bluuebunny/crossref_metadata_2025_split huggingface dataset:
Untersuchungen zum Schweißen in kaltumgeformten Bereichen
Authors: Kuhlmann Ulrike , Kudla Konrad 
Published: October 2015

AbstractDie Prozesse Kaltumformen und Schweißen zählen zu den typischen Fertigungsverfahren im Stahl‐ und Anlagenbau. Durch den Prozess Kaltumformen erfolgt eine Querschnittsformgebung aus dem ebenen Blechzustand in eine profilierte Form. Beim späteren Fügeprozess werden die so gefertigten Bauteile häufig in der kaltumgeformten Zone verschweißt. Durch den Umformprozess wird das Material im Bereich der Umformzone im plastischen Bereich gedehnt und gestaucht. Die Dehnungen führen zu einem Eigenspannungszustand und einer erhöhten Sprödbruchgefahr. Durch den Schweißprozess in der plastisch umgeformten Zone entsteht unter anderem eine Wärmebehandlung, die die Versprödung des Materials begünstigen kann. Durch aktuelle Regelwerke wird das Schweißen im kaltumgeformten Bereich durch Mindestabstände oder durch einzuhaltende Verhältnisse Biegeradius zu Blechdicke r/t eingeschränkt. In diesem Beitrag werden Ergebnisse aus einem Forschungsvorhaben vorgestellt, das sich zum Ziel gesetzt hat, durch experimentelle und numerische Untersuchungen vorhandene Kriterien und Bedingungen zum Schweißen von kaltumgeformten Bauteilen zu überprüfen und weiterzuentwickeln.Investigations on welding in cold‐formed areas. Cold forming and welding are typical production processes for steel and plant construction. Cold forming is a process where a planar metal plate is transformed into a profiled cross‐sectional shape. These cold formed elements are often connected by welding in the cold formed zone. In the cold formed zone, the metal is stretched and compressed into the plastic range. The strains due to cold forming lead to residual stresses and brittle failure becomes more likely. Welding in the plastic formed zones means a heat treatment, which may induce an embrittlement of the material. In current design codes, welding in cold formed zones is restricted to certain minimum distances or limiting ratios of bending radius to plate thickness r/t. The paper presents results of a research project, which includes experimental and numerical investigations. It is the aim of this research project to verify and to improve existing criteria and conditions regarding welding in cold formed zones.
Trapezblechstege im Verbundbau
Authors: Raichle Jochen , Kuhlmann Ulrike 
Published: October 2015

AbstractDie Anwendung von trapezförmig gekanteten Stegen im Verbundbrückenbau bietet zahlreiche Vorteile. Durch die Einbindung des gekanteten Stahlstegs in den Betongurt ist die direkte Übertragung von Schubkräften und Biegemomenten in der Verbundfuge möglich. Die zusätzliche Anordnung von randnahen Kopfbolzen steigert die Tragfähigkeit und verbessert die Gebrauchstauglichkeit der Verbundfuge. Da die Kopfbolzen nahe zum Bauteilrand des Stahlbetongurts angeordnet werden, muss der Einfluss dieser randnahen Ausbildung, insbesondere die hervorgerufenen Spaltzugkräfte, berücksichtigt werden. Dieser Beitrag stellt Forschungsergebnisse von experimentellen und numerischen Untersuchungen zu einer Längsschub‐ und einer Querbiegebeanspruchung der Verbundfuge dar. Es wird das Tragverhalten der Verbindung erläutert. Außerdem werden Bemessungsgleichungen für diese Beanspruchungen bereitgestellt sowie konstruktive Hinweise gegeben.Corrugated steel webs in composite construction – longitudinal shear and transverse bending moment with headed studs close to the concrete surface. The application of corrugated steel webs in composite bridges leads to many advantages. The embedment of the corrugated web allows transferring shear forces and bending moments at the composite connection. The additional arrangement of horizontally lying headed studs increases the carrying capacity and improves the serviceability of the composite connection. As the headed studs are positioned close to the surface of the concrete slab, the edge influence inducing splitting forces has to be considered. This paper shows results of research work on longitudinal shear and transverse bending moment at the composite connection. The load carrying behavior is illustrated. Furthermore design equations of the resistances and some constructional recommendations are given.
Profil‐ und systemabhängige Tragfähigkeiten biegedrillknickgefährdeter Träger aus gewalzten I‐Profilen
Authors: Ebel Rebekka , Kindmann Rolf , Knobloch Markus 
Published: October 2015

