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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Development and applications of the Light Extinction Spectroscopy technique for characterizing small particles

Horvath, Imre Tamas 20 October 2015 (has links)
The purpose of the present research is to develop and apply an experi- mental technique for measuring the size of nanoparticles and nanodroplets in a flow environment. The developed non-intrusive, optical method is called Light Extinction Spectroscopy (LES) and it allows to determine the size of particles from measuring their light transmission spectrum on the Ultraviolet-Near-Infrared range. The most crucial part of the develop- ment work is to obtain a reliable data processing method, which is based on the regularized solution of an ill-conditioned inverse problem. The de- veloped method is first tested using synthetic data, which allows to deter- mine the measurement range and also the measurement errors caused by various sources. This is followed by performing laboratory experiments for validating the LES technique. Validation measurements using calibrated particles and a reference instrument shows that sizing errors are in the order of 5-10%. Afterwards, the technique is applied for characterizing the Brownian coagulation process of nanodroplets, where the growth rate of droplets is successfully measured and is found to agree with theoreti- cal expectations. Next, the LES technique is applied to coagulating solid particles, where the growth rate of these complex non-spherical objects is retrieved. Finally, a particle monolayer is deposited on an air-water inter- face and it is shown that the LES technique can retrieve the particle-water contact angle, which allows the characterization of nanoparticle wettabil- ity and the study of the related interesting physical phenomena. / Doctorat en Sciences de l'ingénieur et technologie / info:eu-repo/semantics/nonPublished
62

Monitoring Physiological Reactions of Construction Workers in Virtual Environment: A Feasibility Study Using Affective Sensing Technology

Ergun, Hazal 12 November 2015 (has links)
This research aims to monitor workers’ physiological reactions in virtual construction scenario. With the objective of leveraging affective sensing technology in construction scenario, experiments with Galvanic Skin Response (GSR) was conducted in a 3D simulation developed based on a real construction site. The GSR results obtained from sensor were analyzed in order (i) to assess the feasibility of using virtual environment to generate real emotions, (ii) to examine the relation between questionnaires used to ask people about their experience and their physiological responses and (iii) to identify the factors that affect people’s emotional reactions in virtual environment. Subjects of the experimental group exhibited incoherent responses, as expected in experiments with human subjects. Based on the various reasons for this incoherence obtained from questionnaire part of the experiment, the potential in research for developing training methods with respect to workers’ physiological response capability was identified.
63

Metodologia não intrusiva baseada na técnica fotoacústica para o estudo de membranas vítreas porosas / Non-instrusive methodology based on the photoacoustic technique for studying porous vitreous membranes

Márcio Tsuyoshi Yasuda 25 September 2003 (has links)
A espectroscopia fotoacústica (PA) vem sendo largamente utilizada em diversos ramos de pesquisa, principalmente nas investigações de materiais quanto às suas propriedades ópticas e térmicas, demonstrando a sua vasta versatilidade. No presente trabalho, desenvolveu-se uma câmara fotoacústica de uso geral e uma metodologia baseada na técnica fotoacústica, técnica não intrusiva e não destrutiva, para a determinação da porosidade aberta de membranas vítreas. A porosidade aberta de membranas vítreas está relacionada diretamente à permeabilidade e à eficiência dessas membranas em processos de filtração. Essas membranas foram processadas utilizando-se a técnica de preenchimento e garrafas de vidro, encontradas comercialmente, como matéria-prima. Através da utilização de NaCl como o material inerte, foram processadas membranas com diferentes percentagens de poros. A metodologia fotoacústica desenvolvida neste trabalho teve como base modelos teóricos fotoacústicos tradicionais de análise. Esta metodologia foi capaz de determinar a porosidade aberta das membranas e de distinguí-las quanto as suas superfícies. Os resultados obtidos através da técnica fotoacústica foram comparados com os resultados obtidos por porosimetria de mercúrio (técnica intrusiva e destrutiva) e por ensaios de permeabilidade (técnica intrusiva e não destrutiva) com as mesmas membranas. Estas duas técnicas de análise são as usualmente utilizadas em estudos de estruturas porosas. A comparação entre os dados experimentais comprovou a validade dos resultados obtidos com a nova metodologia. Além desta metodologia fornecer a porosidade aberta com relativa facilidade, ela demonstrou ser rápida, não-destrutiva e de baixo custo para cada ensaio nas análises / The photoacoustic (PA) spectroscopy has been used in several research lines, mainly in the investigation of thermal and optical properties related to different materials, showing in this way high versatility. In this work is described the development of a general-purpose photoacoustic cell, and of a methodology based on photoacoustic technique for the determination of the opened porosity of vitreous membranes. The technique is non-intrusive and non-destructive in relation to the membranes. The opened porosity of vitreous membranes is directly related to the permeability and also directly related to the efficiency of these membranes in the filtration processes. Membranes with different percentage of pores were processed by means of filler principle. For this purpose were used glass bottles found commercially as raw material and NaCl as inert material. The photoacoustic methodology developed in this work was based on classical theoretical models found in the literature. This methodology was capable to determine the open porosity of the membranes and to distinguish membranes with different surfaces. The results obtained with the photoacoustic technique were compared with that obtained by means of mercury porosimetry (intrusive and destructive technique) and permeability measurements (intrusive and non destructive technique) with the same membranes. These two techniques are usually used in studies of porous structures. The comparison between the experimental data showed the validity of the results obtained with this new methodology. Moreover, it supplies the opened porosity with relative easiness, in a faster and non-destructive way, and with low cost in the analyses
64

