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Design code prescritpions on the service life of ordinary reinforced concrete structures may be difficult to be fulfilled in highly aggressive environments, in which premature degradation of the structural performance is most likely to occur. In these situations, in order to avoid expensive repair activities, advanced systems such as self-healing concrete could be adopted. In the last decade, researchers started to look at this functionality as a way to solve degradation problems in chloride-laden environments.

Pd/C-based electrodes for fuel cells applications were prepared by galvanostatic electrodeposition and DC sputtering of palladium on gas diffusion layers. Different sets of samples were realized by varying the Pd load, for each technique. The surface morphology of the deposits was investigated by scanning electron microscopy. Cyclic voltammetry in acidic solution was applied to study the catalytic behavior of the freshly deposited samples and to follow their evolution with increasing cycle numbers. The results showed that, depending on the sputtering or electrochemical technique and metal load, samples grew with different morphologies and showed different electrochemical behaviors, with electroactive surface values ranging between a few tens to some hundreds m 2/g. Sputtered films were characterized by a microstructure made of sub-micrometric cauliflower-shaped clusters and showed the highest electroactive surface values after prolonged voltammetric scanning. Pd hydride formation with both α and β phases and high hydrogen absorption capability were observed in some of the electrodeposited samples, in association to flower-like micrometric-size clustered structure and hydrogen codeposition during the electrochemical growth process. © 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

This article proposes a mathematical model and develops the numerical simulation of a single stage hydrogen production–separation process during transient behaviour, suited for proton exchange membrane (PEM) fuel cell (FC) applications. Methanol reforming process is performed in a commercial catalytic membrane reactor (CMR), filled with a commercial ZnO–CuO, alumina supported catalyst. The permeate hydrogen is accumulated in a reservoir volume (buffer) connected to the permeate side. This configuration was studied in order to avoid the feed back control of the reactor feeding, even when transient power loads to the cell are applied. By numerical simulation, we verified that the system comprised by the CMR and the PEM, with an appropriate constant reactor feeding flow, is always self-sustaining so that the hydrogen demand by the FC can be satisfied at all power regimes. The achievement of this goal was obtained by redistribution of the hydrogen produced in the reactor between the buffer and the exhaust tail gases. Only the control of two independent variables of the system, such as reactor temperature and pressure, are needed, therefore, the configuration proposed here results in a simplified approach to the control strategy for the entire system. We apply the theoretical analysis to a pilot plant designed and assembled at the University of Rome “La Sapienza”, in order to verify its functional parameters and the theoretical performance of the system before its real operation.

Three techniques were used to produce palladium–ceramic (Pd–ceramic) composite membranes for hydrogen separation and production. They are sputtering, electroless deposition and rolling of thin Pd alloy films over ceramic porous tubes. After studying and developing the three coating techniques, an extensive testing and characterizing work was carried out on these thin film composite membranes. The results show that in the sputtered (0.5–5 μm) and electroless (2.5–20 μm) composite membranes, the thermal cycling of the hydrogenated metallic layer produces membrane failures. Such failures are characterized by crack formation and metal film peeling. This fact has been explained by an evaluation of the shear stresses at the metal–ceramic interface due to the differential elongation between the palladium (Pd) coating and the ceramic support under thermal cycling and hydrogen loading. The rolled membranes (50–70 μm), however, because of the particular coating solution, have shown a complete hydrogen selectivity and good chemical and physical stability in long-term tests.

The study of the water gas shift reaction performance in terms of complete conversions is presented. The behaviour of a membrane reactor (MR) consisting of a tubular microporous ceramic within a thin palladium membrane was compared with a membrane reactor using a palladium/silver membrane. Membranes were developed in order to obtain a metallic layer thick enough to avoid any defects of the metallic layer and ensure infinite hydrogen selectivity with respect to other gases. The lumen of both membrane reactors was filled with the catalyst. The experiments were carried out by using nitrogen as inert gas in the streep having a flow rate ranging between 1×10−4 and 4×10−4 mol s−1 in co-current and counter-current mode in the temperature range 331–350°C and in the feed molar flow range 3.05×10−5–7.1×10−5 mol s−1. Hydrogen was the only one gas passing through both membranes. A complete separation of hydrogen from the other gases of the reaction system was obtained. The water gas shift reaction conversion was close to 100% by using the Pd/Ag membrane. A mathematical model was developed to interpret the experimental data. It described the system under isothermal conditions and considered an axial differential mass balance in terms of partial pressure for each chemical species. The simulation study and the experimental results show a satisfactory agreement and both highlight the possibility to shift towards 100% the conversion of the considered reaction.

