Preliminary Study of CST in Malaysia based on Field Optical Efficiency

Solar is one of the many sources of renewable energy, and Concentrating Solar Tower (CST) is one of the most potential technologies in extracting solar energy. Thermal efficiency of CST is high and suitable to be implemented in a tropical climate country such as Malaysia which is located between at 10 to 70 North latitude and 1000 to 1200 east longitude. Further, Malaysia's direct normal irradiation (DNI) in tropical climate is almost constant throughout a year with the irradiation around 1500 to 2000 kWh/m2. Therefore the aim of this paper is to mathematically calculate the CST field layout in Malaysia in term of thermal efficiency based on cosine efficiency, atmosphere efficiency and mirror efficiency. The preliminary result from this paper shows Malaysia is a suitable location to develop CST with average of atmospheric transmittance efficiency and cosine efficiency of 94% and 63% respectively and the overall optical field efficiency is 52%. In addition, the atmospheric transmittance and cosine efficiency has high value but the efficiency gradually decreases whenever the distance increases. Nevertheless further investigation in term of solar irradiation and raining pattern in Malaysia is needed

Comparison of Soot Particle Movement based on Crank Angle

In a diesel engine, soot was produced due to incomplete fuel combustion in a combustion chamber. Some of this soot sticks to the cylinder wall and interferes with lubricant oil. This soot causes the lubricant oil to contaminate and this increases its viscosity. Contamination of lubricant oil is one of the major causes of engine wear. Therefore, the focus of this study is on soot movement in diesel engine that is the initial step to avoid contamination of lubricant oil. This work uses the data of the formation of soot particles from Kiva-3 v obtained from previous investigation and then simulated it by a Matlab routine. Kiva-3 v produced velocity vectors of the soot, fuel, temperature, pressure and others. Matlab routine uses trilinear interpolation and fourth order Runge Kutta method in order to calculate soot movement in a combustion chamber. In addition, the influence of drag force is considered in the calculation to achieve a higher accuracy. The objective of this study is to compare soot particle movement between 8° ATDC and 18° ATDC. Results show that 8° ATDC has a high risk to contaminate lubrication oil in certain location compare to 18° ATDC

A Pilot Study Comparing Aortic Valve Area Estimates Derived from Fick Cardiac Output with Estimates Based on Cheetah-NICOM Cardiac Output.

Contains fulltext : 221539.pdf (publisher's version ) (Open Access)Cardiac output during cardiac catheterization is often estimated using the modified Fick method (CO(Fick)). In this proof-of-concept, prospective non-randomized study carried out in a single academic healthcare centre, we examined whether replacing CO(Fick) in the Gorlin formula with Cheetah-NICOM monitor cardiac output (CO(Cheetah)) could produce an accurate and precise estimate of aortic valve area in patients with severe aortic stenosis. In twenty-six subjects, CO(Fick) and CO(Cheetah) were obtained concurrently. A spot and 3-minute running average of CO(Cheetah) was used. Bland and Altman analysis was used to derive bias, 95% limits of agreement (LOA) and confidence intervals (CI). The mean difference (bias) between AVA(Cheetah) (average) and AVA(Fick) was 0.11 cm(2) and the 95% LOA were ±0.42 cm(2). The 95% CI of the bias was 0.02-0.2 cm(2). The bias and 95% LOA of AVA(Cheetah) (spot value) were 0.14 ± 0.42cm(2), with a 95% CI of 0.06-0.23 cm(2). No proportional bias was present. AVA(Cheetah) thus appears to be a reasonably accurate measure of AVA in patients with severe aortic stenosis compared to AVA(Fick) measured using a modified Fick CO. However, the limits of agreement were not narrow enough to consider AVA(Cheetah) and AVA(Fick) interchangeable