The process of carcinogenesis may influence normal biochemical reactions leading to alterations in the elemental composition of the tissue. Total reflection X-ray fluorescence analysis (TXRF) was ...applied to the elemental analysis of different brain tumors. The following elements were present in all the neoplastic tissues analyzed: K, Ca, Fe, Cu, Zn and Rb. The results of the analysis showed that the elemental composition of a relatively small fragment of tissue represents satisfactorily the biochemical “signature” of a cancer. On the basis of the element concentrations determined, it was possible to differentiate between some types of brain tumors.
•Elemental composition represents the biochemical signature of brain cancer.•The element levels differentiate some types of brain tumors.•TXRF spectrometry is a useful tool for elemental trace analysis of brain cancer.
Two novel methods of tritium production rate (TPR) measurements applied in HCLL TBM mock-up neutronic experiment are described and discussed. In the first method LiF TLD detectors used for gamma ...radiation dose measurements are applied as detectors of
−β decay of tritium (T) produced by neutrons. TL signal expressed as mGy/h is proportional to energy accumulated in self-irradiation process (SI). However, the TL signal is proportional to tritium activity generated in detector material, recalculation to Bq/mg requires calibration by independent measurement of T activity in the TLD. In our experiments determination of this activity was performed by LSC technique. Good correlation between the
3H activity and TLD signal was observed. The second presented method is based on direct measurement of T in LiPb material with the use of LSC spectrometer. Dissolution of LiPb in nitric acid, and than composing aliquot containing well known mass of irradiated LiPb mixed than with scintillation cocktail, is measured in LS spectrometer providing signal proportional to the T activity. It was proved by series of experiments that procedure performed at controlled conditions ensures no loss of tritium while preparation. Optimization measurement conditions with respect of type of the scintillator used and composition of aliquot/scintillator mixture provide counting efficiency above 22%. Sample material for testing the both techniques was irradiated by neutron flux either at nuclear research reactor “Maria”, Świerk, Poland or at the Frascati Neutron Generator Laboratory in HCLL TBM neutronic experiment. Li
2CO
3 pellets used as reference were irradiated in the same experiment with TLDs, and samples of LiPb-eutectic and then analysed by modified Dierckx method, a well established technique. Measurement results obtained applying the both techniques described above as well as the control Li
2CO
3 pellets were in very good consistency. Direct measurements of T produced in LiPb at different depth in HCLL TBM mockup agrees well with MCNP simulation results. Parameters of the simulation provide additionally information on
6Li abundance and Li content in the LiPb mixture. Spread of the T activity observed at the same depth for different samples correspond with inhomogeneity of the eutectic composition investigated and reported. Direct measurement of T activity seems to be the very promising and relatively simple method of validation of neutronic codes and nuclear data capabilities for calculation TPR in fusion relevant materials provided parameters of the irradiated material are well known.
Industrial waste substrata, rich in heavy metals, are poorly suited for plant growth. Efforts are made to establish an appropriate plant cover to reduce erosion and further contamination. Grasses are ...the usual solution, as they grow fast, thrive on poor substrata and have well-developed root systems. Some of them are also highly dependent on mycorrhizal symbiosis that supports their growth especially on poor and polluted soils. However, the commercially available grasses often meet a lack of well established mycorrhiza on the site and the introduced plant populations dramatically decrease with time, despite large financial input including covering the substratum with soil and intensive watering. The aim of this paper was to select proper plants together with mycorrhizal fungi that could accelerate the establishment of the vegetation and improve its diversity under these extreme conditions, minimizing the financial costs of the reclamation (no use of soil layering and watering). The experiments were carried out under field and laboratory conditions. The plant seeds used originated from dry calcareous grasslands. The seeds were germinated under field conditions or in pots filled with soil supplemented with substratum from the industrial wastes. The seedlings were inoculated with AM fungi and introduced on the field plots a few weeks after germination. The inoculum consisted of either crude inoculum harvested from the dry calcareous grasslands or strains originating from polluted areas. Plants colonized by mycorrhizal fungi established well in the experimental plots. The results suggest that inocula from dry calcareous grasslands are potentially useful in revegetation of industrial wastes. Although in several cases the photosynthetic activity of plants was lower than at the natural sites, almost all plants survived and formed seeds. In all experiments the plant vitality was estimated on the basis of chlorophyll a fluorescence and was useful to show differences between waste substrata, inocula and coexisting plant species. The interactions between mycorrhizal and non-mycorrhizal plants were studied under greenhouse conditions and at least no negative effect of this coexistence was found.
