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Abstract  

This pape discusses the use, of stable Cs as an activatable tracer for measuring performance of plant root intrusion barriers for solid waste disposal site cover systems. Experiments conducted at small-scale demonstrate the effectiveness and practicality of the technique and suggest that the methodology has application to a better understanding of plant root ecology.

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Abstract  

Nuclear chemistry is usually associated with great disasters, especially the atomic bomb; this without reflecting that knowledge of nuclear chemistry has also had many benefits in the field of medicine and health. Whereas in technologically advanced countries, nuclear chemistry is considered to be an important part of the syllabus, including topics such as radioactivity with the emphasis in making conscience in the common citizen of the inherent benefits.

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An attempt is outlined for the compilation of an integrated and harmonized stratified soil physical database serving hydrologic modeling, as the basis of estimating soil hydraulic parameters in the unsaturated zone. Due to the appropriate spatial and thematic resolution and data processing status, the Digital Kreybig Soil Information System (DKSIS) and Hungarian Agrogeological Database (HAD) were chosen as pedological and agrogeological data sources for describing the soil physical properties in the unsaturated zone. The DKSIS contains legacy soil data (as hy, pH, salt, OM, CaCO 3 content, etc.) in finely stratified resolution (3–5 soil layers within 1.5–2.0 m), but lacks particle size data. HAD has a coarser stratification (8–15 layers within 8–10 m) with detailed particle size data. The five-cleft FAO texture classification can serve as an interface in their joint application. The particle size and hy data pairs from the existing Hungarian Soil Monitoring (TIM) network made it possible to define the relation between FAO texture class vs. hy value, and based on the HYPRES database each FAO texture class can be characterized by typical Mualem-van Genuchten parameter sets (Wösten et al., 1999). The compiled, harmonized database characterizes the distinguished soil and sediment layers – with a thickness of at least 10 cm – for a 690 km 2 large model area, describing their thickness and texture classes to the depth of the permanent groundwater level, in every single square kilometer cell of the model area. The compiled database is indispensable in the model simulation based analysis of regional water management problems like drought, flood and inland inundation.

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Journal of Thermal Analysis and Calorimetry
Authors: Blanca Rojas de Gáscue, José Luis Prin, Gilma Hernández, Enrique M. Vallés, Arnaldo T. Lorenzo, and Alejandro J. Müller

Abstract

The application of the Successive Self-nucleation and Annealing (SSA) thermal fractionation technique can yield detailed information of the structural changes induced in linear polyethylene by irradiation. The production of tertiary carbons during the crosslinking reactions can be equivalent to the structural heterogeneity present in branched polyethylenes since in both cases interruption of the linear crystallizable sequences occurs, and these are structural differences that can be easily detected by thermal fractionation. We demonstrate how correlations between melting point and short chain branching content employed for branched polymers can be useful to characterize the distribution of chain heterogeneity produced by crosslinking. As the radiation dose is increased and the crosslinking content also increases, the distribution of chain heterogeneity gets broader as detected by SSA. When the results are coupled with morphological observations made by transmission electron microscopy, valuable information on the morphological changes produced by crosslinking can also be ascertained, since the distribution of lamellar thicknesses substantially broadens with crosslinking. Such a broad distribution can also be predicted from SSA by simple calculations performed employing a modified version of the Gibbs–Thomson equation and is expected on the basis of random crosslinking reactions.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: L. Müller, C. Halldin, C. Lundkvist, C. Swahn, C. Foged, H. Hall, P. Karlsson, N. Ginovart, Y. Nakashima, T. Suhara, and L. Farde

Abstract  

The use of benzhydryl substituted piperazine derivatives and 3-substituted cocaine analogues as radioligands are compared for in vivo visualization of dopamine transporter by PET.

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