7,210 research outputs found
Role of Bose enhancement in photoassociation
We discuss the role of Bose enhancement of the dipole matrix element in
photoassociation, using stimulated Raman adiabatic passage as an example. In a
nondegenerate gas the time scale for coherent optical transients tends to
infinity in the thermodynamic limit, whereas Bose enhancement keeps this time
scale finite in a condensate. Coherent transients are therefore absent in
photoassociation of a thermal nondegenerate gas, but are feasible if the gas is
a condensate.Comment: 14 pages, 2 figure
Network effects and total economic impact in transport appraisal
It is claimed that transport infrastructure projects have network effects which are not taken into account in the appraisal of these projects. This paper reviews the concept of network effects, relates this to transport appraisal practice, and links to the concept of âtotal economic impactâ. The limitations of transport modelling and appraisal in estimating total economic impact are reviewed. Good quality appraisals should be capable of picking up relevant network effects in the transport market, but the state of the art remains limited on the linkages between transport and the wider economy
Rate limit for photoassociation of a Bose-Einstein condensate
We simulate numerically the photodissociation of molecules into noncondensate
atom pairs that accompanies photoassociation of an atomic Bose-Einstein
condensate into a molecular condensate. Such rogue photodissociation sets a
limit on the achievable rate of photoassociation. Given the atom density \rho
and mass m, the limit is approximately 6\hbar\rho^{2/3}/m. At low temperatures
this is a more stringent restriction than the unitary limit of scattering
theory.Comment: 5 pgs, 18 refs., 3 figs., submitted to Phys. Rev. Let
Assessing the Value of Time Travel Savings â A Feasibility Study on Humberside.
It is expected that the opening of the Humber Bridge
will cause major changes to travel patterns around Humberside;
given the level of tolls as currently stated, many travellers
will face decisions involving a trade-off between travel time,
money outlay on tolls or fares and money outlay on private
vehicle running costs; this either in the context of
destination choice, mode choice or route choice.
This report sets out the conclusions of a preliminary
study of the feasibility of inferring values of travel time
savings from observations made on the outcomes of these
decisions. Methods based on aggregate data of destination
choice are found t o be inefficient; a disaggregate mode
choice study i s recommended, subject to caveats on sample size
Recognizing aboriginal oral tradition through blended learning: a success story
The Aboriginal Health and Community Administration Program (AHCAP) is a certificate program developed through the partnership of the Institute for Aboriginal Health and Continuing Studies at the University of British Columbia. This paper examines factors in the programâs blended design and development which have contributed to the exceptionally high completion rate and the strongly positive responses and outcomes for widely diverse learner cohorts. Factors which appear to contribute to the program success include: 1) a holistic approach compatible with traditional Aboriginal oral traditions of teaching and learning; 2) a university partnership that taps into unique networks and capacities; 3) incorporating the 4 Râs of Aboriginal education: relevance, reciprocity, respect and responsibility generated throughout the learning and teaching, both online and face-to-face; and 4) making the program accessible to geographically and technologically diverse communities of learners.\u
On the road to Enlighten-ment: establishing an institutional repository service for the University of Glasgow
Purpose â The purpose of this paper is to chart the development and growth of open access and institutional repositories at the University of Glasgow, Scotland from initial work in 2001 to the University's recently launched service, Enlighten. The University of Glasgow is a signatory to the Scottish Open Access Declaration and recently released a statement on Open Access.<p></p>
Design/methodology/approach â The study will focus on the key lessons learned through a twin track approach of advocacy and service development during the DAEDALUS Project (2002-2005) and the transition of that work to a University service called Enlighten. This service includes a repository for published and peer-reviewed papers which has now had over 2 million hits and over 270,000 PDF downloads since it was established in February 2004.<p></p>
Findings â The paper reveals the lessons learned by the Library and the project team. It also identifies the range of issues which must be addressed in the successful implementation of a repository and its transition to a production service. These include the development of content policies, copyright clearance and the cultural change necessary to populate a repository service. These challenges have and continue to be addressed by the repository team at the University of Glasgow.<p></p>
Originality/value â This paper provides details of the lessons learned in the practical experience of setting up an institutional repository and ensuring its transition to a full and supported University service. It will be of particular interest to institutions implementing a repository or running a pilot service.<p></p>
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Compressed intramolecular dispersion interactions.
