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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 80 for “"Temperature coefficient"”.
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Development of techniques to determine temperature coefficient of resistance
… materials' electrical resistance with respect to temperature. A measurement of this relationship is the temperature coefficient of resistance (TCR). Determining the TCR allows a material to be used as a temperature probe and can be utilized in thermal conductivity measurements. The test apparatus …
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Some factors affecting the temperature coefficient of zinc sulphide type phosphors
… variation in the log of the intensity (B) with temperature for zinc sulphide type phosphors continuously excited ultra-violet radiation. The way in which the temperature coefficient of the phosphors depends on the silver and nickel concentrations is discussed. It is also shown that the …
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Injection compression modeling of non-linear positive temperature coefficient circuit protection devices
Polymeric self-resettable circuit protection devices have been manufactured for many years with an extrusion based process. These devices add negligible resistance to a circuit at normal power operating conditions but increases in resistance by several orders of magnitude at a pre-determined level …
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Determining the moderator temperature coefficient in a PWR by stochastic fluctuation analysis
… passive method for monitoring the moderator temperature coefficient (MTC) in a pressurized water reactor is described and compared to an analytical model. The method correlates fluctuations in the neutron flux with fluctuations in the coolant temperature. Results show that the frequency …
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Neural network calibration of moderator temperature coefficient measurements in pressurized water nuclear reactors
… shown to be capable of predicting the moderator temperature coefficient in a nuc1ear reactor by using the frequency response functions between the in-core neutron flux signal and the ex-core thermocouple signal as inputs. In this work, actual data from a nuc1ear reactor is used by neural networks …
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The Study of the Forward-Voltage to Junction-Temperature Coefficient Degradation in Light-Emitting Diodes
… of a LED are heavily dependent on the junction temperature of the LED. Thermal management for LEDs has become an important field study for LEDs. Unfortunately, as the LEDs grow smaller and more integrated, it becomes impossible at times to directly measure their junction temperature. When this …
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The Effect of Fuel Diameter on The Doppler Temperature Coefficient of Reactivity in Fast Reactor Systems
Made available in DSpace on 2014-12-09T19:52:21Z (GMT). No. of bitstreams: 1 6711884.pdf: 3731951 bytes, checksum: e3c2ac834c37ce5c582f3ade7c0e15c2 (MD5) Previous issue date: 1967
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An improved method for estimating the moderator temperature coefficient of pressurized water reactors using multivariate autoregression
An improved method for evaluating the moderator temperature coefficient (MTC) of reactivity in pressurized water reactors based on a newly established technique is described. Previous work has correlated stochastic fluctuations in the reactor core-exit temperature with similar fluctuations in the …
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A study of the reactivity effects of the V. P. I. nuclear reactor
… V.P.I. Argonaut reactor are: 1) Fuel and coolant temperature changes 2) Graphite temperature changes 3) Xenon poisoning The control rods have to be continuously positioned so that the total reactivity change of these parameters is nullified. The reactivity effects of the fuel and coolant have been …
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Uranium dioxide and urania-thoria fuel cores for the UTR-10 reactor
Theoretial calculations of critical mass, temperature coefficient, and transient behavior have been made for proposed uranium dioxide and urania-thoria fuel cores for the Virginia Polytechnic Institute UTR-10 Reactor.
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Ultra-low noise and low temperature drift power supply system design for RF applications
… to the phase noise of RF transceivers. The temperature drift affects the precision of analog baseband. Though some commercial LDOs show very good noise performance over bench power supplies they cannot be readily integrated into cost effective and widely used CMOS process, because they are …
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Aluminum nitride microelectromechanical infrared detectors with integrated metamaterial absorbers
… arrays (FPAs). A sensitivity metric called the temperature coefficient of reflection coefficient (TCΓ) is defined which is analogous to the temperature coefficient of resistance (TCR) described for conventional uncooled bolometer IR detectors. TCΓ values of 6% were measured, matching the state …
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A nickel hexacyanoferrate based thermo-electrochemical device For efficient heat-to-electricity conversion
… against the climate crisis. Currently, low-temperature waste heat accounts for more than half of the rejected waste thermal energy produced in the United States. Traditional waste heat recovery methods such as steam cycle and thermoelectrics fall short at low temperatures due to …
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Interfacial Phenomena in Electrical Ceramics and the Design and Fabrication of Semiconducting Ceramics
… internal boundary layer capacitors; positive temperature coefficient of resistance thermistors; and ferrites have been considered.
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Solar Cell Temperature Dependent Efficiency and Very High Temperature Efficiency Limits
… is significantly lower than their peak operating temperature. In some thermal concentrating systems, solar cells operate above 300 °C. Since increasing the temperature drastically affects the terminal characteristics, it is important to quantify the losses caused by raising the temperature. …
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Evaluating Fluoride Molten Salt Thermophysical Properties with Transient Grating Spectroscopy
… addition, the data displays a curious positive temperature coefficient. Understanding of heat transfer in simple fluids suggests thermal conductivity should decrease as a function of temperature. Unaccounted-for contributions from convection and radiation may result in the observation of …
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Theory, Fabrication and Characterization of Micromachined Electrolytic Solution Conductivity Sensors
Thin-film nickel RTD has a thickness dependent temperature coefficient that is lower than the bulk material due to free electron boundary scattering. Four-wire resistance measurements are used to eliminate the effect of lead resistance for the RTD fabricated on the probe tip. The RTD integrated on …
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Domain and Grain Boundary Structural Effects on the Resistivity Behavior in Donor Doped, PTCR Barium Titanate
… be made n-type conducting and reveal a positive temperature coefficient of resistivity (PTCR) near the ferroelectric phase transition (T$\sb{\rm c}$). This is accomplished by development of a grain boundary potential barrier, the height of which is low at temperatures below T$\sb{\rm c}$ and high …
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Interfacial Segregation in Perovskites and Applications to Boundary Layer Devices
… new boundary layer devices such as, Positive Temperature Coefficient of Resistance (PTCR) Thermistors, internal Boundary Layer Capacitors (IBLC) and Voltage Dependent Resistors (VDR).
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A High Temperature Wideband Low Noise Amplifier
… required to operate at extreme pressures and temperatures. Coupled with substantial real-time data targets, the need for robust high speed electronics is quickly on the rise. This paper presents a high temperature wideband low noise amplifier (LNA) with zero temperature coefficient maximum …
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