Design of a low-cost detection system for laser-induced plasma spectroscopy

1999 ◽  
Vol 70 (9) ◽  
pp. 3519-3522 ◽  
Author(s):  
R. E. Neuhauser ◽  
B. Ferstl ◽  
C. Haisch ◽  
U. Panne ◽  
R. Niessner
Sensors ◽  
2019 ◽  
Vol 19 (17) ◽  
pp. 3634
Author(s):  
Juri Agresti ◽  
Andrea Azelio Mencaglia ◽  
Salvatore Siano

Here, the development and testing of a portable double peak pulse laser induced plasma spectroscopy (DPP-LIPS) based on passively Q-switched Nd:YAG (Neodymium-doped Yttrium Aluminum Garnet) laser excitation is reported. The latter delivered structured laser pulses at a repetition rate of up to 20 Hz, including two energy peaks of about 100 mJ each with a relative temporal spacing of about 80 µs. Plasma spectra were collected using a low-cost Czerny–Turner spectrometer equipped with a non-intensified CCD (Charge-Coupled Device) array. Such a DPP-LIPS setup is technologically simpler and cheaper than the usual ones. Despite the relatively large temporal separation between the mentioned laser peaks, significant spectral intensity enhancements with respect to the usual single peak pulse configuration were observed. The amplification factor measured ranged between 2 and 10, depending on the specific emission peaks and the Q-switched configuration, and a consequent significant improvement of the detection limit of trace elements was observed. The instrument was calibrated for the quantitative analysis of copper alloy through systematic measurements carried out on reference samples and was then tested in an example archaeometric characterization of a statuette from the Egyptian Museum of Florence.


2021 ◽  
pp. 1-11
Author(s):  
Suphawimon Phawinee ◽  
Jing-Fang Cai ◽  
Zhe-Yu Guo ◽  
Hao-Ze Zheng ◽  
Guan-Chen Chen

Internet of Things is considerably increasing the levels of convenience at homes. The smart door lock is an entry product for smart homes. This work used Raspberry Pi, because of its low cost, as the main control board to apply face recognition technology to a door lock. The installation of the control sensing module with the GPIO expansion function of Raspberry Pi also improved the antitheft mechanism of the door lock. For ease of use, a mobile application (hereafter, app) was developed for users to upload their face images for processing. The app sends the images to Firebase and then the program downloads the images and captures the face as a training set. The face detection system was designed on the basis of machine learning and equipped with a Haar built-in OpenCV graphics recognition program. The system used four training methods: convolutional neural network, VGG-16, VGG-19, and ResNet50. After the training process, the program could recognize the user’s face to open the door lock. A prototype was constructed that could control the door lock and the antitheft system and stream real-time images from the camera to the app.


2021 ◽  
Author(s):  
Mangasi Alion Marpaung ◽  
Erfan Handoko ◽  
Marincan Pardede

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
D. Winzen ◽  
V. Hannen ◽  
M. Bussmann ◽  
A. Buß ◽  
C. Egelkamp ◽  
...  

AbstractThe $$^2{\mathrm{S}}_{1/2}{-}^2{\mathrm{P}}_{{1}/2}$$ 2 S 1 / 2 - 2 P 1 / 2 and $$^2{\mathrm{S}}_{1/2}{-}^2{\mathrm{P}}_{{3}/2}$$ 2 S 1 / 2 - 2 P 3 / 2 transitions in Li-like carbon ions stored and cooled at a velocity of $$\beta \approx 0.47$$ β ≈ 0.47 in the experimental storage ring (ESR) at the GSI Helmholtz Centre in Darmstadt have been investigated in a laser spectroscopy experiment. Resonance wavelengths were obtained using a new continuous-wave UV laser system and a novel extreme UV (XUV) detection system to detect forward emitted fluorescence photons. The results obtained for the two transitions are compared to existing experimental and theoretical data. A discrepancy found in an earlier laser spectroscopy measurement at the ESR with results from plasma spectroscopy and interferometry has been resolved and agreement between experiment and theory is confirmed.


The Analyst ◽  
2015 ◽  
Vol 140 (15) ◽  
pp. 5184-5189 ◽  
Author(s):  
Rudy J. Wojtecki ◽  
Alexander Y. Yuen ◽  
Thomas G. Zimmerman ◽  
Gavin O. Jones ◽  
Hans W. Horn ◽  
...  

The detection of trace amounts (<10 ppb) of heavy metals in aqueous solutions is described using hexahydrotriazines as a chemical indicator and a low cost fluorimeter-based detection system.


2000 ◽  
Vol 55 (11) ◽  
pp. 1771-1785 ◽  
Author(s):  
V Margetic ◽  
A Pakulev ◽  
A Stockhaus ◽  
M Bolshov ◽  
K Niemax ◽  
...  

2014 ◽  
Vol 1035 ◽  
pp. 508-513
Author(s):  
Meng Ke Lu ◽  
Shu Rui Zhao ◽  
Kui Wen Guan ◽  
Yan Ling Wang

Laser induced plasma is a relatively complex process which is closely related to many factors. In this paper, using a short pulse Nd:YAG laser and CCD photoelectric detection system, the variation of laser focus position effected by spectral intensity, the ratio of signal to background as well as the self-absorption of the plasma spectral lines with the standard spectra sample of aluminum for analysis samples was studied. Results show that: when the laser focus position is about 5mm under the surface of the sample, the relative intensity and the ratio of signal to background of the spectral lines are the strongest, and the spectral lines are sharp without obvious self-absorption.


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