12 research outputs found
Analysis of the Aging Processes of Writing Ink: Raman Spectroscopy versus Gas Chromatography Aspects
No full textThis work is devoted to the extremely popular but poorly developed scientific and forensic problem of the estimation of the actual dates of inscriptions placed on paper and made by ballpoint pens. It is shown that the degradation of writing inks with time may be controlled via Raman spectroscopy and gas chromatography. The time intervals for the implementation of each of these methods were determined using the ratios of the Raman peak intensities as degradation characteristics rather than their absolute values. In turn, this eliminates the effect of the concentration of a dye. The mutual influence of the volatile components and dyes of writing inks was also investigated and the time interval within which such influence is critical was found. According to the obtained results, a new methodological scheme for determining the age of documents, which were created at least 40 months ago, was proposed
Low-Frequency Magnetic Scanning Device and Algorithm for Determining the Magnetic and Non-Magnetic Fractions of Moving Metallurgical Raw Materials
No full textThe development of an algorithm to automate the process of measuring the magnetic properties of macroscopic objects in motion is an important problem in various industries, especially in ferrous metallurgy and at factories where ferrous scrap is a strategic raw material. The parameter that requires work control is the hidden mass fraction of a non-magnetic substance that is present in the ferromagnetic raw material. The solution to this problem has no prototypes. In our work, a simple measuring device and a mathematical algorithm for calculating the mass fraction of the non-magnetic fraction in a strongly magnetic matrix were developed. The device is an inductance coil, in which the angle of the electromagnet losses is related to the mass of the magnetic material moving the coil. The magnitude of the instantaneous values of the lost angle integral was compared with the result of weighing the object on scales. This allowed us to calculate the proportion of the magnetic and non-magnetic fractions. The use of this prototype is herein illustrated. The experimental results of the determination of the magnetic-fractional composition depending on the mass of scrap metal and its bulk and the magnetic characteristics are presented
Copper-based nanocatalysts produced via laser-induced ex situ generation for homo- and cross-coupling reactions
No full textAzobenzene/Tetraethyl Ammonium Photochromic Potassium Channel Blockers: Scope and Limitations for Design of Para-Substituted Derivatives with Specific Absorption Band Maxima and Thermal Isomerization Rate
No full textAzobenzene/tetraethyl ammonium photochromic ligands (ATPLs) are photoactive compounds with a large variety of photopharmacological applications such as nociception control or vision restoration. Absorption band maximum and lifetime of the less stable isomer are important characteristics that determine the applicability of ATPLs. Substituents allow to adjust these characteristics in a range limited by the azobenzene/tetraethyl ammonium scaffold. The aim of the current study is to find the scope and limitations for the design of ATPLs with specific spectral and kinetic properties by introducing para substituents with different electronic effects. To perform this task we synthesized ATPLs with various electron acceptor and electron donor functional groups and studied their spectral and kinetic properties using flash photolysis and conventional spectroscopy techniques as well as quantum chemical modeling. As a result, we obtained diagrams that describe correlations between spectral and kinetic properties of ATPLs (absorption maxima of E and Z isomers of ATPLs, the thermal lifetime of their Z form) and both the electronic effect of substituents described by Hammett constants and structural parameters obtained from quantum chemical calculations. The provided results can be used for the design of ATPLs with properties that are optimal for photopharmacological applications
Laser-induced deposition of nanostructured copper microwires on surfaces of composite materials
No full text
Laser-induced copper deposition from aqueous and aqueous - organic solutions: state of the art and prospects of research
No full textnformation about the factors influencing laser-induced deposition of metals, primarily copper, from aqueous and aqueous organic solutions are generalized and described systematically. Laser-induced deposition techniques and mechanisms of chemical and laser-induced deposition of local copper and other metal structures onto the dielectric surface are considered. The effects of the solution composition, the nature of the reducing agent and the properties of the dielectric surface on the deposition process are discussed. Possible photochemical reactions induced by laser radiation and the role of these reactions in the photoreduction of metals are considered. The key trends and prospects in the development of laser-induced chemical liquid phase deposition are mentioned
In situ laser-induced codeposition of copper and different metals for fabrication of microcomposite sensor-active materials
No full textEvaluation of Probabilistic Conclusions of Experts in Criminal Proceedings
No full textВ статье рассматриваются различные теории, лежащие в основе
классификации выводов эксперта и подходов к определению вероятности в экспертной
практике и праве. По мнению авторов, при расчете вероятности возможно применение
теоремы Байеса. Это позволяет перевести выводы эксперта в разряд логических
операций, выполняемых на основе расчетов с использованием байесовского метода.
В результате (при обосновании в заключении эксперта степени вероятности с помощью
количественно-качественных показателей) оказывается, что вероятные выводы
эксперта отличаются от предположительных и могут рассматриваться в качестве
доказательств. Причем доказательственное значение они приобретают лишь при
условии соблюдения общих требований относимости, допустимости и достоверности,
а также особого требования научной обоснованности использованных при их
получении методов (методик)The article discusses various theories underlying the classification of expert
conclusions and approaches aimed at determining probability in expert practice and law.
According to the authors, it is possible to apply Bayes’ theorem while calculating the
probability. This allows to translate the expert’s conclusions into the category of logical
operations performed on the basis of calculations using the Bayesian method. As a result
(when the degree of probability in the expert’s conclusion using quantitative and qualitative
indicators is substantiated), it turns out that the probable conclusions of the expert differ from
the estimated ones and can be considered as evidence. Moreover, they acquire evidentiary
value only if the general requirements of relevance, admissibility and reliability are met,
as well as the special requirement of the scientific validity of the methods (techniques)
used in their productio
