Timelike and Spacelike Matter Inheritance Vectors in Specific Forms of Energy-Momentum Tensor

This paper is devoted to the investigation of the consequences of timelike and spacelike matter inheritance vectors in specific forms of energy-momentum tensor, i.e., for string cosmology (string cloud and string fluid) and perfect fluid. Necessary and sufficient conditions are developed for a spacetime with string cosmology and perfect fluid to admit a timelike matter inheritance vector, parallel to $u^a$ and spacelike matter inheritance vector, parallel to $x^a$. We compare the outcome with the conditions of conformal Killing vectors. This comparison provides us the conditions for the existence of matter inheritance vector when it is also a conformal Killing vector. Finally, we discuss these results for the existence of matter inheritance vector in the special cases of the above mentioned spacetimes.Comment: 27 pages, accepted for publication in Int. J. of Mod. Phys.

Body and canard effects on an attached-flow maneuver wing at Mach 1.62

A wing-body-canard configuration was tested at a Mach number of 1.62 by using both a cambered and an uncambered wing. The cambered wing was designed to produce efficient high lift by using attached supercritical crossflow and was originally tested as an isolated wing. The uncambered wing has the same planform and essentially the same thickness distribution as the cambered wing. The experiment determined the effects of a body and canards on both wings. The experimental data showed that both the body and the canards influenced the wing pressure levels, but that the attached supercritical crossflow, which was achieved in the isolated cambered-wing test, was maintained in the presence of a body and canards. Tables of experimental pressure, force, and moment data are included, as well as photographs of oil flow patterns on the upper surface

Supersonic, nonlinear, attached-flow wing design for high lift with experimental validation

Results of the experimental validation are presented for the three dimensional cambered wing which was designed to achieve attached supercritical cross flow for lifting conditions typical of supersonic maneuver. The design point was a lift coefficient of 0.4 at Mach 1.62 and 12 deg angle of attack. Results from the nonlinear full potential method are presented to show the validity of the design process along with results from linear theory codes. Longitudinal force and moment data and static pressure data were obtained in the Langley Unitary Plan Wind Tunnel at Mach numbers of 1.58, 1.62, 1.66, 1.70, and 2.00 over an angle of attack range of 0 to 14 deg at a Reynolds number of 2.0 x 10 to the 6th power per foot. Oil flow photographs of the upper surface were obtained at M = 1.62 for alpha approx. = 8, 10, 12, and 14 deg

Selection of gonadotrophin surge attenuating factor phage antibodies by bioassay

Peer reviewedPublisher PD

High-precision determination of the light-quark masses from realistic lattice QCD

Three-flavor lattice QCD simulations and two-loop perturbation theory are used to make the most precise determination to date of the strange-, up-, and down-quark masses, $m_s$, $m_u$, and $m_d$, respectively. Perturbative matching is required in order to connect the lattice-regularized bare- quark masses to the masses as defined in the \msbar scheme, and this is done here for the first time at next-to-next-to leading (or two-loop) order. The bare-quark masses required as input come from simulations by the MILC collaboration of a highly-efficient formalism (using so-called ``staggered'' quarks), with three flavors of light quarks in the Dirac sea; these simulations were previously analyzed in a joint study by the HPQCD and MILC collaborations, using degenerate $u$ and $d$ quarks, with masses as low as $m_s/8$, and two values of the lattice spacing, with chiral extrapolation/interpolation to the physical masses. With the new perturbation theory presented here, the resulting \msbar\ masses are m^\msbar_s(2 {GeV}) = 87(0)(4)(4)(0) MeV, and \hat m^\msbar(2 {GeV}) = 3.2(0)(2)(2)(0) MeV, where \hat m = \sfrac12 (m_u + m_d) is the average of the $u$ and $d$ masses. The respective uncertainties are from statistics, simulation systematics, perturbation theory, and electromagnetic/isospin effects. The perturbative errors are about a factor of two smaller than in an earlier study using only one-loop perturbation theory. Using a recent determination of the ratio $m_u/m_d = 0.43(0)(1)(0)(8)$ due to the MILC collaboration, these results also imply m^\msbar_u(2 {GeV}) = 1.9(0)(1)(1)(2) MeV and m^\msbar_d(2 {GeV}) = 4.4(0)(2)(2)(2) MeV. A technique for estimating the next order in the perturbative expansion is also presented, which uses input from simulations at more than one lattice spacing

Pressure and force data for a flat wing and a warped conical wing having a shockless recompression at Mach 1.62

