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The resistance of wear protective coatings against oxidation is crucial for their use at high temperatures. Here, three nanocomposite AlCr(Si)N coatings with a fixed Al/Cr atomic ratio of 70/30 and a varying Si-content of 0 at.%, 2.5 at.% and 5 at.% were analyzed by differential scanning calorimetry, thermogravimetric analysis and X-ray in order to understand the oxidation behavior depending on their Si-content. Additionally, a partially oxidized AlCrSiN coating with 5 at.% Si on a sapphire substrate was studied across the coating thickness by depth-resolved cross-sectional X-ray nanodiffraction and scanning trans-mission electron microscopy to investigate the elemental composition, morphology, phases and residual stress evolution of the oxide scale and the non-oxidized coating underneath. The results reveal enhanced oxidation properties of the AlCr(Si)N coatings with increasing Si-content, as demonstrated by a retarded onset of oxidation to higher temperatures from 1100°C for AlCrN to 1260°C for the Si-containing coatings and a simultaneous deceleration of the oxidation process. After annealing of the AlCrSiN sample with 5 at.% Si at an extraordinary high temperature of 1400°C for 60 min in ambient air, three zones developed throughout the coating strongly differing in their composition and structure: (i) a dense oxide layer comprising an Al-rich and a Cr-rich zone formed at the very top, followed by (ii) a fine-grained transition zone with incomplete oxidation and (iii) a non-oxidized zone with a porous structure. The varying elemental composition of these zones is furthermore accompanied by micro-structural variations and a complex residual stress development revealed by cross-sectional X-ray nanodiffraction. The results provide a deeper understanding of the oxidation behavior of AlCr(Si)N coatings depending on their Si-content and the associated elemental, microstructural and residual stress evolution during high-temperature oxidation. peerReviewed

Cosmogenic radionuclide 10Be and 26Al targets (BeO and Al2O3) for AMS analysis are produced by a growing number of geochemical laboratories, employing different sample processing methods for the extraction of Be and Al from environmental materials. The reliability of this geochronological tool depends on data reproducibility independent from the preparation steps and the AMS measurements. Our results demonstrate that 10Be and 26Al concentrations of targets processed following different, commonly used protocols and measured at two AMS facilities lead to consistent results. However, insoluble fluoride precipitates, if formed during processing, can cause decreased 26Al results, while 10Be concentrations are unaffected.

Contrary to early motivation, the majority of aluminium ion batteries developed to date do not utilise multivalent ion storage; rather, these batteries rely on monovalent complex ions for their main redox reaction. This limitation is somewhat frustrating because the innate advantages of metallic aluminium such as its low cost and high air stability cannot be fully taken advantage of. Here, we report a tetradiketone macrocycle as an aluminium ion battery cathode material that reversibly reacts with divalent (AlCl2+) ions and consequently achieves a high specific capacity of 350 mAh g−1 along with a lifetime of 8000 cycles. The preferred storage of divalent ions over their competing monovalent counterparts can be explained by the relatively unstable discharge state when using monovalent AlCl2+ ions, which exert a moderate resonance effect to stabilise the structure. This study opens an avenue to realise truly multivalent aluminium ion batteries based on organic active materials, by tuning the relative stability of discharged states with carrier ions of different valence states., Aluminium ion batteries have been developed based on the storage of monovalent complex ions, impairing their original motivation of storing multivalent ions. Here, the authors demonstrate the divalent ion storage of tetradiketone macrocycles by tuning the relative stability of discharged states.

The synthesis and spectroscopic characterisation of eight new first-row transition metal (M = Cr, Mn, Fe, Co, Cu) aluminylene complexes is reported. DFT and ab initio calculations have been used to provide detailed insight into the metal–metal bond. The σ-donation and π-backdonation properties of the aluminylene ligand are evaluated via NBO and ETS-NOCV calculations. These calculations reveal that these ligands are strong σ-donors but also competent π-acceptors. These properties are not fixed but vary in response to the nature of the transition metal centre, suggesting that aluminylene fragments can modulate their bonding to accommodate both electron-rich and electron-poor transition metals. Ab initio DLPNO-CCSD(T) calculations show that dispersion plays an important role in stabilising these complexes. Both short-range and long-range dispersion interactions are identified. These results will likely inform the design of next-generation catalysts based on aluminium metalloligands.

Catalysts prepared on ZrO2, Al2O3 and ZrO2–Al2O3 (ZrAl-10) supported with Anderson heteropolyanion (RhMo6) as active phase were investigated for the elimination of NO3 − from water. Raman character...

Space charge injected into a liquid dielectric by an electrode under an impulse voltage causes the electric field to be distorted, which affects the dielectric's insulation performance. In this study, the authors study the surface modification of three-electrode materials, namely aluminium, copper, and stainless steel, by sputtering of titanium dioxide (TiO 2 ) based on magnetron sputtering. The breakdown voltage of propylene carbonate and the surface morphology of the electrodes before and after modification were examined. Furthermore, the distribution of the space charge injected into the propylene carbonate from the different electrode materials was also measured based on the Kerr electro-optic effect. These results indicate that the breakdown voltage of propylene carbonate increased by 7, 4, and 9% after surface modification of aluminium, copper, and stainless steel, respectively. After sputtering of TiO 2 , micro-grooves on the surface of the three-electrode materials became smooth, and the surface roughness decreased, which changed the barrier height of the solid–liquid interface. The space charge injection mode of the three-electrode materials before and after surface modification was bipolar injection; however, the space charge injection amounts were markedly lower for the modified electrodes.

In this work, an investigation of the properties of nanoscale-thick Ti/TiN, TiN, W, WN layers as diffusion barriers between Si and Al is carried out in view of Si-based electronic applications. Heat treatments were performed on the samples to activate interdiffusion between Si and Al. Changing annealing time and temperature, each sample was morphologically characterized by scanning electron microscopy and atomic force microscopy and compositionally characterized by Rutherford backscattering analysis. The aim is to evaluate the efficiency of the layers as diffusion barriers between Si and Al and, at the same time, to evaluate the surface morphological changes upon annealing processes.

Rutherford backscattering spectrometry, X-ray photoelectron and X-ray energy dispersive spectroscopies were employed to analyse Bi incorporation into ZnO:Al and ZnO:Ga transparent and electrically conductive thin films deposited by d.c. magnetron sputtering, with thickness in the range of 300–400 nm. Sputtering was performed in an argon atmosphere from two targets in confocal geometry being one composed of either ZnO:Al2O3 or ZnO:Ga2O3 composites and the other a Bi metal target. The content of bismuth dopant in the ZnO matrix was controlled by the respective target current density (JBi) in order to attain a high optical transparency (>80%) in the visible region. For ZnO:Al,Bi films Bi content varied from 0.1 to a maximum of 1.5 at.% when varying JBi from 0.06 to 0.26 mA cm−2. However, for ZnO:Ga,Bi films, deposited in similar conditions, Bi reached a maximum overall layer content of 2.4 at.%, with a surface enrichment content that varied from 1.3 to 8.8 at.%. It was also observed that the Bi content in the topmost layers of the films is slightly depleted due to thermal evaporation upon thermal annealing in vacuum at 350 °C. It is envisaged applications for these films as transparent photoelectrodes and thermoelectric materials., Fundação para a Ciência e a Tecnologia (FCT, Portugal)/PIDDAC through the Strategic Funds project reference UID/FIS/04650/2013. Filipe Correia is grateful to the Fundação para a Ciência e a Tecnologia for the Ph.D. Grant SFRH/BD/111720/2015. Paulo Salvador is grateful to the Project WinPSC - POCI-01-0247-FEDER-017796, for the research grant, co-funded by the European Regional Development Fund (ERDF), through the Operational Programme for Competitiveness and Internationalisation (COMPETE 2020), under the PORTUGAL 2020 Partnership Agreement. Joana Ribeiro is grateful to University of Minho for the Grant UMINHO/BI/66/2017

