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In this work a free emissivity (dual color) thermographic technique, based on the ratio of monochromatic emissive power, is investigated. It can be performed by equipping the InfraRed (IR) camera of two band pass filters in such a way to consider the emissivity parameter as a constant value. Two colour technique can reveal its utility in fields of applied physics where intrusive techniques are not allowed and/or materials are characterized by unknown emissivity. This physics methodology can be really useful, for example, in temperature determination of (Aero) Space materials (such as TPS-Thermal Protection Systems), tested on ground Plasma Wind Tunnel, solid targets temperature determination due to ions bombarding by means of accelerators for nuclear (Astro) Physics and/or environmental physics applications. In this paper, temperature measurement investigations based on the choice of central wavelength distances of two filters are reported. In particular a numerical model simulation, experimentally validated in the Long and Mid (LW, MW) – Wavelength ranges, was built and used to determine the feasibility of the technique and to choose the best filters combinations. In addition, after the verification capability in MW range, the temperature measurements on an aluminium plate were carried out with the dual colour technique. Moreover the verified numerical model was used to analyze errors of the two color technique in MW range using different curves of materials with variable emissivity. The study was carried out up to 500 °C and the results show that this innovative technique allows measurements of surface temperatures with errors of few % in MW range. [ABSTRACT FROM AUTHOR]

The Accelerator Mass Spectrometry (AMS) is the most sensitive technique, compared either to the Inductively Coupled Plasma (ICP-MS) or Thermal Ionization (TI-MS) mass spectrometer, for the actinide (e.g. 236 U, x Pu isotopes) measurements. They are present in environmental samples at the ultra trace level since atmospheric tests of Nuclear Weapons (NWs) performed in the past, deliberate dumping of nuclear waste, nuclear fuel reprocessing, on a large scale, and operation of Nuclear Power Plants (NPPs), on a small scale, have led to the release of a wide range of radioactive nuclides in the environment. At the Center for Isotopic Research on Cultural and Environmental heritage (CIRCE) in Caserta, Italy, an upgraded actinide AMS system, based on a 3-MV pelletron tandem accelerator, has been developed and routinely operated. At CIRCE a charge state distribution as a function of terminal voltage, the beam emittance, measured in the 20° actinides dedicated beam line, as well as the energy and position validation of the U ions were performed in order to determine the best measurement conditions. A 236 U/ 238 U isotopic ratio background level of about 5×10 −12 or 3×10 −13 , depending on the Time of Flight-Energy (TOF-E) configurations, as well as the spatial distribution of the 235 U, 238 U interferences ions and a 236 U contamination mass of about 0.5 fg have been determined. [ABSTRACT FROM AUTHOR]

Abstract: Accelerator mass spectrometry (AMS) is presently the most sensitive technique for the measurement of long-lived actinides, e.g. 236U and 239Pu. A new actinide line is in operation at the Center for Isotopic Research on Cultural and Environmental heritage (CIRCE) in Caserta, Italy. Using the actinide line a uranium mass sensitivity of around 4μg has been reached measuring with a 16-strip silicon detector, and a 239Pu background level of below 0.1fg has been obtained. In this work we also discuss preliminary results for environmental and structural samples from in and around the Garigliano nuclear power plant (GNPP), presently in the decommissioning phase. Measurements on environmental samples from the vicinity of the plant allow the assessment of contamination, if any, over the years. Measurements of structural samples from the plant are relevant to the optimization of the decommissioning program for the GNPP. [Copyright &y& Elsevier]

Abstract: The reaction plays a key role for the understanding of the production of 7Li in Big Bang nucleosynthesis as well as for the high energy component of the solar neutrino spectrum. The uncertainty in its absolute cross-section arises from systematic differences of the available data sets. In various experiments the cross-section was measured by the detection of the prompt -rays or by the off-line observation of the -rays following the 7Be electron capture; in a few cases both observations were carried out. We report on a new approach based on the use of the recoil separator ERNA (European Recoil separator for Nuclear Astrophysics) to detect directly the 7Be recoils as well as the prompt -rays in coincidence with the recoils. We present technical details of the experimental setup, such as a recirculating 3He gas target, a TOF-E end detector, and a NaI detector array. In addition, the measurement of the separator acceptance is discussed and compared to the expected recoil emittance. The feasibility of the approach is demonstrated by sample spectra, indicating cross-section determinations of in the energy range with high precision and accuracy. [Copyright &y& Elsevier]

