2,951 research outputs found
Flexible temperature probe for biological systems
Probe is sufficiently flexible so that it can be worn comfortably for long periods of time, but relatively rigid to permit easy insertion. Body and electrical leads of small thermistor are imbedded in flexible fluorosilicone matrix contained in vinyl plastic tubing
Contact values of the particle-particle and wall-particle correlation functions in a hard-sphere polydisperse fluid
The contact values of the radial distribution functions
of a fluid of (additive) hard spheres with a given size distribution
are considered. A ``universality'' assumption is introduced,
according to which, at a given packing fraction ,
, where is a common function
independent of the number of components (either finite or infinite) and
is a
dimensionless parameter, being the -th moment of the diameter
distribution. A cubic form proposal for the -dependence of is made and
known exact consistency conditions for the point particle and equal size
limits, as well as between two different routes to compute the pressure of the
system in the presence of a hard wall, are used to express in terms of
the radial distribution at contact of the one-component system. For
polydisperse systems we compare the contact values of the wall-particle
correlation function and the compressibility factor with those obtained from
recent Monte Carlo simulations.Comment: 9 pages, 7 figure
Cosmology with minimal length uncertainty relations
We study the effects of the existence of a minimal observable length in the
phase space of classical and quantum de Sitter (dS) and Anti de Sitter (AdS)
cosmology. Since this length has been suggested in quantum gravity and string
theory, its effects in the early universe might be expected. Adopting the
existence of such a minimum length results in the Generalized Uncertainty
Principle (GUP), which is a deformed Heisenberg algebra between minisuperspace
variables and their momenta operators. We extend these deformed commutating
relations to the corresponding deformed Poisson algebra in the classical limit.
Using the resulting Poisson and Heisenberg relations, we then construct the
classical and quantum cosmology of dS and Ads models in a canonical framework.
We show that in classical dS cosmology this effect yields an inflationary
universe in which the rate of expansion is larger than the usual dS universe.
Also, for the AdS model it is shown that GUP might change the oscillatory
nature of the corresponding cosmology. We also study the effects of GUP in
quantized models through approximate analytical solutions of the Wheeler-DeWitt
(WD) equation, in the limit of small scale factor for the universe, and compare
the results with the ordinary quantum cosmology in each case.Comment: 11 pages, 4 figures, to appear in IJMP
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Optimal Policy Derivation for Transmission Duty-Cycle Constrained LPWAN
Low-power wide-area network (LPWAN) technologies enable Internet of Things (IoT) devices to efficiently and robustly communicate over long distances, thus making them especially suited for industrial environments. However, the stringent regulations on the usage of certain industrial, scientific, and medical bands in many countries in which LPWAN operate limit the amount of time IoT motes can occupy the shared bands. This is particularly challenging in industrial scenarios, where not being able to report some detected events might result in the failure of critical assets. To alleviate this, and by mathematically modeling LPWAN-based IoT motes, we have derived optimal transmission policies that maximize the number of reported events (prioritized by their importance) while still complying with current regulations. The proposed solution has been customized for two widely known LPWAN technologies: 1) LoRa and 2) Sigfox. Analytical results reveal that our solution is feasible and performs remarkably close to the theoretical limit for a wide range of network activity patterns
Catching and rearing postlarval cleaner shrimp for the aquarium trade: results from a WorldFish Center project in Solomon Islands
Between 1999 and 2003, the WorldFish Center in Solomon Islands conducted research into the feasibility of a new fishery based on the capture and culture of postlarval coral reef fish for the live fish trade. The work was carried out in two phases: a research phase from late 1999 to the end of 2002; and a “finetuning” phase in 2003. Most of the species were of value to the marine aquarium trade, with very few live reef food fish recorded. The most valuable ornamentals were the banded cleaner shrimp, Stenopus species. Cleaner shrimp were harvested using crest nets, the method being modified with the addition of a solid, water-retaining cod-end designed to increase survival at capture. Grow-out techniques were improved by rearing the shrimp separately in jars to prevent aggression. The jars were painted black to protect the shrimp from sunlight. An economic model using experimental catch data and farm gate prices indicates that the fishery based on shrimp, supplemented with small numbers of lobster and fish is economically viable. The next step will be setting up a demonstration farm in a village in the Western Province of Solomon Islands.Aquarium culture, Juveniles, Catch culture, Shrimp fisheries, Catch/effort, Solomon I., Stenopus
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