Measurement of liquid scintillation sources of (210)Pb obtained from (222)Rn decay.
Liquid scintillation samples were filled with (222)Rn and the activity was measured with good precision after reaching the secular equilibrium with the progeny (218)Po, (214)Pb, (214)Bi and (214)Po. After decay of most of (222)Rn activity, the samples contain (210)Pb and progeny. The activities of (210)Pb and progeny can be calculated as a function of time using the initial (222)Rn activity. The samples were measured in a TDCR counter and the experimentally determined counting efficiencies are in accordance with previously published results.
Establishment of the 222Rn traceability chain with the Romanian standard system
Abstract This paper presents the results obtained in the establishment of the upper level of the traceability chain, primary and secondary 222 Rn measurements, with the standard system realized at IFIN-HH, Romania. The following subjects are presented: (i) the principle of establishing the traceability chain; (ii) the setting up of the final metallic system for the radon standardization and the experimental method; (iii) results obtained in the realization of the traceability chain, by absolute radon standardization with the liquid scintillation counting method (LSC) and relative measurements of activity, using the HPGe gamma-ray spectrometry method and the CENTRONIC IG12/20A ionization chamber, and its validation. The final purpose of the work is to calibrate adequately the secondary standard systems, HPGe spectrometer and ionization chamber, for using them in the measurement of the working standards, various types of recipients containing radon gas, prepared in the laboratory with the radon system.
Identifying the optimum water flow and number of buckets in laboratory-scale Pelton turbine using Central Composite Design (CCD)
Pelton turbines were a type of water turbines which, principally, turned the water kinetic energy into electrical energy. The working principle of Pelton turbines was to utilize water power to produce turbine power. This paper reported the optimization of design parameters for laboratory-scale Pelton turbine using the central composite design (CCD) as the response surface methodology (RSM). This research obtained the quadratic polynomial equations for the turbine power. The independent variables were water flow (0.11 m3/s; 0.13 m3/s; 0.15 m3/s) and number of buckets (13; 15; 17 pieces). The results, based on the RSM, showed that the most influential parameter on the turbine power was the number of buckets. The optimum turbine power was 24 kW on 0,16 m3/s water flow and 18 buckets of RSM.