To see the other types of publications on this topic, follow the link: Focusing.
Dissertations / Theses on the topic 'Focusing'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Focusing.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Schurig, David. "Indefinite Focusing /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC IP addresses, 2002. http://wwwlib.umi.com/cr/ucsd/fullcit?p3061629.
Full text
2
Eddy, Raymond Greg. "Focusing the Senses." Thesis, Virginia Tech, 2004. http://hdl.handle.net/10919/9953.
Full textAbstract:
This thesis studies increasing awareness of the connectedness of the body to architecture. The objective is to explore and investigate the levels of attention required by each sense to summon the corporeal nature of the observers, to call us to a quietness of mind, transcending our western pace and creating awareness that leads our bodies and mind toward a unified perception of place.<br>Master of Architecture
3
Foreman, Elizabeth Wolf Susan R. "Focusing respect on creatures." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2008. http://dc.lib.unc.edu/u?/etd,1726.
Full textAbstract:
Thesis (Ph. D.)--University of North Carolina at Chapel Hill, 2008.<br>Title from electronic title page (viewed Sep. 16, 2008). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Philosophy." Discipline: Philosophy; Department/School: Philosophy.
4
Martel, Joseph Maurice. "Particle Focusing in Microchannels." Thesis, Harvard University, 2013. http://dissertations.umi.com/gsas.harvard:11206.
Full textAbstract:
The ability to control the motion of particles and cells in microchannels has been a center of fascination since the advent of microfluidics. Entire fields have been created in order to accomplish separation, volume reduction and overall positioning of particles and cells within microfluidic devices in the fastest and most accurate manner possible. While most of these technologies rely on low Reynolds number operation, one technique entitled inertial focusing takes advantage of the inertia of the surrounding fluid and the interaction between a particle and the channel itself which cause the lateral migration of particles across streamlines to equilibrium positions within a flow. The major advantage of inertial microfluidics in biomedical and microfluidic applications is that it is inherently high throughput being dependent on inertia whereas most microfluidic concepts are dependent on low Reynolds number operation.<br>Engineering and Applied Sciences
5
Won, Cassandra L. "(Un)Focusing the Gaze." Scholarship @ Claremont, 2014. http://scholarship.claremont.edu/scripps_theses/343.
Full textAbstract:
This is a piece that engages with Laura Mulvey's idea of the 'male gaze.' It is meant to exaggerate, magnify, and therefore critique the mechanisms that the camera uses to objectify and dominate women's bodies.
6
Valentine, Edward Eugene Jr. "Focusing on the formal." The Ohio State University, 1993. http://rave.ohiolink.edu/etdc/view?acc_num=osu1315340805.
Full text
7
Vorauer, Lynda. "Change, an integrative focusing model." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0004/MQ45132.pdf.
Full text
8
Eliasson, Veronica. "On focusing of shock waves." Doctoral thesis, Stockholm : Mekanik, Kungliga Tekniska högskolan, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4479.
Full text
9
Albrecht, Jacob William. "Micro free-flow isoelectric focusing." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/42435.
Full textAbstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2008.<br>Includes bibliographical references (p. 173-181).<br>To unravel the complexity of cellular systems, protein prefractionation tools can be used to reduce cell lysate complexity and increase assay sensitivity. Rapid free flow isoelectric focusing (FF-IEF) is achieved in a microfluidic device by isolating the electrodes from the focusing region with porous buffer regions. Moving the electrodes enables the use of large electric fields without the detrimental effects of bubble formation in the focusing region of the device. The anode and cathode porous buffer regions, which are formed by acrylamide functionalized with immobilized pH groups, allow ion transport while providing buffering capacity. Thermo-electric cooling mitigates the effects of Joule heating on sample focusing at high field strengths (-500V/cm). This localized cooling was observed to increase device performance. Rapid focusing of low molecular weight isoelectric point markers proteins and protein complexes demonstrate the versatility of the technique. Simulations provide insight into and predict device performance based on a well-defined sample composition. This thesis also presents the first implementation of cascaded stages for a microfabricated free-flow isoelectric focusing device. Both analytical and computational models for IEF suggest device performance will be improved by utilizing multiple stages to reduce device residence time. These predictions are shown to be valid by using focusing of small IEF markers as a demonstration. We also show focusing of fluorescently tagged proteins under different channel geometries, with the most efficient focusing occurring in the cascaded design, as predicted by theory. An additional aim of this work is to demonstrate the compatibility of cascaded FF-IEF with common bioanalytical tools. As an example, outlet fractions from cascaded FF-IEF were analyzed by SDS-PAGE. Processing of whole cell lysate followed by immunoblotting for cell signaling markers demonstrates the reduction of albumin from samples, as well as the enrichment of apoptotic markers. Commercial FF-IEF equipment requires multiple inlets to approximate the linear pH gradient commonly used in IEF. These inlets require many premixed pH buffers and a dedicated pumping system, increasing system cost and complexity.<br>(cont.) As an alternative approach, a preparative scale FF-IEF microfluidic device is also designed and tested. The advantages of the divergent IEF design versus a rectangular design are demonstrated using pH indicators to visualize the formation of pH gradients within the devices. Theoretical and experimental observations indicate that using a divergent channel circumvents many of the difficulties associated with preparative FF-IEF equipment. Protein pI markers are used to demonstrate the devices ability to fractionate samples, even in the presence of salt levels too high for conventional IEF techniques. The devices process complex biological samples, fractionating whole cell lysate at a rate of 2mL/hr. The device performance is further analyzed by 2-D gels of the fractionated outlets to show that cell lysate can be enriched based on pI. These findings underscore the promise of small, inexpensive, and disposable FF-IEF devices in proteomics and systems biology research.<br>by Jacob William Albrecht.<br>Ph.D.
10
Shirazi, Hosseini Alireza Carleton University Dissertation Physics. "Focusing ultrasound with zone lenses." Ottawa, 1991.
Find full text
11
Su, Yu. "Mathematical theory of isoelectric focusing." Diss., The University of Arizona, 1990. http://hdl.handle.net/10150/185122.
Full textAbstract:
A mathematical model describing transient processes in isoelectric focusing (IEF) of M biprotic ampholytes is proposed. The problem consists of nonlinear partial differential equations and algebraic equations under nonlinear boundary conditions. Different models of IEF have been studied. For each model problem, we investigated the qualitative properties such as the local existence, global boundedness, stabilizations, and steady-state structures of its solutions. We have shown that, for all models the solutions of the evolution problem stabilize to the steady-state solutions, which have separate peaks at a certain point (the so-called isoelectric point). This means that for transient IEF processes, the concentrations of ampholytes will focus on their isoelectric points as time goes on. All these analytic results showed good agreement with the laboratory experiments and computer simulations.
