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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]

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]

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]

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]

One of the major demands in gamma spectrometry of environmental samples is the accurate determination of activity concentration of present radionuclides (naturally occurring and those of artificial origin), due to the fact they are commonly of relatively low content. Thus, all these measurements have in common that the detection limit, in the spectral region of interest should be as low as possible. For this reason, the construction of a good passive, as well as active shield requires a detailed knowledge of the origin of the background events in the absence of an environmental sample. In addition, an analysis of the impact on detection limits due to the presence of the sample itself is also important. Also, the knowledge of the statistical basics for low-level counting is helpful to enable the best choice of detector characteristics (relative efficiency, peak to Compton ratio, resolution), measuring time, and required level of precaution against the different background contributions. In this paper, the background spectra of several gamma spectroscopy systems (with passive and active veto shields) are analyzed and discussed, regarding their capabilities for measurements of environmental samples. Furthermore, various environmental samples are analyzed by low-level gamma spectrometry, including the sample measurements in the presence of an active veto shield against cosmic-ray muons. The disturbance of radioactive equilibrium between members of radioactive series in the samples is commented on, together with the possibility of use of certain gamma lines (including their interference and the corresponding intensities) for radionuclide activities determination. • Origin of background events in the low-level gamma spectroscopy is described. • Passive and active shielding designed for environmental samples measurement are explored. • Detection limit without and with presence of environmental sample is considered. • Sample geometry and detection efficiencies are analyzed. • Analysis of activity concentrations of environmental samples is discussed. [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]

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]

Abstract Individuals receive a significant part of their radiation exposure indoors. We anticipate that this exposure is likely to increase in the near future, due to a growing use in the building industry of recycled materials and materials previously regarded as waste. Such materials often contain elevated levels of natural radionuclides. Directive 2013/59/Euratom ('Basic Safety Standards', BSS) pays comprehensive attention to indoor exposure from natural radionuclides, but proper implementation of all corresponding BSS regulations is not straightforward, especially when regarding the regulation of building materials containing so-called Annex XIII materials. In this paper, we discuss the most relevant deficiencies in the BSS and present a practical approach to cope with these. Our most important observation is that adequate methods for assessing the annual dose due to gamma radiation from building materials are not provided by the BSS. This is in particular difficult because compliance of single building materials has to be tested, but the corresponding BSS reference level refers to gamma radiation emitted by all building materials present in a room. Based on a simple model of three layers of building materials, we present a set of operational conditions for building materials, either used for construction purposes ('bulk layers') or for the finishing of walls, floors and ceilings ('superficial layers'). Any customary combination of building materials meeting these conditions will stay below the BSS reference level for gamma radiation. This statement holds for the middle of a reference room, but is not always the case close to the walls, especially when low density materials with a relatively high content of natural radionuclides are present at the inner side of the room. This can be avoided by applying more strict conditions for those kind of materials than presented in this paper. We further focus on the indoor exposure to thoron progeny. Building materials that pass the test for gamma radiation can still be a significant source for indoor air concentrations of thoron progeny. When the average annual thoron inhalation dose were to be restricted to 1 mSv a−1 − a level comparable to the BSS reference level for gamma radiation − the activity concentration of Ra-224 in (especially porous) building materials used for wall finishing purposes should be limited to a value of typically 50 Bq kg−1. Even if our suggested approach of the BSS regulations is fully implemented, it still allows for a significant increase in the average radiation exposure in dwellings due to external radiation and thoron progeny. However, the situation will be worse if a less strict interpretation of the BSS regulations will be applied. Highlights • Use of NORM for sake of sustainability may lead to higher indoor radiation doses. • We present a practical approach to test the BSS compliance of building materials. • Low density building materials with NORM cause relatively high doses close to walls. • BSS-compliant building materials can be a major source for indoor thoron progeny. • Limiting Ra-224 concentrations to 50 Bq kg−1 keeps thoron progeny doses below 1 mSv/a. [ABSTRACT FROM AUTHOR]

Highlights • A gas flow rate measurement method is developed that can be widely applied to low-quality two-phase and three-phase flows. • A Venturi meter was used to measure the pressure drop with a gamma-ray detector to measure the void fraction. • A linear correlation is presented with good accuracy to predict the gas flow rates with wide ranges of void fractions. • The paper discusses the effects of Venturi meter size and fluid properties on the metering accuracy. Abstract Online flow rate measurements are encountered in many areas with a great need for high accuracy, especially in low-quality (0–0.1) flows. This paper concerns gas flow rate measurements using a Venturi meter and gamma-ray attenuation technique. A linear correlation is developed to predict the gas flow rates with wide ranges of void fractions (0–95%). The correlation predictions were compared to experimental data in which the root mean square errors of the oil-air-water multiphase flow prediction results are 7.72%, 8.93% and 9.11% for the gas flow rate, the quality and the gas-liquid slip ratio, respectively. The effect of the Venturi size was tested, and the metering accuracy is found to increase with the inlet diameter. The prediction accuracy is improved for three-phase flows than for the corresponding two-phase flows due to the oil-water stirring in the three-phase flows. The analyses of the results indicate that the measurement accuracy is higher with stable flow regimes than intermittent flow regimes. The present method can be widely applied to both two-phase and three-phase flows in the oil industry even for different Venturis and fluid media. [ABSTRACT FROM AUTHOR]

One of the key challenges in petroleum related industries is how to precisely measure the flow rates of individual phases in a pipeline. To address this challenge, in the present study, an automated two-phase test loop capable of generating different flow patterns in horizontal pathway is used to perform experiments on the flow rates. The measuring package set-up consists of a Cs-137 radiation source with photon energy of 662 keV and one NaI (Tl) scintillation detector to register transmission counts. Multi-layer perceptron (MLP) is the selected processing element. Distinguished property of this paper is considering a feature vector with diverse-nature elements as input and the flow rate values of water and air as the target elements. Several combinations of features were investigated to determine the feature vector which shows the best quality to predict the flow rates. Moreover, two structures of MLP with different scenarios of hidden layers were utilized for examining every feature vector set. Numerous experiments were performed to collect adequate data to train and test the ANN in a wide range of air and water flow rates. The results indicate that the proposed model achieved MAE of less than 1 and 5.9 L/min and MRE% of 1.09% and 1.45% to predict water and air flow rates, respectively. The results show that the presented ANN model outperforms existing methods on multiphase flow rates measurements. Therefore, the proposed feature extraction method is applicable to estimate phase flow rates in a two-phase flow for industrial goals. • This paper considers a feature vector with diverse-nature elements as input vector of an ANN model. • The ANN model is used in order to predict the volumetric flow rates of a two-phase gas-liquid flow. • Wavelet transform and statistical features combination shows the best quality to determine the flow rates in the ANN model. • The results indicated that the proposed model achieved the MRE% of 1.09% and 1.45% to predict water and air flow rates, respectively. [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]

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]

The use of live animal gamma radioisotope tracer techniques in the field of ecotoxicology allows laboratory studies to accurately monitor contaminant biokinetics in real time for an individual organism. However, methods used in published studies for aquatic organisms are rarely described in sufficient detail to allow for study replication or an assessment of the errors associated with live animal radioanalysis to be identified. We evaluate the influence of some important methodological deficiencies through an overview of the literature on live aquatic animal radiotracer techniques and through the results obtained from our radiotracer studies on four aquatic invertebrate species. The main factors discussed are animal rinsing, radioanalysis and geometry corrections. We provide examples of three main techniques in live aquatic animal radiotracer studies to improve data quality control and demonstrate why each technique is crucial in interpreting the data from such studies. The animal rinsing technique is also relevant to non-radioisotope tracer studies, especially those involving nanoparticles. We present clear guidance on how to perform each technique and explain the importance of proper reporting of the validation of each technique for individual studies. In this paper we describe methods that are often used in lab-based radioecology studies but are rarely described in great detail. We hope that this paper will act as the basis for standard operating procedures for future radioecology studies to improve study replication and data quality control. [ABSTRACT FROM AUTHOR]

Tellurite glass is a model material having superior features for several applications. It can be considered as a potential host matrix for different oxides, and this paper aims to study the effects of TeO 2 /B 2 O 3 substitution on synthesis, physical, optical and radiation shielding properties of ZnO–Li 2 O-GeO 2 -Bi 2 O 3 glasses produced by melt quenching technique. The physical and optical features of the fabricated glasses were experimentally investigated by determining pivotal parameters such as density, XRD, tellurium ion concentration (N i), linear refractive index (n o), polaron radius (r p) and inter nuclear distance (r i). Moreover, the relative radiation deposition within the glasses was assessed via the attenuation coefficients (e.g. MAC), specific gamma ray constant (ᴦ), total stopping power (TSP), neutron cross sections, and dose rate (D). Our results suggest that both TeO 2 and B 2 O 3 additives have a significant effect on the fundamental properties of the ZnO–Li 2 O-GeO 2 -Bi 2 O 3 glasses. It also found that the lower thicknesses of the present glasses are required to provide the same level of shielding than ordinary, ilmenite, steel scrap, hematic-serpentine, ilmenite-limonite and basalt-magnetite concretes, RS253-G18 and RS360 glass shields. Therefore, presently investigated glasses are promising photon shields in different technological applications of gamma- and x-rays. [ABSTRACT FROM AUTHOR]

This paper discusses the evaluation of performance of the Atmel Atmega328 under exposure of Cobalt-60(Co-60) source. Geant4 software is used to simulate the passage of particles through matter and calculate the absorb dose rate using Monte Carlo Methods. In the simulation using the Geant4 software, we vary the distance of IC from the source. Experiments also was conducted to measure radiation level of actual Cobalt-60 source using Atmel Atmega328 based Geiger Muller Tubes sensor. The result of the simulation experiments were discussed based on the inverse square law theorem. Following the advantages and limitations of this paper, some recommendations for future researchers were also presented. [ABSTRACT FROM AUTHOR]

The treatment of dye-containing wastewater generated from textile industries is still a challenge, and various technologies, including physical, chemical and biological ones have been used. In recent years, the ionizing radiation (usually including gamma ray generated by radionuclide, such as 60Co and 137Cs, and electron beam generated by electron accelerator) technology has received increasing attention for degrading refractory or toxic organic pollutants in wastewater because of its unique advantages, such as no chemical additives, fast reaction rate, strong degradation capacity, high efficiency, flexibility, controllability. Compared to the conventional wastewater treatment processes, ionizing radiation technology, as a disruptive wastewater treatment technology, is more efficient for the decolorization and degradation of dyes and the treatment of dye-containing wastewater. In this paper, the recent advances in the treatment of dye-containing wastewater by ionizing radiation, in particular by electron beam (EB) radiation were summarized and analyzed, focusing on the decolorization and degradation of various dyes. Firstly, the formation of various reactive species induced by radiation and their interactions with dye molecules, as well as the influencing factors on the removal efficiency of dyes were discussed. Secondly, the researches on the treating dye-containing wastewater by electron beam radiation technology were systematically reviewed. Then, the decolorization and degradation mechanisms by electron beam radiation were further discussed in detail. And the integrated processes that would contribute to the advancement of this technology in practical applications were examined. More importantly, the recent advances of electron beam radiation technology from laboratory to application were reviewed, especially successful operation of dye-containing wastewater treatment facilities in China. And eventually, current challenges, future research directions, and outlooks of electron beam radiation technology were proposed for further advancing this technology for the sustainable development of water resources. [Display omitted] • The treatment of dye-containing wastewater is still a challenge. • Advances in dye-containing wastewater treatment by EB were summarized and analyzed. • Mechanisms of dye decolorization and degradation by EB were discussed in detail. • EB is more efficient for the decolorization and degradation of dyes. • Challenges, future directions and outlooks of EB technology were proposed. [ABSTRACT FROM AUTHOR]

Scaling oil pipelines over time leads to issues including diminished flow rates, wasted energy, and decreased efficiency. In order to take preventative measures in a timely manner and avoid the aforementioned issues, it is crucial to get a precise gauge of the scale within the pipe. Non-invasive gamma attenuation systems are one of the most accurate detection methods. In this investigation, he Monte Carlo N Particle (MCNP) technique was used to model a scale thickness measuring system including a test pipe, two sodium iodide detectors, and a dual-energy gamma source. The three-phase flow was created by simulating water, gas and oil in a homogenous flow regime in the test pipe. Additionally, a scale of varying thicknesses was installed inside the conduit. The photon intensity on the opposite side of the pipe was measured by detectors when gamma rays shone through it. Photopeaks of 241 Am and 133 Ba of the transmission detector and the total count of the scattering detector were derived from the signal received by the detectors. Since there are different variables such as scale layer and volume fractions in the present study, it is not possible to use regular known attenuation formulas for calculating the thickness. So, in this paper, RBF was implemented to solve this issue. By training and optimizing a RBF network, we were able to predict the thickness of a scale with an RMSE of 0.057. Having such a small margin for error confirms the validity of the suggested technology and its practical use in the petroleum and petrochemical industries. • This system measure thickness of scale within the pipe using gamma attenuation. • A dual-energy source and 2 NaI detectors are the main components of this system. • After a large number of simulations, they were used as inputs of RBF network. • RBF was implemented to solve this complex issue with different variables. • This system can predict the thickness of a scale with an RMSE of 0.057. [ABSTRACT FROM AUTHOR]

