Simple active method for reducing magnetic interference in a thermoelectrically cooled photomultiplier tube

2008 ◽  
Vol 79 (4) ◽  
pp. 043102 ◽  
Author(s):  
Petri Kärhä ◽  
Teemu Jaakkola
Keyword(s):  
Photomultiplier Tube ◽  
Active Method

scholarly journals Over/Undervoltage and Undervoltage Shift of Hybrid Islanding Detection Method of Distributed Generation

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Manop Yingram ◽  
Suttichai Premrudeepreechacharn
Keyword(s):  
Control System ◽  
Distributed Generation ◽  
Hybrid Method ◽  
Detection Method ◽  
System Simulation ◽  
Detection Methods ◽  
Islanding Detection ◽  
Active Method ◽  
Passive Method ◽  
Simulation Results

The mainly used local islanding detection methods may be classified as active and passive methods. Passive methods do not perturb the system but they have larger nondetection zones, whereas active methods have smaller nondetection zones but they perturb the system. In this paper, a new hybrid method is proposed to solve this problem. An over/undervoltage (passive method) has been used to initiate an undervoltage shift (active method), which changes the undervoltage shift of inverter, when the passive method cannot have a clear discrimination between islanding and other events in the system. Simulation results on MATLAB/SIMULINK show that over/undervoltage and undervoltage shifts of hybrid islanding detection method are very effective because they can determine anti-islanding condition very fast.ΔP/P>38.41% could determine anti-islanding condition within 0.04 s;ΔP/P<-24.39% could determine anti-islanding condition within 0.04 s;-24.39%≤ΔP/P≤ 38.41% could determine anti-islanding condition within 0.08 s. This method perturbed the system, only in the case of-24.39% ≤ΔP/P ≤38.41% at which the control system of inverter injected a signal of undervoltage shift as necessary to check if the occurrence condition was an islanding condition or not.

Investigation of performance in suppressing various vibrations with energy-recycling semi-active method

2006 ◽  
Vol 58 (10) ◽  
pp. 506-514 ◽  
Author(s):  
Kanjuro Makihara ◽  
Junjiro Onoda ◽  
Masahiro Tsuchihashi
Keyword(s):  
Active Method

A new 'semi-active' method for chemical standoff detection

2004 ◽  
Author(s):  
Tim J. Johnson ◽  
Bruce A. Roberts ◽  
Gerry P. Morgen ◽  
Michael A. Hughes ◽  
Corey D. Heitschmidt ◽  
...  
Keyword(s):  
Active Method ◽  
Standoff Detection

Laser-Excited Fluorescence of Dityrosine

1995 ◽  
Vol 49 (11) ◽  
pp. 1669-1676 ◽  
Author(s):  
Sahar F. Mahmoud ◽  
Stephen E. Bialkowski
Keyword(s):  
Ferrous Iron ◽  
Ferric Iron ◽  
Iron Concentration ◽  
Fluorescence Emission ◽  
Fluorescence Yield ◽  
Photomultiplier Tube ◽  
Alkaline Solutions ◽  
Array Detector ◽  
Fluorescence Maximum ◽  
Fluorescence Efficiency

In this research, laser-excited fluorescence was examined for sensitive detection of aqueous dityrosine. Samples were excited with a 6.3-mW, 325-nm helium-cadmium laser focused into a small volume-fluorescence cell with a 10-cm lens. The resulting fluorescence emission was collected perpendicular to the excitation and detected with two different schemes. An optical bandpass filter was used with a photomultiplier tube for sensitive quantitative measurement, while a photodiode array detector was used in conjunction with a spectrograph for qualitative characterization of fluorescence emission spectra. Dityrosine detection on the order of 2 × 10−11 M was obtained with the use of the photomultiplier tube with bandpass optical filter. The dityrosine fluorescence yield is found to vary with the solution pH, the relative concentrations of ferric and ferrous iron, and the amount of dissolved oxygen. A maximum fluorescence yield is observed for iron-free, oxygen-free alkaline solutions. Fluorescence quenching by oxygen is a cumulative photolysis effect that diminished fluorescence yield with increased irradiation time. Flowing the solutions minimized photolysis effects in oxygenated solutions. Quenching by ferrous and ferric iron is found to be due primarily to complex formation. The ferrous iron complex appears to have a fluorescence efficiency of ∼20% of the free dityrosine. The ferric iron dityrosine complex appears to have two ferric ions per molecule at low iron concentration. Other complexes may form at different concentrations. Solvent effects on dityrosine absorption and fluorescence spectra were also investigated. A red shift in dityrosine fluorescence maximum was observed in 1 M trichloroacetic acid and in N, N-dimethylformamide. The fluorescence emission maximum was shifted to the blue in acetonitrile and glacial acetic acid. These shifts were attributed to typical solvochromic behavior.

Radon concentration in compressed natural gas and liquefied petroleum gas and its release range in residential houses

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Akbar Abbasi ◽  
Hesham M.H. Zakaly ◽  
Mahmoud M. Hessien
Keyword(s):  
Natural Gas ◽  
Radon Concentration ◽  
Concentration Distribution ◽  
Measurement Techniques ◽  
Concentration Measurement ◽  
Liquefied Petroleum Gas ◽  
Compressed Natural Gas ◽  
Radon Exposure ◽  
Active Method

Abstract Radon (222Rn) exposure in the environment is an important issue, and many pathways exist for radon exposure to humans. One of these pathways is 222Rn release through the consumption of natural gas. The issues of 222Rn concentration measurement techniques and worldwide concentration distribution were reviewed in natural gas, with emphasis on performing an active method to determine 222Rn concentration in LPG and CNG gases used in Cyprus. The obtained results were compared with 222Rn concentration in natural gas worldwide and UNSCEAR reports. The average 222Rn concentration value in LPG gas was observed higher than CNG gas. Also, the 222Rn concentration in LPG and CNG gases was less than the UNSCEAR reported value.

scholarly journals Setup of a photomultiplier tube test bench for LHAASO-KM2A

2016 ◽  
Vol 40 (8) ◽  
pp. 086003 ◽  
Author(s):  
Xu Wang ◽  
Zhong-Quan Zhang ◽  
Ye Tian ◽  
Yan-Yan Du ◽  
Xiao Zhao ◽  
...  
Keyword(s):  
Test Bench ◽  
Photomultiplier Tube ◽  
Tube Test

Some results on the sensitivity of the RCA 4522 photomultiplier tube

1977 ◽  
Vol 146 (2) ◽  
pp. 389-390 ◽  
Author(s):  
K.J. Orford ◽  
R.J. Stubbs ◽  
W.D. Waddoup
Keyword(s):  
Photomultiplier Tube
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