repOS HCU Hamburg
Not a member yet
999 research outputs found
Sort by
Energy Improvement Districts : Conceptual and Technical Guidance for Implementing Cooperative Energy Planning at the District Level
Get PDFEuropean Union, European Regional Development Fun
Effects of thermal and mechanical cyclic loads on polyurethane pre‐insulated pipes
Get PDFDistrict heating (DH) pre-insulated pipes are a sandwich assembly composed by a steel heat service pipe, polyurethane (PU) foam and polyethylene casing. The foam acts as bond between the steel pipe and casing. The application has high constraints for the foam, as it is subjected to cyclic multiaxial stresses, high cyclic temperatures and long expected service life. In this study, we evaluate if and how cyclic loads affect the shear strength, shear modulus, toughness and failure behaviour of the PU foam in DH pipes sandwich assembly compared with unaged reference samples. We have found that the simultaneous application of mechanical and thermal loads weakens the strength and increases the stiffness of the foam and that this change is not caused by degradation of the molecular structure. Crack initiation and propagation along the pipe samples follow a very consistent pattern between samples, with cracks initiating in Mode II and propagating in Mode I. The consistent axial displacement of approximately 2 cm from each other suggests the formation of strain localizations
The Development of a Diagnosis Indicator-Based Assessment Tool and Its Application to Rural Settlements in the Region Montes de Maria in Colombia
Get PDFOne of the most affected regions in Colombia in terms of social conflict, deforestation and loss of biodiversity is the region called Montes de Maria. In view of the current land restitution plan the trend of the environmental degradation is most likely to increase due to a higher demand of natural resources caused by the returning population that was displaced during the conflict. With the objective to develop a simple and quick method to diagnose the inefficient and environmentally unsustainable consumption and management of resources for domestic and agricultural purposes from households in that region, the most inclusive method is approached supported by a literature review. As a result, the indicator-based assessment tool pro.eraa was developed with the help of the reference certification tool Green Villages by IGBC of India, the Technical Advice by the One Planet Development of Wales, the local NBA as guidelines and the SDI’s of the SDGs. Pro.eraa consists of a total of 51 indicators in the four resource themes: water, energy, waste and activity. The fourth resource “Activity” was necessary to be added during the process due to the agricultural context of the region. Pro.eraa was validated and pre-tested on two sites (Huamanga and Chalan) in Montes de Maria. The tool serves as a decision-aid tool to support the selection of tailored and effective interventions that benefits efficiency and environmental sustainability in regard to the human well-being of the rural population as well as the local biodiversity. Apart from the design and validation process, the work includes a showcase application and evaluation of a site and instructions for implementation. During the literature review, it was particularly noted that the current state of the art literature lacks adequate indicator-based assessment or certification tools that lay the focus on sustainable rural development
Recyclable Insulating Foams for High-Temperature Applications
Get PDFThe recently approved restriction on diisocyanates highlights the health and safety issues concerning polyurethane manufacturing and the relevance of developing sustainable insulating polymeric foams. This is particularly challenging for applications where the foam is subjected to high temperatures (>80 °C) and bear loads, such as insulating and bonding material for district heating pipes. As part of a PhD project concerning pre-insulated district heating pipes for the circular economy, polybutylene (PB-1) has been identified as a promising candidate for the application, due to its low thermal conductivity, high-temperature mechanical properties, retention, excellent environmental stress cracking resistance (ESCR) and outstanding creep resistance. It is a recyclable thermoplastic and of non-toxic nature, pre-requisites for circular product development. On the contrary to other polyolefins, PB-1 is reported to strain-harden and has high melt strength, required properties for foaming. The purpose of the study is to assess the foamability of PB-1 through extrusion foaming experiments. A twin-screw extruder was used with varying concentrations of a chemical blowing agent. The obtained samples have been characterised for density, expansion ratio and microstructure. Foams with a volume expansion ratio of 1.8 were achieved. The results confirm the foamability of this polymer. The increase of the die pressure and its contribution to strain hardening were identified as key parameters for successful foaming. Further research will include improving the expansion ratio with a physical blowing agent and mechanical characterization of the foam
Citizen involvement in waste management and circular economy in cities: Key elements for planning and implementation
Get PDFThis paper identifies and explores key elements for planning and implementing citizen involvement in the area of waste management and circular economy in cities. The analysis has shown that institutions responsible for waste management regard strategic planning, inclusivity, transparency, continuity, and resources as particularly important for reaching the objectives of citizen involvement. However, not all of the four analysed cities have applied these elements to the same extent, due to e.g. a lack of a strategy for citizen involvement, or limited personal and financial resources
Advancing Values of Humanities in Academia, Society and Industry
No full textoai:repos.hcu-hamburg.de:hcu/2
Types and Roles of Models in Adaptive Architecture
Get PDFIf adaptive architecture is both, a techno-spatial environment and a set of environmental behaviors and practices, its design requires the collaboration of diverse disciplines. During the process of collaboratively developing an adaptive high-rise, models turn out to be the central medium in the multidisciplinary teamwork. They contribute to disciplinary questions of development and realization; they also generate and transfer knowledge and act as translators by facilitating exchange and cooperation between disciplines. The present study examines tasks and relations from the first design model to different functional models for the adaptive high-rise. It shows the initial architectural model as an overall role model and vision. While functional models perform isolated dynamic tasks, analytical models are used for review and discussion
Coastal cliff monitoring using UAS photogrammetry and TLS
Get PDFClimate change and the imminent sea-level rise mean that coastal protection is becoming increasingly important, and measures must be taken to ensure that life and important infrastructure in coastal areas are protected. An essential prerequisite for the implementation of appropriate coastal protection measures is the monitoring of endangered areas through appropriate sensor technology for the documentation and quantification of damages caused. In this contribution, a practical application is introduced using low-cost UAS (unmanned aerial system) to perform aerial flights for the monitoring of a coastal cliff at the Baltic Sea in Germany, since cliffs are exposed to and unprotected from autumn and winter storms. In comparison to UAS-based photogrammetric monitoring with terrestrial laser scanning (TLS), the photogrammetric method showed the same accuracy, but better coverage of the investigated area and a more efficient workflow.Wegen des Klimawandels und des bevorstehenden Meeresspiegelanstiegs wird der Küstenschutz immer wichtiger. Mit zahlreichen Maßnahmen werden Leben und wichtige Infrastrukturen in den Küstengebieten geschützt. Eine wesentliche Voraussetzung für die Umsetzung entsprechender Küstenschutzmaßnahmen ist die Überwachung der gefährdeten Gebiete durch geeignete Sensorik zur Dokumentation und Quantifizierung der verursachten Schäden. In diesem Beitrag wird eine praktische Anwendung vorgestellt, bei der ein Küstenkliff an der Ostsee, das ungeschützt und exponiert gegenüber Herbst- und Winterstürmen ist, mit Hilfe von kostengünstigen UAS (unbemannten Flugsystemen) überwacht wurde. Ein Vergleich des luftgestützten photogrammetrischen Monitorings mit terrestrischem Laserscanning (TLS) zeigte, dass die photogrammetrische Methode die gleiche Genauigkeit aufweist, aber eine bessere Abdeckung des Untersuchungsgebiets und einen effizienteren Arbeitsablauf ermöglicht
Die Viermastbark Peking in Virtual Reality als neue Form der Wissensvermittlung
Get PDFDer Bereich der „Virtual Reality“ (VR) ist eine aufstrebende neue Technologie, welche in den letzten Jahren durch das Aufkommen preiswerter Endgeräte enorm an Bedeutung gewonnen hat. Aufgrund dessen finden sich heute vielfältige Anwendungsgebiete in verschiedensten Branchen wie z.B. der Medizintechnik, Unterhaltungsindustrie, Architektur oder Pflege von Kulturgütern (cultural heritage).
