摘要:

A 16-channel pulse counter is presented, which has been designed primarily for the rationalization of tracer investigations with a great number of control points. It distinguishes itself by lossless recording of any parallel pulse trains, by the possibility to connect detectors (e.g. counters, scintillation counters) over distances up to 250 m, by low weight and small size, by equal measuring intervals in all channels, by automatic background correction and by high operational comfort. A computer programme has been elaborated and is available especially for the evaluation of test series arising with the measurement of gas exchange (air exchange).

ISSN:0021-1915    

DOI:10.1080/10256018508623460

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

The possibility of the use of gamma activation analysis (18 MeV) is analysed for some brown coal and brown coal ash samples. The elemental concentrations of Mg, Ca, Fe, Sr were determined. There is no content of Tl, Mo, and Pb. The sensitivities for above elements were given.

ISSN:0021-1915    

DOI:10.1080/10256018508623461

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Proceeding from a short characterization of neutron activation logging and the differences to conventional well logging techniques, the factors which influence the connection between measured value and interesting geological parameter are considered. A formula for the energy distribution of the γ-rays at the detector is given, which involves a single row matrix. Resulting from this, conditions to achieve an optimum measuring effect and principles for the design of a sonde are derived. The peculiarities of the sonde ANGS 42 are: 1) the neutron source is placed at a definite distance above the detector, 2) the automatic control of the energetical position of the discriminator level. For example the accuracy of content determination in fluorite exploration and the factors which influence this determination are discussed. The possibilities of Ca–, Si– and Al-determinations are mentioned as well as the measuring techniques and technological details to improve the accuracy of measurements and to expand the scope of chemical elements to be analyzed.

ISSN:0021-1915    

DOI:10.1080/10256018508623462

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Determinations of soil moisture witli the aid of neutron moisture meters require calibrations under real conditions. Some efficient methods for calibrating such moisture gauges are described and working examples are presented.

ISSN:0021-1915    

DOI:10.1080/10256018508623463

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

The exchange of hydroyene isotopes H and D between different linkage stages in concrete is experimentally followed tip. The measurements are carried out by Nuclear Magnetic Resonance (proton-NMH). A distribution between chemically bound and physically adsorbed water molecules is possible. The diffusion coefficient of water in concrete serves as a verification for tho D20 – H2O-content and is also measured by a NMR-methode. It can be shown that a extraction of chemically bound D20 by free H20 in concrete occurs at once at the moment of contact, but there are also exchange processes with large time constants.

ISSN:0021-1915    

DOI:10.1080/10256018508623464

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

A cylindrical packing of the flexible polyurethane foam impregnated with a tertiary alkylamine: iodine complex is placed into the column made of a conventional plastic syringe. By passing a 5-dm3sample through the column in a single operation, the radioiodine is separated with 95% yield from water or higher than 80% yield from milk samples in less than 1 hr. The radioactivity of the compressed foam cylinder into 4 cm volume directly in the syringe can be measured in a well-type NaI(Tl) detector with about 45% counting efficiency. A lower limit of determination of about 0.04 Bq/dm3is achieved for 100 min of counting. The method can be used for routine determinations also under field conditions.

ISSN:0021-1915    

DOI:10.1080/10256018508623465

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

The neutron sensitivity as well as minimum and maximum detectable doses for various types of fission fragment track detectors and recoil track detectors has been compared. The calculated sensitivity for each category was compared with the measured one. The sensitivities for recoil track detectors was found to be higher than that for fission fragment track detectors. The parameters affecting the registration efficiency has been discussed.

ISSN:0021-1915    

DOI:10.1080/10256018508623466

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

In order to determine the relative efficiency of a Ge(Li) detector in the region of 8O–1000 keV, measurements of a standardized166mHo solution were performed. The radioactivity concentration of the166mHo solution was determined by measurements of a133Ba reference standard. The total number of calibration measurements was 120. The influence of experimental conditions such as sample manufacture, absorption of the vessels, source positions and dead time, on the accuracy of the measurements, was considered. The observed spectra were analyzed by a simple programme. In comparison with other calibration nuclides, the advantages of the multigamma-ray nuclide166mHo are simple manufacture, large half-life and homogeneous distribution of gamma-rays with absolute intensities greater than 5% in the region of 8O–1000 keV.

ISSN:0021-1915    

DOI:10.1080/10256018508623467

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

In any alloy exists a region in which the constitution of structural elements corresponds to a mean content of metals forming the alloy. A region for which we can prove a presence of all alloy structural elements in the amount corresponding to the mean concentration is named a specific region. In this paper, the rules of choice of the split size for optical density measurement are presented and a thesis constating that a split size for the optical density measurement should be equal to the specific region size is verified. The thesis verification was accomplished using pattern autoradiographs.

ISSN:0021-1915    

DOI:10.1080/10256018508623468

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Sorption of small amounts of silver(I) on lead sulfide has been measured in dependence on pH, time of sorption, and concentrations of sorbate and sorbent. Also, the influence of complexing agents on the sorption process has been studied. Lead sulfide can be used for the preconcentration of silver (I) in a broad range of pH values. The sorption capacity for silver(I) is high, since the process is not restricted only to the surface of the PbS sorbent. Although the presence of complexing agents (e.g. EDTA, citrate) affects the kinetics of the sorption of silver(I), quantitative preconcentration of silver(I) after a given sorption time is possible. However, in the presence of thiosulfate in high concentrations, quantitative preconcentration of silver(I) by the PbS sorbent cannot be performed.

ISSN:0021-1915    

DOI:10.1080/10256018508623469

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor