bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bemerkungen zur Ausnutzung plastischer Querschnitts‐ und Systemreserven
Authors: Hübel H. 
Published: April 2013

AbstractPlastische Tragreserven werden im Stahlbau häufig planmäßig in Anspruch genommen und zumindest auf der Bewertungsseite (Verfahren Elastisch ‐ Plastisch der DIN 18800) oder zusätzlich auch auf der Ermittlungsseite der Beanspruchungen (Verfahren Plastisch ‐ Plastisch) quantitativ berücksichtigt. In diesen Nachweisverfahren lauern jedoch einige Gefahren, die nicht immer leicht zu erkennen sind. Einige davon werden in diesem Beitrag angesprochen.
Negative ions in reactive magnetron sputtering
Authors: Welzel Thomas , Ellmer Klaus 
Published: April 2013

AbstractNegative ions are present in magnetron sputtering if electronegative elements are involved. The majority of the negative ions impinging on transparent conductive oxide (TCO) films during growth is O− produced at the oxidised target surface while it is rather unimportant whether it is bulk oxide or a surface oxide formed in reactive sputtering. O− bombards the film with energies equivalent to the target voltage and by far exceed 100 eV. It is hence apt to cause radiation damage in sensitive TCO films. This is shown by the lateral distribution of the highenergy O− flux in planar magnetron sputtering that exhibits the same pattern imaging the erosion groove as the resistivity of TCO films. This lateral inhomogeneity strongly depends on the erosion groove depth. The emission of O− further depends on the sputtered material, for TiO2 deposition it is much less than for other TCO materials. The emission probability correlates to the secondary electron emission coefficient of the oxide.
Sicher zündende, langzeitstabile Kaltkathode
Authors: Iwicki Jaroslaw , Pongrac Ivan , Gottschalk Patrick , Bauer René , Schlotter Alexander , Flämmich Michael , Bergner Ute 
Published: April 2013

AbstractKaltkathoden werden seit Jahrzenten in verschiedenen Bereichen der Vakuumtechnik verwendet, wo ihre Vorteile trotz magnetischer Streufelder, schlechter Zündcharakteristik im UHV‐Bereich und Langzeitstabilität nicht kritisch oder im Rahmen häufiger Wartungsintervalle praktikabel sind. Selbst dann ist aber oft das Erlöschen der Kaltkathodenentladung im UHV bzw. XHV‐Bereich ein Thema für die Experten.In diesem Artikel wird unter Berücksichtigung der zugrunde liegenden Prozesse und deren Korrelation eine optimierte Kaltkathode vorgestellt. Experimentelle Ergebnisse belegen, dass diese, bei gleichzeitiger Reduzierung des magnetischen Streufeldes auf 1 mT in unmittelbarer Nähe des Vakuummeters, die Bestimmung des Druckes im 10−12 mbar Bereich ermöglicht. Weiterhin konnten die Zündzeiten auf < 60 s bei 1×10−9 mbar reduziert und die Langzeitstabilität des Sensors erheblich verbessert werden.
Evolutionary implications of the distribution and variation of the skeletal muscles of the anuran lymphatic system
Authors: Drewes Robert C. , Hillman Stanley S. , Hedrick Michael S. , Withers Philip C. 
Published: April 2013

AbstractLymphatic return to the circulation in anurans is dependent upon the interaction of a number of skeletal muscles and lung deflation. We define character states and describe variation of these putative lymphatic skeletal muscles: the M. cutaneus pectoris (CP), M. cutaneus dorsi (CD), M. piriformis (P), M. sphincter ani cloacalis (SAC), and the complex of the M. gracilis minor/M. abdominal crenator (GM/AC). We include examination of over 400 specimens of 377 species belonging to 40 of the 42 currently recognized anuran families. Some muscles show limited variation (P) or are clearly linked to phylogeny (CP; CD) and thus have limited value in the determination of form and function. However, the GM/AC and SAC show a high degree of structural variation that appears in taxa across the phylogenetic spectrum. This allows us to make phylogenetically independent determinations of form and function. We define an ancestral state of the GM and conclude that evolution of the GM/AC and SAC has progressed in two directions from this ancestral state: toward either elaboration or reduction. Where present, the character states of both of these muscle groups were observed in all species examined and the number of states correlated within each family as well. The degree of development of the GM/AC and SAC compliance pump system is strongly correlated with previously determined lymph flux rates in a three species test. Our data suggest there may be a relationship between greater elaboration of the GM/AC and SAC system and terrestriality among the Anura.
Evolutionary psychology and consumer behavior: A constructive critique
Authors: Cohen Joel B. , Bernard H. Russell 
Published: April 2013

