bluuebunny/crossref_metadata_2025 huggingface dataset:
Stahl‐ und Stahlverbundtragwerke der Grundschule Berlin‐Lichtenrade
Authors: Lenz D. , Maier M. , Meergans Ch.
Published: April 2013

Im Jahr 1999 wurde in Berlin‐Lichtenrade eine Grundschule in Betrieb genommen. Der aus einem Realisierungswettbewerb hervorgegangene Entwurf umfaßte fünf getrennte Bauwerke. Die statisch‐konstruktiven Besonderheiten des Schulgebäudes, der Sporthalle und des Fußgängersteges ‐ vor allem im Stahlbaubereich ‐ werden beschrieben und erläutert.
Polnische Vertreter des Stahlbaus
Authors: Ziolko J.
Published: April 2013

Es werden vier hervorragende polnische Vertreter aus der Wissenschaft und Praxis des Stahlbaus vorgestellt.
Stahlkonstruktionen von polnischen Umschlag‐ und Fördergeräten
Authors: Jankowiak R. , Rusinski E.
Published: April 2013

Behandelt werden ausgewählte Probleme, die bei der Projektierung und beim Aufbau der Stahlkonstruktionen von Umschlag‐ und Fördergeräten auftreten. Erörtert werden einige Aspekte der computergestützten Dimensionierung der Tragkonstruktionen von Großgeräten und Hebezeugen. Erläutert wird die numerische Unterstützung bei der Dimensionierung von Tragkonstruktionen nach Steifigkeitskriterien, Beanspruchung und Abschätzung der Lebensdauer. Vorgestellt werden Zahlenbeispiele aus der computergestützten Dimensionierung der Tragkonstruktion eines Brückenkrans und Baggeraufbaus.
Zur Diagnose der Qualität von geschweißten Stumpfstößen in bestehenden Eisenbahnbrücken
Authors: Wichtowski B.
Published: April 2013

Um den Zustand von Stumpfstößen in bestehenden Eisenbahnbrücken zu prüfen, wurden über einen Zeitraum von 35 Jahren periodische radiographische Kontrollen durchgeführt. Es wurden Stumpfnähte der Hauptträger von 155 Brücken, darunter 125 Vollwandbalkenbrücken und 30 Fachwerkbrücken, kontrolliert. Die Untersuchung betraf Brücken, die zwischen 1936 und 1975 in Betrieb genommen worden sind. Die Radiogramme ermöglichen die Einordnung der einzelnen Schweißnahtgruppen in die entsprechenden Fehlerklassen. Als Beispiel werden die Ergebnisse der röntgenographischen und materialtechnischen Untersuchungen des ältesten geschweißten Eisenbahnviadukts in Polen angegeben. Diese Brücke wurde im Auftrag der Deutschen Reichsbahngesellschaft in Szczecin errichtet und 1936 in Betrieb genommen.
Nichtlinearer Längskraft‐ und Biegemomentenverlauf in der Schraube vorgespannter L‐Flansche ‐ Näherungslösungen mit und ohne Iteration / Teil 1
Authors: Lehmann D.
Published: April 2013

Längskraft und Biegemoment in der Schraube vorgespannter L‐Flansche unter Zugbelastung zeigen im Versuch einen nichtlinearen Verlauf. Für den elastischen Bereich werden für diese Verläufe nichtlineare Berechnungsverfahren auf der Grundlage der Theorie des elastisch gebetteten Balkens angegeben.

Das bisher ausschließlich für die iterative Berechnung der Schraubenkraft angewandte Verfahren wird auf die Berechnung des Biegemomentes in der Schraube erweitert. Den Schwerpunkt der Betrachtungen bildet das analytische Vorgehen bei dicken Flanschen mit Hilfe eines Systems nichtlinearer Verfahren ohne Iteration. Die nichtlinearen Verläufe der Schraubenkraft und des Biegemomentes werden mit Versuchsergebnissen verglichen.
Festigkeitssteigerung von Schraubenverbindungen bei ermüdungsbeanspruchten, feuerverzinkten Stahlkonstruktionen
Authors: Valtinat G. , Huhn H.
Published: April 2013

