Engineering Flow and Design

The importance of design in natural and engineered flow systems is undisputed. It is not only essential to life, but also plays a crucial role in our technological world. In Nature, it arises organically, spontaneously, and is the constructal path for systems to persist in time. The generation of the best design is the target of engineered flow systems. Fluid dynamics and thermodynamics have played a crucial role in the search for these flow designs. Analytical, numerical (CFD) and experimental studies played crucial roles in many technological breakthroughs. They provide the frameworks for understanding, simulating and interpreting flow phenomena. The collection of the articles in this issue, along with a complementary and expansive volume devoted to the same subject, reflect and reaffirm the importance and relevance of the study of flow design in natural and man-made flow systems in the twenty-first century

Praxisintegrierende duale Studiengänge – Die betriebliche Ausbildung innerhalb der dualen Praxispartner – Eine Untersuchung

Seit einigen Jahren erfreuen sich duale Studiengänge zunehmender Beliebtheit bei den Studierenden. Mit der wachsenden Anzahl der immatrikulierten Studierenden in einem dualen Studium findet auch eine Intensivierung der betrieblichen Ausbildungsbeteiligung statt. Maßgeblich orientiert sich das duale Studium an der Beschäftigungsfähigkeit seiner Absolventen bei den dualen Praxispartnern bzw. am Arbeitsmarkt. Die angestrebte Beschäftigungsfähigkeit der Absolventen bedarf einer engen Abstimmung der theoretischen mit den praktischen Studienanteilen im Ausbildungsunternehmen. Um sich diesem Ziel zu nähern, befasst sich die vorliegende Dissertation mit der Analyse der innerbetrieblichen Ausbildung bei einem Praxispartner der Automobilindustrie. Aus gegenwärtigen und zukünftigen berufsspezifischen Arbeitsaufgaben, mit denen Absolventen eines praxisintegrierenden dualen Studiums konfrontiert sind, sowie den zur Bewältigung dieser Aufgaben notwendigen Kompetenzen aus der Sicht der Absolventen werden die praktischen Studienanteile in Form eines innerbetrieblichen Ausbildungscurriculums abgeleitet. Die empirische Ergründung von Arbeitsaufgaben und die daraus resultierenden Anforderungen an Absolventen eines praxisintegrierenden dualen Studiums erfolgt anhand einer qualitativen Expertenbefragung. Ausgewählt wurde diese empirische Methodik, da die zu ermittelnden Informationen überwiegend aus kognitiven Handlungen bestehen und deshalb nur schwer beobachtbar sind. Darüber hinaus widmet sich die Untersuchung der lernförderlichen Gestaltung von Lehr-Lern-Arrangements zur Bewältigung der Arbeitsanforderungen. Die Ergebnisse dieser Forschungsarbeit liefern detaillierte Erkenntnisse zur unternehmensorientierten und lernförderlichen Ausbildung bei den Praxispartnern im ingenieurwissenschaftlichen Bereich

Special Focus on: Optimal Fluid Systems & Machinery

The competitive cost of numerical simulations over laboratory studies, due to the continued advancements in computing performance, has made computational fluid dynamics an integral tool in the study of engineering problems. This topical special focus issue “Optimal Fluid Systems and Machinery” of the Journal of Research on Engineering Structures & Materials (RESM) covers a varied range of engineering systems. It contains papers selected on the basis of the results of regular peer review of the short manuscripts submitted for consideration by the participants of the Special Session “Fluid Flow, Energy Transfer and Design” at the 13th International Conference on Diffusion in Solids and Liquids (DSL2018) held in Vienna, Austria

Kategorisierte Gewalt und kulturalisierte Grenzen

In der vorliegenden Arbeit wird unter Anwendung der Intersektionalitätstheorie analysiert, ob ungleiche Bedingungen für gesellschaftlich unterschiedlich positionierte Frauen bestehen, im Fall von Gewalt im sozialen Nahraum Zugang zur Schutzeinrichtung eines Frauenhauses zu finden. Es wird dargelegt, dass es notwendig ist, die Kategorie Geschlecht, die im Frauenhauskontext zentral ist, um zusätzliche Kategorien zu erweitern. Der Zugang einer gewaltbetroffenen Frau zum Frauenhaus manifestiert sich als Passage, während derer mehrere Phasen zu durchlaufen sind, und die zu überwindende Barrieren beinhaltet, die als Strukturierungselemente des Zugangs verstanden werden. Es zeigen sich in der Arbeit neben ineinander verschränkten strukturellen und individuellen Barrieren auch sogenannte kulturelle Barrieren, die sich auf durch Fremdzuschreibungen kulturalisierte Zugänge beziehen. Nachdem die Zurückführung einer Barriere auf Struktur, Individuum oder Kultur die Wahl der Gegenstrategie definiert, gilt es zu überprüfen, ob die Verortung jener der Analyse standhält und unter welchen Bedingungen die Gegenstrategien nachhaltig Wirkung zeigen

Synergie-Effekte und wechselseitige Ergänzung von Hochschuldidaktik und Medizindidaktik

Ziel des Beitrags ist es, die Allgemeine Hochschuldidaktik und die Medizindidaktik auf struktureller und inhaltlicher Ebene miteinander zu vergleichen, um daraus Perspektiven für die wechselseitige Ergänzung und die Nutzung von Synergie-Effekten zu entwickeln. Dazu erfolgt ein Vergleich zwischen Hochschuldidaktik und Medizindidaktik auf zwei Ebenen: In struktureller Hinsicht werden jeweils exemplarisch Weiterbildungsangebote und Fachgesellschaften, in inhaltlicher Hinsicht das für beide gleichermaßen aktuelle Prinzip der „Kompetenzorientierung“ gegenüber gestellt. Aus den Ergebnissen des Vergleichs ergibt sich als Zielperspektive, in einer sinnvollen Arbeitsteilung und gegenseitigen Ergänzung das Lehren an Hochschulen zu professionalisieren und die damit korrespondierenden Forschungsaktivitäten auszubauen. 13.12.2010 | Wolfgang Öchsner (Ulm) & Karin Reiber (Tübingen

