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Stockmar A.,Hannover University of Applied Sciences
Light and Engineering | Year: 2011

In general terms, energy efficiency could be regarded as the ratio of the amount or the value of goods produced or services provided to the energy consumed. In the first sense, luminous efficacy is a measure which describes the energy efficiency of a light source (taking into account the additional energy consumed by the control gear if required). In consequence, an energy efficiency measure could be derived as the ratio of the energy consumed during a given time span to the produced/delivered amount of luminous flux, which allows to take into account the variation of the system efficacy over time due to changes of the mode of operation. On the other hand, if lighting is regarded as a service provided, it means the provision of a (required or requested) lighting level (in quantity and quality) in a well defined area (of an interior or an exterior) over a specified time span. In this case the consumed electric energy per time unit, in relation to the reference area and in relation to the lighting level can serve as an energy efficiency measure. Here it is of great importance to consider all relevant influencing factors, such as efficacies and maintenance factors of the light sources, luminous intensity distributions, light output ratios and maintenance factors of the luminaires, installation geometries, modes of operation, and operating times. Due to the large diversity of outdoor areas, tasks, and activities, different energy efficiency measures will be preferable under different circumstances. Examples are given for a number of outdoor lighting applications taking into account the new concepts of adaptive lighting.


Kromker V.,Hannover University of Applied Sciences
Tierärztliche Praxis. Ausgabe G, Grosstiere/Nutztiere | Year: 2015

Mastitis is one of the most common and expensive diseases in dairy cattle. The decision to treat clinical mastitis is usually made without any knowledge of the etiology, and can therefore only be evidence-based to a limited extent. Evidence-based medicine relies essentially on a combination of one's own clinical competence and scientific findings. In mastitis therapy, those insights depend mostly on pathogen-specific factors. Therefore, in evidence-based therapeutic decision making the pathogen identification should serve as a basis for the consideration of scientifically validated therapeutic concepts. The present paper considers evidence-based treatment of clinical mastitis based on a literature review. The authors conclude that an anti-inflammatory treatment using an NSAID should be conducted regardless of the pathogen. However, the choice of an antibiotic therapy depends on the mastitis causative pathogen, clinical symptoms and the animal itself. In principle, a local antibiotic treatment should be chosen for mild and moderate mastitis. It should be noted, that the benefit of an antibiotic therapy for coliform infections is questionable. With knowledge concerning the pathogen, it appears entirely reasonable to refrain from an antibiotic therapy. For severe (i.   e. feverish) mastitis, a parenteral antibiotic therapy should be selected. An extension of the antibiotic therapy beyond the manufacturer's information is only reasonable for streptococcal infections. It is important to make the decision on a prolonged antibiotic therapy only with the knowledge of the mastitis-causative pathogen. In terms of the therapy of a staphylococcus or streptococcus infection, a narrow-spectrum antibiotic from the penicillin family should be adopted when selecting the active agents.


Emmert M.,Friedrich - Alexander - University, Erlangen - Nuremberg | Sander U.,Hannover University of Applied Sciences | Pisch F.,Friedrich - Alexander - University, Erlangen - Nuremberg
Journal of Medical Internet Research | Year: 2013

Background: Physician-rating websites are currently gaining in popularity because they increase transparency in the health care system. However, research on the characteristics and content of these portals remains limited. Objective: To identify and synthesize published evidence in peer-reviewed journals regarding frequently discussed issues about physician-rating websites. Methods: Peer-reviewed English and German language literature was searched in seven databases (Medline (via PubMed), the Cochrane Library, Business Source Complete, ABI/Inform Complete, PsycInfo, Scopus, and ISI web of knowledge) without any time constraints. Additionally, reference lists of included studies were screened to assure completeness. The following eight previously defined questions were addressed: 1) What percentage of physicians has been rated? 2) What is the average number of ratings on physician-rating websites? 3) Are there any differences among rated physicians related to socioeconomic status? 4) Are ratings more likely to be positive or negative? 5) What significance do patient narratives have? 6) How should physicians deal with physician-rating websites? 7) What major shortcomings do physician-rating websites have? 8) What recommendations can be made for further improvement of physician-rating websites? Results: Twenty-four articles published in peer-reviewed journals met our inclusion criteria. Most studies were published by US (n=13) and German (n=8) researchers; however, the focus differed considerably. The current usage of physician-rating websites is still low but is increasing. International data show that 1 out of 6 physicians has been rated, and approximately 90% of all ratings on physician-rating websites were positive. Although often a concern, we could not find any evidence of 'doctor-bashing'. Physicians should not ignore these websites, but rather, monitor the information available and use it for internal and ex-ternal purpose. Several shortcomings limit the significance of the results published on physician-rating websites; some recommendations to address these limitations are presented. Conclusions: Although the number of publications is still low, physician-rating websites are gaining more attention in research. But the current condition of physician-rating websites is lacking. This is the case both in the United States and in Germany. Further research is necessary to increase the quality of the websites, especially from the patients' perspective.


