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A novel green fabrication approach is being proposed based on radiation assisted modification of Whatman filter paper 1 (WFP) for development of Acid Free-Paper based Analytical Devices (A f -PADs). A f -PADs exude immense potential as handy tools for on-site detection of toxic pollutants such as, Cr(VI), boron, etc., which have established detection protocols involving acid mediated colorimetric reactions that necessitate external acid addition. The proposed A f -PAD fabrication protocol asserts its novelty through elimination of external acid addition step, making the detection process safer and simpler. To achieve this, poly(acrylic acid) (PAA) was grafted onto WFP via a single step, room temperature process of gamma radiation induced simultaneous irradiation grafting, introducing acidic -COOH groups in the paper thereon. Grafting parameters namely, absorbed dose and concentrations of monomer, homopolymer inhibitor and acid were optimized. The -COOH groups incorporated in PAA-grafted-WFP (PAA- g -WFP) provide localized acidic conditions for colorimetric reactions between pollutants and their sensing agents, anchored on the PAA- g -WFP. A f -PADs loaded with 1,5-diphenylcarbazide (DPC) have been ably demonstrated for visual detection and quantitative estimation of Cr(VI) in water samples using RGB image analysis, with LOD value of 1.2 mg.L−1 and a measurement range comparable to that of commercially available PADs based Cr(VI) visual detection kits. [Display omitted] [ABSTRACT FROM AUTHOR]

• Water-damaged traditional Japanese paper was contaminated with mesophilic fungi. • The radiosensitivities of conidia, germinating conidia, and mycelia were determined. • Drought stress enhanced radiation sensitivity of germinating conidia and mycelia. • Even a radiation dose of 10 kGy affected the mechanical properties of paper. In this study, we investigated the effect of gamma irradiation on fungal growth and mechanical properties of the traditional Japanese paper, Kohzo-gami, infected by mesophilic fungi such as Aspergillus sydowii , Penicillium chrysogenum , and Cladosporium cladosporioides. The radiation sensitivities of dormant conidium-, germinating conidium-, and mycelium-contaminated wet and dry paper were also determined. A radiation dose capable of inactivating 50% of a 30-sample population was used for comparison. Our results showed that the 50% inactivation dose did not significantly differ between wet and dry dormant conidia. However, the survival percentage of dry dormant conidia was higher than that of wet dormant conidia at a high radiation dose. In contrast, the 50% inactivation doses for dry germinating conidia and dry mycelia were significantly lower than those for wet germinating conidia and wet mycelia, respectively. These results indicate that drought stress increased the radiation sensitivity of germinating conidia and mycelia. We also investigated the mechanical properties of Kohzo-gami irradiated at different doses. The order of the tensile strength of Kohzo-gami relative to that of control samples was as follows: 10 kGy > 30 kGy > 40 kGy. This result suggests that even a 10 kGy radiation dose can affect the mechanical properties of paper. The color change level of Kohzo-gami increased significantly at all doses; however, the National Bureau of Standards rating showed only "slight change" at all doses. The radiation doses required for fungal disinfection varied considerably depending on the fungal species and the total number of fungal cells on contaminated paper. Therefore, it was difficult to determine the standard exposure dose for treatment. However, paper sterilization might not be required, as a combination of low-dose radiation and dryness can effectively kill fungal mycelia on contaminated paper. [ABSTRACT FROM AUTHOR]

Several kinds of paper (Bond, Amate, Rice, Press, and Whatman#1) were studied in their original condition and were then exposed to gamma radiation between 3 and 15 kGy (0.9 kGy/h) with intervals of 3 kGy. The length and width of fibers (SEM) as well as pH were measured, and the chemical composition was determined by EDS. Pyrolysis characteristics (TGA and DTC), transmittance spectra by IR and X-ray diffraction patterns were studied as well. Whatman#1 contains only cellulose; whereas Bond, Press and Rice papers also contain calcite and Amate whewellite. All X-ray diffraction patterns showed Type I semicrystalline cellulose, but a slight presence of Type II was noted in the artisan papers (Amate and Rice). These results were confirmed by IR spectra and thermogravimetric analyses. Due to gamma irradiation no acidification nor change of fiber sizes or alteration of other studied parameters were observed. Therefore, these conditions may be recommended for the treatment of some deteriorated documents. [ABSTRACT FROM AUTHOR]

Even though gamma radiation application, also at the minimum dosage required for disinfection, causes depolymerization and degradation of the paper substrate, recently published papers seemed, instead, to suggest that γ-rays application could be envisaged in some conditions for Cultural Heritage original documents and books. In some of the published papers, the possible application of γ-rays was evaluated mainly by using mechanical tests that scarcely reflect the chemical modifications induced in the cellulosic support. In the present article the effect of low dosage γ-irradiation on cellulosic substrates was studied and monitored applying different techniques: colorimetry, spectroscopic measurements, carbonyl content and average viscometric degree of polymerization. Two different papers were investigated, a non-sized, non-filled cotton paper, and a commercial permanent paper. To simulate a real deteriorated document, which could need γ-rays irradiation, some samples were submitted to a hydrolysis treatment. We developed a treatment based on the exposition of paper to hydrochloric acid vapors, avoiding any contact of the samples with water. This method induces a degradation similar to that observed on original documents. The samples were then irradiated with 3 kGy γ-rays at a 5258 Gy/h rate. The aforementioned analyses were performed on the samples just irradiated and after artificial ageing. All tests showed negative effects of gamma irradiation on paper. Non-irradiated paper preserves better its appearance and chemical properties both in the short term and after ageing, while the irradiated samples show appreciable color change and higher oxidation extent. Since the Istituto centrale restauro e conservazione patrimonio archivistico e librario is responsible for the choice of all restoration treatments that could be applied on library and archival materials under the protection of the Italian State ( http://www.icpal.beniculturali.it/allegati/DM-7-10-2008-Istituto.pdf ), it has been evaluated that the modifications induced by γ-rays irradiation are not acceptable as safe conservation treatment ( http://www.icpal.beniculturali.it/allegati/Nota_uso_raggi_gamma.pdf ). [ABSTRACT FROM AUTHOR]

Abstract At the present time, gamma radiation is once again being employed for mass disinfection of materials in cultural heritage conservation. Its in-depth and homogeneous effect and also the ability to rapidly treat a large number of items are among the undoubted advantages of this method. However, use of the higher doses of gamma radiation necessary for disinfection entails the risk of damage to organic materials. This work is concerned with the effect of various doses of gamma radiation on cellulosic materials (various kinds of paper and cotton textiles) and on proteinaceous materials (silk). The long-term stability of irradiated samples was also studied during artificial ageing by moist heat, along with the post-irradiation effect. The degree of degradation was studied by means of colorimetry, UV/Vis spectroscopy, viscometry (determination of limiting viscosity number or average degree of polymerization), molar weight distribution and mechanical properties. Highlights • Gamma radiation is used for mass disinfestation of cultural heritage objects. • Disinfection doses of γ-radiation entails the risk of damage to organic materials. • Mechanical and chemical properties of paper and textile were studied. • Long term stability and post-irradiation effect of irradiated samples were explored. • Use of gamma radiation for cultural heritage disinfection is not recommendable. [ABSTRACT FROM AUTHOR]

Abstract: Fungi are among the most degradative organisms inducing biodeterioration of paper-based items of cultural heritage. Appropriate conservation measures and restoration treatments to deal with fungal infections include mechanical, chemical, and biological methods, which entail effects on the paper itself and health hazards for humans. Three different conservation treatments, namely freeze-drying, gamma rays, and ethylene oxide fumigation, were compared and monitored to assess their short- (one month, T1) and long-term (one year, T2) effectiveness to inhibit fungal growth. After the inoculation with fungi possessing cellulose hydrolysis ability — Chaetomium globosum, Trichoderma viride, and Cladosporium cladosporioides — as single strains or as a mixture, different quality paper samples were treated and screened for fungal viability by culture-dependent and -independent techniques. Results derived from both strategies were contradictory. Both gamma irradiation and EtO fumigation showed full efficacy as disinfecting agents when evaluated with cultivation techniques. However, when using molecular analyses, the application of gamma rays showed a short-term reduction in DNA recovery and DNA fragmentation; the latter phenomenon was also observed in a minor degree in samples treated with freeze-drying. When RNA was used as an indicator of long-term fungal viability, differences in the RNA recovery from samples treated with freeze-drying or gamma rays could be observed in samples inoculated with the mixed culture. Only the treatment with ethylene oxide proved negative for both DNA and RNA recovery. Therefore, DNA fragmentation after an ethylene oxide treatment can hamper future paleogenetic and archaeological molecular studies on the objects. [Copyright &y& Elsevier]