AbstractWe examine the theoretical basis for the evolutionary narrative common to the target papers by Saad (this issue) and by Griskevicius and Kenrick (this issue) and identify areas of controversy that have sparked debate about evolutionary psychology [EP] among biologists and behavioral ecologists. The two main areas of disagreement are over (1) the role of genetic adaptations resulting from natural selection in ancient times compared to other forces leading to current behavior; and (2) the likelihood that evolution resulted in a set of highly specialized mental modules or information‐processing circuits thought to be instrumental in determining present‐day behavior. We review the EP research discussed by the authors of the target papers as a means of evaluating the evidence in support of the theory and of suggesting future directions of research.
Radial lift on a suspended finite-sized sphere due to fluid inertia for low-Reynolds-number flow through a cylinder
Authors: Bhattacharya Sukalyan , Gurung Dil K. , Navardi Shahin 
Published: April 2013

AbstractThis article describes the radial drift of a suspended sphere in a cylinder-bound Poiseuille flow where the Reynolds number is small but finite. Unlike past studies, it considers a circular narrow conduit whose cross-sectional diameter is only $1. 5$–$6$ times the particle diameter. Thus, the analysis quantifies the effect of fluid inertia on the radial motion of the particle in the channel when the flow field is significantly influenced by the presence of the suspended body. To this end, the hydrodynamic fields are expanded as a series in Reynolds number, and a set of hierarchical equations for different orders of the expansion is derived. Accordingly, the zeroth-order fields in Reynolds number satisfy the Stokes equation, which is accurately solved in the presence of the spherical particle and the cylindrical conduit. Then, recognizing that in narrow vessels Stokesian scattered fields from the sphere decrease exponentially in the axial direction, a simpler regular perturbation scheme is used to quantify the first-order inertial correction to hydrodynamic quantities. Consequently, it is possible to obtain two results. First, the sphere is assumed to follow the axial motion of a freely suspended sphere in a Stokesian condition, and the radial lift force on it due to the presence of fluid inertia is evaluated. Then, the approximate motion is determined for a freely suspended body on which net hydrodynamic force including first-order inertial lift is zero. The results agree well with the available experimental results. Thus, this study along with the measured data would precisely describe particle dynamics inside narrow tubes.
The trapping and release of bubbles from a linear pore
Authors: Dawson Geoffrey , Lee Sungyon , Juel Anne 
Published: April 2013

AbstractStreamwise variation in vessel geometry is a feature of many multiphase flows of practical interest, ranging from natural porous media flows to man-made lab-on-the-chip applications. The variable streamwise geometry typically exerts a dominant influence on bubble motion, and can lead to undesirable phenomena such as clogging of the vessel. Here, we study clogging in a fundamental configuration, where a tube of square cross-section is suddenly expanded over a short streamwise distance. The extent to which a bubble driven by constant flux flow broadens to partially fill the expansion depends on the balance between viscous and surface tension stresses, measured by the capillary number $\mathit{Ca}$. This broadening is accompanied by the slowing and momentary arrest of the bubble as $\mathit{Ca}$ is reduced towards its critical value for trapping. For $\mathit{Ca}\lt {\mathit{Ca}}_{c} $ the pressure drag forces on the quasi-arrested bubble are insufficient to force the bubble out of the expanded region so it remains trapped. We examine the conditions for trapping by varying bubble volume, flow rate of the carrier fluid, relative influence of gravity and length of expanded region. We find specifically that ${\mathit{Ca}}_{c} $ depends non-monotonically on the size of the bubble. We verify, with experiments and a capillary static model, that a bubble is released if the work of the pressure forces over the length of the trap exceeds the surface energy required for the trapped bubble to reenter the constricted square tube.
Receptivity of a high-speed boundary layer to temperature spottiness
Authors: Fedorov A. V. , Ryzhov A. A. , Soudakov V. G. , Utyuzhnikov S. V. 
Published: April 2013