Petrologie a genetické vztahy alkalických intruzivních hornin roztockého intruzivního komplexu / Petrology and genetic relationships of alkaline intrusive rocks of the Roztoky Intrusive Complex

Mysliveček, Jakub January 2019 (has links)
Roztoky Intrusive Center (33-28 Ma) is connected with tertiary volcanic activity in the territory of the Bohemian Massif (Czech Republic). It is located in the České středohoří volcanic complex on the tectonic line of the Ohře rift. The aim of this work was to petrologically describe local rocks and to verify the possible connection of the Roztoky Intrusive Center (RIC) with carbonatite magmatism, as could be suggested by the presence of alkaline rocks including their exotic types (essexites, monzodiorites, sodalitic syenites,…). It is assumed that there is a hidden carbonatite intrusion under the RIC caldera structure, which may also indicate geophysical manifestations of two hidden gravimetric minimas. In a detailed exploration of a drill core from the R-2 borehole from the 1960s, a petrographic rocks composition of a part of the caldera filling was described, including new find of xenolite of carbonatite in 286,5 m of R-2 borehole. By means of geochemical and micro-probe analyzes the well material including carbonatite was examined in detail. Carbonate mineralization with high REE contents was found in carbonatite, but also in the exocontact of the previously described silicocarbonatite (Rapprich et al. 2017). The discovery of carbonatite xenolite and the presence of minerals with high concentrations of...
65

Désagrégation non-intrusive de charges électriques résidentielles

Henao, Nilson January 2018 (has links) (PDF)
No description available.
66

Demand Disaggregation for Non-Residential Water Users in the City of Logan, Utah, USA

Mahmoud Attaallah, Nour Aldin 01 December 2018 (has links)
Non-residential users contribute to a significant portion of the total water delivered by water supplying agencies. However, a very limited number of studies have attempted to investigate the water use behavior of non-residential users. With the emergence of newer “smart” meters, water use now can be measured and recorded at a very high temporal frequency. Smart meters can help determine total water use, timing, and component end uses to better understand water use practices by non-residential users. Water end use disaggregation is the process of separating the water used by each fixture or process within a facility. This is useful because having a breakdown of the consumption of all end uses may encourage users to consume less water and gives them indications on how to do so. This project involved collecting and working with three different datasets with three different temporal scales (monthly billing data, 5-minute water use data, and 5-second water use data). We analyzed monthly billing data to solicit potential participating facilities for the study. For each participating facility, new smart devices were installed on their existing water meters, including an advanced water meter register and a pulse counting data logger. The newer registers logged and transmitted data to a web-accessible data portal at 5-minute intervals, while the pulse counters recorded water use at 5- second intervals. These devices enabled us to measure the timing and volume of different water uses (e.g., indoor versus outdoor versus industrial processes uses). In this project, we identified different water use events, average water used by each end use (from plumbing fixtures to industrial machinery), variability in end uses (faucets/toilets versus showers), variability in use by the type of user (manufacturing facilities versus assisted living homes), and the impact of the business type on the water use.
67

Heart Rate Variability, Cancer-Related Intrusive Thoughts, and Fatigue during Breast Cancer Survivorship

Hughes, Spenser 18 December 2018 (has links)
No description available.
68

An Experimental Study of Longitudinally Embedded Vortices in a Turbulent Boundary Layer via the Non-Invasive Comprehensive LDV Technique

