Isotropic radiators are known to be a useful tool across a wide range of applications, from applications in light dosimetry in human/animal tissue to calibration of sensitive laboratory equipment. While the bene ts are known, constructing such a tool has proven to be di cult. Currently, there are no commercially available isotropic or nearly isotropic radiators. Previous attempts at constructing an isotropic radiator have been limited to a 10% isotropy level. This thesis covers the design, construction, and analysis of a nearly isotropic optical light source. The constructed source has extrema anisotropies, over a solid angle of approximately 3 steradians, of +\-3% (with 95% of that solid angle being within +\- 2.5% anisotropy). / Graduate

Non-common path aberrations (NCPA) in an adaptive optics system are static aberrations that appear due to the difference in optical path between light arriving at the wavefront sensor (WFS) and at the science detector. If the adaptive optics are calibrated to output an unaberrated wavefront, then any optics outside the path of the light arriving at the WFS inherently introduce aberrations to this corrected wavefront. NCPA corrections calibrate the adaptive optics system such that it outputs a wavefront that is inverse in phase to the aberrations introduced by these non-common path optics, and therefore arrives unaberrated at the science detector, rather than at the output of the corrective elements. Focal plane sharpening (FPS) is one technique used to calibrate for NCPA in adaptive optics systems. Small changes in shape to the deformable element(s) are implemented and images are taken and analyzed for image quality (IQ) on the science detector. This process is iterated until the image quality is maximized and hence the NCPA are corrected. The work carried out as described in this paper employs two FPS techniques at Gemini North to attempt to mitigate up to 33% of the adaptive optics performance and image quality degradations currently under investigation. Changes in the NCPA correction are made by varying the Zernike polynomial coefficients in the closed-loop correction file for Altair (the facility adaptive optics system). As these coefficients are varied during closed-loop operation, a calibration point-source at the focal plane of the telescope is imaged through Altair and NIRI (the facility near-infrared imager) at f/32 in K-prime (2.12 μm). These images are analyzed to determine the Strehl ratio, and a parabolic fit is used to determine the appropriate coefficient correction that maximizes the Strehl ratio. Historic calibrations of the NCPA file in Altair's control loop were done at night on a celestial point source, and used a separate, high-resolution WFS (with its own inherent aberrations not common to either NIRI nor Altair) to measure phase corrections directly. In this paper it is shown that using FPS on a calibration source negates both the need to use costly time on the night sky and the use of separate optical systems (which introduce their own NCPA) for analysis. An increase of 6% in Strehl ratio is achieved (an improvement over current NCPA corrections of 11%), and discussions of future improvements and extensions of the technique is presented. Furthermore, a potentially unknown problem is uncovered in the form of high spatial frequency degradation in the PSF of the calibration source.

The Altair 680b Cross-Assembler is a program written in the Nova Assembly Language. It can be used to assemble Altair 680b assembly language programs. The object code can be punched on paper-tape for execution on the Altair 680b microcomputer. This report describes the design and working of the Cross-Assembler. A program listing and a few sample runs are also included. / Thesis / Master of Science (MSc)

Made available in DSpace on 2013-08-07T19:02:29Z (GMT). No. of bitstreams: 1 000436949-Texto+Completo-0.pdf: 1130060 bytes, checksum: 271ba4fb2e36cb9535f95282340f9814 (MD5) Previous issue date: 2011 / In order to promote the reading of silence as a face literary narrative, this paper analyzes the work A parede no escuro, of Altair Martins, proposing, then, a chance reading of literary discourse in silence inserted narrative. The subject is treated from the analysis of the assumptions postulated mainly by the following theory: Erni Orlandi, Discourse Analysis, Lawrence Chacon, of Enunciation, John Cage, Music, Maurice Blanchot and Roland Barthes, Literary Theory. / Visando promover a leitura do silêncio como uma face narrativa literária, esta dissertação analisa a obra A parede no escuro, de Altair Martins, propondo, então, uma possibilidade de leitura do discurso literário inserido no silêncio narrativo. O tema é tratado a partir da análise dos pressupostos postulados, principalmente, pelos seguintes teóricos: Erni Orlandi, da Análise do Discurso; Lourenço Chacon, da Enunciação; John Cage, da Música; Maurice Blanchot e Roland Barthes, da Teoria Literária.

