Doses Of Gamma Radiation Research Articles

Chronic bronchitis and bronchial asthma: the impact of chronic occupational radiation exposure on incidence and mortality of Mayak nuclear workers.

The information about the radiation risk of non-cancer respiratory diseases is inconsistent and mainly corresponds to mortality. Previously, an increased risk of chronic bronchitis incidence was demonstrated in the cohort of workers employed at the first Russian nuclear facility Mayak Production Association who had been chronically exposed to gamma rays (externally) and to alpha-active plutonium aerosols (internally). Within this retrospective study, we performed analyses of incidence of and mortality from chronic bronchitis and bronchial asthma using improved estimates of radiation doses provided by the "Mayak Worker Dosimetry System (MWDS) - 2013". The cohort included 22,377 individuals hired in 1948-1982, and its follow-up was extended by 10 years (to the end of 2018). The excess relative risk of chronic bronchitis incidence per unit radiation dose (ERR/Gy) and the 95% confidence interval (95% CI) were: with the 0-year lag ERR/Gy=0.07 (95% CI -0.01, 0.17) for gamma exposure and ERR/Gy=0.36 (95% CI 0.13, 0.68) for alpha exposure; with the 10-year lag ERR/Gy=0.15 (95% CI 0.04, 0.30) for gamma exposure and ERR/Gy=0.54 (95% CI 0.19, 1.03) for alpha exposure. The chronic bronchitis mortality risk was significantly associated with internal alpha exposure only for certain worker categories: ERR/Gy=4.08 (95% CI 0.59, 14.3) in males; ERR/Gy=7.10 (95% CI 0.31, 70.44) in former smokers; ERR/Gy=7.94 (95% CI 1.71, 30.2) in workers with the smoking index above 20 pack×years. No association was observed in the chronic bronchitis mortality risk with external gamma exposure. No strong evidence was observed for the impact of gamma and alpha exposure on risk of mortality from chronic bronchitis. The study confirmed the significant positive linear association of the chronic bronchitis incidence risk with gamma and alpha radiation doses from occupational chronic external and internal exposure. However, the estimates of ERR/Gy of alpha particles from internal exposure appeared to be almost 2.4-3 times lower than those based on the MWDS-2008. The observed inconsistency requires further clarification. As for bronchial asthma in Mayak workers, no association was demonstrated in the incidence and mortality risks with occupational gamma and alpha radiation exposure.

Long-term Radiation Signal Persistence in Urine and Blood: A Two-year Analysis in Non-human Primates Exposed to a 4 Gy Total-Body Gamma-Radiation Dose.

National security concerns regarding radiological incidents, accidental or intentional in nature, have increased substantially over the past few years. A primary area of intense planning is the assessment of exposed individuals and timely medical management. However, exposed individuals who receive survivable radiation doses may develop delayed effects of acute radiation exposure many months or years later. Therefore, it is necessary to identify such individuals and determine whether their symptoms may have been initiated by radiation and require complex medical interventions. We previously developed early response metabolomic biosignatures in biofluids from non-human primates exposed to a total body gamma radiation dose of 4 Gy (up to 60 days). A follow-up of these animals has been ongoing with samples consistently collected every few months for up to 2 years after exposure, providing a unique cohort to determine if a radiation signal persists longer than 2 months. Metabolic fingerprinting in urine and serum determined that exposed animals remain metabolically different from pre-exposure levels and from age-matched controls, and the pre-determined biosignature maintains high sensitivity and specificity. Significant perturbations in tricarboxylic acid intermediates, cofactors and nucleotide metabolism were noted, signifying energetic changes that could be attributed to or perpetuate altered mitochondrial dynamics. Importantly, these animals have begun developing diseases such as hypertension much earlier than their age-matched controls, further emphasizing that radiation exposure may lead to accelerated aging. This NHP cohort provides important information and highlights the potential of metabolomics in determining persistent changes and a radiation-specific signature that can be correlated to phenotype.

