Search

Introduction: Buildings that constitute cultural heritage and that are the identity of a defined geographical area are increasingly being restored to offer the community historical places to enjoy. Often the restoration preserves the original structure and building materials, which are usually natural stones. In this study, a radioprotection protocol dedicated to this kind of built environment was proposed and validated. Methods: After identifying the two predominant types of building material stones (Rosso ammonitico and Pietra Serena), radiometric measurements for natural gamma-emitting radionuclides (Ra-226, Th-232, and K-40) and measurements of the emanation coefficient and calculation of the exhalation rate of radon gas were carried out. Results: The two types of stone have a content of natural radionuclides that do not exceed the levels recommended by the regulations. The difference between the two types of stone is of an order of magnitude indicating that the red ammonite has a greater radiological impact than the pietra serena. Discussion: The results, in addition to ensuring the radioprotection of the population, highlighted the need to increase the number of this kind of investigations to implement scientific knowledge and serve the stakeholders involved. [ABSTRACT FROM AUTHOR]

Inductively coupled plasma mass spectrometry (ICP-MS) is increasingly used for rapid measurement of medium and long-lived radionuclides. Of the techniques available, tandem ICP-MS/MS is of growing interest owing to the enhanced online interference removal capabilities offered by an additional mass filter and a collision-reaction cell. This can reduce or remove the need for offline chemical separation, further reducing the procedural time. This online interference removal approach can reduce analyte sensitivity, which is an issue for trace-level measurements, particularly for relatively short-lived radionuclides. To help address this, this study investigates the use of desolvating sample introduction combined with ICP-MS/MS for enhanced measurement of multiple radionuclides. Results are shown for actinides, difficult-to-measure radionuclides of high priority for nuclear decommissioning, and shorter-lived radionuclides relevant to paleoclimate measurement. The improved sensitivity and additional interference removal achieved compared to the standard sample introduction system are demonstrated, with the results benefitting end users interested in improved waste characterisation, environmental radioactivity, nuclear forensics, and improved historical climate measurements. [ABSTRACT FROM AUTHOR]

Purpose: To study the adaptation of bacteria to the natural γ-background of mountains and anthropogenic emissions from nuclear power plants; to establish the main factors of variability and speciation of bacteria. Method: Analysis of materials on the radiation background and its impact on living organisms in the landscape of Armenia, calculation of the absorbed dose by microbes due to rock radiation. Results: The review shows the death, reproduction, radioresistance and speciation of bacteria in changing conditions of low variable natural and anthropogenic γ-background. Conclusion: We assume that γ-rays from rocks activate cellular epigenetic mechanisms that regulate genome expression, signaling and, ultimately, variability of bacteria. Some of them have already been studied, others require research. [ABSTRACT FROM AUTHOR]

This paper represents beach sand samples' natural and anthropogenic radionuclide concentrations and calculated external radiation dose levels. The radioactivity concentrations of eU (226Ra), eTh (232Th), 40K, and 137Cs were measured by gamma spectrometry using an HPGe detector. The activity concentrations ranged from 1.8 to 27.7 Bq kg−1, 5.7 to 19.5 Bq kg−1, 49.8 to 457.9 Bq kg−1, and 0.2 to 5.6 Bq kg−1 for eU, eTh, 40K and 137Cs, respectively. The radiological hazard parameters were compared to the international reference values. The results show that all data obtained are below the world average, meaning the radiation hazard is insignificant. [ABSTRACT FROM AUTHOR]

Neodymium doped rubidium titanyl phosphate single crystal was grown from the high-temperature flux technique. To investigate the material stability in the radiation background, for the first-time neodymium doped rubidium titanyl phosphate single crystal was subjected to gamma ray irradiation. After the irradiation of the 2.6-kGy gamma-radiation, the material's optical and electrical properties were analyzed and the results have been compared to that of non irradiated Nd: RTP single crystal. A small absorption band was found in the visible region around 0.08 higher than the non -irradiated Nd: RTP single crystal and there is a small variations in the band gap energy, 3.61 eV for non -irradiated Nd: RTP single crystal and 3.54 eV for gamma irradiated Nd: RTP single crystal. The dielectric constant, dielectric loss, and AC conductivity was observed for non-irradiated and gamma irradiated Nd: RTP single crystals. The Gamma radiation irradiated Nd: RTP single crystal shows little higher value of dielectric constant, loss and conductivity around 0.07, 0.05 and 1.2 S/cm from the non irradiated sample respectively. From the ferroelectric studies there is an increase in polarization and coercive field were observed in the gamma-ray irradiated sample from that of non-irradiated Nd: RTP single crystal. This can be attributed to radiation-induced defects is local strains and movements of ions inside the crystal. Besides the Gamma irradiated sample shows fatigue free nature over the 5000 cyclic period. The gamma-ray induced a defect in material but not far away from application requirements and the radiation effect had been removed through the thermal annealing process. [ABSTRACT FROM AUTHOR]

This study investigates the radiation dose that humans receive from naturally occurring uranium-series radionuclides, with a focus on alpha-emitting polonium-210 (210Po), which has a half-life of 138.4 days. Polonium is efficiently absorbed by living organisms and is estimated to contribute approximately 7% of the total effective dose from ingested natural internal radiation. The primary source of atmospheric 210Po is the decay of radon-222 (222Rn), which precipitates onto land and water surfaces, including crops. In Cannabis sativa, 210Po accumulates primarily through direct deposition on leaf surfaces and from fertilizers, particularly phosphate fertilizers. This study examined 10 samples of dried hemp (Cannabis sativa L.) legally available in Poland, assessing 210Po concentrations through radiochemical analysis. Various consumption methods were analyzed, including smoking with a glass pipe, a water pipe (bong), a cigarette (joint or spliff), and vaporization. The desorption of 210Po during combustion and vaporization was measured, revealing significant differences based on the method used. Results showed that smoking with a glass pipe resulted in the highest desorption of 210Po (approximately 80%), while water pipe and blunt smoking exhibited lower desorption rates (around 40%). The efficiency of 210Po adsorption in filters varied, with water filters showing about 8% absorption and cellulose filters about 20%. Vaporization results indicated that the desorption of 210Po increased with temperature. These findings underscore the importance of considering the method of consumption when calculating the radiation dose from 210Po, as the differences can significantly impact the accuracy of dose assessments. The study highlights the need for further research to optimize safety guidelines for cannabis consumption in relation to radioactive contaminants. [ABSTRACT FROM AUTHOR]

