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Filtering by: Subject Ablative materials -- Mathematical models Remove constraint Subject: Ablative materials -- Mathematical models Degree Name Doctor of Philosophy (Ph.D.) Remove constraint Degree Name: Doctor of Philosophy (Ph.D.)

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  • Exchange interaction studies in magnetic semiconductors by neutron scattering

    Creator:
    Wiren, Zachary Quincy
    Abstract:
    Theories predict that making a dilute magnetic semiconductor strongly p -type would allow it to remain ferromagnetic at room temperature. This is of intrest as a ferromagnetic semiconductor would allow for a great many applications in the field of spintronics. Neutron scattering experiments were undertaken to better understand the antiferromagnetic...
    Resource Type:
    Dissertation
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    the material large enough to be easily detected. Other commercial applications of spintronic devices

  • Automated feature extraction for orientation and slicing in microlamination

    Creator:
    Ariastuti, Retna
    Abstract:
    The research is about developing a computerized design system for microtechnology-based energy, and chemical systems (MECS). MECS devices are a part of microfabrication, which primarily focuses on taking advantage of the extremely high rates of heat and mass transfer available in microstructures. It typically consists of intricate arrays of components...
    Resource Type:
    Dissertation
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    of metal, ceramic, or polymeric material. In terms of size, MECS devices are in-between micro-scale

  • Hybrid Multiscale Methods with Applications to Semiconductors, Porous Media, and Materials Science

    Creator:
    Costa, Timothy B.
    Abstract:
    In this work we consider two multiscale applications with tremendous computational complexity at the lower scale. First, we examine a model for charge transport in semicon- ductor structures with heterojunction interfaces. Due to the complex physical phenomena at the interface, the model at the design scale is unable to adequately...
    Resource Type:
    Dissertation
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    of a mathematical model describing physical phenomena has been to trade resolution for scale. This

  • Thermodynamics of non-dilute saline solutions in variably saturated porous media

    Creator:
    Burns, Erick R.
    Abstract:
    Non-dilute salt strength solutions occur in many near surface geologic environments. In order to better understand the occurrence and movement of the water and salt, mathematical models for this non-ideal fluid need to be developed. Initial boundary value problems may then be solved to predict behavior for comparison with observations....
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    Dissertation
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    better understand the occurrence and movement of the water and salt, mathematical models for this non

  • Developing Design Model for Cellulose Nanocomposites

    Creator:
    Shir Mohammadi, Meisam
    Abstract:
    Today nano scale materials are being used for wide range of applications. One promising topic in nano scale materials is using them for reinforcement of different polymeric materials to reach desirable stiffness properties. The stiffness of these materials is mostly found experimentally because the nanocomposite community lacks a decent analytical...
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    Dissertation
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    more preferably if they are avail- able. Basically analytical model is a mathematical equation that

  • A numerical study of inertial flow features in moderate Reynolds number flow through packed beds of spheres

    Creator:
    Finn, Justin Richard
    Abstract:
    In this work, flow through synthetic arrangements of contacting spheres is studied as a model problem for porous media and packed bed type flows. Direct numerical simulations are performed for moderate pore Reynolds numbers in the range, 10 ≤ Re ≤ 600, where non-linear porescale flow features are known to...
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    Dissertation
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    contacting spheres is studied as a model problem for porous media and packed bed type flows. Direct numeri

  • Three-dimensional, nonlinear viscoelastic analysis of laminated composites : a finite element approach

    Creator:
    Wang, Min
    Abstract:
    Polymeric composites exhibit time-dependent behavior, which raises a concern about their long term durability and leads to a viscoelastic study of these materials. Linear viscoelastic analysis has been found to be inadequate because many polymers exhibit nonlinear viscoelastic behavior. Classical laminate theory is commonly used in the study of laminated...
    Resource Type:
    Dissertation
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    the material. Based on this fact, various mathematical methods have been suggested to represent the

  • A nonlocal damage theory for laminated plate with application to aircraft damage tolerance

    Creator:
    Nahan, Matthew F.
    Abstract:
    Design of commercial aircraft structure, composed of composite material, requires the prediction of failure loads given large scale damage. In particular, a fuselage of graphite/epoxy lamination was analyzed for damage tolerance given a standard large crack that severed both skin and internal structure. Upon loading, a zone of damage is...
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    Dissertation
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    Material Stress vs. Displacement Relation of the Fictitious Crack Model 12 2.2 Stress Distributions

  • Stochastic analysis of flow and transport in porous media

    Creator:
    Vasylkivska, Veronika S.
    Abstract:
    Random fields are frequently used in computational simulations of real-life processes. In particular, in this work they are used in modeling of flow and transport in porous media. Porous media as they arise in geological formations are intrinsically deterministic but there is significant uncertainty involved in determination of their properties...
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    Dissertation
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    appreciate the fact that I didn’t need to write the deterministic solvers for model problems since they were

  • Multiscale analysis of saturated flow in a porous medium with an adjacent thin channel

    Creator:
    Morales, Fernando A.
    Abstract:
    This thesis contains three parts addressing the asymptotic analysis of fluid flow through fully saturated porous medium in the presence of an adjacent thin channel. In the first part the problem is modeled by Darcy's law in both the porous medium and in the channel. The permeability in the channel...
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    Dissertation
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    - ciple. A fully-coupled model with a lower dimensional interface problem is obtained in the limit as an