170 DETERMINATION OF STANNOUS CHLORIDE CONCENTRATION IN ZOLEDRONIC ACID KIT Manisah Saedon, Dr. Ng Yen, Muhammad Fathurrahman Faizul Akhmar, Saifulizan Mohamad, Dr. Siti Aminah Muhamad, Anee Suryani Sued, Muhammad Ridzuan Rosdi dan Wan Hamirul Bahrin Wan Kamal and Nurul Fazliana Amira Mohd Jamil ABSTRACT Detection of cancer bone metastases using radiolabeledbiphosphanate agents are known to be the most specific agent. Zoledronic acid (ZOL), a bisphosphonate agent, is currently being widely used in clinical as osteoclast bone resorption inhibitor with high binding capacity to bone. Development of lyophilized ZOL cold kit as new radio imaging agent for bone is being carried out in our laboratory. Stannous Chloride (SnCl2) plays an essential role in successful radiolabelling of ZOL with Tc-99m radioisotope. SnCl2 serves a critical function as a reducing agent for converting technetium in the +7 state in the pertechnetate to a desired lower oxidation state (1,2). Therefore, the amount of SnCl2 within these kits is pivotal to ensure radiopharmaceutical quality. According to USP requirements(4), aminimum of 50% ofthe initial SnCl2 concentration must be present at the end of the lyophilization process. This paper aimsto demonstrate a highly reliable method for quantifying SnCl2 in zoledronic acid formulations.
171 BRINE SHRIMP LETHALITY ASSAY: A SIMPLE PRELIMINERY TOXICITY TEST N. Mohammad Shafie, Z. Adam, D. Jesus Arapoc, A.H. Abd Aziz, R. Razali, A. A. R. Ossen, N. A. Marsidi, H. Ahmad Hassali and V. Kasiraja ABSTRACT Brine shrimp lethality assay (BSLA) is a widely used bioassay to evaluate potential toxicity, cytotoxicity, or bioactivity of compounds. BSLA employs the use of brine shrimp (Artemia salina) as the test organism and based on the principle that compounds with cytotoxic or bioactive properties can cause mortality in brine shrimp larvae (nauplii) (Sarah et al., 2017). The assay takes advantage of the simplicity and sensitivity of brine shrimp as a biologicalmodel to assess the potential toxic effects of test substances. BSLA requires minimal equipment and can be conducted in a laboratory setting without specialized facilities (Olmedo et al., 2023). It has been used in various fields, including pharmacology, natural product research, and environmental toxicology. BSLA can be used to prioritize substances for further investigation or guide the development of drug candidates with more specific bioassays (Pisutthanana et al., 2004). Chalcone was selected as a case study for preliminary toxicity testing using BSLA due to its availability in our laboratory. Chalcone is a phenolic compound found in small amounts in various natural sources, including fruits, vegetables, and medicinal plants. They also can be synthesized in laboratory for pharmaceutical and industrial purposes. Chalcones are often responsible for the yellow coloration observed in certain flowers and fruits. Due to their natural occurrence, chalcones have been the subject of extensive research for their potentialbiological activities and therapeutic applications. They exhibit diverse pharmacological properties, such as antioxidant, anti-inflammatory, antimicrobial, anticancer, and antidiabetic activities. Proper toxicity assessment is necessary to evaluate the safety profile of chalcones during drug
172 development. (Díaz-Carrillo et al., 2018; Safitri et al., 2021) The objective ofthisstudy isto assessthe toxicity or lethality of chalcone towards brine shrimp nauplii to understand its toxicity effects or provide preliminary data for further toxicological investigations. While the BSLA provides valuable preliminary information, further studies, including in vivo and in vitro tests, are necessary to validate and understand the toxicity or bioactivity of compounds.
173 APOPTOSIS Zainah Adam, Rosniza Razali, Daryl Jesus Arapoc, Abang Abdul Rahim Ossen, Nurmaziah Mohammad Shafie, Azfar Hanif Abdul Aziz and Nor Azizah Marsiddi ABSTRACT Apoptosis is a programmed cell death, essential for maintaining tissue homeostasis, removing damaged cells, and regulating development of new cells. Dysregulation of apoptosis contributes to various diseases such as cancer, autoimmune disorders, and neurodegenerative conditions. Apoptosis plays a crucial role in preventing cancer. Apoptosis acts as a safeguard against the development of cancer by removing abnormal or damaged cells. When this process is impaired, it can contribute to the formation and progression of cancer. Inducing apoptosis process in cancer cells through specific pathways such as activate death receptor and modulation of pro- and anti- apoptotic proteins holds promise for effective cancer treatment. Understanding and targeting the mechanisms involved in apoptosis is a key area of research in cancer treatment and prevention. Apoptotic cells are characterized by distinct morphological changes, including cell shrinkage, chromatin condensation, membrane blebbing, and the formation of apoptotic bodies. Various techniques, including morphological observation, DNA fragmentation analysis, caspase activation assays, and flow cytometry, can evaluate apoptosis. The purpose of this study is to determine the apoptosis induction activity of Bouea macrophylla plant and a chemically synthesized compound, chalcone by using one of the apoptosis assessing methods which is morphological observation technique (Carneiro and El-Deiry, 2020 & Kari et al., 2022).
174 INSIGHTS INTO HOST-PATHOGEN INTERACTIONS: UNVEILING COXILLA BURNETII INTERACTIONS THROUGH VERO CELL CULTURING Daryl Jesus Arapoc, Zainah Adam, Rosniza Razali, Hazlina Hasali, Azfar Hanif, Nurmaziah Mohd Shafie, Abang Abdul Rahim Ossen, Muhammad Marwan Ibrahim and Veshalini Kasiraja ABSTRACT Qfeveris a significantzoonotic illnessthatisregarded as an occupational hazard for persons who deal with animals. Q fever was initially identified in 1935 in Queensland, Australia, after an outbreak of an unexplained febrile sickness (Query fever) among slaughterhouse employees. This Q fever is caused by the Coxiella burnetii (C. burnetti), a gram-negative intracellular bacterium. This bacterium is regarded a biological terrorist agent due to its extraordinarily high infectivity, resistance to harsh environmental conditions, and capacity to cause serious disease in humans (Mohabbati Mobarez et al., 2017). Formerly, embryonated chicken eggs were used to isolate and culture huge numbers of C. burnetii. Cell culture is less expensive and more time-efficient than using embryonated eggs or animal inoculation (Lockhart et al., 2012). Culturing C. burnetii in Vero cells allow researchers to investigate various aspects of host-pathogen interactions in a controlled and reproducible system. Therefore, the purpose of this study is to provide a comprehensive insight of the significance of culturing C. burnetii in Vero cells.
