The history of the rondeau between East and West

The rondeau, as it is known today, is a literary genre originating from medieval and French Renaissance poetry. In this thesis I am relying on the distinction between the rondeau group (relating to all the subgenres from the early triolet) and the rondeau genre (dating from the sixteenth century), established by Gleeson White, Leon Emile Kastner and Hellen Louis Cohen. To understand the genre and trace its history, I compiled a corpus of poems from three literatures: Russian (1898‒1924), German (1885‒1930) and Serbian (1903‒1999). Apart from that, handbooks, treatises and manuals used by poets and researchers have been analysed

Quality control of HPGe detectors for gamma spectrometry of environmental samples

Quality assurance and quality control (QA/QC) is a series of procedures aimed at verifying the validity of the measurement results and are defined in the Standard ISO 17025/17. QC should be planned, described in the quality control documentation, performed in a systematic manner, recorded and reviewed. All proposed measures for QC/QA are implemented in the Radiation and Environment Protection Department of Institute for Nuclear Sciences Vinča, Belgrade. One of these procedures prescribes a regular quality control of the instruments used for the measurement. In this paper, the quality control of three High Purity Germanium (HPGe) detectors, produced by Canberra, are presented. The accuracy and reproducibility of gamma spectrometry systems are verified on a weekly basis. Total background count rate is used to verify that the detector and shield has not been contaminated. Measurement of the total activity of calibration source is used to check the efficiency calibration and general operating parameters of the system such as peak shape and peak drift. These values are observed and verified if they are within the acceptance limits. For that purpose, 60Co and 133Ba point sources, produced by Czech Metrology Institute and traceable to Bureau International des Poids et Mesures (BIPM), are used. The acceptance limits for each controled parameter are defined according to the statistical analysis of the previous QC period. The acceptance limits are set to be ±2σ and ±3σ of the mean value taken over a previous year. Results of the QC measurement falling between ±2σ are considered to be satisfactory, the ones between ±2σ and ±3σ are warning and those exceeding ±3σ indicate that a problem with the measurement system has occurred. Analysing the QC data acquired for 2021, we can conclude that major part of parameters were within the limits of acceptance. Occasional discrepancies were minor and were addressed immediately. Discrepancies of the peak shape were corrected simply by additional cooling of the instrument, peak position by performing an energy calibration and background was corrected by ventilating the laboratory.Twentieth Young Researchers’ Conference - Materials Science and Engineering: Program and the Book of Abstracts; November 30 – December 2, 2022, Belgrade, Serbi

Chemical and radiochemical fractionation of depleted uranium in contaminated soils

The results of the chemical and radiochemical characterization of depleted uranium present in the soils since it was used in Balkan intervention, 1999, are presented. The contamination levels and uranium fractionation in the soil substrates was examined using radiation spectrometry methods and by application of the five-step sequential extraction procedure. Alpha-spectrometric uranium isotopic analysis enabled to find out the recently appeared uranium in the environment mobility and/or fixation into stable forms in the soil, distinguishing depleted from naturally occurring uranium on the basis of 234U/238U and 235U/238U activities ratios.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

Concentration Of The 241Pu In Air Samples From Chernobyl At Belgrade Site Estimated By a 241Am In Growth Method

The surface air samples collected in the first half of May 1986 at VinčaBelgrade site were prepared and measured at the end of the 1991 and beginning of the 1992. year. Activity concentrations of the 137Cs immediately after the Chernobyl accident were determined by means of gamma spectrometry, while the air activity concentration of 238Pu and 239,240Pu were determined by alpha spectrometry, after the plutonium radiochemical separation. The 236Pu was used as a tracer. The same samples were remeasured after 13 years, during the 2004. The surface air activity concentrations of 241Pu were estimated by a 241Am in-growth method. The built up activities of 236Pu progenies were determined from the recorded spectra and also calculated using the Bateman’s equations. The 241Am activity in the remeasured samples, obtained by complex spectral analysis was confirmed by gamma spectrometry. The 241Pu activity concentration in measured air samples ranged from 240 µBq/m3 to 7800 µBq/m3 . The average activity concentration ratio 241Pu/239,240Pu originated from Chernobyl accident was approximately 100.Second European IRPA Congress on Radiation Protection : May 15-19, 2006, Paris, France

