Steel silos for particulate solid materials : part 2 - membrane forces at filling and discharge.

In the paper, the expressions for membrane forces in an axisymmetric steel silo structure at filling and discharge with a particulate solid material are presented. Graphical plots of these expressions are given. They can be used for a quick and easy estimate of membrane forces distribution in all parts of a silo structure. The plots are valid for any silo geometry and for any material stored. The influence of silo geometry and stored material properties on the size and distribution of membrane forces can be thus checked. The paper completes with an illustrative example where actions (pressure loads) at filling and discharge on the walls of a silo are computed and the corresponding membrane forces are evaluated

Steel silos for particulate solid materials. Part 1, Actions at filling and discharge.

In the paper, the expressions for membrane forces in an axisymmetric steel silo structure at filling and discharge with a particulate solid material are presented. Graphical plots of these expressions are given. They can be used for a quick and easy estimate of membrane forces distribution in all parts of a silo structure. The plots are valid for any silo geometry and for any material stored. The influence of silo geometry and stored material properties on the size and distribution of membrane forces can be thus checked. The paper completes with an illustrative example where actions (pressure loads) at filling and discharge on the walls of a silo are computed and the corresponding membrane forces are evaluated

Steel silos for particulate solid materials. Part 1, Actions at filling and discharge.

V članku podajamo izraze za membranske sile v osno-simetričnem jeklenem silosu med procesoma polnjenja in praznjenja s sipkim materialom. Izrazi so predstavljeni tudi v grafični obliki, kar omogoča hitro in enostavno oceno velikosti in razporeditve membranskih sil v posameznih delih silosa. Grafi veljajo za poljubno geometrijo silosa in za poljuben material, ki se hrani. Na podlagi teh grafov lahko preverimo, kakšen je vpliv geometrije silosa in shranjenega materiala na razporeditev in velikost membranskih sil. Na koncu podajamo ilustrativen primer izračuna vplivov (pritiskov) in membranskih sil pri polnjenju in praznjenju silosa.In the paper, the expressions for membrane forces in an axisymmetric steel silo structure at filling and discharge with a particulate solid material are presented. Graphical plots of these expressions are given. They can be used for a quick and easy estimate of membrane forces distribution in all parts of a silo structure. The plots are valid for any silo geometry and for any material stored. The influence of silo geometry and stored material properties on the size and distribution of membrane forces can be thus checked. The paper completes with an illustrative example where actions (pressure loads) at filling and discharge on the walls of a silo are computed and the corresponding membrane forces are evaluated

Stresses in elastically supported cylindrical shells under wind load and foundation settlement

Thin-walled shell structures of a circular cylindrical shape are widely used in structural engineering to serve in applications such as silos, tanks or chimneys. The design of such structures poses some considerable challenges to structural engineers as the load carrying behaviour of cylindrical shells is quite complex, especially for non-axisymetric load cases. Very often a comprehensive analysis causes considerable expenses and the vast amounts of results which are typically generated make it hard to understand the underlying load-carrying principles of the structure. The introduction of an engineering method to handle two typical non-axisymetric load cases on circular cylindrical thin-walled shell structures is the goal of this paper. The proposed method offers a quick way to generate critical section forces and displacements. The load cases discussed herein are wind-loading and foundationsettlement. Ground support for many cylindrical steel structures is often realised by anchoring the lower shell boundary to a concrete foundation. This is accomplished by steel bolts that can be looked at as spring elements providing elastic support for the shell structure. The influence of this type of support on the section forces and displacements under wind loading can be modelled by combining the two abovementioned load cases via an interaction diagram also given in this paper

Steel silos for particulate solid materials : part 2 - membrane forces at filling and discharge.

