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The ever-growing demand for Li-ion batteries requires high-capacity electrode materials that should also be environmentally benign, Co-free, secure and durable, to achieve an optimal compromise between sustainability and functional performances. Spinel LiMn2O4 (LMO) is a state-of-the-art material, which, in principle, could satisfy such requirements. However, an undesired cubic–tetragonal phase transition favors Jahn–Teller (J–T) spinel distortion, leading to severe capacity reduction upon cycling below 3 V. Here, we propose a novel dual-doping strategy for LMO, based on the partial substitution of Mn(III) with Fe(III) and Ti(IV) to design new active materials for high-capacity cathodes, namely LiFexMn2−x−yTiyO4 (LFMT), with Li/Mn ratio ranging between 1 and 1.7. The substitution of Mn with Fe and Ti suppresses the J–T distortion, which is often still evident in the case of Ti-doped LMO. This allows cycling in a wider voltage range (4.8–1.5 V), thus resulting in higher capacity and significantly improved stability. The lithiation mechanisms were investigated by combining ex situ X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS analyses). It demonstrated that the only redox-active metal is Mn, while Fe and Ti are electrochemically inactive. The extensive electrochemical lithiation/delithiation of the LFMT compositions brought unprecedented results, which give evidence of stabilizing cation disorder through the formation of Mn-rich and Mn-poor domains, leading to two spinel phases with different Mn:Ti ratios. These insights into the lithiation mechanism pave the way for a better understanding of the doping chemistry and electrochemistry of Mn-based spinels as cathode materials for Li-ion batteries. [ABSTRACT FROM AUTHOR]

The recently-discovered high pressure material MnFe3O5 displays a rich variety of magnetically ordered states on cooling. Fe spins order antiferromagnetically below a Néel transition at 350 K. A second transition at 150 K marks Mn spin order that leads to spin canting of some of the Fe spins and ferrimagnetism. A further transition at 60 K is driven by charge ordering of Fe2+ and Fe3+ over two inequivalent Fe sites, with further canting of all spins. Electrical resistivity measurements reveal semiconducting behaviour in MnFe3O5 with a change in activation energy at 285 K. [ABSTRACT FROM AUTHOR]

The article reviews an international seminar held on January 26, 2017 in Vienna, Austria which discussed the role of the NATO partnership for the Peace (PfP) in the face of the reorientation of NATO. It discusses opportunities for cooperation for the NATO partners; and international cooperation for the internal stability of neighboring countries of Europe.

A novel approach for using Shape Memory Alloys (SMA) was recently proposed and named highperformance shape memory effect (HP-SME). The HP-SME exploits the thermal cycling of stress-induced martensite for producing extremely high mechanical work with a very stable functional fatigue behaviour in Ni rich NiTi alloy. The latter was found to differ significantly from the functional fatigue behaviour observed for conventional SMA. This study was undertaken in order to elucidate the microstructural modifications at the basis of this particular feature. To this purpose, the functional fatigue was coupled to in situ Synchrotron Radiation X-Ray Diffraction, by recording patterns on wires thermally cycled by Joule effect under a constant applied stress (800 MPa). The accurate analysis the line profile XRD data suggests the accumulation of defects upon functional cycling, while the fibre texture was not observed to change. The functional fatigue exhibits a very similar behaviour as the line broadening of XRD peaks, thus suggesting the accumulation of dislocations as the origin of the mechanism of the permanent deformation.

The CO oxidation reaction on (Co,Mg,Mn,Ni,Zn)(Al,Co,Cr,Fe,Mn) 2 O 4 and (Cr,Mn,Fe,Co,Ni) 3 O 4 high entropy spinel oxides was studied for what concerns its mechanism by means of operando soft X-ray absorption spectroscopy. In the (Cr,Mn,Fe,Co,Ni) 3 O 4 high entropy spinel, CO oxidation starts at ca. 150 °C, and complete conversion to CO 2 is obtained at ca. 300 °C. For the (Co,Mg,Mn,Ni,Zn)(Al,Co,Cr,Fe,Mn) 2 O 4 spinel oxides, in contrast, the reaction starts at ca. 200 °C, and complete conversion needs temperatures of the order of 350 °C. Concerning the reaction mechanism, we found that, in both cases, Mn is the active metal, via the Mn(II)/Mn(III) redox couple. CO is found to adsorb on surface Mn(III) sites and reduces them to Mn(II). The Mn(III) oxidation state is recovered by O 2 , yielding CO 2 . All the other transition metals are found to be inactive and act just as spectators. These findings are discussed in the framework of the present knowledge on high entropy oxides.