Made available in DSpace on 2019-10-06T17:03:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-04-14 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Aims: Cerrado woody species are divided into a small group of aluminum (Al)-accumulating species and the rest of the woody species. Both groups grow well on acidic and Al-rich soils. We found a Cerrado remnant growing on a calcareous soil with high calcium (Ca) and low Al saturations (m%). We checked whether Al deposition differs between leaf veins and leaf blade, and predicted that plants grown on the acidic soil store more Al than those grown on the calcareous soil. Methods: Adult plants of Qualea grandiflora and Q. parviflora, two Al-accumulators, were found in this area, and we compared leaf Ca and Al concentrations with those of the same species growing on a dystrophic Cerrado soil. Results: Leaf Ca concentration reflected differences between the soil types, and Ca was more accumulated in leaf veins. However, Al accumulation was independent of m%, and it was more deposited in the leaf blade of both species, which was confirmed by hystochemical reactions and X-ray spectra in SEM analysis (EDS). Conclusions: The leaf tissue to which Al is preferentially allocated in the leaf blade could not be distinguished. Granules in epidermal cells exhibiting high Al EDS peaks suggest an important allocation for this metal. Programa de Pós-Graduação em Biologia Vegetal Instituto de Biociências Departamento de Botânica Universidade Estadual Paulista (UNESP), Av. 24-A, 1515 Laboratório de Botânica e Ecologia no Domínio Cerrado (LABEC) Universidade Federal de Uberlandia (UFU), Rua 20, 1600 Instituto de Biociências Departamento de Botânica Universidade Estadual Paulista (UNESP), Av. 24-A, 1515 Programa de Pós-Graduação em Biologia Vegetal Instituto de Biociências Departamento de Botânica Universidade Estadual Paulista (UNESP), Av. 24-A, 1515 Instituto de Biociências Departamento de Botânica Universidade Estadual Paulista (UNESP), Av. 24-A, 1515 FAPESP: 2014/14386-0 CNPq: 309149/2017-7

With the excellent solubility, mobility, bioaccumulation and carcinogenesis, hexavalent chromium Cr (VI), widely exists in various industrial effluents such as chrome plating, metal finishing, pigments, and tanning. Cr (VI) is one of the toxic metal pollutants among all the heavy metals. Therefore, the purpose of this work was to convert highly water-soluble Cr (VI) into Cr (III) species using electrocoagulation (EC) process. The Box–Behnken design (BBD) as was applied to investigate the effects of major operating variables and optimization conditions. The predicted values of responses obtained using the model is agreed well with the experimental data. This work demonstrated that the Cr (VI) is entirely converted into Cr (III) in solid-phases in electrocoagulation process. It was also found that reduction increased with current density that suggesting that the reduction efficiency is closely related to the generation of floc. Keywords: Cr (VI), Cr (III), EC, BBD, Fe, Al

We review our recent paper which resolves the long-standing dilemma of the location and nature of the six-fold coordinated aluminum in calcium aluminate silicate hydrate (C-A-S-H) samples. First principles calculations predict that at high Ca:Si and H2O ratios, aluminum is incorporated into the bridging sites of the linear silicate chains and that the stable coordination number is six. We confirm this hypothesis experimentally by one- and two-dimensional dynamic nuclear polarization enhanced 27 Al and 29 Si solid-state NMR experiments in which we correlate the distinctive six-fold coordinated aluminum NMR signal at 5 ppm to 29 Si NMR signals from silicates in C-A-S-H.

The objective of this study is to evaluate the effects of in-egg inoculation with sources of conjugated linoleic acid (CLA) and lauric acid (AL), going by the weight of lymphoid organs and the biochemical profile of the blood of cut quails, from one to 35 days of age. We used 360 quails distributed in a completely randomized design, in six treatments and six replicates of 10 birds per plot. Corn oil (OM) was used to dilute the CLA and AL. The experimental treatments were: healthy eggs (control); eggs inoculated with OM thinner; eggs inoculated with CLA 120 mg / 50 mL OM; eggs inoculated with CLA 240 mg / 50 mL OM; eggs inoculated with AL 60 mg / 50 mL OM and eggs inoculated with AL 90 mg / 50 mL OM. The results were analyzed through Program R at the level of 5% significance. To verify the normal distribution of errors, the Shapiro-Wilk normality test was applied. At 21 days, an effect of p < 0.05 was observed for the total blood cholesterol content, inoculations with CLA reduced, even as AL increased, regardless of the level. At 35 days, it was found (p < 0.05) that the levels of total cholesterol and AST in the blood decreased with inoculations of CLA and AL at the lower levels, compared to those that did not receive the inoculations. The CLA and AL levels supplemented via egg inoculations did not interfere with the weight of the lymphoid organs (thymus, Fabricius bursa) of the birds, at both ages. Supplementation in eggs of cut quails with CLA 240 mg reduced the total blood cholesterol content compared to CLA 120 mg, at 21 days of age. At 35 days of age, higher concentrations of CLA and AL increased the total cholesterol and AST in the blood of birds and AL had a greater effect on the increase than CLA. O objetivo deste trabalho foi avaliar os efeitos da inoculação in ovo com fontes de ácido linoleico conjugado (CLA) e ácido láurico (AL), sobre os órgãos linfoides e o perfil bioquímico do sangue de codornas de corte de um a 35 dias de idade. Foram utilizadas 360 codornas distribuídas em delineamento inteiramente casualizado, em seis tratamentos e seis repetições de 10 aves por parcela. Os tratamentos experimentais foram: ovos íntegros (controle); ovos inoculados com diluidor OM; ovos inoculados com CLA 120 mg/50mL OM; ovos inoculados com CLA 240 mg/50mL OM; ovos inoculados com AL 60 mg/50mL OM e ovos inoculados com AL 90 mg/50mL OM. Aos 21 dias observou-se efeito (P < 0,05) para teor de colesterol total no sangue, as inoculações com CLA reduzem, enquanto o AL aumenta independentemente do nível. Os resultados foram analisados pelo programa R no nível de significância de 5%. Para verificar a distribuição normal dos erros, foi aplicado o teste de normalidade Shapiro-Wilk. Aos 21 dias, observou-se efeito (P < 0,05) para o teor total de colesterol no sangue, inoculações com CLA reduzida, enquanto a AL aumenta independentemente do nível. Aos 35 dias, verificou-se (P < 0,05) que os níveis de colesterol total e AST no sangue diminuíram com as inoculações de CLA e AL em níveis mais baixos, comparados àqueles que não receberam inoculações. Os níveis de CLA e AL suplementados por inoculações de ovos não interferiram no peso dos órgãos linfoides (timo, bursa de Fabricius) de aves em ambas as idades. A suplementação em ovos de codornas de corte com CLA 240 mg reduz o conteúdo total de colesterol no sangue em comparação com o CLA 120 mg aos 21 dias de idade. Aos 35 dias de idade, concentrações mais altas de CLA e AL aumentam o colesterol total e AST no sangue das aves e o AL tem um efeito maior em aumentar o CLA sanguíneo.