A three-dimensional analysis of the dynamics of hydrogen isotopes confined within a metal lattice, like palladium or nickel, is presented. It is assumed that the concentration of the hydrogen isoto...

Palladium and palladium–silver permeators have been obtained by coating porous ceramic tubes with a thin metal layer. Three coating techniques have been studied and characterized: chemical electroless deposition (PdAg film thickness of 10 μm), ion sputtering (about 1 μm) and rolling of thin metal sheets (50 μm). The Pd-ceramic membranes have been used for manufacturing catalytic membrane reactors (CMR) for hydrogen and its isotopes recovering and purifying. These composite membranes and the CMR have been studied and developed for a closed-loop process with reference to the design requirements of the international thermonuclear experimental reactor (ITER) blanket tritium recovery system in the enhanced performance phase of operation. The membranes and CMR have been tested in a pilot plant equipped with temperature, pressure and flow-rate on-line measuring and controlling devices. The conversion value for the water gas shift reaction in the CMR has been measured close to 100% (always above the equilibrium one, 80% at 350°C): the effect of the membrane is very clear since the reaction is moved towards the products because of the continuous hydrogen separation. The rolled thin film membranes have separated the hydrogen from other gases with a complete selectivity and exhibited a slightly larger mass transfer resistance with respect to the electroless membranes. Preliminary tests on the sputtered membranes have also been carried out with a promising performance. Considerations on the use of different palladium alloy in order to improve the performances of the membranes in terms of permeation flux and mechanical strength, such as palladium/yttrium, are also reported.

A model has allowed us to perform the analysis of the tritium inventory and permeation in the international thermonuclear experimental reactor (ITER) breeding blanket under the hypothesis of steady state conditions. Li 2 ZrO 3 (reference) and Li 2 TiO 3 (alternative) have been studied as breeding materials. The total breeder inventory assessed is 7.64 g for the Li 2 ZrO 3 at reference temperature. The model has also been used for a parametric analysis of the tritium permeation. At reference temperature and purge helium velocity of 0.01 m/s, the HT partial pressure is ranging from 10 to 30 Pa in the breeder and 1.5×10 −3 Pa in the beryllium. At 0.1 m/s of purge helium velocity, the HT partial pressure is reduced of one order by magnitude in the breeder and becomes 5×10 −5 Pa in the beryllium. The tritium permeation into the coolant for the whole blanket is ranging from 100 to 250 mCi per day for purge helium velocity of 0.01 m/s. The analysis of the tritium inventory and permeation for the alternative Li 2 TiO 3 breeding material has been carried out too. The tritium inventory in the breeder is in the range from 6 to 375 g larger than in Li 2 ZrO 3 by about a factor 5; the tritium permeation into coolant is comparable to the Li 2 ZrO 3 one. This analysis provides indications on the influence of the operating parameters on the tritium control in the ITER breeding blanket; particularly the control of the tritium inventory by the temperature and the tritium permeation by the purge gas velocity.

Thin palladium and palladium alloy membrane tubes with thickness up to 50 μm have been produced. These metal membranes, used as tube permeators in catalytic membrane reactors for the water gas shift reaction, are thinner than the commercial ones (100–150 μm) and have both complete selectivity to hydrogen and good durability. A manufacturing procedure consisting of several steps of cold-rolling and annealing the metal foils coupled with a simple welding technique of the tubes has been carried out in order to produce the prototype thin palladium permeators. The procedure of rolling and annealing the palladium and palladium alloy foils is described in detail: the work hardening upon rolling of the palladium and palladium alloy foils has been controlled by means of hardness measurements. Model studies and tests on the membranes and the CMRs for the water gas shift reaction have demonstrated the possibility to separate and recover highly pure hydrogen in energy applications such as nuclear fusion fuel cycle and fuel cells fuelling.

