Quality control of glulam: shear testing of bondlines

In quality control of glulam, shear testing of bondlines is required. However, in relevant standards the method of applying shear stress to the bondline is only exemplified by a principle schematic. Based on this schematic a considerable variety of test equipments is in use nowadays. Depending on the respective construction of the test equipment as well as on the execution of testing, the resulting stress in the bondline is not pure shear but rather a combination of shear and normal stresses. When the normal stresses are acting as tensile stresses perpendicular to the bondline, the registered shear strength values range considerably below the pure shear stress level, whereas compression stresses perpendicular to the grain lead to an overestimation of the shear strength of the bondline. To overcome this deficiency, a prototype of a modified shear test device was developed, which ensures a clearly defined state of shear loading of the specimens. Based on extensive comparative testing it is shown that by performing compression tests at an oblique angle to the grain of 14° the above mentioned problems can be avoide

Influence of wood moisture content on bending and shear stiffness of cross laminated timber panels

The bending and shear stiffness of cross-laminated timber (CLT) made from softwood depend on the moisture content of the panel. In principle, the stiffness properties drop with increasing moisture content within the hygroscopic range. However, swelling provokes closing of open gaps of the middle layers and leads to an apparent increase of stiffness due to internal friction. This increase in stiffness is only relevant for low deflections and can provoke misinterpretation of measuring results when deriving stiffness properties of CLT by means of dynamic methods such as modal analysis. Drying, on the other hand causes cracking within CLT, which manifests itself in a distinct reduction of the bending stiffness perpendicular to the grain direction of the face layers. Calculating bending stiffness of CLT perpendicular to the grain direction of the face layers by means of the compound theory not taking into account the face layers therefore is a common and correct procedur

Informationsgewinnung im cyberphysischen Produktionssystem

Im Fokus vieler industrieller Forschungsprojekte steht die intelligente Vernetzung von Entitäten im produktionstechnischen Umfeld. Im Rahmenkonzept Industrie 4.0 wird zum Wandel bestehender hierarchischer Betriebsstrukturen in ein cyberphysisches Produktionssystem beigetragen. Priorität haben Untersuchungen sensorischer Komponenten und deren Verkettung als Führungselement im zukünftigen Produktionsumfeld, welches durch Selbstanalyse, Selbstorganisation und Selbstoptimierung geprägt sein wird. Ziel des Hochschulprojektes (iSensPK) ist die Abwandlung bestehender Sensorkonzepte und deren Nutzbarmachung für das Internet der Dinge. Einen Schwerpunkt wird dabei insbesondere die Definition und Verknüpfung stabiler Kommunikationswege darstellen. Als Demonstrator erfolgt der Aufbau eines 6-Komponenten Kraftmesssystems zur Prüfung und Kalibrierung moderner Greifertechnologien unter Feldbedingungen. Durch die umfangreiche Vernetzung verschiedener Sensoren erfolgt die Erfassung von Störgrößen im Testumfeld. Das gewonnene Abbild der physischen Umgebung dient zur Korrektur der Kraftmessungsergebnisse. Für die Realisierung eines derartigen Kraftmess- und Umfelderfassungssystems wird in den sensorisch relevanten Bereichen der Kommunikation, Sensordatenfusion, Multifunktionsintegration und Selbstorganisation nach Lösungsansätzen gesucht.The main focus of different industrial R&D projects explores possible starting points for the intelligent interconnection of entities in a productional environment. Against a background of ‘Industrie 4.0‘, this contributes to a transformation of existing, hierarchical structures into a cyber physical production system. The focus here is on investigating sensor components and their interlinking as a main element in a future production environment which will be characterised by self-analysis, self-organisation and self-optimisation. The aim of the project iSensPK is to modify sensor concepts in being to facilitate their utilisation in the Internet of Things. Emphasis rests on defining and combining stable lines of communication. A demonstrator is set up, including a six-component force measuring system to enable inspecting and calibration of modern gripping technologies within field conditions. Through adequate linkage of different sensors, the capture of disturbance variables is made possible. The resulting image of the physical environments serves to readjust any measured force values. To implement such a force measuring and environment detecting system, sensorial relevant fields of communication, sensor data fusion, multifunctional integration and self-organisation are searched to conclude approaches to solutions

