Search

The use and availability of diverse advanced X-ray based imaging and guidance systems in the field of interventional pulmonology are rapidly growing. This popularity links inextricably to an increase in ionizing radiation use. Knowing ionizing radiation is hazardous, knowledge and competent use of X-ray imaging and guidance systems are important. The globally implemented As Low As Reasonably Achievable (ALARA) principle demands careful attention to minimize radiation exposure while achieving the precise goals of the intervention and imaging therein. To allow careful and targeted weighing of risk against reward while using X-ray based equipment, proper background knowledge of physics as well as imaging system aspects are needed. This white paper summarizes the principles of ionizing radiation which are crucial to enhance awareness and interpretation of dosimetric quantities. Consecutively, a consensus on standards for reporting radiation exposure in interventional pulmonology procedures is indicated to facilitate comparisons between different systems, approaches and results. Last but not least, it provides a list of practical measures, considerations and tips to optimize procedural imaging as well as reduce radiation dose to patients and staff. [ABSTRACT FROM AUTHOR]

A novel in situ/operando method is introduced to measure the photon beam stability of synchrotron radiation based on orthogonal diffraction imaging of a Laue crystal/analyzer, which can decouple the energy/wavelength and Bragg angle of the photon beam using the dispersion effect in the diffraction process. The method was used to measure the energy jitter and drift of the photon beam on BL09B and BL16U at the Shanghai Synchrotron Radiation Facility. The experimental results show that this method can provide a fast way to measure the beam stability of different light sources including bending magnet and undulator with meV‐level energy resolution and ms‐level time response. [ABSTRACT FROM AUTHOR]

With the advancement of the detector systems for γ-ray radiation, simultaneous measurement of time correlated photoelectric and Compton events recorded by employing segmented HPGe detectors (Clover Detectors) with very high energy resolution and efficiency, allows measuring the polarization of the γ-ray radiation in addition to the energy of the γ-ray radiation. The polarization measurement of the γ-ray radiation provides information regarding its electric or magnetic nature, which is essential for determining the parity of the decaying nuclear state. Data is shown for the low laying states of 136Ce with information on the RDCO and polarization measurements. These measurements were carried out with the help of Indian National Gamma Array (INGA), New Delhi setup. [ABSTRACT FROM AUTHOR]

In the present study, 366 locations were selected from the Faridabad district of Haryana, India, for seasonal gamma radiation measurements in indoor/outdoor environments. It was measured by a radiation monitor PM 1405 (Polimaster instrument/Republic of Belarus). The measured gamma was statistically analysed using the Wilcoxon signed-ranks test, Shapiro–Wilk test, Mann–Whitney test, and ANOVA test. The significance value of the outdoor gamma dose rate in winter (OGDRW) is found to be less than the significance level (0.05), indicating that the geology has a significant impact on OGDRW. The estimated annual effective dose was related to the values stated by UNSCEAR and ICRP. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine the accuracy of electromagnetic radiation and microseismic signals in determining the anti-scour effect resulting from coal seam water injection. We established a simultaneous acquisition system of electromagnetic and microseismic full waveforms for coal rock damages under load, and an image acquisition system that captured the entire coal damage process was used. Uniaxial compression experiments of coal samples with different moisture contents were conducted, and the influence of water on the physical and mechanical properties of the coal samples and the generation of electromagnetic and microseismic signals were theoretically analyzed. The results showed that water reduced the adhesion and friction coefficient of particles in the coal body, promoted coal and rock fracture development, and weakened the generation of electromagnetic and microseismic signals. A significant positive correlation was found among stress drop, electromagnetic radiation signals, and microseismic signals, and the temporal distribution of the three variables was synchronous. As moisture content increased, the electromagnetic radiation and microseismic signal amplitude of the coal samples decreased, and the average signal of both signals exhibited an exponential downward trend. The relationship between the mean value of the signal and moisture content was obtained. To evaluate the water-injection effect of the coal samples, we also determined the theoretical percentage of the signal amplitude reduction corresponding to the increment in moisture content required by the on-site coal seam water injection and anti-erosion. [ABSTRACT FROM AUTHOR]

Real‐time and in‐line transversal monitoring of ionizing radiation beams is a crucial task for several applications which span from medical treatments to particle accelerators in high energy physics. Here a flexible and large area device based on 2D hybrid perovskite thin films (phenylethylammonium lead bromide), fabricated onto a thin flexible polyimide substrate, able to map the transversal beam profile of high energy radiation beams is reported. The performance of this novel tool is here compared with the one offered by standard commercial large‐area technology, namely radiochromic sheets. The great potential of this class of devices is demonstrated by successfully mapping in real‐time a 5 MeV proton beam at fluxes between 108 and 1010 H+ s−1 cm−2, confirming the capability to operate in a radiation‐harsh environment without output signal saturation issues. The versatility and scalability of here proposed detecting system are demonstrated by the development of a multipixel array able to map in real‐time a 40 kVp X‐ray beam spot (dose rate 8 mGy s−1). Perovskite thin film‐based detectors are thus assessed as a very promising class of thin, flexible devices for real‐time, in‐line, large‐area, conformable, reusable, transparent, and low‐cost transversal beam monitoring of different ionizing radiation. [ABSTRACT FROM AUTHOR]

The instability and failure processes of coal-rock combinations are accompanied by the release of acoustic emission (AE) and infrared radiation (IR) signals. To investigate the characteristics of AE and IR signals during the failure process in coal-rock combinations with different ratios, and to analyze the effectiveness and applicability of the monitoring methods for these two signals in various specimen ratios. In this paper, the uniaxial compression tests were conducted on seven coal-rock combinations with different ratios by using the rock mechanics loading system and the cooperative monitoring platform of infrared and acoustic emission. The results show that (1) the AE counts for failure precursors in coal-rock combinations are positively correlated with the coal-rock ratio, whereas the AE peak counts are negatively correlated. Moreover, as the coal-rock ratio decreases, the slope of the cumulative AE count curve during the peak failure stage approaches 1. (2) During the elastic and yield stages, the maximum infrared radiation temperature (MIRT) curve fluctuates, and just before peak failure, the curve displays a distinctive "V" shape. This "V" shape becomes more pronounced as the coal-rock ratio decreases. (3) In the monitoring of damage precursors of coal-rock combinations, when the ratio of coal to rock is 1:3 or less, IR monitoring is better than AE monitoring. Conversely, when the ratio of coal to rock is greater than 1:3, AE monitoring is more suitable. Consequently, the combined monitoring of AE and IR signals can increase the reliability and precision of early warning signals for coal-rock assemblage damage precursors. [ABSTRACT FROM AUTHOR]

