http://ajstd.org/index.php/ajstd/issue/feed ASEAN Journal on Science and Technology for Development 2018-05-16T02:51:20+07:00 Widodo ajstd.journal@gmail.com Open Journal Systems <p>The ASEAN Journal on Science and Technology for Development (AJSTD), an English language, ISSN 0217-5460 (print), 2224-9028 (online) is a refereed Journal of the ASEAN Committee on Science and Technology (ASEAN COST). The coverage is focused but not limited to, the main areas of activity of ASEAN COST, namely, Biotechnology, Non-Conventional Energy Research, Materials Science and Technology, Marine Sciences, Meteorology and Geophysics, Food Science and Technology, Microelectronics and Information Technology, Space Applications, and Science and Technology Policy, Infrastructure and Resources Development.</p><p align="center"><strong>About The ASEAN Committee on Science and Technology</strong></p><p>The ASEAN Committee on Science and Technology was established to strengthen and enhance the capability of ASEAN in science and technology so that it can promote economic development and help achieve a high quality of life for its people. Its terms and reference are:</p><ul><li>To generate and promote development of scientific and technological expertise and manpower in the ASEAN region;</li><li>To facilite and accelerate the transfer of scientific and technological development among ASEAN countries and from more advanced regions of the world to the ASEAN region;</li><li>To provide support and assistance iin the development and application of research discoveries and technological practices of endogenous origin for the common good, and in the more effective use of natural resources available in the ASEAN region and in general; and</li><li>To provide scientific and technological support towards the implementation of existing and future ASEAN projects.</li></ul><p>Information on the activities of ASEAN COST can be obtained at its website http://astnet.asean.org/index.php?option=com_content&amp;view=categories&amp;id=8&amp;Itemid=130</p><hr /><p align="center"><strong>Disclaimer</strong></p><p>While every effort is made to see that no inaccurate or misleading data, opinion ot statement appears in the Journal, articles and advertisements in the Journal are the sole responbility of the contributor or advertiser concerned. They do not necessarily represent the views of the Editors, the Editorial Board nor the Editorial Advisory Committee. The Editors, the Editorial Board and the Editorial Advisory Committee and their respective employees, officers and agents accept no responsibility or liability whatsoever for the consequence of any inaccurate or misleading data, opinion or statement.</p> http://ajstd.org/index.php/ajstd/article/view/399 Influence of TESPT on Tensile and Tear Strengths of Vulcanized Silica-filled Natural Rubbe 2018-05-16T02:48:50+07:00 A.K. NORIZAH azemi.sam@gmail.com S. AZEMI azemi.sam@gmail.com <p style="text-align: justify;">The effectof coupling agent on tensile and tear strengthsof vulcanized NR filledwith 50 pphr of precipitated silica (VN3) was investgated. The amount of coupling agent was varied from 0,1,2,3,4,5 to 8 pphr. In the absence of coupling agent bis[3-(triethoxysilyl)propyl] tetrasulphide (TESPT), the tensile strengthof silica-fille vulcanized NR was lower than the tensile strengthof unfilledvulcanized NR. The enhancement in the tensile strengthwas achieved only when TESPT was incorporated into the rubber compound. The dependence of tensile strengthon the amount of TESPT showed a similar trend as the dependence of tensile strengthon the crosslink concentration. This might imply that varying the amount of TESPT was analogous to varying the crosslink concentration of the rubber network. The effct of TESPT on tearing energy was very strking in silica-filed vulcanized NR. Without Si69, the crack propagated in a steady(smooth) manner where the tearing energy increases with increasing testspeed. When TESPT was added into the silica mix, the crack propagated sideways from the intended tear path producing the so called knotty tearing. The tearing energy was about a factor of ten higher than that without coupling agent in