Im Turm‐ und Mastbau eingesetzte Bauteile sind oszillierenden Beanspruchungen unterlegen, die aus wechselnden Windeinwirkungen resultieren. Aus Gründen des Korrosionsschutzes werden für die in der Regel als Gitterfachwerk ausgebildeten Konstruktionen feuerverzinkte Stäbe verwendet, deren Löcher für die Schraubenverbindungen meistens gestanzt sind. Das Stanzen der Löcher und das Feuerverzinken wirken sich jedoch negativ auf die Ermüdungsfestigkeit der Stabnettoquerschnitte aus. Aus diesem Grund soll deren Ermüdungsverhalten durch geeignete Maßnahmen wieder auf den Stand von Schraubenverbindungen mit gebohrten Löchern gehoben werden. Um dieses Ziel zu erreichen, kommen hochfeste vorgespannte (HV‐)Schrauben zum Einsatz, denn durch das Vorspannen der Schrauben mit Pressungen der Bauteile rechtwinklig zur Oberfläche reduzieren sich die Kerbspannungen am Lochrand, und es entsteht um das Loch herum eine geschützte Zone. Bei anschließender Längsbeanspruchung der Schraubenverbindungen werden dadurch der Rißfortschritt verzögert, die Ermüdungsfestigkeit erhöht und letztendlich die Bauteillebensdauer verlängert.
Messehalle 27 ‐ Formänderung einer sehr großen Halle und ihre konstruktive Bewältigung
Authors: Klee K.‐D.
Published: April 2013

Im Jahre 2002 wurde die Messehalle 27 in Hannover fertiggestellt. Aufgrund der relativ großen Abmessungen der Halle (ca. 201,9 m x 181,9 m) waren umfangreiche Voruntersuchungen zur Ermittlung des Tragwerkssystems unter Berücksichtigung der architektonischen Vorgaben erforderlich. Ziel war u.a. die Minimierung der Verschiebungen des Gesamtsystems im Hinblick auf die Fassadenanbindung. Im Beitrag wird die vielfältige Problematik bei der Konstruktion (Realisierung von Dehnungsfugen), Berechnung und Montage der Halle 27 näher erläutert und ein Vergleich zu den Messehallen 9 und 13 in Hannover getroffen.
Beultragfähigkeit von Stahlquerschnitten unter Druck‐ und Biegebeanspruchung
Authors: Ungermann D. , Brune B.
Published: April 2013

Für den Nachweis beulgefährdeter Stäbe gibt die EN 1993‐1‐3 zur Zeit drei verschiedene Verfahren zur Ermittlung der Beultragfähigkeit von Stahlquerschnitten mit dreiseitig gelagerten Platten an. Alle Verfahren basieren auf der Grundlage der Methode der wirksamen Breiten:

1. das Verfahren im Haupttext, Kapitel 5.5.2. Dieses Verfahren entspricht weitgehend dem Verfahren der EN1993‐1‐1.

2. das Verfahren nach Annex C (Höglund)

3. das Verfahren nach Annex D (Brune)

Es werden die verschiedenen Verfahren für baupraktische Stahlquerschnitte, die dreiseitig gelagerte Platten enthalten, bezüglich der Ermittlung der Beultragfähigkeit gegenübergestellt und im Vergleich mit Versuchsdaten bewertet.

Es wird ein Vorschlag zur Verbesserung des Annex C erarbeitet, welcher im Ergebnis mit dem Annex D übereinstimmt.

Für die Überarbeitung der EN mit dem Ziel eines einheitlichen Verfahrens folgt damit: Zur Bestimmung der Beultragfähigkeit von dreiseitig gelagerten Platten können sowohl der Annex D als auch der in diesem Bericht vorgestellte, modifizierte Annex C verwendet werden.
Bemerkungen zur Ausnutzung plastischer Querschnitts‐ und Systemreserven
Authors: Hübel H.
Published: April 2013

Plastische 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

Negative 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

Kaltkathoden 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.
Tagungen: Vakuum in Forschung und Praxis 2/2013
Authors: Blasek Gerhard
Published: April 2013

Beschichtung, Modifizierung und Charakterisierung von Polymeroberflächen
Climate driver informed short‐term drought risk evaluation
Authors: Henley Benjamin J. , Thyer Mark A. , Kuczera George
Published: April 2013

Key Points

Climate driver informed short‐term drought risk methodology is introduced

Risk evaluated in each time step conditioned on climate driver & initial storage

Traditional approaches underestimate the severity and duration of drought risk
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