Ultraviolet (UV) radiation is closely related to health; however, limited measurements have hindered further investigation of its health effects in China. Machine learning algorithms have been widely used to predict environmental factors with high accuracy, but a limited number of studies have implemented it for UV radiation. The main aim of this study is to develop a UV radiation prediction model using the random forest approach and predict the UV radiation with a daily and 10 km resolution in mainland China from 2005 to 2020. The model was developed with multiple predictors, such as UV radiation data from satellites as independent variables and ground UV radiation measurements from monitoring stations as the dependent variable. Missing satellite-based UV radiation data were obtained using the 3 d moving average method. The model performance was evaluated using multiple cross-validation (CV) methods. The overall R2 and root mean square error between measured and predicted UV radiation from model development and model 10-fold CV were 0.97 and 15.64 Wm-2 and 0.83 and 37.44 Wm-2 at the daily level, respectively. The model that incorporated erythemal daily dose (EDD) retrieved from the Ozone Monitoring Instrument (OMI) had a higher prediction accuracy than that without it. Based on predictions of UV radiation at the daily level, 10 km spatial resolution, and nearly 100 % spatiotemporal coverage, we found that UV radiation increased by 4.20 %, PM 2.5 levels decreased by 48.51 %, and O3 levels increased by 22.70 % from 2013–2020, suggesting a potential correlation among these environmental factors. The uneven spatial distribution of UV radiation was associated with factors such as latitude, elevation, meteorological factors, and season. The eastern areas of China pose a higher risk due to both high population density and high UV radiation intensity. Using a machine learning algorithm, this study generated a gridded UV radiation dataset with extensive spatiotemporal coverage, which can be utilized for future health-related research. This dataset is freely available at 10.5281/zenodo.10884591 (Jiang et al., 2024). [ABSTRACT FROM AUTHOR]

With the accelerated deployment of 5G massive multi‐input multi‐output (MIMO)‐structured base stations (BSs), accurate and efficient testing of massive MIMO arrays is essential to ensure that the 5G massive MIMO antenna array can perform as expected. The increasing trend of both antenna element and array physical size makes massive MIMO antenna pattern measurement in the direct‐far‐field OTA environment unrealistic due to the signal attenuation, long measurement time, and ultra‐high test system construction cost. Therefore, the necessity of a compact, efficient, low‐complex, yet accurate OTA test method is evident, especially for 5G massive MIMO BS arrays. This paper proposes a novel multi‐probe‐enabled midfield (MF) OTA test method for 5G massive MIMO devices in compact measurement settings where antenna pattern measurement can be efficiently performed. The detailed theoretical analysis for the 5G massive MIMO array MF antenna pattern reconstruction method is presented, and the simulated validation results based on the typical 5G BS antenna arrays are provided and analysed, which demonstrate the effectiveness of the proposed MF OTA test method and can provide insights into the radio frequency parametric measurement for 5G massive MIMO devices. [ABSTRACT FROM AUTHOR]

Living beings get inevitable exposure to radiation of which approximately half of the dose is due to natural background radiation. In the present study, an extensive and systematic survey of outdoor GDR (GDR) was carried out in Churu and Jhunjhunu districts of Rajasthan. A total of 687 locations were covered to quantify the outdoor GDR. The portable radiation monitor, based on the Geiger-Muller counter, was used to monitor the outdoor gamma dose, and its associated health risk was estimated. Outdoor GDRs were found to vary from 32 nSv/h to 231 nSv/h and 75 nSv/h to 188 nSv/h in Churu and Jhunjhunu districts, respectively. The annual effective dose at most locations of the study area was greater than 0.07 nSv/h but less than the 1 mSv/y permissible limit recommended by the ICRP. The excess lifetime cancer risk in Churu district was estimated and found to range from 0.147 × 10−3 to 1.063 × 10−3, while in Jhunjhunu district it was 0.345 × 10−3 to 0.865 × 10−3 [ABSTRACT FROM AUTHOR]

Over the past 35 years, the Calibration Laboratory of IPEN (LCI) has seen significant advancements in the development of ionization chambers. This paper highlights the key contributions and achievements in this field. Numerous Master’s and PhD students at LCI/IPEN, under the guidance of Linda Caldas, have devoted their careers to advancing the science and education of medical physics. This review showcases some of their work, all of which was made possible through the initial efforts in dosimetry at the IPEN by Prof. Shigueo Watanabe. [ABSTRACT FROM AUTHOR]

Different coal failure impact types exhibit different damage statuses and failure modes, resulting in distinct signal characteristics of infrared radiation (IR) and acoustic emission (AE). This paper combines IR and AE monitoring methods to innovatively establish coal damage and failure precursor warning models and obtains the IR and AE precursor characteristics for different coal failure impact types. This research shows that there is a good correspondence between IR and AE timing and spatial distribution of different coal impact types. As the impact tendency increases, the intensity of IR and AE signals increases with coal failure, and the AE positioning points and IR high-temperature areas tend to concentrate. The coal body gradually changes from tensile failure to shear failure. The shear cracks in the failure stage of coal with no, weak, and strong impact are 39.9%, 50.9%, and 53.7%, respectively. The IR and AE instability precursor point of coal with no, weak, and strong impact occurred at 55.2%, 66.3%, and 93.4% of coal failure, respectively. After the IR and AE combined instability precursor point, the dissipated energy and combined damage variable increase rapidly, and the coal body will undergo instability and failure. The research results provide a theoretical basis for comprehensive monitoring of coal body failure and rock burst. [ABSTRACT FROM AUTHOR]