12
Kim, Haejune. "Control of emulsion drop production in flow focusing microfluidics." Thesis, [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1563.
Full text
13
Kersten, Mik. "Focusing knowledge work with task context." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/30897.
Full textAbstract:
By making information easy to browse and query, current software tools make it possible for knowledge
workers to access vast amounts of information available in document repositories and on the web.
However, when displaying dozens of web page search hits, hundreds of files and folders in a document
hierarchy, or tens of thousands of lines of source code, these tools overload knowledge workers with
information that is not relevant to the task-at-hand. The result is that knowledge workers waste time
clicking, scrolling, and navigating to find the subset of information needed to complete a task. This
problem is exacerbated by the fact that many knowledge workers constantly multi-task. With each task
switch, they lose the context that they have built up in the browsing and query views. The combination of
context loss and information overload has adverse effects on productivity because it requires knowledge
workers to repeatedly locate the information that they need to complete a task. The larger the amount of
information available and the more frequent the multi-tasking, the worse the problem becomes.
We propose to alleviate this problem by focusing the software applications a knowledge worker uses on
the information relevant to the task-at-hand. We represent the information related to the task with a task
context model in which the relevant elements and relations are weighted according to their frequency and
recency of access. We define operations on task context to support tailoring the task context model to
different kinds of knowledge work activities. We also describe task-focused user interface mechanisms
that replace the structure-centric display of information with a task-centric one.
We validate the task context model with three field studies. Our preliminary feasibility study of six
industry programmers tested a prototype implementation of the task context model and task-focused user
interface for an integrated development environment. Our second study involved sixteen industry
programmers using a production quality implementation of the task context model; these programmers
experienced a statically significant increase in productivity when using task context. Our third field study
tested a prototype implementation of the task context model for a file and web browsing application. The
results of this study showed that task context generalizes beyond programming applications, reducing
information overload and facilitating multi-tasking in a cross-section of knowledge work domains.<br>Science, Faculty of<br>Computer Science, Department of<br>Graduate
14
Eliasson, Veronica. "On focusing of strong shock waves." Licentiate thesis, Stockholm : Department of Mechanics, Royal Institute of Technology, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-565.
Full text
15
Dahlberg, Erik. "Commercial Vehicle Stability - Focusing on Rollover." Doctoral thesis, Stockholm, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3143.
Full text
16
Pearson, Jamie. "An investigation of theories of focusing." Thesis, Durham University, 2001. http://etheses.dur.ac.uk/3779/.
Full textAbstract:
This thesis investigates the proposals of a number of psychological and computational accounts of focusing and pronoun interpretation in view of obtaining experimental evidence for the questions raised by the accounts. Four distinct but related studies were conducted with the aim of bringing together various frameworks as a step towards developing an integrated model of the processes of comprehension. Experiments 1-3 in Chapter 2 show that thematic role and surface position focusing take precedence over the salience from naming, but that naming effects are seen in the absence of thematic role focusing. Experiments 4-5 in Chapter 3 show the effect of clause subordination in certain complex sentences, with main clauses being more prominent than subordinate ones. Experiments 6-8 in Chapter 3 show that this effect may not be generalised to different types of complex sentences, however. Experiments 9-18 in Chapter 4 show that animacy has a strong effect on prominence, overriding thematic role and surface position effects. The presence of these latter two effects is crucially dependent on the pattern of animacy. Experiments 19-21 in Chapter 5 show the effects of grammatical parallelism, in which the features of both the anaphor and the antecedent have an influence, which overlays structural focusing. These results show that a variety of constraints can complete in determining the accessibility of discourse referents. The structural, semantic, and pragmatic discourse context in which referents are introduced and the attributes of the cue used to re-access them have a role. The findings are discussed in terms of an activation-based framework, whereby pronoun resolution is determined by the relative activation of the potential antecedents in the mental representation of the discourse. They suggest a dynamic model of focusing in which an antecedent’s features establish and update the focus, and in which certain linguistic elements may trigger the current focus to be modified.
17
Dvorson, Leonard 1974. "Field emitters with integrated focusing electrode." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/80243.
Full text
18
Biggs, Stephen D. "Two articles focusing on participatory approaches." Olive Organisation Development and Training, 1995. http://hdl.handle.net/10962/75076.
Full textAbstract:
In recent years there has been a growing literature that advocates various forms of participatory development. This is illustrated by the promotion of approaches/tools such as participatory rural appraisal (PRA), participatory technology development (PTD), and participatory process projects 1 These "new" approaches are fast taking on the form of a new generalised orthodoxy for solving development problems. It would seem from the perspective of some of the promoters of this orthodoxy that the problem of development is no longer one of not having the right approaches and methods, but one of getting recalcitrant policy makers, bureaucrats, academics to appreciate and adopt these new methods and techniques. My concerns with this new advocacy are that: i It does not relate to experience; ii It does not address issues of power structure and control over information and other resources in multiple and complex arenas of science and technology (S&T); iii By placing major emphasis on management approaches and tools, the new orthodoxy is cutting itself off from a critical reflective understanding of the deeper determinants of technical and social change. Unfortunately, I suspect that if this new orthodoxy does not develop a more critical reflective view of itself then, like previous dominant orthodoxies, it will soon have to develop a range of "escape hatches" to explain why these participatory approaches are not giving the results that their advocates promise.<br>AVOCADO series; v 06/95
19
Broderick, Jane Tingle. "Documentation: Focusing Inquiry on Creative Explorations." Digital Commons @ East Tennessee State University, 2007. https://dc.etsu.edu/etsu-works/4242.
Full text
20
Barkley, Walter Clifford. "Mars Rover laser focusing and optimization /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2008. http://wwwlib.umi.com/cr/ucsd/fullcit?p1457284.
Full textAbstract:
Thesis (M.S.)--University of California, San Diego, 2008.<br>Title from first page of PDF file (viewed November 13, 2008). Available via ProQuest Digital Dissertations. Includes bibliographical references (p. 56).
21
崎浜, 秀行, та Hideyuki SAKIHAMA. "自己調整 (self-regulation) 研究に関する考察 (1)". 名古屋大学大学院教育発達科学研究科, 2001. http://hdl.handle.net/2237/3070.
