Approximate methods of identifying dynamic systems

Translated from Izmeritel'naya Tekhnika, No. 7, pp. 8–9, July, 1992.     

Features of penetrating obstacles made of combined materials with strikers of different shape

Results of ballistic tests for obstacles made of combined materials in relation to striker shape are presented in the form of penetration curves. It is established that striker shape affects not only quantitative indices, but also the qualitative nature of these curves.Translated from Problemy Prochnosti, No. 1, pp. 60–62, January, 1992.     

Diffraction characteristics of superimposed holographic gratings inplanar optical waveguides

A coupled-mode analysis of superimposed holographic transmission gratings in single-mode planar optical waveguides is presented. The diffraction characteristics are shown to be sensitive to the polarization of the incident wave, the angular separation of the output waves and the relative index modulation between the gratings. The coupling between gratings affects the diffraction efficiencies and decreases the angular and wavelength selectivities. Nevertheless, good channel separation and high fanout can be obtained together     

Calculation of the integral parameters of rotor-type granulators

Translated from Khimicheskoe i Neftyanoe Mashinostroenie, No. 4, p. 19, April, 1992.     

The Influence of the Amount of Fluoride Catalyst on the Morphological Properties of the Anilinepropylsilica Xerogel Prepared in Basic Medium

Anilinepropylsilica hybrid powder was synthesized by a sol-gel route in basic medium using HF as catalyst. The effect of the amount of HF catalyst on the morphologies and on organic content was studied. The xerogels were characterized using FTIR, SEM and N₂ adsorption-desorption isotherms. The increase in the HF quantity results in an slight increase in organic content and changes in the particle size, surface area and pore structure.     

Passive solar systems for heating, daylighting and ventilation for rooms without an equator-facing facade

Spaces without northerly orientations have an impact on the ‘energy behaviour’ of a building. This paper outlines possible energy savings and better performance achieved by different zenithal solar passive strategies (skylights, roof monitors and clerestory roof windows) and element arrangements across the roof in zones of cold to temperate climates typical of the central and central-southern Argentina. Analyses were undertaken considering daylighting, thermal and ventilation performances of the different strategies. The results indicate that heating, ventilation and lighting loads in spaces without an equator-facing facade can be significantly reduced by implementing solar passive strategies. In the thermal aspect, the solar saving fraction reached for the different strategies were averaged 43.16% for clerestories, 41.4% for roof monitors and 38.86% for skylights for a glass area of 9% to the floor area. The results also indicate average illuminance levels above 500 lux for the different clerestory and monitor arrangements, uniformity ratios of 0.66–0.82 for the most distributed arrangements and daylighting factors between 11.78 and 20.30% for clear sky conditions, depending on the strategy. In addition, minimum air changes rates of 4 were reached for the most extreme conditions.