The lattice confinement effect on the dynamics of protons and deuterons embedded within metals such as Pd or Ni is studied. The work is based on the assumption that the H isotope concentration, as an atomic fraction, is close to one. The study takes advantage of the analogy between the lattice space around tetrahedral sites and the radio-frequency trap for ions, created when coherent oscillations of the metal atom electrons close to the Fermi level take place and produce a dipole signal. The classical description of the system is developed through the numerical solution ofmotion equations written in the trap coordinate system. The model for studying the particle trajectories in a Cartesian plane is a two-dimensional analysis. The results show that a collision phenomenon exists between H isotopes confined in the lattice and that the particle trajectories can be very close to the host metal atoms.

The key uncertainty in estimating tritium permeation from fusion reactor cooling system components is the permeability coefficient, which is strongly dependent on the component material, pressure, temperature, chemistry, etc. Published tritium permeability values, for typical cooling system materials, range at least six orders of magnitude, resulting in estimates of tritium permeation carrying a large degree of uncertainty. In this work, both theoretical and empirical approaches are used for estimating tritium permeation and environmental releases for the water cooled SEAFP reactor. The steam generators are the major source of tritium permeation from the primary coolant. The theoretical model is based on the thermodynamic equilibria and the mass transfer phenomena at steady state conditions. A calculation code, from the theoretical model, allowed us to describe the behavior of the system under the main operating conditions. A parametric analysis has been carried out by varying the hydrogen concentration. The beneficial effect of oxide layers in reducing the permeation of hydrogen isotopes through steam generator tube materials has been observed experimentally by others, and is modeled here by a permeation reduction factor (PRF). The oxide layer effect has also been observed in operating steam generators, as demonstrated in the analysis based on CANDU operating experience. Such experience, which covers the range of conditions of the water cooled SEAFP reactor, has been used to estimate tritium permeability for the SEAFP steam generators. Hence, the use of measured data from CANDU plants has reduced the range of uncertainty in tritium permeability to approximately one order of magnitude. It has also permitted a meaningful estimate of tritium permeation to be performed. The best estimate is ≈16 Ci year−1 per steam generator.

The methane steam reforming in a catalytic membrane reactor has been studied. A previous theoretical study of this reaction has been carried out. In the model a global kinetic rate as function of three reactions over nickel catalyst as proposed by Xu and Froment (AIChE J. 1989, 35 (1), 88-96, 97-103) has been considered. It has been shown that the counterflow configuration has, at high temperature (500 °C), a marginal advantage on parallel flow and, also, that the space velocity cannot be considered a design variable for membrane reactors. A laboratory plant was realized utilizing membranes of Pd and Pd/Ag supported on Al2O3. The Pd membranes utilized have been prepared using the co-condensation technique and the electroless plating method. A comparison of the overall membrane performance has also been carried out. The experiments were aimed to study the effects of several parameters such as temperature, feed flow rate, and feed molar ratio on the methane conversion. The experimental results have been compared with the data predicted by the previously developed theoretical model.

The effect of red—ox potential of helium purge gas (variously doped with H2, H2O and O2) was examined on tritium release from Li-ceramics (LiAlO2 and Li2ZrO3 pellets) and on its permeation rate through the 316L stainless steel clads (bare and coated) held at 500°C. Decreasing the H2 content from 1000 vpm (reference ‘R’ gas mixture) to 100 vpm, and substituting H2O for H2, the tritium permeation rate (ca. 1.41010 atoms cm−2 s−1 in R-gas) increases. Tritium inventories in the Li ceramics were increased too. When a strong oxidizing purge (1000 vpm O2 added to He containing 100 vpm H2O) was used, a retention time (τ) of two days at 400°C was measured for Li2ZrO3. In this oxidizing environment the tritium permeation loss dropped by a factor five for the uncoated capsules while an aluminide coating became a very effective tritium barrier: tritium permeation flux at 550°C fell below the measurable limit.