Full text
22
Kan, Kuei-an. "Effects of Experiential Focusing-Oriented Dream Interpretation." Thesis, University of North Texas, 1998. https://digital.library.unt.edu/ark:/67531/metadc277836/.
Full textAbstract:
This study was designed to examine the effects of Experiential Focusing-oriented dream interpretation. The process was twofold. The first part of this study involved a preliminary step of developing an instrument, the Dream Interpretation Effects Questionnaire (DIEQ). The DIEQ assessed specific effects of Experiential Focusing-oriented dream interpretation, e.g., a sense of easing, fresh air, or movement, increased positive energy or self-understanding, development of a new step, enhanced valuation of dreams, or enhanced understanding of the meaning of the dream. Fifty-two adult volunteers participated in the first part of this study. All participants completed Part One of the DIEQ after reporting a dream and freely associating its meaning to another participant. The results were computed to establish the reliability of the DIEQ. The researcher then used the DIEQ along with a structured interview in a pretest-posttest control group design to examine the effects of Experiential Focusing-oriented dream interpretation. Twenty adult volunteers experienced in Experiential Focusing participated in the second part of this study. They were randomly assigned to an experimental group and a waiting-list control group. The experimental participants completed the DIEQ before (pretest) and after (posttest) a 45-minute Experiential Focusing-oriented dream interpretation intervention. By contrast, the control participants completed the DIEQ before (pretest) and after (first posttest) a 45-minute no-intervention waiting period. Then, the control group participants received the same intervention as the experimental group and completed the DIEQ (second posttest). All participants participated in a structured interview to conclude the study.
23
Fernández, Haussmann Isidora. "Aportes de la práctica de focusing al desarrollo de la persona del terapeuta humanista." Tesis, Universidad de Chile, 2016. http://repositorio.uchile.cl/handle/2250/151152.
Full textAbstract:
Magister en Psicología Clínica de Adultos<br>Las investigaciones centradas en la persona del terapeuta se comienzan a desarrollar
hace más de 20 años. Si bien las investigaciones en el campo de la Psicoterapia
Experiencial han aumentado sustancialmente en los últimos 10 años, al considerar la
relevancia de la variable del terapeuta en el desarrollo de los procesos de psicoterapia, se
vuelve necesario fortalecer esta área de investigación.
Así, la presente investigación se centró en cómo la práctica de focusing aporta al
desarrollo de la persona del terapeuta humanista. Respecto a la variable del terapeuta, se
consideraron las habilidades clínicas, el auto cuidado, la visión de cambio terapéutico y la
visión de la alianza terapéutica como los principales aspectos a explorar.
Para el desarrollo de la investigación se utilizó un diseño de investigación cualitativo de
carácter exploratorio-descriptivo. La muestra consistió en 12 terapeutas humanistas que
practicaran el focusing en el trabajo psicoterapéutico. La información obtenida fue
analizada a través de un análisis de discurso, utilizando la codificación abierta y la
codificación axial de la teoría fundamentada.
El fenómeno central que emergió en el transcurso de la investigación consiste en un
modo de aproximarse y de estar con la experiencia de un otro, el cual emerge y se
desarrolla a partir de la integración de la práctica de focusing en el contexto
psicoterapéutico. Se observó que este modo permea tanto la dimensión profesional como la
personal, constituyéndose así como una forma de funcionar de la persona en su totalidad
24
Olson, Michael A. "Signal-to-Noise Measurements and Particle Focusing in Liquid-Core Waveguides." BYU ScholarsArchive, 2014. https://scholarsarchive.byu.edu/etd/4071.
Full textAbstract:
This thesis presents an analysis of the signal-to-noise ratio in liquid core anti-resonant reflecting optical waveguides (ARROWs) and the application of hydrodynamic focusing to the waveguides. These concepts are presented as a method to improve the detection capabilities of the ARROW platform. The improvements are specifically targeted at achieving single molecule detection (SMD) with the devices. To analyze the SNR of the waveguides a test platform was designed and fabricated. This test platform was then used to examine relationship between the SNR and the location of the excitation region. It was determined that the excitation region should be moved closer to the solid-core. By moving the excitation region closer to the solid-core the distance the signal was required to travel in the hollow-core was reduced. This reduction led to a decrease in optical signal loss and resulted in a more than 2x increase in the SNR. Hydrodynamic focusing in the waveguides was developed as a method to increase the consistency of detection of the devices. In hydrodynamic focusing particles in the sample are forced towards the center of the waveguide with a buffer solution. With the particles focused to the center of the channel the percentage that passed through the excitation region can be increased improving the detection consistency of the device. ARROW chips designed for hydrodynamic focusing were simulated, fabricated, and preliminary testing was performed. Initial results have shown a more than 30% increase in particle focusing.
25
Kabush, Danelle. "Focusing skills in a risk-endurance sport." Thesis, University of Ottawa (Canada), 2001. http://hdl.handle.net/10393/9146.
Full textAbstract:
Studies have shown the importance of focusing skills at the elite level. For example, Orlick and Partington (1988) found that attentional focus was one of the two most important skills related to high level performance at the Olympic games. However there has been minimal research investigating how athletes themselves perceive focus. Furthermore, the question of how athletes develop focus and what kinds of focusing skills they use in order to eliminate distractions, to keep concentrated on the immediate task, and to get properly aroused for the task at hand has not been fully answered in the literature. The research objectives of this study on focusing skills among elite athletes in a risk-endurance sport (cross-country mountain bike racing) were fivefold. The first objective was to advance our knowledge on how elite athletes perceive and define focus in relation to their sport. The second and third objectives were to assess what focusing skills the athletes used before and during competition, as well as what kinds of focusing skills the athletes used in training. The fourth objective was to shed light on how the athletes developed and improved their focusing skills. The final objective was to discover other concepts that may have interacted with focus. The present study provides a clearer understanding of how elite athletes perceive focus and the different dimensions it entails. The findings also present a clearer picture of how focus is developed over the course of an athlete's career. There were both commonalities among the athletes and a uniqueness in the way each athlete perceived and developed focusing skills. These findings may enable coaches and sport psychologists to prevent or work more effectively with potential problems and issues that can hinder a great focus in the sport of mountain biking.
26
Lindbom, Erik. "Building preservation focusing on energy saving measures." Thesis, Linköpings universitet, Institutionen för teknik och naturvetenskap, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-93121.
