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A complete simulation chain for the laser-based generation of a microfocus-size gamma ray beam of multi-MeV energy range able to produce radiographic images has been developed. The major interactions needed to obtain such a beam are treated individually. Particle-in-cell is used to study the generation of the electron beam through laser wake-field acceleration (LWFA), and Geant4 is employed for the Bremsstrahlung photon emission and for testing the imaging capabilities of the generated gamma beam. The paper presents detailed discussions about the implementation of each simulation, along with the results obtained. The structure of the article walks through the LWFA of up to 100 MeV electron beam, followed by its attenuation through a tantalum foil generating a 300 μ m spot size photon beam, later used for imaging of a thick lead test-object, assessing a 100 μ m resolution, and confirming the simulated imaging setup suitability for non-destructive testing applications of thick high-density objects. An analysis of the quality control parameters for the generated image along with discussions of possible improvements is also included. [ABSTRACT FROM AUTHOR]

Objective. Prompt gamma timing (PGT) uses the detection time of prompt gammas emitted along the range of protons in proton radiotherapy to verify the position of the Bragg peak (BP). Cherenkov detectors offer the possibility of enhanced signal-to-noise ratio (SNR) due to the inherent physics of Cherenkov emission which enhances detection of high energy prompt gamma rays relative to other induced uncorrelated signals. In this work, the PGT technique was applied to 3 semiconductor material slabs that emit only Cherenkov light for use in a full scale system: a 3 × 3 × 20 mm3TlBr, a 12 × 12 × 12 mm3TlBr, and a 5 × 5 × 5 mm3TlCl.Approach. A polymethyl methacrylate (PMMA) target was exposed to a 67.5 MeV, 0.5 nA proton beam and shifted in 3 mm increments at the Crocker nuclear laboratory (CNL) in Davis, CA, USA. A fast plastic scintillator coupled to a photomultiplier tube (PMT) provided the start reference for the proton time of flight. Time of flight (TOF) distributions were generated using this reference and the gamma-ray timestamp in the Cherenkov detector.Main results. The SNR of the proton correlated peaks relative to the background was 20, 29, and 30 for each of the three samples, respectively. The upper limit of the position resolutions with the TlCl sample were 2 mm, 3 mm, and 5 mm for 30k, 10k, and 5k detected events, respectively. The time distribution of events with respect to the reference reproduced with clarity the periodicity of the beam, implying a very high SNR of the Cherenkov crystals to detect prompt gammas. Background presence from the neutron-induced continuum, prompt gammas from deuterium, or positron activation were not observed. Material choice and crystal dimensions did not seem to affect significantly the outcome of the results.Significance. These results show the high SNR of the pure Cherenkov emitters TlBr and TlCl for the detection of prompt gammas in a proton beam with current of clinical significance and their potential for verifying the proton range. The accuracy in determining shifts of the BP was highly dependent on the number of events acquired, therefore, the performance of these detectors are expected to vary with different beam conditions such as current, pulse repetition, and proton bunch width.

Halide perovskites are essential materials for hard radiation detectors at ambient temperature. To improve detector performance, charge transport must be investigated and optimized. Using photoluminescence (PL) and thermally stimulated current (TSC) spectroscopies, we investigate photogenerated charge carriers in Bridgman-grown CsPbBr3 single crystals to understand the nature of charge transport. PL spectroscopy of these halide perovskites revealed the presence of strong emission bands at the band edge, which were attributed to free or bound excitons. It is shown that a wide broadening of the excitonic linewidth in these halide perovskites arises from strong exciton–phonon coupling, which is substantially dominated by longitudinal optical phonons via Fröhlich interaction. An additional contribution due to the presence of ionized impurities was also observed. Crystals with a detectable sensitivity to high-energy gamma radiation are characterized by a higher intensity and a narrower linewidth of the principal PL peak at 2.326 eV. Defect states beyond 2.214 eV have a negative impact on detector sensitivity to high-energy gamma radiation. TSC spectroscopy reveals an array of trap levels spanning 0.15–0.70 eV, attributed to intrinsic point defects and multiple extrinsic defects involving dopants or impurities. Defects identified included Cs and Br vacancies, as well as Pb interstitials with concentrations in the 1011–1016 cm−3 range. Understanding how the synthesis process impacts the types and concentrations of the defects present is currently under investigation. Elimination or suppression of the defect/trap states should result in halide perovskite materials with longer carrier diffusion lengths and improved detector characteristics. [ABSTRACT FROM AUTHOR]

Borophosphate host glasses doped with zinc oxide (ZnO), titanium dioxide (TiO 2), tellurium dioxide (TeO 2), or cerium oxide (CeO 2) were synthesized using rapid quenching techniques. Fourier transform infrared (FTIR) spectra, along with deconvoluted FTIR spectra, were recorded in the 400–4000 cm−1 range. Using the models of Tauc and Urbach, the optical energy band gaps of these glasses were found to be 3.212, 3.289, 3.262, 3.087, and 2.475 eV respectively. Due to the incorporation of different metal ions into the prepared glasses, the density increased and the molar volume decreased, making the glass structure highly compact. Since the elastic moduli are directly related to the average cross-link density, the shear and longitudinal moduli show a forward proportionality with the average cross-link density. Detailed reporting focused on the mass attenuation coefficients (μ m) and exposure build-up factors (EBF), crucial for evaluating the shielding properties of the material within the energy range of 0.015–15 MeV and penetration depth up to 40 mean free paths (mfp). Glass samples doped with tellurium dioxide exhibited the highest gamma attenuation due to their higher effective atomic number compared to the other samples. Compared to Portland concrete, the prepared glass composites showed higher mass attenuation coefficients across the entire investigated energy range. These results suggest that although Borophosphate glasses doped with cerium oxide have preferred mechanical properties compared with the other prepared glasses, Borophosphate glasses doped with tellurium dioxide could serve as transparent shielding material for medical applications due to their higher attenuation coefficient. [ABSTRACT FROM AUTHOR]

A glass system with the nominal composition 10NaF - (89-x)B 2 O 3 - xBi 2 O 3 - 1Sm 2 O 3 (where x = 15, 20, 25, 30, and 35 mol%) has been fabricated by the melt quenching technique. Densities increased from 3.598 to 4.726 g/cm³ and a corresponding rise in molar volume from 35.880 to 44.089 cm³/mol. The decrement in oxygen packing density (OPD = 75.250–61.239 mol/cm3) and increment in oxygen molar volume (13.289–16.329 cm3/mol) indicate an expansion of the glass structure with the Bi3+ ions. Young's modulus decreases from 58.974 to 41.685 GPa as the concentration of Bi 2 O 3 increases from 15 to 35 mol%. The linear attenuation coefficient (LAC) shows an increasing trend, demonstrating improved attenuation ability with a higher molar concentration of Bi₂O₃. As the Bi₂O₃ concentration increases in the glass matrix, the effective atomic number (Z eff) increases from 61.214 to 72.116 at 59.54 keV, and from 15.829 to 25.988 at 662 keV. The half-value layer (HVL) decreases as bismuth oxide is introduced into the glass matrix, and prepared glasses exhibit lower values than Hematite-Serpentine Concrete, Ilmenite-Limonite Concrete, Basalt-Magnetite Concrete, Ilmenite Concrete, RS253, 55B 2 O 3 :20BaCO 3 :19.5ZnO:5Bi 2 O 3 :0.5Dy 2 O 3 , RS 323, LSGB1, and LSGB2 shielding materials. The mean free path (MFP) values reduced from 0.094 to 0.053 cm at 59.54 keV, and from 2.958 to 2.073 cm at 662 keV with the Bi 2 O 3 concentration. Consequently, the prepared glass can be reliable for gamma radiation shielding applications. [ABSTRACT FROM AUTHOR]

