FEATURES OF CONDUCTING FORENSIC EXPLOSIVE EXAMINATIONS OF OXYGEN CYLINDERS EXPLOSIONS

The article considers the issues on which the procedure for conducting forensic examinations and expert studies related to the study of the circumstances of oxygen cylinder explosions. Conducting such studies is one of the most difficult in explosive examination, because the results of chemical studies of the remains seized at the site of the explosion do not give any results on the explosive transformation of substances and materials. Examination has to be carried out on the results of such phenomena only on those objects that were found at the site of the explosion. However, there is no expert methodology for conducting such research, and the phenomena of such a process have not been fully studied today. The methodological recommendations developed by the staff of the Institute in the main part are not the result of generalizing the literature data. The recommended system of work consisted primarily of processing the material obtained in the process of accumulating experience in fire-technical and explosive-technical expertise and was the result of a generalization of this experience. The structure and content of the recommended research methods is the result of the analysis and generalization of a large amount of factual material over a long period of experts’ work. The provisions in the guidelines are illustrated with examples from practice. In addition to examples of the experts’ work, there are instructive cases of incorrect, unsuccessful solution of certain issues. This is of cognitive value, provides opportunities to more easily, and correctly address issues raised by experts. Yet, this is only the first experience. Therefore, the authors do not claim to be exhaustive of the stated provisions, believing that these recommendations should be improved based on discussions with the practitioners, further accumulation and generalization of facts of similar phenomena and events.

Ability of Naphthoquinondiazide Photoresists to Exothermic Decomposition

The article considers two intermediate products of positive photoresists (1,2-naphthoquinonediazide-(2)-5-sulfonic acid of monosodium salt — Dye M and 1,2-naphthoquinonediazide-(2)-5-sulfochloride — Dye N2) from the standpoint of the tendency to explosive transformation. The experimental values of flash points determined on the OTP setup were 130 °C for Dye M and 95 °C for Dye N2. These values are close to the temperatures of the beginning of intensive exothermic decomposition (132 and 111 °C, respectively) obtained by thermogravimetric analysis. In addition, this analysis showed the presence of exothermic peaks in the studied samples both in the air and in an inert atmosphere of helium, which is a necessary condition for the manifestation of a tendency to explosive transformation. To confirm the possibility of explosive transformation, the flash points of substances were also determined by the calculation method according to the formula, which is a consequence of the problem of thermal explosion during convective heat exchange with the environment, and gave a result close to the experimental one (the values were 138 and 105 °C, respectively). For this calculation the following was used: the kinetic parameters determined by the Kissinger method, the values of the density of substances determined on an automatic pycnometer, as well as the values of the heat of explosive transformation obtained with the help of the Real computer thermodynamic program. The research results confirming the tendency of the investigated compounds to explosive transformation, as well as the critical temperatures, exceeding which is unacceptable, were transferred to the production of FGUP GNTs NIOPIK to create a safe technological process, safe storage and transportation conditions. Considering the accuracy of the measuring devices, the process temperature should not exceed 125 °C for Dye M and 90 °C for Dye N2. The conducted studies and calculations show that the computational and experimental approaches have good convergence, give values in a close temperature range, and increase the reliability of the obtained results.

Construction of Corpus in Artificial Intelligence Age

As a kind of revolutionary technology, artificial intelligence marked an explosive transformation in many fields of study. Nowadays, much of the translation work used to be done by human has been undertaken by machines. The construction of corpus is a crucial step leading to successful machine translation. The paper aims to exploring the mode of corpus construction from the perspective of information mining, information retrieval and information processing. The retrieval system uses web crawlers to collect network information and automatic tagging technology to index the collected information, then applies corresponding language processing techniques to achieve correspondence between two languages and form an index database. In the age of artificial intelligence, machines can keep a track of many users’ searches, queries, so as to record, extract as well as to feed back on different translations to build a new corpus. In this way, machine translation is improving in its scope and accuracy in translation with the goal to take up the tedious work of human translation as well as to increase the speed and reduce the cost of it.