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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.
1

Interim Access to the International Space Station

Smith, Tyson Karl 01 December 2009 (has links)
This thesis evaluates mission scenarios using the existing Evolved Expendable Launch Vehicles for delivering the Crew Exploration Vehicle to the International Space Station. The Space Shuttle is scheduled to retire in the year 2011 and the Ares I is being developed to replace it. With its current schedule, the earliest that the Ares I will become fully operational is 2016. The configurations in this thesis are presented to narrow the gap in which the USA does not have direct access to the International Space Station. They also present "buy down" options for the USA human space operations, if the current development issues of the Ares I cause it to not become operational at all. The three Launch options presented are the Atlas V HLV, the Delta IV Heavy, and the Delta IV with three common core boosters as the first stage and the Orion service module to be used as the second stage. The first configuration, the Atlas V HLV requires significant impulse from the Orion service module in order to reach the final International Space Station orbit. The second option, the Delta IV Heavy, launches the Orion as a passive payload and requires no impulsive maneuvering from the service module in order to reach the International Space Station orbit. The third configuration, the Delta IV Heavy with three common core boosters as the first stage, and the Orion spacecraft acting as the second stage, requires significant impulse from Orion's service module engine to achieve the International Space Station orbit. After final orbit insertion all three configurations still have sufficient propellent for de-orbit and re-entry.The third configuration has a certain appeal, by eliminating the second stage only the common core booster on the Delta IV Heavy system need be human-rated. Finally, reliability and development cost assessments are presented and compared to the Ares I.
2

Studium vzácných rozpadů B-mesonů v experimentu ATLAS / Study of the rare B-meson decays with the ATLAS experiment

Biroš, Marek January 2020 (has links)
Title: Study of the rare B-meson decays with the ATLAS experiment Author: Marek Biroš Institute: Institute of Particle and Nuclear Physics Supervisor: RNDr. Pavel Řezníček, Ph.D., Institute of Particle and Nuclear Physics Abstract: The rare B0 d → K∗0 (892) μμ decay is one of the B-physics channels sensitive to Beyond Standard Model effects. The potential deviation from Standard Model predictions could be observed in the angular distribution of this decay. The work compiles several sub-tasks at the initial stage of this complex analysis: decay angles fit validation and signal event preselection. The fit functions used in the analysis are verified on generated toy Monte Carlo data. Ranges of parameters, for which are these functions positive, are established and within this parametric space, the testing of possible intrinsic fit biases is evaluated. A dependence of the fit bias with respect to the collected number of events (expected in Run 2 as well as at HL-LHC) and to the different signal-to- background ratio is studied. The second part of the thesis deals with processing of raw reconstructed data from the detector into n-tuples resulting in a more compact dataset that would be used in the final analysis. Within the process, baseline cuts are applied in order to minimize size of final datasets by reducing...

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