Human activities, such as plant cultivation, enhance the activity concentrations (ACs) of radionuclides in the topsoil and have the potential to affect humans and the environment. The soil with a high radiation background not only acts as a source of continuous radiation exposure to humans but also as a medium of migration for the transfer of radionuclides to food crops. Some spectrometers can measure the AC of radionuclides in the soil, but long‐term variation of AC is difficult to investigate. Therefore, developing methods for predicting the AC of radionuclides in agricultural soil is an interesting topic that many studies have focused on. In this work, a simple method was introduced to estimate long‐term changes of some radioisotopes in the top layer of soil (0–20 cm). The estimation considered four major processes: fertilization, irrigation, vertical leaching, and plant uptake. The leaching rates (Rl) of radionuclides were predicted by their ACs in the soil water and the infiltration rate of water in the soil. The method was applied to the soils of five study fields in southern Vietnam, and the Rl values of 226Ra were between 7.4 Bq·m−2·y−1 and 60 Bq·m−2·y−1, while the rates of 210Po were between 22.1 and 111 Bq·m−2·y−1. For long‐term assessment, it was found that 226Ra increases in sweat potato soil and tomato soil with annual rates (ΔC) of 0.99 Bq·kg−1·y−1 and 0.69 Bq·kg−1·y−1, respectively. The AC of 210Po was predicted to increase in some soils. The corresponding ΔC values for 210Po were 0.028 Bq·kg−1·y−1 in rice, 0.617 Bq·kg−1·y−1 sweet potato, and 0.099 Bq·kg−1·y−1 in tomato soils. The results imply that interventions are necessary to reduce the radioactivity accumulation in fields with high ΔC values. The effective methods can be changing the fertilizer types and the irrigation systems. [ABSTRACT FROM AUTHOR]

This study investigates the levels of natural and artificial radioactivity in rice samples collected from various local markets in Islamabad, Pakistan. The 226Ra, 232Th, and 40K activity concentrations were measured through gamma-ray spectrometry with a NaI(Tl) detector. The average activity concentrations were 1.67 ± 1.19 Bq kg−1 for 226Ra, 3.31 ± 1.83 Bq kg−1 for 232Th, and 88.51 ± 11.65 Bq kg−1 for 40K. Calculated radium equivalent (Raeq) values ranged from 7.35 to 18.08 Bq kg−1, with a mean value of 11.11 Bq kg−1, all below the permissible maximum of 370 Bq kg−1. The absorbed dose rates ranged from 6.85 to 16.39 nGy h−1, with an average of 10.64 nGy h−1, falling below the acceptable limit of 51 nGy h−1. The outdoor and indoor radiation hazard indices (Hex and Hin) had mean values of 0.03, both below the threshold value of one. The external and internal hazard indices (Iγ and Iα) were both 0.088, also below the critical value of one. The excess lifetime cancer risk (ELCR) ranged from 0.28 to 0.11, with a mean value of 0.18, which is less than the critical value of one. Overall, the radioactivity levels in the analyzed rice samples are within the acceptable limits set by the International Commission on Radiological Protection and are below global averages. These results offer important insights into the radiological safety of rice consumption in the study area. [ABSTRACT FROM AUTHOR]

A ubiquitous distribution of plastic debris has been reported in aquatic and terrestrial environments; however, the interactions between plastics and radionuclides and the radioactivity of environmental plastics remain largely unknown. Here, we characterize biofilms developing on the surface of plastic debris to explore the role of plastic-associated biofilms as an interaction medium between plastics and radiocesium (137Cs) in the environment. Biofilm samples were extracted from plastics (1–50 mm in size) collected from two contrasting coastal areas in Japan. The radioactivity of plastics was estimated based on the 137Cs activity concentration of the biofilms and compared seasonally with surrounding environmental samples (i.e., sediment and sand). 137Cs traces were detected in biofilms with activity concentrations of 21–1300 Bq·kg−1 biofilm (dry weight), corresponding to 0.04–4.5 Bq·kg−1 plastic (dry weight). Our results reveal the interaction between 137Cs and plastics and provide evidence that organic and mineral components in biofilms are essential in 137Cs retention in environmental plastics. Given the ubiquitous distribution of plastic debris in the environment, more attention should be directed to bioaccumulation and the radioecological impacts of plastic-associated radionuclides on ecosystems. [ABSTRACT FROM AUTHOR]

AbstractPurposeConclusionIn this short tale, we describe a year of Pierre Chris Curry’s ionizing radiation (IR) exposure, assessing and summarizing how much he has been exposed to over a year of his fictive life, cumulating the different types of exposures (either due to natural radiation, occupational and medical exposure), while staying reasonably credible. We have limited ourselves to IR exposure. As a recognized specialist in interventional cardiac surgery, Pierre provides lectures at international conferences requiring overseas flights. When not traveling, Pierre lives in Brittany in an area where there is high natural background radiation, owing to significant concentrations of radon, a radioactive gas produced from the natural radioactive decay of uranium found in rocks, granite in this case.Natural exposures correspond to half of Pierre’s total yearly exposure. Therefore, where you live, and your life habits have an important impact on your radiation exposure levels. Medical exposures take the second place in the ranking, but these exposures are punctual. Although his professional exposure is the lowest percentage, this represents a chronic exposure which is continuous over the duration of his working life, and alongside the natural exposure, is building on over-time. Although Pierre calculated total yearly dose was 58.4 mSv, significantly higher than the average in countries such as France, UK or even USA, his excess risk of death from cancer was still very low 0.292%. [ABSTRACT FROM AUTHOR]

High-temperature furnaces and coal-fired boilers are widely employed in the petrochemical and metal-smelting sectors. Over time, the deterioration, corrosion, and wear of pipelines can lead to equipment malfunctions and safety incidents. Nevertheless, effective real-time monitoring of equipment conditions remains insufficient, primarily due to the interference caused by flames generated from fuel combustion. To address this issue, in this study, a through-flame infrared imager is developed based on the mid-wave infrared (MWIR) radiation characteristics of the flame. The imager incorporates a narrowband filter that operates within the wavelength range of 3.80 μm to 4.05 μm, which is integrated into conventional thermal imagers to perform flame filtering. This configuration enables the radiation from the background to pass through the flame and reach the detector, thereby allowing the infrared imager to visualize objects obscured by the flame and measure their temperatures directly. Our experimental findings indicate that the imager is capable of through-flame imaging; specifically, when the temperature of the target exceeds 50 °C, the imager can effectively penetrate the outer flame of an alcohol lamp and distinctly capture the target's outline. Importantly, as the temperature of the target increases, the clarity of the target's contour in the images improves. The MWIR through-flame imager presents considerable potential for the real-time monitoring and preventive maintenance of high-temperature furnaces and similar equipment, such as detecting the degradation of refractory materials and damage to pipelines. [ABSTRACT FROM AUTHOR]

