scholarly journals Automatic determination of optimal spectral peaks for classification of Chinese tea leaves using laser-induced breakdown spectroscopy

Author(s):  
Hongyang Zhang ◽  
◽  
Qibing Zhu ◽  
Min Huang ◽  
Ya Guo
Sensors ◽  
2020 ◽  
Vol 20 (13) ◽  
pp. 3744
Author(s):  
Flavio Cicconi ◽  
Violeta Lazic ◽  
Antonio Palucci ◽  
Ana Cristina Almeida Assis ◽  
Francesco Saverio Romolo

Laser-induced breakdown spectroscopy (LIBS) was tested for all of the relevant issues in forensic examinations of commercial inks, including classification of pen inks on one paper type and on different paper types, determination of the deposition order of layered inks, and analysis of signatures and toners on one questioned document. The scope of this work was to determine the potential of a single LIBS setup that is compatible with portable instruments for different types of ink analysis, rather than building a very large database for inks and papers. We identified up to seven metals characteristic for the examined inks, which allowed to fully discriminate all eight black inks on one type of printing paper. When the inks were tested on ten different papers, the correct classification rates for some of them were reduced for reasons thoroughly studied and explained. The replicated tests on three crossing points, each one involving a pair of blue or black inks, were successful in five cases out of six. In the test simulating documents of forensic interest (questioned documents), LIBS was able to correctly identify the differences in three inks used for signatures on one of the three pages and the use of different printing inks on each page of the document.


Author(s):  
Abeer E. Osman ◽  
Ali A . S. Marouf ◽  
Mubarak M. Ahmed

There is a great number of packaging materials, such as bottles and boxes, are made of plastics (polymers). Additives such as plasticizers, antioxidants, antistatic agents, and lubricants may be used for the production of packaging materials. The worst effect of plastic production is deterioration of the environment. Recycling solves this problem and the initial step is identification and classification of the polymers and determination of different elements present in it. In this research, spectroscopic analyzes were performed using Laser Induced Breakdown Spectroscopy (LIBS) for plastic materials samples of drug containers that collected from manufacturing factories located at Khartoum city, Sudan. The samples were collected before and after used, were irradiated by Nd: YAG laser at 266 nm, repetition rate 2Hz, with pulse energy of 80mJ. The recorded spectra of the samples were analyzed using National Institute Standard and Technology (NIST). and Origin Lab Pro 9 data analysis software. All elements present in plastic drug bottles were detected using laser induced breakdown spectroscopy. The elements that detected are (Ca, Cd , Ra, Ac, W, V, Na, Pm, Cl, K, , Ce, Ar, Nd, Ac, Tc, Sc, Li, Pa, and Pb).


2016 ◽  
Vol 8 (15) ◽  
pp. 3204-3209 ◽  
Author(s):  
Jinmei Wang ◽  
Peichao Zheng ◽  
Hongdi Liu ◽  
Liang Fang

Six types of tea leaves, including Longjing green tea, Mengding Huangya, white tea, Tie Guanyin, Wuyi black tea and Pu'er tea, were analyzed and identified using laser-induced breakdown spectroscopy (LIBS) combined with the discriminant analysis (DA) method.


Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1241
Author(s):  
Nikolaos Gyftokostas ◽  
Eleni Nanou ◽  
Dimitrios Stefas ◽  
Vasileios Kokkinos ◽  
Christos Bouras ◽  
...  

In the present work, the emission and the absorption spectra of numerous Greek olive oil samples and mixtures of them, obtained by two spectroscopic techniques, namely Laser-Induced Breakdown Spectroscopy (LIBS) and Absorption Spectroscopy, and aided by machine learning algorithms, were employed for the discrimination/classification of olive oils regarding their geographical origin. Both emission and absorption spectra were initially preprocessed by means of Principal Component Analysis (PCA) and were subsequently used for the construction of predictive models, employing Linear Discriminant Analysis (LDA) and Support Vector Machines (SVM). All data analysis methodologies were validated by both “k-fold” cross-validation and external validation methods. In all cases, very high classification accuracies were found, up to 100%. The present results demonstrate the advantages of machine learning implementation for improving the capabilities of these spectroscopic techniques as tools for efficient olive oil quality monitoring and control.


2016 ◽  
Vol 242 (10) ◽  
pp. 1685-1692 ◽  
Author(s):  
Gonca Bilge ◽  
Banu Sezer ◽  
Kemal Efe Eseller ◽  
Halil Berberoğlu ◽  
Hamit Köksel ◽  
...  

Talanta ◽  
2013 ◽  
Vol 117 ◽  
pp. 55-59 ◽  
Author(s):  
David A. Rusak ◽  
Ann E. Zeleniak ◽  
Jillian L. Obuhosky ◽  
Scott M. Holdren ◽  
Craig A. Noldy

2016 ◽  
Vol 8 (37) ◽  
pp. 6705-6710 ◽  
Author(s):  
Pengcheng Han ◽  
Daming Dong ◽  
Xiaofan Du ◽  
Leizi Jiao ◽  
Xiande Zhao

Laser-induced breakdown spectroscopy was used for the fast determination of calcium concentration in the internal tissues of a single seed. Compared with conventional methods, LIBS had obvious advantages, such as a little analysis spot, little ablation, high precision, and small influence on the seed vigor.


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