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Pumpkin waste was used as a substrate and support of Lactobacillus casei (ATCC-393). A complete factorial design (2 4 ) was performed in order to study the effect of water content, whey, inoculum concentration and the incubation period on cell growth and viability. According to the results of the experimental design, L. casei could use pumpkin waste as a substrate successfully and the system with 10 mL/g of water and without whey was selected to continue with further assays. The kinetics of the L. casei growth were determined. The maximum specific growth rate (µ max ) was 0.6 h −1 . After washing, centrifugation, and vacuum drying, 87% of viable cells were recovered. L. casei adhered to pumpkin powder was tested as a dietary supplement in chocolate milk or in a soy and apple juice based beverage. Approximately 80% of cells resisted gastrointestinal simulated conditions. Both supplemented beverages were well accepted by consumers. [ABSTRACT FROM AUTHOR]

Abstract: High resolution transmission electron microscopy, nano-beam electronic diffraction, energy dispersive X-rays scanning spectroscopy, vibrating sample magnetometry (VSM) and ferromagnetic resonance (FMR) techniques are used in view of comparing (static and dynamic) magnetic and structural properties of Co2MnGe(13nm)/Al2O3(3nm)/Co(13nm) tunnel magnetic junctions (TMJs), deposited on various single crystalline substrates (a-plane sapphire, MgO(100) and Si(111)). They allow for providing a correlation between these magnetic properties and the fine structure investigated at atomic scale. The Al2O3 tunnel barrier is always amorphous and contains a large concentration of Co atoms, which, however, is significantly reduced when using a sapphire substrate. The Co layer is polycrystalline and shows larger grains for films grown on a sapphire substrate. The VSM investigation reveals in-plane anisotropy only for samples grown on a sapphire substrate. The FMR spectra of the TMJs are compared to the obtained ones with a single Co and Co2MnGe films of identical thickness deposited on a sapphire substrate. As expected, two distinct modes are detected in the TMJs while only one mode is observed in each single film. For the TMJ grown on a sapphire substrate, the FMR behavior does not significantly differ from the superposition of the individual spectra of the single films, allowing for a conclusion that the exchange coupling between the two magnetic layers is too small to give rise to observable shifts. For TMJs grown on a Si or on a MgO substrate, the resonance spectra reveal one mode which is nearly identical to the obtained one in the single Co film, while the other observed resonance shows a considerably smaller intensity and cannot be described using the magnetic parameters appropriate to the single Co2MnGe film. The large Co concentration in the Al2O3 interlayer prevents for a simple interpretation of the observed spectra when using Si or MgO substrates. [Copyright &y& Elsevier]

The microstructure of a Cu/V nanocomposite wire processed by cold drawing was investigated by high-resolution transmission electron microscopy and atom probe tomography. The experimental data clearly reveal some deformation-induced interfacial mixing where the vanadium filaments are nanoscaled. The mixed layer is a 2nm wide vanadium gradient in the face-centered cubic (fcc) Cu phase. This mechanical mixing leads to the local fragmentation and dissolution of the filaments and to the formation of vanadium supersaturated solid solutions in fcc Cu. [Copyright &y& Elsevier]

Abstract: The effect of the microstructure heterogeneity on the global and local tensile properties of friction stir welded joints in 5251 (O temper) and AA2024 (T351 and T6 tempers) aluminium alloys has been investigated. Micro-tensile tests parallel to the welding direction have been carried out in the regions representative of the main microstructural zones. The digital image correlation technique (DIC) has been used during transverse tensile tests for mapping the strain distribution and to determine the local stress–strain curves. A 3-D finite elements model has been developed to predict the weld behaviour from the tensile curves of the individual regions of the weld. The tensile properties of the 5251 O weld are relatively homogeneous leading to high ductility and fracture in the base material. In contrast, the tensile properties of the various regions of the 2024 T351 and 2024 T6 welds are very heterogeneous and essentially controlled by the state of precipitation. The thermo-mechanically affected zone is the weakest region where the strain localises during a transverse tensile test. The 2024 T6 base material is stronger than the 2024 T351 alloy, leading to a more pronounced strain localisation during transverse tensile tests and a lower overall ductility. Local tensile data obtained by strain mapping are in good agreement with the curves obtained by micro-tensile tests, and these results can be safely used in a finite elements model to predict the behaviour of the overall weld assembly. [Copyright &y& Elsevier]

Abstract: During friction stir welding, the temperature history and the deformation rate introduced through the joint vary. For precipitation hardening aluminium alloys, these parameters strongly influence the precipitation distribution, which controls the weld properties. This paper presents a quantitative investigation of the effect of welding on precipitation in the 2024 alloy in the T351 and the T6 states, using small angle X-ray scattering, transmission electron microscopy, differential scanning calorimetry and hardness measurements. Depending on the peak temperature, the main precipitation phenomena are Guinier Preston Bagaryatskii zone dissolution, precipitation of S′(S), which can be either a hardening agent at small sizes or detrimental to the mechanical properties at large sizes. The quantification of the microstructure has allowed modelling of the yield stress evolution through the weld according to an appropriate mixing law for the contributions of the different obstacles. The effect of a T6 post-welding heat treatment has also been studied on a T351 weld. This treatment actually results in a further softening of the thermo-mechanically affected zone. In parallel, the susceptibility to strain localisation during tensile testing of the weld has been evaluated by the digital image correlation technique. [Copyright &y& Elsevier]