The feasibility of the compression of localized virtual orbitals is explored in the context of intramolecular long-range dispersion interactions. Singular value decomposition (SVD) of coupled cluster doubles amplitudes associated with the dispersion interactions is analyzed for a number of long-chain systems, including saturated and unsaturated hydrocarbons and a silane chain. Further decomposition of the most important amplitudes obtained from these SVDs allows for the analysis of the dispersion-specific virtual orbitals that are naturally localized. Consistent with previous work on intermolecular dispersion interactions in dimers, it is found that three important geminals arise and account for the majority of dispersion interactions at the long range, even in the many body intramolecular case. Furthermore, it is shown that as few as three localized virtual orbitals per occupied orbital can be enough to capture all pairwise long-range dispersion interactions within a molecule
Variability in spawning frequency and reproductive development of the narrow-barred Spanish mackerel (Scomberomorus commerson) along the west coast of Australia
The narrow-barred Spanish mackerel (Scomberomorus commerson)
is widespread throughout the Indo-West Pacific region. This study describes the reproductive biology of S. commerson along the west coast of Australia, where it is targeted for
food consumption and sports fishing. Development of testes occurred at a smaller body size than for ovaries, and more than 90% of males were sexually mature by the minimum legal length of 900 mm TL compared to 50% of females. Females dominated overall catches although sex ratios within daily catches vary considerably and females were rarely caught
when spaw n ing. Scomberomorus commerson are seasonally abundant in coastal waters and most of the commercial catch is taken prior to the reproductive season. Spawning occurs between about August and November in the Kimberley region
and between October and January in the Pilbara region. No spawning activity was recorded in the more southerly West Coast region, and only in the north Kimberley region were
large numbers of fish with spawning gonads collected. Catches dropped to a minimum when spawning began in the Pilbara region, when fish became less abundant in inshore waters and inclement weather conditions limited fishing on still productive offshore reefs. Final maturation and ovulation of oocytes took place within a 24-hour period, and females spawned in the afternoon-evening every three days. A third of these spawning females released batches of eggs on consecutive days. Relationships between length, weight, and batch fecundity are presented
To identify the incidence, severity and timing of hypophosphataemia in Glasgow Royal Infirmary Intensive Care Unit (ICU) [poster]
No abstract available
Fully anharmonic infrared cascade spectra of polycyclic aromatic hydrocarbons
The infrared (IR) emission of polycyclic aromatic hydrocarbons (PAHs)
permeates our universe; astronomers have detected the IR signatures of PAHs
around many interstellar objects. The IR emission of interstellar PAHs differs
from their emission as seen under conditions on Earth, as they emit through a
collisionless cascade down through their excited vibrational states from high
internal energies. The difficulty in reproducing interstellar conditions in the
laboratory results in a reliance on theoretical techniques. However, the size
and complexity of PAHs requires careful consideration when producing the
theoretical spectra. In this work we outline the theoretical methods necessary
to lead to a fully theoretical IR cascade spectra of PAHs including: an
anharmonic second order vibrational perturbation theory (VPT2) treatment; the
inclusion of Fermi resonances through polyads; and the calculation of
anharmonic temperature band shifts and broadenings (including resonances)
through a Wang--Landau approach. We also suggest a simplified scheme to
calculate vibrational emission spectra that retains the essential
characteristics of the full IR cascade treatment and can directly transform low
temperature absorption spectra in IR cascade spectra. Additionally we show that
past astronomical models were in error in assuming a 15 cm correction
was needed to account for anharmonic emission effects
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