Publisher's version (útgefin grein), This study reports the direct production of an aluminium–manganese alloy during aluminium electrolysis in fluoride-based melts. Experiments were conducted in a laboratory cell dedicated for current efficiency measurements. The temperature was varied from 965–980 °C at a cathodic current density (CCD) of 0.9 A/cm2 and a cryolite ratio (CR) of 2.2. The manganese content was up to 3.0 wt%. Manganese was added in the form of Mn2O3. Bath samples were collected regularly and analyzed with ICP-MS to observe the decay of manganese during electrolysis. It was possible to produce Al-Mn alloys of up to 21 wt. % Mn. Current efficiency for the electrodeposition of Al–Mn alloy was estimated to be in the range of 93%. Current efficiencies with respect to aluminium were estimated. The solidified surfaces of the metal deposits were mostly flat, but some were deformed., Norges Teknisk-Naturvitenskapelige Universitet

In this study, the nucleation and growth kinetics behavior of aluminum (Al) were investigated in the Choline-chloride (ChCl)-urea deep eutectic solvent (DES) ionic liquids. The studies of cyclic voltammetric and chronoamperometry demonstrated that the electrodeposition process of Al was controlled by three-dimensional progressive nucleation and instantaneous nucleation. And the growth of nuclei is a diffusion-controlled process. The diffusion coefficient of Al ions was calculated at 343 K, that is, 1.773 &times, 10&minus, 10 cm2/s. The Al coating was obtained on the surface of the AZ31 magnesium alloy electrode under appropriate conditions. According to the surface morphology of the Al film, it could be inferred that the theoretical deposit thickness is similar to the actual thickness, and the apparent diffusion rate of Al ions is slower than the diffusion coefficient in the electrolytes. So, in the later deposition, lamellar Al along the diffusion direction were formed, and lamellar depleted Al zones existed around the big grain Al-rich region.

In the present study, nanostructured ?-Cd(OH)2 adsorbent was synthesized, characterized by Fourier-transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy analysis, and applied for Cr(VI) ions capturing (adsorption) from environmental aqueous samples. The central composite design of 18 adsorption experiments was employed for multivariate sorption optimization. Maximum adsorption (%) of Cr(VI) ions was calculated and found to be 98.5% with relative standard deviation (RSD) ? 3.5 at optimum concentration 15 mg L–1, pH 4.0, adsorbent dosage 50 mg, shaking time 20 min and shaking speed 120 rpm at 25°C. Langmuir, Freundlich and Dubinin–Radushkevich isotherms fitted well to adsorption data with correlation coefficient (R2) of 0.993, 0.982 and 0.994, respectively. Mono-layered (Qm ) and multi-layered (Kf ) capacities of ?-Cd(OH)2 adsorbent for Cr(VI) ions retention were calculated and found to be 202.02 ± 2.0 and 4.95 ± 2.5 mg g–1, respectively. Sorption energy was calculated and found to be 8.45 ± 2.0 kJ mol–1, indicated chemisorption or ion exchange mechanism for Cr(VI) ions adsorption onto ?-Cd(OH)2 adsorbent. © 2021 Desalination Publications. All rights reserved.

CuO and Al thin films were successively deposited using direct current (reactive) magnetron sputter deposition. A multilayer of five bilayers was deposited on glass, which can be ignited by heating a Ti resistive thin film. The velocity of the reaction front which propagates along the multilayer was optically determined using a high-speed camera. During the deposition of the aluminum layers, air was intentionally leaked into the vacuum chamber to introduce impurities in the film. Depositions at different impurity/metal flux ratios were performed. The front velocity reaches a value of approximately 20 m/s at low flux ratios but drops to approximately 7 m/s at flux ratios between 0.6 and 1. The drop is rather abrupt as the front velocity stays constant above flux ratios larger than 1. This behavior is explained based on the hindrance of the oxygen transport from the oxidizer (CuO) to the fuel (Al).

The interface between solid electrolytes and lithium metal electrodes determines the performance of an all-solid-state battery in terms of the ability to demand high power densities and prevent the formation of lithium dendrites. This interface depends strongly on the nature of the solid electrolyte surface in contact with the metallic anode. In the garnet electrolyte/Li system, most papers have focused on the role of current inhomogeneities induced by void formation in the Li metal electrode and the presence of insulating reaction layers following air exposure. However, extended defects in the solid electrolyte induced by chemical and/or structural inhomogeneities can also lead to uneven current distribution, impacting the performance of these systems. In this work, we use complementary surface analysis techniques with varying analysis depths to probe chemical distribution within grains and grain boundaries at the surface and in the bulk of garnet-type electrolytes to explain their electrochemical performance. We show that morphology, post-treatments and storage conditions can greatly affect the surface chemical distribution of grains and grain boundaries. These properties are important to understand since they will dictate the ionic and electronic transport near the interfacial zone between metal and electrolyte which is key to determining chemo-mechanical stability.

International audience; Thermite multilayered films composed of alternating thin layers of metal/oxidizers have various uses in microelectromechanical systems (MEMS), microelectronics, and materials bonding applications. Recently, applied research especially on the microinitiator applications has engendered an urgent need to improve ignitability without changing the layering and reactant spacing that both affect the combustion characteristics. This work describes an innovative nanoengineering solution to reduce the energy barriers for mass transport, making it possible to substantially lower ignition energy of CuO/Al reactive multilayers without manipulating the fuel and oxide layers thickness. To that end, gold nanoparticles exhibiting high thermal diffusivity properties are in situ grown uniformly inside the first CuO layer to produce localized hot-spots and promote the Al + CuO reaction. The CuO/Al reactive films with embedded gold nanoparticles exhibit earlier and optimized reaction than standard ones. The effect of gold nanoparticles on the thermite ignition mechanisms and the detailed reaction pathways were characterized by a host of characterization techniques including microscopy, thermal analysis, spectroscopy, and X-ray diffractometry. Altogether, results show that the gold nanoparticles are seeding nodular defects with conical shapes provoking (under thermal stimulation) high stressed zones in the multilayer where the Al + CuO reaction is quickly triggered. The analysis of reaction products showed that the multilayers break the unreacted Al droplets early allowing them to burn into the environment. The results provide a behavioral baseline for future studies of interface engineering to tune internal stress-induced reaction in reactive thin films at large.