Durch den stetigen technologischen Fortschritt können sowohl neue Themenfelder als auch immer immersivere Funktionalitäten für bestehende VR-Projekte entwickelt werden. Die „Peking“ ist eine Viermastbark, die vor über 100 Jahren in Hamburg gebaut wurde. Als restauriertes Museumsschiff soll diese ab 2023 erneut im Hamburger Hafen vor Anker liegen und einen bedeutenden Abschnitt der seefahrerischen Geschichte der Hansestadt für die Öffentlichkeit präsentieren. Durch die Erzeugung vieler Rekonstruktionspläne und weiterer Informationen für das zukünftige Museumsschiff entsteht die einzigartige Gelegenheit mithilfe dieser Datenquellen die „Peking“ in einer virtuellen Umgebung zu visualisieren.
Anhand dieses Beispiels werden neue Möglichkeiten in VR-Projekten untersucht. Diese Thesis erforscht, inwieweit verbreitete Theorien der Wissensvermittlung und Interaktivität in VR-Systemen eingesetzt und genutzt werden können. Zu diesem Zweck wird die „Peking“ durch diverse zur Verfügung gestellte Modelle visualisiert, in einer virtuellen Umgebung implementiert und für den Anwender zugänglich gemacht. Als Hardwarelösung kommt das Head-Mounted-Display HTC Vive Pro zum Einsatz. Weiterhin werden die erzeugte Performance und der benötigte Arbeitsaufwand dieses VR-Projektes analysiert.
In dieser Thesis wird zunächst der Workflow von der Datenerfassung/-erzeugung über die Generierung aller benötigten Elemente bis hin zur Entwicklung einer VR-Applikation mitsamt Navigations- und Interaktionsmöglichkeiten beschrieben und erläutert. Bei der Gestaltung der virtuellen Umgebung werden die Immersion steigernde dynamische Komponenten, wie Wasser, Segel oder auch die Takelage hervorgehoben. Weiterhin werden im Zuge der interaktiven Wissensvermittlung auch geodätische Datenformate wie Punktwolken oder Vermaschungen visuell für den Nutzer dargestellt.
Im Anschluss der Generierung der VR-Anwendung kann diese mit den theoretischen Grundlagen der Wissensvermittlung und Interaktivität qualitativ verglichen werden. Nach Analyse dieses Sachverhaltes resultiert, dass viele Aspekte der Wissensvermittlung und Interaktivität in VR-Systeme integriert werden und einen entscheidenden Anteil zum Lernprozess beitragen können.
Jedoch konnten nicht alle angestrebten Gesichtspunkte in der virtuellen Welt umgesetzt werden. Die Performance der VRApplikation ist von den betrachteten Komponenten abhängig, sodass die erreichte Rechenleistung stark variiert und teilweise das immersive Erlebnis entschieden beeinträchtigt. Der erbrachte Zeitaufwand für die einzelnen Arbeitsschritte entspricht dem prognostizierten Verhältnis zwischen den einzelnen Prozessschritten
Development of a Measuring Tool for Walkability in the Street Scale - the case study of Hamburg
Get PDFThe humanistic approach is a key principle of any urban development with the aim of urban quality improvement. A healthy environment is fundamentally associated with walkable communities. According to a study in 2016 from the Centre for Diet and Activity Research (CEDAR) and the Medical Research Council Epidemiology Unit at the University of Cambridge, the health benefits of walking and cycling override the negative impacts of air pollution on health even in highly polluted cities. Additionally, planning walkable cities promote low carbon emission developments. Measuring walkability of the streets makes it possible for the planners and experts to address the quality of the built environment. This paper reports a practical assessment tool, developed in a master thesis, based on decisive walkability features by applying a weighting system to score those features in order to achieve a tangible outcome. For this reason, an examined weighting system from a previous study led by the Institute of Urban Planning and the University of Duisburg-Essen is optimized. Afterward, the proposed tool is applied for measuring the walkability in a selection of different streets in Hamburg, in order to answer the questions of how these Hamburg's streets differ in their degree of walkability and how their walkability can be improved