JWST has brought us new insights into Cosmic Dawn with tentative detection of the unique signatures of metal-free Population III (Pop III) stars, such as strong He II emission, extremely blue ultraviolet spectrum, and enhanced nitrogen abundance. Self-consistent theoretical predictions of the formation rates, sites, and masses of Pop III stars are crucial for interpreting the observations, but are challenging due to complex physical processes operating over the large range of length-scales involved. One solution is to combine analytical models for the small-scale star formation process with cosmological simulations that capture the large-scale physics such as structure formation, radiation backgrounds, and baryon-dark matter streaming motion that regulate the conditions of Pop III star formation. We build an analytical model to predict the final masses of Pop III stars/clusters from the properties of star-forming clouds, based on the key results of small-scale star formation simulations and stellar evolution models. Our model for the first time considers the interplay between feedback and fragmentation and covers different modes of Pop III star formation ranging from ordinary small (⁠|$\sim\!{10{-}2000}\ \rm M_\odot$|⁠) clusters in molecular-cooling clouds to massive (⁠|$\gtrsim\!{10^{4}}\ \rm M_\odot$|⁠) clusters containing supermassive (⁠|$\sim\!{10^{4}{-}3}\times 10^{5}\ \rm M_\odot$|⁠) stars under violent collapse of atomic-cooling clouds with large gas accretion rates of |$\gtrsim\!{0.1}\ \rm M_\odot \ yr^{-1}$|⁠. As an example, the model is applied to the Pop III star-forming clouds in the progenitors of typical haloes hosting high- z luminous quasars (⁠|$M_{\rm h}\sim 10^{12}\ \rm M_\odot$| at |$z\sim 6$|⁠), which shows that formation of Pop III massive clusters is common (⁠|$\sim\!{20{-}70}{{\ \rm per\ cent}}$|⁠) in such biased (⁠|$\sim\!{4}\sigma$|⁠) regions, and the resulting heavy black hole seeds from supermassive stars can account for a significant fraction of observed luminous (⁠|$\gtrsim\!{10^{46}}\ \rm erg\ s^{-1}$|⁠) quasars at |$z\sim 6$|⁠. [ABSTRACT FROM AUTHOR]

The conformal scalar propagator as an explicit function of the Schwarzschild black-hole space-time has been established in the preceding three projects. The present project examines the precise relation which that propagator has to the amplitude the Schwarzschild black hole emit a scalar particle in a particular mode of positive energy. It is thereby established that the effect of infinite time-dilation on the event horizon results in both, the thermal radiation in the background of a static exterior space-time geometry and the detraction from thermality if energy-conservation is properly imposed as a constraint on scalar propagation. The derivation of the latter signifies an equivalent approach to the result of Parikh and Wilczek from the semi-classical perspective of the distant observer. From that perspective for that matter, Hawking radiation emerges in both contexts as the exclusive consequence of infinite time-dilation on the event horizon. These results are consistent with Hawking radiation as the exclusive consequence of the causal structure of the Schwarzschild black-hole space-time both, in a static exterior geometry and in such dynamical exterior geometry as energy-conservation signifies. The extension of the thermal case to other spin-fields and black-hole geometries is discussed. [ABSTRACT FROM AUTHOR]

This study assessed radionuclide concentration in Murree's natural spring water and the variation of soil mass-attenuation coefficient. Water samples from 20 springs and soil from 15 sites were analyzed. Radium-226, Thorium-232, and Potassium-40 activity concentrations averaged 0.43 ± 0.09, 0.52 ± 0.08, and 1.52 ± 0.19 Bq/L, respectively. Radiation hazard indices, including Radium equivalent, External and Internal hazard indices, External and internal absorbed and equivalent doses, and lifetime cancer risk, were quantified but found non-alarming. Mass-attenuation coefficients for various energies were measured experimentally and theoretically. Various radiation shielding parameters were calculated. Murree's soil demonstrated lower attenuation properties compared to cement, tiles, concrete, and Egyptian soil. [ABSTRACT FROM AUTHOR]

The study assessed the radiological impact of the Kaiga Generating Station (KGS) on the surrounding environment and the safety of the nearby population. Over a period of 15 years (2005–2020), the radiological monitoring detected only trace levels of 3H and 137Cs (attributed to fallout) in the surrounding environment. The study utilized the non-parametric Mann–Kendall test to analyze the long-term trends, identifying either decreasing or no trend in the radioactivity levels across various environmental matrices such as air, water, biota, and dietary items. These findings indicate no significant accumulation of radioactivity, confirming the minimal environmental impact of the KGS operations. [ABSTRACT FROM AUTHOR]

Radiation has been acknowledged to be responsible for deleterious conditions in living tissues. Hence, environmental background gamma radiation (BGR) measurement is crucial from an environmental and health perspective. In this study, due to the absence of comprehensive background gamma radiation data and the increasing numbers of anthropogenic activities that could increase the BGR level, such as where mining activities are active. The BGR in the Minna area of Niger State, Nigeria, was measured and analyzed in this study. In-situ measurement of the background gamma radiation level was carried out using a well-calibrated portable handheld GQ GMC-500 Plus nuclear radiation detector at an elevation of about 1.0 m above ground level. A global positioning system from Garmin (GPSmap 78s) was adopted for identifying geographical locations. A total of 1172 points were surveyed across the study area for background environmental radiation. The BGR values ranged from 0.102 to 0.147 μSv/h, with an overall mean value of 0.126 μSv/h. The average measured dose rate was more than twice the reported world average value of 0.059 μSv/h. The annual effective dose equivalent (AEDE) for the research area was calculated to be 0.221 mSv/y on average. The mean AEDE is lower than the ICRP recommended limit. This shows that the population of the Minna area is radiologically safe based on the estimated AEDE value. Similarly, the excess lifetime cancer risk (ELCR) value ranged from 0.626 × 10−3 to 0.901 × 10−3 mSv/y with a mean value of 0.774 ± 0.09 × 10−3 mSv/y. The mean value of AEDE is below the 0.24 mSv/y permissible limits as recommended by the International Commission on Radiological Protection (ICRP). The mean ELCR value exceeds the average world value of 0.29 × 10−3. Also, the mean organ dose values estimated for the whole body, liver, kidney, testes, bone marrow, ovaries, and lungs are 0.150 ± 0.02, 0.102 ± 0.01, 0.137 ± 0.02, 0.181 ± 0.02, 0.152 ± 0.02, 0.128 ± 0.02 and 0.141 ± 0.02 mSv/y respectively. The differences in the calculated mean of BGR were attributed to natural and human factors. Geological variation is a fundamental factor that influences the changes in BGR. Human activities, mining, building materials, and the use of phosphate fertilizers in agricultural practices are responsible for the differences in BGR. The ELCR implies that terrestrial gamma radiation does not pose any immediate radiological health effects on residents of the area, but there is a tendency for long-term health hazards in the future, such as cancer, due to the dose accumulated. [ABSTRACT FROM AUTHOR]

In this study, we investigate the impact of local stellar radiation in cosmological zoom simulations of the formation of Milky Way-sized galaxies. We include the radiation field as an additional feedback component that is computed alongside gravity with a tree code in an optically thin approximation. We resimulate the initial conditions of five Milk Way-like systems taken from the Auriga project with and without stellar radiation, and study the effects of local stellar radiation on several properties of the galaxies and the circumgalactic medium (CGM). Similar to previous findings, we observe with our current model that local stellar radiation can modify gas cooling in the CGM and thus suppress star formation and the surface densities of young stars and H  i gas, while having little impact on the total gas content. In particular, it also suppresses the peak of the rotation curve and reduces the mass of the stellar bulge. In the CGM region, the young stellar radiation exceeds the external ultraviolet background and dominates the radiation field within the virial halo at all redshifts. Nevertheless, we find that the local stellar radiation, as implemented in the current study, has overall little impact on the radial density and temperature profile of the CGM gas. However, for the ion species H  i and Mg  ii , the column densities within |$\sim 0.3\, R_{\rm vir}$| are reduced, while the O  vi column density is hardly impacted by the radiation field due to a lack of soft X-ray components in our current model. Additional effects can be expected from the radiation of the central active galactic nucleus during phases of quasar activity and from soft X-ray sources, which have not yet been included in the simulations of the present study. [ABSTRACT FROM AUTHOR]

