Rock Matrix Studies with Carbon-14-Polymethylmethacrylate (PMMA); Method Development and Applications

Application of the ¹⁴C-PMMA impregnation method has provided relevant information not available by other methods about the accessible pore space in crystalline rock. Such information is relevant for the assessment of the capability of the geosphere to retard the migration of harmful waste components. In this work further developments of the system (calibration, corrections, options), the impregnation method itself (problems related to infiltration and polymerization of the tracer) and an assessment of the method performance are presented, as well as additional examples of applications.     

Bestimmung der Rührstufenzahl aus mit radioaktiven Nukliden gemessenen Verweilzeitspektren

Die mit Hilfe einer radioaktiven Stoβmarkierung in Mischreaktoren gemessenen Verweilzeitktiruen können zur Ermittlung der äquivalenten Rührstufenzahl n_äq verwendet werden. Die beschriebene Methode beruht auf einem Vergleichsverfahren, wonach das gemessene Verweilzeitspektrum einer Kurvenschar gegenübergestellt wird, die für cine Rührkaskade, bestehend aus n hintereinandergeschalteten idealen Durchlaufrührkesseln, abgeleitet wurde. Zur praktischen Durchführung des Verfahrens werden zwei Hilfsfunktionen φ_A und φ_B definiert und für vorgegebene Werte im Bereich von 1 < n < 100 mit Hilfe eines ZRA 1 berechnet. Ein Teil der Werte ist tabellarisiert, die Funktion φ_B ist graphisch dargestellt. Aus der gemessenen Verweilzeitkurve müssen φ_A ^exp und φ_B ^exp ermittelt und mit den theoretischen Werten φ_A ^theor und φ_B ^theor, die als Funktion von n dargestellt sind, verglichen werden. Das Verfahren wird an einem Beispiel erläutert.     

山阴-平鲁段公路工程地质环境与评价

山阴—平鲁段高速公路是国家重点公路威海—乌海公路的一部分。依据路线走廊带1:1万地质综合调查结果,在阐述和分析了3条预选线路的工程地质环境、沿线工程地质灾害的基础上,对各线路的工程稳定性进行了综合评价,并推荐A线为优先线路。     

Environmental gamma and radon dosimetry in Venezuela

Environmental gamma exposure and radon concentration levels measured in Venezuelan regions are presented. A new generation image analyser was used for particle track counting in CR-39 detectors. Mineral water wells from where water is supplied for massive consumption have an alpha activity around 0.450 Bq L⁻¹ and few of them have concentrations above 50 Bq L⁻¹. Coastal potable water activity is on the average around 5.3 ± 12% Bq L⁻¹. Indoor radon national average is 36 ± 5% Bq m⁻³; in two of the 36 monitored sites, the measured average is above 400 ± 5% Bq m⁻³. In air gamma dose values are between 100 and 144 nGy h⁻¹. In soil, ¹³⁷Cs concentration is around 0.5 and 10 Bq kg⁻¹ at the depth of down to 20 cm. Building materials were included in this study. ⁷Be and ¹³⁷Cs were measured in low concentration in tropical plants on Tepuy-s (sacred mountains in the Amazonas State). Geological active faults were identified by radon concentration measurements using LR-115.     

Carbon stable isotope composition of modern and archaeological Cornelian cherry fruit stones: a pilot study

The carbon stable isotope content of Cornelian cherry stones collected from wild tree stands in Serbia, SE Europe, was measured using elemental analyser-isotope ratio mass spectrometry, with the aim of recording natural carbon isotope composition of the fruit stones and its possible variation. The results show a significant variation in the carbon isotope values; we identified several environmental factors that, along with a number of other possible determinants, likely contributed to this variation. The obtained data are compared with the measurement of carbon isotope content of an archaeological specimen of Cornelian cherry stone discovered at the Neolithic site of Vin?a (ca. 5600–4500 BC) in Serbia. Notwithstanding the limitedness of the data and the complexity surrounding carbon fractionation and the isotopic variation, it is suggested that the differences/similarities in carbon isotope ratios between modern and archaeological Cornelian cherry stones, when measured for much larger assemblages, could potentially offer a glimpse into growing conditions of Cornelian cherry trees in the past.     

重力侵蚀作用下昔格达地层滑坡特征分析

昔格达地层性质特殊,强度低,遇水极易崩解,在地质构造与水力作用下,极易发生滑塌。在调查研究的基础上,介绍了文武坡喇嘛溪沟重力侵蚀作用下昔格达地层滑坡的地层岩性、地质构造等工程地质条件及地表水、地下水等水文地质条件,重点分析了滑坡形成原因及影响因素,认为滑坡发生的易发斜坡坡度、坡角与高度,并按坡度对斜坡按危险性分成了3级,得出了滑坡易发坡度,为滑坡稳定性评价提供了依据,最后提出了适合于地质条件的填方反压结合排水沟的整治措施。     

区域稳定动力学研究(一)——理论与方法体系

将区域稳定工程地质学推进到区域稳定动力学的研究层次上, 系统地构建了区域表层稳定动力学、区域浅层稳定动力学、区域深层稳定动力学、区域活动构造动力学、区域地震动力学、区域非稳定动力学过程及机制模式, 以及区域非稳定动力学环境下的地震工程效应、岩体失稳效应、场地失稳效应及建筑物抗断效应的综合研究及分析评价的区域稳定动力学研究的理论体系与方法体系。