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Dissertations / Theses on the topic 'Thermal object'
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1
Mozok, E. M. "Monitoring condition of thermal object." Thesis, Сумський державний університет, 2014. http://essuir.sumdu.edu.ua/handle/123456789/34870.
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Thermal power plants are producing more than a third of consumed electricity and become main enterprise which generate electricity, both in Ukraine and other countries. To achieve optimal control of the combustion process it is necessary to provide individual adjustment of the following parameters: distribution of the combustion zone according to the project plan; control of air distribution and air/fuel ratio in combustion zone.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/34870
2
Kaba, Utku. "Moving Hot Object Detection In Airborne Thermal Videos." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614532/index.pdf.
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In this thesis, we present an algorithm for vision based detection of moving objects observed by IR sensors on a moving platform. In addition we analyze the performance of different approaches in each step of the algorithm. The proposed algorithm is composed of preprocessing, feature detection, feature matching, homography estimation and difference image analysis steps. First, a global motion estimation based on planar homography model is performed in order to compensate the motion of the sensor and moving platform where the sensors are located. Then, moving objects are identified on difference images of consecutive video frames with global motion suppression. Performance of the proposed algorithm is shown on different IR image sequences.
3
Bergenroth, Hannah. "Use of Thermal Imagery for Robust Moving Object Detection." Thesis, Linköpings universitet, Medie- och Informationsteknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-177888.
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This work proposes a system that utilizes both infrared and visual imagery to create a more robust object detection and classification system. The system consists of two main parts: a moving object detector and a target classifier. The first stage detects moving objects in visible and infrared spectrum using background subtraction based on Gaussian Mixture Models. Low-level fusion is performed to combine the foreground regions in the respective domain. For the second stage, a Convolutional Neural Network (CNN), pre-trained on the ImageNet dataset is used to classify the detected targets into one of the pre-defined classes; human and vehicle. The performance of the proposed object detector is evaluated using multiple video streams recorded in different areas and under various weather conditions, which form a broad basis for testing the suggested method. The accuracy of the classifier is evaluated from experimentally generated images from the moving object detection stage supplemented with publicly available CIFAR-10 and CIFAR-100 datasets. The low-level fusion method shows to be more effective than using either domain separately in terms of detection results.Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet
4
Yigit, Ahmet. "Thermal And Visible Band Image Fusion For Abandoned Object Detection." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/3/12611720/index.pdf.
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Packages that are left unattended in public spaces are a security concern and timely detection of these packages is important for prevention of potential threats. Operators should be always alert to detect abandoned items in crowded environments. However, it is very difficult for operators to stay concentrated for extended periods. Therefore, it is important to aid operators with automatic detection of abandoned items. Most of the methods in the literature define abandoned items as items newly added to the scene and stayed stationary for a predefined time. Hence other stationary objects, such as people sitting on a bench are also detected as suspicious objects resulting in a high number of false alarms. These false alarms could be prevented by discriminating suspicious items as living/nonliving objects. In this thesis, visible band and thermal band cameras are used together to analyze the interactions between humans and other objects. Thermal images help classification of objects using their heat signatures. This way, people and the objects they carry or left behind can be detected separately. Especially, it is aimed to detect abandoned items and discriminate living or nonliving objects
5
López, Mas Joan. "Parallel object-oriented algorithms for simulation of multiphysics : application to thermal systems." Doctoral thesis, Universitat Politècnica de Catalunya, 2016. http://hdl.handle.net/10803/387441.
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The present and the future expectation in parallel computing pose a new generational change in simulation and computing. Modern High Performance Computing (HPC) facilities have high computational power in terms of operations per second -today peta-FLOPS (10e15 FLOPS) and growing toward the exascale (10e18 FLOPS) which is expected in few years-. This opens the way for using simulation tools in a wide range of new
engineering and scientific applications. For example, CFD&HT codes will be effectively used in the design phase of industrial devices, obtaining valuable information with reasonable time expenses. However, the use of the emerging computer architectures is subjected to enhancements and innovation in software design patterns. So far, powerful codes for individually studying heat and mass transfer phenomena at multiple levels of
modeling are available. However, there is no way to combine them for resolving complex coupled problems. In the current context, this PhD thesis presents the development of parallel methodologies, and its implementation as an object-oriented software platform, for the simulation of multiphysics systems. By means of this new software platform, called NEST, the distinct codes can now be integrated into single simulation tools for
specific applications of social and industrial interest. This is done in an intuitive and simple way so that the researchers do not have to bother either on the coexistence of several codes at the same time neither on how they interact to each other. The coupling of the involved components is controlled from a low level code layer, which is transparent to the users. This contributes with appealing benefits on software projects management
first and on the flexibility and features of the simulations, later. In sum, the presented approaches pose a new paradigm in the production of physics simulation programs. Although the thesis pursues general purpose applications, special emphasis is placed on the simulation of thermal systems, in particular on buildings energy assessment and on hermetic reciprocating compressors.Las expectativas puestas en el uso de la computación en paralelo plantean un cambio generacional en simulación y computación. Las más modernas instalaciones computacionales de alto nivel -High Performance Computing (HPC)- alcanzan ya la capacidad de realizar gran cantidad de operaciones por segundo -hoy del orden de peta-FLOPS (1e15 FLOPS) y dirigiéndose hacia exaFlops (1e18 FLOPS)-. Esto abre la posibilidad de usar la simulación por ordenador en un amplio espectro de nuevas aplicaciones en ciencia e ingeniería. Por ejemplo, los códigos de CFD&HT van a poder usarse de una forma más efectiva en la fase de diseño de dispositivos industriales ya que se obtendrán resultados muy valiosos en tiempos de ejecución razonables. Por el momento, hay muchos códigos disponibles para el estudio individual de fenómenos de transferencia de calor i de masa con distintos niveles de modelización. Sin embargo, estos códigos no se pueden combinar entre sí para abordar problemas más complejos, en los cuales varios fenómenos físicos interactúan simultáneamente. Bajo este contexto, en esta tesis doctoral se presenta el desarrollo de una metodología de estrategia paralela, y su implementación en una plataforma informática, para la simulación de sistemas multi-físicos. De éste modo, ahora los distintos códigos pueden ser integrados para la creación de nuevas herramientas de simulación destinadas a aplicaciones específicas de interés tanto social como industrial. Esto se hace de una manera intuitiva y simple de manera que los investigadores no tienen que preocuparse ni por la coexistencia de varios códigos simultáneamente ni en cómo hacer que interactúen entre ellos. El acoplamiento entre los diferentes componentes involucrados en una simulación se realiza mediante un código más básico con el cual el usuario solamente interacciona a través de una interfase. Esto aporta interesantes beneficios tanto en la gestión de los proyectos de programario como en la flexibilidad y las características de las simulaciones. En resumen, la estrategia que se propone plantea un nuevo paradigma en la producción de programas de simulación de fenómenos físicos. Aunque la tesis persigue aplicaciones de propósito general se ha puesto especial atención en la simulación de sistemas térmicos, en particular en la evaluación energética de edificios y en compresores herméticos alternativos.
6
Viau, Claude. "Multispectral Image Analysis for Object Recognition and Classification." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/34532.
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Computer and machine vision applications are used in numerous fields to analyze static and dynamic imagery in order to assist or automate some form of decision-making process. Advancements in sensor technologies now make it possible to capture and visualize imagery at various wavelengths (or bands) of the electromagnetic spectrum. Multispectral imaging has countless applications in various field including (but not limited to) security, defense, space, medical, manufacturing and archeology. The development of advanced algorithms to process and extract salient information from the imagery is a critical component of the overall system performance.
The fundamental objectives of this research project were to investigate the benefits of combining imagery from the visual and thermal bands of the electromagnetic spectrum to improve the recognition rates and accuracy of commonly found objects in an office setting. The goal was not to find a new way to “fuse” the visual and thermal images together but rather establish a methodology to extract multispectral descriptors in order to improve a machine vision system’s ability to recognize specific classes of objects.A multispectral dataset (visual and thermal) was captured and features from the visual and thermal images were extracted and used to train support vector machine (SVM) classifiers. The SVM’s class prediction ability was evaluated separately on the visual, thermal and multispectral testing datasets. Commonly used performance metrics were applied to assess the sensitivity, specificity and accuracy of each classifier.
The research demonstrated that the highest recognition rate was achieved by an expert system (multiple classifiers) that combined the expertise of the visual-only classifier, the thermal-only classifier and the combined visual-thermal classifier.
7
Beyan, Cigdem. "Object Tracking For Surveillance Applications Using Thermal And Visible Band Video Data Fusion." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612743/index.pdf.
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Individual tracking of objects in the video such as people and the luggages they carry is important for surveillance applications as it would enable deduction of higher level information and timely detection of potential threats. However, this is a challenging problem and many studies in the literature track people and the belongings as a single object. In this thesis, we propose using thermal band video data in addition to the visible band video data for tracking people and their belongings separately for indoor applications using their heat signatures. For object tracking step, an adaptive, fully automatic multi object tracking system based on mean-shift tracking method is proposed. Trackers are refreshed using foreground information to overcome possible problems which may occur due to the changes in object&rsquos size, shape and to handle occlusion, split and to detect newly emerging objects as well as objects that leave the scene. By using the trajectories of objects, owners of the objects are found and abandoned objects are detected to generate an alarm. Better tracking performance is also achieved compared a single modality as the thermal reflection and halo effect which adversely affect tracking are eliminated by the complementing visible band data.
8
Yevseienko, Oleg, Anatoliy Gapon, and Dmytro Salnikov. "Searching for Optimal Control Parameters of Thermal Object Using Pulse-Width Modulation (PWM) Control with Predictive Filter." Thesis, Lviv Polytechnic Publishing House, 2015. http://repository.kpi.kharkov.ua/handle/KhPI-Press/41116.