The integrity of materials containing packaging (natural or synthetic polymers) is essential to keep the aseptic condition of commercialized products (health care products, food and pharmaceuticals). The objective of this paper was to study gamma radiation effects (25 kGy, 40 kGy and 50 kGy) on the main properties of paper and multilayer films (polyester and polyethylene). Paper and multilayer films are components of packaging (pouches) for radiation sterilization containing medical equipment or products. Paper was the more radiation sensitive among the studied materials and radiation effects were more pronounced at brightness, pH, tearing resistance, bursting strength and tensile strength. Concerning plastic film, no pinholes were induced by radiation and the effects on the tensile strength were not significant. Although the seal strength packaging (pouches) decreased according to increasing dose, the sealing integrity was preserved. [ABSTRACT FROM AUTHOR]

The effectiveness of ionizing radiations for the preservation of cultural heritage (CH) has been recently demonstrated. Although these processes present many advantages with respect to the traditional methods, physico-chemical modifications induced by radiation (namely side effects) represent a concern for CH restorers, archivists and librarians. The present work is focused on the study of the effect of gamma irradiation parameters on the main features of paper. In particular, total absorbed doses up to 10 kGy (commonly suggested for preservation treatments) have been applied, with dose rates ranging from 3 to 10 kGy/h. Different experimental techniques (FTIR, EPR, viscosity and colorimetric analysis) have been used to study the side effects occurrence. The results indicate that the fine-tuning of irradiation condition allow to minimize the unwanted changes, induced by radiation in the treated paper samples. • Gamma radiation at absorbed doses common for preservation of cultural heritage (up to 10 kGy). • Side effects evaluation with several experimental techniques (FTIR, EPR, DP, colorimetric analysis). • Studies were performed at different dose rate values. • Irradiation parameters optimization to minimize the side effects. • Gamma rays represent a suitable and reliable tool for bio-deteriogens elimination purpose. [ABSTRACT FROM AUTHOR]

Abstract: Books and documents attacked by fungi and insects have already been treated by radiation for disinfestations purposes. However, there is still need to investigate the influence of radiation on the cellulose paper structure. The aim of this research was to study the effects of radiation on paper properties, especially those related to strength and appearance. Paper sheets for this study were prepared in the laboratory, using bleached eucalyptus pulp as raw material. No additives were used to concentrate the attention only on the effects of irradiation on the pure cellulose matrix. The samples were irradiated at IPEN''s 60Co Gammacell irradiator with six radiation doses, from 3 to 15kGy at the dose rate 0.817Gy/s. The properties of paper sheets were tested after irradiation and compared with unirradiated samples according to ISO methods. No significant changes were detected in paper samples irradiated up to 15kGy. [Copyright &y& Elsevier]

Abstract: Fumigants, including methyl bromide and ethylene oxide, are generally used for the preservation of the Korean cultural heritage, especially paper products like letters and books. However, the use of fumigants is banned because of their harmful effects on humans and the environment. Gamma irradiation is being considered as an alternative for the sterilization of insects and fungi in organic products. Therefore, the purpose of this study was to investigate the sterilization effects of radiation and its effect on the mechanical properties of the Korean traditional paper—Hanji. Treatment doses of 9kGy and 8kGy of gamma irradiation inactivated 5 log units of Aspergillus niger and Bacillus cereus spores inoculated on Hanji, respectively. The gamma irradiations up to an absorbed dose of 50kGy resulted in no significant changes in the tensile strength, bursting strength, and appearance of Hanji. These results confirmed that radiation treatment disinfects the Korean traditional paper efficiently without changing its properties and that this treatment could be used to prevent the damage of Korean ancient archives by molds and fungi. [Copyright &y& Elsevier]

Abstract: Museums, libraries and archives are preserving documents that are slowly degrading due to the inherent ageing of the cellulose substrate or to the technological errors of the past (acid paper, iron gall ink). Beside this, large quantities of paper are rapidly damaged by biological attacks following natural disasters and improper storage conditions. The treatment of paper documents with ionizing radiation can be used for mass decontamination of cultural heritage items but conservators and restaurators are still reserved because of the radiation induced degradation. We conducted a study for establishing the dose needed for the effective treatment of paper documents, taking into account the biological burden and the irradiation effects on paper structure. We used physical testing specific to paper industry and less destructive analytical methods (thermal analysis). Our results show that an effective treatment can be performed with doses lower than 10kGy. Old paper appears to be less affected by gamma radiation than recent paper but the sampling is highly affected by the non-uniform degree of the initial degradation status. The extent of testing for degradation and the magnitude of acceptable degradation should take into account the biological threat and the expected life time of the paper documents. [Copyright &y& Elsevier]

In this work, we use paramagnetic defects induced by gamma radiation in some modern paper samples to determine their main dosimetric properties in the decontamination dose range (0.5–10 kGy) of ancient papers. Electron spin resonance (ESR) spectra of photo paper, cigarette paper, white paper napkin (napkin), cash register receipt, straw paper and white photocopy paper recorded before and after irradiation with gamma rays were reported. Photo paper, cigarette paper and napkin samples displayed the radiation-induced cellulose-like ESR signals well known from the literature on cellulose-containing foods. Cash register receipt, straw paper, and white photocopy paper are another set of samples where different ESR spectra were recorded. The ESR signals of these three paper samples were shown to originate from carbonate mineral filler grains. Inorganic mineral fillers are commonly used in paper manufacturing. The dose-response curves associated with the radiation-induced sharp ESR signals originating from the CaCO 3 filler of the cash register receipt (g = 2.0027), the straw paper (g = 1.9995), and the white photocopy paper (g = 1.9996) were found to follow a single exponential saturation function. Despite the observed decreases with time in the signal intensities of cash register receipt and white photocopy paper, detectable ESR signals were obtained even 100 days after irradiation for them and straw paper. The radiation-induced free radicals responsible for the ESR spectrum of straw paper were more stable than those of cash register receipt and white photocopy paper. The results indicate that free radicals induced in mineral CaCO 3 filler grains incorporated within papers have the potential to be used for application to retrospective ESR dosimetry in the range of 0.5–10 kGy. • Radiation-induced ESR signals were examined in six types of modern papers. • Cellulose-like and calcite filler origin signals were observed in the papers. • ESR signals originating from calcite filler increased exponentially in the range 0.5–10 kGy. • The fading behaviors of the signals were investigated depending on the dose. • Common modern papers were tested as potential retrospective ESR dosimeters. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to evaluate the effects of dose and dose rate of gamma irradiation on the physical properties of commercial papers commonly used in libraries and archives to optimize the irradiation conditions. Three different brands of paper of different fiber compositions were treated, using a 32 factorial design with four replicates of the center point, with doses ranging from 2 to 11kGy and dose rates between 1 and 11kGy/h. Chemical, mechanical and optical properties were determined on the samples. With some differences between the different kinds of papers, tensile strength, elongation, TEA, and air resistance were in general, unaffected by the treatment. The minimum loss of tear resistance and brightness were obtained with doses in the range 4–6kGy at any dose rate for all three kinds of paper. These conditions are ideal to remove insects and sufficient to eliminate fungus. [Copyright &y& Elsevier]

Progress in glass science has given rise to innovative functional glasses, unlocking significant applications for creating cutting-edge materials such as solid-state batteries, solar cells, optical reinforcement, and medical technologies. In this study, rice husk silica, Bismuth (Bi) and Tin (Sn) oxide ores were used to fabricate a novel glass series. The electrical conductivity (i.e., dielectric constant) of the glasses increased with the dopant's gravimetric levels. The novel glass series also possesses good optical non-linearity with metallisation criteria ranging from 0.35 to 0.40, which points to a novel non-linear optical material. The non-bridging oxygen content in the new glasses exceeds the bridging oxygen, indicating high polarisation. The transmission coefficient decreased with increasing dopant concentration from 0.76 to 0.75, while the reflection loss decreased from 0.37 to 0.38. For the Caesium-137 energy, GS6 has a minimum HVL of ∼5.02 cm, which is ∼20 % lower than that of commercial Pb/Ba glass. For the two energies, GS6 has the least MFP, suggesting that the addition of dopants improved the efficiency of the glass attenuation. Process capability analysis based on Caesium-137 (661.7 keV) and overall performance analysis of the fabricated glass series revealed that GS3 glass (15 wt% dopant) is the optimal material, even outperforming the commercial Pb/Ba glass. Although Cobalt-60 (1253 keV) yielded comparable outcomes, concentrations beyond 15 wt% in GS3 showed marginal enhancements in the photon attenuation parameters of the glasses. Hence, the fabricated GS3 and the circular synthesis method of the glasses are cost-effective for low-energy gamma/X-ray shielding. The percentage deviation between the experimental data for MAC and that of Monte Carlo simulations for Cs-137 and Co-60 energies are both within 10 %, which validates the methods of this paper. [ABSTRACT FROM AUTHOR]