Abstract Nanoscale Au-ZnO heterostructures were fabricated on 4-in. SiO2/Si wafers by the atomic layer deposition (ALD) technique. Developed Au-ZnO heterostructures after post-deposition annealing at 250 °C were tested for amperometric hydrogen peroxide (H2O2) detection. The surface morphology and nanostructure of Au-ZnO heterostructures were examined by field emission scanning electron microscopy (FE-SEM), Raman spectroscopy, atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), etc. Additionally, the electrochemical behavior of Au-ZnO heterostructures towards H2O2 sensing under various conditions is assessed by chronoamperometry and electrochemical impedance spectroscopy (EIS). The results showed that ALD-fabricated Au-ZnO heterostructures exhibited one of the highest sensitivities of 0.53 μA μM−1 cm−2, the widest linear H2O2 detection range of 1.0 μM–120 mM, a low limit of detection (LOD) of 0.78 μM, excellent selectivity under the normal operation conditions, and great long-term stability. Utilization of the ALD deposition method opens up a unique opportunity for the improvement of the various capabilities of the devices based on Au-ZnO heterostructures for amperometric detection of different chemicals. Graphical abstract

The occurrence of dark subsurface horizons rich in organic matter (OM) associated with polychrome in the B horizon (yellowish over reddish hue) is common in soils from Southern Brazil. The formation of these horizons and the combination with such morphological attributes has not been properly documented, and neither has the cause effect relationship. Four soil profiles with such sombric-like horizons with a yellowish color at the upper part of the B horizon over red subsoil were studied in Southern Brazil. Results from micromorphology, extractable sesquioxide minerals, clay mineralogy and isomorphic substitution of Fe by Al in iron minerals showed that melanization, xanthization, bioturbation, moderate shrinking/swelling and moderate ferralitization were the most evident pedogenetic processes in role. Xanthization is closely related to the sombric-like horizon formation. In the studied area the findings demonstrated that no clay and OM illuviation had taken place. Therefore, the classification of these soils was revisited, so as to take into account the processes that underlie their genesis with emphasis on xanthization, clay illuviation and soil aggregation. The results suggest that the sombric horizon may need redefinition, unless profiles can be found in which illuviation of clay and/or OM can be proven.

Al/p-Si and Al/(carbon nanofiber-PVP)/p-Si diodes were produced using a p-type silicon wafer with 10 omega cm resistivity to determine the polymer interlayer effects on device characteristics. To assess whether carbon nanofiber-PVP interlayer is beneficial for electrical performance, the current-voltage (I-V) and the impedance-voltage (Z-V) measurements were performed in wide range of voltage. Thus, electrical parameters such as series resistance, barrier height, and ideality factor were derived from the forward bias Ln (I-F)-V(F)and Cheung's functions, so that they are compared and voltage dependence of them is explored. Later, the values of intercept voltage, width of depletion layer, doping acceptor atom concentration, and barrier height were also extracted from C-2-Vdata at 1 MHz and then results were compared with each other. The surface states and their energy profile were also extracted from theI(F)-V(F)characteristics by considering barrier height (BH) and n is voltage dependent as well. Experimental results indicate that the carbon nanofiber-PVP interlayer decreases surface states (N-ss), series resistance (R-s) and leakage current, whereas it increases rectifying ratio and shunt resistance. Hence, such polymeric interlayer material forms an interesting alternative to conventional oxide layer due to some advantages of polymers such as desirably low values of cost, weight, and energy consumption. Gazi University Scientific Research Center [GU-BAP.05/2019-26] All authors would like to thank Gazi University Scientific Research Center for the supports and contributions (Project no: GU-BAP.05/2019-26). WOS:000551100300001 2-s2.0-85088306230

MoS2 phases supported on Al2O3 with different content in the range 5–20 wt% were prepared, characterized and tested as catalysts for the H2S oxidative decomposition for the simultaneous production of hydrogen and sulphur. The chemical-physical characterization results have evidenced a good dispersion of MoS2 on Al2O3 support. With respect to the Al2O3, MoS2 loading influenced particularly the value of H2 yield and minimized the SO2 production without substantial differences in H2S conversion (~50%). In particular, the highest H2 yield was observed for the catalyst having a nominal MoS2 loading of 10 wt%. A predictive mathematical model of the H2S oxidative decomposition reaction in presence of 10 wt% MoS2-based catalyst was developed through the identification of the main reactions occurring in the system. The predictive capability of the model was verified in the temperature range between 1073 and 1273 K by varying also the H2S inlet concentration.

The goal of these review papers is to summarize the recent advances in the metallurgy of aluminium alloys and from this analysis, to try to outline future developments in this field. Part I deals with the transformation of aluminium alloys from the liquid to the solid state, while Part II will focus on solid-state transformations. These papers are by no means exhaustive since the literature is very abundant, but the authors wish to give a personal view of what they think are the most relevant scientific contributions that can impact future technological developments. (C) 2018 Academie des sciences. Published by Elsevier Masson SAS.

The Curiosity rover’s alpha particle X-ray spectrometer employs simultaneous XRF and PIXE to analyze rock and soil samples on the Martian surface. The PIXE is accomplished by alpha particle emission from 244Cm, and the XRF by the L X-rays from the daughter. Recent work [1] has shown that fits to these spectra, which extend over a 23 keV range, are improved by accounting rigorously for both X-ray detector non-linearity and the alpha-induced multiple ionization satellites. This work necessitated the insertion of an interim satellite database into the GUPIX-based fitting code GUAPX. The database was assembled from a rather sparse literature and involved considerable extrapolation and interpolation. For 3- 5 MeV alphas, the summed intensity in the KL1 , KL2 , KL3 satellites is of similar order to that of the KL0 diagram line. It is clear that the accuracy of laboratory-based PIXE with alpha particles can be improved by including these in the spectrum fitting procedure. We have therefore started an effort to refine and extend the interim satellite database, using WDX spectroscopy at IJS and IRB. Work has been completed on magnesium, aluminum, silicon and their oxides. The spectra below are from Si and SiO2 ; all individual Voigtians are shown. Comparison of our results for individual line energies and intensities with those of the database has enabled small corrections to the latter. The work will now proceed to elements of higher atomic number. [1] J. L. Campbell, B. Ganly, C. M. Heirwegh, J. A. Maxwell, Nucl. Instr. Meth. B414, 2018, 38.

The individual and combined effects of W and Zr additions on macrostructure, microstructure and mechanical properties of Nb have been investigated. Nb, Nb-10 wt% W, Nb-2.5 wt% Zr and Nb-10 wt% W-2.5 wt% Zr alloy ingots were prepared by electron beam drip melting using high purity Nb, W and Zr rods. Additions of W and Zr resulted in significant improvement in hardness and room temperature tensile strength. It is seen that the effect of 10 wt% W addition is more than that of 2.5 wt% Zr addition in improving room temperature strength of Nb, although on ‘per wt% addition’ basis, Zr is a more effective strengthener than W. It is also observed that the cumulative effects of 10 wt% W and 2.5 wt% Zr on grain refinement and strengthening are more than their respective individual effects.

