Determination of flammability parameters for organic waste resulting from the processing of sunflower seeds

Agricultural waste is found in abundance in the environment, whether it is the plant itself represented by the stem, leaf or seeds that have been peeled or other waste. By drying and crushing the residues from the plants, organic powders will be formed with a variable granulation and humidity. Through the processing of oilseeds such as sunflower seeds, significant amounts of waste from seeds result. Seed shells resulting from technological processes crumble, forming fine powders, whose granulations are different. A certain percentage will be 63μm or smaller and if those fine powders are mixed with air can form clouds with explosive properties. The purpose of this paper was to determine the minimum ignition layer and cloud temperatures. Experimental determination of flammability parameters is particularly important in order to take the proper safety measures so that accidents can be avoided.

Ultrasensitive analysis of genetic instability related to chemical exposure

Our concerns have been raised about whether prolonged exposure to ammunition-related chemicals could correlate with genomic instability predisposing to lung carcinogenesis. The group of professional soldiers engaged in routine ammunition analysis and its explosive properties testing. To assess the presence of an innate genetic profile, DNA isolated from swabs was analyzed with LungCarta and HS Lung Panels and MassARRAY Analyzer 4 mass spectrometry. The presence of new somatic single nucleotide polymorphisms (SNPs) was detected with liquid biopsy technique and circulating cell-free DNA (ccfDNA) isolation, which was further analyzed with UltraSeek Lung Panel. Both genetic profiles obtained for each individual were compared. Genetic analysis revealed that in professional soldiers with long-term exposure to ammunition-related toxic chemicals, new SNPs in genes related to lung carcinogenesis are present. The preliminary data indicate that using modern molecular techniques could be a valuable tool for monitoring the genome instability in context of occupational risk of harmful volatile toxic compounds and improving personnel safety. The analyzed group will be further enlarged, and follow-up studies will be continued.

effect of 1Me-3H additive on the explosive force nanothermite systems SnO2/Al and WO3/Al

Нанотермиты рассматриваются как перспективные энергонасыщенные материалы для создания пиротехнических изделий широкого спектра, ввиду их способности горения в тонких слоях, микрограммовых навесках. Однако из-за высокой чувствительности нанотермитов к электрической искре и трению, сильно осложняется их практическое использование, в связи с чем актуален поиск добавок, снижающих чувствительность, но сохраняющих приемлемые параметры взрывчатых характеристик нанотермитных композиций. В качестве таковых добавок целесообразно использовать высокоэнтальпийные вещества, отличающиеся низкой чувствительностью. Одним из таких веществ является 1-метил-3-нитро-1,2,4-триазол (1Ме-3Н). В работе представлены результаты исследования силы взрыва (F) нанотермитных систем на основе оксида олова и алюминия SnO2/Al, оксида вольфрам и алюминия WO3/Al в зависимости от содержания 1Ме-3Н. Исследован ряд составов разной рецептурной компоновки (I и II): в компоновке I – соотношение компонентов в нанотермитной композиции соответствовало максимальной расчетной теплоте взрыва (Q) при заданном содержании 1Ме-3Н; II – соотношение компонентов базовой нанотермитной пары остается неизменным в тройных смесях. В системе SnO2/Al/1Ме-3Н выявлен экстремальный характер зависимости силы взрыва F от концентрации 1Ме-3Н, при этом максимальные значения F наблюдаются при содержании добавки 10 % для обоих рецептурных компоновок: I – F = 163 %; II – F = 160 %. Для системы WO3/Al/1Ме-3Н обоих рассмотренных рецептурных компоновок наблюдается монотонное снижение силы взрыва с ростом содержания1Ме-3Н: при содержании добавки 15 % композиция теряет взрывчатые свойства (F=0 %). Нанотермитная система SnO2/Al/1Ме-3Н, как и ранее изученные CuO/Al/1Ме-3Н, Bi2O3/Al/1Ме-3Н, MoO3/Al/Ме-3Н проявляет экстремальный характер зависимости силы взрыва F от содержания 1Ме-3Н, подтверждая ранее принятые положения о механизме реакционного взаимодействия в нанотермитных композициях с органическими добавками, тогда как для композиции WO3/Al/1Ме-3Н, по-видимому, присущ отличный от принятого механизм горения, требующий дополнительных исследований. Nanothermites are considered as promising energy-saturated materials for the creation of pyrotechnic products of a wide range, due to their ability to burn in thin layers, microgram quantities. However, due to the high sensitivity of nanothermites to electric spark and friction, their use is very difficult, and therefore the search for additives that reduce sensitivity, but retain acceptable parameters of explosive characteristics of nanothermite compositions is relevant. As such additives, it is advisable to highly use enthalpy substances characterized by low sensitivity. One of these substances is 1-methyl-3-nitro-1,2,4-triazole (1Me-3H). The paper presents the results of a study of the explosion force (F) of nanothermite systems based on tin oxide and aluminum SnO2/Al, tungsten oxide and aluminum WO3/Al depending on the content of 1Me-3H. Several compositions of different prescription configuration (I and II) were studied: in the configuration, I - the ratio of components in the nanothermite composition corresponded to the maximum calculated heat of explosion (Q) at a given content of 1Me-3H; II - the ratio of the components of the base nanothermite pair remains unchanged in triple mixtures. In the SnO2/Al/1Me-3H system, the extreme nature of the dependence of the explosion force F on the concentration of 1Me-3H was revealed, while the maximum values of F were observed at an additive content of 10% for both prescription configuration: I - F = 163%; II - F = 160%. For the WO3/Al/1Me-3H system of both considered compounding arrangements, a monotonous decrease in the explosion force with an increase in the content is observed 1Me-3H: with an additive content of 15%, the composition loses explosive properties (F = 0%). The nanothermite system SnO2/Al/1Me-3H, as well as the previously studied CuO/Al/1Me-3H, Bi2O3/Al/1Me-3H, MoO3/Al/Me-3H, exhibits an extreme dependence of the explosion force F on the content of 1Me-3H, confirming the previously accepted provisions on the mechanism of reaction interaction in nanothermite compositions with organic additives, whereas the composition WO3/Al/1ME-3H, apparently, has a different combustion mechanism from the accepted one, requiring additional research.