AbstractDieser Beitrag analysiert das Tragverhalten biegedrillknickgefährdeter Träger. Im Fokus stehen als Basissysteme Einfeld‐ und Zweifelträger sowie Kragträger jeweils unter einachsiger Biegung. Neben der Spannweite und dem Profil beeinflusst auch das statische System das Tragverhalten. Die Ergebnisse einer umfassenden numerischen Parameterstudie mit Hilfe der Finiten‐Elemente‐Methode zeigen unter anderem eine große profilabhängige Streuung der Tragfähigkeiten auf.Das Tragverhalten wird durch verschiedene Versagenskriterien charakterisiert. Vier unterschiedliche Kriterien begrenzen die Traglasten und charakterisieren Tragverhalten und Versagen. Sie sind abhängig vom statischen System und Profil in unterschiedlichen Schlankheitsbereichen maßgebend. Die Erkenntnisse zum Tragverhalten werden genutzt, um bestehende analytische Verfahren zu bewerten und die Gründe für Abweichungen zu numerischen Berechnungsergebnissen zu analysieren. Abweichungen von teilweise über 20 % zeigen, dass vereinfachte Verfahren system‐ wie auch die profilabhängigen Streuungen nur unzureichend erfassen. Der Beitrag zeigt Folgen einer Iy/IT‐abhängigen Ermittlung von Imperfektionsbeiwerten je System auf. Dieses Vorgehen ermöglicht es, besonders für Einfeldträger mit Streckenlasten die Streuungen im Hauptanwendungsbereich auf 4 % zu begrenzen.Influence of cross sections and static systems on the load bearing capacity of rolled I‐section beams subjected to lateral torsional buckling. This paper analyses the load‐bearing behaviour of beams subjected to lateral torsional buckling. Single span beams, two‐span beams and cantilever beams in uniaxial bending are chosen as basic systems. In addition to the length and the cross section the static system influences the bearing characteristics and capacities. The results of a comprehensive numerical parameter study indicates a large scatter of the bearing capacities.The bearing behaviour is characterised by different failure criteria. The decisive slenderness range of the criteria depends on the static system and the cross section. These results can be used to review commonly used analytical methods. The large scatter of the comparative study indicates that simplified models have difficulties in describing the influence of the static system and the cross section on the load bearing behaviour. Finally the paper presents an Iy/IT‐ratio dependent approach for each system. Especially for the single span beam this approach reduces the scatter to 4 % in the main application range.
Zur Nachhaltigkeit von Stahl‐ und Verbundkonstruktionen bei Büro‐ und Verwaltungsgebäuden – Tragkonstruktionen (Teil 3)
Authors: Stroetmann Richard , Podgorski Christine , Faßl Thomas 
Published: October 2015

