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The accurate calculations of neutron-induced reaction cross sections are relevant for many nuclear applications. The photon strength functions and nuclear level densities are essential inputs for such calculations. These quantities for 235U are studied using the measurement of the gamma de-excitation cascades in radiative capture on 234U with the Total Absorption Calorimeter at n_TOF at CERN. This segmented 4π gamma calorimeter is designed to detect gamma rays emitted from the nucleus with high efficiency. This experiment provides information on gamma multiplicity and gamma spectra that can be compared with numerical simulations. The code DICEBOXC is used to simulate the gamma cascades while GEANT4 is used for the simulation of the interaction of these gammas with the TAC materials. Available models and their parameters are being tested using the present data. Some preliminary results of this ongoing study are presented and discussed.

The n_TOF neutron time-of-flight facility at CERN is used for high quality nuclear data measurements from thermal energy up to hundreds of MeV. In line with the CERN open data policy, the n_TOF Collaboration takes actions to preserve its unique data, facilitate access to them in standardised format, and allow their re-use by a wide community in the fields of nuclear physics, nuclear astrophysics and various nuclear technologies. The present contribution briefly describes the n_TOF outcomes, as well as the status of dissemination and preservation of n_TOF final data in the international EXFOR library.

The 235U neutron-induced cross section is widely used as reference cross section for measuring other fission cross sections, but in the resonance region it is not considered as an IAEA standard because of the scarce experimental data covering the full region. In this work, we deal with a new analysis of the experimental data obtained with a detection setup based on parallel plate ionization chambers (PPACs) at the CERN n_TOF facility in the range from 1 eV to 10 keV. The relative cross section has been normalised to the IAEA value in the region between 7.8 and 11 eV, which is claimed as well-known. Comparison with the ENDF/B-VII evaluation and the IAEA reference file from 100 eV to 10 keV are provided.

The 238U fission cross section is an international standard beyond 2 MeV where the fission plateau starts. However, due to its importance in fission reactors, this cross-section should be very accurately known also in the threshold region below 2 MeV. The 238U fission cross section has been measured relative to the 235U fission cross section at CERN – n_TOF with different detection systems. These datasets have been collected and suitably combined to increase the counting statistics in the threshold region from about 300 keV up to 3 MeV. The results are compared with other experimental data, evaluated libraries, and the IAEA standards.

Ions and radionuclide diffusivity in concrete is one of the most important factors that determine service life and safety assessment of cement based structures in nuclear power plants and radioactive-waste repositories. Apart from the influence of cement paste microstructure, the presence of aggregates may have an impact on transport properties of the material. The well-known interfacial transition zone, denoted by ITZ, is created near the aggregates and characterized by a greater porosity. The goal of this study is to investigate the competition between the more diffusing ITZ zone and the less diffusing aggregates. To this end, several series of tritiated water diffusion tests are conducted on mortars characterized by different water-to-cement ratios and sand volume fractions. In parallel, microstructure of these materials is explored by mercury and water porosimetry. It was observed that at low sand content (0% – 50%), diffusion properties of mortars are dominated by aggregates dilution effect. At 60% sand, diffusion increases significantly suggesting that percolation’s pores threshold has been reached. Results indicate also that sand particle size distribution has a great impact on the diffusivity of mortars.

This article illustrates a contribution of the CEA Laboratory of Concrete and Clay Behavior (“LECBA”s) for the assessment and modeling of the Long-Term behavior of cementitious and clayey materials in the context of nuclear ILW (Intermediate Level Waste) management. In particular, we aim at presenting two main topics that are studied at the Lab. The first one is linked to safety aspects and concern hydrogen transfer within cementitious as well as clayey materials (host rock for French nuclear waste disposal). The second point concerns the assessment of durability properties of reinforced concrete structures in the disposal (pre-closure and post-closure) conditions. Experimental specific tests and phenomenological modelling are presented.

