Comparison of two fast neutron fluence measurement methods based on Np-237 fission-to-capture ratio measurement (spectral index) and a reverse dark current measurement in a planar silicon detector

The idea of the first method is to search the neutron energy for the ratio of fission cross section to capture cross section of the selected actinide isotope from the nuclear data base that is equal to the measured ratio of the fissioned and captured actinide isotope Np-237. The idea of the second method consists in the measurement of the reverse dark current increase, which is linearly proportional to neutron fluence, induced by the fast neutron irradiation in planar silicon detectors. Np-237 samples and planar silicon detectors were placed inside a subcritical assembly (the Quinta assembly at the Joint Institute for Nuclear Research, Russia) very close to each other assuming that in both samples the same neutron fluence should pass. We concluded that minor actinide samples and planar silicon detectors can be used as neutron fluence detectors especially in the high neutron energy range, where measurements are difficult. Considering the importance of high energy neutron measurement in the ADS (Accelerator Driven System), actinide and silicon detectors could be a very useful tool

Comparison of two fast neutron fluence measurement methods based on Np-237 fission-to-capture ratio measurement (spectral index) and a reverse dark current measurement in a planar silicon detector

The idea of the first method is to search the neutron energy for the ratio of fission cross section to capture cross section of the selected actinide isotope from the nuclear data base that is equal to the measured ratio of the fissioned and captured actinide isotope Np-237. The idea of the second method consists in the measurement of the reverse dark current increase, which is linearly proportional to neutron fluence, induced by the fast neutron irradiation in planar silicon detectors. Np-237 samples and planar silicon detectors were placed inside a subcritical assembly (the Quinta assembly at the Joint Institute for Nuclear Research, Russia) very close to each other assuming that in both samples the same neutron fluence should pass. We concluded that minor actinide samples and planar silicon detectors can be used as neutron fluence detectors especially in the high neutron energy range, where measurements are difficult. Considering the importance of high energy neutron measurement in the ADS (Accelerator Driven System), actinide and silicon detectors could be a very useful tool

Disinfection and usage of anthropogenic waste in resource-saving construction technologies

Актуальность. Проблема охраны окружающей среды является одной из острейших проблем настоящего времени. Многостороннее замусоривание всех геосфер неутилизированными отходами привело к резкому ухудшению состояния экологических систем, к гибели некоторых уникальных природных комплексов, к сокращению и исчезновению популяций отдельных видов растений и животных, к опасности непредсказуемых необратимых последствий, к которым могут привести результаты техногенной деятельности человека. Поэтому утилизация техногенных отходов производств, а тем более использование их в ресурсосберегающих технологиях, безусловно, весьма актуальны. Цель работы: показать возможность утилизации, контроля и использования отходов производств, в частности фторангидрита, в ресурсосберегающих строительных технологиях. Методы: химическая нейтрализация отходов, дезинтеграция сырья и получение из него сыпучего клинкерного материала, способы его контроля и применения в разнообразных рецептурах в строительных технологиях; лазерное сканирование поверхности полученной сыпучей смеси; аппроксимация модели поверхности с применением радиальных базисных функций нейронных сетей; создание модели нелинейной функции поверхности по теореме Колмогорова с применением суперпозиции радиальных базисных функций; вычисление объема вещества, ограниченного полученной функцией с применением кубатурной функции методом Гаусса-Кронрода и методом Монте-Карло. Результаты. Рассмотрена технология нейтрализации сульфаткальциевых отходов производства и технологическая схема его дезинтеграции и использования в буровых растворах. Представлена система контроля объема дезинтегрированного вещества, необходимая для учета его количества и дозирования при использовании в рецептурах различных технологий. Показано, что при контроле и оценке количества дезинтегрированного вещества лучшим является способ с аппроксимацией нелинейной функции, так как имеется возможность регулирования ошибки количеством разбиений функции или количеством опытов, а также учитывается модель поверхности вещества. Использование радиальных базисных функций нейронной сети целесообразно для получения модели поверхности сыпучих веществ с целью повышения точности измерения объемов в резервуарных парках и складах производственных предприятий. Наиболее эффективными являются методы моделирования функций поверхности и измерения их объема методами квадратур или Монте-Карло. Использование метода Гаусса-Кронрода в данном случае предпочтительно.Relevance. The environmental protection problem is one of the most important one in the present time. Multilateral pollution of all geospheres with non-utilized wastes led to a sharp deterioration of ecological systems, to the death of some unique natural complexes, to the reduction and disappearance of populations of certain plant and animal species, to the danger of unpredictable irreversible consequences which can be the result of man's technogenic activity. That is why the utilization of industrial wastes of industries and their use in resource-saving technologies, of course, are very relevant. The aim of the work is to show the possibility of utilization, control and use of waste products, in particular fluorine-anhydrite in resource-saving construction technologies. Methods: chemical waste neutralization, disintegration of the obtained raw materials and production of bulk clinker material from it, methods of its control and application in various formulations in construction technologies; laser scanning of the surface of the received bulk mixture; approximation of the surface model using radial basis function neural networks; modeling of a non-linear surface function, by the Kolmogorov theorem, using the superposition of radial basis functions; calculation of the volume of a substance limited by the obtained function using the cubature function by the Gauss-Kronrod method and the Monte Carlo method. Results. The paper considers the technology of calcium sulfate neutralization and technological scheme of its disintegration and use in drilling fluids and introduces the system for controlling the volume of a disintegrated substance, which is necessary to account its quantity and dosing when used in formulations of various technologies. It is shown that when controlling and estimating the amount of a disintegrated substance, the best way is to approximate the nonlinear function, since it is possible to control the error by the number of partitions of the function or the number of experiments, and also the model of the surface of the substance is taken into account. The usage of the radial basis function neural network is advisable for obtaining a model of the surface of bulk materials in order to improve the accuracy of measuring volumes in silo farms and warehouses of manufacturing enterprises. Methods of modeling surface functions and measuring their volume by quadrature or Monte Carlo methods are the most effective ones. Usage of the Gauss-Kronrod method in this case is preferable