Lymphatic 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.
Posterolateral Subluxation Exposure of the Elbow for Injuries Involving the Lateral Column
Authors: Pirela-Cruz Miguel A. , Samocha Yoni
Published: April 2013

The posterolateral subluxation exposure of the elbow is a useful surgical technique for addressing complex radial head or capitellar fractures. It can be modified to allow for exposure of the distal humerus or elbow in more complex cases including those resulting in the terrible triad injury. In this approach, dissection to the radiocapitellar joint via a posterior incision provides great exposure and allows for reduction and internal fixation or placement of a radial head prosthesis. The authors in this video presentation demonstrate the posterolateral approach for radial head fractures and radial head replacement along with some technical caveats.
Evolutionary psychology and consumer behavior: A constructive critique
Authors: Cohen Joel B. , Bernard H. Russell
Published: April 2013

We 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

This 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

Streamwise 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

Two-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

We 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

The 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

Binary 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

The 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

In 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.
Lizu
Authors: Chirkova Katia , Chen Yiya
Published: April 2013

The Lizu (or Lüzu) language (/EPli-zu-hu/ or /EPly-zu-hu/) is spoken by approximately 7000 people who reside along the banks of the Yalong (雅 砻) or Nyag chu River in three counties in Sichuan Province (四 川 省) in the People's Republic of China: (i) Muli Tibetan Autonomous County 木 里 藏 族 自 治 县 (Written Tibetan, hereafter WT, smi li rang skyong rdzong), (ii) Jiulong county (九 龙 县 brgyad zur), (iii) Mianning county (冕 宁 县) (Wang 2010: 3).1 Lizu is currently considered as the western dialect of the Ersu 尔 苏 language (Sun 1982, 1983), which is in turn classified as a member of the Qiangic subgroup of the Tibeto-Burman language family (for more details, see Bradley 1997: 36–37; Sun 2001; Chirkova 2012).
Tena Quichua
Authors: O'Rourke Erin , Swanson Tod D.
Published: April 2013

Tena Quichua (ISO 639-3: quw) belongs to the Quechuan language family, as part of the peripheral variety Quechua IIB (Torero 1964, Cerrón-Palomino 1987, Gordon 2005). It is spoken in the Eastern Amazonian region of Ecuador on the Napo River above the mouth of the Rio Coca, primarily on three tributaries: the Misahualli, the Arajuno, and the Ansuc. Tena Quichua is bounded on the North and East by Napo Quichua and on the South by Pastaza Quichua. Previous research on the division of Ecuadorian dialects is summarized by Carpenter (1984: 3–4). Although it is beyond the scope of this Illustration, we hope that our description of Tena Quichua will prove useful in future work on the relations between these three Amazonian dialects of Ecuadorian Quichua. Below, a brief summary of Tena dialect identification and formation is given, followed by a description of present-day bilingualism in the region and data collection procedures.
Effects of dialect on vowel acoustics and intelligibility
Authors: Oder Austin L. , Clopper Cynthia G. , Ferguson Sarah Hargus
Published: April 2013

A great deal of recent research has focused on phonetic variation among American English vowels from different dialects. This body of research continues to grow as vowels continuously undergo diachronic formant changes that become characteristic of certain dialects. Two experiments using the Nationwide Speech Project corpus (Clopper & Pisoni 2006a) explored whether the Midland dialect is more closely related acoustically and perceptually to the Mid-Atlantic or to the Southern dialect. The goal of this study was to further our understanding of acoustic and perceptual differences between two of the most marked dialects (Mid-Atlantic and Southern) and one of the least marked dialects (Midland) of American English. Ten vowels in /hVd/ context produced by one male talker from each of these three dialects were acoustically analyzed and presented to Midland listeners for identification. The listeners showed the greatest vowel identification accuracy for the Mid-Atlantic talker (95.2%), followed by the Midland talker (92.5%), and finally the Southern talker (79.7%). Vowel error patterns were consistent with vowel acoustic differences between the talkers. The results suggest that, acoustically and perceptually, the Midland and Mid-Atlantic dialects are more similar than are the Midland and Southern dialects.
IPA membership by country (2012)
Authors: Keating Patricia A.
Published: April 2013

The following is a list of the countries of the current membership of the Association, based on the Association's records in November 2012. The numbers in parentheses indicate the total number of members per country (Life, Full, and Student combined). There are a total of 358 members (206 Life, 133 Full, and 19 Student) from 51 countries. Individual members’ names are no longer published.
IPA becomes co-sponsor of two ISCA special interest groups
Authors: Keating Patricia A.
Published: April 2013

