4242 research outputs found
Sort by
Improvisation in Musik und Theater : ein interdisziplinärer Beitrag zur Vermittlung musikalischer Improvisation
Get PDFIn music and in theatre, there are various ways of teaching improvisation. In this comparative Foucauldian discourse analysis, jazz and improvisational theatre are selected as representative parts of the improvisational education and are examined with methods of qualitative research. The study shows amongst other things that in the discourse of German music education, tonal improvisation is still linked with individual teaching and genius cult, and that tonal improvisation is understood as a contrast to composed music. Discursive formations reveal the continuous struggle of the German improvisational pedagogy and improvisation scene for recognition by educational and cultural institutions. Due to the high demands on the sound results, the problem of failure in teaching and learning of tonal improvisation in music is omnipresent. By contrast, in improvisational theatre, failure is perceived as pleasurable and creatively stimulating. Starting from this point the study shows to what extent music education can profit from a comparison of the discursive practice of teaching improvisational theatre and tonal improvisation in music
Long-term behavior of polycrystalline oxide fibers at elevated temperatures
Get PDFCeramic matrix composites based on oxide materials have gained more attention in the last decades, because of their chemical stability, strength and considerably high toughness. The development of this class of material was only possible due to the appearance of suitable oxide fibers. Currently available fibers are based either on alumina for high strength, or on mullite for better long-term performance. However, it is well known that these fibers are prone to loss of their mechanical properties above 1000 degree celsius. Although high, these temperatures are easily reached during processing and in-field applications of composites. Therefore, the aim of this work is to study the mechanical behavior and the degradation mechanisms of oxide fibers at elevated temperatures. For that, two mullite fibers were evaluated: the well-established mullitea alumina NextelTM 720, and the fully crystalline mullite fiber CeraFib 75. Both fibers were analyzed before and after heat treatments at temperatures ranging 1000-1400 degree celsius for 25 h. The characterization approach included microstructural analyses, as well as creep and tensile tests at room and high temperatures. For comparison, the same procedure was conducted with the alumina fibers NextelTM 610 and CeraFib 99. As-received NextelTM 720 fibers present a microstructure of mullite grains with smaller a-alumina grains, whereas the microstructure of CeraFib 75 consists basically of mullite with traces of y-alumina. The higher amount of mullite in CeraFib 75 resulted in lower room-temperature strength. Still, CeraFib 75 showed higher strength retention than NextelTM 720 at temperatures above 1200AdegreeC, while the measured creep rates were in the same order of magnitude. With the thermal treatments performed, two microstructural changes were observed: grain growth and dissociation of the mullite phase. The kinetics of these reactions were quantified and related to the mechanical performance of the fibers. Thus, a strength decrease was observed for all oxide fibers mainly due to grain growth. On the other hand, the phase transformations caused by the thermal exposures improved the thermal stability of the fibers. As a consequence, the treated fibers were more resistant to creep, i.e., the creep rates decreased. In summary, this work presents a more detailed analysis on the long-term behavior of oxide fibers at high temperatures. Based on these results, it is suggested that a fiber with a chemical composition near to the stoichiometric 3/2 mullite would have higher thermal stability
Resource Utilisation and Curriculum Implementation in Community Colleges in Kenya
Get PDFThe study investigated how Catholic-sponsored community colleges in Nairobi utilise the existing physical facilities and teaching and learning resources for effective implementation of Artisan and Craft curricula. The study adopted a mixed methods research design. Proportional stratified random sampling was used to sample 172 students and 18 teachers while four directors of community colleges were purposively selected. Questionnaires were administered to students and teachers, while directors were interviewed. Teaching and learning resources, such as workshops, equipment, lecture rooms, laboratories, raw materials for practical training and reference books, were found to be adequate, although underutilised. However, sports grounds, libraries and course texts were inadequate. Resource inadequacies were often mitigated by signing equipment co-sharing agreements with peer institutions and local firms. Teachers rated highly the influence of physical facilities on curriculum implementation. Both students and teachers rated highly the influence of teaching and learning resources on curriculum implementation. The study concludes that, while some physical facilities and teaching and learning resources are adequate, their underutilisation and the inadequacy of other core facilities and resources, such as libraries and course textbooks, hinder effective teaching and learning in these community colleges
