[en] Cr(VI) and many kinds of Cr(III) are separated by using dowex 50 cation exchanger and perchloric acid eluent. Potassium chromate is purified by recrystallization process to be less than 1/1000.000 of Cr(III), and irradiated by neutron flux of 10¹² det in 1-7 days. The highest activity is of Cr(III) dimer, the negligible one is of Cr(III) polymer. It is possible that Cr(III) is formed by radiolysis and other processes. It can be seen that Cr(III) concentration decreases according to radiation time. (author tr.)

[en] To record the radioactive strengths continuously of a radioactive material which has half life few hours, it is necessary to design an exponential display with the time base can be varied and selected which is equal to the decay time constant of the measured radioactive material. Design and principle operation of this equipment is presented and explained briefly. (author)

[en] This paper describes the basic circuit and the design method for a multidecade logarithmic counting ratemeter. The method is based on the charging and discharging of several RC time constants. An F.E.T. switch is used and the drain current is converted into a proportional voltage by a current to voltage converter. The logarithmic linearity was estimated for 4 decades starting from 50 cps. This circuit can be used in several nuclear instruments like survey meters and counting systems. This circuits has been developed as part of campbell channel instrumentation. (author)

[en] The wide spread use of sup(99m)Tc-labelled radiopharmaceuticals and limitation of the short half-life of the isotope, is associated with an urgent need for a rapid, simple but accurate method for determining the radiochemical purity of the compound. A short paper chromatographic (KK) or thin layer chromatographic (KLT) method using 95% methanol or 0.9% saline solution as solvents, has solved the problem. With these methods, the amount of free sup(99m)Tc pertechnetate in a compound, can be determined in only a few minutes. These methods compare satisfactorily with lengtheir procedures. (author)

[en] A determination of the adsorption capacity of neutral aluminium oxide for molybdenum at various pH, the effect of heating on this adsorption capacity and the effect of eluation with a 0.9% sodium chloride solution on the adsorbed molybdenum has been carried out. The adsorbed molybdenum was determined by spectrophotometry of the unadsorbed molybdenum as thiocyanate complex. (author)

[en] Criteria of the design, construction and operation of PWR type reactor, including hazards and safety evaluations are presented. (author tr.)

[en] Experiments have been done in the preparation of radioiodinated fats and fatty acids by using triolein and oleic acid. The radioiodination (¹³¹I) had been carried out by the iodomonochloride method and the radiochemical purity was determined by paper chromatography. It has been found that the final products are stable after a fiew days under ordinary storage condition. (author)

[en] The instrumentation and control of nuclear research reactor BATAN at Yogyakarta were generally described covering neutronic, non-neutronic and protective systems. In addition the automatic control utilizing neutronic signal were briefly discussed. The design was then compared to the existing nuclear standard criteria. (author)

[en] A converter is designed to convert 2 bateries input voltage of 1.5 volt each, to obtain the desired dc output voltage to perform a low voltage of 10 volt, 3mA and a high voltage of 600 volt, 20 A. The L.V. of 10 volt is operated to provide some transistor bias voltages, to a preamplifier and a discriminator, and the H.V. of 600 volt supply a GM tube (type 18555) bias voltage. The converter comprise of a blocking oscillator, a transformer, a double ended clipper, a rectifier and a filter. The waveform of the ac voltage to be generated in the blocking oscillator is square wave approximately. The 2N 2907-type transistor as a blocking oscillator operates in the linear region. The saturation region of the 58T3-type ferrite transformer never been reached. Even the efficiency is rather low; the bat-tery life can reach 25 hours approximately. (author)

[en] Multisample changer having 72 samples has been design by using transistor component and SCR with programable time sequence. The instrument is coupled with liquid Scintillation Counter SL-20, sample capacity can be greater. (author tr)