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Fusacchia, Gabriele. "Injective modules over semistar Noetherian domains." Doctoral thesis, Università degli studi di Padova, 2011. http://hdl.handle.net/11577/3427410.
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We approach the problem of classifying injective modules over an integral domain by using the tool of semistar operations. In light of the classical results obtained by Matlis in the case of Noetherian rings, we first study the structure of the so called semistar Noetherian domains, then we discuss how every semistar operation over a semistar Noetherian domain determines a special subclass of the injective modules which can be successfully classified in terms of cardinal invariants.<br>Questo lavoro affronta il problema della classificazione dei moduli iniettivi su di un dominio integro, usando lo strumento delle operazioni semistar. Prendendo spunto dai risultati classici di Matlis per il caso Noetheriano, viene prima studiata la struttura dei cosiddetti domini semistar Noetheriani, quindi viene mostrato come ogni operazione semistar su un tale dominio determini una sottoclasse speciale dei moduli iniettivi che può essere classificata in termini di invarianti cardinali.
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White, Robert. "Employee Engagement Processes and Productivity among Las Vegas Five-Star Hospitality Organizations." ScholarWorks, 2017. https://scholarworks.waldenu.edu/dissertations/3478.
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Employee disengagement creates an unhealthy working environment. Disengagement rates among Las Vegas hospitality industry organizations led to dissatisfaction among employees and resulted in low productivity and profitability. This qualitative descriptive study involved exploring employee engagement strategies that hospitality industry supervisors and managers used to implement programs, thereby solving the employee engagement problems of their organizations. The conceptual framework for the study was leader-member exchange theory. Twenty participants with 5 or more years of Las Vegas hospitality experience who had already successfully implemented engagement programs answered open-ended questions in semistructured interviews. Company documents constituted an additional data source. Analyzing the data involved triangulation using multiple data sources in identifying themes such as interaction effects of employee engagement programs on employees, mutual respect between leaders and subordinates, and organizational benefits. Better engagement could lead to positive social change through increased job satisfaction and improved customer service, thereby engendering increased social interactions among members of the local community. The former could reduce stress and contribute to the quality of life of community members including the families of the workers.- The latter could lead to greater profits for the employers, thus potentially increasing the tax base in the community.
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McGregor, Daniel. "On the Structure of Kronecker Function Rings and Their Generalizations." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1523924670762482.
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Bahalkeh, Esmaeil. "Efficient Algorithms for Calculating the System Matrix and the Kleene Star Operator for Systems Defined by Directed Acyclic Graphs over Dioids." Ohio University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1440116216.
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Rose, Donald Gregory. "Peace operations and counterinsurgency : the US military and change /." Search "ADA381155" in "Accession number" field, 2000. http://stinet.dtic.mil/str/tr4%5Ffields.html.
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Hart, Michael, Stuart Jefferies, and Neil Murphy. "Daylight operation of a sodium laser guide star." SPIE-INT SOC OPTICAL ENGINEERING, 2016. http://hdl.handle.net/10150/622016.
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We report photometric measurements of a sodium resonance guide star against the daylight sky when observed through a tuned magneto-optical filter (MOF). The MOF comprises a sodium vapor cell in a kilogauss-level magnetic field between crossed polarizers and has a very narrow transmission profile at the sodium D-2 resonance of approximately 0.008 nm. Our observations were made with the 1.5 m Kuiper telescope on Mt. Bigelow, AZ, which has a separately mounted guide star laser projecting a circularly polarized single-frequency beam of approximately 6.5 W at 589.16 nm. Both the beam projector and the 1.5 m telescope were pointed close to zenith; the baseline between them is approximately 5 m. Measurements of the guide star were made on the morning of 2016 March 24 using an imaging camera focused on the beacon and looking through the full aperture of the telescope. The guide star flux was estimated at 1.20x10(6) photon/m(2)/s while at approximately 45 minutes after sunrise, the sky background through the MOF was 1100 photon/m(2)/s/arcsec(2). We interpret our results in terms of thermal infrared observations with adaptive optics on the next generation of extremely large telescopes now being built.
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Garcia, Gabriel. "Operations strategy in start-up organizations." Thesis, Lancaster University, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.658214.
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Operations strategy (OS) formation in very small and new start-up organizations is a topic that until now, has not been paid much attention by OS scholars. Current OS literature in this area has been generated from studies that have been carried out mainly upon large and well established corporations. In this regard, an action research intervention to investigate how OS is formed in a very small and new start-up firm has been successfully deployed. This research has found a mismatch between what is currently described in current OS formation literature and what actually happens in the very small and new start-up firm in practice. The OS formation observed in this research was a very dynamic process where all four OS perspectives met; bottom-up, top-down, market requirements and resource based perspectives. However, this process was mainly influenced by a resource-based process driven by the emergent effects generated by the effective deployment of the firm's indirect capabilities. The indirect capabilities of this firm turned to be, at the simplest level, the ability that the firm 's founder-manager had for creating a strategic network of external business collaborators and gaining access to their resources and capabilities to foster the development of her firm 's OS. At a more complex level, they turned to be the dynamic ability that the founder-manager had for finding new scenarios to deploy those already accessed resources and capabilities, and managing and influencing them in a way that they would keep providing further access to further external resources and capabilities to foster her firm's OS development. A guideline to help founder-managers with very limited financial resources to foster the development of their firms ' OS formation process is offered.
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Liu, Kuangyi. "Start-up manufacturing firms : operations for survival." Thesis, University of Edinburgh, 2009. http://hdl.handle.net/1842/5929.
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Start-up firms play an important role in the economy. Statistics show that a large percent of start-up firms fail after few years of establishment. Raising capital, which is crucial to success, is one of the difficulties start-up firms face. This Ph. D thesis aims to draw suggestions for start-up firm survival from mathematical models and numerical investigations. Instead of the commonly held profi t maximizing objective, this thesis assumes that a start-up firm aims to maximize its survival probability during the planning horizon. A firm fails if it runs out of capital at a solvency check. Inventory management in manufacturing start-up firms is discussed further with mathematical theories and numerical illustrations, to gain insight of the policies for start-up firms. These models consider specific inventory problems with total lost sales, partial backorders and joint inventory-advertising decisions. The models consider general cost functions and stochastic demand, with both lead time zero and one cases. The research in this thesis provides quantitative analysis on start-up firm survival, which is new to the literature. From the results, a threshold exists on the initial capital requirement to start-up firms, above which the increase of capital has little effect on survival probability. Start-up firms are often risk-averse and cautious about spending. Entering the right niche market increases their chance of survival, where the demand is more predictable, and start-ups can obtain higher backorder rates and product price. Sensitivity tests show that selling price, purchasing price and overhead cost have the most impact on survival probability. Lead time has a negative effect on start-up firms, which can be offset by increasing the order frequent. Advertising, as an investment in goodwill, can increase start-up firms' survival. The advertising strategies vary according to both goodwill and inventory levels, and the policy is more flexible in start-up firms. Externally, a slightly less frequency solvency check gives start-up firms more room for fund raising and/or operation adjustment, and can increase the survival probability. The problems are modelled using Markov decision processes, and numerical illustrations are implemented in Java.
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Hart, Michael, Stuart M. Jefferies, and Neil Murphy. "Daylight operation of a sodium laser guide star for adaptive optics wavefront sensing." SPIE-SOC PHOTO-OPTICAL INSTRUMENTATION ENGINEERS, 2016. http://hdl.handle.net/10150/624361.
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We report contrast measurements of a sodium resonance guide star against the daylight sky when observed through a tuned magneto-optical filter (MOF). The guide star was created by projection of a laser beam at 589.16 nm into the mesospheric sodium layer and the observations were made with a collocated 1.5-m telescope. While MOFs are used with sodium light detecting and ranging systems during the day to improve the signalto- noise ratio of the measurements, they have not so far been employed with laser guide stars to drive adaptive optics (AO) systems to correct atmospherically induced image blur. We interpret our results in terms of the performance of AO systems for astronomy, with particular emphasis on thermal infrared observations at the next generation of extremely large telescopes now being built. (C) 2016 Society of Photo-Optical Instrumentation Engineers (SPIE)
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Diez, Jeffrey L. "HARMONIZATION: THE WESTERN RANGE, ITS USERS, AND START." International Foundation for Telemetering, 1993. http://hdl.handle.net/10150/608882.
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International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, Nevada<br>The Strategic Arms Reduction Treaty (START) introduces an important new
element into the Mission planning and operation processes of the Western
Range and its users. In the past, safe and successful completion of a ballistic or
space operation was the primary mission of the Range. Under START, the
Western Range has the added responsibility of playing a major role in the
verification process necessary for a safe reduction of the world's ballistic
nuclear weapons. This paper describes the impact of the Treaty on both the
Western Range and its users while outlining how the Range has adapted to
meet the challenges introduced by the Treaty.
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Du, Longhuan. "Numerical and experimental investigations of Darrieus wind turbine start-up and operation." Thesis, Durham University, 2016. http://etheses.dur.ac.uk/11384/.
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The performance of small, H-Darrieus vertical axis wind turbines has been investigated numerically and experimentally with particular attention paid to turbine performance at low tip speed ratios (low Reynolds number) and to turbine self-starting. Comprehensive wind tunnel measurements have been performed to provide accurate aerofoil data at low Reynolds numbers and high angles of attack; a unique requirement for vertical axis wind turbine (VAWT) starting studies. Two-dimensional CFD models and blade element momentum (BEM) models were created and assessed to provide new insight into turbine performance for different wind conditions and into different turbine geometries in order to guide the design of the experimental investigation. The experimental and numerical studies have demonstrated that design parameters including turbine solidity, blade profile, blade pitch angle and blade surface roughness have strong influences on turbine performance and turbine self-starting capability. Although other authors have conducted numerical studies of the effect of these parameters, this work represents the first experimental validation for turbine performance at low tip speed ratios. In contrast to some previous studies it is shown that there is no advantage to be gained from the use of cambered blades and that symmetrical blades set at small negative incidence provide the best design solution. It is also shown that increasing the turbine’s solidity can significantly improve self-starting capability and that for a given solidity, increasing the rotor radius with a corresponding increase of blade chord improves performance further. However, these starting performance gains are achieved at the expense of a small loss of peak power output. In addition, bio-inspired blades with tubercle leading edges are demonstrated to be able to significantly improve the turbine self-starting capability by introducing a more gradual stall characteristic. These results are the only reported measurements of the effect of tubercle leading edges on vertical axis wind turbines. Finally, a novel, real-time on-board pressure measurement system was developed and employed to examine the instantaneous blade pressure distribution and its variation when the turbine is rotating. The complex flow physics including dynamic stall, laminar separation and flow curvature were successfully recorded and provide unique, unsteady data to increase our knowledge and understanding of the transient aerodynamics of the H-Darrieus wind turbine. The experimental results were also compared with the available CFD and BEM predictions. It is demonstrated that BEM based approaches are highly sensitive to the quality of the aerofoil data that is provided as input to the model. This thesis provides validation of previous work on the question of whether H-Darrieus wind turbines can start without external assistance and in the light of this research a set of revised design rules are proposed to achieve self-starting turbines.
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Rodriguez, Emily M. "Angel Financing: Matching Start-Up Firms with Angel Investors." Scholarship @ Claremont, 2011. http://scholarship.claremont.edu/cmc_theses/136.
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The hardest time to receive financing for a venture is at its earliest stage. These ventures are among the riskiest investments for an investor, which creates a gap in financing that is often bridged through a source of funding called Angel Financing. Angel investors are one of the best providers of early stage funding. This thesis will explain what angel investing is, how they work, and what angels look for. This information will help entrepreneurs be better equipped to find an angel investor for their venture.
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Furht, B., D. Gluch, J. Parker, P. Matthews, and D. Joseph. "THE REAL/STAR 2000: A HIGH PERFORMANCE MULTIPROCESSOR COMPUTER FOR TELEMETRY APPLICATIONS." International Foundation for Telemetering, 1991. http://hdl.handle.net/10150/612922.
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International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada<br>In this paper we describe the design of the REAL/STAR 2000 system, a highperformance real-time computer for telemetry applications. The REAL/STAR 2000 is a symmetric, tightly-coupled multiprocessor, optimized for real-time processing. The system provides a high level of scalability and flexibility by supporting three configurations: single, dual, and quad processor configurations, based on Motorola 88100 RISC processors. The system runs the multiprocessor REAL/IX operating system, a real-time implementation of the AT&T UNIX System V. It compiles with BCS and OCS standards, meets the POSIX 1003.1 standard, and has the current functionality of the emerging POSIX 1003.4 real-time standard. The REAL/STAR 2000 promotes an open system approach to real-time computing by supporting major industry standards. Benchmark results are also presented in the paper.
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Topel, Monika. "Steam Turbine Thermal Modeling for Improved Transient Operation." Licentiate thesis, KTH, Kraft- och värmeteknologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-156196.
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The growing shares of renewable energy sources in the market and solar thermal power applications have set higher requirements on steam turbine operation.These requirements are related to flexibility during transients. A key aspect sought of such flexibility is the capability for fast starts. Due to the varying temperature gradients during start-up, the speed at which the turbine can start is constrained by thermal stresses and differential expansion. These phenomena either consume component lifetime or may result in machine failure if not carefully controlled. In order to accomplish faster starts while ensuring that lifing requirements are preserved, it is important to analyze the thermal behavior of the machine. For this, a transient thermal model was developed with a focus on adaptability to different turbine sizes and geometries. The model allows for simple and fast prediction of thermo-mechanical properties within the turbine metal, more importantly, of the temperature distribution and the associated thermal expansion. The next step of this work was to validate the assumptions and simplifications of the model. This was done through the study and comparison of two turbines against measured operational data from their respective power plants. Furthermore,validation studies also included comparisons concerning the geometric detail level of the model. Overall, comparison results showed a large degree of agreement with respect to the measured data and between the geometric detail levels. The validated model was then implemented in studies related to reducing start-up times and peak differential expansion. For this, the potential effects of turbine temperature maintaining modifications were investigated and quantified.The modifications studied included: increasing gland steam pressure, increasing back pressure and increasing barring speed. Results yielded significant improvements starting from 9.5% in the start-up times and 7% in the differential expansion.<br><p>QC 20141128</p>
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Price, Daniel. "Start-up Craft Brewery Strategies: A Look into What Factors Correlate with Demand." Scholarship @ Claremont, 2013. http://scholarship.claremont.edu/cmc_theses/780.
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This paper explores the factors related to demand for craft beer and whether there is a specific stereotype of craft beer drinkers that aligns with this demand. Using regression analysis on data from all 50 states, this paper concludes that there is a significant correlation between the number of organic farms, colleges, and 55-64 year olds and the number of craft breweries in a state, suggesting that there is evidence that craft beer drinkers tend to be eco-friendly. The paper then goes on to briefly discuss certain production, distribution, and expansion strategies.
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Goldberg-Morse, Hannah Elizabeth. "It's Hard to Be Sant in the City: How Bhindranwale and the Sikh Militants Invoked the Sikh Past to Rationalize Violence in Post-Partition Punjab." Scholarship @ Claremont, 2014. http://scholarship.claremont.edu/cmc_theses/851.
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1984’s Operation Blue Star, an Indian Army maneuver to rid the Sikh Golden Temple of militants, shocked the world. Bullet holes riddled the temple’s façade in the operation’s aftermath, and the global Sikh community was outraged at the desecration of the site. How did the political conflict in Punjab escalate to this point? What were the factors behind the Sikh militant movement, and how did the militants rationalize their activities, considered by some as rampant terrorism? This thesis examines the circumstances surrounding the rise to arms of the Punjabi Sikh militants and the religious influences of their movement. Identifying how themes of the Sikh past, particularly those of communal identity, martyrdom, and martial tradition, were repurposed and employed by militant Sikhs to ground their violence in Sikh tradition and practice, the thesis finds that leaders of the movement, like Sant Bhindranwale, created rhetorical bridges to the Sikh past and embedded in the community a sense of participating in a greater, cosmic war. There exists a tendency among scholars to overlook the religious elements of the movement in order to assign political, economic or sociological roots to the conflict, but religion was a primary factor in the conflict, as demonstrated through the words and actions of the militants themselves. This research adopts a sociotheological approach to religious studies, drawing upon framework by Mark Juergensmeyer, Émile Durkheim and Pierre Bourdieu, among others, to frame the influence of the Sikh past on the militants’ own plane of reference.
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Thielen, Larissa Elke [Verfasser], and Christian [Akademischer Betreuer] Blöchle. "Profitieren Patienten mit obstruktivem Defäkationssyndrom von der STARR/Transtar - Operation? / Larissa Elke Thielen. Betreuer: Christian Blöchle." Hamburg : Staats- und Universitätsbibliothek Hamburg, 2015. http://d-nb.info/1079655255/34.
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Spelling, James. "Steam Turbine Optimisation for Solar Thermal Power Plant Operation." Licentiate thesis, KTH, Kraft- och värmeteknologi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-35386.
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The provision of a sustainable energy supply is one of the most important issues facing humanity at the current time, given the strong dependence of social and economic prosperity on the availability of affordable energy and the growing environmental concerns about its production. Solar thermal power has established itself as a viable source of renewable power, capable of generating electricity at some of the most economically attractive rates. Solar thermal power plants are based largely on conventional Rankine-cycle power generation equipment, reducing the technological risk involved in the initial investment. Nevertheless, due to the variable nature of the solar supply, this equipment is subjected to a greater range of operating conditions than would be the case in conventional systems. The necessity of maintaining the operational life of the steam-turbines places limits on the speed at which they can be started once the solar supply becomes available. However, in order to harvest as much as possible of the Sun’s energy, the turbines should be started as quickly as is possible. The limiting factor in start-up speed being the temperature of the metal within the turbines before start-up, methods have been studied to keep the turbines as warm as possible during idle-periods. A detailed model of the steam-turbines in a solar thermal power plant has been elaborated and validated against experimental data from an existing power plant. A dynamic system model of the remainder of the plant has also been developed in order to provide input to the steam-turbine model. Three modifications that could potentially maintain the internal temperature of the steam-turbines have been analysed: installation of additional insulation, increasing the temperature of the gland steam and use of external heating blankets. A combination of heat blankets and gland steam temperature increase was shown to be the most effective, with increases in electricity production of up to 3% predicted on an annual basis through increased availability of the solar power plant.<br>Hållbar energiförsörjning är för närvarande en av de viktigaste frågorna för mänskligheten. Socialt och ekonomiskt välstånd är starkt kopplat till rimliga energipriser och hållbar energiproduktion. Koncentrerad solenergi är nu etablerad som en tillförlitlig källa av förnybar energi och är också ett ekonomiskt attraktivt alternativ. Koncentrerade solenergikraftverk bygger till stor del på konventionella Rankine-cykel elgeneratorer, vilka minskar de tekniskt relaterade riskerna i den initiala investeringen. På grund av solstrålningens skiftande karaktär utsätts denna utrustning för mer varierade driftsförhållanden, jämfört med konventionella system. Behovet av att bibehålla den operativa livslängden på ångturbiner sätter gränser för uppstartshastigheten. För att utnyttja så mycket som möjligt av solens energi bör ångturbinen startas så snabbt som möjligt när solstrålningen blir tillgänglig. Eftersom temperaturen i metalldelar hos turbinerna är den begränsande faktorn, har metoder studerats för att hålla turbinerna så varma som möjligt under tomgångsperioder. En detaljerad modell av ångturbiner i ett solenergikraftverk har utvecklats och validerats mot experimentella data från ett befintligt kraftverk. En dynamisk systemmodell av de övriga delarna av anläggningen har också utvecklats för att ge input till ångturbinsmodellen. Tre modifieringar som potentiellt kan bidra till att upprätthålla den inre temperaturen i ångturbiner har analyserats: montering av ytterligare isolering, ökning av temperaturen hos glänsångan och användning av elvärmefiltar. En kombination av elvärmefiltar och en temperaturökning av glänsångan visade sig vara det mest effektiva alternativet. Åtgärderna resulterade i en ökad elproduktion på upp till 3%, beräknat på årsbasis genom ökad tillgänglighet hos kraftverket.<br>QC 20110629<br>TURBOKRAFT
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Fanning, David Tate. "Investigating Inducer Performance over a Wide Range of Operating Conditions." BYU ScholarsArchive, 2019. https://scholarsarchive.byu.edu/etd/7732.
