Recovering vector field patterns by means of a two-dimensional fiber-optics measurement grid

1999 ◽  
Vol 42 (6) ◽  
pp. 541-550 ◽  
Author(s):  
Yu. N. Kul'chin ◽  
O. B. Vitrik ◽  
O. T. Kamenev ◽  
R. V. Romashko
Keyword(s):  
Vector Field ◽  
Fiber Optics ◽  
Two Dimensional ◽  
Field Patterns

Recovering physical fields with a two-dimensional fiber-optics measurement grid

1999 ◽  
Vol 42 (3) ◽  
pp. 237-246 ◽  
Author(s):  
Yu. N. Kul'chin ◽  
O. B. Vitrik ◽  
O. V. Kirichenko
Keyword(s):  
Fiber Optics ◽  
Two Dimensional ◽  
Physical Fields

An obstacle problem for elliptic membrane shells

2018 ◽  
Vol 24 (5) ◽  
pp. 1503-1529 ◽  
Author(s):  
Philippe G. Ciarlet ◽  
Cristinel Mardare ◽  
Paolo Piersanti
Keyword(s):  
Vector Field ◽  
Asymptotic Analysis ◽  
Obstacle Problem ◽  
Displacement Vector ◽  
Middle Surface ◽  
Two Dimensional ◽  
Displacement Vector Field ◽  
Membrane Shells ◽  
Signorini Condition ◽  
Confinement Condition

Our objective is to identify two-dimensional equations that model an obstacle problem for a linearly elastic elliptic membrane shell subjected to a confinement condition expressing that all the points of the admissible deformed configurations remain in a given half-space. To this end, we embed the shell into a family of linearly elastic elliptic membrane shells, all sharing the same middle surface [Formula: see text], where [Formula: see text] is a domain in [Formula: see text] and [Formula: see text] is a smooth enough immersion, all subjected to this confinement condition, and whose thickness [Formula: see text] is considered as a “small” parameter approaching zero. We then identify, and justify by means of a rigorous asymptotic analysis as [Formula: see text] approaches zero, the corresponding “limit” two-dimensional variational problem. This problem takes the form of a set of variational inequalities posed over a convex subset of the space [Formula: see text]. The confinement condition considered here considerably departs from the Signorini condition usually considered in the existing literature, where only the “lower face” of the shell is required to remain above the “horizontal” plane. Such a confinement condition renders the asymptotic analysis substantially more difficult, however, as the constraint now bears on a vector field, the displacement vector field of the reference configuration, instead of on only a single component of this field.

scholarly journals Two Dimensional Interferometric Photon Counting Observations with the 6m Telescope

1982 ◽  
Vol 67 ◽  
pp. 223-227
Author(s):  
J. Boulesteix ◽  
Y. Georgelin ◽  
M. Marcelin ◽  
J.A. Fort
Keyword(s):  
Fiber Optics ◽  
Photon Counting ◽  
Microchannel Plate ◽  
Two Dimensional ◽  
Silicon Target

This detector has been in use since 1977. Following Labeyrie (1977), it consists of a microchannel plate electrostatically focussed intensifier (TH 9304) coupled by fiber optics to an SIT camera (TH 9655), these parts being manufactured by THOMSON-CSF (FRANCE). The diameter of the S20 photocathode is 25mm but the silicon target is only 18mm wide. The scanning electronics are conventional. The detector is cooled to -5°C, the photocathode being in a dry nitrogen chamber. The system has been described by Boulesteix (1978).

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