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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

Numerische Berechnung elektromagnetischer Felder - Erweiterung einer Hybridmethode aus Momentenmethode und Einheitlicher Geometrischer Beugungstheorie um die Verallgemeinerte Multipoltechnik

Balling, Stefan 30 October 2007 (has links) (PDF)
Drei numerische Feldberechnungsverfahren - die Momentenmehtode, die Einheitliche Geometrische Beugungstheorie und die Verallgemeinerte Multipoltechnik - werden schrittweise zu einer Erweiterten Hybridmethode (EHM) kombiniert. Dabei wird jeder einzelne Kombinationsschritt anschaulich anhand von Beispielen erläutert, die den Vorteil der EHM verdeutlichen: Mit diesem Verfahren lassen sich bestimmte Anordnungen äußerst effektiv analysieren.
2

Numerische Berechnung elektromagnetischer Felder - Erweiterung einer Hybridmethode aus Momentenmethode und Einheitlicher Geometrischer Beugungstheorie um die Verallgemeinerte Multipoltechnik

Balling, Stefan 16 May 2007 (has links)
Drei numerische Feldberechnungsverfahren - die Momentenmehtode, die Einheitliche Geometrische Beugungstheorie und die Verallgemeinerte Multipoltechnik - werden schrittweise zu einer Erweiterten Hybridmethode (EHM) kombiniert. Dabei wird jeder einzelne Kombinationsschritt anschaulich anhand von Beispielen erläutert, die den Vorteil der EHM verdeutlichen: Mit diesem Verfahren lassen sich bestimmte Anordnungen äußerst effektiv analysieren.
3

New and improved technology for manufacture of GMT primary mirror segments

Kim, Dae Wook, Burge, James H., Davis, Jonathan M., Martin, Hubert M., Tuell, Michael T., Graves, Logan R., West, Steve C. 22 July 2016 (has links)
The Giant Magellan Telescope (GMT) primary mirror consists of seven 8.4 m light-weight honeycomb mirrors that are being manufactured at the Richard F. Caris Mirror Lab (RFCML), University of Arizona. In order to manufacture the largest and most aspheric astronomical mirrors various high precision fabrication technologies have been developed, researched and implemented at the RFCML. The unique 8.4 m (in mirror diameter) capacity fabrication facilities are fully equipped with large optical generator (LOG), large polishing machine (LPM), stressed lap, rigid conformal lap (RC lap) and their process simulation/optimization intelligence called MATRIX. While the core capability and key manufacturing technologies have been well demonstrated by completing the first GMT off-axis segment, there have been significant hardware and software level improvements in order to improve and enhance the GMT primary mirror manufacturing efficiency. The new and improved manufacturing technology plays a key role to realize GMT, the next generation extremely large telescope enabling new science and discoveries, with high fabrication efficiency and confidence.
4

The GMT-Consortium Large Earth Finder (G-CLEF): an optical Echelle spectrograph for the Giant Magellan Telescope (GMT)

Szentgyorgyi, Andrew, Baldwin, Daniel, Barnes, Stuart, Bean, Jacob, Ben-Ami, Sagi, Brennan, Patricia, Budynkiewicz, Jamie, Chun, Moo-Young, Conroy, Charlie, Crane, Jeffrey D., Epps, Harland, Evans, Ian, Evans, Janet, Foster, Jeff, Frebel, Anna, Gauron, Thomas, Guzmán, Dani, Hare, Tyson, Jang, Bi-Ho, Jang, Jeong-Gyun, Jordan, Andres, Kim, Jihun, Kim, Kang-Miin, Mendes de Oliveira, Claudia Mendes, Lopez-Morales, Mercedes, McCracken, Kenneth, McMuldroch, Stuart, Miller, Joseph, Mueller, Mark, Oh, Jae Sok, Onyuksel, Cem, Ordway, Mark, Park, Byeong-Gon, Park, Chan, Park, Sung-Joon, Paxson, Charles, Phillips, David, Plummer, David, Podgorski, William, Seifahrt, Andreas, Stark, Daniel, Steiner, Joao, Uomoto, Alan, Walsworth, Ronald, Yu, Young-Sam 09 August 2016 (has links)
The GMT-Consortium Large Earth Finder (G-CLEF) will be a cross-dispersed, optical band echelle spectrograph to be delivered as the first light scientific instrument for the Giant Magellan Telescope (GMT) in 2022. G-CLEF is vacuumenclosed and fiber-fed to enable precision radial velocity (PRV) measurements, especially for the detection and characterization of low-mass exoplanets orbiting solar-type stars. The passband of G-CLEF is broad, extending from 3500 angstrom to . This passband provides good sensitivity at blue wavelengths for stellar abundance studies and deep red response for observations of high-redshift phenomena. The design of G-CLEF incorporates several novel technical innovations. We give an overview of the innovative features of the current design. G-CLEF will be the first PRV spectrograph to have a composite optical bench so as to exploit that material's extremely low coefficient of thermal expansion, high in-plane thermal conductivity and high stiffness-to-mass ratio. The spectrograph camera subsystem is divided into a red and a blue channel, split by a dichroic, so there are two independent refractive spectrograph cameras. The control system software is being developed in model-driven software context that has been adopted globally by the GMT. G-CLEF has been conceived and designed within a strict systems engineering framework. As a part of this process, we have developed a analytical toolset to assess the predicted performance of G-CLEF as it has evolved through design phases.
5

