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Conformal image-guided microbeam radiation therapy at the ESRF biomedical beamline ID17
摘要： Purpose: Upcoming veterinary trials in microbeam radiation therapy (MRT) demand for more advanced irradiation techniques than in preclinical research with small animals. The treatment of deep-seated tumors in cats and dogs with MRT requires sophisticated irradiation geometries from multiple ports, which impose further efforts to spare the normal tissue surrounding the target. Methods: This work presents the development and benchmarking of a precise patient alignment protocol for MRT at the biomedical beamline ID17 of the European Synchrotron Radiation Facility (ESRF). The positioning of the patient prior to irradiation is verified by taking x-ray projection images from different angles. Results: Using four external fiducial markers of 1.7 mm diameter and computed tomography-based treatment planning, a target alignment error of less than 2 mm can be achieved with an angular deviation of less than 2?. Minor improvements on the protocol and the use of smaller markers indicate that even a precision better than 1 mm is technically feasible. Detailed investigations concerning the imaging dose lead to the conclusion that doses for skull radiographs lie in the same range as dose reference levels for human head radiographs. A currently used online dose monitor for MRT has been proven to give reliable results for the imaging beam. Conclusions: The ESRF biomedical beamline ID17 is technically ready to apply conformal image-guided MRT from multiple ports to large animals during future veterinary trials.
关键词： microbeam radiation therapy,image-guidance,x-ray imaging,fiducial markers,synchrotron radiation
更新于2025-09-23 15:22:29
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Avalia??o do conhecimento de médicos n?o radiologistas sobre aspectos relacionados à radia??o ionizante em exames de imagem
摘要： Objective: To assess the non-radiologist physicians’ knowledge on the use of ionizing radiation in imaging. Materials and Methods: Cross-sectional study utilizing an anonymous questionnaire responded by physicians in clinical and surgical specialties, divided into two parts as follows: one including questions about the physicians’ characteristics, frequency of imaging studies requests and participation in professional updating events, and another part including multiple choice questions approaching general knowledge about radiation, optimization principles and radioprotection. Results: From a total of 309 questionnaires, 120 (38.8%) were responded, 50% by physicians in surgical specialties and 50% in clinical specialties; respectively 45% and 2.5% of physicians responded that magnetic resonance imaging and ultrasonography use ionizing radiation. Overall, the average grade was higher for surgical specialists with no significant difference, except for the question about exposure in pregnant women (p = 0.047). Physicians who are professionally updated, particularly those attending clinical meetings (p = 0.050) and participating in teaching activities (p = 0.047), showed statistically superior knowledge about ionizing radiation as compared with others. Conclusion: The non-radiologist physicians’ knowledge is heterogeneous and in some points needs to be improved. Multidisciplinary clinical meetings and teaching activities are important ways to disseminate information on the subject.
关键词： Questionnaire.,Knowledge,Ionizing radiation,Imaging diagnosis,Physicians,Radiation protection
更新于2025-09-23 15:22:29
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The extragalactic background light revisited and the cosmic photon–photon opacity ( <i>Corrigendum</i> )
摘要： For some unexplained reasons, all tables in the Franceschini & Rodighiero (2017) paper have been mixed up. Tables 1–3 reported there were identical to those published in Franceschini et al. (2008). We report here in Tables 1, 2, and 4 the corresponding correct values in terms of photon proper number densities and photon–photon optical depths as a function of photon energy. We also took this occasion to add a new table (Table 3) including the predicted extragalactic background light values at redshifts between 2 and 3.5, as requested by some readers of the Franceschini & Rodighiero (2017) paper. Both photon number densities and photon–photon optical depths are calculated including the contributions of the cosmic microwave background assumed as a black-body with T = 2.728 K. Except for the numerical values in the tables, all the rest of the Franceschini & Rodighiero (2017) paper is unaffected by the problem.
