The Poleward Transport of Heat by the Atmosphere

A warm low pressure and a cold high pressure imply the contribution of potential energy to kinetic energy. In the tropics, this represents the typical situation of the Hadley cell, also known as a direct cell. On the other hand, a cold low pressure and a warm high pressure indicate the contribution of the mean kinetic energy to the mean potential energy, which represents the typical process of the Ferell cell (also referred to as an indirect cell). This paper examines the poleward heat transport of the atmosphere. It is noted that eddies play the primary role in poleward heat transport. Furthermore, this is the way the atmosphere counterbalances the deficit of radiation at polar latitudes

The Role of the Available Potential Energy in the Atmosphere

A major problem in atmospheric energetic dynamics is addressed. In using a particular mathematical derivation it is verified that 0.5% of the total potential energy is available for conversion into kinetic energy

Surface Circulation off Kuala Terengganu in the Transitional Period between the Northeast and Southwest Monsoons

The aim of this investigation is to understand the surface current circulation pattern off Kuala Terengganu. A drifting drogue was used to measure surface current during April 1993, the transitional period between the northeast and southwest monsoon seasons. Our results show that the drifting drogue moves in an almost circular motion, suggesting the presence of an eddy. However, further studies are needed to confirm the existence of an eddy off Kuala Terengganu during the transitional period

The Relative Growth Rates of the Two-dimensional and Three-dimensional Waves in the Atmosphere

Using a simple analysis the growth rate of two-dimensional and three-dimensional waves in the atmosphere is addressed. It is verified that a two-dimensional wave grows faster than a three-dimensional wave

Rainfall in Sarawak

Objektif utama manuskrip ini adalah untuk memahami, dalam konteks bulanan, keamatan taburan hujan dan taburan hari hujan di negeri Sarawak. Keputusan kami menunjukkan bahawa: (a) tiada korolasi jelas antara jumlah hari hujan (keamatan taburan hujan) dengan jumlah keseluruhan taburan hujan yang dicatatkan, dan (b) keputusan keamatan taburan hujan adalah tidak berpasangan dengan keputusan untuk jumlah hari hujan

Declining Production of Cockles in Relation to Ammonia Concentrations in Sungai Buloh River, Selangor

This research was conducted in Kampung Bagan, Sungai Buloh, one of the major areas for cockles farming in Selangor. Based on the Fisheries Annual Statistic Report 2000, issued by the Department of Fisheries Malaysia, the total production of cockle landings in Selangor was 6,922 mt utilizing 654 ha farming area with a production rate of 11 mt/ha. Meanwhile, in the 2011 report, the total production of cockle landings had increased remarkably to 26,505 mt with further expansion of 5,593 ha of cockle farming area. It shows an increasing number of productions and area of cockle’s farming. However, the production rates for 2011 had declined to 4.7 mt/ha. The declining of cockle’s production rate was due to several factors. One of the factors is high ammonia concentration in the water. To test this hypothesis, several water samples were collected from the site to test the ammonia concentration in the water by using the colorimeter base on Salicylate method. From these tests, the readings for ammonia concentration in the farm area ranged from 0.3 mg/L up to 4 mg/L. This indicates that ammonia concentration had exceeded the cockle maximum tolerance level towards ammonia. Thus, high ammonia concentration is one of the factors that cause cockles mortality resulting in declining of cockle production in Selangor. Keywords: Cockles, Ammonia concentration, production rat

Observation of temperature and velocity in the coastal water off Kuala Terengganu, Malaysia

Mooring observation of current and temperature was made at 17.8 m layer of 19 m depth about 8 km east to Kuala Terengganu, Peninsular Malaysia. Harmonic analysis was applied to tidal currents for 30 days in September 1993, and to the tides observed at Chendering. The K1 tide was the largest both in tidal currents and the tides. Daily mean temperature, currents, sea level, and winds were analyzed from September 1993 to May 1994. Northeast Monsoon from December to February caused sea level rise of 50 cm and temperature lowering of 1°C

Monthly Distribution of Precipitation in Peninsular Malaysia

A study was made of the monthly distribution of rainfall in Peninsular Malaysia. It is shown that the principal influence is given by the passage of the Inter tropical Convergence Zone (ITCZ), while the secondary influence is the effects of both the NE and the SW monsoon

On the Monthly Distribution of Precipitation in Sarawak

In this investigation the study of the monthly distribution of precipitation and the rainfall variability of Sarawak is addressed. The principal results of this manuscript may be summarized as follows; (i) the total amount rainfall of each station remains unchanged during the months of the southwest monsoon season, (ii) no definite inverse correlation between rainfall variability and precipitation has been established, and (iii) lesser values of rainfall variability are reported south of Sibu during the first six months of the year

Modelling and thermal analysis of organic rankine cycle with superheater and preheater

Escalating fuel prices and carbon dioxide emission are causing new interest in methods the waste heat rejected to the environment and at the same time that can minimize the usage of fuel. One viable means is the conversion of exhaust engine waste heat to a more useful form of energy. The aim of this study is to model and investigate the thermal performance of an Organic Rankine Cycle (ORC) system which is used as waste heat recovery of exhaust gas from a turbofan engine. A simulation study has been done on the ORC in two different types of system configurations in order to predict which design will give a better thermal performance. Parameters such as net power output and the ORC system efficiency are used to represent and compare the thermal performance of both of the designs. The simulation is done by using MATLAB and REFPROP. The selection of the best configurations is based on the thermal efficiency of the system. It is found that the ORC system with superheater gives a better thermal efficiency that the one with preheater. The results also show that thrust specific fuel consumption (TSFC) of the turbofan engine reach a lower value by using ORC with superheater instead of with preheater. Hence implementation of ORC system for waste heat recovery to an aircraft engine can bring a great potential to the aviation industry