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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.
51

NUMERICAL, EXPERIMENTAL AND ANALYTICAL STUDY OF THERMAL HEATING OF SPHERE AND DISK SHAPED BIOCRYSTALS EXPOSED TO 3 <sup>RD</sup>GENERATION SYNCHROTON SOURCES

SAMPATH KUMAR, RAGHAV 02 October 2006 (has links)
No description available.
52

Development of Liquid Crystal Infrared Imaging Sensors

Finnemeyer, Valerie A. 18 July 2016 (has links)
No description available.
53

Convolutional Neural Network Detection and Classification System Using an Infrared Camera and Image Detection Uncertainty Estimation

Miethig, Benjamin Taylor January 2019 (has links)
Autonomous vehicles are equipped with systems that can detect and track the objects in a vehicle’s vicinity and make appropriate driving decisions accordingly. Infrared (IR) cameras are not typically employed on these systems, but the new information that can be supplied by IR cameras can help improve the probability of detecting all objects in a vehicle’s surroundings. The purpose of this research is to investigate how IR imaging can be leveraged to improve existing autonomous driving detection systems. This research serves as a proof-of-concept demonstration. In order to achieve detection using thermal images, raw data from seven different driving scenarios was captured and labelled using a calibrated camera. Calibrating the camera made it possible to estimate the distance to objects within the image frame. The labelled images (ground truth data) were then used to train several YOLOv2 neural networks to detect similar objects in other image frames. Deeper YOLOv2 networks trained on larger amounts of data were shown to perform better on both precision and recall metrics. A novel method of estimating pixel error in detected object locations has also been proposed which can be applied to any detection algorithm that has corresponding ground truth data. The pixel errors were shown to be normally distributed with unique spreads about different ranges of y-pixels. Low correlations were seen in detection errors in the x-pixel direction. This methodology can be used to create a gate estimation for the detected pixel location of an object. Detection using IR imaging has been shown to have promising results for applications where typical autonomous sensors can have difficulties. The work done in this thesis has shown that the additional information supplied by IR cameras has potential to improve existing autonomous sensory systems. / Thesis / Master of Applied Science (MASc)
54

Heat Transfer and Flow Measurements on a One-Scale Gas Turbine Can Combustor Model

Abraham, Santosh 05 November 2008 (has links)
Combustion designers have considered back-side impingement cooling as the solution for modern DLE combustors. The idea is to provide more cooling to the deserved local hot spots and reserve unnecessary coolant air from local cold spots. Therefore, if accurate heat load distribution on the liners can be obtained, then an intelligent cooling system can be designed to focus more on the localized hot spots. The goal of this study is to determine the heat transfer and pressure distribution inside a typical can-annular gas turbine combustor. This is one of the first efforts in the public domain to investigate the convective heat load to combustor liner due to swirling flow generated by swirler nozzles. An experimental combustor test model was designed and fitted with a swirler nozzle provided by Solar Turbines Inc. Heat transfer and pressure distribution measurements were carried out along the combustor wall to determine the thermo-fluid dynamic effects inside a combustor. The temperature and heat transfer profile along the length of the combustor liner were determined and a heat transfer peak region was established. Constant-heat-flux boundary condition was established using two identical surface heaters, and the Infrared Thermal Imaging system was used to capture the real-time steady-state temperature distribution at the combustor liner wall. Analysis on the flow characteristics was also performed to compare the pressure distributions with the heat transfer results. The experiment was conducted at two different Reynolds numbers (Re 50,000 and Re 80,000), to investigate the effect of Reynolds Number on the heat transfer peak locations and pressure distributions. The results reveal that the heat transfer peak regions at both the Reynolds numbers occur at approximately the same location. The results from this study on a broader scale will help in understanding and predicting swirling flow effects on the local convective heat load to the combustor liner, thereby enabling the combustion engineer to design more effective cooling systems to improve combustor durability and performance. / Master of Science
55

Heat Transfer and Flow Measurements in Gas Turbine Engine Can and Annular Combustors

Carmack, Andrew Cardin 31 May 2012 (has links)
A comparison study between axial and radial swirler performance in a gas turbine can combustor was conducted by investigating the correlation between combustor flow field geometry and convective heat transfer at cold flow conditions for Reynolds numbers of 50,000 and 80,000. Flow velocities were measured using Particle Image Velocimetry (PIV) along the center axial plane and radial cross sections of the flow. It was observed that both swirlers produced a strong rotating flow with a reverse flow core. The axial swirler induced larger recirculation zones at both the backside wall and the central area as the flow exits the swirler, and created a much more uniform rotational velocity distribution. The radial swirler however, produced greater rotational velocity as well as a thicker and higher velocity reverse flow core. Wall heat transfer and temperature measurements were also taken. Peak heat transfer regions directly correspond to the location of the flow as it exits each swirler and impinges on the combustor liner wall. Convective heat transfer was also measured along the liner wall of a gas turbine annular combustor fitted with radial swirlers for Reynolds numbers 210000, 420000, and 840000. The impingement location of the flow exiting from the radial swirler resulted in peak heat transfer regions along the concave wall of the annular combustor. The convex side showed peak heat transfer regions above and below the impingement area. This behavior is due to the recirculation zones caused by the interaction between the swirlers inside the annulus. / Master of Science
56