This study aims to measure radon gas concentration, calculate the annual effective dose, and calculate excess lung cancer risk in KufrKhal-Jerash north of Jordan. Radon is a radioactive gas located everywhere and contributes more than 40% of people's total dose from natural radiation. The Risk concerns have resulted from the increase in mortality due to lung cancer in KufrKhal. About 117 well-calibrated dosimeters were among the study area's districts (Hill 1, Hill 2, Hill 3, and village center). Each dosimeter consists of a plastic cup with known dimensions and a piece of solid state nuclear track detector (SSNTD) type CR-39 fixed in the inner bottom of the cup. After 90 days, the retrieved detectors were chemically etched, and the track density (tracks.cm−2) was determined. The results showed that the average radon concentrations drastically varied between the districts of KufrKhal (17.1–128.8 Bqm−3). However, the mean radon values in different districts are closely related (64.4–75.5 Bq.m−3). The lowest concentration (17.1 Bqm−3) was found in the Hill 1 district, and the highest value (128.8 Bqm−3) was found in the village center. However, the overall radon concentration in KufrKhal was approximately 69.2 Bqm−3. This value is within the range of the national average level (43.2 – 77.4 Bq.m−3) and way below the national action level (200 Bq.m−3). Furthermore, the corresponding values of the annual effective dose (AED) and the excess lung cancer risk (ELCR) for dwellers in this village were calculated to be 1.8 mSv.y−1 and 0.2%, respectively. These values, according to Jordan's national regulations are acceptable. [ABSTRACT FROM AUTHOR]

During the process of infrared remote sensing monitoring, obtaining real-time measurements of sky background radiation is extremely inconvenient. The current methods incur a certain amount of lag. In this study, within the existing theoretical framework, a fast transmittance calculation method using interpolation was adopted, and a simplified transmission model was established. This led to the development of a new and simplified method for rapid temperature and humidity retrieval. Compared to the line-by-line integration method, the interpolation method significantly improves the speed of transmittance calculation by several tens of times, while maintaining a high level of accuracy. The relative deviation between the results obtained using the interpolation method and those obtained through line-by-line integration is less than 1 ‱. With the proposed method, temperature and humidity profile information can be retrieved from measured spectra within 5 min and corresponding background spectra can be obtained. The differences between the calculated background radiation and the measured spectra using the new method are smaller, making it more suitable for calculating sky background radiation. Additionally, the rapid retrieval results of the temperature profiles in the lower atmosphere have a certain level of accuracy (the mean deviation is less than 2 K). [ABSTRACT FROM AUTHOR]

Monitoring radioactivity around nuclear power plants is important to avoid the risks of radiation. This study provides an overview of the radioactive emission impact on the near surroundings of the Metsamor nuclear power plant in Armenia. In this context, 29 soil samples were collected from the 40, 80, 120, 160 km radius areas determined in the direction of Iğdır province by accepting the Metsamor nuclear power plant as the center. The activity concentrations of 226Ra, 232Th, 40K and 137Cs in soil samples ranged from 7.90 to 23.44, 7.11 to 33.55, 132.54 to 502.69 and 0.33 to 17.61 Bq/kg, respectively. In addition, the radioactivity concentrations in some agricultural products and the transfer factors from soil to plant were determined. As a result, there is no significant radiological risk in terms of studied radioisotopes for people living in this region. [ABSTRACT FROM AUTHOR]

With the wide use of radioactive materials, it is important to look for locally available and inexpensive materials to serve as efficient absorbers, suitable for shielding against radiation hazards. Due to its widespread availability and affordability, natural bentonitic shale is a viable option for use as a nuclear shielding material. In this study, natural bentonitic samples were cut into cylindrical pellets of varying thicknesses. The chemical composition of the natural bentonitic shale samples was determined through the use of X-Ray Fluorescence (XRF) spectroscopy. The linear and mass attenuation coefficients of bentonitic samples were evaluated using a NaI(Tl) scintillation detector at 662 keV energy of 137Cs, as well as at 1,173 keV and 1,332 keV energies of 60Co, gamma-ray sources. The experimental results indicated that bentonitic samples B3 and M2 exhibited superior shielding parameters compared to other bentonitic samples, attributable to their elevated densities. These two samples are distinguished by a high CaO content and a low AL2O3 content. Furthermore, the Half Value Layer (HVL), Tenth Value Layer (TVL), and mean free path thicknesses were calculated at these energies using linear attenuation coefficients. The theoretical mass attenuation coefficient, calculated with the assistance of the XCOM program and experimental estimates, was found to be in good agreement with the theoretical value. [ABSTRACT FROM AUTHOR]

The study assessed the concentration of natural radionuclides in soil samples from the Bambasi district in Ethiopia's Benishangul Gumuz region using a gamma‐ray spectrometer equipped with a high‐purity germanium (HPGe) detector. The measured activity concentrations of 238U, 232Th, and 40K in soil samples varied from 46.2 ± 2.25 to 88.49 ± 5.73 Bq/kg, 73.4 ± 4.12 to 119.65 ± 8.45 Bq/kg, and 176.78 ± 8.63 to 396.71 ± 25.39 Bq/kg, respectively. The average concentration of 238U and 232Th exceeded the recommended worldwide population weighted average values of 32.0 and 45.0 Bq/kg, respectively, while the average concentration of 40K was below the recommended value of 420.0 Bq/kg. The mean absorbed dose rate was calculated to be 91.6 ± 5.1 nGy/h, which is above the recommended safe value of 59 nGy/h. The average annual effective dose equivalents for indoor and outdoor exposure were determined to be 2.65 ± 0.14 mSv/y and 0.66 ± 0.1 mSv/y, respectively. The calculated mean values of the internal hazard index, external hazard index, and gamma index across all soil samples were 0.72 ± 0.05, 0.55 ± 0.02, and 0.72 ± 0.02, respectively, all below the recommended safe threshold of one. These findings suggest that the activity concentrations observed in the soil samples exceed safe levels, indicating the necessity for further investigation into radioactivity levels and epidemiological studies regarding potential hazards from high background radiation. [ABSTRACT FROM AUTHOR]

This document discusses the health effects of low-dose-rate radiation exposure with cumulative doses. It challenges the linear no-threshold (LNT) paradigm, which asserts that any dose of radiation carries some risk of harm, and argues that low doses of radiation may actually have beneficial effects and stimulate protective biological responses. The document highlights research on animals and populations exposed to radiation, which suggests a possible threshold or hormetic response. It emphasizes the need for further research on low-dose-rate radiation exposure with cumulative doses to inform policymaking and reduce public anxiety. The document also mentions the consequences of improper evacuation during nuclear accidents, particularly for vulnerable populations. Overall, the document suggests that investigating the health effects of low-dose-rate irradiation with cumulative threshold doses is a promising area of research with significant scientific, social, and economic value. [Extracted from the article]