175 ZEBRAFISH BREEDING: HIGH YIELDING EMBRYO A.H. Abd Aziz, D. J. Arapoc, R. Razali, A.A.R Osen, H.A Hassali, N.M. Shafie, Z. Adam and N.A.M Arshad ABSTRACT Zebrafish have gained importance as an invaluable model organism in scientific research due to their genetic similarity to humans and their suitability for experimental manipulation. (Howe et al.,2013) We will provide an overview of the significance of zebrafish as a model organism, highlighting their advantages and their increasing relevance in various fields ofstudy. It highlights the importance of understanding breeding techniques and optimal embryo handling for maximizing the research potential of zebrafish.
176 PROPAGATION AND TITRATION OF NEWCASTLE DISEASE VIRUS IN EMBRYONIC CHICKEN EGGS Abang Abdul Rahim Ossen, Nurmaziah Mohammad Shafie, Zainah Adam, Rosniza Razali, Daryl Jesus Arapoc, Hazlina Ahmad Hassali, Azfar Hanif Abd Aziz, Pheik-Sheen Cheow and Suet Lin Chia ABSTRACT Newcastle Disease virus (NDV) is a non-segmented, single-stranded, negative-sense RNA virusthat belongsto the family paramyxoviridae (AlZiaydi et al., 2020). There has been a recent report on an outbreak of this disease in commercial poultry and backyard farms in Sabah, Malaysia (Syamsiah Aini et al., 2022). NDV mainly affects avian can be propagated by using embryonic chicken eggs, which is an old but a reliable method thatisstill farsuperiorto produce high titre of NDV culture (McGinnes et al., 2006). The titre of the virus can be quantified by using Hemagglutination Assay (HA) test, which is a fast and inexpensive technique that utilized serial dilution and the clumping activity cause by the binding of hemagglutinin neuraminidase protein of the virus with sialic acid residues on the surface of red blood cells (Ryu, 2017). This paper explains the procedure from the viral propagation to titration, which the culture can be utilized in the application of vaccine development not just for avian and veterinary medicine but has the potential to be used on humans as a recombinant vaccine (Kim & Samal, 2016).
177 ISOLATION AND PURIFICATION OF 4-PHENYLCOUMARINS FROM MESUA ASSAMICA BY FAST CENTRIFUGAL PARTITION CHROMATOGRAPHY Hazlina Ahmad Hassali, Rosniza Razali, Fazliana Mohd Saaya, Daryl Jesus Arapoc, Zainah Adam, Nor Azizah Marsiddi Azfar Hanif Abd Aziz, Nurmaziah Mohammad Shafie, Abang Abdul Rahim Ossen, Veshalini Kasiraja, Chan Gomathi and Khalijah Awang ABSTRACT For centuries, natural products continue to play an essential source for discovery of new drugs throughout the world in treating and preventing human illnesses. Natural products are important sources for drug development. The amounts of bioactive natural products in natural medicines are always fairly low. Today, it is very crucial to develop effective and selective methods for the isolation and purification of those bioactive natural products. Many techniques have been invented and upgraded to make this task easier. Fast Centrifugal Partition Chromatography (FCPC), an efficient and easily scalable approach for the isolation and purification of natural products. This paper will depict a few examples of natural products purification by using FCPC, which demonstrates a fast and effective way of natural products isolation. The Mesua (Calophyllaceae) has been known to produce various new chemical compounds of medicinal values. Some Mesua species have yielded new potential anticancer agents that are important to the pharmaceutical industry (Hassali et al., 2022). Mesua assamica (King & Prain) Kosterm. belongs to the family Calophyllaceae. Mesua assamica is commonly known as ‘Sia Nahor’ in Assam and the tree is found along the foothills of the Himalayas in the North Lakhimpur subdivision of Assam, India (Puppalaet al., 2023). Parts of the M. assamica have been used traditionally as refrigerant in order to reduce overheat in the body, as well as to cure dizziness and dry skin. The aqueous extract of the stem bark of the M. assamica has been valued in traditionalmedicine for anti-
178 malarial activity and treating fevers. The preliminary screening findings suggest that non-polar extracts of M. assamica bark particularly hexane extract exhibited good cytotoxic activity and could be potentially useful for the development of therapeutic agents against cancer (Hassali et al., 2022). M. assamica has been identified for its potential anticancerous properties. In vitro cytotoxic evaluation through MTT assay induction against human breast MCF-7 cancer cell lines exhibited that hexane extracts were found to have IC50 value below 30μg/ml and conferred effective in inducing cell death MCF-7. The diversity of phytochemicals present suggests that the stem bark and leaves of Mesua assamica could serve as a potential source of useful drugs. Exploitation of the pharmacological properties involves further work on isolation, purification and identification of the bioactive compounds from this plant(Hassali et al., 2022). Purificationof natural products has frequently been a difficult undertaking for many scientists around the world. FCPC, which demonstrates a quick and efficient method of isolating natural products, will be used in this presentation to illustrate a few examples of natural products purification. Therefore, in this study, the hexane extract of M. assamica bark were further explored for its chemical constituents. Various chromatographic methods were used for the fractionation, isolation and purification of the metabolites from hexane extract of M. assamica bark, including FCPC.
179 UTILISATION OF GAMMA COUNTER IN BIODISTRIBUTION STUDY BY CUT & COUNT APPROACH Anee Suryani Sued, Nurul Fazliana Amira Mohd Jamil, Wan Hamirul Bahrin Wan Kamal, Saifullizan Mohamad, Ng Yen, Siti Aminah Mohamad, Manisah Sadon, Muhammad Ridzuan Rosdi and Muhammad Fathurrahman Faizul Akhmal ABSTRACT Biodistribution (BQC) of 99mTc-DTPA in Sprague Dawley rats was evaluated in six (6) different time points within the range of 5 min to 24 h. Through cut &count approach, three (3) rats were used for each time point. The gamma radiation emitted from 99mTc isotope in 13 organs/samples was counted using Gamma Counter (Wizard2 Perkin Elmer, USA). Prior to use, the Gamma Counter shall undergo normalization, background measurement and Instrument Performance Assessment Measurement. Correction to the Gamma Counter efficiency was performed by applying radioisotope (99mTc) standard data to BQC data. This correction needs to be performed for every isotope used in BQC cut and count study
