Photon counting versus CCD sensors for wavefront sensing: performance comparison in the presence of noise

1994 ◽  
Author(s):  
Andreas Glindemann ◽  
Nicholas P. Rees
Keyword(s):  
Photon Counting ◽  
Performance Comparison ◽  
Wavefront Sensing ◽  
Sensing Performance

Influence of Surface Roughness on Wavefront Sensing Performance of Active Illumination Beacon

2019 ◽  
Vol 46 (7) ◽  
pp. 0705002
Author(s):  
赵旺 Wang Zhao ◽  
董理治 Lizhi Dong ◽  
杨平 Ping Yang ◽  
许冰 Bing Xu ◽  
王帅 Shuai Wang
Keyword(s):  
Surface Roughness ◽  
Wavefront Sensing ◽  
Active Illumination ◽  
Sensing Performance

Performance comparison of centroiding algorithms for laser guide star wavefront sensing with extremely large telescopes

2010 ◽  
Vol 49 (31) ◽  
pp. G78 ◽  
Author(s):  
Olivier Lardière ◽  
Rodolphe Conan ◽  
Richard Clare ◽  
Colin Bradley ◽  
Norbert Hubin
Keyword(s):  
Performance Comparison ◽  
Wavefront Sensing ◽  
Laser Guide Star ◽  
Guide Star ◽  
Laser Guide ◽  
Large Telescopes

scholarly journals Recent Advances in Electrochemical Sensors for Detecting Toxic Gases: NO2, SO2 and H2S

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 905 ◽  
Author(s):  
Md Khan ◽  
Mulpuri Rao ◽  
Qiliang Li
Keyword(s):  
Metal Oxide ◽  
Gas Sensors ◽  
Electrochemical Sensors ◽  
Gas Sensing ◽  
Performance Comparison ◽  
Toxic Gases ◽  
Recent Advances ◽  
Metal Metal ◽  
Sensor Materials ◽  
Sensing Performance

Toxic gases, such as NOx, SOx, H2S and other S-containing gases, cause numerous harmful effects on human health even at very low gas concentrations. Reliable detection of various gases in low concentration is mandatory in the fields such as industrial plants, environmental monitoring, air quality assurance, automotive technologies and so on. In this paper, the recent advances in electrochemical sensors for toxic gas detections were reviewed and summarized with a focus on NO2, SO2 and H2S gas sensors. The recent progress of the detection of each of these toxic gases was categorized by the highly explored sensing materials over the past few decades. The important sensing performance parameters like sensitivity/response, response and recovery times at certain gas concentration and operating temperature for different sensor materials and structures have been summarized and tabulated to provide a thorough performance comparison. A novel metric, sensitivity per ppm/response time ratio has been calculated for each sensor in order to compare the overall sensing performance on the same reference. It is found that hybrid materials-based sensors exhibit the highest average ratio for NO2 gas sensing, whereas GaN and metal-oxide based sensors possess the highest ratio for SO2 and H2S gas sensing, respectively. Recently, significant research efforts have been made exploring new sensor materials, such as graphene and its derivatives, transition metal dichalcogenides (TMDs), GaN, metal-metal oxide nanostructures, solid electrolytes and organic materials to detect the above-mentioned toxic gases. In addition, the contemporary progress in SO2 gas sensors based on zeolite and paper and H2S gas sensors based on colorimetric and metal-organic framework (MOF) structures have also been reviewed. Finally, this work reviewed the recent first principle studies on the interaction between gas molecules and novel promising materials like arsenene, borophene, blue phosphorene, GeSe monolayer and germanene. The goal is to understand the surface interaction mechanism.

scholarly journals Comparison Between Binuclear and Mononuclear Ru(II) Complexes: Synthesis, Structure, Photophysics, and Oxygen Sensing Performance

2021 ◽  
Vol 9 ◽  
Author(s):  
Fei Wang ◽  
Liyuan Yang ◽  
Xue-Quan Xian
Keyword(s):  
Charge Transfer ◽  
Recovery Time ◽  
Oxygen Sensing ◽  
Performance Comparison ◽  
Collision Probability ◽  
Attractive Potential ◽  
Response Recovery ◽  
Ligand Charge Transfer ◽  
Diamine Ligands ◽  
Sensing Performance

Owing to their attractive potential in optoelectronic application, luminescent Ru(II) complexes with diamine ligands are harvesting more and more research efforts. These literature efforts, however, are mostly mononuclear ones, with no detailed discussion on the performance comparison between mononuclear and multinuclear Ru(II) complexes. This work synthesized three diamine ligands having two or multiple chelating sites in each ligand, as well as their Ru(II) complexes. The single-crystal structure, electronic structure, and photophysical parameters of these Ru(II) complexes were analyzed and compared. It was found that multinuclear Ru(II) complexes had a pure MLCT (metal-to-ligand charge transfer)–based emissive center, showing longer emission lifetime and higher emission quantum yield, which were desired for oxygen sensing. Then, the oxygen sensing performance of these mononuclear and multinuclear Ru(II) complexes was systematically compared by doping them into polymer fibers via electrospinning method. Improved oxygen sensing performance was observed from binuclear Ru(II)-doped nanofibrous samples, compared with the sensing performance of mononuclear ones, including higher sensitivity, shorter response/recovery time, and better photostability. The causation was attributed to the fact that the emissive state of multinuclear Ru(II) complexes was MLCT-based ones and thus more sensitive to O2 quenching than monocular Ru(II) complexes whose emissive state was a mixture of MLCT and LLCT (ligand-to-ligand charge transfer). In addition, a multinuclear Ru(II) complex had multiple emissive/sensing components, so that its sensing collision probability with O2 was increased, showing better photostability and shorter response/recovery time. The novelty of this work was the linear oxygen sensing curve, which was rarely reported in the previous work.

Imaging performance comparison between a LaBr3:Ce scintillator based and a CdTe semiconductor based photon counting compact gamma camera

2009 ◽  
Vol 36 (4) ◽  
pp. 1298-1317 ◽  
Author(s):  
P. Russo ◽  
G. Mettivier ◽  
R. Pani ◽  
R. Pellegrini ◽  
M. N. Cinti ◽  
...  
Keyword(s):  
Gamma Camera ◽  
Photon Counting ◽  
Performance Comparison ◽  
Imaging Performance
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