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We consider four subsets of the complexified spacetime algebra, namely the real even part, the real odd part, the imaginary even part and the imaginary odd part. This naturally leads to the four connected components of the Lorentz group, supplemented each time by an additional symmetry. We then examine how these four parts impact the Dirac equation and show that four types of matter arise with positive and negative masses as well as positive and negative charges. [ABSTRACT FROM AUTHOR]

An extension of a previously published model of a bimetric Universe is presented, where the speeds of light associated to positive and negative mass species are different. As shown earlier, the asymmetry of the model explains the acceleration of the positive species, while the negative one slows down. Asymmetry affects scale factors linked to lengths, times and speeds of light; so that if a mass inversion of a craft can be achieved, then interstellar travels would become non-impossible at a velocity less than the speed of light of the negative sector, and possibly much higher than that of the positive sector. [ABSTRACT FROM AUTHOR]

Abstract: Alloy 600 samples were oxidized under different simulated PWR primary water conditions, with varying contents of dissolved hydrogen. The photoelectrochemical techniques, used to characterize the semiconducting behavior and bandgap energies of oxide films have shown that the scale has several components. The first ones, exhibiting photocurrents at photon energies lower than 2.5eV behave as n-type semiconductors, whereas the analyze of the photocurrents measured at higher energies suggests that other components are either n-type or insulating, depending on the hydrogen partial pressure tested: <0.01, 0.3 and 6.5bar (<1, 30 and 658kPa). Furthermore, a novel approach developed recently by our group allowed us determination of the number of semiconducting components in the scales and assessment of the bandgap energy for each of them. These results revealed that the composition, as well as the semiconducting properties of the scales, were influenced by the hydrogen partial pressure used in the corrosion test. [Copyright &y& Elsevier]

• The expansion of the Universe is accelerating and the energy behind is unknown. • The model that explains the observational facts related to this energy is bimetric. • Bimetry implies positive energy states and negative energy states. • Negative energy states are associated with a unitary time reversal operator. • We fix the theoretical framework of such a possibility. The time reversal operator can be unitary or anti-unitary. In the first case, there are necessarily states of negative energy, whereas they do not appear in the second case. For a long time it was believed that these negative energies were irrelevant, until the discovery of the acceleration of the expansion of the universe gave them a meaning. We examine the possibility for the time inversion to be associated with a unitary operator in the quantum level by looking at the usual arguments in favor of the anti-unitarity of this operator and by proposing counter-arguments in order to validate the possibility for this operator to be unitary. [ABSTRACT FROM AUTHOR]

This work presents a multiscale photoelectrochemical characterization of oxide layers, and aims mainly at introducing the mesoscopic scale (ca 30 μm). For the first time, photocurrent energy spectra could be recorded on individual ferritic and austenitic grains of a unique 2205 duplex stainless steel sample oxidized for 5 minutes at 650°C under 20% water vapour in nitrogen. These results allowed us to explain contrasting issues in the photoelectrochemical images obtained from the oxidized sample. Moreover, the bandgap energies obtained by fitting these individual mesoscopic photocurrent energy spectra with a novel approach developed in our laboratory, showed that all oxide scales were constituted of Fe2O3 and Cr2O3 and of an Fe2-xCrxO3 solid solutions, but that the x-value of the latter was different depending on the metallurgic phase of the oxidized substrate. The latter results were shown to be in agreement with those of additional Raman analyses of the oxidized austenitic and ferritic grains. [ABSTRACT FROM AUTHOR]

