332 research outputs found
Marginal material stability
No full text1 online resource (PDF, 62 pages, includes illustrations)Grabovsky, Yury; Truskinovsky, Lev. (2012). Marginal material stability. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/181209
Exact Relations Satisfied by the Effective Tensors of Two-Dimensional Two-Phase Thermoelectric Composites
No full textThermoelectric materials have been used for cooling and heating systems for
over a hundred years. Today practical applications of thermoelectric devices
include cooling car seats, power generation, and
refrigeration. Thermoelectric materials are special for their ability to
convert temperature imbalances into electricity. Their applications can
inform the discourse about the transition to renewable energy
sources---something that our Earth most desperately needs. The goal of this
dissertation is to describe how the effective tensors of two-dimensional
thermoelectric composites made from two isotropic materials depend on
thermoelectric parameters of the constituents. Using the theory of exact
relations and links developed by Grabovsky and his collaborators, we
describe all equations satisfied by the thermoelectric effective tensor of a
composite without the explicit knowledge of its microstructure. In some
special cases, the effective tensor can be determined completely. Even in
the general case, four out of 10 components of the two-dimensional
thermoelectric tensor can be expressed in terms of the remaining 6,
regardless of the microstructure. We started with special cases and worked
our way up to the more general ones.Mathematic
Explicit Solution of an Optimal Design Problem With Non-Affine Displacement Boundary Conditions.
No full textStructural optimization problems with non-affine boundary conditions must usually be solved numerically. Here we present an example of such a problem which can be solved analytically. Our method utilizes extremal composites as structural components, and makes use of the explicit form of a certain optimal energy bound. 1 Introduction. A typical problem of optimal design seeks to arrange fixed quantities of given materials within a set\Omega 2 R n , so that the resulting structure has an "optimal" response to a particular load. The performance of the design may be measured by some functional of the elastic fields in the structure. Then the goal is to minimize or maximize this functional over all possible geometric arrangements of materials (microstructures). In this article we consider an optimal material distribution problem, with the objective functional being the strain-energy -- Z \Omega (C(x)e(u); e(u))dx. Here C(x) is the local Hooke's law which may take only two values corr..
Algebra, Geometry, and Computations of Exact Relations for Effective Moduli of Composites
No full textSynergestic induction of NRF-2 gene by curcumin and sulforaphane and pharmacokinetics/metabolism of 13C/Dim in rats by UPLC/MS
No full textCurcumin (CUR) and Sulforaphane (SFN) have shown remarkable cancer chemopreventive effects in numerous studies and combinations of low doses of chemopreventive agents can reduce toxicity while augmenting efficacy. The first part of the thesis investigated the chemotherapeutic effects elicited by a combination of CUR and SFN on human hepatocarcinoma
cells. The combination treatment- mediated effects on phase II/antioxidant enzymatic induction and antioxidant response element (ARE) was investigated. It was proposed that the combination of CUR and SFN could synergistically enhance the induction of ARE and the nuclear E2-factor related factor 2 (Nrf2)-mediated enzymes. Low doses of CUR and SFN significantly induced the expression of Nrf2-mediated enzymes, HO-1 and UGT1A1, promoted nuclear translocation of
Nrf2– a key regulator of phase II detoxifying /antioxidant enzymes – and synergistically induced the ARE luciferase activity. Chemical inhibitors of mRNA and protein synthesis affected the combination therapy- mediated transcriptional regulation of both HO-1 and UGT1A1. Synergism of CUR and SFN was evident at low concentrations. Such synergism in ARE-luciferase activity may partly explain the significant induction in the expression of Nrf2- mediated expression of HO-1 and UGT1A1 and the nuclear translocation of Nrf2, suggesting that a combination of low doses may be a promising strategy for cancer chemoprevention. For the second part of this thesis, a liquid chromatographic method was validated for the simultaneous analysis and pharmacokinetic evaluation of Indole-3-Carbinol (I3C), Diindolylmethane (DIM), and several I3C metabolites. I3C and DIM are naturally derived phytochemicals with promising in-vitro and
in-vivo anticarcinogenic properties. Using reversed-phase ultra performance liquid
chromatography (UPLC) coupled with mass spectrophotometry (MS), a rapid, specific, and high
throughput method was developed and validated for the quantification and identification of I3C, DIM, and other I3C metabolites in plasma. Recovery, linearity, precision, accuracy, and stability analysis fulfilled the CDER guidelines criteria. The method was successfully applied to the determination of the pharmacokinetic parameters and elucidation of metabolites of I3C or DIM
after oral, intravenous, or intraperitoneal administration to Sprague- Dawley rats.M.S.Includes bibliographical referencesIncludes vitaby Yury Y. Gome
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