6,459 research outputs found
Solid-liquid equilibria for the dimethyl ether plus carbon dioxide binary system
A recently built experimental setup was employed for the estimation of the solid-liquid equilibria of alternative refrigerants systems. The behavior of dimethyl ether (DME) + carbon dioxide was measured down to temperatures of 131.6 K. To confirm the reliability of the apparatus, the triple point of the DME was measured. The triple point data measured revealed a good consistency with the literature. The results obtained for the mixtures were corrected by the Rossini method and interpreted by means of the Schröder equation. © 2010 Akadémiai Kiadó, Budapest, Hungary
Attosecond Streaking in the Water Window: A New Regime of Attosecond Pulse Characterization
We report on the first streaking measurement of water-window attosecond
pulses generated via high harmonic generation, driven by sub-2-cycle,
CEP-stable, 1850 nm laser pulses. Both the central photon energy and the energy
bandwidth far exceed what has been demonstrated thus far, warranting the
investigation of the attosecond streaking technique for the soft X-ray regime
and the limits of the FROGCRAB retrieval algorithm under such conditions. We
also discuss the problem of attochirp compensation and issues regarding much
lower photo-ionization cross sections compared with the XUV in addition to the
fact that several shells of target gases are accessed simultaneously. Based on
our investigation, we caution that the vastly different conditions in the soft
X-ray regime warrant a diligent examination of the fidelity of the measurement
and the retrieval procedure.Comment: 14 Pages, 12 figure
Ice-bridging frustration by self-ejection of single droplets results in superior anti-frosting surfaces
Surfaces capable of delaying the frosting passively and facilitating its
removal are highly desirable in fields where ice introduces inefficiencies and
risks. Coalescence jumping, enabled by highly hydrophobic surfaces, is already
exploited to slow down the frosting but it is insufficient to completely
eliminate the propagation by ice-bridging. We show how the self-ejection of
single condensation droplets can frustrate the ice bridges of all the
condensation droplets leading to a frost velocity lower than 0.5 um/s thus
dropping below the current limits of passive surfaces by a factor of at least
2. Arrays of truncated microcones, covered by uniformly hydrophobic
nanostructures, enable individual condensation droplets to growth and
self-propel towards the top of the microstructures and to self-eject once a
precise volume is reached. The independency of self-ejection on the neighbour
droplets allows a precise control on the droplets' size and distance
distributions and the ice-bridging frustration. The most performant
microstructures tend to cones with a sharp tip on which the percentage of
self-ejection is maximum. Looking towards applications, tapered microstructures
allow maximising the percentage of self-ejecting drops while maintaining a
certain mechanical strength. Further, it is shown that inserted pinning sites
are not essential, which greatly facilitates manufacturing
Host-parasite relationships in root-knot disease of white mulberry
Severe infections of white mulberry feeder roots and heavy soil infestations by Meloidogyne arenaria race 2 were found in southern Spain. This is the first record of M. arenaria on white mulberry in Europe. Morphometric observations, analysis of the esterase electrophoretic pattern, and artificial inoculations of race differentials were used to characterize nematodes. Nematode-induced mature galls were spherical and usually contained one or more females, males, and egg masses with eggs. Feeding sites were characterized by the development of giant cells that contained granular cytoplasm and many hypertrophied nuclei. Giant cell cytoplasm
was aggregated along a thickened cell wall. Vascular tissues within galls appeared disorganized. The relationship between the initial nematode population density (Pi) in a series from 0 to 1,024 eggs and juveniles/cm3 soil and growth of white mulberry seedlings was tested in the greenhouse. A Seinhorst model was fitted to plant height and top fresh weight. Tolerance limits of white mulberry to M. arenaria race 2 for plant height and top fresh weight were, respectively, 1.1 and 1.38 eggs and juveniles/cm3 soil. The minimum relative values for plant height and top fresh weight were 0 at Pi > 64 and Pi > 128 eggs and juveniles/cm3 soil, respectively. Maximum
nematode reproduction rate was 435-fold at the lowest Pi.
Additional keywords: histopathology, Morus alba, pathogenicity, threshold limitPeer reviewe
Development and optimization of a method for analyzing biodiesel mixtures with non-aqueous reversed phase liquid chromatography
Biodiesel (a mixture of fatty acid esters) is normally analyzed using gas chromatography/flame ionization
detection, as specified by the ASTM D6584 and EN14105 standards. This paper proposes a binary gradient
method for analyzing biodiesel mixtures using non-aqueous reverse phase HPLC with a UV detector
capable of overcoming the drawbacks of the gas chromatographic technique normally used. The new analytical
method was developed by means of a statistical sensitivity analysis applied to the main parameters
influencing the recording, using the full factorial design method combined with the Yates algorithm and
the steepest ascent optimization procedure. The present study shows the influence of the main biodiesel
mixture separation analysis parameters. The resulting tool proved valid for analyzing not only biodiesel
but also any traces of unreacted oil
Shifts in the eruptive styles at Stromboli in 2010-2014 revealed by ground-based InSAR data
Ground-Based Interferometric Synthetic Aperture Radar (GBInSAR) is an efficient technique for capturing short, subtle episodes of conduit pressurization in open vent volcanoes like Stromboli (Italy), because it can detect very shallow magma storage, which is difficult to identify using other methods. This technique allows the user to choose the optimal radar location for measuring the most significant deformation signal, provides an exceptional geometrical resolution, and allows for continuous monitoring of the deformation. Here, we present and model ground displacements collected at Stromboli by GBInSAR from January 2010 to August 2014. During this period, the volcano experienced several episodes of intense volcanic activity, culminated in the effusive flank eruption of August 2014. Modelling of the deformation allowed us to estimate a source depth of 482 ± 46 m a.s.l. The cumulative volume change was 4.7 ± 2.6 × 10(5) m(3). The strain energy of the source was evaluated 3-5 times higher than the surface energy needed to open the 6-7 August eruptive fissure. The analysis proposed here can help forecast shifts in the eruptive style and especially the onset of flank eruptions at Stromboli and at similar volcanic systems (e.g. Etna, Piton de La Fournaise, Kilauea)
Solid-liquid equilibria for nitrous oxide+ fluoromethane and triple point measurements for refrigerants
To evaluate the Solid-Liquid Equilibria (SLE) of alternative refrigerants systems, an experimental set-up was employed. The behaviour of the nitrous oxide + fluoromethane (N2O + R41) binary system was measured down to temperatures of 126.5 K. The triple point temperature of carbon dioxide, nitrous oxide and of seven of the most widely applied alternative refrigerants, namely fluoromethane (R41), difluoromethane (R32), trifluoromethane (R23), pentafluoroethane (R125), 1,1,1,2-tetrafluoroethane (R134a), 1,1,1-trifluoroethane (R143a) and 1,1-difluoroethane (R152a), were also measured. All triple point data measured revealed a generally good consistency with the literature. The results obtained for the mixtures were corrected by the Rossini method and interpreted by means of the Schröder equation. © 2012 Old City Publishing, Inc
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