Terrestrial gamma radiation dose (TGRD) rates and radiological risk assessments in Tiru region of the Naga Schuppen Belt, India

The aim of the present study is to assess the levels of dose rates and the potential risks of exposure to terrestrial gamma radiations in indoors and outdoors in houses in Tiru coal mining area. A highly sensitive portable micro-R gamma survey metre incorporated with a NaI (Tl) scintillator has been used for this study. Indoor and outdoor gamma dose rates (GDRs) have been estimated to be 58.5-178.3 nGy h-1 and 55.5-81.9 nGy h-1, respectively, with averages of 89.7 7.4 nGy h-1 and 65.7 5.8 nGy h-1, considerably higher than the reported global population-weighted averages. The annual effective doses (AEDs) for indoors and outdoors have been estimated to be in the ranges of 0.29-0.87 mSv y-1 and 0.07-0.1 mSv y-1, with averages of 0.44 0.04 mSv y-1 and 0.08 0.01 mSv y-1, which are marginally higher than the reported global averages. The excess lifetime cancer risk (ELCR) has been calculated and found to be in the range of 1.2 10-3-3.4 10-3 with an average of 1.8 10-3. This study contributes significantly to the scientific understanding of radiation exposure in an open-cast coal mining area as well as its potential impact on human health.

OPTIMIZATION OF MUTAGEN DOSE FOR EARLY SEEDLING YIELD ASSOCIATED QUANTITATIVE CHARACTERS IN CANOLA GERM PLASM

Pakistan is facing vital shortage in supply of health promoting crops used as vegetable as well as oil source. Brassica napus (Canola) is such a rich crop that occupy an important position in the oilseed crops of world but unfortunately in Pakistan its germ plasm needs genetic improvement due to narrow gene pool. Mutagenesis is a powerful tool for introducing new alleles, therefore different doses of Gamma radiations (750Gy, 1000Gy, 1250Gy) and EMS (0.5%, 1.0% and 1.5%) were used to induce genetic diversity for early yield associated quantitative characters in two Canola genotypes (Hyola-41 and Shiralee). The data was recorded for days to flowering, days to maturity, plant height, number of branches per plant and pod length in M2 and M3 generation. Significant (p≤0.05) variations were observed for most of phenotypic parameters for both mutagens. The mean value of all the phenotypic parameters in M2 generation increased with moderate dose of EMS and Gamma rays in both genotypes as compared to respective controls. whereas in M3 generation both genotypes were more responsive to Gamma rays (1000 Gy) for all studied characters except early maturity in both tested genotypes. Heritability analysis exhibited high heritability and high genetic advance for most of the traits by moderate and highest does of Gamma rays, while reverse is true for EMS in both generations for Shiralee.

The effect of gamma irradiation on the dielectric properties of polyethylene-based composites with the CdS/ZnS binary system

Polyethylene-based composites with the CdS/ZnS binary system were obtained with a component ratio of 10% CdS/ZnS; 30% CdS/ZnS; 50% CdS/ZnS. The temperature dependences of the dielectric constant (ε) and the tangent of the dielectric loss angle (tgδ) of samples of HDPE+CdS/ZnS composites irradiated with a dose of 100 kGy, 50 kGy, and 200 kGy were shown. The dependences of the dielectric constant and the tangent of the dielectric loss angle of HDPE+Cds/ZnS composites on the gamma-irradiation dose have been determined.

Radon and Gamma Radiation Dose to the Population Residing Near the Uranium Mill Tailings Disposal Site in Uranium Mineralized Zone at Jaduguda

Members of the public residing in the villages situated near the uranium mill disposal site, such as those in the vicinity of uranium tailings ponds, may indeed be at risk of radiation exposure. Present study focuses to evaluate the radiological exposure condition for the resident of villages situated in nearby vicinity of the tailing disposal site in the uranium mineralized region of Jaduguda, Jharkhand, India. In this study, the dose from external gamma radiation and radon concentrations, both indoors and outdoors, is evaluated. The natural background radiation dose to the residents of villages located near the uranium mill tailings disposal site is estimated to be 2.99 mSvy-1. Radon and its decay products contribute approximately 57.6% of the radiation dose to the villagers, while gamma radiation accounts for 42.4%. Residents of villages near the uranium tailings ponds receive a radiation dose is within the typical range of global natural background radiation dose of 1-10 mSvy-1 to the members of the public.

