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Magnesium borohydride (Mg(BH4)2) is an attractive candidate as a hydrogen storage material due to its high hydrogen content and predicted favorable thermodynamics. In this work we demonstrate reversible hydrogen desorption in partially decomposed Mg(BH4)2 which was ball milled together with 2 mol% Co-based additives. Powder X-ray diffraction and infrared spectroscopy showed that after partial decomposition at 285 °C, amorphous boron-hydride compounds were formed. Rehydrogenation at equivalent temperatures and hydrogen pressures of 120 bar yielded the formation of crystalline Mg(BH4)2 in the first cycle, and amorphous Mg(BH4)2 with other boron–hydrogen compounds upon the third H2 absorption. Reversibility was observed in the samples with and without Co-based additives, although the additives enhanced hydrogen desorption kinetics in the first cycle. X-ray absorption spectroscopy at Co K-edge revealed that all the additives, apart from Co2B, reacted during the first desorption to form new stable species. [ABSTRACT FROM AUTHOR]

Abstract: A new processing route consisting of a short-time high energy ball milling (HEBM) step followed by cold rolling (CR) to produce MgH2-based nanocomposites was investigated. Samples of pure MgH2 and MgH2-mixtures containing 2 mol% of FeF3 were processed under air atmosphere and their effects on the microstructure and the hydrogen storage properties were studied in detail. X-ray Diffraction (XRD) analysis on all samples revealed crystallite sizes in the nanometer range for the beta-MgH2 and FeF3 phases (beta (beta): ∼8–13 nm and FeF3: ∼16–21 nm). No extra crystallite size reduction was observed for the HEBM + CR samples in comparison with those only cold rolled. Scanning electron microscopy (SEM) evaluation together with elemental composition analysis indicated a finer size distribution of additive particles and also a more intimate level of mixing for the HEBM + CR mixture than for the mixture obtained only by CR. These features were associated with the HEBM step applied before the CR. These characteristics led to a lower hydrogen desorption temperatures and enhanced desorption kinetics behavior for the HEBM + CR samples in comparison with the CR samples. [Copyright &y& Elsevier]

Abstract: In this study we have used cold rolling (CR) as a successful method to incorporate additives into MgH2. The mixtures of MgH2 + 2 Mol% X, with X = Fe, Nb, Fe2O3, Nb2O5, FeF3, were processed by CR using a horizontal rolling mill and then followed by a detailed microstructural characterization which includes X-ray diffraction (XRD) with Rietveld refinement, Differential Scanning Calorimetry (DSC) and kinetic measurements. The CR processing resulted in a drastic crystallite size reduction, ∼8–17 nm, strong texture and partial conversion from the β to the γ-MgH2 phase. The orthorhombic metastable NbH x phase was detected in the XRD pattern of the mixture MgH2 + Nb after CR, indicating the high energy involved in the CR processing. The samples containing Fe and FeF3 as additives presented the lowest desorption temperature ranges. All additives presented beneficial effect on the dehydrogenation kinetic measurements (measured at 623 K and 598 K) compared to pure MgH2, in especial for the samples containing Nb2O5 and FeF3. [Copyright &y& Elsevier]

Abstract: 2 LiNH2–1.1 MgH2–0.1 LiBH4–3 wt.% ZrCoH3 is a solid state hydrogen storage material with a hydrogen storage capacity of up to 5.3 wt.%. As the material shows sufficiently high desorption rates at temperatures below 200 °C, it is used for a prototype solid state hydrogen storage tank with a hydrogen capacity of 2 kWhel that is coupled to a high temperature proton exchange membrane fuel cell. In order to design an appropriate prototype reactor, model equations for the rate of hydrogen sorption reactions are required. Therefore in the present study, several material properties, like bulk density and thermodynamic data, are measured. Furthermore, isothermal absorption and desorption experiments are performed in a temperature and pressure range that is in the focus of the coupling system. Using experimental data, two-step model equations have been fitted for the hydrogen absorption and desorption reactions. These empirical model equations are able to capture the experimentally measured reaction rates and can be used for model validation of the design simulations. [Copyright &y& Elsevier]