Abstract: We present comparative field studies in folded areas (Southern France, Moroccan Western Atlas and Abruzzo, Italy) giving new insights into fracture distribution within folded rocks of the shallow brittle crust. We show that the curvature in folds formed in brittle mechanical units is usually accommodated by multiple “dip-domain boundaries” (appearing as curvature discontinuities at fold scale) corresponding to relatively narrow and dense fracture zones, striking parallel or slightly oblique to the fold axis. They separate “dip-domains” where curvature is absent or moderate. It is shown that the dip-domain boundaries (which are obvious in the case of kink folds or box-fold anticlines) are currently present as multiple subtle hinges even when the curvature appears continuous at first sight. The nature of dip-domain boundaries is studied: they often cut through the whole thickness of the mechanical units. Their internal structure varies, and a non-exhaustive typology is proposed. For each type, an interpretative kinematic scenario shows how the dip-domain boundaries could initiate and develop. We suggest two kinds of origins: (1) they could correspond to the reactivation of inherited, along-strike fracture zones (opening-mode fracture concentrations such as big joints, fracture corridors, inherited faults, etc.); (2) they could be created as mechanical instabilities during the fold formation (syn-folding origin), in particular through small reverse faults. In both cases, early zones of weakness localize the dip-domain boundaries, and control the increase in curvature in association with increasing fracture density within the boundary. Because they represent well-defined vertically and axially persistent sub-seismic fracture zones generally limited to the thickness of the folded unit, dip-domain boundaries could enhance the axial permeability of folded and fractured reservoirs. [Copyright &y& Elsevier]

When a plasma is subjected to a transversal magnetic field and its Hall parameter is non-negligible, it weakens the local electric conductivity value. If an electric discharge is created near a wall and the magnetic field decreases with distance, the electric discharge will follow a path that minimises the streamer's electric resistance, which could expel it far from the wall. One solution to ensure that it remains up against the wall is by inversion of the magnetic field's gradient by arranging that field B be minimal at the wall. In the experiment we are presenting, effected in a low-density gas, in order to obtain a high value for the Hall parameter using simple permanent magnets, we will show the remarkable efficiency of this parietal confinement method and present the main lines of the programme of which this experiment forms part and whose successful realization will be the demonstration of the feasibility of the displacement of disk-shaped MHD aerodynes at supersonic speed without creating either shock waves or turbulence, an approach that we have already set out in numerous publications. [ABSTRACT FROM AUTHOR]

Correction to: Astrophys Space Sci (2018) 363:13910.1007/s10509-018-3365-3The original article has been updated for copyright reasons with Fig. 1 and a too vague formulation intended to give credit to Farnes (2017) for the originally displayed figure. The sentences “JCM explains the confinement of galaxies and their flat rotation curves, as recently showed by Farnes (2017), see Fig. 1. Mysterious dark matter is no longer required, while the mainstream ΛCDM model does.” have been replaced by “JCM explains the confinement of galaxies and the shape of their rotation curves. As we showed in Petit et al. (2001), if one introduces a surrounding repellent negative matter environment, it gives larger rotation velocities at distance, see Fig. 1. Mysterious dark matter is no longer required, while the mainstream ΛCDM model does.” Figure 1 has been replaced. The figure caption of the earlier Fig. 1 has been replaced by “Fig. 1 Circular velocity, after Petit et al. (2001). This can be compared with results from numerical simulations by Farnes (2017)” The original article has been corrected. [ABSTRACT FROM AUTHOR]

From our exact solution of the Janus Cosmological equation we derive the relation of the predicted magnitude of distant sources versus their red shift. The comparison, through this one free parameter model, to the available data from 740 distant supernovae shows an excellent fit. [ABSTRACT FROM AUTHOR]

Please refer to full text. [ABSTRACT FROM AUTHOR]

Abstract: Both oedometric and plane-strain tests were performed with parallelepipedic samples made of synthetic granular, cohesive, frictional and dilatant rock analogue material GRAM2. For the first time parallel sets of fractures that have all the characteristics of natural joints were reproduced in the laboratory. The fractures are regularly spaced, normal to σ3, and have plumose morphology very similar to that of natural joints. These fractures can form at tensile stress σ3 much smaller in magnitude than the tensile strength of material and even at slightly compressive σ3. When mean stress σ exceeds a certain value, the fractures become oblique to σ1 (the obliquity increases with σ), forming networks of conjugate shear bands/fractures. These results of plane-strain experiments are in good agreement with those of better controlled conventional axisymmetric tests on a similar material in Chemenda et al. (2011b) and are closer to real geological situations. Both types of experiments are complementary. Their results lead to the conclusion that at least certain categories of natural fractures (including joints, and conjugate shear fractures/bands) were initiated as deformation localization bands. The band orientation is defined by the constitutive properties/parameters (notably the dilatancy factor) that are sensitive to σ. [Copyright &y& Elsevier]

