Optical Measurement and Control of Spin Diffusion inn-Doped GaAs Quantum Wells

2006 ◽  
Vol 97 (13) ◽  
Author(s):  
S. G. Carter ◽  
Z. Chen ◽  
S. T. Cundiff
Keyword(s):  
Quantum Wells ◽  
Spin Diffusion ◽  
Optical Measurement ◽  
And Control ◽  
Measurement And Control

Image Distortion, between Unwanted Geometric Aberration and the Tool Used to Improve Observation Equipment Performance

2014 ◽  
Vol 555 ◽  
pp. 751-758 ◽  
Author(s):  
Nicolae Guzulescu ◽  
Cornel Todirică ◽  
Daniel Lăpădat
Keyword(s):  
Optical System ◽  
Measurement Errors ◽  
Optical Measurement ◽  
Image Distortion ◽  
Field Of View ◽  
Optical Systems ◽  
Object Appearance ◽  
And Control ◽  
Measurement And Control ◽  
Equipment Performance

An distortion aberration free optical system forms an orthoscopic image mean that is similar to original object, undeformed. Naturally imply that most optical systems are designed so that the image distortion is minimal, not to cause inconvenience to the user about either the object appearance – when it comes to a camera or camcorder, or the deformities that may cause measurement errors – when it comes to optical measurement and control equipment. However there are situations when distortion is desired to improve some performances of the observation optical system. In this article we present how distortion is used to increase the field of view, and also how distortion is used to optimize the field of view – resolution compromise.

scholarly journals Automatic Optical Measurement and Control of Benzene and Benzenoids in Natural Gas Pipelines

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7575
Author(s):  
Rossana Galassi ◽  
Christian Contini ◽  
Matteo Pucci ◽  
Ennio Gambi
Keyword(s):  
Natural Gas ◽  
Optical Measurement ◽  
Gaseous Mixture ◽  
Gas Pipelines ◽  
Natural Gas Pipelines ◽  
Para Xylene ◽  
Benzene Toluene ◽  
And Control ◽  
Measurement And Control ◽  
Related Compounds

The presence of benzene and similar aromatic compounds in civil environments is due to anthropic actions but also to natural sources. Natural gas consists of a gas mixture where benzene and related compounds are usually presents. Thus, the detection of these compounds in natural gas pipelines is of the utmost importance as well as the control of the concentration level, which must remain below the limits consented by law. In this regard, it is of striking interest to engineer devices able to detect these compounds by automatic and continuous remote control. Here, we discuss the application of an optical device designed for the measurement of sulfured odorizing agents in natural gas pipelines aiming at the detection and the measurement of benzene, toluene, and xylenes (BTX) in the same contexts. The instrument consists of a customized UV spectrophotometer connected to an automatic control system able to provide in-field detections of BTX through a continuous and remote check of the gaseous mixture. Relatively to benzene, the instrument is characterized by values of LOD (level of detection) and LOQ (level of quantification) equal to 0.55 and 1.84 mg/Sm3, respectively. Similar limits are found for toluene and xylenes (LOD of 0.81, 1.05, 1.41, and 1.00 mg/Sm3 for toluene, meta-, ortho-, and para-xylene, respectively).

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