2,593 research outputs found
Gallium(III)-Promoted Halocyclizations of 1,6-Diynes
Adrian Landreth was an REU student, summer 2014Cyclization of 1,6-diynes promoted by stoichiometric Ga(III) halides produces vinyl halides in good to excellent yields. Under acidic conditions, initially formed iodocyclization products undergo in situ Friedel-Crafts cyclizations, giving access to iodo-indenopyridines. The application of the vinyl halides in cross-coupling reactions has been explored, and mechanistic aspects of the cyclization are discussed.HIGMS CMLD Initiative (P50 GM067041)
NSF REU - Adrian Landreth support (CHE 1156666)
NSF - NMR purchase (CHE 0619339)
NSF - HRMS purchase (CHE0443618
Energy Localization and Transport in Binary Isotopically Disordered Fermi-Pasta-Ulam Chains
Energy transport in binary isotopically disordered (BID) nonlinear
Fermi-Pasta-Ulam (FPU) chains is a competition between localization and mode transitions. Starting from an arbitrary localized pulse, energy will dissipate ballistically until either Anderson
localization (a disorder effect) or phonon scattering (a nonlinearity effect) slow the rate of dissipation. To reduce computational effort,
we propose starting from a localized energy eigenstate so that in the absence of anharmonicity the energy is stationary and there is no transport. The second moment of the site energies is used to characterize an effective thermal conductivity as a function of impurity
concentration and nonlinearity strength.
Calculating the properties of harmonic BID chains at arbitrary
impurity concentration is complicated by the pure-disordered-pure transition that occurs as the impurity concentration varies from zero to one. The localization length of dilute impurity harmonic BID chains is calculated exactly using scaling laws and the scattering cross section of a single impurity, which is calculated for discrete systems, differs from the continuum result. For arbitrary impurity concentration, the localization length is estimated by assuming independent contributions
from the two limiting cases of pure material.
Information entropy was used to show that the number of modes excited by phonon scattering decreased with increasing impurity concentration, a fact that consistent with density of states calculations. At all impurity concentrations, the second moment of the site energies
increases linearly in time, a fact that is corroborated by the number of
masses participating in energy transport, as calculated from the
localization parameter. The dilute concentration dependence of the effective thermal conductivity was consistent with kinetic theory. At the highest concentrations the thermal conductivity was proportional
to the original localization length because mode suppression and
dense impurities meant that the same length scale remained dominant
over a long period of time
Coupling thermodynamics and digital image models to simulate hydration and microstructure development of portland cement pastes
Equilibrium thermodynamic calculations, coupled to a kinetic model for the dissolution rates of clinker phases, have been used in recent years to predict time-dependent phase assemblages in hydrating cement pastes. We couple this approach to a 3D microstructure model to simulate microstructure development during the hydration of ordinary portland cement pastes. The combined simulation tool uses a collection of growth/dissolution rules to approximate a range of growth modes at material interfaces, including growth by weighted mean curvature and growth by random aggregation. The growth rules are formulated for each type of material interface to capture the kinds of cement paste microstructure changes that are typically observed. We make quantitative comparisons between simulated and observed microstructures for two ordinary portland cements, including bulk phase analyses and two-point correlation functions for various phases. The method is also shown to provide accurate predictions of the heats of hydration and 28 day mortar cube compressive strengths. The method is an attractive alternative to the cement hydration and microstructure model CEMHYD3D because it has a better thermodynamic and kinetic basis and because it is transferable to other cementitious material system
Book Notes
Matt Tomlinson
In God\u27s Image: The Metaculture of Fijian Christianity
2009 Berkeley, CA: The University of California Press
Reviewed by Michael A. Rynkiewich
S. T. Kimbrough Jr. and Kenneth G. C. Newport, eds.
The Manuscript Journal of the Reverend Charles Wesley, M.A. Vols. 1,2
2008. Nashville: Kingswood Books
John R. Tyson
Assist Me to Proclaim: The Life and Hymns of Charles Wesley
2007 Grand Rapids, Michigan: William B. Eerdmans
Reviewed by Kenneth J. Collins
Brian Stanley
The World Missionary Conference, Edinburgh 1910
Studies in the History of Christian Missions
2009. Grand Rapids, MI: Eerdmans
Reviewed by Marcella Hoesl
Geordan Hanunond and David Rainey, eds.
