1,480 research outputs found
A novel reduced order model for vortex induced vibrations of long flexible cylinders
No full textIn this manuscript the development of a reduced order model for the analysis of long flexible cylinders in an offshore environment is proposed. In particular the focus is on the modelling of the vortex induced vibrations (VIV) and the aim is the development of a model capable of capturing both the in-line and cross-flow oscillations. The reduced order model is identified starting from the results of a high fidelity solver developed coupling together a Finite Element Solver (FEM) with a Computational Fluid Dynamics (CFD) solver. The high fidelity analyses are conducted on a reduced domain size representing a small section of the long cylinder, which is nevertheless, already flexible. The section is forced using a motion which matches the expected motion in full scale, and the results are used for the system-parameter identification of the reduced order model. The reduced order model is identified by using a system and parameter identification approach. The final proposed model consists in the combination of a forced van der Pol oscillator, to model the cross-flow forces, and a linear state-space model, to model the in-line forces. The model is applied to study a full scale flexible model and the results are validated by using experiments conducted on a flexible riser inside a towing tank
iPad Usage in Inpatient Care
No full textSchmeer R, Albrecht U-V, Kupka T, Meyenburg-Altwarg I, Matthies HK. iPad Usage in Inpatient Care. In: Ho C, Lin M, eds. Proceedings of E-Learn 2011: World Conference on E-Learning in Corporate, Government, Healthcare, and Higher Education. San Diego, CA: Association for the Advancement of Computing in Education (AACE); 2011: 1698-1705
Please Don’t Leave Me—Separation Anxiety and Related Traits in Borderline Personality Disorder
No full textPurpose of Review: In light of the apparent symptomatic resemblance of separation anxiety disorder (SAD) symptoms on the one hand and abandonment fears, anxiousness, and separation insecurity central to borderline personality disorder (BPD) on the other hand, a comprehensive overview of separation anxiety and related traits in BPD is provided. Recent Findings: Epidemiological, environmental, psychological, and neurobiological data connecting BPD to separation events, feelings of loneliness, insecure attachment styles, dimensional separation anxiety as well as SAD per se suggest a partly shared etiological pathway model underlying BPD and SAD. Differential diagnostic aspects and implications for treatment are discussed, highlighting separation anxiety as a promising transdiagnostic target for specific psychotherapeutic and pharmacological treatment approaches in BPD. Summary: This innovative angle on cross-disorder symptomatology might carry potential for novel preventive and therapeutic avenues in clinical practice by guiding the development of interventions specifically targeting separation anxiety and attachment-related issues in BPD
Sehen, Fühlen, Erfahren: Rechtsmedizin mit mARBLE® erleben
No full textNoll C, von Jan U, Schaft T, Matthies HK, Albrecht U-V. Sehen, Fühlen, Erfahren: Rechtsmedizin mit mARBLE® erleben. In: Reiterer H, Deussen O, eds. Mensch & Computer 2012 : interaktiv informiert - allgegenwärtig und allumfassend!? : 12. Fachübergreifende Konferenz für Interaktive und Kooperative Medien. München: Oldenbourg; 2012: 241-246
ANALISIS TEKSTUR ZIRCALOY-4 MENGGUNAKAN METODE WILLIAM–IMHOF–MATTHIES-VINEL (WIMV)
No full textANALISIS TEKSTUR ZIRCALOY-4 MENGGUNAKAN METODE WILLIAM–IMHOF–MATTHIES-VINEL (WIMV). Zircaloy-4 sebagai kelongsong bahan bakar nuklir telah banyak diteliti secara makroskopik maupun secara mikroskopik, namun penelitian menggunakan teknik difraksi neutron, terutama karakterisasi orientasi kristalit (tekstur) di Indonesia masih jarang dilakukan. Tujuan penelitian ini adalah untuk menerapkan metode WIMV pada karakterisasi tekstur bahan tersebut. Metode WIMV adalah salah satu metode analisis tekstur bahan yang diperoleh dengan teknik difraksi neutron atau difraksi sinar-X. Dari hasil analisis tersebut diperoleh pole figure 002 dengan indeks tekstur (F2) terbesar dibandingkan dengan pole figure yang lain yaitu 100, 101, 102 dan 110. Indeks tekstur (F2) pole figure 002 untuk incomplete pole figure, F2= 4,69 m.r.d dengan faktor reliabilitas RP0 = 3,28%, dan recalculated pole figure, F2 = 4,42 m.r.d. dengan RP1 = 2,97%. Semua pole figure diperoleh faktor reliabilitas dengan pole figure rata-rata RP0 = 6,60%, RP1 = 5,02%, entropy = - 0,5871, dan indeks tekstur, F2= 2,34 m.r.d. Hasil analisis bahan Zircaloy-4 tersebut menyimpulkan bahwa metode WIMV dapat digunakan untuk menentukan arah orientasi tekstur, dimana tekstur yang paling kuat mengarah ke (arah sumbu c) dalam struktur hexagonal.
