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Photoelectrochemical performance of catalyst systems based on Pd deposited TiO2 and Ag incorporated BiFeO3Yilmaz, P. January 2016 (has links)
Since the discovery of titanium dioxide's (TiO2) capability for water-splitting and photocatalytic degradation of organic compounds, semiconductor photocatalysis has received great attention and promises an environmentally clean and sustainable solution by solar hydrogen production and waste water treatment.1,2 In this thesis, the photocatalytic performance of two different photocatalyst systems based on Pd nanoparticle decorated n-type TiO2 nanorods and Ag incorporated ptype BiFeO3 thin films were investigated for solar hydrogen and oxygen production and photodecolourisation of a common textile dye, Rhodamine B. High surface area TiO2 nanorods were grown on glass fibre substrates by a hydrothermal method to produce a mechanically robust photocatalytic filter. Metallic Pd nanoparticles were deposited onto TiO2 nanorods via a photochemical method. It was found that the hybrid Pd/TiO2 catalyst system showed higher photoactivity with a doubled kinetic rate for the photodecolourisation of RhB. Full decolourisation has been achieved in 180 minutes with as-grown TiO2 nanorods whereas this time was reduced to only 90 minutes for the Pd/TiO2 hybrid catalyst. This enhancement was associated with the localised surface plasmon resonance (LSPR) effect due to the interaction of Pd with visible light and the electron scavenging role of Pd for efficient charge separation. The same hybrid Pd/TiO2 photocatalyst system was then developed on FTO coated glass substrates so that the photoelectrochemical experiments can be carried out using a potentiostat. Mott-Schottky curves demonstrated a positive shift in flat band potential and an increased charge carrier density after Pd deposition. The facilitated charge transfer at the interface of Pd and TiO2 was shown by EIS data with a smaller arc size for Pd/TiO2 in Nyquist plots. The photoelectrochemical performance of the bare TiO2 and hybrid Pd/TiO2 samples were compared through the photoelectrocatalysis of Rhodamine B (RhB) and solar hydrogen production in different electrolyte solutions at various applied voltage values. A higher amount of hydrogen by Pd/TiO2 was photogenerated in methanol solution whereas bare TiO2 produced a higher amount of hydrogen in 0.01M Na2SO4 and pure deionised water under the same conditions. The results were discussed by proposing possible reaction mechanisms with an emphasis on the charge trapping role of Pd nanoparticles. P-type BiFeO3 (BFO) thin films were deposited on large scale FTO coated glass substrates by a sol-gel method. A photocurrent density of -0.004mA/cm2 was achieved at 0V vs NHE under AM1.5 G illumination and 1.2μmol of O2 was produced in 2h at an external bias of -0.5V vs Ag/AgCl. These values were significantly increased upon the incorporation of Ag into the BFO matrix. Ag was incorporated into the BiFeO3 matrix at different concentrations as metallic Ag structures and Ag nanowires. The enhancement by Ag modification was attributed to enhanced light absorption due to light scattering effect and efficient charge separation by Ag as they act as electron sinks. These explanations were supported by shifts in flat band and onset potentials after Ag modification in detailed measurements of Mott-Schottky plots and j-v curves.
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Duration materialised : investigating contemporary performance as a temporal mediumManninen, Saini Liina Annikki January 2014 (has links)
Theatre and performance have historically been thought of in terms of the temporal while visual arts have been consigned to the field of spatial representation. Performance’s temporality, the fact that it happens in time, is highlighted in many discourses as performance’s greatest asset. This thesis investigates what we can find out about performance’s temporality by examining the material conditions of production and reception. By placing the focus off the event of performance and exploring issues around labour, work and leisure time; the art historical and economic relationship of performance and visual art; and the material remains of performance, the thesis seeks to reveal how performance’s temporality functions within a capitalist society. The research sets performance’s duration against different economies of time. It does this within a framework of cultural materialism and the materiality of performance while also situating the work art historically. It investigates the sites of negotiation between performance and the capitalist economy’s temporal logic and interrogates how cultural understandings of time affect experiences of attending to performance’s temporality. In focusing on performance work of both extremely long and short duration, as well as more traditionally staged, theatrical performance, the thesis maps out a genealogy of performance interested in making its temporality visible and often tangible. Placing different art forms alongside performance allows for a symbiotic relationship and thus facilitates new and productive ways of thinking about temporality and duration. Such an approach also makes it possible to identify any blind spots in the theorisations of the temporal in performance studies. The thesis thus proposes a re-evaluation of the terms used in discussion on temporality in performance with a focus on the social, economic and material relations within the production and reception of performance.