The topic of data storage, traceability, and data use and reuse in the years following experiments is becoming an important topic in Europe and across the world. Many scientific communities are striving to create open data by the FAIR principles. This is a requirement from the European Commission for EU-funded projects and experiments at EU-funded research infrastructures (RIs) and from many national funding agencies. This is challenging for users of large-scale RIs such as neutron, photon, synchrotron and free-electron laser facilities. Users of photon and neutron (PaN) RIs employ a wide range of scattering, imaging and spectroscopic methods investigating the behaviour of matter with a broad scientific base across physics, chemistry and biology, including engineering, environmental, cultural heritage and medical applications. They produce large data volumes of up to 1 PByte per day in some cases. To ensure all these data are FAIR requires an enormous effort from PaN RIs. It requires not only the expansion of data storage capacity, but also the development and deployment of software for effective data storage, metadata schemes and implementation of effective data pipelines at each individual experiment across RIs. FAIR data also affect the carbon footprint related to large amounts of data and raise questions related to user authentication, rights of access and cyber security. The RIs alone cannot achieve such a transformational process. For successful open science, cooperation of the user communities is essential as they need to create and utilize existing tools to deliver FAIR data. In this white paper, the European PaN community outline and discuss the role and responsibilities of the users and RIs and their common accountability to achieve FAIR data. This paper shall serve as a starting point for a common user and RI approach on the European scale to achieve FAIR data., (open access.)

Metal hydroborates are versatile materials with interesting properties related to energy storage and cation conductivity. The hydrides containing B 3 H 8 - (triborane, or octahydrotriborate) ions have been at the center of attention for some time as reversible intermediates in the decomposition of BH 4 - (3BH 4 - ↔ B 3 H 8 - + 2H 2 ), and as conducting media in electrolytes based on boron-hydride cage clusters. We report here the first observation of two phase transitions in CsB 3 H 8 prior to its decomposition above 230 °C. The previously reported orthorhombic room temperature phase (here named α-CsB 3 H 8 ) with the space group Ama2 changes into a new phase with the space group Pnma at 73 °C (here named β-CsB 3 H 8 ), and then into a face-centered cubic phase, here named γ-CsB 3 H 8 , at 88 °C. These phases are not stable at room temperature thus requiring in situ measurements for their characterization. The phase transitions and decomposition pathway of CsB 3 H 8 were studied with in situ synchrotron powder X-ray diffraction (SR-PXD), in situ and ex situ vibrational spectroscopies (Raman and FTIR), and differential-scanning calorimetry combined with thermo-gravimetric analysis (DSC-TGA). The structure determination was validated by vibrational spectroscopy analysis and modeling of the periodic structures by density functional methods. In γ-CsB 3 H 8 , a significant disorder in B 3 H 8 - positions and orientations was found which can potentially benefit cation conducting properties through the paddle mechanism.

This work presents an in situ nanoscale structural characterization of a SrCl 2 -expanded natural graphite (ENG) composite during ammonia absorption and desorption using small-angle neutron scattering (SANS) together with X-ray powder diffraction and sorption measurements. For the processing of the composite material SANS patterns, we developed and implemented two methods, which showed comparable results. The study allowed following the evolution of the SrCl 2 particles and the nanopores inside the particles during five sorption cycles. The structural changes were compared to the absorption and desorption kinetic measurements, allowing us to make qualitative analysis of the impact of the structural changes on the material properties, such as thermal conductivity and permeability. It was shown that the structural evolution of the composite material did not affect the desorption rate but significantly influenced the absorption rate after the first cycle. We also observed a significant improvement of the absorption kinetics due to the formation of nanopores in the fully deammoniated sample. In addition, the ENG matrix was shown to hinder the agglomeration of the SrCl 2 particles during sorption processes, which is in contrast to literature findings reported for a nonsupported metal halide. The findings presented in this study can be of great interest in the research areas where SrCl 2 -ENG composites are widely studied, i.e., heat storage, heat pumps/refrigerators, deNO x removal, and solid-state ammonia storage.