At the Association's August 2011 General Meeting in Hong Kong, a suggestion was made that the IPA should establish a link with the Special Interest Group on Speech Prosody (SProSIG) of the International Speech Communication Association (ISCA). After discussion with SProSIG, the Council of the IPA has voted to become a co-sponsor of the group. SProSIG's Liaison Officer, Yi Xu of University College London, will serve as the Liaison Officer for the IPA with SProSIG and ISCA.
A cutting critique: transforming ‘older’ through cosmetic surgery
Authors: GARNHAM BRIDGET
Published: April 2013

This 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.
Corrector estimates for the homogenization of a locally periodic medium with areas of low and high diffusivity
Authors: MUNTEAN A. , VAN NOORDEN T. L.
Published: April 2013

We prove an upper bound for the convergence rate of the homogenization limit ε → 0 for a linear transmission problem for a advection–diffusion(–reaction) system posed in areas with low and high diffusivity, where ε is a suitable scale parameter. In this way we rigorously justify the formal homogenization asymptotics obtained in [37] (van Noorden, T. and Muntean, A. (2011) Homogenization of a locally-periodic medium with areas of low and high diffusivity.Eur. J. Appl. Math.22, 493–516). We do this by providing a corrector estimate. The main ingredients for the proof of the correctors include integral estimates for rapidly oscillating functions with prescribed average, properties of the macroscopic reconstruction operators, energy bounds, and extra two-scale regularity estimates. The whole procedure essentially relies on a good understanding of the analysis of the limit two-scale problem.
High-dimensional integration: The quasi-Monte Carlo way
Authors: Dick Josef , Kuo Frances Y. , Sloan Ian H.
Published: April 2013

This paper is a contemporary review of QMC (‘quasi-Monte Carlo’) methods, that is, equal-weight rules for the approximate evaluation of high-dimensional integrals over the unit cube [0,1]s, wheresmay be large, or even infinite. After a general introduction, the paper surveys recent developments in lattice methods, digital nets, and related themes. Among those recent developments are methods of construction of both lattices and digital nets, to yield QMC rules that have a prescribed rate of convergence for sufficiently smooth functions, and ideally also guaranteed slow growth (or no growth) of the worst-case error as s increases. A crucial role is played by parameters called ‘weights’, since a careful use of the weight parameters is needed to ensure that the worst-case errors in an appropriately weighted function space are bounded, or grow only slowly, as the dimension s increases. Important tools for the analysis are weighted function spaces, reproducing kernel Hilbert spaces, and discrepancy, all of which are discussed with an appropriate level of detail.
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.
Perinatal Outcomes in Preterm Growth-Restricted Twins: Effects of Gestational Age and Fetal Condition
Authors: Manzanares Sebastián , Sanchez-Gila Mar , Moreno-Martinez María D. , Ramirez-Arredondo Alejandro , Pineda Alicia
Published: April 2013

Objective:To evaluate the perinatal outcome of intrauterine growth-restricted preterm twins and contribution of prematurity to morbidity and mortality.Study design:A case–control study of 211 preterm twins: 108 growth-restricted twins matched with 103 normal growth twins of the same gestational age. Mortality and morbidity rates were compared between groups.Result:Fetal and overall perinatal mortality rates of growth-restricted fetuses were higher than normal growth ones. Respiratory distress syndrome incidence was lower and neurologic sequelae incidence higher in growth-restricted twins. No differences were observed between groups with respect to neonatal mortality, low Apgar score, neonatal intensive care unit admission, periventricular hemorrhage, sepsis, jaundice, and hematologic or metabolic disorders.Conclusion:Adverse perinatal outcomes of preterm twins complicated with intrauterine growth restriction are represented by a higher antepartum mortality rate, but once born alive, neonatal outcomes seem to be associated only with gestational age at birth, excluding a protective effect on lung maturation and a higher risk of long-term neurologic sequelae.
Dissecting the energy metabolism in Mycoplasma pneumoniae through genome‐scale metabolic modeling
Authors: Wodke Judith A H , Puchałka Jacek , Lluch‐Senar Maria , Marcos Josep , Yus Eva , Godinho Miguel , Gutiérrez‐Gallego Ricardo , dos Santos Vitor A P Martins , Serrano Luis , Klipp Edda , Maier Tobias
Published: April 2013

