ITG Informationstechnik Graz GmbH : von der Magistratsabteilung zum kundenorientierten Unternehmen

Die vorliegende Arbeit befasst sich mit den Strukturreformen der Stadt Graz. Das Hauptthema dabei ist aber die Gründung der ITG Informationstechnik Graz GmbH. Das Unternehmen wird durch Ausgliederung und Zusammenführung zweier IT-Abteilungen der Stadt gebildet und als Shared Service Center ausge-richtet. Die Arbeit zeigt den Weg von der Willenserklärung der Politik, über die Entscheidungsfindung bis zum Echtbetrieb

Wirksamkeit wissenschaftlicher Weiterbildung aus Sicht von Stakeholdern: Kriterien zur Erfolgsbestimmung und den wahrgenommenen Bedingungsfaktoren

Die Weiterbildung an Hochschulen ist an evidenzbasierten Daten interessiert, um Aussagen über die Wirksamkeit von eigenen Angeboten treffen zu können. Oftmals unklar ist, was unter Wirksamkeit verstanden werden kann und welche Voraussetzungen gegeben sein müssen, damit die Weiterbildungen Wirkung entfalten. Der Beitrag stellt eine Studie vor, die beide Aspekte adressiert und Aussagen unterschiedlicher Beteiligter am Weiterbildungsgeschehen wiedergibt. Angebotsseitig wurden Weiterbildungsverantwortliche sowie Lehrpersonen der Hochschule befragt. Nachfrageseitig wurden Teilnehmende berufsbegleitender Studiengänge und Unternehmensvertreter_innen aus ausgewählten Branchen einbezogen. Die erhobenen qualitativen Daten wurden inhaltsanalytisch analysiert und induktiv zu Kategorien zusammengefasst. Die Ergebnisse zeigen insgesamt fünf Oberkategorien auf, die die Wirksamkeit abbilden: (1) Erfolgreicher Praxistransfer; (2) Erwerb von Kenntnissen, Fähigkeiten und Kompetenzen; (3) Strategischer Nutzen; (4) Sozialer/kultureller Nutzen und (5) Resonanz der Teilnehmenden auf die wissenschaftliche Weiterbildung. Die Voraussetzungen lassen sich ebenfalls in fünf Kategorien abbilden: (a) teilnehmenden-, (b) unternehmens-, (c) angebots-, (d) hochschul- und (e) markt-/umfeldbezogene Faktoren. Im Beitrag werden nach der Darstellung der Studienergebnisse Schlussfolgerungen für die Weiterbildungspraxis in Hinblick auf die Themen Evaluation, Theorie-Praxis-Transfer und Marketing/Zielgruppenspezifische Kommunikation diskutiert

Evaluierung von nachhaltiger Wirksamkeit in der wissenschaftlichen Weiterbildung: Erfahrungen und Empfehlungen für die Weiterbildungspraxis aus dem Projekt OTH mind

Evaluationen können einen wichtigen Beitrag für die professionelle Entwicklung der wissenschaftlichen Weiterbildung leisten. Voraussetzung hierfür ist die Berücksichtigung von nachhaltiger Wirksamkeit als Evaluationsziel und -gegenstand, denn daraus lassen sich wichtige Informationen für das professionelle Handeln der Beteiligten am Weiterbildungsgeschehen ableiten. Der Beitrag greift Erfahrungen aus der begleitenden Evaluations- und Wirksamkeitsforschung im Projekt OTH mind auf. Anhand der Evaluationsstandards der Deutschen Gesellschaft für Evaluation (DeGEval-Standards) werden das Vorgehen und die ergriffenen Maßnahmen in Hinblick auf die Qualität der Planung und Durchführung bewertet. Insgesamt werden fünf zentrale Empfehlungen für die Evaluationspraxis formuliert: für (1)die Einbindung von Beteiligten im Evaluationsprozess, (2) eine Nutzenevaluation auf verschiedenen Ebenen, (3) Ziele und Gegenstände einer professionalisierungsbezogenen Evaluation, (4) eine zielbezogene Messung sowie (5) die Nutzung/ Rückkopplung der Ergebnisse an Weiterbildungsverantwortliche. Weiterbildungspraktiker*innen an Hochschulen dienen die Empfehlungen als Impulse für eigene zukünftige Evaluationsanliegen

Stereoscopic Measurements of Blade Deformation on a Shrouded Prop-Fan with Boundary Layer Ingestion by means of Image Pattern Correlation Technique

