Global ETD Search
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 234 for “"Figure of merit"”.
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Coverage optimization using a single satellite orbital figure-of-merit
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2003.
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The effect of quantum confinement on the thermoelectric figure of merit
The thermoelectric figure of merit (Z) determines the usefulness of a material for thermoelectric energy conversion applications. Since the 1960's, the best thermoelectric material has been Bi2Te3 alloys, with a ZT of 1.0 at a temperature ofT = 300 K. The advancement of nano-scale technologies has …
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Device Selection Criteria--Based on Loss Modeling and Figure of Merit
With the increasing speed of the microprocessor and its rapidly increasing demand for power, determining how to power the microprocessors for our computers becomes an important issue. So far, industry has been struggling to operate the VR/VRM at higher and higher switching frequencies while …
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The effect of quantum-well superlattices on the thermoelectric figure of merit
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 1996.
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Thermoelectric figure of merit of two-dimensional materials in a magnetic field
Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Physics, 1994.
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The Development of a Novel Figure of Merit to Analyze Strain-Mediated Magnetoelectric Antennas
… is attributable to predictions stating order of magnitude improvements over current antenna technology. The magnetic antenna design considered herein consists of three layers: 1) a piezoelectric layer, 2) a linear elastic layer, and 3) a magnetoelastic layer. The antenna operates by mediating …
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A high performance zero-crossing based pipelined analog-to-digital converter
… not use any op-amps in the signal path. The use of zero-crossing based circuits made it possible to achieve a much better figure of merit. The ADC is design to operate at 200MS/s with a resolution of 12 bits. The simulated results suggest that the target performance is achievable with less than …
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Oxide based thermoelectric materials for large scale power generation
… gradient and electricity. The effectiveness of the material performance can be described by its figure of merit, ZT, which is defined as ZT = [alpha]²[sigma]T / [kappa] , where a is the Seebeck coefficient of the material, a is the electrical conductivity and [kappa] is the total thermal …
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A Nanoengineering Approach to Oxide Thermoelectrics For Energy Harvesting Applications
The ability of uniquely functional thermoelectric materials to convert waste heat directly into electricity is critical considering the global energy economy. Profitable, energy-efficient thermoelectrics possess thermoelectric figures of merit ZT ≥ 1. We examined the effect of metal nanoparticle – …
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Computational Alchemy: The Rational Design of New Superhard Materials
… to help identify and direct the synthesis of new superhard compounds. An improved figure of merit for hardness is identified and used to show that carbon nitrides are not likely to be harder than diamond.
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Thermoelectric properties of polysilicon inverse opals
… exhibits a remarkable increase in the gure of merit for thermoelectric energy conversion. Here we theoretically and experimentally(partial) investigate a similar enhancement for polycrystalline silicon structured as an inverse opal. An inverse opal provides nanoscale grains and a thin- lm …
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High-speed silicon electro-optic modulator for electronic photonic integrated circuits
The development of future electronic-photonic integrated circuits (EPIC) based on silicon technology critically depends on the availability of CMOS-compatible high-speed modulators that enable the interaction of electronic and optical signals. This thesis investigates electrically driven …
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Study on Thermoelectricc Properties of Mg2(Sn,Si,Ge) for power generation applications
… at an alarming rate. During the production of electricity most of the energy is lost as heat. Thermoelectric devices can convert heat into electrical energy and vice versa. In the past decade there has been extensive research work to improve the efficiency of thermoelectric materials. …
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Modeling And Optimization Of Body Diode Reverse Recovery Characteristics Of Ldmos Transistors
… structures becomes more prevalent. Designers of these new structures will need to make sure they take into consideration the different power losses associated with the different structures and make modifications to reduce or if possible eliminate them. A new 30V LDMOS device has been created …
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A high-speed, low-power analog-to-digital converter in fully depleted silicon-on-insulator technology
… CMOS technology provides a number of benefits for low-power low-voltage analog design. The full dielectric isolation of the silicon island, where the transistors are built,allows higher layout packing density and reduces parasitic junction capacitances. Fully depleted …
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Understanding the viability of impurity-band photovoltaics : a case study of S-doped Si
… impurity-band photovoltaic device. The concept of an impurity-band material envisions the creation of a band of electronic states by incorporating high concentrations of deep-level dopants, which enable the generation of free carriers using photons with energy less than that of the band gap of …
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Electronic, optical, mechanical and thermoelectric properties of graphene
Graphene, a two-dimensional allotrope of graphite with sp^2 bonded carbon atoms, is arranged in honeycomb structure. Its quasi one-dimensional form is graphene nanoribbon (GNR). Graphene related materials have been found to display excellent electronic, chemical, mechanical properties along with …
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Design techniques for Power-Efficient Delta-Sigma Analogue-to-Digital Converters
… and noise-limited, the power efficiency of the former is benchmarked by the Walden Figure-of-Merit (FoMW), and the latter, by the Schreier Figure-of-Merit (FoMS). Technology scaling over the past decades has indicated that FoMS, in noise-limited ADCs, captures more precisely the power …
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Correlation between structure, doping and performance of thermoelectric materials
… However, the low efficiency and high cost of the known material compositions limit their widespread utilization in electricity generation applications. Therefore, there is a strong interest in identifying new thermoelectric materials with high figure of merit. In response to this need, this …
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