This study presents the implementation of an internet of things (IoT)-based device for the accurate and continuous measurement of gamma and ultraviolet (UV) radiation in a rural area of Sincelejo, Colombia. The device, calibrated with an error margin below 5%, allowed for the reliable collection of data during the year 2022. An average effective dose rate of gamma radiation of (0.998±0.037) mSv/year was recorded, a value that approaches the recommended limit. Additionally, the inverse square law of radiation was confirmed, observing a decrease in radiation with an increase in altitude. Concurrently, a constant risk of high to extremely high UV radiation exposure was detected throughout the year. These findings emphasize the need for constant monitoring and the implementation of UV protection measures in the region. The integration of IoT in environmental dosimetry has proven to be an invaluable tool for detailed tracking of radiation levels, significantly contributing to the understanding of radiation in rural areas. The exploration of more advanced sensors and data analysis tools in future research is recommended to further improve the accuracy and utility of these devices. [ABSTRACT FROM AUTHOR]

Purpose : The purpose of this study was to identify the factors that influence the behavior of intensive care unit (ICU) nurses regarding radiation protection, and to provide basic data to improve radiation protection educational programs. Methods : This descriptive research study included 143 nurses working in ICUs. Data were collected through a self-reported structured questionnaire and analyzed using t-test, Pearson's correlation coefficients, and hierarchical multiple regression analysis. Results : Radiation protection environment (β=.35, p=.001), radiation protection self-efficacy (β=.25, p=.002), type of hospital (β=-.25, p=.002) and experience in ICU (β=-.18, p= .022) affected the radiation protection behavior of ICU nurses. The total explanatory power of model was 60.0% (R²=.64, Adj. R²=.60, F=17.71, p<.001). Conclusion : In order to enhance the standards of radiation protection behavior among intensive care unit nurses and improve radiation protection self-efficacy, educational and training programs should be developed. Additionally, administrative support should be considered to create environments with better radiation protection at the organizational level. [ABSTRACT FROM AUTHOR]

Gallium Oxide (Ga2O3) devices have shown great potential for radiation detection. However, developing Ga2O3 detectors for pulsed radiation monitoring is still challenging, which requires high response sensitivity (R), low noise, high time resolution, and linear outputs. Herein, a vertical p‐NiO/β‐Ga2O3 heterojunction diode (HJD) is fabricated and its performance in X‐ray detection is analyzed. Benefiting from the high quality of the p‐n heterojunction, the HJD exhibits a low‐leakage current density of less than 1.73 × 10−7 A cm−2 at 100 V and features a high R of 7.92 μC Gy−1 cm−2, a low noise equivalent dose rate of 9.14 × 10−12 Gy−1 Hz−0.5 at an X‐ray dose rate of 0.383 Gy s−1, and good linear outputs to X‐ray dose rates from 0.0383 to 1.149 Gy s−1. The conductive process of the HJD detector is dominated by the tunneling mechanism, which leads to a longer response time associated with the trapping and releasing process of the deep‐level traps under the continuous X‐ray illumination. However, the pulsed X‐ray response property shows no significant influence from the slow trapping/releasing process of the traps. As a result, pulsed X‐ray radiation detection with a 50 ns full width is achieved, and the time resolution of the detector is characterized to be 3.31 ns by a 20 ps laser source. [ABSTRACT FROM AUTHOR]

Multi-spectral temperature measurement technology has been found to have extensive applications in engineering practice. Addressing the challenges posed by unknown emissivity in multi-spectral temperature measurement data processing, this paper adds emissivity constraints to the objective function. It proposes a multi-spectral radiation temperature measurement data processing model realized through a particle swarm optimization algorithm improved based on multiple strategies. This paper simulates six material models with distinct emissivity trends. The simulation results indicate that the algorithm calculates an average relative temperature error of less than 0.3%, with an average computation time of merely 0.24 s. When applied to the temperature testing of silicon carbide and tungsten, experimental data further confirmed its accuracy: the absolute temperature error for silicon carbide (tungsten) is less than 4 K (7 K), and the average relative error is below 0.4% (0.3%), while two materials maintain an average computation time of 0.33 s. In summary, the improved particle swarm optimization algorithm demonstrates strong performance and high accuracy in multi-spectral radiation thermometry, making it a feasible solution for addressing multi-spectral temperature measurement challenges in practical engineering applications. Additionally, it can be extended to other multi-spectral systems. [ABSTRACT FROM AUTHOR]

Radioactive safety in nuclear facilities is of utmost importance. Prior to workers entering these areas, a 3D radiation field is needed for accurately estimating their exposure. Due to the complex relationship between radiation measurements and radiation fields, implementing neural networks is a promising approach for reconstruction. However, research on direct 3D radiation field reconstruction using neural networks is limited, and there is no standardized open-source dataset for training and evaluation. To address these issues, we created a simplified model of a nuclear facility and utilized the Monte Carlo program MCShield to simulate 3D radiation parameters. MCShield, which is mainly used for shielding calculations, has been verified for accuracy through benchmark tests. In addition, this paper proves the correctness of the MCShield program and the effectiveness of the AIS variance reduction method through calculations on the WinFrith Iron benchmark experiment and the NUREG/CR-6115 benchmark. The results show that the MCShield program as well as the AIS method can be used for dataset calculations. [ABSTRACT FROM AUTHOR]

This work presents a 2D radiochromic dosimeter for ultraviolet (UV) radiation measurements, based on cotton fabric volume-modified with nitroblue tetrazolium chloride (NBT) as a radiation-sensitive compound. The developed dosimeter is flexible, which allows it to adapt to various shapes and show a color change from yellowish to purple-brown during irradiation. The intensity of the color change depends on the type of UV radiation and is the highest for UVC (253.7 nm). It has been shown that the developed dosimeters (i) can be used for UVC radiation dose measurements in the range of up to 10 J/cm2; (ii) can be measured in 2D using a flatbed scanner; and (iii) can have the obtained images after scanning be filtered with a medium filter to improve their quality by reducing noise from the fabric structure. The developed cotton–NBT dosimeters can measure UVC-absorbed radiation doses on objects of various shapes, and when combined with a dedicated computer software package and a data processing method, they form a comprehensive system for measuring dose distributions for objects with complex shapes. The developed system can also serve as a comprehensive method for assessing the quality and control of UV radiation sources used in various industrial processes. [ABSTRACT FROM AUTHOR]