The temperature-resolved structure evolution of quinary and quaternary equimolar oxides containing Mg, Ni, Zn, Co, and Cu is investigated by in situ synchrotron diffraction. Important structural modifications occur already at mild temperatures and depend on the elements involved. All quaternary compounds with χ(Cu) = 0.25 within 250-500 °C show a tetragonal phase. The fraction of Cu dictates the degree of the tetragonal distortion: for χ(Cu) = 0.20 only local distortions are observed, which do not occur in the absence of Cu. Further heating restores the original cubic phase, followed by the segregation of other phases, which depend on the elements available. In the presence of both Cu and Mg, the segregation of guggenite is observed, a phase with a cation connectivity similar to the cubic high entropy oxide, but with a suitable coordination environment for Cu atoms by allowing strong elongation of octahedra. Guggenite acts as a buffer layer facilitating the gradual diffusion of Cu 2+ from the cubic high entropy oxide to tenorite. To conclude, it is demonstrated for the first time that the demixing of the prototypal high entropy oxide does not involve just tenorite or binary oxides, it is rather mediated by the formation of guggenite., (© 2024 The Author(s). Small published by Wiley‐VCH GmbH.)

Introduction: The use of robotic systems in the surgical domain has become groundbreaking for patients and surgeons in the last decades. While the annual number of robotic surgical procedures continues to increase rapidly, it is essential to provide the surgeon with innovative training courses along with the standard specialization path. To this end, simulators play a fundamental role. Currently, the high cost of the leading VR simulators limits their accessibility to educational institutions. The challenge lies in balancing high-fidelity simulation with cost-effectiveness; however, few cost-effective options exist for robotic surgery training., Methods: This paper proposes the design, development and user-centered usability study of an affordable user interface to control a surgical robot simulator. It consists of a cart equipped with two haptic interfaces, a VR visor and two pedals. The simulations were created using Unity, which offers versatility for expanding the simulator to more complex scenes. An intuitive teleoperation control of the simulated robotic instruments is achieved through a high-level control strategy., Results and Discussion: Its affordability and resemblance to real surgeon consoles make it ideal for implementing robotic surgery training programs in medical schools, enhancing accessibility to a broader audience. This is demonstrated by the results of an usability study involving expert surgeons who use surgical robots regularly, expert surgeons without robotic surgery experience, and a control group. The results of the study, which was based on a traditional Peg-board exercise and Camera Control task, demonstrate the simulator's high usability and intuitive control across diverse user groups, including those with limited experience. This offers evidence that this affordable system is a promising solution for expanding robotic surgery training., Competing Interests: MP, ET, FB were employed by Fos SpA. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2024 Neri, Coduri, Penza, Santangelo, Oliveri, Turco, Pizzirani, Trinceri, Soriero, Boero, Ricci and Mattos.)

Scientific and industrial reasons dictate the study of the solid state of imepitoin, a highly safe and tolerable anticonvulsant drug used in the therapy of epileptic dogs that was approved in the Europe Union in 2013. Our investigations allowed us to discover the existence of a new polymorph of imepitoin, which finds itself in a monotropic relationship with the crystalline form (polymorph I) already known and present on the market. This form (polymorph II), obtained by crystallization from xylene, remains metastable under ambient conditions for at least 1 year. Both solid forms were characterized by thermal (DSC and TGA), spectroscopic (FT-IR and Raman), microscopic (SEM and HSM), and diffractometric techniques. The thermodynamic relationship between the two polymorphs (monotropic) is such that it is not possible to study the melting of polymorph II, not even by adopting appropriate experimental strategies. Our measurements highlighted that the melting peak of imepitoin actually also includes an onset of melt decomposition. The ab initio structure solution, obtained from synchrotron X-ray powder diffraction data collected at room temperature, allowed us to determine the crystal structure of the new polymorph (II). It crystallizes in the monoclinic crystal structure, P2 1 / c space group (#14), with a = 14.8687(6) Å, b = 7.2434(2) Å, c = 12.5592(4) Å, β = 107.5586(8)°, V = 1289.61(8) Å3, and Z = 4.

