Antimicrobial activity of herbal extracts from Sedum maximum (L.) Hoffm., Sedum telephium L. received by different methods

The main goal of investigation was antimicrobial activity of herbal extracts from Sedum maximum (L.) Hoffm., Sedum telephium L. received by different methods. Material and Methods. Extractions from the purification of S. maximum (L.) Hoffm. and S. telephium L. obtained by different methods were the object of study. Staphylococcus aureus ATCC 6538P, Pseudomonas aeruginosa ATCC 27835, Escherichia coli ATCC 25922, Candida albicans ATCC 13108 were used as test cultures. Results. The minimum inhibitory concentrations of the investigated flavonoid-containing aqueous solutions of alcohol extracts of the purification were determined for the following test cultures: S. aureus, P. aeruginosa, E. coli. Conclusion. The antibacterial effect of the studied extracts on all strains of bacteria taken in the experiment was detected. The action is most pronounced in relation to S. aureus. Antimycotic activity was not detected.</p

Structure and Properties of Layered Ti-6Al-4V-Based Materials Fabricated Using Blended Elemental Powder Metallurgy

Due to the high specific strength of Ti, materials on its base are indispensable when high-strength and low-weight requests are a chief demand from the industry. Reinforcement of Ti-alloys with hard and light particles of TiC and TiB is a credible pathway to make metal matrix composites (MMC) with enhanced elastic moduli without compromising the material’s low-weight. However, reinforcement of the alloy with hard particles inevitably lowers the value of toughness and plasticity of material. Yet, in many applications simultaneous high hardness and high plasticity are not required through the entire structure. For instance, parts that need enhanced wear resistance or resistance upon ballistic impact demand high hardness and strength at the surface, whereas their core necessitates rather high toughness and ductility. Such combination of mechanical properties can be achieved on layered structures joining two and more layers of different materials with different chemical composition and/or microstructure within each individual layer. Multi-layered structures of Ti-6Al-4V alloy and its metal-matrix composites (MMC) with 5 and10% (vol.) of TiC and TiB were fabricated in this study using blended elemental powder metallurgy (BEPM) of hydrogenated Ti. Post-sintering hot deformation and annealing were sometimes also employed to improve the microstructure and properties. Structure of materials were characterized using light optical microscopy, scanning electron microscopy, electron backscattered diffraction, x-ray microscopy, tensile and 3-point flexural tests. The effect of various fabrication parameters was investigated to achieve desirable microstructure and properties of layered materials. Using optimized processing parameters, relatively large multilayered plates were made via BEPM and demonstrate superior anti-ballistic performance compared to the equally sized uniform Ti-6Al-4V plates fabricated by traditional ingot and wrought technology

Structure and Properties of Layered Ti-6Al-4V-Based Materials Fabricated Using Blended Elemental Powder Metallurgy

Due to the high specific strength of Ti, materials on its base are indispensable when high-strength and low-weight requests are a chief demand from the industry. Reinforcement of Ti-alloys with hard and light particles of TiC and TiB is a credible pathway to make metal matrix composites (MMC) with enhanced elastic moduli without compromising the material’s low-weight. However, reinforcement of the alloy with hard particles inevitably lowers the value of toughness and plasticity of material. Yet, in many applications simultaneous high hardness and high plasticity are not required through the entire structure. For instance, parts that need enhanced wear resistance or resistance upon ballistic impact demand high hardness and strength at the surface, whereas their core necessitates rather high toughness and ductility. Such combination of mechanical properties can be achieved on layered structures joining two and more layers of different materials with different chemical composition and/or microstructure within each individual layer. Multi-layered structures of Ti-6Al-4V alloy and its metal-matrix composites (MMC) with 5 and10% (vol.) of TiC and TiB were fabricated in this study using blended elemental powder metallurgy (BEPM) of hydrogenated Ti. Post-sintering hot deformation and annealing were sometimes also employed to improve the microstructure and properties. Structure of materials were characterized using light optical microscopy, scanning electron microscopy, electron backscattered diffraction, x-ray microscopy, tensile and 3-point flexural tests. The effect of various fabrication parameters was investigated to achieve desirable microstructure and properties of layered materials. Using optimized processing parameters, relatively large multilayered plates were made via BEPM and demonstrate superior anti-ballistic performance compared to the equally sized uniform Ti-6Al-4V plates fabricated by traditional ingot and wrought technology

Argumentar elaboraciуn of typical scenarios of actions crowd for adaptation into system of vocational training the staff of military units and military division of internal armies of the ministry of internal affairs of ukraine to performance for service an

Обґрунтовано розроблення наборів типових сценаріїв дій натовпу для адаптації у систему підготовки особового складу частин та підрозділів внутрішніх військ МВС України до виконання службово-бойових завдань. Проведено аналіз поведінки натовпу, наведена класифікація видів натовпу і визначено поняття “динаміка натовпу” для застосування у службово-бойовій діяльності внутрішніх військ. Запропоновано варіанти сценаріїв можливих типових дій агресивного натовпу для удосконалення заходів професійної підготовки у внутрішніх військах МВС України.Обоснована разработка наборов типовых сценариев действий толпы для адаптации в систему профессиональной подготовки личного состава частей и подразделений внутренних войск МВД Украины к выполнению служебно-боевых задач. Проведено анализ феномена толпы, приведена классификация видов толпы и определенно понятие “динамика толпы” для использования в служебно-боевой деятельности внутренних войск. Предложен вариант сценариев возможных типовых действий агрессивной толпы для усовершенствования мероприятий профессиональной подготовки во внутренних войсках МВД УкраиныIt is carried out the analysis of a phenomenon of crowd, classification of kinds of crowd is resulted and the concept “dynamics of crowd” for use in for service and combat activity of internal armies is certain. The variant of scenarios of possible typical actions of aggressive crowd for improvement of actions of vocational training in internal armies of the Ministry of Internal Affairs of Ukraine is offered

Significant hardening effect of high-temperature aging of alloy Ti-6Al-4V composite reinforced with TiC

Titanium alloy composites, reinforced with a light second phase and made using inexpensive powder metallurgy, attract considerable attention due to the directness of their intentional hardness increase without compromising low weight of materials. In this study the metal-matrix composites (MMC) of Ti-6Al-4V alloy reinforced with light and hard particles of TiC (up to 80%, vol.) were made using blended elemental powder metallurgy of hydrogenated titanium. Post-sintering solution treatment for 45 min. at 880 °C and 1000 °C and water quenching followed by the 5 hrs. aging at 550 °C was used to additionally refine the microstructure and properties of MMC. For the duration of thermal exposure throughout solution treatment and additional aging the matrix and reinforcement phase underwent distinct structural changes that modified the mechanical properties of materials. It has been shown that the used reinforcement presents an exceptional opportunity for hardening of Ti-based composites without compromising their low specific weigh. It can increase the hardness of material by more than 40% due to the ability of TiC to chemically react with the matrix to form a strong interfacial bond and its ability to form hard compounds of Ti2C and Ti3AlC in the expense of the relatively soft matrix alloy