Acta Facultatis Ecologiae - TechnickÃ¡ univerzita vo Zvolene

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39222Rn is produced by radioactive decay of 226 Rain the soil grains. Part of the produced 222 Rn getsinto the soil air. Then it is transported mostly bydiffusion processes into the atmosphere. Decayproducts of 222 Rn remain in the soil because theyare solid state metals. The amount of 222 Rn thatescapes from the soil to the atmosphere depends onthe depth where radon was created and on the permeabilityof the surrounding soil. Radon present inthe atmosphere is created mostly in the top 10 m ofthe soil [6].Exhalation rate of 222 Rn generally dependson 226 Ra content in soil, diffusion and emanationcoefficient and soil properties. Average exhalationrate has been estimated to be 0.7–1.3 atoms.cm –2 s –1 . 222 Rn exhalation from oceans is 2–3 ordersof magnitude lower than from the ground surface[6]. Significant variations in 222 Rn exhalation ratehave not been proved yet.222Rn gets to the atmosphere also by emanationfrom ground water. The mechanism is simple. Afterthe ground water enters the atmospheric environment,the majority of radon is released. Other222Rn sources, mostly of anthropogenic origin, arenegligible when compared to the previously mentionedones [7].METHODSContinual measurements of 222 Rn activity concentrationin the outdoor atmosphere has been carriedout since 1991 at the Faculty of Mathematics,Physics and Informatics. Samples are collectedabove an open grassy area in front of the facultybuilding at a height of 1.5 m above the earth’s surface.A high-volume scintillation chamber has beenused for the measurement of 222 Rn activity concentration.The detector itself is a cylinder made ofbrass, with a diameter of 12 cm and with a length of40 cm. The chamber volume is approximately 4.5l. ZnS(Ag) has been chosen as a scintillation material.At each side of the detector there is a glassywindow and a photomultiplier tube. The drawn-inair enters the peripheral sectors first and then, passingnear the windows, it goes to the inner sectorand finally it is drained out. The air flow throughthe detector is 0.5 l/min.Before the air enters the detector itself, firstlyit passes through a high-volume tube where 220 Rn(T 1/2= 55 s) decays completely. In the next stepthere is a system of freezing traps and silica gelboxes where the H 2O vapour is removed from thesucked air at a temperature of –20 °C. Just beforethe detector there is a membrane filter used forcollecting aerosols with deposited 222 Rn decay products.Using this experimental setup it is ensuredthat only pure air and 222 Rn enters the scintillationchamber [8].RESULTS AND DISCUSSIONBecause of the huge datasets that have to beprocessed, the direct EMH numerical computationsare out of question. For example to solve equation(3) numerically for a single year takes approximately4300 calculations. The only effective solution isthe use of PC along with an appropriately programmedcode. From several programming languagessuitable for our purposes we chose the MATHE-MATICA 5 package. The results of the numericalcomputation could be presented in a form of tablesor by synoptic charts. To be as clear as possible, wehave chosen the second way.Equivalent mixing height was computed in thetime interval from 1.1.2004 to 31.12.2004. Becauseof the limited space available we cannot presentthe full results here. In order to be brief we presentjust illustrative example results for summer as wellas winter season. As one can see in figure 3, the coursesof 222 Rn activity concentration and EMH anticorrelatesnearly ideally (when the 222 Rn volumeactivity is high, EMH gets low and vice versa).Statistical summary of numerical results offersinteresting conclusions. Firstly, daily variations ofEMH are observed. It is clear that the EMH reachesa maximum in the afternoon between 2–4 p.m. anda minimum just before sunrise. This pattern is especiallywell visible in the summer season when theamplitude of the temperature is high enough to boostthe eddy diffusion and convective turbulence.To obtain an evidence of the presence of annualEMH variations we carried out the harmonic Fourieranalysis of the averaged diurnal EMH waves.The tested Fourier series were restricted to the firsttwo harmonic terms:⎛ p ⎞ ⎛ p ⎞f ( x) = A + Bsin ⎜ t + pj⎟ + C sin ⎜ t + py⎝⎟ .12 ⎠ ⎝ 6 ⎠(10)Function (10) is used for characterization of thetime courses of 222 Rn activity concentration and for