Investigating the Suitability of Cu2ZnSnS4 Thin Films for Gamma Radiation Dosimetry Applications in Non-Medical Environments

Abstract The need for the replacement of cadmium, indium, and tellurium in their compounds for sensor applications is a novel study. The Cu2ZnSnS4 thin films were synthesized from Cu (99.99%), Sn (99.99%), and Zn (99.99%) using thermal evaporation method. The same volumetric parameters were maintained throughout the synthesis process. The films were further irradiated using an isotope of cesium-137 from a gamma source at different doses (0–0.6 kGy) and dose rates of 0.1007 kGy/hr at room temperature. Both the pristine and irradiated films were characterized with Raman spectroscopy, field emission scanning electron microscope (FESEM), energy dispersive X-rays (EDX), UV-Vis spectroscopy, and four-point probe techniques. The Raman results confirmed that all the films for both pristine and irradiated films have a main and secondary phases. The EDX results showed the pristine and 0.1 kGy films were Cu-rich film, while the 0.3 kGy and 0.6 kGy films turned out to be Zn-rich films with an increase in gamma dose. The optical property of all the films showed that the band gap decreased from 1.6 eV to 1.48 eV for the pristine and irradiated films. While the electrical resistivity results decreased after irradiation dose. The structural, optical, and electrical properties results responded linearly with the increasing gamma radiation dose, which suggested the possibility of using films as a new solid-state sensor to replace CdTe and CIGS thin films.

Pathomorphological Features of Lung Fibrosis in Individuals Occupationally Exposed to Alpha Radiation

The aim of this study was to search for the specific morphological features of radiation-induced lung fibrosis compared to pulmonary fibrosis of another origin, using biological specimens of lung tissue collected from workers internally exposed to alpha radiation. The morphological features of lung fibrosis were defined using biological specimens of lung tissue that had been collected during autopsy examinations from 56 workers diagnosed with plutonium-induced lung fibrosis during life, from 34 workers with lung fibrosis of another origin (due to chronic inflammatory lung diseases) and from 35 workers without clinical pulmonary pathology (controls). The total lung-absorbed dose of gamma radiation from external exposure did not significantly differ among the studied groups, and the total lung-absorbed dose of alpha radiation from internal exposure was significantly higher in workers with plutonium-induced lung fibrosis. To investigate the extracellular matrix components, mono- and polyclonal labeled antibodies against type I, IV, and V collagens were used. In addition, to evaluate the system of extracellular matrix metabolism regulation, the antibodies against matrix metalloproteinases MMP-2, MMP-9, tissue inhibitors of matrix metalloproteinases TIMP-1 and TIMP-2 were used. The study revealed qualitative and quantitative morphological peculiarities of plutonium-induced lung fibrosis compared to lung fibrosis of another origin. This allows us to conclude that plutonium-induced lung fibrosis is a specific type of lung fibrosis, which is characterized with specific location and architectonics of fibrosis foci within the lung, and with changes in levels of collagen, elastic and reticular fibers in the pulmonary stroma. The analysis demonstrated that hyperproduction of type V collagen plays a key role in the development of plutonium-induced lung fibrosis. In addition, the imbalance between the expression of MMPs and their inhibitors plays an important role in the development of lung fibrosis.