Neonatal resuscitation is an uncommon, albeit critical task that is more likely to succeed if performed properly and promptly. In this context, simulation is an appropriate way for training and assessing the abilities of all medical staff involved in delivery room care. Recent studies have shown that learning is enhanced if the simulation experience is realistic and engaging. Hence, Virtual Reality can be beneficial for newborn resuscitation training. However, the difficulty of providing realistic haptic interaction limits its use. To overcome this constraint, we have designed RiNeo MR, a simulator for newborn life support training, combining a sensorized manikin to monitor in real time resuscitation skills, with a Virtual Reality application. The system includes a Virtual Reality headset, Leap Motion to track the user's hands, sensorized bag valve mask, and manikin to monitor head and mask positioning, ventilation, and chest compression. RiNeo MR can be used in two modalities: 2D to let the trainee practice resuscitation manoeuvres on the physical manikin, while receiving real time feedback; 3D that allows the user to be immersed in a virtual environment and practice in an hospital-like setting. In the 3D mode, virtual and real manikins are overlapped and communicate in real time. Tests on 16 subjects (11 controls without medical expertise and 5 paediatric residents) demonstrated that the simulator is well tolerated in terms of discomfort. Moreover, the simulator is high rated for user experience and system usability, suggesting that RiNeo MR can be a promising tool to improve newborn life support training. RiNeo MR is a proof of concept of a mixed-reality newborn life support simulator that can be a promising tool to spread newborn resuscitation high-quality training among healthcare providers involved in perinatal medicine., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Coduri et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Tin-based metal halide perovskites with a composition of ASnX 3 (where A= MA or FA and X = I or Br) have been investigated by means of X-ray total scattering techniques coupled to pair distribution function (PDF) analysis. These studies revealed that that none of the four perovskites has a cubic symmetry at the local scale and that a degree of increasing distortion is always present, in particular when the cation size is increased, i.e., from MA to FA, and the hardness of the anion is increased, i.e., from Br - to I - . Electronic structure calculations provided good agreement with experimental band gaps for the four perovskites when local dynamical distortions were included in the calculations. The averaged structure obtained from molecular dynamics simulations was consistent with experimental local structures determined via X-ray PDF, thus highlighting the robustness of computational modeling and strengthening the correlation between experimental and computational results.

We present a combined real and reciprocal space structural and microstructural characterization of CeO 2 nanoparticles (NPs) exhibiting different crystallite sizes; ~3 nm CeO 2 NPs were produced by an inverse micellae wet synthetic path and then annealed at different temperatures. X-ray total scattering data were analyzed by combining real-space-based Pair Distribution Function analysis and the reciprocal-space-based Debye Scattering Equation method with atomistic models. Subtle atomic-scale relaxations occur at the nanocrystal surface. The structural analysis was corroborated by ab initio DFT and force field calculations; micro-Raman and electron spin resonance added important insights to the NPs' defective structure. The combination of the above techniques suggests a core-shell like structure of ultrasmall NPs. These exhibit an expanded outer shell having a defective fluorite structure, while the inner shell is similar to the bulk structure. The presence of partially reduced O2-δ species testifies to the high surface activity of the NPs. On increasing the annealing temperature, the particle dimensions increase, limiting disorder as a consequence of the progressive surface-to-volume ratio reduction.

Manipulation by external pressure of the optical response of 2D Metal Halide Perovskites (MHPs) is a fascinating route to tune their properties and promote the emergence of novel features. We investigate here DA 2 PbI 4 and DA 2 GeI 4 (DA = decylammonium) perovskites in the pressure range up to ∼12 GPa by X-ray powder diffraction, absorption, and photoluminescence spectroscopy. Although the two systems share a similar structural evolution with pressure, the optical properties are rather different and influenced by Pb or Ge. DA 2 PbI 4 shows a progressive red shift from 2.28 eV ( P  = 0 GPa) to 1.64 eV at 11.5 GPa, with a narrow PL emission, whereas DA 2 GeI 4 , changes from a non-PL system at ambient pressure to a clear broadband emitter centered around 730 nm with an intensity maximum at about 3.7 GPa. These results unveil the role of the central atom on the nature of emission under pressure in 2D MHPs containing a long alkyl chain., Competing Interests: The authors declare no competing financial interests., (© 2022 The Author(s).)

