713 research outputs found
Photon intermediate direct energy conversion using a Sr-90 beta source
Title from PDF of title page (University of Missouri--Columbia, viewed on March 5, 2013).The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.Dissertation advisor: Dr. Mark PrelasIncludes bibliographical references.Vita.Ph.D. University of Missouri--Columbia 2012."December 2012"This thesis covers an examination of a need for a compact, long lived power source and a proof of concept for one such design. To begin, tests were done dealing with photovoltaics and their lifetime while undergoing radiation damage from the source of interest, Strontium-90 (Sr-90). After completing these tests a system was designed, built, and ultimately tested over a range of pressures in order to test if a Photon Intermediate Direct Energy Conversion (PIDEC) system would be potentially viable. In brief, the PIDEC system tested for this thesis used two excimer gasses, Argon and Xenon, to produce photons. These gasses were excited into excimer production using a 10 mCi Sr-90 source and held in place at pressures ranging from 10-6 to 2400 psi by a pressure vessel. Photons produced were guided towards a photovoltaic by a mirror chamber lined with high efficiency aluminum mirrors. Outside of the pressure vessel a picoammeter read the current off of the photovoltaic and sent the current to a computer for data processing. Of primary interest was how the current changed based on the amount of energy captured by the gas plenum which was related to the pressure of the system. The overall efficiency of this system was low due to a non-optimized waveguide, much of the beta energy being lost beyond the gas plenum, and other factors. However, the results were sufficient to show that the process was successfully completed and making a new system to optimize for these features is warranted.Includes bibliographical reference
Report on the State of Available Data for the Study of International Trade and Foreign Direct Investment
This report, prepared for the Committee on Economic Statistics of the American Economic Association, examines the state of available data for the study of international trade and foreign direct investment. Data on values of imports and exports of goods are of high quality and coverage, but price data suffer from insufficient detail. It would be desirable to have more data measuring value-added in trade as well as prices of comparable domestic and imported inputs. Value data for imports and exports of services are too aggregated and valuations are questionable, while price data for service exports and imports are almost non-existent. Foreign direct investment data are of high quality but quality has suffered from budget cuts. Data on trade in intellectual property are fragmentary. The intangibility of the trade makes measurement difficult, but budget cuts have added to the difficulties. Modest funding increases would result in data more useful for research and policy analysis.
Testing for Factor Price Equality with Unobserved Differences in Factor Quality or Productivity
Large Deviations Analysis for Distributed Algorithms in an Ergodic Markovian Environment
We provide a large deviations analysis of deadlock phenomena occurring in
distributed systems sharing common resources. In our model transition
probabilities of resource allocation and deallocation are time and space
dependent. The process is driven by an ergodic Markov chain and is reflected on
the boundary of the d-dimensional cube. In the large resource limit, we prove
Freidlin-Wentzell estimates, we study the asymptotic of the deadlock time and
we show that the quasi-potential is a viscosity solution of a Hamilton-Jacobi
equation with a Neumann boundary condition. We give a complete analysis of the
colliding 2-stacks problem and show an example where the system has a stable
attractor which is a limit cycle
Effects of ischemia on epicardial segment shortening
To evaluate the effects of nontransmural ischemia on epicardial contractile function, we implanted sonomicrometers in 15 open-chest, anesthetized (halothane) dogs. One cylindrical crystal (radiating ultrasound 360[deg]) was used as a transmitter for three conventional flat plate crystals arrayed to measure epicardial segment shortening along three different axes that were deviated 0[deg] (parallel), 45[deg] (oblique), and 90[deg] (perpendicular) from surface fiber orientation in the anteriorapical or posterior-basal left ventricle. During baseline conditions, epicardial shortening was maximal parallel with fiber orientation. Shortening decreased in a non-linear manner as deviation from fiber orientation increased, but there were significant differences between the two left ventricular regions suggesting that more substantial lateral strain occurs in the anterior-apical than the posterior-basal area. During coronary inflow restriction, changes in epicardial segment shortening also varied greatly depending on location and alignment. At levels of wall thickening impairment associated with normal subepicardial perfusion, changes in epicardial function were restricted to the segments aligned perpendicular to fiber orientation whereas the parallel and oblique segments displayed moderate dysfunction or none at all. Thus, transmural tethering modifies epicardial segmental motion during coronary inflow restriction, but the severity of the influence depends on the alignment and location of the epicardial measurements.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29525/1/0000612.pd
Somatosensory evoked potentials of the dog: recording techniques and normal values
Median and tibial nerve somatosensory evoked potentials (SSEPs) of 5 sedated dogs were studied to determine their normal features and optimal stimulation and recording techniques. Cortical potentials were mapped from an extensive array of skull electrodes as each limb was independently stimulated with subdermal needles. The effects of bandpass and stimulus intensity and rate were also assessed. Three cortical components (P1, N1, P2) were evoked by median or tibial nerve stimulation and were localized along the coronal suture at lateral and medial electrodes, respectively. SSEP voltage varied much more than morphology, topography, or latency. The inion was a stable, indifferent reference site. Cortical SSEP frequency content was mostly below 250 Hz. Maximal SSEP voltage was achieved only at stimulus intensities 2-3 times motor threshold. Appropriate methods minimize technical difficulties and consistently yield legible SSEPs.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27990/1/0000423.pd
Infusion of Reconstituted High-Density Lipoprotein, CSL112, in Patients With Atherosclerosis: Safety and Pharmacokinetic Results From a Phase 2a Randomized Clinical Trial
Background CSL112 is a new formulation of human apolipoprotein AâI (apoAâI) being developed to reduce cardiovascular events following acute coronary syndrome. This phase 2a, randomized, doubleâblind, multicenter, doseâranging trial represents the first clinical investigation to assess the safety and pharmacokinetics/pharmacodynamics of a CSL112 infusion among patients with stable atherosclerotic disease. Methods and Results Patients were randomized to single ascending doses of CSL112 (1.7, 3.4, or 6.8 g) or placebo, administered over a 2âhour period. Primary safety assessments consisted of alanine aminotransferase or aspartate aminotransferase elevations \u3e3Ă upper limits of normal and study drugârelated adverse events. Pharmacokinetic/pharmacodynamic assessments included apoAâI plasma concentration and measures of the ability of serum to promote cholesterol efflux from cells ex vivo. Of 45 patients randomized, 7, 12, and 14 received 1.7â, 3.4â, and 6.8âg CSL112, respectively, and 11 received placebo. There were no clinically significant elevations (\u3e3Ă upper limit of normal) in alanine aminotransferase or aspartate aminotransferase. Adverse events were nonserious and mild and occurred in 5 (71%), 5 (41%), and 6 (43%) patients in the CSL112 1.7â, 3.4â, and 6.8âg groups, respectively, compared with 3 (27%) placebo patients. The imbalance in adverse events was attributable to vessel puncture/infusionâsite bruising. CSL112 resulted in rapid (Tmaxâ2 hours) and doseâdependent increases in apoAâI (145% increase in the 6.8âg group) and total cholesterol efflux (up to 3.1âfold higher than placebo) (P\u3c0.001). Conclusions CSL112 infusion was well tolerated in patients with stable atherosclerotic disease. CSL112 immediately raised apoAâI levels and caused a rapid and marked increase in the capacity of serum to efflux cholesterol. This potential novel approach for the treatment of atherosclerosis warrants further investigation. Clinical Trial Registration URL: http://www.ClinicalTrials.gov. Unique identifier: NCT01499420
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