scholarly journals INFLUENCE OF WATER EXTRACTION METHODS FROM ENVIRONMENTAL SAMPLES ON MEASURED TRITIUM LEVEL

2021 ◽  
Vol 24 (2) ◽  
pp. 89-96
Author(s):  
Carmen Varlam ◽  
◽  
Diana Bogdan ◽  
Irina vagner ◽  
Diana Costinel ◽  
...  
Keyword(s):  
Environmental Samples ◽  
Activity Concentration ◽  
Free Water ◽  
Azeotropic Distillation ◽  
Extraction Methods ◽  
Routine Procedure ◽  
Influence Of Water ◽  
Wild Vegetation ◽  
Ratio Determination ◽  
French Standard

In order to validate the laboratory routine procedure of tritium activity concentration determination in tissue free water of environmental samples, parallel measurements were performed in water extracted from wild vegetation by two methods: azeotropic distillation and lyophilization (recommended by a French standard method). The sample humidity was established using the drying procedure to constant mass of the sample, and isotopic effect that may occur during lyophilization procedure was investigated by deuterium ratio determination in sample and extracted water. Traces of toluene in extracted water by azeotropic distillation made deuterium ration determination useless.

scholarly journals Test spectra experimental construction for evaluating gamma-spectrometry computer codes for the 235U determination

2014 ◽  
Vol 29 (suppl.) ◽  
pp. 1-7 ◽  
Author(s):  
Konstantinos Karfopoulos ◽  
Dimitrios Karangelos ◽  
Marios Anagnostakis ◽  
Simos Simopoulos
Keyword(s):  
Gamma Spectrometry ◽  
Energy Region ◽  
Environmental Samples ◽  
Activity Concentration ◽  
Germanium Detector ◽  
Computer Code ◽  
High Background ◽  
Spectrometry Analysis ◽  
Background Continuum ◽  
Concentration Levels

The determination of 235U in environmental samples from its 185.72 keV photons may require the deconvolution of the multiplet photopeak at ~186 keV, due to the co-existence of the 186.25 keV photons of 226Ra in the spectrum. Successful deconvolution depends on many parameters, such as the detector characteristics, the activity concentration of the 235U and 226Ra in the sample, the background continuum in the 186 keV energy region and the gamma-spectrometry computer code used. In this work two sets of experimental test spectra were constructed for examining the deconvolution of the multiplet photopeak performed by different codes. For the construction of the test spectra, a high-resolution low energy germanium detector was used. The first series consists of 140 spectra and simulates environmental samples containing various activity concentration levels of 235U and 226Ra. The second series consists of 280 spectra and has been derived by adding 137Cs, corresponding to various activity concentration levels, to specific first series test spectra. As the 137Cs backscatter edge is detected in the energy region of the multiplet photopeak at ~186 keV, this second series of test spectra tests the analysis of the multiplet photopeak in high background continuum conditions. The analysis of the test spectra is performed by two different g-spectrometry analysis codes: (a) spectrum unix analysis code, a computer code developed in-house and (b) analysis of germanium detector spectra, a program freely available from the IAEA. The results obtained by the two programs are compared in terms of photopeak detection and photopeak area determination.

Deconvolution of alpha liquid scintillation spectra for quantitative analysis of actinide elements in water samples

2004 ◽  
Vol 92 (3) ◽  
Author(s):  
Jean Aupiais
Keyword(s):  
Quantitative Analysis ◽  
Water Samples ◽  
Environmental Samples ◽  
Liquid Scintillation ◽  
Isotopic Ratio ◽  
Ratio Determination ◽  
Alpha Beta ◽  
Uranium Plutonium ◽  
Actinide Elements

SummaryThe reliability and accuracy of actinide measurement in environmental samples strongly depend on theThe intensity of the internal conversions for thorium, uranium, plutonium and americium have been calculated and normalised to the intensity of the main alpha transition. These data can be used to determine the activity of any above-mentioned actinide by alpha liquid scintillation with alpha/beta discrimination. The quantitative analysis and the isotopic ratio determination of several certified solutions of actinides demonstrate the validity of this approach.

Automated and semi-automated extraction methods for GC–MS determination of pesticides in environmental samples

2016 ◽  
Vol 12 ◽  
pp. 1-12 ◽  
Author(s):  
Irene Domínguez ◽  
Roberto Romero González ◽  
F. Javier Arrebola Liébanas ◽  
José L. Martínez Vidal ◽  
Antonia Garrido Frenich
Keyword(s):  
Environmental Samples ◽  
Extraction Methods ◽  
Automated Extraction

Analysis of residual ionic liquids in environmental samples: Development of extraction methods

