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Dissertations / Theses on the topic 'Spot'
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Jo, Young Ki. "Management of dollar spot and gray leaf spot on turfgrass." Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1118925122.
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Ruckstuhl, Markus. "Wheat spot blotch fungus /." Zürich, 1997. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=12302.
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Cooper, J. F. "Fatigue of spot-welds." Thesis, University of Cambridge, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383069.
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García, Gil Antonio Rafael, and Mernissi Oualid El. "Spot welded ENF-Specimen." Thesis, Högskolan i Skövde, Institutionen för ingenjörsvetenskap, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-9465.
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The behaviour of spot welded joints is to be studied in shear mode by using the end notched flexure (ENF) specimen. The specimen counts on several spot welds spaced with the same gap along the entire length except for the notch. Different configurations of the test specimen spacing gap and spot diameter are to be preliminary designed in software PTC-CREO 2.0 in order to obtain accurate results. The results obtained from the software are to be compared with the experimental analysis performed by means of a servo-hydraulic testing machine. Both the virtual and the experimental results will be used to extract the stress-shear displacement relation around the first spot weld which is in contact with the notch, that is, the corresponding cohesive law. In addition, a comparison between adhesive and spot weld behaviours will be carried out by means of analytical equations in order to prove an existing equalisation between each other. Despite assuming several sources of error and after facing some problems related to the experimental work, accurate convergences between experimental and theoretical results were not accomplished in any of the three tests performed in lab. Due to the plastic deformation of the specimens in lab, the cohesive law was possible to be extracted only from the theoretical analysis, but not from the experimental one. In its place, the load-shear displacement was extracted. Some alternatives to solve this issue and to improve the performance of the tests are given at the end of this paper.
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Andersson, Filip, and Rhodel Bengtsson. "Spot-Weld Fatigue Optimization." Thesis, KTH, Hållfasthetslära (Avd.), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-232529.
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The purpose of this thesis project is to develop a methodology that can be used to minimize the number of spot-welds in a mechanical structure, this is done in a reliable manner via optimization methods. The optimization considers fatigue life in spot-welds and also stiffness and eigenfrequency values. The first chapter of this thesis presents a spot-weld fatigue model proposed by Rupp (1995), common FEmodels of spot-welds and also important aspects about structural optimization in general. The second chapter further describes how topology optimization and size (parameter) optimization are applied on a simple multi-weld model with respect to the aforementioned structural constraints. The topology optimization is later used on a full-size car model, while the size optimization is used to optimize the multiweld model by adding an non-linear structural constraint - a crash indentation constraint. The spot-weld fatigue model proposed by Rupp (1995), is also verified by comparing FE results using different FE-models of spot-welds compared to fatigue data by Long and Khanna (2007). Both optimization methods successfully minimize the total amount of spot-welds on the multi-weld model. The topology optimization,accompanied with thegradient based MFD algorithm,minimizes th etotal spot-welds with around 15% and 3% on the multi-weld model and car body respectively. The size optimization, using design of experiments and response surfaces, manage storeduce the number of welds in the multi-weldmodel by 25%. However, with the size optimization the computational time is several orders of magnitude longer-even without the formulation of the crash constraint. The fatiguespot-weld model fares reasonably well compared to the experimental fatigue data, regardless of the FE model of the spot-weld. It is concluded that the ACM model would be recommended based on its compatibility with fatigue and optimization methods, mesh-independence and also other studies have shown its ability to represent stiffness and eigenfrequency correctly.
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Håkansson, Erik. "SPOT-bombing i Falklandskriget?" Thesis, Försvarshögskolan, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:fhs:diva-9151.
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This study aims to test the strength of Shaun Clarkes air theory SPOT-bombing for small nations, to see if the theory could be of good use for all the small states around the world which are not able to master the capacity needed for large nation air theories. The British use of airpower during the Falkland war serves as case which is compared to the SPOT-bombing theory. The British task force, although much smaller than the Argentine military force, succeeded to win the war through extensive use of airpower. The studies analytic results reveal that the indicators taken from the air theory are not found to any greater extent in the British use of airpower during the war. Therefore this study is not able to strengthen or falsify Clarkes air theory as a whole, but reaches the conclusion that using unconventional methods are useful for a smaller state to get effect on strategic level against a larger opponent. Still, after this study there is more work to be done to test the relevance of the SPOT-bombing for small nations air theory, to be able to state if it is worth for small states to base their airpower doctrines upon it.
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Gey, van Pittius Barend Christiaan. "X marks the spot." Diss., University of Pretoria, 2009. http://hdl.handle.net/2263/30024.
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A new centre for Archaeology and Anthropology : a proposal to create an edificial link towards connecting historical study to future course. CopyrightDissertation (MArch(Prof))--University of Pretoria, 2010.
Architecture
unrestricted
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Shoji, Koichi. "Design of 'Spot Plough'." Kyoto University, 2004. http://hdl.handle.net/2433/148351.
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Dinga, Nasiphi. "Black spot analysis : infrastructure impacts on black spots in the Western Cape N1." Master's thesis, University of Cape Town, 2014. http://hdl.handle.net/11427/13199.
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Includes bibliographical references.This thesis discusses the infrastructural, vehicular and environmental factors that contribute towards road accidents. The role of infrastructure in improving road safety is the primary focus of the research, as infrastructure influences the driving experience. Road design and geometry are important for the consistency of highway performance. Road curvature, paved shoulders and the presence of an at grade intersection influence the drivers’ perception of the highway. The Laingsburg Beaufort West N1 highway has a high incidence of accidents, namely single vehicle accidents. For this reason, the road section has been classified as a hazardous location. These fatal accidents may be influenced by the infrastructural and geometrical factors of the highway. Western Cape geographical data was analysed for the period 2000 to 2007, to investigate the infrastructural and geometrical factors that influence the high accident rate. This was done through an ArcGis analysis, which gave insight into the properties of each of the fatal accidents. In order to get a level of confidence from the findings of the ArcGis analysis, a road safety audit was conducted. This was done through a general inspection of the N1 highway between Laingsburg and Beaufort West, which included driving through the road section at a constant speed, and completing a checklist of the operating elements of the highway. The road safety audit revealed that infrastructural problems (lack of guardrails, sign posts located close to highway) and geometrical factors (average paved shoulder width, single carriageway roads, and dangerous intersections) were present on the road. The Laingsburg Beaufort West analysis was the primary focus of the research. Data for the years 2010 to 2013, which was updated, was obtained from SANRAL and investigated for accident types and potential hotspots. An ArcGis analysis was also performed on the data. Fatal accidents were analysed, to determine whether the Provincial Government of the Western Cape would meet their accident reduction goals of reducing accidents by 50% between the years 2009 and 2014. A high incidence of fatal pedestrian accidents was observed in the Khayelitsha area. Recommendations include the relocation of poles and signs, increasing the paved shoulder width, installation of guardrails along the entire highway, as well as provision of pedestrian bridges and walkways in the Khayelitsha area.
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Conner, Kassie N. Bowen Kira L. "Studies on Cercospora leaf spot." Auburn, Ala., 2006. http://repo.lib.auburn.edu/2006%20Fall/Theses/CONNER_KASSIE_2.pdf.