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The thesis is devote to the temperature control of objects with lumped or distributed parameters. The problems of choosing the right value of regulator’s heater power and prediction period are discussed. The major attention is paid to the process of searching the minimum value of control quantities. It is shown that the approximated second-order plane has an exact accordance with the original data. It is concluded that algorithm of PWM-control with prediction filter provides good quality control.
9
Stigson, Magnus. "Object Tracking Using Tracking-Learning-Detection inThermal Infrared Video." Thesis, Linköpings universitet, Datorseende, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-93936.
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Automatic tracking of an object of interest in a video sequence is a task that has been much researched. Difficulties include varying scale of the object, rotation and object appearance changing over time, thus leading to tracking failures. Different tracking methods, such as short-term tracking often fail if the object steps out of the camera’s field of view, or changes shape rapidly. Also, small inaccuracies in the tracking method can accumulate over time, which can lead to tracking drift. Long-term tracking is also problematic, partly due to updating and degradation of the object model, leading to incorrectly classified and tracked objects. This master’s thesis implements a long-term tracking framework called Tracking-Learning-Detection which can learn and adapt, using so called P/N-learning, to changing object appearance over time, thus making it more robust to tracking failures. The framework consists of three parts; a tracking module which follows the object from frame to frame, a learning module that learns new appearances of the object, and a detection module which can detect learned appearances of the object and correct the tracking module if necessary. This tracking framework is evaluated on thermal infrared videos and the results are compared to the results obtained from videos captured within the visible spectrum. Several important differences between visual and thermal infrared tracking are presented, and the effect these have on the tracking performance is evaluated. In conclusion, the results are analyzed to evaluate which differences matter the most and how they affect tracking, and a number of different ways to improve the tracking are proposed.
10
Samaei, Amiryousef. "Evaluating the effect of different distances on the pixels per object and image classification." Thesis, Mittuniversitetet, Avdelningen för elektronikkonstruktion, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-25880.
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In the last decades camera systems have continuously evolved and have found wide range of applications. One of the main applications of a modern camera system is surveillance in outdoor areas. The camera system, based on local computations, can detect and classify objects autonomously. However, the distance of the objects from the camera plays a vital role on the classification results. This could be specially challenging when lighting conditions are varying. Therefore, in this thesis, we are examining the effect of changing dis-tances on object in terms of number of pixels. In addition, the effect of distance on classification is studied by preparing four different sets. For consideration of high signal to noise ratio, we are integrating thermal and visual image sensors for the same test in order to achieve better spectral resolution. In this study, four different data sets, thermal, visu-al, binary from visual and binary from thermal have been prepared to train the classifier. The categorized objects include bicycle, human and vehicle. Comparative studies have been performed in order to identify the data sets accuracy. It has been demonstrated that for fixed distances bi-level data sets, obtained from visual images, have better accuracy. By using our setup, the object (human) with a length of 179 and width of 30 has been classified correctly with minor error up to 150 meters for thermal, visual as well as binary from visual. Moreover, for bi-level images from thermal, the human object has been correctly classified as far away as 250 meters.
11
Sharma, Vinay. "Simultaneous object detection and segmentation using top-down and bottom-up processing." Columbus, Ohio : Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1196372113.
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Majsniar, Michal. "Tepelně technické posouzení skladby vegetační střechy s vlivem vlhkosti." Doctoral thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-355608.
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Dissertation deals with thermal technical assessment songs vegetation roof with moisture, the more the influence of vegetation on the roof thermal stability of the structure. The aim of this work is to demonstrate the beneficial effect of vegetation roofs, specifically growing Formation of thermo-technical point of view on the favorable temperature conditions in the building. Such speech can be captured only if it is judged-temperature profile dynamically daily operation of real marginal climatic temperatures. Using a stationary or quasi-stationary boundary climatic temperatures which are usually used for the determination of the energy performance of buildings, said effect can not be collected. Demanding simulation calculation, which apply material properties - thermal conductivity, density and thermal capacity, but gives a realistic picture of the thermal processes in progress not only in the roof structure of the building, but also across the entire circuit construction of a building. During the preparation of the dissertation was assembled machine program that works with the energy flow between rooms in the building and the surrounding environment. Furthermore calculates temperature gain of residence of persons, internal lighting and sunlight. The values of the internal environment are calculated from surface temperature, relative humidity, air exchange and, of course, the indoor air temperature with hourly weather data. In constructing the program was included in the calculation of the solar radiation both on flat and on an inclined surface. The output of the energy value and temperature conditions in individual rooms, which include not only thermal insulation but also thermal storage properties of an object. Using experimental measurements were able to demonstrate that the calculated values closely correlate real thermal processes, so it can be demonstrated through the calculated results of the vegetation roof has a favorable effect on the thermal state espe
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Denman, Simon Paul. "Improved detection and tracking of objects in surveillance video." Queensland University of Technology, 2009. http://eprints.qut.edu.au/29328/.
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Surveillance networks are typically monitored by a few people, viewing several monitors displaying the camera feeds. It is then very dicult for a human op- erator to eectively detect events as they happen. Recently, computer vision research has begun to address ways to automatically process some of this data, to assist human operators. Object tracking, event recognition, crowd analysis and human identication at a distance are being pursued as a means to aid human operators and improve the security of areas such as transport hubs. The task of object tracking is key to the eective use of more advanced technolo- gies. To recognize an event people and objects must be tracked. Tracking also enhances the performance of tasks such as crowd analysis or human identication. Before an object can be tracked, it must be detected. Motion segmentation tech- niques, widely employed in tracking systems, produce a binary image in which objects can be located. However, these techniques are prone to errors caused by shadows and lighting changes. Detection routines often fail, either due to erro- neous motion caused by noise and lighting eects, or due to the detection routines being unable to split occluded regions into their component objects. Particle l- ters can be used as a self contained tracking system, and make it unnecessary for the task of detection to be carried out separately except for an initial (of- ten manual) detection to initialise the lter. Particle lters use one or more extracted features to evaluate the likelihood of an object existing at a given point each frame. Such systems however do not easily allow for multiple objects to be tracked robustly, and do not explicitly maintain the identity of tracked objects. This dissertation investigates improvements to the performance of object tracking algorithms through improved motion segmentation and the use of a particle lter. A novel hybrid motion segmentation / optical
ow algorithm, capable of simulta- neously extracting multiple layers of foreground and optical
ow in surveillance video frames is proposed. The algorithm is shown to perform well in the presence of adverse lighting conditions, and the optical
ow is capable of extracting a mov- ing object. The proposed algorithm is integrated within a tracking system and evaluated using the ETISEO (Evaluation du Traitement et de lInterpretation de Sequences vidEO - Evaluation for video understanding) database, and signi- cant improvement in detection and tracking performance is demonstrated when compared to a baseline system. A Scalable Condensation Filter (SCF), a particle lter designed to work within an existing tracking system, is also developed. The creation and deletion of modes and maintenance of identity is handled by the underlying tracking system; and the tracking system is able to benet from the improved performance in uncertain conditions arising from occlusion and noise provided by a particle lter. The system is evaluated using the ETISEO database. The dissertation then investigates fusion schemes for multi-spectral tracking sys- tems. Four fusion schemes for combining a thermal and visual colour modality are evaluated using the OTCBVS (Object Tracking and Classication in and Beyond the Visible Spectrum) database. It is shown that a middle fusion scheme yields the best results and demonstrates a signicant improvement in performance when compared to a system using either mode individually. Findings from the thesis contribute to improve the performance of semi- automated video processing and therefore improve security in areas under surveil- lance.
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Евсеенко, Олег Николаевич, and Сергей Михайлович Савицкий. "Описание метода управления тепловым объектом с распределёнными параметрами с помощью широтно-импульсной модуляции и предсказывающего фильтра." Thesis, Національний технічний університет "Харківський політехнічний інститут", 2013. http://repository.kpi.kharkov.ua/handle/KhPI-Press/48405.
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Предложен метод управления для тепловых объектов, получены разгонные кривые теплового объекта, рассчитан максимально допустимый период дискретизации переходного процесса по теореме Котельникова, выбрана частота дискретизации, проведён эксперимент по управлению инерционным тепловым объектом.Proposed a method of control thermal objects, obtained the acceleration curves of an object, calculated the maximum allowable sampling period of transition with the theorem of Kotelnikov, chosen the sampling frequency, conducted experiments for control the temperature of inertial object.
15
Mikula, Martin. "Termodiagnostika - dotykové a bezdotykové měření teploty." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231525.
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This thesis is concerned with thermodiagnostics in industrial practise, which is very important for the assessment of technical condition of object on the basis of temperature, in today's time. It includes summary of contact and contact-free methods and their principle, advantages and disadvantages for aplication in industrial practise. Because of thesis it was carried out measurement in company Daikin Device Czech republic with the use of contact thermometer and two available thermocameras for solving of topical tasks relating to production.
16
Мозок, Є. М., and І. В. Сердюк. "Апаратно-програмний стенд керування тепловим об’єктом." Thesis, Сумський державний університет, 2018. http://essuir.sumdu.edu.ua/handle/123456789/67549.
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В результаті роботи було розроблено предпроектне рішення АПС керування тепловим об’єктом. Даний АПК передбачає декілька каналів керування (температура нагрівача, оберти вентилятора, поворот заслонки) та збурення (оберти вентилятора, вологість). Запропонований стенд може бути використаний в рамках дисциплін ТАУ - для дослідження характеристик об’єкту зі змінними параметрами та збуреннями, МПП/МПСУ - для розробки ПО керування об’єктом.
17
Fleury, Rob. "Evaluation of Thermal Radiation Models for Fire Spread Between Objects." Thesis, University of Canterbury. Civil and Natural Resources Engineering, 2010. http://hdl.handle.net/10092/4959.
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Fire spread between objects within a compartment is primarily due to the impingement of thermal radiation from the fire source. In order to estimate if or when a remote object from the fire will ignite, one must be able to quantify the radiative heat flux being received by the target. There are a variety of methods presented in the literature that attempt to calculate the thermal radiation to a target; each one based on assumptions about the fire.
