Volume 9 (1997)
Table of Contents
Table of Contents
A Study on Erosion of Soft Sediment Deposits
Erosional pattern of fine cohesive sediment must be defined to predict the transport model in estuarial water Resistance to erosion is largely dependent on physicochemical properties of sediment and fluid, as well as the interparticle bond which is characterized by shear strength. Successively incremental flow-induced bed shear stress is applied to initiate layer by layer erosion of soft cohesive sediment deposit to determine the rate of erosion. A decrease in erosion rate is observed at the end of each time step. This behavior is due to the increasing shear strength with depth. The rate of erosion was found to vary exponentially with cubic root of excess bed shear stress.
Design of Neural Networks for Fault Diagnosis of a Distribution System
The application of a hierarchical distributed neural network to fault diagnosis of a distribution system is presented. The artificial neural network (ANN) design has been developed by considering the structure and functions of the distribution system. Three hierarchical distributed ANN modules are considered for the fault diagnosis of the distribution system. The proposed diagnosis system has been designed for a practical Tenaga Nasional Berhad (TNB) distribution system. In the ANN training process, the data sets are generated using the logic operation of relays and circuit breakers corresponding to the respective fault location for cases of single and multiple faults. The simulation results show that the proposed method using ANNs is encouraging and that the method can be in an on-line environment.
Lateks sebagai Bahan Tambah kepada Konkrit Asfalt (Latex as Additives to Asphalt Concrete)
Mixing a small quantity of latex into bitumen in the road surface construction was found to increase its age and strengths. It was found by mixing 6% latex into bitumen to be the optimum content to increase its age. However this mixture was too viscous and to the extent of reducing its workability. In this Study, the characteristics of concrete asphalt using 6% latex by weight of the bitumen were compared with the natural bitumen and with the bitumen mixture comprising of 3% latex. The 3% latex was chosen because Kuala Lumpur City Hall and Public Works Department have fixed a 3% latex content in asphalt concrete pavement. Marshall specimens were prepared for the three types of bitumen mixture and were tested and analysed. All these specimens passed the Marshall stability tests. The 3% bitumen latex mixture has increased the Marshall stability from 7.73 kN to 13.30 kN but has increased the optimum bitumen content from 5.05% to 5.14% when compared to the natural bitumen. Nonetheless, the 6% bitumen latex mixture has increased the Marshall stability to 12.17% and has reduced its bitumen optimum content to 4.95%.
Penggunaan Elektrod Filem Nipis Emas dalam Analisis Enzim secara Konduktometri (Use of Glod Thin Film in Enzyme Analysis by Conductometry)
A characterization study of thin film gold electrode was performed. The electrode was fabricated using d. c. sputtering technique and analysis was conducted by dip-in method. A microliter plate well was used as the cell for this system. Test was done at room temperature where the exact temperature was entered manually and corrected by conductivity meter (WTW model 539) at a reference temperature of 25°C. The electrode has a good reproducible characteristic (p < 0.05) with response time of one minute and recovery time of one to three minutes. Its application as an analytical tool was shown in determination of Michaelis constants in enzyme kinetic study. Urease was chosen as a model enzyme and urea was used as a substrate. Km value obtained was 3.46 mM and Vmax was 1.930 μScm-1/min.
A Software Design Tool for Microwave Radio
This paper deals with wave propagation calculation and cost optimization software development for microwave radio. The software presents a design tool for line of sight link planning. The main cost factor in a microwave network depends on tower structure and antenna heights. Antenna heights are normally chosen to overcome the first Fresnel zone obstruction. A software tool for the analysis and evaluation of a single microwave relay link has been developed. In addition, cost optimization method for a microwave radio network involving more than two antennas has been developed. This paper includes calculations and analysis of the geographical data in the chosen area in order to determine the effective earth’s radius to achieve better optimization. In addition, terrain profile generation and microwave point-to-point link calculation was considered.
Pakej Pembelajaran Sistem Enjin Diesel (Learning Package of Diesel Engine System)
The process of designing a diesel engine learning package is described, covering all the aspects from equipment to the programming language which are used to develop the system. This package is developed to help users understand how the diesel engine system works. Besides it could be used as a teaching aided tool to help the instructor at the higher learning institutions. Such package could also be resided into internet system, which is useful for distance learners. It is an informative package. The information covers all aspects of component, systems and fault-finding related to the diesel engine operations. The package was developed using Schooner Version 2.01.
Comparison of Rain Prediction Models to be Used in the Equatorial Region
Rain will cause serious attenuation on microwave signals transverse in the atmosphere. Rain attenuation strongly depends on rain attributes. This paper reports the comparison of three models of ]-min. rain rate cumulative distribution for estimating signal attenuation due to rain in the equatorial region. The models are Rice-Dutton (RHDD) model, Tattelman-Scharr (TS) model and Moupfouma model.