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This study proposes the steam reforming of a synthetic biogas stream containing 200 ppm of H2S, carried out in a non-commercial supported Pd-Au/Al2O3 membrane reactor (7-8 mu m selective layer thickness) at 823 K and 150 kPa over a non-commercial Rh(1%)/MgAl2O4/Al2O3 catalyst. This system is able to recover almost 80% of the total hydrogen produced during the reaction and shows good resistance to the H2S contamination, as confirmed by stable methane conversions for more than 400 h under operation. For comparison, the same reaction was carried out in a commercial self-supported Pd-Ag membrane (150 mu m wall thickness), yielding a hydrogen recovery equal to 40% at 623 K and 200 kPa, and presenting stable methane conversions for less than 200 h under operation due to the effect of the H2S contamination. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

The H2020 Program - ERA NET COFUND ERA-PLANET - The European Network for Observing our Changing Planet (Grant Agreement No. 689443) of five-year duration (http://www.era-planet.eu) coordinated by Nicola Pirrone Director of CNR-IIA (www.iia.cnr.it), sees the participation of 34 research organizations, including research centers and universities, belonging to 14 EU countries and an associate country, all leaders in the domain of Earth Observation (EO) in coherence with the European participation to Group on Earth Observation (GEO) and the Copernicus. The main features of ERA-PLANET was the launch of a Joint Trans-national Call, open only to the beneficiaries of the ERA-PLANET Program, which through a two-step selection process, (September 2016 - May 2017) has saw the involvement of two external commissions of expert evaluators. The result of the call was a ranking list with four projects approved and financed. They started on September 1, 2017: SMURBS (SMarturban Solutions for air quality, disasters and city growth) coordinated by the NOA (GR), GEOEssential (Essential Variables workflows for resource efficiency and environmental management) coordinated by UNIGE (SWISS), IGOSP (Integrated Global Observatory Systems for Persistent Pollutants) coordinated by CNR-IIA (IT), iCUPE (Integrative and Comprehensive Understanding on Polar Environments) coordinated by UHEL (FI).

We present a detailed study, done in the framework of the INFN 2006 Roadmap, of the prospects for e+e- physics at the Frascati National Laboratories. The physics case for an e+e- collider running at high luminosity at the phi resonance energy and also reaching a maximum center of mass energy of 2.5 GeV is discussed, together with the specific aspects of a very high luminosity tau-charm factory. Subjects connected to Kaon decay physics are not discussed here, being part of another INFN Roadmap working group. The significance of the project and the impact on INFN are also discussed. All the documentation related to the activities of the working group can be found in http://www.roma1.infn.it/people/bini/roadmap.html., Comment: INFN Roadmap Report: 86 pages, 25 figures, 9 tables

X-ray powder diffraction analysis at 25 °C has been used to further characterize the NpZr phase diagram. We have studied a variety of NpZr aggregate compositions obtained by different preparative methods, including arc melting of the components. For the materials at ambient temperature, obtained by either slow cooling or quenching from elevated temperatures, we observed one or more of the following product phases: α-Np, α-Zr, NpZr2 and one new phase. The last was interpreted tentatively to be either Np4Zr or Np6Zr. Calculations based on the X-ray data suggested a limited solubility of Np in α-Zr and an even lower solubility of Zr in α-Np. The X-ray data for the NpZr2 phase showed that it possesses hexagonal symmetry and is isostructural with UZr2 and PuZr2. Annealing of NpZr composites at selected temperatures did not enhance the formation of NpZr2.

We report here high-pressure X-ray diffraction studies of the two actinide compounds, UBi and CmBi. These compounds existed initially in the NaCl-type (B1) crystal structure and each was studied at room temperature using a diamond anvil cell and energy dispersive X-ray diffraction analysis. The U and Cm monobismuthides were studied up to pressures of 42 and 48 GPa, respectively. All materials exhibited first-order crystallographic phase transitions from their NaCl-type (B1) to a CsCl-type (B2) structure, which were accompanied by volume collapses: UBi at 5 GPa (11% volume change); CmBi at 12 GPa (16% volume change). With curium monobismuthide a subsequent second-order transition from the CsCl-type structure to a tetragonal phase (indexed in space group P4/mmm) occured at 19 GPa. The bulk moduli and their pressure derivatives were derived for each material from the experimental pressure-volume relationships for the B1 phases. These values were: for UBi, 91 GPa and -5.4; for CmBi, 53 GPa and 8.1.

An overview of pressure-induced structural phase transitions and compressibility of actinide compounds will be given. Systematic trends in the nature of the high-pressure phases, the transition pressures, the hysteresis to retransformation on pressure release, and the compressibility are observed in the family of AnX compounds of B1 (NaCl) structure type. The dioxides studied up to now form high-pressure phases of PbCl2 type. UX2 compounds of Fe2As type also tend to have PbCl2 type high-pressure phases. The Th3P4 type compounds studied up to now did not transform up to 50 GPa. The same is true for ThOS and UOSe up to about 45 GPa. Comparison with rare earth compounds will be made where possible.

