No abstract available

No abstract available

No abstract available

[en] In isotopes hydrological studies the input to the water bodies very much dependant on the meteoric water line, without which, the global meteoric water line of aD = 8.a¹⁸O + 10 is adopted. The first three stations were established at Pengkalan Chepa, Kepala Batas and Kuah in early 1980s. The Malaysian meteoric water line then acquired was aD = 8.a¹⁸O + 12.68. With the addition of another four stations, by end of 1990s, the Malaysian meteoric water line for the decade was established as aD = 8.a¹⁸O + 11.76. Taking the overall result between 1980 and early 2000s the Malaysian meteoric water line was established as aD = 8.a¹⁸O + 13.255 and the weighted mean precipitation is (-7.64, -46.74). In establishing this meteoric water line it was observed that the higher altitude station manifested poorer stable isotopes content as compared to lower altitude stations. It was also observed that as the amount of rain increased, the stable isotopes content would decrease and vice versa. The effect is reversed when the amount is due to monsoon rains and tropical storms. (Author)

[en] The quest for Malaysian meteoric water line began in 1981 when environmental isotope hydrology was introduced. In the 1980, and with the establishment of three stations at Pengkalan Chepa, Kepala Batas and Kuah, the Malaysian Meteoric Water Line acquired then was δD = 8δ ¹⁸O + 12.68. With the addition of another four stations, by the end of 1990s, the Malaysian Meteoric Water Line for the decade was established as δD = 8 δ ¹⁸O + 11.76. Taking the overall result between 1980 and mid 2000s the Malaysian Meteoric Water Line was established as δD = 8 δ ¹⁸O + 13.255 and the weighted mean precipitation is (-7.64, -46.74). In establishing this meteoric water line it was observed that the higher altitude station manifested poorer stable isotopes content as compared to lower altitude station. It was also observed that as the amount of rain increased, the stable isotopes content would decrease and vice versa. The effect is reversed when the amount is due to monsoon rains and tropical storms. (Author)

[en] This case study ia an on going project. Initial results from environmental isotopes and CFCs suggested short circuit to the groundwater flow. Removal of confining layer (if any) by mining activities could be the cause. It is also suggested the existence of saltwater / fresh water interface at the south-western fringe of the study area. This study is not yet conclusive. (Author)

[en] Timely water distribution is of prime importance to the MADA irrigation scheme especially during dry season planting. To measure the transit time for various sections of the water conduit. I-131 was employed. At low discharge (600 Cu sec), the water from Pedu took 45 hours to reach Pelubang, which is 67 km downstream. At Pelubang the conduit splits into two. A discharge of 400 Cu sec flows through the North canal and reaches the sea, 50 km downstream, after about another 134 hours. While during high discharge (4000 Cu sec), it took nearly 26 hours to reach Pelubang and another 32 hours to reach the sea. Though not carried out during the same period, with 1700 Cu sec of water discharge at Pelubang through South Canal, it took about 80 hours to reach secondary canal SCD1 (58 km downstream) that is at the end of the distribution line. Generally there is a decrease in speed as the water flows from Pedu Dam downstream. (Author)

[en] A radioactive tracer experiment was carried out in a waste water treatment system at an oleo chemical plant. The aims of the study were to identify of any undesired physical processes such as bypassing in the system and to determine the residence time distribution of waste water flows in the aeration tanks. About 312 mCi of tritium in the form of tritiated water was released at the main inlet of the aeration tanks and samples were collected at the inlets and the outlets of both tanks respectively The samples were then distilled and analysed by a liquid scintillation counting for identifying the input functions and the residence time distribution patterns. The results showed that the tanks behaved as completely-mixed flow with the dispersion value D/μL of between 0. 7 and I. 0. The mean residence time of the tanks during the period of study was between 8 and 12 days

[en] This article reviews some recent development and activities in nuclear technology research in Malaysia. It is covers all activities in utilization of radiations and radioisotopes in industry, medicine, agriculture, etc. The topics reviewed are tracer technology, nucleonic control system, nondestructive testing, radiation processing, radiotherapy, radiotherapeutics, radiopharmaceutical, single photon emission tomography and radiation sterilization of medical products

[en] The filtration velocity of the groundwater was determine by introducing I mCi Br-82 into a borehole. Br-82 was in the form of potassium bromide. The result showed that the filtration velocity varies from 2.3 to 4.5 cm/day depending on the soil matrix with the clayey layer posting more resistance to flow. Au-198 in the form of aurium chloride was introduce into two other boreholes to determine the direction of flow. The general trend of flow was in the direction between N140E and N160E