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Gugan, David John. "Topographic mapping from SPOT imagery." Thesis, University College London (University of London), 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295733.
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Nichols, Alexander Robert Lee. "Is Iceland a wet spot?" Thesis, University of Bristol, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324299.
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Cruz, Christian D. "Impact Of Foliar Diseases On Soybean In Ohio: Frogeye Leaf Spot And Septoria Brown Spot." Columbus, Ohio : Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1228070831.
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Badarinarayan, Harsha. "Fundamentals of friction stir spot welding." Diss., Rolla, Mo. : Missouri University of Science and Technology, 2009. http://scholarsmine.mst.edu/thesis/pdf/Badarinarayan_2009_09007dcc807d7f97.pdf.
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Thesis (Ph. D.)--Missouri University of Science and Technology, 2009.Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed July 16, 2010) Includes bibliographical references (p. 175-181).
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Reilly, Aidan. "Modelling of friction stir spot welding." Thesis, University of Cambridge, 2013. https://www.repository.cam.ac.uk/handle/1810/244946.
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Friction stir spot welding (FSSW) is a solid-state welding process which is especially useful for joining precipitation-hardened aluminium alloys that undergo adverse property changes during fusion welding. It also has potential as an effective method for solid-state joining of dissimilar alloys. In FSSW, heat generation and plastic flow are strongly linked, and the scale of the process in time and space is such that it is difficult to separate and control the influence of all the relevant input parameters. The use of modelling is well-established in the field of welding research, and this thesis presents an analysis of the thermal and mechanical aspects of FSSW, principally using the finite element (FE) technique. Firstly, a thermal FE model is shown, which is subsequently validated by reference to experimental temperature data in both aluminium-to-aluminium and aluminium-to-steel welds. Correlations between high-quality welds and temperature fields are established, and predictions are made for peak temperatures reached under novel welding conditions. Deformation and heating are strongly linked in FSSW, but existing modelling tools are poorly suited to modelling flow processes in the conditions extant in FSSW. This thesis discusses the development and optimisation of two novel techniques to overcome the limitations of current approaches. The first of these uses greatly simplified constitutive behaviour to convert the problem into one defined purely by kinematics. In doing so, the boundary conditions reduce to a small number of assumptions about the contact conditions between weld material and tool, and the model calculation time is very rapid. This model is used to investigate changes in the slip condition at the tool to workpiece interface without an explicit statement of the friction law. Marker experiments are presented which use dissimilar composition but similar strength alloys to visualise flow patterns. The layering behaviour and surface patterns observed in the model agree well with observations from these experiments. The second approach extends the FE method to include deformation behaviour without the need for a fully-coupled approach, guided by the kinematic model. This is achieved using an innovative sequential small-strain analysis method in which thermal and deformation analyses alternate, with each running at a very different timescale. This technique avoids the requirement to either remesh the model domain at high strains or to use an explicit integration scheme, both of which impose penalties in calculation time and model complexity. The method is used to relate the purely thermal analysis developed in the work on thermal modelling to welding parameters such as tool speed. The model enables predictions of the spatial and temporal evolution of heat generation to be made directly from the constitutive behaviour of the alloy and the assumed velocity profile at the tool-workpiece interface. Predictions of the resulting temperature history are matched to experimental data and novel conditions are simulated, and these predictions correlate accurately with experimental results. Hence, the model is used to predict welding outcomes for situations for which no experimental data exists, and process charts are produced to describe optimum welding parameters. The methods and results presented in this thesis have significant implications for modelling friction stir spot welding, from optimising process conditions, to integration with microstructural models (to predict softening in the heat-affected zone, or the formation of intermetallics at the interface in dissimilar welds). The technique developed for sequential small strain finite element analysis could also be investigated for use in other kinematically constrained solid-state friction joining processes.
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Andersson, Oscar. "Process planning of resistance spot welding." Licentiate thesis, KTH, Industriell produktion, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-117807.
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Manufacturing engineering in general has experienced an increased demand of process planning in order to optimize processes to reduce costs, environmental impact and increase time efficiency. Resistance spot welding (RSW) is a common and large-scale joining method in several manufacturing industries indicating significant potentials of efficient process planning. The goal of this thesis is to establish new knowledge for updated and improved process planning of RSW in industrial applications. The goal is expressed by two research questions targeting the issues of process variations and potential of numerical methods of the RSW process. The research questions are expressed in terms of weld size, which is the main interest in RSW process planning. As any large-scale manufacturing process, RSW involves variations in results – the weld size is known to vary, both as a result of intentional dependent parameters such as process parameters and as a result of unintentional variations in welding conditions. A series of physical and numerical analysis have been performed in order to gain knowledge of such variations. The unintentional variations, which result in varying weld sizes in apparently identical conditions, were analyzed through both controlled laboratory welding and welding in industrial production environments. The results of the analysis showed the magnitude of standard deviations in both environments and the distribution of weld sizes. The analysis showed that common standard deviations in controlled laboratories and industrial production are approximately 0.3 mm and 0.9 mm, respectively and that weld sizes are distributed showed promising fit to both Normal and Weibull distributions. The intentional variations of weld sizes due to process parameters, which is the most important aspect of RSW process planning, have traditionally been analyzed through physical testing. In the present thesis two numerical methods were evaluated; regression analysis and FE simulations. For the regression analysis several models were generated and showed a standard deviation of residuals between model and physical results of 0.5 mm. For the FE simulations, material models for the RSW were generated and the simulations showed a standard deviation compared to physical testing of 0.68 mm. In conclusion, the present thesis presents results, which help quantify variations in weld sizes and present the capability of numerical methods of the RSW process.QC 20130205
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Cotton, Brent A. "Strategic improvements to TSA SPOT program." Thesis, Monterey, California: Naval Postgraduate School, 2015. http://hdl.handle.net/10945/45173.
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Approved for public release; distribution is unlimitedThis study of Transportation Security Administration’s Screening Passengers by Observation Techniques (SPOT) program analyzes the Government Accountability Office (GAO) and Office of Inspector General (OIG) recommendations for improvement, as well as strengths and weaknesses of the program not specifically addressed in previous assessments. Any analysis of SPOT must be robust, as it represents one of the few threat agnostic countermeasures not limited by technology and finite detection capabilities. The GAO has recommended Congress withhold funding from SPOT until further evidence of effectiveness can be produced. The first portion of this study revisits the analysis of GAO and OIG in their respective reports. The GAO audits rely on meta-analyses that suggest human lie detection is no more successful than flipping a coin. This study assesses those claims, and reveals some contextual and analytical limitations of the claims. The OIG report offers similar claims, but adds additional insight into critical strategic areas. The second portion of this study focuses on the strengths and weaknesses of the SPOT program, including an analysis of several GAO and OIG conclusions. Many of the recommendations were operational in nature, and provided little strategic direction to improve the relevance, effectiveness, and credibility of the program. Analyzing strengths and weaknesses provides insight into more strategic recommendations that may improve the security value of SPOT.
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Veillet, Isabelle. "Triangulation spatiale de bloc d'images SPOT." Observatoire de Paris, 1991. https://hal.archives-ouvertes.fr/tel-02095460.