Quantitative analysis of grain size, grain shape, morphological and crystallographic texture has been performed in strontium hexaferrites materials, sintered from filter-pressed powders oriented or not with a magnetic field. The results provide evidence for anisotropic and abnormal grain growth at high temperature (T ≥ 1250 °C). A morphological texture develops during heating for oriented samples, with plate-like grains preferentially aligned with their larger facets perpendicular to the direction of field application. A quantitative analysis of the morphological texture in 3D has been performed and the relation between morphological and crystallographic texture is identified from the results. The increase in crystallographic texture is related to grain growth. [Copyright &y& Elsevier]

Abstract: This paper deals with the physical study of the Schottky contact after pulsed-RF saturated life test under enhanced drain bias voltage on power HEMTs. Electrical measurements showed a pinch-off voltage (VP ) shift, a decrease of output power and average drain current while Photon Emission Microscopy (PEM) was used to identify the degradation distribution along the 80 fingers die. Finally, Transmission Electron Microscopy (TEM) is performed to point out the different Schottky degradation between a central finger and an outer one. [Copyright &y& Elsevier]

The properties of bulk nanostructured materials are often controlled by atomic-scale features such as segregation along defects or composition gradients. Here we discuss the complementary use of transmission electron microscopy and atom probe tomography to obtain a full description of nanostructures. The advantages and limitations of both techniques are highlighted on the basis of experimental data collected in severely deformed steels with a special emphasis on carbon spatial distribution. [Copyright &y& Elsevier]

Vacancy defects in tungsten induced by self-ion irradiation were characterized by positron annihilation spectroscopy (PAS) and transmission electron microscopy (TEM). Taking advantage of their complementarity, defects ranging from single vacancies up to vacancy clusters were detected, and the effects of sample purity (99.95 wt.% and 99.9999 wt.%) on their formation and evolution under low damage dose (0.01 to 0.02 dpa) irradiation with 20 and 1.2 MeV-W ions were studied at room temperature (RT), 500 and 700 °C respectively. When irradiation was performed at RT, PAS probed mainly single vacancies. At high irradiation temperatures, larger vacancy clusters were detected by both techniques. Both PAS and TEM revealed larger vacancy clusters in the purest samples after irradiation at 500 and 700 °C. A significant difference in the evolution of vacancy-type defects related to sample purity was observed. In view of the properties (migration, trapping) of some light-element impurities (LEs), present at high concentrations, determined by first-principles calculation, it is reasonable to assign the effect of purity during the irradiation response to the formation of vacancy-impurity complexes, which is critical for the understanding of the behavior of tungsten in the future fusion reactor. [ABSTRACT FROM AUTHOR]

Abstract A surface state analysis of an UO 2 ceramic is performed by combining Raman imaging and electron back-scattering diffraction. Special attention is paid to the behavior of the T 2g band intensity versus the crystalline orientation. In order to clarify the origin of the T 2g intensity variation in the appropriate Raman image, electron back-scattering diffraction (EBSD) measurements are carried out. EBSD data allow a theoretical estimation of the Raman T 2g band intensities. Both maps have been compared in order to correlate them, and to distinguish regions where they are analogous, from those where some physical or chemical effects (stoichiometry, or strains) induce different behavior. More generally, this highlights the interest and the complementarity of combining Raman spectroscopy and EBSD for a better microstructure knowledge. [ABSTRACT FROM AUTHOR]

• A premixed Al/air flame was investigated by experiment and numerical simulations. • Each micron-sized Al/Al2O3 flame can be modeled using Lorenz-Mie core-shell theory. • Optical indices of homogenized Al2O3 nanoparticle shells were fitted from a model. • This basic model can reproduce the radiometric results of a small burner prototype. • A power law for the emissivity was obtained, with exponents close to -0.5. The goal of this article is to contribute to the knowledge of the phenomenology of the poorly understood micron-sized Al/air flames, with the intention of assessing the viability of an energy carrier based on aluminum powders. To this end, the combustion efficiency, temperature, radiative profile, and solid combustion products of a flame prototype have been studied in depth. These fundamental parameters are required to explore the possibilities of recovering the energy released by these flames. In addition, a theoretical model has been established to analyze the radiative properties of the flame, derived for an optically thin collection of independent burning Al particles, each modeled by a core-shell geometry. The structure of the shell, made up of a cloud of alumina nanoparticles, has been modeled with an effective medium following the Maxwell-Garnett relation. This approach can reproduce the experimental results and is thus suggested as a starting point for modeling experiments characterized by strong emission by the nanoparticle cloud. [ABSTRACT FROM AUTHOR]

Abstract: The NiSi silicide that forms by reactive diffusion between Ni and Si active regions of nanotransistors is used nowadays as contacts in nanoelectronics because of its low resistivity. Pt is added to the Ni film in order to stabilise the NiSi phase against the formation of the high-resistivity NiSi2 phase and agglomeration. In situ X-ray diffraction (XRD) experiments performed on material aged at 350°C (under vacuum) showed the complete consumption of the Ni (5at% Pt) phase, the regression of Ni2Si phase as well as the growth of the NiSi phase after 48min. Pt distribution for this heat treatment has been analysed by laser-assisted tomographic atom probe (LATAP). An enrichment of platinum in the middle of the NiSi phase suggests that Pt is almost immobile during the growth of NiSi at the two interfaces: Ni2Si/NiSi and NiSi/Si. In the peak, platinum was found to substitute for Ni in the NiSi phase. Very small amounts of Pt were also found in the Ni2Si phase close to the surface and at the NiSi/Si interface. [Copyright &y& Elsevier]