Application of a cost/performance measurement system on a research aircraft project

The fundamentals of the cost/performance management system used in the procurement of two tilt rotor aircraft for a joint NASA/Army research project are discussed. The contractor's reporting system and the GPO's analyses are examined. The use of this type of reporting system is assessed. Recommendations concerning the use of like systems on future projects are included

The inverse problem for rough controlled differential equations

We provide a necessary and sufficient condition for a rough control driving a differential equation to be reconstructable, to some order, from observing the resulting controlled evolution. Physical examples and applications in stochastic filtering and statistics demonstrate the practical relevance of our result.Comment: added section on rough path theor

Transversity Distribution Does Not Contribute to Hard Exclusive Electroproduction of Mesons

We show that in hard exclusive electroproduction, ep-->eVp, the leading-twist hard-scattering coefficient for the production of a transversely polarized vector meson V vanishes to all orders of perturbation theory. This implies that this process cannot be used to measure the skewed transversity distribution of quarks in a hadron. In contrast, a recent calculation obtained a non-zero value at NLO. We show that this calculation is incorrect because it failed to include the necessary collinear subtractions. Our method of proof also applies to other processes whose hard-scattering coefficients are constrained by chirality and helicity conservation, and thus validates helicity selection rules based on these symmetries.Comment: 5 pages, 3 figures, ReVTe

Boundary critical behaviour at mm-axial Lifshitz points: the special transition for the case of a surface plane parallel to the modulation axes

The critical behaviour of $d$-dimensional semi-infinite systems with $n$-component order parameter $\bm{\phi}$ is studied at an $m$-axial bulk Lifshitz point whose wave-vector instability is isotropic in an $m$-dimensional subspace of $\mathbb{R}^d$. Field-theoretic renormalization group methods are utilised to examine the special surface transition in the case where the $m$ potential modulation axes, with $0\leq m\leq d-1$, are parallel to the surface. The resulting scaling laws for the surface critical indices are given. The surface critical exponent $\eta_\|^{\rm sp}$, the surface crossover exponent $\Phi$ and related ones are determined to first order in \epsilon=4+\case{m}{2}-d. Unlike the bulk critical exponents and the surface critical exponents of the ordinary transition, $\Phi$ is $m$-dependent already at first order in $\epsilon$. The \Or(\epsilon) term of $\eta_\|^{\rm sp}$ is found to vanish, which implies that the difference of $\beta_1^{\rm sp}$ and the bulk exponent $\beta$ is of order $\epsilon^2$.Comment: 21 pages, one figure included as eps file, uses IOP style file

The 26^{26}Al Gamma-ray Line from Massive-Star Regions

The measurement of gamma rays from the diffuse afterglow of radioactivity originating in massive-star nucleosynthesis is considered a laboratory for testing models, when specific stellar groups are investigated, at known distance and with well-constrained stellar population. Regions which have been exploited for such studies include Cygnus, Carina, Orion, and Scorpius-Centaurus. The Orion region hosts the Orion OB1 association and its subgroups at about 450~pc distance. We report the detection of $^{26}$Al gamma rays from this region with INTEGRAL/SPI.Comment: Contribution to Symposium "Nuclei in the Cosmos XIV", Niigata, Japan, Jun 2016; 3 pages, 2 figures; accepted for publication in JPS (Japan Physical Society) Conference Proceedings http://jpscp.jps.jp

Charge Density of the Neutron

A model-independent analysis of the infinite-momentum-frame charge density of partons in the transverse plane is presented for the nucleon. We find that the neutron parton charge density is negative at the center, so that the square of the transverse charge radius is positive, in contrast with many expectations. Additionally, the proton's central u quark charge density is larger than that of the d quark by about 70 %. The proton (neutron) charge density has a long range positively (negatively) charged component.Comment: 7 pages, three figures The replacement mainly concerns correcting an error made in computing the proton up and down quark densities from the correctly computed proton and neutron charge densities. The proton central u quark density is now larger than that of the d quar

Gaseous exhaust emissions from a JT8D-109 turbofan engine at simulated cruise flight conditions

Gaseous emissions from a JT8D-109 turbofan engine were measured in an altitude facility at four simulated cruise flight conditions: Mach 0.8 at altitudes of 9.1, 10, 7, and 12.2 km and Mach 0.9 at 10.7 km. Engine inlet air temperature was held constant at 283 K for all tests. Emissions measurements were made at nominally 6 cm intervals across the horizontal diameter of the engine exhaust nozzle with a single-point traversing gas sample probe. Measured emissions of decreased with increasing altitude from an emission index of 10.4 to one of 8.3, while carbon monoxide increased with increasing altitude from an emission index of 1.6 to one of 4.4. Unburned hydrocarbon emissions were essentially negligible for all flight conditions. Since the engine inlet air temperatures were not correctly simulated, the NOx emission indices were corrected to true altitude conditions by using correlating parameters for changes in combustor inlet temperature, pressure, and temperature rise. The correction was small at the lowest altitude. At the 10.7 and 12.2 km, Mach 0.8 test conditions the correction decreased the measured values by 1 emission index

Measurement of gaseous emissions from a turbofan engine at simulated altitude conditions

Gaseous emission from a TFE 731-2 turbofan engine were measured over a range of fuel-air ratios from idle to full power at simulated from near sea level to 13,200 m. Carbon monoxide and unburned hydrocarbon emissions were highest at idle and lowest at high power settings; oxides of nitrogen exhibited the reverse trend. Carbon monoxide and unburned hydrocarbon levels decreased with increasing altitude. Oxides of nitrogen emissions were successfully correlated by a parametric group of combustor operating variables

Swirl-can combustor performance to near-stoichiometric fuel-air ratio

Emissions and performance characteristics were determined for full-annulus swirl-can modular combustors operated to near stoichiometric fuel air ratios. The purposes of the tests were to obtain stoichiometric data at inlet air temperatures up to 894 K and to determine the effect of module number by investigating 120 and 72 module swirl-can combustors. The maximum average exit temperature obtained with the 120-module swirl-can combustor was 2465 K with a combustion efficiency of 95 percent at an inlet-air temperature of 894 K. The 72-module swirl-can combustor reached a maximum average exit temperature of 2306 K with a combustion efficiency of 92 percent at an inlet air temperature of 894 K. At a constant inlet air temperature, maximum oxides of nitrogen emission index values occurred at a fuel-air ratio of 0.037 for the 72-module design and 0.044 for the 120-module design. The combustor average exit temperature and combustion efficiency were calculated from emissions measurements. The measured emissions included carbon monoxide, unburned hydrocarbons, oxides of nitrogen, and smoke