Papers by Author: I. Daut

Abstract: Reduction in threshold current density is the major challenge in the field of semiconductor laser design. The threshold current density can be minimized by introducing low dimensional material system with narrow band gap. InN has a narrow band gap of 0.7 eV and quantum dot provides three dimensional confinement factor. In this paper, we propose then InN quantum dot as the active layer material that will serve both the purpose of narrow band gap and three dimensional confinement. The simulation results show that the current density reduces drastically with the cavity length.

Abstract: The power loss in laminated transformer cores is always greater than the nominal loss of the electrical steel laminations, by a factor known as the building factor. This paper discussed result of an investigation towards the effect of using two different Grain-Oriented Silicon Iron (3%SiFe) materials to the 100kVA three phase distribution transformer. The thicknesses of the material that have been used in this research are 0.23mm and 0.27mm. The transformer core will be assembled with 60o T-joint with 5mm mitred corner overlap length. Power loss has been measured using no-load test with 29 layer of lamination while nominal loss measured using Epstein test frame. At the operation mode flux density, 1.5T, the building factor of the transformer model core material with 0.23mm thickness is 1.219 while with the building factor for 0.27mm thickness is 1.250. This shows that thinner transformer core lamination is better than the other one by 2.5% during operation mode.

Abstract: This paper presents a case study of Weibull and Hargreaves methods used to determine the wind speed characteristic and solar radiation pattern in Perlis the northern part of Peninsular Malaysia. These two methods are then used to analyze the data of wind and solar that recorded using Davis Vantage Pro2 Weather Station. This paper also discusses the correlation of these two methods in determining the wind and solar energy. Through this case study, this paper conclude that these methods is highly recommended to determine and analyze the potential of wind and solar energy.

Abstract: In this paper, an in house production of a 0.5hp induction motor’s rotor is investigated. This investigation considers the induction motor’s efficiency and losses dissipation as an important aspect to determine the rotors efficiency. Through out this project, a new rotor which has 0.35mm steel sheet thickness and 10mm rotor bar slot size is constructed and compared with the existing rotor which has 0.50mm steel sheet thickness and 10mm rotor bar slot size. Once the construction phase of the rotor has been completed an in house motor experiment is done such as the no load, blocked rotor and dc resistance test. Result shows that thinner steel sheet (0.35mm) of the constructed rotor increase the efficiency up to 3.2% and reduces the losses to 17.2 watts compare to the thicker steel sheet rotor (0.5mm). An economical aspect is presented to show the amount of energy and money that can be saved from replacing the existing rotor (0.5mm) with a thinner rotor (0.35mm). As for the annual energy saving (AES) and total cost saving (TCS), the new rotor manage to save 138.7kWh per year and utility billing by RM45.51 per year per motor.