This research project envisions using a lunar observation platform to measure the full-wave (0.2~100 μm) and shortwave (0.2~4.3 μm) radiation of the Earth, achieving an accurate estimation of the overall radiation budget of the Earth. Based on the lunar platform, the system analyzes Earth's radiation characteristics and geometric attributes, as well as the sampling properties of observation times. Informed by these analyses, an Earth-facing optical radiation measurement system tailored to these specifications is designed. The optical system adopts an off-axis three-mirror configuration with a secondary image plane, incorporating a field stop at the primary image plane to effectively suppress solar stray light, scattered lunar surface light, and background radiation from the instrument itself, ensuring the satisfactory signal-to-noise ratio, detection sensitivity, and observation duration of the instrument. At the same time, stringent requirements are imposed for the surface treatments of instrument components and temperature control accuracy to further ensure accuracy. Simulation analyses confirm that the design satisfies requirements, achieving a measurement accuracy of better than 1% across the entire optical system. This Moon-based Earth-radiation measurement system, with capabilities for Earth-pointing tracking, radiation energy detection, and stray-light suppression, furnishes a more comprehensive dataset, helping to advance our understanding of the mechanisms driving global climate change [ABSTRACT FROM AUTHOR]

In the last twenty years, nanofabrication progress has allowed for the emergence of a new photodetector family, generally called low-dimensional solids (LDSs), among which the most important are two-dimensional (2D) materials, perovskites, and nanowires/quantum dots. They operate in a wide wavelength range from ultraviolet to far-infrared. Current research indicates remarkable advances in increasing the performance of this new generation of photodetectors. The published performance at room temperature is even better than reported for typical photodetectors. Several articles demonstrate detectivity outperforming physical boundaries driven by background radiation and signal fluctuations. This study attempts to explain these peculiarities. In order to achieve this goal, we first clarify the fundamental differences in the photoelectric effects of the new generation of photodetectors compared to the standard designs dominating the commercial market. Photodetectors made of 2D transition metal dichalcogenides (TMDs), quantum dots, topological insulators, and perovskites are mainly considered. Their performance is compared with the fundamental limits estimated by the signal fluctuation limit (in the ultraviolet region) and the background radiation limit (in the infrared region). In the latter case, Law 19 dedicated to HgCdTe photodiodes is used as a standard reference benchmark. The causes for the performance overestimate of the different types of LDS detectors are also explained. Finally, an attempt is made to determine their place in the global market in the long term. [ABSTRACT FROM AUTHOR]

During infrared detection, the thermal radiation from the background generates substantial photon noise and thus severely limit the capability of an infrared detector to identify a target. Going beyond this limitation has been a long‐standing challenge in the development of infrared detectors. This paper proposes to break this limitation by creating a narrow photoresponse band with a high peak responsivity to reject the background radiation and enhance the responsivity to the target with characteristic emission lines. This scheme is numerically demonstrated in a dimerized grating integrated quantum well infrared photodetector, based on critical coupling with a Brillouin zone folding induced quasi‐bound state in the continuum (BIC). The asymmetric deformation of the grating structure folds the photonic band and generates a quasi‐BIC with a tunable high radiation Q factor (QR) at the Γ point. By reducing the doping concentration of the quantum wells for a high absorption Q factor (QA) and tuning the QR to make QR = QA for critical coupling, a narrowband photoresponse with a high peak responsivity is achieved and the background‐limited specific detectivity of 4.55 × 1012 cm Hz1/2 W−1 is obtained for a 2π field of view, surpassing the ideal‐photoconductor limit by 92 times. [ABSTRACT FROM AUTHOR]

Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office 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.)

Exceptional point (EP), a special degeneracy in non‐Hermitian systems, has exhibited various distinctive wave characteristics. However, the conventional synthesis of scattering EPs in acoustics is confined to rather limited methods for breaking Hermiticity, typically requiring intrinsic losses or open interfaces. Here, the concept of synthesizing scattering EPs is theoretically and experimentally demonstrated by leveraging a metasurface with fluid‐solid interaction (FSI) in water. The incorporation of FSI offers a novel mechanism to customize natural radiation losses. Simulations and experiments consistently confirm that synthesized EPs result in extremely asymmetric scattering patterns, even in the case of spatially impenetrable metasurfaces. This enhanced spatial symmetry breaking benefits from the FSI on the interface and the nonlocal interaction between unit cells. The proposed non‐Hermitian framework, involving the interplay of sound in fluids and solids, is expected to open up new possibilities for exploring unique non‐Hermitian physics and underwater acoustic applications. [ABSTRACT FROM AUTHOR]

A poly(para)phenylene conjugated polymer is developed to store information via a quick and facile optical writing method. After exposure to UV light, co‐fluorescence (films with two or more written emission colors –, i.e., "double‐on") and "on‐off" states are written into the flexible polymer films. The hidden information is invisible under ambient lighting and can only be read with an appropriate light source, optical filter, and/or magnifier, thus providing a level of security for information encoded into the films. The physical and chemical mechanisms are discussed responsible for the rapid fluorescence changes that occur under UV exposure and demonstrate microscale multi‐colored artwork and hidden QR codes written into pliable and freestanding films. Depending on the preparation, the written patterns remained easily visible and stable after exposure to water and to ambient levels of UV background radiation. [ABSTRACT FROM AUTHOR]

With low background radiation, tritiate compounds exclusively emit intense beta particles without structural changes. This makes them a useful tool in the drug discovery arsenal. Thanks to the recent rapid progress in tritium chemistry, the preparation and analysis of tritium-labeled compounds are now much easier, simpler, and cheaper. Pharmacokinetics, autoradiography, and protein binding studies have been much more efficient with the employment of tritium-labeled compounds. This review provides a comprehensive overview of tritium-labeled compounds regarding their properties, synthesis strategies, and applications. [ABSTRACT FROM AUTHOR]

Any Geiger counter can be used as an effective cosmic ray detector on its own. In fact, it is known that even in the absence of a radioactive source, the instrument detects what is known as background radiation, which consists of various types of ionizing particles present in the environment. Remarkably, it is estimated that up to 15% of this background radiation is attributable to cosmic rays, high-energy particles originating from outer space. The remaining radiation detected by the Geiger counter originates from terrestrial sources, such as natural radioactivity in the ground and in the air. The main goal of this project is to build a muon detector for scientific and educational purposes using two commercial DIY Geiger counter kits and just a few additional components. To identify cosmic radiation from terrestrial radiation and improve the accuracy of cosmic ray measurements, the use of a coincident circuit is essential. This coincident circuit was introduced in cosmic ray physics by Walther Bothe and Bruno Rossi in the early 1930s and allows for the detection of a subatomic particle passing through two or more sensors, thereby reducing false positives and enhancing the reliability of cosmic ray detection. The following idea is an alternative replica of our AMD5 detectors, instruments that we have been using for years to teach and perform scientific experiments in the cosmic ray field under the umbrella of the ADA project (2023 Particles, Arcani et al.). The resulting device, named AMD5ALI, offers a reliable and inexpensive solution for the same goal, making it a valuable tool for both educational purposes and scientific surveys. Practical applications range from cosmic ray physics to radioactivity, including the relationship between cosmic ray flux and meteorology, the zenithal effect, the Regener–Pfotzer curve in the atmosphere, and the anti-correlation of cosmic particle intensity with solar activity. [ABSTRACT FROM AUTHOR]

