Search Results (3)

Explosion chambers are crucial to the technology used to prevent coal mine gas explosions. Investigating the shock wave propagation law at various coal mine tunnel cross-sections helps ensure mine safety. A self-built, highly explosive experimental setup was used to conduct empirical research on straight tubes, eight sizes of single-stage explosion chambers, and multi-stage tandem explosion chambers. Ansys Fluent numerical simulation software constructed five different tandem explosion chamber models. The wave dissipation efficiency of various types of explosion chambers was calculated, the propagation law and process of shock waves across multiple explosion chambers were examined, and the best size and type of explosion chambers were summarized to increase the wave dissipation efficiency of single-stage explosion chambers. Gun silencers inspired these models. The findings indicate that the three-stage tandem explosion chamber is the best diffusion tandem combination form, the 60° silencer-type explosion chamber is the best single-stage explosion chamber modification program, and the 500 mm × 500 mm × 200 mm explosion chamber is the best single-stage explosion chamber. Full article

With the rapid development of the military industry and the increasing focus on the safety of those in these fields, there is an increasing search for solutions to existing and emerging weapons for the user and the environment. In this case, components for firearm suppression are used to reduce the effects of noxious impulse sound, to minimize the severity of the weapon’s recoil to the user’s body, and maintain important accuracy, maneuverability and other parameters. The analysis and investigation of silencer designs can provide essential values for acoustic characteristics that reduce risk in real situations. The gun silencer analysis was performed in two steps. The modeling processes of the silencer configuration were performed to choose the optimal construction, and the main parameters were selected, including different angles and forms of the tilt. The angle of inclination of the partitions was changed to 60° and 135°. Due to the reduced results observed in the last zones with closed cavities and created additional configurations, the number of partitions was shortened by three partitions and the angle of inclination was adjusted to 60°; the simulation of the initial variant was also supplemented with 135° partitions. The second step was an experimental validation of the optimal tilt angle and form according to the modeling data. The silencer was found to achieve a sound pressure damping value and the sound pressure level during the shot was reduced to below a dangerous level. The search to find the optimal configurations will lead to the parameters of production and efficiency. Full article

The green fluorescent protein (GFP) of jellyfish (Aequorea victoria) has significant advantages over other reporter genes, because expression can be detected in living cells without any substrates. Recently, epigenetic phenomena are important to consider in plant biotechnology experiments for elucidate unknown mechanism. Therefore, soybean immature cotyledons were generated embryogenesis cells and engineered with two different gene constructs (pHV and pHVS) using gene gun method. Both constructs contain a gene conferring resistance to hygromycin (hpt) as a selective marker and a modified glycinin (11S globulin) gene (V3-1) as a target. However, sGFP(S65T) as a reporter gene was used only in pHVS as a reporter gene for study the relation between using sGFP(S65T) and gene silencing phenomena. Fluorescence microscopic was used for screening after the selection of hygromycin, identified clearly the expression of sGFP(S65T) in the transformed soybean embryos bombarded with the pHVS construct. Protein analysis was used to detect gene expression overall seeds using SDS-PAGE. Percentage of gene down regulation was highly in pHV construct compared with pHVS. Thus, sGFP(S65T) as a reporter gene in vector system may be play useful role for transgenic evaluation and avoid gene silencing in plants for the benefit of plant transformation system. Full article