Preliminary test results of a flight management algorithm for fuel conservative descents in a time based metered traffic environment

A flight management algorithm designed to improve the accuracy of delivering the airplane fuel efficiently to a metering fix at a time designated by air traffic control is discussed. The algorithm provides a 3-D path with time control (4-D) for a test B 737 airplane to make an idle thrust, clean configured descent to arrive at the metering fix at a predetermined time, altitude, and airspeed. The descent path is calculated for a constant Mach/airspeed schedule from linear approximations of airplane performance with considerations given for gross weight, wind, and nonstandard pressure and temperature effects. The flight management descent algorithms and the results of the flight tests are discussed

Development and test results of a flight management algorithm for fuel conservative descents in a time-based metered traffic environment

A simple flight management descent algorithm designed to improve the accuracy of delivering an airplane in a fuel-conservative manner to a metering fix at a time designated by air traffic control was developed and flight tested. This algorithm provides a three dimensional path with terminal area time constraints (four dimensional) for an airplane to make an idle thrust, clean configured (landing gear up, flaps zero, and speed brakes retracted) descent to arrive at the metering fix at a predetermined time, altitude, and airspeed. The descent path was calculated for a constant Mach/airspeed schedule from linear approximations of airplane performance with considerations given for gross weight, wind, and nonstandard pressure and temperature effects. The flight management descent algorithm is described. The results of the flight tests flown with the Terminal Configured Vehicle airplane are presented

Towards Rapid Parameter Estimation on Gravitational Waves from Compact Binaries using Interpolated Waveforms

Accurate parameter estimation of gravitational waves from coalescing compact binary sources is a key requirement for gravitational-wave astronomy. Evaluating the posterior probability density function of the binary's parameters (component masses, sky location, distance, etc.) requires computing millions of waveforms. The computational expense of parameter estimation is dominated by waveform generation and scales linearly with the waveform computational cost. Previous work showed that gravitational waveforms from non-spinning compact binary sources are amenable to a truncated singular value decomposition, which allows them to be reconstructed via interpolation at fixed computational cost. However, the accuracy requirement for parameter estimation is typically higher than for searches, so it is crucial to ascertain that interpolation does not lead to significant errors. Here we provide a proof of principle to show that interpolated waveforms can be used to recover posterior probability density functions with negligible loss in accuracy with respect to non-interpolated waveforms. This technique has the potential to significantly increase the efficiency of parameter estimation.Comment: 7 pages, 2 figure

MUSE Illuminates Channels for Lyman Continuum Escape in the Halo of SBS 0335-52E

We report on the discovery of ionised gas filaments in the circum-galactic halo of the extremely metal-poor compact starburst SBS 0335-052E in a 1.5h integration with the MUSE integral-field spectrograph. We detect these features in H${\alpha}$ and [OIII] emission down to surface-brightness levels of $5 \times 10^{-19}$erg s$^{-1}$cm$^{-2}$arcsec$^{-2}$. The filaments have projected diameters of 2.1 kpc and extend more than 9 kpc to the north and north-west from the main stellar body. We also detect extended nebular HeII $\lambda$4686 emission that brightens towards the north-west at the rim of a star-burst driven super-shell, suggestive of a locally enhanced UV radiation field due to shocks. We also present a velocity field of the ionised gas. The filaments appear to connect seamlessly in velocity space to the kinematical disturbances caused by the shell. Similar to high-$z$ star-forming galaxies, the ionised gas in this galaxy is dispersion dominated. We argue that the filaments were created via feedback from the starburst and that these ionised structures in the halo may act as escape channels for Lyman continuum radiation in this gas-rich system.Comment: Revised version after peer review. Accepted for publication in A&A letter

Localizing gravitational wave sources with optical telescopes and combining electromagnetic and gravitational wave data

Neutron star binaries, which are among the most promising sources for the direct detection of gravitational waves (GW) by ground based detectors, are also potential electromagnetic (EM) emitters. Gravitational waves will provide a new window to observe these events and hopefully give us glimpses of new astrophysics. In this paper, we discuss how EM information of these events can considerably improve GW parameter estimation both in terms of accuracy and computational power requirement. And then in return how GW sky localization can help EM astronomers in follow-up studies of sources which did not yield any prompt emission. We discuss how both EM source information and GW source localization can be used in a framework of multi-messenger astronomy. We illustrate how the large error regions in GW sky localizations can be handled in conducting optical astronomy in the advance detector era. We show some preliminary results in the context of an array of optical telescopes called BlackGEM, dedicated for optical follow-up of GW triggers, that is being constructed in La Silla, Chile and is expected to operate concurrent to the advanced GW detectors.Comment: 8 pages, 8 figures, Proceeding for Sant Cugat Forum for Astrophysic

Normal growth in dairy cattle

Male calves of all the breeds studied weighed more at birth than female calves. The birth weights of female calves were as follows: Holsteins, 89 pounds; Guernseys, 65 pounds; Ayrshires, 63 pounds; and Jerseys, 50 pounds. There was considerable variation among individuals in their live weights. Coefficients of variation ranged from above 15 percent in calves to less than 10 percent in 2-year old heifers. The data show that the time of first freshening marks the greatest change in the rate of growth in live weight. Very little difference can be observed in the relative rates at which animals of the different breeds approach mature size. Mature growth values are approached most rapidly in height at withers. This measurement is not even doubled from birth to maturity. Holsteins, Ayrshires and Jerseys are wider in relation to depth than Guernseys. The average weight for mature Holsteins in the Iowa Experiment Station herd may be considered as 1,405 pounds; Ayrshires, 1,111 pounds; Guernseys, 1,072 pounds; and Jerseys, 950 pounds. Gestation and lactation are shown to have considerable influence upon live weight. Late freshening heifers weigh more than heifers calving at the usual time but after freshening the weights of both groups are quite comparable

If Hay Mows Are Empty

Dairy cows fed plenty of silage, properly balanced with a grain mixture, will produce just as well and keep in as good condition as those fed both alfalfa hay and silage as roughage. In other words, apparently cows do not need a dry roughage along with silage

Superlattice with hot electron injection: an approach to a Bloch oscillator

A semiconductor superlattice with hot electron injection into the miniband is considered. The injection changes the stationary distribution function and results in a qualitative change of the frequency behaviour of the differential conductivity. In the regime with Bloch oscillating electrons and injection into the upper part of the miniband the region of negative differential conductivity is shifted from low frequencies to higher frequencies. We find that the dc differential conductivity can be made positive and thus the domain instability can be suppressed. At the same time the high-frequency differential conductivity is negative above the Bloch frequency. This opens a new way to make a Bloch oscillator operating at THz frequencies.Comment: RevTeX, 8 pages, 2 figures, to be published in Phys. Rev. B, 15 Januar 200

The use of water bowls in the dairy barn

1. Dairy cows, watered by means of water bowls, drank approximately 18 percent more water and yielded 3.5 percent more milk and 10.7 percent more butterfat than cows that were watered twice per day at an outside tank. 2. Cows watered with water bowls drank an average of about 10 times in each 24 hours. Approximately two-thirds of the water was consumed in the daytime, that is between 5 a. m. and 5 p. m., and the other one-third at night. 3. Cows watered at the outside tank frequently drank but once per day. This occurred about 30 percent of the times the cows were offered water. This refusal to drink more than once per day was distributed among all of the cows, although certain cows showed a greater disposition to drink but once per day than did others. The inclination to drink but once per day was not consistently correlated with the quantity of milk yielded. 4. One unusual observation was that when the cows were watered with water bowls, they usually yielded not only more milk but milk containing a higher percentage of butterfat. A mathematical treatment of the data shows that the probability is only about 4 in 100 that a result as large and consistent could have come by chance alone. 5. The temperature of the water apparently did not influence the water consumption as greatly as did atmospheric temperature. The relative consumption of water increased as temperature rose