochi Zone is correlated with the lower part of the Malbosiceras paramimounum Subzone of the Tethyan Fauriella boissieri Zone.
Volume displacement effects during bubble entrainment in a travelling vortex ring
Authors: Cihonski Andrew J. , Finn Justin R. , Apte Sourabh V. 
Published: March 2013

AbstractWhen a few bubbles are entrained in a travelling vortex ring, it has been shown that, even at extremely low volume loadings, their presence can significantly affect the structure of the vortex core (Sridhar & Katz, J. Fluid Mech., vol. 397, 1999, pp. 171–202). A typical Euler–Lagrange point-particle model with two-way coupling for this dilute system, wherein the bubbles are assumed subgrid and momentum point sources are used to model their effect on the flow, is shown to be unable to capture accurately the experimental trends of bubble settling location, bubble escape and vortex distortion for a range of bubble parameters and vortex strengths. The bubbles experience significant amounts of drag, lift, added mass, pressure and gravity forces. However, these forces are in balance with each other as the bubbles reach a mean settling location away from the vortex core. The reaction force on the fluid due to the net summation of these forces alone is thus very small and is unable to affect the vortex core. By accounting for fluid volume displacement due to bubble motion, experimental trends on vortex distortion and bubble settling location are captured accurately. The fluid displacement effects are studied by computing various contributions to an effective volume displacement force and are found to be important even at low volume loadings. As the bubble size and hence bubble Reynolds number increase, the bubbles settle further away from the vortex centre and have strong potential for vortex distortion. The net volume displacement force depends on the radial pressure force, the radial settling location of the bubble, as well as the vortex Reynolds number. The resultant of the volume displacement force is found to be roughly at $4{5}^{\circ } $ with the vortex travel direction, resulting in wakes directed towards the vortex centre. Finally, a simple modification to the standard point-particle two-way coupling approach is developed wherein the interphase reaction source terms are consistently altered to account for the fluid displacement effects and reactions due to bubble accelerations.
Large-eddy simulation of three-dimensional dunes in a steady, unidirectional flow. Part 1. Turbulence statistics
Authors: Omidyeganeh Mohammad , Piomelli Ugo 
Published: March 2013

AbstractWe performed large-eddy simulations of flow over a series of three-dimensional dunes at laboratory scale (Reynolds number based on the average channel depth and streamwise velocity was 18 900) using the Lagrangian dynamic eddy-viscosity subgrid-scale model. The bedform three-dimensionality was imposed by shifting a standard two-dimensional dune shape in the streamwise direction according to a sine wave. The statistics of the flow are discussed in 10 cases with in-phase and staggered crestlines, different deformation amplitudes and wavelengths. The results are validated qualitatively against experiments. The three-dimensional separation of flow at the crestline alters the distribution of wall pressure, which in turn may cause secondary flow across the stream, which directs low-momentum fluid, near the bed, toward the lobe (the most downstream point on the crestline) and high-momentum fluid, near the top surface, toward the saddle (the most upstream point on the crestline). The mean flow is characterized by a pair of counter-rotating streamwise vortices, with core radius of the order of the flow depth. However, for wavelengths smaller than the flow depth, the secondary flow exists only near the bed and the mean flow away from the bed resembles the two-dimensional case. Staggering the crestlines alters the secondary motion; the fastest flow occurs between the lobe and the saddle planes, and two pairs of streamwise vortices appear (a strong one, centred about the lobe, and a weaker one, coming from the previous dune, centred around the saddle). The distribution of the wall stress and the focal points of separation and attachment on the bed are discussed. The sensitivity of the average reattachment length, depends on the induced secondary flow, the streamwise and spanwise components of the channel resistance (the skin friction and the form drag), and the contribution of the form drag to the total resistance are also studied. Three-dimensionality of the bed increases the drag in the channel; the form drag contributes more than in the two-dimensional case to the resistance, except for the staggered-crest case. Turbulent-kinetic energy is increased in the separated shear layer by the introduction of three-dimensionality, but its value normalized by the plane-averaged wall stress is lower than in the corresponding two-dimensional dunes. The upward flow on the stoss side and higher deceleration of flow on the lee side over the lobe plane lift and broaden the separated shear layer, respectively, affecting the turbulent kinetic energy.
Rapid gravitational adjustment of horizontal shear flows
Authors: White Brian L. , Helfrich Karl R. 
Published: March 2013