180 RADIATION METROLOGY GROUP (KMS): TECHNICAL SERVICE ACHIEVEMENTS THROUGHOUT ITS ESTABLISHMENT M. K. Matori, H. Salleh, A. B. A. Kadir, W. H. Ismail, A. Ripin, H. Sham, J. K. Sangau, A. Hashim, T. Dolah, N. M. Isa, T. A. T. Ahmad, R. A. Rahim and N. F. S. A. Hamid ABSTRACT The Radiation Metrology Group (KMS), established in 2015, is the result of a merger between the Medical Physics Laboratory (MPL) and the Standard Secondary Dosimetry Laboratory (SSDL) where the objective of the merger is to provide quality technical services in radiation metrology comparable to international laboratories. MPL and SSDL laboratories are laboratories recognized as national standard laboratories for ionizing radiation to meet the requirements of Act 304 (Atomic Energy Licensing Act 1984), Act 514 (Occupational Safety and Health Act 1994), and Act 675 (National Measurement Systems Act 2007). Nuclear Malaysia is the only government agency responsible for providing facilities for ionizing radiation standards, Class H license services, and various dosimetry services, such as calibration of radiation measuring instruments and personal dosimetry in the country. Several laboratories in KMS have been accredited by MS ISO / IEC 17025 by the Malaysian Laboratory Accreditation Scheme (SAMM) for quality services in meeting customers' needs from within and outside the country. KMS services are among the major revenue contributors to the Malaysian Nuclear Agency. This paper details the services and achievements of KMS throughout its establishment. Keywords: Metrology, SSDL, Calibration, Standard
181 PENGALAMAN DAN CABARAN KEROSAKAN PERALATAN UTAMA UNTUK KHIDMAT TENTUKURAN DI MAKMAL FIZIK PERUBATAN Asmaliza binti Hashim, Nur Shahriza binti Zainuddin, Mohamad Yusri bin Yahaya, Asmahani binti Ibrahim, Mohamad Al Rasyidin bin Mohamed Najib, Shahrul Azlan bin Azizan, Mohd Muzammil bin Abd Jalil, Mafuzah binti Abdul Majid, Ahmad Nasir bin Yusof dan Mohd Khalid bin Matori ABSTRACT The Medical Physics Laboratory (MPL) is the only calibration standard laboratory for quality control (QC) test tools for diagnostic radiology in Malaysia and Southeast Asia. This laboratory has received MS ISO/IEC 17025:2005 accreditation since 2013 and joined SSDL in 2019 for compliance with the MS ISO/IEC 17025:2017 standard. The main equipment used as a source of radiation for the purpose of dose measurement at MPL is the Philips MG165 X-Ray System. This X-ray machine has been installed at MPL since 1997. This makes the age of this machine 26 years. During these 26 years, all the important components of this X-ray machine have been damaged and replaced. The process of replacing damaged components takes quite a long time, which causes this calibration service to be temporarily stopped. In 2021, the generator component has major damage, followed by the X-ray tube for this Philips MG165 X-Ray System. In order to overcome the problem of the temporary suspension of this service and not affect the services offered, MPL has collaborated with SSDL by using an X-ray machine at Bunker 19. This is to continue the continuity of calibration services at MPL. Among the challenges and constraints identified are different locations, in terms of logistics to bring laboratory equipment and customer tools, limited usage time, calibration carts that are not suitable and need to reproduce the quality of diagnostic radiological radiation for the X-ray machine in Bunker 19. This paper will discuss the experiences and challenges faced by MPL during the period of using the X-ray machine in Bunker 19.
182 ABSTRAK Makmal Fizik Perubatan (MPL) merupakan satu-satunya makmalstandard tentukuran bagi peralatan ujian kawalan mutu (QC test tools) radiologi diagnostik di Malaysia dan Asia Tenggara. Makmal ini telah mendapat akreditasi MS ISO/IEC 17025:2005 semenjak tahun 2013 dan telah bergabung dengan SSDL pada tahun 2019 bagi pematuhan standard MS ISO/IEC 17025:2017. Peralatan utama yang digunakan sebagai punca sinaran bagi tujuan tentukuran dos di MPL adalah Philips MG165X- Ray System. Mesin sinar-X ini telah dipasang di MPL semenjak tahun 1997. Ini menjadikan usia mesin ini adalah 26 tahun. Sepanjang 26 tahun ini, kesemua komponen penting mesin sinar-X ini pernah mengalami kerosakan dan pernah diganti. Proses penggantian komponen yang rosak mengambil masa yang agak lama dan menyebabkan perkhidmatan tentukuran ini terpaksa dihentikan sementara. Pada tahun 2021, komponen generator telah mengalami kerosakan diikuti dengan tiub sinar-X bagi Philips MG165 X-Ray System ini. Bagi mengatasi masalah pemberhentian sementara perkhidmatan ini serta tidak menjejaskan khidmat yang ditawarkan, MPL telah bekerjasama dengan SSDL dengan menggunakan mesin sinar-X di Bunker 19. Ini bagi meneruskan kelangsungan perkhidmatan tentukuran di MPL. Antara cabaran dan kekangan yang dikenalpasti adalah lokasi yang berbeza, dari segi logistik untuk membawa peralatan makmal dan alat pelanggan, masa penggunaan yang terhad, calibration cart yang kurang sesuai dan perlu menerbitkan semula kualiti sinaran radiologi diagnostik untukmesin sinarX di Bunker 19. Kertas kerja ini akan membincangkan pengalaman dan cabaran yang dihadapi oleh MPL sepanjang tempoh penggunaan mesin sinar-X di Bunker 19 ini. Kata kunci: Peralatan utama, mesin sinar-X, khidmat tentukuran, cabaran
183 STABILITY OF CALIBRATION COEFFICIENT OF TYPE IONIZATION CHAMBERS AT 60CO TELETHERAPY BEAM IN MALAYSIA Nurul Azurin Badruzaman, Mohd Taufik Dolah, Zulkefly Mohamad, Rozaimah Abdul Rahim, Ahmad Bazlie Abdul Kadir dan Mohd Khalid Matori ABSTRACT The accuracy of the absorbed dose to water calibration coefficient (ND, W) of ionization chamber (IC) is significant in contribution of the accurate dose delivery to the patients during external- beam cancer therapy (Reza et al., 2018). In conjunction with dose accuracy, the annual calibration of IC has been recommended by IAEA in achieving of precise and stable ND, W value since it is anticipated that the ND, W of IC would vary with time (IAEA, 2000). Secondary Standard Dosimetry Laboratory (SSDL) of Nuclear Malaysia is a national center for the calibration of radiation measuring devices and most of the ICs belonging to the local radiotherapy centers were calibrated here to determine the value of ND, W. The most popular type chamber that are frequently sent for calibration are Farmer (48.39%), followed by Semiflex (23.66%) and Roos (18.28%), as shown in Table 1. The purpose of this work is to study the long-term stability of ND, W values for these type chambers (TW30013, TW31010 and TW34001).