Emmert M.,Friedrich - Alexander - University, Erlangen - Nuremberg | Sander U.,Hannover University of Applied Sciences | Esslinger A.S.,Friedrich - Alexander - University, Erlangen - Nuremberg | Maryschok M.,Friedrich - Alexander - University, Erlangen - Nuremberg | Schoffski O.,Friedrich - Alexander - University, Erlangen - Nuremberg
Methods of Information in Medicine | Year: 2012

Background: Physician rating websites (PRWs) are gaining in popularity among patients seeking quality information about physicians. However, little knowledge is available about the quantity and type of information provided on the websites. Objective: To determine and structure the quantity and type of information about physicians in the outpatient sector provided on German-language physician rating websites. Methods: In a first step, we identified PRWs through a systematic internet search using German keywords from a patient ́s perspective in the two search engines Google and Yahoo. Afterwards, information about physicians available on the websites was collected and categorised according to Donabedian ́s structure/process/outcome model. Further - more, we investigated whether the information was related to the physician himself/ herself or to the practice as a whole. Results: In total, eight PRWs were detected. Our analysis turned up 139 different information items on eight websites; 67 are related to the structural quality, 4 to process quality, 5 to outcomes, and 63 to patient satisfaction/ - experience. In total, 37% of all items focus specifically on the physician and 63% on the physician's practice. In terms of the total amount of information provided on the PRWs, results range from 61 down to 13.5 items. Conclusions: A broad range of information is available on German PRWs. While structural information can give a detailed overview of the financial, technical and human resources of a practice, other outcome measures have to be interpreted with caution. Specifically, patient satisfaction results are not risk-adjusted, and thus, are not appropriate to represent a provider's quality of care. Consequently, neither patients nor physicians should yet use the information provided to make their final decision for or against an individual physician. © Schattauer 2012.


Yazdani S.,Leibniz University of Hanover | Rust W.J.H.,Hannover University of Applied Sciences | Wriggers P.,Leibniz University of Hanover
Composite Structures | Year: 2016

A First-order Shear Deformation Theory (FSDT) is chosen to simulate composite laminates in the linear and the geometrically non-linear regimes. The formulation is based on the Equivalent Single Layer (ESL) theory that fails to predict the delamination onset in composite laminates. The lack of resolving three-dimensional states and correct transverse stresses in this model is principally improved using post-processing. In order to precisely compute interlaminar stresses, a non-frictional linear adhesive contact model is applied in the context of the eXtended Finite Element Method (XFEM). The discontinuities are imposed within any arbitrary interface by enriching the displacement field. Thus two sub-domains define the plane of the discontinuity. Thereafter, the aforementioned adhesive contact can be formulated at the discontinued interface. Stress values are retrieved at nodal points using the interface constitutive equation. Consequently, the interface formulations are extended into the softening regime to model the delamination growth as a mixed-mode cohesive effect. The accuracy of the proposed method in predicting the interlaminar stresses and the delamination propagation is demonstrated by comparing the results with the ones available in literature. By combining the lower-order plate theory and the novel XFEM technique, the model is able to accurately calculate the delamination onset and the propagation with less computational effort. © 2015 Elsevier Ltd.

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