A simple and inexpensive modulated light calorimeter using an optical fiber light guide

1998 ◽  
Vol 69 (5) ◽  
pp. 2045-2049 ◽  
Author(s):  
N. J. Garfield ◽  
M. A. Howson ◽  
N. Overend
Keyword(s):  
Optical Fiber ◽  
Light Guide ◽  
Fiber Light Guide ◽  
Modulated Light

Silicon-containing polyimides: synthesis, properties, and application as optical fiber light guide coatings

2020 ◽  
Vol 69 (8) ◽  
pp. 1486-1491
Author(s):  
D. A. Sapozhnikov ◽  
A. V. Chuchalov ◽  
B. A. Bayminov ◽  
P. A. Shibaeva ◽  
E. M. Chaika ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Light Guide ◽  
Fiber Light Guide ◽  
Synthesis Properties

Modelling and Experimental Investigation of Luminous Coupling in UVLED Driven Optical Fiber Reactors

2020 ◽  
Vol 1 (1) ◽  
pp. 50-60
Author(s):  
Johannes Robert ◽  
Thomas Jüstel ◽  
Roland Ulber ◽  
Volkmar Jordan
Keyword(s):  
Optical Fiber ◽  
Photocatalytic Oxidation ◽  
Light Guide ◽  
Light Transmission ◽  
Waste Water Treatment ◽  
Sol Gel ◽  
Radiant Flux ◽  
Hydroxyl Ion ◽  
Light Guides ◽  
Reflective Surfaces

Background: Photocatalytic oxidation is a promising tool for waste water treatment and decomposition of biologically non digestible substances. Immersed nanoscale catalyst particles from semiconductor materials such as TiO2 and ZnO can be excited by absorbed UV radiation, leading to hydroxyl-ion formation at the surface of the semiconductor and oxidative degradation of pollutants. Objective: This contribution deals with reactors equipped with catalyst coated light guides to combine the advantages of immobilized catalysts with nearly homogeneous irradiation. With experimental and theoretical methods the coupling and decoupling of radiation were investigated and the performance of catalyst coated light guides was tested by means of methylene-blue degradation. Methods: Radiation models, known from the recent literature, use single ray, parallel ray or multi ray models to approximate the light transmission. These models neglect Fresnel reflection and consider only coupling into the light guide. In this study, the LED was simulated as a Lambertian radiator using 10 4 rays with angle dependent intensities. This well-known model was extended with Fresnelreflection, which predicted the measured coupling efficiencies accurately. The simulations predict the decoupling and catalyst activation at the lateral surface of the light guide for two boundary cases, ideal matt and ideal reflective surfaces. To generate matt surfaces, the light guides were either scratched or coated with TiO2 p25 nanopowder. Sol-gel coating methods were used, to create reflective surfaces. Results: When using matt surfaces, the decoupling rate is very high: 80% of the radiant flux exits the light guide in less than 10 cm. If light guides with reflective surfaces are used, the radiant flux leaving the light guide is low: less than 10% of the radiation exited the light conductor in the first 10 cm. Methyleneblue degradation, seen as a model reaction, was used to determine the reactor performance by comparing the pseudo first order reaction coefficients. Due to the uniform light distribution along the length of the light guides and the resulting even formation of reactive radicals, the quantum yield was increased by a factor of 3, using sol-gel coated light guides, rather than powder coated light guides. Conclusion: The effectiveness of LED driven optical fiber reactors was intensified, if reflective surfaces are used instead of matt surfaces. These surfaces are achieved by sol gel chemistry. However, to use the complete amount of photons, which entered the optical fiber, very long light guides are needed.

scholarly journals Dynamic Measurements of Tank Wall Deformations as a New Method for Assessing its Technical Condition

2021 ◽  
Vol 2096 (1) ◽  
pp. 012026
Author(s):  
E Sh Gaysin ◽  
A R Valeev ◽  
R R Tashbulatov
Keyword(s):  
Optical Fiber ◽  
Light Guide ◽  
Fatigue Cracks ◽  
Technical Condition ◽  
Luminous Flux ◽  
New Approach ◽  
Steel Tank ◽  
Cycle Loading ◽  
The Difference ◽  
Number Of Cycles

Abstract The paper proposes a new approach to assessing the residual resource of the wall of a vertical steel tank by the criterion of low-cycle loading, taking into account its actual deformations. The method is based on the principle of measuring the difference in the power of the luminous flux at the ends of the light tube (light guide) when it is bent. An experiment was carried out using an optical pair (LED and photodiode) and an optical fiber. For this purpose, templates with known radii of curvature were prepared, a prototype of an Arduino-based device was developed and an optical fiber was manufactured, which was subsequently fixed on the wall of a two-hundred-liter metal barrel. As a result of the experiments, a formula was obtained for determining the curvature of the wall depending on the readings of the sensor. The sensitivity of the proposed method is estimated. An algorithm for determining the number of cycles before the formation of fatigue cracks is proposed, taking into account the actual values of the wall deflection.

scholarly journals Vitrectome with Integrated LED Illumination: Development and Testing

2021 ◽  
Vol 7 (2) ◽  
pp. 851-854
Author(s):  
Nicole Sieber ◽  
Christian Lingenfelder ◽  
Madeleine Götz ◽  
Pauline Heine ◽  
Leonie Lichtner ◽  
...  
Keyword(s):  
Feasibility Study ◽  
Light Guide ◽  
Ex Vivo ◽  
Surgical Instruments ◽  
White Led ◽  
Fiber Light Guide ◽  
Ping Pong ◽  
The Future ◽  
Ping Pong Ball

Abstract Background: In current vitrectomy, the surgeon guides the vitrectome and a rigid fiber light guide with one hand each. It would be desirable to have a free hand for other surgical instruments and maneuvers. Methods: In the feasibility study presented here, a 20 gauge vitrectome is equipped with a miniature white LED that could eliminate the need for the separate light guide and therefore free one hand. The functionality of the system is proved in a ping-pong ball filled with agar and an ex-vivo porcine eye. Results: The brightness of the approach appears to be sufficient without any realistic phototoxic retinal hazard while the functionality of the vitrectome, in combination with the LED, is still given. Conclusion: The combination of a 20 gauge vitrectome with a LED illumination unit was successfully tested. The approach can be transferred to small vitrectomes in the future

Hollow light guide and optical fiber for UV laser transmission

1998 ◽  
Author(s):  
Uichi Kubo ◽  
Yuichi Hashishin ◽  
Hitoshi Nakano ◽  
Hiroyuki Tanaka
Keyword(s):  
Optical Fiber ◽  
Light Guide ◽  
Uv Laser
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