The performance of six of these methods, of varying complexity, is investigated in this research. This includes the common point source model, three different cylindrical models, a basic correlation and a planar model. In order to determine the performance of each method, the predictions made by the models were compared with actual measurements of radiant heat flux. This involved taking heat flux readings at numerous locations surrounding a propane gas burner. Different fire scenarios were represented by varying the burner geometry and heat release rate. Video recordings of the experiments were used to determine the mean flame heights using video image analysis software.
After comparing the measured data with predictions made by the theoretical radiation methods, the point source model was found to be the best performing method on average. This was unexpected given the relative simplicity of the model in comparison to some of its counterparts. Additionally, the point source model proved to be the most robust of the six methods investigated, being least affected by the experimental variables. The Dayan and Tien method, one of the cylindrical models, was the second most accurate over the range of conditions tested in this work.
Based on these findings, recommendations are made as to the most appropriate method for use in a radiation sub-model within an existing zone model software. The accuracy shown by the point source model, coupled with its ease of implementation, means that it should be suitable for such a use.
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Braun, Marco. "Optically Controlled Manipulation of Single Nano-Objects by Thermal Fields." Doctoral thesis, Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-206342.
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This dissertation presents and explores a technique to confine and manipulate single and multiple nano-objects in solution by exploiting the thermophoretic interactions with local temperature gradients. The method named thermophoretic trap uses an all-optically controlled heating via plasmonic absorption by a gold nano-structure designed for this purpose. The dissipation of absorbed laser light to thermal energy generates a localized temperature field. The spatial localization of the heat source thereby leads to strong temperature gradients that are used to drive a particle or molecule into a desired direction. The behavior of nano-objects confined by thermal inhomogeneities is explored experimentally as well as theoretically.
The monograph treats three major experimental stages of development, which essentially differ in the way the heating laser beam is shaped and controlled. In a first generation, a static heating of an appropriate gold structure is used to induce a steady temperature profile that exhibits a local minimum in which particles can be confined. This simple realization illustrates the working principle best. In a second step, the static heating is replaced. A focused laser beam is used to heat a smaller spatial region. In order to confine a particle, the beam is steered in circles along a circular gold structure. The trapping dynamics are studied in detail and reveal similarities to the well-established Paul trap. The largest part of the thesis is dedicated to the third generation of the trap. While the hardware is identical to the second generation, using the real-time information on the position of the trapped object to heat only particular sites of the gold structure strongly increases the efficiency of the trap compared to the earlier versions. Beyond that, the optical feedback control allows for an active shaping of the effective virtual trapping potential by applying modified feedback rules, including e.g. a double-well or a box-like potential. This transforms the formerly pure trapping device to a versatile technique for micro and nano-fluidic manipulation. The physical and technical contributions to the limits of the method are explored. Finally, the feasibility of trapping single macro-molecules is demonstrated by the confinement of lambda-DNA for extended time periods over which the molecules center-of-mass motion as well as its conformational dynamics can be studied.
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Toullier, Thibaud. "Simultaneous characterization of objects temperature and radiative properties through multispectral infrared thermography." Thesis, Rennes 1, 2019. http://www.theses.fr/2019REN1S038/document.
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L'utilisation de caméras infrarouges bas coûts pour la surveillance long-terme d'infrastructures est prometteuse grâce aux dernières avancées technologiques du domaine. Une mesure précise de la température des surfaces observées in-situ se heurte au manque de connaissance des propriétés radiatives de la scène. L'utilisation d'une instrumentation multi-capteurs permet d'affiner le modèle de mesure afin d'obtenir une estimation plus précise de la température. A contrario, il est montré qu'il est toujours possible d'exploiter des données climatiques en ligne pour pallier un manque de capteur. Des méthodes bayésiennes d'estimation conjointe d'émissivité et de température sont ensuite développées et comparées aux méthodes de la littérature. Un simulateur d'échanges radiatifs diffus de scènes 3D a été implémenté afin de tester ces différentes méthodes. Ce logiciel utilise l'accélération matérielle de la machine pour réduire les temps de calcul. Les résultats numériques obtenus mettent en perspective une utilisation avancée de la thermographie infrarouge multi-spectrale pour la surveillance de structures. Cette estimation conjointe permet alors d'obtenir un estimé de la température par thermographie infrarouge avec une incertitude connueThe latest technological improvements in low-cost infrared cameras have brought new opportunities for long-term infrastructures monitoring. The accurate measurement of surfaces' temperatures is facing the lack of knowledge of radiatives properties of the scene. By using multi-sensors instrumentation, the measurement model can be refined to get a better estimate of the temperature. To overcome a lack of sensors instrumentation, it is shown that online and free available climatic data can be used. Then, Bayesian methods to estimate simultaneously the emissivity and temperature have been developed and compared to literature's methods. A radiative exchange simulator of 3D scenes have been developed to compare those different methods on numerical data. This software uses the hardware acceleration as well as a GPGPU approach to reduce the computation time. As a consequence, obtained numerical results emphasized an advanced use of multi-spectral infrared thermography for the monitoring of structures. This simultaneous estimation enables to have an estimate of the temperature by infrared thermography with a known uncertainty
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Santos, Sérgio Botassi dos. "Uma contribuição ao estudo do comportamento termomecânico de estruturas maciças de concreto. modelagem viscoelástica linear e aplicações." Universidade Federal do Espírito Santo, 2004. http://repositorio.ufes.br/handle/10/6188.
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Previous issue date: 2004-04-06O estudo realizado nesta dissertação é motivado principalmente pelo interesse em se avaliar a resposta térmica e tensional em estruturas de concreto massa nas primeiras idades considerando a viscoeleasticidade linear do material. Neste trabalho desenvolvem-se modelos numérico-computacionais e implementam-se os softwares PFEM_2DT e PFEM_2DAT, de análise térmica e de tensões no domínio bidimensional, respectivamente. Inicialmente, foi realizada uma revisão bibliográfica do problema termomecânico considerando os mecanismos e modelos físicos para a representação do mesmo, utilizando-se de ferramentas matemáticas e artifícios numéricos para a resolução do problema. Foram pesquisados ainda os parâmetros influentes na análise de temperaturas e de tensões no concreto massa, destacando-se as propriedades viscoelásticas de fluência e retração onde de forma resumida, porém esclarecedora, foram descritos seus principais conceitos, causas e efeitos bem como alguns dos principais modelos de representação dessas deformações diferidas. Por meio desses estudos teóricos e das conseqüentes implementações computacionais, foram analisadas diferentes estruturas de concreto através dos programas computacionais desenvolvidos e, posteriormente, realizadas comparações com resultados experimentais e numéricos obtidos por outros pesquisadores objetivando validar os aplicativos. Na elaboração deste software fez-se uso do novo paradigma de programação Programação Orientada a Objetos, associado à resolução de sistemas de equações lineares pelo Método dos Gradientes Conjugados. Analisou-se o comportamento das temperaturas de diferentes estruturas sujeitas ao calor interno gerado no concreto sob a influência das condições ambientais, que permitem que esse calor seja dissipado, gerando como conseqüência, distribuições de temperatura não-lineares no interior da estrutura. Nos estudos tensionais das estruturas de concreto massa analisadas nesta dissertação pôde-se avaliar a evolução das tensões de origem térmica considerando o material viscoelástico linear, comparando-as com a resistência à tração do material. Por fim, efetuaram-se estudos comparativos de tensões em um bloco de concreto massa utilizando os modelos elástico e viscoelástico linear, avaliando o nível de importância e o grau de magnitude da consideração dos efeitos diferidos associados quando da análise do comportamento termomecânico de estruturas maciças de concreto em fase de construção.
The study accomplished in this dissertation is motivated mainly by the interest in evaluating the temperature and stress field in mass concrete structures at first ages considering material s linear viscoeleasticity. The development and implementation of numeric-computational models are also scope of this work by means the softwares PFEM_2DT and PFEM_2DAT, of thermal stress analysis in the two-dimensional domain. Initially at first step, the bibliographic revision of the thermomechanical problem was accomplished considering physical mechanisms and models for its representation, using mathematical tools and numeric artifices for the resolution of the problem. The influential parameters in the analysis of temperatures and stresses in the mass concrete were also researched, standing out to the creep and shrinkage rheological properties, where in a summarized and elucidated way, its main concepts, causes and effects were described, as well as some of the main representation models of those differed deformations. Considering theoretical studies and the consequent computer implementations, different concrete structures were analyzed through the developed softwares, and compared with experimental and numeric results obtained by other researchers with the objective of validating the applications. In the elaboration of this software was made use of the new programming paradigm Object-Oriented Programming, associated to the resolution of linear systems equations for the Method of the Conjugated Gradients. The temperature field s behavior of different structures subject to the internal heat into the concrete was analyzed, under the influence of the environmental conditions, that allows the heat to be dissipated, generating as consequence, non- linear temperature distributions inside the structure. The termomechanic problems studied in mass concrete structures were analyzed in this dissertation, where the thermal stresses behaviour could be evaluated considering the linear viscoelasticity properties of the material, comparing them with the tensile strength of the material. Finally, comparative studies of the stresses in a mass concrete block were executed using elastic models and linear viscoelasticity, evaluating the importance and magnitude levels of the associated differed effects in the termomechanic behavior analysis of solid concrete structures in a construction stage.
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Hager, Philipp B. [Verfasser]. "Dynamic thermal modeling for moving objects on the Moon / Philipp B. Hager." München : Verlag Dr. Hut, 2013. http://d-nb.info/1043892575/34.
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Nguyen, van Thien an. "Sur la modélisation et la simulation du couplage thermo-chimio-mécanique au sein des élastomères chargés." Thesis, Aix-Marseille, 2012. http://www.theses.fr/2012AIXM4787/document.