TANGRA multidetector systems for investigation of neutron-nuclear reactions at the JINR Frank Laboratory of Neutron Physics

In the framework of TANGRA-project at the Frank Laboratory of Neutron Physics of the Joint Institute for Nuclear research in Dubna (Russia), two experimental setups (Fig. 1) have been designed and tested for investigation of 14-MeV neutron-induced nuclear reactions on a number of important for nuclear science and engineering isotopes. As a source of 14-MeV “tagged” neutrons we are using the VNIIA ING-27 steady-state portable neutron generator with embedded in its vacuum tube 64-pixel charge-particle detector. The “Romashka” system is an array of up-to 24 hexagonal NaI(Tl)-crystal scintillation probes, while the “Romasha” array consists of 18 cylindrical BGO-crystal detectors of neutrons and gamma-rays. In addition to these detectors there is a HPGe gamma-ray spectrometer and a number of Stilbene detectors that can be added for high-resolution gamma-ray spectrometry and neutron-gamma detection. The main characteristics of the neutron-induced nuclear reaction products can be investigated by commissioning the detectors in suitable for these experiments’ geometries. Both setups can be used for doing basic and applied scientific research, because they permit simultaneously to measure the energy, angle and multiplicity distributions of gamma-rays and neutrons, produced in the competitive neutron-induced nuclear reactions (n, n’γ), (n,2n), (n, xnγ) and (n, f) in pure or complex substances

Everything you do: young adult fiction and surveillance in an age of security

Espionage, surveillance and clandestine operations by secret agencies and governments were something of an East–West obsession in the second half of the twentieth century, a fact reflected in literature and film. In the twenty-first century, concerns of the Cold War and the threat of Communism have been rearticulated in the wake of 9/11. Under the rubric of ‘terror’ attacks, the discourses of security and surveillance are now framed within an increasingly global context. As this article illustrates, surveillance fiction written for young people engages with the cultural and political tropes that reflect a new social order that is different from the Cold War era, with its emphasis on spies, counter espionage, brainwashing and psychological warfare. While these tropes are still evident in much recent literature, advances in technology have transformed the means of tracking, profiling and accumulating data on individuals’ daily activities. Little Brother, The Hunger Games and Article 5 reflect the complex relationship between the real and the imaginary in the world of surveillance and, as this paper discusses, raise moral and ethical issues that are important questions for young people in our age of security