We have analysed the petrography, major element abundances and bulk Al-Mg isotope systematics of 19 ferromagnesian chondrules from the CV3 chondrites Allende, Mokoia, and Vigarano, together with an Al-rich chondrule and refractory olivine from Mokoia. Co-variations of Al/Mg with Na/Mg and Ti/Mg in our bulk chondrules suggest their compositions are dominantly controlled by reworking of different proportions of chondrule components (e.g. mafic minerals and mesostatis); their precursors are thus fragments from prior generations of chondrules. Our samples show a range in fractionation corrected 26Mg/24Mg (Δ′26Mg) ∼ 60 ppm, relative to precisions 27Al/24Mg. The data can be used to calculate model initial 26Al/27Al, or (26Al/27Al)0, of the chondrule precursors. Our resolvably radiogenic chondrules yield model (26Al/27Al)0 ∼ 1–2 × 10−5, equivalent to model “ages” of precursor formation ≦1 Ma post CAI. However, many of our chondrules show near solar Δ′26Mg and no variability despite a range in 27Al/24Mg. This suggests their derivation either from younger precursor chondrules or open system behaviour once 26Al was effectively extinct ((26Al/27Al)0 < 0.8 × 10−5, given the resolution here). Evidence for the latter explanation is provided by marked rims of orthopyroxene replacing olivine, indicating reaction of chondrules with a surrounding silicate vapour. Concurrent isotopic exchange of Mg with a near chondritic vapour during late reworking could explain their isotopic systematics. One ferromagnesian object is dominated by a high Mg# olivine with elevated Ti and Ca abundances. This refractory olivine has a markedly negative Δ′26Mg = −16 ± 3 ppm (2se), reflecting its early removal (model age of 26Mg. If representative of the chondrule forming region, this grain defines a minimum interval of radiogenic ingrowth for CV chondrites commensurate with (26Al/27Al)0 > 3.4 ± 0.6 × 10−5. Overall, our samples record a sequence of events from the formation of ferromagnesian objects within 0.5 Ma of CAI to re-equilibration of chondrules and silicate vapour >2 Ma post CAI, assuming an initially homogeneous 26Al/27Al. Metamorphism on the asteroid parent body may have played a subsequent role in affecting Mg isotope composition, but we argue this had a minor influence on the observations here.

International audience; Al/CuO energetic structure are attractive materials due to their high thermal output and propensity to produce gas. They are widely used to bond components or as next generation of MEMS igniters. In such systems, the reaction process is largely dominated by the outward migration of oxygen atoms from the CuO matrix toward the aluminum layers, and many recent studies have already demonstrated that the interfacial nanolayer between the two reactive layers plays a major role in the material properties. Here we demonstrate that the ALD deposition of a thin ZnO layer on the CuO prior to Al deposition (by sputtering) leads to a substantial increase in the efficiency of the overall reaction. The CuO/ZnO/Al foils generate 98% of their theoretical enthalpy within a single reaction at 900 °C, whereas conventional ZnO-free CuO/Al foils produce only 78% of their theoretical enthalpy, distributed over two distinct reaction steps at 550 °C and 850 °C. Combining high-resolution transmission electron microscopy, X-ray diffraction, and differential scanning calorimetry, we characterized the successive formation of a thin zinc aluminate (ZnAl2O4) and zinc oxide interfacial layers, which act as an effective barrier layer against oxygen diffusion at low temperature.

We report the first preparation of nanoporous Al-Mg alloy films by selective dissolution of Mg from a Mg-rich alloy AlxMg1-x. We show how to tune the stoichiometry, the porosity, and the oxide contents in the final film by modulating the starting ratio between Al and Mg and the dealloying procedure. The obtained porous metal can be exploited for enhanced UV spectroscopy. In this respect, we experimentally demonstrate its efficacy in enhancing fluorescence and surface Raman scattering for excitation wavelengths of 360 and 257 nm, respectively. Finally, we numerically show the superior performance of the nanoporous Al-Mg alloy in the UV range when compared to equivalent porous gold structures. The large area to surface ratio provided by this material makes it a promising platform for a wide range of applications in UV/deep-UV plasmonics.

A properly CaO-Ca 12 Al 14 O 33 -Ni material with combined sorbent properties and catalyst activity was developed for H 2 production from hydrocarbons via sorption enhanced steam reforming (SE-SR) with simultaneous CO 2 capture. The combined sorbent-catalyst material (CSCM) was successfully prepared by multi-step approach method. At first a mixed calcium-aluminium oxide (CAO) ceramic was prepared by wet mixing/sintering method and used both as spacer for CaO-based sorbent and support for nickel catalyst. Subsequently, the sorbent and catalyst were prepared by wet mixing/sintering (900 °C) and wet impregnation/calcination (500 °C) methods, respectively. Then, an intimately powdery 1:1 mixture of two functional materials were cold-pressed and air-sintered at 900 °C obtaining the desired one-body sorbent-catalyst. The CSCM characteristics were investigated in detail by XRD, SEM-EDS, TG-DTG, BET physisorption, and TPR techniques. The CO 2 sorbent properties were assessed over 200th multiple sorption/desorption cycles and the stabilizing role of spacer Ca 12 Al 14 O 33 ceramic against sorbent decay was confirmed, whereas the presence of foreign Ni ions did not affect the sorbent CO 2 carrying capacity. A H 2 -rich gas (> 90%) with low concentrations of CO 2 and CO was produced over ten consecutive steam methane reforming (600 °C)/regeneration (750 °C) cycles at steam/carbon=3 molar ratio using CSCM. This good performance of SE-SR of methane process was attributed to the synergistic effect of high CO 2 capture capacity and catalytic activity, the latter thanks also to the facile surface NiAl 2 O 4 spinel to Ni° reduction in the low temperature range of 400–600 °C.

Applications of aluminium (Al) salt or lanthanum (La) modified bentonite (LMB) have become popular methodologies for immobilizing phosphorus (P) in eutrophic lakes. The presence of humic substances, has been shown to inhibit this form of treatment due to the complexation with La/Al. However, the effects of other dissolved organic matter (DOM), especially that derived from phytoplankton (the dominant source in eutrophic lakes) are unknown. In this study, the interaction with La/Al of Suwannee River Standard Humic Acid Standard II (SRHA) and algae-derived DOM (ADOM) were investigated and compared. Differed to SRHA which was dominated by polyphenol-like component (76.8%, C1-SRHA), majority in ADOM were protein-like substance, including 41.9% tryptophan-like component (C2-ADOM) and 21.0% tyrosine-like component (C3-ADOM). Two reactions of complexation and coprecipitation were observed between SRHA/ADOM and La/Al. Complexation dominated at low metal inputs less than 10 μM and coprecipitation was the main reaction at higher metal inputs. For ADOM, the tryptophan-like component (C2-ADOM) was the important component to react with metal. The reaction rate for C2-ADOM with La were about two-third of that for C1-SRHA, indicating that the influence of C2-ADOM was significant during the P immobilization by La/Al-based treatment in eutrophic lakes. The P removal data in the presence of ADOM confirmed the significant inhibition of ADOM. In addition, based on the composition of coprecipitates and relatively biodegradable character of tryptophan-like substances (C2-ADOM), the coprecipitation of ADOM was assumed to reduce the stability of precipitated P in eutrophic lakes. The release of P from the potential biodegradation of the coprecipitates and thus the possible decline of the performance of P immobilization by La/Al-based treatments is an important work in the future.