In radiation therapy, various radioprotective materials protect normal cells from the damage produced by ionizing radiation. Plant-based chemical compounds possess antioxidant properties and can scavenge free radicals produced by nuclear radiation. Determining radiation shielding parameters and understanding how nuclear radiation interacts with plant-based radioprotectors are crucial for choosing the optimal plant-based radioprotectors. In the present work, the interaction of gamma, neutron, electron, proton, and alpha particles with plant-based radioprotectives such as ferulic acid, genistein, hesperidin, lycopene, psoralidin, sesamol, troxerutin, vanillin, and zingerone has been studied. The interaction parameters such as MAC, Zeff, EBF, and EABF for gamma energy, MAF for thermal and fast neutrons, and MSP for electrons, protons, and alpha have been calculated for the plant-based radioprotectors using the software EpiXs, PyMLBUF, NGCal, ESTAR, PSTAR, and ASTAR. Results show that genistein and lycopene show high and low effective atomic numbers in the higher energy region of gamma photons, respectively. The neutron mass attenuation factor is found to be highest for lycopene and lowest for genistein for both thermal and fast neutrons. Among the selected plant-derived radioprotectives, troxerutin and lycopene are the most effective plant-based compounds for gamma and neutron radiation therapy applications. The shielding parameters of selected plant-based radioprotector materials are compared with those of some chemical radioprotectors. Besides, the shielding parameters of selected plant-based radioprotector materials are comparable to chemical radioprotectors except for lycopene. [ABSTRACT FROM AUTHOR]

AbstractPurposeMaterials and methodsResultsConclusionKernel texture plays a principal role in determining technological flour properties and end-use quality of wheat products. Hence, a multi-year mutation induction programme was conducted to isolate advanced wheat mutant lines with agro-morphologically superior performance, higher disease resistance and harder grain texture.Radiation mutagenesis was employed in soft textured wheat variety HPW 89 using gamma rays dose of 250, 300 and 350 Gy (Co60: BARC, Mumbai) and evaluated across M1–5 generations. Promising superior mutants selected were evaluated during M4 and M5 generation for induced variability and trait association for agro-morphological and quality traits. The screened mutants were also determined for induced changes at genetic level using gene specific markers for puroindoline genes.A total of 293 agro-morphologically superior mutants isolated showed significant genetic variation in the M4 generation. Single kernel characterization system categorized 267 mutants (8.79–50.06) with higher grain hardness than the HPW 89 variety (7.39). Among these, 108 mutants were selected for agro-morphological and molecular characterization. Significant variations were found in these mutants in either pina and pinb or both puroindoline genes. Clustering among these mutants led to the formation of five clusters and a total of eleven mutants were found with better set of agro-morphological, disease resistance and quality traits.These mutants can serve as important genetic resource for developing harder texture bread wheat varieties in the future grain quality improvement programmes. These mutants will also bridge the need of bakers and millers’ requirement of varieties with specific texture and quality. [ABSTRACT FROM AUTHOR]

Background: Fenugreek (Trigonella foenum-graecum L.) is highly esteemed for its therapeutic properties and is widely used in traditional medicine and modern pharmacology. Enhancing its genetic traits and phytochemical profile, particularly its trigonelline content, can significantly increase its medicinal and agricultural value. This study aims to investigate the effects of gamma rays and Ethyl Methane Sulphonate (EMS) as mutagenic agents on the genetic and phytochemical characteristics of the M2 generation of fenugreek, focusing on genetic diversity and desirable trait enhancement. Methods and results: To achieve this, various concentrations of EMS and gamma rays were administered to fenugreek seeds, and 27 traits were assessed in the resulting M2 generation. These traits were analyzed for variance, mean values, and correlations. The genetic diversity of 23 M2 offspring was investigated using nine Start Codon Targeted (SCoT) markers. The genetic diversity assessment involved Principal Coordinate Analysis (PCoA) and cluster analysis, utilizing the Dice similarity coefficients and the Unweighted Pair Group Method with Arithmetic Mean (UPGMA). A Bayesian model provided deeper insights into the genetic structure. Results revealed that lower doses of gamma rays (100 Gy) and EMS (0.2%) positively impacted specific traits. In comparison, higher doses (200 Gy and 0.4% EMS) increased seed trigonelline content to 0.71 mg/g dry weight. Among the SCoT markers, SCoT-9 was the most efficient, segregating the populations into three clusters. The first three principal components in the PCoA explained 20% of the total variance, leading to seven subgroup populations distinction. Conclusions: These findings underscore the potential of induced mutagenesis in enhancing desirable traits in fenugreek. [ABSTRACT FROM AUTHOR]

The application of terahertz technology in space is frontier for the development of 6G technologies. Terahertz transceiver devices based on gallium arsenide Schottky barrier diodes (GaAs SBDs) have the characteristics of small size, light weight and low power consumption, making them suitable for application on spacecraft. However, there is currently a lack of experimental assessments on their space adaptability. Here, we study the radiation hardness of terahertz devices to determine their adaptability in complex space environments. We exposed GaAs SBDs and terahertz multipliers as typical terahertz devices to gamma rays and protons. The experimental results showed that the terahertz devices exhibited good tolerance to protons, but prolonged exposure to gamma rays could significantly increase the leakage current of the GaAs SBDs and alter its C-V characteristics, leading to the failure of the terahertz multiplier. Nevertheless, the terahertz devices maintained a good level of radiation hardness, making them highly suitable for use in Low Earth Orbit (LEO) satellites. The comparison between the results of proton and gamma ray tests indicated that the terahertz devices exhibited high inherent radiation hardness against displacement damage but were more sensitive to ionization damage, requiring higher shielding requirements. Terahertz technology holds tremendous potential for application in high-speed, high-capacity space communication missions, yet there currently exists a lack of research on the space adaptability of its key components. The authors have conducted radiation hardness testing of gallium arsenide terahertz devices through ground-based simulated irradiation experiments. [ABSTRACT FROM AUTHOR]

Starch is an important and abundant macromolecule which has a wide application in food, textile, pharmaceuticals, etc. Due to this, a novel characteristic of the starch is necessary compared to native starch which has limited application due to high shear stress, digestibility, strong hydrophobicity, low thermal stability, mechanical strength, as well as high retrogradation and syneresis. These limitations can be overcome through starch modification. However, most starch modifications are not environmentally and energy‐sustainable while some chemical methods have led to the release of hazardous substances into the environment. To surmount these challenges, there is a need for sustainable methods of starch modification to bring about desirable properties. Therefore, this article reviews critically some sustainable technologies such as pulsed electric field, cold plasma treatment, ultrasonication, microwave, gamma radiation, and dynamic pressure used in starch modification. Their effects on the physicochemical and functional properties of starch such as crystallinity, granular, and molecular structures are reviewed. Applications of the starch as affected by various sustainable techniques in various food and non‐food systems are also reviewed. In general, the sustainable techniques of starch modification improve the functionalities of the starch and help in meeting the ever‐increasing market for reliable food and industrial ingredients. [ABSTRACT FROM AUTHOR]