The CERN Neutron Time-Of-Flight (n_TOF) facility is well suited to measure low cross sections as those of neutron-induced fission in subactinides. The cross section ratios of natPb and 209Bi relative to 235U and 238U were measured using PPAC detectors and a fragment coincidence method that allows us to identify the fission events. The present experiment provides first results for neutron-induced fission up to 1 GeV. Good agreement is found with previous experimental data below 200 MeV. The comparison with proton-induced fission indicates that the limiting regime where neutron-induced and proton-induced fission reach equal cross sections is close to 1 GeV.

In the framework of the ICERR (International CEntres based on Research Reactors) project, the effect of neutron/gamma irradiation on material has been studied. In this work, we investigate the mixed neutron/gamma irradiation effects on the optical properties of epoxy resin polymers. Photoluminescence (PL) measurements are used in epoxy resin films irradiated in the dose range from 0 to 900 Gy. For more information about the carriers dynamics, we studied their activation energy and phononic processes through the analysis of the PL spectrum evolution as a function of temperature. Mostly, materials irradiation studies by ionizing sources show a generation of defects and subsequently lead to the damage and degradation on the different properties. In this study we have shown an advantage of neutron/gamma irradiation, it is the improvement of the luminescence properties. The 500 Gy dose has the highest quantum yield at low temperature. But the 600 Gy dose shows the highest yield at room temperature. For the 500 Gy dose, the neutron/gamma treatment mainly favored the activation of carriers from lower to higher levels. On the other side with the 600 Gy dose, there was a combination between the activation of carriers from lower to higher levels and the ionization of trapped electrons in the defects centers. [ABSTRACT FROM AUTHOR]

The title compound (disodium dipotassium copper(II) tris-[molybdate (VI)]) is prepared by form melt and characterized by single crystal X-ray diffraction and UV-vis spectroscopy. It crystallizes in the triclinic space group P-1 with a = 7.4946(8) Å, b = 9.3428(9) Å, c = 9.3619(9) Å, α = 92.591(7)°, β = 105.247(9)°, γ = 105.496(9)°, V = 604.7 Å3, and Z = 2. Its structure is isotypic with that of Na4Mn(MoO4)3. It is formed by Cu2O10 distorted bi-octahedral dimers linked by two bridging bidentate Mo2O4 tetrahedra and, additionally, two monodentate Mo1O4 tetrahedra to form Cu2Mo4O20 units. These units are linked by the insertion of Mo3O4 tetrahedra to build infinite ribbons disposed along the c axis. All of these ribbons form a one-dimensional framework. Both K1 and K3 cations are located in the inversion center, and all the other atoms are at general positions. The structure model is supported by the bond valence sum (BVS) and charge distribution CHARDI methods. The Cu2+ cations adopt the [4+2] CuO6 Jahn-Teller distortion giving rise to an intense d-d transition in the UV-vis absorption spectra. [ABSTRACT FROM AUTHOR]

The title compound (disodium dipotassium copper(II) tris-[molybdate (VI)]) is prepared by form melt and characterized by single crystal X-ray diffraction and UV-vis spectroscopy. It crystallizes in the triclinic space group P-1 with a = 7.4946(8) Å, b = 9.3428(9) Å, c = 9.3619(9) Å, α = 92.591(7)°, β = 105.247(9)°, γ = 105.496(9)°, V = 604.7 Å3, and Z = 2. Its structure is isotypic with that of Na4Mn(MoO4)3. It is formed by Cu2O10 distorted bi-octahedral dimers linked by two bridging bidentate Mo2O4 tetrahedra and, additionally, two monodentate Mo1O4 tetrahedra to form Cu2Mo4O20 units. These units are linked by the insertion of Mo3O4 tetrahedra to build infinite ribbons disposed along the c axis. All of these ribbons form a one-dimensional framework. Both K1 and K3 cations are located in the inversion center, and all the other atoms are at general positions. The structure model is supported by the bond valence sum (BVS) and charge distribution CHARDI methods. The Cu2+ cations adopt the [4+2] CuO6 Jahn-Teller distortion giving rise to an intense d-d transition in the UV-vis absorption spectra. [ABSTRACT FROM AUTHOR]