The formation, structure and deuterium desorption properties of Mg 2 Fe x Co (1-x) D y (0 ≤ x ≤ 1 and 5 ≤ y ≤ 6) complex hydrides were investigated. The synthesis was carried out by reactive ball milling, using a mixture of powders of the parent elements in D 2 atmosphere. The formation of quaternary deuterides was identified from Rietveld refinements of powder X-Ray diffraction and powder neutron diffraction patterns, and from infrared attenuated total reflectance analysis. It was observed that the crystal structure of deuterides depends on the transition metal fraction. For Co-rich compositions, i.e. up to x = 0.1, hydrides have the tetragonal distorted CaF 2 -type structure (space group P4/nmm) of Mg 2 CoD 5 at room temperature. For Fe-rich compositions, i.e. x ≥ 0.5, a cubic hydride is observed, with the same K 2 PtCl 6 -type structure (space group Fm[Formula: see text]m) as Mg 2 FeD 6 and as Mg 2 CoD 5 at high temperatures. For x = 0.3, both the cubic and the tetragonal deuterides are detected. Differential scanning calorimetry coupled with thermogravimetric and temperature programmed desorption analyses show rather similar deuterium desorption properties for all samples, without significant changes as a function of composition. Finally, hydrogen sorption experiments performed for Mg 2 Fe 0.5 Co 0.5 H 5.5 at 30 bar of H 2 and 673 K showed reversible reactions, with good kinetic for both absorption and desorption of hydrogen.

This paper is a collection of selected contributions of the 1st International Workshop on Mechanochemistry of Metal Hydrides that was held in Oslo in May 2018. In this paper, the recent developments in the use of mechanochemistry to synthesize and modify metal hydrides are reviewed. A special emphasis is made on new techniques beside the traditional way of ball milling. High energy milling, ball milling under hydrogen reactive gas, cryomilling and severe plastic deformation techniques such as High-Pressure Torsion (HPT), Surface Mechanical Attrition Treatment (SMAT) and cold rolling are discussed. The new characterization method of in-situ X-ray diffraction during milling is described.

