Volume 8 (1996)
Table of Contents
Table of Contents
Modelling of Solid Waste Incineration
A model for incineration of municipal solid wastes was formulated based on material and energy balances and reaction kinetics. The model was tested for various air supply rates. The study has given a picture of variations in the incineration chambers. The simulations has also shown that the slowest stages in the incineration process is the initial feed heating and the water vapourisation.
Prediction of Voltage Collapse in Electric Power Systems
With the increased loading and exploitation of the power transmission system, the problem of voltage instability and voltage collapse has become a growing concern. Voltage instability of large power systems has been considered as a complex problem due to the large number of power system components participating in the voltage collapse process. As a result, two distinct methods have been adopted for voltage stability analysis, that is, the power flow based static method and the time simulation based dynamic method. This paper analyses the basic mechanism of voltage collapse by using the static and dynamic load models. A newly developed indicator using the line stability factors is proposed with the aim of predicting voltage collapse in transmission networks. The mathematical concept of the line stability factors is explained and the factor which acts as indicator of proximity to voltage collapse is defined such that it varies in the range between 0 (system stable) and 1 (voltage collapse). The line stability factors are easily calculated and uses information of a normal load flow. Tests carried out by using the line stability factors as indicators of proximity to voltage collapse illustrate the advantages and simplicity of using the factors. The prediction of voltage collapse caused by a uniform increase of the load as well as due to other contingencies such as line outage and step increase in mechanical load, is accurately obtained by using the line stability factors.
|3.||Kesan Belok ke Kiri Semasa Merah terhadap Kapasiti Persimpangan Berlampu Isyarat (Effects of Left Tum During Red to the Capacity of Signallised Junction)
Ismail Abdul RahmanAbstract
This paper discusses the increase in capacity of the approach road and signallised junction with the implementation of left turn during red. The factors that influenced the effectiveness of this strategy are also discussed in addition to the steps undertaken in estimating the actual capacity obtained with the implementation of this strategy. Data obtained from the study site was analysed manually and using the Signalized Intersection Capacity Analysis and Highway Capacity softwares. Results of analyses indicated that the increase in approach capacity of up to 15.8% and the total junction capacity of 5.4% were obtained with the implementation of this strategy.
Density of Statically Deposited Bed
Variation of density for statically deposited cohesive sediment bed was investigated under the effect of salinity and consolidation period. The density of natural mud and kaolinite bed was found to increase with depth. This was due to the variation in initial suspension concentration and overburden. Salinity is found to have little effect on bed density, while consolidation causes the bed density to increase with depth. Overall density for kaolinite is higher than natural mud. The density profile for seven test beds is nearly S shape.
Shear Strength Characteristics of an Estuarine Bed
Shear strength of estuarine low strength clay deposit is characterized by the interparticle bonds which must be broken to initiate erosion. The bonding strength is influenced by the physico-chemical factors prevailing in the estuarine environment. Successively incremental flow-induced bed shear stress is applied to induce layer by layer erosion of soft sediment deposit to determine the shear strength. Thickness of each eroding layer is noted. In general, shear strength τ s increases with depth. Salinity and bed consolidation period influence the shear strength behavior. A sudden decrease in erosion rate was observed for a greater value of characteristic shear stress.
A Simplified Elastic Composite Floor Section Analysis with Incomplete Interaction
This paper presents a simplified partial interaction elastic analysis of composite floor panels. A theoretical analysis is carried out on repeating section composing of two elastic beam elements connected longitudinally by linearly elastic connection. The analysis is based on the assumption that a continuous imperfect connection exists between the two separate elements. By applying method of elastic equivalence, expressions for stiffness along the major axis of such composite section is developed. Results obtained from the authors’ full scale experimental studies involving profiled steel sheet/dryboard composite floor panels are compared with results obtained from the simplified expressions, and with theoretical results obtained by other researchers. It is concluded that these expressions are able to predict with reasonable accuracy the behaviour of composite floor panels.
Out-of Plane Bending Stiffness Along the Major Axis of Profiled Steel Sheet Dryboard Composite Floor Panels
This paper presents the experimental investigation of the out-of plane bending behaviour of newly developed composite floor panels namely Profiled Steel Sheet Dryboard (PSSDB) composite panels. Such panels are formed by attaching dryboards to a core of profiled steel sheeting using mechanical connectors. It is very light and therefore easily transportable and can be erected quickly by semi-skilled labour. A series of out-of plane bending tests to investigate the overall structural performance, and the influence of connector modulus and spacing on the performance of the PSSDB panels will be described. The suitability of the component materials for these panels is also investigated. It will be shown that connector modulus and spacing play major roles in influencing the stiffness of such composite panels. Suitable choice of connector and spacing is important in determining the stiffness of these panels. Partial interaction approach developed by the authors can safely be used to design composite PSSDB floor panels along the major axis of bending. This theoretical approach will be shown to be giving acceptable conservative stiffness values.