The paper focuses on the nuclear analyses of the ITER Equatorial Port Visible/Infrared Wide Angle Viewing System (VIS/IR WAVS). This instrument comprises of viewing systems in the 4 Equatorial Ports (EP) 3, 9, 12 and 17. The main mission of this diagnostic is to support the operation of the tokamak by providing visible and infrared viewing and temperature data of the first wall to protect it from damage. Its design is driven by both the tokamak severe environment and the high performances required for machine protection. New nuclear studies have been carried out for the development of the diagnostic and for test purposes under ITER-like irradiation conditions in order to choose the most appropriate materials for the optical components. Thus, three neutronic analyses have been carried out: the first in order to verify if silver could be used as a covering material for the optical components in different location of the Interspace area; the second in order to establish the irradiation time required in a Co-60 gamma facility (at CIEMAT) for testing purposes of the sapphire vacuum window; and the third to give more detailed specifications for the irradiation campaigns under gamma (in the Co-60 facility) and neutrons (at SCK·CEN BR2 reactor), about the time required to achieve the same dose than the one accumulated in ITER at the end-of-life (EOL) in the different components of the Port Area for the materials proposed as substrate and coatings. The neutronic and activation calculations have been performed using the Monte Carlo code MCNP5, the activation code ACAB and the cross section libraries FENDL 2.1 and EAF-2007. The description of the simulations and their results are presented in this paper. [ABSTRACT FROM AUTHOR]

This paper presents the volumetric and Marshall Stability characteristics of irradiated waste polyethylene terephthalate fiber-reinforced asphalt mix utilizing the analysis of variance. Exposing polymers to gamma radiation boosts its mechanical and thermal properties which have a direct impact on improving its strength. The influences of irradiated fiber and binder contents on the volumetric and strength properties have been identified via response surface methods (RSM). The RSM was used to determine the optimized contents of irradiated fiber and binder through central composite design (CCD). The results indicate that the interactions between the two independent variables are both influential. The high values of the coefficient of determination (R2) show a good agreement between the actual and predicted values. The numerical optimization elucidates that the optimal irradiated fiber and binder contents were 0.53% and 5.25% respectively. The absolute percent errors between the actual and predicted values were observed to be less than 7% for all the responses. [ABSTRACT FROM AUTHOR]

Lithium tetraborate is one of the tissue equivalent material that has been modified with numerous dopant/codopant to improve its Thermoluminescence and Optical stimulated Luminescence properties. Lithium tetraborate doped with Aluminum is being investigated for Optical stimulated Luminescence dosimetry in this paper. Polycrystalline nano-phosphor samples were synthesized using two step solid state reaction method with optimized concentration of Aluminum equals to 2% (by wt.). Formation of the same and its morphology was confirmed using X-ray Diffractometry and Transmission Electron Microscopy. The various dosimetric properties of the obtained phosphor along with related Optical stimulated Luminescence kinetic parameters have been studied. The phosphor exhibits good linearity for gamma radiation in the range of 0.1–500 Gy with other properties such as low fading, satisfactory reusability & reproducibility and minimum detectable dose of 0.05 Gy. In this paper we have also explored the Temperature-Assisted Optical stimulated Luminescence properties of the obtained phosphor in the range of 25 ֯C to 200 ֯C and the optimized temperature corresponding to the maximum Optical stimulated Luminescence intensity was found to be 125 ֯C with activation energy equals to 0.108 ± 0.02 eV. The studied nanophosphor has also shown linear response with dose gamma (1–200 Gy) and beta (0.05–3 Gy) at 125 ֯C. • Tissue equivalent Li 2 B 4 O 7 :Al nanophosphor is developed using solid state reaction with two stage heating process. • The optimized level of Al doping in Li 2 B 4 O 7 shows non-toxic, robust response for reusable dosimetry. • CW-OSL/TA-OSL studies of gamma and beta irradiated Li 2 B 4 O 7 :Al are reported for the first time. • Linear CW-OSL/TA-OSL response in the observed dose range has been observed. • Optimized elevated temperature corresponding to the maximum OSL intensity is found to be 125 ֯C. • Activation energy equals 0.108±0.02 eV is calculated using Arrhenius equation. [ABSTRACT FROM AUTHOR]

The present paper reports the thermoluminescence (TL) based personnel neutron dosimetry studies of LiMgBO 3 : Dy3+ phosphor. It offers the great advantage of being a near tissue equivalent material with Z eff = 9.1. Also, the presence of both Li and B in the host matrix directly induce TL signal for neutrons. This is highly advantageous over CaSO 4 : Dy based TL neutron dosimeters where it requires to mix some thermal neutron sensitive species with the host matrix to induce neutron response. LiMgBO 3 : Dy3+ was synthesized by sol gel method and its structural characterizations were done by XRD, SEM and EDS techniques. TL upon irradiation with neutrons showed the glow peak at ~140 °C (413K). TL response up to 200 mSv of neutron dose showed very good linearity with adj. R2 = 0.998. 30% borated rubber discs were successfully utilised for the segregation of the gamma dose from the total dose in the mixed field (neutron + gamma) environments. The minimum detectable dose of the material was found to be 27.5 μGy and 2.7 μSv for gamma and thermal neutrons respectively. The TL sensitivity of LiMgBO 3 : Dy3+ for neutron and gamma radiation is 0.6 times and 0.3 times respectively with respect to that of standard TLD-100 [LiF: Mg, Ti] material. The proposed LiMgBO 3 :Dy3+ was also found to have better n/γ dose discrimination capability as compared to the commercially available TLD-100 material [LiF: Mg, Ti]. The kinetic parameters (viz. E, b and s) of the neutron irradiated TL glow peak were determined by Chen's peak shape and by variable heating rate methods. [ABSTRACT FROM AUTHOR]

