Assessment of high performance SAPO-34/S-PEEK composite coatings for adsorption heat pumps

In this work, a new composite adsorbent coating on aluminum support, based on SAPO34 zeolite filler embedded into sulfonate polyether ether ketone matrix is investigated for adsorption heat pumps (AHP) applications. Composite zeolite/polymer mixtures, with 80–95 wt% content of SAPO-34 zeolite filler have been prepared and coated on aluminum substrates. The as prepared coatings showed a pull-off adhesion strength up to 2.0 MPa, significantly higher than conventional values of composite zeolite coatings reported in the literature. Scanning electron microscopy analysis demonstrated that the coating has a homogeneous morphology with zeolite filler well interconnected in the composite coating structure. Water adsorption isobars were carried out at equilibrium in the temperature range 30–120°C. The best adsorption performances for AHPs applications were observed for the PZ-95 batch, where a maximum water uptake of ∼29.0 wt% was reached, highlighting that the polymer matrix presence does not alter the zeolite adsorption capability (31.3 wt%).     

Renal involvement in mushroom poisoning: The case of Orellanus syndrome

Although mushroom poisoning is a rare cause of acute renal injury, in some cases it may lead to the development of a severe and irreversible renal failure. Orellanus syndrome is the most important example of organic renal damage related to mushroom consumption. It is caused by the ingestion of orellanine, the main toxin of different types of Cortinarius mushrooms (Cortinarius speciosissimus, C. orellanus, C. orellanoides, etc.), and it is characterized by progressive clinical phases with a predominant kidney involvement, finally requiring renal replacement therapy in about 10% of cases. Renal damage is often late and associated with a histological picture of interstitial nephritis. Diagnosis is essentially clinical and no specific therapy has been shown to be effective in preventing and treating renal damage. Here, we describe the case of a patient with mixed wild mushroom poisoning, presenting the typical clinical signs and course of the Orellanus syndrome. This case offers us the opportunity to review the main clinical features of this severe and little‐known intoxication.     

Depth-resolved residual stress analysis of thin coatings by a new FIB-DIC method

A new methodology for the measurement of depth sensitive residual stress profiles of thin coatings with sub-micrometer resolution is presented. The two step method consists of incremental focused ion beam (FIB) ring-core milling, combined with high-resolution in situ SEM-FEG imaging of the relaxing surface and a full field strain analysis by digital image correlation (DIC). The through-thickness profile of the residual stress can be obtained by comparison of the experimentally measured surface strain with finite element modeling using Schajer's integral method. In this work, a chromium nitride (CrN) CAE-PVD 3.0 μm coating on steel substrate, and a gold MS-PVD 1.5 μm on silicon were selected for the experimental implementation. Incremental FIB milling was conducted using an optimized milling strategy that produces minimum re-deposition over the sample surface. Results showed an average residual stress of σ = −5.15 GPa in the CrN coating and σ = +194 MPa in the Au coating. These values are in reasonable agreement with estimates obtained by other conventional techniques. The depth profiles revealed an increasing residual stress from surface to the coating/surface interface for both coatings. This observation is likely related to stress relaxation during grain growth, which was observed in microstructural cross sections, as predicted by existing models for structure-stress evolution in PVD coatings. A correlation between the observed stress gradients and the in-service mechanical behavior of the coatings is proposed. Finally, critical aspects of the technique and the influence of microstructure and elastic anisotropy on stress analysis are analyzed and discussed.     

The role of chemistry in the research on advanced materials in Italy (I). The ZIC paradigm

This paper reviews the main achievements of the Targeted Project Special Materials for Advanced Technology (TP SMAT [1989–1993]).It describes the analysis of funding provided by TP SMAT and the most important results of TP SMAT with reference to both scientific publications issued (together with the relative impact factor) and technology demonstrators produced. Human skills developed and new facilities are also taken into account.It also analyzes a new way of managing Targeted Project based upon cross-functional process, where timing and mode of development are merged in a single goal: an innovative electrical car (Zero Impact Car—ZIC). In this process the various topics were combined, with typical concurrent engineering tools, in a complete harmonious way in order to produce a demonstrator of new materials, technologies and integrated design (i.e. design of both structures and microstructures-materials). This new managing model is the so called: ZIC paradigm.Chairman of the CNR National Committee of Experts for Chemical SciencesChairman of the Commission for the feasibility study of the Targeted Project on Special Materials for Advanced Technology IIDirector of the Targeted Project on Special Materials for Advanced Technology IManagement staff for the Targeted Project on Special Materials for Advanced Technology I     

