Formfinding and statical analysis of cable nets with flexible covers

Nowadays cable nets are built as roofs, enclosures for animals in zoos, facades, safety barriers in buildings, etc. Some of the advantages are high resistance against damage and high transparency. In the first part of this this paper the problems of the cable net calculation are described. The key problem is the generation of the assembly plan. This procedure is according to the cutting pattern generation process. In case of cable nets we have to create as big as possible fields. The reason for this purpose is the boundary patterning, this means: the patterns are restricted to the region along the boundary cables and equidistant rectangular meshes remain in the inner part of the fields. The calculation of the formfinding and the statical analysis of equidistant rectangular nets will be pointed out step by step. We also show the specific characteristic of small sized 60°-degree cable nets, produced e. g. by the German company Carl Stahl. This kind of cable net is characterized by a high flexibility and the adaptability to free forms. By the so called S-twist in the cable pieces between the clamps we have to consider special statical properties. The usage of physical nonlinear material laws and the node stiffness caused by the clamps will be explained. As opposed to the calculation of cable nets we have to consider additional material properties as shear- and crimp- stiffness for membranes and foils. The cutting pattern generation can be performed here as usual with surface seams. The disadvantage of cable nets is that an additional cover is needed if the usage requires a weather protection. In the last chapter we will show the calculation of the composite material cable net – membrane cover

Tailored composite wings with elastically produced chordwise camber

Four structural concepts were created which produce chordwise camber deformation that results in enhanced lift. A wing box can be tailored to utilize each of these with composites. In attempting to optimize the aerodynamic benefits, researchers found that there are two optimum designs that are of interest. There is a weight optimum which corresponds to the maximum lift per unit structural weight. There is also a lift optimum that corresponds to maximum absolute lift. Experience indicates that a large weight penalty accompanies the transition from weight to lift optimum designs. New structural models, the basic deformation mechanisms that are utilized, and typical analytical results are presented. It appears that lift enhancements of sufficient magnitude can be produced to render this type of wing tailoring of practical interest

Best Practice aus der Schülerperspektive

Wer ist ein ‚guter’ Lehrer? Mögliche Antworten auf diese Frage sind ab¬hängig von der Perspektive des Befragten. In dieser Arbeit werden die Aussagen von gewerblich-technischen Auszubildenden des dritten Ausbildungsjahres an einer Berufsschule mit Interviewaussagen ihrer Lehrer verknüpft. Die interviewten Lehrer sind durch die Schüler selbst als ‚gute’ Lehrer eingeschätzt worden. Im Ergebnis wird deutlich, dass es den ‚guten’ Lehrer nicht gibt. Aus der Schülerperspektive erlangt ein Lehrer dann Bedeutung, wenn es ihm ge¬lingt für die Wirklichkeit des Schülers relevante Angebote bereitstellen zu können. Schüler im dritten Ausbildungsjahr des dualen Systems orientieren sich in ihrer Ein¬schätzung ‚guter’ Lehrer zunächst daran, ob die Unter¬richtssituation Leistungen er¬möglicht. Dies steht im engen Zusammenhang mit dem Ziel der Schüler mit Bestehen der Prüfung einen Berufsabschluss zu erreichen. Ein größerer Teil der Schüler sieht im Berufsabschluss die Grundlage für die erfolgreiche Einmündung in den gelernten Beruf und präferiert Lehrer die fachpraktische Wissensbestände ver¬mitteln. Die übrigen Schüler sehen den Berufsabschluss als Chance zur Neu¬justierung ihres Lebens und entsprechend präferieren sie Lehrer, die lebens¬praktische Wissensbestände vermitteln.Who is a ‘good’ teacher? A possible answer depends on the point of view of the person answering the question. This paper combines the statements from students in the third year of vocational training with self-assessment of their teachers. The teachers interviewed for the paper were named as ‘good’ teachers form the students. The main result of the paper is that there will be no single ‘ideal-type’ of a ‘good’ teacher. In the students’ view teachers become significants for them when they are able to present relevant information for the needs and interests of their personal life. Students in the third year of vocational training, just before the final examinations, first look for the abilitiy of the lessons to help them learning. This belongs to their main gool – success in the final examination. The majority of the students look forward to work in their new profession. So they prefer teachers who can help them to be good in their job. A minority of students wants to leave their profession and use the exam as a starting position for a change in their life. Therefore they prefer teachers presenting them knowledge helping them to handle their life

Optimal energy systems design applied to an innovative ocean–wind energy converter

System level optimization is used to design an innovative ocean–wind energy converter to meet the “as good as it can be done” design objective. This general design procedure is then applied to the design of a 20 kW energy system and it is demonstrated that a combined energetic and economical design procedure is required for an optimal solution

Techno-Economic Comparison of Renewable Energy Systems Using Multi-Pole System Analysis (MPSA)

The recently published method of multi-pole system analysis (MPSA) is used to techno-economically compare two wind-energy converters: offshore wind turbines and the energy ship concept. According to the method, both systems are (i) modeled, (ii) energetically and economically analyzed, (iii) techno- economically optimized and, finally, (iv) expected uncertainties are calculated and assessed. The results of the method are used to derive the necessary cost reduction of the wind-energy converters to be economically competitive to fossil-fuel-based technologies

Granulomatous Inflammation in ANCA-Associated Vasculitis

ANCA-associated vasculitis (AAV) comprises granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). While systemic vasculitis is a hallmark of all AAV, GPA is characterized by extravascular granulomatous inflammation, preferentially affecting the respiratory tract. The mechanisms underlying the emergence of neutrophilic microabscesses; the appearance of multinucleated giant cells; and subsequent granuloma formation, finally leading to scarred or destroyed tissue in GPA, are still incompletely understood. This review summarizes findings describing the presence and function of molecules and cells contributing to granulomatous inflammation in the respiratory tract and to renal inflammation observed in GPA. In addition, factors affecting or promoting the development of granulomatous inflammation such as microbial infections, the nasal microbiome, and the release of damage-associated molecular patterns (DAMP) are discussed. Further, on the basis of numerous results, we argue that, in situ, various ways of exposure linked with a high number of infiltrating proteinase 3 (PR3)- and myeloperoxidase (MPO)-expressing leukocytes lower the threshold for the presentation of an altered PR3 and possibly also of MPO, provoking the local development of ANCA autoimmune responses, aided by the formation of ectopic lymphoid structures. Although extravascular granulomatous inflammation is unique to GPA, similar molecular and cellular patterns can be found in both the respiratory tract and kidney tissue of GPA and MPA patients; for example, the antimicrobial peptide LL37, CD163+ macrophages, or regulatory T cells. Therefore, we postulate that granulomatous inflammation in GPA or PR3-AAV is intertwined with autoimmune and destructive mechanisms also seen at other sites

Disease heterogeneity of adult diabetes based on routine clinical parameters at diagnosis: Results from the German/Austrian DPV registry.

AIMS To cluster adults with diabetes using parameters from real-world clinical care at manifestation. MATERIALS AND METHODS We applied hierarchical clustering using Ward's method to 56,869 adults documented in the Prospective Diabetes Follow-up Registry (DPV). Clustering variables included age, sex, BMI, HbA1c, diabetic ketoacidosis (DKA), components of the metabolic syndrome (hypertension/dyslipidemia/hyperuricemia), and beta-cell antibody status. Time until use of oral antidiabetic drugs (OAD), use of insulin, chronic kidney disease (CKD), cardiovascular disease (CVD), retinopathy, or neuropathy were assessed using Kaplan Meier analysis and Cox regression models. RESULTS We identified eight clusters: Four clusters comprised early diabetes onset (median age between 40 and 50 years), but differed with regard to BMI, HbA1c, DKA and antibody positivity. Two clusters included adults with diabetes onset in their early 60s who met target HbA1c, but differed in BMI and sex distribution. Two clusters were characterized by late diabetes onset (median age 69 and 77 years) and relatively low BMI, but differences in HbA1c. Earlier insulin use was observed in adults with high HbA1c, and earlier OAD use was observed in those with high BMI. Time until CKD or CVD was shorter in those with late onset, whereas retinopathy occurred earlier in adults with late onset and high HbA1c, and in adults with early onset, but high HbA1c and high percentage of antibody positivity. CONCLUSIONS Adult diabetes is heterogeneous beyond classical type 1/type 2 diabetes, based on easily available parameters in clinical practice using an automated clustering algorithm which allows both continuous and binary variables. This article is protected by copyright. All rights reserved

Dual fluorescence of 9-anthryl-substituted oligothiophenes in nonpolar environment

9-Anthryl-oligothiophenes (9A-Tn, n = 1–4) have been studied in n-hexane solution between helium and room temperature using absorption, fluorescence emission and excitation spectra and time resolved fluorescence measurements. These compounds are reference systems for studies on intramolecular energy and charge transfer in donor/acceptor-substituted conjugated chain molecules. The absorption spectra show contribution of both substituents anthracene and oligothiophene, but no additional bands due to mixed electronic states. Dual fluorescence is observed at Tgreater-or-equal, slanted 120 K for the compounds 9A-Tn (n = 1–3), but not for 9A-T4. Time resolved spectroscopy reveals a dynamical coupling between the two emission components whose relative quantum yields are strongly temperature dependent. The occurrence of the dual fluorescence is explained by an intramolecular torsional motion between the two molecular subunits

Zusammenhänge erkennen, konzeptuelles Denken entwickeln: Konzept eines Lehr-Lern-Modells für den Sachunterricht

Besonders im Sachunterricht ist es aufgrund seiner diversen Bezugsdisziplinen herausfordernd, eine Basis für Anschlussfähigkeit zur nächsten Bildungsstufe zu schaffen. Die Schwierigkeit liegt vordringlich darin, gleichsam das Wesen des Sachunterrichts, mit seinem Anspruch der ganzheitlichen Welterschließung, und die fachlich orientierten Anforderungen der Sekundarstufe zu berücksichtigen. Das Verbindende dieser beiden Ansätze sind zentrale Konzepte diverser Inhalte aus den Bezugsdisziplinen. Die Fähigkeit, Inhalte auf diese Weise zu vernetzen, ist jedoch anspruchsvoll und muss erlernt werden. Dazu fehlt es an Theorien mit Vorschlägen zu konkreten Handlungsideen. Dieser Artikel skizziert ein Lehr-Lern-Modell für den Sachunterricht, das diese Problematik aufgreift und zu lösen sucht. Es zeigt einen theoretischen Ansatz zum verstehensorientierten und konzeptbezogenen Lernen, verknüpft mit fachdidaktischen Tools zur unterrichtlichen Planung, Gestaltung und Umsetzung kompetenzorientierten Sachunterrichts. Ausgehend von der Entwicklung des Lehr-Lern-Modells werden theoretische Hintergründe erläutert, bevor das Modell selbst und seine Einbeziehung in die Unterrichtspraxis vorgestellt werden