AbstractDer folgende Beitrag zur Nachhaltigkeit von Tragkonstruktionen für Büro‐ und Verwaltungsgebäude ist eine Fortsetzung des Aufsatzes in [1] und [2]. Im ersten Teil wurden zunächst eine Übersicht über das AIF‐FOSTA‐Projekt P881 gegeben und die Objektanforderungen an die Tragkonstruktionen sowie Deckensysteme in Stahl‐ und Verbundbauweise beschrieben. Nach einer Darstellung zur Normungssituation und zu Bewertungssystemen wurde die im Forschungsprojekt angewendete Methodik zur Beurteilung der ökologischen und ökonomischen Qualität von Tragkonstruktionen erläutert. Ferner ging der Beitrag auf Untersuchungen zur Optimierung von Deckensystemen ein. Gegenstand des zweiten Teils war die Querschnittswahl und Bemessung der Gebäudestützen für ständige und vorübergehende Bemessungssituationen sowie für den Brandfall unter Nachhaltigkeitskriterien. Anschließend wurden die Ergebnisse aus Parameterstudien zur Optimierung von Tragsystemen mit Unterzugsdecken vorgestellt, in denen die Decken, Trägersysteme und Stützen einbezogen wurden.In diesem Beitrag werden Parameterstudien zur Ökologie und zu den Kosten von Slim‐Floor‐Systemen, eine Gegenüberstellung mit Unterzugsdecken sowie Untersuchungen zum Einfluss der Anschlüsse vorgestellt. Abschließend werden zusammenfassende Erläuterungen zur Wahl der Deckensysteme und Stützen sowie Hinweise auf die im Projekt P881 erarbeiteten Planungshilfen gegeben.Sustainability of steel and composite structures of office and administration buildings – Structural systems (part 3). The following paper on the sustainability of structural systems of office and administration buildings is a sequel of the articles in [1] and [2]. In the first part, an overview on the AIF FOSTA Project P881 was given and the requirements resulting from the building and structural design as well as slab systems in steel and composite construction were described. After an overview on the standardization situation and assessment systems, the methods used in the research project to assess the environmental and economic performance of structural systems were explained. In addition, the paper discussed studies on the optimization of slab systems. The choice of the cross‐section and the dimensioning of the building columns for persistent and transient design situations as well as for the case of fire considering sustainability criteria were the subject of the second part.In this paper, the results of parametric studies on the ecology and costs of slim floor systems, a comparison with slabs with downstand beams, and studies on the influence of joints are presented. Finally, summarizing remarks on the choice of floor systems and columns as well as comments on the planning tools developed in Project P881 are given.
Brief Report: Immune Microenvironment Determines the Immunogenicity of Induced Pluripotent Stem Cell Derivatives
Authors: Todorova Dilyana , Kim Jinchul , Hamzeinejad Sara , He Jingjin , Xu Yang 
Published: October 2015

Abstract
The breakthrough of induced pluripotent stem cells (iPSCs) has raised the possibility that patient-specific iPSCs can provide autologous cells for cell therapy without the concern for immune rejection. However, the immunogenicity of iPSC-derived cells remains controversial. Using syngeneic C57BL/6 (B6) mouse transplantation model, several studies indicate that B6 iPSC-derived cells exhibit some levels of immunogenicity when transplanted into B6 mice subcutaneously. In contrast, one recent study has concluded that various lineages of B6 iPSC-derived cells exhibit no immunogenicity when transplanted under the kidney capsule of B6 mice. To resolve the controversy concerning this critical issue of iPSC biology, we used the same B6 transplantation model to demonstrate that the immune response toward antigens is dependent on the immune environment of the transplantation site. Immunogenic antigen-expressing B6 embryonic stem cells (ESCs) as well as B6 iPSCs and their terminally differentiated cells survived under the kidney capsule but are immune rejected when transplanted subcutaneously or intramuscularly. The cotransplantation of mature B6 dendritic cells under the kidney capsule leads to immune rejection of B6 iPSC-derived grafts but not B6 ESC-derived grafts, indicating that the lack of detectable immune response to iPSC-derived grafts under the kidney capsule is due to the lack of functional antigen presenting cells.
P-Selectin Sustains Extramedullary Hematopoiesis in the G
ata1low Model of Myelofibrosis
Authors: Spangrude Gerald J. , Lewandowski Daniel , Martelli Fabrizio , Marra Manuela , Zingariello Maria , Sancillo Laura , Rana Rosa Alba , Migliaccio Anna Rita 
Published: October 2015

