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G Massonnet

Publications and source records attributed to G Massonnet.

5 recordsLinked to original sources

Nicephor[e]: a web-based solution for teaching forensic and scientific photography.

Nicephor[e] is a project funded by "Swiss Virtual Campus" and aims at creating a distant or mixed web-based learning system in forensic and scientific photography and microscopy. The practical goal is to organize series of on-line modular courses corresponding to the educational requirements of undergraduate academic programs. Additionally, this program could be used in the context of continuing educational programs. The architecture of the project is designed to guarantee a high level of knowledge in forensic and scientific photographic techniques, and to have an easy content production and the ability to create a number of different courses sharing the same content. The e-learning system Nicephor[e] consists of three different parts. The first one is a repository of learning objects that gathers all theoretical subject matter of the project such as texts, animations, images, and films. This repository is a web content management system (Typo3) that permits creating, publishing, and administrating dynamic content via a web browser as well as storing it into a database. The flexibility of the system's architecture allows for an easy updating of the content to follow the development of photographic technology. The instructor of a course can decide which modular contents need to be included in the course, and in which order they will be accessed by students. All the modular courses are developed in a learning management system (WebCT or Moodle) that can deal with complex learning scenarios, content distribution, students, tests, and interaction with instructor. Each course has its own learning scenario based on the goals of the course and the student's profile. The content of each course is taken from the content management system. It is then structured in the learning management system according to the pedagogical goals defined by the instructor. The modular courses are created in a highly interactive setting and offer autoevaluating tests to the students. The last part of the system is a digital assets management system (Extensis Portfolio). The practical portion of each course is to produce images of different marks or objects. The collection of all this material produced, indexed by the students and corrected by the instructor is essential to the development of a knowledge base of photographic techniques applied to a specific forensic subject. It represents also an extensible collection of different marks from known sources obtained under various conditions. It allows to reuse these images for creating image-based case files.

Computer-Assisted Instruction↗

A comparison of efficiency of manual and automatic fibres search with the Maxcan fibre finder.

The aim of this work was to study the efficiency of automatic fibre searching with the Maxcan fibre finder (Cox Analytical Systems, Sweden) in comparison to manual searching. The influence of some parameters (color, thickness, background noise) on the results of a fibre search was considered. Eighteen experimental tapes with different target fibres and different background noises were prepared in the laboratory. Searching of fibres was performed manually and with the Maxcan fibre finder by different operators from four European laboratories. Two laboratories have the Maxcan fibre finder system and the two instruments were used and compared in this study. The results show that searching with the Maxcan is generally as efficient as manual searching, except for very pale or very dark fibres. Note that the tapes used for these experiments were prepared in laboratory, and are not completely representative of the tape that could be obtained in real cases. To generalize the results obtained, further research on real case samples would be necessary.

Journal Article↗

Raman spectroscopy and the forensic analysis of black/grey and blue cotton fibres Part 1: investigation of the effects of varying laser wavelength.

Raman spectroscopy was investigated to determine the optimal conditions, mainly laser wavelength/s, for the analysis of the commonly encountered black/grey and blue cotton fibres dyed with reactive dyes. In this first part, a single blue cotton fibre, its three dye components, and an undyed cotton fibre were analysed with five different laser wavelengths from two different Raman microprobe spectrometers. The quality of the spectra, fibre degradation and speed of acquisition were used to determine that, under the conditions used, the 785 and 830 nm lasers gave superior results. The 632.8 nm laser wavelengths provided good results with little acquisition time and no spectral degradation. Results indicate that, at least, the major dye component could be identified using Raman spectroscopy.

Journal Article↗

A market study of green spray paints by Fourier transform infrared (FTIR) and Raman spectroscopy.

A market study of 40 different green spray paints was carried out using infrared (FTIR) and Raman spectroscopy. The infrared technique distinguished between the 12 main groups based on their binder and extender composition. After visual comparison of the spectra 22 subgroups were observed. Raman spectroscopy was also carried out on the 40 reference paints in order to determine the pigment content. Analyses were undertaken using two different excitation sources: Argon ion (514.5 nm) and Helium-Neon (632.8 nm). The first generated strong fluorescence for most of the samples and created eight groups. Using the red laser, 15 classes were observed. Finally, using an analytical sequence starting with infrared spectroscopy followed by Raman Helium-Neon and then by Raman Argon laser, most of the paints were differentiated. In this study infrared and Raman spectroscopy complemented each other. FTIR supplied information about the binder and some extenders, and Raman provided information on the main organic pigments present.

Journal Article↗