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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.
131

Use of Distance Weighted Metrics to Investigate Landscape-Stream Temperature Relationships Across Different Temporal Scales

Watson, Eric Craig 16 August 2016 (has links)
Stream ecosystems have experienced significant negative impacts from land use, resource exploitation, and urban development. Statistical models allow researchers to explore the relationships between these landscape variables and stream conditions. Weighting the relevant landscape variables based on hydrologically defined distances offers a potential method of increasing the predictive capacity of statistical models. Using observations from three grouped watersheds in the Portland Metro Area (n=66), I have explored the use of three different weighting schemes against the standard method of taking an areal average. These four different model groups were applied to four stream temperature metrics: mean seven-day moving average maximum daily temperature (Mean7dTmax), number of days exceeding 17.8 °C (Tmax7d>17.8), mean daily range in stream temperature (Range_DTR), and the coefficient of variation in maximum daily temperature (CV_Tmax). These metrics were quantified for the 2011 dry season. The strength of these model groups were also examined at a monthly basis for each of the four months within the dry season. The results demonstrate mixed effectiveness of the weighting schemes, dependent on both the stream temperature metric being predicted as well as the time scale under investigation. Models for Mean7dTmax showed no benefit from the inclusion of distance weighted metrics, while models for Range_DTR consistently improved using distance weighted explanatory variables. Trends in the models for 7dTmax>17.8 and CV_Tmax varied based on temporal scale. Additionally, all model groups demonstrated greater explanatory power in early summer months than in late summer months.
132

Compartment Fire Temperature Calculations and Measurements / Mätning och beräkning av temperatur i brandceller

Byström, Alexandra January 2017 (has links)
This thesis is devoted to heat transfer and fire dynamics in enclosures. It consists of a main part which summarizes and discusses the theory of heat transfer, conservation of energy, fire dynamics and specific fire scenarios that have been studied. In the second part of this thesis, the reader will find an Appendix containing seven scientific publications in this field. In particular, one- and two-zone compartment fire models have been studied. A new way of calculating fire temperatures of pre- and post-flashover compartment fires is presented. Three levels of solution techniques are presented including closed form analytical expressions, spread-sheet calculations and solutions involving general finite element temperature calculations. Validations with experiments have shown good accuracy of the calculation models and that the thermal properties of the surrounding structures have a great impact on the fire temperature development. In addition, the importance of the choice of measurement techniques in fire engineering has been studied. Based on the conclusions from these studies, the best techniques have been used in further experimental studies of different fire scenarios. / Denna avhandling behandlar problem kopplade till värmeöverföring och branddynamik i slutna utrymmen med tonvikt på värmeöverföring mellan gaser och utsatta konstruktioner. Avhandlingen består av en huvuddel och ett appendix innehållande sju vetenskapliga artiklar. I huvuddelen sammanfattas och diskuteras grundläggande teorier och principer inom värmeöverföring och branddynamik samt studier av ett antal specialfall av brandscenarion som baseras på dessa teorier. I de avslutande bilagorna (Artiklar A1-A3 och Artiklar B1-B2) finns sju vetenskapliga artiklar som grundligare beskriver de ovan nämnda specialfallen. Huvudfokus i avhandlingen ligger på temperaturutveckling vid brand i slutna utrymmen. I avhandlingen studeras i synnerhet en- och två-zonsmodeller för brand i slutna utrymmen, och en ny metod för att beräkna brandgastemperaturer före och efter övertändning i rumsbränder är framtagen. Validering av dessa modeller med experiment visar att deras noggrannhet är bra. Modellerna visar också att de termiska egenskaperna hos de omgivande ytorna har stor inverkan på brandtemperatursutvecklingen. I tillägg studeras i denna avhandling betydelsen av val av mätmetoder i brandtekniska tillämpningar. På grundval av slutsatserna från dessa studier har de främsta mätteknikerna använts i ytterligare experimentella studier av olika brandscenarier.
133

Mikroprocesorem řízené měření a regulace teploty / Microprocessor Controlled Measurement and Control Temperature

Vožda, Michal January 2011 (has links)
The aim of the project is a design of the temperature controler based on microprocessor. There are described the most widely used sensors for the temperature measuring and their involvement in the electric circuit. The temperature controler is based on the Peltier’s thermoelectric battery. Project desribes power control of this thermoelectric battery and also a design of the entire system and a description of the blocks takes a part.
134

Digitální prostorový termostat ovládaný přes internet / Digital room thermostat controlled via internet

Bača, Martin January 2013 (has links)
This diploma thesis deals with the ideological design and realization of digital room thermostat and a temperature sensor selection. The device is designed as three units communicating wirelessly. Outdoor unit and control units sensor provide data for the control circuit of microcontroller ATmega16. Microcontroller choose the boiler operation based on senzor data. Thermostat can be remotely controled
135

Systém pro měření tepelné účinnosti solárních absorbérů / System for measuring of thermal efficiency of solar absorbers

Řiháček, Jan January 2013 (has links)
The thesis deals with the measurement system for determining the thermal efficiency of the newly developed types of solar absorbers. Measuring equipment allows simultaneous indoor or outdoor thermal efficiency detection of up to four samples absorbers. Emphasis is placed on the flow and heat transfer medium temperature changes. For this purpose is used Biotech FCH-m-POM-LC and LM35DZ sensors. Sensor signal is transferred to a PC using the measuring module NI USB-6221. Here it is further processed by proposed evaluation program. The software is implemented in LabVIEW integrated development environment. In a final part are performed a verification measurements to assess system performance and evaluate the thermal efficiency of various types of solar absorbers. This path is also demonstrated high efficiency applications absorbent layer coating color RABSORB 5.
136