Solid sponges as support for heterogeneous catalysts in gas-phase reactions
Get PDFSolid sponges combine large specific surface areas and low pressure losses with excellent heat transport properties. Thus, they are promising catalyst supports for endo- and exothermic processes. Nevertheless, design tradeoffs regarding the porosity and window diameter of solid sponges with respect to high catalyst densities, low pressure losses, and high effective thermal conductivities remain unsolved. Therefore, a 2-d pseudo-homogeneous multi-scale reactor model for solid sponges is developed in this work. The model is validated against polytropic lab-scale experiments for the methanation of carbon dioxide in a fixed-bed reactor. In order to quantify and analyze the design tradeoffs, the model is used to solve the outlined multi-objective optimization problem. Moreover, tailored graded solid sponges with an optimal porosity distribution in the radial direction are introduced to successfully resolve the existing design tradeoffs
Operative Planning with Exchangeable and Mandatory Tasks : Applications to Lot Size Planning and Transportation Planning
Get PDFLot-sizing problems of manufacturers and transportation planning problems of forwarders are presented and analyzed in this thesis. These problems represent crucial planning tasks in supply chain management. Due to high fluctuations and competitive markets, companies within supply chains use internal and external resources for the fulfillment of tasks. The thesis claims to contribute to the following topics: (1) introducing mandatory tasks for the DULR, IOTPP, CTPP, and CIOTPP as well as (2) presenting computational studies that demonstrate how much the costs of companies increase due to mandatory tasks. Mandatory tasks are tasks, which have to be fulfilled by appointed resources due to contractual obligations. A lack of research is identified in terms of this topic. It is usually assumed that a task can be fulfilled by any internal or external resources. The thesis describes how these planning tasks with mandatory tasks can be solved by using operations research. Therefore, existing mathematical models and solution approaches have to be extended. The thesis focuses on the determination of the impact of mandatory tasks based on computational studies
SystemC Through the Looking Glass : Non-Intrusive Analysis of Electronic System Level Designs in SystemC
Get PDFDue to the ever increasing complexity of hardware and hardware/software co-designs, developers strive for higher levels of abstractions in the early stages of the design flow. To address these demands, design at the Electronic System Level (ESL) has been introduced. SystemC currently is the de-facto standard for ESL design. The extraction of data from system designs written in SystemC is thereby crucial e.g. for the proper understanding of a given system. However, no satisfactory support of reflection/introspection of SystemC has been provided yet. Previously proposed methods for this purpose %introduced to achieve the goal nonetheless either focus on static aspects only, restrict the language means of SystemC, or rely on modifications of the compiler and/or parser. In this thesis, approaches that overcome these limitations are introduced, allowing the extraction of information from a given SystemC design without changing the SystemC library or the compiler. The proposed approaches retrieve both, static and dynamic (i.e. run-time) information
Supporting Vocational Students' Development of Preventive Behaviour at Work: A Phenomenological Analysis of Teachers' Experiences
Get PDFStatistics indicate that even if young workers complete vocational training, as a group they are at risk of sustaining injury. It appears that a lack of training in the area of injury prevention may explain some of this effect. Teachers are considered to be key actors in injury-prevention training and in the process of developing students' preventive behaviour at work, but little is known about the reality. The objective of this study was to understand how teachers experience their activities in support of students' development of injury-prevention behaviour at work. Semi-structured interviews were conducted with eleven teachers from four different vocational training programs. The content of the interviews was then examined using phenomenological analysis. Results show representations participants form of occupational health and safety, of injury-prevention behaviour and of their roles as teachers in relation to prevention. A closer look at these roles reveals the daily challenges teachers encounter. Among other things, there seems to be a lack of continuity in the training process, insufficient pedagogical resources and resistance on the students' part. Results offer an insight into teachers' experience with their part in the support of vocational students' development of injury-preventing behaviour. It appears they recognize having to play an active role in the development of injury-preventing behaviour at work among students, but have to face daily challenges affecting their teaching. Results of this study can serve as a starting point to make improvements to the injury-prevention training offered in vocational training centres
