Flight data display studies for real time computer flight evaluation Final report

Real time displays for in-flight monitoring of Saturn launch vehicle

Multi-level study of C3H2: The first interstellar hydrocarbon ring

Cyclic species in the interstellar medium have been searched for almost since the first detection of interstellar polyatomic molecules. Eleven different C3H2 rotational transitions were detected; 9 of which were studied in TMC-1, a nearby dark dust cloud, are shown. The 1 sub 10 yields 1 sub 01 and 2 sub 20 yields 2 sub 11 transitions were observed with the 43 m NRAO telescope, while the remaining transitions were detected with the 14 m antenna of the Five College Radio Observatory (FCRAO). The lines detected in TMC-1 have energies above the ground state ranging from 0.9 to 17.1 K and consist of both ortho and para species. Limited maps were made along the ridge for several of the transitions. The HC3N J = 2 yields 1 transition were mapped simultaneously with the C3H2 1 sub 10 yields 1 sub 01 line and therefore can compare the distribution of this ring with a carbon chain in TMC-1. C3H2 is distributed along a narrow ridge with a SE - NW extension which is slightly more extended than the HC2N J = 2 yields 1. Gaussian fits gives a FWHP extension of 8'5 for C3H2 while HC3N has a FWHP of 7'. The data show variations of the two velocity components along the ridge as a function of transition. Most of the transitions show a peak at the position of strongest HC3N emission while the 2 sub 21 yields 2 sub 10 transition shows a peak at the NH3 position

Magnetic Fields in Star-Forming Molecular Clouds I. The First Polarimetry of OMC-3 in Orion A

The first polarimetric images of the OMC-3 region of the Orion A filamentary molecular cloud are presented. Using the JCMT, we have detected polarized thermal emission at 850 microns from dust along a 6' length of the dense filament. The polarization pattern is highly ordered and is aligned with the filament throughout most of the region. The plane-of-sky magnetic field direction is perpendicular to the measured polarization. The mean percentage polarization is 4.2% with a 1 sigma dispersion of 1%. This region is part of the integral-shaped filament, and active star formation is ongoing along its length. The protostellar outflow directions do not appear to be consistently correlated with the direction of the plane-of-sky field or the filament structure itself. Depolarization toward the filament center, previously detected in many other star-forming cores and protostars, is also evident in our data. (abstract abridged)Comment: 9 pages plus 2 figures (1 colour); accepted for publication in the March 10, 2000 issue (vol. 531 #2) of The Astrophysical Journa

Heat transfer investigation of Langley Research Center transition models at a Mach number of 8, volume 2

The results are presented of a wind tunnel test program to determine aerodynamic heat transfer distributions on delta body and straight body transition models of the space shuttle. Heat transfer rates were determined by the phase-change paint technique on Stycast and RTV models using Tempilag as the surface temperature indicator. The nominal test conditions were: Mach 8, length Reynolds numbers of 5 million and 7.4 million, and angles of attack of 20, 40, and 60 deg. Model details, test conditions, and reduced heat transfer data are included. Data reduction of the phase-change paint photographs was performed by utilizing a new technique

Growth adaptation to temperature in N. crassa wild-type strains

Growth adaptation to temperature in N. crassa wild-type strain

Kinetic and Spectroscopic Characterization of the H178A Methionyl Aminopeptidase from \u3cem\u3eEscherichia coli\u3c/em\u3e

