Siti Fazlili Abdullah

Taguchi Optimization of a SiGe/Si Quantum Dot SOI-Based Lateral PIN Photodiode

A high performance lateral silicon photodiode was designed on a Silicon–on-insulator (SOI)-based substrate with SiGe/Si quantum dot technology. The device has the potential of being a serious candidate for applications in sensing applications as well as in optical fiber communications. Five device process parameters and two device noise factors were identified to make the virtual device design insensitive to variation in the selected fabrication parameters. An L9 array from Taguchi method was used to optimize the device design. The simulator of ATHENA and ATLAS were used for photodiode fabrication process and electrical characterization, respectively. The results obtained for responsivity and frequency response after the optimization approach were 0.36 A/W and 21.2 GHz respectively which correspond to the optimization value for the intrinsic region length of 6 μm, photo-absorption layer thickness of 0.505 μm, incident optical power of 0.5 mW/cm2 and bias voltage of 3.5 V. As a conclusion, the optimum solution in achieving the desired high speed photodiode was successfully predicted using Taguchi optimization method.

Friction measurement system using load cell for Tribotronic system on Pin-On-Disc (POD) tribometer

This paper discusses part of Tribotronic system on Pin-On-Disc (POD) Tribometer focusing on friction measurement using load cell. The analysis conducted using MATLAB software to measure Coefficient of Friction (CoF) of 2 sample types in order to prove the validity of the measurement. The 2 samples are lubricant (Shell Helix Fully synthetic oil) and lubricant (Shell Helix Fully synthetic oil) with additive. It is revealed that the measurement of the lubricant with additive shows better CoF (0.006) than lubricant without additive, CoF of 0.02.

Charge transport of novel blue dibenzothiophene phenylenediamine copolymer

We report the charge transport characteristics of dibenzothiophene phenylenediamine copolymer (DBT-PD). Fig. 1 shows DBT-PD (Mw = 77,000) which is a 50∶50 molar ratio random copolymer consisting of DBT and a hole-transporting phenylenediamine group with tertiarybutyl substituents. The quoted ratio is of the starting monomers introduced into the reaction and may change slightly after polymerization due to differences in reactivity, possible side reactions and so on. Arylamine moieties of the type used here are extensively utilised in LED and photodetector materials due to their very good hole transport properties, low ionisation potentials (facilitating hole injection) and overall stability to oxidation [1]. They have been widely used in xerographic applications for many years.

A techno-economic analysis of biogas plant from palm oil waste

Renewable energy is one of the vital sources to meet partially the global energy demand of developed as well as developing countries. Biogas plant can be one of the major sources of renewable energy in Malaysia as huge amount of palm oil waste is available. Biogas plant can be of different types of which fixed dome and floating cover are in use in many countries for many years. The bag design is becoming popular in many countries. The fixed dome design is used in various palm oil mills. The generated gas can be used for cooking, lighting, power generation and the sludge can be used as fertilizer for land. Palm oil waste is easily available and inexpensive, the major share of costs are incurred at the initial stage. The operating and the maintenance costs are quite low. In the present work an attempt has been taken to study the technological parameters for commonly used fixed dome biogas plant for two different sizes. The costs related to the fabrication of plant are collected from various sources and the other items were estimated on the basis of available information. Net present worth, internal rate of return, benefit cost ratio and payback period were calculated. On the basis of calculated values it was found that the biogas plant is economically viable and viability increased with the increase of plant size. The technological suitability in the context of prevailing situation, economic viability and future scope of biogas plants has been evaluated. The findings of this study would give some directions and guidelines for future planning and implementation of biogas plants in Malaysia.