particular at low tear rates regions. The results here indicated clearly that in silica-filledvulcanized NR, coupling agent was essential to induce the strengthanisotropy necessary for the occurrence of knotty tearing. The result also showed that TESPT also influencedthe amount of hysteresisin silica-filledvulcanized NR. Both tensile and tear strengths were affected by the hysteresi</p> 2018-04-04T09:44:12+07:00 ##submission.copyrightStatement## http://ajstd.org/index.php/ajstd/article/view/400 Assessment of Natural Radioactivity Level and Radiological Index in the Vicinity of Lynas Rare-earth Processing Plants 2018-05-16T02:49:47+07:00 W.M. ZAL U’YUN zaluyun@nuclearmalaysia.gov.my M.W. YII zaluyun@nuclearmalaysia.gov.my K. MOHD ASHHAR zaluyun@nuclearmalaysia.gov.my M.K. KHAIRUDDIN zaluyun@nuclearmalaysia.gov.my I. ABDUL KADIR zaluyun@nuclearmalaysia.gov.my Y. MOHD ABD WAHAB zaluyun@nuclearmalaysia.gov.my <p>The findingsof the sudy on assessment of natural radioactivity level and radiation hazard parameters in the vicinity of Lynas rare-earth processing plants are reported. This studyaims to quantify the environmental levels of natural radionuclides in soil collected in the vicinity of Lynas rare-earth processing plants and thereby to assess potential radiological hazards to the environment. About 31 terrestrialsampling locations were chosen for collection of the soil samples. The activity concentrations of the naturally occurring radioactive material (NORM) members, i.e. 226Ra, 228Ra, 238U, 232Th and 40K were measured using HpGe gamma spectrometer after reaching 30 days of secular equilibrium with their daughters. The mean activity concentration of 226Ra 228Ra 238U, 232Th and 40K in soil samples were 35 Bq/kg, 62 Bq/kg, 38 Bq/kg, 60 Bq/kg and 245 Bq/kg, respectively. The estimatedRaeq and Hex readings due to natural environmental radiation in respectively lower than the recommended value of 370 Bq/kg and unity. Meanwhile, the total air absorbed dosage rate was slightly higher than the estimatedaverage global terrestrialradiation but much lower compared to other regions in Malaysia. The results indicated that the radiation hazard in the vicinity of the Lynas rare-earth processing plants was negligible. Thus, it could be concluded that there were no additional radiation level and no radiological hazard effects to the people living in the surrounding areas.</p> 2018-04-04T09:44:12+07:00 ##submission.copyrightStatement## http://ajstd.org/index.php/ajstd/article/view/401 Thermal Efficient Design of Distributed MemorGenerator for Dual-port RAM Using Unidirectional High-performance IO Standard 2018-05-16T02:50:22+07:00 B. DAS engr.bhagwandas@hotmail.com M.F.L. ABDULLAH engr.bhagwandas@hotmail.com <p style="text-align: justify;">he distributeddual-port RAM offersthe high-speed data rate transmission for differentmemory access modes such as: busy mode; interrupt mode; JTAG mode; maser mode; slave mode; and sleep mode, at high-frequency operation. The execution of these modes at high-frequency operation increases the on-chip temperature of distributeddual-port RAM. It might short the distribute dual-port RAM forever. Currently, differenttechniques have been reported, but significanton-chip temperature consumption is not reduced for distributeddual-port RAM. In this paper, the thermal-efficiendesign for disributed dual-port RAM was achieved using IO sandard technique. The distributeddual-port RAM was designed using differentIO standardssuch as; LVTTL IO standardand Mobile_DDR IO standard.It was determined that distributeddual-port RAM was operated at 625 MHz high-frequency operation for busy mode, interrupt mode, JTAG mode, mastermode, slave mode, and sleep mode using LVTTL IO standardand Mobile_DDR IO standard.It was observed that for busy mode 53%, for interrupt mode 61%, for JTAG mode 68%, for mastermode 62%, for slave mode 59%, and for sleep mode 76% temperature was reduced when distrbuted dual-port RAM was designed using Mobile_DDR IO stndard compared to LVTTL IO stndard. The designed distributd dual-port RAM using Mobile_DDR IO stndard offerd the thermal efficiendesign solution for differentmemory access modes at high-frequency data rate transmission that provided the low on-chip temperature consumption. The developed distibuted dual-port RAM will be helpful to produce green computing devices.