Die Zeitschrift für Hochschulentwicklung – Rückblick und Analyse

Die Zeitschrift für Hochschulentwicklung hat einen langen und interessanten Werdegang. In diesem Artikel wollen wir diesen beschreiben und einer Analyse unterwerfen, um die Entwicklung über die Zeit darzustellen. Es wird gezeigt, wie sich Themen und Schwerpunkte verlagern und mit der Hochschul-Praxis einhergehen. Um die Vergleichbarkeit und den Impact der Zeitschrift vorzustellen, werden Überlegungen angestellt, die untermauern, wie wichtig die Rolle der Zeitschrift für die Hochschulen im deutschsprachigen Raum ist, aber auch darüber hinaus. 40 Jahre, davon beinahe 20 Jahre als Open Access, ist ein beachtlicher Zeitraum für ein solches Medium. Dies ist uns daher Anlass, die Entwicklung der Zeitschrift zu reflektieren

Non-Motor Symptoms in Patients Suffering from Motor Neuron Diseases.

The recently postulated "disease spreading hypothesis" has gained much attention, especially for Parkinson's disease (PD). The various non-motor symptoms (NMS) in neurodegenerative diseases would be much better explained by this hypothesis than by the degeneration of disease-specific cell populations. Motor neuron disease (MND) is primarily known as a group of diseases with a selective loss of motor function. However, recent evidence suggests disease spreading into non-motor brain regions also in MND. The aim of this study was to comprehensively detect NMS in patients suffering from MND. We used a self-rating questionnaire including 30 different items of gastrointestinal, autonomic, neuropsychiatric, and sleep complaints [NMS questionnaire (NMSQuest)], which is an established tool in PD patients. 90 MND patients were included and compared to 96 controls. In total, MND patients reported significantly higher NMS scores (median: 7 points) in comparison to controls (median: 4 points). Dribbling, impaired taste/smelling, impaired swallowing, weight loss, loss of interest, sad/blues, falling, and insomnia were significantly more prevalent in MND patients compared to controls. Interestingly, excessive sweating was more reported in the MND group. Correlation analysis revealed an increase of total NMS score with disease progression. NMS in MND patients seemed to increase with disease progression, which would fit with the recently postulated "disease spreading hypothesis." The total NMS score in the MND group significantly exceeded the score for the control group, but only 8 of the 30 single complaints of the NMSQuest were significantly more often reported by MND patients. Dribbling, impaired swallowing, weight loss, and falling could primarily be connected to motor neuron degeneration and declared as motor symptoms in MND.S

Divergence of regulatory networks governed by the orthologous transcription factors FLC and PEP1 in Brassicaceae species.

Genome-wide landscapes of transcription factor (TF) binding sites (BSs) diverge during evolution, conferring species-specific transcriptional patterns. The rate of divergence varies in different metazoan lineages but has not been widely studied in plants. We identified the BSs and assessed the effects on transcription of FLOWERING LOCUS C (FLC) and PERPETUAL FLOWERING 1 (PEP1), two orthologous MADS-box TFs that repress flowering and confer vernalization requirement in the Brassicaceae species Arabidopsis thaliana and Arabis alpina, respectively. We found that only 14% of their BSs were conserved in both species and that these contained a CArG-box that is recognized by MADS-box TFs. The CArG-box consensus at conserved BSs was extended compared with the core motif. By contrast, species-specific BSs usually lacked the CArG-box in the other species. Flowering-time genes were highly overrepresented among conserved targets, and their CArG-boxes were widely conserved among Brassicaceae species. Cold-regulated (COR) genes were also overrepresented among targets, but the cognate BSs and the identity of the regulated genes were usually different in each species. In cold, COR gene transcript levels were increased in flc and pep1-1 mutants compared with WT, and this correlated with reduced growth in pep1-1 Therefore, FLC orthologs regulate a set of conserved target genes mainly involved in reproductive development and were later independently recruited to modulate stress responses in different Brassicaceae lineages. Analysis of TF BSs in these lineages thus distinguishes widely conserved targets representing the core function of the TF from those that were recruited later in evolution