AbstractTwo-dimensional direct numerical simulation (DNS) of the receptivity of a flat-plate boundary layer to temperature spottiness in the Mach 6 free stream is carried out. The influence of spottiness parameters on the receptivity process is studied. It is shown that the temperature spots propagating near the upper boundary-layer edge generate mode F inside the boundary layer. Further downstream mode F is synchronized with unstable mode S (Mack second mode) and excites the latter via the inter-modal exchange mechanism. Theoretical assessments of the mode F amplitude are made using the biorthogonal eigenfunction decomposition method. The DNS results agree with the theoretical predictions. If the temperature spots are initiated in the free stream and pass through the bow shock, the dominant receptivity mechanism is different. The spot–shock interaction leads to excitation of acoustic waves, which penetrate into the boundary layer and excite mode S. Numerical simulations show that this mechanism provides the instability amplitudes an order of magnitude higher than in the case of receptivity to the temperature spots themselves.
Invariant recurrent solutions embedded in a turbulent two-dimensional Kolmogorov flow
Authors: Chandler Gary J. , Kerswell Rich R. 
Published: April 2013

AbstractWe consider long-time simulations of two-dimensional turbulence body forced by $\sin 4y\hat {\boldsymbol{x}} $ on the torus $(x, y)\in \mathop{[0, 2\mathrm{\pi} ] }\nolimits ^{2} $ with the purpose of extracting simple invariant sets or ‘exact recurrent flows’ embedded in this turbulence. Each recurrent flow represents a sustained closed cycle of dynamical processes which underpins the turbulence. These are used to reconstruct the turbulence statistics using periodic orbit theory. The approach is found to be reasonably successful at a low value of the forcing where the flow is close to but not fully in its asymptotic (strongly) turbulent regime. Here, a total of 50 recurrent flows are found with the majority buried in the part of phase space most populated by the turbulence giving rise to a good reproduction of the energy and dissipation p.d.f. However, at higher forcing amplitudes now in the asymptotic turbulent regime, the generated turbulence data set proves insufficiently long to yield enough recurrent flows to make viable predictions. Despite this, the general approach seems promising providing enough simulation data is available since it is open to extensive automation and naturally generates dynamically important exact solutions for the flow.
Resonance theory of water waves in the long-wave limit
Authors: Kataoka Takeshi 
Published: April 2013

AbstractThe instability due to resonant interactions of finite-amplitude water waves is examined in the long-wave limit. In contrast to the well-known case of a small-amplitude limit in which the resonance is considered for a flat surface, here we consider a periodic approximate of the finite-amplitude solitary wave which is the long-wave limit of the periodic wave. The resonance conditions for the corresponding perturbations yield a new family of resonance curves that are totally different from those of the small-amplitude limit obtained by Phillips and Mclean. Under these resonance conditions, we conduct a systematic asymptotic analysis for small wavenumbers to obtain the growth rates of the perturbations explicitly and clarify whether each resonance curve is associated with instability. These results are verified numerically by showing that the instability bands for finite-amplitude periodic waves in shallow water are located along these unstable resonance curves.
Travelling convectons in binary fluid convection
Authors: Mercader Isabel , Batiste Oriol , Alonso Arantxa , Knobloch Edgar 
Published: April 2013

AbstractBinary fluid mixtures with a negative separation ratio heated from below exhibit steady spatially localized states called convectons for supercritical Rayleigh numbers. With no-slip, fixed-temperature, no-mass-flux boundary conditions at the top and bottom stationary odd- and even-parity convectons fall on a pair of intertwined branches connected by branches of travelling asymmetric states. In appropriate parameter regimes the stationary convectons may be stable. When the boundary condition on the top is changed to Newton’s law of cooling the odd-parity convectons start to drift and the branch of odd-parity convectons breaks up and reconnects with the branches of asymmetric states. We explore the dependence of these changes and of the resulting drift speed on the associated Biot number using numerical continuation, and compare and contrast the results with a related study of the Swift–Hohenberg equation by Houghton & Knobloch (Phys. Rev.E, vol. 84, 2011, art. 016204). We use the results to identify stable drifting convectons and employ direct numerical simulations to study collisions between them. The collisions are highly inelastic, and result in convectons whose length exceeds the sum of the lengths of the colliding convectons.
Response of a hypersonic turbulent boundary layer to favourable pressure gradients
Authors: Tichenor N. R. , Humble R. A. , Bowersox R. D. W. 
Published: April 2013