</p> 2018-04-04T09:44:12+07:00 ##submission.copyrightStatement## http://ajstd.org/index.php/ajstd/article/view/402 Adsorption and Diffusion Characteristics of 2-Naphthol from Aqueous Media by Chitosan-ENR Biocomposites 2018-05-16T02:50:36+07:00 R. GUNASUNDERI rgunasunderi@usm.my M. R. H. MAS HARIS rgunasunderi@usm.my <p style="text-align: justify;">Chitosan entrapped ENR-50 (CTS-t-ENR) biocomposites developed were studiedfor the absorption and desorption of 2-naphthol in aqueous media. Biocomposites comprising chitosan (CTS) immobilized or trapped in a partially crosslinked ENR (designated as CTS-t-ENR) was prepared by homogenising CTS in ENR-50 latex with curative agents in the presence of acetic acid. It was found that absorption increased with the increase in the initial 2-naphthol concentrations. Chitosan powder was found to be a poor absorbent compared CTS-t-ENR biocomposites. Desorption studyrevealed that the 2-naphthol diffusedslowly in water. The biocomposites exhibited a good slow-release properties and this was proven by the kinetic studyusing zero order, firsorder, Higuchi equation and Kosmeyer Peppas equation. Thus, these biocomposites with a good controlled release and swelling properties could be very useful in agricultural application.</p> 2018-04-04T09:44:12+07:00 ##submission.copyrightStatement## http://ajstd.org/index.php/ajstd/article/view/403 Preparation and Characterisation of Crosslinked Natural Rubber (SMR CV 60) and Epoxidised Natural Rubber (ENR-50) Blends 2018-05-16T02:50:59+07:00 M. SASITARAN manroshan@lgm.gov.my S. MANROSHAN manroshan@lgm.gov.my C.S. LIM manroshan@lgm.gov.my B. N. KRISHNA VENI manroshan@lgm.gov.my S.K. ONG manroshan@lgm.gov.my R. GUNASUNDERI manroshan@lgm.gov.my In this sudy, the influenceof di(tert-butylperoxyisopropyl)benzene (DTBPIB) on the properties of natural rubber (NR) blend with epoxidized natural rubber (ENR) was determined. Fourier transform infrared spectroscopy with attenuated total refletance analysis and gel content confired crosslinking occurred in the rubber blends in the presence of peroxide DTBPIB percentage. Studies including tensile properties, dynamic mechanical properties, thermogravimetric analysis (TGA) and water absorptivity showed the changes in properties of the crosslinked NR/ENR blends. Tensile properties analysis disclosed the improvements in the modulus at 300% elongation and tensile stength with increasing NR ratios. Dynamic mechanical analysis revealed the blends to be incompatible and immiscible, with ENR showing a more viscous behaviour compared to the polymer blends. Thermal properties improved by blending NR with ENR as the onset temperature of NR/ENR: 50/50 was higher than pure NR by approximately 10oC and ENR by approximately 2oC. Water absorptivity experiment revealed a two-fold reduction in the presence of crosslinking for all blend ratios. 2018-04-04T09:44:13+07:00 ##submission.copyrightStatement## http://ajstd.org/index.php/ajstd/article/view/404 Quantitative Analysis of Microcystin-LR in Drinking Water Comparing On-Line Solid Phase Extraction and Direct Injection LC/MS/MS 2018-05-16T02:51:20+07:00 R. MALARVILI malar@kimia.gov.my Y.Y. LOW malar@kimia.gov.my A. ZAITON malar@kimia.gov.my <p>An efficienmethod for microcystin-LRin drinking water at the sub-ng/l level applying on-line solid phase extraction (SPE) with LC/MS/MS detection and comparing it to direct injection LC/MS/MS is presented. The performance of the method of direct injection did not signifiantly deviate from the SPE approach. However, the direct injection method used less sample volume (100 µl) in shorter analysis time (4 min) and allowed more sample throughput. Conversely, the uncertainty of measurement could be reduced using SPE.</p> 2018-04-04T09:44:13+07:00 ##submission.copyrightStatement## http://ajstd.org/index.php/ajstd/article/view/405 Ediorial Board 2018-04-04T09:44:13+07:00 Editorial Board ajstd.journal@gmail.com 2018-04-04T09:44:13+07:00 ##submission.copyrightStatement##