• Natural and anthropogenic radionuclides along the Domitia sandy beaches. • The natural (238U, 232Th, 226Ra, 40K) activities increase in the sand fraction. • The Cesium (137Cs) activity excludes any contribution of the nuclear plant. • The Plutonium ratios (240Pu/239Pu) exclude any contribution of the nuclear plant. • The applied methodology can be used as a reference for sand analyses. The work aims to investigate the distribution versus depth of natural (238U, 232Th, 226Ra, 40K) and anthropogenic radionuclides (137Cs, 239Pu, 240Pu) along the Domitia coastal zone (Campania Region, Southern Italy) downstream the Garigliano and Volturno rivers, to value the influence of the decommissioned Garigliano Nuclear Power Plant (GNPP) releases. Despite the coastal systems are in continuous evolution, they hold memory of the radioactive contamination to be monitored in order to disseminate new knowledge both about the geochemistry of the isotopes and on their possible interactions with the geologic-sedimentologic context. Given the limited scientific investigations during the years in this field, the present work attempted to fill the gap of knowledge, trying to investigate the presence of radionuclide pollution in the Campanian coastal littoral. A constant distribution of natural radioisotopes in the medium-fine sand fraction is found, with an increase in the coarse fraction, showing an interesting correlation between the radioactive content with the lithology and mineralogy. About the anthropogenic cesium, the low concentrations (due to its strong solubility in the water) allowed to exclude any contribution of the GNPP. Furthermore the 239,240Pu actinides results, detected for both the ivestigated areas and for the used techniques, falls completely in the reference range values: the isotopic ratio is in the global fallout range allowing to exclude any contribution from the GNPP. The extraction and purification method has allowed to obtain excellent results to detect 239,240Pu actinides both for the ICP-MS, at Risø National Laboratory, and for the AMS technique, at CIRCE laboratory. For these reason the method is so reliable and reproducible that it could be considered as a reference for future environmental radioactivity studies on the sandy matrix. [ABSTRACT FROM AUTHOR]

The reentry conditions endured by a vehicle entering the atmosphere from an Earth orbit or from an interplanetary trajectory are the most critical phases for materials used as Thermal Protection Systems (TPSs), since the spacecraft surfaces have to withstand extremely high heat fluxes and loads due to the hot plasmas generated downstream of the high energy shock waves due to the extreme deceleration. The gases are highly excited and heated to values up to 10000 K immediately downstream of the shock waves. The TPS surfaces are then heated by these gases through convection and radiation, producing very high wall heat fluxes and associated temperatures, which can produce TPS surface temperatures of up to 2300 K. Passive and active TPSs are employed to protect the inner cold structures of the spacecraft which are made from aluminium or metallic alloys. Passive TPS are classified as reusable or single use (ablative) materials. Facilities such as plasma wind tunnels are used to experimentally reproduce the atmospheric reentry of such vehicles. Their use allows the testing and qualification of the TPS which is subjected to thermal and mechanical stresses induced by the hypersonic jet in spite of the unavoidable intrinsic limitations when the complex flight physics phenomena are reproduced in ground test facilities. One of the most complex issues, associated with aerospace safety during a hypersonic Plasma Wind Tunnel test campaign is to measure the free jet temperature and monitor the high heat fluxes generated by the hot plasma, the correlated TPS surface temperatures, and the erosion rate (i.e., recession rate) affecting the behavior of materials representative of space vehicle subcomponents. The purpose of the present work is to review the diagnostic methodologies used in hypersonic test facilities associated with the working principles, the development, the potential and the limitations of arc jet plasma wind tunnels for the evaluation of the aforementioned critical parameters. At the same time, this review aims to illustrate the most advanced and sensitive non-intrusive diagnostics for the determination of the free jet temperature and its oxygen composition by means of spontaneous Optical Emission Spectroscopy (OES) and Laser Induced Fluorescence (LIF) respectively, and for the determination of the TPS temperature and erosion rate using free emissivity Dual Color Infrared Thermography (DCIT) and on Surface Layer Implantation (SLI) of radioactive tracers techniques. [ABSTRACT FROM AUTHOR]