In this paper, cubic-phase Lu 2 O 3 :Bi3+ nanoparticles, with a range of sizes between 110 and 180 nm, were obtained by a combination of co-precipitation and thermal annealing techniques. For these nanoparticles upon UV or X-ray excitation, strong broadband emission peaks at 410 and 480 nm corresponding to Bi3+ occupying S 6 and C 2 (Lu3+(S 6) and Lu3+(C 2)) sites, respectively, can be observed. On the basis of the concentration-dependent luminescence intensity ratios (I 480 (C 2)/I 410 (S 6)) of Bi3+(C 2) to Bi3+(S 6), the energy transfer from Bi3+(S 6) to Bi3+(C 2) can be confirmed at high Bi3+ concentration. In particular, their X-ray absorption coefficient, emission wavelength, afterglow level (60 ppm) and response time (465 ns) are almost comparable to those of the commercial Bi 4 Ge 3 O 12 crystals. By the means of dispersing Lu 1.98 Bi 0.02 O 3 nanoscintillators into organic polymer (PMMA)-acetone solution, the Lu 1.98 Bi 0.02 O 3 -PMMA flexible composite films exhibiting rapid response to X-ray photons, high X-ray sensitivity and radiation resistance, good mechanical performance and excellent environmental stability were prepared using a spin-coating technique. On the surface of X-ray imaging screen formed by the flexible dense composite films, the spatial resolution can reach to 6.0 lp/mm at a safe irradiation dose (4.6 μGy). Meanwhile, for the imaging screen using the flexible composite films after bended for thousands of times, we can observe clear image of each reed gap (300 μm) of the music box. For the Lu 2 O 3 :Bi3+-PMMA composite films, our results suggest that not only their scintillation properties are almost comparable to those of the commercial broadband Bi 4 Ge 3 O 12 crystals, but also they might be applied in large-area and non-planar X-ray imaging. [ABSTRACT FROM AUTHOR]

Gd 2 O 3 is often used as an absorber in nuclear fuel shielding because of its excellent neutron absorption capacity. However, Gd element releases prompt gamma rays when absorbing neutrons, which threatens the safety of personnel and equipment. In this paper, a new absorber, Gd 2 O 3 @W core-shell powder, is proposed, which can simultaneously absorb thermal neutrons and prompt gamma rays. Firstly, MCNP5 software was used to explore the influence of tungsten layer thickness on γ-ray attenuation ratio, and the thickness of tungsten layer required to shield prompt γ-ray was obtained. Then, in order to explore an effective tungsten plating method, Gd 2 O 3 @W core-shell powders were prepared by three methods: powder coverage sintering, sol-gel method and immersion method. The Gd 2 O 3 @W core-shell powders prepared by the above three methods were observed and analyzed by SEM and EDS. The results show that the core-shell powder prepared by immersion method is more uniform and dense. Finally, the composition and shell thickness of the Gd 2 O 3 @W core-shell powder prepared by immersion method was further studied. The results show that the W layer thickness is about 200–600 nm, and there is a diffusion zone between the shell and the core, resulting in new phases Gd 2 W 2 O 9 and Gd 2 WO 6. The prepared Gd 2 O 3 @W core-shell powder in this paper.can be used as a co-absorber of neutron and gamma rays for shielding composites. [ABSTRACT FROM AUTHOR]

The aim of this work is to investigate, in a wide range of gamma-ray energies, the validity of the "Virtual Point Detector" (VPD) approach to evaluate Full-Energy-Peak Efficiency (FEPE) values for a Cerium-doped Lanthanum Bromide scintillator (LaBr 3 :Ce). With VPD approximation, the detector is assumed equivalent to a virtual point inside the crystal where all the interactions can be considered to occur. The distance of VPD from detector cap is evaluated through experimental point source measurements. The knowledge of the trend of VPD depth as a function of gamma radiation energy allows the evaluation of FEPE values starting from an experimental reference value. The validation of the procedure has been performed by applying the VPD approach to measurement geometries already characterized such as a disk source, an Havar foil irradiated inside a target of a medical cyclotron, and a parallelepided sample geometry, an atmospheric particulate paper filter reduced to 6 cm × 6 cm × 0.7 cm dimensions. FEPE values determined by VPD approach lead to radionuclide activities very close to the ones already obtained with measurements carried out with other detectors. • Validity of Virtual Point Detector approach for a LaBr 3 :Ce scintillator. • Efficiency evaluation for a LaBr 3 :Ce scintillator through a VPD approximation. • Experimental validation of VPD approach also for disk and volume sources. • Knowledge of the detector size and composition is not necessary. [ABSTRACT FROM AUTHOR]

Samples of nine different papers in use in the library, including two mould-contaminated papers, were irradiated with 14.4 kGy in a Co-60 facility. Five of the samples were subsequently subjected to an accelerated UV-ageing process. mechanical (tensile energy absorption and stretch) and optical properties were measured on control and irradiated samples, before and after ageing.For most samples, the effect of ageing on mechanical properties turned out to be larger than that of irradiation. Irradiated and control samples were similarly affected by the accelerated ageing. Mould contaminated samples were still in acceptable conditions of use after irradiation. No discoloration effect was observed after irradiation and/or ageing. [Copyright &y& Elsevier]

Cellulose, the main constituent of paper-made objects of cultural heritage (CH), is a favorable substrate for fungal growth. Gamma irradiation is a well-established low-cost treatment convenient for decontamination of such objects. Since side-effects to paper-based CH are always a concern the aim of this work was to investigate if a synergism of microbiological contamination and gamma irradiation effects exists and if it induces changes in paper's appearance and structure. The dose rate plays an important yet generally neglected role in the efficacy of the radiation treatment so another goal was to assert its influence on decontamination efficiency and paper properties. Irradiation conditions for treating the highly resistant secondary colonizer Cladosporium sphaerospermum , as well as the naturally occurring mycobiota were evaluated. Untreated and inoculated samples of paper were irradiated with doses commonly applied to CH objects, as well as to significantly higher doses, at two dose rates that differ for two orders of magnitude. Microbiological analysis of irradiated samples was conducted. Colorimetric analysis, UV-vis and FTIR measurements were performed after short lived reaction species have decayed. The results have shown that in the case of high contaminations (104 CFU/g) the applied dose needs to be adjusted and that the corresponding dose rate needs to be high enough. While at the dose rate of 31 kGy/h the irradiation dose of 7 kGy seems to be effective to obtain proper reduction of mycobita, at the dose rate that was two orders of magnitude lower the required dose increased approximately ten times. Thus the reevaluation of the recommended dose of 8 ± 2 kGy is needed. Considering the side effects of radiation treatment the dose rate effect has also been observed. At the higher of the investigated dose rates the irradiation doses needed for decontamination did not alter the appearance of paper, while at the lower one the changes were hardly perceptible. The main species showing their contribution to color change were the carbonate anion-radicals that were formed on the CaCO 3 paper filler. No oxidation or change in crystallinity of cellulose was detected. Overall changes were too insignificant to make any conclusion on the contribution of mycobiota to the irradiation side-effects on the paper under the studied conditions. • Dose rate determines radiation treatment efficiency and appearance of side effects. • Reevaluation of recommended 8 ± 2 kGy taking into account the dose rate is needed. • Electron beam treatment of paper-based cultural heritage may be encouraged. • Observable changes occurred at larger doses than needed for cultural heritage. • For samples irradiated to high doses carbonate radical anion absorption appeared. [ABSTRACT FROM AUTHOR]

This paper presents an analysis of the updated version of the Front-End Board (FEB) for the NectarCAM camera, developed for the Cherenkov Telescope Array Observatory (CTAO). The FEB is a critical component responsible for reading and converting signals from the camera's photo-multiplier tubes into digital data and generating module-level trigger signals. This study provides an overview of the design and performance of the new FEB version, including the use of an improved NECTAr3 chip with advanced features. The NECTAr3 chip contains a switched capacitor array for sampling signals at 1 GHz and a 12-bit analog-to-digital converter (ADC) for digitization upon receiving a trigger signal. The integration of the new NECTAr3 chip results in a significant reduction of NectarCAM's deadtime by an order of magnitude compared to the previous version. The paper also presents the results of laboratory testing, including measurements of timing performance, linearity, dynamic range, and deadtime, to characterize the new FEB's performance. [ABSTRACT FROM AUTHOR]

The authors of the title paper (Kalaiselvi et al. Optik 125 (2014) 1825–1828) claim to have synthesized a new nonlinear optical (NLO) gamma bis glycinium oxalate (GBGOx) crystal by slow evaporation solution technique. In this communication, many points of criticism, concerning the characterization of this so called GBGOx NLO crystal are highlighted to prove that the title paper is completely erroneous. [ABSTRACT FROM AUTHOR]

