2,843 research outputs found
Fuels characterization studies
Current analytical techniques used in the characterization of broadened properties fuels are briefly described. Included are liquid chromatography, gas chromatography, and nuclear magnetic resonance spectroscopy. High performance liquid chromatographic ground-type methods development is being approached from several directions, including aromatic fraction standards development and the elimination of standards through removal or partial removal of the alkene and aromatic fractions or through the use of whole fuel refractive index values. More sensitive methods for alkene determinations using an ultraviolet-visible detector are also being pursued. Some of the more successful gas chromatographic physical property determinations for petroleum derived fuels are the distillation curve (simulated distillation), heat of combustion, hydrogen content, API gravity, viscosity, flash point, and (to a lesser extent) freezing point
Holographic Thermal Helicity
We study the thermal helicity, defined in arXiv:1211.3850, of a conformal
field theory with anomalies in the context of AdS/CFT. To do
so, we consider large charged rotating AdS black holes in the
Einstein-Maxwell-Chern-Simons theory with a negative cosmological constant
using fluid/gravity expansion. We compute the anomaly-induced current and
stress tensor of the dual CFT in leading order of the fluid/gravity derivative
expansion and show their agreement with the field theoretical replacement rule
for the thermal helicity. Such replacement rule is reflected in the bulk by new
replacement rules obeyed by the Hall currents around the black hole.Comment: 20 pages + 47 pages of appendices ; v2: minor correction
Covariant Noether Charge for Higher Dimensional Chern-Simons Terms
We construct a manifestly covariant differential Noether charge for theories
with Chern-Simons terms in higher dimensional spacetimes. This is in contrast
to Tachikawa's extension of the standard Lee-Iyer-Wald formalism which results
in a non-covariant differential Noether charge for Chern-Simons terms. On a
bifurcation surface, our differential Noether charge integrates to the
Wald-like entropy formula proposed by Tachikawa in arXiv:hep-th/0611141.Comment: 45 pages; v2: minor corrections and JHEP versio
Right-Handed Neutrinos and T-Violating, P-Conserving Interactions
We show that experimental probes of the P-conserving, T-violating triple
correlation in polarized neutron or nuclear -decay provide a unique
probe of possible T-violation at the TeV scale in the presence of right-handed
neutrinos. In contrast to other possible sources of semileptonic T-violation
involving only left-handed neutrinos, those involving right-handed neutrinos
are relatively unconstrained by present limits on the permanent electric dipole
moments of the electron, neutral atoms, and the neutron. On the other hand, LHC
results for missing transverse energy imply that an order of
magnitude of improvement in -coefficient sensitivity would be needed for
discovery. Finally, we discuss the interplay with the scale of neutrino mass
and naturalness considerations.Comment: 6 pages, 2 figure
Reduced hadronic uncertainty in the determination of
We analyze the universal radiative correction to neutron and
superallowed nuclear decay by expressing the hadronic -box
contribution in terms of a dispersion relation, which we identify as an
integral over the first Nachtmann moment of the interference
structure function . By connecting the needed input to existing data
on neutrino and antineutrino scattering, we obtain an updated value of
, wherein the hadronic uncertainty is reduced.
Assuming other Standard Model theoretical calculations and experimental
measurements remain unchanged, we obtain an updated value of , raising tension with the first row CKM unitarity constraint. We
comment on ways current and future experiments can provide input to our
dispersive analysis.Comment: 5 pages, 5 figures, references updated; version submitted to PR
Copolymers of tetrahydrofuran and epoxidized vegetable oils : application to elastomeric polyurethanes
The Lewis acid ring-opening of epoxidized vegetable oils (EVO's) in the presence of tetrahydrofuran (THF) gives rise to polyether polyol co-polymers p(THF-stat-EVO). The effect of Lewis acid, vegetable oil substrate (epoxidised methyloleate EMO, epoxidised cocoa butter ECB, and epoxidised palm oil EPO) and conditions (concentration, temperature and time) on the molecular weight, polydispersity, hydroxyl value and thermal properties of the p(THF-stat-EVO) macromonomers was determined. Elastomeric polyurethanes were prepared from p(THF-stat-EVO) macromonomers and MDI and their mechanical and thermal properties determined. The properties of the polyurethane derived from p(THF-EPO) were compared to that derived from the homopolymer of epoxidised palm oil (EPO) prepared by Lewis acid ring-opening in the absence of THF. The co-polymer incorporating THF gave rise to a material with significantly greater tensile strength [p(THF-EPO-MDI) = 9.1 MPa, p(EPO-MDI) = 1.5 MPa] and elongation at break [p(THF-EPO-MDI) = 425%, p(EPO-MDI) = 70%] with little compromise on thermal stability [p(THF-EPO-MDI) Tdecomp10% = 378 °C, Tdecomp50% = 414 °C, p(EPO-MDI) Tdecomp10% = 379 °C Tdecomp50% = 424 °C]
Parity-violating deep-inelastic electron-deuteron scattering: Higher twist and parton angular momentum
We study the effect of parton angular momentum on the twist-four correction to the left-right asymmetry in the electron-deuteron parity-violating deep-inelastic scattering (PVDIS). We show that this higher-twist correction is transparent to the dynamics of parton angular momentum needed to account for the Sivers and Boer-Mulders functions and spin-independent parton distribution functions. A sufficiently precise measurement of the PVDIS asymmetry may, thus, provide additional information about the parton dynamics responsible for nucleon spin
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