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Outre la qualité de ses images, l'atout majeur du système SPOT est sa précision géométrique. Cette étude a pour objet d'évaluer l'apport d'une triangulation de bloc au traitement géométrique d'images SPOT, afin de traiter globalement la géométrie de l'ensemble des images d'un chantier de spatiocartographie. Tant l'intérêt réel du calcul de blocs que sa faisabilité sont ici démontrés. Au préalable, il est indispensable d'analyser la modélisation de la prise de vues SPOT. Une modélisation simple, robuste et proche de la réalité physique de la prise de vues SPOT est proposée. Avec un nombre restreint de points d'appui, l'exactitude obtenue reste inférieure à 10 mètres en planimétrie et 6 mètres en altimétrie, ce qui est conforme à la plupart des standards de cartographie à l'échelle du 1:50000. Sans point d'appui, une précision de 15 mètres a été obtenue sur des blocs couvrant 200 km x 200 kmBesides its image quality, the main advantage of Sport system is its geometric accuracy. The aim of this study is the evaluation of what block adjustment can bring to Spot images geometric processing, in order to process together all the images of a space mapping project. The actual advantage of this kind of computation is shown here. Before, a model of the image-ground relationship must be given. The proposed model is simple, robust and close to the physical image acquisition. With very few control points, the resulting accuracy is less than 10 meters in planimetry, and 6 meters in altimetry. These figures fit most standards of 1:50000 scale topographic maps. Without any ground control point, the accuracy is 15 meters on 200 km x 200 km area
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Provost, Jean-Noël. "Classification bathymétrique en imagerie multispectrale SPOT." Brest, 2001. http://www.theses.fr/2001BRES2009.
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Turner, Anthony James. "Spot impact welding of aluminum sheet." Columbus, Ohio : Ohio State University, 2002. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1144697888.
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Thesis (M.S.)--Ohio State University, 2002.Advisor: Glenn S. Daehn, Dept. of Materials Science and Engineering. Includes bibliographical references (leaves 112-118). Available online via OhioLINK's ETD Center
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Farnsworth, Jacob S. "Hot Spot Identification and Analysis Methodology." BYU ScholarsArchive, 2013. https://scholarsarchive.byu.edu/etd/3878.
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The Utah Department of Transportation (UDOT) Traffic and Safety Division continues to advance the safety of roadway sections throughout the state. To aid UDOT in meeting their goal the Department of Civil and Environmental Engineering at Brigham Young University (BYU) has worked with the Statistics Department in developing analysis tools for safety. The most recent of these tools has been the development of a hierarchical Bayesian Poisson Mixture Model (PMM) statistical model of traffic crashes and safety on UDOT roadways statewide and the integration of the results of this model in a Geographic Information System (GIS) framework. This research focuses on the enhancement of the framework for highway safety mitigation in Utah with its six primary steps: 1) network screening, 2) diagnosis, 3) countermeasure selection, 4) economic appraisal, 5) project prioritization, and 6) effectiveness evaluation. The framework was enhanced by developing a methodology for accomplishing the steps of network screening, diagnosis, and countermeasure selection. This methodology is titled, "Hot Spot Identification and Analysis." The hot spot identification and analysis methodology consists of the following seven steps: 1) identify problematic segments with safety concern, 2) identify problem spots within the segments, 3) micro analysis of problematic segments and spots, 4) defining the segment, 5) defining the problem, 6) evaluation of possible countermeasures, and 7) selection and recommendation of feasible countermeasures. The methodology is to help in the identification of hot spots with safety concerns so that they can be analyzed and countermeasures can be identified to mitigate the safety issues. Examples of how the methodology is to function are given with specific examples from Utah's state roadway network.
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Lowry, Nicholas. "Biology and fisheries for the spot prawn (Pandalus platyceros, Brandt 1851) /." Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/5388.
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Govik, Alexander. "Modelling of the Resistance Spot Welding Process." Thesis, Linköping University, Linköping University, Department of Management and Engineering, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-17835.
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A literature survey on modelling of the resistance spot welding process has been carried out and some of the more interesting models on this subject have been reviewed in this work. The underlying physics has been studied and a brief explanation of Heat transfer, electrokinetics and metallurgy in a resistance spot welding context have been presented.\nl\hsLastly a state of the art model and a simplified model, with implementation in the FEM software LS-DYNA in mind, have been presented.
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Karlsson, Carin, and Bodil Renfors. "Side Blind Spot Detection : Sensortekniker och hårdvara." Thesis, Linköping University, Department of Science and Technology, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2889.
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Denna rapport är resultatet av ett examensarbete, på 20 högskolepoäng, som har utförts på Scania CV AB, Tekniskt centrum, Södertälje. Examensarbetet behandlar Side Blind Spot Detection och har resulterat i ett prototypsystem som detekterar objekt i döda vinklarna på sidorna av en lastbil. Systemet är ett aktivt säkerhetssystem som syftar till att förhindra olyckor och ge ökad trafiksäkerhet på vägarna.
Examensarbetet har varit tvådelat för att uppnå detta mål. Denna rapport behandlar främst val av sensorteknik för att upptäcka objekt i de döda vinklarna på sidan av en lastbil. Den behandlar också hårdvara till användargränssnittet samt installation av användargränssnittet och sensorerna i en lastbil. Den andra delen av examensarbetet har bestått av utformning av användargränssnittet och programmering av systemet. Detta kan läsas i rapporten "Side Blind Spot Detection - System och användargränssnitt" författad av Jenny Hedenberg och Hanna Torell, Chalmers Tekniska högskola, 2005.
I rapporten har sex olika sensortekniker studerats och utvärderats. De sex sensorteknikerna är ultraljud, passiv IR, lidar (aktiv IR), kamera, IR kamera och radar. Resultatet av utvärderingen visade att radar är den mest lämpade sensortekniken för den här typen av applikationer och det är därför radar används som sensor i prototypsystemet.
Systemet har tre olika lägen beroende på hur mycket information föraren önskar få när ett objekt befinner sig i döda vinkeln vilket styrs av en systemknapp. Föraren får informationen från användargränssnittet som består av två LED- displayer som är placerade i dörrkarmarna på vardera sida. Förutom att visa varningarna visuellt i LED-displayen används också ljud vid varning. Resultatet blev som förväntat och visar de funktioner som användargränssnittet har på ett bra sätt. Vad gäller resultatet av hela prototypsystemet så visar det att radar är ett bra val för denna applikation för att den klarar av de krav som ställs. Tester av systemet visar dock att den införskaffade radarn har begränsningar som försvårar filtreringen. Detta leder till att systemet inte är helt tillförlitligt eftersom systemet ibland missar objekt och ibland felvarnar för objekt som inte finns eller för objekt som inte är relevanta.
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Kocak, Okan Okay. "Defect Assessment Of Spot Welds By Ndi." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/4/1027382/index.pdf.
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Resistance spot welding is used frequently as a successful joining method for
a variety of work commonly in automotive and other manufacturing
processes. Spot weld nugget is generally hidden between two sheets,
causing its inspection difficult and expensive. Undersized nuggets, brittle or
cracked nuggets, and excessive indentation of electrodes reveals the lack of
fusion between the parts that can make the weld sub-standard.
