Engineering, Technology & Applied Science Research

381-386

Authors: R. Marin Galvin, J. M. Rodriguez Mellado

The THM level in the Spanish drinking water is limited to less than 0.100 mg/L, due to its potential toxicological effect on humans. This paper investigates the comparison of the results obtained in a small supply of water that historically presented THM contents out of the Spanish normative, versus the results there obtained when the treatment was modified with the inclusion of a nanofiltration system. So, the conventional treatment first applied was that of pre-oxidation with chlorine and/or KMnO4, followed by coagulation with aluminum salts directly on closed sand filter, and disinfection final by chlorination: with this system, THM levels lower than 0.100 mg/L were not always secured. Thus, to improve the water quality, a full system of nanofiltration was implemented, after the above treatment, consisting in: pre-filtration through cartridges, filtration over activated carbon, post-filtration for retaining impurities, and finally, nanofiltration and chlorination of water after nanofiltration. In this order, the new treatment scheme has usually produced water with maximum THM levels of 0.058 mg/L, and average values of 0.013 mg/L, 0.30 mg/L for organic matter concentrations, and water always microbiologically pure. Also, the contents of Fe, Mn and Al in the treated water were significantly reduced with respect to the previous situation without nanofiltration.

391-395

Authors: B. Nayak, S. S. Dash

This paper presents the analysis for different control techniques in Z-source inverters. The voltage gain versus modulation index from simulation result is compared with the mathematical calculated voltage gain. Further detailed analysis of %THD, %harmonics of output voltage at different modulation indexes for different boosting techniques of a Z-source inverter are also performed with respect to the traditional VSI by MATLAB based simulation

402-407

Authors: E. A. Ogbonnaya, R. Poku, E. Adigio

In order to keep focus on the important agenda of sustainability which has lately become an issue of priority, the maritime industry must implement technologies on existing vessels and on those under construction so as to reduce their emissions into the environment. This study examines three potential sources of emission and also identifies a set of emission control measures that are available and could, if fully applied, reduce emission by 19.058%. With the waste heat recovery system, about 2500 kW of energy are saved, thereby increasing the efficiency to 59.11% having about 10.13% gain compared to engines without a waste heat recovery system. It is therefore recommended that the use of waste heat recovery systems should be encouraged on marine vessels to reduce the impact of noxious gasses into the atmosphere.

413-415

Authors: L. Caccetta, M. Alameen, M. Abdul-Niby

This paper proposes an effective hybrid approach that combines domain reduction with the Clarke and Wright algorithm to solve the capacitated vehicle routing problem. The hybrid approach is applied to solve 10 benchmark capacitated vehicle routing problem instances. The dimension of the instances was between 21 to 200 customers. The results show that domain reduction can improve the classical Clarke and Wright algorithm by about 18%. The hybrid approach improves the large instances significantly in comparison with the smaller size instances. This paper will not show the time taken to solve each instance, as the Clarke and Wright algorithm and the hybrid approach took almost the same CPU time.