V članku podajamo izraze za membranske sile v osno-simetričnem jeklenem silosu med procesoma polnjenja in praznjenja s sipkim materialom. Izrazi so predstavljeni tudi v grafični obliki, kar omogoča hitro in enostavno oceno velikosti in razporeditve membranskih sil v posameznih delih silosa. Grafi veljajo za poljubno geometrijo silosa in za poljuben material, ki se hrani. Na podlagi teh grafov lahko preverimo, kakšen je vpliv geometrije silosa in shranjenega materiala na razporeditev in velikost membranskih sil. Na koncu podajamo ilustrativen primer izračuna vplivov (pritiskov) in membranskih sil pri polnjenju in praznjenju silosa.In the paper, the expressions for membrane forces in an axisymmetric steel silo structure at filling and discharge with a particulate solid material are presented. Graphical plots of these expressions are given. They can be used for a quick and easy estimate of membrane forces distribution in all parts of a silo structure. The plots are valid for any silo geometry and for any material stored. The influence of silo geometry and stored material properties on the size and distribution of membrane forces can be thus checked. The paper completes with an illustrative example where actions (pressure loads) at filling and discharge on the walls of a silo are computed and the corresponding membrane forces are evaluated

Composites

IASS-IACM 2008 Session: Composites -- "Multiscale analysis of delamination in composites laminate" by Pierre KERFRIDEN, Olivier ALLIX, Pierre GOSSELET (ENS Cachan) -- "Modeling and simulation of bio-based polymer/clay nanocomposites through a multilevel FE approach" by Mahmoodul HAQ, Rigoberto BURGUENO (Michigan State University) -- "Multilayer composite timber beams: Kinematical modeling and analytical solutions" by Thomas MOOSBRUGGER, Werner GUGGENBERGER (TU Graz) -- "Reduced order anisotropic micro-mechanical creep model for composite materials" by Erez GAL (Ben-Gurion University), Jacob FISH (RPI) -- "Material layout optimization of natural fiber composite cellular panels" by Rigoberto BURGUENO, Christina ISAAC (Michigan State University) -- "Lamination parameter constraints for stacking sequence optimization of frp composites" by Rigoberto BURGUENO, Jun WU (Michigan State University) -- "Modeling biocomposites using laminate plate theory" by Sarah SCHRASS-CHRISTIAN, Sarah BILLINGTON (Stanford University

Erwerbsarbeit und Arbeitslosigkeit in Deutschland Entwicklung, Ursachen und Massnahmen. Anlageband 3: Zukunft der Arbeit sowie Entkoppelung von Erwerbsarbeit und sozialer Sicherung

Der Band enthaelt die folgenden Gutachten: 1. Zukunft der Arbeit -Perspektiven fuer den deutschen Arbeitsmarkt: Szenarien zur Beschaeftigungsentwicklung und arbeitsmarktpolitische Optionen; Arbeitsmarktbezogene Zukunftszenarien - Gesellschaftliche Bedeutung von Taetigkeiten ausserhalb der Erwerbsarbeit. 2. Staerkung von Kreativitaet, Dynamik und Innovationsbereitschaft - Aufrechterhaltung und Schaffung individueller und kollektiver Kreativitaet, Dynamik und Innovationsbereitschaft. 3. Entkopplung von Erwerbsarbeit und sozialer Sicherung - Moeglichkeiten und Grenzen der Entkopplung von Erwerbsarbeit und sozialer Sicherung. (IAB2)Available from IAB-61420 BF 972 (3) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Structural Stability