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Inducer performance is investigated for a variety of inducer geometries operating at multiple flow conditions using computational fluid dynamics. Inducers are used as a first stage in turbopumps to minimize cavitation and allow the pump to operate at lower inlet head conditions. The formation of inlet flow recirculation or backflow in the inducer occurs at low flow conditions and can lead to instabilities and cavitation-induced head breakdown. Backflow formation is often attributed to tip leakage flow. The performance of an inducer with and without tip clearance is examined. Removing the tip clearance eliminates tip leakage flow; however, backflow is still observed. Analysis suggests that blade inlet diffusion, not tip leakage flow, is the fundamental mechanism leading to the formation of backflow. Performance improvements in turbopump systems pumping cold water have been obtained through implementation of a recirculation channel called a stability control device (SCD). However, many inducers actually pump cryogenic fluids, such as liquid hydrogen. To determine the real world effects of SCD implementation, inducer performance at on and off design flow coefficients with and without an SCD were modeled with liquid hydrogen as the working fluid. Relevant thermodynamic effects present in liquid hydrogen at cryogenic temperatures are considered. The results reveal that the SCD yields marginal changes in the head coefficient. However, a stabilizing effect occurs at all considered flow coefficients, where a reduction in backflow occurs over much of the pump operational range. This occurs due to the SCD maintaining consistent, low incidence angles at the inducer leading edge.The final consideration of this work is the acceleration of an inducer from rest to the operating rotational rate. Rapid acceleration of rocket engine turbopumps during start-up imparts significant transient effects to the resulting flow field, causing pump performance to vary widely when compared to quasi-steady operation. A method to simulate turbopump start-up using CFD is developed and presented. The defined outlet pressure is modified based on the difference between simulation inlet pressure and target inlet pressure of a previous simulation. This process is repeated until simulation inlet pressure is essentially constant during start-up. Using this novel simulation method, the performance of a centrifugal turbopump during start-up is simulated. Analysis suggests this simulation method provides a reasonable prediction of cavitation formation and inducer performance.
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Gustafsson, Annica. "Analysis of uncertainties in fatigue load assessment : a study on one Kaplan hydro turbine during start operation." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-264237.
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In the future, hydropower plants are expected to operate more flexibly. This will lead to a more varied operation of the turbine and the generator, such as more start and stop in order to stabilise the frequency in the grid. Studies show that these transient operations are more costly in terms of fatigue degradation, i.e. consumption of fatigue life. Vattenfall has developed a methodology with the aim to analyse fatigue loads, acting on the runner and the rotor in hydropower units during operation. With a numerical model, the loads are assessed with input data gathered from measurements together with given data on several parameters. Some of the input data are bearing structure stiffness, bearing oil properties, and point of action of forces, etc. Several of these input parameters are subject to a degree of uncertainty, which affect the assessed fatigue load, determined with the methodology. This study will focus on analysing one fatigue force component acting on the runner. The aim with this study is to answer the following research questions: (i) Which input parameters, that are subject to a degree of uncertainty, contribute the most to the combined standard uncertainty in the assessed fatigue force? (ii) How much does the combined standard uncertainty in the assessed fatigue force amount to? (iii) How does the uncertainty in the assessed fatigue force affect the fatigue damage?. The combined standard uncertainty in the fatigue force is determined with methods in uncertainty propagation. In order to evaluate the effect from the uncertainty in the fatigue load on the fatigue damage, a statistical analysis of the ratio between the fatigue damage associated with a probability of exceedance and the expected fatigue damage is conducted. From the results it can be observed that the governing uncertainty parameter is the offset of the shaft displacement signal, which amount to 40 % of the combined standard uncertainty in the fatigue force. Of the nine analysed uncertainty parameters, three parameters are bearing properties parameters, i.e. the bearing clearance, the oil film temperature and the point of action of bearing forces, which amount to 47.5 % of the combined standard uncertainty in the fatigue force. Therefore, in order to decrease the uncertainties, focus should be kept on the bearing properties. Given each parameters uncertainty, the ratio between the combined standard uncertainty in the fatigue force and the expected fatigue force amount to 7 %. This corresponds to a ratio between the standard uncertainty in the fatigue damage and the expected fatigue damage of 35 %, due to the value of the index of S-N curve of five. Given the standard uncertainty in the fatigue force together with the index of S-N-curve, the ratio between the fatigue force associated with a probability of exceedance and the expected fatigue force can be assessed, i.e. the fatigue force ratio. Consequently, the fatigue force ratio amount to 1.32 for a probability of 0.0032 %, 1.09 for a probability of 10 % and 1.04 for a probability of 30 %. These probabilities correspond to the fatigue damage ratios, i.e. the ratios between the fatigue damage associated with a probability of exceedance and the expected fatigue damage of 4, 1.56 and 1.20. Thereby, the uncertainty in the fatigue force can greatly affect the uncertainty in the fatigue damage, dependent on the value of the index of S-N-curve. The results from this study imply the importance of considering the uncertainties in fatigue load assessments. These results provide support for assessing load levels for runner dimensioning to finally, be able to derive a correct margin of safety. This in order to not underestimate fatigue damage and thereby decrease the risk for unexpected fatigue failure.<br>Det finns ett förväntat behov av att kraftproduktionen i vattenkraftverk skall vara mer flexibel i framtiden. Detta leder till mer varierande driftlägen för turbinen och generatorn, såsom fler start och stop med syfte att stabilisera frekvensen i elnätet. Studier påvisar att transienta driftlägen är mer kostsamma i form av utmattningsdegradering, d.v.s. konsumtion av utmattningsliv. Vattenfall har utvecklat en metodik för att analysera inverkan av utmattningslaster verkande på löphjulet och rotorn i vattenkraftsaggregat under drift. Med en numerisk modell kan utmattningslasterna bedömas. Den ingående datan till modellen är bland annat är uppmätta storheter och given data på parameterar. Några av de ingående storheterna är lagerstyvhet, angreppspunkter för lagerkrafter och lageroljans egenskaper, etc. Flera av dessa ingående parametrar innehar osäkerheter, vilket påverkar bedömningen av utmattningslasterna. Denna studie kommer att fokusera på en kraftkomponent verkande på löphjulet. Malet med detta arbete är att svara på följande forskningsfrågor: (i) Vilka ingående parametrar, som innehar en osäkerhet, bidrar med en styrande osäkerhet i den bedömda kraften? (ii) Hur mycket uppgår den kombinerade standardosäkerheten i den bedömda kraften till? (iii) Hur påverkar kraftens osäkerhet utmattningsskadan? Den kombinerade standardosäkerheten i kraften är beräknad med metoder i fortplantning av osäkerheter. För att kunna bedöma påverkan på delskadan givet osäkerheten i kraften, så sker en statistisk analys av förhållandet mellan delskadan sammanhängande med en sannolikhet för överskridande och den förväntade delskadan. Resultatet påvisar att den styrande ingående parametern är offset i signalen för axelförskjutning, vilken uppgår till 40 % av den kombinerade standardosäkerheten i utmattningskraften. Av de nio analyserade parametrarna härrör tre av dessa lageregenskaper, d.v.s. lagerspel, oljetemperatur och angreppspunkter för lagerkrafterna, vilka tillsammans uppgår till 47.5 % av den kombinerade standardosäkerheten i utmattningskraften. Därför, för att reducera den totala osäkerheten bör fokus ligga på lageregenskaperna. Givet alla standardosäkerheter i de analyserade parametrarna så uppgår förhållandet mellan standardosäkerheten i utmattningskraften och den förväntade utmattningskraften på löphjulet till 7 %. Detta motsvarar att förhållandet mellan standardosäkerheten i delskadan och väntevärdet för delskadan uppkommer till 35 %, givet ett index av S-N-kurvan på fem. Givet standardosäkerheten i kraften och index av S-N-kurvan, kan förhållandet mellan utmattningskraften förenad med en sannolikhet för överskridande, och den förväntade utmattningskraften, d.v.s. kvoten av utmattningskraften, utvärderas. Detta resulterar att kvoten av utmattningskraften uppgår till 1.32 för en sannolikhet för överskridande på 0.0032 %, 1.09 för en sannolikhet på 10 % och 1.04 för en sannolikhet på 30 %. Dessa sannolikheter motsvarar att kvoten av delskadan, d.v.s. kvoten mellan delskadan förenad med en sannolikhet för överskridande, och den förväntade delskadan uppgår till 4, 1.56 och 1.20. Därför kan osäkerheten i utmattningskraften påverka osäkerheten i delskadan med en betydande faktor, beroende på värdet på index av S-N-kurvan. Således, resultaten från denna studie påvisar betydelsen att beakta osäkerheterna i de ingående parameterna vid bedömning av utmattningslast. Dessa resultat tillhandahåller stöd vid bedömning av lastnivåer för dimensionering av löphjul, för att slutligen kunna erhålla en korrekt säkerhetsmarginal. Detta för att inte underskatta utmattningsskadan och därmed minska risken oför oväntat utmattningshaveri.
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Steward, Michael. "Extending the Skolem Property." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1492517341492202.
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Dahlbacka, S. (Sebastian). "Optimal pH-management during operations requiring hypothermic circulatory arrest:an experimental study employing pH- and/or α-stat strategies during cardiopulmonary bypass". Doctoral thesis, University of Oulu, 2007. http://urn.fi/urn:isbn:9789514284779.