This investigation quantifies the activity concentrations of natural radionuclides (226Ra, 232Th, and 40K) in the soils and certain rocks of the Koytash–Ugam Range, Uzbekistan, and assesses their radiological risks. Gamma-spectrometric analysis of soil and rock samples revealed activity concentrations ranging from 456.2 ± 56.0 to 813.9 ± 76.0 Bq kg−1 for 40K, 18.2 ± 6.3 to 70.0 ± 12.0 Bq kg−1 for 226Ra, and 30.1 ± 2.9 to 57.9 ± 10 Bq kg−1 for 232Th. This data indicates a heterogeneous distribution of radionuclides, informing radiation safety and health risk assessments on a global scale. The calculation of radiological hazard indices, including the alpha-index (ranging from 0.09 to 0.35), gamma-index (ranging from 0.40 to 0.73), and both internal (ranging from 0.40 to 0.54) and external (ranging from 0.36 to 0.54) hazard indices, was undertaken to ascertain potential health risks. The radium equivalent activity ranged from 108.4 to 199.3 Bq kg−1, and the absorbed dose rates were 51.0–93.3 nGy h−1 indoors and 96.6–178.2 nGy h−1 outdoors. These metrics underlie the estimated annual effective dose of 536.5–988.5 × 10−3 mSv y−1, highlighting the variability in radiation exposure. Additionally, the potential lifetime cancer risk was projected at 1770.4 to 3262.0 per million, with an annual gonadal dose equivalent of 361.9 to 655.5 μSv y−1, reflecting natural background radiation influence. The results underscore the importance of safe material use in construction and the necessity for routine natural radioactivity monitoring. Radon flux density (RFD) values within acceptable construction limits (26–176 mBq m−2 s−1) suggest the area's suitability for development, considering recommended safety guidelines. This study not only aids local environmental and public health frameworks but also enriches the international knowledge base, facilitating comparative studies for the advancement of global radiation protection standards. Through a detailed examination of radionuclide distribution in an under-researched area, our research highlights the critical need for integrated international approaches to natural radiological hazard assessment. [ABSTRACT FROM AUTHOR]

All humans are exposed to radon, the primary source of natural radiation, which can harm people due to natural processes rather than human activity. Thus, it is of significant importance to determine the levels of radon in indoor, soil gas, water, and outdoors. Radon concentration (CRn) was measured in Kiraz district, İzmir, and the correlation between the indoor and soil gas CRn values was investigated. The indoor CRn values measured in 40 randomly selected dwellings in Kiraz exhibited a wide range from 19.50 ± 2.50 to 204.70 ± 8.00 Bq m−3 with an average value of 61.11 ± 4.23 Bq m−3. The measured indoor CRn values were compared to the reference levels in the world to help control radon in the dwellings. Indoor CRn values were lower than the ICRP reference level of 300 Bq m−3 in all of the dwellings studied. Furthermore, in 34 dwellings (representing 85% of the total number of dwellings studied), indoor CRn values were lower than the WHO reference level of 100 Bq m−3. Health hazard indices, namely annual effective dose (AED) and excess lifetime cancer risk (ELCR), were also calculated for each dwelling and compared with internationally acceptable levels to estimate the risk to human health. The AED values varied from 0.49 ± 0.06 to 5.16 ± 0.20 mSv y−1 with an average value of 1.54 ± 0.11 mSv y−1, which exceeds the world average of 1.15 mSv y−1 as reported by UNSCEAR. The ELCR values ranged from 2.05 ± 0.26 × 10−3 to 21.55 ± 0.84 × 10−3 with an average value of 6.43 ± 0.44 × 10−3, exceeding the world average of 0.29 × 10−3 as reported by UNSCEAR. The soil gas CRn values measured exhibited a wide variation ranging from 129.25 ± 6.38 Bq m−3 to 6172.64 ± 44.06 Bq m−3 with an average value of 1291.79 ± 18.70 Bq m−3. The soil gas CRn values were less than 10,000 Bq m−3; hence, the research area is categorized as "low radon risk areas" according to Sweden Criteria, and so no special constructions are required in the studied area. When soil gas CRn values were compared to indoor CRn values, no linear relationship was found between the CRn values. However, a strong positive linear correlation was found between indoor and soil gas CRn values less than 200 Bq m−3 and 2500 Bq m−3, respectively. [ABSTRACT FROM AUTHOR]

Mountains exhibit a high degree of endemism and diversity, however, quantifying their biodiversity can be challenging. Similar to islands, species isolation in mountainous regions results in comparable patterns of evolution and extinction, rendering their biodiversity unique and highly susceptible to anthropogenic threats. The topographic relief in mountains plays a crucial role in creating habitat complexity, which in turn contribute to high plant diversity. Here, we investigated plant diversity in the volcano mountaintop vegetation on the Poços de Caldas Plateau, a region situated in the ecotone between the Atlantic Forest and Cerrado, characterized by natural radiation and significant anthropogenic intervention. We employed an automated approach through the filtering of georeferenced and non-georeferenced data to obtain a list of plant species in the region. Additionally, we statistically investigated the similarity among different high-altitude vegetations belonging to the campos de altitude from the Atlantic Forest and campos rupestres from the Cerrado. The plateau exhibits high plant diversity, including 1,659 specific and infraspecific taxa, especially belonging to Asteraceae and Poaceae. Our analyses suggest that geographical distance is a strong predictor of dissimilarity and that the Poços de Caldas Plateau is more floristically related to the campos rupestres, despite being associated with campos de altitude. The region possesses a unique set of biodiversity, indicating that it may be a distinct formation. Additionally, we hypothesize that Pleistocene events likely influenced the conformation of the current floristic composition in the region through species interchange between the Cerrado and Atlantic Forest. Our study also highlights the few taxa assessed for conservation status and anthropogenic threats that this habitat is facing. [ABSTRACT FROM AUTHOR]

Purpose: Given the growing use of cone-beam computed tomography (CBCT) scans, this study assessed radiation exposure from these scans in the context of national guidelines and recommended dose limits. Materials and Methods: The current literature was reviewed to quantify the benefit of opportunistic diagnosis of carotid artery calcification relative to the potential risk of radiation-induced cancer. Results: The average radiation from CBCT at its largest field of view and highest resolution possible amounts to a reasonable but still low ionizing radiation exposure. This exposure is comparable to 22 days of background radiation and is notably lower than the radiation exposure from medical CT scans. According to the risk assessment analysis, the risk of stroke events involving internal and external carotid artery calcification (CAC) was 202 and 67 per 100,000 individuals, respectively. In contrast, the estimated risk of radiation-induced cancer associated with CBCT was notably lower, at 0.6 per 100,000. Conclusion: The present study advocates for a comprehensive assessment of CBCT scans encompassing the areas of the internal and external carotid arteries by a knowledgeable professional, given the potential advantages of early detection of vascular abnormalities. Dental professionals who take scans involving these areas need to be mindful of reporting these findings and refer patients to their primary care physician for further investigation. [ABSTRACT FROM AUTHOR]