A computer model has been developed to evaluate tritium permeation to coolant and in vanadium tubes inventory in Safety and Environmental Assessment of Fusion Power (SEAFP) blanket. The mean tritium partial pressure in gaseous breeder phase are in the range from 0.5 to 5 Pa for helium purge gas velocity from 0.1 to 0.4 m/s; in these conditions the tritium permeation to coolant changes from 32.8 to 16.4 g/day and the tritium inventory in vanadium tubes from 4000 to 2000 g. The H/T ratio involves a relevant tritium permeation variation: with 0.2 m/s helium purge gas velocity varying the H/T ratio from 100 to 50 the tritium permeation to coolant ranges from 23.2 to 32.7 g/day. The analysis shows that defects free thin permeation barriers (SiC and Al{sub 2}O{sub 3}) are very effective to making negligible the tritium permeation to coolant and the tritium inventory in tubes. 9 refs., 5 figs., 1 tab.

The analysis of the tritium inventory in Li 2 O, carried out for the Safety and Environmental Assessment of Fusion Power (SEAFP) helium-cooled ceramic blanket, is based on a diffusion and desorption tritium release model. Within the specific range of breeder temperatures taken into account, desorption was the dominant mechanism so it can be defined as the rate controlling step. At steady state, the model for the tritium inventory in the solid Li 2 O breeder is supported by a computer code for several operating conditions. At reference conditions of breeder temperatures, by varying the mean grain radius from 1 to 5 μm, a tritium inventory from 0.5 to 2.8 g can be obtained. A helium purge gas velocity from 0.1 to 0.4 m/s gives rise to gas pressure losses from 0.22 to 0.9 MPa, which could probably be reduced by increasing the pebble diameter to 1 mm. This breeder configuration seems to ensure reactor safety.

The future fusion reactor fuel will be a mixture of deuterium and tritium. Deuterium is produced using traditional separation technology. Tritium must be produced by means of a nuclear reaction between neutrons and lithium atoms within the reactor breeder which, in this study, is supposed to be a ceramic lithiated material. The tritium produced in the breeder needs a proper extraction process to reach the required purity level. A conceptual modified version of the tritium recovery plant for the considered ceramic breeder, working with two membrane reactors, each acting as a reaction/separation unit, is studied in this work. The first considered membrane unit is a catalytic ceramic membrane reactor to remove, via oxidation, the hydrogen isotopes from the purge gas (He). The second one is a tritiated water-gas shift reaction. In the latter process unit, the effect of selective hydrogen permeation on the conversion is studied. A detailed description of the experimental equipment, of the material used and some experimental results are presented.

A theoretical and experimental work concerning a catalytic ceramic membrane reactor is described in this paper. A tubular catalytic ceramic membrane reactor prototype has been developed to separate hydrogen at low concentration from an inert gas stream via oxidation. A mathematical model has also been carried out either to analyze the experimental results or to develop the reactor optimization. The experimental results are in agreement with the theoretical previsions. The optimization study shows that it is possible to reach very high conversion values. Such preliminary work points out the role of either the materials technology or the membrane catalytic coating.

A mathematical model has been developed to analyze the behavior of a composite or integrated membrane—fixed bed tubular reactor by considering the catalytic reaction of water with carbon monoxide. Such a reaction is a typical example of an equilibrium controlled reaction, where the conversion is enhanced when one of the products (i.e. the hydrogen) is removed selectively from the reactor. The application considered for such a reactor concept is that of tritium recovery from the solid blanket purge gas and/or from the plasma exhaust gas of a fusion reactor, where a small number of process components, modularity and continuous operations are required. The analysis has been performed taking into account that parameters such as the hydrogen gas diffusion coefficient, film mass transfer resistance and gas linear velocity are not constant along the reactor axis. In an adiabatic reactor, the gas specific heat, temperature and the kinetic parameters are not constant. For this reason, the reactor has been assumed as a series of tubular catalytic membrane reactors. The results show that, with proper optimization, it is possible to achieve very high conversion.