Radiation grafting modification represents an eco-friendly approach to material alteration. In recent years, the application of electron beam radiation has seen substantial advancements due to its superior safety, controllability, and efficiency. Textiles, as vital human materials, are extensively employed in diverse sectors such as daily life, industrial production, medicine, and environmental protection. By undergoing physical and chemical modifications, textiles can gain additional functionalities and applications, thereby enhancing their effectiveness and broadening their usage scope. This paper offers a comparative analysis of the merits and drawbacks of plasma radiation, gamma radiation, and electron beam radiation for textile modification. It also provides an in-depth exploration of the impact of the electron beam radiation grafting modification method on textile fibers and fabric substrates. Additionally, this paper presents a comprehensive review of recent advancements in the application of electron beam radiation grafting methods in areas such as antibacterial textiles, flame retardant textiles, and hydrophilic/hydrophobic textiles. The current strengths, weaknesses, and development trends within this field are discussed, along with future prospects. • This study elucidates the impacts of electron beam radiation on textile materials and fibers. • Introduction to the principles of electron beam radiation grafting for textile modification. • Plasma, gamma and electron beam radiation modified textiles were compared. • Recent advances in the study of electron beam radiation graft-modified textiles are summarized. [ABSTRACT FROM AUTHOR]

Multiphase flow has many applications, such as oil and gas industries. Flow meter devices must be calibrated with field or laboratory data. One of the best methods to calibrate the devices and determine flow parameters is artificial neural networks. In addition, due to development of multiphase flow sensors and computer systems, artificial neural networks are employed to determine the flow regime and phase volume fractions along the pipeline. Up until now, different methods of measurement such as flow pressure signal, radioactive, ultrasonic, impedance, and their combination with neural networks have been presented. In this paper, a review of these works is performed. The type of neural network, measurement method, neural network inputs and development of each method are investigated. Studies show that the use of the gamma-ray method is the most prevalent among the papers presented. Also, examining the flow regime detection and flow rate measurement over time has moved to the use of flow parameters, including pressure, temperature, velocity, viscosity, etc. This simple method (using flow parameters) has the potential to gradually replace more advanced techniques like ultrasonic and electrical, along with expensive techniques like gamma ray. The results of this review indicate that employing intricate neural networks with many layers and neurons slightly increases the accuracy of the results. It can also be said that the use of a combination of several techniques has led to improved results. • An extensive investigation has been conducted on using neural networks for the measurement of multiphase flow parameters. • This paper explores the utilization of 20 distinct neural network types within the realm of multiphase flow analysis. • Research has been conducted on the measurement of flow rates, volume fractions, and the identification of flow regimes. • The measurement methods are categorized into radioactive, ultrasonic, electrical, pressure signals, and flow parameters. [ABSTRACT FROM AUTHOR]

• New experimental data on fragmentation of 200 MeV/u 40-Ar in copper. • Fine-resolution depth-profiles of nuclides induced by 200 MeV/u 40-Ar in copper. • FLUKA simulations of the experimental depth-profiles of the induced nuclides. • Comparison of the measured and simulated profiles. • Experimental data for development of physical models implemented in FLUKA. This work is a further contribution to our long-term experimental studies of activation- and fragmentation-related effects induced by high-energy heavy-ion irradiation in selected accelerator-construction materials. A stacked-foil copper target consisting of thin foils with different thicknesses was irradiated by 200 MeV/u 40Ar ions. Gamma spectra of the radiation emitted from the activated foils were measured and the nuclides created in the foils as a result of nuclear interaction between the 40Ar ions and the copper target nuclei were identified. The activities of all identified nuclides have been determined from the gamma spectra. The measured activity of each nuclide has been converted to the number of nuclei (of that nuclide) contained in the foil. Finally, the depth-profiles of the induced nuclides, i.e. the number of the induced nuclei as a function of the target depth, have been constructed and analyzed. The measured depth-profiles provide information on physical mechanisms of the high-energy heavy-ion fragmentation. The measured depth-profiles have been also compared with the simulated ones obtained with FLUKA2020. Keeping in mind complexity of the nucleus-nucleus interactions in the broad energy interval, the measured and simulated depth-profiles show a reasonable agreement. However, in some cases, discrepancies between the measured and the simulated depth-profiles have been observed. These cases are presented and discussed in the paper, as they can serve improvement of physical models implemented in the simulation codes. [ABSTRACT FROM AUTHOR]

In this paper, a novel nuclear shielding material capable of shielding neutrons and gamma rays, WB-reinforced Al (WB/Al) composites, was prepared by spark plasma sintering (SPS) process. The microstructure of the composites was characterized, and the effects of WB content, heat treatment and matrix type on the properties of the composites were discussed. The results demonstrate that the WB particles are uniformly dispersed in the aluminum matrix and formed a good binding interface with the matrix. WAl 12 as an interfacial reaction product is identified, and segregation of Si and Mg elements at the reinforcement/matrix interface occurs. The mechanical properties of the WB/Al composites are sensitive to the WB content. The hardness, elastic modulus and bending strength of the composites increase monotonously as the WB volume fraction increasing, up to 234%, 107% and 91.6% higher respectively than those of the monolithic 6061Al. However, the tensile strength reaches a peak point when the volume fraction is 20%. The effects of T6 treatment and matrix type are not pronounced, especially for the composites with high WB content. The thermal neutron and gamma ray shielding properties of the composites both increase with the increase of material thickness and WB content. The WB/Al composites developed in this work show good application prospects in the field of nuclear radiation protection, due to their good mechanical properties and well neutron and gamma-ray shielding performance. [ABSTRACT FROM AUTHOR]

A direct approach to functionalize and reduce pre-shaped graphene oxide 3D architectures is demonstrated by gamma ray irradiation in gaseous phase under analytical grade air, N 2 or H 2 . The formation of radicals upon gamma ray irradiation is shown to lead to surface functionalization of the graphene oxide sheets. The reduction degree of graphene oxide, which can be controlled through varying the γ-ray total dose irradiation, leads to the synthesis of highly crystalline and near defect-free graphene based materials. The crystalline structure of the graphene oxide and γ-ray reduced graphene oxide was investigated by x-ray diffraction and Raman spectroscopy. The results reveal no noticeable changes in the size of sp2 graphitic structures for the range of tested gases and total exposure doses suggesting that the irradiation in gaseous phase does not damage the graphene crystalline domains. As confirmed by X-ray photoemission spectroscopy, the C/O ratio of γ-ray reduced graphene oxide is increasing from 2.37 for graphene oxide to 6.25 upon irradiation in hydrogen gas. The removal of oxygen atoms with this reduction process in hydrogen results in a sharp 400 times increase of the electrical conductivity of γ-ray reduced graphene oxide from 0.05 S cm −1 to as high as 23 S cm −1 . A significant increase of the contact angle of the γ-ray reduced graphene oxide bucky-papers and weakened oxygen rich groups characteristic peaks across the Fourier transform infrared spectra further illustrate the efficacy of the γ-ray reduction process. A mechanism correlating the interaction between hydrogen radicals formed upon γ-ray irradiation of hydrogen gas and the oxygen rich groups on the surface of the graphene oxide bucky-papers is proposed, in order to contribute to the synthesis of reduced graphene materials through solution-free chemistry routes. [ABSTRACT FROM AUTHOR]

This paper reports the improved gamma radiation attenuation ability of six composite shields prepared using high density polyethylene (HDP) reinforced Al 2 O 3 , Fe 2 O 3 , and PbO. The radioactive source 226Ra was used at different γ-ray energies (0.295, 0.352, 0.609, 1.12, and 1.747 MeV) and the transmitted γ-radiation from the studied shields was detected via a NaI(Tl) detector. The proposed shields' μ , MFP , HVL , TF , RPE , and d Pb values were determined as a function of γ-ray energy. The experimental results were compared with those calculated using the XMuDat computer program. The measured values of all parameters were consistent with the theoretical results. It was demonstrated that the gamma radiation attenuation capacity of Al 2 O 3 , Fe 2 O 3 , and PbO can be significantly enhanced via HDP reinforcement. [ABSTRACT FROM AUTHOR]