AbstractThe role of streamline curvature-driven favourable pressure gradients in modifying the turbulence structure of a Mach 4.9, high-Reynolds-number (${\mathit{Re}}_{\theta } = 43\hspace{0.167em} 000$) boundary layer is examined. Three pressure gradient cases ($\beta = (\mathrm{d} p/ \mathrm{d} x)({\delta }^{\ast } / {\tau }_{w} )= 0. 07, - 0. 3$ and $- 1. 0$) are characterized via particle image velocimetry. The expected stabilizing trends in the Reynolds stresses are observed, with a sign reversal in the Reynolds shear stress in the outer part of the boundary layer for the strongest favourable pressure gradient considered. The increased transverse normal strain rate and reduced principal strain rate are the primary factors. Reynolds stress quadrant events are redistributed, such that the relative differences between the quadrant magnitudes decreases. Very little preferential quadrant mode selection is observed for the strongest pressure gradient considered. Two-point correlations suggest that the turbulent structures are reoriented to lean farther away from the wall, accompanied by a slight reduction in their characteristic size, consistent with previous flow visualization studies. This reorientation is more pronounced in the outer, dilatation-dominated region of the boundary layer, whereas the alteration in structure size is more pronounced nearer the wall, where the principal strain rates are larger. In addition, integration of a simplified form of a Reynolds stress transport closure model provided a framework to assess the role of the strain-rate field on the observed Reynolds shear stresses. Given the simple geometry, the present data provide a suitable test bed for Reynolds stress transport and large-eddy model development and validation.
Blood flow in small tubes: quantifying the transition to the non-continuum regime
Authors: Lei Huan , Fedosov Dmitry A. , Caswell Bruce , Karniadakis George Em 
Published: April 2013

AbstractIn small vessels blood is usually treated as a Newtonian fluid down to diameters of${\sim }200~\mathrm{\mu} \mathrm{m} $. We investigate the flow of red blood cell (RBC) suspensions driven through small tubes (diameters$10\text{{\ndash}} 150~\mathrm{\mu} \mathrm{m} $) in the range marking the transition from arterioles and venules to the largest capillary vessels. The results of the simulations combined with previous simulations of uniform shear flow and experimental data show that for diameters less than${\sim }100~\mathrm{\mu} \mathrm{m} $the suspension’s stress cannot be described as a continuum, even a heterogeneous one. We employ the dissipative particle dynamics (DPD) model, which has been successfully used to predict human blood bulk viscosity in homogeneous shear flow (Fedosovet al. Proc. Natl Acad. Sci. USA, vol. 108, 2011, pp. 11772–11777). In tube flow the cross-stream stress gradient induces an inhomogeneous distribution of RBCs featuring a centreline cell density peak, and a cell-free layer (CFL) next to the wall. For a neutrally buoyant suspension the imposed linear shear-stress distribution together with the differentiable velocity distribution allow the calculation of the local viscosity across the tube section. The viscosity across the section as a function of the strain rate is found to be essentially independent of tube size for the larger diameters and is determined by the local haematocrit ($H$) and shear rate. Other RBC properties such as asphericity, deformation, and cell-flow orientation exhibit similar dependence for the larger tube diameters. As the tube size decreases below${\sim }100~\mathrm{\mu} \mathrm{m} $in diameter, the viscosity in the central region departs from the large-tube similarity function of the shear rate, since$H$increases significantly towards the centreline. The dependence of shear stress on tube size, in addition to the expected local shear rate and local haematocrit, implies that blood flow in small tubes cannot be described as a heterogeneous continuum. Based on the analysis of the DPD simulations and on available experimental results, we propose a simple velocity-slip model that can be used in conjunction with continuum-based simulations.
A cutting critique: transforming ‘older’ through cosmetic surgery
Authors: GARNHAM BRIDGET 
Published: April 2013