Systém pro měření teploty, tlaku a vlhkosti ve výrobní hale / Temperature, pressure and humidity monitoring system for a workshop floor

Kudera, Tomáš January 2017 (has links)
This thesis deals with the design of overall concept of distributed system which is used for temperature, pressure and humidity measurement. The system is adapted to be used in instrument transformers and sensors production hall of ABB s.r.o. Brno. Firstly, the requirements for the measuring system are defined. After that market research focused on sensors and measurement modules is performed. The selected sensor is afterwards built into own measurement module for which hardware and software part is designed. The work continues with design of local and remote database of measured values. Besides, the PC software used for local and remote data storage is designed afterwards. The components of the measurement system are tested in the final part of the thesis.
137

Theoretical analyses and design, construction and testing of a flow loop for the study of generalised forced and natural convection boiling heat transfer phenomena on typical light-water nuclear reactor fuel pin configurations

Govinder, Kuvendran January 2019 (has links)
In a worldwide pursuit for more Accident Tolerant nuclear Fuel (ATF), the quest to obtain and certify alternative nuclear fuel cladding tubes for light-water nuclear power reactors is still a key challenge. One of the facets in this program to develop more ATF is the heat transfer evaluation between the various proposed clad tubes manufactured from suitable replacement materials and the current problematic zirconium-alloy based clad tubes used in nuclear power reactors. For the heat transfer analysis, the accurate measurement of the temperature on the heat transfer surface of heated tubes to be tested was one of the important objectives for the effective analysis of the heat transfer characteristics to the water coolant. After extensive investigations, a suitable technique was developed and validated against recognised forced-convection heat transfer correlations. The results showed that this technique was well suited for external forced convection heat transfer studies from heated surfaces exposed to forced convection water coolants. / Dissertation (MSc)--University of Pretoria, 2019. / Mechanical and Aeronautical Engineering / MSc (Applied Science - Mechanics) / Unrestricted
138

Parameter Identification Methodology for Thermal Modeling of Li-ion Batteries

Khanna, Yatin 06 September 2022 (has links)
No description available.
139

Validation Of Wideband Ocean Emissivity Radiative Transfer Model

Crofton, Sonya 01 January 2010 (has links)
Radiative Transfer Models (RTM) have many applications in the satellite microwave remote sensing field, such as the retrieval of oceanic and atmospheric environmental parameters, including surface wind vectors and sea surface temperatures, integrated water vapor, cloud liquid, and precipitation. A key component of the ocean RTM is the emissivity model used to determine the brightness temperature (Tb) at the ocean’s surface. A new wideband ocean emissivity RTM developed by the Central Florida Remote Sensing Laboratory (CFRSL) calculates ocean emissivity over a wide range of frequencies, incidence angles, sea surface temperatures (SST), and wind speed. This thesis presents the validation of this CFRSL model using independent WindSat Tb measurements collocated with Global Data Assimilation System (GDAS) Numerical weather model environmental parameters for frequencies between 6.8 to 37 GHz and wind speeds between 0 – 20 m/s over the July 2005 – June 2006 year. In addition, the CFRSL emissivity model is validated using WindSat derived ocean wind speeds and SST that are contained in the Environmental Data Record (EDR) and combined with the GDAS environmental parameters. Finally, the validation includes comparisons to the well-established XCAL ocean emissivity RTM. The focus of this validation and comparison is to assess performance of the emissivity model results with respect to a wide range of frequency and wind speeds but limited to a narrow range of incidence angles between approximately 50° - 55°
140

Support for autonomously driven systems in harsh environments. : Degree project for Master of Science in mechanical engineering with focus on innovation and sustainable product development

Aljafari, Mohammed January 2023 (has links)
Symptoms of harsh environments create pressure on autonomous machines to work wellwith the use of measurement devices. Sensors used within construction equipment vehiclessuffer from being covered with fogs of dirt, oil, water, and dust. Autonomous vehicle’sdependency on fully functional sensors paves roads for research to be made on ways to keepsensor data from being compromised and automation to be improved.In cooperation with Dynapac Compaction Equipment AB, this master’s thesis problemopted for innovative and sustainable product development to tackle the problem. The thesiscomprises of 30 credits. In this thesis, work will be done emphasizing on ways to keepautonomous performance at peak for construction equipment vehicles with low to no capacityfor sophisticated equipment and supply of power and water. For reference, the project targetsasphalt rollers due to their relevance at Dynapac.With the use of innovative product development tools, the problem is to be tackled with anengineering approach revolving around the design thinking process. All progress will beconstituted at Dynapac’s facilities in Karlskrona. Interviews and dialogue with relevantindividuals are to be held to create value based on customer needs which has been of highpriority and is to be iteratively monitored throughout the project. Prototyping will play a partwith large amount of testing to prove concept, including processes of 3dmodeling andmanufacturing of components.With measurement incorrections reaching up to 80 degrees out of a measurement spanwithin the range of 0 to 150 degrees, three concepts have been established, each of which areequipment neutral to benefit construction vehicles which has shown to be valuable within theindustry.A pipe concept which’s purpose is to hide the sensor further and create distance betweensensor lens and measurement surface has been established. The concept is feasible for theconstruction industry, protects the sensor from debris and supports autonomous systems.

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