High-pressure X-ray diffraction studies were performed on ThOS up to 43.3 GPa and on UOSe up to 47.5 GPa, at room temperature, using a diamond anvil cell and synchrotron radiation. The tetragonal structure ( P 4/ nmm ) of these compounds was retained over the whole pressure range. The bulk modulus B 0 and its pressure derivative B 0 ′ were determined for each compound.

We use a time-independent perturbation series in theSU(3)f-breaking piece of the strong Hamiltonian, saturated in a «closure approximation», to describe the symmetry breaking in baryonic ground states. In this analysis we show that lowest-order formulae overestimate the strange-quark scalar density in the nucleon. The formalism is extended to axial charges and magnetic moments: the EMC polarization-asymmetry data, with a correct QCD treatment of the Ellis-Jaffe sum rule, can be made to agree with much less polarization of the nucleon strangequark content, andall data on magnetic moments can be reproduced without quark anomalous moments.

Plutonium monoselenide was studied under high pressure up to 47 GPa, at room temperature, using a diamond anvil cell in an energy dispersive X-ray diffraction facility. At ambient pressure, PuSe has the NaC1-type (B1) structure. The compound has been found to undergo a second-order crystallographic phase transition at around 20 GPa. This phase can be described as a distorted B1 structure, with a rhombohedral symmetry. PuSe transforms to a new phase at around 35 GPa, which can be indexed in the cubic CsCl-type (B2). The volume collapse at this phase transition is 11%. When releasing pressure, we observed a strong hysteresis to the inverse transformation down to 5 GPa. From the pressure-volume relationship, the bulk modulus has been determined to B 0 = 98 GPa and its pressure derivative as B 0 = 2.6. These results are compared to those obtained with other actinide monmictides and monochalcogenides.

We criticize a recent analysis of baryon β-decays by Jaffe and Manohar, coming to opposite conclusions: we show how data on axial charges coming from asymmetries and rates do not disagree, and how, with a proper averaging procedure, evidence begins to emerge for first-orderSU(3) violations, as advocated by Lipkin.

Low-energy theorems are derived for two cases of violations of the quark-line rule in scalar-isoscalar, meson-meson channels from the hypothesis of dominance of the so-called «longitudinal» instantons, advanced for the dynamics of gluons in such channels by the ITEP school. The results seem in reasonable agreement with phenomenological information, and solve a long-standing puzzle in the «accepted values» for the sigma terms in a «natural» way (i.e. without further, specific assumptions on hadronic wave functions).

Current algebra sum rules for kaon-nucleus elastic-scattering amplitudes are re-written as off-mass-shell, finite-contour forward dispersion relations. Saturating these latter with narrow levels, both in the meson-nucleus continua and in the bound-state spectra, we produce a general formula for the dependence of the real parts of kaon-nucleus scattering lengths on the target quantum numbers. We introduce explicitly a shell-model description of nuclear ground-states, which was instrumental in reproducing with satisfactory accuracy the corresponding pion-nucleus data: most of the effects observed there (up to and including the 2s−1d shell) were consistent with a naive spherical-harmonic-oscillator picture. An output of this analysis is the (average) kaon-nucleon sigma-term: the value derived here stays as large as found in two previous estimates by ourselves, the first from a slightly less sophisticated analysis of (mostly) the same data, the second derived from the dispersion-relation evaluations of the zero-energy, fixed-t kaon-nucleon scattering amplitudes made by Oades. Such a large value (about 640 MeV) confirms the hypothesis, advanced by Donoghue and Nappi, of a large, nonperturbative, strange-quark scalar density in the nucleon.

At ambient temperature and pressure, a majority of the actinide monopnictides and monochalcogenides exhibit a face-centered cubic (f.c.c.) structure (NaCl-type, B1). Two exceptions are ThTc and ThBi, which have a body-centered cubic (b.c.c.) structure (CsCl-type, B2). Several of these B1 compounds undergo at least one structural transformation under pressure. Frequently, the transition is from the initial NaCl-type to a CsCl-type cubic structure, although other structural forms are encountered. In addition to providing structural information, high pressure studies reveal important information about chemical bonding. Presented here are efforts to generate a pressure-ionic model and geometrical correlations for these materials, which are useful for predicting the high pressure transition pressures, structures and volume changes accompanying the transitions. This model relies on ionic radii and lattice parameters at ambient pressure as the input parameters. One of the correlations established is that plots of transition pressures as a function of the ratio of the radii (rAny+/rXz−; An  actinide, X  metalloid), for a specific pnictide or chalcogenide anion, can be fitted by a first-order equation: P(GPa) = −339r+/r− + C, where C = 174, 145 or 136, respectively, for anions of the fourth, fifth or sixth periods in the Periodic Table. Correlations were also found for volume collapses accompanying the phase transitions, but these were more complex in nature.

We present in this contribution the basic formulae for the analisys of low-momentum charged-and neutral-kaon interactions in hydrogen, including as well a (brief) description of the problems left open by past experiments and of the improvements DAPHNE can be expected to offer over them. Interactions in deuterium and other light nuclei will be only briefly mentioned, and only in those respects touching directly upon the more 'elementary' aspects of kaon-nucleon interactions.