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Abstract
Cessation of the blood circulation for some time during surgery of the aortic arch and repair of congenital heart defects is normally required to allow a bloodless operation field. Hypothermia is the most important mechanism for end-organ protection, particularly the brain, during such operations. Cardiopulmonary bypass is used for core cooling before total hypothermic circulatory arrest (HCA) or selective cerebral perfusion (SCP) are initiated. During hypothermic cardiopulmonary bypass, pH can be managed according to either pH- or alpha-stat principles. In the present work, the optimal pH management strategy for operations requiring HCA or SCP was explored.
An experimental porcine model was used. Firstly, outcome was evaluated in a HCA model using either the α- or pH-stat perfusion strategy (I). Secondly, we sought to determine which acid-base management is more effective in attenuating ischemic brain injury during combined HCA and embolization conditions (II). In the third study, the impact of propofol anesthesia and α-stat perfusion strategy on outcome was explored (III). Finally, the acute effects of perfusion strategies in a SCP porcine were compared (IV). Hemodynamics, temperature, EEG (I-III), brain microdialysis, intracranial pressure (I-III), brain tissue oxygen partial pressure (I-III), and intravital microscopy (IV) were monitored intraoperatively. In the chronic studies, survival, postoperative neurologic recovery and brain histopathologic examination were evaluated (I-III).
pH-stat strategy was associated with superior outcome compared to the α-stat strategy during a 75-minute period of deep HCA (I). In addition, despite the pH-stat strategy-related cerebral vasodilatation, this method provided better neuroprotection in a setting of cerebral particle embolization prior to a 25-minute period of deep HCA (II). Propofol anesthesia combined with α-stat perfusion strategy was observed to deteriorate the brain injury during HCA evaluated by key brain microdialysis parameters (III). Finally, when employing moderately hypothermic SCP, the differences between pH- and α-stat strategies in cerebral metabolism and microcirculation were minimal.
These findings are clinically relevant since α-stat perfusion strategy is still the most commonly used acid-base perfusion strategy during hypothermic cardiopulmonary bypass in adults, and propofol one of the most used anesthetics in clinical practice. It is also noteworthy that the pH-stat strategy is not currently used in adults because of the perceived increased risk of atherosclerotic embolization. However, the advantage of pH-stat strategy over α-stat strategy could not be observed when employing SCP.
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Dilworth, Joyce Carroll. "The relationship of nutritional status to unreimbursable costs and length of hospital stay." CSUSB ScholarWorks, 1992. https://scholarworks.lib.csusb.edu/etd-project/721.
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Bergquist, Tiffany. "Impact of Empowerment and Autonomy on the Nursing Director's Intent to Stay." ScholarWorks, 2018. https://scholarworks.waldenu.edu/dissertations/5606.
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Retention of nursing directors is important to the viability and success of the healthcare industry because they have a large impact on nursing job satisfaction, overall retention of nurses in an institution, productivity, and patient outcomes. Factors that retain nurse directors, such as autonomy and empowerment, appear to be important to job satisfaction, but there is little in the current research to corroborate these findings. The purpose of this quantitative study was to determine what factors impact nursing directors' intent to stay in their current role and what effect role autonomy and empowerment have on their intent to stay as compared to traditional job satisfiers. Kanter's empowerment theory was used to evaluate the key factors that influence job satisfaction and retention, namely, empowerment and autonomy. The key variables were measured with Attitude toward Professional Autonomy Scale for Nurses, Conditions for Work Effectiveness Questionnaire-II, Intention to Stay Scale, and Minnesota Satisfaction Questionnaire. Nursing directors were recruited American Organization of Nurse Executives and LinkedIn. Seventy-six participants answered 4 survey tools on the key. Data were analyzed using Pearson's r, multiple and logistic regression. Results revealed that empowerment had a significant relationship to nursing directors' intent to stay and that traditional job satisfiers were significantly related to predicting intent to stay. The results could affect positive social change because increasing job satisfaction of nursing directors would lead to their desire to remain in their position and would stabilize overall retention of nurses, productivity, and patient outcomes. Future research is needed to devise, and test interventions designed to enhance empowerment and positively affect intent to stay.
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Kruger, Heinrich. "A stratigic architecture for a start-up short term insurer operating on mutual principles in South Africa." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/97339.
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Thesis (MBA)--Stellenbosch University, 2015.<br>ENGLISH ABSTRACT: This research investigates the short-term insurance industry in South Africa in order to develop a strategic architecture for a new player to enter the market, differentiated primarily by operating on mutual principles.
Mutual insurance is not something new and is widely applied across the world. However, in South Africa there is only one company that operates completely as a mutual. That company is known as the Professional Provident Society (PPS), and has been in operation since 1941. Although PPS operates completely as a mutual, it has only recently started to take part in the short-term insurance industry. Apart from them, there is no other short-term insurer that operates on mutual principles.
In order to develop a strategic architecture, a thorough understanding of the industry and market was obtained by analysing the external and internal environments of short-term insurers in South Africa. The research is based on solid statistical data on all registered insurers, available from the governing body for insurers in South Africa, the Financial Services Board, as well as more qualitative data in the form of reports on industry analysis, performed by major auditors like KPMG and PWC. It also takes into consideration “cutting edge” approaches to starting up a new business, regardless of industry, through the application of the “Customer Development Model”, an approach based on lean and agile principles to mitigate the risk of developing a product / service at high cost before knowing if the market actually has a need or appetite for it.
This research concludes by offering a strategic architecture and strategic implementation plan for a new player to enter the market, based on the analysis performed though the application of various strategic tools and frameworks.
The primary findings of this research are that the industry is highly competitive, with longstanding ‘giants’ supported by parent companies. Those ‘giants’, however, all operate as stock insurers, and a transition by any one of them to mutual insurer, is highly unlikely. As mentioned, the industry currently only has one mutual insurer. This means there is really only one competitor (PPS) in terms of the profit sharing model and in that, PPS has a rather niche focus since its products are only available to graduate professionals.
This research uses further external and internal environment analysis methods to extract industry information used in the formulation of a strategic architecture and business model for a new player to compete in the environment described above. It suggests that there is, in fact, room for a new player and that it can differentiate itself from stock insurers by applying the mutual model. It can further differentiate itself from stock insurers and PPS by expanding its market focus (i.e. not only for graduate professionals) and by utilising technology in productive and creative ways that encourages engagement with customers in a new way.
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Choudhury, Niren Ch. "Implementation of basic software tools to start a VLSI program at Ohio University with a high speed parallel multiplier as an example." Ohio : Ohio University, 1985. http://www.ohiolink.edu/etd/view.cgi?ohiou1183752120.
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Pešout, Jakub. "Provozně technický stav objektů separace na úpravnách vody." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-227682.
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The goal of this thesis was to determine the operational and technical parameters of the separation objects in water treatment. The first part is a theoretical and provides basic information on this issue. The second part contains the evaluation criteria created by the obtained information for individual objects and gained in practice by personal visits of selected treatment plants of water. In the last part we can find application of these criteria in water treatment in practice. There is also included the final evaluation of the researched condition.
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Steiner, Martin. "Současný stav a budoucnost nekonvenční technologie vodního paprsku v podmínkách průmyslu České republiky." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2008. http://www.nusl.cz/ntk/nusl-228103.
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Description of basic principle of water jet unconventional method. Description and characteristics of water jet machining. Analysis of technological potential and operation severity. Status quo and future in the Czech Republic industry condition. Comparison of water jet to other jet methods.
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Naldini, Federico. "Algoritmi Euristici per la Schedulazione degli Interventi nel Blocco Operatorio." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/11685/.
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Questa tesi riguarda il problema della schedulazione degli interventi nel blocco operatorio di un presidio ospedaliero, noto anche come Operating Theatre Planning & Scheduling. Il blocco operatorio è la struttura che eroga servizi a più alto impatto sui costi di un presidio ospedaliero ed è legato ad attività ad alto rischio. E' quindi fondamentale gestire in modo ottimale questa risorsa.
In questa tesi, si considera come caso studio l'applicazione reale di un presidio ospedaliero dell'Emilia Romagna con un orizzonte temporale di una settimana, ovvero la cosiddetta programmazione operativa. L'obiettivo è quello di ottenere un utilizzo efficiente del blocco operatorio, garantendo al contempo la priorità agli interventi più urgenti.
Data la complessità del problema, vengono proposti algoritmi euristici che permettano di ottenere buone soluzioni in tempi di calcolo ridotti. Studi precedenti hanno infatti evidenziato la difficoltà di trovare soluzioni ottime al problema, mediante l'utilizzo di solver commerciali per modelli di Programmazione Lineare Intera, senza introdurre ipotesi semplificative.
Sono stati elaborati tre algoritmi euristici costruttivi di tipo multi-start che permettono di generare soluzioni ammissibili con diverse caratteristiche. Gli algoritmi si differenziano principalmente per le modalità con cui collocano gli interventi nel tempo disponibile delle risorse (induction room, operating room, recovery room), cercando di migliorarne l’utilizzazione e dando priorità ai pazienti più urgenti.
Gli algoritmi sono stati implementati utilizzando il linguaggio JAVA e sono stati testati su istanze realistiche fornite dal presidio ospedaliero. I risultati hanno evidenziato un alto grado di utilizzazione delle sale operatorie, un fattore molto rilevante per una ottimale gestione del blocco operatorio.
E' stata, infine, svolta un'analisi di sensitività alla variabilità delle durate.
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Atkinson, Terry. "Modeling of magnetic optic for the short pulse mode operation of Energy Recovery Linac based light sources." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät, 2015. http://dx.doi.org/10.18452/17300.
