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1

Wstęp do radiobiologii

Bolewski A., Kuc T., Wasilewska-Radwańska M.

Acta Bio-Optica et Informatica Medica. Inżynieria Biomedyczna

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2012

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Vol. 18, nr 2

90-93

PL

W pracy przedstawiono program zajęć z przedmiotu "Wstęp do radiobiologii", opracowany dla studentów V roku kierunku Inżynieria Biomedyczna. Zajęcia prowadzone były jako obieralne w wymiarze: 30 godzin wykład + 30 godzin laboratorium. Program wykładu zawierał podstawy fizyczne obejmujące: rodzaje promieniowania jonizującego i ich źródła, procesy oddziaływania promieniowania jonizującego z materią, detektory promieniowania, wpływ promieniowania jonizującego na komórkę i na organizm człowieka, wielkości dozymetryczne, metody ich pomiaru, podstawowe zasady ochrony radiologicznej oraz radiobiologię w radioterapii. Zajęcia laboratoryjne miały na celu praktyczne zapoznanie z metodami pomiarowymi w zakresie fizyki jądrowej.

EN

The paper shows the curriculum of course "Introduction to radiobiology" prepared for students of the 5th y ear o f Biomedical Engineering study. The program of this course is realized in a form of: 30 hours of lectures + 30 hours of practical classes. The main issues of the course include: physical fundamentals of nature of ionizing radiation and its sources, interaction of radiation with matter, radiation detectors, biological effects of radiation, quantities and units in dosimetry, radiation dose measurement, principles of radiation protection, and radiobiology in radiotherapy. The aim of the practical classes was to acquaint students with the measuring methods used in nuclear physics.

2

Assessment of denitrification rates in fissured-karstic aquifer near Opole (south-west Poland): combined use of gaseous and isotope tracers

Żurek A., Różański K., Mochalski P., Kuc T.

Biuletyn Państwowego Instytutu Geologicznego

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2010

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nr 441 Hydrogeologia z. 10

209--216

EN

Denitrification is the only process leading to reduction of nitrate concentration in groundwater. In this paper the authors report the results of combined measurements of excess gaseous nitrogen and 18O and 15N isotope composition of dissolved nitrate in fissured-karstic Triassic aquifer located in southwestern Poland, in the vicinity of Opole. Generally, the wells located in the confined part of the aquifer reveal greatly reduced nitrate content (ca. 0.3 and 2.7 mg NO3/dm3). Such decrease of nitrate content together with δ18O and δ15N data for those wells suggest well-advanced denitrification process. Enrichment in 15N and 18O of the remaining nitrate corresponds to initial nitrate content in the order of 1.5 to 12 mg NO3/dm3. Lack of tritium in those wells suggest the pre-bomb age of water and natural range of initial nitrate content. In majority of the measured wells nitrogen excess has been below the detection limit of ca. 3.5 mg NO3/dm3. This method is not sensitive enough to detect denitrification of natural nitrate which concentrations in groundwater in the study area were generally below 10 mg NO3/dm3. The presented study demonstrated that combining isotope analyses of nitrates with tritium or other transient tracers may provide additional insights into the dynamics of water and nitrate transformation in groundwater systems.

3

Comparison of two methods for the determination of nitrogen and oxygen isotope composition of dissolved nitrates

Chmura W. M., Różański K., Kuc T., Gorczyca Z.

Nukleonika

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2009

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Vol. 54, No. 1

17-23

EN

Two methods of sample preparation for isotopic analyses of nitrates dissolved in water are presented: (i) chemical conversion of NO3– to N2 and CO2, and (ii) bacterial reduction of NO3– to N2O, followed by the measurement of nitrogen and oxygen isotope composition of these gases. Both methods have been successfully used for routine isotope analyses of dissolved nitrates in different types of water. The chemical conversion method, requiring ca. 300 mi mol of NO3– yields relatively good precision, in the order of 0.3‰ for delta15N, and 0.6‰ for delta18 O. The bacterial reduction method was modified in this study to accommodate samples of intermediate size (ca. 30 mmol of NO3–) to provide sufficient amount of N2O gas for isotope analysis using conventional IRMS. The method demonstrated satisfactory results, although sample preparation was more complicated and required access to microbiological laboratory.

4

Radiocarbon dating of plant remnants in Quaternary sediments at Starunia palaeontological site and vicinity (Carpathian region, Ukraine)

Kuc T., Różański K., Stachowicz-Rybka R.

