Danube University Krems

About: Danube University Krems is a education organization based out in Krems, Niederösterreich, Austria. It is known for research contribution in the topics: Stroke & Population. The organization has 498 authors who have published 1572 publications receiving 68797 citations.

Impacts of external insulation and reduced internal heat loads upon energy demand of offices in the context of climate change in Vienna, Austria

Abstract: As a consequence of global climate change, a vicious circle of raising outdoor temperatures and consequently increasing CO 2 emissions associated with raising energy demands for cooling during hot summers is anticipated for office buildings in general. This paper investigates possible mitigation and adaptation strategies by applying regionally downscaled weather data from future climate scenarios in dynamic thermal simulation of four sample office buildings in Vienna, Austria. The effects of the appliance of external insulation and reduced levels of internal heat loads upon overall net energy demand and final energy demand under future climatic conditions are shown: By trend, external thermal insulation slows down nocturnal cooling processes in summer. It is this fact which frequently arises the question whether thermal insulation might prove counterproductive under climate change premises. However, it is shown here that winter savings due to external insulation will continue to outweigh summer constraints even in the future. Different levels of energy efficiency in IT equipment and artificial lighting influence net cooling demand in the sample buildings to a more significant extent than does the influence of a changing climate. Still, it has to be kept in mind that the reduction of internal loads in turn increases heating demand during cold periods as they compensate for heat losses then. Thus, reasonable combinations of improvements in internal heat loads and external insulation of the building envelope have to be developed.. The novelty of the approach presented here lies in that it simultaneously takes effects of external insulation and reduction of internal heat loads as well as their respective counter effects into account.

Transforming Government by Leveraging Disruptive Technologies: Identification of Research and Training Needs

Abstract: While the public sector traditionally lags behind business in innovation, significant changes are anticipated with the broad diffusion of so-called disruptive technologies. The use of such technologies in public service, along with possible benefits, need to be well researched, and challenges be carefully discussed, analysed and evaluated. This paper applies scenario-based science and technology roadmapping to identify research and training needs in the implementation of disruptive technologies in public service. 70 experts reviewed 13 future scenarios and derived a number of research and training needs regarding internet of things, artificial intelligence, virtual and augmented reality, big data and other disruptive technologies. The identified needs serve as a starting point for a broader and more informed discussion about how such new (disruptive) technologies can be successfully deployed in the public sector - leveraging the benefits of these technologies while at the same time constraining the drawbacks affiliated with them.

MEMS Flow Sensors Based on Self-Heated aGe-Thermistors in a Wheatstone Bridge

Abstract: A thermal flow transduction method combining the advantages of calorimetric and hot-film transduction principles is developed and analyzed by Finite Element Method (FEM) simulations and confirmed experimentally. The analyses include electrothermal feedback effects of current driven NTC thermistors. Four thin-film germanium thermistors acting simultaneously as heat sources and as temperature sensors are embedded in a micromachined silicon-nitride membrane. These devices form a self-heated Wheatstone bridge that is unbalanced by convective cooling. The voltage across the bridge and the total dissipated power are exploited as output quantities. The used thin-film thermistors feature an extremely high temperature sensitivity. Combined with properly designed resistance values, a power demand in sub-1mW range enables efficient gas-flow transduction, as confirmed by measurements. Two sensor configurations with different arrangements of the membrane thermistors were examined experimentally. Moreover, we investigated the influence of different layouts on the rise time, the sensitivity, and the usable flow range by means of two-dimensional finite element simulations. The simulation results are in reasonable agreement with corresponding measurement data confirming the basic assumptions and modeling approach.