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Das Forschungsfeld der Synchrotronstrahlungsquellen hat sich in den letzen Jahren entscheidend weiterentwickelt. Alle Zukunftsideen, unabhängig von ihrer Komplexität, haben dennoch eines gemeinsam: die Erzeugung kurzer Pulse. Die Naturwissenschaften haben die Spitzenbrillanz, die mit Hilfe kürzester Pulse produziert werden kann, als neues Schlüsselwerkzeug entdeckt. Die Nutzergemeinschaft verlangt nicht mehr nur ein statisches Bild, sondern vielmehr eine Reihe von bewegten Aufnahmen atomarer Substrukturen und den dazugehöringen Prozessen. Existierende dritte Generation Synchrotronstrahlungsquellen werden an die neuen Herausforderungen angepasst: Verbesserungen an der Magnet-Optik sowie der Einbau modernster Beschleunigertechnologie ermöglichen die Erzeugung kürzester Pulse mit höchster Brillanz für zeitaufgelöste Experimente. Ein möglicher Kandidat für die Lichtquelle der nächsten Generation ist ein Linear-Beschleuniger mit Energierückgewinnung. Durch die Verwendung langer Beschleunigungsstrukturen kann es, selbst bei hohen Energien, nicht zur Ausbildung des Emittanzgleichgewichts wie in Speicherringen kommen. Durch die Verwendung Impulsabhängiger-Umlaufbahnen und der Rückgewinnung der Strahlenergie ist es mit `Energy Recovery Linac'' (ERL)-basierten Quellen energieeffizient möglich, hochenergetische Elektronen-Pulse im Femtosekundenbereich zu erzeugen. Die longitudinale Elekronstrahldynamik solcher ERLs ist eines der Hauptthemen dieser Arbeit. Umfangreiche Simulationen über die gesamte Maschine wurden im Rahmen der `Femto-Science Factory'' Lichtquellen Studie durchgeführt. Die Begrenzungen des Kurzpulsmodus Betriebes wurden untersucht und mit den Erwartungen verglichen. Besondere Aufmerksamkeit lag dabei auf den 6D Elektronenstrahleigenschaften, insbesondere auf der Vermeidung von Strahlaufweitungen, die mit der Erzeugung von Ultra-Kurzpulsen einhergehen können.<br>Synchrotron light sources are entering a new era. No matter how elaborate, all the next generation proposals share a common necessity; the production of ultra-short electron bunches. There is an evolution in the field of science under investigation using the high peak brilliance generated from such bunches. The user community is demanding not just pictures but videos of atomic substructures and the processes that define them. Existing 3rd generation facilities are modifying their magnetic lattices and upgrading the acceleration schemes in order to keep up with this trend of generating short pulses with ultimate brilliance for time resolved experiments. A possible candidate for the next generation light source is one based on ERL technology. Using long linacs to accelerate to high energies overcomes the present limitation of emittance equilibrium in storage rings. By implementing independent arcs for acceleration and deceleration while recuperating the beams energy, ERL based sources are theoretically capable of efficiently producing high energy femtosecond long bunch lengths. The study of the longitudinal motion of the beam through single pass magnetic optic in combination with linacs is the main topic of this thesis. Dedicated start-to-end simulations in the framework of the Femto-Science Factory large scale light source are undertaken. The expectations and restrictions on the short pulse mode (SPM) operation are comprehensively examined in this work. Particular attention is given to the 6D electron beam properties and with it the beam degradation caused by the production of ultra-short bunches.
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Tengeh, Robertson Khan. "A business framework for the effective start-up and operation of African immigrant-owned businesses in the Cape Town Metropolitan area, South Africa." Thesis, Cape Peninsula University of Technology, 2011. http://hdl.handle.net/20.500.11838/1687.
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Thesis submitted in partial fulfilment of the requirements for the degree Doctor of Technology: Public Management in the Faculty of Business at the Cape Peninsula University of Technology<br>The purpose of this study is to develop a business framework for the effective start-up and operation of African immigrant businesses in the Cape Town Metropolitan Area of South Africa. The question that guides this research is: how do African immigrants use their entrepreneurial attributes to acquire the resources necessary to start-up and operate successful businesses in the Cape Town Metropolitan Area?The study was conducted within the context of the economic development mandate as prescribed by the constitution of the Republic of South Africa Act, 1996. The development agenda also includes community, social and welfare promotion premised on the Keynesian principles that the government introduces interventions where there is an economic failure. In the South African context, this relates to unemployment and due to the prevailing economic down turns a greater reliance by the populace for social and welfare support. In recent years, immigrants especially from African countries have found themselves in a similar situation (That is in need of economic, social and welfare support). However, the government, particularly local government does not have the resources, especially financial resources to assist all local entrepreneurs, including immigrant entrepreneurs. Although there is a wide coverage of immigrant entrepreneurship in developed countries, much still has to be done as far as developing countries are concerned. From a South African perspective, there is so far no study entirely devoted to African immigrant entrepreneurship. This notwithstanding, there seems to be a growing consensus on the fact that SMMEs in South Africa are disproportionately constrained by start-up and operational factors such as finance, insufficient demand, lack of business skills and lack of information, although one cannot generalise especially as immigrant entrepreneurs face a slightly different dynamic. No studies focusing on immigrant-owned businesses in general and particularly how they tap into their entrepreneurial traits to start-up and grow successful businesses has been conducted in South Africa. At one level, the finding of this study provides vital information for new immigrants venturing into self employment. At another level, the study may provide vital insight into immigrant entrepreneurship in South Africa. Limited job opportunities force African immigrants into self-employment. However, due to the numerous challenges that they face, only a few of the immigrant-owned businesses get off the ground, let alone grow. It may be argued that most of these African immigrant-owned businesses fail to reach their full potential because they (the owners) are unable to exploit the entrepreneurial attributes that they bring or have at their disposal upon arrival. Three interrelated concepts: entrepreneurial attributes, business start-up and operation resources, and business success, are linked in this study to develop a framework for the effective start-up and operation of immigrant-owned businesses. The proposed framework seeks to encourage African immigrants to match the entrepreneurial attributes that they come with to the business opportunities and challenges that they may face in establishing and growing their businesses in South Africa.The study was designed within the quantitative and qualitative research paradigms, in which a triangulation of three methods was utilised to collect and analyse the data. From a quantitative perspective, the survey questionnaire was used. To complement the quantitative approach, personal interviews and focus groups were utilised as the methods within the qualitative approach paradigm.
The research revealed that an African immigrant entrepreneur is most likely to be a male within the age range of 19 and 41 who has been forced to immigrate because of political circumstances back home. The decision to immigrate as well as the choice of South Africa as a host country was entirely dependent on the immigrant. Once in South Africa, limited job opportunities forced these immigrants into setting up their own businesses within the informal sector as their starting point. In order of importance, financial, physical, human, and informational resources were identified as being critical for the start-up and operation of a business in South Africa.
In terms of acquiring the resources to start-up and operate a business, and from a financial perspective point, African immigrant entrepreneurs unwillingly made use of personal savings to finance their businesses during the start-up phase of the business. Financial resources played a double role in that they determined the main sources of physical resources used. From a human resource standpoint, African immigrant entrepreneurs preferred employing South Africans during the start-up phase of the business, and the reverse was true during the growth or operational phase. To a limited extent, family labour was involved at both the start-up as well as the operational phases of the business; with formal education and prior experience playing a significant role as far as the human resource mix was concerned. In terms of information, African immigrant entrepreneurs made use of two primary sources of information namely, their ethnic networks and friends from somewhere else.
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Whiteman, Don, and Robert Sakahara. "SPACE-BASED TELEMETRY AND RANGE-SAFETY STUDY TEST RESULTS AND FUTURE OPERATIONAL SYSTEM GOALS." International Foundation for Telemetering, 2003. http://hdl.handle.net/10150/605563.
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International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada<br>The use of remote ground stations for telemetry data-relay in space launch applications is costly and
limits the geographic locations for launches of future Reusable Launch Vehicle (RLV) systems. The
National Aeronautics and Space Administration Space-based Telemetry and Range-Safety (STARS)
Study is investigating the use of satellite data relay systems as a replacement or supplement for
ground-based tracking and relay stations. Phase-1 of STARS includes flight testing that evaluates
satellite data-relay feasibility, defines satellite system performance limitations, and generates
requirements for the development of future satellite telemetry data relay systems. STARS Phase-1
ground-test results and goals for the Phase-2 system development and flight-testing are also
presented.
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Tsvetkova, Galina Valeryevna. "An autonomous long-term fast reactor system and the principal design limitations of the concept." Diss., Texas A&M University, 2003. http://hdl.handle.net/1969.1/36.
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The objectives of this dissertation were to find a principal domain of promising and technologically feasible reactor physics characteristics for a multi-purpose, modular-sized, lead-cooled, fast neutron spectrum reactor fueled with an advanced uranium-transuranic-nitride fuel and to determine the principal limitations for the design of an autonomous long-term multi-purpose fast reactor (ALM-FR) within the principal reactor physics characteristic domain. The objectives were accomplished by producing a conceptual design for an ALM-FR and by analysis of the potential ALM-FR performance characteristics. The ALM-FR design developed in this dissertation is based on the concept of a secure transportable autonomous reactor for hydrogen production (STAR-H2) and represents further refinement of the STAR-H2 concept towards an economical, proliferation-resistant, sustainable, multi-purpose nuclear energy system. The development of the ALM-FR design has been performed considering this reactor within the frame of the concept of a self-consistent nuclear energy system (SCNES) that satisfies virtually all of the requirements for future nuclear energy systems: efficient energy production, safety, self-feeding, non-proliferation, and radionuclide burning. The analysis takes into consideration a wide range of reactor design aspects including selection of technologically feasible fuels and structural materials, core configuration optimization, dynamics and safety of long-term operation on one fuel loading, and nuclear material non-proliferation. Plutonium and higher actinides are considered as essential components of an advanced fuel that maintains long-term operation. Flexibility of the ALM-FR with respect to fuel compositions is demonstrated acknowledging the principal limitations of the long-term burning of plutonium and higher actinides. To ensure consistency and accuracy, the modeling has been performed using state-of-the-art computer codes developed at Argonne National Laboratory. As a result of the computational analysis performed in this work, the ALM-FR design provides for the possibility of continuous operation during about 40 years on one fuel loading containing mixture of depleted uranium with plutonium and higher actinides. All reactor physics characteristics of the ALM-FR are kept within technological limits ensuring safety of ultra-long autonomous operation. The results obtained provide for identification of physical features of the ALM-FR that significantly influence flexibility of the design and its applications. The special emphasis is given to existing limitations on the utilization of higher actinides as a fuel component.