This paper focuses on the evaluation of the radiation attenuation properties of 15CaF 2 -10CaO-5B 2 O 3 -(65-x)P 2 O 5 -xNiO-5BaO (where 0 ≤ x ≤ 1.0 mol%) bioactive glasses. The radiation attenuation features of these glasses were investigated by determining different factors including mass attenuation coefficient (μ/ρ), exposure and absorption buildup factors (EBF and EABF), neutron removal cross section (NRCS), and effective atomic number (Z eff) for photon, proton, and carbon ion interactions. Geant4 toolkit and Phy-X program were employed for simulations and calculations procedures. The results revealed that NiO content in the studied bioactive glasses has a significant effect on photon interaction and an insignificant effect on the charged particle interactions. The Z eff values of the studied glasses were observed in the range of 18–20 for photon interaction, 10.7–10.9 for proton interaction, and 10.0–10.7 for carbon ion interaction. The NRCS values were 0.087, 0.088, 0.089, 0.090, and 0.091 cm-1 for x = 0, 0.4, 0.6, 0.8 and 1.0 mol%, respectively. The studied bioactive glasses showed a good ability to attenuate gamma radiation at energies of medical applications. [ABSTRACT FROM AUTHOR]

In this paper, the role of TeO 2 in radiation attenuating characteristics of xTeO 2 -10CaF 2 -(60–0.6x) B 2 O 3 -(30–0.4x) CaO glass system with x = 20, 25, 30, 35 and 40 wt% was investigated. The gamma radiation studies were carried out by utilizing Geant4 simulations and the newly developed Phy-X/PSD program. The gamma-shielding characteristics of the present glass samples were examined in terms of mass attenuation coefficient (μ/ρ), and some other related factors such as the effective atomic number (Z eff), and mean free path (MFP). The electron radiation-shielding characteristics were tested by determining the stopping power (ψ e) and CSDA range for each glass specimen. The neutron radiation-shielding characteristics were explored by evaluating the removal cross section (RCS) for the tested glasses. Moreover, the G-P method was employed to investigate the exposure buildup factor (EBF) for photon energies up to 15 MeV. The results showed that the TeO 2 content had a significant influence on the shielding ability of the investigated glasses against gamma and neutron radiations. In contrast, the TeO 2 content had an insignificant influence on the electron radiation-shielding capacity of the glasses involved. Additionally, the nuclear-shielding properties of the studied samples were compared with those of standard nuclear radiation shields. It can be concluded that the present calcium boro-tellurite glasses have a promising future to be used as a shielding material against gamma, electron and neutron radiation, wherein the TeO 2 concentration can be balanced according to the desired application. [ABSTRACT FROM AUTHOR]

In this research paper, we studied the optical and nuclear shielding efficiency of newly developed BGO glasses with the following compositions (in wt%): 32Bi 2 O 3 –68GeO 2 , 42Bi 2 O 3 –58GeO 2 , 47Bi 2 O 3 –53GeO 2 , 52Bi 2 O–48GeO 2 , 62Bi 2 O 3 –38GeO 2. BGO glasses were prepared by traditional melt quenching method. To obtain the band gap values of fabricated BGO glasses, optical absorption spectra were used for evaluation of optical properties. The mass attenuation coefficients (μ/ρ) were achieved for prepared glasses at 0.015–15 MeV photon energies employing MCNPX Monte Carlo code and WinXcom program. Moreover, broad-range of nuclear shielding parameters for gamma ray, neutrons and charged particles such as mass attenuation coefficient, half value layer, effective atomic number, buildup factors, mass stopping powers, projected ranges, fast neutron removal cross sections and damage factors were calculated. The refractive index is calculated from E opt , As Bi 2 O 3 concentration is enhanced, E opt is also increased as well as the optical electronegativity and consequently the refractive index. In addition, the results showed that BIGE5 glass sample with highest Bi 2 O 3 contribution has excellent nuclear radiation shielding ability among the other fabricated glass samples. [ABSTRACT FROM AUTHOR]

• A technique for the clustering of electrical signals is proposed. • The clustering algorithm has been customized for the electrical pulses from high-energy particle detectors. • Clustering has been applied on the electrical signal coming from scintillator under radiation. • The ability to identify neutrons and gamma patterns has been verified. In several nuclear applications, scintillators, coupled with a photomultiplier and pulse amplifier, are used in order to detect high energy particles, i.e. neutrons and gamma rays. The different particles incident on the scintillator produce electrical pulses having different shape; moreover, the amplitude of these signals is related to the particles energy. The electrical pulses of the scintillator chain are acquired by digital systems that, generally, perform a triggered acquisition consisting of a stream of pulse windows. The aim of this study is the development of a simplified clustering algorithm able to produce reference patterns in compliance with the pattern recognition algorithm based on the matched filter technique, starting from a stream of pulses generated by particles having different energy and type. This paper contains a general description of the clustering algorithm and of the main customizations performed for the scintillator signals. In order to test in real case the efficiency, the algorithm has been applied on the data acquired during a radiation test performed at Frascati Neutron Generator for Stilbene scintillator. The results show that this algorithm works properly, deriving the centroids of the clusters representing the neutron and gamma shapes, together with their occurrences in the analysed data stream. [ABSTRACT FROM AUTHOR]

This paper aims to evaluate not only photon and neutron but also proton and alpha shielding effectiveness of barium bismuth borate glasses doped by CeO 2. The mass attenuation coefficients (μ/ρ) of these glasses have been computed utilizing MCNPX (2.6.0) code in a wide energy range of 0.02–20 MeV and compared with the results of WinXCOM software. Afterwards, some photon attenuation parameters such as half-value layer, (HVL), tenth-value layer (TVL), mean free path (MFP), effective atomic number (Z eff), effective electron density (N el), photon transmission factors (TF) and neutron effective removal cross-sections (Σ R) for the cerium oxide substituted barium bismuth borate glasses have been estimated. Using G-P fitting method, exposure buildup factor (EBF) values have been found over the energy range 0.015–15 MeV up to 40 mfp. In addition, Mass stopping power (MSP) and projected range (PR) values have been calculated for proton particles (H1) and alpha particles (He+2). The results exhibit that the density of the glass can be related to the photon and neutron shielding. A10 glass has the highest Σ R values whereas the lowest TF values in gamma and neutron radiation have been observed for A1 sample. A1 and U glasses possess the highest values of Z eff as well as the smallest values of EBF. It can be concluded that A1 and A10 glasses are alternative materials with terms of photon and neutron attenuation, respectively. [ABSTRACT FROM AUTHOR]

Abstract The GAMMA-400 currently developing space-based gamma-ray telescope is designed to measure the gamma-ray fluxes in the energy range from ∼20 MeV to several TeV in the highly elliptic orbit (without shadowing the telescope by the Earth) continuously for a long time. The physical characteristics of the GAMMA-400 gamma-ray telescope, especially the angular and energy resolutions (at 100-GeV gamma rays they are ∼0.01° and ∼1%, respectively), allow us to consider this space-based experiment as the next step in the development of extraterrestrial high-energy gamma-ray astronomy. In this paper, a method to improve the reconstruction accuracy of incident angle for low-energy gamma rays in the GAMMA-400 space-based gamma-ray telescope is presented. The special analysis of topology of pair-conversion events in thin layers of converter was performed. Applying the energy dependence of multiple Coulomb scattering for pair components, it is possible to estimate the energies for each particle, and to use these energies as weight in the angle reconstruction procedure. To identify the unique track in each projection the imaginary curvature method is applied. It allows us to obtain significantly better angular resolution in comparison with other methods applied in current space-based experiments. When using this method for 50-MeV gamma rays the GAMMA-400 gamma-ray telescope angular resolution is about 4°. [ABSTRACT FROM AUTHOR]