AbstractThe evolution of a horizontal shear layer in the presence of a horizontal density gradient is explored by three-dimensional numerical simulations. These flows exhibit characteristics of both free shear flows and gravity currents, but have complex dynamics due to strong interactions between the turbulent features of each. Vertical vortices produced by horizontal shear are tilted and stretched by the gravitational adjustment, rapidly enhancing vorticity. Shear intensification at frontal convergences produces high-wavenumber vertical vorticity and the slumping of the density interface produces horizontal Kelvin–Helmholtz vortices typical of a gravity current. The interaction between these instabilities promotes a rapid transition to three-dimensional turbulence. The flow development depends on the relative time scales of shear instability and gravitational adjustment, described by a parameter $\gamma $ (where the limits $\gamma \rightarrow \infty $ and $\gamma \rightarrow 0$ represent a pure gravity current and a pure mixing layer, respectively). The growth rate of three-dimensional instability and the mixing increase for smaller $\gamma $. When $\gamma $ is sufficiently small, there are two distinct regimes: an early period of during which the interface grows rapidly, followed by horizontal diffusive growth. Numerical results are consistent with field observations of tidal separation flows in the Haro Strait (Farmer, Pawlowicz & Jiang, Dyn. Atmos. Oceans., vol. 36, 2002, pp. 43–58), including the magnitude of downwelling vertical currents, horizontal scales of surface vortex features and mixing rate.
Off-plane motion of a prolate capsule in shear flow
Authors: Dupont C. , Salsac A.-V. , Barthès-Biesel D. 
Published: March 2013

AbstractThe objective of this study is to investigate the motion of an ellipsoidal capsule in a simple shear flow when its revolution axis is initially placed off the shear plane. We consider prolate capsules with an aspect ratio of two or three enclosed by a membrane, which is either strain-hardening or strain-softening. We seek the equilibrium motion of the capsule as we increase the capillary number$\mathit{Ca}$, which measures the ratio between the viscous and elastic forces. The three-dimensional fluid–structure interaction problem is solved numerically by coupling a boundary integral method (for the internal and external flows) with a finite element method (for the wall deformation). For any initial inclination with the flow vorticity axis, a given capsule converges towards a unique equilibrium configuration which depends on$\mathit{Ca}$. At low capillary number, the stable equilibrium motion is the rolling regime: the capsule aligns its long axis with the vorticity axis, while the membrane tank-treads. As$\mathit{Ca}$increases, the capsule takes a complex wobbling motion at equilibrium, precessing around the vorticity axis. As$\mathit{Ca}$is further increased, the capsule long axis oscillates about the shear plane, while the membrane rotates around a capsule cross-section that also oscillates over time (oscillating–swinging regime). The amplitude of the oscillations about the shear plane decreases as$\mathit{Ca}$increases and the capsule finally takes a swinging motion in the shear plane. It is found that the transitions from rolling to wobbling and from wobbling to oscillating–swinging depend on the mean energy stored in the membrane.
Visualization of the Ludford column
Authors: Andreev Oleg , Kolesnikov Yurii , Thess André 
Published: March 2013