Annales Societatis Geologorum Poloniae

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2009

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Vol. 79, No 3

289-296

EN

Radiocarbon dating applied on several occasions in the past to date animal bones and animal soft tissue originating from the area of the Starunia palaeontological site turned out to be very controversial. Although investigations of Pleistocene flora in the Starunia area go back to the beginning of the 20th century, no published 14C dates of such material are available to date. Sixteen boreholes drilled in the area of the Pleistocene mammals discoveries, in the framework of a multidisciplinary research project (2006-2009), have been selected for radiocarbon dating of plant macrofossils. Moreover, five samples of plant remnants extracted from two outcrops in the area were 14C-dated. The nature of the dated plant material, in some cases soaked with oil, posed specific methodological problems. Although applied chemical treatment of macrofossil samples led to complete removal of contaminating hydrocarbons in the case of small pieces, some ageing effects in terms of radiocarbon dating cannot be completely ruled out. Radiocarbon ages of macrofossil samples originating from the close neighbourhood of the location, where the "second" woolly rhinoceros was found at a depth of 12.5 m, suggest that the minimum age of sediments in which the Pleistocene mammals were found is in the range of ca. 35-40 ka BP. A broad consistency between palynological reconstruction of Younger Dryas/Preboreal boundary and the corresponding radiocarbon ages of macrofossils is observed for locations, where the natural sedimentary sequence for late Glacial and early Holocene was not disturbed by extensive mining activity in the area.

5

A multi-layer box model of carbon dynamics in soil

Kuc T.

Nukleonika

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2005

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Vol. 50, nr 2

49-55

EN

Abstract A multi-layer box model (MLB) for quantification of carbon fluxes between soil and atmosphere has been developed. In the model, soil carbon reservoir is represented by two boxes: fast decomposition box (FDB) and slow decomposition box (SDB), characterised by substantially different turnover time (TT) of carbon compounds. Each box has an internal structure (sub-compartments) accounting for carbon deposited in consecutive time intervals. The rate of decomposition of carbon compounds in each sub-compartment is proportional to the carbon content. With the aid of the MLB model and the 14C signature of carbon dioxide, the fluxes entering and leaving the boxes, turnover time of carbon in each box, and the ratio of mass of carbon in the slow and fast box (Ms/Mf) were calculated. The MBL model yields the turnover time of carbon in the FDB (TTf) ca. 14 for typical investigated soils of temperate climate ecosystems. The calculated contribution of the CO2 flux originating from the slow box (Fs) to the total CO2 flux into the atmosphere ranges from 12% to 22%. These values are in agreement with experimental observations at different locations. Assuming that the input flux of carbon (Fin) to the soil system is doubled within the period of 100 years, the soil buffering capacity for excess carbon predicted by the MLB model for typical soil parameters may vary in the range between 26% and 52%. The highest values are obtained for soils characterised by long TTf, and well developed old carbon pool.

6

Radiocarbon concentration in urban area

Rakowski A. Z., Kuc T., Nakamura T., Pazdur A.

Geochronometria

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2005

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Vol. 24

63-68

EN

Radiocarbon concentration has decreased in recent years due to the exchange of 14CO2 between the atmosphere and the oceans, but also due to 12CO2 emission from burning fossil fuels. This second phenomenon known as Suess effect can be observed in the highly industrialized and/or urban areas. New data of radiocarbon concentration in tree rings from Nagoya (Central Japan) and Kraków (Poland), which covered last 20 years, were obtained recently. These data were used to find the relationship between the radiocarbon concentrations in atmosphere and biosphere. Additionally, data of radiocarbon concentration in atmospheric CO2 in Kraków were compared with those derived from annual tree rings, to calculate the time of CO2 uptake for pine trees in this region. These data show that radiocarbon concentration of the CO2 in .urban air. is systematically lower than that in "clean air". Data of radiocarbon concentration were fitted by exponential and linear functions to calculate the time of exchange and predict the future level. Using data of carbon dioxide and radiocarbon concentration from Schauinsland fossil component Cf in carbon dioxide concentration level was calculated in Nagoya and Kraków.

7

Carbon dynamics in soil recorded by 14C: model calculations

Kuc T., Gorczyca Z., Kapusta M.

