High-contrast dark resonance on the D2 - line of 87Rb in a vapor cell with different directions of the pump - probe waves

We propose a novel method enabling to create a high-contrast dark resonance in the 87Rb vapor D2-line. The method is based on an optical pumping of atoms into the working states by a two-frequency, linearly-polarized laser radiation propagating perpendicularly to the probe field. This new scheme is compared to the traditional scheme involving the circularly-polarized probe beam only, and significant improvement of the dark resonance parameters is found. Qualitative considerations are confirmed by numerical calculations.Comment: 7 pages, 4 figure

Virtual hybrid simulation of beams with web openings in fire

Purpose: Perforated composite beams are an increasingly popular choice in the construction of buildings because they can provide a structurally and materially efficient design solution while also facilitating the passage of services. The purpose of this paper is to examine the behaviour of restrained perforated beams, which act compositely with a profiled slab and are exposed to fire. The effect of surrounding structure on the composite perforated beam is incorporated in this study using a virtual hybrid simulation framework. The developed framework could also be used to analyse other structural components in fire. Design/methodology/approach: A finite element model is developed using OpenSees and OpenFresco using a virtual hybrid simulation technique, and the accuracy of the model is validated using available fire test data. The validated model is used to investigate some of the most salient parameters such as the degree of axial and rotational restraint, arrangement of the openings and different types of fire on the overall fire behaviour of composite perforated beams. Findings: It is shown that both axial and rotational restraint have a considerable effect on time-displacement behaviour and the fire performance of the composite perforated beam. It is observed that the rate of heating and the consequent development of elevated temperature in the section have a significant effect on the fire behaviour of composite perforated beams. Originality/value: The paper will improve the knowledge of readers about modelling the whole system behaviour in structural fire engineering and the presented approach could also be used for analysing different types of structural components in fire conditions

Il lavoro delle macchine e degli operaj, ovvero Una visita ad un lanificio : lettura popolare tenuta nel teatro scientifico di Mantova il giorno 27 aprile 1873 / per Alessandro Ferretti

Il lavoro delle macchine e degli operaj, ovvero Una visita ad un lanificio : lettura popolare tenuta nel teatro scientifico di Mantova il giorno 27 aprile 1873 / per Alessandro Ferretti Firenze : Tipografia dell'Associazione, 1874 72 p. ; 19 cm Estr. da: Giornale delle Arti e delle Industrie

University High Highlights 1/20/1960

This is the student newspaper from University High School, the high school that was on the campus of Western Michigan University, then called University High Highlights, in 1960