Models of Patient Derived Hematopoietic Stem Cell Xenografts for Assessing Individual Human Radiosensitivity

There are different approaches to assessing the human individual radiosensitivity. In this study, individual radiosensitivity was assessed in terms of survival and recovery of human hematopoietic stem cells (HSC) after acute gamma irradiation of humanized mice. Immunodeficient NOD SCID mice were transplanted with cord blood HSC intravenously, peripheral or umbilical cord blood HSC intraosseously. The estimated D0 value for human HSCs was 1.19 Gy (95٪ CI 0.90 to 1.74), 0.99 Gy (95٪ CI 0.87 to 1.15), and 0.93 Gy (95٪ CI 0.61 to 1.91) for the three methods of obtaining humanized mice, respectively. For all three methods of mouse humanization, statistically similar models that describe the dependence of HSC survival on the acute gamma irradiation dose in the range of 0.5—1.5 Gy were obtained. Thus, intraosseous administration of peripheral blood HSCs to immunodeficient mice can be effectively used to assess the response of human HSCs to radiation exposure. Comparison of the HSC number (CD34+ cells) and their descendants (CD45+ cells) in non-irradiated and irradiated mice humanized with cells from the same donor on days 3 and 14 after irradiation makes it possible to evaluate the processes of radiation-induced death and recovery of HSCs. A coefficient calculated as the ratio of the proportion of HSCs among all human cells in the bone marrow of humanized mice on the 14th day to the proportion of HSCs on the 3rd day after irradiation was proposed to assess the response to radiation exposure. This coefficient had an inverse linear dependence on the radiation dose, differed in mice with increased and normal radiosensitivity, and increased with the use of the radioprotector cysteamine in humanized mice. We propose to use this coefficient for a comparative assessment of human radiosensitivity.

Metabolomic changes in preterminal serum samples of rhesus macaques exposed to two different lethal doses of total-body gamma-radiation

Exposure to ionizing radiation induces cellular and molecular damage leading to a cascade of events resulting in tissue and organ injury. Our study strives to characterize and validate metabolomic changes in preterminal stage (immediately prior to death) samples collected from rhesus macaques lethally irradiated with one of two different doses of radiation. Peripheral blood samples were collected pre-exposure, post-exposure, and at the preterminal stage of nonhuman primates (NHPs that did not survive exposure with 7.2 Gy or 7.6 Gy total-body radiation (LD60-80/60)). We analyzed global metabolomic alterations using ultra-performance liquid chromatography (UPLC) quadrupole time-of-flight mass spectrometry (QTOF-MS) in serum samples collected at various timepoints in relation to radiation exposure. The goal of this study was to validate the metabolic shifts present in samples collected just prior to death, which were reported earlier in a preliminary study with a limited number of samples and a single dose of radiation. Here, we demonstrate that radiation exposure induced significant time-dependent metabolic alterations compared with pre-exposure samples. We observed significant metabolite dysregulation in animals exposed to 7.6 Gy compared to 7.2 Gy. Greater metabolic disruption was observed in the preterminal groups than all of the other post-irradiation timepoints in both cohorts. Metabolomic shifts in these preterminal groups also revealed consistent disturbances in sphingolipid metabolism, steroid hormone biosynthesis, and glycerophospholipid metabolism pathways. Overall, the sphingolipid metabolism pathway appears to be representative of the preterminal phenotype, confirming the results of our preliminary study. These results offer important and novel insights for identification and validation of biomarkers for lethality, and such observations would be valuable for triage during a radiological/nuclear mass casualty scenario.

The radiological hazard and potential for generating acid mine drainage from a coal tailings dam.

The aim of this study was to analyze the radiological hazards and the potential for generating acid mine drainage from the fine coal waste commonly stored in tailings dams. The magnetic susceptibility, natural gamma radioactivity, and net neutralization potential of the tailings are characterized. The results show that the fine coal waste has a uranium equivalent concentration (eU) of 46-48Bqkg-1, which is 37.14% higher than the world average, and 39-47Bqkg-1 equivalent concentration of thorium (eTh), which is 56.66% higher than the world average. Also, the absorbed gamma radiation dose rate is higher than the world average. Acid-base balance tests indicate that the net neutralization potential ranged from 0.38 to 2.44. The physical properties indicate a possible radiological risk, while the chemical properties show that generating and non-generating acid drainage can coexist in the fine dam tailings.

