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Filtering by: Creator Hobbs, P. V. Remove constraint Creator: Hobbs, P. V. Degree Level Doctoral Remove constraint Degree Level: Doctoral

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  • Growth and characterization of zinc ferrite thin films for high frequency applications

    Creator:
    Hu, Jiqing
    Abstract:
    Ferrites have been used for various high frequency applications as bulk materials. These applications, however, are limited to large dimension devices. In this thesis, thin film ferrites were deposited from a low temperature solution-based deposition process that is suitable for micro-scale high frequency applications. The low temperature nature of this...
    Resource Type:
    Dissertation
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    V. Because of the applied voltage, charges will accumulate at the external surface of the two

  • Design techniques for low-voltage and low-power analog-to-digital converters

    Creator:
    Ahn, Gil Cho
    Abstract:
    With the ever-increasing demand for portable devices used in applications such as wireless communication, mobile computing, consumer electronics, etc., the scaling of the CMOS process to deep submicron dimensions becomes more important to achieve low-cost, low-power and high-performance digital systems. However, this downscaling also requires similar shrinking of the supply...
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    Dissertation
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    -digital converters. To demonstrate the proposed design techniques, a 0.6 V, 82 dB, 2-2 cascaded au- dio

  • Enhanced-accuracy oversampled data converters

    Creator:
    Ceballos, Jose Luis
    Abstract:
    Digital-to-analog converters (DACs) suffer from static and dynamic nonlinearity problems, which degrade their accuracy and performance. Mismatch errors in the analog components restrict the maximum achievable linearity. This thesis presents various techniques for correcting these errors. It describes a correction process for the nonlinear behavior of DACs, on three different...
    Resource Type:
    Dissertation

  • A direct-drive wave energy converter with contactless force transmission system

    Creator:
    Agamloh, Emmanuel B.
    Abstract:
    Commonly proposed ocean wave energy converters (OWEC) use inefficient and maintenance demanding intermediate hydraulic and pneumatic systems. We propose a novel rotary direct-drive OWEC that eliminates these intermediate stages. The new device employs a contactless force transmission system (CFTS) comprising a “piston” and a “cylinder” and a ball screw to...
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    Dissertation
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    potential function φ can be defined, from which the velocity field u(u,v,w) can be derived as φ−∇=u or

  • Quantities of prostaglandins in whole and extended bovine semen and their potential effect on fertility following insemination

    Creator:
    Jaeger, John Ralph
    Abstract:
    Our objectives were to determine 1) the concentration of prostaglandin F2α (PGF2α) in whole and extended bovine semen, 2) if concentrations of prostaglandins in extended bovine semen are correlated to fertility, and 3) if PGF2α administered at the time of artificial insemination would improve conception rate. Concentration of PGF2α tended...
    Resource Type:
    Dissertation

  • Regression calibration and maximum likelihood inference for measurement error models

    Creator:
    Monleon-Moscardo, Vicente J.
    Abstract:
    Regression calibration inference seeks to estimate regression models with measurement error in explanatory variables by replacing the mismeasured variable by its conditional expectation, given a surrogate variable, in an estimation procedure that would have been used if the true variable were available. This study examines the effect of the uncertainty...
    Resource Type:
    Dissertation
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    small or P(Y=1 | X) is small and f(X|W) is normal (Kuha 1994). When the degree of non-linearity in the

  • Chunking professional-technical programs to create pathways to degree completion in community colleges

    Creator:
    Dins, Kate
    Abstract:
    The purpose of this study was to explore the phenomenon of community colleges creating pathways to degree completion in professional-technical programs by breaking degree programs into smaller portions, referred to as "chunks." The purpose or possible advantage of chunking was that it would improve the rate of degree completion among...
    Resource Type:
    Dissertation
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    .........................................................188 Chapter V - Summary, Discussion, and Implications

  • Use of nondestructive spectroscopy to assess chlorophyll and nitrogen in fresh leaves

    Creator:
    Ding, Pinghai
    Abstract:
    Four aspects of factors influencing the accuracy of nondestructive chlorophyll (Chl) and nitrogen (N) measurement in fresh leaves were studied: (1) optimum wavelength (OW) identification; (2) indices development and evaluation; (3) influence of leaf properties; and (4) influence of meter parameters and sampling technique. Results were used to develop indices...
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    Dissertation
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    sensitivity curves (C-F) of four poplar (Populus trichocarpa x P. deltoids) leaves (S1-S4) with different

  • Channel estimation and data detection for mobile MIMO OFDM systems

    Creator:
    Gao, Jie
    Abstract:
    Designing spectral efficient, high-speed wireless links that offer high quality- of-service and range capability has been a critical research and engineering challenge. In this thesis, we mainly address the complexity and performance issues of channel estimation and data detection in multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems over...
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    Dissertation
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    network (WMAN), and home audio/visual (A/V) network. WLAN provides homes, businesses, and campuses with

  • Population demography, resource use, and movement in cooperatively breeding Micronesian Kingfishers

    Creator:
    Kesler, Dylan C.
    Abstract:
    Island systems and species are susceptible to extinction because of their small population size and an ecological naiveté from an evolutionary past lacking strong competition and predation. For example, only one-fifth of the world’s bird species occur on islands, yet more than 90% of the avian extinctions witnessed during historic...
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    Dissertation
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    ............................................................................................................ 107 6.1. Models of annual survival (φ ) and recapture probabilities (p) for color-banded Pohnpei

