16 research outputs found
Probabilistic Dose Assessment from SB-LOCA Accident in Ujung Lemahabang Using TMI-2 Source Term
Probabilistic dose assessment and mapping for nuclear accident condition are performed for Ujung Lemahabang site in Muria Peninsula region in Indonesia. Source term is obtained from Three-Mile Island unit 2 (TMI-2) PWR-type SB-LOCA reactor accident inverse modeling. Effluent consisted of Xe-133, Kr-88, I-131, and Cs-137 released from a 50 m stack. Lagrangian Particle Dispersion Method (LPDM) and 3-dimensional mass-consistent wind field are employed to obtain surface-level time-integrated air concentration and spatial distribution of ground-level total dose in dry condition. Site-specific meteorological data is obtained from hourly records obtained during the Site Feasibility Study period in Ujung Lemahabang. Effluent is released from a height of 50 meters in uniform rate during a 6-hour period and the dose is integrated during this period in a neutrally stable atmospheric condition. Maximum dose noted is below regulatory limit of 1 mSv and radioactive plume is spread mostly to the W-SW inland and to N-NE from the proposed plant to Java Sea. This paper has demonstrated for the first time a probabilistic analysis method for assessing possible spatial dose distribution, a hypothetical release, and a set of meteorological data for Ujung Lemahabang region
Assessment of Offshore Piping Composite Repair Technology for Life Extension Program Case in Pertamina Hulu Energy West Madura Offshore
The pipe work repair method such as clamps and pipe connector as the use of metallic repair component have been used for maintenance and repair application in oil and gas industry and cover the most common types of defect to pressurize system like internal and external corrosion and also cover situations where the damage is severe. On the other hand with a process safety precausion and production concern, in oil and gas facility the use of metallic repair is very challenging and most of the time will come as last option scenario. Composite repair which are now increasing in application to pipe repair situations may come as a solution. This paper provides assessment of offshore piping composite repair for life extension program of pressure system in West Madura Offshore. Assessment come to a conclusion that the composite repair at field PHE WMO which operate on envelop of 700 psi and temperature range of 20°C-80°C are still in good condition and retain the integrity of the asset, from where then the repair is considered to extent its lifetime
Investigation of the Music's Effect on Human Brain Activity Using Electrical Capacitance Volume Tomography Brain Scanner and Electroencephalo-Graphy
In this study, ECVT brain scanner is used to measure electrical signals generated by the activity of the human brain to the audio response. The basic principle of ECVT is the permittivity distribution mapping of objects based on data measured capacitance. Data capacitance is a response to changes in the permittivity distribution in the brain which are affected by brain electrical potential. ECVT system consists of shaped-helmet sensors, 32-channel data acquisition system, and a computer for image reconstruction process and display the results of scanning. Based on the experimental results, the electrical signals from the electrode capacitance shows a clear distinction, when subjects listened to classical, pop and rock music. Furthermore, it also showed that the brain electrical signal of right hemisphere is higher than the left hemisphere when listening to music. These results from ECVT are consistent with the results of measurement using EEG. Analysis of the reconstructed image show that there is an increase in brain activity in the temporal lobe when listening to rock music when compared to the classical music. ECVT brain scanners can be used to observe the electrical activity of the brain that includes auditory activity
Studi Distribusi Radionuklida 134Cs pada Sistem Perairan Tawar
Distribusi radionuklida 134Cs pada sistem perairan tawar telah dipelajari dengan cara memantau akumulasi 134Cs pada berbagai komponen lingkungan yaitu air, tanah , enceng gondok dan ikan lele dalam sistem perairan yang telah dikontaminasi 134Cs dengan konsentrasi sebesar
11,565 Bq/ml. Pengamatan dilakukan lima hari sekali selama 65 hari dengan cara mengukur aktivitas 134Cs dalam bagian tubuh ikan lele yang terbagi atas bagian daging dan non daging,, enceng gondok yang terbagi atas bagian akar dan non akar serta yang terdapat pada tanah .