An efficient and easy-to-use protocol for induction of haploids in cucumber through parthenogenic embryo development

BackgroundCucumber (Cucumis sativus L.) is a model crop to study cell biology, including the development of haploids and doubled haploids in vegetable crops. In plant breeding, haploid and doubled haploids are valuable tools for developing pure homozygous inbred lines and accelerating genetic progress by reducing the time required for breeding cycles. Besides, the haploids are also valuable in genomic studies. We are reporting the induction of haploids in cucumber involving gynoecious and parthenocarpic genotypes for the first time. This study aimed to assess the efficient induction of haploids through pollination with gamma-irradiated pollen in cucumber. The effect of gamma irradiation dose on pollen viability and germination, fruit setting percentage, seed development, and haploid embryo development in cucumber hybrid genotypes were studied in detail. The goal was to utilize this information to produce haploid plants for genomics and transformation works in this model vegetable crop.ResultsPollination was done on six cucumber genotypes using varying doses of gamma rays (100, 200, 300, 400, and 500 Gy). Genotypes, doses of irradiation, and embryo developmental stage influenced the successful generation of in-vitro haploid plants. The optimal timeframe for embryo rescue was found to be 25 to 30 days after pollination. Haploid embryos were effectively induced using irradiated pollen at 400 to 500 Gy doses. Parthenogenetic plantlets were analyzed, and their ploidy level was confirmed through stomatal physiology, cytology (mitosis), and flow cytometry methods.ConclusionThrough parthenogenic embryo development, it is possible to induce a large number of haploids in cucumber. This technique’s power lies in its ability to streamline the breeding process, enhance genetic gain, and produce superior cultivars that contribute to sustainable agriculture and food security.

Gamma radiation dose rate measurements in granite quarries and schools in two mountainous towns in Benin

Gamma radiation dose rate measurements in granite quarries and schools in two mountainous towns in Benin

Genetic variability increase by gamma irradiation of soybean seeds

The increase of genetic variability by the appearance of new genes of agronomic interest may be favored by the use of gamma radiation. The objective of this study was to evaluate different doses of gamma irradiation on dry seeds of VX04-5692 soybean line, aiming to increase the genetic variability and, with this, the identification of possible mutant plants. The doses of 0, 50, 150 and 250 Gy of gamma radiation were applied from a60Co source. The newly irradiated seeds were sown in the field, giving rise to the M1 cycle. Selected plants originated the M2 cycle. The number of seedlings was counted on the 21st day after sowing. Ten plants of each row were identified and evaluated for the various agronomic characteristics and for chemical composition. The data were submitted to analysis of variance. The F test was applied and the results were presented by boxplots and biplot (canonical variables). There was effect of gamma radiation doses at plant height at full bloom and maturity, number of nodes, pods with one seed and seeds per pod. The use of gamma radiation increases the variability in soybean, with consequent increase in the probabilities of identification of new mutants and gains in the chemical composition, useful for breeding programs that aim at better agronomic performance and gains in oil and protein contents. More satisfactory results in the generation of variability are obtained by the application of gamma radiation on soybean dry seeds between 50 and 150 Gy.

Investigating adsorption and removal of divalent Ca2+ and Pb2+ ions from aqueous solutions by gamma-irradiation using quartz tuning fork (QTF) sensor technique