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Dans ce travail prospectif, nous proposons une modélisation intégrant un couplage thermo-chimio-mécanique pour les élastomères chargés et dissipatifs. En se basant sur les résultats et les observations de la littérature, nous avons développé un cadre thermodynamique général et proposé trois modèles phénoménologiques de comportement. Nos outils principaux sont la thermodynamique des processus irréversibles, la notion d'états intermédiaires, les matériaux standards généralisés. Une variable interne correspondant au degré de réticulation est introduite. L'évolution de cette variable prend en compte une influence thermique et mécanique à travers la pression hydrostatique. Il s'agit d'une des originalités de cette approche. Ce travail se place dans le cadre général des grandes transformations. Un schéma numérique de résolution monolithique des équations bilan par éléments finis est proposé. Ce schéma tient compte de l'hypothèse de faible compressibilité du matériau par un choix judicieux de relations faibles entre inconnues et par le choix des approximations pour ces dernières. La résolution en temps est traitée par un schéma d'Euler implicite associé à une technique de linéarisation de Newton-Raphson. Un modèle orienté objet du matériau thermo-chimio-mécanique est proposé et implémenté en langage Java dans le code FEMJava. Quelques exemples de simulation illustrent le potentiel de ces modèles en reproduisant de manière qualitative des observations expérimentalesIn this prospective study, we propose a new thermo-chemo-mechanical coupled model for dissipative filled rubber. This work is based on experimental observations and results from the literature. In this context, we have developed three phenomenological constitutive laws within a generic thermodynamical framework. The models enters the category of the thermodynamics of irreversible processes. Intermediate states are taken into account in the model which is build within the generalized standard materials framework. The degree of cure is introduced as an internal variable. The evolution of this variable takes into account the thermal influence and the mechanical influence via the hydrostatic pressure. This is one of the features making this model original. A finite strains approach is considered. A finite element model is applied to the global problem. A monolithic solution scheme is built based on an implicit Euler scheme associated to a of Newton-Raphson linearization technique. This scheme takes into account the weak compressibility of the material condition through, first, a judicious choice of weak relations between unknowns, and second, an adequate choice of approximations for the unknowns of problem to enforce the stability of the numerical scheme. An object-oriented model for the constitutive equations of the thermo-chemo-mechanical model is proposed and is implemented in Java into the FEMJava code. Some simulations illustrate the high potential of these models in qualitatively reproducing these experimental observations
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Tyagi, Sidhanth. "Objects interacting with a solidification front." Electronic Thesis or Diss., Université Paris sciences et lettres, 2020. http://www.theses.fr/2020UPSLS025.
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L’interaction du front de solidification avec des objets (gouttelettes, bulles, particules ou cellules biologiques) est unphénomène courant rencontré dans une multitude de situations, allant des procédés industriels aux événements naturels, tels que la formation de glace de mer, la croissance de monocristaux, la métallurgie, la cryobiologie, l’ingéniériealimentaire ou la purification de l’eau. Ces processus, pourtant bien identifiés, sont complexes et une compréhensionapprofondie reste à développer. Les objets (rigides ou déformables) peuvent avoir différents comportements lors de leurrencontre avec un front de solidification en mouvement. Le front peut intégrer l’objet, le piégeant dans le cristal en croissance, ou le repousser. Les conséquences de cette interaction ont un impact sur la microstructure finale et déterminentnotamment les propriétés structurelles et fonctionnelles du matériau solidifié. En outre, la plupart de ces phénomènesse produisent en présence de solutés (ou d’impuretés), qui peuvent être ségrégés à l’interface lors de la solidification.Dans cette étude, nous analysons l’interaction d’objets sphériques déformable (gouttelettes et bulles) ou de particulesrigides avec une front de solidification eau-glace en mouvement. La microscopie cryo-confocale permet une imagerierapide in situ de la croissance des cristaux de glace, de la phase liquide et de la dynamique des objets qui rencontrentle front de solidification. Nous décrivons l’impact de la concentration des solutés (ou des impuretés) et leur influencesur la géométrie de l’interface, la dynamique des objets et la microstructure de solidification. Nous explorons plusieursaspects importants des interactions de particules multiples dans des systèmes réalistes et discutons des conséquencesde la redistribution des particules par rapport aux systèmes idéaux décrits dans les modèles physiques précédemmentdéveloppés. Nos résultats montrent comment une concentration croissante de soluté dans le liquide et sa ségrégationlors de la solidification peuvent modifier de façon spectaculaire la nature attendue des interactions entre l’objet et lefront et les microstructures de solidification. La congélation des suspensions par microscopie cryo-confocale peut servird’analogue pour étudier l’interaction in situ d’objets avec une front de solidification en mouvementThe interaction of solidification fronts with objects (droplets, bubbles, particles, or biological cells) is a common phenomenon encountered in a plethora of situations, ranging from industrial to natural occurrences, such as the formation ofsea ice, growth of single crystals, metallurgy, cryobiology, food science, and filtration or water purification. The process,though well-known, is complex and an unambiguous quantification of the mechanisms in situ is yet to be developed. Theobjects (soft or hard) can have diverse outcomes owing to their confrontation with an advancing solid-liquid interface. Thefront can engulf the object, trapping it into the growing crystal, or the front can repel the object, pushing it ahead of itself.The consequences of this interaction impacts the final microstructure and hence, determines the structural as well asfunctional properties of the solidified material. Furthermore, many of these phenomena occur in the presence of solutes(or impurities), which can segregate at the interface during the growth of a solid. In this study, we analyse the interactionof spherical soft objects (droplets and bubbles) and rigid particles with an approaching ice-water interface. Our customcryo-confocal microscopy setup enables a rapid imaging of the growth of ice crystals, the liquid phase, and the dynamicsof objects encountering the solidification front. We depict the impact of solute (or impurity) concentration and their influence on the interface geometry, object dynamics, and the solidified microstructure. We explore several important aspectsof multiple particle interactions in realistic systems and discuss the consequences of particle redistribution in comparisonto the ideal systems considered by the past physical models. Our results demonstrate how an increasing concentration ofsolute in the bulk liquid and their subsequent segregation can dramatically alter the predicted nature of object-front interactions and the solidification microstructures. We suggest that the freezing of suspensions using cryo-confocal microscopymay serve as an analogue for studying the in situ interaction of foreign objects with a moving solid-liquid interface
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Fehlman, William L. "Classification of non-heat generating outdoor objects in thermal scenes for autonomous robots." W&M ScholarWorks, 2008. https://scholarworks.wm.edu/etd/1539623338.
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We have designed and implemented a physics-based adaptive Bayesian pattern classification model that uses a passive thermal infrared imaging system to automatically characterize non-heat generating objects in unstructured outdoor environments for mobile robots. In the context of this research, non-heat generating objects are defined as objects that are not a source for their own emission of thermal energy, and so exclude people, animals, vehicles, etc. The resulting classification model complements an autonomous bot's situational awareness by providing the ability to classify smaller structures commonly found in the immediate operational environment. Since GPS depends on the availability of satellites and onboard terrain maps which are often unable to include enough detail for smaller structures found in an operational environment, bots will require the ability to make decisions such as "go through the hedges" or "go around the brick wall." A thermal infrared imaging modality mounted on a small mobile bot is a favorable choice for receiving enough detailed information to automatically interpret objects at close ranges while unobtrusively traveling alongside pedestrians. The classification of indoor objects and heat generating objects in thermal scenes is a solved problem. A missing and essential piece in the literature has been research involving the automatic characterization of non-heat generating objects in outdoor environments using a thermal infrared imaging modality for mobile bots. Seeking to classify non-heat generating objects in outdoor environments using a thermal infrared imaging system is a complex problem due to the variation of radiance emitted from the objects as a result of the diurnal cycle of solar energy. The model that we present will allow bots to "see beyond vision" to autonomously assess the physical nature of the surrounding structures for making decisions without the need for an interpretation by humans.;Our approach is an application of Bayesian statistical pattern classification where learning involves labeled classes of data (supervised classification), assumes no formal structure regarding the density of the data in the classes (nonparametric density estimation), and makes direct use of prior knowledge regarding an object class's existence in a bot's immediate area of operation when making decisions regarding class assignments for unknown objects. We have used a mobile bot to systematically capture thermal infrared imagery for two categories of non-heat generating objects (extended and compact) in several different geographic locations. The extended objects consist of objects that extend beyond the thermal camera's field of view, such as brick walls, hedges, picket fences, and wood walls. The compact objects consist of objects that are within the thermal camera's field of view, such as steel poles and trees. We used these large representative data sets to explore the behavior of thermal-physical features generated from the signals emitted by the classes of objects and design our Adaptive Bayesian Classification Model. We demonstrate that our novel classification model not only displays exceptional performance in characterizing non-heat generating outdoor objects in thermal scenes but it also outperforms the traditional KNN and Parzen classifiers.
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Shanmugam, Kumar. "Multiscale modelling of sintering in thermal barrier coatings." Thesis, University of Oxford, 2010. http://ora.ox.ac.uk/objects/uuid:a8075c89-8417-4e3e-8af5-d07cc786f509.