Visual inspection, pry testing and physical teardown with chisel and hammer
method or a combination of them are being used traditionally. However, this
study presents a more effective nondestructive inspection method based
upon an ultrasonic pulse-echo technique. The theory of the technique together with the experimental verification are presented and its advantages over the other destructive and nondestructive
techniques are considered.
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Kobayashi, Minoru, Yuichi Sasayama, Ajai K. Srivastav, and Nobuo Suzuki. "Grayish spot on goldfish chest : An explanation." Laboratory of Freshwater Fish Stocks Bioscience Center Nagoya University, 1997. http://hdl.handle.net/2237/13819.
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Tifenbach, Bradley Dale. "Numerical methods for modeling energy spot prices." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/mq64984.pdf.
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Saleem, Jawad. "Power electronics for resistance spot welding equipment." Licentiate thesis, Mittuniversitetet, Institutionen för informationsteknologi och medier, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-16699.
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Resistance spot welding is an inexpensive and efficient way ofjoining metals. It has extensive applications in household appliancesand in automotive industries. The traditional approach in relation tospot welding machines is to use 50 Hz welding transformers. Thedrawback associated with these transformers is that they are both heavyand bulky. Moreover, the fusing requirements become larger due toincreased welding power.With the development of high power semiconductor switches andDC-DC converter topologies, it is now possible to develop inverterdrive resistance spot welding equipment (RSE) which can be operatedat frequencies higher than the 50Hz frequency. The advantage of usinghigh frequencies is the reduction in the size of the transformer.Moreover, the fusing requirements are relaxed, as the power is sharedbetween three phases.In many industrial applications long welding arms are requiredbetween the transformer and the weld spot, which increases theinductance. The parasitic inductance in welding arms limits themaximum rate of change of the current. In order achieve a higher powerthe current has to be rectified. To rectify a current of the order of tenthof kA is challenging task and is one of the major sources of loss.The full bridge converter topology is used for the inverter drive RSE.The power switches used in the converter are IGBT. In RSE, the DClink capacitors are used to store high energy. In the case of circuitfailure, the stored energy can cause the IGBT device to rupture and inorder to avoid this, a protection scheme is discussed in this work.A controller circuit, using a DSPIC33FJ16GS502 controller, isdeveloped in order to drive a high frequency full bridge converter,which can also be used to drive the IGBTs in the RSE.The secondary side welding current is of the order of kilo amperes.A requirement for the welding control is that the current must be sensedprecisely and in order to fulfill this, a Hall sensor system has beendeveloped. This developed circuit is used in the feed-back control of theRSE. The presence of metallic objects and tools in the vicinity of theHall sensor system can affect its precision. We have estimated theivexclusion distance for the metal objects from the sensor by means of amodel developed in COMSOL Multiphysics software.
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Serackis, Artūras. "Image reconstruction technologies for protein spot parametrisation." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2009. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2008~D_20090122_094213-80420.
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The problems of protein parametrisation in two-dimensional electrophoresis (2DE) gel image is analysed in this work. Analysis of the proteins gives possibility to observe the health state of living organisms. In proteomics two-dimensional electrophoresis is used for protein separation in the gel according to their isoelectric point and molecular mass. The resulting gel is scanned and analysed by automatic gel image analysis systems. Those systems are not able to deal with specific protein spot distortions found in the gel image. The over-saturated protein spots prevent proper segmentation of the 2DE gel images. The aim of the work is to investigate the possibility of image reconstruction applications for object parametrisation by creating new methods for protein spot parametrisation in 2DE gel images.
Three main tasks are resolved in this work: new mathematical models for parametrisation of saturated protein spots in 2DE gel images are proposed; new method for over-saturated protein spot search and reconstruction in 2DE gel images is proposed; new method for parametrisation of overlapped protein spots in 2DE gel images is proposed.
The thesis is divided into introduction, four chapters and generalisation. The review of image reconstruction techniques and current 2DE gel image analysis problems are presented in first chapter. In the second chapter – the new mathematical models for parametrisation of saturates protein spots are proposed and experimental investigation results... [to full text]Disertacijoje nagrinėjamos baltymų pėdsakų parametrizavimo dvimatės elektroforezės (2ME) gelių vaizduose problemos. Proteomikoje, analizuojant baltymus, tiriami gyvame organizme vykstantys pokyčiai. 2ME metu baltymai išskiriami pagal jų molekulines savybes. Deja 2ME gelių vaizdų automatinei analizei skirtose programose pritaikytos technologijos netinka iškraipytiems baltymų pėdsakams (dėl baltymų įsisotinimo, persisotinimo ar susiliejimo) aptikti ir parametrizuoti. Pagrindinis disertacijos tikslas – ištirti galimybę taikyti vaizdo rekonstravimo technologijas trimačiams objektams parametrizuoti, sukuriant ir ištiriant baltymų pėdsakų 2ME gelių vaizduose parametrizavimo metodus. Disertacijoje sprendžiami trys pagrindiniai uždaviniai: naujų baltymų pėdsakų matematinių modelių, tinkamų įsisotinusiems baltymų pėdsakams parametrizuoti, kūrimas; baltymų persisotinimų paieškos ir rekonstravimo metodo kūrimas ir susiliejusių baltymų pėdsakų parametrizavimo metodo kūrimas. Disertaciją sudaro įvadas, keturi skyriai ir rezultatų apibendrinimas. Įvadiniame skyriuje nagrinėjamas problemos aktualumas, iškeliamos hipotezės, formuluojamas darbo tikslas bei uždaviniai, mokslinis darbo naujumas, darbo praktinė reikšmė ir disertacijos struktūra. Pirmajame skyriuje apžvelgtos parametrizavimui taikomos vaizdo rekonstravimo technologijos. Skyriuje apžvelgtos vaizdo rekonstravimo technologijos, taikomos objektui parametrizuoti, kai naudojami keli, skirtingu kampu, gauti objekto vaizdai, taikomos... [toliau žr. visą tekstą]
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Chalamandaris, George. "Liquidity risk in spot foreign exchange markets." Thesis, Imperial College London, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325567.
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Roberts, D. R. "Ultrasonic spot weld testing with automatic classification." Thesis, Swansea University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.638690.
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Spot welds are used to join sheet steel in automobile bodies. To ensure vehicle integrity, these welds, must be tested. Ideally, non-destructive testing would be employed. However, spot weld quality in the automotive industry is currently assessed using destructive methods. Spot welds can be tested non-destructively with ultrasound. Operators place a single crystal ultrasonic probe on a weld and interpret the returning signal to estimate the quality of the weld. However, this ultrasonic method has not been widely accepted in the past, possibly due to difficulties in manually quantifying the information contained in the signals. In an attempt to make ultrasonic testing viable for automotive use, a system has been created which automatically interprets the ultrasonic signals and classifies welds as good or bad. There are two main aspects to the systems. Firstly, echoes occurring within the signal are identified by an algorithm. This was developed after discovering the sequence in which the critical intermediate echoes occur. The second aspect of the system is classification of the spot weld based upon certain features of the identified echoes. The strength of the intermediate echoes was found to be primary source of information on weld size. Extensive experimental studies were designed and conducted to identify other potential information sources. Notably, the attenuation rate of the back-wall echoes in the signal was investigated. Most published papers in the field report that signal attenuation may be used to estimate weld size. It has been generally believed that the grain structure of the welded steel significantly increases ultrasound scattering, leading to higher attenuation is not caused by weld grain structure. The evidence gathered strongly favours weld surface irregularities as the primary cause of ultrasound attenuation in spot welds.
