bluuebunny/crossref_metadata_2025_split huggingface dataset:
Advanced Solute Conservation Equations for Dendritic Solidification Processes Part II: Numerical Simulations and Comparisons
Authors: El‐Bealy Mostafa Omar 
Published: April 2013

AbstractThe mathematical model of derived solute equations in part I for equiaxed dendritic solidification with melt convection streams and interdendritic thermo‐metallurgical strain is applied numerically to predict macrosegregation distributions with different diffusing mechanisms in dendritic solid. Numerical and experimental results are present for solidification of a Al–4.5% Cu alloy inside horizontal rectangular cavity at different superheats. The numerical simulations were performed by using simpler method developed by Patanker. The experiments were conducted to measure the cooling curves via thermocouples and the metallurgical examinations to measure the grain size and macrosegregation distributions in Part I. Preliminary validity of the model is demonstrated by the qualitative and quantitative agreements between the measurements and predications of cooling curves and predicted macrosegregation distributions including mushy permeability and interdendritic strain. In addition, several important features of macrosegregation in equiaxed dendritic solidification are identified through this combined experimental and numerical study. Also, quantitative agreements between the numerical simulations and experiments reveal several areas for future research work. The differences and errors between predicted macrosegregation results under different diffusing mechanisms have been discussed.
Dry Granulation of Molten Slag using a Rotating Multi‐Nozzle Cup Atomizer and Characterization of Slag Particles
Authors: Qin Yuelin , Lv Xuewei , Bai Chenguang , Chen Pan , Qiu Guibao 
Published: April 2013

AbstractBlast furnace slag is the main byproduct in the ironmaking process, which contains large amounts of sensible heat. In addition, it's the major raw material for cement. However, the sensible heat is wasted not only without any recovery in the traditional water granulation process at this present. The main challenge is to granulate the slag at a high cooling rate while the heat is also being recovered. This paper describes the hot experiments where a rotating multi‐nozzle cup atomizer (RMCA) is used to atomize the molten blast furnace slag without water impingement. The atomization process shows good agreement with Rayleigh's mechanism. The particle size of the slag particle is strongly controlled by the rotating speed and the nozzle diameter, and the higher rotating speed and smaller nozzle diameter are beneficial for obtaining smaller and more uniform slag particles. Moreover, the slag particle still has a high content of glass, which is suitable for cement manufacture.
Untersuchung von Zug‐Druck‐Kalottenlagern im Großversuch
Authors: Mang F. , Herion St. , Fleischer O. , Koch E. 
Published: April 2013

AbstractDieser Beitrag beschreibt die versuchstechnischen Untersuchungen von zug‐ und druckbelasteten Brückenlagern, die im Auftrag der Deutschen Bahn AG an der Versuchsanstalt für Stahl, Holz und Steine der Universität Karlsruhe (TH) durchgeführt wurden, und stellt die daraus gewonnenen Ergebnisse dar. Dabei handelte es sich um eine Prüfung der Funktionalität der Lager und Untersuchungen zum Langzeitverhalten von Zug‐Druck‐Kalottenlagern, wie sie beim Bauprojekt "Lehrter Bahnhof Berlin" eingesetzt werden. Die Großversuche erfolgten an zwei Original‐Lagern im Maßstab 1:1 unter realistischen Auflagerlasten. Darüber hinaus werden Ermüdungsversuche an vorgespannten HV‐Schrauben M 36 der Festigkeitsklasse 10.9 beschrieben und die Ergebnisse dieser Versuche diskutiert. Diese Schrauben werden ebenfalls in den zuvor erwähnten Lagern eingesetzt.
Bruchmechanische Methoden im Sicherheitssystem des Stahlbaus
Authors: Sedlacek G. , Höhler S. , Kuhn B. , Langenberg P. 
Published: April 2013