The material presented herein describes the implementation of optical blade deformation measurements based on the image pattern correlation technique (IPCT) in a stereoscopic imaging configuration applied to the first rotor of a counter-rotating shrouded fan stage (CRISPMulti) which has a diameter of about 1m. The correlation-based stereoscopic image analysis is discussed, as well as the difficulties with regard to the correlation-based stereomatching of two camera views for the highly curved blade surface involving pattern displacements up to 12% of the image height. Cross-correlation of speckle images at reference positionwith images of the displaced positions recovered the full 3c displacement field in the optically assessable area of the suction side. The three-dimensional displacements could be evaluated with triangulation errors below 0.5mm at blade tip velocities exceeding 250m/s (4830rpm). Comparative measurements using a third camera imaging the blade tip match the stereo IPCT results within deviations of 0.5mm for the axial component whereby the circumference component matches closely

Multi-Resolution, Time-Resolved PIV Measurements of a Decelerating Turbulent Boundary Layer near Separation

We report on measurements of the time-evolving velocity profile of a turbulent boundary layer subjected to a strong adverse pressure gradient (APG) at Reynolds numbers up to Re_theta ~55000 with an upstream friction Reynolds number exceeding Re_tau ~10000. Near the point of flow separation high-resolution imaging at high camera frame rates captured the time evolving velocity profile using the so-called "profile-PIV" technique in a nested imaging configuration of two cameras operating at different image magnifications. One camera used an image magnification better than unity to resolve the viscous scales directly at the wall while the remainder of the roughly 200 mm thick boundary layer is simultaneous captured by the second camera. In the APG the variance of the stream-wise velocity exhibits no "inner peak" commonly found in turbulent boundary layers without pressure gradient influence. Spectral analysis further shows that the peak energy within the boundary layer shifts away from the wall toward lower frequencies. The overlap between the simultaneously imaged areas allows to assess and, to first order, correct for the effect of spatial smoothing on statistical quantities, spectra and related quantities. A multi-frame cross-correlation algorithm was used to process the extensive database. In addition, a newly developed 2D-2C "Shake-The-Box" algorithm(STB) provided highly resolved particle tracking data beyond the reach of conventional PIV processing

Experimental and Numerical Investigation of a Multi-Jet Impingement Cooling Configuration

In order to protect turbine blades from thermal damage or thermally induced aging, internal impingement cooling has found common use throughout engine design, both in stationary gas turbines as well as aircraft engines, but also finds applications in other areas requiring cooling. The present investigation is focused on a generic impingement cooling configuration that can be easily modelled with computational fluid dynamics (CFD) and at the same time can be studied in detail experimentally. The acquired experimental data can be directly used for the validation of the CFD simulations, ultimately allowing their application in more complex, realistic configurations where experimental investigations become prohibitively expensive or otherwise impossible. The investigated configuration consists of 9 evenly spaced jets of Reynolds number Re D = 10000 issuing into a square channel that is sealed at one end. The jets directly impinge on a uniformly heated target plate. With previous work on similar configurations well described in literature, the focus of the present contribution is to further exploit the potentials offered by snap-shot based and time-resolved measurements. The flow field within the channel is characterized with both conventional, snap-shot particle image velocimetry (PIV) as well as with high-speed, time-resolved PIV (TR-PIV) to, respectively, capture overview data as well as detailed information on temporally evolving flow structures. In addition, measurements of the unsteady surface temperature distribution on the heated channel wall are performed by means of a newly developed unsteady temperature sensitive paint (iTSP) measurement technique. The interaction of the turbulent jets with the wall and with its neighbors is studied in detail using correlation and spectral analysis as well as modal decomposition. Where possible, this is supplemented with corresponding data obtained from numerical modelling. None of the applied postprocessing methods reveal a significant interaction between jets suggesting that the jet-driven dynamics of heat transfer at the wall are restricted to their immediate vicinity which may simplify the requirements on numerical models of similar cooling configurations

Measurement of Aerodynamically Induced Blade Distortion on a Shrouded Counter-Rotating Prop-Fan

Blade deformation on a 1 m diameter composite fan rotor is measured simultaneously using stereoscopic image pattern correlation technique (IPCT) and blade-tip imaging. Absolute referencing of the blades is made possible by simultaneously tracking a marker on the hub using a fourth camera. Illumination is provided by microsecond pulses of high-power LEDs. Rise and fall time in the 100ns regime are achieved using a self-designed high-current drive circuit. A high-speed microcontroller provides accurate, speed-independent angular delays to enable phase-locked triggering of cameras and LEDs. Mean and RMS deformation of the blade are acquired for different aerodynamic loading conditions induced by imposing a non-uniformity upstream of the rotor aimed at mimicking boundary layer ingestion