184 Table 1: The details of the 94 therapy level ionization chambers belongings to 34 radiotherapy centres in Malaysia calibrated at SSDL Malaysia from 2017- May, 2023
185 KHIDMAT UJIAN KAWALAN MUTU RADAS X-RAY PELANGGAN LUAR NEGARA (BRUNEI) AGENSI NUKLEAR MALAYSIA: PENGALAMAN DAN CABARAN Shahrul Azlan bin Azizan, M. K. Matori, A. Ripin, N. Ayob, M.H. Salleh, dan W.H. Ismail ABSTRACT Malaysian Nuclear Agency through its Radiation Metrology Group, Medical Physics Laboratory has been providing Quality Control services for medical X-ray apparatus used in private clinics and hospitals since 1997. The Medical Physics Groups services is endorsed by the Malaysian Ministry of Health (MOH) and is in accordance with the Malaysian Standard MS 838 and the Atomic Energy Licensing Act, 1984.Untiltoday, the scopes of testing services also include all types of medical x-ray apparatus. The quality control (QC) in diagnostic radiology is considered as part of quality assurance program which provide accurate diagnostic information at the lowest cost and the least exposure of the patients to radiation. Many experience and obstacles were faced by MedicalPhysics Group. This paper will discuss the experiences and challenges during the providing of QC services to the country of Brunei, so that it can be shared by the citizens of the Malaysian Nuclear Agency. The results of quality assurance inspection of all types of X-ray apparatus for medical conducted by Agency Nuclear Malaysia will be presented in brief Keywords: Quality control, diagnostic radiology ABSTRAK Agensi Nuklear Malaysia melalui Kumpulan Metrologi Sinaran, Makmal Fizik Perubatan telah menyediakan perkhidmatan kawalan mutu untuk radas sinar-X perubatan yang terdapat di klinik- klinik dan hospital swasta semenjak tahun 1997. Perkhidmatan yang Kumpulan Metrologi
186 Sinaran berikan ini adalah diperakui oleh Kementerian Kesihatan Malaysia (KKM) dan adalah selaras dengan Standard Malaysia MS 838 serta Akta Pelesenan Tenaga Atom, 1984. Sehingga ke hari ini, skop perkhidmatan ujian juga telah merangkumi kesemua jenis radas x-ray yang digunakan untuk perubatan. Kawalan mutu ini adalah sebahagian daripada program jaminan kualiti yang mana dilaksanakan untuk menghasilkan maklumat diagnostik yang tepat pada kos dan dedahan sinaran yang paling rendah kepada pesakit. Sepanjang tempoh tersebut pelbagai pengalaman dan pencapaian telah dilalui oleh kumpulan Metrologi Sinaran. Kertas kerja ini akan membincangkan pengalaman dan cabaran semasa pemberian perkhidmatan QC di luar negara iaitu negara Brunei supaya ianya dapat dikongsi bersama-sama oleh warga Agensi Nuklear Malaysia. Hasil pemeriksaan jaminan kualiti terhadap radas sinar-X untuk perubatan yang dijalankan oleh Agensi Nuklear Malaysia akan dibentangkan dengan lanjut. Kata kunci: Kawalan Mutu, Radiologi Diagnostik
187 PENGUJIAN DAN PENTAULIAHAN PINTU PLUMBUM P2 DSRS Wan Ismail bin Wan Yusof, Muhamad Nor bin Atan, Mohd Zaid bin Hassan@Abdul Rahman, Muhammad Hannan bin Bahrin, Mohd Rizal bin Mamat @ Ibrahim, Azraf bin Azman, Anwar bin Abdul Rahman, Rohyiza binti Ba'an ABSTRAK Kertas kerja ini menerangkan tentang proses pengujian dan pentauliahan pintu plumbum. Proses ini meliputi penilaian reka bentuk, pemantauan pembinaan, pemasangan sistem automasi dan pengujian kebocoran radiasi. Kajian kali ini memberi fokus kepada kaedah pengukuran lengkung pada permukaan pintu pada pemasangan di bilik perisai radiasi. Melalui kaedah pengukuran yang diperkenalkan dapat menjadi rujukan dalam penilaian terhadap prestasi reka bentuk pembuatan, kaedah pengangkutan dan pengangkatan semasa pemasangan pintu plumbum. Kata kunci: Rekabentuk, Pintu plumbum, pengukuran lengkung, bunker
188 SEALED RADIOACTIVE SOURCES LEAK TEST USING BOILING LIQUID IMMERSION TEST METHOD Syed Asraf Fahlawi Wafa bin S M Ghazi, Azimawati binti Ahmad, Mohd Fazlie bin Abdul Rashid, Hasbi Husein bin Sulkifli, Noor Ezati binti Shuib, Noor Fadilla binti Ismail, Muhamad Zahidee bin Taat, Faizal Azrin bin Abdul Razalim, Raymond Yapp Tze Loong, Khairuddin bin Mohamad Kontol, Andy Kong Shin Shyen and Suzilawati binti Muhd Sarowi ABSTRACT The sealed radioactive sources leak test is a crucial procedure to ensure the integrity and safety of sealed radioactive sources used in various applications, including medical, industrial, and research fields. One of the methods employed for leak test is the Boiling Liquid Immersion Test (BLIT), which is designed to detect any leaks or breaches in the containment of the radioactive material. The BLIT method involves immersing the sealed radioactive source in a boiling liquid, typically water, while monitoring for the release of radioactive particles or gases. This test takes advantage of the principle that if there is a leak in the source, the boiling liquid will provide a medium for the radioactive material to escape and become detectable. This abstract presents an overview of the BLIT method forthe leak test. It outlinesthe key stepsinvolved in conducting the test and highlights its significance in ensuring radiation safety. The abstract also briefly discusses the equipment required for performing the BLIT, including a suitable containment vessel, temperature control system, radiation detectors, and monitoring instruments. Furthermore, the abstract provides an insight into the analysis and interpretation of the test results. It emphasizes the importance of setting appropriate detection limits and describes the criteria for determining the test's success or failure based on the measured radiation levels. In conclusion, the Sealed Radioactive Sources Leak Test using the Boiling Liquid Immersion Test method is an effective and widely adopted approach to verify the integrity of sealed radioactive sources. By providing a concise summary of the test procedure, equipment requirements, and result analysis, this abstract serves as a valuable reference for professionals involved in radiation safety and source management. Keywords: Leak Test, Sealed Radioactive Source, Boiling Liquid Immersion Test
189 X-RAY BEAM UNIFORMITY MEASUREMENT FOR CALIBRATION OF KVP METER USE IN QUALITY CONTROL TEST OF MEDICAL DIAGNOSTIC X-RAY SYSTEM Wan Hazlinda Ismail, Mohamad Al Rasyidin Mohamed Najib, Asmahani Ibrahim, Mafuzah Abdul Majid, Azuhar Ripin and Dr. Mohd Khalid Matori ABSTRACT The kVp meter use in quality control test measurement of medical diagnostic x-ray is also considered important to ensure the accuracy of kilovoltage of an x-ray imaging system. Since it affects the output of the x-ray in term of dose to patient and contrast to image. Therefore, it is essential to calibrate the kVp meter accordingly. Two methods that are usually employed in kVp meter calibration are the invasive and noninvasive calibration method. In this study, we investigate the uniformity of the standard x-ray beam use for calibration because it will influence the uncertainty of the kVp meter measurement.