AbstractBruchmechanische Methoden haben im Stahlbau Fuß gefaßt, um die Sicherheit von Tragwerken nicht nur hinsichtlich ihrer Festigkeit, sondern auch hinsichtlich ihrer Zähigkeit nachweisen zu können. Zähigkeitsnachweise sind erforderlich, wenn ausreichende Sicherheit gegenüber Sprödbruch erzielt werden muß. Für standardisierte Fälle führt der Zähigkeitsnachweis zu einfachen Verfahren der Stahlgütewahl, z.B. nach Teil 1.10 der EN 1993 oder nach EN 13445. Diesem Zähigkeitsnachweis liegen Werkzeuge der Bruchmechanik zugrunde, die nicht nur im konstruktiven Stahlbau, sondern auch im Behälterbau im Rahmen der Europäischen Vereinheitlichung der technischen Regelwerke harmonisiert sind. Die neuen Methoden der Stahlgütewahl führen nicht nur zu sicheren Entscheidungen für die Wahl von Werkstoff und Bauteilgestaltung, sie erhöhen gegenüber den früheren empirischen Verfahren auch die Wirtschaftlichkeit durch die Verwendbarkeit größerer Blechdicken und höherer Stahlfestigkeiten. Die Methoden der Stahlgütewahl gelten bislang für das Temperaturübergangsverhalten der Zähigkeit, jedoch noch nicht für das Hochlageverhalten. Hochlagennachweise sind aber besonders dort, wo Tragfähigkeitsnachweise mit der Annahme der Bildung plastischer Zonen geführt werden, z.B. bei Erdbebenbeanspruchung und in Fällen von Sondereinwirkungen wie Anprall und Explosion, von großer Bedeutung. Hier gibt es in Deutschland bislang nur ein empirisches Prüfverfahren, den Aufschweißbiegeversuch.
Modellierungsvarianten und Empfehlungen bei der Ermittlung von Struktur‐ und Kerbspannungen auf Basis Finiter Element‐Berechnungen
Authors: Feldmann Markus , Eichler Björn , Boos Bernd , Henkel Joachim , Mack Benjamin 
Published: April 2013

AbstractBei Einsatz von hochfesten Baustählen im Kran‐ und Brückenbau gewinnen Betriebsfestigkeitsuntersuchungen zunehmend an Bedeutung. Während beispielsweise im Offshore‐Sektor die Beurteilung des Ermüdungsverhaltens von Bauteilen mittels numerischer Methoden etabliert ist, werden Finite‐Element‐Berechnungen zur Bestimmung von Struktur‐ bzw. Kerbspannungen im Bauwesen oder auch im Kranbau seltener herangezogen. Hier dominierten bisher Nennspannungskonzepte mit einer Vielzahl an Kerbdetails. Mittlerweile weisen jedoch bereits gängige Computersysteme Leistungsressourcen auf, mit denen auch komplexeste Geometrien mit angemessenem Rechenaufwand simuliert werden können. Anhand zweier einfacher Beispiele (Stumpfstoß, Längssteife) werden wesentliche Anforderungen an das FE‐Modell und die maßgeblichen Modellierungsparameter unter Berücksichtigung von IIW‐Empfehlungen aufgezeigt. Insbesondere wird dabei auf die Vernetzung und die Elementanforderungen eingegangen. Für geschweißte Stumpfstoßverbindungen wurden darüber hinaus aus umfangreichen Parameteruntersuchungen Näherungsformeln zur Berechnung von Kerbformzahlen abgeleitet.Modeling variations and recommendations for the evaluation of structural and notch stresses based on finite element simulations. Structural durability analyses become increasingly important when using high strength structural steels in crane‐ and bridge construction. While the numerical based assessment of the fatigue behavior is established in the offshore‐sector, finite element computations for the derivation of structural and notch stresses are rarely used in civil engineering and in crane construction. Nominal stress concepts with a variety of notch details are dominating here until now. However, in the meantime common computer systems exhibit acceptable capabilities that allow for the simulation of the most complex geometries with reasonable efforts. Two simple examples (butt joint, longitudinal attachment) will demonstrate the essential requirements of the FE‐model and the relevant model parameters by taking the IIW‐recommendations in consideration. In particular, meshing details and element specifications are addressed. Furthermore, approximation formulas derived from parametric studies have been developed for the estimation of notch stress concentration factors for welded butt joints.
Beanspruchungskollektive von Turmdrehkranen
Authors: Eiwan Christoph , Fischl Andreas , Bucak Ömer , Seeßelberg Christoph 
Published: April 2013

AbstractUm im internationalen Wettbewerb konkurrenzfähig zu bleiben, müssen Hersteller bereits bei der Bemessung von Turmdrehkranen innovativ arbeiten. Die Bemessung von Turmdrehkranen erfolgt dabei auf dem schmalen Grat zwischen Wirtschaftlichkeit und Sicherheit. Für den Betriebsfestigkeitsnachweis wie auch den statischen Festigkeitsnachweis von Turmdrehkranen ist es daher wichtig, genaue Kenntnisse der Einsatzbedingungen und des Betriebsverhaltens der Krane zu erhalten.Load spectras of tower cranes. To remain competitive in international competition, manufacturers already have to work innovatively when designing tower cranes. The design of tower cranes is carried out on the thin line between profitability and safety. For the fatigue design, as well as the static strength analysis of tower cranes, it is important to obtain accurate knowledge of the working conditions and the operational performance of the cranes.
Schweißen auf der Baustelle
Authors: Trommer Gerd 
Published: April 2013