The magnetic properties of SrFe 12 O 19 nanocrystallites produced by hydrothermal synthesis and consolidated by Spark Plasma Sintering (SPS) were optimized by varying the compaction parameters: sintering time, sintering temperature, uniaxial pressure or pre-compaction in a magnetic field. Highly textured compacts with a high degree of crystallite alignment were produced. Qualitative and quantitative textural information was obtained based on X-ray diffraction pole figure measurements. The optimum sintering conditions, relating the degree of alignment and bulk magnetic properties, were identified based on the resulting magnetic properties. It was found that one must strike a balance between the degree of crystallite alignment for high saturation magnetisation and coercivity ( H c ) to gain the highest energy product (BH max ). It was found that the coercive field drops when the crystallite alignment increases. This was particularly pronounced in the case of magnetically pre-aligned powders prior to SPS, where H c and BH max decreased as the pellets became increasingly textured. The best BH max value of 29(4) kJ m -3 was found for the sample sintered at 950 °C for 2 minutes with an applied pressure of 100 MPa for a powder pre-aligned in an applied field of 0.55 T. The results presented here show the potential of SPS consolidation of SrFe 12 O 19 with high relative densities and emphasize the effect of the degree of alignment on the decrease of coercive field and its influence on the magnetic performance., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Magnesium borohydride (Mg(BH 4 ) 2 ) is a promising material for solid state hydrogen storage. However, the predicted reversible hydrogen sorption properties at moderate temperatures have not been reached due to sluggish hydrogen sorption kinetics. Hydrogen (H) → deuterium (D) exchange experiments can contribute to the understanding of the stability of the BH 4 - anion. Pure γ-Mg(BH 4 ) 2 , ball milled Mg(BH 4 ) 2 and composites with the additives nickel triboride (Ni 3 B) and diniobium pentaoxide (Nb 2 O 5 ) have been investigated. In situ Raman analysis demonstrated that in pure γ-Mg(BH 4 ) 2 the isotopic exchange reaction during continuous heating started at ∼80 °C, while the ball milled sample did not show any exchange at 3 bar D 2 . However, during ex situ exchange reactions investigated by infrared (IR) and thermogravimetric (TG) analyses a comparable H → D exchange during long exposures (23 h) to deuterium atmosphere was observed for as received, ball milled and γ-Mg(BH 4 ) 2 + Nb 2 O 5 , while the Ni 3 B additive hindered isotopic exchange. The specific surface areas (SSA) were shown to be very different for as received γ-Mg(BH 4 ) 2 , BET area = 900 m 2 g -1 , and ball milled Mg(BH 4 ) 2 , BET area = 30 m 2 g -1 , respectively, and this explains why no gas-solid H(D) diffusion was observed for the ball milled (amorphous) Mg(BH 4 ) 2 during the short time frames of in situ Raman measurements. The heat treated ball milled sample partially regained the porous γ-Mg(BH 4 ) 2 structure (BET area = 560 m 2 g -1 ). This in combination with the long reaction times allowing for the reaction to approach equilibrium explains the observed gas-solid H(D) diffusion during long exposure. We have also demonstrated that a small amount of D can be substituted in both high surface area and low surface area samples at room temperature proving that the B-H bonds in Mg(BH 4 ) 2 can be challenged at these mild conditions., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The low cost, rare earth free τ-phase of MnAl has high potential to partially replace bonded Nd 2 Fe 14 B rare earth permanent magnets. However, the τ-phase is metastable and it is experimentally difficult to obtain powders suitable for the permanent magnet alignment process, which requires the fine powders to have an appropriate microstructure and high τ-phase purity. In this work, a new method to make high purity τ-phase fine powders is presented. A high purity τ-phase Mn 0.55 Al 0.45 C 0.02 alloy was synthesized by the drop synthesis method. The drop synthesized material was subjected to cryo milling and  followed by a flash heating process. The crystal structure and microstructure of the drop synthesized, cryo milled and flash heated samples were studied by X-ray in situ powder diffraction, scanning electron microscopy, X-ray energy dispersive spectroscopy and electron backscatter diffraction. Magnetic properties and magnetic structure of the drop synthesized, cryo milled, flash heated  samples were characterized by magnetometry and neutron powder diffraction, respectively. The results reveal that the 2 and 4 hours cryo milled and flash heated samples both exhibit high τ-phase purity and micron-sized round particle shapes. Moreover, the flash heated samples display high saturation magnetization as well as increased coercivity.

Actinic keratosis (AK) is considered a premalignant form of skin cancer due to chronic sun exposure. In addition, human papilloma virus (HPV) has been advocated a role in the pathogenesis of this clinical condition. HPV proteins (mainly E6 and E7) seem to act synergistically with ultraviolet (UV) radiation in reducing the defensive mechanisms of keratinocyte apoptosis after UV damage. Data regarding the involvement of other viruses, i.e. human herpes viruses (HHV), in the pathogenesis of AK are so far controversial. HHV8 is considered the infective agent involved in the development of Kaposi sarcoma. Some experimental data have shown that AK lesions carry HHV8 in more than 30% of the bioptic samples. Topical piroxicam was shown to be effective in the treatment of AK. In addition, the molecule shows antiviral action against HPV and HHV8. Here, we report the efficacy of a medical device containing a film-forming substance (polyvinyl alcohol), chemical and physical sun filters (SPF 50+), and 0.8% piroxicam (Actixicam™, Difa Cooper; ACTX) in the treatment of multiple scalp AK lesions, unresponsive to other treatments, in a subject with Kaposi sarcoma and a history of severe contact dermatitis. The subject presented with severe involvement of the scalp, with multiple hypertrophic AK lesions. Previous lesion-directed and field-targeted treatments have not been effective. The subject was treated with ACTX applied twice daily on the affected scalp. Relevant clinical improvement was observed as soon as 1 month of therapy. Complete clinical resolution of all scalp lesions was observed after 3 months of treatment. The product was well tolerated., Competing Interests: E.S. and S.D. declare no conflicts of interest. M.M. is an employee of Difa Cooper, IFC group.