Background Purpose Methods Results Conclusion Light‐sharing detector designs for positron emission tomography (PET) systems have sparked interest in the scientific community. Particularly, (semi‐)monoliths show generally good performance characteristics regarding 2D positioning, energy‐, and timing resolution, as well as readout area. This is combined with intrinsic depth‐of‐interaction (DOI) capability to ensure a homogeneous spatial resolution across the entire field of view (FoV). However, complex positioning calibration processes limit their use in PET systems, especially in large‐scale clinical systems.This work proposes a new 3D positioning in‐system calibration method for fast and convenient (re‐)calibration and quality control of assembled PET scanners. The method targets all kinds of PET detectors that achieve the best performance with individual calibration, including complex segmented detector designs. The in‐system calibration method is evaluated and empirically compared to a state‐of‐the‐art fan‐beam calibration for a small‐diameter proof of concept (PoC) scanner. A simulation study evaluates the method's applicability to different scanner geometries.A PoC scanner geometry of 120 mm inner diameter and 150 mm axial extent was set up consisting of five identical finely segmented slab detectors (one detector under test and four collimation detectors). A 22Na point source was moved in a circular path inside the FoV. Utilizing virtual collimation and by selecting gamma rays incident approximately perpendicular to the detector normal of the detector under test, training data was created for the training of a 2D positioning model with the machine‐learning technique gradient tree boosting (GTB). Data with oblique ray angles was acquired in the same measurement for subsequent angular DOI calibration. For this, a 2D position estimate in the detector under test was calculated first. On this basis, the DOI label was calculated geometrically from the ray path within the detector to finally establish up to 3D training data.With a mean absolute error (MAE) of 0.8  and 1.19 mm full‐width at half maximum (FWHM) along the planar‐monolithic slab dimension, the in‐system methods performed similarly within 1% to the fan‐beam collimator results. The DOI performance was at ∼90% with 1.13 mm MAE and 2.47 mm FWHM to the fan‐beam collimator. Analytical calculations suggest an improved performance for larger scanner geometries.The functionality of the 3D in‐system positioning calibration method was successfully demonstrated with the measurements within a PoC scanner configuration with similar positioning performance as the bench‐top fan‐beam setup. The in‐system calibration method can be used to calibrate and test fully assembled PET systems to enable more complex light‐sharing detector architectures in, for example, large PET systems with many detectors. The acquired data can further be used for more complex energy and time calibrations. [ABSTRACT FROM AUTHOR]

The primary interactions of polypropylene (PP), poly(vinyl acetate) (PVA), ethylene‐vinyl acetate (EVA), polyvinyl chloride (PVC), polychloroprene (CR) and polyurethane (PUR) polymers preferred in the nuclear industry with gamma and neutron radiations, secondary radiations formed after neutron interactions and damages given to polymers by these ionizing radiations are investigated. The gamma interaction parameters Were determined in the photon energy range of 0.03‐20 MeV using WinXCOM, GEANT4 and FLUKA methods. Also, energy absorption and exposure buildup factors and Kerma parameters are calculated at different photon energies. To investigate the interactions of the studied polymers with neutron, the effective removal cross‐section for fast neutrons with theoretical and the partial neutron rates passing through the studied polymer at 4.5 MeV, 100 eV and 0.025 eV energies are determined with simulation codes. The numbers of secondary gamma‐rays and neutrons Were obtained with GEANT4. The Total Ionizing Dose and Displacements per Atom parameters are studied with the help of FLUKA simulation. It is observed that the interaction of PVC polymer with gamma radiation and PP polymer with neutron particles is higher than the others. The secondary radiation from PVC and CR is less. The PP, PVA, and EVA exhibit superior resistance to radiation damage. [ABSTRACT FROM AUTHOR]

This paper introduces a new probability distribution called the mixture symmetric gamma (MSG) distribution, which is defined as a mixture of two symmetric gamma distributions. Its statistical properties and applications are explored. We first examine its mathematical properties, including the possible shapes of the corresponding probability density function, as well as the moments, and the moment‐generating function. We then look at parameter estimation using various frequentist and Bayesian methods, such as moment estimation, maximum likelihood method, least‐squares method, and Bayesian approaches. In addition, the prediction of future observations under the MSG model is extensively covered, considering both frequentist and Bayesian perspectives, including median prediction, best unbiased prediction, and Bayesian prediction. A comprehensive simulation study is conducted to evaluate the performance of the proposed estimation and prediction techniques. Finally, the practical applicability of the MSG model is demonstrated through the analysis of four real‐world datasets. It is shown to outperform several well‐known competing models in terms of goodness‐of‐fit. The results highlight the inherent simplicity, efficiency, robustness, and intuitive interpretability of the MSG distribution, making it a compelling choice for modeling data with a symmetric pattern, with potential applications in diverse domains. [ABSTRACT FROM AUTHOR]

This paper reports on the development of a method for enhanced non-destructive assay (NDA) of radioactive waste using the novel technique neutron-gamma emission tomography (NGET). The technique relies on the detection of correlated fast neutrons and gamma rays emitted in spontaneous or induced fission. It is based on fast organic scintillators and enables sensitive detection and three-dimensional (3D) localization of the fission events. The technique is passive and does not require moving components. In this work, we apply the NGET technique to the category of radioactive waste which is often referred to as historic or legacy waste. This can include mixed wastes encased in shielded containers many decades ago, before the advent of detailed waste description criteria. These low or intermediate level wastes are often associated with lacking, limited or conflicting documentation. This poses a challenge when assigning the waste to the proper disposal route as well as in deciding whether the waste needs to undergo sorting and conditioning to fulfil waste acceptance criteria both with regards to safe interim storage and to its ultimate disposal. Actinides, such as isotopes of uranium and plutonium, with their typically long half-lives and decay chains are of special interest in this regard since they may challenge the long-term safety assessment in repositories predicated on mainly shorter half-life radionuclides if undetected. Accurate identification and localisation of actinides is also important from a safeguards perspective, especially since they are generally difficult to detect and localise by established passive means due to their relatively weak radiation emissions, in particular in shielded containments and in the presence of strong radiation fields from other radioactive materials. In this paper we present findings of measurements on shielded containments of long-lived radioactive waste performed at the Studsvik site in Sweden, as well as measurements on a laboratory assembly simulating a grouted waste drum. Similarities and differences between the novel NGET technique and a commercially available gamma imaging system are also briefly discussed. [ABSTRACT FROM AUTHOR]