Mycoplasma pneumoniae, a threatening pathogen with a minimal genome, is a model organism for bacterial systems biology for which substantial experimental information is available. With the goal of understanding the complex interactions underlying its metabolism, we analyzed and characterized the metabolic network of M. pneumoniae in great detail, integrating data from different omics analyses under a range of conditions into a constraint‐based model backbone. Iterating model predictions, hypothesis generation, experimental testing, and model refinement, we accurately curated the network and quantitatively explored the energy metabolism. In contrast to other bacteria, M. pneumoniae uses most of its energy for maintenance tasks instead of growth. We show that in highly linear networks the prediction of flux distributions for different growth times allows analysis of time‐dependent changes, albeit using a static model. By performing an in silico knock‐out study as well as analyzing flux distributions in single and double mutant phenotypes, we demonstrated that the model accurately represents the metabolism of M. pneumoniae. The experimentally validated model provides a solid basis for understanding its metabolic regulatory mechanisms.
Performance of lambs grazing an annual Mediterranean pasture or fed supplements based on olive oil cake or maize and its influence on system outputs
Authors: Vera Raul R. , Aguilar Claudio , Toro Paula , Squella Fernando , Perez Patricio
Published: April 2013

Three lamb feeding strategies were compared, including finishing of suckling lambs on an annual Mediterranean pasture (GRAZE), weaned followed by a concentrate plus hay diet (CONC), or weaned and fed a concentrate with 33% dry olive oil cake plus hay (CAKE). Grazing lambs averaged a liveweight gain of 334 g/day during the 28-day experimental period, which was higher (P < 0.05) than that of CONC and CAKE (283 and 276 g/day, respectively); however, there were no differences in empty body or dressed carcasses weights due to dietary treatment. The feed conversion of the olive seed cake supplement (kg supplement/kg gain) was lower (P < 0.01) than that of the maize-based supplement. Despite some significant differences between carcasses traits, all were small and of little commercial consequence. Simulation modelling of whole-system performance suggested that early weaning of lambs followed by concentrate feeding would reduce the finishing period, marginally increase the liveweight of ewes and would have little effect on pasture availability. It was further concluded that olive oil cake can be a large proportion of concentrate diets without negatively affecting carcass quality.
Ammonia and other microclimatic conditions at an Australian pre-export sheep assembly depot
Authors: Pines Mathew K. , Muller Tracy , Phillips Clive J. C.
Published: April 2013

Noxious gases produced at hazardous concentrations in animal housing systems may affect the health and wellbeing of both animals and workers. In order to determine if the gaseous emissions from a pre-export assembly depot for sheep constituted a risk, atmospheric ammonia was measured in eight sheep buildings at an Australian assembly depot. Additionally, meteorological variables and distance from excreta were measured to determine their influence on ammonia, carbon dioxide and hydrogen sulfide concentrations. Repeat measurements were made at 12 sites in each building on 4 separate days, and four buildings were mapped using longitudinal and latitudinal transects. Concentrations of ammonia, carbon dioxide and hydrogen sulfide were all below the recommended safety thresholds for humans and livestock. There were positive correlations between ammonia and the following variables: ambient temperature and moisture content, and negative correlations with distance from animal excreta. Understanding these relationships will help to understand the reasons for ammonia accumulation in such buildings.
Dairying in the Antipodes: recent past, near prospects
Authors: Clark Dave , Malcolm Bill , Jacobs Joe
Published: April 2013

The majority of dairy farmers and processors in Australia and New Zealand are considered world class due to their ability to produce dairy products at a cost that is competitive on the world market without requirement for subsidy. International and domestic forces beyond the farm influence the international competitiveness of Antipodean dairy systems, as much or more than, the within-farm characteristics of the systems. Critical external forces include: world population growth, protein demand from increasingly wealthy developing countries, dairy supply from domestic and international producers, international dairy prices and exchange rate volatility. Within farm, the keys to persistent profitability, business survival, and growth will continue to be management ability and labour skill as well as the relationship between milksolids (milk fat + milk protein) produced per system and total production costs. Domestic forces will include competition for resources such as land, water, quality labour and capital, and public expectation that farms will meet the costs of community environmental and welfare objectives. Public and industry investment in research, development and extension in innovations that increase productivity is essential if dairying is to remain competitive. The operation of the comparative advantage principle determines which industries thrive, or decline, in an economy. New Zealand dairying has a strong comparative advantage over alternative pastoral industries which will continue. In Australia, the comparative advantage of dairy farming over alternative activities is less clear-cut. History shows that the best farmers and processors handle risks such as market and climate volatility and other challenges better than others, and their prospects are positive. However, world class performers in the future dairy industry will certainly not be all, or even the majority, of the current population of dairy farmers.
Critical Review of Water Radiolysis Processes, Dissociation Products, and Possible Impacts on the Local Environment: A Geochemist
Authors: Das Soumya
Published: April 2013