AbstractSchweißer und ihre Tätigkeit auf Baustellen stellen spezifische Anforderungen an ihr Werkzeug. Moderne, dem aktuellen Stand der Technik entsprechende Stromquellen erfüllen sie umfassend. Beispielhaft dafür steht ein Elektroden‐ und WIG‐DC‐Schweißsystem der 150‐A‐Klasse. Seine Leistungsmerkmale und sein Anwendungsspektrum bilden eine gelungene Verbindung aus Technik, Qualität, Wirtschaftlichkeit und Bedienerfreundlichkeit.
“Anatomy Lesson of Frederik Ruysch” of 1670: A Tribute to Ruysch’s Contributions to Lymphatic Anatomy
Authors: IJpma Frank F. A. , van Gulik Thomas M. 
Published: April 2013

AbstractBackgroundFrederick Ruysch was one of the most prominent Dutch physicians of the seventeenth and eighteenth centuries. For more than 65 years, he was the Praelector Anatomiae (Lecturer of Anatomy) of the Amsterdam Guild of Surgeons. During his career, he conducted many dissections at the guild’s theatre to teach anatomy. Ruysch was internationally renowned for his great dissection skills and his innovative techniques for preserving anatomical specimens. The “Anatomy Lesson of Dr. Frederik Ruysch” painted in 1670, is thought to be a group portrait undertaken to commemorate the officials of the Guild of Surgeons. Ruysch was portrayed performing an anatomical dissection of inguinal lymph nodes on the corpse of an executed criminal. This portrait is one of the earliest paintings focusing on the “lymphatic system.”MethodsWe investigated the medical background of the painting by revisiting Ruysch’s original work from the mid‐seventeenth century. His contributions to the early history of “lymphatic anatomy” are assessed and interpreted from the perspective of the renewed interest in “lymphatic imaging” today.Results and conclusionsFrederik Ruysch should be considered one of the pioneers contributing to the early knowledge of the lymphatic system. He succeeded in dissecting the lymphatic vessels and valves with the aid of his innovative dissection and preservation techniques. The famous group portrait of the Amsterdam Guild of Surgeons with Ruysch demonstrating the lymph nodes pays tribute to his work on which we still rely today.
Extended Lymphadenectomy in Esophageal Cancer is Debatable
Authors: Herbella Fernando A. M. , Laurino Neto Rafael M. , Allaix Marco E. , Patti Marco G. 
Published: April 2013

AbstractSurgery is an essential part of the treatment of patients with esophageal carcinoma. However, there is no consensus on whether the surgical technique can be improved to promote better survival outcome. Specifically, the real value of the addition of a radical lymphadenectomy to the esophageal resection is still elusive and controversial. This paper focuses on the debate of esophagectomy and lymphadenectomy for the treatment of esophageal cancer.
Stability and sensitivity analysis in a simplified solid rocket motor flow
Authors: Boyer G. , Casalis G. , Estivalèzes J. L. 
Published: April 2013

AbstractThe present article aims at enhancing the computation of the global stability modes of the internal flow of solid rocket motors (SRMs) approximated by the Taylor–Culick solution. This modal approach suffers from the consequences of the non-normality of the global linearized incompressible Navier–Stokes operator, namely the lack of robustness of the eigenvalues that can lead to the computation of pseudo-modes rather than actual eigenmodes. In this respect, the effects of non-normality associated with strongly amplified eigenfunctions are highlighted on a simplified convective–diffusive stability problem with uniformly accelerated base state, the latter property being a typical characteristic of the Taylor–Culick flow. Non-convergence zones for the eigenvalues are exhibited for large Reynolds numbers and are related to the critical sensitivity to disturbances applied to one of the boundary conditions. For this reason, and according to experimental and numerical data related to the stability of simplified SRMs, a global stability analysis is performed assuming that the hydrodynamic fluctuations emerge from a geometrical defect applied at the sidewall. This comes to fix the upstream boundary condition at the abscissa of the sidewall disturbance. The resulting eigenmodes are shown to be discrete, numerically converged, well identified by a finite number of points of undefined phase of the velocity fluctuations. They marginally depend on Reynolds number variations, but are modified by changes on the boundaries location. As in the simplified problem, the inflow boundary condition is the most critical in terms of sensitivity to numerical errors, although not dramatic. Finally, the sensitivity analysis to infinitesimal base flow changes indicates that the variations applied close to the inflow boundary condition induce the largest move of the eigenvalues. In spite of the large non-normal effects induced by the large polynomial growth of the eigenfunctions, this paper shows that discrete instabilities may emerge from a wall defect, in contrast to configurations without such a geometrical perturbation whose dynamics may be rather driven by pseudo-modes.
The Bulge of M31
Authors: Mould Jeremy 
Published: April 2013

