New Natural Injection-Moldable Composite Material from Sunflower Oil Cake

Through a twin-screw extrusion process the native structure of sunflower oil cake was completely transformed (globular protein denaturation/texturization and husk fiber defibration) into a simpler matrix-fiber structure, as could be seen on SEM micrographs. Further chemical reduction of protein disulfide bridges greatly reduced the melt viscosity of the moistened composite that it could be injection-molded. The molded specimens were tested and their tensile and flexural properties and water absorption calculated. Their water resistance appeared to be particularly high, and could be enhanced further after a thermal treatment (N2, 200°C). The proteic matrix seemed to behave like a natural thermoset resin. Sunflower oil cake could be used without any additives to make biodegradable, water resistant and exceptionally cheap material

In situ relationships between microbiota and potential pathobiota in Arabidopsis thaliana.

A current challenge in microbial pathogenesis is to identify biological control agents that may prevent and/or limit host invasion by microbial pathogens. In natura, hosts are often infected by multiple pathogens. However, most of the current studies have been performed under laboratory controlled conditions and by taking into account the interaction between a single commensal species and a single pathogenic species. The next step is therefore to explore the relationships between host-microbial communities (microbiota) and microbial members with potential pathogenic behavior (pathobiota) in a realistic ecological context. In the present study, we investigated such relationships within root-associated and leaf-associated bacterial communities of 163 ecologically contrasted Arabidopsis thaliana populations sampled across two seasons in southwest of France. In agreement with the theory of the invasion paradox, we observed a significant humped-back relationship between microbiota and pathobiota α-diversity that was robust between both seasons and plant organs. In most populations, we also observed a strong dynamics of microbiota composition between seasons. Accordingly, the potential pathobiota composition was explained by combinations of season-specific microbiota operational taxonomic units. This result suggests that the potential biomarkers controlling pathogen\u27s invasion are highly dynamic

A noiseless kilohertz frame rate imaging detector based on microchannel plates read out with the Medipix2 CMOS pixel chip

A new hybrid optical imaging detector is described that is being developed for the next generation adaptive optics (AO) wavefront sensors (WFS) for ground-based telescopes. The detector consists of a photocathode and proximity focused microchannel plates (MCPs) read out by the Medipix2 CMOS pixel ASIC. Each pixel of the Medipix2 device measures 55x55 um2 and comprises pre-amplifier, a window discriminator and a 14-bit counter. The 256x256 Medipix2 array can be read out noiselessly in 287 us. The readout can be electronically shuttered down to a temporal window of a few us. The Medipix2 is buttable on 3 sides to produce 512x(n*256) pixel devices. Measurements with ultraviolet light yield a spatial resolution of the detector at the Nyquist limit. Sub-pixel resolution can be achieved using centroiding algorithms. For the AO application, very high continuous frame rates of the order of 1 kHz are required for a matrix of 512x512 pixels. The design concepts of a parallel readout board are presented that will allow this fast data throughput. The development status of the optical WFS tube is also explained

Strong, Ultra-narrow Peaks of Longitudinal and Hall Resistances in the Regime of Breakdown of the Quantum Hall Effect

With unusually slow and high-resolution sweeps of magnetic field, strong, ultra-narrow (width down to $100 {\rm \mu T}$) resistance peaks are observed in the regime of breakdown of the quantum Hall effect. The peaks are dependent on the directions and even the history of magnetic field sweeps, indicating the involvement of a very slow physical process. Such a process and the sharp peaks are, however, not predicted by existing theories. We also find a clear connection between the resistance peaks and nuclear spin polarization.Comment: 5 pages with 3 figures. To appear in PR

Simultaneous solvent extraction and transesterification of jatropha oil for biodiesel production, and potential application of the obtained cakes for binderless particleboard

This study investigated biodiesel production from jatropha seeds in a single step, i.e. by simultaneous solvent extraction and transesterification of jatropha oil, and possibility to transform the obtained cakes into binderless particleboards. n-Hexane was used as extracting solvent. The best operating conditions were identified to obtain optimal biodiesel yield and quality, and optimal physical and mechanical properties for binderless particleboards. Biodiesel yield was usually influenced by operating conditions, and the influences of both n-hexane to seed and methanol to oil ratios were most significant. An increase in n-hexane to seed ratio (from 1:1 to 3:1) combined with the decrease in methanol to oil ratio (from 13.3:1 to 8.0:1) led to an improvement in biodiesel yield. The best biodiesel yield (92% with a fatty acid methyl ester purity >98%) was obtained from 2:1 n-hexane to seed ratio, 10.6:1 methanol to oil ratio, 200–600 rpm stirring speed, 50 °C temperature and 6 h reaction time. Operating conditions had no significant effect on the biodiesel quality, except the n-hexane to seed ratio. Moreover, cohesive particleboards were produced from the obtained cakes, proteins and fibers acting respectively as binder and reinforcing fillers. An increase in the cake moisture content significantly improved the particleboard properties. The most promising binderless particleboard was manufactured from cake B under 20% cake moisture content and 160 °C pressing temperature. Its properties were 0.87 g/cm3 density, 8.4% moisture content, 7.2 MPa modulus of rupture, 10.4 GPa modulus of elasticity, 0.14 MPa internal bonding strength, 52% water absorption and 20% thickness swelling after 24 h immersion in water