Derlaga, Joseph Michael 05 June 2012 (has links)
This report documents the measurements of turbulence quantities resulting from vortices embedded in a zero pressure gradient turbulent boundary layer. Turbulent boundary layers are found in most flow regimes over large scale vehicles and have been studied for many years. Various systems to control separation of boundary layers have been proposed, but vortex generators have proven to be an economical choice as they are often used to fix deficiencies in a flow field after large scale production of a vehicle has commenced. In order to better understand the interaction between vortex generators and the boundary layer in which they are embedded, an experiment has been performed using through non-invasive Comprehensive Laser Doppler Velocimeter. The results show that normalization on edge velocity is appropriate for comparison with previous work. The 1/S parameter and vq^2 parameter were found to be most appropriate to correlate the Reynolds stresses and triple products, respectively. The higher inflow edge velocity and greater momentum thickness, creating a lower vortex generator to boundary layer height ratio, result in a more diffuse vortex as compared to previous work conducted in the same wind tunnel, with the same geometry, but with different inflow conditions. / Master of Science
69

Methods for Validation of a Turbomachinery Rotor Blade Tip Timing System

Pickering, Todd Michael 21 April 2014 (has links)
This research developed two innovative test methods that were used to experimentally evaluate the performance of a novel blade tip timing (BTT) system from Prime Photonics, LC. The research focused on creating known blade tip offsets and tip vibrations so that the results from a BTT system can be validated. The topic of validation is important to the BTT field as the results between many commercial systems still are not consistent. While the system that was tested is still in development and final validation is not complete, the blade tip offset and vibration frequency validation results show that this BTT system will be a valuable addition to turbomachinery research and development programs once completed. For the first test method custom rotors were created with specified blade tip offsets. For the blade tip offset alternate measurement, the rotors were optically scanned and analyzed in CAD software with a tip location uncertainty of 0.1 mm. The BTT system agreed with the scanned results to within 0.13 mm. Tests were also conducted to ensure that the BTT system identified and indexed the blades properly. The second developed test method used an instrumented piezoelectric blade to create known dynamic deflections. The active vibration rotor was able to create measureable deflection over a range of frequencies centered on the first bending mode of the blade. The results for the 110 Hz, 150 Hz, 180 Hz first bending resonance, 200 Hz, and 1036 Hz second bending resonance cases are presented. A strain gage and piezoelectric sensor were attached to the active blade during the dynamic deflection tests to provide an alternate method for determining blade vibration frequency. The BTT system correctly identified the active blade excitation frequencies as well as a 120 Hz frequency from the drive motor. This thesis also explored applying BTT methods and testing to more realistic blade geometry and vibration. Blade vibrations are usually classified by their frequency relative to the rotation speed. Synchronous vibrations are integer multiples of the rotational speed and are often excited by struts or vanes fixed to the engine case. For this reason, special probe placement algorithms were explored that use sine curve fitting to optimize the probe placement. Knowing how the blade will vibrate at operation before testing is critical as well. In preparation for future research, ANSYS Mechanical was used to predict the first three modes of a PT6A-28 first stage rotor blade at 1,966, 5,539, and 7,144 Hz. These frequencies were validated to within 4% using scanning laser vibrometry. The simulation was repeated at speed to produce a Campbell Diagram to highlight synchronous excitation crossings. / Master of Science
70

Petrology, Geochemistry and Structure of the Late Intrusives of the Jaffray-Melick Area, North Western Ontario.

Festeryga, G. Michael 05 1900 (has links)
<p> Crosscutting all of the major lithologies of the Jaffray-Melick area are numerous sharply discordant late synkinematic and post kinematic minor intrusions. In terms of field relationships, petrography and geochemistry, these intrusions may be subdivided into four main Groups: Group 1 Undeformed suite of microgranites, layered pegmatitic-microgranitic mixed intrusives and granite pegmatites. </p> <p> Group 2 Deformed suite of microgranites, mixed intrusives and pegmatites very similar to the above Group 1. </p> <p> Group 3 Deformed microgranodioritic to microgranitic intrusives temporally associated with the Group 2 suite. </p> <p> Group 4 Deformed microgranodioritic intrusions which are chemicaly and morphologicaly distinct from the above 3 Groups. </p> <p> The form of the intrusives is usually dike like, as they commonly intrude along preformed joint surfaces. Analysis of the orientation of these surfaces for the undeformed Group 1 dikes combined with observations on dike distribution suggests that the emplacement of the dikes was controlled by structures developed by intrusion of the elliptical Dalles body. </p> <p> Comparison of the geochemical data on the late intrusives with analyses of one phase of the Dalles intrusion, suggests that the source melt for the Groups 1-3 dikes was a residual phase of the large Dalles body. The chemical differences between these groups, which are not large, could have developed due to polybaric fractionation of the residual phase induced by rapid pressure loss associated with the emplacement of the dikes. </p> <p> Once expelled from source area, the undersaturated, granitic melt became strongly enriched in volatiles due to a process of along dike accretional crystallization. In this way the pegmatite intimately associated with the microgranites was formed. </p> <p> Fig. 1 Groups 1 and 2 dikes on outcrop. </p> / Thesis / Bachelor of Science (BSc)

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