A method to determine the concentration of deuterium inside a palladium cathode during the electrolysis of LiOD–heavy water solution is described. This method is based on the measurement of the host metal lattice parameter which is linearly related to the concentration in a wide range. A hard‐x‐ray beam which is able to cross two glass walls and few centimeters of water solutions without suffering a strong attenuation has been used. The measurement of the lattice parameter is performed in situ, during the electrolysis, by using energy dispersive x‐ray diffraction. The sample volume illuminated by the x‐ray beam is limited to a small region close to the surface and depends on the incident photon energy. In principle, this allows one to study the dynamics of the charging process and to determine the concentration profile in the range from few up to tens of micrometers. The deuterium concentration, determined by this method, was then checked by degassing the cathode in a known volume and was always found in ...

The aim of this work is to obtain a multicomponent, numerically simplified and stable distillation model, with simultaneous correction of the temperature and flow-rate (liquid and vapor phases) profiles along the column. The proposed model should be considered as an introduction to the multicomponent distillation calculation via computer and not an alternative to the existing rigorous methods. In the model the compositions are evaluated by solving a system of linear equations, while the flow rates are calculated `explicitly` by means of enthalpy balances. A few iterations are required to obtain the solution and the temperature profile. 12 refs., 3 figs.

An experiment based on the electrolysis of heavy water with a palladium cathode is reported. The production of excess power during the electrolysis has been measured with the help of a quite accurate and reliable calorimeter. The correlation of the detected power excess with some meaningful parameters of the experiment is investigated. Some of the features of the experiment permit to investigate the dynamics of deuterium in the palladium lattice, which is thought of as the basic phenomenon for excess power production.

Depending on the final decision on the operation time of ITER (International Thermonuclear Experimental Reactor), the Driver Blanket might become a basic component of the machine with the main function of producing a significant fraction (close to 0.8) of the tritium required for the ITER operation, the remaining fraction being available from external supplies. The Driver Blanket is not required to provide reactor relevant performance in terms of tritium self-sufficiency. However, reactor relevant reliability and safety are mandatory requirements for this component in order not to significantly affect the overall plant availability and to allow the ITER experimental program to be safely and successfully carried out. Within the framework of the ITER Conceptual Design Activities (CDA, 1988–1990), a conceptual design of the ITER Driver Blanket has been carried out by ENEA Fusion Dept., in collaboration with ANSALDO S.p.A. and SRS S.r.l., and in close consultation with the NET Team and CFFTP (Canadian Fusion Fuels Technology Project). Such a design has been selected as EC (European Community) reference design for the ITER Driver Blanket. The status of the design at the end of CDA is reported in the present paper.

The future fusion reactor fuel will be a mixture of deuterium and tritium. Deuterium is produced using traditional separation technology. Tritium, on the contrary, must be produced by means of a nuclear reaction between neutrons and lithium atoms within the reactor breeder which could be a lithiated ceramic material or a liquid metal containing lithium. The tritium produced in the breeder needs a proper extraction process to reach the required purity level. A conceptual modified version of the tritium recovery plant for a solid ceramic breeder, working with two membranes reaction/separation units, is studied in this work. The first considered membrane unit is a catalytic ceramic membrane reactor to remove, via oxidation, the hydrogen isotopes from the purge gas (He); the second is a Pd/Ag membrane permeator to separate the hydrogen isotopes from the water shift reactor gaseus products. The modelling and the mass balances have been obtained either on the basis of data in the literature or on experimental results.

One of the objectives assigned to a DEMO blanket will be to limit tritium leakage to the steam circuit by permeation through the steam generator tubing of the tritium unavoidably present in the coolant. The control of these losses will require, on one hand, to minimize the amount of tritium reaching the coolant under both nominal and accidental conditions, and, on the other hand, to have an efficient tritium recovery process and chemistry control for maintaining at a low level the concentration in reduced tritiated species in the coolant.

The DEMO specifications defined so as to ensure the consistency of the various blanket conceptual design studies performed within the framework of the European Test Blanket Program me have been recently updated. A very first attempt has been made to adapt the European Ceramic Breeder Inside-Tube DEMO blanket to these new specifications. Two solutions have been investigated. The first would ensure tritium self-sufficiency of the plant with a large safety margin. The other one, which fully preserves the design simplicity and reliability of the initial design, appears to be somewhat marginal from the tritium breeding capability point of view, but to offer good improvement prospects.

Tritium diffusion and transport behaviour through porous γ-LiAlO2 solid breeder rods of a blanket for a Commercial Tokamak, has been studied for a typical reactor start-up from a “clean” breeder. The proposed tritium transport model accounts for grain diffusion, (using a simplified model), desorption from the surface and pore diffusion, and has been used for the evaluation of the overall characteristic time of the transient tritium release into the helium purge gas. Because of the strong dependence of diffusion and desorption coefficients on temperature, also a detailed thermal analysis has been performed. This study considers a bidimensional axisymmetrical geometry for the blanket and the calculations have been carried out using the general-purpose Finite Element program TRIO E.F.

A blanket option featured by helium cooling and lithiated ceramics inside tubes is under development at CEA/ENEA within the framework of the European Test Blanket Program. A first conceptual design...

A mathematical analysis of a bio-artificial pancreas is described. The analysis accounts for both bulk convective flow and diffusion through the device. The transient response to a step change in the glucose signal is determined. The analysis indicates that the system shows promise as an artificial device for insulin production.

An approximate analysis is developed for enzyme catalysis under batch conditions. The result is a plot similar to a Lineweaver-Burk plot. The variables plotted are the inverse of the reaction rate and the inverse of the initial substrate concentration. The plot can be used to determine the kinetic parameters. In addition, a comparison of the intercepts of plots for batch and inhibition conditions can be used to determine the type of inhibition.

A research activity has started some years ago in the framework of collaboration between the ENEA (Italy) and the SRI (USA), aimed to the identification of traces of nuclear reactions in condensed matter. This work has also involved crosslinked analysis in order to identify effects due to contaminants that could affect the isotopic shift estimate. Nickel thin films have been sputtered on a polymeric substrate and loaded with hydrogen by electrolysis. Reference and active thin films have been prepared contemporaneously during the same sputtering process to have on both the same deposition and the same impurities composition. Secondary Ion Mass Spectroscopy (SIMS) has been used to analyze the isotopic composition of the electrolyzed and blank substrates. Preliminary results (Violante et al., Proc. 10th Int. Conf. Cold Fusion (ICCF-10), Cambridge, 2003) indicated that a reasonable reproducible apparent shift of the isotopic composition of the Cu element occurred in some of the electrolyzed films, with an increasing of mass 65, while the natural value was always observed for all the blank samples. Cu was particularly suitable for being used as a marker elements because of its only two mass isotopes (63/65) that do not overlap with isotopes of other elements having the same masses. In this work, new experiments have been reproduced to increase the statitistics and further analysis has been performed in order to exclude that the revealed shift was traceable to an artifact.These included SIMS scanning of the sample surface, depth profile analysis by SIMS, mass spectrometric analysis of the electrolyte, SUPER-SIMS [2] analysis of one couple of reference and active films. In particular, the possible contribution from mass interferences on the 65-mass extrasignal has been considered, coming from contaminants or double ionized species. On the basis of the new results, a more complex scenario has been evidenced

Study Of Lattice Potentials On Low Energy Nuclear Processes In Condensed Matter V. VIOLANTE, G. MAZZITELLI, L. CAPOBIANCO Associazione EURATOM-ENEA sulla Fusione, Centro Ricerche Frascati, C.P. 65 00044 Frascati (Rome) Italy F. SARTO, E. SANTORO ENEA, Unita Tecnico Scientifica Fusione, Centro Ricerche Casaccia, Via Anguillarese Km 1.300, 00100 Rome Italy M. MCKUBRE, F. TANZELLA SRI International 333 Ravenswood Ave Menlo Park CA (USA) G.H MILEY, N. LUO, P.J. SHRESTHA Nuclear, Plasma and Radiological Engineering Dept. Un. Illinois, 103 S Goodwin Urbana, IL 61801 C. SIBILIA INFM-Dipartimento di Energetica, La Sapienza University, Via Scarpa 16, Rome