190 RADIO FREQUENCY SAFETY ASSESSMENT FROM BASE TRANSCEIVER STATIONS (BTS): COMPARISON AMONG DIVERSE TECHNOLOGY SPECTRUM Shamesh Raj Parthasarathy, Muhammad Khairul Amir Hamid, Zulkifli Yusof and Amierah Hazimah Mohd Hashim ABSTRACT The world has witnessed a lot of change in technology from the invention of wheel to sending one of our kinds into outer space. Malaysia was not late to catch on these fast-moving train that we called technology race. An article was published in 2023 hasshown thatMalaysiawasranked 36th out of 132 countries in the Global Innovation Index (GII) 2022. Many may not be impressed by this number but considering Malaysia was in the 3rd place among the 36 uppermiddle-income nations wassomething that we be proud of (Astro Awani, 2023). This statement can be strengthened by an article that was done in 2023 that shows Malaysia almostreached 50%coverage of populated areasin 5G network with around 3900 more at the end of 2022 (Malaysia Gazette, 2023). 5G along with other technology spectrum like radio, TV, 2G and 4G is one of the mediums that we used in communication. These technology spectrum falls under the radio frequency spectrum with frequency ranging from 88 MHz-3600 MHz (Malaysian Communications and Multimedia Commission (MCMC), 2023). 3G technology spectrum was not mentioned because it was sunsetted as an initiative under the Jalinan Digital Negara plan (JENDELA) to cater for future demands in better quality communication services. Data transfer through radio frequency (RF) involves encoding information into electromagnetic waves in the radio frequency spectrum. The signals are sent to and received from antennasthat are attached to the base station. Due to most of these towers are located near public areas, it is quite understandable that the public will concern about the health risks involving the radio frequency radiated from these base stations. The purpose of this study is to measure the radiation from selected Base Transceiver Stations (BTS) and segregate each radiation level from the diverse technology spectrum, namely RF radiation level from the radio, TV, mobile technology of 2G, 4G and 5G respectively. In addition, the recorded results were compared with the reference level stated in the guidelines published by International Commission on Non-Ionizing Radiation Protection (ICNIRP) and the Malaysian Communications and Multimedia Commission (MCMC).
191 ENVIRONMENTAL SOLAR ULTRAVIOLET RADIATION (UVR): CASE STUDY OF SEVERAL LOCATIONS IN BANGI, CYBERJAYA & PUTRAJAYA Shamesh Raj Parthasarathy, Amierah Hazimah Mohd Hashim, Zulkifli Yusof, Muhammad Khairul Amir Hamid and Ahmad Bazlie bin Abdul Kadir ABSTRACT UVR is classified into three major categories which are ultraviolet A (UVA), ultraviolet B (UVB), and ultraviolet C (UVC). This category is based on their wavelength, that is measured in nanometres (nm=0.000000001 meters or 1×10-9 meters). There are many benefits of UVR that includes the production of a vital nutrient, vitamin D. However, overexposure may cause risks to humans. Sunburn, premature aging, and skin cancer are all risks to overexposure. That is why we need to take safety precaution. UV radiation has two sources, natural source and artificial sources. Natural source is the sun and artificial source is made by humans. For example, tanning beds, mercury vapor lighting, some halogen, fluorescent, and incandescent lights (Centres for Disease Control and Prevention 2023). UVR has been a public concern for quite some time. UV has many benefits to human, however over exposed to UVR may cause health risks. This includes our skin and eyes. Safety precautions need to be taken into actions. This research includes analysing irradiance of the sun, hazard analysis and safety assessment.However,thisresearch does not include effects of UVR to human’s health. The objectives of this research are to determine the irradiance of ultraviolet natural sources and to analyse the safety level of solar ultraviolet radiation (UVR) at selected locations in Bangi, Cyberjaya and Putrajaya. David kaki stated that the highest UV intensity is at mid hours of the day. Safety measures need to be taken for people who need to go out during 12.00 pm and 2.00 pm (Kaki, D. K., Akaagerger, N. B., & Gyaase, V. K 2017).
192 PERSONAL RF ASSESSMENT: STUDYING THE EXPOSURE FROM VARIOUS RF SOURCES AND DEVICES Shamesh Raj Parthasarathy, Muhammad Khairul Amir Hamid, Zulkifli Yusof, Amierah Hazimah Mohd Hashim and Muhammad Shaheir Abu Samah ABSTRACT Radio frequency can be defined as the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system (Radio Frequency - Wikipedia, n.d.). These waves have a frequency range from 3 kHz-300 GHz (RF Basics and Components - Radio Frequency for Engineers | Udemy, n.d.). The application of radio frequency has been implemented in many industries nowadays such as mainly in telecommunications and broadcasting, the medical field, manufacturing plant, identification technologies and even everday commercial use. A paper was published in 2011 explaining how radio frequency identification can be used to record the presence of tagged birds at a fixed location (Bonter & Bridge, 2011). Radio frequency can also be used in the medical field where radio frequency ablation can be used as a treatment option and serves as an alternative to radiation therapy (Dupuy et al., 2002). Besides an alternative treatment, radio frequency has also been implemented in the medical field as an aesthetic treatment. They used the resistance of tissues within the various layers of the skin that will transform the radio frequency waves into thermal energy (Sadick & Rothaus, 2016). Even though radio frequency helped us in many aspects of our daily life, let’s not forget the dangerthey brought along with them. Eventhough radio frequency does not have enough energy to break the atomic bonds, but it does have biological effects on humans. The intensity of this radiation has to be very high to pose a threat on human health. Radio Frequency fields over 1000 W/m2 can produce harmful effects, like skin burns or ocular cataracts with fields of frequency over 10 GHz (Gherardini et al., 2014).
193 STATISTICAL ANALYSIS FOR DISUSED SEALED RADIOACTIVE SOURCES (DSRS) IN WASTE TECHNOLOGY DEVELOPMENT CENTRE (WasTeC) Ahmad Hasnulhadi Che Kamaruddin and Noor Hadirah Kamarulzaman ABSTRACT The preparation of inventory data for Disused Sealed Radioactive Sources or DSRS is very important for developing a safety assessment and determining the borehole design. Detailed information of the devices and radioactive sources is usually required not only in the early stages of purchase, but also applied when it is time for disposal activities to be carried out. Radioactive waste was generated by waste generators in a few sectors such as industrial, public, education, medical and research and in the form of disused sealed radioactive sources (DSRS), liquid, solid and gas. However, this study only limited to DSRS which had been collected and received by Waste TechnologyDevelopment Center(WasTeC) from2019 until 2022 prior to final disposal. These data will be analyzed with descriptive analysis and the results will be discussed.
194 ENERGY DISPERSIVE X-RAY FLUORESCENCE (ED-XRF) ANALYSIS ON DEIONIZED WATER AND ACIDS USED FOR IMPURITIES REMOVAL FROM RARE EARTH-LOADED ORGANIC Norhazirah Azhar, Roshasnorlyza Hazan, Jacqueline Kones, Khaironie Mohamed Takip, Nuraqilah Sapiee and Wilfred Sylvester Paulus ABSTRACT Removing impurities after solvent extraction during the rare earth purification process is crucial to avoid any interference in the stripping process afterwards. The acids used to remove impurities via liquid-liquid extraction are HNO3 and HCl at low concentrations of 0.01, 0.1, 0.3, 0.5 and 0.7M at room temperature. While deionized water is used to remove of impurities at different temperatures. This paper will discuss on results of impurities removed from the rare earth-loaded organic via Energy Dispersive X-ray Fluorescence (ED-XRF). Keywords: ED-XRF, liquid-liquid extraction, scrubbing, rare earth, tributyl phosphate.
195 DOSE MEASUREMENT – DEPTH DOSE DOSIMETRY COMPARISON STUDY OF ENERGIES 3.0 MeV ELECTRONS Siti Zulaiha Hairaldin, Ruzalina Bt. Baharin, Shalina Bt. Sheik Muhamad, Mohd Suhaimi Jusoh @ Yusoff, Shahrina Akma Mansur, Hasan Sham, Ahmad Zainuri Mohd Dzomir, Leo Kwee Wah, Harzawardi Hasim and Ros Anita Ahmad Ramli ABSTRACT Performance Qualification (PQ) uses specific product to demonstrate that the facility consistently operates in accordance with predetermined criteria to deliver specified doses, thereby resulting in product that meets the specified requirements. In this work, film dosimeter cellulose triacetate (CTA) was utilized with aluminium (Al) wedges to determine the depth dose distribution profiles of EPS3000 machine. The CTA was placed underneath the Aluminium wedges and irradiated at 80 kGy. The absorbed dose measured using a UV-VIS spectrometer and analysed by aerode sofware. The purpose of this work is to analyses the depth dose distribution profile of electron beams energy of 3.0 MeV. The delta (∆) of depth dose distribution and Dose Uniformity Ratio (DUR) show consistencies with previous testing and within acceptance criteria variation range within ±3% and ±10% respectively. Based on these results, the EPS3000 Electron beam machine is capable to deliver the dose required for the intended application. Keywords: Dosimetry, depth dose profile, Performance qualification (PQ), electron beam irradiation facility, aluminium stepwedge, Dose Uniformity Ratio (DUR), dose distribution,
196 IONIZING RADIATION DETECTION ALGORITHM FOR CMOS SENSOR FROM CONSUMER CAMERA DEVICE MegatHarunAlRashidMegatAhmad,NashihahAbKarim, Lahasen@NormanshahDahing, HearieHassan, Roslan Yahya, Suhairy Sani,IsmailMustapha, Nor Pa’izaMohamadHasan and Shaharuddin Sayuti ABSTRACT Inexpensive and readily available consumer camera device with CMOS sensor has been shown able to detect ionizing radiation [1]. An ionizing event on this detector can be observed as clustering of bright pixels on the detector image frame which are quite similar in appearance to bright celestial objects in astronomical image observation. Similar method for detecting these astronomical objectstherefore can be applied to detect ionizing events on CMOS image frame. The Laplacian of Gaussian (LoG) algorithm is one of the techniques quite commonly used for astronomical objects identification by edge detection. Herewith, we applied the LoG to identify the central pixel position for each ionizing event on the CMOS image frame allowing us to quantify and give a reference area coordinate for further data computation of charge collection valuesthat can be used to discriminate energy spectrum.
197 The description of CMOS sensor used and experimental procedure were the same in previous report [1] with modifications i.e. the CMOS sensor instead functioned as a camera in which a movie of ionizing events was first taken for each radiation exposure before data processing and this resulted in more data frame per exposure time. The movie recording cycle was about 3.3 seconds (total of 99 frames or 30 frames/second). Three measurements were carried out for each source to detector distance of 0 to 5 cm. Noise removal from all image data frames were done by subtracting each pixel values with the frame median value. The source of radiation used was 241Am (100 μCi). The movie was later processed frame by frame using the LoG function in scikit-image python library. The software tool for experimental control and details of data processing can be found in Ref [2]. Table 1: Common photon (gamma and *X-rays) energies. Source (Nuclide) Energies, keV (photons/100 disintegration) 241Am 59.54 (35.92), 26.34 (2.31), 33.20 (0.12), *11.89-22.2 (37.66) The thin layer of the CMOS indicates that the probability of any ionizing event is very low. The 241Am source used with its relatively low energy gamma photons allowed higher ionizing event to be captured for better statistics.
198 The output of LoG algorithm in scikit-image python library provides a list of image coordinates (center of rings as shown in Figure 4). Charge collection value was then calculated by summing all pixel intensities in the pixel area of 441 (21 x 21). Summation value for all the bright pixels inside the cluster area were then discriminated into channels to obtain a 241Am spectrum for evaluation. Two visible peaks can be discerned in Figure 5 spectra for 0 and 1 cm source to detector distances. These peaks are at around 700 and 1300 of charge collection values. At much larger source to detector distances, no discernible peaks can be seen because of insufficient ionization events and thus poor statistics. These two peaks perhaps represent gamma energy at 59.5 and 11-22keV. Keywords: Laplacian of Gaussian, CMOS, ionizing radiation, sensor.
199 INDUSTRIAL COMPUTED TOMOGRAPHY IMAGING ROOM Susan Sipaun, Nur Adlin Syahira Mohd Faizal, Mohamad Rabaie Shari, Airwan Affandi Mahmood and Nurliyana Abdullah ABSTRACT In the industrial sector, ionising radiation has become an important tool used in process diagnostics, controlling production process and plant component inspection [1]. X-ray computed tomography (CT) systems are commonly used in medical imaging, material science and product manufacturing. When operating computed tomography systems, radiation exposure arises from the x-ray source within the CT system, which is directed at the object under inspection. Radiation safety is a concern for operators, users and staff, including visitors to a CT facility [2]. This paper describes the radiation exposure levels while the x-ray CT is in operation.
200 OPTICAL CONTACT ANGLE MEASUREMENT WITH TOPOGRAPHY: PRINCIPLE AND APPLICATION Norliza Ishak, Nor Azwin Shukri and Natasha Isnin ABSTRACT Optical Contact Angle (OCA) measurements serve multiple purposes and provide valuable information in a wide range of disciplines. The contact angle analysis performs a number of key functions, such as the assessment of wettability, the calculation of surface free energy, the control of surface quality, and the optimization of surface treatments. In most cases, the angle at which liquid droplets encounter solid surfaces is used to determine whether a material is hydrophilic or hydrophobic. Factors such as roughness and heterogeneity of the surface may affect wetting behavior accuracy. Thus, the advanced mode of OCA with topography measurement will improve data interpretation reliability by providing a corrected contact angle. The information is vital to understanding the interaction between liquids and solids, as well as its application to material science, coating development, and surface modification. Keywords: Optical contact angle, Topography, Wetting behaviour, Surface quality, Advanced mode
201 PENYENGGARAAN DAN PENJAGAAN SISTEM TOMOGRAFI BERKOMPUTER SINAR-X Susan Sipaun, Mohamad Rabaie bin Shari, Izuhan bin Ismail, Ramzah bin Mohamed, Hearie bin Hassan, Airwan Affandi Mahmood dan Nurliyana binti Abdullah ABSTRAK Sistem tomografi sinar-x yang telah dibangunkan di Pusat Tomografi Berkomputer dan Pengimejan Industri, Bahagian Teknologi Industri (BTI) mempunyai empat komponen utama iaitu mesin sinar-x YXLON MG 165/4.5, pengesan tatasusunan linear LAD Xscan f3 series, meja berputar boleh laras 6K4 Time & Precision, sistem kawalan dan pemerolehan data. Keupayaan sistem tomografi untuk menghasilkan imej yang baik bagi jangka masa lama bergantung kepada penyenggaraan dan penjagaan sistem yang berkesan. Ini termasuklah mengadakan penyenggaraan berkala bagi menguji fungsian kesemua komponen sistem. Kertas kerja ini menerangkan kerja-kerja penyenggaraan dan penjagaan yang telah dijalankan ke atas sistem tomografi sinar-x bagi mencapai prestasi optima sistem.
