No description available.

No / A multivariable model of an automotive gas turbine, obtained from the linearized system equations is investigated. To facilitate vehicle speed changes, whilst protecting the system against thermal damage, control of the power turbine inlet gas temperature and gas generator speed is proposed by feedback regulation. Fuel flow and the power turbine nozzle area variations are the selected, manipulatable inputs. Owing to the limited control energy available for regulation purposes a multivariable, optimum, minimum control effort strategy is employed in the inner loop controller design study. Simulated, open and closed loop system responses are presented for purposes of comparison. Significant improvements in the transient response interaction reaction times and low steady state output interaction achieved using passive compensation and output feedback alone. Simplification of the closed loop configuration is proposed in the final implementation without performance penalties.

В первом разделе работы рассмотрены факторы, определяющие климатические условия в помещении и методика расчета теплопотерь. Также приведено описание современных способов регулирования температуры в помещении и рассмотрены два реализованных алгоритма для управления температурным режимом в помещении, основанные на математическом анализе и на базе нечеткой логике. Во втором разделе рассматривается тепловая модель здания для традиционной системы регулирования температуры, реализованная в Matlab-Simulink. По рассмотренной модели проведен сравнительный анализ использования различного вида регуляторов и его выбор для реализации интеллектуальной системы управления температурным режимом. В третьем разделе описана реализация алгоритма для предикции температуры на базе нейронных сетей. А также представлено описание реализации аппаратной и программной части интеллектуальной системы. / In the first section of the dissertation, the factors that determine the climatic conditions in the room and the method for calculating heat loss are considered. It also provides a description of modern methods of room temperature control and considers two implemented algorithms for controlling the temperature regime in a room, based on mathematical analysis and on the basis of fuzzy logic. The second section examines a building thermal model for a traditional temperature control system implemented in Matlab-Simulink. Based on the considered model, a comparative analysis of the use of various types of controllers and its choice for the implementation of an intelligent temperature control system is carried out. The third section describes the implementation of an algorithm for predicting temperature based on neural networks. It also provides a description of the implementation of the hardware and software of the intelligent system.

No description available.

No / Experimental observations of melt temperature profiles and melting performance of extruder screws are reported. A novel temperature sensor consisting of a grid of thermocouple junctions was used to take multiple temperature readings in real time across melt flow in a single screw extruder. Melt pressure in the die and power consumption were also monitored. Three extruder screws at a range of screw speeds were examined for a commercial grade of low density polyethylene. Results showed melt temperature fields at low throughputs to be relatively independent of screw geometry with a flat-shaped temperature profile dominated by conduction. At high throughputs, melting performance and measured temperature fields were highly dependent upon screw geometry. A barrier-flighted screw with Maddock mixer achieved significantly better melting than single flighted screws. Low temperature "shoulder" regions were observed in the temperature profiles of single-flighted screws at high throughput, due to late melting of the solid bed. Stability of the melt flow was also dependent upon screw geometry and the barrier-flighted screw achieving flow with lower variation in melt pressure and temperature. Dimensionless numbers were used to analyze the relative importance of conduction, convection, and viscous shear to the state of the melt at a range of extrusion conditions.