ABSTRACTThis paper engages with a cultural politics of ‘older’. At the centre of this politics are essentialist discourses of corporeal ‘ageing’ that limit and stigmatise the subjective experience of ‘older’. Drawing together theoretical insights from Foucault's work on care of the self with data from in-depth interviews with ‘older’ people who have undergone cosmetic surgery and cosmetic surgery practitioners, this paper advances the proposition that cosmetic surgery can be re-imagined as an ethical practice of self-care. To critique the limitations imposed by ‘natural ageing’ through an ethic of ‘ageing gracefully’, the paper explores how older people who have undergone cosmetic surgery stylise the ethical experience of ‘older’ through active resistance of an ‘elderly’ identity. It argues that the practice of cosmetic surgery by ‘older’ people constitutes a cutting critique of the limits of ‘older’ and an experiment with the possibility of exceeding and ultimately transforming those limits.
Atomistic-to-continuum coupling
Authors: Luskin Mitchell , Ortner Christoph 
Published: April 2013

Atomistic-to-continuum (a/c) coupling methods are a class of computational multiscale schemes that combine the accuracy of atomistic models with the efficiency of continuum elasticity. They are increasingly being utilized in materials science to study the fundamental mechanisms of material failure such as crack propagation and plasticity, which are governed by the interaction between crystal defects and long-range elastic fields.In the construction of a/c coupling methods, various approximation errors are committed. A rigorous numerical analysis approach that classifies and quantifies these errors can give confidence in the simulation results, as well as enable optimization of the numerical methods for accuracy and computational cost. In this article, we present such a numerical analysis framework, which is inspired by recent research activity.
Alternative Feeding Strategies to Maximize Fish Oil and Fish Meal Sparing in Largemouth Bass Culture while Maintaining Production Performance and Product Value
Authors: Coursey Andrew R , Trushenski Jesse T , Kohler Christopher C 
Published: April 2013

Abstract
Feeding trials were conducted to determine (1) the optimal inclusion of poultry byproduct meal (PBM) and poultry fat (PF) as alternatives to fish meal (FM) and fish oil (FO) in diets for Largemouth Bass Micropterus salmoides and (2) whether the poultry-based formulations could be used in conjunction with FO-based finishing feeds in a strategy to minimize the use of marine-derived ingredients while maintaining performance and fillet composition. In trial 1, fish (mean ± SE = 16.0 ± 0.5 g) were reared for 9 weeks on diets (∼40% protein, ∼10% lipid) containing graded levels of FM (0, 7.5, or 15%) and FO (0, 3, or 6%), with PBM and PF replacing FM and FO, respectively. The results indicated that complete replacement of marine feedstuffs with PBM and PF had no significant effects on production performance; all diets yielded equivalent weight gain (mean ± SE = 277 ± 45%), feed conversion ratio (FCR; 1.4 ± 0.4), and feed consumption (39 ± 6 g/fish), although fillet fatty acid profile reflected the diet. Based on these results, the 7.5% FM–0% FO and 0% FM–0% FO diets were further evaluated. In trial 2, fish (mean ± SE = 39 ± 3 g) were reared for 16 weeks on the 7.5% FM–0% FO or 0% FM–0% FO feeds, followed by an additional 12 weeks on the assigned diet or a 15% FM–6% FO finishing diet. The performance and fillet composition of these fish were compared with those of their counterparts that only received the finishing feed or a commercially available Largemouth Bass feed. All approaches yielded equivalent weight gain (mean ± SE = 496 ± 65%), FCR (2.0 ± 0.2), and feed consumption (407 ± 65 g/fish). Fillet fatty acid profiles reflected dietary intake, but finishing significantly increased the n-3 fatty acid and long-chain polyunsaturated fatty acid levels. The use of poultry-byproduct-based Largemouth Bass feeds may offer cost savings, and undesired effects on fillet nutritional value may be attenuated by the use of finishing feeds.