Abstract
Splenomegaly is a major manifestation of primary myelofibrosis (PMF) contributing to clinical symptoms and hematologic abnormalities. The spleen from PMF patients contains increased numbers of hematopoietic stem cells (HSC) and megakaryocytes (MK). These MK express high levels of P-selectin (P-sel) that, by triggering neutrophil emperipolesis, may cause TGF-β release and disease progression. This hypothesis was tested by deleting the P-sel gene in the myelofibrosis mouse model carrying the hypomorphic Gata1low mutation that induces megakaryocyte abnormalities that recapitulate those observed in PMF. P-selnullGata1low mice survived splenectomy and lived 3 months longer than P-selWTGata1low littermates and expressed limited fibrosis and osteosclerosis in the marrow or splenomegaly. Furthermore, deletion of P-sel disrupted megakaryocyte/neutrophil interactions in spleen, reduced TGF-β content, and corrected the HSC distribution that in Gata1low mice, as in PMF patients, is abnormally expanded in spleen. Conversely, pharmacological inhibition of TGF-β reduced P-sel expression in MK and corrected HSC distribution. Spleens, but not marrow, of Gata1low mice contained numerous cKITpos activated fibrocytes, probably of dendritic cell origin, whose membrane protrusions interacted with MK establishing niches hosting immature cKITpos hematopoietic cells. These activated fibrocytes were not detected in spleens from P-selnullGata1low or TGF-β-inhibited Gata1low littermates and were observed in spleen, but not in marrow, from PMF patients. Therefore, in Gata1low mice, and possibly in PMF, abnormal P-sel expression in MK may mediate the pathological cell interactions that increase TGF-β content in MK and favor establishment of a microenvironment that supports myelofibrosis-related HSC in spleen.
Coordination Polymers with Different Dimensionalities: from 2D Layer to 3D Framework
Authors: Zhang Yongde , Du Zhongwei , Luo Xuegang 
Published: October 2015

AbstractTwo coordination polymers, namely [Cd(HL)2]n·nH2O (1) and [Zn(L)]n (2) (H2L = benzimidazole‐2‐butanoic acid), were prepared by solvothermal reaction of Cd(NO3)2 or Zn(NO3)2 and H2L. The structures of these two compounds were determined by the single‐crystal X‐ray diffraction analyses and further characterized by IR spectroscopy, elemental analyses, powder X‐ray diffraction analyses, and thermal analyses. Compound 1 is a two‐dimensional (2D) layer framework, which is further packed into a 3D supramolecular framework by intermolecular hydrogen bonds, whereas compound 2 is a three‐dimensional (3D) framework with 3‐connected etb topology. The H2L ligand in compounds 1 and 2 displays two different anionic forms (HL– and L2–), which then adopt two different coordination modes. Moreover, thermal stabilities and luminescent properties of these two compounds were also investigated.
V16N1.5: Metastable or Missing in the Binary Phase Diagram?
Authors: Widenmeyer Marc , Wessel Claudia , Dronskowski Richard , Niewa Rainer 
Published: October 2015

AbstractThe stability of V16N1.5 was investigated by experiments and density functional calculations. Three synthetic approaches besides the classical reaction of vanadium with flowing ammonia were evaluated: (i) The ammonolysis of β‐V2H, (ii) the reaction of vanadium and δ‐VN at elevated temperatures in sealed ampoules, and (iii) the thermal decomposition of δ‐VN in dynamic vacuum at high temperatures. However, none of them was suitable to provide single phase V16N1.5 yet. The results achieved by experiments and by simulations both indicate an absence of significant homogeneity range for V16N1.5. The high‐temperature experiments suggest a strongly enhanced thermal stability for V16N1.5 than reported in literature, suggesting V16N1.5 to represent a thermodynamically stable compound rather than being metastable. Temperature dependent powder X‐ray diffraction proves stability of V16N1.5 up to 700 °C. During a thermal analysis experiment in argon V16N1.5 was still observed after 24 h at 1300 °C. Consequently, first‐principle calculations of the thermodynamic properties of V16N1.5 revealed an endothermal decomposition to V and β‐V2N.
Tricarbonylrhenium(I) Complexes with N‐Heterocyclic Thiones and Selenols
Authors: Meltzer Antje , Cargnelutti Roberta , Hagenbach Adelheid , Schulz Lang Ernesto , Abram Ulrich 
Published: October 2015