• definition of a standard technique able to determine the emissivity spectral trend; • novel approach to measure material spectral emissivity from NIR to LW range at high temperatures; • new setup with a black body, pyrometer, and thermal cameras for precise emissivity detection across multiple wavelenghts; • global and spectral emissivity analysis of ISiComp®, a C/SiC composite by CIRA and Petroceramics, made in Italy. One of the most critical phases for a space mission involving a transportation system from space to Earth is the atmospheric re-entry since the high kinetic energy of orbital flight shall be reduced and converted in thermal energy. In these conditions, one of the design parameters that allow the TPS to withstand the aerothermal loads and to guarantee temperatures compatible with the selected materials is the emissivity. This parameter depends on several factors such as mechanical features, chemical composition, surface roughness, angle of sight, wavelength and temperature. For TPS materials, emissivity characteristics are difficult to evaluate due to harsh, and critical to simulate on-ground, operative environment characterized by material surface and plasma flow interaction. In this work, a novel approach to detect the material spectral emissivity at several wavelengths, ranging from NIR (Near InfraRed) to the LW (Long Wavelength) spectral range, is presented. An experimental set-up composed of a black body, a pyrometer and two thermal cameras has been used for performing an accurate detection of the emissivity value at several wavelengths. The experimental analyses guarantee a systematic approach able to provide quantitative information of the spectral and global materials emissivity. The ISiComp® material, a long carbon fiber reinforced SiC matrix composite (C/SiC) made in Italy and developed by CIRA and Petroceramics, has been used. [ABSTRACT FROM AUTHOR]

The variation of the 236U and 239Pu concentrations as a function of depth has been studied in a soil profile at a site in the Southern Hemisphere well removed from nuclear weapon test sites. Total inventories of 236U and 239Pu as well as the 236U/239Pu isotopic ratio were derived. For this investigation a soil core from an undisturbed forest area in the Herbert River catchment (17°30′ – 19°S) which is located in north-eastern Queensland (Australia) was chosen. The chemical separation of U and Pu was carried out with a double column which has the advantage of the extraction of both elements from a relatively large soil sample (∼20 g) within a day. The samples were measured by Accelerator Mass Spectrometry using the 14UD pelletron accelerator at the Australian National University. The highest atom concentrations of both 236U and 239Pu were found at a depth of 2–3 cm. The 236U/239Pu isotopic ratio in fallout at this site, as deduced from the ratio of the 236U and 239Pu inventories, is 0.085 ± 0.003 which is clearly lower than the Northern Hemisphere value of ∼0.2. The 236U inventory of (8.4 ± 0.3) × 1011 at/m2 was more than an order of magnitude lower than values reported for the Northern Hemisphere. The 239Pu activity concentrations are in excellent agreement with a previous study and the 239+240Pu inventory was (13.85 ± 0.29) Bq/m2. The weighted mean 240Pu/239Pu isotopic ratio of 0.142 ± 0.005 is slightly lower than the value for global fallout, but our results are consistent with the average ratio of 0.173 ± 0.027 for the southern equatorial region (0–30°S). [ABSTRACT FROM AUTHOR]

