摘要:

Radioisotopes of both natural and artificial origin are widely used in environmental research and protection to tackle problems in which high specificity and sensitivity are required. The paper exemplifies the capabilities guided by some recent investigations in various fields of application: dating of river and marine sediments, determination of dry deposition rates for airborne particulates, studies of the uptake of organic compounds by plants and of the internal distribution processes in plants, investigation of transport phenomena in soil, groundwater or surface waters, development of trace analytical procedures, application of neutron activation analysis, detection of trace gases by means of ionization detectors, and the exploration of mud fields in tidal rivers using a radiometric density gauge.

ISSN:0021-1915    

DOI:10.1080/10256018608623691

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The main peculiarities of constructing set of equipment for analysis of α-autoradiographic images are discussed. Hardware, software and metrological means are analysed. The structure of the equipment is presented providing for inspecting homogeneity of plutonium dioxide distribution by means of α-autoradiography under shop conditions. The software has been written on the basis of “RAFOS” (RT-II) operational system. The basic programming language is “FORTRAN IV”. The necessary components and structure of application programs are discussed. As far as metrological means are concerned, built-in and application devices providing for control of the equipment operating characteristics stability are described.

ISSN:0021-1915    

DOI:10.1080/10256018608623692

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Some aspects of forming of α-autoradiogram images by dielectric track detectors made from cellulose nitrate are considered The nature of interaction of α-radiation and irradiation medium material and track registration detector material, as well as linear dependence between image optical density and the number of α-particles registered by the detector allow to understand the process of forming images to linear images and characterize it as a modulation transfer function. This mathematical formalism is applied to some examples which are considered in detail.

ISSN:0021-1915    

DOI:10.1080/10256018608623693

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The quantity of silver in districts of blackening of the autoradiograms is determined by means of the X-ray spectral microprobe analyzer MS-46 “Cameca”. The experiments were made by applying63Ni. A calibration chart allows to determine the distribution coefficients of Ni in different phases and some examples show the usefulness of this suggested technique.

ISSN:0021-1915    

DOI:10.1080/10256018608623694

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Es wird eine Methode zur Synthese von14CH3Bis(dimethylphosphino)-ethan beschrieben, die von Ethan-1,2-bistris-(hydroxymethyl)-phosphoniumchlorid ausgeht. Durch stufenweise Abspaltung von Hydroxymethylgruppen und nachfolgender Phosphoniumsalzbildung mit Hilfe von [14C]Methyliodid wird nach mehreren Sequenzen das Syntheseziel erreicht. Für die Radio-DC-Analyse wird ein geeignetes chromatographisches System zur Untersuchung von [14CH3]-Bis(dimethylphosphino)-ethandihydrochlorid und dessen Oxidationsprodukten vorgestellt.

ISSN:0021-1915    

DOI:10.1080/10256018608623695

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Zur dynamischen Schichtdickenbestimmung dünner und vornehmlich flüssiger Schichten existieren für viele Anwendungsfälle keine technisch nutzbaren Lösungen. Im vorliegenden Artikel wird deshalb die Anwendbarkeit offener, γ-strahlender Radionuklide für eine nichtisotope, physikalische Markierung untersucht. Bei diesen Tracern ist ein Zusammenhang zwischen der Schichtdicke und der ermittelten Zählrate zu erkennen. Mit99mTc ist die Meβaufgabe unter günstigen geometrischen Bedingungen lösbar. Für allgemeine Fälle werden Radionuklide mit höheren γ-Energien empfohlen. Auβerdem wird theoretisch und praktisch eine Optimierung des Meβaufbaus an einer rotierenden Walze vorgenommen.

ISSN:0021-1915    

DOI:10.1080/10256018608623696

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The introductory paper to the pathophysiology session of the 19th Annual Meeting of European Society for Radiation Biology, 1985, outlines cell membrane-related phenomena elicited by lower doses of low LET radiations than the cell killing one. Through micromorphological appearances, functional activities like that of receptors and binding sites, early appearing temporary alterations are demonstrated. It is suggested that the injuries of cells, cell-to-cell and cell-to-extra-cellular matrix contacts, the disabled conditions of surviving cells contribute to the development of non-stochastic effects in tissues.

ISSN:0021-1915    

DOI:10.1080/10256018608623697

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

A comparative study on the sorption behaviour of tungsten and rhenium between anion exchange resin, charcoal and alumina and aqueous media of HNO3, HCl and NaCl were carried out. The equilibrium distribution coefficient obtained for the different systems were evaluated and discussed in terms of the separation factor between W and Re. It is found that the systems based on alumina and HCl or NaCl are the most promising systems to be used for development of188W-188Re generator. The capacity of a chromatographic column loaded with alumina for188W from 0.01 M HCl, 0.7% NaCl and 1.2% NaCl was found to equals 75.3, 91.0 and 126.0 mg/cm, respectively. A recommended procedure was adopted for188W-188Re generator.

ISSN:0021-1915    

DOI:10.1080/10256018608623698

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

ISSN:0021-1915    

DOI:10.1080/10256018608623699

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The method of radioactive indicators and the method of autoradiography are the most convenient for determination of the crystallization front and the depth of the liquid phase. The aim of this work is to create an unified method for investigation of the processes of crystallization in continuous and semicontinuous founding of ferrous and non-ferrous metals. Au-198 was chosen as radioisotope. The techniques of investigation are described and some are discussed. The full picture of the form and the magnitude of the liquid phase in these technologies can be obtained only by means of this method.

ISSN:0021-1915    

DOI:10.1080/10256018608623700

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor