956 research outputs found
Effects Of Cellulase Supplementation And Wheat Bran On Mineral Utilization In Broilers
In this experiment, 3-week-oId broiler type chicks were assigned to 24 groups of 10 chicks each for two replicates of 12 treatments. A completely randomized experiment with a 4 x 2 factorial arrangement involved feeding 0, 10 or 20% wheat bran or 20% wheat bran plus cellulase. The birds were housed in electrically heated batteries with raised wire floors. Feed and water were supplied ad libitum. The wheat bran was defatted and the cellulase (imported from Boerhinger, Mannheim, Gmn H. W. Germany) was mixed at .008% in the total diet. The enzyme supplementation to the diet was as a dry preparation
Cosmological Parameter Extraction from the First Season of Observations with DASI
The Degree Angular Scale Interferometer (\dasi) has measured the power
spectrum of the Cosmic Microwave Background anisotropy over the range of
spherical harmonic multipoles 100<l<900. We compare this data, in combination
with the COBE-DMR results, to a seven dimensional grid of adiabatic CDM models.
Adopting the priors h>0.45 and 0.0<=tau_c<=0.4, we find that the total density
of the Universe Omega_tot=1.04+/-0.06, and the spectral index of the initial
scalar fluctuations n_s=1.01+0.08-0.06, in accordance with the predictions of
inflationary theory. In addition we find that the physical density of baryons
Omega_b.h^2=0.022+0.004-0.003, and the physical density of cold dark matter
Omega_cdm.h^2=0.14+/-0.04. This value of Omega_b.h^2 is consistent with that
derived from measurements of the primordial abundance ratios of the light
elements combined with big bang nucleosynthesis theory. Using the result of the
HST Key Project h=0.72+/-0.08 we find that Omega_t=1.00+/-0.04, the matter
density Omega_m=0.40+/-0.15, and the vacuum energy density
Omega_lambda=0.60+/-0.15. (All 68% confidence limits.)Comment: 7 pages, 4 figures, minor changes in response to referee comment
Some Effects Of Enzyme Supplementation And Various Wheat Bran Levels In A Broiler Diet On Apparent Digestibility
It is generally recognized that birds do not have an enzyme in their digestive fluid which digests cellulose. However, cellulosic materials are major renewable resources available in large quantities which need to be properly utilized to help meet our needs for energy, chemicals, food and feed for a long-range solution. A variety of lignocellulosic materials containing acid-detergent fibers, are available and microorganisms capable of degrading either one or more of the three main constituents, viz., cellulose, hemicelluose and lignin, have been studied. A further variety of strategies are being explored, including thermal methods of degradation such as pyrolysis or biological methods such as enzymatic hydrolysis and fermentation
DASI Three-Year Cosmic Microwave Background Polarization Results
We present the analysis of the complete 3-year data set obtained with the
Degree Angular Scale Interferometer (DASI) polarization experiment, operating
from the Amundsen-Scott South Pole research station. Additional data obtained
at the end of the 2002 Austral winter and throughout the 2003 season were added
to the data from which the first detection of polarization of the cosmic
microwave background radiation was reported. The analysis of the combined data
supports, with increased statistical power, all of the conclusions drawn from
the initial data set. In particular, the detection of E-mode polarization is
increased to 6.3 sigma confidence level, TE cross-polarization is detected at
2.9 sigma, and B-mode polarization is consistent with zero, with an upper limit
well below the level of the detected E-mode polarization. The results are in
excellent agreement with the predictions of the cosmological model that has
emerged from CMB temperature measurements. The analysis also demonstrates that
contamination of the data by known sources of foreground emission is
insignificant.Comment: 13 pages Latex, 10 figures, submitted to Ap
Archeops: an instrument for present and future cosmology
Archeops is a balloon-borne instrument dedicated to measure the cosmic
microwave background (CMB) temperature anisotropies. It has, in the millimetre
domain (from 143 to 545 GHz), a high angular resolution (about 10 arcminutes)
in order to constrain high l multipoles, as well as a large sky coverage
fraction (30%) in order to minimize the cosmic variance. It has linked, before
WMAP, Cobe large angular scales to the first acoustic peak region. From its
results, inflation motivated cosmologies are reinforced with a flat Universe
(Omega_tot=1 within 3%). The dark energy density and the baryonic density are
in very good agreement with other independent estimations based on supernovae
measurements and big bang nucleosynthesis. Important results on galactic dust