The temperature of melt blowing (MB) and melt spun fibers is frequently measured using infrared thermography (IRT). However, measurements are affected by the size and curvature of the fiber and by reflected radiation from the nozzle. A procedure was developed to obtain accurate measurements of fiber temperature, which corrects fiber size, fiber curvature, and reflected radiation. This procedure is more general than the ones used so far to correct fiber temperature because it corrects the three abovementioned factors using a single correction formula, this being the first time that fiber temperature correction for reflected radiation has been accounted for. It is also more accurate because it uses the local fiber diameter to correct fiber curvature, instead of mean fiber diameter. The procedure was used to measure the temperature of MB adhesive fibers produced by two multi-hole nozzle designs, the results indicating that, in melt blowing applications, the distortion caused by fiber curvature and reflected radiation on the measurement proves to be far more significant than that caused by fiber size, while correction generally leads to an increase in fiber temperature. Considerations as to the effect of different parameters on temperature correction, as well as the quality of thermographic images, are also provided throughout the text. The conclusions emerging from this study allow more accurate temperature measurements of melt blown and melt spun fibers to be obtained. [ABSTRACT FROM AUTHOR]

This study aims to establish comprehensive relationships between patient size, focusing on effective diameter (Deff) and water-equivalent diameter (Dw), in conjunction with anterior-posterior (AP) and lateral (LAT) dimensions. The primary goal is to refine precise patient dose estimations in pediatric head computed tomography (CT) examinations. Our examination involved a dataset of 105 pediatric head CT images sourced from a Moroccan pediatric university hospital. These images, selected from the central scanning range, underwent quantification for LAT, AP, Deff, and Dw, with measurements carried out using RadiAnt Dicom Viewer for lateral and anteroposterior dimensions. Our analytical approach encompassed modeling Deff and Dw as functions of LAT, AP, and combined AP + LAT dimensions. Additionally, Dw was modeled as a function of Deff and calculated Size Specific Dose Estimates (SSDE) based on Dw was compared to SSDE computed from one single dimension. The outcomes revealed strong correlations among Deff, Dw, and fundamental geometric dimensions (LAT, AP, and AP + LAT), as indicated by consistently high coefficients of determination (R² > 0.8). SSDE calculated from Dw shows impressive correlation with SSDE computed from a single dimension (R² > 0.9). This study offers insights into the relationships between patient size and critical dimensions, identifying high correlations that can represent a significant advancement in predicting doses for pediatric head CT examinations. This introduces the potential for streamlining the determination of head diameter and dose by relying on a single dimension, thereby enhancing the efficiency of dose predictions by facilitating the monitoring of radiation exposure of this population in clinical routine. [ABSTRACT FROM AUTHOR]

The aim of the study was to measure the spectral luminescent characteristics of potato tubers, calculate their energy and statistical parameters, and develop a technique for photoluminescent control of the greening process. For this research, potatoes of the Udacha variety were used. At the beginning of the greening, and then for 3 weeks, the spectral characteristics of potatoes were measured using a hardware-software complex based on a diffraction spectrofluorimeter. We measured the spectral characteristics of excitation in the range of 180–700 nm, and then the spectral characteristics of photoluminescence. The averaged spectral characteristics were used to determine the integral energy (absorption capacity and photoluminescence flux) and statistical (mathematical expectation, dispersion, asymmetry, kurtosis, etc.) parameters. All excitation spectra have several maxima, the largest of which are 362 nm, 422 nm, 264 nm, 482 nm, and 623 nm. Both for the entire investigated spectral range and for the majority of particular ranges, the value of the integral absorbance decreases during the process of greening. The photoluminescence spectra are located in the range of 390–470 nm and are qualitatively similar to each other. In the process of solanization, they shift down, with the largest shift occurring in the first week of solanization. The most suitable parameter for controlling the greening of potatoes is the photoluminescence flux Φ, recorded upon excitation by radiation with a wavelength of 362 nm. The developed technique for luminescent control of potato tubers greening includes excitation with 362 nm radiation and measurement of the integral photoluminescence flux in the range of 390–470 nm, amplification and processing of the received signal, taking into account the a priori obtained dependence Φ(t). [ABSTRACT FROM AUTHOR]

Accurate and precise measurement of radiation energy delivered to and absorbed by the patient's tissue is of great importance in radiation therapy (RT) quality assurance. Radioluminescence (RL) dosimetry has shown great potential for high spatiotemporal resolution dose measurement of RT fields. Implementation of efficient RL dosimetry in RT requires multidisciplinary effort and skills in optics, medical physics, radiation physics, electronics, and imaging science. In this review, a wide overview of fundamentals and applications of RL properties of media for RT dosimetry with emphasis on their potential use for multidimensional, small‐field, and ultra‐high dose rate RT dosimetry is provided. [ABSTRACT FROM AUTHOR]

This study delves into the investigation of cosmic-ray radiation exposure levels for workers and their impact on the signal correlation subsystems at the Atacama Large Millimeter/ submillimeter Array (ALMA) observatory sites. The analysis presents a detailed examination of secondary cosmic ray spectra and flux at the ALMA sites, encompassing the operational period from 2010 to the present day, with a particular focus on the consequences of extreme solar flares. In terms of radiation exposure for ALMA employees, the annual exposure at the highest site (AOS) reaches approximately 4.8 mSv. This value exceeds the exposure level of a typical nuclear fuel cycle worker or those working at high-altitude Antarctica stations. The exposure is approximately 2.7 times lower at the ALMA Operations Support Facility (OSF). Furthermore, the additional ambient dose equivalent resulting from solar events, while low for events similar to those observed since the 1950s, can reach up to approximately 1 mSv when considering more ancient solar events based on environmental archives. Our analysis includes radiation effects measurements in the Baseline Correlator at the AOS and, more generally, underscores the significance of employing accurate modeling and simulation techniques to assess the effects of galactic cosmic rays and extreme solar events on the integrated circuits utilized or planned in the ALMA correlation subsystem. [ABSTRACT FROM AUTHOR]