Komponen lingkungan tersebut didestruksi dengan larutan HCl 5M dan kandungan radionuklidanya dideteksi dengan menggunakan spektrometer gamma. Dari hasil penelitian
diketahui bahwa konsentrasi pada lele mengalami kejenuhan pada hari ke 55, sedangkan pada enceng gondok terjadi kejenuhan pada hari ke 15. Ikan yang telah mencapai kejenuhan mengakumulasi radionuklida 134Cs kemudian dipelihara dalam air yang tidak dikontaminasi untuk
menetukan laju pembuangannya. Faktor transfer ditentukan dengan membandingkan konsentrasi radionuklida 134Cs dalam bagian daging setelah mencapai kejenuhan dengan konsentrasi
radionuklida tersebut dalam air. Dari penelitian ini diperoleh besarnya faktor transfer pada daging lele (yang dikonsumsi) sebesar 18,6 ml/gr.. Faktor transfer pada Enceng gondok sebesar 83,51 ml/gr pada bagian akar dan 108,53 ml/gr pada bagian non akarnya. Faktor transfer pada
tanah sebesar 68,52 ml/gr. Distribusi radionuklida 134Cs terbanyak pada tanah yaitu 85% hal ini karena massanya jauh lebih besar dari enceng gondok dan lele
ISOLASI DAN IDENTIFIKASI BAHAN AKTIF PENYEBAB PEMANCARAN CAHAYA PADA BAKTERI Photobacterium phosphoreum YANG DIISOLASI DARI CUMI LAUT JEPARA INDONESIA
Isolation and Identification of Active Compound Cause Light Emmitting of Bacterial Photobacterium phosphoreum Isolated from the Indonesia Jepara Marine Squid. This research carried out to study the bioluminescence process of bacterial Photobacterium phosphoreum isolated from Indonesia marine squid. The method used in the present study involved isolation, purification, electrophoresis, and the absorbance and light intensity measurement. This result show that the luciferace enzyme of bacterial Photobacterium phosphoreum or called LBPP catalyzes the emission of visible light from the reaction of reduced flavin mononucleotide (FMNH2), molecular oxygen(O2), and an aldehyde (RCOH). The electrophoresis data show that LBPP comprised of two different subunits α and β with 41kD and 38 kD molecular weights. The absorb pattern showed that the bioluminescence process centered around 516 nm and are consistent with the fluorescence data. This result concluded that the excitation state formed after LBPP bind subtracts and the ground state formed after LBPP releases product and visible light.Keywords: Bioluminescence, Photobacterium phosphoreum, α and β subunits, absorbance and light intensitymeasuremen
Dose Volume Product (DVP) As Descriptor for Estimating Total Energy Imparted to Patient Undergoing CT Examination
The purpose of this study is to expand a descriptor for estimating the total energy imparted to a patient undergoing a CT examination and to investigate its relationship to the currently used descriptor. Estimating the total energy imparted to a patient has previously been characterized by dose length product (DLP). We propose a descriptor which we call the dose volume product (DVP), defined as the product of the size specific-dose estimate (SSDE) and the volume irradiated in the patient (V). We also present algorithm to automate the calculation of DVP. There are several steps in calculating the DVP: the first is to contour the patient automatically, the second is to calculate the area of patient in every single slice, the third is to calculate the volume of the radiated part of the patient, the fourth is to calculate the water equivalent diameter (DW) automatically, the fifth is to calculate the SSDE, and the last is to calculate the DVP. To investigate the effectiveness of the algorithm, we used it on images of phantoms and patients. The results of this study show that the automated calculations of DVP for both body and head phantoms were in good agreement with theoretical calculations. The differences between them were within 2%. DVP and DLP had a linear relationship with R2 = 0.971 (slope 1099 cm2, 95% confidence interval (CI), 1047 to 1157 cm2) and R2 = 0.831 (slope 248.6 cm2: CI, 237.6 to 259.7 cm2), for thorax and head patients respectively
Modul praktikum hemat biaya, bersih lingkungan dan manfaat tinggi: bidang fisika
+99999hlm.;24c
Scatter index measurement using a CT dose profiler
The CT dose index (CTDI) is usually measured using a pencil chamber with a length of 100 mm on a CTDI phantom with a length of 150 mm. The scattering radiation dose beyond 100 mm is usually still significant despite using a small beam width (below 10 mm). This study aims to measure the scattering index of CT dose for several variations of input parameters. The scatter index measurements were performed on a multi-slice CT (MSCT) Alexion™ using a CT dose profiler detector connected to a Black Piranha electrometer (RTI Electronic, Sweden). The measurements used the helical mode and a beam width of 2 x 4 mm, and resulted in 150 mm dose profiles. Values of CTDI150, CTDI130 and CTDI100 were calculated and used to obtain values of the scatter indices (SI130 and SI150). We varied input parameters, such as tube voltage, tube current, and pitch, and used two types of CTDI phantoms, i.e. body and head. In the tube voltage variation (from 80 to 135 kV), we found SI130 and SI150 values of 1.13 ± 0.01 and 1.19 ± 0.01 for the body CTDI phantom; and SI130 and SI150 values of 1.08 ± 0.01 and 1.11 ± 0.01 for the head CTDI phantom. For tube current variations from 25 to 120 mA, and pitch variations from 0.75 to 1.5, SI130 and SI150 values were 1.14 ± 0.00 and 1.20 ± 0.00 for the body CTDI phantom; and 1.08 ± 0.00 and 1.11 ± 0.00 respectively for the head CTDI phantom. We showed that the more frequently used CTDI100 value is too small because it ignores scattering beyond the 100 mm boundary, even for beam widths less than 10 mm. The scatter index values were strongly influenced by the size of the CTDI phantom, and were slightly affected by the tube voltage. Variations in tube currents and pitch did not affect the value of the scatter index. The scatter index values of SI130 and SI150 were significantly different, and suggests that the use of SI150 is even more appropriate for describing the scattering dose
Assessment of Offshore Piping Composite Repair Technology for Life Extension Program Case in Pertamina Hulu Energy West Madura Offshore
The pipe work repair method such as clamps and pipe connector as the use of metallic repair component have been used for maintenance and repair application in oil and gas industry and cover the most common types of defect to pressurize system like internal and external corrosion and also cover situations where the damage is severe. On the other hand with a process safety precausion and production concern, in oil and gas facility the use of metallic repair is very challenging and most of the time will come as last option scenario. Composite repair which are now increasing in application to pipe repair situations may come as a solution. This paper provides assessment of offshore piping composite repair for life extension program of pressure system in West Madura Offshore. Assessment come to a conclusion that the composite repair at field PHE WMO which operate on envelop of 700 psi and temperature range of 20°C-80°C are still in good condition and retain the integrity of the asset, from where then the repair is considered to extent its lifetime