The Hamburg University of Applied science is an institution of higher education and applied research located in Hamburg, Germany. Formerly known as Fachhochschule Hamburg the Hamburg University of Applied science was founded in 1970. In terms of student enrollment, the HAW is the second largest university in Hamburg, with a student body of 14,928 . Wikipedia.
Winkler W.,Hamburg University of Applied Sciences
Applied Energy | Year: 2011
The necessary reduction of the human footprint demanded by Sustainable Development can be measured by the entropy flow of the society to the environment. The classic tools of process evaluation as e.g. exergetic or life cycle analysis are able to evaluate existing solutions. But their use during the design phase is quite limited because of lacking information about the system and its components. They may be helpful for evolutionary development strategies on a long term only. But reversible process structures can be used as benchmarks already in the conceptual design phase to introduce the demands of the second law. It can be shown that basic human demands on housing, mobility, communication, and infrastructure and industry can be principally supplied by reversible process structures. Because the process logic is a virtual one, real processes can be engineered with a reversible structure however its components produce irreversible entropy flows. Hybrid cars are the most common examples here. The use of exergetic efficiencies allows a transfer of the results of reversible structures to real technology easily. The here presented methodology of sustainable engineering can be summarized by three design rules as using reversible structures, considering technology by exergetic efficiencies, and minimizing components' entropy export. The still increasing utilization of electricity in upcoming technologies is very helpful for introducing reversible structures within hybrid technologies. © 2011 Elsevier Ltd.
Lewandowski D.,Hamburg University of Applied Sciences
Online Information Review | Year: 2010
Abstract Purpose - The purpose of this paper is to measure the coverage of Google Scholar for Library and Information Science (LIS) journal literature as identified by a list of core LIS journals from a study by Schlogl and Petschnig. Design/methodology/approach - The paper checked every article from 35 major LIS journals from the years 2004 to 2006 for availability in Google Scholar. It also collected information on the type of availability - whether a certain article was available as a PDF for a fee, as a free PDF or as a preprint. Findings - The paper found that only some journals are completely indexed by Google Scholar, that the ratio of versions available depends on the type of publisher, and that availability varies a lot from journal to journal. Google Scholar cannot substitute for abstracting and indexing services in that it does not cover the complete literature of the field. However, it can be used in many cases to easily find available full texts of articles already identified using another tool. Originality/value - The study differs from other Google Scholar coverage studies in that it takes into account not only whether an article is indexed in Google Scholar at all, but also the type of availability. © Emerald Group Publishing Limited.
Lewandowski D.,Hamburg University of Applied Sciences
Aslib Proceedings: New Information Perspectives | Year: 2011
Purpose: The purpose of this paper is to test major web search engines on their performance on navigational queries, i.e. searches for homepages. Design/methodology/approach: In total, 100 user queries are posed to six search engines (Google, Yahoo!, MSN, Ask, Seekport, and Exalead). Users described the desired pages, and the results position of these was recorded. Measured success and mean reciprocal rank are calculated. Findings: The performance of the major search engines Google, Yahoo!, and MSN was found to be the best, with around 90 per cent of queries answered correctly. Ask and Exalead performed worse but received good scores as well. Research limitations/implications: All queries were in German, and the German-language interfaces of the search engines were used. Therefore, the results are only valid for German queries. Practical implications: When designing a search engine to compete with the major search engines, care should be taken on the performance on navigational queries. Users can be influenced easily in their quality ratings of search engines based on this performance. Originality/value: This study systematically compares the major search engines on navigational queries and compares the findings with studies on the retrieval effectiveness of the engines on informational queries. © Emerald Group Publishing Limited.
Reintjes R.,Hamburg University of Applied Sciences
Journal of Health Politics, Policy and Law | Year: 2012
Communicable diseases do not respect national boundaries and are important challenges to health internationally. This article aims to support the improvement and integration of surveillance systems in Europe and beyond by drawing on research comparing national systems. Definitions and concepts of epidemiological surveillance are described as a continuous systematic process that observes and reflects the real situation in society not only within but also across political boundaries. Outbreaks that affect more than one country show that a systematic comparative analysis of surveillance systems in Europe can help improve disease control. National surveillance systems from six European Union countries and from a later comparison of twenty- six European countries are examined. An effective surveillance system can provide information for action and act as a monitoring body for health authorities. Nevertheless, many European surveillance systems still require improvement in the interests of public health. © 2012 by Duke University Press.
Biallas G.,Hamburg University of Applied Sciences
International Journal of Fatigue | Year: 2013
Fatigue crack growth thresholds ΔKth were determined for friction stir welded butt joints made from aluminium alloys AA2024 and AA6013. Plotting the thresholds as a function of load ratio R showed distinctly higher amounts for welded joints as compared to those for parent material at small load ratios, but differences became smaller with increasing load ratio, until thresholds became finally identical for the highest R values. Applying Döker's concept of two controlling parameters, namely ΔK and K max , and plotting ΔKth versus Kmax, however, revealed that the effective threshold ΔKth ,eff determined at very high R ratios was nearly independent on the alloy and, simultaneously, was identical for parent material and respective welded joints. Thus, differences in threshold behaviour were only caused by the second threshold Kmax,th, which was significantly higher for welded joints as compared to parent material. Differences in Kmax,th coincided with compressive residual stresses determined by cut-compliance measurements in terms of stress intensity factors Krs acting at the crack tip. Based on the analytical approach described by Döker , only one characteristic Krs value was needed to calculate all thresholds of welded joints for 0 ≤ R ≤ 1 provided a base material master curve is available. © 2012 Elsevier Ltd. All rights reserved.