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Multiscale (analytical and computational) models have been developed based on a thermodynamic variational principle (TVP) to model sintering and eventual mudcracking in thermal barrier coatings (TBCs) made using the electron beam physical vapour deposition (EB-PVD) process. It is assumed that the sintering occurs by interfacial diffusion at local contacts between columns and driven by changes in interface free energy and elastic stored energy of the coating. The models link diffusional processes at the scale of contacting feathery columns with the macroscopic deformation and sintering response. In service, the columns can come into contact and sinter together. As sintering progresses there is a build up of strain energy in the system which reduces the driving force for sintering and leads to either complete or incomplete sintering of the TBC depending on the magnitude of effective modulus (E) of the coating. By seeding the coating with initial imperfections, different types of behaviour are observed depending on the value of E and the spacing between imperfections. For compliant coatings, the response is insensitive to the presence of imperfections and the coating fully sinters. At higher values of E, strain energy is released by the development of intercolumnar cracks in the coating, which can propagate to the interface with the TGO (thermally grown oxide), deflect into the interface and propagate, leading to spallation of regions of the coating and loss of thermal protection. It is observed that cracks develop at initial imperfections in the structure. The greater the spacing between imperfections the faster the development of cracks at these locations. If a TBC contains a distribution of imperfections there is progressive formation of cracks, with the average spacing decreasing with time, after an initial incubation period. The crack density eventually saturates to a constant value, which depends on the mechanical properties of the TBC. Initially, a crack spacing, CS, in the range 1.5H ≤ CS ≤ 3H has been predicted based on trapezoidal contact models. Here H is the thickness of the coating. Crack spacing predicted using this model is consistent in the lower range of experimentally observed crack spacing. However, axisymmetric contact models predict a crack spacing, CS, in the range 4H ≤ CS ≤ 8H, which is in good agreement with experimentally observed crack spacing range 3H ≤ CS ≤ 10H reported in the literature. Compared to the trapezoidal contact models, axisymmetric contact models more accurately predict the sintering response.
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Pothecary, N. M. "The interaction of high frequency fields with physical objects and the resultant thermal response." Thesis, University of Bristol, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385685.
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Pustějovský, Jakub. "Administrativní objekt ve Fulneku." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-372325.
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The subject of this thesis is to create a project documentation of the design of a new office building construction in Fulnek – Jerlochovice. The building is located between residential and industrial zone. It has three aboveground levels. There is a technical backgroud, toilets, archive, rest zone for employees and two openspace offices located on the ground floor. The second floor is designed on the same basis. There are two openspace offices situated on the west side, background for company managment, toilets and day room with kitchen. The third floor is designed as conference room with kitchen and toilets. Construction system is cast-in-place concrete frame. The building is roofed with the flat roof. Foundations are made of one-stage concrete footing.
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Jones, Graham. "Thermal analysis and testing of a spaceborne passive cooler." Thesis, University of Oxford, 1994. http://ora.ox.ac.uk/objects/uuid:cef5bd18-c80d-442c-bb70-6414fdf29b61.
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This thesis describes the thermal design and thermal testing of the development model radiative cooler for the Composite Infra-Red Spectrometer (CIRS) due for launch on the Cassini spacecraft in 1997. The radiative cooler is used to cool the instrument's Focal Plane Assembly (FPA) to approximately 80K. The FPA holds two arrays of HgCdTe detectors for the mid infra-red spectrometer of the instrument which covers the wavelength range 7μm to 17μm. The FPA is mounted from the optics on a titanium alloy tripod and is cooled conductively by the radiator via a flexible link and a cold finger. A range of thermal models of the system have been developed ranging from a simple, analytical model to a finite difference numerical model. A calorimeter was designed to perform heat leak measurements on samples of Multi- Layer Insulation (MLI) blankets to determine the number and type of shields required for the MLI blanket covering the back of the cooler radiator. A test facility incorporating a vacuum system, a space simulator target, and a simulator for the CIRS instrument was designed and constructed for testing the assembled cooler. Various configurations of the Development Model (DM) CIRS cooler were tested as components became available and the results obtained compared to the thermal model predictions. It was found that the cooler will attain a temperature of 80K in operation, but with less excess cooling power than predicted by the thermal models.
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O'Dowd, Devin Owen. "Aero-thermal performance of transonic high-pressure turbine blade tips." Thesis, University of Oxford, 2010. http://ora.ox.ac.uk/objects/uuid:e7b8e7d0-4973-4757-b4df-415723e7562f.
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Guan, Juan. "Investigations on natural silks using dynamic mechanical thermal analysis (DMTA)." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:c16d816c-84e3-4186-8d6d-45071b9a7067.
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This thesis examines the dynamic mechanical properties of natural silk fibres, mainly from silkworm species Bombyx mori (B. mori) and spider species Nephila edulis, using dynamic mechanical thermal analysis, DMTA. The aim is not only to provide novel data on mechanical properties of silk, but also to relate these properties to the structure and morphology of silk. A systematic approach is adopted to evaluate the effect of the three principal factors of stress, temperature and hydration on the properties and structure of silk. The methods developed in this work are then used to examine commercially important aspects of the ‘quality’ of silk. I show that the dynamic storage modulus of silks increases with loading stress in the deformation through yield to failure, whereas the conventional engineering tensile modulus decreases significantly post-yield. Analyses of the effects of temperature and thermal history show a number of important effects: (1) the loss peak at -60 °C is found to be associated the protein-water glass transition; (2) the increase in the dynamic storage modulus of native silks between temperature +25 and 100 °C is due simply to water loss; (3) a number of discrete loss peaks from +150 to +220°C are observed and attributed to the glass transition of different states of disordered structure with different intermolecular hydrogen bonding. Excess environmental humidity results in a lower effective glass transition temperature (Tg) for disordered silk fractions. Also, humidity-dynamic mechanical analysis on Nephila edulis spider dragline silks has shown that the glass transition induces a partial supercontraction, called Tg contraction. This new finding leads to the conclusion of two independent mechanisms for supercontraction in spider dragline silks. Study of three commercial B. mori cocoon silk grades and a variety of processed silks or artificial silks shows that lower grade and poorly processed silks display lower Tg values, and often have a greater loss tangent at Tg due to increased disorder. This suggests that processing contributes significantly to the differences in the structural order among natural or unnatural silks. More importantly, dynamic mechanical thermal analysis is proposed to be a potential tool for quality evaluation and control in silk production and processing. In summary, I demonstrate that DMTA is a valuable analytical tool for understanding the structure and properties of silk, and use a systematic approach to understand quantitatively the important mechanical properties of silk in terms of a generic structural framework in silk proteins.
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van, Paridon Andrew. "Thermal modelling and control of high pressure turbine subsystems." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:2475deb2-208f-4d1d-83b0-1ff5bd90a79e.
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The control and monitoring of aircraft engine subsystems is one of the leading fields of research for improving overall performance. As engine sophistication increases, more sensor information becomes available to the digital control system, as well as options for active flow control technologies. It is important to develop control systems that can take full advantage of these developments. For instance, active control of the turbine casing can reduce excess rotor blade tip clearance; for every 0.0254mm of clearance eliminated, specific fuel consumption can be reduced by up to 0.1 and turbine entry temperature by up to 1K. However, the tip clearance changes between 0.1mm and 0.4mm throughout a flight due to differences in the expansion of the rotor disc and seal casing. Active tip clearance control can be used to mitigate this variation and thereby minimise fuel burn. Equally, turbine discs and blades experience large temperature ranges that affect their lives. These can be also be improved by active cooling flow modulation. Clearly, both tip clearance problems and cooling flow modulation require sophisticated real-time models and actuation systems. This thesis has two key objectives; the validation of an active impingement system, and the development of reduced order models for discs and casings. The thesis describes the design and development of a novel facility capable of reproducing typical conditions in a large civil engine's oversegment cavity. The facility recreates the air system at cruise-level temperatures (770K), pressures (1.35MPa) and mass flows (1.0kg/s), with a test casing that is instrumented to capture the complete three-dimensional thermal response. The facility has been designed specifically to validate a novel active clearance control concept - step climb alleviation (SCA). The SCA concept uses hot impingement jets from the oversegment cavity to heat the casing, providing a rapid thermal actuation system for tip clearance control during fast engine transients. Research at the facility allows better understanding of the circumferential heat transfer coefficients and the sealing effectiveness of the SCA impingement plates. The development of the facility considers different air system architectural solutions. A novel concentric double-vessel has been designed to accommodate the high temperatures and pressures using predominantly low cost steels. The electric heater and flow bypass system can deliver rapid changes to the test air flow rate without compromising the temperature. The rail system allows rapid change out of test geometries and accommodates the thermal growth of the facility. The commissioning results of the rig show that it can recreate engine realistic conditions. The facility has also been used to provide data for the development of reduced order models. In the second half of the thesis, a model of the test casing is developed using the newly defined LPV-SVD methodology. This method uses singular value decomposition (SVD) to identify modes of spatial coherence, and linear parameter varying (LPV) systems to model the non-linear dynamics. This is a low order thermal model capable of being run in real-time that requires only a small number of inputs already available in the engine measurement suite. When this is applied to the casing, an accuracy of +/-30K is achieved. The LPV-SVD model is capable of being applied directly to other engine components, using either experimental or simulated data for system identification. As such, it has also been applied to modelling the axisymmetric temperature of an IP disc using simulated data from SC03. In this context, the model is built and validated using flight relevant trajectories. The disc model uses only spool speed, pressure altitude, and compressor exit temperature as inputs, and produces temperature distributions to an accuracy of +/-32K, with all but a few points performing much better. The thesis also presents a Kalman filter augmentation to the LPV-SVD model, which helps track noisy trajectories outside the training data set. The filtered model has been validated against a previously unseen noisy flight profile, and achieves an accuracy of +/-30K. Finally, a second model of disc temperature has been developed using a physics based approach, a so called grey-box model. Heat transfer from air to disc is modelled using empirical rotor-stator aerodynamics matched to validated computational fluid dynamic analyses. Lumped capacitance models and simplified explicit conduction models simulate the heat diffusion through the axial and radial profile. This physics based model is also capable of being run in real-time, but proves to be less accurate than the LPV-SVD model in like-for-like comparisons. Overall, the LPV-SVD model recreates temperatures with far greater spatial resolution, making it a superior choice for disc life monitoring applications.
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Pe, Juan-Diego. "On the thermal behaviour of gas turbine filament seals." Thesis, University of Oxford, 2017. https://ora.ox.ac.uk/objects/uuid:1de17ef5-2f1c-4ac2-aae8-90a2efd53e8f.