A European nuclear-fusion technology program is currently, except of other acivities, on the stage of validating the capability of neutronic codes and nuclear data for use in the ITER project. This ...requires a technique for reliable measurements of tritium produced by a neutron flux and these estimates must have a qualified uncertainty. The application of LiF TL detectors, calibrated by the direct measurement of tritium activity using the Liquid Scintillation Counting (LSC) technique, is a new approach to the assessment of the tritium production rate in fusion related benchmark experiments.
Lithium Fluoride Thermoluminescent Detectors (TLD) are commonly used for measurements of thermal neutron dose using the
6Li(n,α)
3H reaction. The accumulation of radioactive tritium in the LiF detectors is usually considered as an undesired effect to the detectors, increasing intrinsic background after high-dose neutron exposure. The same effect may be exploited for the measurement of generated tritium activity. A TL signal corresponding to the energy deposited in the
−β decay of
3H, expressed as mGy/h to be recalculated to Bq/mg, requires calibration by an independent measurement of
3H activity. This calibration can be performed by applying e.g. LSC-technique. A good correlation was obtained in the tested range of tritium activity: 17–25 Bq/mg of LiF (0.080–0.118 mGy/h) with a slope of regression line: 1.75 × 10
−4 mGy/h/Bq,
r
2 = 0.94. The thermal treatment of the TLDs after irradiation (annealing: 400 °C, 1 h) leads to a loss of 37% of the initial tritium content. Prolonged storage of the irradiated TLDs at room temperature, pressure and humidity causes the escape of less than 5% of the accumulated tritium after 100 days. Thus LiF TLDs after calibration can be used as one of techniques for the assessment of tritium production in neutronic experiments.
Total reflection X-ray fluorescence spectrometry and chemical pre-concentration procedures have been applied for the analysis of trace concentrations of copper, mercury, and lead in drinking water ...samples. A simple total reflection module has been used in X-ray measurements. The elements under investigation were pre-concentrated by complexation using a mixture of carbamates followed by solvent extraction with methyl isobutyl ketone. The preconcentration procedure was tested with the use of twice-distilled water samples and samples of mineral and tap water spiked with known additions of copper, mercury, and lead. The obtained recovery and precision values are presented. The minimum detection limits for the determination of these elements in mineral and tap water samples were found to be 40 ng l
−1, 60 ng l
−1, and 60 ng l
−1, respectively.
•Tritium escape from LiPb is estimated using bi-velocity diffusion model.•We performed experimental validation of the diffusion model.•We propose conception of LSS application to TPR in HCLL TBM ...measurement.
Validation of the calculated Tritium Production Rate (TPR) in the Test Blanket Modules (TBMs) needs relatively simple measurement procedure. Measurement system in TBM based on Tritium determination directly in LiPb and/or in Li compound(s) with application of the Liquid Scintillator Counting (LSC) is proposed. Expected high temperature in TBM while ITER operation in sample not less than 150°C when cooled irradiated material, and 300–400°C without cooling, impose constraints on the possible methods and technical design. Preliminary results performed on irradiated LiPb eutectic pellets housed at controlled conditions of elevated temperature showed remarkable loss of Tritium. Observed escape of Tritium ranged from ca. 91% (temp.: 300°C, t=60min) to ca. 52% (temp.: 370–390°C, t=10min) being in fair agreement with calculated values by use of dedicated code (rCADiff). Basic limitation of direct radiometric measurement of Tritium activity in LiPb is parasitic activity induced in Pb, predominantly coming from 203Pb and also from impurities present in Pb. Demand of obtaining information on TPR in relatively short time points to other lithium compounds used as monitors which after irradiation, followed by an easy preparation procedure, can be measured using simple version of LSC. Most promising monitors seem to be Li2O and LiF. Two different possible versions of the proposed systems were considered: (1) LSC measurement starts after long period of time since irradiation (not less than 20 days); (2) LSC measurement starts shortly after irradiation (an hour or less to several hours).
