Zero-Shear, Low-Disturbance Optical Delay Line

A design concept has been proposed for an optomechanical apparatus that would implement a variable optical delay line with a fixed angle between its input and output light beams. The apparatus would satisfy requirements that emphasize performance in interferometric applications: to contain a minimum number of optical surfaces, each used at low angle-of-incidence, and to be nominally free of shear (transverse motion of the beam) on any optical element. As an additional advantage, the apparatus would afford partial compensation of vibration disturbances associated with adjustment of the optical delay by both reducing the amount of motion required to achieve a desired optical delay and by splitting the total motion between two assemblies. As compared to prior art implementations of delay lines, the only disadvantage of the concept is that the motions of the optical elements must be well coordinated through mechanical linkages or electronic controls. The optical elements would be two flat mirrors -- M1 and M2 -- mounted on linear actuators. The actuation axes of M1 and M2 would be parallel to the incoming and outgoing light beams, respectively. M1 would be mounted on its actuator at a fixed angle required to aim the beam reflected from it to the center of M2. In turn, M2 would be mounted on its actuator at a fixed angle required to aim the outgoing beam in the desired direction. Moreover, the angles of M1 and M2 would be chosen so that the angle between M1 and the incoming beam equals the angle between M2 and the outgoing beam

Self-Referencing Hartmann Test for Large-Aperture Telescopes

A method is proposed for end-to-end, full aperture testing of large-aperture telescopes using an innovative variation of a Hartmann mask. This technique is practical for telescopes with primary mirrors tens of meters in diameter and of any design. Furthermore, it is applicable to the entire optical band (near IR, visible, ultraviolet), relatively insensitive to environmental perturbations, and is suitable for ambient laboratory as well as thermal-vacuum environments. The only restriction is that the telescope optical axis must be parallel to the local gravity vector during testing. The standard Hartmann test utilizes an array of pencil beams that are cut out of a well-corrected wavefront using a mask. The pencil beam array is expanded to fill the full aperture of the telescope. The detector plane of the telescope is translated back and forth along the optical axis in the vicinity of the nominal focal plane, and the centroid of each pencil beam image is recorded. Standard analytical techniques are then used to reconstruct the telescope wavefront from the centroid data. The expansion of the array of pencil beams is usually accomplished by double passing the beams through the telescope under test. However, this requires a well-corrected, autocollimation flat, the diameter or which is approximately equal to that of the telescope aperture. Thus, the standard Hartmann method does not scale well because of the difficulty and expense of building and mounting a well-corrected, large aperture flat. The innovation in the testing method proposed here is to replace the large aperture, well-corrected, monolithic autocollimation flat with an array of small-aperture mirrors. In addition to eliminating the need for a large optic, the surface figure requirement for the small mirrors is relaxed compared to that required of the large autocollimation flat. The key point that allows this method to work is that the small mirrors need to operate as a monolithic flat only with regard to tip/tilt and not piston because in collimated space piston has no effect on the image centroids. The problem of aligning the small mirrors in tip/tilt requires a two-part solution. First, each mirror is suspended from a two-axis gimbal. The orientation of the gimbal is maintained by gravity. Second, the mirror is aligned such that the mirror normal is parallel to gravity vector. This is accomplished interferometrically in a test fixture. Of course, the test fixture itself needs to be calibrated with respect to gravity

Compact, Precise Inertial Rotation Sensors for Spacecraft

A document describes a concept for an inertial sensor for measuring the rotation of an inertially stable spacecraft around its center of gravity to within 100 microarcseconds or possibly even higher precision. Whereas a current proposal for a spacecraft-rotation sensor of this accuracy requires one spacecraft dimension on the order of ten meters, a sensor according to this proposal could fit within a package smaller than 1 meter and would have less than a tenth of the mass. According to the concept, an inertial mass and an apparatus for monitoring the mass would be placed at some known distance from the center of gravity so that any rotation of the spacecraft would cause relative motion between the mass and the spacecraft. The relative motion would be measured and, once the displacement of the mass exceeded a prescribed range, a precisely monitored restoring force would be applied to return the mass to a predetermined position. Measurements of the relative motion and restoring force would provide information on changes in the attitude of the spacecraft. A history of relative motion and restoring-force measurements could be kept, enabling determination of the cumulative change in attitude during the observation time

Laser Ablation (imaging) For Mapping And Determining Se And S In Sunflower Leaves.