This study aims to assess effective radiation doses (EDs) for pediatric computed tomography (CT) procedures in Madinah (single hospital), Saudi Arabia, and propose diagnostic reference levels (DRLs) for these procedures. This retrospective study collected data from 600 pediatric patients who underwent five CT procedures. The data were categorized by the type of CT procedure and the age of the patients. EDs and proposed DRLs for the pediatric CT procedures were computed. The highest EDs were found for abdominal (6.3 mSv) and head (4.8 mSv) CT procedures in pediatric patients aged <1 year. DRLs of the CTDIvol and DLP for abdominal and head CT procedures in pediatric patients aged <1 year were 4.2 mGy, 94 mGy.cm and 25 mGy, 414 mGy.cm, respectively. Chest EDs had the lowest EDs among all pediatric CT procedures, with EDs of 1.93, 1.51, 1.91, and 2.05 mSv in patients aged <1, 1 ≤ to < 5, 5 ≤ to < 10, and 10 ≤ to ≤ 15 years, respectively. It can be concluded that optimization is required for abdominal and head CT procedures in pediatric patients aged <1 year. Frequent updates on ED and DRL calculations will help monitor radiation doses and minimize radiation risks for patients undergoing these procedures. [ABSTRACT FROM AUTHOR]

In this study, a millimeter-wave far-field range antenna measurement system is proposed for W-band monopulse antenna measurements. Since the W-band monopulse antenna installed in radar systems has many input/output ports, multiple calculations are required to measure all the ports. We propose a system structure capable of the simultaneous measurement of multiple channels to quickly and accurately measure the performance of a monopulse antenna. The proposed measurement system includes a multi-channel rotary joint, a pair of diplexers, and multiple vector network analyzer extenders. In addition, an RF sub-system is implemented to reliably measure the phase of the W-band radiation pattern. It utilizes a shared local oscillator source and external power amplifiers for the transmit and receive paths. Employing the proposed multi-channel antenna measurement system, the sum/difference channels of a monopulse antenna were simultaneously measured according to the azimuth angle. In addition, a comparison of the far-field measurements provided by the proposed system and the near-field measurements was conducted. [ABSTRACT FROM AUTHOR]

Ocean surface radiation measurement best practices have been developed as a first step to support the interoperability of radiation measurements across multiple ocean platforms and between land and ocean networks. This document describes the consensus by a working group of radiation measurement experts from land, ocean, and aircraft communities. The scope was limited to broadband shortwave (solar) and longwave (terrestrial infrared) surface irradiance measurements for quantification of the surface radiation budget. Best practices for spectral measurements for biological purposes like photosynthetically active radiation and ocean color are only mentioned briefly to motivate future interactions between the physical surface flux and biological radiation measurement communities. Topics discussed in these best practices include instrument selection, handling of sensors and installation, data quality monitoring, data processing, and calibration. It is recognized that platform and resource limitations may prohibit incorporating all best practices into all measurements and that spatial coverage is also an important motivator for expanding current networks. Thus, one of the key recommendations is to perform interoperability experiments that can help quantify the uncertainty of different practices and lay the groundwork for a multi-tiered global network with a mix of high-accuracy reference stations and lower-cost platforms and practices that can fill in spatial gaps. [ABSTRACT FROM AUTHOR]

Detector networks that measure environmental radiation serve as radiological surveillance and early warning networks in many countries across Europe and beyond. Their goal is to detect anomalous radioactive signatures that indicate the release of radionuclides to the environment. Often, the background H · *(10) is predicted using meteorological information. However, in dense detector networks the correlation between different detectors is expected to contain markedly more information. In this work, we investigate how the joint observations by neighbouring detectors can be leveraged to predict the background H · *(10). Treating it as a stochastic vector, we show that its distribution can be approximated as multivariate normal. We reframe the question of background prediction as a Bayesian inference problem including priors and likelihood. Finally, we show that the conditional distribution can be used to make predictions. To perform the inferences we use PyMC. All inferences are performed using real data for the nuclear sites in Doel and Mol, Belgium. We validate our calibrated model on previously unseen data. Application of the model to a case with known anomalous behaviour – observations during the operation of the BR1 reactor in Mol – highlights the relevance of our method for anomaly detection and quantification. [ABSTRACT FROM AUTHOR]

The advancement of the aviation sector has made the temperature measurement technology for aero-engine turbine blades essential for maintaining the engine's safe and steady performance. The non-contact temperature measurement technology is a trending research focus in turbine blade temperature measurement due to its benefits of not requiring direct touch with the object being measured and its suitability for high-temperature and high-speed conditions. This paper provides a concise overview of various key non-contact temperature measurement methods for aero-engines, such as fluorescence temperature measurement, fiber-optic temperature measurement, and radiation temperature measurement. It discusses the temperature measurement principle, technical characteristics, and the current research status both domestically and internationally. Based on this, this Review further discusses the main challenges faced by the non-contact temperature measurement technology and the development trend of the future. [ABSTRACT FROM AUTHOR]

The project of the Visible Spectroscopy diagnostics for the Z eff radial profile measurement and for the divertor visible imaging spectroscopy, designed for the new tokamak DTT (Divertor Tokamak Test), is presented. To deal with the geometrical constraints of DTT and to minimize the diagnostics volume inside the access port, an integrated and compact solution hosting the two systems has been proposed. The Z eff radial profile will be evaluated from the Bremsstrahlung radiation measurement in the visible spectral range, acquiring light along ten Lines of Sight (LoS) in the upper part of the poloidal plane. The plasma emission will be focused on optical fibers, which will carry it to the spectroscopy laboratory. A second equipment, with a single toroidal LoS crossing the plasma centre and laying on the equatorial plane, will measure the average Z eff on a longer path, minimizing the incidental continuum spectrum contaminations by lines/bands emitted from the plasma edge. The divertor imaging system is designed to measure impurity and main gas influxes, to monitor the plasma position and kinetics of impurities, and to follow the plasma detachment evolution. The project aims at obtaining the maximum coverage of the divertor region. The collected light can be shared among different spectrometers and interferential filter devices placed outside the torus hall to easily change their setup. The system is composed of two telescopes, an upper and a lower one, allowing both a perpendicular and a tangential view of the DTT divertor region. This diagnostic offers a unique and compact solution designed to cope the demanding constraints of this next-generation tokamak fusion devices, integrating essential tools for wide-ranging impurity characterization and versatile investigation of divertor physics. [ABSTRACT FROM AUTHOR]