Here we report on the impact of reducing the crystalline size on the structural and magnetic properties of γ-Fe 2 O 3 maghemite nanoparticles. A set of polycrystalline specimens with crystallite size ranging from ~2 to ~50 nm was obtained combining microwave plasma synthesis and commercial samples. Crystallite size was derived by electron microscopy and synchrotron powder diffraction, which was used also to investigate the crystallographic structure. The local atomic structure was inquired combining pair distribution function (PDF) and X-ray absorption spectroscopy (XAS). PDF revealed that reducing the crystal dimension induces the depletion of the amount of Fe tetrahedral sites. XAS confirmed significant bond distance expansion and a loose Fe-Fe connectivity between octahedral and tetrahedral sites. Molecular dynamics revealed important surface effects, whose implementation in PDF reproduces the first shells of experimental curves. The structural disorder affects the magnetic properties more and more with decreasing the nanoparticle size. In particular, the saturation magnetization reduces, revealing a spin canting effect. Moreover, a large effective magnetic anisotropy is measured at low temperature together with an exchange bias effect, a behavior that we related to the existence of a highly disordered glassy magnetic phase.

Here we report on the first structural and optical high-pressure investigation of MASnBr 3 (MA = [CH 3 NH 3 ] + ) and CsSnBr 3 halide perovskites. A massive red shift of 0.4 eV for MASnBr 3 and 0.2 eV for CsSnBr 3 is observed within 1.3 to 1.5 GPa from absorption spectroscopy, followed by a huge blue shift of 0.3 and 0.5 eV, respectively. Synchrotron powder diffraction allowed us to correlate the upturn in the optical properties trend (onset of blue shift) with structural phase transitions from cubic to orthorhombic in MASnBr 3 and from tetragonal to monoclinic for CsSnBr 3 . Density functional theory calculations indicate a different underlying mechanism affecting the band gap evolution with pressure, a key role of metal-halide bond lengths for CsSnBr 3 and cation orientation for MASnBr 3 , thus showing the impact of a different A-cation on the pressure response. Finally, the investigated phases, differently from the analogous Pb-based counterparts, are robust against amorphization showing defined diffraction up to the maximum pressure used in the experiments.

A study was performed to investigate the hydrogen embrittlement behavior of 18-Ni 300 maraging steel produced by selective laser melting and subjected to different heat treatment strategies. Hydrogen was pre-charged into the tensile samples by an electro-chemical method at the constant current density of 1 A m -2 and 50 A m -2 for 48 h at room temperature. Charged and uncharged specimens were subjected to tensile tests and the hydrogen concentration was eventually analysed using quadrupole mass spectroscopy. After tensile tests, uncharged maraging samples showed fracture surfaces with dimples. Conversely, in H-charged alloys, quasi-cleavage mode fractures occurred. A lower concentration of trapped hydrogen atoms and higher elongation at fracture were measured in the H-charged samples that were subjected to solution treatment prior to hydrogen charging, compared to the as-built counterparts. Isothermal aging treatment performed at 460 °C for 8 h before hydrogen charging increased the concentration of trapped hydrogen, giving rise to higher hydrogen embrittlement susceptibility.

A ferrite in the Sr 2 Tl 2 O 5 -type MFe 3 O 5 family with M = Co has been synthesized at 12 GPa pressure. Neutron diffraction shows the sample to be Co deficient with composition Co 0.6 Fe 3.4 O 5 . The Co/Fe cation distribution is found to be profoundly different from those of MFe 3 O 5 analogs and lies between normal and inverse limits, as Co 2+ substitutes across trigonal prismatic and one of the two octahedral sites. CoFe 3 O 5 shows complex magnetic behavior with weak ferromagnetism below T C1 ≈ 300 K and a second transition to ferrimagnetic order at T C2 ≈100 K. Spin scattering of carriers leads a substantial increase in the hopping activation energy below T C1 , and a small negative magnetoresistance is observed at low temperatures.