Chemometrics and Numerical Methods in Libs -

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Résumé :

List of Contributors xiii

Preface xvii

Introduction and Brief Summary of the LIBS Development 1

Part I Introduction to LIBS 5

1 LIBS Fundamentals 7
Mohamad Sabsabi

1.1 Interaction of Laser Beam with Matter 8

1.2 Basics of Laser-Matter Interaction 9

1.3 Processes in Laser-Produced Plasma 10

1.4 Factors Affecting Laser Ablation and Laser-Induced Plasma Formation 11

1.4.1 Influence of Laser Parameters on the Laser-Induced Plasmas 11

1.4.2 Laser Wavelength (?) 12

1.4.3 Laser Pulse Duration (?) 12

1.4.4 Laser Energy (E) 13

1.4.5 Influence of Ambient Gas 13

1.5 Plasma Properties and Plasma Emission Spectra 14

References 15

2 LIBS Instrumentations 19
Mohamad Sabsabi and Vincenzo Palleschi

2.1 Basics of LIBS instrumentations 19

2.2 Lasers in LIBS Systems 20

2.3 Desirable Requirements for Atomic Emission Spectrometers/Detectors 22

2.4 Spectrometers 23

2.4.1 Czerny-Turner Optical Configuration 23

2.4.2 Paschen-Runge Design 24

2.4.3 Echelle Spectrometer Configuration 25

2.5 Detectors 26

2.5.1 Photomultiplier Detectors 26

2.5.2 Solid-State Detectors 27

2.5.3 The Interline CCD Detectors 27

2.5.3.1 The Image Intensifier 28

References 29

3 Applications of LIBS 31
Vincenzo Palleschi and Mohamad Sabsabi

3.1 Industrial Applications 31

3.1.1 Metal Industry 31

3.1.2 Energy Production 34

3.2 Biomedical Applications 34

3.3 Geological and Environmental Applications 36

3.4 Cultural Heritage and Archaeology Applications 37

3.5 Other Applications 37

References 38

Part II Simplications of LIBS Information 45

4 LIBS Spectral Treatment 47
Sabrina Messaoud Aberkane, Noureddine Melikechi and Kenza Yahiaoui

4.1 Introduction 47

4.2 Baseline Correction 47

4.2.1 Polynomial Algorithm 48

4.2.2 Model-free Algorithm 49

4.2.3 Wavelet Transform Model 52

4.3 Noise Filtering 55

4.3.1 Wavelet Threshold De-noising (WTD) 55

4.3.2 Baseline Correction and Noise Filtering 59

4.4 Overlapping Peak Resolution 60

4.4.1 Curve Fitting Method 61

4.4.2 The Wavelet Transform 64

4.5 Features Selection 66

4.5.1 Principal Component Analysis 68

4.5.2 Genetic Algorithm (GA) 68

4.5.3 Wavelet Transformation (WT) 68

References 71

5 Principal Component Analysis 81
Mohamed Abdel-Harith and Zienab Abdel-Salam

5.1 Introduction 81

5.1.1 Laser-Induced Breakdown Spectroscopy (LIBS) 81

5.2 The Principal Component Analysis (PCA) 82

5.3 PCA in Some LIBS Applications 83

5.3.1 Geochemical Applications 83

5.3.2 Food and Feed Applications 85

5.3.3 Microbiological Applications 88

5.3.4 Forensic Applications 91

5.4 Conclusion 94

References 94

6 Time-Dependent Spectral Analysis 97
Fausto Bredice, Ivan Urbina, and Vincenzo Palleschi

6.1 Introduction 97

6.2 Time-Dependent LIBS Spectral Analysis 98

6.2.1 Independent Component Analysis 98

6.2.2 3D Boltzmann Plot 102

6.2.2.1 Principles of the Method 103

6.3 Applications 109

6.3.1 3D Boltzmann Plot Coupled with Independent Component Analysis 109

6.3.2 Analysis of a Carbon Plasma by 3D Boltzmann Plot Method 109

6.3.3 Assessment of the LTE Condition Through the 3D Boltzmann Plot Method 114

6.3.4 Evaluation of Self-Absorption 114

6.3.5 Determination of Transition Probabilities 118