AbstractBulges are not just elliptical subgalaxies situated in the centers of large spirals, though it might seem so from their ages and chemistry. In fact, bulge kinematics have been known to be different since the first long slit spectra were obtained. M31 presents the best opportunity to investigate all the issues of the stellar populations of bulges. This review collects the array of probing data that has been accumulated during the last decade. But the intriguing question ‘how did it form like this?’ remains.
Primary mastoid cyst
Authors: Tan C Y , Chong S , Shaw C-K L 
Published: April 2013

AbstractObjective:To report an unusual case of a primary mastoid cyst (congenital or developmental) in a patient without otological symptoms.Method:Case report and review of the English language literature.Results:Primary mastoid cyst is a newly reported and very rare pathological entity. Mastoid cysts usually occur secondary to chronic infection, inflammation or trauma. Review of the medical literature highlights the rarity of this condition.Conclusion:This report describes the experience gained by the diagnosis and management of this patient. It emphasises the importance of clinical vigilance so that proper treatment may be instituted in a timely manner.
The Politicization of Women Workers at War: Labour in Chongqing's cotton mills during the Anti-Japanese War
Authors: HOWARD JOSHUA H. 
Published: April 2013

AbstractBuilding on recent scholarship that highlights social change caused by the Anti-Japanese War, this paper traces the politicization of women working in the cotton mills of Chongqing, the Nationalist wartime capital. Upon joining the workforce in the late 1930s, most cotton mill hands were young, uneducated women expected to endure hard work and remain physically confined to the factories. By 1945, women workers were at the forefront of a militant labour movement, writing manifestoes and petitioning government officials. This process of politicization stemmed from their decision to work in factories, which breached societal norms, and their experience of disciplined labour regimes and brutal working conditions, which fostered an incipient class-consciousness. Moreover, Nationalist-sponsored factory education campaigns had the unintended effect of leading women to challenge class exploitation and sexual discrimination. Their participation in the labour movement, which was fuelled by their struggle for economic justice and desire for higher social status, used both legal forms— especially petitions and letters to the press couched in the wartime nationalist rhetoric of shared sacrifice—and extralegal means, namely class violence. The paper concludes that the social changes and conflict that accompanied women's wartime work helped prepare the terrain for Communist rule.
Identification of compounds from Paris polyphylla (ChongLou) active against Dactylogyrus intermedius
Authors: LI ZE-HONG , WAN JIA-YU , WANG GUI-QIN , ZHAO FU-GUANG , WEN JI-HONG 
Published: April 2013

SUMMARYThe present study was designated to ascertain the anthelmintic activity of the rhizomes of Paris polyphylla and to isolate and characterize the active constituents. The methanol extract from rhizomes of P. polyphylla showed signiﬁcant anthelmintic activity against Dactylogyrus intermedius with the median effective concentration (EC50) 22·5 mg L−1. Based on this finding, the methanol extract was fractionated by silica gel column chromatography in a bioassay-guided fractionation yielding 2 bioactive compounds, the structures of these compounds were elucidated as formosanin C and polyphyllin VII. The in vivo tests revealed that formosanin C and polyphyllin VII were significantly effective against D. intermedius with EC50 values of 0·6 and 1·2 mg L−1, respectively. The acute toxicities (LC50) of formosanin C and polyphyllin VII for grass carp were 2·8 and 2·9 mg L−1, respectively. The overall results provide important information for the potential application of formosanin C and polyphyllin VII in the therapy of serious infection caused by D. intermedius.
Genetic dissection of drug resistance in trypanosomes
Authors: ALSFORD SAM , KELLY JOHN M. , BAKER NICOLA , HORN DAVID 
Published: April 2013