Context. Solar eruptive events, including solar flares and coronal mass ejections (CMEs), are typically characterised by energetically significant X-ray emissions from flare-accelerated electrons and hot thermal plasmas. However, the intense brightness of solar flares often overshadows high-coronal X-ray emissions from the associated eruptions due to the limited dynamic range of current instrumentation. Occulted events, where the main flare is blocked by the solar limb, provide an opportunity to observe and analyse the X-ray emissions specifically associated with CMEs. Aims. This study investigates the X-ray and extreme ultraviolet (EUV) emissions associated with a large filament eruption and CME that occurred on February 15, 2022. This event was highly occulted from the three vantage points of Solar Orbiter (∼45° behind the limb), Solar–TErrestrial RElations Observatory (STEREO-A), and Earth. Methods. We utilised X-ray observations from the Spectrometer/Telescope for Imaging X-rays (STIX) and EUV observations from the Full Sun Imager (FSI) of the Extreme Ultraviolet Imager (EUI) on board Solar Orbiter, supplemented by multi-viewpoint observations from STEREO-A/Extreme-UltraViolet Imager (EUVI). This enabled a comprehensive analysis of the X-ray emissions in relation to the filament structure observed in the EUV. We used STIX's imaging and spectroscopy capabilities to characterise the X-ray source associated with the eruption. Results. Our analysis reveals that the X-ray emissions associated with the occulted eruption originate from an altitude exceeding 0.3 R⊙ above the main flare site. The X-ray time profile shows a sharp increase and exponential decay, and consists of both a hot thermal component at 17 ± 2 MK and non-thermal emissions (> 11.4 ± 0.2 keV) characterised by an electron spectral index of 3.9 ± 0.2. Imaging analysis shows an extended X-ray source that coincides with the EUV emission as observed from EUI, and was imaged until the source grew to a size exceeding the STIX imaging limit (180″). Conclusions. Filament eruptions and associated CMEs have hot and non-thermal components, and the associated X-ray emissions are energetically significant. Our findings demonstrate that STIX combined with EUI provides a unique and powerful tool for examining the energetic properties of the CME component of solar energetic eruptions. Multi-viewpoint and multi-instrument observations are crucial for revealing such energetically significant sources in solar eruptions that might otherwise remain obscured. [ABSTRACT FROM AUTHOR]

Diketone derivatives have significant medicinal actions, in particular their anti-cancer properties. In the present investigations, gamma and neutron interaction parameters such as MAC, Zeff, Zeq, EABF, and EBF of the diketone derivaties such as DKD1 (C17H10O5), DKD2 (C27H23NO4), DKD3 (C41H43NO4), DKD4 (C33H48O2), DKD5 (C30H34O2), and DKD6 (C32H35NO2) were studied using EpiXS and NGCal software. The EBF and EABF increase with increasing MFP values, shifting the peak position from a lower to a higher energy region. The results suggest that diketone derivatives such as DKD1 have good gamma absorption and DKD4 have good neutron absorption samples. [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]

Study of gamma-backscattered peaks is important for the estimation of composition, density, defects and thickness of the scattering materials. In the present study, gamma rays from a point source of 137Cs were scattered onto materials of different atomic numbers and NaI(Tl) scintillator detector was used for collection of backscattered events. It is observed that the area under the backscattering peak is dissimilar for materials of different atomic numbers with variable thickness. Simulation of the experiment was carried out using GEANT4 for the validation of the experimental findings. [ABSTRACT FROM AUTHOR]

Stellar evolution theory predicts that the Sun was fainter in the past, which can pose difficulties for understanding Earth's climate history. One proposed solution to this Faint Young Sun (FYS) problem is a more luminous Sun in the past. In this paper, we address the robustness of the solar luminosity history using the yrec code to compute solar models including rotation, magnetized winds, and the associated mass-loss. We present detailed solar models, including their evolutionary history, which are in excellent agreement with solar observables. Consistent with prior standard models, we infer a high solar metal content. We provide predicted X-ray luminosities and rotation histories for usage in climate reconstructions and activity studies. We find that the Sun's luminosity deviates from the standard solar model trajectory by at most 0.5 per cent during the Archean (corresponding to a radiative forcing of 0.849 W m |$^{-2}$|⁠). The total mass-loss experienced by solar models is modest because of strong feedback between mass and angular momentum loss. We find a maximum mass-loss of |$1.35 \times 10^{-3} \,{\rm M}_\odot$| since birth, at or below the level predicted by empirical estimates. The associated maximum luminosity increase falls well short of the level necessary to solve the FYS problem. We present compilations of paleotemperature and CO |$_2$| reconstructions. One-dimensional 'inverse' climate models demonstrate a mismatch between the solar constant needed to reach high temperatures (e.g. 60–80 |$^{\circ }$| C) and the narrow range of plausible solar luminosities determined in this study. Maintaining a temperate Earth, however, is plausible given these conditions. [ABSTRACT FROM AUTHOR]

Aluminum‐dependent stoppage of root growth requires the DNA damage response (DDR) pathway including the p53‐like transcription factor SUPPRESSOR OF GAMMA RADIATION 1 (SOG1), which promotes terminal differentiation of the root tip in response to Al dependent cell death. Transcriptomic analyses identified Al‐induced SOG1‐regulated targets as candidate mediators of this growth arrest. Analysis of these factors either as loss‐of‐function mutants or by overexpression in the als3‐1 background shows ERF115, which is a key transcription factor that in other scenarios is rate‐limiting for damaged stem cell replenishment, instead participates in transition from an actively growing root to one that has terminally differentiated in response to Al toxicity. This is supported by a loss‐of‐function erf115 mutant raising the threshold of Al required to promote terminal differentiation of Al hypersensitive als3‐1. Consistent with its key role in stoppage of root growth, a putative ERF115 barley ortholog is also upregulated following Al exposure, suggesting a conserved role for this ATR‐dependent pathway in Al response. In contrast to other DNA damage agents, these results show that ERF115 and likely related family members are important determinants of terminal differentiation of the root tip following Al exposure and central outputs of the SOG1‐mediated pathway in Al response. Summary Statement: Aluminum dependent stoppage of root growth in Arabidopsis thaliana requires a SUPPRESSOR OF GAMMA RADIATION 1 controlled transcriptional program that includes ERF115 and family members. Loss of ERF114 and ERF115 results in prevention of the severe response to Al normally seen in the Al hyperresponsive mutant als3‐1. [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA) is a widely used biopolymer and is currently produced on a global scale. However, PLA has low melt strength, which limits its application. Poly(butylene adipate-co-terephthalate) (PBAT) is a fully biodegradable polymer and one of the most attractive polymers for hardening PLA. As PLA and PBAT are immiscible, they need to be compatibilized to improve the properties of the blend. In this context, the compatibilization of PLA/PBAT blends was investigated through an irradiation process. PLA was previously irradiated, at different absorbed doses, in a cobalt-60 source to assess the compatibility of its blends with PBAT. Differential scanning calorimetry showed a reduction in the glass transition, cold crystallization and melting temperatures, and a second melting peak was observed after polymer irradiation. Also, X-ray diffraction analyses revealed a slight increase in the crystalline fraction. Thermogravimetric analysis showed that as the absorbed dose increased, the thermal stability of PLA decreased. Fourier-transform infrared spectroscopy shows bands attributed to oxidized terminations of polymer chains with carbonyls attributed to the effect of irradiation exposure. For samples irradiated above 100 kGy, an increase in tensile strength and tensile modulus can be observed as the dose increases. Rheological measurements showed a decrease in the complex viscosity of irradiated PLA with increasing absorbed dose. The surface of the polymer blend with PLA irradiated with gamma rays at 150 kGy appears to be more homogeneous according to scanning electron analysis. The polymer blend with 150 kGy irradiated PLA showed improved interaction between the components. [ABSTRACT FROM AUTHOR]

This study compares the accuracy, efficiency, and reliability of variance reduction (VR) methods for Monte Carlo radiation transport simulations involving wide-area ground plane (i.e., "surface") and buried (i.e., "volumetric") gamma source emissions from environmental soil. The simulation models are idealized external exposure scenarios intended as a basis for deriving site-specific dose-based or carcinogenic risk–based regulatory limits in the radiological site remediation process. These simulations are computationally resource intensive since particle tracks are transported from an extremely large source region to a relatively small detector region. For each simulation, several VR methods are compared with metrics of accuracy, efficiency, and reliability. The MCNP deterministic transport (DXTRAN) VR method was most effective for problems involving sources emitting low-energy gamma rays, and a coupled multicode method was more effective for problems involving sources emitting higher-energy gamma rays that undergo significant attenuation in the soil. [ABSTRACT FROM AUTHOR]

