[en] A radiotracer investigation was carried out in Hoogly estuary at Kolkata Port Trust, Kolkata to examine the suitability of a dumping site for dredged sediment located at south of shipping channel. Scandium-46 (8Ci) as scandium glass powder having the particle size distribution ranging from 40-100 microns was used as a radiotracer. The tracer was injected onto the seabed at the site using a remotely operated injection system and its movement was tracked using waterproof scintillation detector. The tracer concentration curves were plotted for different trackings. From the tracer concentration curves iso-activity contours were plotted and parameters such as general direction of movement on seabed, transport velocity, transport thickness and bed load movement rate were determined. The analysis of data indicated that the sediment predominantly moves towards north-east direction during the period of the study and coming in the shipping channel. Based on the investigations, it was found that the proposed site is not suitable for dumping the dredged material, as the movement of sediment is towards form the shipping channel. (author)

[en] This paper describes sediment transport investigations carried out at two different locations in Hugli estuary along the shipping channel leading to Haldia Dock Complex of the Kolkata Port Trust, Kolkata. The objectives of these investigations were to evaluate the suitability of the proposed dumping sites for optimizing the dredging operation and implementing the recommendations of the River Regulatory Measures, Kolkata Port Trust, Kolkata

[en] Nuclear grade aluminum capsules (AA-1070) was filled with 2 mg, 4 mg, 6 mg of target Sc₂O₃. The irradiation process of the capsule was performed in the Central Irradiation Position (CIP) G.A Siwabessy research reactor for 58.61 h. At the end of irradiation, ⁴⁶Sc radioactivity was 26.67; 57.81; 85.48 mCi/capsule. The SS-316 capsule swab test, its was found that ⁴⁶Sc radioactivity contamination was 2.198 Bq, 0.089 Bq and 0.218 Bq which were declared free of contamination. The gamma energy attenuation test for the thickness of the SS-304 plate, indicating that there is significant relationship between plate thickness and ⁴⁶Sc gamma energy intensity. (author)

[en] Over the past 10 years the Australian Atomic Energy Commission has had a program of research into the use of radioisotope techniques for studying termite infestations. The studies have been divided between two aspects of termite behaviour: their behaviour in a natural environment, and their behaviour in an urban environment where they co-exist with man and have to cope with his attempts to disturb or eradicate them. Scandium-46 oxide was incorporated into a sawdust-agar gel mixture packed into a hole drilled in wood dowelling. Later lanthanum 140 in a diethylenetriaminepentaacetic acid complex was used, both in the natural environment and in surveys of historic buildings in Sydney. Other termites will accept a bait made from agar gel into which either gold-190 colloid or iodine-131 iodide has been incorporated

[en] This paper describes a novel approach for preparation of scandium oxide-glass microspheres for use as radiotracer in radioactive particle tracking (RPT) experiments conducted for flow visualization in industrial systems. The approach involves preparation of scandium (1 % Sc₂O₃) glass, crushing the glass into small particles of different sizes, converting the non-spherical particles into spherical particles using an indigenously developed novel approach. The obtained spherical glass microspheres were irradiated with thermal neutrons in a nuclear reactor and the activity of Scandium-46 was measured. The activity of the scandium glass microsphere of size 500-1500 μm was found to be 40-325 μCi. (author)

[en] With an objective to develop a cost-effective bone pain palliation agent, we have demonstrated a viable method for large-scale production of ⁴⁵Ca (t_½ = 163 d, E_bmax = 0.3 MeV) using moderate flux research reactor, its purification from radionuclidic impurities adopting solvent extraction approach and preclinical utilization as ⁴⁵CaCl₂. Irradiation parameters were optimized by theoretical calculations for large-scale production of ⁴⁵CaCl₂. The radioisotope was produced in reactor by irradiation of isotopically enriched (> 98 % in ⁴⁴Ca) CaO target at a thermal neutron flux of ~ 1 × 10¹⁴ n.cm^-2.s^-1 for 4 months. Scandium-46 impurity co produced along with ⁴⁴Ca was efficiently removed by solvent extraction approach using tributyl phosphate in dodecane (30 % tributyl phosphate in dodecane) as extractant. The bone specificity of ⁴⁵CaCl₂ was established by in vitro studies involving its uptake in hydroxyapatite (HA) particles and also evaluating its biodistribution pattern over a period of 2 weeks after in vivo administration in Wistar rats. Thermal neutron irradiation of 100 mg of ⁴⁴CaO target followed by radiochemical processing and solvent extraction based purification procedure yielded ~ 37 GBq of ⁴⁴Ca with a specific activity of ~370 GBq/g and radionuclidic purity > 99.99 %. The reliability and reproducibility of this approach was amply demonstrated by process demonstration in several batches. In vitro studies indicated significant uptake of ⁴⁵CaCl₂ (up to 65 %) in HA particles. In vivo biodistribution studies in Wistar rats showed specific skeletal accumulation (40-46 %ID/g) with good retention over a period of 2 weeks. To the best of our knowledge, this is the first study on utilization of ⁴⁵CaCl₂ in context of nuclear medicine. The results obtained in this study hold promise and warrants further investigations for future translation of ⁴⁵CaCl₂ to the clinics, thereby potentially enabling a cost-effective approach for metastatic bone palliation especially in developing countries. (author)

[en] Conical liquid-solid fluidized beds have various industrial applications due to their high heat and mass transfer characteristics. However, knowledge of these reactor performances in detail is not accessed yet. The literature available on conical liquid-solid fluidized bed is confined to development of empirical correlations. Therefore, a lagrangian study has been performed in the present work. An in-situ technique called radioactive particle tracking technique is used for local parameter study. Further, the effect of particle size, inlet velocity and bed composition is studied in the present work. A gamma ray emitting source is used as tracer in RPT technique to track the discrete phase present in the bed. Scandium-46 is the radioactive tracer used in the present work. A conical column of 0.05 m bottom diameter with 0.8 m height and 5.4° tapered angle is used. Solid material of same density (2500 kg/m³) and different size (0.6 mm and 1 mm) are used in the experiment. Tap water is used as fluid. Experiments are performed at 2, 3, 4 times of minimum fluidization velocity of 1 mm particle to understand the velocity effect. The bed compositions used are 100:0, 50:50, 75:25, 25:75 and 0:100 ratio of smaller to bigger particle. The total mass of the bed for each experiment is maintained as 1.36 kg. Particles are being tracked individually in binary bed. The intensity of radiation emitted by tracer is recorded by a number of scintillation detectors placed around the column. The lagrangian position data is obtained from post processing. Further, other parameters like instantaneous velocities, mean velocities, rms velocities, kinetic energy of fluctuations, stresses etc. are obtained. In addition, time series quantities like autocorrelation function, R/S analysis, kolmogorov entropy, correlation dimension and solid diffusivities are calculated to understand the chaotic nature of the fluidized bed for each operating condition. (author)

[en] Cobalt-60 is usually used for calibration standard that nowadays, it hard to fabricated. This research aims to fabricate of Sealed Source ⁴⁶Sc as alternative Calibration Standard. Sealed source ⁴⁶Sc radioactivity was 1.17 ± 0.08 µCi, sealed with an aluminum label. Radiation exposure on the surface opened container is 19.27 ± 0.09 µSv/h, a closed is 10.78 ± 0.15 µSv/h and the distance of 1 m from an open container is 4.40 ± 0.04 µSv/h whereas closed has 2.40 ± 0.04 µSv/h. Multi-channel analyzer γ-spectrometry showed the ⁴⁶Sc gamma spectrum similar with characteristics from standard ⁶⁰Co source. (author)

No abstract available

No abstract available