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Advanced rotating shaft seals have the potential to significantly increase the efficiency and performance of steam and gas turbines. Two such seals, brush and leaf seals, rely on the use of thousands of flexible filaments to close clearances between rotating components and their static casings. The current life of the components is poor compared to the rest of the gas turbine, limiting the seals' deployment, particularly in the jet engine at high temperature and pressure. Poor understanding of the seal installation response to frictional heat generated at the point of filament-rotor contact during operation has limited the ability to predict engine closures and hence seal behaviour and life. The resulting temperature rises may compromise the mechanical integrity of the engine rotor in extremis leading to a shaft failure. This thesis considers the heat transfer mechanisms that govern frictional heating, of both the fluid and solid components in the vicinity of such seals, characterising the process both experimentally and using numerical models. Through the identification of key features of the heat transfer a simple numerical methodology is shown to predict the thermal behaviour of the seal installation sufficiently accurately for engine design purposes. A low order heat transfer model, using a simple electrical analogy for heat transfer is used to investigate frictional heat generation. When contact occurs between the rotor surface and the seal filaments, mechanical energy is dissipated as heat at the interface. This is conducted into the rotor and the seal filaments in proportions that depend on the heat transfer characteristics of both contacting bodies (thermal resistances). To calculate the heat partition ratio and the resulting contact temperature, the thermal resistances of both rotor and seal need to be known. To that end, a new test facility, the Seal Static Thermal Test Facility (SSTTF), is developed. This is first used to study the convective heat transfer occurring in the vicinity of the seal; heat transfer coefficients based on appropriate, scalable, gas reference temperatures are reported. Importantly the results show a larger area on the rotor surface affected by the presence of the seal than was assumed by previous workers. The test rig is further modified to generate heating in a static test rig equivalent to the frictional heating at the filament tips. The test rig allows the contact temperature between rotor and seal, a critical previously unknown parameter to be measured in a well-conditioned environment. The presence of many thousands of vanishingly small flow passages in filament seals makes their explicit modelling unfeasible for engine design purposes. Thus the results from the experimental campaign are used to develop a simple computational fluid dynamic model of the seal, including empirically derived frictional heating, and seal porosity models, to achieve similar leakage and surface heat transfer to the rotor as was seen in the static experiments. The low order CFD methodology presented in the thesis is finally employed to model the transient operation of a brush seal under engine representative rotor surface speeds and differential pressures. Experimental data were generated in the Oxford Engine Seal Test Facility for a typical brush seal rubbing against a high growth rotor. These experiments were modelled using CFD and finite element analysis using parameters derived from static tests for the porous modelling of the seal leakage. Comparison of results shows that, without further tuning, the thermal behaviour is captured well with a moderate conservative overestimation of rotor heating with increased differential pressure across the seal allowing the strategy to be used as an engine design tool.
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Stejskalová, Michaela. "Objekt pro požární sport." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2020. http://www.nusl.cz/ntk/nusl-410096.
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The Subject of these thesis is project new sport hall for Fire sport. The building is divided to two parts connected together. First part SO01 is main sport hall, second SO02 is background for sportsmen. The Building SO01 is making from LLENTAB system. The main support elements are from steel thin-walled profile, This part is single-storey building, without basement, build on foundation pad. Building SO02 is making from hollow bricks Heluz, floor structure is from prestressed concrete panels. The building has two floor with flat roof, build on concrete strip foundation. External wall is contact thermal insulated by mineral wool. All building is design according valid building standards.
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Veleba, Jakub. "Objekt věznice v Moravských Budějovicích." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2016. http://www.nusl.cz/ntk/nusl-240437.
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Theme of this diploma thesis is a newly buil building of prison in Moravské Budějovice. The buiding has four ground floors and is without cellar. The structural system of the building is made up of permanent formwork and system Porotherm. Ceiling construction is made up of reinforced hollow core slab. The building is covered with a flat roof.
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Choi, Myeonggeun. "Thermal control of gas turbine casings for improved tip clearance." Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:14a9ce6a-2af6-4187-afe7-8c6f8e113855.
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A thermal tip clearance control system provides a robust and flexible means of manipulating the closure between the casing and the rotating blade tips in a jet engine, reducing undesirable tip leakage flows. This may be achieved using an impingement cooling scheme on the external casing of the engine in conjunction with careful thermal management of internal over-tip seal segment cavity. For a reduction in thrust specific fuel consumption, the mass flow rate of air used for cooling must be minimised, be at as low a pressure as possible and delivered through a light weight structure surrounding the rotating components in the turbine. This thesis first characterises the effectiveness of a range of external impingement cooling arrangements in typical engine casing closure system. The effects of jet-to-jet pitch, number of jets, inline and staggered alignment of jets, arrays of jets on flange, on an engine representative casing geometry are assessed through comparison of the convective heat transfer coefficient distributions in a series of numerical studies. A baseline case is validated experimentally. The validation data allowed the suitability of different turbulence closure models to be assessed using a commercial RANS solver. Importantly for each configuration the thermal contraction of an idealised engine casing is predicted using thermo-mechanical finite element models, at a series of operating conditions representing engine idle to maximum take-off conditions. Cooling is provided by manifolds attached to the outside of the engine. The assembly tolerance of these components leads to variation in the standoff distance between the manifold and the casing. For cooling arrangements with promising performance, the study is extended to characterise the variation in closure with standoff distance. It is shown that where a sparse array of non-interacting jets is used the system can be made tolerant of large build misalignments. The casing geometry itself contributes to the thermal response of the system, and, in an additional study, the effect of casing thickness and circumferential thermal control flanges are investigated. Restriction of the passage of heat into the flanges was seen to be dramatically change their effectiveness and slight necking of the flanges at their root was shown to improve the performance disproportionally. High temperature secondary air flowing past the internal face of the engine casing tends to heat the casing, causing it to grow. Experimental and numerical characterisation of a heat transfer within a typical over-tip segment cavity heat transfer is presented in this thesis for the first time. A simplified modelling strategy is proposed for casing and a means to reduce the casing heat pickup by up to 25 % was identified. The overall validity of the modelling approach used is difficult to validate in the engine environment, however limited data from a test engine temperature survey became available during the course of the research. By modelling this engine tip clearance control system it was shown that good agreement to the temperature distribution in the engine casing could be achieved where full surface external heat transfer coefficient boundary conditions were available.
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Lambourne, Alexis. "Spray forming of Si-Al alloys for thermal management applications." Thesis, University of Oxford, 2007. http://ora.ox.ac.uk/objects/uuid:719651c0-9e12-41c7-ae7b-2abaa1320ea1.
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This thesis describes the processing and characterisation of Al-70Si alloys manufactured by gas atomised spray forming at Sandvik-Osprey (Neath, UK) and Oxford University using a newly commissioned spray forming pilot-plant facility. Spray formed Al-70Si (CE7) provides an attractive balance of thermophysical properties making it suitable for thermal management applications. Microstructural characterisation of CE7 was conducted using optical microscopy, image analysis, electron probe micro analysis (EPMA) and electron backscatter diffraction (EBSD). Microscopy revealed an interpenetrating network microstructure consisting of fine, randomly oriented polycrystalline primary Si interpenetrated by large, α-Al grains devoid of eutectic Si. Mechanical testing and thermal cycling simulated a service environment and revealed for the first time crack initiation, growth and blunting mechanisms, the effect of intermetallic phases on the bulk mechanical properties, and anisotropy effects resulting from macrosegregation of Al during solidification. A relationship between the inter-phase interface length and the fracture toughness has been proposed and methods of interface length refinement have been investigated, including chill casting and spray forming. Spray formed CE7 modified with separate additions of B, P, P+Ce and Sr have been microstructurally and mechanically characterised and compared with binary CE7. While alloy additions were effective in refining primary and eutectic Si in chill cast alloys, spray formed alloys showed little change in interface length. Particle injection of Si-Al powder was effective in refining the scale of the spray formed microstructure, and improving mechanical properties. The deleterious effect of intermetallic phases on bulk mechanical properties has been demonstrated and highlighted the importance of melt cleanliness and materials control during manufacturing.
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Warren, Tristram. "Exploring the moon in the thermal infrared : the space environment goniometer." Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:6c4f5fac-6d82-43f7-9987-d2e57ce18992.
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Measurements of the light scattering behaviour of the regolith of airless bodies in the Solar System, across wavelengths from the visible to the far infrared are essential to understanding their physical properties. This thesis describes the design, build and calibration of a novel instrument to measure the angular directionality of thermal infrared emission from surfaces (direction emissivity, DE). This work was originally motivated by the need for new DE measurements to support analysis of data collected by the thermal and far infrared Diviner Lunar Radiometer instrument (8-400 μm) currently in orbit around the Moon. To fully interpret the brightness temperatures measured by the Diviner instrument a three dimensional thermal physical model is required. These models typically assume that infrared radiation is scattered isotropically from the lunar surface. Although generally the models are in very good agreement with Diviners measured brightness temperatures, there are some discrepancies particularly in permanently shadowed regions near the lunar poles. One possible reason for these discrepancies is that the thermal infrared DE of the lunar surface is not isotropic as is typically assumed by many of these models. The "Oxford Space Environment Goniometer" (OSEG) was developed to measure the DE of surface across wavelengths from the visible to the thermal and far infrared. Analysis and modelling of initial DE measurements made with the OSEG show that the DE is dependent on the optical properties and roughness of the surface. DE measurements of the lunar regolith analogue material JSC-1AF have been incorporated into a three dimensional thermal physical model to show that the predicted surface temperatures of a polar lunar-like permanently shadowed region can differ by 10 K compared to assuming an isotropic DE.
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Sui, Tan. "Thermal-mechanical behaviour of the hierarchical structure of human dental tissue." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:2c8e9604-ec4b-4cfa-b6df-fff3e6579492.