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MEDEIROS, LUCIO DE. "SPOT PRICE FORECASTING IN THE ELECTRICITY MARKET." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2003. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=4777@1.
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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOO objetivo da tese é propor uma metodologia para previsão do preço de curto prazo (spot) da energia elétrica no Brasil baseada em sistemas neuro-fuzzy e nos programas do planejamento da operação do sistema elétrico brasileiro. Com essa abordagem, obtém-se distribuições estimadas do preço spot para o curto prazo com menor dispersão do que as obtidas somente com os programas do planejamento da operação. Além disso, por ser rápido, o sistema de previsão final possibilita análises de cenários ou simulações Monte Carlo. As principais variáveis que afetam o preço spot no Brasil são consideradas, tais como a energia natural afluente e a energia armazenada, entre outras. Ainda, é possível incluir também variáveis que não têm um histórico definido ou dados suficientes para o treinamento, tais como o plano de obras, limites de intercâmbio, demanda etc. Comparações com modelos de redes neurais são feitas. Apresenta-se, também, o estado da arte em modelagem para a política e o mercado de energia elétrica e os principais conceitos de gerenciamento de risco no mercado de eletricidade.
This thesis focuses on spot price forecasting and risk management in the Brazilian electricity industry. It is proposed a new methodology for the problem based on neuro- fuzzy systems and the dispatching and planning operation programs. The main advantage of the approach is to be able to get more informative spot price distributions than using the operation and planning programs alone. Furthermore, it allows Monte Carlo simulations or scenarios analysis as the forecasting system runs in less than 1 minute. The main variables which affect the spot price (inflow river, storage capacity of reservoir, among others) are included in the model. Even variables such as the interchange limits, without a well-defined time series and which could be important, could also be included because of the intrinsic characteristics of each fuzzy model. Comparisons with neural networks models are made. It is also presented the state-of-the-art in the market and politics modelling for the electricity market around the world, as well as some main concepts of the risk management.
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Daryanian, Bahman. "Scheduling of electricity consumption under spot prices." Thesis, Massachusetts Institute of Technology, 1989. http://hdl.handle.net/1721.1/14431.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1989.Title as it appears in M.I.T. Graduate List, Feb. 1989: Optimal scheduling of electricity usage under spot prices.
Includes bibliographical references.
by Bahman Daryanian.
Ph.D.
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Leopando, Paul Jeffrey Ramirez, and Kyle A. C. Rocca. "Carrier strategies in the spot trucking market." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/92645.
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Thesis: M. Eng. in Logistics, Massachusetts Institute of Technology, Engineering Systems Division, 2014.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 76-78).
How an owner-operator chooses a specific load is a relatively unstudied field in transportation literature. Stakeholders in the decisions, such as freight brokers, stand to benefit from a better understanding of the selection process. Using load board data from a freight brokerage, we identified four parameters available to a carrier when a load is presented: length of haul, revenue per mile (RPM), the probability of finding an onward load from the destination, and the required mileage to reposition to the shipment origin. We also identified preferences of the owner-operators based on experience, literature, and the data, such as owner-operators' preference for long haul routes. We tested selection strategies that disintegrated the four load parameters and incorporated owner-operator preferences in a computerized simulation. We found that strategies combining two or more of the identified parameters provide better results in terms of revenue and utilization (% loaded) maximization. Furthermore, we found that including consideration of the empty repositioning distance was critical to success. Our simulated carriers outperformed peers in the dataset by up to 16%. Carriers can apply these insights to improve their operating strategies. Freight brokerages can apply the quantitative approach to advise their carrier clients and optimize the matching of freight with available carrier capacity.
by Paul Jeffrey R. Leopando and Kyle A.C. Rocca.
M. Eng. in Logistics
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Kim, Ŭi-hwan. "Analyses of resistance spot welding lobe curve." Thesis, Massachusetts Institute of Technology, 1989. http://hdl.handle.net/1721.1/100653.
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Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1989.Title as it appears in the M.I.T. Graduate List, June 1989: Analysis of resistance spot welding lobe curve.
Includes bibliographical references (leaves 298-301).
by Euiwhan Kim.
Sc.D.
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Thomas, Meredith Murphy. "Evolution of the 'Beetle Daisy' petal spot." Thesis, University of Cambridge, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.611587.
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Lövenborn, David. "3D FE Simulations of Resistance Spot Welding." Thesis, KTH, Hållfasthetslära (Inst.), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-184219.
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Resistance spot welding (RSW) is thedominant joining technology in theautomotive industry. This is due to its lowcosts and high efficiency. Other advantageswith RSW is the high ability for automation,low consumption of energy, lack of need foradded materials and low degree of pollution,no expensive equipment or education ofpersonal compared to arc welding and laserwelding. A modern automobile containsapproximately 4000 resistance spot welds,which is why it is of great interest to be ableto predict the properties of the resistance spotwelds. The most important measurementused to ensure the quality of the weld is thenugget size, as it correlates to the weldsmechanical strength. This is usuallymeasured by destructive testing, and the mostcommon method is the coach peel test. Thistest is performed by manually peeling thespecimen and then measuring the largest andsmallest nugget diameter. It is also possibleto perform non-destructive testing onresistance spot welds with both ultrasonicandx-ray tests, however none of thesemethods have the same accuracy as thedestructive methods and they arecumbersome to use in large-scale. Toimprove the efficiency and lower the cost forthe optimization of the welding parameters,simulation tools have been developed. Thereare both 2D- and 3D-simulation software tomodel the RSW process. When the spotwelds are simulated with 2D or 2D axissymmetry,the number of elements is lowercompared to a full 3D model, which reducesthe computation times. The disadvantageswith the 2D model are the inabilities tomodel misalignments or other asymmetricalgeometries. In contrast, the 3D-simulationsare not limited by these factors, and they arealso capable of modeling the shunt effectsoccurring when a weld is placed close to aprevious weld.The aims of this thesis was to evaluate such a3D-simulation software, Sorpas 3D, and itspotential to be used in industrial processplanning, and to assess the software’susefulness for both simple and more complexcases.The results from this work show a goodcorrespondence between the simulations andthe physical tests. However, in order toachieve these results a number ofmodifications in the material properties wererequired. Another critical limitation in thesoftware is that no expulsion criterion isimplemented. Considering the possibility thatthe problems can be solved with a number ofupdates in the software, Sorpas 3D can be auseful tool in the process planning industry inorder to decrease process times and materialcosts and improve the weld quality in thefuture.Punktsvetsning är den mest frekventanvända svetsmetoden inomfordonsindustrin. Detta beror främst på attdet är en relativt billig och tidseffektivmetod. Andra fördelar är att den är lätt attautomatisera, har låg