In this study, gold-coated quartz tuning forks (QTFs) sensing devices functionalized with self-assembled monolayers (SAM) of a lower-rim functionalized calix[4]arene methoxy ester were used for the detection of divalent Ca2+ and Pb2+ ions in aqueous solutions by utilizing adsorption behavior and the radiative effect. The gold-coated QTF functionalized calix[4]arene methoxy ester sensing device was tested by measuring the respective frequency shifts obtained using small (60 µL) samples of aqueous PbCl2 at two different concentrations (10−6 and 10−4 M). For 10−4 M solutions of PbCl2, results showed that the resonance frequency shift Δf = 317 Hz, from 32,867 Hz (fCalix) to 32,550 Hz (fCalix⊃Pb2+) due to the absorption of lead (Pb2+) ions (10-4 M) by calixl[4]arene methoxy ester receptor molecules on the QTF sensing layer from the aqueous solution to forming the ([Calix ⊃ Pb2+]) complex. The most significant frequency changes were observed at a concentration of 10−6 M CaCl2, where CaCl2 exhibited the biggest change of 356 Hz, from 32,893 Hz (fCalix) to 32,537 Hz (fCalix⊃Ca2+), compared to 317 Hz for PbCl2 (10−4 M). The limit of detection was 100 femtomolar (fM) for CaCl2 and 245 fM for PbCl2. After that, we irradiated the receptor molecules which was holding Pb2+ ions in the complex ([calix ⊃ Pb2+]) on the QTF sensing layer with a radiation dose ranging from 7.5 to 50 µGy of gamma rays from the Cesium-137 source for 30 min. Interestingly, it was observed that the resonance frequency shift (Δf = 54 Hz) back to 32,604 Hz from 32,550 Hz (f(Calix⊃Pb2+)), which strongly suggests that the Pb2+ ion removed from ([calix ⊃ Pb2+]) complex on the QTF sensing layer due to gamma radiation dose. To follow up on the radiation effect of the ([calix ⊃ Pb2+]) on the QTF sensing layer, we stopped the gamma radiation source and kept it for an additional 10 min to see if there was any resonance frequency. It was noticed that an additional resonance frequency shifted (Δf = 33 Hz) back to 32,637 Hz from 32,604 Hz after stopping the gamma radiation source for 10 min. We assume that the complex ([calix ⊃ Pb2+]) absorbs the gamma radiation and continues the removal of Pb2+ ions from the complex on the sensing layer. A similar phenomenon was also observed for the absorption of lead (Pb2+) ions (10-6 M) by calix[4]arene methoxy ester receptor molecules on the QTF sensing layer from the aqueous solution to forming the ([Calix ⊃ Pb2+]) complex. The resonance frequency shift Δf = 142 Hz, from 32,706 Hz (fCalix) to 32,564 Hz (fCalix⊃Pb2+) due to the absorption of lead (Pb2+) ions (10-6 M) by calix[4]arene methoxy ester receptor molecules on the QTF sensing layer from the aqueous solution to forming the ([Calix ⊃ Pb2+]) complex. Subsequent exposure to gamma radiation, with doses ranging from 7.5 to 50 µGy from a Cesium-137 source over 30 min, prompted a resonance frequency shift (Δf = 37 Hz) back to 32,606 Hz from 32,564 Hz (f(Calix⊃Pb2+)). This shift strongly suggests the removal of Pb2+ ions from the ([calix ⊃ Pb2+]) complex on the QTF sensing layer due to gamma radiation dose. X-ray photoelectron spectroscopy (XPS) analysis confirmed the chemical adsorption of Pb2+ ions onto the gold-coated QTFs functionalized calix[4]arene adsorbent sensing layer surface. Therefore, the technology underlying the calix[4]arene-functionalized sensing device holds promise for diverse industrial applications, supporting potential advancements in water pollution mitigation through the proposed adsorption and irradiation mechanism.