Concrete is the favored construction material, with more than 7 billion cubic meters manufactured annually. Aggregates constitute the crucial component of its structure and quality, responsible for its exceptional characteristic features. The characteristics of aggregates determine the mechanical durability and radiation performance of concrete. In this investigation, fabricated concrete specimens were generated by replacing sand and aggregate sizes with pyrophyllite in 10%–20%–30%–100% proportions. The study investigated the mechanical properties of concrete specimens using both pressure and ultrasound methods, as well as their durability under freeze–thaw and high-temperature (200°C–1,000°C) conditions. In addition, the microstructure and radiation permeability properties were examined over a 7–28–90-day period. Notably, the use of pyrophyllite sand and aggregate significantly increased the compressive strength of the specimens by 21%–63% when compared to the reference concrete after 7–28–90 days, while also reducing mass loss by up to 4.6% during freeze–thaw cycles. After subjecting the specimens to high temperatures, it was discovered that those with an air-cooling regime achieved a compressive value 45% higher than the reference concrete. Microstructure images revealed the formation of C─ S─ H, CH, and portlandite hydration products over 90 days, supporting the observed compressive strength values. The study also has an effective linear attenuation coefficient (LAC) for radiation-shielding properties. According to some radiation-shielding parameters calculated through LAC values, it was revealed that these concrete samples were suitable shielding materials. Pyrophyllite-reinforced specimens have demonstrated potential for high-strength concrete production, suitability for use in high-temperature environments, and effectiveness as shielding in areas with radiation sources. [ABSTRACT FROM AUTHOR]

Aims: This pilot study aimed to compare the marginal adaptation of composite resin at the tooth-restoration interface, before and after radiation. Subjects and Methods: Fifteen extracted premolars were divided into 2 experimental groups (based on the timing of irradiation) and 1 control group of 5 teeth each. In Group I (control group), teeth were restored but not exposed to radiation at any stage, Group II: teeth were irradiated before cavity preparation and restoration, and Group III: after cavity preparation and restoration employing selective etch technique, teeth were exposed to radiation. The samples were then sectioned buccolingually to analyze the extent of the marginal gap under scanning electron microscopy and compositional alteration of dental hard tissues by X-ray diffraction study. The data collected were analyzed statistically. Statistical Analysis Used: The statistical software used was IBM SPSS version 23 New York, USA, and analysis was done using two-way ANOVA followed by Turkey's post hoc test, this difference in the mean marginal gap between all three groups was nonsignificant (P ≥ 0.05). Results: In the control group (Group I), a minimum gap (4.203 µm ± 0.533) was observed at the tooth-restoration interface, indicating the highest level of adaptation as compared to Group II (5.816 µm ± 0.762) and Group III (4.862 µm ± 1.018). This suggests that radiation adversely affected the bonding between composite materials and both enamel and dentin, attributed to the alterations induced by radiotherapy in the chemical, physical, and morphological properties of both tooth structure and composite resin. Conclusions: Ionizing radiations adversely affect the bonding between enamel, dentin, and composite resin. Hence, restorative procedures should be performed before undergoing radiotherapy. [ABSTRACT FROM AUTHOR]

Despite the therapeutic advances in treating malignancies, the efficient radiotherapeutic approaches with deprived adverse reactions still represent a potential clinical inquiry. The current study aims to elucidate the role of gallic acid (GA) in modifying the hazardous renal cytotoxicity induced by acute exposure to radiation. The MTT test was used to evaluate the viability of Vero cells exposed to 2 Gy gamma radiation with or without incubation of GA. In an in vivo model, male Wistar rats were divided into four experimental groups (n = 6): Control, Irradiated (IRR, 5 Gy), GA (100 mg/kg, i.p.) + IRR, and Glycogen synthase kinase inhibitor (GSKI, 3 mg/kg, i.p.) + IRR. Based on the MTT toxicity assay, from 0 and up to 5 μM dosages of GA did not demonstrate any cytotoxicity to Vero cells. The optimal GA dose that could protect the cells from radiation was 5 μM. Furthermore, GA exerted a protective effect from gamma radiation on renal tissue as indicated by corrected renal functions, decreased LDH level in serum, and balanced oxidative status, which is indicated by decreased tissue contents of NOx and TBARS with a significant increase of reduced GSH. These outcomes were inferred by the upregulation of nuclear factor erythroid 2‐related factor 2 (Nrf2) expression. The overall molecular impact of radiation in damaging the renal tissue may be explained by modifying the upstream AKT activity and its downstream targets GSK‐3β/Notch‐1. Here, we concluded that the anticipated adverse reaction in the course of radiation exposure could be protected by daily administration of GA. [ABSTRACT FROM AUTHOR]

The current study aims to synthesize of poly-methyl methacrylate (PMMA)-polyethylene glycol (PEG) doped with tin oxide (SnO2) and silicon carbide (SiC) nanostructures for gamma ray attenuation and photonics applications. The microstructure and optical characteristics of PMMA-PEG-SnO2-SiC nanostructures were studied. The obtained results indicated that the PMMA-PEG absorbance increased of 69.6% and the transmittance decreased of 46% when the SnO2/SiC NPs ratio rise to 4.8 wt%. The PMMA-PEG's energy gap (Eg) decreased to 3.95 eV when the SnO2/SiC NPs ratio reached of 4.8 wt%. The optical constants (coefficient of absorption (α), index of refractive (n), coefficient of extinction (k), real (ε1) and imaginary (ε2) parts of dielectric constants, and conductivity of optical (σop) were increased of 69.6%, 22.1%, 69.6%, 39.4%, 76.3, and 76.3%, respectively, when SnO2/SiC NPs reached of 4.8 wt% at wavelength (λ = 540 nm). These results make the PMMA-PEG-SnO2-SiC nanostructures are appropriate for optical and electronic applications. Finally, the gamma radiation attenuation coefficients were increased with rising nanoparticles concentrations. The (PMMA-PEG-SnO2-SiC) nanostructures have highest attenuation coefficients for gamma radiation. [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]

Background: Neutron beams utilized for performing BNCT are composed of a mixture of neutrons and gamma rays. Although much of the dose delivered to the cancer cells comes from the high LET particles produced by the boron neutron capture reaction, the dose delivered to the healthy tissues from unwanted gamma rays cannot be ignored. With the increase in the number of accelerators for BNCT, a detector system that is capable of measuring gamma ray dose in a mixed neutron/gamma irradiation field is crucial. Currently, BeO TLDs encased in quartz glass are used to measure gamma ray dose in a BNCT irradiation field. However, this type of TLD is no longer commercially available. A replacement dosimetry system is required to perform the recommended ongoing quality assurance of gamma ray measurement for a clinical BNCT system. Purpose: The purpose of this study is to evaluate the characteristics of a BeO OSLD detector system under a mixed neutron and gamma ray irradiation field and to assess the suitability of the system for routine quality assurance measurements of an accelerator‐based BNCT facility. Methods: The myOSLD system by RadPro International GmbH was evaluated using the accelerator‐based neutron source designed for clinical BNCT (NeuCure BNCT system). The readout constancy, linearity, dose rate effect, and fading effect of the OSLD were evaluated. Free‐in‐air and water phantom measurements were performed and compared with the TLD results and Monte Carlo simulation results. The PHITS Monte Carlo code was used for this study. Results: The readout constancy was found to be stable over a month‐long period and similar to the TLD results. The OSLD readout signal was found to be linear, with a high coefficient of determination (R2 ≥ 0.999) up to a proton charge of 3.6 C. There was no significant signal fading or dose rate dependency. The central axis depth dose and off‐axis dose profile measurements agreed with both the TLD and Monte Carlo simulation results, within one standard deviation. Conclusion: The myOSLD system was characterized using an accelerator system designed for clinical BNCT. The experimental measurements confirmed the OSLD achieved similar, if not superior to, the currently utilized dosimetry system for routine QA of an accelerator‐based BNCT system. The OSLD system would be a suitable replacement for the current TLD system for performing routine QA of gamma ray dose measurement in a BNCT irradiation field. [ABSTRACT FROM AUTHOR]