Full textAbstract:
The project is based on a building, consisting of building timber, which was built in the early 1900s. The project aims to generate knowledge, guidelines and provide inspiration for how the building can be designed to serve as residence. The project also shows measures on how to maintain the building’s appearance from the time of construction and investigates how an acceptable thermal insulation can be obtained and how it effects the building’s character. The knowledge is primarily acquired from relevant literature and university courses in building- and urban planning and building physics. The results show a plan arrangement and propose measures for increased thermal insulation where the impact on the building’s cultural value is limited. The measures take account of old building techniques and materials and are largely reversible, which allowsna restoration to the original condition. The thermal insulating ability of the building’s enclosing element’s are calculated forthree cases, the building’s condition today and after the measures considered feasible without cultural value being lost. The final calculation is implemented in a version where the government authority requirements for new construction are achieved. The conclusion is that the building can be adapted to function as a residence. Measures to increase the thermal insulating capability can be implemented without affecting the cultural values. The proposal reduces the building’s heat transfer coefficient by at least half of today’s performance. In order to fulfill the government authority requirement, measures have to be taken that may cause loss of character and cultural value.<br>Arbetet utgår från en byggnad av liggtimmer som i sitt nuvarande utförande uppfördes i början av 1900-talet. Arbetet syftar till att ta fram kunskap och riktlinjer samt att utgöra en inspiration för hur byggnaden kan utformas för att fungera som bostad. Arbetet påvisar även åtgärder för att bevara ett utseende som återspeglar tiden för byggnadens uppförande samt utreder hur en acceptabel värmeisoleringsförmåga (U-värde) kan erhållas och hur det påverkar byggnadens karaktär och kulturvärde. Som underlag för lämnade riktlinjer ligger kunskap som inhämtats i huvudsak genom litteratur samt universitetskurser inom byggnads- och samhällsplanering och byggnadsfysik. Resultatet visar en planlösning samt förslag på åtgärder för en ökad värmeisoleringsförmåga där påverkan på byggnadens kulturvärde begränsas. Åtgärderna tar hänsyn till gamla byggnadstekniker och material och är i stor utsträckning reversibla vilket möjliggör en återställning till det ursprungliga skicket. Den värmeisolerande förmågan i byggnadens omslutande delar beräknas utifrån tre fall, byggnadens skick idag och efter de åtgärder som anses genomförbara utan att kulturvärdet går förlorat. Den sista beräkningen genomförs på ett utförande där myndigheternas krav för nybyggnationer uppnås. Slutsatsen är att byggnaden går att anpassa för att fungera som bostad. Åtgärder för att öka den värmeisolerande förmågan går att genomföra utan att kulturvärdet påverkas. Enligt de förslag som presenteras minskar byggnadsdelarnas U-värde med minst hälften mot dagens utförande. För att uppnå myndighetskrav krävs sådana åtgärder som gör att byggnadens karaktär och kulturvärden riskerar att gå förlorade.
27
Schmidt, Jeffrey C. "Electromagnetic focusing properties of chirped metallic gratings." Master's thesis, University of Central Florida, 1992. http://digital.library.ucf.edu/cdm/ref/collection/RTD/id/22716.
Full textAbstract:
University of Central Florida College of Engineering Thesis<br>The focusing properties of chirped diffraction gratings have long been studied and often used in applcations at optical frequencies. Chirped metallic gratings of this type have also been studied theoratically at microwave frequencies, but no attempt has been made to experimentally examine or utilize the focusing properties of these structures at microwave frequencies. This thesis presents an experimental analysis of the focusing properties of chirped metallic gratings. These gratings are designed to focus electromagnetic energy at a predetermined position by varying strip wideth and spacing as a function of position. The diffraction gratings are characterized, and experimentally measured results are compared to theoretical data.<br>M.S.;<br>Electrical and Computer Engineering<br>Engineering;<br>Electrical Engineering<br>58 p.<br>vii, 58 leaves, bound : ill. ; 28 cm.
28
Silva, Carina Brunehilde Pinto da. "Combinatorial analysis: focusing on teaching problem solving." Universidade Federal do CearÃ, 2013. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=10084.
Full textAbstract:
A AnÃlise CombinatÃria à o conjunto de tÃcnicas para a resoluÃÃo de problemas de contagem. à usada quando à preciso conhecer a quantidade de elementos de um conjunto finito, sem necessidade de elencar cada um. Neste trabalho, discute-se a maneira como este assunto tÃo importante à apresentado para os alunos que cursam o Ensino MÃdio, a fim de aprimorÃ-la. Ao final do trabalho, à sugerido um software educacional, de prÃpria autoria, capaz de resolver problemas de contagem, com a finalidade de auxiliar e dinamizar o desempenho do professor em sala de aula.<br>The Combinatory Analysis is the technical set used to solve counting problems. It's useful when is necessary to know how much elements are in a set finite, without the need to list each one. In this work, let's discuss the way in which this important matter is taught to high school
students, and give suggestions to make it better. At the end, is suggested an educational software, of our own authorship, which is able to solve counting problems. It was developed to help and to stimulate the teacher performance during the classes.
29
White, Jenny. "A phenomenological enquiry into focusing on music." Thesis, University of East Anglia, 2017. https://ueaeprints.uea.ac.uk/67665/.
Full textAbstract:
This thesis develops the findings of my MA research and presents a phenomenological enquiry into the experiencing involved in focusing on music. It carries forward the notion that music can hold implicit meaning in what Eugene Gendlin, creator of focusing, terms as a “felt sense”. It asks participants to select music that says something about how they are feeling right now in order to establish if focusing on personally selected relevant music can unravel implicit experiencing. Music experiencing is further investigated by a semi-structured interview with the composer of one of the participants’ pieces of music. The Literature Review explores further avenues into research on music emotions and feeling including neuroscience and quantitative research into music and sadness. In Methodology, Gendlin’s Philosophy of the Implicit is positioned against the background of phenomenological philosophy including William James and Merleau-Ponty, providing an account of the formation of the Experiencing Scale and how it can contribute a further phenomenological layer to the analytical tool Interpretative Phenomenological Analysis. This approach is presented in the Analysis section, which produces the main themes of the research alongside observations from the Experiencing Scale. The Discussion chapter explores the analysis from the theoretical perspectives gathered in the Literature Review, particularly through Philosophy of the Implicit and Gendlin’s philosophical treatise: A Process Model. The thesis concludes with an opportunity to conceptualize music by thinking further with Gendlin’s concepts.
30
Zhang, Xuetao. "Human-robot Collaboration Focusing on Image Processing." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-282897.