IASS-IACM 2008 Session: Structural Stability -- Session Organizer: Herbert MANG (Technical University of Vienna) -- Plenary Lecture: Abstract, Slides and Video: "Answers to three not quite straightforward questions in structural stability" by Andreas STEINBOECK, Gerhard HOEFINGER, Xin JIA, Herbert A. MANG (Technical University of Vienna) -- Keynote Lecture: "Limit-point and postbuckling behavior of steel trusses under thermal and mechanical loadings" by Yeong Bin YANG , T.J. LIN (National Taiwan University) -- "Modeling thin-walled cold-formed steel members and systems" by Benjamin W. SCHAFER , R. H. SANGREE, Cristopher MOEN, M. SEIF, Y. SHIFFERAW, V. ZEINODDINI, Z. J. LI, O. IUORIO, Y. GUAN (Johns Hopkins University) -- "Multi parametrical instability of straight bars" by Jan B. OBREBSKI (Warsaw University of Technology) -- "The effect of predetermined delaminations on buckling and post-buckling behavior of spatial composite timber beams and frames" by Miran SAJE , Urban RODMAN, Dejan ZUPAN, Igor PLANINC (University of Ljubljana) -- Keynote Lecture: "Buckling and sensitivity analysis of imperfect shells involving contact" by Karl SCHWEIZERHOF , Eduard EWERT (University of Karlsruhe) -- Keynote Lecture: "Determining the stability of tensegrities and generic global rigidity" by Robert CONNELLY (Cornell University) -- "Initial imperfection identification in shell buckling problems" by Christopher J. STULL , Christopher J. EARLS, Wilkins AQUINO (Cornell University) -- "Buckling phenomena, analysis and design of axially compressed cylindrical shells with co-existent external pressure" by Werner GUGGENBERGER , Medhanye B. TEKLEAB (TU Graz

Whole-Body [18^{18}F]FDG PET/CT Can Alter Diagnosis in Patients with Suspected Rheumatic Disease

The 2-deoxy-d-[$^{18}$F]fluoro-D-glucose (FDG) positron emission tomography/computed tomography (PET/CT) is widely utilized to assess the vascular and articular inflammatory burden of patients with a suspected diagnosis of rheumatic disease. We aimed to elucidate the impact of [$^{18}$F]FDG PET/CT on change in initially suspected diagnosis in patients at the time of the scan. Thirty-four patients, who had undergone [$^{18}$F]FDG PET/CT, were enrolled and the initially suspected diagnosis prior to [18F]FDG PET/CT was compared to the final diagnosis. In addition, a semi-quantitative analysis including vessel wall-to-liver (VLR) and joint-to-liver (JLR) ratios was also conducted. Prior to [$^{18}$F]FDG PET/CT, 22/34 (64.7%) of patients did not have an established diagnosis, whereas in 7/34 (20.6%), polymyalgia rheumatica (PMR) was suspected, and in 5/34 (14.7%), giant cell arteritis (GCA) was suspected by the referring rheumatologists. After [$^{18}$F]FDG PET/CT, the diagnosis was GCA in 19/34 (55.9%), combined GCA and PMR (GCA + PMR) in 9/34 (26.5%) and PMR in the remaining 6/34 (17.6%). As such, [$^{18}$F]FDG PET/CT altered suspected diagnosis in 28/34 (82.4%), including in all unclear cases. VLR of patients whose final diagnosis was GCA tended to be significantly higher when compared to VLR in PMR (GCA, 1.01 ± 0.08 (95%CI, 0.95–1.1) vs. PMR, 0.92 ± 0.1 (95%CI, 0.85–0.99), p = 0.07), but not when compared to PMR + GCA (1.04 ± 0.14 (95%CI, 0.95–1.13), p = 1). JLR of individuals finally diagnosed with PMR (0.94 ± 0.16, (95%CI, 0.83–1.06)), however, was significantly increased relative to JLR in GCA (0.58 ± 0.04 (95%CI, 0.55–0.61)) and GCA + PMR (0.64 ± 0.09 (95%CI, 0.57–0.71); p < 0.0001, respectively). In individuals with a suspected diagnosis of rheumatic disease, an inflammatory-directed [$^{18}$F]FDG PET/CT can alter diagnosis in the majority of the cases, particularly in subjects who were referred because of diagnostic uncertainty. Semi-quantitative assessment may be helpful in establishing a final diagnosis of PMR, supporting the notion that a quantitative whole-body read-out may be useful in unclear cases