Structure integrated shape memory polymer composites for multidimensional forming

Large-scale curved structures such as wind turbine wings usually require a special and cost intensive transport to the installation destination. These transport and installation costs can be reduced by a flat transport condition and the possibility of layering several structural components. For this reason, the focus at the Department of Lightweight Structures and Polymer Technology at TU Chemnitz was on a novel active material composite, which enables resource-efficient mass production and has a new component architecture. The large-volume multidimensional curvature of the active structure could be achieved by using a shape memory polymer (SMP). The associated reduction of the specific investment costs, the use of materials and the possibility of an integrative design, can contribute to the fact that, for example, the small wind turbines will become an economically viable investment in the future. The active structure influencing was represented by means of a finite element simulation (FEM) for different material composites and could be verified by generic demonstrators regarding its validity

Rare Copy Number Variants in \u3cem\u3eNRXN1\u3c/em\u3e and \u3cem\u3eCNTN6\u3c/em\u3e Increase Risk for Tourette Syndrome

Tourette syndrome (TS) is a model neuropsychiatric disorder thought to arise from abnormal development and/or maintenance of cortico-striato-thalamo-cortical circuits. TS is highly heritable, but its underlying genetic causes are still elusive, and no genome-wide significant loci have been discovered to date. We analyzed a European ancestry sample of 2,434 TS cases and 4,093 ancestry-matched controls for rare (\u3c 1% frequency) copy-number variants (CNVs) using SNP microarray data. We observed an enrichment of global CNV burden that was prominent for large (\u3e 1 Mb), singleton events (OR = 2.28, 95% CI [1.39–3.79], p = 1.2 × 10−3) and known, pathogenic CNVs (OR = 3.03 [1.85–5.07], p = 1.5 × 10−5). We also identified two individual, genome-wide significant loci, each conferring a substantial increase in TS risk (NRXN1 deletions, OR = 20.3, 95% CI [2.6–156.2]; CNTN6 duplications, OR = 10.1, 95% CI [2.3–45.4]). Approximately 1% of TS cases carry one of these CNVs, indicating that rare structural variation contributes significantly to the genetic architecture of TS

Synaptic processes and immune-related pathways implicated in Tourette syndrome

Tourette syndrome (TS) is a neuropsychiatric disorder of complex genetic architecture involving multiple interacting genes. Here, we sought to elucidate the pathways that underlie the neurobiology of the disorder through genome-wide analysis. We analyzed genome-wide genotypic data of 3581 individuals with TS and 7682 ancestry-matched controls and investigated associations of TS with sets of genes that are expressed in particular cell types and operate in specific neuronal and glial functions. We employed a self-contained, set-based association method (SBA) as well as a competitive gene set method (MAGMA) using individual-level genotype data to perform a comprehensive investigation of the biological background of TS. Our SBA analysis identified three significant gene sets after Bonferroni correction, implicating ligand-gated ion channel signaling, lymphocytic, and cell adhesion and transsynaptic signaling processes. MAGMA analysis further supported the involvement of the cell adhesion and trans-synaptic signaling gene set. The lymphocytic gene set was driven by variants in FLT3, raising an intriguing hypothesis for the involvement of a neuroinflammatory element in TS pathogenesis. The indications of involvement of ligand-gated ion channel signaling reinforce the role of GABA in TS, while the association of cell adhesion and trans-synaptic signaling gene set provides additional support for the role of adhesion molecules in neuropsychiatric disorders. This study reinforces previous findings but also provides new insights into the neurobiology of TS

Struktura konsumpcji turystów zagranicznych w Polsce podróżujących tanimi liniami lotniczymi i jej efekty ekonomiczne w świetle wyników badania pilotażowego

