6,177 research outputs found
Application of special-purpose digital computers to rotorcraft real-time simulation
The use of an array processor as a computational element in rotorcraft real-time simulation is studied. A multilooping scheme was considered in which the rotor would loop over its calculations a number of time while the remainder of the model cycled once on a host computer. To prove that such a method would realistically simulate rotorcraft, a FORTRAN program was constructed to emulate a typical host-array processor computing configuration. The multilooping of an expanded rotor model, which included appropriate kinematic equations, resulted in an accurate and stable simulation
To identify the incidence, severity and timing of hypophosphataemia in Glasgow Royal Infirmary Intensive Care Unit (ICU) [poster]
No abstract available
Assessing the Value of Time Travel Savings – 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
A real-time, dual processor simulation of the rotor system research aircraft
A real-time, man-in-the loop, simulation of the rotor system research aircraft (RSRA) was conducted. The unique feature of this simulation was that two digital computers were used in parallel to solve the equations of the RSRA mathematical model. The design, development, and implementation of the simulation are documented. Program validation was discussed, and examples of data recordings are given. This simulation provided an important research tool for the RSRA project in terms of safe and cost-effective design analysis. In addition, valuable knowledge concerning parallel processing and a powerful simulation hardware and software system was gained
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
Sub-Natural-Linewidth Quantum Interference Features Observed in Photoassociation of a Thermal Gas
By driving photoassociation transitions we form electronically excited
molecules (Na) from ultra-cold (50-300 K) Na atoms. Using a second
laser to drive transitions from the excited state to a level in the molecular
ground state, we are able to split the photoassociation line and observe
features with a width smaller than the natural linewidth of the excited
molecular state. The quantum interference which gives rise to this effect is
analogous to that which leads to electromagnetically induced transparency in
three level atomic systems, but here one of the ground states is a
pair of free atoms while the other is a bound molecule. The linewidth is
limited primarily by the finite temperature of the atoms.Comment: 4 pages, 5 figure
The incidence, severity, timing and circadian variation of hypophosphataemia in Glasgow Royal Infirmary Intensive Care Unit [poster]
No abstract available
Rogue decoherence in the formation of a macroscopic atom-molecule superposition
We theoretically examine two-color photoassociation of a Bose-Einstein
condensate, focusing on the role of rogue decoherence in the formation of
macroscopic atom-molecule superpositions. Rogue dissociation occurs when two
zero-momentum condensate atoms are photoassociated into a molecule, which then
dissociates into a pair of atoms of equal-and-opposite momentum, instead of
dissociating back to the zero-momentum condensate. As a source of decoherence
that may damp quantum correlations in the condensates, rogue dissociation is an
obstacle to the formation of a macroscopic atom-molecule superposition. We
study rogue decoherence in a setup which, without decoherence, yields a
macroscopic atom-molecule superposition, and find that the most favorable
conditions for said superposition are a density ~ 1e12 atoms per cc and
temperature ~ 1e-10.Comment: 10 pages, 4 figures, 46+ references; submitted to PR
The Effect of Natural Dissolved Organic Carbon on the Acute Toxicity of Copper to Larval Freshwater Mussels (\u3cem\u3eGlochidia\u3c/em\u3e)
The present study examined the effect of dissolved organic carbon (DOC), both added and inherent, on Cu toxicity in glochidia, the larvae of freshwater mussels. Using incremental additions of natural DOC concentrate and reconstituted water, a series of acute copper toxicity tests were conducted. An increase in DOC from 0.7 to 4.4 mg C/L resulted in a fourfold increase (36–150 μg Cu/L) in the 24-h median effective concentration (EC50) and a significant linear relationship (r2=0.98, p=0.0008) between the DOC concentration and the Cu EC50 of Lampsilis siliquoidea glochidia. The ameliorating effect of added DOC on Cu toxicity was confirmed using a second mussel species, the endangered (in Canada) Lampsilis fasciola. The effect of inherent (i.e., not added) DOC on Cu toxicity was also assessed in eight natural waters (DOC 5–15 mg C/L). These experiments revealed a significant relationship between the EC50 and the concentration of inherent DOC (r2=0.79, p=0.0031) with EC50s ranging from 27 to 111 μg Cu/L. These laboratory tests have demonstrated that DOC provides glochidia with significant protection from acute Cu toxicity. The potential risk that Cu poses to mussel populations was assessed by comparing Cu and DOC concentrations from significant mussel habitats in Ontario to the EC50s. Although overall mean Cu concentration in the mussel’s habitat was well below the acutely toxic level given the concentration of DOC, episodic Cu releases in low DOC waters may be a concern for the recovery of endangered freshwater mussels. The results are examined in the context of current Cu water quality regulations including the U.S. Environmental Protection Agency’s (U.S. EPA) biotic ligand model
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