Moon is an auspicious environment for the study of Galactic cosmic rays (GCR) and Solar Particle Events (SEP) due to the absence of magnetic field and atmosphere. The same characteristics raise the radiation risk for human presence in orbit around it or at the lunar surface. The secondary (albedo) radiation resulting from the interaction of the primary radiation with the lunar soil adds an extra risk factor, because neutrons are produced, but also it can be exploited to study the soil composition. In this paper, the design of a comprehensive radiation monitor package tailored to the lunar environment is presented. The detector, named LURAD, will perform spectroscopic measurements of protons, electrons, heavy ions, as well as gamma-rays, and neutrons. A microdosimetry monitor subsystem is foreseen which can provide measurements of LET(Si) spectra in a wide dynamic range of LET(Si) and flux for SPE and GCR, detection of neutrons and biological dose for radiation protection of astronauts. The LURAD design leverages on the following key enabling technologies: (a) Fully depleted Si monolithic active pixel sensors; (b) Scintillators read by silicon photomultipliers (SiPM); (c) Silicon on Insulator (SOI) microdosimetry sensors; These technologies promise miniaturization and mass reduction with state-of-the-art performance. The instrument's design is presented, and the Monte Carlo study of the feasibility of particle identification and kinetic energy determination is discussed. [ABSTRACT FROM AUTHOR]

This work was directed towards studying the specific activity of natural radioactivity (40k, 238U, and 232Th) in 13 samples of foodstuff that are consumed by children in Iraq. The foodstuffs such as biscuit, cocoa powder, milk powder, indomie, and soup were collected from markets in the Al-Najaf governorate. This food was analyzed in the laboratory, which belongs to the University of Kufa, using a scintillation detector (NaI(Tl)) detector (gamma spectrometer systems) and provided with software MESTRO-32. The results found that, the specific activity for potassium-40 were ranged from 52.11 Bq/kg to 619.61 Bq/kg, while the specific activity for uranium-238 ranged between 4.11 Bq/kg to 18.9 Bq/kg, but for thorium-232 were ranged from 0.39 Bq/kg to 12.06 Bq/kg. The specific activity for 40K, 238U, and 232Th for all samples was found to be within the worldwide range for radioactivity in food 420, 30, and 45 Bq/kg, respectively, except for cocoa powder samples have specific activity for 40K higher than worldwide. This study has shown that the levels of radioactivity in most samples of children food were within the limit value of organization UNSCEAR. Finally, the present study will provide data about natural radioactivity in food used by children in all governorates of the country to protect all children. [ABSTRACT FROM AUTHOR]

Emerging data processing techniques brought back into attention the HF range communication as an interesting alternative to third-party solutions for IoT applications, such as data transmission in distributed energy production facilities. The physical size of HF antennas, often comparable to the surrounding objects, require in situ radiation measurements resulting in site-customized antenna design and positioning, and consequently in a higher reliability of such HF grid communications. Drone-borne measuring systems are already known as a flexible solution, but are mostly restricted to higher frequency ranges where full-wave, wide-band probes are feasible. In this work, we propose to use an electrically small, folded dipole as a probe for drone-borne measurements on HF antennas. We also propose a calibration approach for the effects related to the near-field zone, and to the drone body proximity; corrections on these two effects are the key methodological steps. We show that despite a realized gain figure in the order of −20 dBi, such a probe can provide stable results for near-field measurements, even at input power levels as low as 1 mW. Compared to other similar approaches, our configuration provides a wider frequency band of operation, higher stability in terms of pattern diagram, and a lower cost. [ABSTRACT FROM AUTHOR]

Copyright of Nuclear Safety is the property of Nuclear & Radiation Safety Center and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objectives: The purpose of this study was to develop a prototype for controlling the water level of a three-dimensional (3D) water phantom using ultrasound sensors and Arduino technology and evaluate its performance in setting up the 3D water phantom for radiation beam measurements. Materials and Methods: A prototype consisted of an Arduino Nano board and two types of ultrasound sensors (US015 and SR04). The accuracy of both sensors was tested at various distances and the performance was evaluated through statistical analysis. The distance measurement test was performed rigorously at intervals of 2 cm from 5 cm to 21 cm, measuring an average error and a maximum deviation for each sensor. Results: Both sensors demonstrated the measurement accuracy within 2 mm. When using the traditional and prototype-based setup methods, the measured photon and electron beam profiles did not show any significant difference. This result suggests the equivalent setup capability when using these two different 3D water phantom setup methods. Conclusion: The ultrasound sensor-based prototype is demonstrated as a more effective device in maintaining the 3D water phantom setup consistently compared to the traditional method, which is prone to human error, and it will aid in facilitating precise phantom setup during the commissioning and routine quality assurance (QA) of linear accelerators in radiotherapy clinics. [ABSTRACT FROM AUTHOR]

The assessment of the radioactivity level and associated risks has been performed for the mangrove plants. Twenty-five mangrove samples were collected from the Abu Fasi, Marsa Shaab, and Sowmaa mangroves in the Marsa Shaab area of the Egyptian Red Sea coast. The activity concentration values of the nuclides 226Ra, 232Th, and 40K for samples collected from sediments associated with the mangrove environments were measured. The specific activities in mangrove samples obtained in the Abu Fasi region varied as follows: 15± 0.8 Bq.kg-1 to 42± 2.1 Bq.kg-1 for 226Ra, 10± 0.5 Bq.kg-1 to 39± 1.9 Bq.kg-1 for 232Th, and 103± 5.2 Bq.kg-1 to 340± 17 Bq.kg-1 for 40K. Additionally, the activity concentrations of the mangrove samples collected from Marsa Shaab and Sowmaa mangrove areas ranged as follows: 28± 1.4 to 56± 2.8 Bq.kg-1 for 226Ra, 18± 0.9 to 58± 2.9 Bq.kg1 for 232Th, and 164± 8.2 to 531± 26.5 Bq.kg-1 for 40K. Moreover, the mangrove samples collected from the Sharm el El Madfea area showed activity concentrations ranging as follows: 25± 1.3 to 52± 2.6 Bq.kg-1, 15± 0.8 to 61± 3 Bq.kg-1, and 250± 9.1 to 583± 29.2 Bq.kg-1 for 226Ra, 232Th, and 40K, respectively. The highest average values were observed in samples collected from Marsa Shaab and Sowmaa mangroves for the 226Ra and 232Th. However, the highest average value for 40K was measured in samples collected from the Sharm El Madfea area. The radiation hazard calculations for the collected mangrove samples showed much lower values than the criterion and worldwide recommended limits. [ABSTRACT FROM AUTHOR]

Far infrared (FIR) emission from the Earth's polar regions has become an area of increasing scientific interest and value. FIR emission is important for understanding Earth's radiative balance and improving global climate models, especially in rapidly changing Arctic conditions. Far‐infrared emission from Earth is not currently being monitored from space, except as part of broadband emission channels of Earth radiation budget measurements like those from the CERES project, and only limited measurements in the FIR spectrum exist. The Absolute Radiance Interferometer (ARI), developed as a prototype of the infrared spectrometer for CLARREO at the University of Wisconsin‐Madison, Space Science and Engineering Center, measures absolute spectrally resolved infrared (IR) radiance from 200 to 2,000 cm−1 (or 5–50 μm) at 0.5 cm−1 resolution with high accuracy (<0.1 K 3‐sigma brightness temperature at scene temperature). This instrument was taken into the field in Madison, Wisconsin, USA, during the winters of 2021 and 2022, where the weather can reach polar‐like conditions to measure high spectral resolution radiances of various sample types. Sample materials included water, snow, ice, evergreen leaves, dry grass, and sand, all characteristic of high latitude regions. Radiances collected from both a sky view and the sample view in clear‐sky conditions were used to retrieve FIR emissivity. This paper describes the ARI instrument configuration and capability for ground‐based measurements in the FIR region, and documents retrieved emissivities of various analyzed samples. The retrieved emissivity results are publicly available, and comparisons are made to simulated emissivity estimates. Key Points: Absolute Radiance Interferometer used to obtain high spectral resolution far infrared radiation measurements in semi‐controlled environmentsRadiation measurements of the sky and samples, including snow, water, ice, sand, and vegetation, allowed for retrieval of sample emissivityThe retrieved far infrared emissivity spectra and radiance measurements are available for model intercomparisons and other uses [ABSTRACT FROM AUTHOR]

Copyright of Atomic Energy Science & Technology is the property of Editorial Board of Atomic Energy Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Natural radioactivity measurement, radiation monitoring of the region, dose assessment and interpretation of radiological-related parameters are crucial aspects from the public awareness and environmental safety point of view. The ionising radiations (gamma-rays) emitted from radionuclides such as 226Ra, 232Th and 40K present in environmental materials contributes significantly to the external radiation dose received by the public. High-efficiency gamma spectrometry based on a 4″ × 4″ NaI (Tl) detector was employed for estimating activity concentrations of the gamma-emitting radioelements. The spectra from the detector were recorded using a PC-based 1k multichannel analyser system (WinTMCA 32). Each sample spectrum was acquired for a counting period of 60 000 s (16.67 hr). Assuming the daughter products of 226Ra and 232Th in equilibrium, the activity concentration of these radionuclides were estimated by using the prominent gamma photo peaks of daughter products. Using the same technique, dose-related radiological parameters were calculated for all the samples. The activity concentrations of the radionuclides and the dose-related parameters for the samples were found to be comparable with the global literature values. The data generated from our study will contribute to the baseline radiological data of the region. [ABSTRACT FROM AUTHOR]

In this paper, work on a compact multi-slot patch antenna with a parasitic load and shorting-pin has been presented for its use in long range (LoRa) defense applications. Initially the antenna is designed and simulated using HFSS and a parametric study has been carried out for achieving an optimized antenna configuration. This is followed by the fabrication of antenna prototype based on the optimal performances obtained from the simulated results. Further, the return loss along with free space co-polar and cross-polar radiation pattern measurements has been carried out for the fabricated antenna. The experimental results show a good comparison with that of the simulated one. The proposed antenna resonates at an operating frequency of 866 MHz, providing a -10 dB bandwidth from 856 MHz-877 MHz, which covers the wireless standard used for LoRa technology. Finally, a comparative analysis of the proposed antenna with the recently reported works is presented. [ABSTRACT FROM AUTHOR]

We quantified the level of backscatter radiation generated from physicians' heads using a phantom. We also evaluated the shielding rate of the protective eyewear and optimal placement of the eye-dedicated dosimeter (skin surface or behind the Pb-eyewear). We performed diagnostic X-rays of two head phantoms: Styrofoam (negligible backscatter radiation) and anthropomorphic (included backscatter radiation). Radiophotoluminescence glass dosimeters were used to measure the eye-lens dose, with or without 0.07-mm Pb-equivalent protective eyewear. We used tube voltages of 50, 65 and 80 kV because the scattered radiation has a lower mean energy than the primary X-ray beam. The backscatter radiation accounted for 17.3–22.3% of the eye-lens dose, with the percentage increasing with increasing tube voltage. Furthermore, the shielding rate of the protective eyewear was overestimated, and the eye-lens dose was underestimated when the eye-dedicated dosimeter was placed behind the protective eyewear. We quantified the backscatter radiation generated from physicians' heads. To account for the effect of backscatter radiation, an anthropomorphic, rather than Styrofoam, phantom should be used. Close contact of the dosimeter with the skin surface is essential for accurate evaluation of backscatter radiation from physician's own heads. To assess the eye-lens dose accurately, the dosimeter should be placed near the eye. If the dosimeter is placed behind the lens of the protective eyewear, we recommend using a backscatter radiation calibration factor of 1.2–1.3. [ABSTRACT FROM AUTHOR]