40h [m]h [m]400,0350,0300,0hA Rn250,0200,0150,0100,050,00,001.07.04 00:00 03.07.04 00:00 05.07.04 00:00 07.07.04 00:00 09.07.04 00:00 11.07.04 00:00 13.07.04 00:00 15.07.04 00:00t [dd.mm.yy hh.mm]400,0350,0300,0hA Rn250,0200,0150,0100,050,00,001.01.04 00:00 03.01.04 00:00 05.01.04 00:00 07.01.04 00:00 09.01.04 00:00 11.01.04 00:00 13.01.04 00:00 15.01.04 00:00t [dd.mm.yy hh.mm]14,012,010,08,06,04,02,00,014,012,010,08,06,04,02,00,0ARn [Bq/m3]ARn [Bq/m3]Fig. 3 Comparison of EMH and 222 Rn volume activity in outer atmosphere during January 2004 (left)and July 2004 (right)
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Page 20 and 21: 19are lower in ill patients compare
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Page 25 and 26: 24- multimode cavities are usually
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Page 29 and 30: 28Tradescantia paludosa 02 test and
Page 31 and 32: 30Tab. 5: Results of positive contr
Page 36 and 37: 35DISCUSSIONThe ionising radiation
Page 42 and 43: 41180160140this reason we also pick
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Page 47 and 48: 46deposit is that stripped in off-l
Page 49 and 50: 48TruenessTrueness was determined i
Page 51 and 52: 50MATERIAL AND METHODSChloroform (p
Page 53 and 54: 52absorbance [a.u.]1,000,750,500,25
Page 55 and 56: 54Tab. 1: Rrequirements determinati
Page 57 and 58: 56Methods of VOC testing were set a
Page 60 and 61: 59Tab. 6: ContinuedSamples withsurf
Page 64 and 65: 63One of the possible explanations
Page 66 and 67: 65Ai - Ai-1 [Bq.m -3 ]86420-2-4-6-8
Page 70 and 71: 69BiodegradabilityThe great variety
Page 72 and 73: 71degradation starts of late days,
Page 74 and 75: 73Fig. 4 Treated (after 28 days of
Page 76: 75parameters of the cutting process
Page 80 and 81: 79Fraction: D (residual rest) prese
Page 82: 81was not confirmed. Maximum of mer
Page 85 and 86: 84Fig. 1 Schematic diagram of atomi
Page 87 and 88: 86Alpha spectrometryAlpha spectrome
Page 89 and 90: 8880007000y = 6622xR 2 = 0.939SIMS
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91ACTA FACULTATIS ECOLOGIAE, 16: Su
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93Gemer according to the German mod
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95Tab. 1 Results of the chemical an
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97Continuation of Tab. 2 Results of
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99Vlčia Dolina and from the reserv
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101ACTA FACULTATIS ECOLOGIAE, 16: S
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103mg.dm -3mg.dm -35,004,003,002,00
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105year and the average value repre
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109Sample site 1 Sample site 2 Samp
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111As for the sampling time (Fig. 5
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115Typha latifolia, Carex sp., Scir
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117conditions for decomposition of
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121from the background (derived fro
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12311. PETROVSKÝ, E., ELWOOD, B.:
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1272.52.0Correlation coefficient 0,
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131RESULTS AND DISCUSSIONTable 2 gi
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135V-1 BOREHOLEThe courses of 222 R
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137AV-2 (40m) 2006A ( 222 Rn) [kBq/
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139soaks into the soil, another par
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143Fig. 2 The continuous monitoring
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145Indoor radon activity concentrat
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149Fig. 1 Podlipa dump-fieldCanada)
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151concentrations of Fe. Cu. Cd. Ni
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153DUMP-FIELDREFERENCE SITEppm15001
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155Fig. 5 Compression of wood forma
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157decrease in the following order:
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161SPECIFIC EXAMPLES OFFACTORS THAT
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165The methods developed to incorpo
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167The effects of wind on ozone con
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169Fig. 6 Mean total and stomatal f
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171transport modelling in North Ame
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Acta Facultatis Ecologiae, Volume 1
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