Crystal structure determination is essential for characterizing materials and their properties, and can be facilitated by various tools and indicators. For instance, the Goldschmidt tolerance factor (T) for perovskite compounds is acknowledged for evaluating crystal structures in terms of the ionic packing. However, its applicability is limited to perovskite compounds. Here, we report on extending the applicability of T to ionic compounds with arbitrary ionic arrangements and compositions. By focussing on the occupancy of constituent spherical ions in the crystal structure, we define the ionic filling fraction (IFF), which is obtained from the volumes of crystal structure and constituent ions. Ionic compounds, including perovskites, are arranged linearly by the IFF, providing consistent results with T. The linearity guides towards finding suitable unit cell and composition, thus tackling the main obstacle for determining new crystal structures. We demonstrate the utility of the IFF by solving the structure of three hydrides with new crystal structures.

Magnesium borohydride (Mg(BH4)2) is one of the most promising complex hydrides presently studied for energy-related applications. Many of its properties depend on the stability of the BH4(-) anion. The BH4(-) stability was investigated with respect to H→D exchange. In situ Raman measurements on high-surface-area porous Mg(BH4 )2 in 0.3 MPa D2 have shown that the isotopic exchange at appreciable rates occurs already at 373 K. This is the lowest exchange temperature observed in stable borohydrides. Gas-solid isotopic exchange follows the BH4(-) +D˙ →BH3D(-) +H˙ mechanism at least at the initial reaction steps. Ex situ deuteration of porous Mg(BH4)2 and its dense-phase polymorph indicates that the intrinsic porosity of the hydride is the key behind the high isotopic exchange rates. It implies that the solid-state H(D) diffusion is considerably slower than the gas-solid H→D exchange reaction at the surface and it is a rate-limiting steps for hydrogen desorption and absorption in Mg(BH4)2., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The effect of transition metal fluorides on the decomposition of NaBH4 has been investigated for NaBH4 ball milled with TiF3, MnF3 or FeF3. The compounds were examined by thermal programmed desorption with residual gas analysis, thermo gravimetric analysis and volumetric measurements using a Sieverts-type apparatus. The phase formation process during thermal decomposition was studied by in situ synchrotron radiation powder X-ray diffraction on the as-milled powders. NaBF4 was among the products in all mechano-chemical reactions. (11)B-NMR spectra analysis gave NaBF4 : NaBH4 ratios of 1 : 150 for Na-Ti, 1 : 40 for Na-Mn, and 1 : 10 for Na-Fe. Pure NaBH4 possessed a hydrogen release onset temperature of 430 °C. The hydrogen release in the NaBH4-MnF3 system began as low as 130 °C. FeF3 decreased the onset temperature to 161 °C and TiF3 to 200 °C. TiF3 reacted completely with NaBH4 below 320 °C. All the examined systems have negligible emissions of diborane species. H-sorption studies performed at selected temperatures above 300 °C exhibited relatively fast desorption kinetics. Partial hydrogen re-absorption was observed for the Na-Mn and Na-Fe samples.

The possibilities to produce quaternary Mg-based transition-metal complex hydrides have been explored. Mg2Mn1--xFex (x = 0.5, 0) elemental powder mixtures were ball milled in a reactive D2 atmosphere (about 5 MPa). The results were compared with the formation of Mg2(FeD6)0.5(CoD5)0.5 from Mg-Fe-Co powders. The changes of D2 pressure were monitored during milling and deuterium absorption was detected within the first 15 h of milling. Powder X-ray and neutron diffraction analysis for the as-milled Mg2Mn0.5Fe0.5 powder showed a large fraction of unreacted elemental Mn, as well as the formation of a cubic K2PtCl6-type phase (a = 6.452 A). The latter could be identified as Mg2FeD6. Infrared spectroscopy confirmed the presence of [FeD6]4- anions (stretching band at 1261 cm(-1)) and ruled out the formation of [MnH6]5- complexes. As for the as-milled Mg2Mn, powder diffraction analysis showed the formation of MgD2 as the main reaction product. A small fraction of a cubic K2PtCl6-type phase (a = 6.526 A) was also observed. This was identified as a Mg2FeD6-type compound. It was likely formed as a result of Fe impurities originating from the milling media and detected by EDX analysis. Infrared spectroscopy confirmed the presence of the [FeD6]4- complex (stretching band at 1259 cm(-1)) and showed an additional band at 1313 cm(-1). The likelihood of this band arising from Mn-D bonds is discussed. Finally, deuterium desorption upon heating, was investigated for all systems by differential scanning calorimetry.