Full textAbstract:
The future manufacturing industry calls for a new generation of production so-lutions with high efficiency and flexibility. Therefore, research towards Human-Robot Collaboration (HRC) has recently aroused much attention in the field ofmanufacturing as it provides the possibility for harmonizing the accuracy of arobot with the flexibility of a human. The objective of the thesis is to proposea novel architecture for a Human-Robot Collaboration input system. The sys-tem receives video frames and depth information from an Intel®RealSense™Depth Camera D435 and recognize the closest point to the target object in the3D point cloud environment. Moreover, different algorithms and technologies,which are image filters for video preprocessing and nearest neighbor search algo-rithms for target detection, are applied to the system and evaluated to optimizethe performance. In this thesis, the system workflow is elaborated and an anal-ysis towards the performance of the system is presented based on quantitativemeasurements including refresh rate and error calculation.<br>Den framtida tillverkningsindustrin kräver en ny generation produktionslösningarmed hög effektivitet och flexibilitet. Därför har forskning om samarbete mel-lan människa och robot nyligen väckt stor uppmärksamhet på tillverkning-sområdet eftersom den ger möjlighet att harmonisera en robots noggrannhetmed en människas flexibilitet. Syftet med avhandlingenär att föreslå en nyarkitektur för ett inmatningssystem för människa-robot-samarbete. Systemettar emot videoramar och djupinformation från en Intel®RealSense™DepthCamera D435 och känner igen den närmaste punkten till målobjektet i den tred-imensionella bilden. Dessutom tillämpas olika algoritmer och tekniker, i formav bildfilter, för förbehandling av videon och närmaste granne-sökalgoritmer för måldetektering, på systemet och utvärderas för att optimera prestanda. Idenna avhandling utarbetas systemstrukturen och en analys av systemets pre-standa presenteras på grundval av kvantitativa mätningar, inklusive uppdater-ingshastighet och felberäkning.
31
Montgomery, Robbie. "Development and implementation of dynamic isoelectric focusing /." Available to subscribers only, 2008. http://proquest.umi.com/pqdweb?did=1650505481&sid=16&Fmt=2&clientId=1509&RQT=309&VName=PQD.
Full text
32
Wilson, Shannon Courtney. "Applications and Advancements of Dynamic Isoelectric Focusing." OpenSIUC, 2014. https://opensiuc.lib.siu.edu/dissertations/865.
Full textAbstract:
The work in the dissertation expands the applications of DIEF and describes the development of incorporating DIEF in a microfluidic chip to create a comprehensive proteomics tool. Proof-of-concept DIEF experiments have been done previously, so the focus of this work is to explore the capabilities of DIEF. Dynamic isoelectric focusing (DIEF) is a separation technique invented by Dr. Luke Tolley. It is similar to capillary isoelectric focusing except it uses four high voltage electrodes to form a pH gradient instead of only two. The additional two electrodes are able to manipulate the pH gradient resulting in selection of the region and of the range of pH within a pre-defined sampling or extraction point. One of the first applications described for DIEF was to isolate a single protein from a complex mixture. The protein isolated was a cellulase enzyme capable of degrading multiple cellulose materials over a wide range of environmental conditions. DIEF did isolate the protein in a pH span of 0.005 which is equivalent to 0.075% of the total pH range. Fractions were collected for sequencing analysis, but the fractions were contaminated with keratin both times. DIEF was also successfully performed in an open air channel. Though other electromigration techniques have been successfully done in open air channels, these techniques were severely time and pH limited. In contrast, DIEF in an open air channel is capable of using the entire 3-10 pH range and can perform isolations until the proteins are completely separated. The device developed was also an improvement on increasing sample capacity. The channel was significantly bigger than the traditional glass capillaries used. Since the channel was open, fraction collection was made simpler by collecting using a pipette. This work also demonstrated that DIEF can be made through the use of silicone molding compounds and polyurethane. The amount of milling needed is reduced, the pieces are produced quickly, and a single mold can produce several pieces. Machining pieces with fragile bits is not needed to be done as much since only one acrylic piece is required produce a mold. The mold can produce several polyurethane pieces. This fabrication method has proven useful for making DIEF holders. The next step was to make DIEF a truly comprehensive proteomic tool by incorporating it into a microfluidic chip. Multiple sample fractions are rapidly generated on chip through the use of multiple bubbles simultaneously injected into the separation channel. This stops the separation and, since each droplet is isolated from others by a bubble on each side, the protein peaks are not able to broaden. This novel use of digital microfluidics is still a work in progress, but the fundamentals have been demonstrated. The fabrication protocol for making molds and PDMS casts was developed using materials and procedures that can be done in a common laboratory environment. DIEF is a separation technique still in its infancy, with a wide variety of available applications. DIEF will continue to be tested in other areas and developed into a comprehensive proteomic tool.
33
Dwyer, Edward J. "Thinking Time: Focusing Attention on Individual Students." Digital Commons @ East Tennessee State University, 1991. https://dc.etsu.edu/etsu-works/3377.
Full text
34
Weber-Salgo, Amy. "Focusing Professional Development by Differentiating for Teachers." ScholarWorks, 2011. https://scholarworks.waldenu.edu/dissertations/1021.
Full textAbstract:
This study addressed the problem of low student achievement in elementary school mathematics and investigated the level of knowledge held by the teachers. Previous studies have shown that students who succeed in mathematics are more successful during their school years, including college, and earn a higher income level as adults. A theoretical framework of andragogy framed three research questions for investigation. The first question focused on the current professional development needs of the teachers. The other two questions investigated whether the mathematical knowledge relating to teaching (MKT) correlates with the socioeconomic level of the school or correlates with annual yearly progress (AYP) status. Randomly selected elementary teachers from 12 schools participated by completing a survey and taking an online assessment to determine their MKT level. There was no significant correlation between the teachers' MKT scores and the socioeconomic level of their school or the AYP status of the school. Results indicated the need for professional development in mathematical progressions and instructional techniques. Data also suggested that this professional development be adapted to meet the individual needs of the participating teachers. These data informed the creation of 45 professional development training modules for teachers. This study, with the recommended training modules, can initiate social change by providing teachers with individualized training and new instructional strategies to implement in their classrooms with their students, thereby promoting higher levels of student achievement in mathematics.
35
Lagerqvist, Pierre. "Comparison of heating system : focusing on costs." Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-167489.