AbstractWhen a liquid metal flows around a truncated cylinder in the presence of a magnetic field which is parallel to the axis of the cylinder, a stagnant region develops above the cylinder. We call this region a Ludford column. The Ludford column represents the magnetohydrodynamics (MHD) analogue of the well-known Taylor columns in rotating flows. Whereas Taylor columns can be easily visualized using dye, the visualization of Ludford columns has remained elusive up to now because liquid metals are opaque. We demonstrate that this fundamental limitation of experimental MHD can be overcome by using a superconducting 5 T magnet. This facility permits us to perform MHD experiments in which the opaque liquid metals are replaced with a transparent electrolyte while maintaining the key MHD effects. We report results of a series of flow experiments in which an aqueous solution of sulphuric acid flows around a bar with square cross-section (which for simplicity shall be referred to as a cylinder). We vary the Reynolds number in the range$5\lt Re\lt 100$and the Hartmann number in the range$0\lt Ha\lt 14$. The experimental procedure involves flow visualizations using tracer particles as well as velocity measurements using particle image velocimetry (PIV). Our experiments provide direct access to the Ludford column for the first time and reveal the spatial structure of this basic feature of MHD flows.
Purba Pakistan Zindabad: Bengali Visions of Pakistan, 1940–1947
Authors: BOSE NEILESH 
Published: March 2013

AbstractThis paper details the history of the concept of Pakistan as debated by Bengali intellectuals and literary critics from 1940–1947. Historians of late colonial South Asia and analysts of Pakistan have focused on the Punjab along with colonial Indian ‘Muslim minority’ provinces and their spokesmen like Muhammed Ali Jinnah, to the exclusion of the cultural and intellectual aspects of Bengali conceptions of the Pakistan idea. When Bengal has come into focus, the spotlight has centred on politicians like Fazlul Huq or Hassan Shahid Suhrawardy. This paper aims to provide a corrective to this lacuna by analyzing Bengali Muslim conceptualizations of the idea of Pakistan. Bengali Muslim thinkers, such as Abul Mansur Ahmed, Abul Kalam Shamsuddin, and Farrukh Ahmed, blended concepts of Pakistan inside locally grounded histories of the Bengali language and literature and worked within disciplines of geography and political economy. Many Bengali Muslim writers from 1940 to 1947 creatively integrated concepts of Pakistan in poetry, updating an older Bengali literary tradition begun in earlier generations. Through a discussion of the social history of its emergence along with the role of geography, political thought, and poetry, this paper discusses the significance of ‘Pak-Bangla’ cultural nationalism within late colonial South Asian history.
A Marginalized Voice in the History of ‘Hindi’
Authors: KUMAR AISHWARJ 
Published: March 2013

AbstractThis paper examines the history of ‘Hindi’1as a modern Indian language in Bihar between 1850 and 1900. It looks beyond the North-Western Provinces, hitherto the focus of most studies of Hindi, and issues that were important here but not in Bihar like, for example, the ‘Hindi’-Urdu conflict. Instead, it looks at how the ways in which the history of ‘Hindi’ unfolded in Bihar and was distinct from that in other parts of North India. It demonstrates how the regional languages of Bihar were more crucial to the development of ‘Hindi’ in this region than standardized ‘Hindi’, at least until the early twentieth century. A prime focus in this paper is Sir George Abraham Grierson who postulated the theory of an independent ‘Bihari’ language and collected materials to support it. These materials reflect the continuing popularity of Bihari cultural traditions throughout the nineteenth century despite the avowed support for a standardized ‘Hindi’ by the colonial government and the intelligentsia of Bihar. They add a dimension to the historical development of ‘Hindi’ that was distinctive to Bihar. Focussing on this, this paper stresses the part played in the history of ‘Hindi’ by an agent whose voice was marginalized and later ignored or suppressed in canonical accounts of its development as a modern Indian language.
Putting ‘The Grave’ into Social Policy: State Support for Funerals in Contemporary UK Society
Authors: WOODTHORPE KATE , RUMBLE HANNAH , VALENTINE CHRISTINE 
Published: March 2013

