4,543 research outputs found
Shot Noise in Gravitational-Wave Detectors with Fabry-Perot Arms
Shot-noise-limited sensitivity is calculated for gravitational-wave interferometers with Fabry–Perot arms, similar to those being installed at the Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Italian–French Laser Interferometer Collaboration (VIRGO) facility. This calculation includes the effect of nonstationary shot noise that is due to phase modulation of the light. The resulting formula is experimentally verified by a test interferometer with suspended mirrors in the 40-m arms
16 x 25 Ge:Ga Detector Arrays for FIFI LS
We are developing two-dimensional 16 x 25 pixel detector arrays of both
unstressed and stressed Ge:Ga photoconductive detectors for far-infrared
astronomy from SOFIA. The arrays, based on earlier 5 x 5 detector arrays used
on the KAO, will be for our new instrument, the Far Infrared Field Imaging Line
Spectrometer (FIFI LS). The unstressed Ge:Ga detector array will cover the
wavelength range from 40 to 120 microns, and the stressed Ge:Ga detector array
from 120 to 210 microns. The detector arrays will be operated with multiplexed
integrating amplifiers with cryogenic readout electronics located close to the
detector arrays. The design of the stressed detector array and results of
current measurements on several prototype 16 pixel linear arrays are reported.
They demonstrate the feasibility of the current concept. ***This paper does not
include Figures due to astro-ph size limitations. Please download entire file
at http://fifi-ls.mpe-garching.mpg.de/spie.det.ps.gz ***Comment: 8 pages, SPIE Proceedings, Astronomical Telescopes and
Instrumentation 200
Consistent Forecasting for the 1980\u27s in State Iron Industry Development
A large-scale model, SIMLAB, was used to project the iron ore industry through the decade of the 1980\u27s for the state of Minnesota. This forecast shows that past trends in the industry are unlikely to continue through 1990, although output is seen to increase slightly during this period. Future studies will deal with different development scenarios to estimate the impacts of alternate future assumptions from this baseline trend analysis
The Economics of Primary School Closings: A Cost Analysis
Because of declining demands for a number of urban public services, public officials have had to make difficult adjustments towards more efficient levels of these services. One such adjustment of very great concern has been the modification of education services in response to declining enrollments. This study investigates the impacts of changing enrollments, enrollment scale, capacity utilization, and age of schools on per student instructional costs and per student cost of land and buildings. The resulting model has been estimated for Duluth, Minnesota primary schools and these regression estimates provide a good explanation for per student instructional costs. The residuals for the per student instructional costs are also examined. These residuals provide an important source of information for making managerial decisions regarding service levels since they indicate which schools are performing above or below cost norms
Electromagnetic multipole theory for optical nanomaterials
Optical properties of natural or designed materials are determined by the
electromagnetic multipole moments that light can excite in the constituent
particles. In this work we present an approach to calculate the multipole
excitations in arbitrary arrays of nanoscatterers in a dielectric host medium.
We introduce a simple and illustrative multipole decomposition of the electric
currents excited in the scatterers and link this decomposition to the classical
multipole expansion of the scattered field. In particular, we find that
completely different multipoles can produce identical scattered fields. The
presented multipole theory can be used as a basis for the design and
characterization of optical nanomaterials
Motional sidebands and direct measurement of the cooling rate in the resonance fluorescence of a single trapped ion
Resonance fluorescence of a single trapped ion is spectrally analyzed using a
heterodyne technique. Motional sidebands due to the oscillation of the ion in
the harmonic trap potential are observed in the fluorescence spectrum. From the
width of the sidebands the cooling rate is obtained and found to be in
agreement with the theoretical prediction.Comment: 4 pages, 4 figures. Final version after minor changes, 1 figure
replaced; to be published in PRL, July 10, 200
Loading a vapor cell magneto-optic trap using light-induced atom desorption
Low intensity white light was used to increase the loading rate of Rb
atoms into a vapor cell magneto-optic trap by inducing non-thermal desorption
of Rb atoms from the stainless steel walls of the vapor cell. An increased Rb
partial pressure reached a new equilibrium value in less than 10 seconds after
switching on the broadband light source. After the source was turned off, the
partial pressure returned to its previous value in times as short as 10
seconds.Comment: 7 pages, 6 figure
Family Socioeconomic Status and Ethnicity, Acculturation and Enculturation, and Parent Beliefs about Child Behavior, Learning Methods, and Parenting Roles
Relationships between family socioeconomic status and ethnicity, acculturation and enculturation, and parent beliefs about desired child behavior, child learning methods, and parenting roles in children’s learning desired behavior were examined in a study of 207 parents of preschoolers from seven ethnic and cultural groups. Different subgroups of participants were identified from patterns of acculturation and enculturation. Family ethnicity, family SES, and acculturation were differentially related to the parent beliefs whereas enculturation and combinations of acculturation and enculturation were unrelated to beliefs. Findings are discussed in terms of the high degree of specificity in the relationships between the predictor variables and parent beliefs about child behavior, learning methods, and parenting roles. The results are consistent with an individual-oriented concept of culture. Cautions are therefore raised in terms of overgeneralizations about attributing traditional beliefs broadly to families from the same ethnic or cultural group
Elektrolyte und renale Enzymausscheidung
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