Radionuclide content in samples of berries

After the Chernobyl accident, the presence of artificial radionuclides in foodstuff, especially in berries (blueberries, cranberries etc.), was heightened. Legislative, presented in Rulebook on Radioactivity Control of Goods During the Import, Export and Transit (Official Gazette RS, 86/19 and 90/19), establishes the mandatory gamma spectrometry measurement of berries, while the limits of radionuclide content in these products is defined in the Rulebook on Limits of radionuclide content in drinking water, foodstuff, feedstuff, medicines, items of general use, building materials and other goods placed on the market (Official Gazette RS, 36/18). At the Radiation and Environment Protection Department of the Vinča Institute of Nuclear Sciences, measurements of the radionuclide activity in foodstuff are readily performed. In this paper, the results of the investigation of berries in the period of 2014 to 2021 are presented along with the amount of this produce that can be ingested by the various age groups without exceeding the annual effective dose limit of 0.1 mSv

Comparison of results of radon level measurements obtained with charcoal canisters and airthings detectors during summer at TCAS

Radon is the main source of natural radiation and has been classified as a carcinogen by the relevant international organizations. It is released from soil, water, building materials in the atmosphere and the most significant part of dose due to radon is received by the inhalation of 222Rn and its progeny in closed spaces. At Technical College of Applied Sciences in Zrenjanin (TCAS) two-day long radon concentration measurements were performed in eight rooms during summer holidays by using open charcoal canisters (EPA520 method) and by simultaneously engaged active type Airthings radon detectors. During the measurements open charcoal canisters and Airthing detector were placed one near the other at the table of about 1 m height, windows and doors in the rooms were kept closed and rooms were also not ventilated for some time before the start of the measurements. These studies were performed in order to check radon concentration levels at TCAS as part of the project Radon Level Measurement activities financed by the Provincial Secretariat for Higher Education and Scientific Research. The results were compared and discussed.RAD 2023 : 11th International Conference on Radiation Natural Sciences, Medicine, Engineering, Technology and Ecology (RAD 2023) 19–23.06.2023; Herceg Novi, Montenegr

Green Alkali Activated Materials Based on The Different Precursors

The main goal of this study was the evaluation of physical–chemical, as well as radiological properties of residual materials used for synthesis of alkali activated materials (AAMs) for the possible application as new materials in a civil engineering industry. Also, the purpose of this research was to investigate the hydrophobicity of new alumino-silicate materials and the influence of Si/Al ratio on their surface properties. Contact angle measurement (CAM) as reliable indicator of hydrophobicity was determined for synthesized AAMs using water and ethylene glycol as reference liquids. Alkali-activated materials were synthesized from various precursors: kaolin, bentonite and diatomite. Characterization of phase structure and microstructure was performed by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Scanning electron microscopy and Energy-dispersive X-ray (SEM/EDX) spectroscopy. Contact angle measurements confirmed that the alkali-activated materials synthesized from metakaolin are the most porous, which can be explained by the smallest Si/Al ratio. The maximum value of contact angle and free surface energy (110.2 mJ/m2 ) has been achieved for alkali-activated materials synthesized by diatomite (GPMD). Concentration of 40K and radionuclides from the 238U and 232Th decay series in waste precursors, their metaphases and AAM samples synthetized by alkali activation were determined together with corresponding absorbed dose rate (D˙) and the annual effective dose rate. Natural activity concentrations in the alkali-activated materials were found to be lower than that of both residual materials and calcined ones

Alkali activation of different type of ash as a production of combustion process

Presented study deals with the final structure and radiological properties of different fly-ash based geopolymers. Lignite fly-ash (lignite Kolubara – Serbia) and wood fly ash were obtained in combustion process together with commercial fly-ash. Synthesis of the geopolymers was conducted by mixing fly-ash, sodium silicate solution, NaOH and water. The samples were strengthened 60 °C for 48 hours after staying at room temperature in covering mold for 24 hours. The X-ray diffraction, Fourier transform infrared and SAM measurements were conducted on the samples after 28 days of geopolymerization process. The X-ray diffraction measurements of lignite fly-ash samples show anhydrite as the main constituent, while wood fly-ash samples consist of calcite, albite and gypsum minerals. Besides determination of physicochemical properties, the aim of this study was radiological characterization of lignite fly-ash, wood fly-ash and the obtained geopolymer products. Activity concentration of 40K and radionuclides from the 238U and 232Th decay series, in ash samples and fly-ash based geopolymers, were determined by means of gamma-ray spectrometry, and the absorbed dose rate, D, and the annual effective dose rate, E, were calculated in accordance with the UNSCEAR 2000 report