202 THERMOGRAVIMETRIC ANALYSIS OF IRRADIATED FILM: EFFECT OF INSTRUMENTAL FACTORS Nurul Aizam Idayu Mat Sani and Norzita Yacob ABSTRACT Thermogravimetric analysis (TGA) is performed to observe the thermal analysis throughout the heating process. In this study, the effect of radiation and heating rate on the thermal decomposition of synthetic films was investigated. Studies showed that the radiation affected the thermal stability and the shape of the curves changed with the heating rate. Keywords: Thermal decomposition, PE, flow rate, radiation
203 SMALL GAMMA-RAY ATTENUATION TECHNIQUE-BASED SCANNER FOR DETERMINING MATERIAL DENSITY: PRELIMINARY STUDY Soleha Mohamat Yusuff, Ainul Mardhiah Terry, Nurliyana Abdullah, Hearie Hassan, Mohamad Rabaie Shari, Airwan Affandi Mahmood, Ahmad Hambali Ismail, Lahaseng@Norman, Nazrul Hizam Yusof, Mohd Fitri Abdul Rahman, Nor Pa’iza Hassan, Ismail Mustapha and Maziah Jamaludin ABSTRACT The present study developed a portable gamma-ray attenuation techniquebased scanner to characterize the solid materials (merbau wood, kempas wood, keranji wood, polyethylene, acrylic, aluminum, and stainless steel) by giving density values. The density of samples was calculated analytically based on their mass attenuation coefficient (mm) values obtained using three radioactive materials (Barium, Cesium, and Cobalt) at a distance of 4 cm with optimum high voltage of 700 V. This study also investigated the effect of different thicknesses of samples on density. Results found no significant difference between density values calculated using the portable gamma-ray attenuation technique-based scanner and the density values listed in the database. Mass attenuation coefficient and intensity strongly depend on the chemical composition and density of the materials. Three radioactive materials provide permanent records of density for all samples. The sample's density follows the order steel > aluminum > keranji > acrylic > polyethylene > kempas > plywood > meranti > compact wood. In addition, the density ofmaterials does not depend on the thickness of solid materials. In conclusion, the portable gamma-ray attenuation technique-based scanner was successfully developed to characterize the solid materials by giving density value. The portable gamma-ray attenuation technique-based scanner is applicable by researchers and engineers to indicate unknown, modified, or advanced material in the laboratory or at fieldwork. Keywords: gamma-ray attenuation technique, density, material.
204 PENGIRAAN MASA IRADIASI BUAH NANGKA Mohd Rizal bin Md Chulan, Syuhada binti Ramli, Wan Muhammad Ikram bin Wan Ibrahim, Cosmos George, Zarina binti Mohd Nor, Shaiful Rizaidi bin Mohd Yakin, Nor Ishadi bin Ismail dan Ahsanul Khaliqin bin Abdul Wahab ABSTRAK Penyinaran buah segar seperti buah nangka termasuk juga di dalam proses penyinaran makanan. Oleh itu ianya tertakluk di bawah Akta Makanan 1983 (Peraturan-Peraturan Iradiasi Makanan 2011). Dos sinaran yang diperlukan bagi proses penyinaran buah-buahan segar mesti mengikut panduan yang telah ditetapkan seperti mana yang terdapat di dalam Jadual Ketiga Kelas 2 (Buah-buahan dan Sayur-sayuran Segar), Akta makanan 1983 (Peraturan-peraturan Iradiasi Makanan) mengikut tujuan rawatan dijalankan. Di dalam penyinaran buah nangka ini, tujuan rawatan adalah untuk kawalan kurantin (membunuh segala serangga) pada buah tersebut. Jadi, dossinaran yang diperlukan adalah antara 0.15 kGy hingga 1.0 kGy. Untuk kemudahan sinaran gama di MINTec-SINAGAMA, dos sinaran untuk tote komersial ditentukan oleh masa iradiasi untuk satu pusingan untuk 18 kedudukan. Oleh itu masa iradiasi ini perlu ditentukan atau dikira untuk mendapatkan dos terserap yang diperlukan untuk satu pusingan Kaedah yang digunakan untuk pengiraan tersebut adalah dengan menggunakan prinsip perlindungan sinaran dimana dos yang terhasil berkadaran dengan masa. Untuk pengiraan tersebut, nilai perkadaran dos telah didapati daripada pemetaan dos sinaran satu rak punca Co-60 dengan menggunakan ‘dummy’.