Highlights • A Gamma accelerated degradation model based on the principle of degradation mechanism invariance is proposed. • The existence of the maximum likelihood estimate of the parameters of the proposed model is proved. • The approximate confidence interval for the shape parameter based on Cornish–Fisher expansion is derived. • The generalized confidence intervals for other model parameters and some important quantities are developed. Abstract This paper proposes a Gamma constant-stress accelerated degradation model based on the principle of the degradation mechanism invariance. The maximum likelihood estimators of the parameters of the proposed model are derived. Based on Cornish–Fisher expansion, the approximate confidence interval for the shape parameter of the Gamma degradation process is developed. Since it is difficult to obtain the exact confidence intervals for other model parameters and some quantities such as the mean degradation in unit time, the quantile and the reliability function of the lifetime at the normal stress level, the generalized confidence intervals for these quantities are proposed. The percentiles of the proposed generalized pivotal quantities can be obtained by the simulation. The performances of the proposed confidence intervals are evaluated by the Monte Carlo simulation method. In the simulation study, the proposed confidence intervals are compared with the Wald and the bootstrap- p confidence intervals. The simulation results show that the proposed confidence intervals outperform the Wald and the bootstrap- p confidence intervals in terms of the coverage percentage. Finally, a real example is used to illustrate the proposed procedures. [ABSTRACT FROM AUTHOR]

Abstract The paper strives to identify through geostatistical simulations the parameters which build up a correlation between radionuclide activity concentrations measured on core samples and corresponding in situ total gamma count rates measured into boreholes drilled within the contaminated soil. This numerical exercise demonstrates that a linear relationship should exist between logarithmic values of in situ count rates and logarithmic values of activity concentrations when the contamination is strongly structured through space. A sensitivity analysis to some parameters (geostatistical range of the contamination structure, core sampling method, soil water content, multiple gamma-emitter contamination, etc.) is undertaken to identify which situations may impede the use of such a correlation. Then this approach is applied on Chernobyl measurements undertaken in 2015 and compared to the co-kriging method which considers the localization of the measurements and the additional measurements. It appears that co-kriging is a better estimator than linear regression, but the latter remains an acceptable way of estimating activity from gamma emitters and presents better results than lognormal regression. Therefore, total gamma logging measurements performed into boreholes of porous media contaminated by gamma-emitting radionuclides can be used for characterizing contamination and dealing with its spatial variability with the use of co-kriging. Graphical abstract Image 1 Highlights • The correlation between 137Cs activity and gamma count rates exists as long as 137Cs activity is structured in space. • Lognormal transformation is the best way to build this correlation but the bias induced has to be corrected in the back transformation. • Linear regression to estimate 137Cs activity by gamma count rates remains acceptable but cokriging is the best option to do so. [ABSTRACT FROM AUTHOR]

Highlights • Investigation of the influence of homogenization on nuclear heating and shielding. • Heterogeneous model with detailed description of the BSM cooling system. • Homogeneous model simplified by removing pipes and introducing mixed materials. • Nuclear heating was calculated for several components and on a fine mesh for both models. • Homogenization tends to underestimate the local heat deposition and overestimates shielding. Abstract The electron cyclotron-heating upper launcher (ECHUL) will be installed in four upper ports of the ITER tokamak thermonuclear fusion reactor. Each ECHUL is able to deposit 8 MW power into the plasma for plasma mode stabilization via microwave beam lines. These beam lines and other components needed for the guidance of the microwaves are mounted into the upper port plug. In order to protect these components and to mitigate radiation leaving the reactor, several shield blocks are also included in the port plugs design. The ECHUL components which are closest to the fusion plasma are heated by the gamma and neutron radiation and therefore will need to be actively cooled. This paper reports on the influence of material homogenization by comparing results obtained in the neutronic analyses performed for the cooling system of the ECHUL blanket shield module (BSM). A small reduction in shielding performance of the BSM was found in the case of a heterogeneous description of the BSM compared to the standard approach of homogenizing the materials of the BSM by removing pipes and cooling circuits for the neutronic analyses. [ABSTRACT FROM AUTHOR]

Sensor technologies will play a key role in the success of Remote Maintenance (RM) systems for future fusion reactors. In this paper, three key types of sensor technologies of particular interest in the robotics field at the moment are evaluated, namely: Colour-Depth cameras, LIDAR (Light Detection And Ranging), and Millimetre-Wave (mmWave) RADAR. The evaluation of the sensors is performed based on the following criteria: the types of data they provide, the accuracy at different distances, and the potential environmental resistance of the sensor (namely gamma radiation). The authors review the progress in making these three types of sensor capable of operating in Fusion facilities and discuss possible mitigations. Experiments are performed to demonstrate the pros and cons of each type of sensor by collecting data from radar, colour-depth camera and LIDAR, simultaneously. The paper concludes with a performance comparison between sensors, as well as discussing the possibility of combining them, fostering redundancy in case of failure of any individual sensor device. [ABSTRACT FROM AUTHOR]

• Piezoelectric technology is suitable for working under ITER conditions, with a good behavior in radiation environments. • The tested piezo actuator can work after being irradiated, although its maximum speed has been reduced by around 12%. • The controller to drive the piezo actuator can be located up to 110 m away, to keep electronics away from radiation. The Wide Angle Viewing System (WAVS) for ITER is a major diagnostic for machine protection, plasma control and physics analysis. The diagnostic will measure the surface temperature of the plasma facing components by infrared thermography being one of its main roles to protect them from damage. It will also image the plasma emission in the visible range. The full system is composed of 15 lines of sights located in four equatorial ports (3, 9, 12 and 17). As part of the ex-vessel optics, the first element of the optical chain is the Optical Hinge (OH). It is constituted by two folding mirrors which face the port plug exit optical beam. The mission of this component is to compensate the differential motion between the vacuum vessel and the building, during normal operation and baking. This function will be performed by means of a piezo actuator coupled to the OH upper mirror (and a set of reference switches) to drive the vertical displacement of the mirror in order to get the desired alignment position of the optical beam. The piezo actuator has been identified as the main critical item of the OH what has motivated the fabrication of an OH prototype (for one line of sight) aimed at performing a set of tests to validate the piezo actuator under operation conditions. The tests have consisted in the characterization of the piezo actuator behavior with the nominal load after being irradiated to 272.40 kGy of total accumulated gamma dose, which is the dose expected in ITER. Moreover, additional tests have been conducted to find out the influence of the cable length from the piezo actuator to the controller in the performance. A description of these tests and the results obtained will be presented in the paper. [ABSTRACT FROM AUTHOR]

