A predictive model for failure properties of thermoset resins

A predictive model for the three-dimensional failure behavior of engineering polymers has been developed in a recent NASA-sponsored research program. This model acknowledges the underlying molecular deformation mechanisms and thus accounts for the effects of different chemical compositions, crosslink density, functionality of the curing agent, etc., on the complete nonlinear stress-strain response including yield. The material parameters required by the model can be determined from test-tube quantities of a new resin in only a few days. Thus, we can obtain a first-order prediction of the applicability of a new resin for an advanced aerospace application without synthesizing the large quantities of material needed for failure testing. This technology will effect order-of-magnitude reductions in the time and expense required to develop new engineering polymers

Public Education\u27s Perfect Storm

Today, a confluence of six sets of trends are serving to create what is likely to become regarded as the “perfect storm” for funding of public higher education

SCIENTIFICALLY BASED RESEARCH IN EDUCATIONAL PRODUCTS: VENDORS AND CONSUMERS ON FILLING THE CERTIFICATION GAP

SCIENTIFICALLY BASED RESEARCH IN EDUCATIONAL PRODUCTS:VENDORS AND CONSUMERS ON FILLING THE CERTIFICATION GAPByBill CaruthersUniversity of OklahomaCo-Major Professors: Jeffrey Maiden, Ph.D. and Courtney A.Vaughn, Ph.D.The 2002 reauthorization of the Elementary and Secondary Education Act, or No Child Left Behind (NCLB) changed school law in the United States. Public schools can utilize federal funds to purchase only those educational products subject to scientifically based research. No dedicated certification intermediary (CI) exists to determine individual product compliance with SBR. This research undertakes to: 1.)Examine the NCLB Scientifically Based Research (SBR) requirement; 2.) Document the historical development of certification intermediaries; and 3.) Study the research question: How do educational product vendors and education administrators agree and/or differ in relation to the SBR mandate and on the potential to produce an SBRcertification entity valuable to each?The historical and contextual review of scientifically based research and the development of certification intermediaries throughout industrial history suggest the potential emergence of a certification intermediary in this area. Utilizing the grounded theory methodology of Strauss and Corbin, appropriate here due to the lack of specific research in this area; the subject was examined from the vendor and consumer perspectives. The emergent data supports the theory that: Concerning the SBR mandate, vendors and consumers have far more in common than initially known; and, Vendors and consumers support the emergence of an independent certification intermediary for SBR compliance through a marketplace stakeholder coalition. Future empirical researchon this theory is encouraged

Canonically conjugate pairs and phase operators

For quantum mechanics on a lattice the position (``particle number'') operator and the quasi-momentum (``phase'') operator obey canonical commutation relations (CCR) only on a dense set of the Hilbert space. We compare exact numerical results for a particle in simple potentials on the lattice with the expectations, when the CCR are assumed to be strictly obeyed. Only for sufficiently smooth eigenfunctions this leads to reasonable results. In the long time limit the use of the CCR can lead to a qualitativel wrong dynamics even if the initial state is in the dense set.Comment: 4 pages, 5 figures. Phys. Rev. A, in pres

Analysis of Chlamydia pneumoniae-infected monocytes following incubation with a novel peptide, acALY18, implicates the inflammasome in clearance of infection

Chlamydia pneumoniae infection may be a trigger for the pathology observed in sporadic lateonset Alzheimer’s disease as a function of initiating neuroinflammation following entry of the organism into the brain. We have hypothesized that one entry mechanism may be by bloodborne infected monocytes trafficking the infection into the brain. This study focuses on infection of monocytes in vitro followed by analysis using immunofluorescence labeling and RT-PCR-microarray techniques. The microarrays utilized consisted of an Alzheimer’s disease pathway array and an innate and adaptive immunity array from SAbiosciences. Analysis by real time PCR for both gene arrays was performed on uninfected and C. pneumoniae-infected THP1 monocytes at 48 hr post-infection. In addition, we analyzed innate and adaptive immunity gene regulation changes following treatment of infected cells with a unique peptide, acALY18, derived from the endogenously expressed endoplasmic reticulum protein TRPC1. The peptide appears to stimulate the innate immune system through activation of the inflammasome. C. pneumoniae prominently infected THP1 monocytes at 24-48hr. Numerous large inclusions were identified using specific chlamydial monoclonal antibodies. Monocyte gene expression changes induced by infection with C. pneumoniae revealed significant up-regulation of 45 genes in the Alzheimer’s disease pathway. These included genes involved in: b-amyloid processing and clearance, apoptosis, proteases and protein kinases, and lipid metabolism. In contrast, infection resulted in significant changes in 30 genes governing innate and adaptive immunity including those for: the inflammatory response, host defense against bacteria, cytokines, chemokines, and an antibacterial humoral response. Intriguingly, following incubation of C. pneumoniae-infected cells with the acALY18 peptide (25-50nM) at 24hr post-infection, there was significant clearance of the organism from the monocytes as well as up-regulation of 38 genes. Our data suggest that C. pneumoniae infection of monocytes has a profound effect on gene regulation for both innate and adaptive immunity and for Alzheimer’s disease. Stimulating the innate immune response using the novel peptide, acALY18, promotes clearance of C. pneumoniae from infected monocytes; thereby implicating the inflammasome as a key component in eradicating this infection.https://digitalcommons.pcom.edu/posters/1005/thumbnail.jp

Theoretical analysis of the electronic structure of the stable and metastable c(2x2) phases of Na on Al(001): Comparison with angle-resolved ultra-violet photoemission spectra

Using Kohn-Sham wave functions and their energy levels obtained by density-functional-theory total-energy calculations, the electronic structure of the two c(2x2) phases of Na on Al(001) are analysed; namely, the metastable hollow-site structure formed when adsorption takes place at low temperature, and the stable substitutional structure appearing when the substrate is heated thereafter above ca. 180K or when adsorption takes place at room temperature from the beginning. The experimentally obtained two-dimensional band structures of the surface states or resonances are well reproduced by the calculations. With the help of charge density maps it is found that in both phases, two pronounced bands appear as the result of a characteristic coupling between the valence-state band of a free c(2x2)-Na monolayer and the surface-state/resonance band of the Al surfaces; that is, the clean (001) surface for the metastable phase and the unstable, reconstructed "vacancy" structure for the stable phase. The higher-lying band, being Na-derived, remains metallic for the unstable phase, whereas it lies completely above the Fermi level for the stable phase, leading to the formation of a surface-state/resonance band-structure resembling the bulk band-structure of an ionic crystal.Comment: 11 pages, 11 postscript figures, published in Phys. Rev. B 57, 15251 (1998). Other related publications can be found at http://www.rz-berlin.mpg.de/th/paper.htm