Determination of inorganic compounds in drinking water on the basis of household water heater scale

The concept of fractional extraction from sediment - in our analyses it is scale, is based on the assumption that uranium with a solid substance conform bonds of different strength and that these bonds can be gradually fractionated by the action of reagents of increasing dissolving power whereby the separated phases of extraction are defined according to their function or the type of bond in that substance. The advantage of this analytical procedure is that it enables simultaneous observing of different forms of uranium emergence in sediment (solid substance), which cannot be achieved by using individual extraction methods. Using the method of fractional analysis, it has been found that uranium is mostly connected with mobile fraction - manganese and iron oxides (94.20 and 87.96 wt.%) which represents the fraction that is potentially accessible to human organism.Princip frakcione ekstrakcije iz sedimenta, u slučaju naših ispitivanja kamenca, zasniva se na shvatanju da uran može da formira sa čvrstom supstancom veze različite jačine i da te veze mogu biti postupno raskinute delovanjem reagenasa rastuće jačine, pri čemu se pojedinačne faze ekstrakcije definišu na osnovu njihove funkcije ili oblika vezanosti u toj supstanci. Prednost ovog analitičkog postupka je u tome što omogućava istovremeno sagledavanje različitih oblika pojavljivanja urana u sedimentu (čvrstoj supstanci), što se ne može postići primenom pojedinačnih ekstrakcionih metoda. Metodom frakcione ekstrakcije, primenjenom u ovom radu utvrđeno je da je uran najviše vezan za potencijalno-pristupačnu i mobilnu frakciju - okside gvožđa i mangana (94,20 odn. 87,96%), što predstavlja frakciju koja je potencijalno pristupačna ljudskom organizmu

Radon measurements with charcoal canisters temperature and humidity considerations

Radon testing by using open-faced charcoal canisters is a cheap and fast screening method. Many laboratories perform the sampling and measurements according to the United States Environmental Protection Agency method - EPA 520. According to this method, no corrections for temperature are applied and corrections for humidity are based on canister mass gain. The EPA method is practiced in the Vinca Institute of Nuclear Sciences with recycled canisters. In the course of measurements, it was established that the mass gain of the recycled canisters differs from mass gain measured by Environmental Protection Agency in an active atmosphere. In order to quantify and correct these discrepancies, in the laboratory, canisters were exposed for periods of 3 and 4 days between February 2015 and December 2015. Temperature and humidity were monitored continuously and mass gain measured. No significant correlation between mass gain and temperature was found. Based on Environmental Protection Agency calibration data, functional-dependence of mass gain on humidity was determined, yielding Environmental Protection Agency mass gain curves. The results of mass gain measurements of recycled canisters were plotted against these curves and a discrepancy confirmed. After correcting the independent variable in the curve equation and calculating the corrected mass gain for recycled canisters, the agreement between measured mass gain and Environmental Protection Agency mass gain curves was attained

THE EFFECTS OF ESTRADIOL AND HUMAN CHORIONIC GONADOTROPIN ON ACTH CELLS IN PERIPUBERTAL FEMALE RATS: A HISTOLOGICAL AND STEREOLOGICAL STUDY

The effects of estradiol (EDP) and human chorionic gonadotropin (HCG) on histological and stereological features of adrenocorticotropic (ACTH) cells in peripubertal female rats were examined. The first group of females received five injections of EDP (0.25 mg/kg b.w.), every second day from the 4th to 14th day after birth, and was killed at the peripubertal stage. The second group of females was given two injections of pregnyl-gonadotrophinum chorionicum (HCG; 50 IU/kg body weight) on the 36th and 37th days after birth, and it was killed 24 h after the last treatment. The controls were injected with an equivalent volume of the corresponding vehicle. ACTH cells were immunohistochemically labeled and stereologically evaluated. Stereological analysis showed that the volume of ACTH cells and their volume density in peripubertal females treated with EDP, were decreased by 15.6\% and 53.8\% (p < 0.05), respectively, compared to the controls. In HCG-treated animals, the observed parameters were increased by 39.2\% and 15.4\% (p < 0.05), respectively, in comparison with the control females. These findings suggest that the application of EDP or HCG exerted opposite effects on the stereological features of pituitary ACTH cells.Ministry of Education, Science and Technological Development of the Republic of Serbia {[}ON 173009

P estimation of radiological impact on residents due to household storage of coal used for heating in Serbia

This pa per aims to es ti mate a po ten tial ra dio log i cal risk from dif fer ent kinds of coals used for do mes tic heat ing in Ser bia, by mea sur ing the ac tiv ity con cen tra tion of radionuclides and ra don ex ha la tion rate. The ob tained ra don mass ex ha la tion rate ranges from (5.3 +/- 3.1) mu Bqkg-1s-1 to (70.3 +/- 9.4) mu Bqkg -1s-1 and was high est for lig nite type of coal. It is es ti mated that coal stored in the base ment could con trib ute up to 50 Bqm-3 of in door ra don con cen tra tion at the ground level. Ac tiv ity con cen tra tions of 226Ra, 232Th, 40K, 238U, 235U, and 210Pb in ana lysed coal sam ples agree with pre vi ously re ported con cen tra tions of coal used in Ser bia. The values of radium equivalent concentration and external hazard index indicate that the used coal does not represent a significant radiation hazard

First steps towards national radon action plan in Serbia

Radon problem has a special attention in many countries in the world and the most of them have established national radon programmes. The radon issues in Serbia have not been approached in a systematic and organized way. Currently, there are many research groups and institutions working in radon field, and it is a good basis to integrate all these activities into a comprehensive national programme to define the strategic objectives and action plan for the next few years. Also, Serbia as a candidate for membership in the EU is obliged to harmonize its legislation, including the field of radiation protection in which the radon issues has an important role. In this report, a brief history of radon research, present status and plans for the future activity on radon issues in Serbia are presented. Regarding the long-term plans, the establishment and implementation of the Radon Action Plan with the primary goal of raising awareness about the harmful effects of public exposure to radon and implementing a set of measures for its reduction. In that sense, the synergy between the national, regional and local organizations responsible for public health and radiation protection must be achieved