Zn2+ is a heavy metal ion, and hazardous sludge from the electroplating and alloy industry is rich in Zn and impure Al and Ca. Such sludge is commonly recycled by dissolution in strong acid and then selective extraction to recycle Zn2+ by a special extraction reagent. In this process, impurity Al3+ is dissolved and then participates in the extraction of Zn2+, so Al3+ should be removed first. Here, a new strategy was reported for the effective removal of Al3+ and recovery of Zn2+ from a simulated Al/Zn-bearing sludge via an improved acid solution–precipitation route. The sludge was simulated by coagulating Zn-bearing waste water (290 mg/L Zn2+) with 600 mg/L polyaluminium chloride. The sludge was dissolved in sulphuric acid and nitric acid to form an acidic solution with Al3+ and Zn2+ concentrations of 3.2 g/L and 5.7 g/L, respectively. The solution was treated directly by hydrothermal method at 270 °C, in which 55% Al3+ was precipitated as boehmite and Al hydroxide. After the addition of 0.2 mL of ethylene glycol, the removal rate of Al3+ dramatically increased to 99.8%, with Zn2+ loss of 1.5%. The residual Zn2+ was 5620 mg/L in the treated solution and further directly precipitated by adjusting the pH of the solution to pH 7.5 with NaOH. The precipitated Zn2+ was in the form of simonkolleite with ZnO content of 63.1%, with Al content of only 0.8%. In the hydrothermal precipitation, the removal rate of Al3+ increased with the temperature and extension of reaction time. Al3+ was hydrolysed and precipitated as aluminium oxonium sulphate hydroxide and then recrystallised in boehmite form. Then, H+ was generated and consumed in the redox reaction of nitrate and ethylene glycol, accelerating the Al3+ precipitation. This method provides a way to efficiently separate Al3+ from a Zn-bearing solution and can be applied in the recycling of Al/Zn-bearing sludge.

Al-Ti-based alloys are of enormous technical relevance due to their specific properties. For studies in atomic dynamics, surface physics and industrial processing the precise knowledge of the thermophysical properties of the liquid phase is crucial. In the present work, we systematically measure mass density, ρ (g cm−3), and the surface tension, γ (N m−1), as functions of temperature, T, and compositions of binary Al-Ti melts. Electromagnetic levitation in combination with the optical dilatometry method is used for density measurements and the oscillating drop method for surface tension measurements. It is found that, for all compositions, density and surface tension increase linearly upon decreasing temperature in the liquid phase. Within the Al-Ti system, we find the largest values for pure titanium and the smallest for pure aluminum, which amount to ρ(L,Ti) = 4.12 ± 0.04 g cm−3 and γ(L,Ti) = 1.56 ± 0.02 N m−1; and ρ(L,Al) = 2.09 ± 0.01 g cm−3 and γ(L,Al) = 0.87 ± 0.06 N m−1, respectively. The data are analyzed concerning the temperature coefficients, ρ T and γ T, excess molar volume, V E, excess surface tension, γ E, and surface segregation of the surface active component, Al. The results are compared with thermodynamic models. Generally, it is found that Al-Ti is a highly nonideal system.

Words as Silence, Language as Rhymes is an artist book published in 2012 by Lebanese contemporary artist Marwa Arsanios, included in her Al-Hilal project (2011–ongoing). This project is based on an examination of the Egyptian cultural magazine Al-Hilal, and more particularly of two issues dating back to Nasser’s presidency. These praised Nasser’s ideology of Arab socialism and nationalism by highlighting technological and scientific innovations, social progress and women’s emancipation. More than half a century later, after the failure of Nasser’s policy and ideology, Words as Silence, Language as Rhymes analyses the rhetoric of modernism and its promises in the magazine. It takes a particular interest in the expression of Egypt’s dream of space conquest, and in the representation of women, and more particularly of female Algerian freedom fighters. By re-engaging and manipulating Al-Hilal’s textual and visual language, Arsanios plays with a multiplicity of temporal layers and uses the prospective potentialities of science fiction to re-imagine the modernist ideals and assert the importance of a utopian thought for the present. This article invokes Svetlana Boym’s concepts of off-modernism and nostalgia to consider Words as Silence, Language as Rhymes as a feminist historiographical critique of modernism as conveyed by Al-Hilal.

The objective of this study is to examine the sudden drop in properties of aluminum, titanium and chromium thin films prepared by the glancing angle deposition method. The thin films were deposited by DC magnetron sputtering under identical deposition conditions. A substrate-holder with seven different orientations with respect to the target normal was used. The thickness and the column tilt angles (β) of the thin films were determined by scanning electron microscopy. The residual stress of the thin films was evaluated using the wafer curvature technique and calculated by the Stoney's formula. The thickness variation and column tilt angle versus the orientation of the substrate indicated that the critical point is around 60° for all metallic materials and a critical angle of 60° is also found for the residual stress. Simulations of the particles transport are compared to the experimental data and moderate the critical angles analyses. Frnch Ministry of Higher Education and Research

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The gibbsite bearing shale occurrence in the Paleozoic sedimentary sequence of SW Sinai, Egypt, was found to be associated with several metal values. From sulfate liquor prepared by proper leaching, the recovery of these metal values has been studied. Alumina was first separated in the form of potash alum followed by Cu-selective extraction by hydroxyoxime LIX-973N solvent. Then U recovery using an anionic exchange resin Amberlite IRA-400 was achieved. For the associated heavy metal Zn, it was subsequently extracted using di-2-ethylhexyl phosphoric acid. The relevant factors affecting the extraction process were adequately studied.

Advanced pulsed current gas metal arc based processes are increasingly attempted for the joining of aluminium alloys and galvanised steel sheets. The bead profile and the thickness of the interfacial Fe-Al intermetallic (IMC) layer significantly influence the failure strength of these joints. Although several experimental studies have examined the nature and extent of the IMC phases and consequent joint strength, quantitative efforts to estimate bead profile and the IMC layer thickness as function of process conditions and resulting heat input are scarce. We present here for the first time a coupled theoretical and experimental study to estimate the bead profile and Fe-Al IMC layer thickness for joining of galvannealed steel and aluminium alloy sheets in a typical lap joint configuration. The computed values of bead profile and IMC layer thicknesses are validated with the corresponding experimental results.

The present paper reviews original data obtained by the authors from recent separate publications with additional unpublished data, specifically concerning the Lanthanum (La)’s role in the solidification pattern and graphite formation in gray cast irons. Iron melting at 0.018–0.056%S, a 3.7–4.1% carbon equivalent (CE) and less than 0.005%Alresidual are inoculated with La-bearing FeSi alloys at different associations with other inoculating elements. Complex Al-La small inclusions as possible better nucleation sites for (Mn,X)S compounds and La-Ca presence in the body of these sulfides, which possibly provide better nucleation sites for flake graphite, are identified in 0.026%S cast iron. At a lower sulfur content (0.018%S), La,Ca,Al-FeSi alloy still has a high efficiency, but more complex La-bearing alloys are recommended for a higher dendritic austenite amount (LaBaZrTi–FeSi) or for lower eutectic recalescence (LaBaZr–FeSi). La has limited but specific benefits at 0.05–0.06%S irons, including favorable graphitizing factors (a higher amount of graphite precipitated at the end of solidification), lower eutectic recalescence, and a lower value of the first derivative at the end of solidification. When La,Ca,Ba,Al,Zr,S-FeSi treatment (0.035%S base iron) is used, Scanning Electron Microscopy (SEM) analysis finds that the first formed micro-compound is a complex Al-silicate (Zr,La,Ca,Ba presence), which supports the nucleation of the second compound (Mn,Ca,La)S type. At the sulfide-graphite interface, there is a visible thin (nano size) Al-silicate layer (O-Al-Si-Ca-La system), which is more favorable for graphite nucleation (it has better crystallographic compatibility). La is identified in all three important areas of nucleants (the first is formed oxidic nucleus, the second is nucleated Mn-sulfide and the third is a sulfide-graphite interface), thereby increasing the efficiency of graphite nucleation sites.