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Gradh, Anders. "En stabs nätverkstrafik : En analys av användningen av datornätverkskapacitet i en operativ stab under övningen VIKING 11." Thesis, Försvarshögskolan, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:fhs:diva-5426.
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FM köpte satellitkapacitet för närmare 20 miljoner kronor under 2014 för utbildning, övning och internationella operationer. Enligt HKV räcker dock inte upphandlad kapacitet för att täcka behoven ute hos förbanden. Syftet med denna studie är att ta reda på mer hur kapacitetsanvändningen ser ut vid en operativ stab utifrån deras arbete och därigenom se om det finns någon militär nytta att vinna kopplad till kapacitetsanvändning. Utgångspunkten för arbetet är insamlad information om datornätverkstrafiken i de olika nätverken. Detta kvantitativa data jämförs med stabens arbete utifrån kvantitativ och kvalitativ data i krigsdagbok, styrdokument och deltagande studie. Studien visar på att kapacitetsanvändningen ej är relaterad till stabens arbete utan snarare är kopplad till när personal är på plats och personalens internetanvändning. Studien pekar på att det kan finnas en potential att få mer militär nytta, dock måste mekanismer för prioritering i nätverket införas och vidare studier avseende trafiken genomföras.<br>In 2014 the Swedish Armed Forces (SwAF) spent almost SEK 20 million on the procurement of satellite capacity for use during training, exercises and operations. However, according to SwAF Headquarters, the capacity procured did not meet unit demands. The aim of this study is to gain a better understanding of the capacity usage in an operational headquarters, based on the headquarters’ staff procedures and to see if there is any military utility to be gained in connection with this capacity. The starting point for the study is quantitative data about network usage. This quantitative data is then compared with staff work based on quantitative and qualitative data from war diaries, governing documentation and studies. The study shows that capacity usage is not related to staff work, but is instead linked to the presence of staff and their use of the Internet. The study also indicates that there could be potential for greater military utility of network capacity, but this will require the introduction of network priority mechanisms and further studies into user traffic.
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Mohammed, Anwaruddin. "ACHIEVING ULTRAFINE GRAINS IN Mg AZ31B-O ALLOY BY CRYOGENIC FRICTION STIR PROCESSING AND MACHINING." UKnowledge, 2011. http://uknowledge.uky.edu/ms_etds/1.
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This thesis presents results from the application of cryogenic cooling on multiple-pass friction stir processing and the subsequent orthogonal machining on friction stir processed and as-received Mg AZ31B-O disks, and shows their combined effects on microstructure and microhardness values. A simple friction stir tool, a specially designed fixture and liquid nitrogen are used to perform multiple-pass friction stir processing experiments on Mg AZ31B-O alloy. The friction stir processed and as-received sheets are then made into disks for the orthogonal machining experiments. This study analyzes the microhardness, microstructure changes by cryogenic friction stir processing and the effect of machining conditions such as dry, MQL and cryogenic and cutting parameters on the Mg AZ31B-O alloy. Four different speeds and three different feed rates are used for the orthogonal machining experiments. The effects of stirring parameters such as the translational feed, rotational speed, cooling conditions and the machining parameters are studied. The resulting microstructure and microhardness from these processes hold a key to the mechanical properties of the alloy. This analysis would help to understand and evaluate the specific aspects of grain size and microhardness that influence the fatigue life of a component.
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Sweetman, Paul J. "Evaluating the Fate of Manure Nitrogen in Confined Dairy Waste Operations: a Full-Scale Waste Analysis and Start-Up Protocol for an Anammox-Based Treatment Technology Applicable to Dairy Waste Management." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/41237.
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In an effort to develop cost-effective technologies for the removal of ammonium nitrogen from dairy waste, a novel biological wastewater treatment process, utilizing anaerobic ammonium oxidation (anammox), referred to as Oxygen-Limited Autotrophic Nitrification and Denitrification (OLAND) was examined. Due to the potential use of OLAND-based systems in dairy manure management, a detailed water quality assessment of a modern dairy farm manure treatment-system was conducted. The Johnson Highland Dairy Farm, Glade Spring, Virginia, was selected for this assessment and a comprehensive analysis of the wastewater characteristics throughout the confined animal feeding operation was completed. The results suggest that ammonia concentrations in the anaerobic storage facility was high enough to justify use of treatment technologies that reduce ammonia loads in stored dairy waste. A lightly loaded Fixed Film Bioreactor (FFBR), in which the OLAND process was desired to occur, was then constructed in the laboratory and monitored over 51 days. Of particular interest was the time taken to achieve stable performance of this OLAND system. Furthermore, a protocol was developed to determine whether OLAND based metabolism was occurring. Ammonium nitrogen removal efficiency in the FFBR throughout the 51-day monitoring period was high, averaging approximately 95 % for the length of the study. From day 32 to 51, simultaneous removal of both ammonium and nitrite with a low level of concomitant nitrate production was observed, a key indicator of possible anammox activity. Stoichiometric ratios calculated for the FFBR compared favorably with those already established for OLAND systems. The developed protocol, incorporating anaerobic and aerobic batch experiments, to verify the occurrence of OLAND based metabolism did not yield expected results and described poorly what was being observed in the FFBR. Volatilization of ammonia during the experimental test was suspected and should be controlled when the protocol is performed in the future.<br>Master of Science
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Zare, Ali. "Characterisation of transient diesel engine performance and emissions with oxygenated fuels." Thesis, Queensland University of Technology, 2017. https://eprints.qut.edu.au/106950/1/Ali_Zare_Thesis.pdf.
Full textAbstract:
Globally there are over one billion road vehicles using internal combustion engines many of which are now using alternative fuels as well as or instead of petroleum fuels. This thesis advances knowledge of the use of these fuels under different engine operating conditions by providing an extensive amount of new and fundamental information on a wide range of engine performance and emission parameters. The resource addresses real-world conditions covering combinations of transient (including driving cycle, acceleration and load increase), steady-state operation, cold-start and hot-start. This study will be a useful reference for engine combustion researchers and emission regulation authorities.
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Zehr, Brock Allyn. "Entrepreneurial Qualities for Successful Development and Sustainability of New Small and Medium-Sized Enterprises." ScholarWorks, 2016. https://scholarworks.waldenu.edu/dissertations/3130.
Full textAbstract:
Entrepreneurial small businesses are significant to the U.S. economy, as they represent 99% of employer firms and employ 49% of the private sector. Nearly half of new businesses fail within the first 5 years of operation. While external factors beyond the control of business owners account for some failures, many occur because of managerial inadequacies. The purpose of this phenomenological study was to explore the lived experiences of successful entrepreneurs to understand the qualities needed to create and sustain new small and medium-sized enterprises (SMEs) beyond 5 years. The sample consisted of 21 entrepreneurs from Northeastern Indiana who created and operated SMEs successfully for at least 5 years. The conceptual framework for this study was human capital theory and entrepreneurial leadership theory. The data were collected from semistructured interviews. Participants completed transcript reviews and member checking was conducted to enhance data credibility and trustworthiness. The phenomenological reduction method was used for data analysis and included bracketing, horizontalizing, clustering, integrating invariant statements, and synthesizing composites. The following themes emerged in addressing the guiding question: entrepreneurial intention recognized at a young age, creative problem-solving skills, business and support systems, entrepreneurial passion, opportunity recognition and seizure, and task and managerial delegation. The study findings can help inform best practices to help future entrepreneurs, and those who educate, train, and mentor them, create and operate successful new ventures.
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Mjogolo, Festo. "Operational effectiveness of connected vehicle smartphone technology on a signalized corridor." UNF Digital Commons, 2019. https://digitalcommons.unf.edu/etd/877.
Full textAbstract:
Over the last decade, extensive research efforts have been placed on performance evaluation and the benefits of innovative CV applications. Findings indicate that CV technology can effectively mitigate the safety, mobility, and environmental challenges experienced on transportation networks. Most of research evaluated CV technology through simulation studies. However, a field study provides a more ideal method of assessing CV technology effectiveness. Therefore, a field study to obtain the actual effectiveness of CV technology was warranted, to validate previous findings, and to add to the body of knowledge surrounding this topic. This thesis presents both a field study and simulation evaluation of the effectiveness of CV smartphone technology on a 1.1 mile segment of State Road 121, containing five intersections, in Gainesville, Florida. Field observations were conducted using a CV application, developed by Connected Signals, Inc., that uses a smartphone application, called EnLighten, to communicate intersection information to driver’s smartphone, which serves as a vehicle on-board unit.
Traffic operation and safety performance was evaluated using start-up lost time, discharge distribution model, and speed harmonization. Findings show that the CV smartphone technology improved intersection performance with a reduction in start-up lost time of approximately 86%. Additionally, driving safety improved with a reduction in speed variability by nearly 61% between vehicles in a specific lane for a 100% CV penetration rate. Cost analyses of deploying CV smartphone technology indicate that implementation may result in an average total economic cost savings associated with crashes of nearly $6.8 million at the study site, and approximately $5.6 billion statewide.
Findings of the simulation evaluation revealed that the CV technology improved performance of intersections operating at a Level of Service (LOS) B or better, compared to lower operating levels. Operational performance improved at intersections operating at a LOS C with a 30% to 60% CV penetration rate.