• FOCS will be used to perform current measurements in the ITER harsh environment, with the sensing fibre located directly on the vacuum vessel. • Samples of candidate FOCS optical fibres were exposed in neon atmosphere at 110 °C to Co60 gamma radiation up to 3 MGy, and then annealed at 210 °C, which is representative for service condition during ITER nuclear operation. • The fibre sequential ageing was addressed using gravimetry and microscopic optical inspection. • The applied stress is beyond the standard limits, but the fibres survived the exposure without critical degradation. • The results are attributed to the use of the inert atmosphere. ITER is expected to achieve new milestones on the way to commercial fusion energy production. This will be still a research machine where numerous diagnostic systems are deployed, both already used on existing tokamaks and developed specifically for burning plasma operation. One of the innovative diagnostics is the Fibre Optics Current Sensor (FOCS). This paper describes recent results of the ITER FOCS development, concentrating on the front-end design. The FOCS sensing fibre, likely acrylate coated, will be located directly on the external surface of the vacuum vessel. During operation, it will be exposed to temperatures of 100–110 °C and multi-MGy level total radiation doses, while during vacuum vessel baking intervals the temperature will be 200–210 °C with low levels of radiation. Such temperatures are outside the nominal range for acrylate coatings even for acrylate coatings specially designed for high temperature applications. We provide experimental results that indicate that acrylate coated fibres FOCS fibres nevertheless can survive ITER environment without critical degradation and attribute this to the system design, for which the fibre operates in an inert gas (neon) atmosphere. [ABSTRACT FROM AUTHOR]

In this paper, we explore the possibility of a linearly polarized gamma-ray signal from dark matter annihilations in the Galactic center. Considering neutral weakly interacting massive particles, a polarized gamma-ray signal can be realized by a two-component dark matter model of Majorana fermions with an anapole moment. We discuss the spin alignment of such dark matter fermions in the Galactic center and then estimate the intensity and the polarizability of the final-state electromagnetic radiation in the dark matter annihilations. For low-mass dark matter, the photon flux at sub-GeV energies may be polarized at a level detectable in current X-ray polarimeters. Depending on the mass ratio between the final-state fermion and DM, the degree of polarization at the mass threshold can reach 70% or even higher, providing us with a new tool for probing the nature of dark matter in future gamma-ray polarization experiments. [ABSTRACT FROM AUTHOR]

The International Fusion Materials Irradiation Facility (IFMIF) aims to provide an accelerator-based, D-Li neutron source to produce high energy neutrons at sufficient intensity and irradiation volume for fusion materials qualification. The LIPAc is a 125 mA 9 MeV continuous wave deuteron accelerator whose components are under construction mainly in Europe, which is being installed in Rokkasho (Japan) with the purpose of validating the IFMIF accelerator design. The beam generated by the LIPAc accelerator will be stopped by a copper cone (2.5 m long, 6.8° angle), cooled by water flowing at high velocity along its outer surface. This piece is surrounded by a shield made of iron and low Z materials for attenuating the neutron and gamma radiation originated by the interaction of the deuterons with the copper. It incorporates dedicated diagnostics for beam dump monitoring: accelerometers for detection of localized heating due to incorrect alignment of the beam and ionization chambers, which ensure that the deuteron beam footprint remains within the beam dump design limits. A lead shutter has been designed to be inserted in the beam tube during beam-off periods to stop the gamma radiation from the activated copper cone escaping through the beam tube, allowing access inside the accelerator vault. The junction of the beam dump to the beam tube has a special design to allow its remote disconnection, enabling the end of life decommissioning operations of the facility. The design and material selection of the beam dump and neighboring elements are driven by a maintenance-free requirement after a short period of operations, as the cartridge activation precludes any maintenance activities in the beam dump and neighboring elements downstream the lead shutter. This paper describes the design and manufacturing of the beam dump and related elements explaining the interrelations between them and the reasons behind their main features. [ABSTRACT FROM AUTHOR]

As an efficient image contrast enhancement (CE) tool, adaptive gamma correction (AGC) was previously proposed by relating gamma parameter with cumulative distribution function (CDF) of the pixel gray levels within an image. ACG deals well with most dimmed images, but fails for globally bright images and the dimmed images with local bright regions. However, such two categories of brightness-distorted images are universal in real scenarios, such as those incurred by improper exposure and white objects. In order to attenuate such deficiencies, in this paper we propose an improved AGC technique. The novel strategy of negative images is used to realize CE of the bright images, and the gamma correction modulated by truncated CDF is employed to enhance the dimmed ones. As such, local over-enhancement and structure distortion can be alleviated effectively. Extensive qualitative and quantitative experimental results show that our proposed method yields consistently good CE results. [ABSTRACT FROM AUTHOR]

Graft copolymer of natural rubber (NR) and styrene to used as a blend with styrene-butadiene for green tire can be produced via three techniques: emulsion polymerization (EP), electron beam irradiation (EB), and gamma ray irradiation (GR). Products from all techniques had similar cross-linking properties; leading to similar mechanical properties. Therefore, producing the graft copolymer using less resources is the best choice as it is a cleaner production. This paper compared the environmental impact assessment of these three production processes. SimaPro version 7.3 software using Eco-indicator 99 method for environmental impact assessment was used throughout this study. The functional unit (FU) used was 100 g of grafted rubber product, with the considered system boundary starting from raw materials for the production of a specified product and continuing to the end of copolymerization processes (cradle-to-gate). The results indicated that, at the laboratory scale, the EB technique had the largest contribution of environmental impacts, followed by EP and GR techniques. However, operating at the maximum capacity led to an overall reduction of all impacts. The reduction was improved by 86.32% for EB and by 60.5% for GR. However, production by EB still contributed the highest overall environmental impact, while GR contributed the least. In decreasing order of significance, the main impacts of EB were resources (R), human health (HH), and ecosystem quality (EQ). The essential factors which caused these impacts were, in decreasing order of significance, the usages of electricity, NR, and styrene. Therefore, GR method was the choice for scaling up the green production process in both saving the electricity usage and for improvement in the environmental impacts. [ABSTRACT FROM AUTHOR]