Wesley & Methodist Studies. Volume I
2009. Manchester, UK- Didsbury Press
Reviewed by Howard A. Snyde
3D Printing In Zero-G ISS Technology Demonstration
The National Aeronautics and Space Administration (NASA) has a long term strategy to fabricate components and equipment ondemand for manned missions to the Moon, Mars, and beyond. To support this strategy, NASA and Made in Space, Inc. are developing the 3D Printing In ZeroG payload as a Technology Demonstration for the International Space Station (ISS). The 3D Printing In ZeroG experiment ('3D Print') will be the first machine to perform 3D printing in space. The greater the distance from Earth and the longer the mission duration, the more difficult resupply becomes; this requires a change from the current spares, maintenance, repair, and hardware design model that has been used on the International Space Station (ISS) up until now. Given the extension of the ISS Program, which will inevitably result in replacement parts being required, the ISS is an ideal platform to begin changing the current model for resupply and repair to one that is more suitable for all exploration missions. 3D Printing, more formally known as Additive Manufacturing, is the method of building parts/objects/tools layerbylayer. The 3D Print experiment will use extrusionbased additive manufacturing, which involves building an object out of plastic deposited by a wirefeed via an extruder head. Parts can be printed from data files loaded on the device at launch, as well as additional files uplinked to the device while onorbit. The plastic extrusion additive manufacturing process is a lowenergy, lowmass solution to many common needs on board the ISS. The 3D Print payload will serve as the ideal first step to proving that process in space. It is unreasonable to expect NASA to launch large blocks of material from which parts or tools can be traditionally machined, and even more unreasonable to fly up multiple drill bits that would be required to machine parts from aerospacegrade materials such as titanium 64 alloy and Inconel. The technology to produce parts on demand, in space, offers unique design options that are not possible through traditional manufacturing methods while offering cost-effective, highprecision, lowunit ondemand manufacturing. Thus, Additive Manufacturing capabilities are the foundation of an advanced manufacturing in space roadmap. The 3D Printing In ZeroG experiment will demonstrate the capability of utilizing Additive Manufacturing technology in space. This will serve as the enabling first step to realizing an additive manufacturing, printondemand "machine shop" for longduration missions and sustaining human exploration of other planets, where there is extremely limited ability and availability of Earthbased logistics support. Simply put, Additive Manufacturing in space is a critical enabling technology for NASA. It will provide the capability to produce hardware ondemand, directly lowering cost and decreasing risk by having the exact part or tool needed in the time it takes to print. This capability will also provide the muchneeded solution to the cost, volume, and upmass constraints that prohibit launching everything needed for longduration or longdistance missions from Earth, including spare parts and replacement systems. A successful mission for the 3D Printing In ZeroG payload is the first step to demonstrate the capability of printing on orbit. The data gathered and lessons learned from this demonstration will be applied to the next generation of additive manufacturing technology on orbit. It is expected that Additive Manufacturing technology will quickly become a critical part of any mission's infrastructure
A Global Review of Innovative Practices in Regional SME Exporting Strategies and Foreign Direct Investment Attraction
This Co-Learning Plan describes findings from the MSU Center for Community and Economic Development based on research conducted at a global scale to identify innovative practices in regional exporting strategies and foreign direct investment (FDI) attraction
Positional artifacts in microarrays: experimental verification and construction of COP, an automated detection tool
Microarray technology is currently one of the most widely-used technologies in biology. Many studies focus on inferring the function of an unknown gene from its co-expressed genes. Here, we are able to show that there are two types of positional artifacts in microarray data introducing spurious correlations between genes. First, we find that genes that are close on the microarray chips tend to have higher correlations between their expression profiles. We call this the ‘chip artifact’. Our calculations suggest that the carry-over during the printing process is one of the major sources of this type of artifact, which is later confirmed by our experiments. Based on our experiments, the measured intensity of a microarray spot contains 0.1% (for fully-hybridized spots) to 93% (for un-hybridized ones) of noise resulting from this artifact. Secondly, we, for the first time, show that genes that are close on the microtiter plates in microarray experiments also tend to have higher correlations. We call this the ‘plate artifact’. Both types of artifacts exist with different severity in all cDNA microarray experiments that we analyzed. Therefore, we develop an automated web tool—COP (COrrelations by Positional artifacts) to detect these artifacts in microarray experiments. COP has been integrated with the microarray data normalization tool, ExpressYourself, which is available at . Together, the two can eliminate most of the common noises in microarray data
Removal of odorants from animal waste using Fenton’s reaction
The purpose of this study was to evaluate Fenton’s reaction as a means of mitigating the problem of offensive odors emitted from livestock manures. The hypothesis to be tested was that hydroxyl radicals generated during this reaction would oxidize odorant compounds, breaking them down to nonodorous products. The deodorization effect was assessed using various chromatographic techniques to determine the concentration of selected odor indicators present in swine slurry and reactor headspaces before and after treatment. The indicators included seven volatile fatty acids, three phenols, and two indoles that were positively correlated with malodors from animal manure. The extent of their removal strongly depended on the concentration of Fenton’s reagents (0 to 40 mM FeCl3, and 0 to 800 mM H2O2), the initial pH of swine slurry (2.0 to 6.5), and the total solids content (0.6 to 2.9% TSC). Control samples treated with no FeCl3 or H2O2 did not show significant reduction of odorant concentration at all pH and TSC levels tested. Acceptable removals of total odorants (65 to 90%) were observed between pH 3.5 and 5.5. When swine slurry (0.7% TSC, pH 5.0) was treated for 2 h with 40 mM FeCl3 at 400 mM H2O2, all odorants were removed completely (100%), except for small amounts of propionic acid. Odorant removal from swine slurry was in good agreement with that from the headspace air (90-100% removal for most measured odorants). Pilot-scale treatment produced encouraging results, surpassing the expectations based on the outcome of laboratory experiments
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