SUMMARYThe trypanosomes cause two neglected tropical diseases, Chagas disease in the Americas and African trypanosomiasis in sub-Saharan Africa. Over recent years a raft of molecular tools have been developed enabling the genetic dissection of many aspects of trypanosome biology, including the mechanisms underlying resistance to some of the current clinical and veterinary drugs. This has led to the identification and characterization of key resistance determinants, including transporters for the anti-Trypanosoma bruceidrugs, melarsoprol, pentamidine and eflornithine, and the activator of nifurtimox-benznidazole, the anti-Trypanosoma cruzidrugs. More recently, advances in sequencing technology, combined with the development of RNA interference libraries in the clinically relevant bloodstream form ofT. bruceihave led to an exponential increase in the number of proteins known to interact either directly or indirectly with the anti-trypanosomal drugs. In this review, we discuss these findings and the technological developments that are set to further revolutionise our understanding of drug-trypanosome interactions. The new knowledge gained should inform the development of novel interventions against the devastating diseases caused by these parasites.
Comparison of psychotherapies for adult depression to pill placebo control groups: a meta-analysis
Authors: Cuijpers P. , Turner E. H. , Mohr D. C. , Hofmann S. G. , Andersson G. , Berking M. , Coyne J. 
Published: April 2013

BackgroundThe effects of antidepressants for treating depressive disorders have been overestimated because of selective publication of positive trials. Reanalyses that include unpublished trials have yielded reduced effect sizes. This in turn has led to claims that antidepressants have clinically insignificant advantages over placebo and that psychotherapy is therefore a better alternative. To test this, we conducted a meta-analysis of studies comparing psychotherapy with pill placebo.MethodTen 10 studies comparing psychotherapies with pill placebo were identified. In total, 1240 patients were included in these studies. For each study, Hedges’ g was calculated. Characteristics of the studies were extracted for subgroup and meta-regression analyses.ResultsThe effect of psychotherapy compared to pill placebo at post-test was g = 0.25 [95% confidence interval (CI) 0.14–0.36, I2 = 0%, 95% CI 0–58]. This effect size corresponds to a number needed to treat (NNT) of 7.14 (95% CI 5.00–12.82). The psychotherapy conditions scored 2.66 points lower on the Hamilton Depression Rating Scale (HAMD) than the placebo conditions, and 3.20 points lower on the Beck Depression Inventory (BDI). Some indications for publication bias were found (two missing studies). We found no significant differences between subgroups of the studies and in meta-regression analyses we found no significant association between baseline severity and effect size.ConclusionsAlthough there are differences between the role of placebo in psychotherapy and pharmacotherapy research, psychotherapy has an effect size that is comparable to that of antidepressant medications. Whether these effects should be deemed clinically relevant remains open to debate.
Using structural neuroanatomy to identify trauma survivors with and without post-traumatic stress disorder at the individual level
Authors: Gong Q. , Li L. , Tognin S. , Wu Q. , Pettersson-Yeo W. , Lui S. , Huang X. , Marquand A. F. , Mechelli A. 
Published: April 2013

BackgroundAt present there are no objective, biological markers that can be used to reliably identify individuals with post-traumatic stress disorder (PTSD). This study assessed the diagnostic potential of structural magnetic resonance imaging (sMRI) for identifying trauma-exposed individuals with and without PTSD.MethodsMRI scans were acquired from 50 survivors of the Sichuan earthquake of 2008 who had developed PTSD, 50 survivors who had not developed PTSD and 40 healthy controls who had not been exposed to the earthquake. Support vector machine (SVM), a multivariate pattern recognition technique, was used to develop an algorithm that distinguished between the three groups at an individual level. The accuracy of the algorithm and its statistical significance were estimated using leave-one-out cross-validation and permutation testing.ResultsWhen survivors with PTSD were compared against healthy controls, both grey and white matter allowed discrimination with an accuracy of 91% (p < 0.001). When survivors without PTSD were compared against healthy controls, the two groups could be discriminated with accuracies of 76% (p < 0.001) and 85% (p < 0.001) based on grey and white matter, respectively. Finally, when survivors with and without PTSD were compared directly, grey matter allowed discrimination with an accuracy of 67% (p < 0.001); in contrast the two groups could not be distinguished based on white matter.ConclusionsThese results reveal patterns of neuroanatomical alterations that could be used to inform the identification of trauma survivors with and without PTSD at the individual level, and provide preliminary support to the development of SVM as a clinically useful diagnostic aid.