Experiments accessing extreme conditions at x-ray free electron lasers (XFELs) involve rapidly evolving conditions of temperature. Here, we report time-resolved, direct measurements of temperature using spectral streaked optical pyrometry of x-ray and optical laser-heated states at the High Energy Density instrument of the European XFEL. This collection of typical experiments, coupled with numerical models, outlines the reliability, precision, and meaning of time dependent temperature measurements using optical emission at XFEL sources. Dynamic temperatures above 1500 K are measured continuously from spectrally- and temporally-resolved thermal emission at 450–850 nm, with time resolution down to 10–100 ns for 1–200 μ s streak camera windows, using single shot and integrated modes. Targets include zero-pressure foils free-standing in air and in vacuo, and high-pressure samples compressed in diamond anvil cell multi-layer targets. Radiation sources used are 20-fs hard x-ray laser pulses at 17.8 keV, in single pulses or 2.26 MHz pulse trains of up to 30 pulses, and 250-ns infrared laser single pulses. A range of further possibilities for optical measurements of visible light in x-ray laser experiments using streak optical spectroscopy are also explored, including for the study of x-ray induced optical fluorescence, which often appears as background in thermal radiation measurements. We establish several scenarios where combined emissions from multiple sources are observed and discuss their interpretation. Challenges posed by using x-ray lasers as non-invasive probes of the sample state are addressed. [ABSTRACT FROM AUTHOR]

The assessment of a population's radiological impact due to radiation emitted by natural radionuclides is important because it is associated with the health of the people. The objective of the study was to provide reliable baseline data and analyse the impact of the natural outdoor gamma radiation dose of Nagaur, Kheenvasar, and Jayal blocks of Nagaur district, Rajasthan. A total of 80 locations of Nagaur, 31 locations of Kheenvasar, and 51 locations of Jayal were selected for the analysis. The gamma radiation exposure was found to vary from 66 nSv/h to 163 nSv/h, which lies within the normal range specified by UNSCEAR (20 to 200 nSv/h) for all the sites. Statistical analysis through the Shapiro-Wilk test (p < 0.05) rejects the normality of data for all three blocks, which specified the not suitability of data for the parametric test. The Jonckheere-Terpstra test (p < 0.05) confirmed that there was no significant difference among the radiation doses of different blocks. Annual effective dose (AED) and Excess lifetime cancer risk (ELCR) were computed to determine the number of cancer cases originating from outdoor gamma radiation. Average cancer cases due to outdoor gamma radiation were estimated at 49, 45 and 48 per hundred thousand in Jayal, Kheenvasar, and Nagaur blocks, respectively. The Effective Equivalent Dose for Bone-marrow (red), colon, lung, stomach, breast, reminder tissues, Gonads, Bladder, Oesophagus, Liver, Thyroid, Bone surface, brain, salivary, glands, and skin was also calculated and found within the prescribed limit. [ABSTRACT FROM AUTHOR]

Natural gypsum has been studied as a building material, and it has been discovered that it is one of the potential sources of indoor radioactivity due to naturally occurring radioactive elements in it. The levels of radioactive elements obtained in natural gypsum available in Abay gorge Dejen district were accomplished by a well shielded and calibrated gamma spectrometry with high purity Ge detector to evaluate the radiation hazard to workers in Dejen gypsum factories and dwellers in buildings decorated with gypsum products. The results of this study revealed that radioactive elements 238U, 232Th, and 40K are found in raw gypsum samples, with specific activity ranging from 1.47 ± 0.26 to 2.42 ± 0.37 Bqkg−1, 1.10 ± 0.26 to 2.60 ± 0.48 Bqkg−1, and 4.27 ± 1.92 to 44.53 ± 2.84 Bqkg−1, respectively. The mean specific activities are 1.90 ± 0.33 Bqkg−1 for 238U, 1.99 ± 0.39 Bqkg−1 for 232Th, and 28.16 ± 2.57 Bqkg−1 for 40K, which are significantly lower than the intercontinental approved values. All of the calculated radioactive risk indices were significantly lower than the global recommended values for building materials. The values of various radioactive indices indicate that the use of gypsum powder obtained from studied samples in the construction of residences is considered safe. [ABSTRACT FROM AUTHOR]

Nonlinear wave propagation in large extra spatial dimensions (on and above d = 2) is investigated in the context of nonlinear electrodynamics theories that depend exclusively on the invariant F (= − (1 / 4) F μ ν F μ ν) . In this vein, we consider propagating waves under the influence of external uniform electric and magnetic fields. Features related to the blackbody radiation in the presence of a background constant electric field such as the generalization of the spectral energy density distribution and the Stefan–Boltzmann law are obtained. Interestingly enough, anisotropic contributions to the frequency spectrum appear in connection to the nonlinearity of the electromagnetic field. In addition, the long wavelength regime and Wien's displacement law in this situation are studied. The corresponding thermodynamics quantities at thermal equilibrium, such as energy, pressure, entropy, and heat capacity densities are contemplated as well. [ABSTRACT FROM AUTHOR]

The prevalence of light element enhancement in the most metal-poor stars is potentially an indication that the Milky Way has a metallicity floor for star formation around |$\sim 10^{-3.5}$| Z |$_{\odot }$|⁠. We propose that this metallicity floor has its origins in metal-enriched star formation in the minihaloes present during the Galaxy's initial formation. To arrive at this conclusion, we analyse a cosmological radiation hydrodynamics simulation that follows the concurrent evolution of multiple Population III star-forming minihaloes. The main driver for the central gas within minihaloes is the steady increase in hydrostatic pressure as the haloes grow. We incorporate this insight into a hybrid one-zone model that switches between pressure-confined and modified free-fall modes to evolve the gas density with time according to the ratio of the free-fall and sound-crossing time-scales. This model is able to accurately reproduce the density and chemo-thermal evolution of the gas in each of the simulated minihaloes up to the point of runaway collapse. We then use this model to investigate how the gas responds to the absence of H |$_{2}$|⁠. Without metals, the central gas becomes increasingly stable against collapse as it grows to the atomic cooling limit. When metals are present in the halo at a level of |$\sim 10^{-3.7}$|  Z |$_{\odot }$|⁠ , however, the gas is able to achieve gravitational instability while still in the minihalo regime. Thus, we conclude that the Galaxy's metallicity floor is set by the balance within minihaloes of gas-phase metal cooling and the radiation background associated with its early formation environment. [ABSTRACT FROM AUTHOR]