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Human dental tissues are fascinating nano-structured hierarchical materials that combine organic and mineral phases in an intricate and ingenious way to obtain remarkable combinations of mechanical strength, thermal endurance, wear resistance and chemical stability. Attempts to imitate and emulate this performance have been made since time immemorial, in order to provide replacement (e.g. in dental prosthodontics) or to develop artificial materials with similar characteristics (e.g. light armour). The key objectives of the present project are to understand the structure-property relationships that underlie the integrity of natural materials, human dental tissues in particular, and the multi-scale architecture of mineralized tissues and its evolution under thermal treatment and mechanical loading. The final objective is to derive ideas for designing and manufacturing novel artificial materials serving biomimetic purposes. The objectives are achieved using the combination of a range of characterization techniques, with particular attention paid to the synchrotron X-ray scattering (Small- and Wide-Angle X-ray Scattering, SAXS and WAXS) and imaging techniques (Micro Computed Tomography), as well as microscopy techniques such as Environmental Scanning Electron Microscopy (ESEM), Transmission Electron Microscopy (TEM) and Atomic Force Microscopy (AFM). Mechanical properties were characterized by nanoindentation and photoelasticity; and thermal analysis was carried out via thermogravimetric analysis (TGA). Experimental observations were critically examined and matched by advanced numerical simulation of the tissue under thermal-mechanical loading. SAXS and WAXS provided the initial basis for elucidating the structure-property relationships in human dentine and enamel through in situ experimentation. Four principal types of experiment were used to examine the thermal and mechanical behaviour of the hierarchical structure of human dental tissue and contributed to the Chapters of this thesis: (i) In situ elastic strain evolution under loading within the hydroxyapatite (HAp) in both dentine and enamel. An improved multi-scale Eshelby inclusion model was proposed taking into account the two-level hierarchical structure, and was validated against the experimental strain evaluation data. The achieved agreement indicates that the multi-scale model accurately reflects the structural arrangement of human dental tissue and its response to applied forces. (ii) The morphology of the dentine-enamel junction (DEJ) was examined by a range of techniques, including X-ray imaging and diffraction. The transition of mechanical properties across the DEJ was evaluated by the high resolution mapping and in situ compression measurement, followed by a brief description of the thermal behaviour of DEJ. The results show that DEJ is a narrow band of material with graded structure and mechanical properties, rather than a discrete interface. (iii) Further investigation regarding the thermo-mechanical structure-property relationships in human dental tissues was carried out by nanoindentation mapping of the nano-mechanical properties in ex situ thermally treated dental tissues. (iv) In order to understand the details of the thermal behaviour, in situ heat treatment was carried out on both human dental tissues and synthetic HAp crystallites. For the first time the in situ ultrastructural alteration of natural and synthetic HAp crystallites was captured in these experiments. The results presented in this thesis contribute to the fundamental understanding of the structure-property integrity mechanisms of natural materials, human dental tissues in particular. These results were reported in several first author publications in peer-reviewed journals, conference proceedings, and a book chapter.
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Hillson, William Rawstron. "The role of thermal processing and protein oxidation in peanut allergy." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:88d64b79-a7e6-4e41-acee-47c215d39f6b.
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Food allergies are an increasing health problem throughout the developed world. Among these, peanut allergy is particularly significant, due to its exceptional severity and frequent lifelong duration. Much of its aetiology remains unclear. In particular, it remains unknown why, unlike other food allergies, peanut allergy incidence correlates poorly with average dietary peanut consumption. A popular explanation for this discrepancy is that peanut allergy is more common in regions where predominantly dry-roasted (DR) peanuts are consumed, leading to speculation that DR-induced chemical modifications may contribute to pathological Th2 responses in humans. Yet to date, no research group has demonstrated an enhanced immunogenicity of DR peanuts relative to raw in a murine model of sensitisation. This thesis begins with the hypothesis that dry-roasting does indeed alter the chemical composition of peanut proteins in such a way as to increase immunogenicity and allergenicity. To test this hypothesis robustly, I have first addressed flaws in previous studies by developing a methodology to thoroughly characterise samples of raw and DR peanut protein, as well as purifying samples of individual peanut allergens. Using these samples, I have demonstrated an enhanced immunogenicity of DR peanut protein relative to raw, in intragastric, subcutaneous and epicutaneous models of mouse sensitisation, and furthermore, that such enhanced responses feature a pronounced Th2 bias and functional IgE production. I will present evidence that this difference is not caused by either protein aggregation or the presence of other non-protein substances, but is due to an intrinsic property of the DR peanut proteins. I will go on to clarify candidate molecular mechanisms of this effect, examining several putative receptors and probing the effects of roasting on dendritic cell binding and interactions of peanut proteins. I conclude in light of these investigations that the dry-roasting hypothesis remains the most plausible explanation for the epidemiological distribution of peanut allergy, although many additional questions remain regarding the nature of the chemical modifications produced by roasting and the molecular basis of their recognition by the immune system.
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Alkandri, Ahmad. "Design and performance assessment of correlation filters for the detection of objects in high clutter thermal imagery." Thesis, University of Sussex, 2014. http://sro.sussex.ac.uk/id/eprint/49954/.
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The research reported in this thesis has examined means of enhancing the performance of the Optimal Trade-off Maximum Average Correlation Height (OT-MACH) filter for target detection in Forward Looking Infra-Red (FLIR) imagery acquired from a helicopter and border security FLIR camera in northern Kuwait. The data acquired with these FLIR sensors allows real-world evaluation of the comparative performance of the various filters that have been developed in the thesis. The results obtained have been quantified using well known performance measures such as Peak to Side-lobe Ratio (PSR) and Total Detection Error (TDE). The initial focus was to study the effect of modifying the OT-MACH parameters on the correlation metrics. A new optimisation technique has been presented, which computes statistically the filter alpha parameter associated with controlling the response of the filter to clutter noise. A further modification of the OT-MACH filter performance using the Difference of Gaussian bandpass filter (named the D-MACH filter) as a pre-processing stage has been described. The D-MACH has been applied to several test images containing single and multiple targets in the scene. Enhanced performance of the modified filter is demonstrated with improved metrics being obtained with less false side peaks in the correlation plane, especially when multiple targets are present in the test images. A further pre-processing technique was investigated using the Rayleigh distribution as a pre-processing filter (named the R-MACH filter). The R-MACH filter has been applied to multiple target types with tests conducted across various image data sets. The filter demonstrated an improvement over the Difference of Gaussian filter in terms of 6 reducing the number of parameters needing to be tuned whilst producing further enhanced correlation plane metrics. Finally, recommendations for future work has been made to improve the use of the OT-MACH filter in target detection and identification. A novel training image representation is proposed for further investigation, which will minimise the computational intensity of using the MACH filter for unconstrained object recognition.
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Braun, Marco [Verfasser], Dieter [Gutachter] Braun, and Frank [Gutachter] Cichos. "Optically Controlled Manipulation of Single Nano-Objects by Thermal Fields / Marco Braun ; Gutachter: Dieter Braun, Frank Cichos." Leipzig : Universitätsbibliothek Leipzig, 2016. http://d-nb.info/1240482795/34.
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Virdi, Amandeep Singh. "Aero-thermal performance and enhanced internal cooling of unshrouded turbine blade tips." Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:62c3e94a-a1ff-47a8-bb81-e870b0013f11.
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The tips of unshrouded, high-pressure turbine blades are prone to significantly high heat loads. The gap between the tip and over-tip casing is the root cause of undesirable over-tip leakage flow that is directly responsible for high thermal material degradation and is a major source of aerodynamic loss within a turbine. Both must be minimised for the safe working and improved performance of future gas-turbines. A joint experimental and numerical study is presented to understand and characterise the heat transfer and aerodynamics of unshrouded blade tips. The investigation is undertaken with the use of a squealer or cavity tip design, known for offering the best overall compromise between the tip aerodynamics, heat transfer and mechanical stress. Since there is a lack of understanding of these tips at engine-realistic conditions, the present study comprises of a detailed analysis using a high-speed linear cascade and computational simulations. The aero-thermal performance is studied to provide a better insight into the behaviour of squealer tips, the effects of casing movement and tip cooling. The linear cascade environment has proved beneficial for its offering of spatially-resolved data maps and its ability to validate computational results. Due to the unknown tip gap height within an entire engine cycle, the effects of gap height are assessed. The squealer's aero-thermal performance has been shown to be linked with the gap height, and qualitative different trends in heat transfer are established between low-speed and high-speed tip flow regimes. To the author's knowledge, the present work is the first of its kind, providing comprehensive aero-thermal experimental research and a dataset for a squealer tip at engine-representative transonic conditions. It is also unique in terms of conducting direct and systematic validations of a major industrial computational fluid dynamics method for aero-thermal performance prediction of squealer tips at enginerepresentative transonic conditions. Finally, after recognising the highest heat loads are found on the squealer rims, a novel shaped squealer tip has been investigated to help improve the thermal performance of the squealer with a goal to improve its durability. It has been discovered that a seven percent reduction in tip temperature can be achieved through incorporating a shaped squealer and maximising the internal cooling performance.
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Kleinerová, Jana. "Optimalizace nákladů provozní fáze stavebních objektů." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2016. http://www.nusl.cz/ntk/nusl-240394.
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The thesis discusses the operating costs and the possibilities for their optimization. Specifically, it focuses on one of the greatest possible operating costs and it's heating costs. In the first part of the thesis are defined in general expenses, the price and the production, operating costs, optimization of these costs, life cycle of buildings and technological methods to improve the thermal and technical properties of the object. Finally, the theoretical part describes the terms for calculating the energy performance of the building and the payback period, which evaluates the effectiveness of investments. The practical part is assessed according to specific building energy performance, and especially in terms of its demand for heating. The building is designed for six variants of insulation, which is again judged on their energy performance. Subsequently these measures for better thermal insulating properties of the object assessed according to their cost efficiency and return on investment of individual variants.