Single crystals of new triple molybdate - sodium potassium copper(II) tetra-[molybdate(VI)] Na0.45K1.55Cu3(MoO4)4 - are synthesized by a solid-state reaction and its crystal structure is determined. The compound crystallizes in the monoclinic space group P21/c with a = 5.097(2) Å, b = 14.594(3) Å, c = 19.905(3) Å, β = 94.00(2)°, V = 1476.9(7) Å3, Z = 4. K2 and Na1 cations are located at the same general site with occupancies of 0.55 and 0.45 respectively. The structure is formed by infinite Cu3Mo3O23-type ribbons. These ribbons are connected by a tridentate tetrahedron sharing vertices to build layers parallel to the (001) plane. All these layers are connected by vertices to form a three-dimensional framework. The structural model is supported by the bond valence sum. The electrical properties of the title compound are investigated using complex impedance spectroscopy. [ABSTRACT FROM AUTHOR]

Single crystals of new triple molybdate - sodium potassium copper(II) tetra-[molybdate(VI)] Na0.45K1.55Cu3(MoO4)4 - are synthesized by a solid-state reaction and its crystal structure is determined. The compound crystallizes in the monoclinic space group P21/c with a = 5.097(2) Å, b = 14.594(3) Å, c = 19.905(3) Å, β = 94.00(2)°, V = 1476.9(7) Å3, Z = 4. K2 and Na1 cations are located at the same general site with occupancies of 0.55 and 0.45 respectively. The structure is formed by infinite Cu3Mo3O23-type ribbons. These ribbons are connected by a tridentate tetrahedron sharing vertices to build layers parallel to the (001) plane. All these layers are connected by vertices to form a three-dimensional framework. The structural model is supported by the bond valence sum. The electrical properties of the title compound are investigated using complex impedance spectroscopy. [ABSTRACT FROM AUTHOR]

Silica fume cement based materials have long been used in nuclear industry particularly for low-level waste (LLW) and intermediate-level waste (ILW) management. The durability of these materials is therefore of a great importance for the safety of nuclear waste storage. This study investigates the durability in the aspect of tritiated water (HTO) diffusion in relation with the porosity and the microstructure within silica fume cement pastes. Silica fume (SF) was used as a slurry; a liquid mixture of undensified powder and water. Due to its better dispersion, it was found that slurried silica fume improves the pore structure and diffusion properties of SF pastes compared to the use of a densified form of SF. The effect of silica fume and water content were also explored. Silica fume (SF) replacement varying from 0 to 20% by weight of cement was used to prepare cement pastes at water-to-binder ratios (w/b) ranging from 0.3 to 0.5. The manufactured pastes were tested by through-out diffusion and their microstructure characterized by water and mercury porosimetry (MIP), thermogravimetric analysis (TGA) and by scanning electron microscopy (SEM) associated to (EDS) analysis. Test results showed that despite an increase in total porosity, the addition of slurried silica fume has a positive impact on pore refinement and on reducing the effective diffusion coefficients. Finally, HTO diffusion coefficients seem to increase linearly with w/b ratio especially for cement pastes without SF where the increase is more important compared to SF pastes. [ABSTRACT FROM AUTHOR]