AbstractReactions of (NEt4)2[Re(CO)3Br3] with N‐heterocyclic thiols such as 2‐mercaptobenzimidazole (H2Sbenzim), 2‐mercaptothiazoline (HSthiaz), or 5‐mercapto‐1‐methyltetrazole (HSmetetraz) give rhenium(I) complexes of various compositions: (NEt4)[Re(CO)3Br2(H2Sbenzim)], [Re(CO)3(HSthiaz)3]Br, and (NEt4)[Re2(CO)6(μ‐S‐Smetetraz‐κS)(μ‐N,S‐Smetetraz‐κS,N)2]. Corresponding reactions with 2‐mercaptopyridine (HSpy) and bis(2‐pyridine)diselenide [(Sepy)2] did not give defined products in reasonable yields, whereas [Re(CO)5Br] reacts with HSpy and (Sepy)2 with formation of [Re(CO)3(HSpy)3]Br and [Re2(CO)6(Sepy)2], respectively. All reactions were performed without the addition of a supporting base and the sulfur‐containing organic ligands are coordinated in their thione forms with the exception of Smetetraz– in its μS‐bridging coordination mode in (NEt4)[Re2(CO)6(μ‐S‐Smetetraz‐κS)(μ‐N,S‐Smetetraz‐κS,N)2], which can be regarded as thiolate. The bonding mode of the selenium containing ligands in the dimeric compound [Re2(CO)6(Sepy)2] (C–Se distance: 1.93 Å) can also best be described as selenolate. The products are stable on air at an ambient temperature. They were studied spectroscopically and by X‐ray diffraction.
Dietary Linseed Oil Reduces Growth While Differentially Impacting LC‐PUFA Synthesis and Accretion into Tissues in Eurasian Perch (Perca fluviatilis)
Authors: Geay F. , Wenon D. , Mellery J. , Tinti E. , Mandiki S. N. M. , Tocher D. R. , Debier C. , Larondelle Y. , Kestemont P. 
Published: October 2015

AbstractThe aim of this study was to evaluate the impact of replacing dietary fish oil (FO) with linseed oil (LO) on growth, fatty acid composition and regulation of lipid metabolism in Eurasian perch (Perca fluviatilis) juveniles. Fish (17.5 g initial body weight) were fed isoproteic and isoenergetic diets containing 116 g/kg of lipid for 10 weeks. Fish fed the LO diet displayed lower growth rates and lower levels of DHA in the liver and muscle than fish fed the FO diet, while mortality was not affected by dietary treatment. However, DHA content recorded in the liver and muscle of fish fed the LO diet remained relatively high, despite a weight gain of 134 % and a reduced dietary level of long‐chain polyunsaturated fatty acids (LC‐PUFA), suggesting endogenous LC‐PUFA biosynthesis. This was supported by the higher amounts of pathway intermediates, including 18:4n‐3, 20:3n‐3, 20:4n‐3, 18:3n‐6 and 20:3n‐6, recorded in the liver of fish fed the LO diet in comparison with those fed the FO diet. However, fads2 and elovl5 gene expression and FADS2 enzyme activity were comparable between the two groups. Similarly, the expression of genes involved in eicosanoid synthesis was not modulated by dietary LO. Thus, the present study demonstrated that in fish fed LO for 10 weeks, growth was reduced but DHA levels in tissues were largely maintained compared to fish fed FO, suggesting a physiologically relevant rate of endogenous LC‐PUFA biosynthesis capacity.
Differences and overlap in self-reported symptoms of bipolar disorder and borderline personality disorder
Authors: Baryshnikov I. , Aaltonen K. , Koivisto M. , Näätänen P. , Karpov B. , Melartin T. , Heikkinen M. , Ketokivi M. , Joffe G. , Isometsä E. 
Published: October 2015