energikonsumtion, attden inte kräver något tillsatsmaterial samtatt den är miljövänlig, inte kräver dyrutrustning eller utbildning av personaljämfört med bågsvetsning ochlasersvetsning. En modern bil innehållerungefär 4000 punktsvetsar, vilket gör attdet är av stort intresse för fordonsindustrinatt kunna förutse egenskaperna hos varjesvets. Det viktigaste måttet på enpunktsvets kvalitet är dess pluggstorlek,vilket korrolerar med svetsens mekaniskastyrka. Denna mäts vanligen genomförstörande provning, främst genom ett såkallat fläkprov. Detta görs genom att enprovbit innehållandes en svets manuelltfläks isär, varpå den största och den minstapluggdiametern mäts och ett medelvärdeberäknas. Det förekommer ävenoförstörande provning på punktsvetsar,både genom ultraljudstest och genomröntgentest. Dock har det visat sig att ingenav dessa metoder har samma precision somden förstörande provningen, samt att de ärbesvärliga att använda för storskaligtestning. För att öka effektiviteten ochminska kostnaderna för optimeringen avprocessparametrarna har både 2D- och 3Dprogrammvarorutvecklats. Vid 2Dsimuleringarav punktsvetsprocessenminskar antalet element i modellen, vilketleder till kortare beräkningstider jämförtmed 3D-simuleringar. Nackdelar med attsimulera i 2D är att det inte finns någonmöjlighet att undersöka fenomen somsnedställningar och and icke-symetriskageometrier. Detta är däremot möjligt attåstadkomma med 3D modeller. Att utförasimuleringarna i 3D ger också möjlighetenatt undersöka shunteffekter somuppkommer då en svets placeras nära enredan befintlig svets.Målet med detta arbete var att utvärdera enprogramvara för simuleringar avpunktsvetsning i 3D, Sorpas 3D, samt attundersöka potentialen hos dennaprogramvara som ett verktyg inomprocessindustrin för både simpla och merkomplexa plåtkombinationer.Resultaten från detta arbete visar på en godöverensstämmelse mellan de simuleradeoch de fysiska testen. Dock krävdes det ettantal modifieringar avmaterialegenskaperna för att erhålla dessa.En ytterligare begräsning medprogramvaran är att den inte innehållernågot sprutkriterium. Om dessa bristerskulle åtgärdas med hjälp av ett antaluppdateringar i programvaran skulleSorpas3D kunna fylla en funktion somhjälpmedel inom processindustrin för attminska ledtider och materialkostandersamt att förbättra svetskvalliten iframtiden.
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Abu-Rabie, Paul. "Direct analysis of dried blood spot samples." Thesis, University of Greenwich, 2015. http://gala.gre.ac.uk/18203/.
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The aim of the research reported herein was to identify and develop a dried blood spot (DBS) direct analysis technique that could support high sample throughput quantitative bioanalysis in a regulated drug development environment. An initial literature review, coupled with proof of concept testing of the most prominent direct analysis techniques coupled to mass spectrometers (MS), resulted in direct elution (direct extraction of DBS via a confined solvent, producing a liquid extract) being selected as the most suitable technique to develop for this application. Direct elution technology was then developed into fully automated techniques with sufficient functionality to enable compatibility with high sample throughput quantitative bioanalysis. Proof of concept robustness data demonstrated that direct elution, despite the lack of sample clean up, was a reliable technique which had no detrimental effects on detector or chromatographic performance compared to conventional wet plasma extraction and analysis. A proof of concept investigation also demonstrated that a method of improving internal standard (IS) performance by spraying IS solution onto DBS samples prior to extraction, allowed the analyte of interest and IS to be co-extracted, while retaining adequate analytical performance. The foregoing proof of concept data was then combined to produce a fully automated DBS direct elution instrument designed to introduce sample extracts into a LC-MS/MS system. This instrument incorporated a 500 DBS card capacity, an intelligent visual recognition system, a dynamic IS applicator module, and a highly effective wash system that virtually eliminates carryover. Ultimately, this work led to the production of a fully automated DBS direct elution system that is now commercially available. Subsequent research focused on optimising the system, and using this technology to address some of the issues that are currently inhibiting the development of DBS usage in drug development applications, namely haematocrit (HCT) based assay bias, and the decreased sensitivity on offer from DBS sampling. It was demonstrated that using the IS sprayer enabled the IS to integrate sufficiently with the DBS sample prior to extraction to nullify HCT based recovery bias. The direct elution mechanism was also optimised with a view to maximising assay sensitivity while retaining acceptable analytical and chromatographic (LC-MS/MS) performance. Generic optimised direct elution conditions were developed which demonstrated that increases in assay sensitivity of up to 30 fold (compared to conventional manual extraction methods) were possible using a set of representative small molecule compounds.
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Cruz, Caroline. "Conectados podemos más. Spot televisivo de Movistar." La Mirada de Telemo, 2013. http://repositorio.pucp.edu.pe/index//handle/123456789/20413.
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En base a la difusión de un spot televisivo de la empresa Movistar, la autora reflexiona en torno a los procesos de representación de las identidades en un escenario multicultural como el nuestro Lo inicialmente emotivo, termina disfrazando una visión que dista mucho de ser integradora y articuladora de las verdaderas y palpables diferencias que podemos experimentar en nuestro país
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Octavio, de Alba Alvarez Ricardo. "Vibration analysis of uncertain spot-welded structures." Thesis, University of Southampton, 2012. https://eprints.soton.ac.uk/348956/.
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Spot-welded structures contain inherent variability in location and/or stiffness due to the complexity of the manufacturing process. Therefore, an analysis that includes the uncertainty generated in the joints will provide a range of response predictions, adding more value to the design process compared to deterministic results. Finite element (FE) analysis is frequently used in conjunction with Monte Carlo simulations (MCS) to predict the variability in the vibration response of assembled structures, however this is usually computationally expensive. Small numerical spot weld models must be used since real spot welded structures usually possess many spot welds and modelling each of them in detail would lead to additional computational effort, current models provide results sensitive to the element size. In this thesis, a method to quantify the variability in the dynamic characteristics of structures due to uncertainty in the location and diameter of the spot welds is proposed and experimentally validated. Component mode synthesis (CMS) is used in combination with multipont constraint (MPC) connection models in order to improve the computational efficiency of the uncertainty analysis. However, if the number of degrees of freedom (DOFs) involved in the connection is large, then the CMS size reduction is less effective. Two techniques are proposed to overcome this problem: (i) characteristic constraint modes and (ii) application of a low rank update theory to the CMS matrices. A spot weld model based on MPCs is proposed and validated as part of the original contributions of this work. This model improves convergence and minimizes the sensitivity to the element size. The application of the new method is experimentally validated in a double hat structure. Results show that the method presented is accurate when predicting the structure’s natural frequencies and it can identify which modes are sensitive to the uncertainties in the spot welds and which modes are not.
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ALPHONSE, MYRIAM. "Interet des spot-tests en dermatologie courante." Aix-Marseille 2, 1988. http://www.theses.fr/1988AIX20332.
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Fredriksson, Daniel, and Göransson Milou Carlfors. "Evaluation of Shunt Distancein Resistance Spot Welding." Thesis, KTH, Materialvetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-277903.
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The purpose of this study was to generate a greater understanding of how the shunt distance affects the shunting phenomena which occurs when working with resistance spot welding (RSW). Shunting affects the quality of the weld and the goal of the study was to create guidelines for RSW to minimize its impact on the weld quality. In order to minimize waste from production and to reduce the welding time there is need for understanding of what the shunt effect depends on. To evaluate what impact the shunt distance will have on the weld, two different experiments were performed. In the first experiment, a one-dimensional welding lobe was manufactured for various materials and the current range was compared over three different shunt distances. The second experiment consisted of welding with a constant current on different shunt distances to investigate how this would impact the second weld performed in the welding sequence. A range of different steel grades and sheet thicknesses was used in the experiments to further explore what impact different material properties will have on the shunt effect. The result showed that the shunt distance has little impact on the acceptable weld-current range, with minor deviations. However, the shunt distance will affect the size of the shunted weld, which decreases as the shunt distance is reduced. Overall, the data collected in this study is not expansive enough to make guidelines that could be implemented in today´s industry. The phenomena of shunting require more data to fully be understood.Syftet med denna studie var att skapa en större förståelse för hur shuntavståndet påverkar det shunt-fenomen som uppstår när man arbetar med punktsvetsning (RSW). Shuntning påverkar svetsens kvalitet och målet var att skapa riktlinjer för arbete med RSW för att minimera shunt-effektens påverkan på svetsen. I syfte att kunna minimera spill i produktionen samt att minska svetstiden krävs det förståelse av vad shunt effekten beror på. För att utvärdera vilken påverkan shuntavståndet kommer att ha på svetsen utfördes två olika experiment. I det första experimentet skapades en endimensionell svetslob för varje material och det genererade strömintervallet jämfördes över tre olika shuntavstånd. Det andra experimentet bestod av svetsning med en lika stor ström vid olika shuntavstånd för att undersöka hur detta skulle påverka den andra svetsen. En rad olika stålsorter och plåttjocklekar användes för att ytterligare se vilken påverkan dessa faktorer kom att ha på shunteffekten. Resultatet visade att shuntavståndet hade liten inverkan på det acceptabla svetsströmintervallet, med mindre avvikelser. Emellertid påverkar shuntavståndet storleken på den shuntade svetsen genom att storleken minskar när shuntavståndet minskas. Sammantaget räcker inte de uppgifter som samlats in i denna studie för att skapa riktlinjer som skulle kunna implementeras i dagens industri, utan det krävs mer data för att fullständigt kartlägga shunteffekten.
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Petersen, Nicole Jade. "Estimating farm dam storage using SPOT imagery." Master's thesis, University of Cape Town, 2011. http://hdl.handle.net/11427/11341.
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Includes abstract.Includes bibliographical references.
The objective of this study is to establish a methodology in which remote sensing can be used to support the monitoring of water resources. SPOT XS imagery and object-oriented classification was used to identify farm dams and their surface area. Two equations applied to determining the capacity of dams were used to convert surface area to volume. The results showed a similarity between fieldwork and object-oriented classification data for surface area. Overall, there appears to be a strong positive correlation between object-oriented classification and unsupervised classification. The correlation between object-oriented classification and supervised classification ranged from strong positive association to little or no association. This study concludes that remote sensing is a useful tool in identifying water bodies and generating an estimate of volume stored.
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Raath, Neill D. "Failure prediction of spot welded boron steel." Thesis, University of Warwick, 2014. http://wrap.warwick.ac.uk/73276/.
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A methodology of material characterisation and finite element model discretisation is presented for spot welded boron steel sheets, with the aim of predicting failure during quasi-static loading. The predicted load-displacement curves from the Finite Element model are compared with experimentally measured curves for lap-shear and cross-tension weld destructive geometries, and serve as model validation. During spot welding, the weld and surrounding material are exposed to a wide range of temperatures, from the melting point at the weld centre to room temperature in the base material. As a consequence, the weld exhibits varying microstructures with corresponding varying material properties which have a profound influence on its load bearing capacity and failure strength as a whole. In addition, boron steel spot welds exhibit unique hardness profiles, with high hardness values in the nugget and outlying base material, and a sudden drop in the area between these regions. This sudden decrease in material properties leads to further difficulties in modelling the failure of boron steel welds. The weld process inherently produces localised residual strains which also need to be accounted for in the model simulation, together with significant plastic strain redistributions resulting from the mechanical loading of the spot weld to its ultimate failure. The initial residual strains were measured in weld samples using neutron diffraction and were subsequently input into the FEA models. This thesis aims to quantify the varying material constitutive behaviour throughout the weld, required for the failure prediction. In particular, the following constitutive properties were extracted: the stress-strain response of certain weld regions, failure loci consisting of fracture strain versus stress state for the corresponding regions, and the residual stress distribution through the weld. Due to the small size of the weld, cutting test specimens directly from the weld is unachievable. To overcome this problem, specific weld and heat affected zone micro-structures were recreated onto practical tensile specimens through use of a Gleeble thermo-mechanical physical simulator. These specimens were subjected to the same thermal histories as specific points in the actual weld. From these tensile specimens, stress-strain curves relating to specific weld regions could be obtained. In a similar fashion, three additional destructive specimen sets were created to obtain failure loci. These failure loci give fracture strain as a function of stress state: specifically shear, uniaxial and plane-strain states. Due to the practical limitations in the accuracy of the Gleeble technique, deviations from the target microstructures were expected in the Gleeble samples. To gauge the extent of these deviations, a method of extracting reference material properties directly from the weld was required. Instrumented indentation offers such a solution, where the load and displacement of the indenter are measured and run through an algorithm to calculate the yield strength of the indented locations. These yield strengths are then compared with the yield from the Gleeble stress-strain curves to gauge the accuracy with which the weld microstructures were recreated. This technique serves to quantify the deviation of the Gleeble microstructures from the target material microstructures. It is common practice to discretise the weld into a small number of bulk regions during the design process, with material constitutive behaviour assigned to these discretised parts. In the new methodology, the extracted material constitutive behaviour is modelled as a continuously varying function of the distance from the weld centre. By performing appropriate interpolation, the data may be finely or roughly discretised. The data at a certain distance from the weld centre may then be assigned to the corresponding element in the finite element model. This means one may discretise the model by choosing the level of data interpolation refinement. The following results were observed in the thesis: • Residual strain distributions of boron steel spot welds, which have not been measured before, were presented. Clear correlations between hardness and residual stress distributions were seen. • A new application of instrumented indentation was attempted by verifying the accuracy of heat treated samples with respect to their target microstructures by comparing yield strengths. • The boron steel HAZ was characterised in a finer level of detail than seen in other literature works. • Through physical simulation, stress - strain and failure loci corresponding to certain HAZ areas were successfully extracted and used to model weld failure. • A new method of finite element model discretisation was presented, where material properties may be input as a relatively smooth function through the length of the model.
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Kuchen, Ernesto. "Spot-Monitoring zum thermischen Komfort in Bürogebäuden /." Tönning ; Lübeck ; Marburg : Der Andere Verl, 2008. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=016738639&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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He, Yi. "Topics in contract pricing and spot markets." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24792.