To gain insight into the role of the strictly conserved histidine residue, H178, in the reaction mechanism of the methionyl aminopeptidase from Escherichia coli (EcMetAP-I), the H178A mutant enzyme was prepared. Metal-reconstituted H178A binds only one equivalent of Co(II) or Fe(II) tightly with affinities that are identical to the WT enzyme based on kinetic and isothermal titration calorimetry (ITC) data. Electronic absorption spectra of Co(II)-loaded H178A EcMetAP-I indicate that the active site divalent metal ion is pentacoordinate, identical to the WT enzyme. These data indicate that the metal binding site has not been affected by altering H178. The effect of altering H178 on activity is, in general, due to a decrease in kcat. The kcat value for Co(II)-loaded H178A decreased 70-fold toward MGMM and 290-fold toward MP-p-NA compared to the WT enzyme, while kcat decreased 50-fold toward MGMM for the Fe(II)-loaded H178A enzyme and 140-fold toward MP-p-NA. The Km values for MGMM remained unaffected, while those for MP-p-NA increased approximately 2-fold for Co(II)- and Fe(II)-loaded H178A. The kcat/Km values for both Co(II)- and Fe(II)-loaded H178A toward both substrates ranged from ∼50- to 580-fold reduction. The pH dependence of log Km, log kcat, and log(kcat/Km) of both WT and H178A EcMetAP-I were also obtained and are identical, within error, for H178A and WT EcMetAP-I. Therefore, H178A is catalytically important but is not required for catalysis. Assignment of one of the observed pKa values at 8.1 for WT EcMetAP-I was obtained from plots of molar absorptivity at λmax(640) vs pH for both WT and H178A EcMetAP-I. Apparent pKa values of 8.1 and 7.6 were obtained for WT and H178A EcMetAP-I, respectively, and were assigned to the deprotonation of a metal-bound water molecule. The data reported herein provide support for the key elements of the previously proposed mechanism and suggest that a similar mechanism can apply to the enzyme with a single metal in the active site

The reverberation signatures of rotating disc winds in active galactic nuclei

The broad emission lines (BELs) in active galactic nuclei (AGN) respond to ionizing continuum variations. The time and velocity dependence of their response depends on the structure of the broad-line region: its geometry, kinematics and ionization state. Here, we predict the reverberation signatures of BELs formed in rotating accretion disc winds. We use a Monte Carlo radiative transfer and ionization code to predict velocity-delay maps for representative high- (C$~IV$) and low-ionization (H$\alpha$) emission lines in both high- and moderate-luminosity AGN. Self-shielding, multiple scattering and the ionization structure of the outflows are all self-consistently taken into account, while small-scale structure in the outflow is modelled in the micro-clumping approximation. Our main findings are: (1) The velocity-delay maps of smooth/micro-clumped outflows often contain significant negative responses. (2)~The reverberation signatures of disc wind models tend to be rotation dominated and can even resemble the classic "red-leads-blue" inflow signature. (3) Traditional "blue-leads-red" outflow signatures can usually only be observed in the long-delay limit. (4) Our models predict lag-luminosity relationships similar to those inferred from observations, but systematically underpredict the observed centroid delays. (5) The ratio between "virial product" and black hole mass predicted by our models depends on viewing angle. Our results imply that considerable care needs to be taken in interpreting data obtained by observational reverberation mapping campaigns. In particular, basic signatures such as "red-leads-blue", "blue-leads-red" and "blue and red vary jointly" are not always reliable indicators of inflow, outflow or rotation. This may help to explain the perplexing diversity of such signatures seen in observational campaigns to date.Comment: 15 pages, 17 figures, 2 tables. Accepted by MNRAS 20/7/201

Feeding of Conserved Forage - Implications to Grassland Management and Production

This review will focus on the use of conserved forages in pastoral dairy farm systems; especially on their conservation as an aid to good grazing management during periods of rapid pasture growth, and on their consumption as an aid to good feeding management and grazing management during periods of slow pasture growth. Conservation of pasture, in order to move it from one time to another later time, always involves “costs”, either financial expenditure or physical losses (of dry matter/quality) or both, which must be evaluated in the whole system. Most of the data is drawn from New Zealand and Australia, with some from England and Ireland. The topic has been reviewed before (e.g. Rogers, 1984 and 1985; Leaver, 1985; Phillips, 1988; Mayne, 1991; Stockdale et al., 1997), but the present review will put greater emphasis on the effects on pasture management and on the whole pastoral system, and on recent results, because the cows’ ability to respond to supplementary feeds is now larger than it used to be, as a result of steady genetic improvement in milk producing capacities. In recent years there has been marked increase in supplement use on pasture based dairy farming systems in New Zealand often driven by perceived limitations to production increases in existing systems rather than profit (Attrill and Miller 1996). This review attempts to identify, and discuss, the factors involved in supplementary feeding (i.e. the responses of cows and farming systems to extra feed) to enable sustainable increases in productivity and profitability on pastoral based systems