Neptunium monoselenide transforms to a CsCl-type (B2) allotrope at approximately 23 GPa. Its compressibility data are K0 = 60(3) GPa, K0′ = 2.5(5).

The author evaluates unitary corrections to the Cheng-Dashen method for the evaluation of sigma terms for both the pi N and the KN systems. Results agree with previous estimates of the effect in the pi N system, and predict smaller effects than previously expected in the KN system.

S-wave π—}-nucleus scattering lengths are derived fromKα-line data in π-mesonic atoms for nucleides of mass numbers 2 through 24, solving the Klein-Gordon bound-state equation in a simple approximation.

A formula for K−-nucleus scattering lengths is deriveda la Fubini-Furlan from current algebra and PCAC. From a fit to kaonic atom and scattering data we estimate Σ0(KN)≃ (512 ± 101) MeV and Σ1 (KN)⩽ 78 MeV, consistent with very small nonstrange “current” quark masses.

K−-nucleus scattering lengths have been analysed in terms of Fubini-Furlan sum rules (supplemented with a gray-sphere model to describe the Λ(1405) absorption inside the nucleus), which extrapolate the current-algebra results to the physical threshold. A value of about 600 MeV is obtained for theI t =0KN sigma term, consistent with large violations of the Zweig rule in the scalar-isoscalarN\(\bar N\) system att=0.

We re-express current-algebra sum rules for pion-nucleus elastic-scattering amplitudes as off-mass-shell, finite-contour forward dispersion relations. Saturating these latter with narrow levels, both in the continua and in the bound-state spectra, we analyse all available data on the real parts of pion-nucleus scattering lengths. We find that a good description of these data requires introducing explicitly a shell-model picture of the nuclear ground states: indeed, most of the effects observed in light nuclei (up to and including the 2s-1d shell) are described by a very naive, spherical-harmonic-oscillator picture, save for the few-nucleon systems lighter than4He, which behave as loosely bound nucleon clusters (and for6Li, a loosely bound d-α cluster). An output of this analysis is the pion-nucleon sigma-term, which turns out smaller than, but still consistent with, the estimate by the Karlsruhe-Helsinki collaboration from pion-proton scattering amplitudes: this originates in a reduction in the pion decay constantfπ from the mass-shell toq2=0, needed to reproduce the isospin dependence in the data; the accord between the two estimates is recovered by extrapolating the πN amplitude inboth the variablest andq2 and imposing elastic unitary.

Reviews present information on current quark masses from both the mesonic and baryonic sectors of the hadronic world. The authors find that both sectors yield mutually consistent results which are equally consistent with the model for the chiral-symmetry breaking proposed by Gell-Mann et al. (1968). Evidence claimed by Gunion et al. (1976) to support a different scheme is found to be either radically changed by the new data or not as compelling as claimed by those authors.

An off-mass-shell unitarity approach, already introduced to evaluate the complete correction to the Cheng-Dashen relation between the nonflip, elastic meson-nucleon amplitudes, at zero laboratory energy and momentum transfert=2mi2, and the matrix elements of the corresponding sigma commutator, is extended to extrapolate the kaon-nucleon zero-energy elastic amplitudes from negativet-values to the current algebra point at zero kaon four-momenta. Using determinations of these amplitudes obtained by Oades with finite-contour dispersion relations, and allowing for arbitrary amounts of violation of the Okubo-Zweig rule, we find an estimate of (680±210) MeV for the isoscalar part of the sigma-term in this system, which can be narrowed down to about (640±110) MeV requiring consistency (within a 20% accuracy) with the analogous result for the pion-nucleon system. Such values can be taken as signals of a remarkably large violation of the rule in the scalar channel att=0. Estimates for the isovector term are in the range between 27 and 165 MeV, consistent with the expectation of about 35 MeV from baryon mass differences andSU3.

We present a subjective, admittedly biased view of our recent attempts at determining the pion-nucleon and kaon-nucleon σ-terms. A general, less biased introduction is given on the connection of their values to characteristics of the nucleon wave function at rest, particularly to its content of a sizeable strange-quark sea component. The survey tries to span the most recent literature on the subject (here the choice has also been biased by the speaker sympathies, for which we donot apologize), and only cursory references are given to more «classic» works.

A brief account is given of the systematic differences between π-nuclear and\(\bar K\)-nuclear systems, and of their consequences for the derivation of their scattering lengths from mesic atom data. The scattering lengths for negative kaons on light nuclei are then derived, keeping track of these systematic effects as far as possible, even if in approximate way.

In the application of current algebra techniques to dipion cascade decays we propose to replace low-momentum, linear expansions with a simple «pole plus remainder» model, and we apply it, with systematic use of the hypothesis of partial conservation of the axial vector current, to the processes allowed by the quark line rule of Zweiget al. η′→ηππ, ϱ′→ϱππ and ω′→ωππ, as well as to the forbidden decays ϕ′→ϕππ,ψ′→ψππ and ϒ′→ϒππ. The scheme can easily satisfy prescriptions from quark model dynamics, such as for instance theansatz on chiral-symmetry breaking by Gell-Mann, Oakes and Renner and quantum chromodynamics, and it reproduces fairly well the scarce available information.