5,661 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
A simple framework for investigating the properties of policy games
The paper extensively studies the static model of non-cooperative linear quadratic games in which a set of agents chooses their instruments strategically to minimize their linear quadratic criterion. We first derive the necessary and sufficient conditions for the existence of a Nash equilibrium as well as for multiple equilibria to arise. Furthermore, we study the general condition for policy neutrality and Pareto efficiency of the equilibrium by introducing a new concept of decisiveness.Conflict of interest, Nash equilibrium existence, multiplicity, policy invariance, controllability, Pareto efficiency
Role of Metal Ions and Hydrogen Bond Acceptors in the Tautomeric Equilibrium of Nitro-9[(Alkylamino)Amino]-Acridine Drugs
3-nitro-9-[2-(dialkylamino)ethyl)]aminoacridines (alkyl = methyl or ethyl) have been used as ligands
towards platinum(If). The end product is a complex in which the acridine acts as a tridentate ligand
contributing the two exocyclic nitrogen atoms and one of the two peri carbons. The metallation takes place
predominantly at the peri position of the unsubstituted ring. The coordinated acridine is in the imino
tautomeric form although, in the free state, it occurs exclusively in the amino form (both in the solid state and
in solution). The imino tautomer is considered to be the biologically active form. In the platinated species the
N(10)H of the acridine can be involved in strong hydrogen bonding with a chloride ion leading to formation
of an association complex, the formation constant has been found to be 1.4±103 M−1. The N(10)H┄CI
interaction can influence the tautomeric equilibrium of the acridine dye also in the uncoordinated species,
however, the shift in favor of the imino tautomer is not complete
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
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
Decrypting geophysical signals at Stromboli Volcano (Italy): Integration of seismic and Ground-Based InSAR displacement data
We present the integration of seismic and Ground‐Based Interferometric Synthetic Aperture Radar system (GBInSAR) displacement data at Stromboli Volcano. Ground deformation in the area of summit vents is positively correlated with both seismic tremor amplitude and cumulative amplitudes of very long period (VLP) signals associated with Strombolian explosions. Changes in VLP amplitudes precede by a few days the variations in ground deformation and seismic tremor. We propose a model where the arrival of fresh, gas‐rich magma from depth enhances gas slug formation, promoting convection and gas transfer throughout the conduit system. At the shallowest portion of the conduit, an increase in volatile content causes a density decrease, expansion of the magmatic column and augmented degassing activity, which respectively induce inflation of the conduit, and increased tremor amplitudes. The temporal delay between increase of VLP and tremor amplitudes/conduit inflation can be interpreted in terms of the different timescales characterizing bulk gas transfer versus slug formation and ascent
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
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
Alternative biofuels:PVTx measurements for DME + propane
This study presents the experimental results for the dimethyl ether (DME) ? propane system obtained using the Burnett method. The apparatus was calibrated using helium. PVTx measurements were taken for four isotherms (344, 354, 364, and 375 K), performing 16 Burnett expansions in pressures ranging from about 3,000 to 70 kPa. The second and third virial coefficients were derived from experimental results. The experimental uncertainty in the second and third virial coefficients was estimated to be within ±5 cm 3/mol and ±1,000 cm6/mol2,respectively
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