Selectively substituted o-teraryls are obtained by palladium/norbornene-catalyzed reaction of aryl iodides, aryl bromides and aryl boronic acids in ordered sequence; high selectivity is attained thanks to the addition of diethyl maleate acting as palladium ligand.

Mg2(Fe0.5Co0.5) elemental powder mixtures were processed by reactive ball milling in a H2 (orD2) atmosphere at about 50 bar. The changes of pressure were monitored during milling and hydrogen absorption was detected within the first 10 h of milling. X-ray and neutron powder diffraction analysis, followed by Rietveld refinement, suggests an almost complete conversion of the starting metals into the quaternary hydride Mg2(FeH6)0.5(CoH5)0.5. The latter has a cubic K2PtCl6-type structure (space group Fm3m) with a cell parameter a approximately 6.42 A degrees. Fe and Co atoms are disorderly distributed in the 4a position. Hydrogen desorption upon heating was investigated by both in situ x-ray diffraction and temperature programmed desorption analysis.Hydrogen is released in a one-step desorption reaction at temperatures between 500 and 600 K,with Mg and a FeCo solid solution as desorption products. Finally, Mg2(FeH6)0.5(CoH5)0.5 was also synthesized by ball milling equi-molar mixtures of Mg2FeH6 and Mg2CoH5 in Ar.

Among the thermodynamic properties of novel materials for solid-state hydrogen storage, the heat of formation/decomposition of hydrides is the most important parameter to evaluate the stability of the compound and its temperature and pressure of operation. In this work, the desorption and absorption behaviors of three different classes of hydrides are investigated under different hydrogen pressures using high-pressure differential scanning calorimetry (HP-DSC). The HP-DSC technique is used to estimate the equilibrium pressures as a function of temperature, from which the heat of formation is derived. The relevance of this procedure is demonstrated for (i) magnesium-based compounds (Ni-doped MgH2), (ii) Mg-Co-based ternary hydrides (Mg-CoHx) and (iii) Alanate complex hydrides (Ti-doped NaAlH4). From these results, it can be concluded that HP-DSC is a powerful tool to obtain a good approximation of the thermodynamic properties of hydride compounds by a simple and fast study of desorption and absorption properties under different pressures.

Background & Aim: The relationship between Helicobacter pylori infection and peptic ulcer disease in cirrhosis remains controversial. The purpose of the present study was to investigate the role of H pylori infection and portal hypertension gastropathy in the prevalence of active peptic ulcer among dyspeptic patients with compensated hepatitis C virus (HCV)-related cirrhosis., Methods: Patients undergoing upper endoscopy with compensated HCV-related cirrhosis were enrolled. Child-Pugh's score was determined at the entry. Variceal size was measured endoscopically and the severity of portal hypertensive gastropathy was graded. H pylori infection status was determined by urea breath testing and/or histology., Results: A total of 178 patients positive for HCV (A and B Child-Pugh's score) were prospectively included. The prevalence of H pylori infection was 43%. An active peptic ulcer was found in 14 patients (8%) and was significantly more common among those with H pylori infection (16% versus 2% in H pylori uninfected patients, odds ratio: 8.0). No association was observed between H pylori infection and variceal size, or hypertensive gastropathy., Conclusions: Patients with compensated cirrhosis and H pylori infection showed higher risk of developing a peptic ulcer. Clinical relevance of this result would be that dyspeptic patients with HCV-related cirrhosis may benefit from preventive screening and eradication of H pylori, especially those with features of insufficient hemostasis.