Radiolysis of water is the process whereby water dissociates due to various types of ionizing radiation (α, β, and γ) into hydrogen and hydroxide radicals (instead of hydrogen and hydroxide ions as in ionization). During radiolysis, water breaks down to highly reactive radicals such as •OH, •H, eaq–, HO2, and O2–• and molecular species such as H2, O2, and H2O2. Yields of these dissociation products are largely dependent on factors including the type of radiation, vapour pressure of the system, and linear energy transfer. These dissociated radicals are highly reactive and can affect the local environment by changing redox conditions and, in turn, inducing and enhancing metal mobility in the environment. This article reviews the process of water radiolysis, dissociation products, and possible effects on the environment.
Gene similarity networks provide tools for understanding eukaryote origins and evolution
Authors: Alvarez-Ponce David , Lopez Philippe , Bapteste Eric , McInerney James O.
Published: April 2013

The complexity and depth of the relationships between the three domains of life challenge the reliability of phylogenetic methods, encouraging the use of alternative analytical tools. We reconstructed a gene similarity network comprising the proteomes of 14 eukaryotes, 104 prokaryotes, 2,389 viruses and 1,044 plasmids. This network contains multiple signatures of the chimerical origin of Eukaryotes as a fusion of an archaebacterium and a eubacterium that could not have been observed using phylogenetic trees. A number of connected components (gene sets with stronger similarities than expected by chance) contain pairs of eukaryotic sequences exhibiting no direct detectable similarity. Instead, many eukaryotic sequences were indirectly connected through a “eukaryote–archaebacterium–eubacterium–eukaryote” similarity path. Furthermore, eukaryotic genes highly connected to prokaryotic genes from one domain tend not to be connected to genes from the other prokaryotic domain. Genes of archaebacterial and eubacterial ancestry tend to perform different functions and to act at different subcellular compartments, but in such an intertwined way that suggests an early rather than late integration of both gene repertoires. The archaebacterial repertoire has a similar size in all eukaryotic genomes whereas the number of eubacterium-derived genes is much more variable, suggesting a higher plasticity of this gene repertoire. Consequently, highly reduced eukaryotic genomes contain more genes of archaebacterial than eubacterial affinity. Connected components with prokaryotic and eukaryotic genes tend to include viral and plasmid genes, compatible with a role of gene mobility in the origin of Eukaryotes. Our analyses highlight the power of network approaches to study deep evolutionary events.
Limits of social mobilization
Authors: Rutherford Alex , Cebrian Manuel , Dsouza Sohan , Moro Esteban , Pentland Alex , Rahwan Iyad
Published: April 2013

The Internet and social media have enabled the mobilization of large crowds to achieve time-critical feats, ranging from mapping crises in real time, to organizing mass rallies, to conducting search-and-rescue operations over large geographies. Despite significant success, selection bias may lead to inflated expectations of the efficacy of social mobilization for these tasks. What are the limits of social mobilization, and how reliable is it in operating at these limits? We build on recent results on the spatiotemporal structure of social and information networks to elucidate the constraints they pose on social mobilization. We use the DARPA Network Challenge as our working scenario, in which social media were used to locate 10 balloons across the United States. We conduct high-resolution simulations for referral-based crowdsourcing and obtain a statistical characterization of the population recruited, geography covered, and time to completion. Our results demonstrate that the outcome is plausible without the presence of mass media but lies at the limit of what time-critical social mobilization can achieve. Success relies critically on highly connected individuals willing to mobilize people in distant locations, overcoming the local trapping of diffusion in highly dense areas. However, even under these highly favorable conditions, the risk of unsuccessful search remains significant. These findings have implications for the design of better incentive schemes for social mobilization. They also call for caution in estimating the reliability of this capability.