• We recycled cathode ray tubes waste glasses using melt-quench process. • Bi 2 O 3 addition strategies are achieved. • Mass density increased from 2.86 to 3.08 g/cm3. • Maximum attenuation is found around 1.586 cm2/g for energy of 0.1 MeV. • CRT-Bi20 has a potential use for shielding application. Cathode-ray tubes (CRTs) from computer monitors and television sets are considered as one of the main sources of waste materials worldwide. Therefore, a new application for such out of use materials is required to solve the relatively huge amount of this waste. In this paper, the popular melt-quench technique was used to synthesis glass samples with the structure: x Bi 2 O 3 –(100- x) waste CRTs (where x = 0, 10 & 20 wt%) and designated as CRT-Bi0, CRT-Bi10, and CRT-Bi20 accordingly. The physical, structural, optical and radiation absorption competence of the glasses were investigated. The XRD analysis of the glasses reveals an amorphous structure while the mass density increased linearly with the Bi 2 O 3 content of the glasses from 2.86 to 3.08 g/cm3. The optical absorbance of the glasses initially increased and later declined in the visible region as the weight fraction of Bi 2 O 3 increased. The direct optical bandgap E g values were found to be 3.26, 2.72, and 2.64 eV whereas the indirect E g values were equal to 3.15, 2.30, and 2.26 eV for CRT-Bi0, CRT-Bi10, and CRT-Bi20, respectively. The gamma-ray interaction parameters of the glasses obtained through FLUKA simulations and XCOM computation showed that mass attenuation falls within the range 0.6991–0.0256, 1.1426–0.0276, 1.5860–0.0301 cm2/g for photon energy range 0.1–10 MeV. Generally, the computed gamma ray interaction quantities show that the gamma ray shielding ability of the CRT-Bi glasses follows the order: CRT-Bi0 < CRT-Bi10 < CRT-Bi20. This order is conserved in the computed interaction cross sections for thermal (25 meV) neutrons. On the other hand the fast neutron removal cross section follows a reverse order with values of 0.0891 cm−1, 0.0867 cm−1, and 0.0850 cm−1 for weight fraction of Bi 2 O 3 from 0 to 20 wt%. The comparison of the gamma–ray attenuation capacity of the CRT-Bi20 with common shielding materials reveals good potential for shielding application. Out of use CRT glasses may thus be recycled for use as radiation shielding glasses as described in this study for gamma radiation protection applications. [ABSTRACT FROM AUTHOR]

This paper investigates the influence of ZnCl 2 on the gamma attenuation and radiation shielding properties of tellurite glasses incorporating Bi 2 O 3 and B 2 O 3. Employing Geant4 simulation and XCOM program, the study explores the impact of varying ZnCl 2 content on different gamma attenuation parameters such as linear attenuation coefficient (μ), radiation protection efficiency (RPE), effective atomic number (Z eff), and HVL. Moreover, the relation between these factors and the density of the studied glass system is discussed in details. It is found that the incremental addition of Bi 2 O 3 significantly enhanced the photon attenuation properties of the tellurite glasses involved. The maximum Zeff values are observed at the low energy region between 0.015 and 0.1 MeV with the values of 53.016, 60.133, 65.950, 70.370, and 73.791 for the glass samples namely TBBZC1, TBBZC2, TBBZC3, TBBZC4, and TBBZC5, respectively. Furthermore, the HVL values fall between 0.0016 cm and 4.3546 cm indicates that the current glass system can be utilizes for gamma shielding applications. The results provide insights into the potential enhancement of radiation shielding efficiency in tellurite glasses, contributing valuable knowledge for the development of advanced materials in nuclear safety applications. • Radiation protection of TeO 2 –ZnCl 2 –B 2 O 3 –Bi 2 O glass system. • Significant influence of ZnCl 2 on the radiation shielding. • Monte Carlo simulations are employed. • A good agreement between the theory and the simulation. • TBBZC5 system has a potential use in nuclear and medical applications. [ABSTRACT FROM AUTHOR]

Emerging thorium-based reactor designs and fuel cycles present challenges to traditional non-destructive assay techniques used in international safeguards. Specifically, assaying the masses of 233U and 235U when they are present together in samples with high gamma ray backgrounds is difficult because of similar passive neutron signatures and relatively weak gamma-ray emissions of 233U. The Pacific Northwest National Laboratory (PNNL) and the Massachusetts Institute of Technology (MIT) are developing a portable neutron resonance transmission analysis (pNRTA) system as one potential solution to these challenges. This method provides isotopic concentration data for a sample via neutron time-of-flight (TOF) measurements that exploit epithermal neutron resonance cross-sections. A recently developed pNRTA system uses a commercially available, pulsed deuterium-tritium neutron generator with a ∼2 m flight path and a GS20 lithium glass scintillator detector. This paper describes the prototype pNRTA system design, a refined radiation transport model of the system, preliminary measurements with thorium and uranium sources, and demonstration of a quantitative isotopic estimation algorithm. [ABSTRACT FROM AUTHOR]

Ionizing radiations are a unique and powerful means of modifying physico-mechanical properties of various polymers and composites. Modification of properties by irradiation technique has become a pioneer area of research due to its extraordinary results and toxic-free route. Many studies revealed that radiations act differently on polymers and composites. At the optimal radiation dose; various mechanical properties such as tensile, compression, impact and flexural strength/modulus were improved upto some extent. This paper gives a clear overview of different types of radiations used for altering the properties of polymers and its composites reinforced with natural and synthetic fillers. Furthermore, the current area of research has been documented in this review. In nutshell, high-energy gamma rays and electron beam act a promising technology and bettter alternative of traditionally used chemical methods to modify various chemical and physico-mechanical aspects of commerical available polymers and composites. [ABSTRACT FROM AUTHOR]

Microbiological analysis of wheat (Triticum aestivum L.) treated with different doses of ionizing radiation (0.2 kGy, 0.5 kGy, 1 kGy, 5 kGy and 10 kGy) is presented in this paper. The aim was to determine the influence of different irradiation doses on the microbial population profile of wheat. In all samples, the total bacterial count and the populations of Enterobacteriaceae , Escherichia coli , Salmonella spp , coagulase-positive Staphylococci , Pseudomonas aeruginosa , Bacillus cereus , Clostridium perfringens , yeasts and molds were examined. The analyses were carried out twice: immediately after irradiation and nine months after treatment. Obtained results revealed the presence of Bacillus cereus , Enterobacteriaceae , yeasts and molds in all examined samples. Salmonella spp , Pseudomonas aeruginosa , Escherichia coli and Clostridium perfringens , were not detected. It has been found that the number of microorganisms decreases with the increase in the irradiation dose, with no viable microorganisms detected at the dose of 10 kGy. In all examined samples, nine months after irradiation, there was a noticeable reduction in the number of microorganisms. Only yeasts and molds were detected at a dose of 5 kGy, while no microbial growth was observed at 10 kGy. There are no reference studies on Enterobacteriaceae inactivation in wheat by ionizing radiation and storage. Therefore this study is the first contribution to understanding this microbial community decrease by gamma radiation after room temperature storage. The results highlighted the prolonged effect of ionizing radiation treatment on the microbiological safety of wheat. • The microbiota of wheat (Triticum aestivum L.) consists of Bacillus cereus, Enterobacteriaceae, yeasts and molds. • The detected microbial populations followed an inactivation by gamma radiation in a dose-dependent manner. • The inactivation of the Enterobacteriaceae population growth in wheat samples was verified only at 5 kGy. • Inactivation of microbial growth after irradiation and storage period was achieved at 10 kGy. [ABSTRACT FROM AUTHOR]

Gamma ray spectrometry of volume sample involves sample matrix that acts as source as well as absorber. In this paper, Monte Carlo simulation using MCNP4C code is used to determine self-attenuation correction, Cutshall factor and Cutshall revision factor for geological volume samples using transmission method. Dependence of Cutshall factor on composition, quantity, packing density and U 3 O 8 concentration of sample is studied by simulating 152Eu point source over various samples in a plastic container. It is observed that Cutshall factor satisfactorily estimates the self-attenuation for quartz, Gulcheru quartzite, granite and Gogi limestone. For samples of varying quantity having same density, relation between Cutshall revision factor and Cutshall factor is obtained. No variation in Cutshall factor is observed with packing density. Thus, a relation between self-attenuation correction and height of sample is obtained. Variation of Cutshall factor with concentration of U 3 O 8 is also studied by varying the concentration of U 3 O 8 in quartz matrix from 0.26% to 15%. • Variation in Cutshall factor for self-attenuation with different parameters was studied in volume samples by MCNP4C. • Cutshall factor satisfactorily estimated the self attenuation of all gamma rays for different compositions. • Samples of varying quantity having same density showed a linear relation between Cutshall revision factor and Cutshall factor. • Cutshall factor did not show any variation with packing density. • Variation of Cutshall factor with increasing %U 3 O 8 concentrations was studied for different energies. [ABSTRACT FROM AUTHOR]

