Search

Several statistical distributions are used in generating synthetic temperature data such as normal, gamma and others distribution. However, selecting a best marginal distribution from a variety of distribution is time consuming. If the marginal distribution is misidentified, it led to the underestimation of multivariate model. Hence, this synthetic temperature data failed to represent the actual temperature data. Therefore, a more accurate and general application of probability distribution and a study on how to reduce the discrepancy between variance of observed and synthetic data are needed. In this study, the values of the synthetic variances are observed by incorporating the appropriate level of dependence among the individual monthly amount. Three selected meteorological stations which are Alor Setar, Bayan Lepas and Chuping are used from January 1994 to December 2017. The gamma distribution is proposed to fit the marginal distribution which will be used later to transform the data to uniform unit formed. The correlation coefficient is calculated. Next, the synthetic data will be generated using skew-t copula and the correlation coefficient will be noted. The correlation coefficient of the observed data will be matched to the correlation coefficient of the synthetic data. The result shows gamma distribution is suitable for modelling the marginal distribution of the temperature data. It is found that the skew-t copula can be used to generate synthetic temperature data that is close to the observed data with strong correlation values between the temperature stations. It also shown that the skew-t copula is ideal for modelling synthetic temperature data for strong correlated stations. The synthetic generation of temperature data is important in cases where data is limited or unavailable. The copula model is also expected to reflect approximately real situation of the temperature data in Malaysia that can support flood risk management. [ABSTRACT FROM AUTHOR]

In hot and humid climates thermal discomfort is a major problem to the occupants of many residential terrace houses especially when they are not equipped with an air-conditioning system. This paper presents a study on an assessment of the level of thermal comfort in a naturally ventilated residential terrace house in Malaysia using computational fluid dynamics (CFD) method. Actual measurements were made to obtain the average air temperature, relative humidity and air flow pattern in various sections of the house. CFD simulations were conducted on a simplified model of the house to predict and visualize the temperature distribution and air flow pattern and its velocity in the house. The level of thermal comfort in the house was found to be well outside the comfort limits as specified by ASHRAE standards. [ABSTRACT FROM AUTHOR]

Currently the world's second largest palm oil producer Malaysia produces large amount of oil palm biomass each year. The abundance of the biomass introduces a challenge to utilize them as main feedstock for heat and energy generation. Although some oil palm parts and derivatives like empty fruit bunch and fibre have been commercialized as fuel, less attention has been given to oil palm fronds (OPF). Initial feasibility and characterization studies of OPF showed that it is highly feasible as fuel for gasification to produce high value gaseous fuel or syngas. This paper discusses the experimental gasification attempt carried out on OPF using a 50 kW lab scale downdraft gasifier and its results. The conducted study focused on the temperature distributions within the reactor and the characteristics of the dynamic temperature profile for each temperature zones during operation. OPF feedstock of one cubic inch in individual size with 15% average moisture content was utilized. An average pyrolysis zone temperature of 324°Cand an average oxidation zone temperature of 796°Cwere obtained over a total gasification period of 74 minutes. A maximum oxidation zone temperature of 952°Cwas obtained at 486 lpm inlet air flow rate and 10 kg/hr feedstock consumption rate. Stable bluish flare was produced for more than 70% of the total gasification time. The recorded temperature profiles produced closely similar patterns with the temperature profiles recorded from the gasification of woody materials. Similar temperature profile was obtained comparing the results from OPF gasification with that of woody biomass. Furthermore, the successful ignition of the syngas produced from OPF gasification ascertained that OPF indeed has a higher potential as gasification feedstock. Hence, more detailed studies need to be done for better understanding in exploiting the biomass as a high prospect alternative energy solution. In addition, a study of the effect of initial moisture content of OPF feedstock on the temperature distribution profile along the gasifier bed showed that initial moisture content of feedstock in the range of 15% gives satisfactory result, while experiment with feedstock having higher moisture content resulted in lower zone temperature values. [ABSTRACT FROM AUTHOR]