Full textAbstract:
The purpose of this report was to compare different types of commonly occurring waterborne heating systems to see which of the alternatives has the lowest total cost in terms of materials and labor costs. The work is based on a reconstruction of an ongoing project of the rescue station in Varberg Municipality in Halland County. The comparison was made so that all the alternatives would have the same indoor climate as possible.The systems that were dimensioned and compared were radiators / convectors, underfloor heating, and heat strips. It turned out that heat strips had the lowest total cost of about SEK 145,000 compared to the underfloor heating alternative, which turned out to be the most expensive with a price tag of about SEK 270,000. The system of radiators / convectors lies in between with a total cost of about SEK 200,000. Heat strips had the lowest total cost, which is due to the fact that the material cost were lower compared to the other systems.The high cost of the underfloor heating system has to do with the fact that there is extensive plumbing and material prices. In addition to these, the foundation needs additional insulation when applying underfloor heating. This extra cost of the additional insulation is not included in this project and will thus be higher than the figure I landed in.All systems have pros and cons. Which type of business affects and thus controls the choice of heating systems in a building. All the systems compared have a long life expectancy, that’s why this report did not compare that aspect more closely. The conclusion for the report was that apart from the business, one should choose a system with heat strips. Furthermore, the operation is not something that one can disregard if it is to have practical bearing and is therefore at least as important as the total cost of the systems. Thus, on the basis of this report, one should take into account total costs as well as planned type of business when deciding on a particular heating system. It is also important to plan carefully for upcoming heating strokes so that the distances becomes short while they are placed in construction. As an add-on, an alternative with comfort modules has been mentioned which is economically advantageous from a heating system perspective. This option is more complicated and encompasses more systems thereof, it is only included as an add-on in the report.<br>Syftet med rapporten var att jämföra olika typer av vanligt förekommande vattenburna värmesystem för att se vilket av alternativen som har lägst totalkostnad sett till material och arbetskostnader. Arbetet grundar sig i en till-ombyggnad av ett pågående projekt av räddningsstationen i Varbergs kommun i Hallands län. Jämförelsen gjordes så att alla alternativen skulle ha så lika inomhusklimat som möjligt. De systemen som dimensionerades och jämfördes var radiatorer/konvektorer, golvvärme, och värmestrips. Det visade sig att värmestrips hade lägst totalkostnad på ungefär 145 000 kr jämfört med golvvärmealternativet, som visade sig vara de dyraste med en prislapp på ungefär 270 000 kr. Systemet med Radiator/konvektorer ligger mittemellan med en totalkostnad på ungefär 200 000 kr. Värmestrips hade låg totalkostnad vilket har att göra med att materialkostnaden var lägre jämfört med de andra systemen. Golvvärmesystemets höga kostnad har att göra med att det är omfattande rörläggning och materialpriser. Utöver de behöver bottenplattan tilläggsisoleras när man lägger golvvärme. Kostnaden för tilläggsisoleringen är inte medräknad i detta projekt och kommer därmed bli högre än den siffran jag landade i. Alla systemen har för och nackdelar. Vilken typ av verksamhet påverkar och styr därmed val av värmesystem i en byggnad. Samtliga system som jämförts har lång förväntad livslängd, vilket gjorde att rapporten inte jämförde den aspekten noggrannare. Slutsatsen för rapporten blev att bortsett från verksamheten borde man välja ett system med värmestrips. Vidare är verksamheten inte något man kan bortse från ifall det skall ha praktisk bäring och är därmed minst lika viktig som totalkostnaden för systemen. Därmed, bör man utifrån denna rapport ta hänsyn till totalkostnader såväl som planerad typ av verksamhet när man bestämmer sig för ett visst värmesystem. Det är också viktigt att planera för kommande värmestråk noggrant så avstånden blir korta samtidigt som de förläggs byggnadspraktiskt. Som bisats har ett alternativ med komfortmoduler nämnts vilket är ekonomiskt fördelaktigt ur ett värmesystemsperspektiv. Detta alternativ är mer komplicerad omfattar fler system därav är det bara med som en bisats i rapporten.
36
Mohamed, Ahmed. "Nonlinear inertial waves focusing in rotating flows." Electronic Thesis or Diss., Ecully, Ecole centrale de Lyon, 2023. http://www.theses.fr/2023ECDL0058.
Full textAbstract:
Nous étudions la propagation des ondes inertielles générées par l’oscillation d’un tore axisymétrique dans un fluide en rotation. Ces ondes inertielles se propagent à partir du tore oscillant avec un angle de propagation θf, déterminé par la relation de dispersion. Elles convergent vers une région focale où des interactions non linéaires peuvent induire une turbulence. Notre étude utilise des simulations numériques directes pour modéliser cet écoulement, en tenant compte des régimes linéaires et non linéaires, et en utilisant deux configurations de forçage du tore. Le premier modèle simplifie le tore en tant que force volumique locale en utilisant une fonction delta de Dirac (anneau de Dirac) le long de la direction d’oscillation du tore dans les équations de conservation de la quantité de mouvement. Le deuxième modèle, plus réaliste, met en œuvre un tore en 3D en utilisant la méthode de pénalisation. Nos résultats révèlent l’émergence d’un vortex central résultant des interactions non linéaires des ondes inertielles propagées. Dans le cas de l’anneau de Dirac et du régime linéaire, nos résultats montrent une relation entre l’énergie cinétique verticale et l’angle de propagation au point focal, avec une énergie maximale se produisant à θf = 35o. De même, dans le scénario de forçage en 3D du tore, aussi bien dans les simulations linéaires que non linéaires, indiquent un angle optimal de θf = 30o, conduisant à une vitesse verticale maximale et à une dissipation maximale, signifiant un transfert efficace d’énergie de la source oscillante vers la région focale. Dans le régime non linéaire, nous présentons la distribution spectrale détaillée de l’énergie cinétique dans la zone focale et effectuons une analyse spatio-temporelle du champ de vitesse. Cette analyse identifie les résonances triadiques des ondes inertielles, qui génèrent une zone turbulente et un mode à grande échelle similaire à l’écoulement moyen géostrophique<br>We investigate the propagation of inertial waves generated by the oscillation of an axisymmetric torus in a rotating fluid. These inertial waves propagate from the oscillating torus with a propagation angle θf, determined by the dispersion relation. They focus to a focal region where nonlinear interactions may induce turbulence. Our study employs direct numerical simulations to model this flow, considering both linear and nonlinear regimes, and using two torus forcing configurations. The first model simplifies the torus as a local volume force using a Dirac delta function (Dirac ring) along the torus’s oscillation direction in the momentum conservation equations. The second, more realistic model implements a 3D torus using the penalization method. Our findings reveal the emergence of a central vortex as a result of the nonlinear interactions of the propagated inertial waves. In the case of the Dirac ring and the linear regime, our results demonstrate a relationship between vertical kinetic energy and propagation angle at thefocal point, with maximum energy occurring at θf = 35o. Similarly, in the 3D torus forcing scenario, both linear and nonlinear simulations indicate an optimal angle of θf = 30o, leading to maximum vertical velocity and dissipation, signifying efficient energy transfer from the oscillating source to the focal region. In the nonlinear regime, we show the detailed spectral distribution of kinetic energy within the focal zone and conduct spatio-temporal analysis of the velocity field. This analysis identifies triadic resonances of the inertial waves, which drive the generation of a turbulent patch and a large-scale mode similar to the geostrophic mean flow
37
Chang, Michael Ming Yuen. "A computer-controlled system in transmission electron microscopy." Thesis, University of Cambridge, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292941.
Full text
38
Yekta, Karizbala A. A. "The clinical significance of fixation disparity in binocular vision." Thesis, University of Bradford, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233694.
Full text
39
Ingraham, John. "Model automatic focusing system for linewidth measuring instruments /." Online version of thesis, 1985. http://hdl.handle.net/1850/11372.
Full text
40
HINO, Rei, Tetsuya KUSUMI, Jae-Kyu YOO, and Yoshiaki SHIMIZU. "Job Shop Scheduling Focusing on Role of Buffer." The Japan Society of Mechanical Engineers, 2006. http://hdl.handle.net/2237/9231.
Full text
41
AHMAD, FAHEEM, and PRAMOD KAKKERLA. "FOCUSING OF UWB RADAR SIGNALS USING TIME REVERSAL." Thesis, Högskolan i Gävle, Avdelningen för elektronik, matematik och naturvetenskap, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-15500.
Full textAbstract:
Focusing techniques and detection of targets is usually associated to defense and military use. However in recent past things have moved ahead. Now target detection using UWB radars is being done in many industries and corporations. Radarbolaget AB is one of them; one of their projects uses UWB radars to detect steel strips inside a furnace. This research solves a potential problem of detecting middle steel strip out of total three strip edges which can be seen by radar placed on the front. For better understanding of the reader, existing system and introductory UWB radar principles are discussed. As there can be many solutions to focusing of targets here (steel strip edge detection). Available focusing techniques have been discussed in detail along with the possible physical and simulation setups. Later in the document, detection methods have been proposed. UWB time reversed signal detection is a fairly new method and a very limited research has been done so far. PRBS sequence has been focused on in detection mechanism. Results section show that the pulse of the PRBS works better and produces more promising results rather than a repetitive signal. Time reversal methods for locating the target have been used to find the approximate location of the target. Manual distance calculations from target to the transmitter and receiver have been done. Comparison of actual distance from target to the transmitter is compared with simulation results. Different model simulation setups and their results have proved that using UWB Time reversed signals; a still or moving target can be detected with centimeter window precision.
42
Dubard, Philippe. "Multi-rogue solutions to the focusing NLS equation." Phd thesis, Université de Bourgogne, 2010. http://tel.archives-ouvertes.fr/tel-00625446.
Full textAbstract:
The study of rogue waves is a booming topic mainly in oceanography but also in other fields. In this thesis I construct via Darboux transform a multi-parametric family of smooth quasi-rational solutions of the nonlinear Schödinger equation that present a behavior of rogue waves. For a general choice of parameters the second-order solutions give a model of "three sisters" (three higher than expected waves in a row) while for a particular choice of parameters we obtain the solutions given by Akhmediev et al. in a serie of articles in 2009. Then these solutions allow me to construct rational solutions of the KP-I equation that describe waves in shallow water.
43
Zhou, Mingyan, and 周明艳. "Hepatoprotective actions of adiponectin: focusing on mitochondrial regulation." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B45817650.
Full text
44
Votruba, Paul Matthew. "Focusing transition radiation with cylindircal and elliptical optics." Thesis, Monterey, California. Naval Postgraduate School, 1991. http://hdl.handle.net/10945/28226.
Full text
45
Smith, David Alexander. "Single-impulse magnetic focusing of launched cold atoms." Thesis, Durham University, 2005. http://etheses.dur.ac.uk/2756/.
Full textAbstract:
This thesis concerns the use of pulsed magnetic lenses with cold atoms. Specifically, an experiment was designed and built to focus a launched cloud of cold rubidium atoms. An atomic fountain was realised, based on launching a compact cold cloud of atoms using the technique of moving molasses. Analytical and numerical simulations were conducted to formulate the optimum strategies for focusing. Focusing aberrations are investigated and characterised, and techniques for minimising their deleterious effects are presented. A Baseball Lens was constructed to enable the experimental 3-dimensional focusing of launched cold atoms with a single magnetic impulse. Typically 7x1๙ 85Rb atoms were loaded into a magneto-optical trap (MOT), before undergoing an optical molasses stage. Subsequently a moving molasses phase was realised to launch the atoms vertically at a speed of approximately 2 m տ՜՛ to bring them to an apex 20.5 cm above the MOT in a remote vacuum chamber. During their flight the atoms were pumped into the weak-field-seeking 5(^2)S(_2)[ғ = 3,m = з) state. The centre of the Baseball Lens was located 16.5^ cm above the MOT. Fluorescence images were taken at the apex of flight to characterise the width of the focussed cloud. Results were obtained for four different configurations of the Baseball Lens, which varied the relationship between the axial and radial angular frequencies of the lens. Compact focussed clouds were seen for all four configurations with a minimum observed volume of 60 士 3 mm(^3)which is a factor of 17 smaller than the unfocussed cloud. 3-dimensional magnetic focusing of cold atoms with a single magnetic impulse has been observed for the first time.
46
Barker, Stuart E. "Attention-focusing artificial neural networks for image analysis." Thesis, Nottingham Trent University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321971.
Full text
47
An, Kimin. "The focusing-oriented approach applied to couple therapy." Thesis, University of East Anglia, 2012. https://ueaeprints.uea.ac.uk/52524/.
