Validation of the expert methodology «Detection of condensed traces of the gunshot residue containing heavy metal compounds on various objects by scanning electron microscopy and X-ray microanalysis»

2021 ◽  
Vol 87 (12) ◽  
pp. 63-72
Author(s):  
S. A. Smirnova ◽  
I. B. Afanasyev ◽  
G. I. Bebeshko ◽  
G. G. Omel’yanyuk
Keyword(s):  
Electron Microscopy ◽  
Heavy Metal ◽  
Scanning Electron Microscopy ◽  
Electron Microscope ◽  
Standard Sample ◽  
Gunshot Residue ◽  
Test Results ◽  
Metal Compounds ◽  
X Ray ◽  
Scanning Electron

We present and discuss the results of the validation of a forensic qualitative testing technique which consists in the detection of condensed traces of the gunshot residue (GSR) in the form of individual microparticles on the objects under study and their identification by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) using a scanning electron microscope Mira III (Tescan, Czech Republic) equipped with a system of X-ray microanalysis INCA GSR 450 (Oxford Nanoanalysis, Great Britain). The procedure for detecting GSR particles containing heavy metal compounds, systems of their classification and interpretation of test results are described. The suitability of the methodology for solving forensic problems has been confirmed. The validation procedure consists in assessing the reliability by comparing the test results obtained by experts (A and B) in two laboratories at different times using the same device, and in confirming the competence of experts proceeding from the results of blind tests. A standard sample ENFSI GSR PT 2018 A-03-07 is used. Each of the experts determined the number of particles classified as GSR present in control samples taken in a ballistic laboratory during a full-scale experiment: from the hands of the shooter; from the hands of a person who did not shoot; without microparticles (clean stage of an electron microscope). The reliability of the technique is characterized by the index (probability) of correct results of detecting GSR particles in the standard sample of at least 95.8% and by a small proportion of false results (no more than 5.4%). The competence of the experts is proved by the consistent results of «blind» testing of control full-scale samples, containing and not containing GSR particles obtained in different laboratories. The results of the validation indicate the suitability of the method for obtaining reliable and valid information about the presence of GSR particles on the objects under study.

scholarly journals The use of scanning electron microscopy to the study of the painting from the Church in Radcze

2013 ◽  
Vol 12 (4) ◽  
pp. 095-105
Author(s):  
Beata Klimek
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Microscope ◽  
Historic Buildings ◽  
X Ray ◽  
Composition And Structure ◽  
The Church ◽  
Diagnosis Technique ◽  
Scanning Electron

One of the main tasks in the study of historic buildings is the need to identify the original materials and extensions, which often have historic character. The next task concerns the determination of the composition and structure of the historical, diagnosis technique to develop original paint. The article presents the preliminary results of paintings. Methods were used with the scanning electron microscope was equipped with an energy dispersive X-ray spectrometer (SEM-EDS).

scholarly journals Quantitative Evaluation of Crystalline and Amorphous Phases in Clay-Based Cordierite Ceramic

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1122
Author(s):  
Zdeněk Klika ◽  
Marta Valášková ◽  
Lucie Bartoňová ◽  
Petra Maierová
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Chemical Analysis ◽  
Test Results ◽  
Mineral Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Amorphous Phases ◽  
Cordierite Ceramic ◽  
Scanning Electron

An innovative chemical quantitative mineral analysis (CQMA) was successfully tested on a cordierite-based clay ceramic sample to quantify crystalline and amorphous components. The accuracy of this method was demonstrated on an added module to the CQMA program that used oxide formulas of amorphous phases obtained by energy dispersive X-ray spectroscopy (EDS) microprobe chemical analysis. This CQMA method was tested for three variants calculated using chemical analysis, i.e., X-ray diffraction (XRD) identification of crystalline (cordierite and enstatite) and amorphous phases by scanning electron microscopy (SEM)/EDS texture and microanalyses. The test results from CQMA suggest their application possibilities as well as the limits of their utilization.

Chemical and Morphological Study of Gunshot Residue Persisting on the Shooter by Means of Scanning Electron Microscopy and Energy Dispersive X-Ray Spectrometry

2011 ◽  
Vol 17 (6) ◽  
pp. 972-982 ◽  
Author(s):  
Zuzanna Brożek-Mucha
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Probability Of Detection ◽  
Energy Dispersive ◽  
Gunshot Residue ◽  
Time Intervals ◽  
X Ray ◽  
Irregular Shapes ◽  
The Face ◽  
Scanning Electron

AbstractPersistence of gunshot residue (GSR) simultaneously collected from hands, face and hair, and clothing of the shooting person was examined. Samples were collected from five shooters in nine time intervals after a single shoot with a Luger 9 mm pistol, in the range of 0–4 h and examined with scanning electron microscopy and energy dispersive X-ray spectrometry. Numbers of particles, frequencies of occurrence of certain compositions of particles, and their sizes in function of the time intervals were inspected. The greatest numbers of particles were observed in samples collected from hands right after shooting, but they decrease quickly with time. In samples collected from the face smaller initial numbers of particles were found, but they lasted at a similar level longer. The estimated half-life times of particles were less than 1 h for samples taken from the hands, over 1 h for clothing and about 2–3 h for the face. In samples collected at longer intervals after shooting, there were particles present of small sizes and irregular shapes. The results demonstrate that including evidence collected from the suspect's face and hair may increase the probability of detection of GSR in cases when the suspect has not been apprehended immediately after the investigated incident.

Fabrication of g-C3N4/Y-TiO2 Z-scheme heterojunction photocatalysts for enhanced photocatalytic activity

2021 ◽  
Author(s):  
SongSik Pak ◽  
KwangChol Ri ◽  
Chenmin Xu ◽  
Qiuyi Ji ◽  
Dunyu Sun ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Photocatalytic Activity ◽  
Electron Microscope ◽  
Photoelectron Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

The g-C3N4/Y-TiO2 Z-scheme heterojunction photocatalysts were successfully synthesized. The powder X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscope, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy were used for...

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