Others

Pigments used in an ancient Nepalese manuscript have been analysed and assigned and an ancient glass burial ornament has been probed to identify the specific colouring additives used.

Tips and Tricks for Photographing Images with a forensic light source

Magnetite is used in various applications from speaker production and high speed disk drives to a color additive in cement.

The simplest and most important rule for photographing evidence with an FLS is “What You See is What You Get”. However you see the evidence is exactly as the camera should see it.

Measuring and controlling the particle size distribution of cement is important both in order to achieve the desired product performance and to control manufacturing costs. Laser diffraction is the more popular method to determine the particle size distribution as the technique is quick, easy, reproducible, and provides a complete picture of the full size distribution.

New aqueous cleaning system for acrylic paint films on paper supports has been developed. Isotonic aqueous cleaning solutions that match the pH and conductivity readings of acrylic paint films and paper supports obtained from agarose gel pellets have been shown to be effective in reducing or removing dirt, dust, active mold growth and associated stains, tide line stains, and discoloration.

The main application regarding Questioned documents and the use of alternate light sources revolve around “ink differentiation”. Many inks have different formulations, even within the same apparent color type. A tunable forensic light source can be used to identify slight variations in ink type by viewing ink responses as the color of the light is tuned through the visible and infrared regions.

The XGT-9000 Series can be used for identification of trace evidences such as collected gunshot residues, glass fragments, and fibers with sizes even down to tens of micron.

μ-XRF is one of the powerful non-destructive analytical technique in forensic science application. Thanks to the elemental mapping and the spectrum search function, XGT-9000 enables to reveal intentional alternation and identify the ink used on a document.

The behavior of an abrasive material is influenced by the hardness, size, and shape of the particles. A harder particle will be more aggressive in altering the surface of the work piece. Larger particles generate higher impact force removing the material surface quicker and producing a heavier texture. Particle shape also plays a role.

In this study we have chosen to investigate pyrite and its surrounding minerals in order to identify the different mineral phases as well as the chemical variations from micro- to nano-scale. Using the different microscopes instruments and being co-localized allows a comprehensive characterization of the sample and a precise superimposition of all the images.

Gemstones for jewelry are treated by heating, irradiation, or filling of cracks to make them flawless. We performed imaging analyses using an XGT-9000 X-ray Analytical Microscope on a ruby provided by Mineralab. The transmission X-ray imaging revealed that the ruby included several internal defects, and the fluorescent X-ray imaging revealed that the ruby surface was treated by filling with Pb, Mg and Si which are representative of lead glass.

The XGT-9000 Series can be equipped with various probes and spot sizes providing comprehensive and detailed understanding of geological and mineral samples.

Micro-XRF analysis of gun shot residues allows individual microscopic particles to be characterized for elemental composition. In addition, automated element imaging provides high spatial resolution element distribution maps, allowing particle shapes and sizes to be accurately analyzed.

Simultaneous XRF and transmission x-ray imaging provides valuable insight into the composition and structure of pearls. Such information is vital for customs officials, who can quickly determine whether pearls are natural, cultured or imitation.

Lapis lazuli is a deep-blue metamorphic rock used as a semiprecious stone which contains inclusions that can impact its value. Pyrite impurities and major elements distribution are studied with the XGT-9000, HORIBA’s new X-ray microscope.

High spatial resolution elemental mapping experiments are demonstrated to provide a useful method of fingerprint analysis in situations where traditional methods struggle. Fingerprints on glossy paper and finely woven fabrics have been chemically treated, and subsequently imaged.

Natural rocks composing the Earth are complex. They consist of an aggregate of one or more minerals. Each mineral can be defined by its chemical composition and its crystalline structure and sometimes can also contain fluid inclusions. Geologists need a powerful characterization technique to get detailed information on the rock formation history. Raman spectroscopy is extremely information-rich (chemical identification, characterization of molecular structures, effects of bonding, environment and stress on a sample). With its non-destructive properties and high spatial resolution (< 1 μm), it is thus a tool of choice for geological studies.

International terrorism, security concerns, and the remains of forgotten landmines throughout the world have increased interest in detection of explosive materials.

Forensic and Alternate light sources are useful tools to detect both fluorescent and non-fluorescent trace evidence.

There are several different types of residues found both in ammunition and explosives, which fluoresce. By using a tunable Forensic Light Source, observations can be made on items without touching the surface, to see if fluorescent residues are present.

On some individuals, a tunable or multiple wavelength forensic light source may reveal bruise and patterned wound details that are invisible under normal white light illumination.

Historically, the primary application of a forensic light source is for enhancing the detection of latent fingerprints. The use of fluorescent enhancement processes that compliment a light source greatly increases the types of surfaces from which a latent fingerprint can be detected.

Since body fluids like semen, saliva, and vaginal fluids are naturally fluorescent, the use of a light source offers a unique method for locating them. A crime scene investigator can narrow down the specific locations of stains for collection instead of testing entire, large pieces of evidence such as a mattress, a carpet, a sheet, an article of clothing, etc. The dried body fluids will actually glow under the light source illumination.

This technical note serves as a guideline to selecting the best solid state detector with the Fluorolog-QM modular research spectrofluorometer for a given series of photoluminescence experiments.