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Keskin, Robin, and Ersad Colic. "Hur stark påverkan har aktiekursen på kapitalstrukturen? : En kvantitativ studie om sambandet mellan aktiekursen och kapitalstrukturen på Stockholmsbörsen." Thesis, Södertörns högskola, Institutionen för samhällsvetenskaper, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:sh:diva-35512.
Full textAbstract:
Today, the capital structure is an established research area in economics. Capital structure refers to the relationship between equity and liabilities, which through history has been explored through many different aspects. Capital structure is influenced by several factors and the results is ambiguous as to which of these factors are related to capital structure and which can explain the capital structure. The purpose of this study is to investigate the relationship between the share price and capital structure as well as investigate which control variable is correlating with capital structure. The study is of quantitative form, where data was collected between 2009-2017 from the 15 largest companies, set at market value, from Large Cap and Mid Cap listings from Nasdaq Stockholm. The result of the study shows that the share price and capital structure have a positive relationship for both lists, also share price could explain variations in the capital structure. The control variables result differ significantly depending on the list and variables. Profitability is the variable that explains the capital structure best, especially on the Large Cap list. Company size has no connection with the capital structure, and the explanation rate is reasonably comparable to share price as a single independent variable. Firm age has no connection with the capital structure and only affects the explanation negatively.<br>Idag är kapitalstruktur ett etablerat forskningsområde inom företagsekonomi. Kapitalstruktur avser förhållandet mellan eget kapital och skulder vilket har genom tiden utforskats ur mängder av aspekter. Utformningen av kapitalstrukturen påverkas av flera faktorer och idag är empirin tvetydig angående vilka av dessa faktorer som har samband med kapitalstrukturen och vilka som är kan förklara kapitalstrukturen. Syftet med denna studie är att undersöka sambandet mellan aktiekursen och kapitalstrukturen samt undersöka vilka kontrollvariabler som korrelerar kapitalstrukturen. Studien är av kvantitativ form och data samlades in mellan 2009–2017 från de 15 största företagen, sett till börsvärde, från Large Cap och Mid Cap listorna från Nasdaq Stockholm. Resultatet från studien visar att aktiekursen och kapitalstrukturen har ett positivt samband för båda listorna och att aktiekursen kan förklara variationer i kapitalstrukturen. Kontrollvariablerna skiljer sig i resultatet markant beroende på lista och variabel. Lönsamhet är den kontrollvariabeln som förklarar kapitalstrukturen bäst bland kontrollvariablerna, speciellt på Large Cap listan. Företagsstorlek har inget samband med kapitalstrukturen och ökar förklaringsgraden någorlunda jämförelsevis med aktiekurs som ensam oberoende variabel. Företagsålder har inget samband med kapitalstrukturen och påverkar förklaringsgraden endast negativt.
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Tibola, Jonas Roberto. "Controle e supervisão de fonte ininterrupta de energia híbrida." Universidade Federal de Santa Maria, 2017. http://repositorio.ufsm.br/handle/1/12301.
Full textAbstract:
This work presents contributions to the modeling, control and management of an
hybrid uninterrupted power supply (UPS) based on Otto cycle power generator set and
lead acid battery bank. The proposed configuration is called hybrid due to the presence
of two energy storage elements: i) the fuel fed the Otto cycle internal combustion engine
(ICE) of the generator set and ii) a lead acid battery bank, which can be recharged from
the grid or from the generator. With the hybridization it is possible to add up the advantages
of UPS’s such as uninterrupted power supply and high output energy quality with
the advantages of power generator sets, such as high autonomy and lower installation cost
for high autonomy. In addition, with the hybrid topology it is possible to explore degrees
of freedom that do not exist in the independent configurations, such as: i) variable
speed operation and ii) start-stop operation of the MCI in order to reduce consumption/
emissions in lower loads, (iii) use of Otto cycle engine with lower cost in relation to
a Diesel ICE. The hybrid UPS is composed of an Otto cycle internal combustion engine
(ICE), a three-phase/three-wire rectifier, which can be connected via contactors to the
grid, or to the permanent magnet synchronous generator (PMSG), a battery bank connected
to the DC bus through a bi-directional boost converter, and a three-phase/four-wire
inverter at the output. Experimental results are provided indicating that variable speed
operation can achieve a reduction of up to 32% in specific fuel consumption, depending
on the load range. For start-stop operation, the reduction in specific fuel consumption
can reach up to 39%, depending on the load range.<br>Este trabalho apresenta contribuições a modelagem, controle e gerenciamento de
uma fonte ininterrupta de energia (UPS) híbrida baseada em grupo motor ciclo Otto e
bateria chumbo ácido. A configuração proposta é denominada híbrida devido a presença
de dois armazenadores de energia: i) o combustível para alimentar o motor a combustão
interna (MCI) ciclo Otto do grupo motor gerador e ii) um banco de baterias chumbo ácido,
a qual pode ser recarregado pela rede ou pelo gerador. Com a hibridização é possível
agregar as vantagens das UPSs tais como, ininterruptibilidade de fornecimento de energia
e alta qualidade de energia da tensão de saída, com as vantagens dos grupos motores
geradores, tais como, elevada autonomia e menor custo de instalação para autonomias
elevadas. Além disso, com a topologia híbrida é possível explorar graus de liberdade não
existentes nas configurações independentes, tais como: i) utilização de velocidade variável
e ii) operação em regime start-stop no MCI afim de reduzir consumo/emissões em baixas
cargas, iii) utilização de motor ciclo Otto com menor custo em relação a um MCI Diesel.
A UPS híbrida é composta por um motor a combustão interna (MCI), um retificador
trifásico a três/quatro fios, o qual pode ser conectado através de contatoras à rede, ou
ao gerador síncrono de ímãs permanente (PMSG), um banco de baterias conectado ao
barramento através de um conversor boost bidirecional, e um inversor a quatro fios na
saída. Resultados experimentais são apresentados indicando que a operação em velocidade
variável pode alcançar um redução de até 32% no consumo específico de combustível,
dependendo a faixa de carga. Já para a operação em regime start-stop a redução no
consumo específico de combustível pode alcançar até 39%, dependendo da faixa de carga.
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Kemp, Phillip. "The influence of business incubation in developing new enterprises in Australia." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2013. https://ro.ecu.edu.au/theses/864.
Full textAbstract:
Australia was an early adopter of business incubation, and made substantial investments in it in the early 2000s, however local interest has declined with the closure of big government-funded projects, at a time when international interest in business incubation is increasing. This study revisits the question of business incubators and their usefulness in economic development, describing a case study conducted on a university-linked business incubator in Australia. It investigates the impact of its operations on developing start-up businesses operating from within the facility; the motivations, perceptions and priorities of small businesses tenants and former tenants; and the role of the manager in influencing the development of new enterprises. The study builds on the theoretical understanding of business incubation and a model has been developed that demonstrates the ways in which options theory, coproduction theory, networking theory and social capital theory explain stages of incubation.
The study found the principle motivation for tenants to locate their business within a business incubator was the price for the office space and not the business development assistance that is the primary service of the business incubator. Once operating from within the business incubator, however, the principle advantage perceived by tenants was the provision of business assistance in the development and growth of their businesses. The only disadvantage raised was price as it reduced the pressure to strive for profits and business growth on the tenant businesses. The interaction with the manager was found to have a positive impact on the tenant businesses and contributed to their development. The tenants believed that the interaction was on their own terms and that they could seek advice whenever they needed from the manager. The manager believed that he could add value by assisting the tenants directly, with connecting them and introducing tenants to other service providers and businesses when required.
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Jára, Jaroslav. "Návrh postupu při obnově napájení vlastní spotřeby zdrojů Tepláren Brno po rozsáhlé systémové poruše v ES." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-220373.
Full textAbstract:
This work deals with the issue of supply restoring for heating plant Teplárny Brno, a. s. Špitálka division, after a system-wide failure of the “blackout”. The thesis solves the “black start” of the Špitálka Teplárny Brno operation by delivering a voltage from the hydroelectric power Vír I, proposes a methodology for commissioning of individual devices, up to phasing the generators with subsequent possibility of creating an “island mode” in the area of Brno city, which the work already does not deal with. The work also deals with the preparation of the operational test, while starts of the selected devices are tested. The schedule of commissioning of each device is supported by calculations of the parameters for the entire system with regard to voltage drops while connecting the high load. The result of this work is the proposal of methodological process of supply restoring for power plant Teplárny Brno – Špitálka division, by submission a voltage from the hydroelectric power Vír I, which can be used both in any system-wide failure of the “blackout”, or during the operational test.
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Chiappori, Guido Jose. "Système de stabilisation de la tension batterie pour la fonction Stop-Start automobile : solution à composants de puissance commandés en linéaire." Thesis, Ecole centrale de Lille, 2015. http://www.theses.fr/2015ECLI0005/document.
Full textAbstract:
Cette thèse présente un nouveau système de stabilisation de la tension batterie spécialement destinés aux véhicules Stop-Start, économique et compact, nommé LVSS (Linear Voltage Stabilization System). Le LVSS se comporte comme une résistance variable et limite le courant à l’aide de transistors MOSFET fonctionnant en mode linéaire. Il permet donc de stabiliser la tension de la batterie pendant le démarrage du moteur à combustion interne (ICE). Un prototype a été conçu et testé sur une voiture. Les résultats ont montré que la tension était stabilisée tout en limitant le courant de démarrage. De plus la solution proposée n’impacte pas sur les performances globales du système Stop-Start et comme les transistors fonctionnent en mode linéaire, cette solution n’émet pas de perturbations CEM<br>This thesis presents a new Linear Voltage Stabilization System (LVSS) specially designed for µ-hybrid vehicles using the Stop-Start function. The LVSS stabilizes the battery voltage during the start-up of the Internal Combustion Engine (ICE) limiting the start-up current using parallels MOSFETs working in linear mode. A prototype was developed and tested in a car. Results have shown the battery voltage properly stabilized limiting the start-up current. Furthermore the proposed solution does not impact on the overall performance of the Stop-Start. Main advantages are its small volume, low price and the fact that there is no EMC perturbation as transistors work in linear mode
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Cardoso, Rafael Felipe Silva. "Incentivo fiscal e alavancagem operacional: um estudo de caso sobre a desoneração da folha de pagamento em uma empresa start-up." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/12/12136/tde-02082016-153102/.