Associazione EURATOM-ENEA sulla Fusione, Centro Ricerche Frascati, C.P. 65 - 00044 Frascati (Rome) Italy F. SARTO, A. ROSADA, E. SANTORO ENEA, Unita Tecnico Scientifica Fusione, Centro Ricerche Casaccia, Via Anguillarese Km 1.300, 00100 Rome Italy M. MCKUBRE, F. TANZELLA SRI International 333 Ravenswood Ave Menlo Park CA (USA) C. SIBILIA INFM-Dipartimento di Energetica, La Sapienza University, Via Scarpa 16, Rome Electrochemical experiments have been carried out in order to identify traces of nuclear processes occurring in condensed matter. The experimental activity was primarily designed to reduce the background element impurities by using ultra-pure cleaning procedures to eliminate contamination. The working conditions allowed to obtain a clear signal from the investigated phenomena. Neutron activation, SIMS and high resolution Mass Spectrometer analysis yielded experimental data greater than the measurement error and well above the detection limits of the instruments. The isotopic abundance has been studied for some elements and a strong difference as been observed between experimental data and natural values. A correlation has been observed between the shift of the isotopic composition and a weak emission of X-rays, in some experiments.

A nickel-hydride thin film was studied by the Attenuated Total Reflection (ATR) method. The differences between a “black” film and a pure nickel film “blank” behaviour are showed. The black Ni-hydride film has been obtained by a short electrolysis with 1 M Li2SO4 electrolyte in light water. A shift in the minimum of the observed reflected light occurs, together with a change in the minimum shape, i.e. its half-height width increases. This two phenomenon are due to the change in the electronic band structure of the metal induced by the electron added in the lattice by hydrogen. The changing of the electronic structure, revealed by the laser coupling conditions, leads to consider that an hydride phase was created. Both the blank (not hydrogenated) and black (hydrogenated) specimens were taken under He-Ne laser beam at the reflectance minimum angle for about three hours. A SIMS analysis was also implemented to reveal differences in the isotopic composition of Cu, as marker element, between the blank and black films, in order to study the coupled effect of electrolysis and plasmon-polariton excitation on LENR processes in condensed matter.

Recent progress in understanding the screening effects of core level atomic electrons is summarized in this paper. Some preliminary results on core electron screening were reported before [1]. The studies focus on two types of nuclear reactions in some metal lattices: fusion between deuterons and also proton capture by medium and heavy lattice nuclei. In both reactions the energy of the light nuclear species, proton or deuteron, is on the KeV (1000 electron volts) scale, while that of heavy nuclei is essentially zero. A standard atomic code is used to obtain the core electron charge density and the potential profile in the metal atom. This Hartree-Fock-Slater type code was originally written by Herman and Skillman [2] and later modified by others and available online [3]. For the D-D reaction, the charge density obtained then gives an estimate on the screening length. The corresponding enhancement in Coulomb barrier tunneling can be obtained from this data. For the proton capture reaction, an ion dynamic code [4] written to simulate the motion of KeV protons in Pd/Ni lattice, CLAIRE, was modified to take into account the realistic atomic potential, including core electron contributions. In both cases, our result shows a significant nuclear reaction enhancement. The reaction rate calculated roughly matches the scale of excess heat observed in some metal hydride/deuteride [5] experiments.

Transglutaminases (Enzyme Commission 2.3.2.13) are a large family of enzymes that show the common capacity to catalyze cross-linking of protein substrates. Some members of this family of enzymes are also capable of catalyzing other reactions important for the cell life. The distribution and the role of these enzymes have been widely studied in numerous cell types and tissues, but only recently their expression and functions started to be investigated in the central nervous system. One of the main biochemical properties of the transglutaminase enzymes is to form large protein aggregates that are insoluble in all known protein detergents, such as urea, guanidinium, and sodium dodecyl sulfate. Recently, the transglutaminase activity has been hypothesized to be involved in the pathogenetic mechanisms responsible for the formation of cellular inclusions present in Huntington disease and in all the other polyglutamine (polyQ) diseases hitherto identified, such as spinobulbar muscular atrophy or Kennedy disease, spinocerebellar ataxias (SCA-1, SCA-2, SCA-3 or Machado-Joseph disease, SCA-6 and SCA-7) and dentatorubropallidoluysian atrophy. In this review we describe the biochemical properties of the transglutaminase enzymes and some recent findings about the physiopathological roles played by these enzymes in the central nervous system.

