Study of Argon Afterglow with the Air Addition

The reaction kinetics in argon flowing afterglow (post-discharge) with the air addition was studied by optical emission spectroscopy. The optical emission spectra were measured along the~post-discharge flow tube. A zero-dimensional kinetic model for the reactions in the afterglow was developed. This model allows to calculate the time dependencies of particle concentrations

Early Badenian transgression on the outer flank of Western Carpathian Foredeep, Hluchov area, Czech Republic

This multidisciplinary study, based on borehole cores from the Hluchov area in Czech Republic, docu- ments an early Badenian marine transgression on the outer flank of the Western Carpathian Foredeep . The shallow-marine deposits represent coastal transgression over a terrestrial topography of weathered pre-Cenozoic bedrock. The lower facies association (FA1) consists of siliciclastic sediment derived from local substrate erosion. Facies indicate a wave-dominated environment with unstable bottom, variable rate of sediment supply and an incremental rise of relative sea level. The upper facies association (FA2) consists of carbonates indicating a major landward shift of shoreline, decline in siliciclastic input and further sea-level rise. The succession represents a transgressive to highstand systems tract. The maximum flooding surface, ca . 1 m above the FA1/FA2 boundary, is signified by an anomalous decrease in K and Th, an increased Th/K ratio and highest U concentration. The heavy-mineral assemblages in FA1 confirm local sediment provenance, whereas those in FA2 indicate broader sediment derivation, including volcanic component from contemporaneous rhyolitic to rhyodacitic eruptions. The deposits contain a wide range of marine fauna, with the foraminifers and molluscs indicating an early Badenian age. Molluscs, bryozoans and echinoderms indicate a normal-salinity environment with a decreasing hydraulic energy. Foraminifers indicate salinity fluctua- tions in the lowest part of the succession. The isotopic composition of mollusc shells shows marked inter-species differences and a general negative shift in the d 13 C and d 18 O values, indicating diagenetic alteration. The impact of diagenetic processes appears to have been controlled by sedimentary facies. The highly negative d 13 C and d 18 O values correspond to sediment layers with the highest Th/K ratios and hence low clay content. Sediment permea- bility was thus probably crucial in controlling the differential circulation and impact of diagenetic fluids

Sedimentological and palaeocological records of the evolution of the south west ern part of the Carpathian Foredeep (Czech Republic) during the early Badenian

The depositional environment of the southern part of the Carpathian Foredeep in the Czech Republic was studied in two boreholes using sedimentological and palaeontological methods. Eight lithofacies were recognised within cores of the early Badenian deposits, comprising two facies associations, namely deposits of a coarse-grained Gilbert delta and offshore deposits. As sem blages of foraminifers document the early Badenian (Middle Miocene age). Two types of assemblages were recognised: (1) primary taphocoenoses reflecting the original environment of sedimentation, i. e. a relatively deep sublittoral (circalittoral) environment with low to normal ox ygen bottom conditions and deep-water euryoxibiont foraminifers, numerous planktonic foraminifers, agglutinated foraminifers and mixed assemblages of deep- and shallow-water foraminifers, (2) secondary taphocoenoses of shallower sublittoral (infralittoral) condition redeposited into the basin by gravity currents. These assemblages contain shallow-water foraminifers coupled with an abundant and diverse bryozoan fauna

Medical radiation exposure of the Czech Republic paediatric population due to diagnostic nuclear medicine

BACKGROUND: The information on the results of the survey of collective effective dose SE to children in the Czech Republic (CR) due to nuclear medicine examinations performed during the one-year period July 1995?June 1996. METHODS: The estimate of SE was based on the annual frequency of nuclear medicine procedures and the type and amount of administered radiopharmaceuticals provided by the General Health Insurance Company covering 75% of the CR population. RESULTS: In the period considered, 15,281 examinations of children younger than 18 years were performed, which represented 7.5% of total nuclear medicine examinations in the CR. The annual SE 43.8 man Sv formed 5.1% of the collective effective dose to all patients examined by nuclear medicine procedures in the CR. The contributions of procedures in various body systems of children to the annual SE: urinary tract 32.8%, bone 30.4%, brain 12.8 %, cardiovascular 6.4%, GIT 6.0%, thyroid 4.4%, lungs 3.0%, other 4.2%. In comparison with a similar survey performed in the CR in 1987 (based on a questionnaire)there was an increase in SE to children younger than 15 years by a factor of 2.8, mainly due to the expansion of kidney and bone investigations. CONCLUSIONS: The mean effective dose per exam to children younger than 15 years was 60% of that for adults, which was in agreement with the requirement that the radiation burden of children should not exceed that of adults. The use of data from the Insurance Company for regular conducting of such surveys appeared to be not as cumbersome and time-consuming as questionnaire surveys

Local catastrophe caused by tephra input near Přemyslovice (Moravia, Czech Republic) during the Middle Miocene

Colonization by marine organisms such as foraminifers, molluscs, bryozoans, brachiopods and red algae during the Middle Miocene (Early Badenian) transgression near Přemyslovice (Carpathian Foredeep) was initially affected by a cool water current of unclear origin. However, shortly afterwards, fallout of volcanic material caused a total termination of the biota. After this catastrophe, the biota started recolonize the area. The succeeding association, adopted to warm-water input, is characteristic of the climatic optimum during the Early Badenian and is comparable with those of other sections referred to this interval in the Carpathian Foredeep (such as Kralice nad Oslavou, Podbřežice, and Hluchov)