Upward Terrestrial Gamma‐Ray Flashes (TGFs) are mainly produced during the upward propagating negative leaders inside thunderclouds. The exact source position of TGFs, which is crucial to understanding TGF source properties, is still unclear. The link between positive energetic in‐cloud pulses (+EIPs) and TGFs provides us with a potential target to aim at. In this study, the low‐frequency radio emissions of 75 +EIPs are analyzed to retrieve the source altitudes with an improved ray theory model. Furthermore, the meteorology contexts of +EIPs derived from the ground‐based weather radars and satellite‐based infrared cloud top temperature measurements are investigated. +EIPs are produced at 8.8–13.7 km, with an average of 11.3 km inside thunderclouds, and at an average of ∼2.5 km below cloud tops. These altitudes indicate that a total number of 1.7 × 1016 to 2.6 × 1018 gamma ray photons with energy greater than 1 MeV are required for an EIP‐TGF to be measured by spaceborne detectors. Plain Language Summary: Terrestrial gamma‐ray flashes (TGFs) are high‐energy photon emissions generated during thunderstorms and related to the initial development of intra‐cloud discharges. How TGFs are produced inside thunderclouds is still an open question, and one crucial issue is where TGFs are produced. Till now, it has been challenging to obtain the TGF positions directly. Recently, a distinct type of high‐peak current events, which are named energetic in‐cloud pulses (EIPs), are found to be closely linked to TGFs. The radio emissions of EIPs can be measured by ground‐based radio sensors deployed hundreds of kilometers away from the source. In this study, a ray theory model is improved to retrieve the signature of very low‐frequency/low‐frequency radio signals of EIPs propagating in the Earth‐ionosphere waveguide to obtain the source altitudes of EIPs. A total of 75 EIPs were found to be produced at 8.8–13.7 km, with an average of 11.3 km inside thunderclouds, and at an average of ∼2.5 km below cloud tops. With the source position information and combining the previously reported method to estimate the total number of source electrons, we suggest a total number of about 1017 is needed for TGFs being detected by spaceborne gamma ray detectors. Key Points: An improved ray theory model is developed to retrieve energetic in‐cloud pulse (EIP) positionsSeventy‐five +EIPs are located at 8.8–13.7 km, with a mean altitude of 11.3 kmA mean gap of ∼2.5 km between EIPs and cloud tops was estimated [ABSTRACT FROM AUTHOR]

AbstractPurposeMaterials and methodsResultsConclusionsSwiss Cheese (Monstera adansonii) is an ornamental plant valued for its exotic leaves with openings and for the variety of colors. The technique of controlled exposure to gamma radiation was investigated to induce variegation (color change) in the leaves of this plant.Monstera adansonii cuttings were irradiated with different doses of radiation with 60Co gamma rays (0, 1, 5, 10, 15, and 20 Gy) and evaluated for size, color, health, and growth.Cuttings irradiated with 1 and 5 Gy exhibited temporary variegation in leaf color, but did not maintain these characteristics over time. Cuttings with higher doses of radiation (10, 15, and 20 Gy) did not survive well and showed a reduction in growth, number of leaves, health, and sprouting rate.This research concludes that gamma radiation can affect the development of cuttings and shows the potential to induce variegation at lower doses, but more studies and prolonged observation are needed to determine whether this technique can produce variegation in a consistent and lasting way in M. adansonii. Therefore, although promising initial results have been observed, it is premature to state that gamma radiation is an effective method for inducing variegation in this plant. [ABSTRACT FROM AUTHOR]

For energy storage applications, attaining high dielectric permittivity as well as low loss factor is the foremost target. This could be accomplished via filling polymer matrices with inorganic filler which is characterized by relatively high dielectric permittivity. In the present study, polyvinyl butyral (PVB) was used as a matrix material for preparing nanocomposite films filled with different weight fractions (2, 5, 10, and 15%) of barium titanate (BaTiO3) using the casting approach. The results show that BaTiO3 (BT) is well incorporated inside the PVB matrix. Although the dielectric permittivity has been decreased from 3.61 to 2.41 at 1 kHz upon filling the PVB matrix with 5 wt. % of BT, the PVB-BT-NPs-5 nanocomposite film shows the lowest loss factor ~ 0.0049, nearly half that for PVB, 0.0092, which implies the increased film ability to keep its stored energy. The PVB-BT-NPs-5 has been irradiated with gamma radiation to investigate its impact on the structure beside its dielectric and thermal properties. The crystallite size of BT has been decreased from 20.64 to 17.77 nm as PVB-BT-NPs-5 nanocomposite film has been irradiated at a dose of 0.5 kGy. The dielectric permittivity has been decreased from 2.41 to 2.37 at 1 kHz, whereas an increase from 0.0049 to 0.0073 in the loss factor is observed. Furthermore, the thermal stability has been decreased due to the deformation induced by gamma rays inside the nanocomposite films. Therefore, these nanocomposite films could be better exploited in energy storage applications in its un-irradiated form. [ABSTRACT FROM AUTHOR]

In the field of nuclear medicine, various radiopharmaceuticals require wideband x-ray/gamma-ray imaging devices for clinical and treatment monitoring. Compton cameras, which perform imaging using high-energy gamma rays, have the potential to significantly increase the variety of radioactive nuclides that can be imaged. However, artifacts caused by the so-called "Compton cone" have hindered their clinical use. Therefore, we propose the use of a collimator to improve the contrast of images obtained using Compton cameras. In this study, we developed a high-contrast Compton camera by attaching a tungsten collimator to its front surface. The contrast is improved by applying weighting to the signals based on the distance that the high-energy gamma rays penetrated the collimator walls. As a demonstration, we visualized 198 Au plates that emit 412-keV gamma rays with and without the collimator. In addition, low-energy (<200 keV) x-ray/gamma-ray imaging, which is difficult for conventional Compton cameras, was achieved by performing single-photon emission computed tomography (SPECT) using the collimator and scatterer of the Compton camera. We demonstrated broadband gamma-ray imaging by visualizing a 133 Ba standard source using 81-keV and 356-keV gamma rays based on the principles of SPECT and Compton cameras, respectively. [ABSTRACT FROM AUTHOR]

