Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 619 for “"210"”.
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Applications of PB-210/RA-226 and PO-210/PB-210 disequilibria in the study of marine geochemical processes
The distribution of Pb-210 and Po-210 in dissolved (<O.4 micron) and particulate (>0.4 micron) phases has been measured at ten stations in the tropical and eastern North Atlantic and at two stations in the Pacific. Both radionuclides occur principally in the dissolved phase. Unsupported Pb-210 …
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Applications of Pb-210/Ra-226 and Po-210/Pb-210 disequilibria in the study of marine geochemical processes.
Thesis. 1976. Ph.D.--Massachusetts Institute of Technology. Dept. of Earth and Planetary Sciences.
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The Aquatic Geochemistry of the Particle-Reactive Radionuclides PO-210, PB-210, and BE-7
… and bulk precipitation samples for Be-7 and Pb-210 analysis were collected from November 1982 through October 1983 at two sites in lower Chesapeake Bay. Atmospheric deposition fluxes for Be-7 in wet-only and bulk precipitation averaged 0.013 and 0.014 pCi/cm<sup>2</sup>/d, respectively, and for …
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Polonium-210 radioactivity in Lake Mead fish
Polonium-210, a naturally occurring radioisotope, has been found at high concentrations in marine fish. One publication reports much lower concentration (on the order of 10{dollar}\sp{-1}{dollar}) of {dollar}\sp{210}{dollar}Po in fresh-water fish compared to salt-water, although the visceral organs …
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Investigating the ocean’s biological pump using thorium-235 and polonium-210
… the two radioisotope pairs 234Th/238U and 210Po/210Pb are utilized. Chapter 2 is an update of the 234Th/238U measurement method which simplifies the protocol, and allows for expansion of use. Chapter 3 presents an unprecedentedly extensive, non-steady state study of 234Th/238U to assess POC …
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Three-dimensional modeling of sealing and wear of XTS-210 engine Apex seals
… that constrain the performance of the XTS-210 and provides recommendations for improving its sealing system through advanced modeling and design optimization.
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Polonium-210 in Freshwater Environments: Analytical Advances, Predictive Modelling, Food Web Transfer and Dose Assessment
Polonium-210 (²¹⁰Po) is a naturally occurring radionuclide of high radiological relevance, yet its occurrence, environmental behaviour and biological transfer in freshwater ecosystems remain poorly characterized. Advances in understanding have been constrained by analytical challenges and by …
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Aufbau eines Experimentes zur Messung der Emissionswahrscheinlichkeit von Bremsstrahlung im alpha-Zerfall von Polonium-210
Die Emissionswahrscheinlichkeit von Bremsstrahlung kann in den meisten Fällen sehr gut semi-klassisch beschrieben werden. Beim Alpha-Zerfall jedoch tunnelt das Alpha-Teilchen durch die Coulomb-Barriere des Kernes, ein Prozess, der nur quantenmechanisch begriffen werden kann. Hierbei stellt sich die …
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Quantification of sugars and organic acids in 210 cucumber (cucurbis sativus) varieties for genome-wide association studies (GWAS)
… (TA), and three main organic acids via HPLC in 210 GWAS cucumber samples. A histogram and Agglomerative Hierarchical Clustering (AHC) were performed for each measured variable. The °Brix ranged from 1% – 4.6%. The content of fructose, glucose, and sucrose ranged from 2.88 - 62.28 mg/mL, 3.99 – …
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Investigating the Use of Fallout Radionuclides Beryllium-7 and Excess Lead-210 as Short-Term Stream Sediment Chronometers in the Agricultural Upper Midwest, USA
… radionuclides beryllium-7 and excess lead-210 to estimate the relative time since precipitation exposure, or “age”, of suspended sediment at various points in a stream system in eastern Wisconsin during storms. The purpose of this work was to characterize patterns of sediment transport in …
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Measurements of fl̳t̳, ft̳t̳, and f'l̳t̳ structure functions in a non-quasi-elastic ²H(e[right arrow],e'p) reaction at 210 (MeV/c) missing momentum
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Physics, 1999.
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An experimental low Reynolds number comparison of a Wortmann FX67-K170 airfoil, a NACA 0012 airfoil, and a NACA 64-210 airfoil in simulated heavy rain
Thesis: M.S., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 1987
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The Adsorption of Nitric Oxide and Thiophene on Platinum Single Crystals
The adsorption of nitric oxide on Pt(210), Pt(100), and Pt(111) was studied using X-ray photoelectron (XPS) and Auger electron (AES) spectroscopies. Nitric oxide was found to molecularly adsorb on Pt(210) at room temperature but to dissociate upon heating to 450 K. The same behavior was noted on …
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The effect of eccentric exercise velocity on selected measures of muscle function and soreness of the Human elbow flexors in untrained males and females
… at 30°•s-1 (LVE) compared to the equivalent at 210°•s-1 (HVE). Subjects performed 120 seconds of eccentric exercise of the elbow flexors using a Cybex 6000 Isokinetic Dynamometer. At 30°-s-1, a total of 30 repetitions were required whilst at 210°•s-1, 210 contractions were performed (at a 1:7 …
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Radiopurity measurement of acrylic for the DEAP-3600 dark matter experiment
… contamination from uranium and thorium, the Pb-210 from Rn-222 diffusion during manufacturing must be measured. The limit for the DEAP-3600 acrylic vessel is 1.1 × 10^−20 g/g Pb-210. By vaporizing a large quantity of acrylic and counting the concentrated residue with an ultralow background HPGe …
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Natural alpha-radioactivity in bone, liver and blood samples from the various species
… in count rate over a time period enables Po-210 activity to be determined. Additional alpha spectroscopic techniques are used to identify specific alpha emitting isotopes in the samples. Bone tissue alpha-activity levels are used as a basis for comparing levels between the species. Liver is …
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