An assessment of tritium deposition on the earth's surface

Tritium, radioactive isotope of hydrogen, is produced naturally in the upper atmosphere between nitrogen atoms with high energy cosmic rays. Anthropogenic production has disturbed the natural levels of tritium by nuclear atmospheric tests between 1945 and 1963. Tritium is a pure beta emitter with half-life of 12.32 years. Since the main way to eliminate tritium from the atmosphere is through precipitation, whether of natural or artificial origin, tritium easily reaches surface waters and soil from where it can infiltrate into the groundwater and thus enters in the hydrological cycle. Accordingly, knowing the concentration of tritium in precipitation is of essential importance. This paper presents determination of tritium in precipitation collected at Reference Meteorological Station Zeleno Brdo in Belgrade during 2019. Analysis is done in composite monthly samples. Sample preparation involves the first distillation, electrolysis and the second distillation. Samples were measured by Liquid Scintillation Spectrometer Quantulus 1220 after electrolytic enrichment by mixing 8 ml of sample with 12 ml of scintillation cocktail. Tritium activity concentration in analyzed precipitation samples follows normal seasonal variations with maximum in spring-summer months. Based on the monthly amount of precipitation, that is available on the website of the Republic Hydrometeorological Servise of Serbia, it is possible to estimate the deposition of tritium on the earth's surface. The wettest months of 2019 were May and June, and since tritium concentrations are the highest in these months (June: 2.89 Bq/l), the highest value of deposited tritium is obtained in June: 400,8 Bq/m2 . In accordance with the legislation in the Republic of Serbia, the permitted values of tritium are defined only for drinking water (100 Bq/l). An elevated tritium level may indicate the presence of other artificial radionuclides. If an increased activity of tritium is detected, it is necessary to perform an analysis of specific activities for the other artificial radionuclides.Twentieth Young Researchers’ Conference - Materials Science and Engineering: Program and the Book of Abstracts; November 30 – December 2, 2022, Belgrade, Serbi

Activity concentration of 210Pb in aerosol in Serbia in the period of 2014-2020 and the comparison between results from urban and rural sampling stations

Aerosol sampling and monitoring of naturally occurring and artificial radionuclides is readily performed within the frame of Environmental radioactivity monitoring in the Republic of Serbia. It provides information important for the preservation of the public health and the environment from the harmful effects of ionizing radiation. This type of monitoring has been performed in Institute of Nuclear Sciences Vinča for more than 30 years now. The radionuclides that are measured are: naturally occurring 210Pb, artificial radionuclide 137Cs and cosmogenic radionuclide 7 Be. Particle reactive radionuclides such as 210Pb and 7 Be have been used as atmospheric tracers for studying environmental processes such as cloud scavenging and precipitation [1], aerosol transit and residence times in the troposphere [2], and aerosol deposition velocities [3]. The fission product 137Cs is an indicator of anthropogenic pollution caused by nuclear weapon atmospheric tests and nuclear power plant accidents. Seasonal variation in 137Cs in air is an indicator of the stratosphere-troposphere exchange processes [4]. In most aerosol samples in later years, the activity concentration of 137Cs is below the minimal detectable activity and therefore it was not taken into the consideration in this paper. The activity concentration of 7 Be is dependent on the movements of large air masses and vertical mixing in the atmosphere and also was not discussed in this paper. In this paper, the activity concentration of 210Pb in aerosol samples, obtained over the period from 2014. to 2020., was discussed. Sampling is performed using constant air flow pumps and Whatman filter papers on 6 measuring stations distributed in various parts of the country. Three stations are in urban areas of cities of Belgrade, Vranje and Zaječar and other three are in rural areas (Palić and Zlatibor) or removed from the urban part of the city (Meteorological station in Vinča). The monthly composite sample from each sampling station was ashed at the temperature below 400o C. After ashing, the residue aerosol is measured on HPGe detectors using a standard gamma spectroscopy method [5]. The results for 210Pb are of the order of magnitude of 10-4 to 10-3 Bq/m3 . The activity concentration in all investigated samples shows temporal dependence with the maxima in the winter months and minima observed during the spring and summer. Also, the comparison between the results obtained from the rural and urban locations was performed in order to investigate the influence of the air pollution present in the urban areas on the activity concentration of 210Pb. The values, obtained at stations located in rural parts, ranged from (0.056 – 3.3) mBq/m3 , while for stations located in urban areas the range was from (0.125 – 2.9) mBq/m3 . It can be seen that from all the data that the activity concentration of 210Pb was lower in rural areas. Two outliers were observed at Palic station, located in the plane and along the path of the prevailing south – east wind, possibly bringing aerosols from Deliblatska pescara (Deliblato Sands) [6].IV International Conference on Atmospheric Dust : October, 4-7, 2021, Torre Cintola Conference Centre | MONOPOLI | Italy