129 research outputs found
Mode detection with an optimised array in a model turbofan engine intake at varying shaft speeds
No full textModal measurement techniques in engine intakes have been used previously to analyse the generated fan noise. A proven method is to use a wall-mounted array of Kulite transducers and operate the (model) turbofan under constant shaft speeds. A drawback of this method is the large number of (expensive) microphones and acquisition channels needed to obtain complete m-mode spectra at high engine orders. Furthermore, to get a full scan of the m-mode spectra as a function of shaft speed, many measurements are required. The issue of the large number of microphones was addressed by using a sparse array instead of an equidistant array. An array optimisation technique, similar to a technique used for the design of phased microphone arrays for sound source localisation, was used to define such a sparse intake array. This array consists of 100 Kulites and is able to determine without aliasing the modal spectrum from m = (79 to m = (79, which is appropriate to determine the modal content up to 3 BPF of a modern turbofan. This array was tested in a Rolls-Royce model fan rig at Ansty as a part of the RESOUND project. A new digital data-acquisition system made it possible to simultaneously and continuously record the Kulite pressure data as the engine speed was varied continuously from idle to maximum speed or vice versa, with each acceleration/deceleration lasting for a period of 9 minutes. Time histories of the Kulites were processed giving power spectra of the engine orders, which revealed the rotor locked tonal components. For each rotor revolution, a Discrete Fourier Transform was applied and, after averaging over a number of revolutions, the m-mode spectra were determined. In this way, a full modal scan with respect to shaft speed in a very limited testing time was obtained
Hinders for Eco-friendly Media Selection
No full textThis study shows that, despite organizations claiming to care for the green environment through documented environmental policies, marketing communication such as advertising media selection does not seem to be much guided by green environmental concerns. Problems with consistency and control thus seem to exist between companies’ ideas/decisions (documented environmental policies) and their actions (advertising media selection), causing the need for justification and/or hypocrisy. This study adds to prior research on the non-use of models in practice by showing that the non-use of models also exists among marketing managers when selecting advertising media for marketing communication purposes. It was found that 64 percent of the marketing managers do not make use of media selection models. In the attempt to investigate differences in the factors guiding media selection between marketing managers who use media selection models (users) and those who do not use any model (non-users), it was found that the users take a medium’s eco-friendly characteristics less into consideration than the non-users. The paper discusses that the use of models can be viewed as attempts for making more rational decisions. The findings thus suggest that rational decision-making (users) may hinder eco-friendly media selection while non-rationality (non-users) may develop more powerful organizational ideologies such as acting responsibly towards the green environment. However, this study points out a link between the use of media selection models, previous experience and rules of thumb, i.e. the users tend to make more use of previous experience and rules of thumb than the non-users. Thus, the author argues that a new approach to model use may be needed and that the media selection should not be too much influenced by the marketing managers’ previous experience and rules of thumb. Otherwise, new factors may be overlooked such as consumers’ increasing concern for the green environment in relation to consumer advertising media attitudes. Previous studies have found that current approaches to marketing planning pay too little attention to the impact of technological advances on changes in consumer media habits. Thereby the risk may exist for focusing on mainly conventional media and not selecting “new media”. The present study seems to contradict these previous findings by showing that the selection of “new media” such as media using the Internet was found among the most selected advertising media by both the users and non-users for the two communication objectives studied, i.e. brand-building and to increase sales. Thus, the results indicate that while the marketing managers adapt their media selection to changes in technological media advances they tend to overlook consumers’ increasing concern for the green environment and the environmental aspect of advertising media. The results also show differences among the marketing managers in their selection of advertising media. At the same time as the non-users tend to be more precise with the recycling of paper, they are more inclined to select paper-based media such as catalogues and brochures than the users. The users on the other hand, tend to select more electronic media such as TV, radio and cinema than the non-users. In the attempt to explain the factors guiding media selection and in particular to what extent the environmental aspect of advertising media is considered, green environmental responsibility attitudes (GERA) of the users and non-users are assessed.Media Selection; Advertising; Green Environment; Marketing Managers; Models; Green Environmental Responsibility Attitude (GERA); Rationality; Non-rationality
Magnesium uit zeewater door electrolyse van gesmolten MgCL2
No full textDocument(en) uit de collectie Chemische Procestechnologie Deel I zie: Rademaker, R., Chemical Process Design 1085DelftChemTechApplied Science
[en] THE LOGIC ON LAWS IALC: IMPLEMENTATION OF SOUNDNESS AND COMPLETENESS PROOFS AND A PROPOSAL FOR FORM- ALIZATION OF BRAZILIAN LAW
No full text
Produktie van allylalkohol uit propeen en zuurstof, via allylacetaat
No full textDocument uit de collectie Chemische ProcestechnologieDelftChemTechApplied Science
Fabrieksschema betreffende de "Bereiding van Magnesium uit Zeewater": Deel I
No full textDocument(en) uit de collectie Chemische Procestechnologie Deel II zie: Deeg, J.F., Chemical Process Design 1101DelftChemTechApplied Science
Oriderzoek naar de electrochemische condities aan de tip van een corrosievermoeiingsscheur in staal in zeewater
No full textTechnische MateriaalwetenschappenApplied Science
Differences in the mediolateral control of balance during gait between 2D and 3D bodyweight support systems
No full textTraining with bodyweight support (BWS) systems can improve the likelihood of regaining normal locomotor abilities for neurologically impaired patients. It is known that people alter their gait parameters when walking with BWS. However, it is unclear whether 2D (vertical and lateral support) and 3D (only vertical support) BWS systems affect these gait parameters differently. In this study, participants walked overground in both a 2D and a 3D BWS system to investigate the effects of this lateral support. To compare the contribution of the vestibular system between the different BWS systems, participants received galvanic vestibular stimulation (GVS). Motion capture and force plates were used to find the coupling between the GVS stimulus and the mediolateral ground reaction forces and to calculate the gait parameters. Differences in gait parameters were observed between the 2D and the 3D system. Compared to unsupported gait, participants increased their step width variability by ~10% in the 3D system. Contrarily, participants decreased step width variability by more than 15% in the 2D system. Mean step width decreased slightly in only the 3D system. The margin of stability did not change significantly in any condition. The coupling between the GVS signal and mediolateral ground reaction forces decreased in the 2D and 3D systems compared to unsupported gait, but no significant differences were observed between different BWS conditions. These results suggest that 2D and 3D BWS systems influence gait parameters differently and that they influence the contribution of the vestibular system to balance, but no significant differences between the systems can be observed in this aspect.Mechanical Engineering | BioMechanical Desig
Development of an Energy Management PFD using Total Energy Control Principles
No full textNavigation accidents can be classified into a number of root causes. Lack of energy awareness is identified as a systematic cause of aviation incidents and accidents. A new format of the Primary Flight Display has been developed to increase the pilots awareness of the aircraft's energy state. In this display format, energy relations between speed and altitude are directly visualized, together with the relations between their derivatives: acceleration and vertical speed. It is hypothesized that the method of visualization described in this paper also allows decoupling of the control actions for a simultaneous tracking of flight path and speed targets. To provide the possibility for accurate anticipatory control, quickened symbology is added to the display format. The level of detail of the conceptual design was increased by means of a participative design approach. This paper describes the design iterations that resulted in the current format.Applied SciencesInformation Technology and SystemsTelecommunications and Traffic Control Systems Grou
- …