A successful attempt to produce a multi-function glass shield for attenuating neutrons and gamma rays by reinforcing a silicate glass network with boron and bismuth has been accomplished. A composition of 20SiO2-80Na2O (BSiBi0) was proposed to be used as a host glass network and prepared using the melt/annealing techniques. The low concentration of SiO2 in BSiBi0 was not sufficient to form a stable glass network. Then, the proposed BSiBi0 was modified with 10, 20, 30, and 40 mol% of each of B2O3 and Bi2O3 (BSiBi1, BSiBi2, BSiBi3, and BSiBi4) simultaneously. The structural effects of adding B3+ and Bi3+ were studied through X-ray diffraction, density, and FTIR, which all showed enhancement of glass forming ability, a former role of Bi3+ ions, and crowded the glass network by BO4 units. The derived structural parameters - molar volume, mean silicon – silicon separation, mean boron – boron separation, oxygen packing density, packing density, and number of bridging/non-bridging oxygen - were extensively discussed to explore the impact of B3+ and Bi3+ on the formed network. The richness of the proposed host glass network by B3+ and Bi3+ enhanced its thermal stability. The obtained elastic properties by ultrasonic measurements reflect the increase of the glass rigidity with increasing concentrations of B3+ and Bi3+ ions. The obtained glasses have high visible light transparency and almost complete UV absorption. The measured shielding parameters against two types of neutron energies (total slow and slow) and a wide range of gamma rays' energies showed a significant improvement in the shielding efficiency of the considered glasses. The total slow neutrons, slow neutrons, and gamma rays' attenuation abilities were improved by 22.9, 135.5, and 73.8 - 199.5%. High thermal stability, elasticity, visible light transparency, and neutrons and gamma rays' attenuation performance features give the produced glasses, especially BSiBi4 glass, preference as shielding materials in nuclear fields. [ABSTRACT FROM AUTHOR]

Background: While gamma irradiation's damaging biological effects are well-established, the natural radioprotective agents from agricultural waste remain an underexplored area of significant potential. Aim of study: This study was to investigate the novel use of pomegranate peel ethanol extract (PE) as a radioprotective agent against gamma radiation damage. Methods: We pretreated Wistar rats with PE (100 mg/kg) for 14 days prior to 6 Gy gamma irradiation. We analyzed blood biochemicals, oxidative stress, and inflammatory markers. These included tests of red cell membrane integrity, lipid and protein oxidation, antioxidant enzyme levels, and cytokine profiles. Results: The study showed that PE demonstrated remarkable radioprotective effects across multiple parameters. Antioxidants were significantly enhanced, as evidenced by increased glutathione peroxidase activity (87.00 ± 6.11 mg/ml in PE-treated irradiated rats compared to 26.40 ± 1.21 mg/ml in irradiated controls). Oxidative damage was markedly reduced, with MDA levels dropping from 9.59 ± 0.24 nmol/ml in irradiated controls to near-control levels in PE-treated rats. Notably, PE treatment resulted in unprecedented maintenance of red blood cell membrane integrity post-irradiation. Furthermore, PE exhibited novel modulation of inflammatory cytokines, effectively reducing pro-inflammatory markers IL-6 and TNF-α while simultaneously boosting anti-inflammatory IL-4 and IL-10 levels. These multifaceted protective effects highlight PE's potential as a comprehensive radioprotective agent. Conclusion: This study presents PE as an effective new natural radioprotective agent. Its protective effect is due to its high polyphenol content, which enhances antioxidant defenses, reduces oxidative damage, and prevents inflammation. The findings open new avenues for sustainable, cost-effective radioprotection strategies and demonstrate the potential for repurposing agricultural byproducts for critical health applications. [ABSTRACT FROM AUTHOR]

Featured Application: This research presents a novel image reconstruction method for Boron Neutron Capture Therapy (BNCT)-Single Photon Emission Computed Tomography (SPECT) using Bayesian estimation with limited view-angle projection data. The method aims to address the inherent challenges in BNCT-SPECT imaging where conventional algorithms struggle with incomplete data from restricted projection angles. By improving the image accuracy under such conditions, this technique has potential applications in clinical settings, where accurate tumor localization and dose distribution are critical for the success of BNCT treatments. This method could lead to enhanced treatment planning and monitoring, ultimately improving patient outcomes. Boron Neutron Capture Therapy (BNCT) is an emerging radiation treatment for cancer, and its challenges are being explored. Systems capable of capturing real-time observations of this treatment's effectiveness, particularly BNCT-SPECT methods that measure gamma rays emitted instantaneously from outside the body during nuclear reactions and that reconstruct images using Single Photon Emission Computed Tomography (SPECT) techniques, remain unavailable. BNCT-SPECT development is hindered by two main factors, the first being the projection angle. Unlike conventional SPECT, the projection angle range which is achievable by rotating a detector array cannot exceed approximately 90 degrees. Consequently, Fourier-based image reconstruction methods, requiring projections from at least 180 degrees, do not apply to BNCT-SPECT. The second limitation is the measurement time. Given these challenges, we developed a new sequential approximation image reconstruction method using Bayesian estimation, which is effective under the stringent BNCT-SPECT conditions. We also compared the proposed method with the existing Maximum Likelihood-Expectation Maximization (ML-EM) image reconstruction method. Numerical experiments were conducted by obtaining BNCT-SPECT projection data from true images and reconstructing images using both the proposed and ML-EM methods from the resulting sinograms. Performance comparisons were conducted using a dedicated program applying Bayesian estimation and this showed promise as a new image reconstruction method useful under BNCT-SPECT conditions. [ABSTRACT FROM AUTHOR]

Radiation-shielding is essential in fields involving storage and transport of radiation active material, such as medicine and nuclear engineering. The risk of radiation spill is a source of constant concern with its potential impact on local environment and life. Radiation spills that occur in laboratory are considered minor and containment of radiations in such cases using conventional techniques is not practical. Current practice involves using a suitable chemical absorbent, cleaning the spill region using agents and requires monitoring the spill region regularly for activity. Although this technique is effective in managing minor/laboratory grade spills, it requires careful application and constant monitoring before the area can be deemed safe for work. In this paper, we provide a detailed review of the radiation-shielding properties of polymer nanocomposites and their fabrication. The paper outlines radiation-shielding mechanisms, measurement of radiation attenuation, and factors that influence radiation attenuation. The review also compares analytical attenuation measurement methods against experimental methods. This review would be helpful in not only understanding the underlying energy transfer mechanism, but also aid in exploring polymer nano-composite materials as a viable green option for containing medium to low-level radiation spills. [ABSTRACT FROM AUTHOR]

We conducted a phase‐wise study to evaluate the efficacy of the gamma ray‐produced oligosaccharides of alginate and chitosan in enhancing the yield in rice. Initially, we irradiated the dry powder of alginate and chitosan with 200–500 kGy dose of gamma ray to produce their oligosaccharides. Subsequently, we assessed efficiency of the aqueous solution (50–400 ppm) of these oligosaccharides to stimulate the growth in rice seedling. The elicitors which stimulated the seedling growth were later tested in the field for their ability to enhance the growth and yield in rice under six different treatment regimens. In the next two seasons we evaluated the elicitor and treatment regimen, which enhanced the yield and yield contributing factors, at a larger scale. The observations suggest that 200 ppm of alginate oligosaccharide (28.1 kDa) produced by 500 kGy of gamma ray enhances the yield in rice by 13% and improves the seed quality when sprayed during seedling, pre‐flowering and grain‐filling stages. Such treatment improves the overall growth and development of the plant, which probably enhances the yield and grain quality of the produce. [ABSTRACT FROM AUTHOR]