The article aims to present and interpret the results of a pilot survey carried out among passengers at the Warsaw Modlin Airport in 2016. It is discussed in the context of the development of the Polish airline market in recent years, selected elements of its structure and changes thereof. Flights to and from the Modlin airport are solely operated by low-cost airlines, which significantly facilitates access to and the separation of the group of passengers who do not permanently reside in Poland (defined as foreign visitors) as well as determining their characteristics. The survey whose main results are presented below was a pilot study, designed as the first stage of a larger research project mostly aimed at estimating the impact of inbound tourist traffic served by LCCs on the economy and, indirectly, also on public finance (the budget, taxes). The objective of the first stage of the survey referred to in the article was to test the hypothesis that LCC passengers permanently residing abroad had attributes which called for further research. Taking into consideration a number of important criteria, their image does not significantly differ from the characteristics of all tourists visiting Poland. Neither do they account for a marginal share of air transport in the low-cost segment. In the opinion of the Author, the hypothesis was confirmed by the pilot survey results.Artykuł ma na celu zaprezentowanie i zinterpretowanie wyników badania pilotażowego przeprowadzonego wśród pasażerów w porcie lotniczym w Modlinie w roku 2016. Jest ono omawiane w kontekście rozwoju polskiego rynku lotniczego w ostatnich latach, wybranych elementów jego struktury i jej zmian. Loty do i z portu lotniczego w Modlinie są obsługiwane wyłącznie przez tanie linie lotnicze, co znacznie ułatwia dostęp i wyodrębnienie grupy pasażerów, którzy nie mieszkają na stałe w Polsce (określani jako goście zagraniczni), jak również ustalenie ich charakterystyk. Badanie, którego główne wyniki są prezentowane poniżej, było badaniem pilotażowym pomyślanym jako pierwszy etap większego projektu badawczego, przede wszystkim mającego na celu oszacowanie wpływu turystyki przyjazdowej obsługiwanej przez tanie linie lotnicze na gospodarkę i, pośrednio, na finanse publiczne (budżet, podatki). Celem pierwszego etapu badania, o którym jest mowa w artykule, było sprawdzenie hipotezy, że pasażerowie tanich linii lotniczych stale mieszkających za granicą posiadają cechy wymagające dalszych badań. Biorąc pod uwagę liczbę istotnych kryteriów, ich wizerunek nie różni się znacznie cech wszystkich turystów odwiedzających Polskę, ani też nie stanowią one marginalnego udziału transportu lotniczego w segmencie niskokosztowym. Zdaniem autorów wyniki badania pilotażowego potwierdziły postawioną hipotezę

Fatigue behaviour of material-adapted fibre-reinforced polymer/metal joints

By regarding the needs and requirements in modern multi-material joining, the Flow Drill Joining Concept (FDJ) was developed at the Chemnitz University of Technology. The technology allows an efficient and material-adapted joining of thin metal sheets with continuous fibre-reinforced thermoplastics, as required in modern lightweight engineering. For a better understanding of their fatigue behaviour, single-lap FDJ joints were examined in quasi-static and dynamic tests regarding shear loads, cross tension and superimposed shear/cross tension loads. By way of example, joints between micro-alloyed steel with high yield strength for cold forming and a continuous glass/carbon fibre-reinforced polyamide 6 were investigated. The fatigue curves show inclinations between k = 8.01 (shear loads) and k = 5.17 (cross tension loads), depending on the applied load angle. The results of the fatigue testings represent a basis for the enhancement of a failure criterion for FRP/metal joints in highly stressed multi-material designs.Unter Berücksichtigung der bekannten Probleme und Anforderungen im Bereich moderner Fügetechnologien, wurde am Institut für Strukturleichtbau der TU Chemnitz das Thermomechanische Ausformfügeverfahren (TAF) entwickelt. Die Technologie erlaubt das effiziente und materialgerechte Verbinden von dünnwandigen Metallblechen mit endlosfaserverstärkten Thermoplasten. Für ein tieferes Verständnis des Ermüdungsverhaltens von TAF-Verbindungen, wurden einschnittige TAF-Proben in Scherzug-, Kopfzug- und überlagerten Scher- und Kopfzugversuchen quasi-statisch und dynamisch geprüft. Dabei wurden exemplarische Verbindungen zwischen einem mikrolegierten Stahl mit hoher Streckgrenze zum Kaltumformen (HX420LAD+Z100, 1,5 mm) und endlosfaserverstärktem Polyamid 6 (Glas- und Kohlenstofffaser) untersucht. Die Wöhlerlinien zeigen je nach Lastfall Steigungen zwischen k = 7,51 (Scherzug) und k = 4.10 (Kopfzug). Die Ergebnisse der Schwingfestigkeitsuntersuchungen werden als Basis für die Erweiterung einer neuartigen Auslegungsstrategie für Faser-Kunststoff-Verbund/Metall-Verbindungen in hochbelasteten Strukturanwendungen verwendet

