10 research outputs found

    The efficiency of gas-filled surge arresters in the environment contaminated by non-ionizing radiation of fusion reactors

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    The research presents an experiment with a model of an electronic generator for energy injection into the plasma of a fusion reactor. By recording a non-ionizing field in the vicinity of a fusion reactor, it was determined that this field has an extremely high growth rate. At the site of the maximum intensity of the field of non-ionizing radiation, commercial surge arresters with a flexible model of surge arresters were used for experimentation. It has been found that the commercial surge arresters have an efficiency of about 20%. For the efficiency of the flexible model, it was found to be slightly less than 40% (and to be achieved by the application of alpha particle radiation). Since neither of these efficiencies guarantee reliable operation of the gas-filled surge arrester, it was concluded that essential electronics in the vicinity of the fusion generator must be protected. However, since this protection can only be implemented in a fusion reactor, the fact remains that the environment of such a reactor is extremely contaminated with non-ionizing radiation. Commercial surge voltages are isolated for testing since the protection of electronic circuits from fast overvoltages is a critical point for the functioning of modern electronics

    Possibility of application nuclear magnetic resonance for measurement of fluid-flow

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    The paper considers the application of nuclear magnetic resonance for measurement of fluid-flow. The paper is of an experimental nature. Flowmeter based on nuclear magnetic resonance is extremely precise. The combined measurement uncertainty can be 0.1 %. Such a value of measurement uncertainty indicates that it is a matter of a deterministic and not of a stochastic quantity. This high degree of reliability of the method is theoretically and mathematically described. The paper presents a measurement scheme for flow measurement. Water flow measurement was performed on the principle of nuclear magnetic resonance and on the basis of tritiated water (which is considered to be the most accurate classical method). The obtained results show that the measurement of flow based on nuclear magnetic resonance is more accurate (especially at higher flow). This is explained by the higher inertial mass of HTO tritiated water molecules than the standard H2 O mass and the possible transition of tritiated water to H3HeO. In this way, it has been proven that tracing water based on nuclear magnetic resonance is the only real tracing of water by water. The obtained results show that tracing water with tritiated or heavy water is not tracing water by water which is explained by different inertial masses

    Deep Learning Model for Global Spatio-Temporal Image Prediction

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    Mathematical methods are the basis of most models that describe the natural phenomena around us. However, the well-known conventional mathematical models for atmospheric modeling have some limitations. Machine learning with Big Data is also based on mathematics but offers a new approach for modeling. There are two methodologies to develop deep learning models for spatio-temporal image prediction. On these bases, two models were builtā€”ConvLSTM and CNN-LSTMā€”with two types of predictions, i.e., sequence-to-sequence and sequence-to-one, in order to forecast Aerosol Optical Thickness sequences. The input dataset for training was NASA satellite imagery MODAL2_E_AER_OD from Terra/MODIS satellites, which presents global Aerosol Optical Thickness with an 8 day temporal resolution from 2000 to the present. The obtained results show that the ConvLSTM sequence-to-one model had the lowest RMSE error and the highest Cosine Similarity value. The advantages of the developed DL models are that they can be executed in milliseconds on a PC, can be used for global-scale Earth observations, and can serve as tracers to study how the Earthā€™s atmosphere moves. The developed models can be used as transfer learning for similar image time-series forecasting models

    Sustainable Utilization of Cathode-Ray Tube Waste Glass in Cementitious Materials ā€“ A Review

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    The advances in the electronic industry have led to a generation of an extensive amount of electrical waste (E-waste) before the end of its proper life span. Excessive usage and production of cathode-ray tubes (CRT), which is the fundamental part of old monitors and screens, has become an immense problem worldwide regarding the environmental issues, since the last few decades thin-film transistors (TFT) and liquid crystal display (LCD) replaced CRTs almost entirely. Consequently, it is of crucial importance to expand and deploy new, renewable methods to manage CRT glass waste. There is an appreciable prospective to use CRT waste glass for new products manufacture, or as an admixture to existing ones, hence the requirement for reusing this kind of waste is favorable. Many investigations have confirmed the positive effect of using grounded CRT waste glass as a fine aggregate. However, this waste is classified as hazardous due to the high lead content. Mixing CRT glass with mortar constructively decreases the amount of cement consumption. Features of this paper relate to a review of recent developments regarding the reuse of CRTs in cementitious materials. Emphasis was placed on their physico-mechanical properties to evaluate the possibility of CRT usage in mortar mixtures

    Passive and active shielding against electromagnetic radiation

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    In nuclear physics experiments, it is very important to isolate the measured quantities from electromagnetic noise. Without this possibility, it is impossible to obtain usable experimental results since natural electromagnetic noise can be several orders of magnitude larger than the measured magnitude. In order to enable such measurements, it is necessary to eliminate electromagnetic noise from the experimental procedure. This is achieved by shielding against electromagnetic radiation. In this paper, experiments were performed to protect a room from electromagnetic noise. By applying all known methods of shielding against electromagnetic radiation, it was concluded that the room can be protected from the electrical component, but it is impossible to protect it from the magnetic component of electromagnetic radiation