关键词： addenda,gamma rays: galaxies,diffuse radiation,errata,cosmic background radiation,BL Lacertae objects: general
更新于2025-09-23 15:22:29
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Solar radiation exergy and quality performance for Iraq and Turkey
摘要： The present study is conducted with two primary objectives: First, a new formulation for the maximum efficiency of the solar radiation conversion is developed by considering the radiative energy transfer between two surfaces at different temperatures for a constant volume system. Second, a new methodology is introduced for estimating the exergy value of the monthly average daily horizontal global radiation, including many parameters, such as monthly average daily value of the horizontal extraterrestrial radiation, the number of sunny hours, the day length, the mean temperature and the mean wind velocity. Seven statistical parameters are used to validate the accuracy of all models. The results of the two new models are found to be more reliable than the results obtained from other models. This study, which was conducted for four locations in Iraq and Turkey. The findings would help in predicting the maximum availability of solar radiation based on weather parameters.
关键词： empirical models,solar radiation,solar radiation exergy
更新于2025-09-23 15:22:29
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Global Solar Radiation Prediction Using Hybrid Online Sequential Extreme Learning Machine Model
摘要： Accurate global solar radiation prediction is highly essential for related research on renewable energy sources. The cost implication and measurement expertise of global solar radiation emphasize that intelligence prediction models need to be applied. On the basis of long-term measured daily solar radiation data, this study uses a novel regularized online sequential extreme learning machine, integrated with variable forgetting factor (FOS-ELM), to predict global solar radiation at Bur Dedougou, in the Burkina Faso region. Bayesian Information Criterion (BIC) is applied to build the seven input combinations based on speed (Wspeed), maximum and minimum temperature (Tmax and Tmin), maximum and minimum humidity (Hmax and Hmin), evaporation (Eo) and vapor pressure deficiency (VPD). For the difference input parameters magnitudes, seven models were developed and evaluated for the optimal input combination. Various statistical indicators were computed for the prediction accuracy examination. The experimental results of the applied FOS-ELM model demonstrated a reliable prediction accuracy against the classical extreme learning machine (ELM) model for daily global solar radiation simulation. In fact, compared to classical ELM, the FOS-ELM model reported an enhancement in the root mean square error (RMSE) and mean absolute error (MAE) by (68.8–79.8%). In summary, the results clearly confirm the effectiveness of the FOS-ELM model, owing to the fixed internal tuning parameters.
关键词： global solar radiation,West Africa region,energy harvesting,FOS-ELM model,input optimization
更新于2025-09-23 15:22:29
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[IEEE 2018 Eleventh International Conference "Management of large-scale system development" (MLSD 2018) - Moscow (2018.10.1-2018.10.3)] 2018 Eleventh International Conference "Management of large-scale system development" (MLSD - Portable Devices for Monitoring Ultraviolet Radiation
摘要： The article deals with issues related to the use of the new elemental base in some control and monitoring systems for the principles of large-scale objects, constructing portable devices for monitoring ultraviolet radiation. These are the semiconductor sensors - a doser that gives a quantitative result on a digital indicator, either delivering a light or sound signal when reaching a predetermined radiation dose and a dosimeter that measures the intensity of UV radiation or the dose received in real physical units of measurement.
关键词： UV radiation,control systems,sensor,large-scale objects,semiconductor,monitoring,portable device
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE Sciences and Humanities International Research Conference (SHIRCON) - Lima, Peru (2018.11.20-2018.11.22)] 2018 IEEE Sciences and Humanities International Research Conference (SHIRCON) - A Visible Fluorescence Method Induced by UV Radiation for Detection of Infestation in Canary Beans
摘要： The proposed study aims to present an algorithm for the detection of infestation of canary beans of the species "Phaseolus Vulgaris" by generating a visible fluorescence under UV radiation, which allows the bean to be distinguished as healthy or infested. Currently, since many of the symptoms of infestation cannot be detected by the human eye, the beans sample analysis is highly subjective. The proposed method uses images of the beans taken under UV radiation within a hermetic enclosure. Then the image is acquired and an image segmentation algorithm is executed in order to identify the beans. Each bean is labeled so that the infestation can be detected by an algorithm based on histogram analysis. For the validation of the proposed method, several samples were evaluated and the results were compared with those obtained by two experts through an exhaustive visual analysis. The results were expressed through specificity and sensitivity, obtaining 99.78% for specificity and 90.70% for sensitivity.