205 INFLUENCE OF PRESERVATIVES ON THE STABILITY OF CARRAPGP Maznah binti Mahmud, Norzita binti Yacob, Norhashidah binti Talip, Sarada binti Idris and Akid Daniel bin Mohd Jeffrey Lee ABSTRACT Influence of preservatives on the stability of CarraPGP Maznah Mahmud, Akid Daniel Mohd Jeffery Lee, Norzita Yacob, Norhashidah Talip, Sarada Idris, Norafifah Ahmad Fabillah, Nurul Aizam Idayu & Mohd Nalrazmi Mohd Shukri Product stability is crucial characteristic in product development process, and it can be investigated through storage study. The storage study determines product shelf life, product safety and efficacy, optimal storage condition and assuring the product overall quality for consumers. The factors of time and storage conditions including temperature, humidity, light exposure, and atmospheric pressure possibly will influence the product stability. The low molecular weight ƙ-carrageenan solution (CarraPGP) which has potential as plant growth promoter is developed through radiation processing technology at Nuclear Malaysia. The gamma radiation induces chain-scission reaction of ƙ-carrageenan to produce low molecular weight ƙcarrageenan. As a shorter-chain of complex carbohydrate-based substance, the CarraPGP has high tendency of deterioration during storage. This study was conducted to observe the influence of sodium benzoate and EDTA, respectively on the stability of CarraPGP over time and storage condition. The sodium benzoate and EDTA were added into the CarraPGP at three different concentrations which were 500, 750 and 1000 ppm. CarraPGP samples were placed at three different storage conditions which were (i) outside the building with direct sunlight exposure, (ii) in the dry and dark room and (iii) in cool and dry room. The sampling of CarraPGP samples were carried out every two months for 8 months. The stability of the preserved CarraPGP was evaluated in terms of pH value, viscosity and microscopic image of particle size and distribution. Although the
206 study focused on physical and chemical characteristics of CarraPGP, the element of biological and microbial activities cannot be neglected. As the CarraPGP is formulated from natural substances, commonly it changes over time due to natural reaction occurs among the substances. Keywords: Carrageenan; rheology; preservatives; particle agglomeration; degradation ABSTRAK Pengaruh pengawet kimia terhadap kestabilan CarraPGP Maznah Mahmud, Akid Daniel Mohd Jeffery Lee, Norzita Yacob, Norhashidah Talip, Sarada Idris, Norafifah Ahmad Fabillah, Nurul Aizam Idayu & Mohd Nalrazmi Mohd Shukri Kestabilan produk adalah unsur penting dalam proses pembangunan sesuatu produk dan ia boleh ditentukan melalui kajian penyimpanan. Kajian penyimpanan membantu dalam menentukan jangka hayat produk, aspek keselamatan dan keberkesanan produk, keadaan penyimpanan optima serta memastikan pelanggan yakin dengan keseluruhan kualiti produk yang ditawarkan. Faktor masa dan keadaan penyimpanan seperti suhu, kelembapan, kadar dedahan cahaya serta tekanan persekitaran boleh mempengaruhi kestabilan sesuatu produk. Produk larutan ƙ-karagenan berberat molekul rendah (CarraPGP) yang berpotensi sebagai produk penggalak pertumbuhan tanaman telah dibangunkan melalui teknologi pemprosesan sinaran di Nuklear Malaysia. Sinar gamma mengaruh tindak balas pemutusan rantai ƙ-karagenan menghasilkan ƙ-karagenan berberat molekul rendah. CarraPGP, produk berasaskan bahan karbohidrat komplek berantai pendek bersifat mudah merosot semasa penyimpanan. Kajian ini dijalankan untuk melihat pengaruh sodium benzoate dan EDTA dalam memeliharan kestabilan CarraPGP dalam suatu tempoh masa dan keadaan simpanan tertentu. Sodium benzoate dan EDTAmasing-masing ditambah dalamCarraPGP pada tiga kepekatan berbeza iaitu 500, 750 dan 1000 ppm. Kemudian CarraPGP yang ditambah dengan sodium benzoate dan EDTA tadi diletakkan pada tiga keadaan penyimpanan berbeza iaitu (i) di luar bangunan dengan kadar
207 dedahan cahayamatahariterus, (ii) di dalam bilik kering dan gelap serta (iii) di dalam bilik berhawa dingin dan kering. Pesampelan CarraPGP dilakukan setiap dua bulan sekali selama lapan bulan. Kestabilan CarraPGP yang telah ditambah pengawet kimia tadi dianalisa dari aspek nilai pH, kelikatan serta pengimejan saiz dan taburan partikel menggunakan mikroskop. Walaupun kajian ini hanya meliputi pencirian fizikal dan kimia produk namun elemen biologi serta mikrob perlu dititikberatkan. CarraPGP yang diformulasikan dari bahan semulajadi sudah pasti mengalami perubahan dari pelbagai aspek akibat dari tindak balas semulajadi yang lazimnya berlaku pada bahan semulajadi dari semasa ke semasa. Kata kunci: Karagenan; rheologi; pengawet; gumpalan butiran; degradasi
208 APPLICATION OF SILICON PHOTOMULTIPLIER (SiPM) IN SCINTILLATOR BASED GAMMA DETECTOR Megat Harun Al Rashid Megat Ahmad, Megat Hilmi Salihin Megat Nirman Bukhari, Hearie Hassan, Nazrul Hizam Yusof, Hanafi Ithnin, Lahasen@Normanshah Dahing, Airwan Affandi Mahmood, Mohd Fitri Abdul Rahman, Roslan Yahya, Suhairy Sani, Ismail Mustapha, Nor Pa’iza Mohamad Hasan and Shaharuddin Sayuti ABSTRACT Radiation spectrometry based on scintillation traditionally used photomultiplier tube (PMT) that utilizesseries of dynodestomultiply the small amount of photons produced by the scintillator million of times. This type of PMT usually requires hundreds of volts in operating voltage that may not be suitable to be used in industrial premise because of safety precaution. The current alternative to this classical PMT is Silicon Photomultipliers (SiPM) that can be operated in tens of volts only. The SiPM is an already established photodetector having used in many fields of basic scientific research [1]. The SiPM is a solid-state semiconductor photodetector made of an array of hundreds or thousands of singlephoton avalanche diodes (SPADs) or Geiger-mode avalanche photodiodes (Gm-APD). All these SPAD are independent and connected to a common readout. A SPAD can generates a large electric output signal even when exposed to a single photon due to internal avalanche multiplication. Herewith, we evaluate an SiPM as a replacement for PMT in a simple radiation detection setup using a single crystal Bismuth Germanate (BGO) scintillator. Detection pulses characteristics from the SiPM were then analyzed.
209 The SiPM (SensL MICROFC-SMTPA-30035-GEVB) was placed on a breadboard inside an in-house designed photon tight container. The teflon coveredBGO was placed on top ofthe SiPM array cell.Ageneric bias filter was used to stabilize the input voltage from a 9V battery (Energizer Max) that amplified to 29.5V breakdown overvoltage using a DC to DC converter (XL6009E1). Direct measurement were carried out using an oscilloscope (Tektronix TDS 2004B). Small gammaradiation sources ( 60Co and 137Cs) were then used to observe pulses from the oscilloscope by placing them right on top of the BGO scintillator. Pulses obtained show a variation in height. 60Co pulses are mostly higher compare to 137Cs pulses indicating the energy discriminating capability of SiPM. Some of the lower height pulses resulted from scintillation caused by photons from Compton inelastic scattering and photoelectric effect aswell as pair production in the case of 60Co source. All pulses have a decay time of about 2 µs.
210 Some data contained more than one pulse per measurement. This event as well asthe shape and height of the pulses allows us to properly design the signal processing electronics later on. This initial work also provides further insight on development of other scintillator-based particle detectors in particular for neutron scattering and muon tomography as well as using SiPM in photonic based analogue computation. Keywords: SiPM, scintillator, ionizing radiation, sensor.
211 MELT FLOW INDEX OF IRRADIATED GROUND TIRE RUBBER Norshafarina Ismail, Muhamad Nur Falah Karoji and Nur Amisha Mahizan ABSTRACT MFI is an instrument used to measure the ease of flow of the melted thermoplastic polymer. The result gives an indication of whether the material is viscous or non-viscous in the molten state under a known applied pressure and temperature. The MFI value provides information about the flowability of the polymer. Ground tire rubber has the potential to be incorporated into the polymer to produce thermoplastic elastomer. The 3D network formed during vulcanization, however, hinders the movement of this material affecting flowability. Electron beam irradiation is applied to degrade and modify the GTR by breaking down the 3D network. Irradiation doses from 50 to 750kGy are subjected to the GTR before being compounded with HDPE by melt mixing method. MFI for these compounds is measured and reported as a function of irradiation dose to assess how the flowcharacteristicsofthematerial change with varying levels of irradiation, which can provide valuable insights into the modified GTR's suitability for thermoplastic elastomers. Keywords: Fluidity, melt flow index, polymer processing, rheology, thermoplastic polymer, viscosity