Implementation of Infrared Non-Destructive Evaluation in Fiber-Reinforced Polymer Bouble-Web I-Beams

Mehl, Nicholas 27 February 2006 (has links)
When taking steps away from tried and true designs, there is always a degree of uncertainty that arises. With the introduction of fiber-reinforced polymers (FRP) in double-web I-beams (DWIB) to replace steel beams in bridge applications, there are many benefits along with the disadvantages. A bridge has been built with this new type of beam after only short-term proof testing for validation. Nondestructive evaluation (NDE) is a way to implement health monitoring of the bridge beams and needs to be assessed. The principal underlying infrared thermal imaging (IR) nondestructive evaluation (NDE) is to induce a thermal gradient in the beam through heating and monitor how it changes. Delaminations determined by others to be the critical form of deterioration, would be expected to affect the heat conduction in these beams. This project used a halogen lamp to heat the surface of the beam followed by an observation with an IR camera. Calculations of an ANSYS finite element analysis (FEA) model were compared with a series of laboratory tests. The experimental results allowed for validation of the model and development of an IR inspection procedure. This work suggests that for high quality beams of the type considered that an IR procedure could be developed to detect delaminations as small as one inch in length; however, the size would be underestimated. / Master of Science
57

Development of 3D Vision Testbed for Shape Memory Polymer Structure Applications

Thompson, Kenneth 01 January 2015 (has links) (PDF)
As applications for shape memory polymers (SMPs) become more advanced, it is necessary to have the ability to monitor both the actuation and thermal properties of structures made of such materials. In this paper, a method of using three stereo pairs of webcams and a single thermal camera is studied for the purposes of both tracking three dimensional motion of shape memory polymers, as well as the temperature of points of interest within the SMP structure. The method used includes a stereo camera calibration with integrated local minimum tracking algorithms to locate points of interest on the material and measure their temperature through interpolation techniques. The importance of the proposed method is that it allows a means to cost effectively monitor the surface temperature of a shape memory polymer structure without having to place intrusive sensors on the samples, which would limit the performance of the shape memory effect. The ability to monitor the surface temperatures of a SMP structure allows for more complex configurations to be created while increasing the performance and durability of the material. Additionally, as compared to the previous version, both the functionalities of the testbed and the user interface have been significantly improved.
58

Estimating Envelope Thermal Characteristics from Single Point in Time Thermal Images.

Alshatshati, Salahaldin Faraj January 2017 (has links)
No description available.
59

Evaluation of implement monitoring systems

Rakhra, Aadesh 25 September 2012 (has links)
During monitoring of rear-mounted equipment, frequent rearward turning of tractor drivers in awkward postures can cause musculoskeletal disorders related to the back, neck, and shoulders. A camera-based monitoring system, consisting of one or more cameras placed on the implement and a monitor placed inside the tractor cab, has potential ergonomic benefits compared with traditional implement monitoring strategies by reducing the rearward turning and twisting movements of tractor drivers. A camera-based monitoring system was compared with two traditional monitoring strategies (direct looking and using rear-view mirrors) in a lab environment using a Tractor Air-Seeder Driving Simulator. The operator’s reaction time and response errors, head/neck movement (acceleration), and neck muscle temperature were compared for the three monitoring strategies. The camera-based monitoring system yielded significantly (α=0.05) better outcomes in terms of acceleration and muscle temperature values. No significant difference was observed for response errors.
60

Evaluation of implement monitoring systems

Rakhra, Aadesh 25 September 2012 (has links)
During monitoring of rear-mounted equipment, frequent rearward turning of tractor drivers in awkward postures can cause musculoskeletal disorders related to the back, neck, and shoulders. A camera-based monitoring system, consisting of one or more cameras placed on the implement and a monitor placed inside the tractor cab, has potential ergonomic benefits compared with traditional implement monitoring strategies by reducing the rearward turning and twisting movements of tractor drivers. A camera-based monitoring system was compared with two traditional monitoring strategies (direct looking and using rear-view mirrors) in a lab environment using a Tractor Air-Seeder Driving Simulator. The operator’s reaction time and response errors, head/neck movement (acceleration), and neck muscle temperature were compared for the three monitoring strategies. The camera-based monitoring system yielded significantly (α=0.05) better outcomes in terms of acceleration and muscle temperature values. No significant difference was observed for response errors.

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