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The study gives a general overview of the CFD-simulated gas flow via the nozzle of a De Laval rocket engine. In CFD software, the mesh is generated using the nozzle’s geometry. In this work, CFD methods are used to compare a number of factors with those derived from classical theory, such as pressure, velocity, temperature, and arear ratios. The results of computational modelling of CFD simulation are comparable to those found from theoretical calculations.

Firers normally try to maintain the point of aim on the target when shooting as well as the maximum shifting allowable to ensure that their projectiles are still able to hit target. The shifting of hit position in the vertical direction has relationship with the angle of departure (AoD). The effect of changes to AoD above the limit could cause the target to be missed. Maintaining AoD during firing is difficult especially for small arm weapons. In this study, the prediction of projectile trajectory using six degrees of freedom (6-DOF) is conducted using the PRODAS modelling program to study the allowable limit of change of AoD in the vertical direction during firing that causes change to the height of hit on the target according to specified distance. The static target in the modelling program is assumed as a personnel. The small arm weapon calibres selected based on the target suitability are 5.56, 7.62 and 9 mm. The results obtained show that changing AoD would change the trajectory of the projectile and the position of hit on the target. It would miss the target at the range intended to hit if change of AoD is more than is allowed. Therefore, the firer needs to maintain the AoD when pulling the trigger of the gun in order to hit the target. [ABSTRACT FROM AUTHOR]

Background: Several compounds isolated from Dryobalanops have been reported to exhibit cytotoxic effects to several cancer cell lines. This study investigated the cytotoxic effects, cell cycle arrest and mode of cell death in ampelopsin E-treated triple negative cells, MDA-MB-231. Methods: Cytotoxicity of ampelopsin E, ampelopsin F, flexuosol A, laevifonol, Malaysianol A, Malaysianol D and nepalensinol E isolated from Dryobalanops towards human colon cancer HT-29, breast cancer MDA-MB-231 and MCF-7, alveolar carcinoma HeLa and mouse embryonic fibroblast NIH/3 T3 cells were determined by MTT assay. The cells were treated with the compounds (0.94-30 µM) for 72 h. The mode of cell death was evaluated by using an inverted light microscope and annexin V/PI analysis. Cell cycle analysis was performed by using a flow cytometer. Results: Data showed that ampelopsin E was most cytotoxic toward MDA-MB-231 with the IC50 (50 % inhibition of cell viability compared to control) of 14.5 ± 0.71 µ M at 72 h. Cell shrinkage, membrane blebbing and formation apoptotic bodies characteristic of apoptosis were observed following treatment with ampelopsin E. The annexin V/PI flow cytometric analysis further confirmed that ampelopsin E induced apoptosis in MDA-MB-231 cells. Cell cycle analysis revealed that ampelopsin E induced G2/M phase cell cycle arrest in the cells. Conclusion: Ampelopsin E induced apoptosis and cell cycle arrest in MDA-MB-231 cells. Therefore, ampelopsin E has the potential to be developed into an anticancer agent for treatment of triple negative breast cancer. [ABSTRACT FROM AUTHOR]