A conical nonlinear flow computer code was used to design a warped (cambered) wing which would produce a supercritical expansion and shockless recompression of the crossflow at a lift coefficient of 0.457, an angle of attack of 10 deg, and a Mach number of 1.62. This cambered wing and a flat wing the same thickness distribution were tested over a range of Mach numbers from 1.6 to 2.0. For both models the forward 60 percent is purely conical geometry. Results obtained with the cambered wing demonstrated the design features of a supercritical expansion and a shockless recompression, whereas results obtained with the flat wing indicated the presence of crossflow shocks. Tables of experimental pressure, force, and moment data are included, as well as selected oil flow photographs

Evolving UK policy on diversity in the armed services: multiculturalism and its discontents

Reflecting a generally multiculturalist rhetoric, UK policy in this area has hitherto focussed on enhancing the degree to which the armed services represent or reflect the ethnic makeup of the UK population. Ambitious targets have been set and some progress made in moving towards them. However, the dynamics of population change, together with the diverse preferences of ethno-religious minorities, have meant that the goal of representativeness has remained out of reach. At the same time, the armed services have continued to struggle with an ongoing recruitment problem while the volume of operational commitments has shown little sign of reducing

Multiwavelength study of 20 jets that emanate from the periphery of active regions

We present a multiwavelength analysis of 20 EUV jets which occurred at the periphery of active regions close to sunspots. We discuss the physical parameters of the jets and their relation with other phenomena such as H alpha surges, nonthermal type III radio bursts and hard X-ray emission. Using AIA wavelength channels sensitive to coronal temperatures, we studied the temperature distribution in the jets using the line-of-sight Differential Emission Measure technique. We also investigated the role of the photospheric magnetic field using the LOS magnetogram data from the HMI. The lifetime of jets range from 5 to 39 minutes with an average of 18 minutes and their velocities range from 87 to 532 km/s with an average of 271 km/s. Most of the jets are co-temporal with nonthermal type III radio bursts observed by the Wind/WAVES spacecraft. We confirm the source region of these bursts using the Potential Field Source Surface technique. 10 out of 20 events showed that the jets originated in a region of flux cancellation and 6 jets in a region of flux emergence. 4 events showed flux emergence and then cancellation during the jet evolution. DEM analyses showed that for most of the spires of the jets, the DEM peaked at around log T [K] = 6.2/6.3. In addition, we derived an emission measure and a lower limit of electron density at the location of the spire and the footpoint. These results are in agreement with those obtained earlier by studying individual active region jets. The observation of flux cancellation, the association with HXR emission and emission of nonthermal type III radio bursts, suggest that the initiation and therefore, heating is taking place at the base of the jet. This is also supported by the high temperature plasma revealed by the DEM analysis in the jet footpoint. Our results provide substantial constraints for theoretical modeling of the jets and their thermodynamic nature.Part of the work was done when one of the authors (SMM) was a Junior Research Fellow at Inter-University Centre of Astronomy and Astrophysics (IUCAA), India. S.M.M. and D.T. acknowledge support from DST under the Fast Track Scheme (SERB/F/3369/2012/2013). S.M.M. also ackowledges support from the Cambridge Trust, University of Cambridge, UK. H.E.M. and G.D.Z. acknowledge the support of STFC. AIA data are courtesy of SDO (NASA) and the AIA consortium. RHESSI work is supported by NASA contract NAS 5-98033. The authors thank the open data policy of WIND/WAVES instrument team. This work utilizes data obtained by the Global Oscillation Network Group (GONG) Program, managed by the National Solar Observatory, which is operated by AURA, Inc. under a cooperative agreement with the National Science Foundation. The data were acquired by instruments operated by the Big Bear Solar Observatory, High Altitude Observatory, Learmonth Solar Observatory, Udaipur Solar Observatory, Instituto de AstrofÃŋsica de Canarias, and Cerro Tololo Interamerican Observatory.This is the final version of the article. It first appeared from EDP Sciences via http://dx.doi.org/10.1051/0004-6361/20152747

Anti-self-dual Maxwell solutions on hyperk\"ahler manifold and N=2 supersymmetric Ashtekar gravity

Anti-self-dual (ASD) Maxwell solutions on 4-dimensional hyperk\"ahler manifolds are constructed. The N=2 supersymmetric half-flat equations are derived in the context of the Ashtekar formulation of N=2 supergravity. These equations show that the ASD Maxwell solutions have a direct connection with the solutions of the reduced N=2 supersymmetric ASD Yang-Mills equations with a special choice of gauge group. Two examples of the Maxwell solutions are presented.Comment: 9 page