Monitoring Arthropods in Azorean Agroecosystems : the project AGRO-ECOSERVICES

We provided an inventory of all arthropods recorded in four Azorean agroecosystems (citrus orchards, low and high elevation maize fields and vineyards) from Terceira Island. A total of 50412 specimens were collected, belonging to four classes, 20 orders, 81 families and 200 identified species of arthropods. A total of 127 species are considered introduced (n = 22646) and 69 native non-endemic (n = 24117). Four endemic species were recorded with very few specimens (n = 14) and 3635 specimens belong to unidentified taxa recorded only at genus or family level. Five species are new records for Terceira Island, with Lagria hirta (Linnaeus, 1758) (Coleoptera, Tenebrionidae) being also a new record for the Azores. This publication contributes to a better knowledge of the arthropods communities present in agro-ecosystems of Terceira Island and will serve as a baseline for future monitoring schemes targeting the long-term change in arthropod diversity and abundance.This work was financed by FEDER (European Regional Development Fund) in 85% and by Azorean Public funds by 15% through the Operational Program Azores 2020, under the project AGRO-ECOSERVICES (ACORES-01-0145-FEDER-000073). The Darwin-Core database was prepared within the scope of the project AZORESBIOPORTAL -PORBIOTA (ACORES-01-0145-FEDER-000072).info:eu-repo/semantics/publishedVersio

SPHERE: the exoplanet imager for the Very Large Telescope

Observations of circumstellar environments to look for the direct signal of exoplanets and the scattered light from disks has significant instrumental implications. In the past 15 years, major developments in adaptive optics, coronagraphy, optical manufacturing, wavefront sensing and data processing, together with a consistent global system analysis have enabled a new generation of high-contrast imagers and spectrographs on large ground-based telescopes with much better performance. One of the most productive is the Spectro-Polarimetic High contrast imager for Exoplanets REsearch (SPHERE) designed and built for the ESO Very Large Telescope (VLT) in Chile. SPHERE includes an extreme adaptive optics system, a highly stable common path interface, several types of coronagraphs and three science instruments. Two of them, the Integral Field Spectrograph (IFS) and the Infra-Red Dual-band Imager and Spectrograph (IRDIS), are designed to efficiently cover the near-infrared (NIR) range in a single observation for efficient young planet search. The third one, ZIMPOL, is designed for visible (VIR) polarimetric observation to look for the reflected light of exoplanets and the light scattered by debris disks. This suite of three science instruments enables to study circumstellar environments at unprecedented angular resolution both in the visible and the near-infrared. In this work, we present the complete instrument and its on-sky performance after 4 years of operations at the VLT.Comment: Final version accepted for publication in A&

Direct Calophyllum oil extraction and resin separation with a binary solvent of n-hexane and methanol mixture

This study investigated the use of a mixture of n-hexane and methanol as a binary solvent for the direct oil extraction and resin separation from Calophyllum seeds, in a single step. Optimal oil and resin yields and physicochemical properties were determined by identifying the best extraction conditions. The solvent mixture tested extracted oil and resin effectively from Calophyllum seeds, and separated resin from oil. Extraction conditions affected oil and resin yields and their physicochemical properties, with the n-hexane-to-methanol ratio being the most critical factor. Oil yield improved as n-hexane-to-methanol ratio increased from 0.5:1 to 2:1, and resin yield increased as methanol-to-n-hexane ratio increased from 0.5:1 to 2:1. Physicochemical properties of oil and resin, particularly for acid value and impurity content, improved as the n-hexane-to-methanol ratio decreased from 2:1 to 0.5:1. The best oil (51% with more than 95% triglycerides) and resin (18% with more than 5% polyphenols) yields were obtained with n-hexane-to-methanol ratios of 2:1 and 0.5:1, respectively, at a temperature of 50 °C, with an extraction time of 5 h. The best values for physicochemical property of oil were a density of 0.885 g/cm3, a viscosity of 26.0 mPa.s, an acid value of 13 mg KOH/g, an iodine value of 127 g/100 g, an unsaponifiable content of 1.5%, a moisture content of 0.8% and an ash content of 0.04%