Diffusivity of cement-based materials is an important factor regarding durability and the service life prediction of concrete structures. The present research focuses on investigating the influence of aggregates on tritiated water diffusivity of cement-based materials containing slurried silica fume. Effective diffusion coefficients of mortars with several sand volume fractions varying from 0 to 65% were determined by through-out diffusion tests. Microstructure was examined by scanning electron microscopy associated to energy dispersive spectrometry analysis, thermogravimetric analysis, water and mercury porosimetry, and BET adsorption analysis. It was found that large agglomerated particles of silica fume observed in cement paste and mortar with a low sand content (here 10%), reduce pozzolanic reactivity and thus affect the effectiveness of silica fume on the materials sustainability parameters. The clusters present in these formulations are mainly due to the interaction of silica fume with calcium hydroxide of the mixing solution and not to the initial state of the slurry, which was well stirred and whose particles size were checked before use. However, the presence of high content of aggregates (more than 30% of sand volume fraction) during mortar's mixing improves the dispersion of slurried silica fume particles and helps to ‘shear’ and break up agglomerates of silica fume providing a better homogenization of the material and improving the microstructural and diffusivity parameters. The addition of superplastizer in mortars with more than 50% sand content may also participate in dispersing silica fume. [ABSTRACT FROM AUTHOR]

The present study aims to investigate the influence of microstructure, particularly the effect of aggregates content and interfacial transition zone (ITZ), on tritiated water (HTO) diffusivity in mortars. To this end, three different series of mortars were prepared and HTO diffusion tests were conducted. Variables are water-to-cement ratio, sand volume fractions, and particle size distribution. In parallel, the microstructure of these materials was characterized by water porosimetry, mercury porosimetry, and by backscattered electron microscopy associated to images analysis. It was observed that at low sand content (0%–50%), diffusion properties of mortars are dominated by aggregates dilution effect. Beyond 50% of standard sand, other effects related to the large number of sand grains appear, such as air voids and porous areas mainly due to the difficulty of obtaining well-compacted materials. [ABSTRACT FROM AUTHOR]

The diffusion coefficients of ions and radionuclides in cementitious materials are the basic parameters to evaluate the state of the degradation of structures. In this article, three different tracers (two ions, and a radionuclide) were tested on the same formulations of mortars (sand volume fractions from 0 to 60%) in terms of the through-out diffusion, to determine the effective diffusion coefficients of each tracer and each formulation. The aim of this study is to prove the validity of the formation factor equation relating the effective diffusivity of a tracer in cementitious material to its diffusion coefficient in pure water. This result is extremely interesting because once the geometric formation factor of a material is known, it is possible to determine the values of the effective diffusion coefficients of any other diffusing species in this material. [ABSTRACT FROM AUTHOR]

This study is a linear stability analysis of the flows induced by ultrasound acoustic waves (Eckart streaming) within an infinite horizontal fluid layer heated from below. We first investigate the dependence of the instability threshold on the normalized acoustic beam width Hb for an isothermal fluid layer. The critical curve, given by the critical values of the acoustic streaming parameter, Ac, has a minimum for a beam width Hb≈0.32. This curve, which corresponds to the onset of oscillatory instabilities, compares well with that obtained for a two-dimensional cavity of large aspect ratio [Ax=(length/height)=10]. For a fluid layer heated from below subject to acoustic waves (the Rayleigh-Bénard-Eckart problem), the influence of the acoustic streaming parameter A on the stability threshold is investigated for various values of the beam width Hb and different Prandtl numbers Pr. It is shown that, for not too small values of the Prandtl number (Pr>Prl), the acoustic streaming delays the appearance of the instabilities in some range of the acoustic streaming parameter A. The critical curves display two behaviors. For small or moderate values of A, the critical Rayleigh number Rac increases with A up to a maximum. Then, when A is further increased, Rac undergoes a decrease and eventually goes to 0 at A= Ac, i.e., at the critical value of the isothermal case. Large beam widths and large Prandtl numbers give a better stabilizing effect. In contrast, for Prandtl numbers below the limiting value Prl (which depends on Hb), stabilization cannot be obtained. The instabilities in the Rayleigh-Bénard-Eckart problem are oscillatory and correspond to right- or left-traveling waves, depending on the parameter values. Finally, energy analyses of the instabilities at threshold have indicated that the change of the thresholds can be connected to the modifications induced by the streaming flow on the critical perturbations. [ABSTRACT FROM AUTHOR]