This paper presents the fabrication of glasses with chemical formula [(TeO 2) 0.70 – (ZnO) 0.22 – (PbO) 0.08 ] 1-x (MnO 2) x where x = 0.02, 0.04, 0.06, 0.08 and 0.1 using melt quenching technique. The main objective is to explore the structural, elastic and gamma ray shielding efficiency of the glasses. The study was conducted using density and molar volume measurements, X-ray diffraction analysis, Fourier transform infrared analysis, non-destructive ultrasonic analysis, and theoretical assessment of the glasses' gamma ray shielding efficiency using the Phy-X/PSD software. High density values in the range of 5.611–5.735 gcm−3 and the XRD analysis showed no sharp peak indicating the amorphous nature of the glasses. The FTIR spectra revealed the presence of both TeO 3 and TeO 4 structural units. The values of the elastic moduli microhardness, Debye and softening temperatures, acoustic impedance, diffusion constant, Thermal expansion coefficient and latent heat of melting were studied and discussed among others. Efficiency parameters of radiation shielding such as the coefficients of mass and linear attenuation, effective atomic number, half and tenth value layers, mean free path and effective electron density were calculated theoretically and discussed. Based on the results discussed, the studied MnO 2 doped TeO 2 -PbO-ZnO glasses appeared to be mechanically strong, and thermally stable for radiation shielding applications. Moreso, the glasses appeared to be better in terms of radiation shielding efficiency than commercial concrete materials like serpentine, barite, ferrite, and chromite. • MnO 2 doped TeO 2 – PbO – ZnO glass system were fabricated using melt-quenching technique. • FTIR, XRD, non-destructive ultrasonic analysis/technique, and density & molar volume were used in the measurements and characterization of the studied glasses. • The high-density value in the range of 5.611–5.735 gcm−3 were recorded and Elastic moduli, Softening & Debye's temperatures, thermal expansion coefficient (α p), acoustic impedance (Z), latent heat of melting (ΔH m) and diffusion constant (D i) were studied. • Phy-X/PSD software was used in calculating the radiation shielding parameters such as Linear Attenuation Coefficient (LAC), Mass Attenuation Coefficient (MAC), and others and the results are discussed. • High values of density, elastic moduli, LAC, MAC, and other parameters suggests the glasses possess great potential for radiation shielding application. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive investigation of borate-based glasses doped with BaO, assessing their physical, structural, optical, and radiation shielding properties through experimental and theoretical analyses. XRD patterns reveal the amorphous nature of the prepared glass samples. Density and molar volume values, and FTIR spectra indicate the impact of BaO concentration on the glass matrix, affecting structural properties. Thermal analysis via TGA/DSC reveals improved thermal properties with the substitution of B 2 O 3 with BaO. UV–visible absorption spectroscopy shows a decrease in energy band gap with rising BaO content, suggesting potential non-bridging oxygen formation. Mass attenuation coefficient (μ m) values exhibit an exponential decay trend with photon energy, influenced by photoelectric absorption, Compton scattering, and pair creation. The glasses prepared had, in general, a better μ m values compared to that of concretes and other glass compositions containing barium oxide. Experimental and theoretical (XCOM) results for mean free path (MFP) and half-value layer (HVL) demonstrate close agreement, validating the accuracy of the experimental data. Both MFP and HVL increase with energy and decrease with BaO addition, emphasizing the potential for these glasses in radiation shielding applications. • Borate based glass samples of the composition (70-x)B 2 O 3 –20Bi 2 O 3 –5ZnO–5WO 3 -xBaO; x = 0, 5, 10, 15 and 20 mol% have been successfully prepared by melt-quenching process. • The addition of BaO in the glass system improves its density, thermal and gamma radiation shielding properties. • The study elucidates structural modifications of borate glasses imparted by the doping of BaO. • Non-toxic and environmentally friendly nature, along with effective shielding behavior, of our prepared glass samples makes it a practical solution for gamma shielding applications. [ABSTRACT FROM AUTHOR]

The Fast Discharge Units (FDUs) of the Superconducting (SC) Toroidal Field (TF) coils in the European demonstration fusion power plant DEMO warrant the machine integrity over its full lifetime against severe failure events, such as SC coil quenches or any other plant events requiring the safe TF magnet system discharge. A low (75 kA) and a high current (105 kA) configuration are under study for the TF coils for DEMO. The FDUs must be extremely reliable for the purpose of commutating in short time (∼1 s) the currents and to discharge the TF magnets safely into resistors outside of the tokamak building. Malfunctions of the FDUs must be avoided. The FDUs are considered as Safety Important Class (SIC) components that need to discharge high amounts of energy of about 161 GJ (@75 kA) resp. 118 GJ (@105 kA) stored in the DEMO TF coils. The TF FDUs Circuit Breakers (CBs) shall be installed in the lower level of the tokamak to minimize the length of the connecting busbars. The FDUs integration is challenging because of the high neutron and gamma radiation and stray magnetic fields of the tokamak. Since in DEMO the neutron fluence over lifetime is much higher than in ITER, the problems of using FDUs with electronic subsystems was expected to be more severe, so that their integration has been considered from the beginning of the DEMO project. Sufficient shielding or possible re-positioning of the whole FDUs or sensitive FDU components compared to ITER are being investigated, to reduce the neutron fluxes and neutron and gamma ray fluences. Alternative concepts, e.g., fully mechanical CBs are studied in the EUROfusion Work Package Plant Electrical System (WPPES) in parallel. This paper presents the CAD integration work on the DEMO TF FDUs supported by neutronics assessments. It is assumed the same FDU technology as in ITER. The magnet feeder´s integration is commenced at the same time. [ABSTRACT FROM AUTHOR]

• Alternative procedure for components TID radiation qualification. • Comparative analysis between gamma rays versus X-rays as TID radiation source. • Medical LINAC valid for a TID characterization as a radiation source of electronic components. Ionizing radiation can cause temporary or permanent failures in electronic components used in space applications. The characterization of these components and the design of on-board electronic systems that are tolerant and functional under these conditions are fundamental requirements in flight systems engineering. This paper presents experimental results from tests performed with 60 Co as gamma radiation source, comparing them with those results obtained with a medical LINAC (LINear ACcelerator) producing X-rays with similar energy. Following ESA ESCC-22900 standard it was shown that the results achieved with both radiations are equivalent, and therefore we prove that medical LINACs, that are much more easily accessible than 60 Co facilities, are suitable for testing electronic systems for space applications. [ABSTRACT FROM AUTHOR]

• A new type of foamed metal matrix composite shielding material was proposed. • It is excellent at shielding neutrons and gamma rays. • Compared with Fe/water shielding, its effect is better and the quality is lighter. • The shielding combination of W and B 4 C has the best shielding effect. The research and development of new composite shielding materials is of great practical significance for radiation shielding of reactors. Foam metal is light in weight, and has the characteristics of high specific strength and high specific area. From the structural characteristics of the foam metal, a new type of foam metal matrix composite shielding material can be prepared. The foam metal matrix composite shielding material consists of two parts: metal matrix and filling material. In this paper, there are three kinds of foam metal matrix (RAFM, tungsten and nickel) and eight kinds of filling materials (B 4 C, three kinds of lead-boron polyethylene compounds, two kinds of borated polyethylene compounds, polyimide resin, air). The shielding effect of the above-mentioned foam metal matrix composite shielding material on neutrons and gamma at different porosities is explored through MCNP simulation, and several high-performing shielding combination schemes are obtained. The neutron transmittance less than 50% and the gamma ray transmittance less than 30% are used as shielding targets. The shielding combination schemes obtained above are applied to the shielding model, and then the minimum thickness of the shielding target can be achieved by simulation. The results show that when the foam metal matrix is tungsten, the filling material is B 4 C and the porosity is 80%, its thickness of 8.5CM can reach the shielding target, which is the best shielding scheme. Compared with the traditional iron/water mixed shielding, the thickness reduction rate of this solution is 84.45% and the mass reduction rate is 47.53% when the above-mentioned shielding target is reached. In addition, the above optimal scheme is compared with the experimental data of nickel-based foam metal to further illustrate the reliability of the new foam metal matrix composite shielding material. [ABSTRACT FROM AUTHOR]

Fermi satellite released fairly accurate measurement of extragalactic gamma-ray background (EGB) from 100 MeV to 820 GeV, which dramatically improves our understanding of the high energy gamma-ray background. But for TeV band, space detectors are useless, and we must rely on ground based gamma-ray telescopes such as imaging atmospheric Cherenkov telescopes (IACTs). Until now, the extragalactic TeV gamma-ray background has not been well investigated. In this paper, we calculate the lower bound of extragalactic TeV gamma-ray background radiation by using the energy spectrum of low state of 61 TeV sources, including 53 blazars, 6 radio galaxies, and 2 star-burst galaxies, respectively. Our results show that blazars are the main contributor of the extragalactic TeV gamma-ray background, especially for Mrk 501 and Mrk 421, whose contribution at 0.5-4.5 TeV is about 58 %. And the contribution above 4.5 TeV are mainly from the sources H 1426+428, 1ES 1959+650, and 1ES 0229+200, their energy spectrum distribution has been extended to more than 10 TeV. Finally, we calculate the contribution of blazars, radio galaxies, and star-burst galaxies, respectively. Similar calculation is used to subclass of blazars and sources with different redshifts. [ABSTRACT FROM AUTHOR]