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Re-constructing success : a perspective from small firms' owner-managersMorel d'Arleux, Corinne January 2000 (has links)
The present dissertation is composed of two main parts. The first step lies in a conceptualisation research effort, which aims at re-constructing success and providing a new understanding of success as a subjective, individual-based concept encompassing three dimensions : professional, familial and personal success. Success is defined as : an ideal state of global satisfaction that may relate to family, personal or work fulfilment feelings, according to individual preferences. The second part is an empirical study which is designed to illustrate this conceptual framework and contribute to extend our knowledge on small firms owner-managers' visions of success. An evaluation method, based on the Index for Global Success (IGS), is elaborated for that purpose. Three analyses are developed : the first one describes the respondents' global characteristics and visions of success, the second study explores males' and females' visions of success, and the last one applies the IGS method to compare high- and low success perceivers, test the link between IGS, business performance and individual satisfaction, and thus test the IGS method relevance. The findings prove that success needs to be studied at the individual's level as a subjective construct and that the use of a composite index to evaluate success enables the gathering of overlapping dimensions composing success. The importance of personal and familial dimensions, beyond professional success, receives empirical support. Females appear to have different visions of success than males, placing higher concern on the personal dimension. Finally, the Index for Global Success enables the testing of subsamples which differ in their levels of satisfaction and firm's performance. Statistical analyses establish that `success' (evaluated through the Index for Global Success), business performance and individual satisfaction are positively correlated. It is concluded that the IGS method is a relevant tool to evaluate success, and that success is a complex rather than simple unidimensional construct.
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Performance and Oscillation Behavior of PBI-Phosphoric Acid based Higher-Temperature Vapor Feed Direct Methanol Fuel CellsDong, Yan 29 April 2015 (has links)
Operation of a Direct Methanol Fuel Cell (DMFC) at high temperature with vapor feed can avoid many of the issues of conventional low temperatures DMFC, such as crossover, low efficiency and high catalyst loading. Here we investigate the behavior of a PBI-phosphoric acid membrane based DMFC. This project has two goals. The first goal is to investigate the effect of temperature and methanol concentration on the performance of Direct Methanol Fuel Cell (DMFC). The second goal is to investigate the effect of temperature and methanol on its oscillatory behavior under constant current or constant voltage operation. In this project, we use a commercial polybenzimidazole (PBI)-phosphoric acid based membrane electrode assembly (MEA), namely, Celtec-P 1100 from BASF. The Celtec-P 1100 MEA is actually designed for high temperature operation with referenced hydrogen. This kind of MEA operates at temperatures between 140℃ to 180℃, tolerating high concentrations of carbon monoxide and running independently of humidification. This study uses different vaporized concentration methanol instead of hydrogen at the anode and oxygen at the cathode. We tested in different conditions, the concentration of methanol from 1M to 10M and the operating temperature from 160℃ to 180℃. Results show that the performance of fuel cell increases with temperature up to 180℃ and the effect of methanol concentration is small. Further, oscillatory behavior is observed and reported for the first time. The oscillation is not significantly affected by the temperature and methanol concentration, current density or voltage. However, the oscillation is in special region in different condition.
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µLeech: A Side-Channel Evaluation Platform for Next Generation Trusted Embedded SystemsMoukarzel, Michael A 10 September 2015 (has links)
"We propose a new embedded trusted platform module for next generation power scavenging devices. Such power scavenging devices are already in the current market. For instance, the Square point-of-sale reader uses the microphone/speaker interface of a smartphone for both communications and to charge up the power supply. While such devices are already widely deployed in the market and used as trusted devices in security critical applications they have not been properly evaluated yet. Our trusted module is a dedicated microprocessor that can preform cryptographic operations and store cryptographic keys internally. This power scavenging trusted module will provide a secure cryptographic platform for any smartphone. The second iteration of our device will be a side-channel evaluation platform for power scavenging devices. This evaluation platform will focus on evaluating leakage characteristics, it will include all the features of our trusted module, i.e. complicated power handling including scavenging from the smartphone and communications through the microphone/speaker interface. Our design will also included the on-board ports to facilitate easy acquisition of high quality power signals for further side-channel analysis. Our evaluation platform will provide the ability for security researchers to analyze leakage in next generation mobile attached embedded devices and to develop and enroll countermeasures."