Geochronometria

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2004

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Vol. 23

45-50

EN

Time records of 14CO2 from soil respiration collected in the years 1998 to 2003 on sites representing different ecosystems (mixed wood, agricultural field and grassland, southern Poland), were analysed by use of MLB model built for this purpose. The modelled turnover time (TT) is maximum 22 yr for the agriculturally cultivated soil and only 14 yr for soil under grassland and mixed forest. About 22% of an old component of 1500 yr was admixed to the agriculturally cultivated soil while it was only 12% under mixed forest. Estimated ratio of carbon content in slow and in fast decomposition boxes varies from 22 to 40 in southern Poland pointing to slow decomposing organic compounds as the major pool of carbon in soil. The lowest ratio was observed for soil of low proportion of organics content in mixed forest, and the highest for grassland of well developed soil profile. D14C time records for not cultivated soils (under grassland and mixed forest) showed higher values than local atmospheric CO2, moreover 14CO2 from the mixed forest soil respiration remarkable exceeded "clean air" reference level for Central Europe.

8

Seasonal variability of the soil CO2 flux and its isotopic composition in southern Poland

Gorczyca Z., Rozanski K., Kuc T., Michalec B.

Nukleonika

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2003

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Vol. 48, nr 4

187-196

EN

The flux and isotopic composition of soil CO2 has been monitored at three sites located in the southern Poland, during the time period: January 1998 - December 2000. The sites represent typical ecosystems appearing in central Europe: mixed forest, cultivated agricultural field and grassland. To monitor the flux and isotopic composition of soil CO2, the method based on the inverted cup principle was used. The flux of soil CO2 reveals distinct seasonal fluctuations, with maximum values up to ca. 20 mmolźm-2 h-1 during summer and around ten times lower values during winter. Also significant differences among the monitored sites were detected, the CO2 flux being the highest for the mixed forest site and ca. two times lower for the grassland site. The 13C content of the soil CO2 flux is nearly constant throughout the year, with d13C values essentially reflecting the isotopic composition of the soil organic matter and the vegetation type. The 18O content of the soil CO2 flux shows a remarkable seasonality, with distinctly less negative d18O values recorded during summer. This seasonality is highly reduced in the CO2 sampled from different depths of the soil. The radiocarbon content of the CO2 flux turned out to be non-distinguishable, within the uncertainty of the measurements, from current 14C levels in atmospheric carbon dioxide. However, significant reduction of the radiocarbon content was measured in the soil CO2 sampled at 80 cm, when compared to the uppermost layer, reflecting increasing age of soil organic matter with depth.

9

Główne gazy cieplarniane w atmosferze Polski południowej CH4, CO2. Stężenie i skład izotopowy

Kuc T., Zimnoch M, Nęcki J., Różański K.

Postępy Techniki Jądrowej

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2002

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Vol. 45, z. 3

12-18

10

Radiocarbon dated wood debris in floodplain deposits of the San river in the Bieszczady Mountains

Kukulak J., Pazdur A., Kuc T.

Geochronometria

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2002

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Vol. 21

129-136

EN

Tree logs and smaller fragments of wood debris occur in floodplain alluvium (1-3 m above the river level) of the San river in the Bieszczady Mountains (Polish East Carpathians). The greatest accumulations of wood debris occur in the lower part of the alluvium, beneath a layer of sandy muds. The wood debris in these accumulations was dated by radiocarbon method. The dates fall within the time interval 3270š70 BP to 103.7š1.1 pMC, but most of them are from 17 th to 19 th century. The abundance of the wood debris in the alluvium is the result of its intense supply to the river channel, caused by deforestation and large floods. The age of the wood accumulations corresponds to the phase of settlement in the upper San valley in the 16 th to 17 th centuries. The older wood debris could be redeposited to the young alluvium from older alluvial terraces.

11

Aromatic Solvent Effect on Polarity and Proton-Transfer Equilibrium in Phenol-Triethylamine Systems

Pawełka Z., Kuc T.

Polish Journal of Chemistry

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2001

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Vol. 75, nr 6

845-855

EN

Dipole moments of hydrogen-bonded complexes of 4-nitrophenol-triethylamine and 2,4,6-trichlorophenol-triethylamine have been determined in various aromatic solvents. On this basis, the Gibbs energy _GPT of the proton-transfer equilibrium has been estimated. The aromatic solvent effect on the proton transfer has been discussed in terms of two solvation contributions, arising from a local complex-aromatic molecules interaction and a long-range dielectric effect. The microstructure of the solvent near a complex has been taken into account, utilizing a dielectric model of two spherical solvent layers. The crucial effect of the size of the aromatic solvent molecules on _GPT has been simulated by variation of the thickness of the first solvation layer.