Chemosphere ◽  
2009 ◽  
Vol 74 (4) ◽  
pp. 515-521 ◽  
Author(s):  
Joanna Nichthauser ◽  
Wojciech Mrozik ◽  
Aleksandra Markowska ◽  
Piotr Stepnowski
Keyword(s):  
Ionic Liquids ◽  
Environmental Samples ◽  
Extraction Methods

scholarly journals Estimation of Uranium Sources in Environmental Samples Using the Isotopic Ratio Determination

2020 ◽  
Author(s):  
Junko Shikimori ◽  
Takeshi Ohno ◽  
Yusuke Fukami ◽  
Yasuhito Igarashi
Keyword(s):  
Environmental Samples ◽  
Isotopic Ratio ◽  
Ratio Determination ◽  
Uranium Sources

scholarly journals Study on the Influence of Sudden Change of Water Level on High Fill Canal Segment

2021 ◽  
Vol 30 (3) ◽  
Author(s):  
Chenyang Yuan ◽  
Xinyong Xu ◽  
Xiangtian Nie ◽  
Weifeng Bai
Keyword(s):  
Water Level ◽  
Pore Pressure ◽  
Sudden Change ◽  
Development Program ◽  
Free Water ◽  
Element Model ◽  
Secondary Development ◽  
Fluid Structure ◽  
Influence Of Water ◽  
Complex Foundation

Extreme conditions will cause the water level of high fill canal segment to change suddenly, which will affect the velocity and pore pressure of the slope. In this paper, numerical method is used to study the influence of water level sudden change on seepage characteristics of high fill canal segment. HyperMesh software is used to establish the finite element model of typical high fill canal segment under complex foundation conditions. Through the combination of secondary development program and fluid-structure coupling calculation method, the fluid structure cou-pling effect of canal under sudden change of water level is analyzed in ABAQUS. The results show that when the water level changes suddenly, the pore pressure below the free water surface and the velocity near the free surface will be greatly affected.

scholarly journals Activity Concentrations Of Environmental Samples Collected In Samarkand Region Of Uzbekistan

2020 ◽  
Vol 02 (10) ◽  
pp. 138-144
Author(s):  
G. Akhmedova ◽  
◽  
R. Eshburiev ◽  
U. Tukhtaev ◽  
Sh. Khasanov ◽  
...  
Keyword(s):  
Environmental Samples ◽  
Building Materials ◽  
Activity Concentration ◽  
Natural Radionuclides ◽  
Decay Period ◽  
Marinelli Beaker ◽  
Radiation Spectra ◽  
Activity Concentrations ◽  
Γ Spectrometer ◽  
Low Activity

The results of the investigations of the activity concentration of natural radionuclides in certain building materials and foodstuff samples obtained from the Nurabad district of the Samarkand region of Uzbekistan are presented. The gamma radiation spectra of the samples were measured in Marinelli beaker geometry on γ- spectrometer with a Ge(Li) detector and energy resolution 6% on the 1332 keV line of 60Co. A personal computer and standard computer programs were used to accumulate and process the spectra. The characteristic density of the samples ranged from 140 to 1810 g/l. The activity concentration of 40K was observed to be comparatively higher than that of both 226Ra and 232Th in all the studied samples. The results reveal that the low activity of 137Cs in the samples is attributed due to its half-life decay period.

Brief Analysis of Floor Grouting Method in Soft Rock Roadway Based on Engineering Materials and Engineering Mechanics

2013 ◽  
Vol 345 ◽  
pp. 442-446 ◽  
Author(s):  
Peng Wei Hao ◽  
Hai Long Dong ◽  
Zhao Hui Liu ◽  
Jing Pei Li ◽  
Lai Wang Jing
Keyword(s):  
Free Water ◽  
Soft Rock ◽  
Practical Method ◽  
Floor Heave ◽  
Influence Of Water ◽  
Engineering Mechanics ◽  
Soft Rock Roadway ◽  
Surrounding Rock Stress ◽  
Rock Roadway

Floor grouting in soft rock roadway is one of the effective ways in floor heave control, and this method is being promoted quietly and quickly, but the applying effect is far from satisfied, the reasons are that: the depth of floor grouting is not enough and the influence of water hiding in floor hasnt been attached great importance. This paper analyzed the characteristics of floor broken rock zone in soft rock roadway and pointed out the importance of floor grouting in soft rock roadway, then proposed a practical method of floor grouting. The analysis conclusions show that: the depth of floor broken rock zone that can reach more than 4m is much greater than that of roof broken rock zone due to the double influences of surrounding rock stress and water; the important role of floor grouting in soft rock roadway is draining off free water from broken rock zone in order to strengthen roadway floor; floor grouting includes three important steps: plugging water channels, pumping out free water and grouting in deep holes. The article has revealed common blind spots of floor grouting methods existing, the method this article has noted can solve floor heave of soft rock roadway well, and it has very good application prospects. Key words: soft rock roadway, floor grouting, broken rock zone, free water in floor

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