Composite sandwich with aluminum foam core and adhesive bonded Carbon Fiber Reinforced Thermoplastic cover layer

The combination of metals and fiber reinforced plastics is also known as hybrid metal composites. They offer the fusion of the good static mechanical properties of the fiber reinforced plastics and the good dynamic mechanical properties of the metal. For that reason, parts made of hybrid metal composites are predestined for the use as load relevant parts. The purpose of this study was to develop new technologies for semi finished hybrid metal composite materials. Thermoplastic Fiber-Reinforced Composites (TP-FRC) were arranged with new, isotropic, closed pore Aluminum Foam (AF) structures to an Extrinsically Combined Composite Sandwich (ECCS) by adhesive bonding. They form the basis for novel weight-optimized as well as cost-effective applications. The entire manufacturing process for the continuous semi-finished product was examined and verified according DIN EN 2563. This was done with regard to subsequent characterization by the specific bending modulus and specific bending stiffness. The examinations show a high bending stiffness and high strength structures combined with excellent damping properties at high damage tolerances. These are the most requested in automotive applications

Behavior of Cathodic dip Paint Coated Fiber Reinforced Polymer/Metal Hybrids

Increasing mechanical, economic and environmental requirements lead to multi material designs, wherein different classes of materials and manufacturing processes are merged to realize lightweight components with a high level of functional integration. Particularly in automotive industry the use of corresponding technologies will rise in the near future, as they can provide a significant contribution to weight reduction, energy conservation and therefore to the protection of natural resources. Especially the use of continuous fiber reinforced polymers (FRP) with thermoplastic matrices offers advantages for automotive components, due to its good specific characteristics and its suitability for mass production. In conjunction with isotropic materials, such as steel or aluminum, optimized lightweight structures can be produced, whose properties can be easily adapted to the given component requirements. The present paper deals with the development of innovative hybrid laminates with low residual stresses, made of thin-walled steel sheets and glass fiber reinforced thermoplastic (GFRP) prepregs layers. Thereby the interlaminar shear strength (ILSS) was increased by an optimization of the FRP/metal-interfaces, carried out by examining the influence of several pre-operations like sanding, cleaning with organic solvents and applying primer systems. Based on these findings optimized compound samples were prepared and tested under realistic Cathodic dip paint conditions to determine the influence on the ILSS

Structure integrated shape memory polymer composites for multidimensional forming

Large-scale curved structures such as wind turbine wings usually require a special and cost intensive transport to the installation destination. These transport and installation costs can be reduced by a flat transport condition and the possibility of layering several structural components. For this reason, the focus at the Department of Lightweight Structures and Polymer Technology at TU Chemnitz was on a novel active material composite, which enables resource-efficient mass production and has a new component architecture. The large-volume multidimensional curvature of the active structure could be achieved by using a shape memory polymer (SMP). The associated reduction of the specific investment costs, the use of materials and the possibility of an integrative design, can contribute to the fact that, for example, the small wind turbines will become an economically viable investment in the future. The active structure influencing was represented by means of a finite element simulation (FEM) for different material composites and could be verified by generic demonstrators regarding its validity

Compensation of Pressure Peaks in PWK-Type Hydraulic Pumps

score: 8collation: 33-4