Abstract: This study aimed to examine the susceptibility of indicator bacteriophages towards γ-radiation to evaluate their appropriateness as viral indicators for water quality control. The effects of γ-radiation on naturally occurring somatic coliphages, F-specific coliphages and Escherichia coli were examined in raw sewage and sewage sludge. As well, the effects of radiation on bacteriophages ΦX174 and MS2, and E. coli all grown in the laboratory and seeded in distilled water, autoclaved raw sewage and a 1% peptone solution were evaluated. The inactivation of E. coli was fairly similar in all matrices. In contrast, inactivation of bacteriophages was significantly greater in distilled water than in the other matrices. These results showed the great influence of the matrix characteristics on virus inactivation. Somatic coliphages in raw sewage and sewage sludge and ΦX174 in autoclaved sewage were inactivated similarly and were far more resistant than F-specific coliphages, MS2 and E. coli. As well, F-specific RNA bacteriophages in raw sewage and sewage sludge and MS2 in autoclaved sewage were inactivated similarly and were more resistant than E. coli. In contrast, MS2 was more susceptible to γ-radiation than E. coli in distilled water. Our results showed that ΦX174 is a suitable indicator for estimating virus inactivation by γ-irradiation and corroborate the use of somatic coliphages to survey the viral quality of treated water and sludges. [Copyright &y& Elsevier]

To date, there have been many studies on the possibility of using lithium CPS as a plasma-facing material in fusion reactors. For use such liquid-lithium systems in fusion reactors, it is necessary to determine the interaction parameters of the surface facing the plasma with the working gases under conditions simulating the real operation of the facility, i.e. under conditions of neutron and gamma radiation. Therefore, this paper is devoted to the study of the processes of hydrogen isotopes interaction with lithium CPS under reactor irradiation. The experiments presented in work were carried out at the IVG1.M research reactor by using dynamic sorption method with the presence of deuterium under the lithium CPS sample. The results of reactor experiments simulation, in particular, the distribution of tritium concentration in lithium volume and traps, and the flows of tritium released through the inner surface of the CPS into the experimental chamber at different temperatures are presented. Based on the simulation results, the following interaction parameters of tritium with lithium were determined: temperature dependences of tritium capture constant by lithium and the dissociation constant of LiT. The obtained model can be applied for analysis of tritium generation and release from different lithium-containing materials used as a filling of CPS structure (for example, lithium and tin-lithium eutectics). • Tritium absorption constants of lithium and LiT dissociation constant were determined. • Tritium concentration gradient is located in the sample surface layer. • Free tritium and LiT atoms are uniformly distributed throughout the sample. [ABSTRACT FROM AUTHOR]

This paper includes a comprehensive analysis of the radiation shielding, optical properties, and structural makeup of polymer composites that contain Dy 2 O 3 additions. XRD-pattern investigates the effect of loading Dy 2 O 3 content on PS, with the average crystallite size of Dy 2 O 3 decreases from 39 nm to 30 nm as Dy 2 O 3 increases from 2.5 to 7.5 wt% in the PS matrix. The optical properties of the nanocomposites showed that with the increase in the Dy 2 O 3 content, the transmittance, as well as the direct and indirect band gap, decreased. The E g Indirect bandgap decreased from 3.1 to 2.75 eV with a Dy 2 O 3 increase from 0 to 7.5 wt%, while the E g direct Bandgap reduced from 4.6 to 4.35 eV. While the Urbach energy Eu and the refractive index increase, Eu rises from 0.48 to 0.60 e V, and n improves from 1.4 to 1.78 from 0 to 7.5 wt%. In order to conduct an accurate analysis of the gamma-ray attenuation capabilities of the selected new polymer composites, these composites were manufactured with varying proportions of the additive components. With the assistance of a Na(Tl) detector, experimental assessments were carried out on the gamma rays throughout a broad spectrum of photon energies, ranging from 81 keV up to 1416 keV. The sample encased in PS/Dy7.5 demonstrates excellent radiation attenuation, and it is important to note that this novel polymer shielding material does not include any hazardous components. • "Dy2O3 in PS enhances radiation shielding". • "Increased Dy2O3 reduces PS's transmittance". • "Dy2O3 addition lowers bandgap energy". • "Higher Dy2O3 increases refractive index". • "Dy2O3/PS composites ideal for radiation protection". [ABSTRACT FROM AUTHOR]

In a compact multi-radiation imaging system, the substitution of traditional charge-coupled devices with a plastic scintillators array coupled with silicon photomultiplier detectors significantly enhances the radiation tolerance of the detection and imaging module, thereby reducing the system footprint. We present a detailed structure of a compact fast neutron/gamma-ray dual-modality imaging system based on a plastic scintillators array and evaluate its performance in imaging various samples. The detector array consists of nine 14.7 × 14.7 × 100 mm3 EJ-276 plastic scintillators coupled with corresponding silicon photomultiplier units, arranged in a 3 × 3 grid. The usage of EJ-276 plastic scintillators allows for discrimination between neutron and gamma signals through pulse shape discrimination techniques, enabling data separation between neutrons and gamma rays. In this paper, we present the experimental procedure and results of fast neutron-gamma imaging for objects containing aluminum and polyethylene materials. Fast neutrons and gammas are delivered by an Cf-252 source. The experimental results demonstrate that the system achieves dual-modality grayscale imaging and has resolution for sample thickness. Reconstructed image contrast allows qualitative differentiation of sample materials, especially detecting low-Z materials encapsulated by high-Z materials. [ABSTRACT FROM AUTHOR]

Glass is an essential category of materials because of its inherent transparency, which sets it apart from many other material systems. Due to its unique characteristics, radiation shielding applications have begun implementing it, particularly when optical clarity is required. Researchers have been compelled to examine glass materials that offer optimal performance in radiation shielding against high photon energy and particles. The literature has encompassed various papers examining many types of glass and their responses to ranged energy levels. This mini-review aims to demonstrate the glass systems that have been reviewed and their respective radiation shielding characteristics against photon energies. To achieve this objective, the publication numbers for radiation shielding materials and glass were initially collected over several years from the widely utilized Web of Science (WoS) database. Subsequently, the glass systems that were primarily examined in the context of radiation shielding glass investigations were identified and classified as borate (B), germanate (G), phosphate (P), silicate (S), tellurite (T), and waste (W). The current trajectory of these glass systems has been illustrated over the years. After providing a broad description, each glass system was examined using an approach that involved sorting based on the highest-citation and newest-first criteria. Five publications were selected for each way, and then the chemical composition, density, and linear attenuation coefficient at 662 keV were obtained. Furthermore, the Phy-X/PSD software facilitated the comprehension of the attenuation properties of the glass systems at energy levels of 1173 and 1332 keV. Plus, some computations aided in understanding variations in exposure build-up factors (EBF). As demonstrated by the published data, there has been a significant rise in the number of publications on radiation shielding materials and glass investigations, especially in the last five years. In another development, there has been a recent push towards lead-free glass systems, even though inserting PbO into the glass composition can achieve a high-density value, namely higher than 5 g/cm3. Among the several glass systems of interest, T -glass has emerged as a notable choice for photon energies due to its high-density glass formulation while also being free of lead content. The T -glass series had LAC values (at 1173 keV) ranging from 0.28 to 0.35 cm−1, whereas the B , G , P , S , and W - glass series showed changes between 0.13 and 0.36, 0.17 and 0.39, 0.16 and 0.28, 0.16 and 0.35, and 0.12 and 0.25 cm−1 respectively. It is also essential to acknowledge that W - glass systems have gained popularity from sustainability perspective. Yet, W - glass systems have been found effective against low photon energies. Hence, this concise evaluation strongly highlights the significant potential of T -glass and W - glass systems for future research, owing to the facts that both systems facilitate low-melting temperatures, reduced carbon emissions, and easy preparation while also offering promising radiation shielding properties. • Borate, germanate, phosphate, silicate, tellurite, and waste glass systems have been reviewed. • Glass investigations have lately accounted for up to 30% of all radiation shielding material studies. • T -glass has emerged as a notable choice against high photon energies owing to its high density. • LAC 662 keV could be achieved greater than 0.50 cm−1 with tellurite glass as a lead-free option. • Radiation shielding systems made of waste glass can become prominent in future studies. [ABSTRACT FROM AUTHOR]