This paper summarizes the results of investigations of hybrid concrete containing scale and granulated lead–zinc slag wastes as substitutes for sand. Specifically, scale and granulated lead–zinc slag wastes are completely substituted for natural sand in concrete. The aim of this study was to investigate the effects of these waste materials on gamma radiation shielding and on the compressive strength properties of concrete. The linear attenuation coefficient (μ, cm −1 ) and compressive strength of the samples were measured experimentally and calculated, and the experimental values were subsequently compared with those of conventional concrete. The results clearly showed that hybrid scale waste/granulated lead–zinc slag waste concrete (Sc/Glzs-C) has better radiation shielding and compressive strength properties than conventional concrete. An additional objective of this study was to calculate the thickness of the hybrid concrete shield to be used instead of conventional concrete. The results showed that the produced concrete demonstrates better radiation attenuation properties with thinner thickness compared to conventional concrete. As a result, the new concrete containing scale waste and granulated lead–zinc slag waste is suitable for gamma radiation attenuation. [ABSTRACT FROM AUTHOR]

• Liquid film thickness profiles in gas–liquid annular flow can be reconstructed from stereoscopic X-ray data. • Using X-ray data, the film thickness can be obtained at hundreds of points around the pipe perimeter. • The film thickness detection limit is approximately 30 µm with the presented setup. • The method is applicable to 2-phase or 3-phase systems, to horizontal or inclined pipes, and to steady or dynamic systems. • Experiments have been performed with high-density SF6 gas and Exxsol D60 oil. This paper presents a method for reconstructing the thickness profile of the thin liquid film being present in steady, fully developed gas–liquid annular pipe flow, taking advantage of nonintrusive X-ray measurements. Experiments have been performed with low liquid loading, annular flows, in a near horizontal pipe system (inclination +2.5°), using a high-density gas (SF 6) and Exxsol D60 oil. Special care was taken to ensure the flows were fully developed, and statistically steady. The superficial gas velocity was maintained at a constant value of 10 m/s, while the superficial liquid velocity was varied between 0.5 mm/s and 42 mm/s. The X-ray measurements were supplemented by gamma ray densitometer data and isokinetic data. An explicit mathematical method is presented, whereby the shape and thickness of very thin liquid films can be reconstructed if X-ray images of the flow have been obtained from two independent directions: one with a vertical view of the pipe, and another with a horizontal side view. The method can be straightforwardly applied to cases where the film volume dominates the total volume of droplets suspended in the gas phase. This condition is generally satisfied for the experiments presented in this paper, as verified by isokinetic measurements. Mean liquid hold-up values determined by gamma densitometer are in reasonable agreement with the X-ray results. It is found that the mean film thickness at any position on the pipe wall increases with the superficial liquid velocity. While the film thickness is maximal at the pipe bottom in virtually all experimental cases, its profile exhibits multiple local maxima and minima, with the smallest thickness apparently 20°–30° away from at the pipe top. The presented film reconstruction method is highly sensitive; even at extremely low liquid levels, with a superficial liquid velocity less than 0.01% of the mixture velocity, the film and its thickness profile are clearly detected. An analytical fit for the film profile as a function of perimeter angle and superficial liquid velocity is given. The fit captures the main features of the profile as derived from X-ray measurements, for thin films with maximum thickness less than 5% of the pipe diameter. [ABSTRACT FROM AUTHOR]

This study focuses on one of the resistivity imaging tools owned by Schlumberger; Full-bore Formation Micro Imager (FMI). The objective of this paper is to analyze quantitative analysis that is carried out focusing on calculating the volume on clay volume and net-to-gross measurement. Clay volume in a thinly bedded interval was estimated based on the gamma ray log and one FMI trace (out of 192 traces). The gamma ray log data resolution is considerably lower than the FMI log to reflect accurate lithology changes in thinly bedded reservoirs. It has been found afterthought some calibrations and corrections on the FMI resistivity log, the new processed log is used for clay volume and net to gross calculation of the reservoir, indicating the potential of this log for analysis of thin beds. A comparison between VNG-NERGE, NORTH SEA WELL, NERWING and LAGIA-8, LAGIA, EGYPT indicates the calculation for shale volume at different intervals using FMI tools. [ABSTRACT FROM AUTHOR]

Considering safety is the priority concern of nuclear power plants, equipment qualification testing of the nuclear components manufactured should be paid special attention to. Thereinto, equivalent conversion (1:1) from the absorbed beta doses to gamma doses is a rule of thumb for irradiation qualification testing of the polymers used as nuclear cables, however whether it is reasonable and applicable to Chinese domestic polymers still requires investigation. In this paper, both gamma and beta irradiation testing with the actual dose rates and total absorbed doses in China Advanced Passive (CAP) series nuclear power plant was performed upon one domestically manufactured ethylene-propylene rubber intended for nuclear cable insulation in China. The mechanical and the electrical properties before and after irradiation were measured to compare the extent and the trend of degradation between the two irradiation types, and related oxidation degradation mechanism especially its attenuation along the thickness was quantitatively addressed. [ABSTRACT FROM AUTHOR]

In this paper, we report ab initio studies of structural, electronic and elastic properties of a II-V group semiconductor compound, Zn 3 As 2 along with its experimental Compton profile (CP). For experimental CP, 59.54 keV gamma ray (radiation source:5 Ci 241 Am) spectrometer is used and to deal with the theoretical part, density functional theory, Hartree-Fock as well as the hybrid functional theory, implemented in CRYSTAL code, are used. A full structure optimization following an equation of state calculation is performed to get the structural parameters. Further directional CPs, band structure, density of states, Mulliken population analysis and elastic properties have also been computed. A concurrence-test with experimental CP proves hybrid scheme to provide the best results in the present case. [ABSTRACT FROM AUTHOR]

The problem of how to accurately measure the flow rate of oil–gas–water mixtures in a pipeline remains one of the key challenges in the petroleum industry. This paper proposes a new methodology for identifying flow regimes and predicting volume fractions in gas-oil-water multiphase systems using dual energy fan-beam gamma-ray attenuation technique and artificial neural networks. The novelty of this study in comparison with previous works, is using just 4 extracted features (photo peaks of 241 Am and 137 Cs in 2 detectors) from the gamma ray spectrums instead of using the whole gamma ray spectrum, which reduces the undesired noises and also improves the speed of recognition in real situations. Radial basis function was used for developing the neural network model in MATLAB software in order to classify the flow patterns (annular, stratified and homogenous) and predict the value of volume fractions. The ideal and static theoretical models for flow regimes have been developed using MCNP-X code. The proposed networks could correctly recognize all the three different flow regimes and also determine volume fractions with mean absolute error of less than 5.68% according to the recognized regime. [ABSTRACT FROM AUTHOR]

