3,123 research outputs found
DSTP-AN: A Distributed System for Transaction Processing Based on Data Resource Migration in ATM Networks
The dynamic migration of data resources has become a strong tool for transaction processing in broadband networks such as ATM. In this paper, a distributed system that takes advantage of data resource migration for transaction processing in ATM networks has been proposed. The proposed system provides mechanisms to select the transaction processing method, to migrate data resources in a way that reduces the time delay and message traffic in locating and accessing them. The first mechanism selects one of the two transaction processing methods: the traditional method that uses two phase commit protocol and other new method based on data resource migration. The second mechanism attempts to improve performance by making each site follow a local policy for directing requests to locate and access data resources as well as migrating them through the system. For this, a new scheme that focuses on reducing the time delay and message traffic needed to access the migratory data resources is proposed. The performance of the proposed scheme has also been evaluated and compared with one of the existing schemes by a simulation study under different system parameters such as frequency of access to the data resources, frequency of data resource migrations, scale of network, etc
Bacteriological examination of drinking water in Burdwan, India with reference to coliforms
Most probable number (MPN) test was done to detect the coliform in water samples collected from mobile vendors, sweet shops and tap water supplied from Burdwan municipality. The study revealed that the number of coliforms was very high (1600) in water samples collected from mobile vendors. The bacteria were identified as Escherichia coli. Bacteriological examination of water samples collected from different sources showed that the water of mobile vendors and sweet shops of Burdwan marketarea was not potable while the municipal tap water was found to be safe for drinking
Dielectric and Raman studies of Ba-0.06(Na1/2Bi1/2)(0.94)TiO3-NaNbO3 ceramics
In this work the X-ray diffraction, scanning electron microscopy, Raman and dielectric studies of lead free perovskite (1-x)Ba-0.06(Na1/2Bi1/2)(0.94)TiO3-xNaNbO(3) (0 <= x <= 1.0) ceramics, prepared using a standard solid state reaction method, were investigated. X-ray diffraction studies of all the ceramics suggested the formation of single phase with crystal structure transforming from rhombohedral-tetragonal to orthorhombic symmetry with the increase in NaNbO3 content. Raman spectra also confirmed the formation of solid solution without any new phase. Dielectric studies showed that the phase transition is of diffusive character and diffusivity parameter decreases with increasing NaNbO3 content. The compositional fluctuation was considered to be the main cause of diffusivity
Systematic study of the effect of short range correlations on the form factors and densities of s-p and s-d shell nuclei
Analytical expressions of the one- and two-body terms in the cluster
expansion of the charge form factors and densities of the s-p and s-d shell
nuclei with N=Z are derived. They depend on the harmonic oscillator parameter b
and the parameter which originates from the Jastrow correlation
function. These expressions are used for the systematic study of the effect of
short range correlations on the form factors and densities and of the mass
dependence of the parameters b and . These parameters have been
determined by fit to the experimental charge form factors. The inclusion of the
correlations reproduces the experimental charge form factors at the high
momentum transfers (). It is found that while the parameter
is almost constant for the closed shell nuclei, He, O and
Ca, its values are larger (less correlated systems) for the open shell
nuclei, indicating a shell effect in the closed shell nuclei.Comment: Latex, 21 pages, 6 figures, 1 tabl
Factors affecting greenhouse microclimate and its regulating techniques: a review
This paper reviews factors affecting greenhouse microclimate and its regulating techniques towards upgrading the greenhouse applications in the area of southeast China which have little or very basic technology integration. The microclimate of greenhouse is apparently influenced by the shape and its orientation, the wind direction, the property of covering material, and the use of insect-proof screen as they eventually affect the total solar radiation, the thermal characterises, and the flow pattern inside. The natural ventilation and sun block are the most common method to cool the greenhouse, but more efficient evaporative cooling such as pad-fan system, misting/fogging system and roof sprinkler are required with extreme temperatures. The earth to air heat exchanger and the heat storage using phase change material may be used for heating or cooling throughout the year which are more economic and energy-saving than other traditional thermal technologies. The reviewed knowledge provides insights into upgrading greenhouse applications in Ningbo area towards more sustainable and efficient greenhouse farming
The complex light-curve of the afterglow of GRB071010A
We present and discuss the results of an extensive observational campaign
devoted to GRB071010A, a long-duration gamma-ray burst detected by the Swift
satellite. This event was followed for almost a month in the
optical/near-infrared (NIR) with various telescopes starting from about 2min
after the high-energy event. Swift-XRT observations started only later at about
0.4d. The light-curve evolution allows us to single out an initial rising phase
with a maximum at about 7min, possibly the afterglow onset in the context of
the standard fireball model, which is then followed by a smooth decay
interrupted by a sharp rebrightening at about 0.6d. The rebrightening was
visible in both the optical/NIR and X-rays and can be interpreted as an episode
of discrete energy injection, although various alternatives are possible. A
steepening of the afterglow light curve is recorded at about 1d. The entire
evolution of the optical/NIR afterglow is consistent with being achromatic.
This could be one of the few identified GRB afterglows with an achromatic break
in the X-ray through the optical/NIR bands. Polarimetry was also obtained at
about 1d, just after the rebrightening and almost coincident with the
steepening. This provided a fairly tight upper limit of 0.9% for the
polarized-flux fraction.Comment: 11 pages, 3 figures, MNRAS, in pres
The complex light-curve of the afterglow of GRB071010A
We present and discuss the results of an extensive observational campaign
devoted to GRB071010A, a long-duration gamma-ray burst detected by the Swift
satellite. This event was followed for almost a month in the
optical/near-infrared (NIR) with various telescopes starting from about 2min
after the high-energy event. Swift-XRT observations started only later at about
0.4d. The light-curve evolution allows us to single out an initial rising phase
with a maximum at about 7min, possibly the afterglow onset in the context of
the standard fireball model, which is then followed by a smooth decay
interrupted by a sharp rebrightening at about 0.6d. The rebrightening was
visible in both the optical/NIR and X-rays and can be interpreted as an episode
of discrete energy injection, although various alternatives are possible. A
steepening of the afterglow light curve is recorded at about 1d. The entire
evolution of the optical/NIR afterglow is consistent with being achromatic.
This could be one of the few identified GRB afterglows with an achromatic break
in the X-ray through the optical/NIR bands. Polarimetry was also obtained at
about 1d, just after the rebrightening and almost coincident with the
steepening. This provided a fairly tight upper limit of 0.9% for the
polarized-flux fraction.Comment: 11 pages, 3 figures, MNRAS, in pres
- …