Radiation monitoring using unmanned aircraft detection systems can reduce the impact of radioactive element activity and contamination. The design of an early warning system using unmanned aircraft and real-time and visual monitoring is a crucial step towards achieving national security by providing an early warning of the dangers of radioactivity that cannot be measured in the environment and can be a health threat. Unmanned aircraft are equipped with detectors and other supporting devices to obtain data: date, time, coordinates, altitude, radiation value, temperature, humidity, battery status, and pressure. The data is managed in the phpMyAdmin database by adjusting the table structure. The receiving device is equipped with the MIT App Inventor application, which was previously designed. The MIT App Inventor display design was prepared by inserting a user interface with labels, text boxes, layout settings, and connectivity to the IP server. Meanwhile, the programming is saved in the installed XAMPP folder. The information data is then processed to obtain radiation level monitoring results in visual form and integrated with databases and servers. The results of developing this technology not only facilitate data analysis in knowing the location and level of radiation when monitoring the environment or solving problems in affected areas but also pave the way for further advancements in radiation monitoring systems. [ABSTRACT FROM AUTHOR]

Accurate knowledge of solar radiation data or its estimation is crucial to maximize the benefits derived from the Sun. In this context, many sectors are re-evaluating their investments and plans to increase profit margins in line with sustainable development based on knowledge and estimation of solar radiation. This scenario has drawn the attention of researchers to the estimation and measurement of solar radiation with a low level of error. Various types of models, such as empirical models, time series, artificial intelligence algorithms and hybrid models, for estimating and measuring solar radiation have been continuously developed in the literature. In general, these models require atmospheric, geographical, climatic and historical solar radiation data from a specific region for accurate estimation. Each analysis model has its advantages and disadvantages when it comes to estimating solar radiation and, depending on the model, the results for one region may be better or worse than for another. Furthermore, it has been observed that an input parameter that significantly improves the model's performance in one region can make it difficult to succeed in another. The research gaps, challenges and future directions in terms of solar radiation estimation have substantial impacts, but regardless of the model, in situ measurements and commercially available equipment consistently influence solar radiation calculations and, subsequently, simulations or estimates. This article aims to exemplify, through a case study in a multi-family residential building located in Viana do Castelo, a city in the north of Portugal, the difficulties of capturing the spectrum of radiations that make up the total radiation that reaches the measuring equipment or site. Three pieces of equipment are used—a silicon pyranometer, a thermopile pyranometer and a solar meter—on the same day, in the same place, under the same meteorological conditions and with the same measurement method. It is found that the thermopile pyranometer has superior behavior, as it does not oscillate as much with external factors such as the ambient temperature, which influence the other two pieces of equipment. However, due to the different assumptions of the measurement models, the various components of the measurement site make it difficult to obtain the most accurate and reliable results in most studies. Despite the advantages of each model, measurement models have gained prominence in terms of the ease of use and low operating costs rather than the rigor of their results. [ABSTRACT FROM AUTHOR]

This research forms a part of the comprehensive Indian Environmental Radiation Monitoring Network program, focusing on the continuous measurement of absorbed dose rate in outdoor air due to natural gamma radiation (cosmic and terrestrial) in Bengaluru, Karnataka, India. Over the course of a decade (2013–2023), data were collected from 41 monitoring locations in the city using permanently field-installed Geiger-Mueller detector-based environmental radiation monitors. This paper presents an analysis of the extensive long-term monitoring results. The mean absorbed gamma dose rate in outdoor air across the monitoring locations ranged from 84 ± 9 to 156 ± 4 nGy.h−1, with a calculated mean value of 124 ± 15 nGy.h−1. The estimated mean annual effective dose due to outdoor natural gamma radiation varied from 0.10 ± 0.01 to 0.19 ± 0.01 mSv.y−1, with an overall mean of 0.15 ± 0.02 mSv.y−1. [ABSTRACT FROM AUTHOR]

The accurate representation of Cold Air Outbreaks (CAOs) and affiliated mixed‐phase boundary layer (BL) clouds in models is challenging. How BL cloud properties evolve during CAOs and their dependence on meteorological conditions is not well understood but is important for the simulation of Earth's energy budgets. Here the properties of polar BL clouds over the North Atlantic (NA) and Southern Ocean (SO) are compared using observations from the Measurements of Aerosol Radiation and CloUds over the SO (MARCUS) and CAOs in the Marine BL Experiment (COMBLE) conducted over the NA. MARCUS observations show a stronger BL inversion than COMBLE, with a higher mean EIS (estimated inversion strength)/LTS (lower tropospheric stability) of −0.03 K/13 K compared to COMBLE's −3.2 K/9.3 K. 39% of CAOs observed during COMBLE were intense with M > 5 K, while MARCUS only had 1.3%. 78%/72% of clouds sampled in CAOs during COMBLE/MARCUS had cloud top heights <4 km. The mean BL cloud top height was over 400 m higher, and the BL was over 500 m deeper for M of 10 K compared to 0 K for both regions. MARCUS observed a 27% moister BL structure than COMBLE when M > 5 K due to stronger BL inversion trapping more moisture within the BL. Under the same LTS, EIS, and M conditions, MARCUS observed a 12% drier BL structure, and clouds were 46% more turbulent than COMBLE. During CAOs, 54% of single‐layer BL clouds sampled during MARCUS had liquid‐dominated bases compared to 39% during COMBLE. Plain Language Summary: The Arctic and SO have large areas of sea ice, providing ideal conditions for development of frequent and intense cold air outbreaks (CAOs). CAOs occur when cold air over ice moves away from the poles over warmer oceans. Clouds over high latitudes that occur during CAOs impact Earth's radiative balance, but prior observations of them are very limited and hence how the properties of these clouds depend on environmental conditions are not well known. Two field campaigns conducted over the Southern Ocean and North Atlantic provide measurements that allow the dependence of the environmental impact on clouds to be uncovered, and to determine whether the properties of these clouds differ whether they form in the Northern or Southern Hemisphere. The dependence of vertical cloud structure, the composition of clouds (whether ice or water dominates at temperatures <0°C), and the vertical structure of the lowest layer of the atmosphere on environmental conditions are presented. Results show that low‐level clouds dominate in both regions during CAOs, with clouds higher and deeper in more intense CAOs. Even accounting for dependence on environmental conditions, there are still differences in cloud properties over the North Atlantic and Southern Ocean that need further investigation. Key Points: Boundary layer clouds are common during cold air outbreaks in both North Atlantic and Southern Ocean regionsCold air outbreaks are more intense over the North Atlantic, whereas boundary layer inversion is stronger over the Southern OceanBoundary layer cloud properties differ with location even when accounting for environmental conditions [ABSTRACT FROM AUTHOR]