As part of ongoing efforts to develop the data base required for the gamma dose rate baseline in Kuwait, a survey of ambient outdoor gamma-ray dose rates was carried out in 112 locations within the country. Measurements were performed, during the period from August 2013 to March 2016, in various undisturbed open areas in the desert using a NaI dosimeter/spectrometer. The dose rates were recorded along with the corresponding gamma-ray spectra for in-situ relative contribution of the primordial radionuclides and 137 Cs in the outdoor environment. Soil samples were also collected from the surface layers in a few locations for laboratory gamma spectrometric analysis and dose rate calculations. The dose rates obtained range from 31 to 59 nSv/h with a mean value of 46.5 nSv/h. There was no anomaly in the relative contributions of the primordial radionuclides to the dose rate values, while 137 Cs was not detected within the investigated locations. The significance of using the NaI-based dosimeter in the present survey is discussed in the paper. [ABSTRACT FROM AUTHOR]

Tungsten trioxide nanoparticles (WO 3 NPs) find a wide variety of use in industrial applications, and particularly they possess good gas sensing capabilities. In this paper, WO 3 NPs have been prepared by a microwave method and successively irradiated with 60 Co gamma rays at different doses (0, 50 and 100 kGy). The effect of gamma irradiation on structural, electrical and gas sensing properties of irradiated WO 3 nanoparticles (NPs) were investigated. The morphological and microstructural characteristics were studied using transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR), respectively. The results of characterization have shown that γ-irradiation induces significant changes in the WO 3 microstructure, favoring the tetragonal to triclinic transformation, along with a reduction of the grain size. Resistive sensors fabricated using γ-irradiated WO 3 NPs were tested for detection of NH 3 , CO and CO 2 in air. It was found that the response to NH 3 decreased after γ-irradiation, while that of CO 2 increased. Further, γ-irradiated WO 3 based sensor exhibited improved recovery time for NH 3 , when compared to that of pristine WO 3 based sensor. The behavior observed suggests that the acid-base characteristics of WO 3 NPs sensing layer were also largely modified as a results of the surface microstructure changes after the γ-irradiation treatment. Results demonstrated that the γ-irradiation process could be an effective tool for tailoring the sensing properties of WO 3 NPs. [ABSTRACT FROM AUTHOR]

Triclosan is an antimicrobial agent which has been frequently detected in the environment. In this paper, the biodegradation of triclosan after radiation-induced advanced oxidation was investigated. The results show that the removal efficiency of triclosan in the combined irradiation and biological treatment process ranged from 88% to 97%, depending on the absorbed dose, while it was only 54% in the single biological treatment process. The removal efficiency of total organic carbon (TOC) was in the range of 53.1%,−59.2% at dose of 1–5 kGy in the combined irradiation and biological treatment process. In comparison, the removal efficiency of TOC in the single biological treatment process was 24.5%, suggesting that irradiation can enhance the mineralization of triclosan. The dechlorination efficiency of triclosan ranged from 48.6% to 78.4% at dose of 1–5 kGy. The intermediates of triclosan degradation were tentatively identified by LC-MS analysis and the possible degradation pathway was proposed. Based on the above results, the combined irradiation and biological treatment process could be an alternative process for treating triclosan-containing wastewater. [ABSTRACT FROM AUTHOR]

An extensive network of dose rate monitoring stations continuously measures ambient dose rate across Europe, as part of the EURDEP system. Its purpose is early warning in radiological emergencies and documenting its temporal and spatial evolution. In normal conditions, when there is no contribution to the dose rate signal coming from fresh anthropogenic contamination, the data represent the radiation "background", i.e. the combined natural radiation and existing anthropogenic contamination (by global and Chernobyl fallout). These data are being stored, but have so far not been evaluated in depth, or used for any purpose. In the framework of the EU project 'European Atlas of Natural Radiation' the idea has emerged to exploit these data for generating a map of natural terrestrial gamma radiation. This component contributes to the total radiation exposure and knowing its geographical distribution can help establishing local 'radiation budgets'. A further use could be found in terrestrial dose rate as a proxy of the geogenic radon potential, as both quantities are related by partly the same source, namely uranium content of the ground. In this paper, we describe in detail the composition of the ambient dose equivalent rate as measured by the EURDEP monitors with respect to its physical nature and to its sources in the environment. We propose and compare methods to recover the terrestrial component from the gross signal. This requires detailed knowledge of detector response. We consider the probes used in the Austrian, Belgian and German dose rate networks, which are the respective national networks supplying data to EURDEP. It will be shown that although considerable progress has been made in understanding the dose rate signals, there is still space for improvement in terms of modelling and model parameters. An indispensable condition for success of the endeavour to establish a Europe-wide map of terrestrial dose rate background is progress in harmonising the European dose rate monitoring network. [ABSTRACT FROM AUTHOR]

The environmental radiation exposure in Canada has been monitored since 2002 by Health Canada's Fixed Point Surveillance network. The network consists of over eighty 7.6 cm × 7.6 cm sodium iodide spectrometers, and routinely reports to the public the environmental gamma radiation level throughout Canada. This paper describes the latest dose calibrations to air kerma and ambient dose equivalent for the future upgraded network. The calibration curves were developed using Monte Carlo techniques and further optimized via experiments in various reference fields. The dose calibration was validated over a wide range of gamma energy, dose measurement range, and angle of incidence under laboratory conditions. In environmental monitoring situations, the angular distribution of radiation exposure was analytically calculated by assuming a semi-infinite plume source, semi-infinite planar source, and infinite volume sources for the respective exposure scenarios of radioactive plume, ground contamination, and soil source. By coupling the resultant radiation angular distribution with detector's angular variation on dose response, the overall accuracy of dose measurement in each of these environmental scenarios was estimated. The accuracy is expected to be within ±3.7% for plume radiation, −5.6% for 137Cs ground contamination, and 0% to −17.1% for soil radioactive sources. The under-estimation for soil sources is mainly caused by absorption of radiation in the electronic system underneath the crystal. • The detectors of Health Canada's Fixed Point Surveillance network were calibrated to air kerma and ambient dose equivalent. • Dose calibration was based on Monte Carlo method and validated with empirical data. • The linearity, energy dependence and angular dependence of dose measurement were checked under laboratory conditions. • The overall accuracy of dose measurement was estimated in a few environmental monitoring scenarios. • The conformity of dose calibration to international standards on the dose response and accuracy was reviewed. [ABSTRACT FROM AUTHOR]