Confocal Raman imaging and chemometrics applied to solve forensic document examination involving crossed lines and obliteration cases by a depth profiling study

The Analyst ◽  
2017 ◽  
Vol 142 (7) ◽  
pp. 1106-1118 ◽  
Author(s):  
Flávia de Souza Lins Borba ◽  
Tariq Jawhari ◽  
Ricardo Saldanha Honorato ◽  
Anna de Juan
Keyword(s):  
Analytical Method ◽  
Depth Profiling ◽  
Raman Imaging ◽  
Confocal Raman ◽  
Document Examination ◽  
Non Destructive

This article describes a non-destructive analytical method developed to solve forensic document examination problems involving crossed lines and obliteration.

3D confocal Raman imaging of oil-rich emulsion from enzyme-assisted aqueous extraction of extruded soybean powder

2018 ◽  
Vol 249 ◽  
pp. 16-21 ◽  
Author(s):  
Longkun Wu ◽  
Limin Wang ◽  
Baokun Qi ◽  
Xiaonan Zhang ◽  
Fusheng Chen ◽  
...  
Keyword(s):  
Raman Imaging ◽  
Aqueous Extraction ◽  
Soybean Powder ◽  
Confocal Raman

The Prs2O3 /Si(001) Interface: a Mixed Si-Pr Oxide

2003 ◽  
Vol 765 ◽  
Author(s):  
Dieter Schmeißer ◽  
Jarek Dabrowski ◽  
Hans-Joachim Müssig
Keyword(s):  
Depth Profiling ◽  
Dielectric Materials ◽  
Interface Properties ◽  
Silicide Formation ◽  
Silicate System ◽  
No Formation ◽  
Interface Characteristics ◽  
Reactive Interface ◽  
Non Destructive ◽  
Natural Way

AbstractWe studied the Pr2O3/Si(001) interface by a non-destructive depth profiling using synchrotron radiation and photo-electron spectroscopy (SR-PES) at the undulator beam line U49/2-PGM2 and ab initio calculations. Our results provide evidence that a chemical reactive interface exists consisting of a mixed Si-Pr oxide such as (Pr2O3)(SiO)x(SiO2)y. There is no formation of neither an interfacial SiO2 nor interfacial silicide: all Si-Pr bonds are oxidized and all SiO4 units dissolve in the Pr oxide. Under ultrahigh vacuum conditions, silicide formation is observed only when the film is heated above 800°C in vacuum. Interfacial silicates like (Pr2O3)(SiO)x(SiO2)y are promising high-k dielectric materials, e.g., because they represent incremental modification of SiO2 films by Pr ions, so that the interface characteristics can be similar to Si-SiO2 interface properties. The Pr silicate system formed in a natural way at the interface between Si(001) and Pr2O3 offers an increased flexibility towards integration of Pr2O3 into future CMOS technologies.

Single Layer Graphene for Estimation of Axial Spatial Resolution in Confocal Raman Microscopy Depth Profiling

2018 ◽  
Vol 91 (1) ◽  
pp. 1049-1055 ◽  
Author(s):  
Carol Korzeniewski ◽  
Jay P. Kitt ◽  
Saheed Bukola ◽  
Stephen E. Creager ◽  
Shelley D. Minteer ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Depth Profiling ◽  
Single Layer ◽  
Raman Microscopy ◽  
Single Layer Graphene ◽  
Confocal Raman Microscopy ◽  
Layer Graphene ◽  
Confocal Raman

Characteristics of Immersion Sampling Technique in Confocal Raman Depth Profiling

2002 ◽  
Vol 56 (6) ◽  
pp. 776-782 ◽  
Author(s):  
J. Vyörykkä ◽  
M. Halttunen ◽  
H. Iitti ◽  
J. Tenhunen ◽  
T. Vuorinen ◽  
...  
Keyword(s):  
Light Scattering ◽  
Depth Profiling ◽  
Sampling Technique ◽  
Depth Resolution ◽  
Cover Glass ◽  
Actual Measurement ◽  
Fluid Layers ◽  
Immersion Technique ◽  
Confocal Raman ◽  
Measurement Depth

The confocal Raman technique is widely used for the depth profiling of thin transparent polymer films. Reported depth resolutions are on the order of two micrometers. The depth resolution is worsened and the actual measurement depth is changed by the use of metallurgical “dry” objectives. Also, if the sample is strongly light scattering, the measurement depth is reduced drastically. In this work, we demonstrate how these problems can be circumvented by using an immersion technique in confocal Raman depth profiling. In the method, two different immersion fluid layers and a cover glass, which separates the two fluid layers, are used. This configuration allows the fluid that is in contact with the sample to be selected with respect to the requirements dictated by the refractive index of the sample, sample–immersion fluid interaction, Raman spectra overlapping, or fluorescence quenching properties. The use of the immersion technique results in major improvements in the depth resolution and in the depth profiling capability of the confocal Raman technique when applied to strongly light scattering materials.

scholarly journals An overview on the non-destructive in-depth surface analysis of corrosion-resistant films: A case study of W-xCr deposits in 12 M HCl solution

BIBECHANA ◽  
2021 ◽  
Vol 18 (1) ◽  
pp. 201-213
Author(s):  
Jagadish Bhattarai
Keyword(s):  
Corrosion Resistance ◽  
Depth Profiling ◽  
Surface Films ◽  
High Corrosion Resistance ◽  
Corrosion Rates ◽  
High Corrosion ◽  
Depth Analysis ◽  
Sputter Deposited ◽  
Non Destructive ◽  
Hcl Solution

Non-destructive in-depth analysis of the surface films formed on the sputter-deposited binary W-xCr (x = 25, 57, 91 at %) alloys in 12 M HCl solution open to air at 30 °C was investigated using an angle-resolved X-ray photoelectron spectroscopic (AR-XPS) technique to understand the synergistic corrosion resistance effects of showing very low corrosion rates, even lower than both alloying metals of the deposits. The average corrosion rates of these three tungsten-based sputter deposits found to be more than five orders of magnitude (between 3.1 × 10−3 and 7.2 × 10−3 mm/y) to that of chromium and also nearly one order of magnitude lower than that of tungsten metals. Such high corrosion resistance of the sputter-deposited W-xCr alloys is due to the formation of homogeneous passive double oxyhydroxide film consisting of Wox and Cr4+ cations without any concentration gradient in-depth after immersion in 12 M HCl solution open to air at 30 °C from the study of the non-destructive depth profiling technique of AR-XPS. Consequently, both alloying elements of tungsten and niobium are acted synergistically in enhancing high corrosion resistance properties of the alloys in such aggressive electrolyte. BIBECHANA 18 (2021) 201-213

scholarly journals Questioned document examination with the use of alternative and complementary non-destructive methods

2021 ◽  
Vol 57 ◽  
pp. 149-167
Author(s):  
Rafał Cieśla
Keyword(s):  
Forensic Science ◽  
Legal Proceedings ◽  
Examination Methods ◽  
Document Examination ◽  
Reliable Knowledge ◽  
Important Position ◽  
Non Destructive ◽  
Destructive Methods

Questioned document examination occupies an important position in forensic science. Its purpose is to provide the authority conducting legal proceedings with reliable knowledge confirming or excluding authenticity of a document, therefore every effort should be made to use relevant and legally admissible examination methods. For many years reliable non-destructive methods have been developed, whose use in expert examination will enable subsequent control both by the authority conducting legal proceedings and other parties in the proceedings. This article proposes the use of alternative non-destructive methods in examination of documents.

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