During the last decade, ultrasonic manipulation has matured into an important tool with a wide range of applications, from fundamental cell biological research to clinical and industrial implementations. The contactless nature of ultrasound makes it possible to manipulate living cells in a gentle way, e.g., for positioning, sorting, and aggregation. However, when manipulating cells using ultrasound, especially using high acoustic amplitudes, a great deal of heat can be generated. This constitutes a challenge, since the viability of cells is dependent on a stable physiological temperature around 37°C.      In this Thesis we present applications of ultrasonic manipulation of fluids, particles, and cells in temperature-controlled micrometer-sized devices fabricated using well established etching techniques, directly compatible with high-resolution fluorescence microscopy. Furthermore, we present ultrasonic manipulation in larger up to centimeter-sized devices optimized for fluid mixing and cell lysis. In the present work, two new ultrasonic manipulation platforms have been developed implementing temperature control. These platforms are much improved with increased performance and usability compared to previous platforms. Also, two new ultrasonic platforms utilizing low-frequency ultrasound for solubilization and cell lysis of microliter-volumed and milliliter-volumed samples have been designed and implemented.      We have applied ultrasound to synchronize the interaction between large numbers of immune, natural killer cells, and cancer cells to study the cytotoxic response, on a single cell level. A heterogeneity was found among the natural killer cell population, i.e., some cells displayed high cytotoxic response while others were dormant. Furthermore, we have used temperature-controlled ultrasound to form up to 100, in parallel, solid cancer HepG2 tumors in a glass-silicon multi-well microplate. Next, we investigated the immune cells cytotoxic response against the solid tumors. We found a correlation between the number of immune cells compared to the size of the tumor and the cytotoxic outcome, i.e., if the tumor could be defeated.             Finally, the effect of high acoustic pressure amplitudes in the MPa-range on cell viability has been studied in a newly developed platform optimized for long-term stable temperature control, independent on the applied ultrasound power. Lastly, we present two applications of ultrasonic fluid mixing and lysis of cells. One platform is optimized for small microliter-sized volumes in plastic disposable chips and another is optimized for large milliliter-sized volumes in plastic test tubes. The latter platform has been implemented for clinical sputum sample solubilization and cell lysis for genomic DNA extraction for subsequent pathogen detection / Ultraljudsmanipulering har under de senaste tio åren mognat och utvecklats till ett verktyg med ett brett användningsområde. Idag kan man finna applikationer inom allt från cellbiologisk grundforskning till industri samt sjukvård. Ultraljudsmanipuleringens kontaktlösa natur gör det till en varsam metod för att manipulera celler, till exempel inom positionering, sortering och aggregering. När ultraljud med hög amplitud används kan värmeutvecklingen, som är oundviklig, bli ett problem. För att kunna säkerställa hög cellviabilitet krävs temperaturkontroll som kan hålla en fysiologisk, stabil temperatur på 37°C.      I denna avhandling presenterar vi tillämpningar av temperaturkontrollerad ultraljudsmanipulering i mikrometerstora anordningar fabricerade med väletablerade etsningstekniker.  Dessa anordningar är optimerade för att vara fullt kompatibla med högupplöst fluorescensmikroskopi.  Vi demonstrerar även ultraljudsmanipulering i centimeterstora anordningar optimerade för omrörning och blandning av vätskor samt lysering av celler. Två nya plattformar för ultraljudsmanipulering med inbyggd temperaturkontroll har utvecklats. Dessa två plattformar erbjuder ökad prestanda, flexibilitet samt även användarvänlighet. Utöver dessa plattformar har ytterligare två anordningar för lågfrekvent ultraljudssolubilisering och cellysering av mikroliter- och milliliterstora prover konstruerats.      I denna avhandling har vi tillämpat ultraljud för att synkronisera interaktionen mellan populationer utav immunceller (natural killer-celler) och cancerceller för att på cellnivå studera det cytotoxiska gensvaret. Vi fann en heterogenitet hos immuncellspopulationen. Det manifesterade sig i en fördelning av immuncellerna, från celler med stort cytotoxiskt gensvar till inaktiva immunceller. Vi har dessutom använt temperaturkontrollerad ultrasljudsmanipulering för att skapa solida cancertumörer utav HepG2-cancerceller, upp till 100 stycken parallellt, i en multihåls-mikrotiterplatta bestående av glas och kisel. Med hjälp av dessa tumörer har vi studerat det cytotoxiska gensvaret från immuncellerna. Vi fann att förhållandet mellan antalet immunceller och storleken på tumören bestämde utfallet, det vill säga om tumören kunde bekämpas.      Vi presenterar dessutom effekten utav högamplitudsultraljudsexponering av cancerceller i en plattform speciellt designad för höga tryckamplituder med implementerad ultraljudseffektsoberoende temperaturkontroll. Slutligen presenterar vi två tillämpningar av ultraljud för vätskeblandning och cellysering. Den första tillämpningen är anpassad för små volymer i plastchip för engångsbruk och den andra är optimerad för större volymer i plastprovrör. Den senare tillämpningen är speciellt framtagen för ultraljudssolubilisering och cellysering utav kliniska sputumprover för att möjliggöra DNA-extrahering för detektion av smittämnen. / <p>QC 20150522</p>