Oszillatorische Gehirnaktivität von Patienten mit schizophrenen Störungen und Gesunden bei multistabiler Wahrnehmung
Get PDFObjective: Patients with schizophrenia seem to be impaired in binding single visual stimuli-features into coherent objects. For this process, interaction of top-down and bottom-up processing has to be intact. Neural oscillations seem to be a fundamental mechanism for coordinated communication of neural circuits. They have been proposed to reflect the spatio-temporal integration of sensory and cognitive information for creating coherent perception. Method: An EEG examination of schizophrenia patients as well as healthy control subjects was performed during the processing of an apparent motion stimulus, a stroboscopic effect, which induces two possible endogenously generated perceptions. Furthermore, a modified control stimulus was presented with exogenous reversals of the stimulus. Event-related oscillations resp. event-related spectral perturbation (ERSP) of delta (0-4 Hz), theta (3-8 Hz), alpha (8-13 Hz), beta (14-28 Hz) and gamma oscillations (28-48 Hz) were analyzed. Results: The reaction time of patients in the control conditions is significantly slower. They show anslightly reduced delta power for both conditions, their theta-activity was significantly less increased than in the control group. Moreover, patients had a stronger decrease of alpha activity during the reversal activity over posterior electrodes. Both groups show this decrease in the beta frequency. In ambiguous perception, there are topographical differences between the groups. Patients show a shift from posterior to central regions in the gamma response. Conclusion: The results indicate a functional involvement of all five frequencies in multistable perception. Patients with schizophrenia seem to suffer from an impaired top-down influence of delta and theta in perceptual organisation of ambiguous patterns. With respect to the weaker performance in reaction time, it seems as if there is a reduced impact of top-down organisation, while generating the coherent percepts. Posterior alpha and beta desynchronizations are interpreted as reflecting bottom-up mechanisms which help to fulfill the endogenous reversals. It becomes obvious that patients depend more on the sensory input, which can be interpreted as a compensation of the inferior top-down control. The reduced gamma posterior synchronisation in the patient group while reversal processing is debated in literature in respect to inefficient binding to features. There are no obvious group differences for the gamma frequency in multistable processing. Significance: This is the first comparative study, that takes into account the event-related oscillations of all frequency bands during perceptual organization of the apparent motion. Therewith, dysfunctional integration processing in schizophrenia patients is investigated. Coherent perception of the environment originates from an intact interaction of sensory and cognitive processing. An understanding of altered oscillatory dynamics in schizophrenia may provide new insights in the pathomechanisms of the disorder
Late Neogene to Quaternary paleoproductivity of the western Indian Ocean and the eastern South Atlantic from coccolithophore assemblage and coccolith geochemistry
Get PDFRecent productivity reconstructions off South Africa have demonstrated the link between climate perturbations and coccolithophore productivity, especially over the glacial/interglacial cycles. These studies suggested enhanced productivity during glacial periods reaching maxima during terminations, and fluctuating in concert with orbital periodicities, suggesting that long-termed climatic variability have controlled the productivity patterns in this region. However most of these studies have focused on the highly productive regions of the northern and eastern Indian Ocean, and the Benguela upwelling area of the South Atlantic, whereas productivity reconstructions outside of these high-nutrient environments remain relatively scarce. Thus this research fills this gap by investigating sediment cores collected off Tanzania, the Natal Valley, the Mozambique Channel, and the Walvis Ridge. The strategic positions of the selected study sites allowed inter-basin and latitudinal comparisons, and accordingly a comprehensive productivity reconstruction of the western Indian Ocean and the eastern South Atlantic over the past 500 kyr, and across the Plio-Pleistocene transition. The coccolithophore assemblage composition and species distributions, preservation, and coccolith fraction geochemistry provided the groundwork for this reconstruction
Mom using the Bible : the controversial debate in The Binding of Isaac
Get PDFReview of the video game. The Binding of Isaac concerning the controversial debate this game had cause among the gamers