Abstract: The oxidation of iron and chromium that are present as impurities in zirconium metal or as alloying elements in Zircaloy-4 was investigated with PhotoElectroChemical techniques (PEC), highlighting the chemical nature, the size and the lateral distribution of Fe and Cr-containing phases in thin zirconia scales formed during the oxidation of pure zirconium and Zircaloy-4 at 470°C in oxygen. In the case of zirconium, iron and chromium impurities led to the formation of oxides distributed in a homogeneous way in the zirconia scale, while in the case of Zircaloy-4 these elements, present in the form of intermetallic particles in the substrate, led to the formation of localised haematite Fe2O3, rhomboedric solid solution (Fe x Cr1−x )2O3 and chromia Cr2O3 phases. These phases were accurately studied via the measurement of their respective band-gap (Fe2O3: 2.2eV, (Fe x Cr1−x )2O3: 2.6eV and Cr2O3: 3.0eV). It is concluded that PEC techniques represent a sensitive and powerful way to locally analyse the various semiconductor phases in the oxide scale at a micron scale. [Copyright &y& Elsevier]

Background and Aims: Climate change is modifying grape berry composition and affecting wine quality and typicity. We evaluated the effects of leaf‐to‐fruit ratio and exogenous abscisic acid (ABA) application on the accumulation of primary and secondary metabolites in berries, in order to optimise climate change adaptation strategies. Methods and Results: A range of leaf‐to‐fruit ratios (2, 4, 6, 8, 10 or 12 leaves per bunch) and exogenous ABA (400 mg/L) applied to Vitis vinifera L. cv. Cabernet Sauvignon fruiting‐cuttings in a greenhouse prior to veraison were evaluated over six consecutive growing seasons (2013–2018). Reducing the leaf‐to‐fruit ratio decreased berry sugar and anthocyanin concentration, slightly increased total organic acids, and modified the composition of free amino acids. Exogenous ABA significantly enhanced sugar and anthocyanin concentration and partially restored the balance of sugar and anthocyanins under a low leaf‐to‐fruit ratio, without altering free amino acid concentration or sugar to acids ratios. Conclusions: Combining manipulation of the leaf‐to‐fruit ratio with application of exogenous ABA offers a potential method to reduce berry sugar concentration, while maintaining anthocyanin concentration. Significance of the Study: This study paves the way for possible adaptation strategies for viticulture to global climate change. [ABSTRACT FROM AUTHOR]

A thermal oxide scale has been grown on a high-chromium iron-nickel alloy under very low oxygen partial pressure (1050 °C, 10 −10 Pa). In this paper, a special attention has been paid to morphological and chemical characterizations of the scale by scanning transmission electron microscopy and energy dispersive X-ray analysis at high resolution on a cross-section thin lamella beforehand prepared by using a combined focused ion beam/scanning electron microscope instrument. The complexity of the oxide layer is highlighted, and the correlation between the present results and the ones of a photoelectrochemical study is discussed. [ABSTRACT FROM AUTHOR]

The present work is focused on the oxidation at 1050 °C of a model chromia-forming alloy, paying special attention to the control of the oxygen partial pressure. Taking benefit of a recently developed approach to describe and fit photocurrent energy spectra, photoelectrochemical characterizations allowed to reveal the presence, in the scale formed at low P(O2) (10-15 atm), of an unexpected high number of oxide phases. This result underlines the complexity of the scale in term of chemical composition as well as of the semiconducting types of the individual phases. [ABSTRACT FROM AUTHOR]

Abstract: Room temperature photoelectrochemistry was used to characterise oxide phases grown during the initial stages of oxidation of the ferritic stainless steel AISI441 at 650°C and 850°C in synthetic air or in water vapour. Grazing incidence X-ray diffraction and Raman spectroscopy were additionally used to discuss PEC results. Haematite Fe2O3 (∼2.0eV), chromia Cr2O3 (3.0 and 3.5eV) and their mutual solid solution (∼ 2.5eV) were detected by their respective bandgap values determined from photocurrent vs. energy curves. The Cr/Fe ratio of the films increased with time/temperature and was higher in air-grown than in H2O-grown oxides. Observation of photocurrent vs. potential curves indicated that chromia was N-type in all specimens, resulting from thermodynamic equilibrium with the metallic substrate and not with the gas phase. [Copyright &y& Elsevier]