Schon seit längerer Zeit wird versucht, Konstruktion und Berechnung zu verschmelzen. Ein Hindernis ist dabei oft, dass Berechnungsexpertise erforderlich ist, um aussagefähige Modelle zu erstellen. Da meistens die Finite Elemente Analyse verwendet wird, sind Geometrievereinfachungen und Vernetzung erforderlich. Beides braucht Expertise und vor allem Zeit. Obwohl es schon Software gibt, die diese Prozesse automatisiert, gibt es immer wieder Limitationen. Mit SimSolid gibt es nun eine Software, die keine Geometrievereinfachung und -vernetzung erfordert und damit einige Hindernisse für die konstruktionsnahe Berechnung aus dem Weg schafft. In SimSolid ist eine vernetzungsfreie Finite Elemente Methode implementiert. Sie basiert auf der Anwendung der Ritz-Galerkin Methode. Der Vortrag gibt eine kurze Übersicht über die mathematischen Grundlagen. Die Vorteile liegen auf der Hand: Die Software kann CAD-Geometrie direkt und ohne Vereinfachung verarbeiten. Bauteilgruppen und Produkte können als Ganzes geladen und simuliert werden. Die gegenwärtige Implementation erlaubt lineare und nichtlineare Statik, stationäre thermische, Eigenfrequenz- sowie modale dynamische Berechnungen. Weiterhin verwendet der Lösungsalgorithmus adaptive Verfeinerungen der Formfunktionen. Dies geschieht automatisch in mehreren Lösungsschritten. Lokale Anreicherungen des Funktionsraumes sind auch möglich, um zum Beispiel genauere Spannungsaussagen zu bekommen. Kontakt und nichtlineare Materialien sind verfügbar. Altair SimSolid wird die konstruktionsnahe Berechnung verändern. Es können nun neben einfacher linearer Statik auch komplexere Phänomene im Konstruktionsstadium schnell analysiert werden. Natürlich muss der Konstrukteur beim Aufsetzen der Berechnungen über geeignete Material- und Lastdaten verfügen, wobei sich aber durch die Betrachtung von ganzen Baugruppen die Definition von Rand- und Lagerbedingungen dramatisch vereinfacht. Insgesamt wird SimSolid auch durch seine einfache Handhabung bald als Konstruktionswerkzeug nicht mehr wegzudenken sein.

Made available in DSpace on 2015-04-14T13:38:37Z (GMT). No. of bitstreams: 1 436949.pdf: 1130060 bytes, checksum: 271ba4fb2e36cb9535f95282340f9814 (MD5) Previous issue date: 2011-12-27 / In order to promote the reading of silence as a face literary narrative, this paper analyzes the work A parede no escuro, of Altair Martins, proposing, then, a chance reading of literary discourse in silence inserted narrative. The subject is treated from the analysis of the assumptions postulated mainly by the following theory: Erni Orlandi, Discourse Analysis, Lawrence Chacon, of Enunciation, John Cage, Music, Maurice Blanchot and Roland Barthes, Literary Theory / Visando promover a leitura do sil?ncio como uma face narrativa liter?ria, esta disserta??o analisa a obra A parede no escuro, de Altair Martins, propondo, ent?o, uma possibilidade de leitura do discurso liter?rio inserido no sil?ncio narrativo. O tema ? tratado a partir da an?lise dos pressupostos postulados, principalmente, pelos seguintes te?ricos: Erni Orlandi, da An?lise do Discurso; Louren?o Chacon, da Enuncia??o; John Cage, da M?sica; Maurice Blanchot e Roland Barthes, da Teoria Liter?ria

Ride and handling are important areas for safety and improved vehicle control during driving. To meet the demands on ride and handling a number of measures can be taken. This master thesis work has focused on the early design phase. At the early phases of design, the level of details is low and the design freedom is big. By introducing a tool to support the early vehicle body design, the potential of finding more efficient structures increases. In this study, topology optimization of a vehicle front structure has been performed using OptiStruct by Altair Engineering. The objective has been to find the optimal topology of beams and rods to achieve high stiffness of the front structure for improved ride and handling. Based on topology optimization a proposal for a beam layout in the front structure area has been identified. A vital part of the project has been to describe how to use topology optimization as a tool in the design process. During the project different approaches has been studied to come from a large design space to a low weight architecture based on a beam-like structure. The different approaches will be described and our experience and recommendations will be presented. Also the general result of a topology-optimized architecture for vehicle body stiffness will be presented.