The purpose of this work is to study the effect of mixed neutron–gamma radiation (MNGR) on structural, optical and paramagnetic properties on epoxy resin nanostructure thin films [ER]NSTF. These films were prepared and irradiated in the nuclear reactor with dose range between 100 and 900 Gy. After exposure to MNGR, FT-IR results demonstrated the broad ν(OH) and ν(C=O) band to increase with increase in radiation dose, while the ν(C–H) band decreased with increase in radiation dose. This is due to the formation of chain stretch, bending and scission/cross-linking through MNGR that lead to a decrease in the crystallinity region contained within the [ER]NSTF. XRD data confirm these results and show that the crystalline phase was destroyed by MNGR irradiation. PL is used to determine the fundamental transition and defects transitions in [ER]NSTF at 300 K. It was found that MNGR leads to significant enhancement of the luminescence properties. Samples of [ER]NSTF irradiated with 600 Gy dose presented the highest response. Therefore, EPR results confirmed that MNGR induces the paramagnetic center's formation of the [ER]NSTF whose concentration varies differently. [ABSTRACT FROM AUTHOR]

Abstract: The neutron capture and fission cross-sections of 233U have been measured at the neutron time-of-flight facility n_TOF at CERN in the energy range from 1eV to 1keV using a high performance BaF2 Total Absorption Calorimeter (TAC) as a detection device. In order to separate the contributions of neutron capture and neutron induced fission in the TAC, a methodology called Calorimetric Shape Decomposition (CSD) was developed. The CSD methodology is based on the study of the TAC''s energy response for all competing reactions, allowing to discriminate between s originating from neutron induced fission and those from neutron capture reactions without the need for fission tagging or any additional detection system. In this article, the concept behind the CSD is explained in detail together with the necessary analysis to obtain the TAC''s response to neutron capture and neutron induced fission. The discrimination between capture and fission contributions is shown for several neutron energies. A comparison between the 233U neutron capture and fission yield extraction with ENDF/B-VII v1. library data is also provided. [Copyright &y& Elsevier]

Abstract Blended cements with high content of blast furnace slag (CEM III/C) can be used for nuclear waste conditioning because of their low hydration heat as compared to ordinary Portland cements (CEM I). They however contain some sulfide, an impurity whose role needs to be investigated. Indeed, they can have an effect on the radiolytic H 2 production under irradiation. To study the impact of sulfide species on H 2 production, gamma irradiation, at a dose rate of 356 Gy h−1, was performed during 6 months in a closed system without O 2 on a cement paste made with CEM III/C. At short time, the radiolytic H 2 production rate is higher than that measured using CEM I. On the basis of reaction data collected in the literature on sulfur species, radiolysis simulations performed for both systems confirm this behavior. Moreover, they suggest that the sulfide concentration, initially imposed in pore solution by the slag is of the order of 180 mM, and is responsible for this H 2 production. For the first two irradiation months, the following phenomena are then evidenced in CEM III/C: 1) conversion of sulfide into polysulfide anions; 2) pH increase; 3) production of H 2 due to the H•+ H 2 S reaction having a very high rate constant. Nevertheless, in the medium term, the residual sulfide concentration is not sufficient any more for this mechanism to occur. It imposes a reducing environment, leading to a very efficient recombination of H 2 in pore solution. The resulting equilibrium state is reinforced by the high liquid saturation level in the cement paste porosity. Therefore, even if the presence of sulfide species in blended cements momentarily increases the H 2 production rate, it strongly reduces it at long times. Highlights • Reaction between H• radical and H 2 S explains the initial exacerbated H 2 formation. • Residual sulfide leads to efficient H 2 recombination at longer times in closed system. • Radiolysis simulation in pore water is performed with complete sulfur reaction system. • Experiment and simulation match for initial sulfide concentration about 180 mM. [ABSTRACT FROM AUTHOR]