Qualitative and quantitative methods were developed for selenium and sulphur mapping/quantification in sunflower (Helianthus annuus L.) leaves. The plants were grown for 50 days in a greenhouse, being divided into two groups, one irrigated with only deionized water and the other treated with a daily dose of 7.58 mg of Na(2)SeO(3). Leaves were collected during the growth period for directly evaluating the distribution of Se and S in these structures. For quantification analysis, pellets were produced from both CRM (100 and 1575a for Se and S, respectively) and the sunflower materials. The pellets were doped with 25 and 1200 μg g(-1) Se and 5 and 20 mg g(-1) S and analyzed by LA-ICP-MS. For accuracy purposes all the samples were also decomposed via microwave and analyzed by ICP-MS. To avoid polyatomic interferences Se and S were monitored as SeO(+) and SO(+) at m/z 96 and 48, respectively, (12)C(+) was used as an internal standard, and the ratios between SeO(+)/C(+) and SO(+)/C(+) were used for measurements. Statistic tests (t test at 95% confidence level) confirming good agreement between LA-ICP-MS and ICP-MS indicated the accuracy of this technique.562-

The Invisible Histories Project: Documenting the Queer South

The Invisible Histories Project works with archives and Queer communities in Alabama, Georgia, and Mississippi to identify and collect material documenting the history of the Queer South

Instalación y configuración de OTRS con ITSM versión 5, en el departamento de procesamiento de datos de la Universidad de San Carlos de Guatemala

Implementar una aplicación capaz de llevar el control y la gestión de los servicios de TI, así configurar un prototipo de flujo de procesos dentro de la aplicación, que involucre servicios, clientes, agentes e incidentes

Fluxo de caixa como ferramenta de perpetuação e inovação entre micro e pequenas empresas

Orientadora : Marcia Bortolocci EspejoMonografia (especialização) - Universidade Federal do Paraná, Setor de Ciências Sociais Aplicadas. Curso de Especialização em Contabilidade e FinançasInclui referênciasResumo : Pesquisa publicada pelo Sebrae no ano de 2007 aponta aumento considerável na sobrevivência de empresas no triênio de 2002 a 2005, creditando tal resultado ao desempenho positivo de três variáveis macroeconômicas aliado ao aumento da capacitação dos empresários. Não obstante aos efeitos positivos da capacitação destes empresários, seis anos após a divulgação da referida pesquisa, observa-se um cenário macroeconômico com as mesmas três variáveis apresentando tendências contrárias às observadas no período alvo da pesquisa. Realizou-se um estudo aprofundado do comportamento destas variáveis e de que forma suas tendências atuais podem impactar negativamente às micro e pequenas empresas. A sugestão apresentada à problemática em questão é a adoção de gestão financeira por meio de ferramenta de fluxo de caixa, considerada uma inovação de processo pela metodologia do programa Agentes Locais de Inovação. Além dos argumentos teóricos, o contexto do presente trabalho é sustentado pela exposição dos resultados obtidos junto aos empresários pertencentes à amostra utilizada para criação desta Monografia

USO DE SERIES TEMPORALES PARA LA DETECCIÓN DE PATRONES Y PROYECCIÓN DE TIEMPOS PERDIDOS EN LA FABRICACIÓN DE AZÚCAR

La presente investigación tiene como propósito mostrar que el uso adecuado de los registros relacionados a los tiempos perdidos en una fábrica de producción de azúcar, puede ser una herramienta útil para tomar decisiones al momento de elaborar planes de acción que mitiguen los paros en la producción. El objetivo general de esta investigación consiste en describir los problemas que causan la mayor cantidad de tiempo perdido en la producción de azúcar analizando series de tiempo y generar un pronóstico para el período de zafra 2020-2021 que pueda ser utilizado en la toma de acciones preventivas por parte de los miembros de la organización. Los resultados se elaboraron mediante la categorización de los paros de molienda, identificando con el principio de Pareto, las causas que mayor influencia tuvieron en los tiempos perdidos. También se utilizó la descomposición clásica de las series temporales en cuanto a la duración y frecuencia de los paros de molienda, con el fin de identificar patrones en su ocurrencia, posteriormente se aplicaron los métodos de Holt-Winters y ARIMA para pronosticar los tiempos perdidos para los primeros 15 días de la zafra 2020-2021. Con todo lo anterior, se identificó que los problemas que más influyeron en la continuidad de la producción de la fábrica analizada son los relacionados a la calidad de la materia prima y a los fallos en los equipos, que pueden acumular hasta 4,600 minutos en paros de molienda para la zafra 2020-2021. Se concluyó que el enfoque adecuado para los planes de mitigación debe tomar en cuenta la materia prima y el mantenimiento de los equipos y se recomienda seguir categorizando los problemas registrados para facilitar próximos análisis