SOOT PARTICLE TRAJECTORIES OF A DI DIESEL ENGINE AT 18° ATDC CRANKSHAFT ANGLE

Among the major pollutants of diesel engine is soot. Soot is formed as an unwelcomed product in combustion system. Soot emission to the atmosphere leads to air global warming and health problem. Furthermore, deposition of soot particle on cylinder wall contaminates lubricant oil hence increases its viscosity. This reduces durability of lubricant oil, causing pumpability problems and increasing wear. Therefore, it is necessary to study soot formation and its movement in diesel engines. This study focuses on soot particle trajectories in diesel engine by considering diameter of soot particles that were formed at 18° ATDC crankshaft angle. These soot particle movement are under the influence of drag force with different radial, axial and angular settings and simulated by using MATLAB routine. Mathematical algorithm which was used in the MATLAB routine is trilinear interpolation and 4th order of Runge Kutta. Simulation was carried out for a combustion system of 4 valves DI diesel engine from inlet valve closing (IVC) to exhaust valve opening (EVO). The results show that small diameter of soot particles were transferred near the cylinder wall while bigger soot particle mostly moved in inner radius of the combustion chamber

Synthesis and elastic behaviour of borate glass doped with high tellurite content

A systematic series of quality binary glass system of (x)TeO2)-(1-x)B2O3 with x = 60 to 80 (wt. %) were successfully synthesized by the rapid quenching method. The densities of each glass samples were determined using Archimedes method with acetone as a floatation medium. The molar volume have been estimated and analyzed for borate glasses doped with tellurite. Ultrasonics methods have been used to study the elastic properties of TeO2B2O3 glasses where the sound wave velocities have been measured in each glass samples at a frequency of 15 MHz and at room temperature. The velocities, both longitudinal and transverse, increase linearly with increasing of TeO2 content in a borate glass network. Their elastic moduli such as longitudinal, Young's, bulk and shear modulus have been calculated as a function of TeO2 concentration. Poisson's ratio and Debye temperature were also found to increase nonlinearly with TeO2 concentration. The glass transition temperature were determined by the differential thermogravimetric analysis at heating rate of 20 K min-1. However the glass transition temperature (Tg) slowly decrease as more tellurite is added into the borate glass network. © 2006 Asian Network for Scientific Information

Neuroprotective effects of glucomoringin-isothiocyanate against H₂O₂-Induced cytotoxicity in neuroblastoma (SH-SY5Y) cells

Neurodegenerative diseases (NDDs) are pathological conditions characterised by progressive damage of neuronal cells leading to eventual loss of structure and function of the cells. Due to implication of multi-systemic complexities of signalling pathways in NDDs, the causes and preventive mechanisms are not clearly delineated. The study was designed to investigate the potential signalling pathways involved in neuroprotective activities of purely isolated glucomoringin isothiocyanate (GMG-ITC) against H₂O₂-induced-induced cytotoxicity in neuroblastoma (SH-SY5Y) cells. GMG-ITC was isolated from Moringa oleifera seeds, and confirmed with NMR and LC-MS based methods. Gene expression analysis of phase II detoxifying markers revealed significant increase in the expression of all the genes involved, due to GMG-ITC pre-treatment. GMG-ITC also caused significant decreased in the expression of NF-kB, BACE1, APP and increased the expressions of IkB and MAPT tau genes in the differentiated cells as confirmed by multiplex genetic system analysis. The effect was reflected on the expressed proteins in the differentiated cells, where GMG-ITC caused increased in expression level of Nrf2, SOD-1, NQO1, p52 and c-Rel of nuclear factor erythroid factor 2 (Nrf2) and nuclear factor kappa-B (NF-kB) pathways respectively. The findings revealed the potential of GMG-ITC to abrogat