76 research outputs found
Neutron to proton ratios of quasiprojectile and midrapidity emission in the Zn + Zn reaction at 45 MeV/nucleon
Simultaneous measurement of both neutrons and charged particles emitted in
the reaction Zn + Zn at 45 MeV/nucleon allows comparison of the
neutron to proton ratio at midrapidity with that at projectile rapidity. The
evolution of N/Z in both rapidity regimes with increasing centrality is
examined. For the completely re-constructed midrapidity material one finds that
the neutron-to-proton ratio is above that of the overall Zn + Zn
system. In contrast, the re-constructed ratio for the quasiprojectile is below
that of the overall system. This difference provides the most complete evidence
to date of neutron enrichment of midrapidity nuclear matter at the expense of
the quasiprojectile
Isotope correlations as a probe for freeze-out characterization: central 124Sn+64Ni, 112Sn+58Ni collisions
124Sn+64Ni and 112Sn+58Ni reactions at 35 AMeV incident energy were studied
with the forward part of CHIMERA multi-detector. The most central collisions
were selected by means of a multidimensional analysis. The characteristics of
the source formed in the central collisions, as size, temperature and volume,
were inspected. The measured isotopes of light fragments (3 <= Z <=8) were used
to examine isotope yield ratios that provide information on the free neutron to
proton densities.Comment: 4 pages, Contribution to 8th International Conference on
Nucleus-Nucleus Collisions, Moscow 200
Separation and recovery of a hemicellulose-derived sugar produced from the hydrolysis of biomass by an acidic ionic liquid
ABSTRACT: Biomass processing with ionic liquids (ILs) has been one of the most topical research areas in recent years. However, separation and recovery of biomass products and ILs are currently a challenge. Recovery of produced monosaccharides from an IL postreaction solution and the possibility to reuse the IL are strongly required to guarantee the sustainability of biomass processing. The present study demonstrates a novel approach that aims at separating a biomass hemicellulose-derived product, namely, xylose, and 1-ethyl-3-methylimidazolium hydrogensulfate ([emim][HSO4]). High polarity of a postreaction system composed of xylose, IL, and water is one of the major hindrances in the separation performance. A proposed solution is fine-tuning of the system polarity by the addition of moderately polar acetonitrile. To scrutinize the potential of xylose and IL separation, phase equilibria of a system constituted by [emim][HSO4], water, and acetonitrile were studied. Additionally, preparative chromatography experiments with alumina as a stationary phase were performed to determine the conditions required for efficient separation of the sugar and the IL by selective adsorption of xylose on alumina in detriment of IL. The amount and treatment of the stationary phase, eluent polarity, and amount of loaded sample were also scrutinized in this study. Treatment of alumina was considered as a necessary step to achieve recovery yields of 90.8 and 98.1 wt% for the IL and xylose, respectively, as separate fractions.info:eu-repo/semantics/publishedVersio
Mass and charge identification of fragments detected with the Chimera Silicon-CsI(Tl) telescopes
Mass and charge identification of charged products detected with
Silicon-CsI(Tl) telescopes of the Chimera apparatus is presented. An
identification function, based on the Bethe-Bloch formula, is used to fit
empirical correlation between Delta E and E ADC readings, in order to
determine, event by event, the atomic and mass numbers of the detected charged
reaction products prior to energy calibration.Comment: 24 pages, 7 .jpg figures, submitted to Nucl.Instr.
Isoconversional kinetic analysis applied to five phosphoniumcation-based ionic liquids
Thermal degradation of five phosphonium cation-based ionic liquids ([P66614][BEHP], [P66614][(iC8)2PO2],[P66614][NTf2], [P44414][DBS] and [P4442][DEP]) was studied using dynamic methodology (25–600◦C at 5,10 and 20◦C/min) in both inert (nitrogen) and reactive (oxygen) atmospheres. In addition, isothermalexperiments (90 min at 200, 225 and 250◦C) were carried out with [P66614][(iC8)2PO2]. Results indicatethat thermal stability is clearly dominated by the coordination ability of the anion, with [P66614][NTf2] out-performing the other ones in both pyrolytic and oxidising conditions. Although the thermal degradationmechanism is affected by atmospheric conditions, the degradation trend remains practically constant.As the dynamic methodology usually overestimates the long-term thermal stability, an isoconversionalmethodology is better for predicting the long-term thermal stability of these ionic liquids in order to beused as base oil or additive in lubricants formulation. Finally, the model-free methodology can predict atlower costs the ILs performance in isothermal conditions
Activity Coefficients at Infinite Dilution for Organic Compounds Dissolved in 1-Alkyl-1-methylpyrrolidinium Bis(trifluoromethylsulfonyl)imide Ionic Liquids Having Six-, Eight-, and Ten-Carbon Alkyl Chains
International audienceActivity coefficients at infinite dilution (gamma(proportional to)(1,2)) for 40 diverse probe solutes, including various (cyclo)alkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, thiophene, ethers, nitroalkanes, and ketones, were measured by inverse gas chromatography at temperatures from 323 to 343 K in three homologous 1-alkyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ionic liquids (ILs), bearing hexyl, octyl, and decyl side chains. The retention data were further converted to gas-to-IL and water-to-IL partition coefficients using the corresponding gas-to-water partition coefficients. Both sets of partition coefficients were analyzed using the modified Abraham solvation parameter model, with the derived equations tightly correlating the experimental gas-to-IL and water-to-IL partition coefficient data to within average standard deviations of 0.088 and 0.111 log units, respectively
Activity Coefficients at Infinite Dilution for Organic Solutes Dissolved in Three 1-Alkyl-1-methylpyrrolidinium Bis(trifluoromethylsulfonyl)imide Ionic Liquids Bearing Short Linear Alkyl Side Chains of Three to Five Carbons
Amino-functionalized ionic liquids as carbon dioxide scavengers. Ab initio thermodynamics for chemisorption
SAFT-VR modelling of the surface and bulk properties of imidazolium and pyridinium based ionic liquids with ten different anions
Separation of binary mixtures based on gamma infinity data using [OMMIM][NTf 2 ] ionic liquid and modelling of thermodynamic functions
- …