The isotopes 236 U, 239 Pu and 240 Pu are present in surface soils as a result of global fallout from nuclear weapons tests carried out in the 1950's and 1960's. These isotopes potentially constitute artificial tracers of recent soil erosion and sediment movement. Only Accelerator Mass Spectrometry has the requisite sensitivity to measure all three isotopes at these environmental levels. Coupled with its relatively high throughput capabilities, this makes it feasible to conduct studies of erosion across the geographical extent of the Australian continent. In the Australian context, however, global fallout is not the only source of these isotopes. As part of its weapons development program the United Kingdom carried out a series of atmospheric and surface nuclear weapons tests at Maralinga, South Australia in 1956 and 1957. The tests have made a significant contribution to the Pu isotopic abundances present in the region around Maralinga and out to distances ∼1000 km, and impact on the assessment techniques used in the soil and sediment tracer studies. Quantification of the relative fallout contribution derived from detonations at Maralinga is complicated owing to significant contamination around the test site from numerous nuclear weapons safety trials that were also carried out around the site. We show that 236 U can provide new information on the component of the fallout that is derived from the local nuclear weapons tests, and highlight the potential of 236 U as a new fallout tracer. [ABSTRACT FROM AUTHOR]

• Freejet hypersonic plasma generated by 70 MW Scirocco facility has been analyzed through the OES (Optical Emission Spectroscopy). • The 70 MW Scirocco Plasma Wind Tunnel allows to reproduce the hypersonic atmospheric re-entry. • Plasma roto-translational temperature (referred often as "static temperature") and NO vibrational temperature have been measured at hypersonic high enthalpy conditions. • Emission spectrum associated to the NO emission in the spectral range 200–300 nm has been acquired and analyzed. • The experimental results coming from OES analysis have been compared to the CFD numerical results. In this work the hypersonic plasma flow generated by SCIROCCO hypersonic facility has been experimentally characterized as test case, using a high resolved Optical Emission Spectroscopy (OES) during a high enthalpy test campaign. The CIRA methodology to measure roto-translational and NO vibrational temperatures of a free jet via analyses performed in the Ultra Violet spectral range has been improved and a comparison between experimental data and Computational Fluid Dynamics (CFD) simulations has been carried out. The revised methodology estimates the roto-translational and vibrational temperatures using high definition spectroscopy carried out at conditions of high values of pressure and enthalpy. In particular, attention is mainly focused on the NO emission band at Non-Local Thermal Equilibrium (NLTE) conditions in the hypersonic flight regime which means equilibrium between the molecular rotational and translational degrees of freedom but not between the roto-translational and vibrational degrees of freedom. Three tests at high enthalpy hypersonic conditions (23.8, 24.0 and 26.0 MJ/kg at a total pressure of about 2.5 bars) have been investigated and experimental data have been compared with numerical simulations in order to verify sensitivity of the method in estimating the small variation in NO roto-translational and vibrational temperatures by changing slightly the total enthalpy fluid-dynamic conditions. The current work presents a high definition spectral method which can be used to determine the temperature of NLTE hypersonic free jets, and may serve as a benchmark in determining the accuracy of various numerical models dedicated to these flow regimes. [ABSTRACT FROM AUTHOR]

Abstract: The radiative capture reaction has been investigated in the energy range to 4.5 MeV. This experiment focused in particular on the cascade transition to the 0+ state at in 16O and was performed by detecting the capture γ-rays with a NaI detector array at the windowless 4He gas target of the recoil mass separator ERNA in coincidence with the 16O ejectiles. The 6.05 MeV transition has been considered recently as a component accounting for up to 15% of the total cross section at astrophysical energies. The arrangement of the detector array yielded additional information on the γ-ray multipolarity, i.e. the ratio , and it was found that the 6.05 MeV transition is entirely E2 in the studied energy range. The results for this transition are analyzed in an R-matrix formalism and extrapolated to the relevant Gamow energy of stellar helium burning, . In contrast to a previous analysis, the present extrapolation suggests a negligible contribution from this amplitude, . Additional data for cascade transitions to excited states at , 6.92, and 7.12 MeV, respectively, as well as to the ground state were obtained and the corresponding S factors in the studied energy range are given. [Copyright &y& Elsevier]