Perovskites have been largely implemented into optoelectronics as they provide several advantages such as long carrier diffusion length, high absorption coefficient, high carrier mobility, shallow defect levels and finally, high crystal quality. The brisk technological development of perovskite devices is connected to their relative simplicity, high-efficiency processing and low production cost. Significant improvement has been made in the detection performance and the photodetectors' design, especially operating in the visible (VIS) and near-infrared (NIR) regions. This paper attempts to determine the importance of those devices in the broad group of standard VIS and NIR detectors. The paper evaluates the most important parameters of perovskite detectors, including current responsivity (R), detectivity (D*) and response time (τ), compared to the standard photodiodes (PDs) available on the commercial market. The conclusions presented in this work are based on an analysis of the reported data in the vast pieces of literature. A large discrepancy is observed in the demonstrated R and D*, which may be due to two reasons: immature device technology and erroneous D* estimates. The published performance at room temperature is even higher than that reported for typical detectors. The utmost D* for perovskite detectors is three to four orders of magnitude higher than commercially available VIS PDs. Some papers report a D* close to the physical limit defined by signal fluctuations and background radiation. However, it is likely that this performance is overestimated. Finally, the paper concludes with an attempt to determine the progress of perovskite optoelectronic devices in the future. [ABSTRACT FROM AUTHOR]

This paper investigates the theoretical and experimental cooling performance of textile materials utilizing radiative cooling technology. By applying Kirchhoff's law, the emissivity of surfaces is determined, revealing that materials with high transmission values can achieve comparable cooling performance to those with high reflection values. Notably, materials exhibiting moderate reflectance and transmittance in the solar range tend to absorb minimal solar radiation, thus offering high theoretical cooling performance. However, practical applications like building envelopes or clothing present challenges due to the impact of background radiation on overall cooling capacity. Despite their intrinsic cooling properties, a significant portion of solar radiation is transmitted, complicating matters as the background can significantly affect overall cooling performance. This study provides a solution that accounts for the influence of background materials. Based on spectral data, various background materials and their impact on different semi-transparent comparison materials can be considered, and cooling performance can be simulated. This enables the simulation of cooling performance for various application scenarios and facilitates comparisons between transparent, semi-transparent, and opaque textile materials. [ABSTRACT FROM AUTHOR]

Ultraviolet-B (UVB) radiation is a major physical factor that induces structural changes in human skin. The aim of this study was to determine whether the novel silent information regulator 1 (sirtuin 1 SIRT1) protein activator, penilumamide, exerted any protective effects against UVB-induced skin damage using human HaCaT keratinocytes as a model. Enzymatic assays were performed to determine the SIRT1-activating ability of penilumamide, which was compared with that of resveratrol, a potent natural product SIRT1 activator with antioxidant and anti-inflammatory properties. Penilumamide markedly activated SIRT1 enzyme activity compared to resveratrol. To further investigate the protective effect of penilumamide against UVB-induced cytotoxicity, HaCaT cells were pretreated with penilumamide (10 μM) for 24 hr followed by irradiation with UVB (40 mJ/cm2). UVB (40 mJ/cm2) irradiation significantly reduced cell viability in a time-dependent manner, whereas pretreatment with penilumamide blocked this effect. Further, penilumamide decreased the levels of intracellular reactive oxygen species (ROS) generated by UVB irradiation in HaCaT cells. Pretreatment with penilumamide also prevented UVB irradiation-induced changes in mitochondrial membrane potential (ΔΨm). In addition, pretreatment with penilumamide significantly reduced the expression levels of pro-inflammatory cytokines, interleukin (IL)-6, IL-8, and IL-10 and phosphorylation of nuclear factor-kB (NF-kB). These results indicate that penilumamide protects HaCaT cells from UVB-induced inflammation. Taken together data demonstrate that penilumamide exerted protective effects against UVB-induced ROS generation in HaCaT cells. Therefore, penilumamide may be considered to be used as a new SIRT1 activator to protect human keratinocyte against UVB-induced damage. [ABSTRACT FROM AUTHOR]

The ability of Deinococcus bacteria to survive in harsh environments, such as high radiation, extreme temperature, and dryness, is mainly attributed to the generation of unique pigments, especially carotenoids. Although the limited number of natural pigments produced by these bacteria restricts their industrial potential, metabolic engineering and synthetic biology can significantly increase pigment yield and expand their application prospects. In this study, we review the properties, biosynthetic pathways, and functions of key enzymes and genes related to these pigments and explore strategies for improving pigment production through gene editing and optimization of culture conditions. Additionally, studies have highlighted the unique role of these pigments in antioxidant activity and radiation resistance, particularly emphasizing the critical functions of deinoxanthin in D. radiodurans. In the future, Deinococcus bacterial pigments will have broad application prospects in the food industry, drug production, and space exploration, where they can serve as radiation indicators and natural antioxidants to protect astronauts' health during long-term space flights. [ABSTRACT FROM AUTHOR]

An important method for measuring radionuclide activity is alpha spectrometry. Ten soil samples were collected from the studied area. The activity concentrations of 238U and 234U in the collected soil samples ranged between 135 and 218 Bq kg–1 and between 117 and 183 Bq kg–1, respectively. 232Th, 230Th and 228Th activity concentrations ranged between 101 and 339, between 122 and 234 and between 106 and 385 Bq kg–1, respectively. When calculating the amount of radionuclide transport across the food chain, assessment models usually employ a transfer factor. Through root uptake, U and Th are transferred from the soil to food plants. To monitor the movement of radionuclides from the uranium series in diverse environments, it may be possible to use the ratios of uranium and thorium isotopes. Uranium mobility in soil depends on different physicochemical, organic and enzymatic factors and mechanisms. The high mobility of uranium is the main reason for the accumulation of uranium in the soil at root level and the possibility of its transfer to plants. A group of plants were selected that are grown in this area and the population relies on them mainly to meet their food needs. The concentration and transfer factor values of uranium isotopes were the highest in roots as compared with leaves and stems. Uranium in plants accumulates in roots and is then transferred to leaves. The mobility of uranium in plant tissues is constrained because it frequently adsorbs cell wall components. As a result, concentrations are frequently higher in tissues located in lower parts of the plant, with root surfaces having the highest concentrations. [ABSTRACT FROM AUTHOR]

Coherence Imaging Charge Exchange Recombination Spectroscopy (CICERS) is an imaging diagnostic installed in Wendelstein 7-X from which 2D maps of ion temperature (Ti) and impurity density (nZ) are obtained. The improved spatial resolution and coverage, as compared to standard Charge eXchange Recombination Spectroscopy (CXRS), with which these parameters can be assessed, come at the expense of spectral resolution, requiring the development of new strategies to isolate the active charge exchange contribution from passive and Bremsstrahlung radiation. In this work, a new approach based on the modeling of background radiation is presented and applied to the derivation of 2D Ti maps. These are compared to the Ti profiles derived from standard CXRS, which found excellent agreement up to the edge (ρ > 0.8). The CICERS view is implemented in the pyFIDAsim code, which is used to provide further insight into the spatial localization of the radiation as measured by the diagnostic. Moreover, an absolute intensity calibration is carried out, and, coupled with pyFIDAsim, the first 2D nC maps are obtained and validated against CXRS data. [ABSTRACT FROM AUTHOR]