Full textAbstract:
Many couple therapists prefer an integrative approach to working with couples. They also have shown more interest in the humanistic approach in recent times than they used to do in the past. However there has been almost no discussion in the literature of how the focusing-oriented approach can be used in couple therapy, probably because most focusing-oriented therapists remain individual counsellors. The present research is a contribution to bringing the focusing-oriented approach into couple therapy, but is also a contribution to the integrative approach to working with couples. The aims of this research are: 1. To examine how couple therapists usually work with couples. 2. To investigate how widespread the use of the focusing-oriented approach is as a therapeutic approach when working with couples. 3. To explore what are seen as the common factors of therapeutic change in standard couple therapy and in focusing-oriented psychotherapy. 4. To examine what elements of focusing-oriented therapy can be brought into couple therapy. 5. To ascertain whether there is any evidence for the focusing-oriented approach being effective in working with couples. 6. To discover how using the focusing-oriented approach can make a difference to couple therapy. This research aims to demonstrate how the focusing-oriented approach can apply to couple therapy. With this end in view, the research for the thesis was conducted in three parts. Part One collected quantitative data about the extent to which focusing-oriented therapists are involved in working with couples and how couple therapists normally work with couples. Part Two observed and recorded focusing sessions with the Diploma students in focusing-oriented and experiential psychotherapy at the University of East Anglia for two years. The aim of this part of the research was to understand the focusing process and to find what elements of Focusing might apply to working with couples. Part Three involved interviews with fourteen counsellors. Seven counsellors worked with couples as couple therapists and the other seven counsellors were trained in the focusing-oriented approach and had experience of working with couples. The interviews and analysis revealed how they worked with couples, and what the possibilities are for integrating the focusing-oriented approach into couple therapy.
48
Kabana, Dana P. "Focusing America's national powers." 2006. http://doclib.jfsc.ndu.edu/2006kabana.pdf.
Full textAbstract:
Thesis (M.S. in Joint Campaign Planning and Strategy)--Joint Forces Staff College, Joint Advanced Warfighting School, 2006.<br>"14 April 2006." Electronic version of original print document. Includes bibliographical references.
49
Forbes, Andrew. "Photothermal refraction and focusing." Thesis, 1997. http://hdl.handle.net/10413/4873.
Full textAbstract:
This thesis begins with an introduction to the interaction and refraction of light
in continuous media. It is shown how these properties can be exploited to achieve
focusing of parallel light rays in such a medium. Past work on Gas Lenses is reviewed,
highlighting the progress in design of gas lenses, leading to a justification
for the research described in the rest of the chapter. Original work by the author
on the subject of continuous gas lenses at low and high pressure is then presented.
Experiments show that gas lenses at low pressure have stable foci, but long focal
lengths, while at high pressure two foci are produced, both of unstable character.
These results are explained by a simple theory, and future applications of such lensing
properties are presented.
Chapter two introduces the concept of the Colliding Shock Lens (CSL), and presents
shallow water wave simulations, conducted by the author, as a useful analogy to the
interaction of shocks in the CSL. All the properties of the CSL lensing action are
reproduced in the water simulations, yielding useful insight, by means of a simple
experiment, into the physics of interacting shock waves.
Chapter three presents original work by the author on the subject of multiple pulse
thermal lensing. A theory is developed which predicts the behaviour of thermal
lenses seen in an industrial laser chain. Experiments on thermallensing, as well as
some solutions, are presented and discussed.
Chapter four revises the theory of Zernike Polynomials and their application to the
study of aberrations. Thermal aberrations are studied, including the aberrations
introduced by thermal lensing and thermal blooming. The relationship between
aberrations and subsequent beam quality and beam propagation is explored.
Chapter five looks at the use of adaptive mirrors for mode matching. Although the
theory of adaptive systems is well known, no-one has as yet tackled the problem of
correcting for mode matching changes. A new way of thinking about mode matching
is proposed, and the merits of this system, called characterisation space, are
explained.
Chapter six comprises the theory and design of a novel vacuum chamber which has
applications in gas lens designs. All the gas lenses used in pressure experiments were
housed in compressional vacuum chambers. The idea of a Tensional Vacuum Vessel
(TVV) is introduced, and experiments show that such chambers are very successful
low vacuum chambers. The advantages and applications of TVVs are discussed,
specifically those relating to gas lens applications.
At the end of this thesis it was apparent that more questions had been generated
than answers. This is probably true of any study. Chapter seven therefore outlines
some as yet unanswered questions, and gives some suggestions for starting points.
Some of this work is presently being undertaken by the author.<br>Thesis (Ph.D.)-University of Natal, 1997.
50
Whalley, Matthew Sean. "Focusing of expansion waves." Thesis, 2016. http://hdl.handle.net/10539/20626.
Full textAbstract:
A dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science in Engineering, February 2016.<br>The flow field which results from an expansion wave entering a cavity, and the focusing effect which occurs was studied using both numerical and experimental methods. Previous research into cavity flows has looked at shock waves entering a cavity as well as shock wave focusing phenomenon; however no previous work on expansion wave cavity flows was found. The type of flow was analysed for different cavity geometries, different expansion wave pressure ratios and different expansion wave widths. The numerical work was done using the commercial CFD codes, Ansys Fluent and STAR CCM+. An inviscid solver was found to be sufficiently accurate to model the flow. The experimental work was performed using a unique shock tube with windows at the diaphragm and in the driver section. A number of sub-studies were done during the development of the shock tube. These included a short study on the use of different materials as a diaphragm in a shock tube in order to get the best possible expansion wave for the experiments. Hundred micron thick aluminium sheets were found to give the best burst as it responded well to scoring and once scored gave a consistent symmetrical burst. Another study was performed into the straightening of an initially curved expansion wave. This was done to try and improve the experimental results as a diaphragm will always have some curvature at burst resulting in an initially curved expansion wave. It was found that by curving the walls of a shock tube the leading edge of an expansion wave could be made to straighten faster, however this introduced additional undesirable two-dimensional waves behind the leading edge of the expansion which resulted in a simple straight walled shock tube being used in the experiments.
The numerical and experimental work showed that a focus region forms when an expansion wave enters a cavity, and this region has very low fluid property values, especially temperature and pressure. The basic focus region can be described as a region of flow enclosed by compression or shock waves in which two dimensional expansion waves repeatedly reflect to create very low pressures and temperatures. The effect of an initially curved expansion wave was considered and it was found that the flow is significantly affected by the shape of the expansion. For a plane expansion wave a focus region develops in the driver section of the tube and collapses towards the end of the driver. For a curved expansion wave the focus region develops at the centre of the curvature. The pressure ratio over the expansion wave was also studied by changing the initial diaphragm pressure ratio in the shock tube. It was found that as the wave strength was increased, the focusing happened later and was stronger until the pressure ratio was sufficiently high for supersonic flow to occur. At this point the focusing changed, most significantly for the cylindrical cavity where the flow pattern seen for subsonic flow disappeared completely, and was replaced by a different focusing pattern. The width and thus the gradient of the expansion wave was also found to be important as once the expansion wave starts to widen, the focusing becomes significantly weaker and may not even be noticeable.