68 research outputs found
A review of nanotechnology applications in the oil and gas industries
Nanotechnology encompasses the science and technology of objects with sizes ranging from 1 nm to 100 nm. Today, exploration and production from conventional oil and gas wells have reached a stage of depletion. Newer technologies have been developed to address this problem. Maximum oil production at a minimum cost is currently a huge challenge. This paper reviews nanotechnology applications in the oil and gas production sector, including in the fields of exploration, drilling, production, and waste management in oil fields, as well as their environmental concerns. The paper reviews experimental observations carried out by various researchers in these fields. The effect of various nanoparticles, such as titanium oxide, magnesium oxide, zinc oxide, copper oxide, and carbon nanotubes in drilling fluids and silica nanoparticles in enhanced oil recovery, has been observed and studied. This paper gives a detailed review of the benefits of nanotechnology in oil exploration and production. The fusion of nanotechnology and petroleum technology can result in great benefits. The physics and chemistry of nanoparticles and nanostructures are very new to petroleum technology. Due to the greater risk associated with adapting new technology, nanotechnology has been slow to gain widespread acceptance in the oil and gas industries. However, the current economic conditions have become a driving force for newer technologies
Orbital Optimization in the Density Matrix Renormalization Group, with applications to polyenes and \beta-carotene
In previous work we have shown that the Density Matrix Renormalization Group
(DMRG) enables near-exact calculations in active spaces much larger than are
possible with traditional Complete Active Space algorithms. Here, we implement
orbital optimisation with the Density Matrix Renormalization Group to further
allow the self-consistent improvement of the active orbitals, as is done in the
Complete Active Space Self-Consistent Field (CASSCF) method. We use our
resulting DMRGCASSCF method to study the low-lying excited states of the
all-trans polyenes up to C24H26 as well as \beta-carotene, correlating with
near-exact accuracy the optimised complete \pi-valence space with up to 24
active electrons and orbitals, and analyse our results in the light of the
recent discovery from Resonance Raman experiments of new optically dark states
in the spectrum.Comment: 16 pages, 8 figure
Resonant enhancement of ultracold photoassociation rate by electric field induced anisotropic interaction
We study the effects of a static electric field on the photoassociation of a
heteronuclear atom-pair into a polar molecule. The interaction of permanent
dipole moment with a static electric field largely affects the ground state
continuum wave function of the atom-pair at short separations where
photoassociation transitions occur according to Franck-Condon principle.
Electric field induced anisotropic interaction between two heteronuclear ground
state atoms leads to scattering resonances at some specific electric fields.
Near such resonances the amplitude of scattering wave function at short
separation increases by several orders of magnitude. As a result,
photoaasociation rate is enhanced by several orders of magnitude near the
resonances. We discuss in detail electric field modified atom-atom scattering
properties and resonances. We calculate photoassociation rate that shows giant
enhancement due to electric field tunable anisotropic resonances. We present
selected results among which particularly important are the excitations of
higher rotational levels in ultracold photoassociation due to electric field
tunable resonances.Comment: 14 pages,9 figure
- β¦