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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Autonomní venkovní systém pro pěstování rostlin / Autonomous outdoor system for growing plants

Schmidt, Dominik January 2015 (has links)
This diploma thesis deals with maintaining possibilities for appropriate climatic conditions in outdoor greenhouse. The importance for growing plants is an appropriate temperature, humidity and adequate supply of water. The aim of the study is to suggest an apparatus sustaining beforehand defined conditions in the greenhouse with minimal requirements for maintenance. Apparatus uses analogue control by applying photosezistor and thermistor. For power supply are DC-DC converters used.
2

Autonomní venkovní systém pro pěstování rostlin / Autonomous outdoor system for growing plants

Schmidt, Dominik January 2015 (has links)
This diploma thesis deals with maintaining possibilities for appropriate climatic conditions in outdoor greenhouse. The importance for growing plants is an appropriate temperature, humidity and adequate supply of water. The aim of the study is to suggest an apparatus sustaining beforehand defined conditions in the greenhouse with minimal requirements for maintenance. Apparatus uses analogue control by applying photosezistor and thermistor. For power supply are DC-DC converters used.
3

Návrh tepelně-regulačního systému pro přesnou stabilizaci teploty s využitím Peltierových termoelektrických modulů / Design of thermal system for accurate temperature stabilization using Peltier thermoelectric modules

Motl, Jakub January 2011 (has links)
This master’s thesis describes design procedure of a heat-regulating system to stabilize its temperature using a Peltier module. The implementation uses eight-bit microcontroller ATmega16 made by company ATMEL for the local and remote control system. The temperature sensors communicate with the microcontroller by serial SPI interface. To display user data, it has a DEM16217SYH type character LCD display with HD44780 control circuit. To collect data from the cooling areas of Peltier module, accurate ADT7320 temperature sensors are used, made by company Analog Devices. The Control of the Peltier module happens in two points of the electrode system and a bistable hysteresis software regulator is used. The first part summarizes the theory, which concerns with the design. Next part concerned with issues of the Peltier module, overview of temperature sensors, description of the microcontroller, the display unit and the used regulator. Last part describes the hardware and software implementation.
4

Controle térmico de alta exatidão e sua aplicação na determinação de propriedades térmicas de materiais

Nascimento, Leonaldo José Lyra do 14 December 2012 (has links)
Made available in DSpace on 2015-05-08T14:59:50Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 5685009 bytes, checksum: 7c7cec127c61d91393979e6be4ef4ab5 (MD5) Previous issue date: 2012-12-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This paper presents a theoretical and experimental study of a PID control-Proportional, Integral and Derivative using PELTIER module that achieves precision of about 0.01oC. It is developed to study the integrated instrumentation and control heat transfer. Based on this we developed a heat signal generator on a flat surface and applied to the measurement of thermal properties, in a system similar to electrical circuit. After several experiments, the results indicates the validity of the proposal. / Neste trabalho apresenta-se um estudo teórico e experimental de um controle P.I.D.- Proporcional, Integral e Derivativo, utilizando módulos Peltier s que alcançam precisão de cerca de 0.01oC. É desenvolvido o estudo da instrumentação e controle integrado à transferência de calor. Baseado neste controle foi desenvolvido um gerador de sinais térmicos em uma superfície plana e aplicado na medida de propriedades térmicas, em um sistema semelhante ao circuito elétrico. Após vários ensaios experimentais usando amostras sólidas, os resultados indicam a validade da proposta.
5

Inkubátor s regulací teploty a vlhkosti / Incubator with adjustable temperature and humidity

Hikaník, Matúš January 2011 (has links)
This project deals with comparing types and properties of commercial produced incubators for exotic birds. It searches the best solution from these area. In this project are compars individual components and their choice for realization in this project. Then in this project is solution of regulation temperature and humidity in engineered mechanism and discovered parameters of specifically space. Then is developed solution of thermostat and hydrosatat for this prototype. Temperature is changed by Peltier module, who is involved in correct system. Humidity is regulated by resistor humidifier. Complex system is managed by microcontroler. System communicates with PC via USB interface and Ethernet. Solution of this project is maked functional prototyp.
6

Development of a Temperature Controlled Cell for Surface Enhanced Raman Spectroscopy for in situ Detection of Gases

Appelblad, André January 2014 (has links)
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.

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