8 research outputs found

    Наклеп при накатке отверстий

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    Tolerancing has long been identified as a crucial part in the development of optical systems. It aims at finding the best balance between quality and cost as tolerances closely tie together manufacturing expenses and performance. Tolerance effects have been included into the optimization function (merit function) by some lens designers to find insensitive designs1-5 and frequently compensators are employed to further improve the performance of assembled lenses. Compensators are limited to a small number of system parameters, but selective assembly of components can extend the number of parameters available for compensation. It can be employed to reduce tolerance effects of disturbed parameters by finding the best matches out of a set of components. In this work we discuss how desensitization and selective assembly can be combined to loosen tolerances and increase as-built performance. The investigations concentrate on tolerance insensitive design forms under the presence of selective assembly compensators. In contrast to desensitizing a given lens or introducing new design means we focus on introducing new assembly strategies into the design procedure and investigate how using selective assembly as a compensator while desensitizing the remaining design parameters can lead to even less sensitive designs

    Нижний кембрий Западного Саяна

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    A miniaturized solid state laser for marking applications has been developed featuring novel assembly strategies to reduce size, cost and assembly effort. Design and setup have been laid out with future automation of the assembly in mind. Using a high precision robot the optical components composing the laser system are directly placed on a planar substrate providing accurate positioning and alignment within a few microns. No adjustable mounts for mirrors and lenses are necessary, greatly simplifying the setup. Consisting of either a ND:YAG or a Nd:YVO4 crystal pumped with a fiber coupled diode laser, a q-switch for pulse generation and a beam expander the entire assembly is confined in a 100ml space and delivers 4 W of continuous output power at 1.064 ?m with an efficiency greater than 40%. Pulse lengths of 10-20 ns and repetition rates of up to 150 kHz have been obtained with an acousto-optic modulator. In addition, a custom designed electro-optic modulator with integrated high voltage switch has been realized. A supply unit for the entire system, including scanner and water cooling, is integrated in a 19" industrial chassis and can be operated via a graphical user interface on a standard personal computer

    Response of a multi-domain continental margin to compression: study from seismic reflection-refraction and numerical modelling in the Tagus Abyssal Plain

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    The effects of the Miocene through Present compression in the Tagus Abyssal Plain are mapped using the most up to date available to scientific community multi-channel seismic reflection and refraction data. Correlation of the rift basin fault pattern with the deep crustal structure is presented along seismic line IAM-5. Four structural domains were recognized. In the oceanic realm mild deformation concentrates in Domain I adjacent to the Tore-Madeira Rise. Domain 2 is characterized by the absence of shortening structures, except near the ocean-continent transition (OCT), implying that Miocene deformation did not propagate into the Abyssal Plain, In Domain 3 we distinguish three sub-domains: Sub-domain 3A which coincides with the OCT, Sub-domain 3B which is a highly deformed adjacent continental segment, and Sub-domain 3C. The Miocene tectonic inversion is mainly accommodated in Domain 3 by oceanwards directed thrusting at the ocean-continent transition and continentwards on the continental slope. Domain 4 corresponds to the non-rifted continental margin where only minor extensional and shortening deformation structures are observed. Finite element numerical models address the response of the various domains to the Miocene compression, emphasizing the long-wavelength differential vertical movements and the role of possible rheologic contrasts. The concentration of the Miocene deformation in the transitional zone (TC), which is the addition of Sub-domain 3A and part of 3B, is a result of two main factors: (1) focusing of compression in an already stressed region due to plate curvature and sediment loading; and (2) theological weakening. We estimate that the frictional strength in the TC is reduced in 30% relative to the surrounding regions. A model of compressive deformation propagation by means of horizontal impingement of the middle continental crust rift wedge and horizontal shearing on serpentinized mantle in the oceanic realm is presented. This model is consistent with both the geological interpretation of seismic data and the results of numerical modelling. (C) 2008 Elsevier B.V. All rights reserved.Instituto Nacional de Engenharia, Tecnologia e Inovacao(INETI); Landmark Graphics Corporation; Landmark University Grant Program; LATTEX/IDL [ISLF-5-32]; FEDERinfo:eu-repo/semantics/publishedVersio

    Assessment of Ventricular Repolarization From Body-Surface ECGs in Humans

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    Superluminous Supernovae

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