propiolactone (BPL) appears as an important element of many medicinal applications particularly in the production of vaccines. Since it also shows some carcinogenic properties, the controlled usage of BPL in every step of the production of new substances extra attention must be paid. In this work, based on the density functional theory (DFT), the adsorption properties of BPL between silicon/aluminum doped fullerenes were examined. The results of the investigations showed that aluminum doped fullerenes more strongly interacts with BPL and the water media as solvent strongly effects the charge mobility of the examined system leading different level of sensitivity to the presence of BPL of the examined fullerene cages. © 2020 Elsevier B.V., Ege Üniversitesi: FGA-2019-20390, Authors acknowledge Fencluster system of Ege University for the calculations. This work was supported by Ege University Scientific Research Projects Coordination Unit (Project Number: FGA-2019-20390)., Authors acknowledge Fencluster system of Ege University for the calculations. This work was supported by Ege University Scientific Research Projects Coordination Unit (Project Number: FGA-2019-20390 ).

In this paper, a comprehensive study was carried out on the application of perovskite catalyst in dry reforming of CH4. The perovskite catalyst was prepared using a sol&ndash, gel method. The prepared samples were characterized by N2 adsorption/desorption, TPR, XRD, CO2-TPD, TGA, TPO, Raman, and SEM techniques. In addition, the effect of operating pressure, namely, 1 bar, 3 bar, 5 bar, and 7 bar, temperature (500&ndash, 800 &deg, C) was evaluated. The characterization results indicated that catalysts operated at 1 bar, gas hourly space velocity of 84000 (mL/g/h) gave the best catalytic performance. CH4 and CO2 conversions of 77 and 80% were obtained at 1 bar and at 700 &deg, C reaction temperature. The increase of reaction temperatures from 500 &deg, C to 800 &deg, C increased the reaction rate and hence the methane and carbon dioxide conversions were increased. A unity ratio of H2/CO was obtained at 1 bar for temperatures 600 &deg, C and above. Similarly, the time on stream tests, obtained at a 700 &deg, C reaction temperature, showed that the best ratio in terms of the closeness of unity and the stable profile could be attained when the pressure was set to 1 bar. The TGA analysis showed the drop of mass due to oxidation of carbon deposits, which started at 500 &deg, C. The catalyst operated at 1 bar produced the least amount of carbon, equivalent to 35% weight loss, while the 3 and 5 bar operated catalysts generated carbon formation, equivalent to 65% weight loss. However, the 7 bar operated catalyst resulted the highest accumulation of carbon formation, equivalent to 83% weight reduction. Hence, the TGA profile indicated the relative carbon deposition on the catalyst, which was dependent of the operated pressure and hence confirmed the suitability operation pressure of 1 bar. The characterizations of the Raman, EDX, TGA, and TPO all presented the formation of carbon.

Publisher's version (útgefin grein), This paper reports results on the interaction between an aluminum oxide film, deposited on technically pure titanium of grade VT1-0 by the magnetron reactive sputtering method, and a hydrogen-containing atmosphere. Such a study is important in order to find protective coatings that would prevent the penetration of hydrogen inside a product. A given system aged in a hydrogen atmosphere in the interval of 1‒4 hours at a pressure of 2∙105 Pa (2 bar) and a temperature of 400 °C. We have acquired data on the distribution of hydrogen along a film thickness and its content in a thin-film system. It is shown that hydrogen diffuses into the film and builds up in it up to three hours, and only then it begins to penetrate the substrate. We have managed to increase aging duration in a hydrogen-containing environment and increase the temperature of heating up to the stage of film destruction. In the case of the starting film and after aging from 1 to 3 hours the adhesion force between a film and a substrate increases, apparently due to the formation of hydrogen bonds film-substrate. The adsorption of hydrogen atoms at the surface of the Al2О3 film is accompanied by an increase in its conductivity by not larger than 4 % with the increased time of aging. Such a change in the conductivity of the Al2О3 film can be explained based on the formation of a zone structure. Thin oxide films may possess continuous one-side conductivity, but in the case the film is thick (0.5 µm and above), it is not possible to argue about the one-side conductivity. The data acquired on the influence of aging duration in a hydrogen atmosphere indicate an increase in adhesive strength by almost 6 times within 3 hours and by 2.5 times in 4 hours. The determined coefficient of film friction increases by not larger than 2.5 times. By measuring the electrical conductivity of the film surface, it was found that it increases with an increase in the time of aging in a hydrogen atmosphere. This pattern is obviously linked to the creation of transitions of the p-n-type in the film of aluminum oxide at the expense of hydrogen ions

Materials such as W, TiN, and SrRuO3 (SRO) have been suggested as promising alternatives to Au and Ag in plasmonic applications owing to their stability at high operational temperatures. However, investigation of the reproducibility of the optical properties after thermal cycling between room and elevated temperatures is so far lacking. Here, thin films of W, Mo, Ti, TiN, TiON, Ag, Au, SrRuO3 and SrNbO3 are investigated to assess their viability for robust refractory plasmonic applications. These results are further compared to the performance of SrMoO3 reported in literature. Films ranging in thickness from 50 to 105 nm are deposited on MgO, SrTiO3 and Si substrates by e-beam evaporation, RF magnetron sputtering and pulsed laser deposition, prior to characterisation by means of AFM, XRD, spectroscopic ellipsometry, and DC resistivity. Measurements are conducted before and after annealing in air at temperatures ranging from 300 to 1000° C for one hour, to establish the maximum cycling temperature and potential longevity at elevated temperatures for each material. It is found that SrRuO3 retains metallic behaviour after annealing at 800° C, while SrNbO3 undergoes a phase transition resulting in a loss of metallic behaviour after annealing at 400° C. Importantly, the optical properties of TiN and TiON are degraded as a result of oxidation and show a loss of metallic behaviour after annealing at 500° C, while the same is not observed in Au until annealing at 600° C. Nevertheless, both TiN and TiON may be better suited than Au or SRO for high temperature applications operating under vacuum conditions.

