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Abstract: The application of diffuse reflectance UV–VIS–NIR spectroscopy is proposed to differentiate 20 office paper samples, which had been deemed similar by a preliminary visual examination under several different lighting sources. The samples were firstly screened on the basis of the qualitative appearance of their spectra. A further discrimination was obtained by taking into account three parameters: the average reflectivity of the paper samples in the range 680–900nm, and the integrated intensity of the absorption peak in the UV range at 272nm and at 360nm. The homogeneity of these parameters on both sides of the paper sheets was assessed, detecting a very uniform distribution of the optical brighteners. A special focus was posed on the determination of the discriminative power, in order to give a quantitative parameter on the proposed procedure, which is important when reporting results to the Court. The remarkable achievement of differentiating all the examined samples was obtained by UV–VIS spectroscopy, a very less expensive technique which is readily available in practically all forensic laboratories. [Copyright &y& Elsevier]

The article focuses on an experiment for the analysis of microbial activity in topsoil. It is stated that topsoil is the topmost layer of soil, which contains large amounts of bacteria and other microorganisms, that make the soil rich in nutrients to be used by plants. The microorganisms include bacteria, viruses, fungi, algae, and protozoa. In the experiment, qualitative analysis of microbial activities in topsoil is done by using white copy paper and a handmade cadmium sulfide-light emitting diode (CdS-LED) reflection photometer. White paper sheets are dipped in a soil solution, and treated with iodine, which results in a blue color. The depth of the blue color is measured by using the handmade reflection photometer.