[en] The measurement of a radiocarbon date is a complex process which involved all the stages from advice given prior to submission of samples right through to reporting of results. The aim of our radiocarbon dating is to determine the residual ¹⁴C content of a sample, the value of which is translated into an age that is an estimate of the time elapsed since the given sample was removed from the environment in which it had formed in equilibrium with respect to 14-C radioactive decay and metabolic assimilation. Carbon is obtained from carbon containing samples in the form of carbon dioxide, which is then reacted with lithium forming lithium carbide. The carbide is then hydrolysed to acetylene before it was polymerised to benzene using a high-efficiency vanadium-alumina-silica catalyst to produce benzene with up to 96% yield. Sample, background and modem standard activities are measured with a coincidence scintillation counter using in glass vials of 21 ml capacity. An improved chemical procedure was used to obtain and purify the benzene from the samples for measurement using a liquid scintillation counter. Radiocarbon dating measurements of samples collected reveal some results. The validity of the data have yet to be confirmed by the results of the measurements on two international control samples. (Author)

[en] As a follow-up to the setting up of the MINT Radiocarbon Dating facility. an exercise on the IAEA standard reference materials was carried out. Radiocarbon laboratories frequently used these 8 natural samples to verify their systems. The materials were either pretreated or analysed directly to determine the activity of ¹⁴C isotopes of the five samples expressed in % Modern (pMC) terms and to make recommendations on further use of these materials. We present the results of the five materials and discuss the analyses that were undertaken. (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] This study was carried out to establish the transit times for high and low flow from the Pedu Dam through the northern part of the Muda irrigation Scheme. The result of the study would assist in the management of water released from the Pedu Dam into the irrigation system thus sustaining the rice production in the area. Peak to peak method was employed and I was used as a tracer. At high discharge, it took 3.3 days for the water from the Pedu Dam to reach the end of the system, whereas at low discharge it took 7.5 days. The transit time at high discharge seems to be more linear with distance as compared to the low discharge. For low discharge, the linearity was observed to hold only from Pedu to Kampong Kubu, after which the gradient of transit time against distance curve increased with increase of distance along the North Canal, and then decreased along the Arau Canal. For high discharge, the transit time gradient could be divided into three portions, but the differences were not significant. (Author)

[en] Radiocarbon dating has become the most aspiring science in the 20th century. The technique has enabled scientists and archaeologists to come up with a decisive answer on the carbon content left in the archaeological, hydrological and environmental samples thus lead to the estimation of age. MINT Radiocarbon Dating Laboratory has been equipped with Direct Absorption Method-CARBOSORB as an alternative to benzene-derived method for radiometric technique. The latter technique is fast, less cumbersome and convenient as compared to the current technique. A constant weight of C/P solutions for each standard, background and sample is placed in a vial. Liquid Scintillation Counter (LSC) has been widely used to determine the beta activity remained in the samples for the analysis. (Author)

[en] The MINT radiocarbon dating technique was introduced and a very well-designed vacuum line was developed to generate benzene from samples containing carbon. A liquid scintillation counter provides a very good prerequisite for precise measurement of the C-14 activity in the benzene. From time to time, assessment on the status of the analytical capabilities of the system and advice on improvement and upgrading required was made. For routine analysis, standard sampling, pretreatment, carbon dioxide conversion and measurement procedures were adopted. Radiocarbon dating is now, one of the most important developments of the twenties century in the comprehension of the history of human development, a quick, easy, reliable and scientifically acceptable method to determine the age of historical artefacts and archaeological samples. (Author)