AbstractThere is a long tradition in the assessment of UK social policy of examining benefit entitlement and access, yet little attention has been paid towards benefits associated with bereavement and, in particular, what happens for those people who cannot afford a funeral and require state assistance. This is despite the fact that every year approximately one in ten deaths in the UK results in a claim to the Department for Work and Pensions’ Funeral Payment for a contribution towards funeral costs. Beyond a paper in this journal over ten years ago, no research has been conducted into how the scheme is administered and what happens to those people who claim. Drawing on a study with both successful and unsuccessful Funeral Payment claimants, funeral directors and key stakeholders, this paper evaluates the Funeral Payment in terms of eligibility and entitlement, and timing and cost. It argues that closer attention needs to be paid to the issue of financial support for funerals to avoid the evolution of an unwieldy system at a time when the UK death rate is predicted to rise owing to the ageing of the population.
Analytical perspectives on performance-based management: an outline of theoretical assumptions in the existing literature
Authors: Wadmann Sarah , Johansen Sarah , Lind Ane , Okkels Birk Hans , Hoeyer Klaus 
Published: March 2013

AbstractPerformance-based management (PBM) has become a dominant form of governance in health care and there is a need for careful assessment of its function and effects. This article contains a cross-disciplinary literature synthesis of current studies of PBM. Literature was retrieved by database searches and categorized according to analytical differences and similarities concerning (1) purpose and (2) governance mechanism of PBM. The literature could be grouped into three approaches to the study of PBM, which we termed: the ‘functionalist’, the ‘interpretive’ and the ‘post-modern’ perspective. In the functionalist perspective, PBM is perceived as a management tool aimed at improving health care services by means of market-based mechanisms. In the interpretive perspective, the adoption of PBM is understood as consequence of institutional and individual agents striving for public legitimacy. In the post-modern perspective, PBM is analysed as a form of governance, which has become so ingrained in Western culture that health care professionals internalize and understand their own behaviour and goals according to the values expressed in these governance systems. The recognition of differences in analytical perspectives allows appreciation of otherwise implicit assumptions and potential implications of PBM. Reflections on such differences are important to ensure vigilant appropriation of shifting management tools in health quality governance.
THE POTENTIAL HIERARCHY OF SETS
Authors: LINNEBO ØYSTEIN 
Published: March 2013

AbstractSome reasons to regard the cumulative hierarchy of sets as potential rather than actual are discussed. Motivated by this, a modal set theory is developed which encapsulates this potentialist conception. The resulting theory is equi-interpretable with Zermelo Fraenkel set theory but sheds new light on the set-theoretic paradoxes and the foundations of set theory.
The unexpected discovery of a novel low-oxygen-activated locus for the anoxic persistence of Burkholderia cenocepacia
Authors: Sass Andrea M , Schmerk Crystal , Agnoli Kirsty , Norville Phillip J , Eberl Leo , Valvano Miguel A , Mahenthiralingam Eshwar 
Published: March 2013

Abstract
Burkholderia cenocepacia is a Gram-negative aerobic bacterium that belongs to a group of opportunistic pathogens displaying diverse environmental and pathogenic lifestyles. B. cenocepacia is known for its ability to cause lung infections in people with cystic fibrosis and it possesses a large 8 Mb multireplicon genome encoding a wide array of pathogenicity and fitness genes. Transcriptomic profiling across nine growth conditions was performed to identify the global gene expression changes made when B. cenocepacia changes niches from an environmental lifestyle to infection. In comparison to exponential growth, the results demonstrated that B. cenocepacia changes expression of over one-quarter of its genome during conditions of growth arrest, stationary phase and surprisingly, under reduced oxygen concentrations (6% instead of 20.9% normal atmospheric conditions). Multiple virulence factors are upregulated during these growth arrest conditions. A unique discovery from the comparative expression analysis was the identification of a distinct, co-regulated 50-gene cluster that was significantly upregulated during growth under low oxygen conditions. This gene cluster was designated the low-oxygen-activated (lxa) locus and encodes six universal stress proteins and proteins predicted to be involved in metabolism, transport, electron transfer and regulation. Deletion of the lxa locus resulted in B. cenocepacia mutants with aerobic growth deficiencies in minimal medium and compromised viability after prolonged incubation in the absence of oxygen. In summary, transcriptomic profiling of B. cenocepacia revealed an unexpected ability of aerobic Burkholderia to persist in the absence of oxygen and identified the novel lxa locus as key determinant of this important ecophysiological trait.
Acetate oxidation by syntrophic association between Geobacter sulfurreducens and a hydrogen-utilizing exoelectrogen
Authors: Kimura Zen-ichiro , Okabe Satoshi 
Published: March 2013

