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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Estimates of stratal shortening in South Wales and South-West Ireland

Hanna, Samir S. January 1983 (has links)
No description available.
22

Structural and alteration characteristics of the Indarama lode gold deposit, Zimbabwe : implications for craton-wide tectonism and mineralization

McKeagney, Catherine Judith January 1998 (has links)
No description available.
23

OSSOS III—RESONANT TRANS-NEPTUNIAN POPULATIONS: CONSTRAINTS FROM THE FIRST QUARTER OF THE OUTER SOLAR SYSTEM ORIGINS SURVEY

Volk, Kathryn, Murray-Clay, Ruth, Gladman, Brett, Lawler, Samantha, Bannister, Michele T., Kavelaars, J. J., Petit, Jean-Marc, Gwyn, Stephen, Alexandersen, Mike, Chen, Ying-Tung, Lykawka, Patryk Sofia, Ip, Wing, Lin, Hsing Wen 24 June 2016 (has links)
The first two observational sky "blocks" of the Outer Solar System Origins Survey (OSSOS) have significantly increased the number of well characterized observed trans-Neptunian objects (TNOs) in Neptune's mean motion resonances. We describe the 31 securely resonant TNOs detected by OSSOS so far, and we use them to independently verify the resonant population models from the Canada-France Ecliptic Plane Survey (CFEPS), with which we find broad agreement. We confirm that the 5:2 resonance is more populated than models of the outer solar system's dynamical history predict; our minimum population estimate shows that the high-eccentricity (e > 0.35) portion of the resonance is at least as populous as the 2:1 and possibly as populated as the 3:2 resonance. One OSSOS block was well suited for detecting objects trapped at low libration amplitudes in Neptune's 3:2 resonance, a population of interest in testing the origins of resonant TNOs. We detected three 3:2 objects with libration amplitudes below the cutoff modeled by CFEPS; OSSOS thus offers new constraints on this distribution. The OSSOS detections confirm that the 2:1 resonance has a dynamically colder inclination distribution than either the 3:2 or 5:2 resonances. Using the combined OSSOS and CFEPS 2:1 detections, we constrain the fraction of 2:1 objects in the symmetric mode of libration to 0.2-0.85; we also constrain the fraction of asymmetric librators in the leading island, which has been theoretically predicted to vary depending on Neptune's migration history, to be 0.05-0.8. Future OSSOS blocks will improve these constraints.
24

Coupled belt-pulley mechanics in serpentine belt drives /

Kong, Lingyuan. Unknown Date (has links)
Thesis (Ph. D.)--Ohio State University, 2003. / Title from first page of PDF file. Document formatted into pages; contains xiii, 166 p.: ill. Includes bibliographical references (p. 159-166). Available online via OhioLINK's ETD Center.
25

Small bodies in the outer solar system from Kuiper Belt objects to centaurs to satellites /

Sheppard, Scott S. January 2004 (has links)
Thesis (Ph. D.)--University of Hawaii at Manoa, 2004. / Includes bibliographical references (leaves 246-257).
26

Synchronous belt mechanics and life prediction : a fundamental investigation into the mechanics of toothed belts for automotive camshaft drives, and the prediction of belt life in operation

Parker, Ian Kenneth January 1992 (has links)
No description available.
27

Proces zavádění Six Sigma ve farmaceutické firmě

Fialka, Radek January 2009 (has links)
No description available.
28

Granite petrogenesis and crustal evolution studies in the Damara Pan-African orogenic belt, Namibia

McDermott, P. F. January 1986 (has links)
Major and trace element data for Damara granitoids distinguish three geochemically distinct granitoid groups, - crustal-melt granitoids, calc-alkaline granitoids and within-plate granitoids. The overwhelming majority of the Oamara granitoids are peraluminous crustal-melt leucogranites which have elevated <sup>87</sup>Sr/<sup>86</sup>Sr ratios (> 0.710) and old model Nd ages (~ 2.0 Ga). Calc-alkaline diorites are metaluminous and have the lowest <sup>87</sup>Sr/<sup>86</sup>Sr ratios (0.704 - 0.707) and model Nd ages (OM) in the range 1.1 -1.7 Ga. Within-plate granitoids are characterised by elevated high-field strength (HFS) abundances and have model Nd ages (OM) in the range 1.1 - 1.6 Ga. All Damara granitoids have model Nd ages (OM) older than about 1.0 Ga suggesting that intracrustal reworking was the dominant process and crustal growth was negligible. Damara granitoids define a hyperbola on an ∈ Sr vs. ∈ Nd diagram but cannot be modelled as simple binary mixtures between old continental crust and depleted mantle end-members. An episodic intracrustal remobilisation model is proposed to explain the hyperbola defined by granitoid data on an ∈ Sr vs. ∈ Nd diagram. Within the 10 km thick Damara metasedimentary pile <sup>87</sup>Sr/<sup>86</sup>Sr ratios increase systematically with depth. This trend is accompanied by a decrease in <sup>143</sup>Nd/<sup>144</sup>Nd ratios. Model Nd ages (CHUR) for the stratigraphically oldest Damara metasediments (Nosib Group) are about 2.0 Ga whereas the younger metasediments (Kuiseb Formation and Nama Group) have model Nd ages (CHUR) about 1.0 Ga reflecting sediment input from younger source terrains. The ratio of model ages (T<sup>Nd</sup><sub>CHUR</sub>/T<sup>Sr</sup><sub>BE</sub>) is used as an index of intracrustal reworking since it provides a measure of Rb/Sr fractionation (increases) relative to SmlNd fractionation. The older Damara metasediments (Nosib Group) have the highest model age ratios suggesting that their source terrains have suffered the largest amount of intracrustal reworking. However, the rate of intracrustal reworking was greatest in source terrains sampled by the younger Damara metasediments (Kuiseb Formation and Nama Group). This suggests that the rate of intracrustal reworking increased through time in the interval (2.0 - 1.0 Ga) in this segment of continental crust.
29