    In fluence of gamma radiation on Josephson junction

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    Quantum mechanics consideration, supported by a concrete example, yielded standard sources of di rect volt age mea sured by frequency (which is the most ac cu rate measur able phys-ical quantity) and extremely sensitive instrument for measuring magnetic induction SQUID (which is an ac ro nym based on the term Supercon duct ing Quan tum Inter fer ence Device). The pos sibility of these mea sure ments is based on the Josephson junc tion. In this paper, the in flu ence of gamma ra diation on the mea sure ment un cer tainty Type A, of a com mercial Josephson compound, is investi gated. The conclu sion is that both dy namic gamma radiation and the dose of gamma ra di ation, un der the con ditions of the ex per iment, have a neg ligible ef-fect on the mea sure ment uncer tainty of the Josephson junc tion. Based on the ob tained re sult, it was con cluded that in the primary metrological con di tions, the mea sure ment un cer tainty type A of the Josephson junc tion is neg ligible, i. e., that the secondary cosmic radiation does not af fect the stan dard of the DC volt age source. Ā© 2021, Vinca Inst Nuclear Sci. All rights reserved

    Possibility of Harmless Utilization of CRT Waste Glass in the Art Field

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    Elevation in the electronics industry has experienced a significant increase in the amount of waste generated, resulting in the generation of a substantial amount of electrical waste (E-waste). The excessive usage and production of cathode-ray tubes (CRT), a critical component of older monitors and screens, has become a significant environmental issue globally over the past few decades. With the advent of novel technologies, CRTs have been almost entirely replaced. It is now essential to develop new and renewable methods to manage CRT glass waste. The reuse of CRT waste glass for the manufacturing of new products or as an admixture to existing ones presents a significant opportunity, and thus it is obligatory to find contemporary ways to recycle this waste. Grounded CRT waste glass has been found to have a positive impact when used as a fine aggregate, but it is classified as hazardous due to its high lead content. However, after comprehensive series of cleaning and grinding the utilization of CRT glass can be beneficial in various fields. This paper focuses on reviewing recent developments related to the reuse of CRTs, and the aim is to evaluate the feasibility of its safe application in the art field

    Influence of gamma radiation on measurement fast pulse voltages by Kerr electro-optic effect

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    In this paper, the possibility of measuring the electronic pulse from an electronic generator for plasma heating by electro-optical method is considered. The experiments are performed by applying the Kerr effect on an electronic generator model. Kerr effect shows very good characteristics for measuring nanosecond pulse rate. However, the results obtained show that these characteristics are significantly spoiled by gamma radiation in a dynamic state as well as by the absorbed dose of gamma radiation. When the simplicity of measuring with a capacitive probe is added to that, it can be concluded that the Kerr electro-optical effect is not recommended for measurement in fusion experiments

    Comparison of Measurement Reliability of Nanosecond Rectangular Voltage Pulses by Kerr Effect and by High-Speed Voltage Probe

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    Recently, the idea of injecting energy with electromagnetic radiation in order to heat the plasma to achieve controlled fusion has been abandoned. This initially favored mechanism was rejected because it has been shown that after a certain temperature the plasma glows and acts as a mirror that reflects electromagnetic radiation. For that reason, today the energy is injected into the plasma by electrons. For this purpose, pulses from several electron beam generators, based on a Marx generator, are synchronously fired into the plasma. In addition to economic problems, the biggest problem of this method is the appearance of jitter, i.e., pulses with a width of about 5 ns are not simply added up but propagated in time due to the impossibility of synchronizing simultaneous triggering of the multiple electronic generators. In order to avoid this, the possibility of monitoring the pulses from an individual electron beam generator for the purpose of online synchronization is investigated in this paper. The voltage pulse monitoring of the electron beam generator was measured by instruments with the fastest responseā€”the electro-optical Kerr effect and a fast capacitive probe. The obtained results showed that the electro-optical Kerr response is somewhat faster but much more complicated, so the use of fast capacitive probes is recommended for practice

    A Comparative Evaluation of Self-Attention Mechanism with ConvLSTM Model for Global Aerosol Time Series Forecasting

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    The attention mechanism in natural language processing and self-attention mechanism in vision transformers improved many deep learning models. An implementation of the self-attention mechanism with the previously developed ConvLSTM sequence-to-one model was done in order to make a comparative evaluation with statistical testing. First, the new ConvLSTM sequence-to-one model with a self-attention mechanism was developed and then the self-attention layer was removed in order to make comparison. The hyperparameters optimization process was conducted by grid search for integer and string type parameters, and with particle swarm optimization for float type parameters. A cross validation technique was used for better evaluating models with a predefined ratio of train-validation-test subsets. Both models with and without a self-attention layer passed defined evaluation criteria that means that models are able to generate the image of the global aerosol thickness and able to find patterns for changes in the time domain. The model obtained by an ablation study on the self-attention layer achieved better outcomes for Root Mean Square Error and Euclidean Distance in regards to developed ConvLSTM-SA model. As part of the statistical test, a Kruskalā€“Wallis H Test was done since it was determined that the data did not belong to the normal distribution and the obtained results showed that both models, with and without the SA layer, predict similar images with patterns at the pixel level to the original dataset. However, the model without the SA layer was more similar to the original dataset especially in the time domain at the pixel level. Based on the comparative evaluation with statistical testing, it was concluded that the developed ConvLSTM-SA model better predicts without an SA layer
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