The roadmap to the realization of fusion energy describes a path towards the development of a DEMO tokamak reactor, which is expected to provide electricity into the grid by the mid of the century (Romanelli, 2013). The DEMO diagnostic and control (D&C) system must provide measurements with high reliability and accuracy, not only constrained by space restrictions in the blanket, but also by adverse effects induced by neutron, gamma radiation and particle fluxes. In view of the concept development for DEMO control, an initial selection of suitable diagnostics has been obtained (Biel et al., 2019). This initial group of diagnostic consists of 6 methods: Microwave diagnostics, thermo-current measurements, magnetic diagnostics, neutron/gamma diagnostics, IR interferometry/polarimetry, and a variety of spectroscopic and radiation measurement systems. A key aspect for the implementation, performance and lifetime assessment of these systems on DEMO, is mainly attributable to their location, that must be well protected, and meet their own set of specific requirements. With this in mind, sightline analysis, space consumption and the evaluation of optical systems are the main assessment tools to obtain a high level of integration, reliability and robustness of all this instrumentation; essential features in future commercial fusion power nuclear plants. In this paper we concentrate on spectroscopic and radiation measurement systems that require sightlines over a large range of plasma regions and inner reactor surfaces. Moreover, this paper outlines the main results and strategies adopted in this early stage of DEMO conceptual design to assess the feasibility of this initial set of diagnostic methods based on sightlines and the integration of these needed for DEMO D&C. [ABSTRACT FROM AUTHOR]

• We provide correlations among structural, thermal, and mechanical properties of medical device polymers following gamma, X-ray, and electron beam irradiation. • For most of the polymers investigated, little to no variation in properties was observed among the various radiation sources at a given dose. • This study supports medical product polymer selection for sterilization radiation resistance in view of product design and function. Stemming from security threats and shortages in supply, a recent push has emerged to expand alternatives to radioisotope Cobalt-60 gamma radiation for sterilization of polymeric medical products, including electron beam (E-beam) and X-ray machine-based sources. However, before large-scale implementation, the effects of these non-isotope-based methods must be thoroughly investigated from several perspectives, involving their potential detrimental effects on the structural, thermal, and mechanical properties of polymers in medical devices. This paper investigates such effects in commonly used medical device polymers, including polypropylene homopolymer (PPH), polyolefin elastomer (POE), low-density polyethylene (LDPE), acrylonitrile butadiene styrene (ABS), and chlorobutyl rubber (CIIR). To connect radiation-driven changes in polymer structural and thermal properties and corresponding changes in mechanical properties, several characterization techniques were utilized, including gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC). We found that the tensile strength of X-ray irradiated PPH, as well as X-ray, E-beam, and gamma irradiated CIIR decreases due to chain scission, which is corroborated by GPC and DMA. The GPC results of LDPE suggest chain scission, but interestingly without a corresponding decline in tensile strength. By comparison, POE and ABS appear to undergo further crosslinking with increasing irradiation dose, which generally strengthens them. Importantly, in the vast majority of the cases, there were small to no changes in properties upon changing radiation technologies (at a given dose), i.e., no radiation source dependence. However, in a few specific cases, radiation method dependencies did arise, for instance, in terms of the molecular weight of PPH being significantly increased upon X-ray irradiation, while the melting temperature, glass transition temperature, and elongation at break reduced compared to gamma. Overall, this study provides valuable insight into radiation-driven chemical and structural changes in polymers that produce changes in physical and functional properties. [ABSTRACT FROM AUTHOR]

Reservoir characterization is extremely important for understanding and determining the behavior of hydrocarbon reservoirs. The geophysical well logging, widely applied in the oil industry, helps to obtain essential physical properties (acoustic, electrical, mechanical, radioactive and thermal) by deploying measurement devices in the drilled well. This project aims to carry out the geological characterization of hydrocarbon reservoirs in the Amazonas Basin through the analysis of well geophysical logs. Despite the oil-producing potential of the basin, there are few published papers that use geophysical well logging for reservoir characterization. For this study, composite log data publicly provided by ANP were used. Six exploratory wells drilled in AM-T-84 and AM-T-85 exploratory blocks in the Amazonas Basin were selected. By analyzing the geophysical logs of gamma ray, resistivity, density and neutron from these wells, it was possible to identify the hydrocarbon reservoir interval within the Monte Alegre formation and obtain estimates of thickness, shale volume and porosity. The identified reservoir is relatively thin, with an average thickness of 16 m. The obtained shale volume values were relatively high, due to the influence of shale layers present in the Monte Alegre formation. The effect of clay content affected the interpretation process of the well logs; however, it did not significantly impact the reservoir porosity estimation, which ranged between 10.4 and 23.4 %. • The analysis and interpretation of well logs can provide petrophysics properties of the petroleum reservoir. • The Amazonas Basin is one of the pioneering areas for hydrocarbon exploration in northern Brazil. • Despite the clay content present in the formation, relatively good porosity values were obtained for the reservoir. • The temperature values obtained range from 70 to 95 °C. They are contained in the oil generation range (65–165 °C). [ABSTRACT FROM AUTHOR]

In this study, four alloys composed of highly pure elements (lead, zinc, tin and bismuth), named Pb–Zn50, Pb–Sn50, Sn–Zn50 and Sn–Bi50 were prepared by rapid solidification process (RSP) using melt-spun technique. The structural, mechanical properties (elastic and plastic deformations), and microhardness have been investigated and analyzed using X-ray diffraction, tensile test machine, and vickers microhardness respectively. According to results, the yield strength, ultimate tensile strength (UTS), toughness, and Vickers hardness (Hv) were improved due to the advantages of rapid solidification technology including elimination of grain boundary segregation, improvement in alloy homogeneity, refinement of grain size, formation of novel metastable crystalline, rises in the equilibrium solid solubility's of solute elements and reduction in the degree of order. This can be ascribed to reinforcement of Zn and Bi particles, refined β-Sn, Zn and Bi grains that could obstruct the dislocation slipping. In addition, the shielding performance of these alloys for gamma radiation were examined and analyzed utilizing WinXCom software over energy range 0.015–15 MeV. The alloys under study found to be good shielding materials against γ-ray relative to common shielding materials and newly studied materials. The results indicate that the Sn–Bi50 alloy has the highest values of μm, Z eff and Z eq ranging from 0.039 to 81.3 cm2/g, 60.41–73.83, and 64.02–70.793 respectively. While it has the smallest values of HVL (ranging from 8.73E-4 to 1.86 cm) which means that it is the best choice as a γ-ray shielding material. In aspects of neutron attenuation characteristics, the results also indicate that the Pb–Zn50 alloy has the highest value of Σ R (0.133 cm−1) amongst all other alloys, frequently used neutron shielding materials, and recently studied materials. Furthermore, proton (H+1) and alpha particles (He+2) projected range (PR) and mass stopping power (MSP) values have been calculated. It can be concluded that Zn–Pb alloy among the examined samples is superior in terms of shielding against proton and alpha particles. This paper provides a comprehensive examination of the use of lead and the development of new safety lead-free shielding materials in many applications including nuclear medicine. • Conventional and lead-free binary alloys. • Rapid solidification process using melt-spun technique. • Structural features, microhardness and mechanical properties. • X-ray diffraction (XRD), Vickers microhardness and tensile test machine techniques. • X/Gamma-rays, fast neutron, proton and alpha particles shielding features. [ABSTRACT FROM AUTHOR]

The utilization of ionizing radiation, such as gamma ray and electron beam, in medical product sterilization has seen significant growth in recent years, driven by concerns regarding the safety of ethylene oxide sterilization. This paper examines the effects of these radiation modalities on silicone rubber, and its applicability on a silicone rubber-containing medical device, specifically a silicone foley catheter, by assessing its functional properties before and after irradiation at varying absorbed doses. Analysis of the irradiated samples revealed the presence of carbonyl groups, indicating radiation-induced oxidation. Gamma irradiation did not exhibit fundamental changes in the polymer structure but showed degradation at higher temperatures due to oxidation mechanisms. Moreover, a significant decrease in elongation at break was observed indicating that the already highly crosslinked silicone rubber experienced additional crosslinking affecting its mechanical properties. In contrast, both irradiations led to degradation, as evidenced by a decrease in TG residue. However, the mechanical properties, including tensile strength and elongation at break, were less affected. This suggests limited crosslinking and fragmentation of the polymer backbone. At a lower dose, a decrease in both strength and elongation indicated the formation of branched structures, limiting mobility, introducing irregularities, and weakening the polymer's overall strength. Despite these effects, the functional properties of the silicone foley catheter were practically unaffected at low absorbed doses, except for the discoloration of the syringe ports. Overall, the study provides insights into the effects of ionizing radiation on silicone rubber, highlighting the complex interplay between crosslinking, chain scission, and oxidation mechanisms. The findings contribute to understanding the changes in the polymer's structure and properties under different radiation modalities and doses, facilitating the development of effective sterilization techniques for medical devices containing silicone rubber. • Irradiation induced carbonyl groups in silicone rubber, observed across different catheter polymers. • Gel fraction and swelling ratio stable, but thermal profile indicated side-chain degradation. • %Elongation at break reduced due to increased polymer backbone crosslinking, making it rigid. • Potential sterilization doses: 15 kGy gamma ray or 15–35 kGy electron beam. [ABSTRACT FROM AUTHOR]