Epileptic rat brain tissue analyzed by 2D correlation Raman spectroscopy.

Absence epilepsy is the neurological disorder characterized by the pathological spike-and wave discharges present in the electroencephalogram, accompanying a sudden loss of consciousness. Experiments were performed on brain slices obtained from young male WAG/Rij rats (2-3weeks old), so that they were sampled before the appearance of brain-damaging seizures symptoms. Two differing brain areas of the rats' brain tissue were studied: the somatosensory cortex (Sc) and the dorsal lateral geniculate nucleus of the thalamus (DLG).

Examination of the chemical changes in cured phenol-formaldehyde resins during storage.

Chemical changes occurring within cured phenol-formaldehyde resins (resite and novolak type) during their storage were investigated by FT-NIR, py-GCMS and inverse gas chromatography. It was shown that a mixture of resite with novolak was less stable than resite or novolak itself as regards bulk properties. This aging phenomenon is mainly due to reaction of ammonia (product of hexa decomposition) with CH2OH groups present in resite.

Assessment of the chemical changes during storage of phenol-formaldehyde resins pyrolysis gas chromatography mass spectrometry, inverse gas chromatography and Fourier transform infra red methods.

The chemical changes occurring in the phenol-formaldehyde resins (resol and novolac type) during their storage were investigated. In this paper the FT-IR, py-GCMS and inverse gas chromatography methods were applied for assessment of the changes occurring during storage of the phenolic resins. We have found that during storage some examined resins occurred partial curing.

Characterization of blue pigments used in automotive paints by Raman spectroscopy.

Micro-Raman spectroscopy was applied to forensic identification of pigments in paint chips and provided differentiation between paint samples. Sixty-six blue automotive paint samples, 26 solid and 40 metallic were examined. It was found that the majority of the collected Raman spectra provided information about the pigments present.

Comparison of pigment content of paint samples using spectrometric methods.

The aim of the paper was to evaluate the influence of pigment concentration and its distribution in polymer binder on the possibility of colour identification and paint sample comparison. Two sets of paint samples: one containing red and another one green pigment were prepared. Each set consisted of 13 samples differing gradually in the concentration of pigment.

Chemical analysis of post explosion samples obtained as a result of model field experiments.

Five different explosives were detonated in a series of field experiments. Each experiment (detonation of the charge of each specific explosive) was repeated three times. The experiments were conducted under controlled conditions, exceeding those of research published so far.

Application of infrared and Raman spectroscopy in paint trace examination.

Raman spectroscopy has proved to be a promising technique in forensic examinations, where optical microscopy, micro-infrared spectroscopy, and microspectrophotometry in the visible and UV range are used for identification and differentiation between paint traces. Often no organic pigments are detected using Fourier transform infrared spectroscopy, because their content in a trace is usually undetectable. Application of a micro-Raman spectrometer equipped with several excitation lasers helps forensic experts in paint analysis enabling identification of main pigments.

Establishing of chemical composition of printing ink.

The subject of the examinations was primarily court tax marks of 50 and 200 PLN, which were suspected not to be genuine. Both inks on the questioned marks as well as comparative genuine marks and inks sent by the manufacturer were analyzed. No information about their chemical composition was available from manufacturer.

Black painted pottery, Kildehuse II, Odense County, Denmark.

This work aimed at characterization of a black layer covering a Bronze Age (period VI) pot surface. To solve research problems plane polarized light microscopy (PLM), scanning microscopy with X-ray microanalyser (SEM/EDS), Raman and FTIR microspectroscopies were applied. Observation of the black layer under the PLM suggests that we deal with an opaque, isotropic layer, purposely put on leather-hard, burnished surface of a pot.

The use of rigid, fibrillar Congo red nanostructures for scaffolding protein assemblies and inducing the formation of amyloid-like arrangement of molecules.

The ordered amyloid-like organization of protein aggregates was obtained using for their formation the rigid fibrillar nanostructures of Congo red as the scaffolding. The higher rigidity of used dye nanoparticles resulted from the stronger stacking of molecules at low pH (near the pK of the dye amino group) because of the decreased charge repulsion. The polylysine, human globin, and immunoglobulin L chain were arranged in this way to form deposits of amyloid properties.

Differentiation and evaluation of evidence value of styrene acrylic urethane topcoat car paints analysed by pyrolysis-gas chromatography.

Pyrolysis (Py)-GC/MS was applied to differentiate between automobile paint samples. The method was used for analysis of 36 samples of styrene acrylic urethane clearcoats that were indistinguishable on the basis of their infrared spectra and elemental composition. Differences observed in the obtained pyrograms of the compared paint samples were relatively small.

Pyrolysis-gas chromatography/mass spectrometry analysis as a useful tool in forensic examination of automotive paint traces.

Pyrolysis (Py)-GC/MS was applied in comparative analysis of polymer binder of 150 automobile clearcoat samples. It was found that binders of identical type and similar infrared spectra can be, in most cases, effectively differentiated, sometimes based only on the presence of peaks of very low intensity originating from minor paint components. The qualitative procedure of pyrograms comparison was developed.

PRAXIS--combined mu-Raman and mu-XRF spectrometers in the examination of forensic samples.

Recently, two analytical techniques--Raman and XRF spectroscopy--have been often applied in criminalistic examinations of different kinds of trace evidences. In this paper, the application of the new combined mu-Raman and mu-XRF spectrometer in analysis of multilayer paint chips, modern inks, plastics and fibres was evaluated. It was ascertained that the apparatus possesses real advantages and could be helpful in the identification of examined materials after some modifications, i.

The effect of re-annealing on the distribution of refractive index in a windscreen and a windowpane classification of glass samples.

Tiny glass fragments of two typical objects being of interest in forensic investigations: car windscreen and windowpane were examined from the point of view of their importance as crime evidence. Both examined objects were made from float glass and were toughened. The present paper concerns examination of refractive index distribution across the objects under investigation before and after the glass fragments were annealed according to previously chosen procedure.

Comparison of the effectiveness of Tenax TA and Carbotrap 300 in concentration of flammable liquids compounds.

The aim of research was to compare two adsorbents, Tenax TA and Carbotrap 300, to evaluate their usefulness as passive adsorbents of flammable liquids compounds. It was also to determine whether Carbotrap 300 could be used in a passive adsorption mode, contrary to manufacturer recommendations. To compare the adsorption properties and the thermal desorption efficiency for Tenax TA and Carbotrap, the components of test mixture were adsorbed and then chromatographically analyzed.

The influence of the type of accelerant, type of burned material, time of burning and availability of air on the possibility of detection of accelerants traces.

The presented research consisted in a series of field experiments and laboratory analyses of obtained samples. Their aim was to investigate how different factors influence the possibility of identification of accelerant traces in conditions that are as similar as possible to those of real fires. The studied factors were: type of burned material, type of accelerant, length of time between lighting and extinguishing of fire and the air availability level.

Application of false discovery rate procedure to pairwise comparisons of refractive index of glass fragments.

This study was undertaken to apply a new method of controlling type I error when performing pairwise comparisons. The Benjamini and Hochberg false discovery rate (FDR) controlling procedures have proved to be very powerful tools in solving many practical problems but have not yet been applied to pairwise comparisons of refractive index of glass samples. Students t-test and Welch test (unequal variance Student's t-test) were applied to all possible pairwise comparisons.

Application of the micro-FTIR spectroscopy, Raman spectroscopy and XRF method examination of inks.

In routine examination of inks on questioned documents non-destructive analytical methods, such as microscopic and optical techniques are applied first. However, they are often insufficient to identify the inks used for the preparation of the document. In such cases, it is necessary to apply chemical methods that normally cause partial destruction of the examined material.

Differentiation between used motor oils on the basis of their IR spectra with application of the correlation method.

Two brands of motor oils (Elf and Castrol) that had been used for various periods of time were examined. The aim was to differentiate these samples (of varying degree of use) on the basis of their infrared spectra, for criminalistic purposes. The correlation method was used.

A chemical and physicochemical study of an Egyptian mummy 'Iset Iri Hetes' from the Ptolemaic period III-I B.C.

Chemical and physicochemical examinations of the fragments of an Egyptian mummy dated between the 3rd and 1st century B.C. were performed.