The Improvement of Picric Acid Synthesis Methodology

Explosives have the greatest importance in human practical activities, not only at time of war, but at tranquility as well. Nowadays, huge amount different type of explosives is synthesized, and fabricated for military and civilian applications. Nevertheless, this fact doesn’t exclude necessity of synthesis of new explosives for optimization of their characteristics, such as prime cost, power, safety during production, storage, transfer and etc. Picric acid is a fairly strong and energetic explosive, at the same time, beside to its explosive properties, it is characterized with antibacterial nature and it is the best yellow dye, especially for dyeing animal and plant tissues. The synthesis of picric acid structural analogues, is the main purpose of the research. One of the reasons of synthesis picric acid and further preparation of its structural analogues is safe nature of substances of this group, which makes them safe to various manipulations. On the other hand, it is well known that the synthesis and production of explosives is classified as high risk and costly technology. Therefore, even a small increase of their production productivity, is interesting from the economic effect point of view. During an investigation, changing of reaction conditions (temperature, concentrations and dosage of reagents) the improved method for syntheses of picric acid was developed. As result the significant increase of practical yield of picric acid, from 46% to 86% was achieved. Synthesized picric acid was placed in steel tube and tested on initiation of detonation in explosive camera. The description of modified method, comparisons to conventional technology, as well as explosion testing results is described in the paper.

Polymer-bonded secondary explosives

In this paper, a review of the available literature on physical and explosive properties of explosive compositions containing a secondary explosive and a polymer binder (PBX) is presented. The review focused on an analysis of the properties of compositions containing mostly synthetic polymers. The review showed that, at the moment, the most commonly used composition is a hexogen-based explosive bonded with a chemically cross-linked hydroxylterminated polybutadiene. The use of energetic polymers in PBX compositions was observed only in the experimental systems tested on a laboratory scale. The most popular methods of forming compositions include pressing a previously phlegmatized explosive or chemical cross-linking of the composition in the projectile shell. Compositions which can be formed and reloaded using injection machines are known, but due to many limitations, the method is not widely used.

The Fire and Explosion Hazard of Coloured Powders Used during the Holi Festival

During the world-famous Holi festival, people throw and smear each other with a colored powder (Holi color, Holi powder, Gulal powder). Until now, adverse health and environmental effects (skin and eye irritation, air pollution, and respiratory problems) have been described in the available literature. However, the literature lacks data on the flammable and explosive properties of these powders during mass events, despite the fact that burns, fires, and explosions during the Holi festival have taken place many times. The aim of the article is to present the fire and explosion parameters of three currently used Holi dust and cornflour dust types as reference dust. The minimum ignition temperature of the dust layer and dust cloud, the maximum explosion pressure and its maximum rate of growth over time, the lower explosion limit, the limit of oxygen concentration, and the minimum ignition energy were determined. Tests confirmed that the currently available Holi powders should be classified as flammable dusts and low-explosive dusts. The likelihood of a fire or explosion during mass incidents involving a Holi dust-air mixture is high.

Benzimidazole Derivatives as Energetic Materials: A Theoretical Study

The explosive properties and stability of benzimidazole compounds are studied to determine the influence of substituents and their position. The results obtained reveal the conjugation of substituents as one of the crucial factors for the thermal stability of these compounds. We also found that two -CH3 substituents increase the thermal stability of the parent compound, while nitro groups decrease it. Moreover, the study clearly exhibits that the combination of an -NO2 substituent with -CH3 does not change the stability of the benzimidazole. On the other hand, nitro groups increase the chemical stability and explosive properties of the compounds under investigation, but their sensitivity could not fully satisfy the requirements of their safety and increase their toxicity. The main results of the study indicate that high thermal and chemical stability, low toxicity and sensitivity, and good explosive properties could be achieved by the precise combination of nitro, -CH3, and triazole ring substituents. These findings are very important for the design of new, effective, and non-sensitive explosives.

Tests of Samples of Emulsion Explosive Senatel Magnum before and after Introduction of the Marking Composition for Explosive Properties and Safety Criteria

The article is devoted to testing samples of the emulsion explosive Senatel Magnum before and after the introduction of the marking composition for explosive properties and safety criteria. It was established that the mixture of marking substances, which was introduced into the composition of the emulsion explosive Senatel Magnum, does not affect its explosive properties, as well as its safety in use during operation and conduct of blasting operations, since no inconsistencies were detected during tests by the specialists of explosive materials testing laboratory of the Expert Certification Center of Explosive Materials LLP. Various dyes were selected as marking agents. This choice is due to the fact that the dyes have a relatively low price, are very common on sale, when mixed with other substances, in particular industrial explosives, are determined visually. The technology was tested related to the introduction of marking additives into the compositions of multicomponent explosives without disrupting the technological process of their manufacture. Laboratory and field studies were carried out concerning safety criteria for explosives containing a marking composition. Thus, the urgent task is to ensure the possibility of marking (tagging) industrial explosives at the stage of their production with hidden marking additives, which will allow the product itself to be identified with the help of technical means — as an explosive, and to establish the brand of the detected explosive, manufacturer, and other required information.