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Šusták, Jakub. "Vzduchotechnika hotelového objektu." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-226002.
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This thesis addresses the issue of the creation of the internal environment in the hotel. The subject is the evaluation of indoor environments, the selection and design of an appropriate ventilation system. The experimental part deals with the measurement of temperature and humidity with subsequent evaluation according to the applicable legal requirements and comparing with the calculation programmes.
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Sharer, Sahir Zalilah. "Investigation of protective mechanisms of organic coatings by thermal testing and electrochemical techniques." Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:8fb242d3-4836-4082-ae95-b7990b593f8a.
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This work investigated the protection of mechanism of organic coatings on steel exposed to 3% sodium chloride solution at 50°C, coupled with the use of electrochemical impedance spectroscopy (EIS) to monitor progress of corrosion and degradation of coating. Unlike Walter, EIS measurement was conducted at 50°C as well as after cooling, and measurements at intermediate temperatures have been used to characterize the dependence of the process involved. The proposition that corrosion rate is controlled by the ionic resistance of an organic coating has been tested. EIS results were fitted to a model circuit and changes in the film resistance and charge-transfer resistance with temperature were analyzed to deduce activation energies for the processes involved. Surprisingly, the calculated activation energy for coating resistance is significantly lower than the activation energy for the charge transfer resistance. This suggests that ion conduction in the coating, as apparent in an AC measurement, cannot be controlling the corrosion rate. Potentiostatic pulse tests on coated metal enable iR-corrected polarization curves to be plotted at different temperatures. From this, the activation energy determined from the corrosion currents also higher matches the higher activation energy value calculated from the charge transfer resistance. However, measurements of coating resistance on free films of the same coating also generate higher activation energy values, leaving two possible models that can account for the results.
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Trojanowski, Albin S. "Thermomechanical properties of polymers at high rates of strain." Thesis, University of Oxford, 1997. http://ora.ox.ac.uk/objects/uuid:a2c20a83-094d-4293-8c5f-665640c1ce5a.
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-1 were achieved when testing specimens and this rate was obtained using a split Hopkinson pressure bar. A substantial number of preliminary tests were conducted in order to obtain a suitable specimen size which was then used in the temperature measurement process. Quasistatic, intermediate and high strain-rate tests were performed; the last utilised the radiometer for temperature measurement. An Eyring plot was constructed from which fundamental values for activation volumes and enthalpies were obtained. Full descriptions of the testing techniques used have been included and a brief photoelastic analysis has been carried out on a partially deformed specimen which shows molecular alignment.
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O'Neill, David Patrick. "Mathematical modelling of the effects of hepatic radiofrequency ablation." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:b9ff47fd-0e1a-4ca6-a937-a7e4d49841ba.
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Liver cancer is a major cause of death worldwide and the impact that it has is set to increase in the coming decades. More than half a million cases are diagnosed each year and it is likely many more sufferers are dying unidentified in parts of the world with poor healthcare. Survival rates for untreated cases after diagnosis are low with few patients living beyond one year. A key cause for low survival rates being that the standard treatment is surgical resection; fewer than one quarter of patients are suitable for invasive surgery and five year survival rates rarely exceeds 66 %. RadioFrequency Ablation (RFA) is a minimally invasive technique which utilises the electrically resistive property of tissue to deposit heat energy locally in the vicinity of the tips of an RFA needle. Heat is transferred away through the tissue by conduction, convection of large blood vessels, and bulk flow of blood in smaller vessels. Liver cells, both cancerous and benign, when exposed to the resultant abnormally high temperatures die considerably more rapidly than in cases of natural hyperthermia. It is thus the radiotherapist’s objective to place the RFA needle in a position that maximises destruction of tumour cells, but minimises the collateral damage of surrounding healthy cells. The learning curve of this nontrivial task is reflected unfavourably in the statistics that relate patient survival rate to clinician experience. In this thesis two mathematical models are presented that could be combined into a ‘global’ model of the effects of RFA. To predict cell death in these conditions under RFA, the O’NeillModel is presented in which cells are accounted for by one of three states: alive, vulnerable, and dead. A mechanistic interpretation of the O’Neill Model is attained through comparison to a model from the literature. A known, but little investigated occurrence of tissue swelling in the annular region peripheral to the ablation volume is modelled in a novel way through equations from the literature that track ion transport across the cell membrane; the O’Neill Model for cell death is also incorporated into this model of oedema.
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Pladas, Karolis. "Kvartalo/objekto aprūpinimo šilumine energija variantų analizė." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20140611_130205-57334.
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Magistro baigiamajame darbe aptariamas Lietuvos ir Europos Sąjungos šalių energetikos sektorius. Apžvelgiamos direktyvos, strategijos, plėtros planai bei teisės aktai skirti energetikos plėtojimui šalyje. Tiriamuoju objektu pasirenkama Trakų Vokės katilinė, kuri aprūpina šiluma kvartalą degindama gamtines dujas vandens šildymo katiluose. Šiame darbe yra nagrinėjamos penkios alternatyvos: kogeneratorius ir dujiniai katilai, kogeneratorius su akumuliacine talpa ir dujiniais katilais, kogeneratorius su akumuliacine talpa ir biokuro katilais, kogeneratorius su akumuliacine talpa ir šilumos siurbliu, medienos dujofikavimo reaktorius su kogeneratoriumi ir vandens šildymo katilais. Alternatyvos yra nagrinėjamos dviem skirtingais scenarijais, kai kogeneratoriaus pagaminta elektra parduodama pagal VIAP tarifus ir pagal „Nord pool spot“ Lietuva biržos kainas. Tiriamasis darbas atliekamas naudojantis „energyPRO“ modeliavimo programa. Atlikus modeliavimą, sistemų veikimas įvertinamas pirminės energijos suvartojimu, ekologiniu ir ekonominiu požiūriais. Atliekama jautrumo analizė keičiant ekonominius rodiklius bei vertinant šilumos gamybą be kogeneracijos. Pagal gautus rezultatus suformuluojamos išvados. Darbą sudaro 10 skyrių. Apimtis – 79 psl. teksto be priedų, 47 iliustracijų, 10 lentelių, 74 bibliografiniai šaltiniai.In this master thesis, Lithuanian and European Union’s countries energy sector was discussed. An overview was made on EU directives, Lithuanian strategies, development plans and legalizations. Investigation object was Trakų Vokė boiler house with its district heating system. In the boiler house heat produced by combusting natural gas. During the research five alternatives were analysed: cogeneration and heat only boilers, cogeneration with thermal storage and heat only boilers, cogeneration with thermal storage and biomass heat only boilers, cogeneration with thermal storage and high temperature heat pump, biomass gasification reactor with cogeneration and heat only boilers. Alternatives are analysed based on two scenarios, first on when cogeneration is working by fixed electricity tariffs and second when cogeneration is working by liberalized electricity market conditions. Thesis carried out using “energyPRO” modelling software. All modelled systems are assessed by techno-economic and ecological approach. A sensitivity analysis was made by changing economical values and assessing systems without cogeneration. Based on the results conclusion was formed. Thesis includes 10 chapters. Size of work – 79 pages excluding appendixes, 47 pictures, 10 tables, 74 reference sources.
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Palin, Richard Mark. "Using metamorphic modelling techniques to investigate the thermal and structural evolution of the Himalayan-Karakoram-Tibetan orogen." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:f86580ad-c183-4ecd-bcbd-17f3a1b74548.
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Metamorphic rocks constitute a vast volumetric proportion of the Earth’s continental lithosphere and are invaluable recorders of the mechanisms and rates of deformation and metamorphism that occur at the micro-, meso- and macro-scale. As such, they have the potential to provide detailed insight into important tectonic processes such as the subductive transport of material into, and back from, mantle depths and also folding, faulting and thickening of crust that occurs during collisional orogeny. The Himalayan-Karakoram-Tibetan orogen is the youngest and most prominent example of a continent-continent collisional mountain belt on Earth today and is a product of the on-going convergence of the Indian and Asian plates that initiated in the Early Eocene. Thus, it provides an exceptional natural laboratory for the investigation of such processes. Recent advances in the computational ability to replicate natural mineral assemblages through a variety of metamorphic modelling techniques have led to improvements in the amount (and quality) of petrographic data that may be obtained from a typical metamorphic rock. In this study, phase equilibria modelling (pseudosection construction) using THERMOCALC, amongst other techniques, has been integrated with in-situ U–Pb and Th–Pb geochronology of accessory monazite in order to constrain the tectonothermal evolution of four regions intimately associated with the Himalayan-Karakoram-Tibetan orogen. These regions comprise the Karakoram metamorphic complex (north Pakistan), the Tso Morari massif (north-west India), the eastern Himalayan syntaxis (south-east Tibet) and the Day Nui Con Voi metamorphic core complex of the Red River shear zone (North Vietnam). Each case study documents previously unreported metamorphic, magmatic or deformational events that are associated with the India-Asia collision. These data have allowed original interpretations to be made regarding the tectonic evolution of each individual region as well as the large-scale evolution of the Himalayan-Karakoram-Tibetan orogenic system as a whole.
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Kolesa, Jiří. "Polyfunkční dům ve Strakonicích." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-265574.
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The subject of this thesis is the design and project documentation of a new multifunctional house in Strakonice. The building has four floors, without basement, and is located on a slightly sloping land in the suburban part of the town of Strakonice. It is based on shallow foundations and covered with a flat roof. It is a transverse wall structural system, build with clay block masonry, with the semi-assembled ceiling structures of ceramic and concrete beams and inserts. It is conceived as a double-aisle layout. The ground floor of each wing consists of the establishment of shops and house facilities. The overground floors are designed as six residential units of varying size category. Both tracts have separate entrances to both the residential portion and to individual businesses. The building is designed from traditional building materials. In addition to the architectural construction and civil-engineering design, a part of this project is also a fire safety design and an assessment from the perspective of building physics.