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Micro-machine model studies of a ship's power supply systemHill, Brian Edgar January 1984 (has links)
This thesis describes the development of a micromachine model and associated data acquisition system, which is used to study the improvement of the transient response of a ship's diesel generator set following a severe disturbance. The improvement in response is obtained by the use of transient rotor acceleration as a single extra feedback signal into the excitation and governor systems of the micromachine model. The response of the ship system is predicted by theoretical studies, which use a multiprocessor system to implement a Park's two axes, five winding model of the ship's generator together with the associated automatic voltage regulator and diesel governor models. The optimal feedback gains obtained from the theoretical studies are then used to obtain results from the micromachine system, a comparison between the theoretical and experimental results confirms the conclusion that a significant improvement in the system's transient response is obtained. This improvement is maintained when changes are made to the alternator load and the fault duration, without any alterations to the system feedback gains.
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Coordination and collective performance : exploring teamwork as an emergent propertyAllsop, Jamie S. January 2019 (has links)
Working in groups is a ubiquitous feature of daily life. For this reason, finding ways to maximise group outputs is of utmost importance. Efforts to enhance group outputs have typically focused on socially relevant interventions, often designed to increase rapport or motivation. Moreover, such interventions are usually implemented and measured at the level of the individual, thereby designating the group to being nothing more than the simple sum of its parts. Although long acknowledged as a key component of group performance, the role of coordination is relatively under-researched. The present thesis focused on understanding whether interpersonal coordination, as viewed through the theoretical lens of coordination dynamics, is able to shed further insight into the relationship between teamwork and productivity. A novel object movement task well-suited for investigating the effects of both social and physical parameters on group productivity was developed and validated. Different extensions of the task were explored across five studies. Shifting the unit of analysis from the individual to the group yielded novel insight into the issue of group productivity. The nature of the dependencies between participants (i.e., positive vs. negative) were seen to change patterns of coordination both within and between teams. Cooperating pairs were also more coordinated and accurate than competing pairs. When interdependence was high, stable modes of coordination enhanced accuracy, but not overall productivity. More broadly speaking, participants spontaneously adopted modes of coordination that were both functionally consistent with the task demands and conformed to the characteristic patterns inherent to self-organised coordination dynamics. The implications of this work are discussed with respect to extant theories of interpersonal coordination and suggestions are made for future research.
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Elements of shamanism within performance artBabot, Philip January 2011 (has links)
No description available.
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An efficiency prediction theory for a residential, corrugated parallel plate electrostatic precipitatorMojibian, Mansour January 2010 (has links)
Digitized by Kansas Correctional Industries
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Third Area : a feminist reading of performance at London's Institute of Contemporary Arts in the 1970sRoberts, Eleanor January 2016 (has links)
Focussing on the 'long 1970s' (1968-1980), this thesis offers a new account of the emergence of performance forms, including Happenings, participatory art, performance art, and performances for the camera, in visual art and related contexts at the ICA. The research is driven by two central aims: firstly, to create space for discourse about women artists and feminist concerns in art in the UK, and secondly, to build a feminist methodology and historiography that allows for a re-thinking of performance events and approaches to interpreting them. My research involves methods drawn from performance studies, history of art and visual studies, cultural history, and feminist theory. Chapters are organised around works by important UK-based artists including Carlyle Reedy, Rose Finn-Kelcey, Cosey Fanni Tutti, and David Medalla, as well as international visitors Carolee Schneemann and Charlotte Moorman. Initially focussing on historical 'recovery' of performances by women artists in order to challenge received or dominant histories of performance, I then shift over the course of the thesis towards reflecting on feminist implications and effects of my historiographical approach. Here the ICA functions as an organising principle rather than a central subject, and so while research begins with the ICA Collection held at Tate Archive, the scope of the study is also broadened to include other sites and archival repositories. As a methodological counterpoint to this, I also question and critique the limits of institutional and archival representation, and conduct interviews with artists and arts professionals. Considered through the lens of each case study, I argue that the 1970s, as a period which saw new performance forms emerge dialogically alongside feminist practice, is a rich area of research for thinking about pre-histories of live art in the UK, as well as questions of identity, identification, and diversity which resonate into the present.
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