Polyurethane is a highly versatile material used in comfort, packaging and isolation industries. The global production of polyurethane generates several million tons of non-biodegradable wastes. In this research, the chemical recovery of polyol from polyurethane flexible foam (PUF) wastes was explored. The polyol recovery from PUF was carried out via glycolysis with diethylene glycol (DEG) as a glycolysis agent, Zn/Sn/Al hydrotalcite (HTC) as a heterogeneous catalyst under inert atmosphere using several reaction conditions. The most suitable reaction conditions were achieved for 3 h of reaction, PUF/DEG mass ratio of 1.5 and HTC/DEG of 0.001. The HTC was characterized by FTIR, XRD, TEM and chemical analysis. The recovered polyol was characterized using IR, viscometry and GPC; density and water content was also determined. The recovered polyol was used in the synthesis of PUF as a partial replacement of virgin polyols, and the resultant foams were analyzed using compression tests. RESUMEN : El poliuretano es un material altamente versátil usado en la industria de aislamiento, empaque y comodidad. La producción global de poliuretano genera millones de toneladas de residuos no biodegradables. En esta investigación se exploró la recuperación por métodos químicos del poliol a partir de desechos de espuma flexible de poliuretano (PUF). El poliol se recuperó del PUF mediante glicólisis con dietilenglicol (DEG) como agente de glicólisis, la hidrotalcita Zn/Sn/Al (HTC) como catalizador heterogéneo bajo atmósfera inerte usando varias condiciones de reacción. Las condiciones más adecuadas de reacción fueron 3 h, relación másica PUF/DEG de 1,5 y HTC/DEG de 0,001. La HTC se caracterizó por FTIR, XRD, TEM y análisis químico. El poliol recuperado se caracterizó usando IR, viscosimetría y GPC; adicionalmente se determinó la densidad y el contenido de agua. El poliol recuperado se usó en la síntesis de PUF como reemplazo parcial del poliol comercial y la espuma obtenida se analizó usando pruebas de compresión. COL0001941

We report the first catalytic methods for the transformation of C–H bonds of unactivated arenes into C–Al bonds., We report the first catalytic methods for the transformation of C–H bonds of unactivated arenes into C–Al bonds. The catalytic reactions occur at 25 °C (benzene, toluene and xylenes) with palladium loadings as low as 0.1 mol%. Remarkably, the C–H activation of toluene and xylenes proceeds with ortho- and meta-selectivity. This selectivity is highly unusual and complementary to both Friedel–Crafts and the majority of C–H borylation methods. Through a detailed mechanistic analysis (Eyring analysis, KIE, DFT, QTAIM) we show that unusual Pd–Al intermetallic complexes are on the catalytic cycle and that the selectivity is determined by weak attractive dispersion forces in the transition state for C–H bond breaking.

Aluminum–aluminum wafer bonding is becoming increasingly important in the production of CMOS microelectromechanical systems. So far, successful bonding has required extreme processing temperatures of 450 °C or more, because the chemically highly stable oxide layer acts as a diffusion barrier between the two aluminum metallization layers. By using the ComBond® system, in which a surface treatment and subsequent wafer bonding are both performed in a high vacuum cluster, for the first time successful Al–Al wafer bonding was possible at a temperature of 150 °C. The bonded interfaces were characterized using C-mode scanning acoustic microscopy and transmission electron microscopy, and featured areas of oxide-free, atomic contact.

The exotic electrodynamics properties of graphene come from the linearly dispersive electronic bands that host massless Dirac electrons. A similar behavior was predicted to manifest in freestanding silicene, the silicon counterpart of graphene, thereby envisaging a new route for silicon photonics. However, the access to silicene exploitation in photonics was hindered so far by the use of optically inappropriate substrates in experimentally realized silicene. Here we report on the optical conductivity of silicon nanosheets epitaxially grown on optically transparent Al2O3(0001) from a thickness of a few tens of nanometers down to the extreme two-dimensional (2D) limit. When a 2D regime is approached, a Dirac-like electrodynamics can be deduced from the observation of a low-energy optical conductivity feature owing to a silicene-based interfacing to the substrate. © 2018 American Chemical Society.

Among the Li-ion conducting inorganic materials, lithium lanthanum zirconate (LLZO) is believed to possess good chemical stability against Li metal and hence considered to be a promising solid electrolyte for Li-ion batteries. However, systematic sets of studies conducted here at regular intervals during storage of Al-doped LLZO (cubic garnet) sintered pellets in ambient atmosphere have raised serious concerns over their structural/mechanical stability/integrity upon exposure to air. Spontaneous cracking/disintegration/pulverization of LLZO pellets takes place after about three weeks of exposure, primarily due to formation of La2Zr2O7 in the LLZO bulk; as found to be thermodynamically feasible at room temperature upon reaction with CO2/moisture. Steep increase in La2Zr2O7 content coincides with the spontaneous cracking/disintegration. Estimation suggests that internal stresses associated with the formation of La2Zr2O7 from LLZO can be high enough to cause spontaneous fracture. This mandates the development/fabrication/usage of solid-state cells using LLZO under stringent controls against exposure to atmospheric species.

International audience; The possibility of using the parameters involved in the ESR dating of optically bleached quartz grains in a purpose of source determination was checked. In that aim, samples previously taken in different sedimentary formations of the Middle Loire Basin (Central France) and dated by ESR have been observed. First discrimination was made using the thorium and potassium content in the sediments obtained by gamma spectrometry. The plot of these 119 data on the Th/K Schlumberger diagram clearly demonstrated that it was possible to discriminate the clays associations included in the sediment from which the dated quartz are extracted. Clay's nature could then be indicative of the geological nature of the substratum of rivers from their sources. Second discrimination was made using the ESR intensities calculated from Al, Ti–H and Ti–Li paramagnetic centres on 18 samples. It appears that the combination of the non-bleachable aluminum trap (DAT) saturation intensity and the Ti–H/Ti–Li ratio intensities make possible the discrimination of the two main sources of the sediment: Massif Central and Paris Basin. More deeply, The Ti/OBAT (Optically bleachable aluminum traps) intensities made possible the discrimination of quartz grains of different geological sources or with different geothermal history within the Massif Central group.

Garnet-type Li7La3Zr2O12 (LLZrO) is a candidate solid electrolyte material that is now being intensively optimized for application in commercially competitive solid state Li+ ion batteries. In this study we investigate, by force-field-based simulations, the effects of Ga3+ doping in LLZrO. We confirm the stabilizing effect of Ga3+ on the cubic phase. We also determine that Ga3+ addition does not lead to any appreciable structural distortion. Li site connectivity is not significantly deteriorated by the Ga3+ addition (>90% connectivity retained up to x = 0.30 in Li7–3xGaxLa3Zr2O12). Interestingly, two compositional regions are predicted for bulk Li+ ion conductivity in the cubic phase: (i) a decreasing trend for 0 ≤ x ≤ 0.10 and (ii) a relatively flat trend for 0.10 < x ≤ 0.30. This conductivity behavior is explained by combining analyses using percolation theory, van Hove space time correlation, the radial distribution function, and trajectory density.

In this study we present a three-step process for the low-temperature chemical bath deposition of crystalline ZnO films on glass substrates. The process consists of a seeding step followed by two chemical bath deposition steps. In the second step (the first of the two bath deposition steps), a natural polysaccharide, namely hyaluronic acid, is used to manipulate the morphology of the films. Previous experiments revealed a strong influence of this polysaccharide on the formation of zinc oxide crystallites. The present work aims to transfer this gained knowledge to the formation of zinc oxide films. The influence of hyaluronic acid and the time of its addition on the morphology of the resulting ZnO film were investigated. By meticulous adjustment of the parameters in this step, the film morphology can be tailored to provide an optimal growth platform for the third step (a subsequent chemical bath deposition step). In this step, the film is covered by a dense layer of ZnO. This optimized procedure leads to ZnO films with a very high electrical conductivity, opening up interesting possibilities for applications of such films. The films were characterized by means of electron microscopy, X-ray diffraction and measurements of the electrical conductivity.