Full textAbstract:
Os incentivos fiscais concedidos pelos entes públicos às empresas nacionais suscitam cada vez mais o interesse de estudos aprofundados em relação a seu impacto dentro das organizações. Esta pesquisa tem como objetivo analisar os efeitos dos incentivos fiscais, especificamente, da desoneração da folha de pagamento instituída pelo Plano Brasil Maior do Governo Federal em 2011, no grau de alavancagem operacional de uma empresa start-up brasileira. A pesquisa foi realizada através de um estudo de caso em uma empresa start-up atuante no Brasil no setor de tecnologia desde 2011. As análises do estudo de caso confirmaram que há uma relação direta entre a desoneração da folha de pagamento e o grau de alavancagem operacional de uma empresa. A interpretação dos dados sugere que para uma melhor eficiência dos incentivos fiscais, estes devem alterar o comportamento dos custos e despesas fixas para variáveis, diminuindo assim a exposição ao risco operacional da empresa.<br>Tax incentives granted by public entities to domestic companies tend to raise more interest of extensive studies in relation to its impact within organizations. This research aims to analyze the effects of tax incentives, specifically, the payroll tax exemption established by the \"Plano Brasil Maior\" of the Brazilian Federal Government in 2011, on the degree of operating leverage of a Brazilian start-up company. The research was conducted through a case study of a start-up company operating in Brazil in the technology sector since 2011. The analysis of the case study confirmed that there is a direct relation between the payroll tax exemptions and the degree of operating leverage of a business. The interpretation of the case suggests that, for a more efficiency of the tax incentives, the incentive must directly modify the fixed and variable costs and therefore reducing the company\'s exposure to operational risk
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Metawa, Noura s. "The Impact of Governance Mechanism on Performance and Survival of Entrepreneurial Firms." ScholarWorks@UNO, 2018. https://scholarworks.uno.edu/td/2475.
Full textAbstract:
The dissertation consists of two essays.
The first essay studies governance structures and their effectiveness for start-up companies and their survival. We utilize data from the Kauffman Survey, which tracks a sample of firms from their inceptions through their first eight years of existence. We hypothesize and find evidence that a startup's governance system affects its survivability as well as its performance. We show that controlling for the firm size and the industry, cross-sectional variations in the performance of the start-up firms can be explained by governance variables; the presence of one or more independent board member on the board, the separation between the person holding the CEO position and the chair of the board. From the startup survival perspective, we show that the presence of one or more independent board member(s), the separation between CEO and board chair, and external funding are effective factors that promote a start-up's longevity.
The second essay studies the direct and indirect relations between Governance and firm survival and performance through Entrepreneurial Orientation. Entrepreneurial orientation (EO) is defined as the attributes, including innovativeness, autonomy, risk-taking attitude, proactiveness, and competitive aggressiveness, that a business organization displays at the time of entry. Several researchers have studied the linkage between EO and organizational performance as well as the survival rate of new firms and find conflicting results. Reasons for the contradictory results might very well be the way the researchers have defined the EO attributes and the data source they use which is based on subjective responses. In the hopes of reducing inconsistent results, we propose that it is the governance factors that influence the performance and survival of these firm via mediating role of entrepreneurial orientation. Governance factors remove the definition as well as data measurement problems. By using the 8-year longitudinal data of 4928 startups, we show that governance system significantly impacts a start-up’s performance and survival via entrepreneurial orientation.
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Škařupová, Karolína. "Návrh sanace vybrané části stokové sítě ve městě Valašské Meziříčí." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2014. http://www.nusl.cz/ntk/nusl-226903.
Full textAbstract:
The aim of this master´s thesis was design of rehabilitation of selected parts of the sewer network in Valašské Meziříčí. The work is divided into several parts. The first part is a description of the preliminary research based on appointments with the operator of the sewer network. The second section describes the basic information on the assessment of the sewer network. In the third part, the evaluation of technical and operational conditions according to ČSN EN 13 508. This section was supplemented by creation of supportive software program in Microsoft Office Excel, which is based on the proposed TNV 756905. In the next part the environmental assessment was performed digging and trenchless technology and then selected a possibility representative to design of selected parts. The fifth and sixth section contains technical and economic evaluation designed technology. A final section deals with the choosing optimal rehabilitation technologies for the design of selected parts of the sewer network.
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Apostolopoulos, Nikolaos. "Design and implementation of an SPB converter for fault tolerant PMSynRel motor control." Thesis, KTH, Elektrisk energiomvandling, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-179141.
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The stacked polyphase bridges (SPB) converter topology is investigated in the presentthesis as a fault-tolerant choice for permanent-magnet synchronous reluctance (PMSyn-Rel) motor control. Integrated motor drive systems are studied as they offer great benefitsfor propulsion applications. Moreover, the importance of a modular topology, like theSPB, for an electric powertrain is discussed. The latter consists of a number of seriesconnected, 3-phase 2-level inverter submodules that supply separate sets of windings ina multi-star motor. The specifications of building a four-board SPB setup are examined,while the challenges of an active voltage balancing controller are analyzed. The designprocess is explained step-by-step and the final printed circuit boards (PCBs) are presented.Furthermore, the significance of low electromagnetic interference design for a converterthat requires high speed communication is highlighted. Finally, the prototype is testedthoroughly and the expected fault-tolerant capabilities are validated on a PMSynRel motor.<br>I detta examensarbete unders¨ok SPB-omriktartopologin (stacked polyphase bridges converter)i termer av ett feltolerant elektriskt drivsystem f¨or en permamentmagnetassisteradsynkron reluktansmaskin (PMSynRel). SPB-omriktaren best°ar av ett antal seriekoppladetrefasomriktare av tv°aniv°atyp som, var och en, f¨orser effekt till en trefaslindningtillh¨orande en modul¨ar elmaskin av multifastyp. Specifikation, design och konstruktion aven SPB-omriktare med fyra seriekopplade moduler studeras. Designproceduren presenterasi en steg-f¨or-steg-process och de tillverkade kretskorten presenteras utf¨orligt. Kommunikationenmellan de olika kretskorten unders¨oks med s¨arskild tonvikt p°a l°ag elektromagnetiskinterferens vilket ¨ar n¨odv¨andigt om h¨og kommunikationshastighet skall kunnauppn°as. Den f¨ardigst¨allda prototypen har utv¨arderats experimentellt och kapaciteten f¨orfeltolerans har demonstrerats vid drift av en PMSynRel-maskin utrustad med en multifaslindning.
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Stringham, Bryan Jay. "Non-Dimensional Modeling of the Effects of Weld Parameters on Peak Temperature and Cooling Rate in Friction Stir Welding." BYU ScholarsArchive, 2017. https://scholarsarchive.byu.edu/etd/6710.
Full textAbstract:
Methods for predicting weld properties based on welding parameters are needed in friction stir welding (FSW). FSW is a joining process in which the resulting properties depend on the thermal cycle of the weld. Buckingham's Pi theorem and heat transfer analysis was used to identify dimensionless parameters relevant to the FSW process. Experimental data from Al 7075 and HSLA-65 on five different backing plate materials and a wide range of travel speeds and weld powers was used to create a dimensionless, empirical model relating critical weld parameters to the peak temperature rise and cooling rate of the weld. The models created have R-squared values greater than 0.99 for both dimensionless peak temperature rise and cooling rate correlations. The model can be used to identify weld parameters needed to produce a desired peak temperature rise or cooling rate. The model can also be used to explore the relative effects of welding parameters on the weld thermal response.
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Janečka, Jan. "Návrh zařízení pro měření a hodnocení tepelného stavu prostředí." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2012. http://www.nusl.cz/ntk/nusl-234012.
Full textAbstract:
The thesis deals with evaluation of the environmental thermal state in closed rooms with people inside the room. The achievement of thermal comfort is related to thermal balance of human body. People are producing heat during their work, which has to be carried away from the body to surrounding area by radiation, convection, conduction, respiration and evaporation. The intensity of heat removal is influenced by environmental parameters, especially by air temperature, mean radiant temperature, air velocity and humidity. Personal factors as energy expenditure of human body and clothing resistance are influencing the intensity of heat removal as well. People are able to influence the thermal comfort by their behaviour in given environment, appropriate clothing and regulation of basic environmental parameters. CSN EN ISO 7730 standard states that environmental parameters should be estimated or measured. The operative temperature is than evaluated from collected data. This operative temperature is defined as the temperature of black enclosed area where the human body will be by convection and radiation sharing the same amount of heat as in real inconsistent environment. Nowadays on the market there is no cheap solution for sensor which is able to evaluate the operating temperature and could be used in buildings. There are a lot of professional sensors which have very high accuracy, but are very expensive. Therefore are mainly used only for research or for single and exceptional measurement of environmental thermal state in rooms. The thesis is therefore focused on proposal of suitable (compact) operative temperature sensor assembled according to valid regulations and standards. Emphasis is placed mainly on the sensor price together with guarantee of sufficient accuracy. The proposed sensor is providing information to control system which is than able to adjust the parameters of environment using appropriate way based on relevant requirements. Here is some space for energy savings due to possible continuous measurement and evaluation of environmental thermal state in different rooms. Therefore, during continuous measurement no unnecessary rooms overheating in winter as well as unreasonable cooling in summer should occur. This research and solution is than reflected in reduction of energy consumption used for building operation and subsequently reduction of the pollutants production. This issue is being watched with increasing interest. Another advantage is that whole system is able to work autonomously without human intervention. People no longer have to continuously adjust air temperature because the control system is able to evaluate the most appropriate adjustments based on objective data obtained from the sensor. The thesis includes subsequent verification of proposed sensor as well as the definition of sensor technical parameters including analysis of measurement uncertainties.