103,897 research outputs found
Multivectorial strategy to interpret a resistive behaviour of loads in smart buildings
In Smart buildings, electric loads are affected by an
important distortion in the current and voltage waveforms,
caused by the increasing proliferation of non linear electronic
devices. This paper presents an approach on non sinusoidal
power theory based on Geometric Algebra that clearly improves
traditional methods in the optimization of apparent power and
power factor compensation. An example is included that
demonstrates the superiority of this approach compared with
traditional methods.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
A new intermediate mass protostar in the Cepheus A HW2 region
We present the discovery of the first molecular hot core associated with an
intermediate mass protostar in the CepA HW2 region. The hot condensation was
detected from single dish and interferometric observations of several high
excitation rotational lines (from 100 to 880K above the ground state) of SO2 in
the ground vibrational state and of HC3N in the vibrationally excited states
v7=1 and v7=2. The kinetic temperature derived from both molecules is 160K. The
high-angular resolution observations (1.25'' x 0.99'') of the SO2
J=28(7,21)-29(6,24) line (488K above the ground state) show that the hot gas is
concentrated in a compact condensation with a size of 0.6''(430AU), located
0.4'' (300AU) east from the radio-jet HW2. The total SO2 column density in the
hot condensation is 10E18cm-2, with a H2 column density ranging from 10E23 to 6
x 10E24cm-2. The H2 density and the SO2 fractional abundance must be larger
than 10E7cm-3 and 2 x 10E-7 respectively. The most likely alternatives for the
nature of the hot and very dense condensation are discussed. From the large
column densities of hot gas, the detection of the HC3N vibrationally excited
lines and the large SO2 abundance, we favor the interpretation of a hot core
heated by an intermediate mass protostar of 10E3 Lo. This indicates that the
CepA HW2 region contains a cluster of very young stars
COMPARING THE IMPACTS OF RETIREE VERSUS WORKING-AGE FAMILIES ON A SMALL RURAL REGION: AN APPLICATION OF THE WISCONSIN ECONOMIC IMPACT MODELING SYSTEM
The Wisconsin Economic Impact Modeling System, a conjoined input-output/econometric model of Wisconsin counties, is used to simulate the economic and fiscal impact of two alternative residential development patterns. Under the first scenario, the impact of migrating retirees on a small tri-county region in northern Wisconsin is examined. Under the second scenario, the impact of the migration of younger families with children is examined. A comparison-contrast between the two scenarios demonstrates that the characteristics of the migrating household can have a significant impact on the nature of the impacts.Community/Rural/Urban Development,
THE IMPACT OF THE YOUNG-OLD AND THE OLD-OLD ON A SMALL RURAL REGION: AN APPLICATION OF THE WISCONSIN ECONOMIC IMPACT MODELING SYSTEM
The literature on the economic and fiscal impacts of in-migrating retirees on rural communities concentrates on the young, newly-retired. An issue not systematically addressed are the impacts on the communities as these retirees age. The Wisconsin Economic Impact Modeling System, a county level conjoined input-output/econometrics simulation model, is used to assess the impact of an aging rural population. Using data from the US Bureau of Labor Statistics' Consumer Expenditure Survey, profiles of two household types are constructed and used to simulate the economic impact of an additional 500 elderly households into a small rural economy. Household types vary by age and, as a result, have different income levels and expenditure patterns. As hypothesized, the magnitude and nature of impacts is in direct proportion to relative household size and income level.aging, economic impacts, development policy, Community/Rural/Urban Development,
A common garden design reveals population-specific variability in potential impacts of hybridisation between populations of farmed and wild Atlantic salmon, Salmo salar L
Released individuals can have negative impacts on native populations through various mechanisms; including competition, disease transfer and introduction of maladapted gene-complexes. Previous studies indicate that the level of farmed Atlantic salmon introgression in native populations is population-specific. However few studies have explored the potential role of population diversity or river characteristics, such as temperature, on the consequences of hybridisation. We compared freshwater growth of multiple families derived from two farmed, five wild, and two F1 hybrid salmon populations at three contrasting temperatures (7°C, 12°C, and 16°C) in a common garden experiment. As expected, farmed salmon outgrew wild salmon at all temperatures, with hybrids displaying intermediate growth. However, differences in growth were population-specific and some wild populations performed better than others relative to the hybrid and farmed populations at certain temperatures. Therefore, the competitive balance between farmed and wild salmon may depend both on the thermal profile of the river and the genetic characteristics of the respective farmed and wild strains. While limited to F1 hybridisation, the present study shows the merits in adopting a more complex spatially resolved approach to risk management of local populations
Spectroscopy of a narrow-line laser cooling transition in atomic dysprosium
The laser cooling and trapping of ultracold neutral dysprosium has been
recently demonstrated using the broad, open 421-nm cycling transition.
Narrow-line magneto-optical trapping of Dy on longer wavelength transitions
would enable the preparation of ultracold Dy samples suitable for loading
optical dipole traps and subsequent evaporative cooling. We have identified the
closed 741-nm cycling transition as a candidate for the narrow-line cooling of
Dy. We present experimental data on the isotope shifts, the hyperfine constants
A and B, and the decay rate of the 741-nm transition. In addition, we report a
measurement of the 421-nm transition's linewidth, which agrees with previous
measurements. We summarize the laser cooling characteristics of these
transitions as well as other narrow cycling transitions that may prove useful
for cooling Dy.Comment: 6+ pages, 5 figures, 5 table
- …
