9,484 research outputs found

    McCutcheon v. FEC: Sacrificing Campaign Finance Regulation in the Name of Free Speech

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    Lit Review Story

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    In this comic, the student reflects on the process of writing a “literature review,” a requirement for a course taught by Dean Scheibel called “Introduction of Research in Communication Studies.” The comics were created by students as a final course assignment. Students were instructed to create comics using photographs, drawings, or a computer program called Comic Life 3. The idea of reflection is important in education. These comics could be viewed as a response to reflective learning (or metacognition) about the idea of the literature review, or “research as inquiry.” Through reflection on what we do, we learn more deeply about our everyday experiences of life, death, love, God, and even literature reviews. Although “comix” have been the objects of critique by academics, these comics subject the work of the academy—the faculty member as teacher—to critique. Research is a process, and by having students reflect on the fears, errors, or mistakes made during that process they will experience new insights and discoveries

    Suzuki Coupling Catalyzed by (8-(dimesitylboryl)quinoline)palladium(0) Species: A Theoretical Analysis

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    The Suzuki reaction is a catalyzed cross-coupling reaction which is of upmost importance in the formation of carbon-carbon (C-C) bonds in modern organic synthesis. Recently a new catalyst including an 8-(dimesitylboryl)quinoline for the coupling of aryl halides with phenylboronic acids was synthetized. We synthesized ligand that includes a frustrated Lewis pair, (quinolin-8-yl)dimesitylborane (DMBQ), complexed it with group X metals (nickel (Ni), palladium (Pd), and platinum (Pt)), and studied the process of oxidative addition with carbon-fluorine (C-F) bonds and activation towards Suzuki coupling. Mayer bond analysis and electron localization function maps showed a bond between the boron center in the ligand and the palladium center, but electron density, gradient and Laplacian maps showed no interaction. Thus, an elaborate extended transition state method involving natural chemical valence (ETS-NOCV) theory was performed to further characterize this interaction

    Effects of Episodic Turbulence on Diatoms: with Comments on the use of Evans Blue Stain for Live-Dead Determinations

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    Episodic turbulence is a short-lived, high-intensity phenomenon in marine environments produced by both anthropogenic and natural causes, such as boat propellers, strong winds, and breaking waves. Episodic turbulence has been shown to cause mortality in zooplankton, but its effects on marine phytoplankton have rarely been investigated. This study focused on two diatoms: Thalassiosira weissflogii and Skeletonema costatum. I found that exposure for 45 s to turbulence intensities above 2.5 cm2 s-3 caused 24-32% reduction in diatom abundance and increased the amount of intact dead cells to 22%. Turbulence also caused extracellular release of optically reactive DOM. At a turbulence level of 4.0 cm2 s-3, photosynthetic efficiency (Fv/Fm) decreased from 0.51 to 0.38 and 0.55 to 0.50 in T. weissflogii and S. costatum respectively. These turbulence levels are comparable to those under breaking surface waves and are much smaller than those generated by boat propellers. Despite its relatively short duration, episodic turbulence has the potential to affect phytoplankton via lethal and sublethal effects. An improved technique using the Evans Blue stain was developed to enable visual live/dead plankton cell determinations. When used in conjunction with preservation and flow cytometry, this staining method allows the study of phytoplankton mortality due to turbulence and other environmental stresses

    Microkelvin thermometry with Bose-Einstein condensates of magnons and applications to studies of the AB interface in superfluid 3^3He

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    Coherent precession of trapped Bose-Einstein condensates of magnons is a sensitive probe for magnetic relaxation processes in superfluid 3He-B down to the lowest achievable temperatures. We use the dependence of the relaxation rate on the density of thermal quasiparticles to implement thermometry in 3He-B at temperatures below 300 Îź\muK. Unlike popular vibrating wire or quartz tuning fork based thermometers, magnon condensates allow for contactless temperature measurement and make possible an independent in situ determination of the residual zero-temperature relaxation provided by the radiation damping. We use this magnon-condensate-based thermometry to study the thermal impedance of the interface between A and B phases of superfluid 3He. The magnon condensate is also a sensitive probe of the orbital order-parameter texture. This has allowed us to observe for the first time the non-thermal signature of the annihilation of two AB interfaces.Comment: 26 pages, 7 figures, manuscript prepared for EU Microkelvin Collaboration Workshop 2013. Accepted for publication in Journal of Low Temperature Physic

    Vacancy assisted arsenic diffusion and time dependent clustering effects in silicon

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    We present results of kinetic lattice Monte Carlo (KLMC) simulations of substitutional arsenic diffusion in silicon mediated by lattice vacancies. Large systems are considered, with 1000 dopant atoms and long range \textit{ab initio} interactions, to the 18th nearest lattice neighbor, and the diffusivity of each defect species over time is calculated. The concentration of vacancies is greater than equilibrium concentrations in order to simulate conditions shortly after ion implantation. A previously unreported time dependence in the applicability of the pair diffusion model, even at low temperatures, is demonstrated. Additionally, long range interactions are shown to be of critical importance in KLMC simulations; when shorter interaction ranges are considered only clusters composed entirely of vacancies form. An increase in arsenic diffusivity for arsenic concentrations up to 1019cm−310^{19} \text{cm}^{-3} is observed, along with a decrease in arsenic diffusivity for higher arsenic concentrations, due to the formation of arsenic dominated clusters. Finally, the effect of vacancy concentration on diffusivity and clustering is studied, and increasing vacancy concentration is found to lead to a greater number of clusters, more defects per cluster, and a greater vacancy fraction within the clusters.Comment: 22 pages, 16 figure
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