emission polarization and their implications for Planck are also addressed.Comment: 4 pages, 2 figures, to appear in Proceedings of the Multiwavelength
Cosmology Conference, June 2003, Mykonos Island, Greec
The Impact of Atmospheric Fluctuations on Degree-scale Imaging of the Cosmic Microwave Background
Fluctuations in the brightness of the Earth's atmosphere originating from
water vapor are an important source of noise for ground-based instruments
attempting to measure anisotropy in the Cosmic Microwave Background. This paper
presents a model for the atmospheric fluctuations and derives simple
expressions to predict the contribution of the atmosphere to experimental
measurements. Data from the South Pole and from the Atacama Desert in Chile,
two of the driest places on Earth, are used to assess the level of fluctuations
at each site.Comment: 29 pages, 7 figures, 1 table, appears in The Astrophysical Journa
Modulator noise suppression in the LISA Time-Delay Interferometric combinations
We previously showed how the measurements of some eighteen time series of
relative frequency or phase shifts could be combined (1) to cancel the phase
noise of the lasers, (2) to cancel the Doppler fluctuations due to non-inertial
motions of the six optical benches, and (3) to remove the phase noise of the
onboard reference oscillators required to track the photodetector fringes, all
the while preserving signals from passinggravitational waves. Here we analyze
the effect of the additional noise due to the optical modulators used for
removing the phase fluctuations of the onboard reference oscillators. We use a
recently measured noise spectrum of an individual modulator to quantify the
contribution of modulator noise to the first and second-generation Time-Delay
Interferometric (TDI) combinations as a function of the modulation frequency.
We show that modulator noise can be made smaller than the expected proof-mass
acceleration and optical-path noises if the modulation frequencies are larger
than MHz in the case of the unequal-arm Michelson TDI combination
, GHz for the Sagnac TDI combination , and
MHz for the symmetrical Sagnac TDI combination . These
modulation frequencies are substantially smaller than previously estimated and
may lead to less stringent requirements on the LISA's oscillator noise
calibration subsystem.Comment: 17 pages, 5 figures. Submitted to: Phys. Rev. D 1
DASI First Results: A Measurement of the Cosmic Microwave Background Angular Power Spectrum
We present measurements of anisotropy in the Cosmic Microwave Background
(CMB) from the first season of observations with the Degree Angular Scale
Interferometer (DASI). The instrument was deployed at the South Pole in the
austral summer 1999--2000, and made observations throughout the following
austral winter. We have measured the angular power spectrum of the CMB in the
range 100<l<900 with high signal-to-noise. In this paper we review the
formalism used in the analysis, in particular the use of constraint matrices to
project out contaminants such as ground and point source signals, and to test
for correlations with diffuse foreground templates. We find no evidence of
foregrounds other than point sources in the data, and find a maximum likelihood
temperature spectral index beta = -0.1 +/- 0.2 (1 sigma), consistent with CMB.
We detect a first peak in the power spectrum at l approx 200, in agreement with
previous experiments. In addition, we detect a peak in the power spectrum at l
approx 550 and power of similar magnitude at l approx 800 which are consistent
with the second and third harmonic peaks predicted by adiabatic inflationary
cosmological models.Comment: 8 pages, 1 figure, minor changes in response to referee comment
Anisotropy in the Cosmic Microwave Background at Degree Angular Scales: Python V Results
Observations of the microwave sky using the Python telescope in its fifth
season of operation at the Amundsen-Scott South Pole Station in Antarctica are
presented. The system consists of a 0.75 m off-axis telescope instrumented with
a HEMT amplifier-based radiometer having continuum sensitivity from 37-45 GHz
in two frequency bands. With a 0.91 deg x 1.02 deg beam the instrument fully
sampled 598 deg^2 of sky, including fields measured during the previous four
seasons of Python observations. Interpreting the observed fluctuations as
anisotropy in the cosmic microwave background, we place constraints on the
angular power spectrum of fluctuations in eight multipole bands up to l ~ 260.
The observed spectrum is consistent with both the COBE experiment and previous
Python results. There is no significant contamination from known foregrounds.
The results show a discernible rise in the angular power spectrum from large (l
~ 40) to small (l ~ 200) angular scales. The shape of the observed power
spectrum is not a simple linear rise but has a sharply increasing slope
starting at l ~ 150.Comment: 5 page
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