This work describes a master’s thesis in engineering physics at Umeå University carried out during the spring semester of 2014. In the thesis the student has constructed and tested a temperature controlled cell for cooling/heating of surface-enhanced-Raman-spectroscopy (SERS) substrates for rapid detection of volatile substances. The thesis was carried out at the Swedish Defence Research Agency (FOI) in Umeå, Sweden. A Linkam Scientific Instruments TS1500 cell was equipped with a Peltier element for cooling/heating and a thermistor temperature sensor. A control system was constructed, based on an Arduino Uno microcontroller board and a pulse-width-modulated (PWM) H-bridge motor driver to control the Peltier element using a proportional-integral (PI) control algorithm. The temperature controlled cell was able to regulate the temperature of a SERS substrate within -15 to +110 °C and maintain the temperature over prolonged periods at ±0.22 °C of the set point temperature. Gas phase of 2-chloro-2-(difluoromethoxy)-1,1,1-trifluoro-ethane (isoflurane) was flowed through the cell and SERS spectra were collected at different temperatures and concentrations. This test showed that the signal is increased when the substrate is cooled and reversibly decreased when the substrate was heated. Keywords: temperature control, Raman scattering, surface enhanced Raman spectroscopy SERS, SERS substrate, volatile substances, Peltier module, thermistor, PWM, H-bridge, PI(D) control. / Detta dokument beskriver ett examensarbete för civilingenjörsexamen i teknisk fysik vid Umeå Universitet som utförts under vårterminen 2014. I examensarbetet har en kyl-/värmecell för temperaturkontroll av substratytor för ytförstärkt ramanspektroskopi (SERS) för snabb detektion av farliga flyktiga ämnen konstruerats och testats. Arbetet utfördes vid Totalförsvarets forskningsinstitut (FOI) i Umeå, Sverige. Utgångspunkten var ett Linkam Scientific Instruments TS1500 mikroskopsteg, vilket utrustades med ett Peltierelement för kylning/värmning och en termistor för temperaturövervakning. Ett styrsystem baserat på ett Arduino Uno mikrostyrenhetskort konstruerades med ett motordrivkort (H-brygga) vilket använder pulsbreddsmodulering (PWM) för att reglera spänningen till Peltierelementet utifrån en PI-regulator. Den färdiga cellen klarade att reglera temperaturen på ett SERS-substrat i ett temperaturspann på ungefär -15 till +110 °C med en temperaturstabilitet på ±0.22 °C av måltemperaturen. Cellen testades sedan på flyktiga ämnen för att visa dess funktion. Difluorometyl-2,2,2-trifluoro-1-kloroetyleter (isofluran) i gasfas, med instrumentluft som bärargas, flödades genom cellen och SERS-spektra erhölls vid olika koncentrationer och temperaturer. Vid samtliga koncentrationer visades att lägre temperatur ger ökad signalstyrka. När ytan sedan värmdes upp sjönk signalen reversibelt tillbaka till ursprungsvärdet. Nyckelord: temperaturkontroll, ytförstärkt ramanspektroskopi, SERS, flyktiga ämnen, Peltierelement, thermistor, PWM, H-brygga, PI(D)-regulator.