AbstractBackgroundDifferential diagnosis between bipolar disorder (BD) and borderline personality disorder (BPD) is often challenging due to some overlap in symptoms and comorbidity of disorders. We investigated correlations in self-reported symptoms of BD and BPD in screening questionnaires at the levels of both total scores and individual items and explored overlapping dimensions.MethodsThe McLean Screening Instrument (MSI) for BPD and the Mood Disorder Questionnaire (MDQ) for BD were filled in by patients with unipolar and bipolar mood disorders (n = 313) from specialized psychiatric care within a pilot study of the Helsinki University Psychiatric Consortium. Pearson's correlation coefficients between total scores and individual items of the MSI and the MDQ were estimated. Relationships between MDQ and MSI were evaluated by exploratory factor analysis (EFA).ResultsThe correlation between total scores of the MDQ and MSI was moderate (r = 0.431, P < 0.001). Significant correlations were found between the MSI items of “impulsivity” and “mood instability” and all MDQ items (P < 0.01). In the EFA, the MSI “impulsivity” and “mood instability” items had significant cross-loadings (0.348 and 0.298, respectively) with the MDQ factor. The MDQ items of “irritability”, “flight of thoughts” and “distractibility” (0.280, 0.210 and 0.386, respectively) cross-loaded on the MSI factor.ConclusionsThe MDQ and MSI items of “affective instability”, “impulsivity”, “irritability”, “flight of thoughts” and “distractibility” appear to overlap in content. The other scale items are more disorder-specific, and thus, may help to distinguish BD and BPD.
On Knudsen-minimum effect and temperature bimodality in a dilute granular Poiseuille flow
Authors: Alam Meheboob , Mahajan Achal , Shivanna Deepthi 
Published: October 2015

The numerical simulation of gravity-driven flow of smooth inelastic hard disks through a channel, dubbed ‘granular’ Poiseuille flow, is conducted using event-driven techniques. We find that the variation of the mass-flow rate ($Q$) with Knudsen number ($Kn$) can be non-monotonic in the elastic limit (i.e. the restitution coefficient$e_{n}\rightarrow 1$) in channels with very smooth walls. The Knudsen-minimum effect (i.e. the minimum flow rate occurring at$Kn\sim O(1)$for the Poiseuille flow of a molecular gas) is found to be absent in a granular gas with$e_{n}<0.99$, irrespective of the value of the wall roughness. Another rarefaction phenomenon, the bimodality of the temperature profile, with a local minimum ($T_{\mathit{min}}$) at the channel centerline and two symmetric maxima ($T_{\mathit{max}}$) away from the centerline, is also studied. We show that the inelastic dissipation is responsible for the onset of temperature bimodality (i.e. the ‘excess’ temperature,${\rm\Delta}T=(T_{\mathit{max}}/T_{\mathit{min}}-1)\neq 0$) near the continuum limit ($Kn\sim 0$), but the rarefaction being its origin (as in the molecular gas) holds beyond$Kn\sim O(0.1)$. The dependence of the excess temperature${\rm\Delta}T$on the restitution coefficient is compared with the predictions of a kinetic model, with reasonable agreement in the appropriate limit. The competition between dissipation and rarefaction seems to be responsible for the observed dependence of both the mass-flow rate and the temperature bimodality on$Kn$and$e_{n}$in this flow. The validity of the Navier–Stokes-order hydrodynamics for granular Poiseuille flow is discussed with reference to the prediction of bimodal temperature profiles and related surrogates.