Environmental effects on the durability and the mechanical performance of flax fiber/bio-epoxy composites

The growing usage of bio-composite materials in different engineering applications demands a thorough understanding of their performance during their service. Extreme environmental conditions, such as warm, humid, and freezing environments, among others, can degrade the mechanical properties of the bio-composites when they are exposed to harsh environmental conditions. In addition, the use of these composites in underwater applications can also shorten their life cycle. In this work, the durability and mechanical performance (tensile and flexural behavior)of flax/bio-epoxy composites exposed to different environmental conditions were evaluated. These conditions were chosen to replicate those found outdoors that can affect the durability of these materials: water immersion, warm humid environment and freeze-thaw conditions. Moisture and water absorption behavior were evaluated and the water content (or exposure time)was related to the physical changes and mechanical properties. Results show that the mechanical properties of flax/bio-epoxy composites are clearly degraded by water ageing when they are compared to the ?as manufactured? composites. The tensile strength and modulus is decreased approximately by 9% and 57%, respectively for water saturated (immersed in water until saturation)samples compared to as manufactured samples. On contrary, this reduction rate is only 0.8% and 3%, respectively in case of humidity saturated (exposed to humid environment until saturation)samples. Furthermore, water incurred more severe effects on the flexural properties of the composites, since their flexural strength and modulus is decreased by 64% and 70%, respectively, as compared to as manufactured samples. It was found, however, that these properties can be partially regained after drying the water aged composites. Warm humid environments and freezing-thawing cycles have very little effect on the bio-composites.Fil: Moudood, Abdul. Griffith University; AustraliaFil: Rahman, Anisur. Griffith University; AustraliaFil: Khanlou, Hossein Mohammad. Griffith University; AustraliaFil: Hall, Wayne. Griffith University; AustraliaFil: Öchsner, Andreas. Hochschule Esslingen; AlemaniaFil: Francucci, Gaston Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin

Detecting Small Vessel Pathology in Cocaine Use Disorder

BackgroundCocaine use is associated with an increased risk of cerebrovascular accidents. Small vessel pathology has been linked to the risk of stroke in cocaine users, but can be challenging to detect on conventional magnetic resonance (MR) scans. Fluid-attenuated inversion recovery (FLAIR) scans permit better resolution of small vessel lesions.ObjectivesFLAIR scans are currently only acquired based on the subjective judgement of abnormalities on MR scans at face value. We sought to evaluate this practice and the added value of FLAIR scans for patients with cocaine use disorder (CUD), by comparing microbleeds detected by MR and FLAIR scans. We hypothesised that microbleeds are more pronounced in CUD patients, particularly so in participants who had been selected for a FLAIR scan by radiographers.MethodsSixty-four patients with CUD and 60 control participants underwent a brain scan. The MR of 20 CUD patients and 16 control participants showed indicators of cerebral infarction at face value and were followed up by a FLAIR scan. We determined the volume of microbleeds in both MR and FLAIR scans and examined associations with various risk factors.ResultsWhile MR lesion volumes were significantly increased in CUD patients, no significant differences in lesion volume were found in the subgroup of individuals who received a FLAIR.ConclusionThe current practice of subjectively evaluating MR scans as a basis for the follow-up FLAIR scans to detect vascular pathology may miss vulnerable individuals. Hence, FLAIR scans should be included as a routine part of research studies.</jats:sec

Development of Surface-Coated Polylactic Acid/Polyhydroxyalkanoate (PLA/PHA) Nanocomposites

This work reports on the design and development of nanocomposites based on a polymeric matrix containing biodegradable Polylactic Acid (PLA) and Polyhydroxyalkanoate (PHA) coated with either Graphite NanoPlatelets (GNP) or silver nanoparticles (AgNP). Nanocomposites were obtained by mechanical mixing under mild conditions and low load contents (<0.10 wt %). This favours physical adhesion of the additives onto the polymer surface, while the polymeric bulk matrix remains unaffected. Nanocomposite characterisation was performed via optical and focused ion beam microscopy, proving these nanocomposites are selectively modified only on the surface, leaving bulk polymer unaffected. Processability of these materials was proven by the fabrication of samples via injection moulding and mechanical characterisation. Nanocomposites showed enhanced Young modulus and yield strength, as well as better thermal properties when compared with the unmodified polymer. In the case of AgNP coated nanocomposites, the surface was found to be optically active, as observed in the increase of the resolution of Raman spectra, acquired at least 10 times, proving these nanocomposites are promising candidates as surface enhanced Raman spectroscopy (SERS) substrates

Complex joint geometry

The finite element method is particularly suited to analyse complex joint geometries. Adhesively bonded joints are increasingly being used in engineering applications where the loading mode, the adherends shape and the material behaviour are extremely difficult to simulate with a closed form approach. A detailed description of finite element studies concerning non-conventional adhesive joints is presented in this chapter. Various types of joints, local geometrical features such as the spew fillet and adherend rounding, three dimensional analyses, hybrid joints and repair techniques are discussed. Special techniques to save computer power are also treated. It is shown that the finite element method offers unlimited possibilities for stress analysis but also presents some numerical problems at sharp edges. © 2008 Springer Berlin Heidelberg