Abstract: This article deals with the interaction between the passive layer formed on UNS S30403 and S31254 stainless steels and an enzymatic solution containing glucose oxidase (GOx) and its substrate d -glucose. This enzymatic solution is often used to reproduce in laboratory the ennoblement occuring in non-sterile aerated aqueous environments because of the biofilm settlement on the surface of the metallic material. GOx catalyses the oxidation of d-glucose to gluconic acid by reducing oxygen to hydrogen peroxide and produces an organic acid. Thanks to photocurrent measurements, XPS analysis and Mott-Schottky diagrams, it is here shown that such an environment generates modifications in the chemical composition and electronic structure of the passive layer: it induces a relative enrichment of the n-type semi-conducting phase containing chromium (chromine Cr2O3) and an increase of the donors density in the space charge region. [Copyright &y& Elsevier]

Abstract: Important compressive stress developed in TiO2 films thermally grown on pure titanium in oxygen is known to induce scale decohesion at the metal–oxide interface. If such a phenomenon is identified in the literature to play a key role on life time of many materials used at high temperatures, no data at the microscopic level can be found at this time. In the present work using photoelectrochemical microscopy, new information in the form of two specific images ICI (interface cohesion image) and SQI (structural quality image) could be obtained. Such images revealed the level of scale decohesion induced by growth stress as well as the structural quality of the oxide layer. [Copyright &y& Elsevier]

Abstract: AA5182 aluminium alloy cold rolled samples were coated by thin films of emeraldine base (EB) obtained from a 5% solution in N-methylpyrrolidinone. Accelerated corrosion tests prove this coating very effective for corrosion protection of aluminium alloys in neutral environment. This study underlines the prominent role of surface cathodic intermetallic particles in pit initiation and coating break down in enhanced corrosion conditions and suggest that, beside the EB barrier properties, the enhanced corrosion resistance observed on the EB coated samples could partly arise from two other mains factors: [•] a weak redox activity of the polymer which passivate the metal, [•] a proton involving self-healing process taking place at the polymer–metal interface, which contributes to delay local acidification in first steps of corrosion on EB coated aluminium surfaces. [Copyright &y& Elsevier]

Abstract: The oxide films formed on AISI 304L stainless steel at 300°C in the oxidation time range between 2 and 4h have been studied by photoelectrochemistry. Photocurrents were investigated as a function of the wavelength of the incident light and the electrode potential. The investigation allowed the determination of the semiconductive properties of the oxides. The oxide films showed n-type behaviour. A duplex structure of the oxide films has been suggested on the basis of the photocurrent spectra, with an internal oxide layer having an optical gap (E g2 =2.16–2.3eV) depending on the applied potential and oxidation time, higher to that of the external oxide layer (E g1 ≈1.9eV). Significant variations in the amplitude of the photocurrent were detected as a function of the applied potential and the oxidation time. [Copyright &y& Elsevier]

Abstract: Four ligands whose general formula is R-terpy with terpy=2,2′:6′,2″ terpyridine bearing at the 4′-position a substituent R=2-furyl, 2-pyrrolyl, 2-thienyl and 5-2,2′bithienyl were synthesised. The absorption spectra and the electrochemical behaviour of the corresponding homoleptic Ru(II) complexes were investigated and compared to those of the parent complex [Ru(terpy)]2+. Due to the donor effect of the grafted heterocyclic groups, the absorption and emission maxima are red-shifted and the energy levels of the HOMO Π(t2g) metal orbitals are slightly higher. The incorporation of these heterocyclic moieties extends the electronic delocalisation over the corresponding ligands, leading to higher emission quantum yields. Cyclic voltammetric studies of pyrrolyl-, thienyl- and bithienyl-functionalised complexes show that an electroactive layer can be deposited on the electrode. Preliminary results point out that an electrodeposited film could be used as a photocathode in an aqueous electrolyte. [Copyright &y& Elsevier]