Abstract
Anodic microbial communities in acetate-fed microbial fuel cells (MFCs) were analyzed using stable-isotope probing of 16S rRNA genes followed by denaturing gradient gel electrophoresis. The results revealed that Geobacter sulfurreducens and Hydrogenophaga sp. predominated in the anodic biofilm. Although the predominance of Geobacter sp. as acetoclastic exoelectrogens in acetate-fed MFC systems has been often reported, the ecophysiological role of Hydrogenophaga sp. is unknown. Therefore, we isolated and characterized a bacterium closely related to Hydrogenophaga sp. (designated strain AR20). The newly isolated strain AR20 could use molecular hydrogen (H2), but not acetate, with carbon electrode as the electron acceptor, indicating that the strain AR20 was a hydrogenotrophic exoelectrogen. This evidence raises a hypothesis that acetate was oxidized by G. sulfurreducens in syntrophic cooperation with the strain AR20 as a hydrogen-consuming partner in the acetate-fed MFC. To prove this hypothesis, G. sulfurreducens strain PCA was cocultivated with the strain AR20 in the acetate-fed MFC without any dissolved electron acceptors. In the coculture MFC of G. sulfurreducens and strain AR20, current generation and acetate degradation were the highest, and the growth of strain AR20 was observed. No current generation, acetate degradation and cell growth occurred in the strain AR20 pure culture MFC. These results show for the first time that G. sulfurreducens can oxidize acetate in syntrophic cooperation with the isolated Hydrogenophaga sp. strain AR20, with electrode as the electron acceptor.
Severe plant invasions can increase mycorrhizal fungal abundance and diversity
Authors: Lekberg Ylva , Gibbons Sean M , Rosendahl Søren , Ramsey Philip W 
Published: March 2013

Abstract
Invasions by non-native plants can alter ecosystem functions and reduce native plant diversity, but relatively little is known about their effect on belowground microbial communities. We show that invasions by knapweed (Centaurea stoebe) and leafy spurge (Euphorbia esula, hereafter spurge)—but not cheatgrass (Bromus tectorum)—support a higher abundance and diversity of symbiotic arbuscular mycorrhizal fungi (AMF) than multi-species native plant communities. The higher AMF richness associated with knapweed and spurge is unlikely due to a co-invasion by AMF, because a separate sampling showed that individual native forbs hosted a similar AMF abundance and richness as exotic forbs. Native grasses associated with fewer AMF taxa, which could explain the reduced AMF richness in native, grass-dominated communities. The three invasive plant species harbored distinct AMF communities, and analyses of co-occurring native and invasive plants indicate that differences were partly driven by the invasive plants and were not the result of pre-invasion conditions. Our results suggest that invasions by mycotrophic plants that replace poorer hosts can increase AMF abundance and richness. The high AMF richness in monodominant plant invasions also indicates that the proposed positive relationship between above and belowground diversity is not always strong. Finally, the disparate responses among exotic plants and consistent results between grasses and forbs suggest that AMF respond more to plant functional group than plant provenance.
Compensating scheme for limiting secondary arc current of 1000 kV ultra‐high voltage long parallel lines
Authors: Xu Zhenyu , Yan Xiaoqing , Zhang Xu , Wen An 
Published: March 2013

Optimal compensating schemes for the secondary arc current limiting using neutral reactor for 1000 kV ultra‐high voltage long parallel transmission lines in maintenance state are investigated in this study. For maintenance safety, the line in maintenance must be electrically isolated from the line in normal operation state. The influential factors such as transposition degree, arc resistance, load current and fault location are studied. Finally, the sensitivity of secondary arc current against the variation of neutral reactor value is investigated. Real‐time digital simulator (RTDS) simulation tests have been carried out to verify the correctness and validity of the analysis presented in this study.