Time resolved, in-situ, energy dispersive x-ray diffraction was performed in an electrolysis cell during electrochemical loading of palladium foil cathodes with hydrogen and deuterium. Concentrations of H:Pd (D:Pd) up to 1:1 in 0.1 M LiOH (LiOD) in H2O (D2O) electrolyte were obtained, as determined by both the Pd lattice parameter and cathode resistivity. In addition, some indications on the kinetics of loading and deloading of hydrogen from the Pd surface were obtained. The alpha-beta phase transformations were clearly delineated but no new phases at high concentration were determined.

In this work, the tritiated water shift reaction and the hydrogen isotope separation are obtained in one step by means of a single process unit (reactor/separator) working in continuous mode. Such a solution offers two positive effects: the first is the reduction of the process-item number, the second one is the possibility to obtain a very high conversion value.

During the ITER conceptual design phase a reference driver blanket concept has been selected, based on the use of ceramic breeder (LiAlO2 or Li2O) with low-temperature (60–100 °C) water cooling and on-line tritium recovery via He purging gas. Since tritium release from breeder materials requires operation temperature > 400–450 °C, the combination of low-temperature cooling and tritium on-line recovery are conflicting design requirements, leading to the need of insulating thermal barriers between breeder and coolant which provides an increase of design complexity and feasibility concerns. To overcome this problem while maintaining the benefits of low temperature and pressure cooling a tritium batch recovery procedure has been preliminarly analysed: the tritium could be accumulated in the breeder material during normal low-temperature operation and then periodically recovered during scheduled reactor shutdown by heating the breeder via hot gas or steam and using decay heat. The results show that, assuming a maximum allowable tritium accumulation of about 500 gr in the breeder material, one reactor shutdown every 5 days of continuous burning (corresponding to about 40 normal operation days at 12% reactor availability) is required for tritium extraction. The tritium recovery phase is expected to take 0.5 to 1.5 days, depending on the specific ceramic breeder used in the blanket and the recovery temperature.

The Computer code, TRIDYN, has been developed to study the mass and energy transient of a PIN blanket concept under pulsed load (burn/off-burn). In the model the tritium release is controlled by means of two mechanisms: diffusion within the bulk and desorption at the surface of the grain. The model includes the thermal profile evaluations in the breeder and, by taking into account the thermal transient, evaluates the tritium inventory, permeation, and purge concentration evolution.

In the ceramic blanket concept, a sweep gas is required to recover the “in situ” tritium produced. The tritium is removed mainly in an oxidate form. Two process options for the tritiated water reduction step have been developed in the present work. Both options have been studied under a NET contract. The reduction is achieved by means of a catalytic water gas shift reactor. A model has been developed to evaluate the behavior of all the process components. The hydrogen isotopes produced are removed by means of a Pd/Ag membrane separator, and the residual tritiated water is trapped in molecular sieves and recirculated to the shift reactor.

The advanced ENEA poloidal solid breeder-in-tube (BIT) blanket design for a DEMO fusion reactor is presented. Its main operating conditions and features are max. neutron fluence = 3×1022 n/cm2; max. beryllium vol. swelling = 4%; max. beryllium differential swelling = 3%; module poloidal length = 8.5 m; helium inlet/outlet temperature = 250/500°C; pumping power percentage >4%; max. structure temperature >550°C; ceramic breeder min/max. temperature 450/750°C; purge circuit separated from the coolant circuit; coaxial manifolding system; 3-D value of the t.b. r ≈ 1.20; and thermal cycle efficiency 35%.