“TNOs are Cool”: A survey of the trans-Neptunian region

Kovalenko, I. D., Doressoundiram, A., Lellouch, E., Vilenius, E., Müller, T., Stansberry, J. 30 November 2017 (has links)
Context. Gravitationally bound multiple systems provide an opportunity to estimate the mean bulk density of the objects, whereas this characteristic is not available for single objects. Being a primitive population of the outer solar system, binary and multiple trans-Neptunian objects (TNOs) provide unique information about bulk density and internal structure, improving our understanding of their formation and evolution. Aims. The goal of this work is to analyse parameters of multiple trans-Neptunian systems, observed with Herschel and Spitzer space telescopes. Particularly, statistical analysis is done for radiometric size and geometric albedo, obtained from photometric observations, and for estimated bulk density. Methods. We use Monte Carlo simulation to estimate the real size distribution of TNOs. For this purpose, we expand the dataset of diameters by adopting the Minor Planet Center database list with available values of the absolute magnitude therein, and the albedo distribution derived from Herschel radiometric measurements. We use the 2-sample Anderson-Darling non-parametric statistical method for testing whether two samples of diameters, for binary and single TNOs, come from the same distribution. Additionally, we use the Spearman's coefficient as a measure of rank correlations between parameters. Uncertainties of estimated parameters together with lack of data are taken into account. Conclusions about correlations between parameters are based on statistical hypothesis testing. Results. We have found that the difference in size distributions of multiple and single TNOs is biased by small objects. The test on correlations between parameters shows that the effective diameter of binary TNOs strongly correlates with heliocentric orbital inclination and with magnitude difference between components of binary system. The correlation between diameter and magnitude difference implies that small and large binaries are formed by different mechanisms. Furthermore, the statistical test indicates, although not significant with the sample size, that a moderately strong correlation exists between diameter and bulk density.
30

The Curiously Warped Mean Plane of the Kuiper Belt

Volk, Kathryn, Malhotra, Renu 19 July 2017 (has links)
We measured the mean plane of the Kuiper Belt as a function of semimajor axis. For the classical Kuiper Belt as a whole (the nonresonant objects in the semimajor axis range 42-48 au), we find a mean plane of inclination i(m) = 1 degrees.8(-0 degrees.4)(+0 degrees.7) and longitude of ascending node Omega(m) = 77 degrees(+18 degrees)(-14 degrees) (in the J2000 ecliptic-equinox coordinate system), in accord with theoretical expectations of the secular effects of the known planets. With finer semimajor axis bins, we detect a statistically significant warp in the mean plane near semimajor axes 40-42 au. Linear secular theory predicts a warp near this location due to the nu(18) nodal secular resonance; however, the measured mean plane for the 40.3-42 au semimajor axis bin (just outside the nu(18)) is inclined similar to 13 degrees to the predicted plane, a nearly 3 sigma discrepancy. For the more distant Kuiper Belt objects of semimajor axes in the range 50-80 au, the expected mean plane is close to the invariable plane of the solar system, but the measured mean plane deviates greatly from this: it has inclination i(m) = 9 degrees.1(-3 degrees.8)(+6 degrees.6) and longitude of ascending node Omega(m) = 277 degrees(+18 degrees)(-44 degrees). We estimate this deviation from the expected mean plane to be statistically significant at the similar to 97%-99% confidence level. We discuss several possible explanations for this deviation, including the possibility that a relatively close-in (a less than or similar to 100 au), unseen, small planetary-mass object in the outer solar system is responsible for the warping.

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