Berechnung und Auslegung faserverstärkter Umlenkrollen für die Aufzugstechnik

Katkowski, Mikolaj Jan 05 July 2019 (has links)
Im Rahmen von FuE-Kooperationen arbeitet die TU Chemnitz, Professur für Strukturleichtbau und Kunststoffverarbeitung zusammen mit der AMB berlungwitz GmbH aktuell an der Entwicklung von langfaserverstärkten Kunststoffseilrollen für Aufzugsanlagen, welche die in diesem Bereich vorhandenen Leichtbauanforderungen erfüllen. Dabei wird die gesamte Entwicklungskette von der Bauteilkonstruktion und -berechnung über die Prozesskettengestaltung und Prozessparameterfindung bis hin zur Prüfung und Validierung von Probekörpem ausgeführt. Der grundsätzliche Technologieansatz zur Fertigung der Seilrollen-Rohteile ist das Fließpressen von glasmattenverstärkten Thermoplasten (GMT). Die vorliegende Arbeit beschäftigt sich schwerpunktmäßig mit der Berechnung und Auslegung der Bauteile.
6

Advanced structural design for precision radial velocity instruments

Baldwin, Dan, Szentgyorgyi, Andrew, Barnes, Stuart, Bean, Jacob, Ben-Ami, Sagi, Brennan, Patricia, Budynkiewicz, Jamie, Chun, Moo-Young, Conroy, Charlie, Crane, Jeffrey D., Epps, Harland, Evans, Ian, Evans, Janet, Foster, Jeff, Frebel, Anna, Gauron, Thomas, Guzman, Dani, Hare, Tyson, Jang, Bi-Ho, Jang, Jeong-Gyun, Jordan, Andres, Kim, Jihun, Kim, Kang-Min, Mendes de Oliveira, Claudia, Lopez-Morales, Mercedes, McCracken, Kenneth, McMuldroch, Stuart, Miller, Joseph, Mueller, Mark, Oh, Jae Sok, Ordway, Mark, Park, Byeong-Gon, Park, Chan, Park, Sung-Joon, Paxson, Charles, Phillips, David, Plummer, David, Podgorski, William, Seifahrt, Andreas, Stark, Daniel, Steiner, Joao, Uomoto, Alan, Walsworth, Ronald, Yu, Young-Sam 22 July 2016 (has links)
The GMT-Consortium Large Earth Finder (G-CLEF) is an echelle spectrograph with precision radial velocity (PRV) capability that will be a first light instrument for the Giant Magellan Telescope (GMT). G-CLEF has a PRV precision goal of 40 cm/sec (10 cm/s for multiple measurements) to enable detection of Earth-like exoplanets in the habitable zones of sun-like stars'. This precision is a primary driver of G-CLEF's structural design. Extreme stability is necessary to minimize image motions at the CCD detectors. Minute changes in temperature, pressure, and acceleration environments cause structural deformations, inducing image motions which degrade PRV precision. The instrument's structural design will ensure that the PRV goal is achieved under the environments G-CLEF will be subjected to as installed on the GMT azimuth platform, including: Millikelvin (0.001 K) thermal soaks and gradients 10 millibar changes in ambient pressure Changes in acceleration due to instrument tip/tilt and telescope slewing Carbon fiber/cyanate composite was selected for the optical bench structure in order to meet performance goals. Low coefficient of thermal expansion (C 1E) and high stiffness-to-weight are key features of the composite optical bench design. Manufacturability and serviceability of the instrument are also drivers of the design. In this paper, we discuss analyses leading to technical choices made to minimize G-CLEF's sensitivity to changing environments. Finite element analysis (FEA) and image motion sensitivity studies were conducted to determine PRV performance under operational environments. We discuss the design of the optical bench structure to optimize stiffness to -weight and minimize deformations due to inertial and pressure effects. We also discuss quasi-kinematic mounting of optical elements and assemblies, and optimization of these to ensure minimal image motion under thermal, pressure, and inertial loads expected during PRV observations.
7

