2,196 research outputs found
The ephemerides of the Earth-Moon barycenter, Venus, Mars, and Mercury considering the Earth and Moon as separate bodies
Ephemerides of Earth-Moon barycenter, Venus, Mars, and Mercury considering Earth and Moon as separate bodie
Self-Consistency in Estimating Future Electrical Energy Consumption
A socio economic computer simulation model for the State of Oregon is described. The Oregon State Simulation Model (OSSIM) includes a thirty-seven sector model of electrical energy consumption. Coupling between this model and the OSSIM ensures self-consistent scenarios of socio economic phenomena which underlie energy consumption. One of the purposes of this effort is to help state-level decision makers understand the determinants of electricity consumption within a context of changing economic conditions
Finite element analysis of the influence of a fatigue crack on magnetic properties of steel
Fatigue can affect the magnetic properties of materials due to microstructural changes. Previous investigations have shown that several structure sensitive magnetic properties, such as coercivityHc and remanenceBr, changed systematically as a result of fatigue. When approaching failure the accumulated changes in microstructure resulted in the occurrence of fatigue cracks and the magnetic properties showed dramatic changes which mainly resulted from the geometrical changes in samples due to the cracks. It was found that the remanenceBr followed the changes in stress, while the coercivityHc sometimes showed different trends. In this article the influence of the size and the position of a fatigue crack on magnetic field and magnetic induction were studied using finite element modeling. Models were constructed to simulate the geometry of the test sample and sensor. It was found that, for a given coil current in the exciting coil, the magnetic induction was mainly determined by the geometry of the crack, while the magnetic field was influenced by both the size and the position of the crack
The Influence of Consumer Price Information on Retail Pricing and Consumer Behavior
Comparative price information for major Ottawa supermarkets was collected over a twenty-eight-week period and published in daily newspapers during a five-week test period. In response to the information, the dispersion of prices across store and chains narrowed, the average level of prices of the market dropped, and consumer satisfaction increased relative to the control market. Consumers transferred patronage to the lower priced stores. Consumers indicated a willingness to pay US$ .34 per week on average for the price comparison information. Estimated consumer benefits far exceeded the cost of the program.competition, consumer benefit, food prices, food retailing, information
Thermal expansion, heat capacity and magnetostriction of RAl (R = Tm, Yb, Lu) single crystals
We present thermal expansion and longitudinal magnetostriction data for cubic
RAl3 (R = Tm, Yb, Lu) single crystals. The thermal expansion coefficient for
YbAl3 is consistent with an intermediate valence of the Yb ion, whereas the
data for TmAl3 show crystal electric field contributions and have strong
magnetic field dependencies. de Haas-van Alphen-like oscillations were observed
in the magnetostriction data of YbAl3 and LuAl3, several new extreme orbits
were measured and their effective masses were estimated. Zero and 140 kOe
specific heat data taken on both LuAl3 and TmAl3 for T < 200 K allow for the
determination of a CEF splitting scheme for TmAl3
A Low Frequency Survey of the Galactic Plane Near l=11 degrees: Discovery of Three New Supernova Remnants
We have imaged a 1 deg^2 field centered on the known Galactic supernova
remnant (SNR) G11.2-0.3 at 74, 330, and 1465 MHz with the Very Large Array
radio telescope (VLA) and 235 MHz with the Giant Metrewave Radio Telescope
(GMRT). The 235, 330, and 1465 MHz data have a resolution of 25 arcsec, while
the 74 MHz data have a resolution of 100 arcsec. The addition of this low
frequency data has allowed us to confirm the previously reported low frequency
turnover in the radio continuum spectra of the two known SNRs in the field:
G11.2-0.3 and G11.4-0.1 with unprecedented precision. Such low frequency
turnovers are believed to arise from free-free absorption in ionized thermal
gas along the lines of site to the SNRs. Our data suggest that the 74 MHz
optical depths of the absorbing gas is 0.56 and 1.1 for G11.2-0.3 and
G11.4-0.1, respectively. In addition to adding much needed low frequency
integrated flux measurements for two known SNRs, we have also detected three
new SNRs: G11.15-0.71, G11.03-0.05, and G11.18+0.11. These new SNRs have
integrated spectral indices between -0.44 and -0.80. Because of confusion with
thermal sources, the high resolution (compared to previous Galactic radio
frequency surveys) and surface brightness sensitivity of our observations have
been essential to the identification of these new SNRs. With this study we have
more than doubled the number of SNRs within just a 1 deg^2 field of view in the
inner Galactic plane. This result suggests that future low frequency
observations of the Galactic plane of similar quality may go a long way toward
alleviating the long recognized incompleteness of Galactic SNR catalogs.Comment: 31 pages, 9 figures. Figure 7 is in color. Accepted to A
Electron-deuteron scattering in a current-conserving description of relativistic bound states: formalism and impulse approximation calculations
The electromagnetic interactions of a relativistic two-body bound state are
formulated in three dimensions using an equal-time (ET) formalism. This
involves a systematic reduction of four-dimensional dynamics to a
three-dimensional form by integrating out the time components of relative
momenta. A conserved electromagnetic current is developed for the ET formalism.
It is shown that consistent truncations of the electromagnetic current and the
interaction kernel may be made, order-by-order in the coupling constants,
such that appropriate Ward-Takahashi identities are satisfied. A meson-exchange
model of the interaction is used to calculate deuteron vertex functions.
Calculations of electromagnetic form factors for elastic scattering of
electrons by deuterium are performed using an impulse-approximation current.
Negative-energy components of the deuteron's vertex function and retardation
effects in the meson-exchange interaction are found to have only minor effects
on the deuteron form factors.Comment: 42 pages, RevTe
Potential use of pyriproxyfen for control of Aedes aegypti (Diptera: Culicidae) in Iquitos, Peru
Los efectos del pyriproxyfen fueron evaluados contra una poblaciĂłn local de Aedes aegypti (L.) en Iquitos, PerĂş. Los bioensayos mostraron que el pyriproxyfen previene la emergencia de adultos con concentraciones extremadamente bajas (LC50 = 0,012 ppb). No hubo emergencia de adultos de las muestras de agua obtenidas de los tanques de almacenamiento que habĂan sido tratados con el equivalente de 50-83 ppb (AI) de pyriproxyfen. Cinco meses despuĂ©s del tratamiento, a pesar de las constantes diluciones de estos tanques, las muestras de agua de estas fuentes continuaron siendo letales para las larvas y pupa
Accelerated seawater ageing and fatigue performance of glass fibre reinforced thermoplastic composites for marine and tidal energy applications
The use of thermoplastic composites as a sustainable alternative to thermosets is gaining increasing popularity due to their improved recyclability at the end of life. The fatigue performance of glass fibre/acrylic, glass fibre/acrylic- polyphenylene ether, and glass fibre/epoxy specimens, under three distinct upper stress levels (R-ratio=0.1; f=5 Hz) was studied. S-N curves were established for these specimens both before and after immersing them for three months in seawater (temperature: 50°C). The dry thermoplastic composites exhibited similar fatigue performance to the thermoset counterpart at higher stress levels, with thermosets showing greater endurance at lower stress levels. Interestingly, the aged specimens showed comparable fatigue endurance, with a slight advantage in favour of the thermoplastic composites and less variability in their data. This study offers important insights into the fatigue performance of thermoplastic composites, emphasising their potential as sustainable alternatives to conventional thermoset composites for various marine applications
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