Natural fiber composites are a renewable and environmentally friendly alternative to conventional synthetic materials that combine the biodegradability and essential durability of natural fibers with adaptability. Improved adhesion between fibers and matrix can be accomplished by comparing surface treatments applied to sugarcane, water hyacinth, and banana plant wastes. This will allow us to produce composite materials that are more durable and sustainable. To study the mechanical and morphological characteristics of the composites, two surface treatments were applied: gamma radiation at a dose of 1, 2, 3, 4 and 5 kGy and alkali treatment at a concentration of 5, 10, and 15%. The study revealed that with the increasing treatment of alkali solution, improvements in the composite's mechanical characteristics whereas gamma irradiation treatment enhanced the mechanical properties to a certain extent (2 kGy) after that the mechanical traits dwindled significantly. SEM, XRD, and FTIR analysis of the developed composite samples also revealed the reasons for the improvements in mechanical properties after alkali and gamma radiation treatments. As an ecofriendly and lightweight substitute for conventional materials, bio epoxy composites reinforced with natural fibers can be used for car interior panels, eco‐friendly furniture and as a replacement for any plasticware offering eco‐sustainability for contemporary living space. Highlights: Natural fiber composites offer a renewable and eco‐friendly alternative to synthetic materials, combining biodegradability with durability.Surface treatments like gamma radiation and alkali treatment enhance composite's mechanical properties.Higher concentrations of alkali treatment improve mechanical characteristics, while gamma irradiation peaks at 2 kGy.Surface treatments offer promising avenues for advancing environmentally friendly materials, contributing to sustainable innovations in material science. [ABSTRACT FROM AUTHOR]

Passive dosimeters enabling accurate measurement of doses from gamma rays to visible light are necessary to ensure efficient utilization of electromagnetic radiation in numerous fields like medical diagnostics and industrial manufacturing. The specific requirements for dosimeters in terms of dosimetry range, sensitivity, accuracy, and stability for each application have led to the development of various dosimeters based on new materials and new mechanisms. Here, a comprehensive review of different types of dosimeters classified according to the response signal, namely electron paramagnetic resonance, electrical, and optical, is provided. This review starts with a general introduction to dosimetry, a classification of dosimeters, and an elucidation of the necessity of dosimeters in various ranges of the electromagnetic spectrum. This is followed by an overview of the fundamental requirements of dosimeters, an explanation of the general dosimetry procedure, and the dosimetric quantities. Emphasis is given to the working mechanism, the design concept, and applications of each type of dosimeter as well as their respective strengths and drawbacks. Challenges and prospects are presented at the end of the review. This review provides an insightful overview of the material‐mechanism‐characteristics‐application relationship of different types of dosimeters that hopefully can serve as inspiration for the development of new devices. [ABSTRACT FROM AUTHOR]

Background: MDU-1 is a high yielding, indeterminate cluster bean variety. In order to develop determinate mutant with high yield, MDU-1 cluster bean variety was irradiated using gamma rays, electron beam and combination of gamma rays and EMS with different doses and the variability induced in M5 generations were studied. Methods: Twenty one best individual plants from M4 generation were selected based on plant height and higher yield and forwarded to M5 generation where they were evaluated in RBD with three replications. Fourteen non-segregating mutant lines with desirable traits were identified in M5 generation and were evaluated for variability along with the parent MDU1. Result: Five best mutant lines namely ACMC-020-04, ACMC-020-11, ACMC-020-08, ACMC-020-10 and ACMC-020-11 were selected from the 14 accessions based on per se performance and variability analysis. The selected mutants needs to be forwarded for stability testing in different environments. [ABSTRACT FROM AUTHOR]

A novel polymeric composite was created using polyethylene polymers as the primary component, supplemented with varying weight proportions of micro-sized basalt rock powder. Basalt was incorporated into the base material at concentrations ranging from 20 to 40% by weight. The homogenous distributions of the basalt powder within the epoxy layers were affirmed using the scanning electron microscope (SEM) as well as the FTIR spectra for the fabricated composites were analyzed. The gamma-ray shielding properties for the fabricated composites were examined using the narrow beam transmission method on NaI (Tl) detector. The linear attenuation coefficient measurement shows an enhancement in the linear attenuation coefficient from 0.134 to 0.156 cm−1 by raising the basalt powder ratio from 0 to 40 wt%. These results were associated with an enhancement in the radiation shielding properties of the fabricated composites from 12.6 to 14.2% and the lead equivalent thickness reduced from 9.3to 8 cm by raising the basalt powder concentration from 0 to 40 wt%, respectively. Based on the findings, incorporating micro-sized basalt powder into the epoxy resin improves the gamma-ray shielding capabilities of the produced composites in comparison to various polymers documented in prior studies, especially E-B40. In terms of radiation protection, it can be inferred that E-B40 shows promising potential as a shielding material for gamma rays with low energy, offering increased protection with reduced thickness. [ABSTRACT FROM AUTHOR]

Accurate evaluation of total organic carbon (TOC) content and porosity is of paramount significance for assessment and target interval selection for shale reservoirs. This study takes shales from the western Chongqing area as an exemplary case to delve into the applicability and reliability of ensemble learning in evaluating TOC content and porosity. The results indicate that although both Light Gradient Boosting Machine (LightGBM) and Random Forest (RF) algorithms are suitable for evaluating TOC content and porosity in shales, LightGBM algorithm is preferred due to its comprehensive advantages, including higher accuracy, stronger generalization capability, and faster operating speed. For TOC content evaluation, the four most important logging parameters identified by LightGBM and RF are consistent, but exhibit different orders: DEN (compensated density) > GR (gamma ray) > U (uranium) > CNL (compensated neutron) and DEN > U > GR > CNL, respectively. For porosity evaluation, LightGBM and RF identify the same type and order of the three most important logging parameters: AC (acoustic transit time) > DEN > U. This similarity may be attributed to the fact that both algorithms utilize Classification and Regression Tree (CART) as base learners. The dependence plots between SHAP (SHapley Additive exPlanations) values and logging parameters reveal that the role of each logging parameter in the evaluation model is segmented, rather than exhibiting a continuous linear contribution. In conclusion, given the exceptional performance of ensemble learning algorithms, they, especially LightGBM algorithm, are highly recommended for shale evaluation. [ABSTRACT FROM AUTHOR]

The SPARC tokamak will have scrape-off layer parallel heat fluxes on the order of GW/m2. Managing power exhaust of this magnitude will be mandatory for a reactor-scale device. To enable this mission, a thermal diagnostic suite will be deployed to measure the in-vessel structural temperatures to ensure they do not exceed their design limits and to determine the spatial distribution and magnitude of energy deposited onto the first wall. Thermocouples and fiber Bragg gratings have been selected for their environmental compatibility and proven useful on other fusion devices. High-density thermocouple arrays in the divertor will have two spring-loaded thermocouples per divertor target tile, which are being used as calorimeters, and will look to resolve the temperature distribution within the tile due to a swept or static strike point. All systems will need to survive the vacuum vessel bake, set at a minimum plasma facing surface temperature of 350 °C, which presents a particularly challenging environment for the fiber-based subsystem. Along with this temperature design requirement, all the materials in the primary vacuum need to be ultra-high vacuum compatible, able to handle the expected neutron and gamma radiation, as well as tritium exposure, all of which restrict material options. Finally, due to the expected activated environment in SPARC, there will be little chance to replace defective sensors, so system resilience is ensured through toroidal redundancy, probe material selection, and mitigating the impact of common-mode failures. Initial testing of sensors show that intershot structural measurements are sufficiently captured with the raw output, but intrashot measurements of the plasma facing material requires model-based interpretive tools. [ABSTRACT FROM AUTHOR]