COVID-19-Associated Pulmonary Aspergillosis in Russia

We studied the risk factors, etiology, clinical features and the effectiveness of therapy of COVID-19-associated pulmonary aspergillosis (CAPA) in adult patients. In this retrospective study, we included 45 patients with proven (7%) and probable (93%) CAPA. The ECMM/ISHAM, 2020 criteria were used to diagnose CAPA. A case-control study was conducted to study the risk factors of CAPA; the control group included 90 adult COVID-19 patients without IA. In CAPA patients, the main underlying diseases were diabetes mellitus (33%), and hematological and oncological diseases (31%). The probability of CAPA developing significantly increased with lymphocytopenia >10 days (OR = 8.156 (3.056–21.771), p = 0.001), decompensated diabetes mellitus (29% vs. 7%, (OR = 5.688 (1.991–16.246), p = 0.001)), use of glucocorticosteroids (GCS) in prednisolone-equivalent dose > 60 mg/day (OR = 4.493 (1.896–10.647), p = 0.001) and monoclonal antibodies to IL-1ß and IL-6 (OR = 2.880 (1.272–6.518), p = 0.01). The main area of localization of CAPA was the lungs (100%). The clinical features of CAPA were fever (98% vs. 85%, p = 0.007), cough (89% vs. 72%, p = 0.002) and hemoptysis (36% vs. 3%, p = 0.0001). Overall, 71% of patients were in intensive care units (ICU) (median—15.5 (5–60) days), mechanical ventilation was used in 52% of cases, and acute respiratory distress syndrome (ARDS) occurred at a rate of 31%. The lung CT scan features of CAPA were bilateral (93%) lung tissue consolidation (89% vs. 59%, p = 0.004) and destruction (47% vs. 1%, p = 0.00001), and hydrothorax (26% vs. 11%, p = 0.03). The main pathogens were A. fumigatus (44%) and A. niger (31%). The overall survival rate after 12 weeks was 47.2%

Agent-Based Modeling of Autosomal Recessive Deafness 1A (DFNB1A) Prevalence with Regard to Intensity of Selection Pressure in Isolated Human Population

An increase in the prevalence of autosomal recessive deafness 1A (DFNB1A) in populations of European descent was shown to be promoted by assortative marriages among deaf people. Assortative marriages became possible with the widespread introduction of sign language, resulting in increased genetic fitness of deaf individuals and, thereby, relaxing selection against deafness. However, the effect of this phenomenon was not previously studied in populations with different genetic structures. We developed an agent-based computer model for the analysis of the spread of DFNB1A. Using this model, we tested the impact of different intensities of selection pressure against deafness in an isolated human population over 400 years. Modeling of the “purifying” selection pressure on deafness (“No deaf mating” scenario) resulted in a decrease in the proportion of deaf individuals and the pathogenic allele frequency. Modeling of the “relaxed” selection (“Assortative mating” scenario) resulted in an increase in the proportion of deaf individuals in the first four generations, which then quickly plateaued with a subsequent decline and a decrease in the pathogenic allele frequency. The results of neutral selection pressure modeling (“Random mating” scenario) showed no significant changes in the proportion of deaf individuals or the pathogenic allele frequency after 400 years

TANGRA – an experimental setup for basic and applied nuclear research by means of 14.1 MeV neutrons

For investigation of the basic characteristics of 14.1 MeV neutron induced nuclear reactions on a number of important isotopes for nuclear science and engineering, a new experimental setup TANGRA has been constructed at the Frank Laboratory of Neutron Physics of the Joint Institute for Nuclear Research in Dubna. For testing its performance, the angular distribution of γ-rays (and neutrons) from the inelastic scattering of 14.1 MeV neutrons on high-purity carbon was measured and the angular anisotropy of γ-rays from the reaction 12C(n, n′γ)12C was determined. This reaction is important from fundamental (differential cross-sections) and practical (non-destructive elemental analysis of materials containing carbon) point of view. The preliminary results for the anisotropy of the γ-ray emission from the inelastic scattering of 14.1- MeV neutrons on carbon are compared with already published literature data. A detailed data analysis for determining the correlations between inelastic scattered neutron and γ-ray emission will be published elsewhere