Time and the Making of New Zealand:A Theme in the Development of a Settler Society, 1840 to 1868

Morris, Gerard S. January 2012 (has links)
The thesis seeks to reveal, through the use of numerous case studies, the timekeeping processes that helped to make New Zealand. Whilst the period under review covers primarily the period 1840 to 1868 there is also a discussion of the emergence of clock time in thirteenth century Britain and Europe and its development through to the late nineteenth century. This is because the settlers‟ apprehension of time and their use of clocks and watches had evolved over the preceding centuries. The importance of reliable time was recognised by the Church from the medieval period but as ownership of public and private clocks proliferated the decentralisation of clock time commenced. Clock time commanded the lives of people and imprinted itself through the inculcation of such notions as punctuality and productivity. Better clocks brought a new emphasis to workplace efficiency underpinning the belief that time was money and facilitated the efficient coordination of Land, Labour and Capital. The discovery of New Zealand required timekeeping at sea. The achievements of James Cook, underpinned by improved chronometers, facilitated the large-scale British colonisation of New Zealand and seldom brought respite from the rule of time. Once on land, the settlers looked to establish a temporal order similar to Britain. The challenge to establish and disseminate the „true‟ local time within communities led to the setting up of observatories and the use of public clocks, time ball stations, bells and guns to signal clock time. The myriad of local times was not a problem at first but once the telegraph began to link communities they hindered its optimal efficiency. This led to the introduction of „telegraph time‟ in early 1868, dual time systems in communities using the telegraph, and public debate. Whilst most provinces accepted the new clock time, Otago saw it as an affront to their community‟s autonomy and identity. The province challenged the imposition of telegraph time, instigated a Parliamentary debate, and argued for the introduction of a common New Zealand time. Parliament‟s 1868 decision was a triumph for convenience and economic rationality over tradition and local identity. New Zealand was the first country entirely to abandon local times and regulate its time in relation to Greenwich mean time.
8

Sezónní dynamika vybraných krevních parametrů u vybraných masných plemen ovcí chovaných v podhorských podmínkách / Seasonal dynamics of selected blood parametres of selected flesh breeds of sheep bred in foothills conditions

ŽÁČKOVÁ, Klára January 2009 (has links)
Sheep breeding is nowadays a developing branch of agriculture again. There is a lot of different breed and they react distinctly on the same conditions of the enviroment. Sheep of breeds charollais, suffolk, šumavská ovce and valaška bred in similar conditions were observed in spring and autumn of years 2007 and 2008. In these seasons were taking blood samples (from {$\pm$}7{--}24) ewes and lambs and were analyzed in hematology laboratory. There were determined haemoglobin level, haematocrit indicator, erytrocytes and leucocytes levels, glucose, cholesterol, triglycerides levels, urea and plasmatic proteins, activity of ALP and GMT enzymes, phosphor, calcium, magnesium, zinc and copper levels. The main objective of this project was determine seasonal changes in observed parametres. Next objectives were determine different changes in blood parametres in different breeds and different aimes of breeds. There were recognized that all the observed breeds don`t react the same way on similar conditions. There were not provably determined seasonal changes in observed parametres, but average Hb level was higher in autumn than in spring. Urea level was conversely higher in spring season than in autumn. The demostrable fact is, that the similar conditions induce different answers not only in different breeds but also in different aimes of breeds.

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