Influence of gamma-irradiation on the physical properties of epoxy/polyaniline composites and application as gamma dosimeter

Abstract The epoxy/pani samples doped with a specified weight ratio of polyaniline pani ware prepare by casting method. Using different doses of gamma rays (0, 2, and 4 kGy) were used to irradiated the prepared samples. Irradiated and non-irradiated samples were imaged using a FE-scanning electron microscope and were found to have regular morphology, and irradiation had obvious effect on this morphology at 4 kGy. When studying the crystal structure of the samples, it was found the samples have a polycrystalline structure, and this structure tends to improve after irradiation, this was verified using X-ray diffraction. Likewise, D.C electrical conductivity increased with increasing gamma radiation doses. Also study the effect of irradiation with gamma rays on optical properties and demonstrate the clear effect of these rays on optical properties. It was also found that the optical energy gap with (indirect allowed transition) was decreases after the irradiation process. Together, these results indicate the possibility of using these samples in the manufacture of gamma dosimeters.

Effect of Gamma Irradiation Dose on Papain Toxicity

Effect of Gamma Irradiation Dose on Papain Toxicity

Synthesis of Activated Carbon from Banana Peel Biomass Using NaCl and Gamma Co-60 Irradiation

Abstract Indonesian Institute of Sciences (LIPI) stated that the potential for biomass resources in Indonesia is estimated at 49,810 MW originating from plants and waste in 2013 and of course it continues to grow, considering that the source of biomass is from nature. An example of biomass is banana peel. This banana peel can be used as activated carbon. Known from several journals that activated carbon can be applied in various ways such as being a hydrogen storage material, water purification, etc. There are three steps to synthesis activated carbon that divided into initial steps, the first is synthesis of activated carbon, which begins with drying banana peels and then cutting them, then drying them below the sun. Then it is carbonized at 400°C and immersed chemically activated with a salt activator, NaCl. The second step is combining or modifying activated carbon via gamma irradiation and the last step is characterization using BET to know surface area and FTIR to analyze the functional group. The result shows that as an effect of the modification of gamma irradiation doses by 10 kGy, 30 kGy and 50 kGy on activated carbon banana peel, the FTIR spectra increased markedly by the widening of the last stretch. Modification the banana peel with gamma irradiaton Co-60 is the surface area is increase than those without irradiation, but not significantly. It occurred due to the process of carbon degrade due to gamma irradiation of Co-60 can degrade cellulose structures.

Polaron formation via doping process in an organic semiconductor polymer based on thiophene-phenylene

In this research, we synthesized and analyzed the polymer 5-(5-(10-chlorodecyloxy)-2-methoxy-4-(5-methylthiophen-2-yl)phenyl)-5′-(2-(2-ethylhexyloxy)-5-methoxy-4-(5-methylthiophen-2-yl)phenyl)-2,2′-bithiophene (PTBT46). The polymer was dissolved in chloroform and subjected to gamma radiation doses ranging from 0 to 100 Gy (gray). We observed that PTBT46 can be doped with H+ions, as indicated by visible color changes, optical measurements, and a tenfold increase in conductivity. When analyzing PTBT46 in solution using THF (tetrahydrofuran) and chloroform, we found a notable solvent dependence. In chloroform, new absorption bands appeared at approximately 680 nm and 2630 nm after radiation doses of 25 to 100 Gy, which were not present in THF. These bands are attributed to polarons and bipolarons resulting from the doping process. Additionally, we observed a spectral “blue shift” with increasing H+concentration due to changes in molecular conjugation, without degradation of the polymer chain. This shift, confirmed by Fourier-transform infrared (FTIR) spectroscopy, is reversible and suggests potential applications in optoelectronic devices and advanced radiation sensors.

Расчетное определение радиационных характеристик активируемых средне- и высокоактивных радиоактивных отходов, образующихся при эксплуатации АЭС с ВВЭР

The article describes the methodology of computational determination of specific activity of radionuclides in the radioactive waste in the form of spent neutron measurement channels (NMCs) TVS-2M of VVER-1000 reactor. The results of research on the dependence of the specific activity of radionuclides on the NMC lifetime, number of fuel elements, gadolinium amount, enrichment and initial burn-up of fuel assemblies are given. The calculations have been carried out by the Monte Carlo method using the MCU-6 computer program. To verify the results of calculations, a method based on measurements of the gamma radiation dose rate from activated radioactive waste is proposed.