  • Expression and Function of Populus Homologs to TERMINAL FLOWER 1 Genes: Roles in Onset of Flowering and Shoot Phenology

    Creator:
    Mohamed, Rozi
    Abstract:
    We isolated and characterized the expression of two genes from Populus trichocarpa that are homologous to the TERMINAL FLOWER 1 (TFL1) gene from the model annual plant Arabidopsis. In Arabidopsis, overexpression of the TFL1 gene extends the vegetative growth phase, and the homozygous mutant tfl1 allele causes early flowering and...
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    Dissertation
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    ......................... 45 8 Early-flowering phenotypes of transgenic Populus tremula x P. alba carrying an RNAi construct

  • Advanced propulsion systems for linear motion with high performance requirements

    Creator:
    Zhou, Xiaolin
    Abstract:
    Traditionally linear actuator applications are addressed by the use of hydraulic systems. The high maintenance cost and poor reliability will always be the most critical problem in the real applications. Benefited from both the high mechanical advantage of the roll screw and the simple structure of the switched reluctance motor,...
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    Dissertation
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    . 16 Parameter Formula Value Unit Stroke s 5.6 inch Operating thrust F 1,100 Lb Speed v

  • Structure elucidation of bioactive natural products from Madagascar marine algae and cyanobacteria

    Creator:
    Andrianasolo, Eric Hajaniriana
    Abstract:
    This thesis is an investigation of the natural products deriving from marine algae and cyanobacteria and has resulted in the discovery of eleven new secondary metabolites. The structure elucidations of these new molecules were performed using a variety of spectroscopic techniques. Four new macrolides were isolated and characterized from the...
    Resource Type:
    Dissertation

  • Developing a basis for characterizing precision of estimates produced from non-probability samples on continuous domains

    Creator:
    Cooper, Cynthia
    Abstract:
    This research addresses sample process variance estimation on continuous domains and for non-probability samples in particular. The motivation for the research is a scenario in which a program has collected non-probability samples for which there is interest in characterizing how much an extrapolation to the domain would vary given similarly...
    Resource Type:
    Dissertation

  • Dynamics of the Laurentide Ice Sheet

    Creator:
    Carlson, Anders Eskil
    Abstract:
    This dissertation concentrates on the controlling factors on the instability of the Laurentide Ice Sheet (LIS) and their effects on abrupt climate change. Northern Hemisphere climate fluctuated abruptly during the last deglaciation possibly related to variability in Atlantic meridional overturning circulation (AMOC) and reduced aerial extent of the LIS. Reductions...
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    Dissertation
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    Planetary Science, v. 27, p. 149-182. Alley, R.B., Clark, P.U., Huybrechts, P., and Joughin, I., 2005, Ice

  • Design of a 14-bit continuous-time Delta-Sigma A/D modulator with 2.5MHz signal bandwidth

    Creator:
    Li, Zhimin
    Abstract:
    In recent years, there has been growing interest in both industry and academia to use continuous-time (CT) Δ-Σ A/D converters for wideband wireless and wireline communication applications. So far no reported CT Δ-Σ A/D modulator achieves 14-bit or higher dynamic range (DR) with more than 2MHz signal bandwidth (equivalently 4MS/s)....
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    Dissertation
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    f p ap er s CT DSM PAPERS ALL DSM PAPERS Figure 1.1 Number of papers on Δ-Σ A/D

  • The experience of gifted girls transitioning from elementary school to sixth and seventh grade

    Creator:
    Pepperell, Jennifer L.
    Abstract:
    The purpose of this dissertation was to explore the experience of gifted girls transitioning from elementary school to sixth and seventh grade. The current counseling literature in this area found that gifted girls often struggle emotionally when transitioning to sixth and seventh grade. The bulk of this literature was based...
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    Dissertation
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    travel on to the next stage. I can’t wait to see what we do next! To Deborah P., thank you for

  • Heavy fermion effective mass in the superconducting vortex state

    Creator:
    Townsend, Emily A.
    Abstract:
    The extended-Lifshitz-Kosevitch formalism (ELK) unifies the treatment of the de Haas-van Alphen (dHvA) effect, allowing it to transcend its traditional roles of mapping Fermi surfaces and measuring effective masses. Here we exploit the capabilities of dHvA as a probe of many-body effects to examine heavy-fermion su- perconductivity. ELK successfully describes...
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    Dissertation
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    , i.e. the specific heat and zero-field paramagnetic susceptibility are enhanced ( [16] p 73, [17] p

  • Biogeographic and experimental evidence for local scale dispersal limitation in central Panamanian forest birds

    Creator:
    Moore, Randall Phillips, 1965-
    Abstract:
    I examined the avian biogeography of the islands of Lago Gatun, Panama, in an effort to better understand the effects of forest fragmentation in this biodiverse region, and specifically to understand the importance of fragment isolation and the mechanism behind its effects on tropical bird distribution. I combined exhaustive surveys...
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    Dissertation
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    distance flown for any single release trial, by species………………………………………………………………………….. 5. 3- P

  • Advances in expression of heterologous protein products by Streptococcus gordonii

    Creator:
    Warren, Travis Kent
    Abstract:
    Streptococcus gordonii is a bacterial species that naturally colonizes the oral cavity of most healthy humans. It resides in the mouth as an adherent to dental surfaces and, with few exceptions, does not cause disease in individuals it inhabits. It possesses qualities that encourage its use as a vector to...
    Resource Type:
    Dissertation