Predictive significance of the six-minute walk distance for long-term survival in chronic hypercapnic respiratory failure

Background: The 6-min walk distance ( 6-MWD) is a global marker of functional capacity and prognosis in chronic obstructive pulmonary disease ( COPD), but less explored in other chronic respiratory diseases. Objective: To study the role of 6-MWD in chronic hypercapnic respiratory failure ( CHRF). Methods: In 424 stable patients with CHRF and non-invasive ventilation ( NIV) comprising COPD ( n = 197), restrictive diseases ( RD; n = 112) and obesity-hypoventilation- syndrome ( OHS; n = 115), the prognostic value of 6-MWD for long- term survival was assessed in relation to that of body mass index (BMI), lung function, respiratory muscle function and laboratory parameters. Results: 6-MWD was reduced in patients with COPD ( median 280 m; quartiles 204/350 m) and RD ( 290 m; 204/362 m) compared to OHS ( 360 m; 275/440 m; p <0.001 each). Overall mortality during 24.9 (13.1/40.5) months was 22.9%. In the 424 patients with CHRF, 6-MWD independently predicted mortality in addition to BMI, leukocytes and forced expiratory volume in 1 s ( p <0.05 each). In COPD, 6-MWD was strongly associated with mortality using the median {[} p <0.001, hazard ratio ( HR) = 3.75, 95% confidence interval (CI): 2.24-6.38] or quartiles as cutoff levels. In contrast, 6-MWD was only significantly associated with impaired survival in RD patients when it was reduced to 204 m or less (1st quartile; p = 0.003, HR = 3.31, 95% CI: 1.73-14.10), while in OHS 6-MWD had not any prognostic value. Conclusions: In patients with CHRF and NIV, 6-MWD was predictive for long- term survival particularly in COPD. In RD only severely reduced 6-MWD predicted mortality, while in OHS 6-MWD was relatively high and had no prognostic value. These results support a disease-specific use of 6-MWD in the routine assessment of patients with CHRF. Copyright (C) 2007 S. Karger AG, Basel

Multi-resolution, time-resolved particle image velocimetry of a turbulent boundary layer approaching separation

The evolution and characteristics of turbulent boundary layers subjected to a positive pressure gradient are common in many flows of industrial relevance and appear, for instance, on the suction side of high-lift wing sections or turbomachinery blading. The pressure gradient is associated with a deceleration of the external flow which results in a thickening of the boundary layer and reduction of the wall friction. Under strong adverse pressure gradient conditions, the wall friction reduces to zero as the flow begins to separate. From a numerical perspective these flows are difficult to model with methods of engineering relevance, such as Reynolds averaged Navier-Stokes simulations (RANS) and motivate experiments such as the one presented here to provide relevant validation data

Modification of turbulence models for pressure-induced separation on smooth surfaces using the DLR VicToria experiment

A new experiment of a turbulent boundary layer flow at a large adverse pressure gradient at a high Reynolds number is presented. The strong pressure gradient leads to pressure-induced separation on the smooth surface of the geometry model with a thin separation bubble. The experiment was performed within the DLR internal project VicToria. First, the design of the test case, the set-up in the wind tunnel, and the measurement technique using both large-scale and high-magnification particle imaging and Lagrangian particle tracking are described. Then the experimental results for the mean velocity are described as the flow evolves downstream from the zero-pressure gradient region into the adverse pressure gradient region. From the measurement data a wall law for the mean velocity with a thin log-law region and a half-power law region above the log-law is observed in the adverse pressure gradient region. Then the differential Reynolds stress transport model SSG/LRR-omega is considered. Based on the observation that the length-scale equation is not consistent with the assumed wall laws at adverse-pressure gradient, a modification of the equation for the dissipation rate omega in the model is proposed, so that the modified model can predict the observed wall law at adverse-pressure gradient. Finally, the numerical results using the modified SSG/LRR-omega model are shown. The modification causes a reduction of the mean velocity in the inner part of the boundary layer at adverse-pressure gradients, making the modified model more susceptible for flow separation. The numerical predictions of the modified model are found to be in good agreement with the experimental data