Best Shape for a Thin Lens

2009 ◽  
pp. 11-21
Keyword(s):  
Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 417
Author(s):  
Paolo Madonia ◽  
Gloria Campilongo ◽  
Marianna Cangemi ◽  
Maria Luisa Carapezza ◽  
Salvatore Inguaggiato ◽  
...  

Although groundwater is a strategic source in volcanic islands, most hydrogeochemical research on this topic has been focused on volcanic activity monitoring, overlooking general hydrogeological aspects. The same applies to one of the most studied volcanoes in the world, Stromboli Island (Italy). Here, we provide a hydrogeological scheme of its coastal aquifer, retrieving inferences about its potential use as a water supply source and for optimizing monitoring protocols for volcanic surveillance. Starting from the hydrogeochemical literature background, we analyzed new data, acquired both for volcano monitoring purposes and during specific surveys. Among these, there were saturated hydraulic conductivity measurements of selected rock samples and precise determinations of water table elevations based on GNSS surveys of wells. We identified a ubiquitous thin lens of brackish water floating on seawater and composed of a variable mixing of marine and meteoric components; inlets of hydrothermal fluids to the aquifer are basically gases, mainly CO2. Based on its hydrogeochemical character, the coastal aquifer of Stromboli could be used as a water supply source after desalinization by reverse osmosis, while the wells located far from the seashore are the most interesting for volcano monitoring, because they are less disturbed by the shallow geochemical noise.


1918 ◽  
Vol 20 (3) ◽  
pp. 58-66
Author(s):  
T Y Baker ◽  
L N G Filon
Keyword(s):  

2001 ◽  
Vol 39 (6) ◽  
pp. 342-343 ◽  
Author(s):  
Soumya Chakravarti ◽  
P. B. Siegel
Keyword(s):  

2009 ◽  
Vol 68 (2) ◽  
Author(s):  
W. F. Harris ◽  
R. D. Van Gool

It is generally supposed that thin systems, including refracting surfaces and thin lenses, have powers that are necessarily symmetric.  In other words they have powers which can be represented assymmetric dioptric power matrices and in the familar spherocylindrical form used in optometry and ophthalmology.  This paper shows that this is not correct and that it is indeed possible for a thin system to have a power that is not symmetric and which cannot be expressed in spherocylindrical form.  Thin systems of asymmetric power are illustratedby means of a thin lens that is modelled with small prisms and is chosen to have a dioptric power ma-trix that is antisymmetric.  Similar models can be devised for a thin system whose dioptric power matrix is any  2 2 ×  matrix.  Thus any power, symmetric, asymmetric or antisymmetric, is possible for a thin system.  In this sense our understanding of the power of thin systems is now complete.


2019 ◽  
pp. 188-214
Author(s):  
B. D. Guenther

Discuss the limits imposed by the paraxial approximation. Define the sign convention based on the cartesian coordinate system, the foiundation of analytic geometery. Demonstrate ray tracing technique to derive the ABCD maxtrix which will generate both the gaussian and Newtonian form of the thin lens equation and the lens maker’s equation. The cardinal points of a lens are also derived. The ABCD matrix is used to explore the methods used in ray tracing to locate the aperture stop of a Cooke’s triplet lens system. In the problem set, the student is asked to use the aperture stop to locate the entrance and exit pupil of a Cooke’s triplet.


2022 ◽  
pp. 429-455
Author(s):  
Lakshminarayan Hazra
Keyword(s):  

2011 ◽  
Vol 61 (3) ◽  
pp. 268
Author(s):  
Soo Chang
Keyword(s):  

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