Le travail de recherche présenté s'inscrit pleinement dans les préoccupations énergétiques de la Réunion, en proposant d'évaluer le potentiel de la technologie solaire thermodynamique avec ou sans système à concentration en zone tropicale et les réseaux électriques non interconnectés. Le solaire thermodynamique désigne la production d'électricité à partir du rayonnement solaire via un cycle thermodynamique. En soumettant le cycle thermodynamique à une source « froide » (eau ou air ambiant) et une source « chaude » générée par des capteurs solaires l'on obtient un travail mécanique en sortie de turbine. En couplant la turbine à un alternateur de l'électricité est produite. Utilisation de capteurs à faible ou sans concentration permettent de diminuer le seuil de rentabilité des installations solaires thermodynamiques. Dans ce cas, ce type de technologie n'est plus réservé aux climats désertiques ou méditerranéens. Une étude préliminaire montre qu'elles sont exploitables en zone tropical. De plus, le couplage de l'installation à des systèmes de stockage thermique ou à des installations d'appoint utilisant de la biomasse par exemple permet de produire une énergie électrique de façon continue. Ce projet de recherche à pour but de définir les technologies adéquates, étudier finement les microclimats locaux propices à ces technologies et de réaliser un modèle numérique pour l'étude des conditions d'opération des installations solaires thermodynamiques. Ce projet permettra d'explorer une filière énergétique d'avenir et développer une expertise locale qui contribuera au rayonnement de la Réunion dans la zone océan Indien. / This thesis focuses on the study of the direct solar resource received in Reunion and numerical modeling of a solar power plant consists of: 1 / a field of linear Fresnel collectors in which circulates synthetic oil; 2 / two sensible heat storage tanks; 3 / an organic Rankine cycle. The main goal is to evaluate the performance of such power plant in the island area identified as suitable.To meet this goal, several studies have been conducted: (i) a beam solar radiation map of Reunion was made from satellite images of MeteoSat 7. This map was used to assess the availability of this resource; (ii) a new global-to-diffuse irradiance decomposition model was made from based-ground measurements at Saint-Pierre. This model is based on the representation of higher probabilities of occurrence of the diffuse fraction; (iii) the geometry of the solar collector and beam solar irradiance were modeled from an existing ray-tracing code. This code has been used, firstly, to dimension the collector using an optimization method. And secondly, to develop a fast method in order to simulate absorbed flux distribution on the linear receiver elements; (iv) unsteady-state heat transfers within the solar collector was modeled with a nodal approach; (v) annual electricity production of the power plant running in the south of the island was simulated with a monitoring and control strategy relevant for the demand of the local electricity grid.The models that have been developed during this thesis are design support tools and allow the study of control strategies control of solar power plants with linear Fresnel collector.

Neste trabalho é apresentado o desenvolvimento de instrumentação eletrônica para controle e automação de um sistema de crescimento de semicondutores por Epitaxia por Feixes Moleculares. Envolve uma variedade de circuitos analógicos e digitais como: um módulo de aquisição de dados e controle baseado em uma UCP Z-80, contendo algumas interfaces digitais e analógicas multiplexadas, e comunicando-se com um microcomputador através de uma interface serial. Envolve ainda o desenvolvimento de controladores de temperatura analógicos tipo P.I.D., atuação por motores de passo e circuitos de condicionamento de sinal. / In this work is presented the development of electronic instrumentation for automation and control of a Molecular Beam Epitaxy semiconductor growth system. A variety of analog and digital instrumentation circuits have been designed and implemented, including a data acquisition and control system based on a Z-80 CPU, which controls some multiplexed digital and analog interfaces and talks to a microcomputer using serial communication. Other circuits have been also developed, including analog temperature controllers, stepper motor actuators and circuits for signal conditioning.

In response to global climate change, many important earth-systems-oriented science programs have been established in the past. One such program, the Fluxnet program, studies the response of world forests and other natural ecosystems by measuring biospheric fluxes of carbon dioxide (CO2), water vapour, and energy with eddy-covariance (EC) techniques to assess the role of world ecosystems in offsetting increases in CO2 emissions and related impacts on global climate. The EC methodology has its limitations particularly when weather is inclement and during system stoppages. These limitations create non-trivial problems by creating data gaps in the monitored data stream, diminishing the integrity of the dataset and increasing uncertainty with data interpretation. This Thesis deals with the development of a parsimonious, semi-empirical approach for gap filling of net ecosystem productivity (NEP) data. The approach integrates the effects of environmental controls on diurnal NEP. The approach, because of its limited number of parameters, can be rapidly optimized when appropriate meteorological, site, and NEP target values are provided. The procedure is verified by applying it to several gap-filling case studies, including timeseries collected over balsam fir (Abies Balsamea (L.) Mill.) forests in New Brunswick (NB), Canada and several other forests along a north-south temperaturemoisture gradient from northern Europe to the Middle East. The evaluation showed that the model performed relatively well for most sites; i.e., r2 ranged from 0.68-0.83 and modelling efficiencies, from 0.89-0.97, demonstrating the possibility of applying the model to forests outside NB. Inferior model performance was associated with sites with less than complete input datasets.