The reaction Be (p 7 , γ) 8 B plays an important role in the Sun, where it determines the high energy component of the solar neutrino spectrum. The importance of this reaction triggered several experiments over the last decades. A combined analysis of their results produces an overall consistent picture for the energy dependence of the cross section, while an inflation of the quoted uncertainties is needed to accommodate the observed discrepancy in the absolute scale of the different data sets. The origin of this discrepancy needs to be understood for a reliable estimate of the astrophysical rate of Be (p 7 , γ) 8 B and its uncertainty. In addition, there is a question about possible common systematic effects, considering that all measurements performed so far share the same experimental approach, i.e. an intense proton beam impinging on a Be 7 radioactive target. A direct measurement using a radioactive Be 7 ion beam on a pure hydrogen gas target has been since long envisioned as a way to improve the situation. First attempts showed the feasibility of an experiment based on the use of a recoil mass separator to collect reaction products with high efficiency, but failed to reach a useful statistical significance because of the low beam intensity. Here we present the results obtained using the intense Be 7 beam available at the Tandem Accelerator Laboratory at CIRCE, University of Campania, Italy coupled to the recoil mass separator ERNA in the energy range E cm =367 to 812 keV. Our results are compatible only with a part of previous measurements, in particular those indicating a low value of the astrophysical S-factor at zero energy S 17 , thus exacerbating the discrepancy between existing measurements. The analysis of our data together with the results of previous data provides an estimate S 17 (0) =20.0±0.8 eV⋅b, where systematic uncertainties are inflated to obtain a statistically compatible data set. [ABSTRACT FROM AUTHOR]

The plasma membrane enzyme gamma-glutamyltransferase (GGT) is regarded as critical for the maintenance of intracellular levels of glutathione (GSH). GGT expression has been implicated in drug resistance through elevation of intracellular GSH. The dependence of intracellular GSH on GGT expression was not conclusively ascertained. The present study was designed to investigate the role of GGT and of intracellular GSH levels in modulating proliferation and sensitivity to cisplatin of melanoma cells. GGT transfection resulted in increased growth, both in vitro and in tumour xenografts. In addition, GGT-transfected cells exhibited reduced sensitivity to cisplatin associated with lower DNA platination. A decrease in intracellular GSH levels, rather than an increase, was observed in GGT-transfected cells; moreover, in cysteine-deficient conditions, the expression of GGT did not provide transfected cells with the ability of utilising extracellular GSH. In conclusion, these results indicate that GGT activity confers a growth advantage unrelated with intracellular glutathione supply, and are consistent with the interpretation that cisplatin resistance is the consequence of modifications of cellular pharmacokinetics as a result of extracellular drug inactivation by thiol metabolites originated by GGT-mediated GSH cleavage. [ABSTRACT FROM AUTHOR]

The dual color infrared thermography is a non-intrusive temperature measurement technique, based on the ratio principle between the signals collected at two near wavelengths in local grey body hypotheses and applicable when a thermal camera is equipped with a suitable pair of narrow band filters. In this work, the applicability at high temperatures has been investigated by using an analytical model based on Planck's Law integration, convoluted with the real response curves of sensors, optics, filters and attenuators. The presented model has been validated at high temperature and used to optimize the hardware set up for dual color measurements both in terms of operative spectral band and also for choosing the best pair of filters. Furthermore, spectral emissivity trend curves for different materials, available in literature, and at different temperatures have been used in the theoretical model in order to simulate and replicate experimental results. The experimental simulations obtained with dual color technique have been compared with those obtained through classical techniques based on the a priori knowledge and setting of the emissivity average values. The aim is to establish in which conditions and for which class of Thermal Protection System (TPS) materials used to protect the inner cold structure of hypersonic space vehicles made of aluminium or metallic alloys, the dual color technique can be used for a more accurate and precise temperature measurement compared to the classical techniques. The applicability study was carried out up to high temperature (2000 °C) which are reached by the TPS surfaces during the re-entry phase from Earth orbit or from interplanetary trajectories due to the high heat flux loads produced by the strong shock wave during the deceleration phase. [ABSTRACT FROM AUTHOR]