Experimental Strategy and Mechanistic View to Boost the Photocatalytic Activity of Cs3Bi2Br9 Lead-Free Perovskite Derivative by g-C3N4 Composite Engineering

The rational design of heterojunctions based on metal halide perovskites (MHPs) is an effective route to create novel photocatalysts to run relevant solar-driven reactions. In this work, an experimental and computational study on the synergic coupling between a lead-free Cs₃Bi₂Br₉ perovskite derivative and g-C₃N₄ is presented. A relevant boost of the hydrogen photogeneration by more than one order of magnitude is recorded when going from pure g-C₃N₄ to the Cs₃Bi₂Br₉/g-C₃N₄ system. Effective catalytic activity is also achieved in the degradation of the organic pollutant with methylene blue as a model molecule. Based upon complementary experimental outputs and advanced computational modeling, a rationale is provided to understand the heterojunction functionality as well as the trend of hydrogen production as a function of perovskite loading. This work adds further solid evidence for the possible application of MHPs in photocatalysis, which is emerging as an extremely appealing and promising field of application of these superior semiconductors.     

Random spray Retinex: a new Retinex implementation to investigate the local properties of the model.

In order to investigate the local filtering behavior of the Retinex model, we propose a new implementation in which paths are replaced by 2-D pixel sprays, hence the name "random spray Retinex." A peculiar feature of this implementation is the way its parameters can be controlled to perform spatial investigation. The parameters' tuning is accomplished by an unsupervised method based on quantitative measures. This procedure has been validated via user panel tests. Furthermore, the spray approach has faster performances than the path-wise one. Tests and results are presented and discussed.     

The effect of temperature and pressure on the hydrogen permeation through Pd-coated Ti26Ni21V53 alloy membrane under different atmospheres

The paper introduces Ti₂₆Ni₂₁V₅₃ alloy membrane as a potential replacement for Pd-based membrane. The pressure–temperature–hydrogen permeation relationships of Pd-coated Ti₂₆Ni₂₁V₅₃ alloy membrane have been investigated under pure hydrogen and mixed hydrogen gas with carbon dioxide and carbon monoxide in a pressure range from 0.5 to 2 atm over a wide temperature range including the typical hydrogen membrane operating temperature range (350–450 °C). The experiments show that the hydrogen flux was directly proportional to the temperature at constant pressure according to an Arrhenius-type relationship, whereas it was not proportional to the square root of hydrogen partial pressure in little accordance with the Sievert's law. The hydrogen permeability values obtained for the Pd-coated Ti₂₆Ni₂₁V₅₃ alloy membrane under present conditions are higher than the pure palladium and those previously published in the Ti–Ni–V ternary systems.     

Block iterative eigensolvers for sequences of correlated eigenvalue problems

In Density Functional Theory simulations based on the LAPW method, each self-consistent field cycle comprises dozens of large dense generalized eigenproblems. In contrast to real-space methods, eigenpairs solving for problems at distinct cycles have either been believed to be independent or at most very loosely connected. In a recent study (Di Napoli et al., 2012)  [13], it was demonstrated that, contrary to belief, successive eigenproblems in a sequence are strongly correlated with one another. In particular, by monitoring the subspace angles between eigenvectors of successive eigenproblems, it was shown that these angles decrease noticeably after the first few iterations and become close to collinear. This last result suggests that we can manipulate the eigenvectors, solving for a specific eigenproblem in a sequence, as an approximate solution for the following eigenproblem. In this work we present results that are in line with this intuition. We provide numerical examples where opportunely selected block iterative eigensolvers benefit from the reuse of eigenvectors by achieving a substantial speed-up. The results presented will eventually open the way to a widespread use of block iterative eigensolvers in ab initio electronic structure codes based on the LAPW approach.