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Thesis (Ph.D.)--Industrial and Systems Engineering, Georgia Institute of Technology, 2008.Committee Chair: Anton Kleywegt; Committee Member: Dong Jun Wu; Committee Member: Ellis Johnson; Committee Member: George L. Nemhauser; Committee Member: Pinar Keskinocak.
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Berthet-Duroure, Nathalie. "Adressage et immobilisation de biomolécules sur des surfaces : Interaction spot-dans-spot et bioélectrochimie localisée à l'échelle 1-50μm." Phd thesis, INSA de Toulouse, 2009. http://tel.archives-ouvertes.fr/tel-01071232.
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Le domaine des biopuces et biocapteurs évolue dans le sens de la miniaturisation. La problématique qui apparait alors concerne l'adressage et l'immobilisation des biomolécules sur des structures devenant de plus en plus petites et intégrées dans des environnements fragiles. Le robot Bioplume a été retenu comme méthode d'adressage, pour la pertinence de l'échelle concernée (1-50µm) et le fort potentiel pressenti de la technique. Le dépôt de biomolécules et la technique spot-dans-spot ont été développés, ce qui réduit de 106 à 109 fois les quantités d'échantillons biologiques. Quatre méthodes d'immobilisation ont ensuite été mises en œuvre, afin d'appréhender les performances et les contraintes de chacune : la silanisation par GPTS, l'auto-assemblage d'alcanethiols, l'utilisation du polymère PLLgPEG et enfin l'électrodépôt par oxydation de pyrrole. L'adaptation de cette méthode électrochimique au robot Bioplume a permis d'apporter une solution efficace à la fois en termes d'adressage et en termes d'immobilisation, car la réaction d'immobilisation est réalisée simultanément au dépôt. Elle a donc été retenue pour deux applications : d'abord la réalisation de matrices de cellules isolées, avec détection par SPRi, puis le dépôt sur la section de fibres optiques. Enfin, trois nouvelles pistes dans le domaine de l'électrochimie localisée ont été explorées : l'électrodésorption de PLLgPEG, la miniaturisation des gouttes grâce à des pointes nanométriques, et enfin l'électrodépôt sur des microélectrodes dédiées. L'une des perspectives principales est la valorisation industrielle du robot Bioplume. Un nouveau prototype est ainsi développé afin de produire des biopuces à haute densité.
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Berthet, Nathalie. "Adressage et immobilisation de biomolécules sur des surfaces : interaction spot-dans-spot et bioélectrochimie localisée à l'échelle 1-50µm." Toulouse, INSA, 2009. http://eprint.insa-toulouse.fr/archive/00000279/.
Full textAbstract:
Le domaine des biopuces et biocapteurs évolue dans le sens de la miniaturisation. La problématique qui apparait alors concerne l’adressage et l’immobilisation des biomolécules sur des structures devenant de plus en plus petites et intégrées dans des environnements fragiles. Le robot Bioplume a été retenu comme méthode d’adressage, pour la pertinence de l’échelle concernée (1-50µm) et le fort potentiel pressenti de la technique. Le dépôt de biomolécules et la technique spot-dans-spot ont été développés, ce qui réduit de 106 à 109 fois les quantités d’échantillons biologiques. Quatre méthodes d’immobilisation ont ensuite été mises en œuvre, afin d’appréhender les performances et les contraintes de chacune : la silanisation par GPTS, l’auto-assemblage d’alcanethiols, l’utilisation du polymère PLLgPEG et enfin l’électrodépôt par oxydation de pyrrole. L’adaptation de cette méthode électrochimique au robot Bioplume a permis d’apporter une solution efficace à la fois en termes d’adressage et en termes d’immobilisation, car la réaction d’immobilisation est réalisée simultanément au dépôt. Elle a donc été retenue pour deux applications : d’abord la réalisation de matrices de cellules isolées, avec détection par SPRi, puis le dépôt sur la section de fibres optiques. Enfin, trois nouvelles pistes dans le domaine de l’électrochimie localisée ont été explorées : l’électrodésorption de PLLgPEG, la miniaturisation des gouttes grâce à des pointes nanométriques, et enfin l’électrodépôt sur des microélectrodes dédiées. L’une des perspectives principales est la valorisation industrielle du robot Bioplume. Un nouveau prototype est ainsi développé afin de produire des biopuces à haute densitéThe trend towards miniaturization of biochips and biosensors raises new issues. Indeed, the surfaces on which biomolecules must be addressed and grafted are getting smaller and smaller, and are also increasingly integrated into more and more complex systems. The Bioplume technology enables surface patterning at the 1-50μm scale. This promising approach was adapted to biomolecules deposition. The spot-in-spot technology was developed and proved to reduce biological samples expenses by 106 -109 times. Several grafting techniques were also carried out (GPTS silanisation, alcanethiols auto-assembly, PLLgPEG grafting and pyrrole electropolymerization), so that difficulties and performances were better clarified. Pyrrole electropolymerization was then adapted to the Bioplume system. This approach proved to be very efficient for depositing and grafting biomolecules on the surface in a single step. Thus, it was applied to the manufacture of single cell biochips and the functionalization of optical fibers. In the end, localised electrochemistry was further explored with three new approaches : PLLgPEG electrodesorption, droplet miniaturization using nanotips, and deposition onto dedicated microelectrodes. The major prospect is the industrial promotion of the Bioplume system. A new prototype will be developed to enable high-density protein chip manufacturing
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McDonald, Steven J. "Dollar spot and gray leaf spot severity as influenced by irrigation practice and disease management with plant protection materials." College Park, Md. : University of Maryland, 2005. http://hdl.handle.net/1903/3118.
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Thesis (M.S.) -- University of Maryland, College Park, 2005.Thesis research directed by: Dept. of Plant Science and Landscape Architecture . Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Franks, David. "Occurrence and Evaluation of White Spot Lesions in Orthodontic Patients: A Pilot Study." Master's thesis, Temple University Libraries, 2014. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/286676.
Full textAbstract:
Oral BiologyM.S.
Orthodontic treatment may cause an increase in the rate of enamel decalcification on tooth surfaces, producing White Spot Lesions (WSL). Orthodontic patients are at a higher risk for decalcification because orthodontic appliances retain food debris which leads to increased plaque formation. Dental plaque, an oral biofilm formed by factors including genetics, diet, hygiene, and environment, contains acid producing bacterial strains with a predominance of Mutans Streptococcus (MS). MS and others metabolize oral carbohydrates during ingestion, the byproducts of which acidify the biofilm to begin a process of enamel decalcification and formation of WSL. This study tests if patients in orthodontic treatment at Temple University can be used as subjects for further longitudinal study of WSL risk factors. Twenty patients between the ages of ten to eighteen after three months or greater of treatment were enrolled to determine if duration of treatment, hygiene, sense of coherence, obesity, diet frequencies, age and gender correlated with development of WSL. Of these, age is positively correlated with the number of untreated decayed surfaces. WSL and plaque levels may negatively correlate with increased brushing frequency and duration, while flossing frequency demonstrated a statistically significant negative correlation. This population may be suitable for further study because of its high incidence of WSL (75%), however difficulty in enrollment and patient attrition necessitates that future studies be modified.
Temple University--Theses