关键词： canary bean,UV radiation,image processing,infestation,visible fluorescence,specificity,sensitivity,detection
更新于2025-09-23 15:22:29
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Reverse annealing studies of irradiated silicon by use of current–voltage measurements
摘要： The annealing behaviour of irradiated silicon p-i-n diodes has been investigated by use of I–V measurements. The radiation-induced damage is achieved by the use of 1 MeV neutrons. The results have been analysed and a striking feature is easily noticeable where defects that do not anneal out alter their activity and behave more as generation centres. This means that they are situated in the upper half of the band gap where they act to increase the carrier density and the measured current. The increase in current starts to occur at around 100 days and a change in trap activity at around 180 days after irradiation. The device behaviour, however, remains ohmic throughout indicating that a defect level that is responsible for relaxation behaviour is stable. This study would assist in demonstrating stability of silicon radiation detectors during their operational time.
关键词： Diode,Current,Radiation,Semiconductor,Silicon,Annealing
更新于2025-09-23 15:22:29
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[IEEE 2018 International Ural Conference on Green Energy (UralCon) - Chelyabinsk (2018.10.4-2018.10.6)] 2018 International Ural Conference on Green Energy (UralCon) - Comparative Analysis of Approaches to Consider Rationale of use of Solar Panel Plants for Power Supply of Off-Grid Consumers
摘要： The values of solar radiation for different monitoring periods from reference books were compared with calculated values from recent data of meteorological stations. The choice of meteorological stations depended on the differences of their latitude location, their position in the zone of the off-grid power supply, available data in different reference books on solar potential of the stations under study and presence of power plants located in different latitude zones using power resources for energy generation. The Sakha Republic (Yakutia) corresponded to these conditions. The comparative analysis of the initial values of solar potential showed that deviations amounted to 5–10%. The authors compared the results of recalculation of solar radiation values on the inclined surface using two approaches and showed the advantages of these approaches. They also investigated how the application of different approaches affected the optimal power of solar panel plants and calculated the payback periods of their construction. The payback period of the existing solar panel plants on the territory of the Sakha Republic (Yakutia) was compared with the calculated one. The application of different methodological approaches at different stages of rationale of solar panel plant construction was efficient for the power supply of off-grid consumers. It was proved that a simplified approach was reasonable for investigations of economic viability of power potential use on the territory under study. Detailed calculations are necessary for the determination of technical and economic parameters of a solar panel plant in a concrete settlement and for the estimation of economic effectiveness of its construction taking into account recent meteorological data.
关键词： recalculation on an inclined surface,optimal power,deviation of values,Solar radiation,payback period
更新于2025-09-23 15:22:29
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Frequency variations of solar radio zebras and their power-law spectra
摘要： Context. During solar ?ares several types of radio bursts are observed. The ?ne striped structures of the type IV solar radio bursts are called zebras. Analyzing them provides important information about the plasma parameters of their radio sources. We present a new analysis of zebras. Aims. Power spectra of the frequency variations of zebras are computed to estimate the spectra of the plasma density variations in radio zebra sources. Methods. Frequency variations of zebra lines and the high-frequency boundary of the whole radio burst were determined with and without the frequency ?tting. The computed time dependencies of these variations were analyzed with the Fourier method. Results. First, we computed the variation spectrum of the high-frequency boundary of the whole radio burst, which is composed of several zebra patterns. This power spectrum has a power-law form with a power-law index –1.65. Then, we selected three well-de?ned zebra-lines in three di?erent zebra patterns and computed the spectra of their frequency variations. The power-law indices in these cases are found to be in the interval between –1.61 and –1.75. Finally, assuming that the zebra-line frequency is generated on the upper-hybrid frequency and that the plasma frequency ωpe is much higher than the electron-cyclotron frequency ωce, the Fourier power spectra are interpreted to be those of the electron plasma density in zebra radio sources.
关键词： plasmas,Sun: radio radiation,turbulence
更新于2025-09-23 15:22:29