Background: The vast majority of chronic myeloid leukemia (CML) patients have a single translocation t(9;22)(q34;q11), BCR/ABL1 fusion genes, which is regarded as the hallmark of CML. However, around 5 to 10% of CML patients exhibit the involvement of a third chromosome. In some very rare cases a fourth or even fifth chromosome can be involved with the t(9;22)., Methods: This case report is based on a 40-year-old Saudi Arabian male patient, diagnosed with CML in lymphoid blast crisis, and observed to have a four-way 46 XY, t(9;22;5;2)(q34;q11.2;p13;q44) translocation. The BCR/ABL1 fusion was identified by fluorescent in situ hybridization (FISH). Additionally, the BCR/ABL1 p210 mRNA fusion transcripts were identified by a molecular test., Results: The clinical and prognostic impact of additional partner chromosomes to t(9;22) remains unknown. The CML patient with this novel four-way translocation t(9;22;5;2) progressed to blast crisis and was resistant to Tyrosine Kinase Inhibitor (TKI) therapy. Therefore, this case is more in alignment with the negative impact of additional partner chromosomes to the translocation at t(9;22)., Conclusion: Here we report for the first time a novel four-way translocation at t(9;22;5;2)(q34;q11.2;p13;q44)., (© 2022 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals LLC.)

Non-covalent interactions between polysaccharides and phenolics affect the physical properties of polysaccharide solutions. These interactions may in turn be influenced by polysaccharide-polysaccharide interactions. To test this hypothesis, we studied the influence of polysaccharide concentration (with guar, β-glucans, and xanthan) on the variations of rheological and water-binding properties upon addition of phenolics compounds (vanillin, caffeic acid, gallic acid, and epigallocatechin gallate). Addition of phenolics led to increased flow behavior index and decreased flow consistency index, with maximum effects at polysaccharide concentrations ranging between 0.6 × C* and 1.4 × C*, where C* is the critical overlap concentration of each polysaccharide. Water mobility was generally not significantly influenced by the addition of phenolics. The results showed that the ability of phenolic compounds to induce aggregation of polysaccharides in solution was strongly influenced by polysaccharide concentration around C* and therefore by polysaccharide-polysaccharide interactions., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Purpose: To summarize the main findings from research on food uses of Pine Bark Phenolic Extracts (PBPE), their origin, methods of extraction, composition, health effects, and incorporation into food products., Methods: A narrative review of all the relevant papers known to the authors was conducted., Results: PBPE are mainly extracted from the bark Pinus pinaster. They are generally rich in procyanidins and their effects on health in the form of nutritional supplements include effect on some forms of cancer, on diabetes, on eye and skin health. Their method of extraction influences greatly their composition and yield, and commercially suitable methods are still to be developed. Incorporation into food products raises challenges related to bioavailability and subsequent bioactivity and sensory properties of the final products., Conclusion: PBPE represent an opportunity for the development of functional foods with phenolic-rich bioactive compounds., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Hereditary axonal motor and sensory neuropathy or Charcot-Marie-Tooth type 2 (CMT2) is a common inherited peripheral neuropathy. Major symptomatologic signs vary from minimal to significant weakness and loss of sensation, feet usually affected more than hands. It may also cause visual acuity impairment, hearing loss, and skeletal deformity. CMT2 classification is based on the clinical, electrophysiological, and genetic inheritance pattern. Dominant CMT2 is classified from CMT2A to CMT2N and recessive CMT2 into CMT2B1 and CMT2B2. CMT2A is the most frequent subtype of CMT2 and caused by mutations in the mitofusin 2 (MFN2) gene. We hereby report a Saudi Arabian CMT2A patient with a variant c.58C>T of the MFN2 gene mutation.