TEXTURE ANALYSIS OF ZIRCALOY-4 USING WILLIAM-IMHOF-Matthies-VINEL (WIMV) METHOD. Zircaloy-4 as a nuclear fuel cladding has been widely examined macroscopically and microscopically, but research using neutron diffraction technique, especially the characterization of crystallite orientation (texture) in Indonesia is still rare. The purpose of this study is to apply the methods of William-Imhof-Matties-Vinel (WIMV) on the characterization of zircaloy-4 material texture. WIMV is one of data analysis method for textures materials obtained by neutron or x-ray diffractions technique. The analysis is obtained that 002 pole figure has the largest texture index (F2) compared to the others pole figures, that are 100, 101, 102 and 110. Index texture (F2) of pole figure 002 for incomplete pole figures, F2 = 4.69 m.r.d with a reliability factor RP0 = 3.28%, and recalculated pole figures, F2 = 4.42 m.r.d with RP1 = 2.97%. For all pole figures, it is obtained that a reliability factor of the average RP0= 6.60%, RP1 = 5.02%, entropy = - 0.5871, and texture index (F2) = 2.34 m.r.d. Data analysis showed that the WIMV method can be used to determine the direction of the crystallite orientation of the pole figure where the most powerful texture leads to the (c-axis direction) in a hexagonal structure
Validity and failure of the Boltzmann approximation of kinetic annihilation
No full textThis paper introduces a new method to show the validity of a continuum description for the deterministic dynamics of many interacting particles. Here the many-particle evolution is analyzed for a hard sphere flow with the addition that after a collision the collided particles are removed from the system. We consider random initial configurations which are drawn from a Poisson point process with spatially homogeneous velocity density f (0)(v). Assuming that the moments of order less than three of f (0) are finite and no mass is concentrated on lines, the homogeneous Boltzmann equation without gain term is derived for arbitrary long times in the Boltzmann-Grad scaling. A key element is a characterization of the many-particle flow by a hierarchy of trees which encode the possible collisions. The occurring trees are shown to have favorable properties with a high probability, allowing us to restrict the analysis to a finite number of interacting particles and enabling us to extract a single-body distribution. A counter-example is given for a concentrated initial density f (0) even to short-term validity
Professionalisierung (angehender) Lehrkräfte für sprachbildenden Fachunterricht im Berufsfeld Ernährung und Hauswirtschaft mittels OER-Lektionen
No full textMeyer A, Dehn F, Gövert A, Schlegel-Matthies K, Niederhaus C. Professionalisierung (angehender) Lehrkräfte für sprachbildenden Fachunterricht im Berufsfeld Ernährung und Hauswirtschaft mittels OER-Lektionen. In: Gerholz K-H, Hochleitner T, Maidanjuk I, Beil S, eds. Sprache(n) im Beruf: Gestaltung und Förderung beruflicher Sprachbildung an den verschiedenen Lernorten. Bonn: Barbara Budrich; 2025: 169-186
Environmental decision support systems: Current issues methods and tools
No full textCopyright © 2005 Elsevier Ltd All rights reserved.Development of environmental decision support systems (EDSS) is rapidly progressing. The sustainable management of natural resources has a growing research focus as the awareness of the complexity of interactions between socio-cultural, economical and biophysical system components is increasingly acknowledged. As better data and methods become available, the complexity of the system representation is augmenting. At the same time realism and relevance are increasing and allowing direct support for management and policy development. This article gives the background of recent developments in EDSS and summarises a selected set of papers that were presented at the 2nd Biennial Conference of the International Society of Environmental Modelling and Software (IEMSS 2004). Recent developments show a continuum between integrated assessment modelling and EDSS with varying levels of stakeholder participation in both EDSS development and application. There is a general tendency towards better utilisation of interdisciplinary data, integration and visualisation of temporal and spatial results. Future developments appear directed towards better representation of reality in models, improving user-friendliness and use in a negotiation or group discussion context.Michael Matthies, Carlo Giupponi and Bertram Ostendor
Biological flora of Central Europe: Leucojum aestivum L
No full textLeucojum aestivum L. (Amaryllidaceae) is a polycarpic C-S-European/W-Asiatic geophyte. It is a threatened wetland species and is protected in several European countries, as a consequence of the destruction or alteration of its habitats across Europe and the harvesting of its bulbs for medical purposes (alkaloids). This paper deals with the taxonomic status, morphology, distribution, ecology and population biology of this species, with special emphasis on habitat requirements, reproductive biology, and seed germination. A detailed study in N-Italy found that L. aestivum grows on alluvial soils with high nitrogen levels. The mean size of the plants increased with the water content of the soil. Similarly, within the habitats, the water and nitrogen contents of the soil were higher in plots with L. aestivum than in those without the species. Seed set of the plants was not influenced by the size of a population, but strongly increased with the density of flowering plants. This was due to a decrease in the proportion of unfertilised eggs, indicating pollen limitation of reproduction in low-density populations. Germination tests revealed that the optimal germination temperature is between 20 °C and 25 °C. © 2011 Perspectives in Plant Ecology, Evolution and Systematics
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