7,021 research outputs found
Optical Pressure Measurement Principle System
Surface pressure measurements are critical to aerodynamic testing in wind tunnel. A new pressure measurement technique is being developed to augment current capabilities that are an optical-based technique using pressure sensitive paint (PSP). Compared with the traditional surface pressure measurement, an important feature of optical pressure measurement is much more complete surface information with relatively simple procedures and instrumentation. So optical pressure measurement technique will provide an alternative to conventional methods for the pressure measurement. After studying the chapter of “Optical Pressure Measurement System”, readers are expected to grasp the measurement principle and know how to establish the corresponding measurement system. In this chapter, the measurement principle, measurement system, component characteristics and its application of optical pressure measurement technique are introduced based on the authors’ research
Local U(2,2) Symmetry in Relativistic Quantum Mechanics
Local gauge freedom in relativistic quantum mechanics is derived from a
measurement principle for space and time. For the Dirac equation, one obtains
local U(2,2) gauge transformations acting on the spinor index of the wave
functions. This local U(2,2) symmetry allows a unified description of
electrodynamics and general relativity as a classical gauge theory.Comment: 18 pages, LaTeX, typo in second formula on page 6 corrected
(published version
A novel technique for the measurement of the avalanche fluctuation of gaseous detectors
We have developed a novel technique for the measurement of the avalanche
fluctuation of gaseous detectors using a UV laser. The technique is simple and
requires a short data-taking time of about ten minutes. Furthermore, it is
applicable for relatively low gas gains. Our experimental setup as well as the
measurement principle, and the results obtained with a stack of Gas Electron
Multipliers (GEMs) operated in several gas mixtures are presented.Comment: 7 pages, 7 figures. For the proceedings of VCI2016, to be published
in Nucl. Instrum. Methods Phys. Res.
Non Markovian Quantum Repeated Interactions and Measurements
A non-Markovian model of quantum repeated interactions between a small
quantum system and an infinite chain of quantum systems is presented. By
adapting and applying usual pro jection operator techniques in this context,
discrete versions of the integro-differential and time-convolutioness Master
equations for the reduced system are derived. Next, an intuitive and rigorous
description of the indirect quantum measurement principle is developed and a
discrete non Markovian stochastic Master equation for the open system is
obtained. Finally, the question of unravelling in a particular model of
non-Markovian quantum interactions is discussed.Comment: 22 page
Evaluation of 2.1µm DFB lasers for space applications
This paper presents the results obtained in the frame of an ESA-funded project called “Screening and Preevaluation of Shortwave Infrared Laser Diode for Space Application” with the objective of verifying the maturity of state of the art SWIR DFB lasers at 2.1µm to be used for space applications (mainly based on the occultation measurement principle and spectroscopy). The paper focus on the functional and environmental evaluation test plan. It includes high precision characterization, mechanical test (vibration and SRS shocks), thermal cycling, gamma and proton radiation tests, life test and some details of the Destructive Physical Analysis performed. The electro-optical characterization includes measurements of the tuning capabilities of the laser both by current and by temperature, the wavelength stability and the optical power versus laser current
- …