Recent applications of the transonic wing analysis computer code, TWING

An evaluation of the transonic-wing-analysis computer code TWING is given. TWING utilizes a fully implicit approximate factorization iteration scheme to solve the full potential equation in conservative form. A numerical elliptic-solver grid-generation scheme is used to generate the required finite-difference mesh. Several wing configurations were analyzed, and the limits of applicability of this code was evaluated. Comparisons of computed results were made with available experimental data. Results indicate that the code is robust, accurate (when significant viscous effects are not present), and efficient. TWING generally produces solutions an order of magnitude faster than other conservative full potential codes using successive-line overrelaxation. The present method is applicable to a wide range of isolated wing configurations including high-aspect-ratio transport wings and low-aspect-ratio, high-sweep, fighter configurations

Integrated processing of peanut for the separation of major constituents

Bench-scale experiments were carried out on the processing of peanut by a new method. The decuticled kernels were pasted, and the paste was subjected to the Skipin process to recover approximately 30% oil; the residual paste was made into a dispersion at 10.0 pH and clarified to get a carbohydrate meal (15.7% moisture-free); the clarified dispersion was centrifuged to obtain another 12% fat and the remaining dispersion was acidified to get the protein (21.9% moisture-free). Fifteen batches of 100-1b. (45.4 kg.) each have been processed, and the reproducibility of the yields has been ascertained. The scope for increasing the oil yield and for improving protein quality is discussed

A.Eye Drive: gaze-based semi-autonomous wheelchair interface

Existing wheelchair control interfaces, such as sip & puff or screen based gaze-controlled cursors, are challenging for the severely disabled to navigate safely and independently as users continuously need tointeract with an interface during navigation. This putsa significant cognitive load on users and prevents them from interacting with the environment in other forms during navigation. We have combined eyetracking/gaze-contingent intention decoding with computervision context-awarealgorithms and autonomous navigation drawn fromself-driving vehicles to allow paralysed users to drive by eye, simply by decoding natural gaze about where the user wants to go: A.Eye Drive. Our “Zero UI” driving platform allows users to look and interact visually with at an objector destination of interest in their visual scene, and the wheelchairautonomously takes the user to the intended destination, while continuously updating the computed path for static and dynamic obstacles. This intention decoding technology empowers the end-user by promising more independence through their own agency

Magnetic diffusivity tensor and dynamo effects in rotating and shearing turbulence

The turbulent magnetic diffusivity tensor is determined in the presence of rotation or shear. The question is addressed whether dynamo action from the shear-current effect can explain large-scale magnetic field generation found in simulations with shear. For this purpose a set of evolution equations for the response to imposed test fields is solved with turbulent and mean motions calculated from the momentum and continuity equations. The corresponding results for the electromotive force are used to calculate turbulent transport coefficients. The diagonal components of the turbulent magnetic diffusivity tensor are found to be very close together, but their values increase slightly with increasing shear and decrease with increasing rotation rate. In the presence of shear, the sign of the two off-diagonal components of the turbulent magnetic diffusion tensor is the same and opposite to the sign of the shear. This implies that dynamo action from the shear--current effect is impossible, except perhaps for high magnetic Reynolds numbers. However, even though there is no alpha effect on the average, the components of the alpha tensor display Gaussian fluctuations around zero. These fluctuations are strong enough to drive an incoherent alpha--shear dynamo. The incoherent shear--current effect, on the other hand, is found to be subdominant.Comment: 12 pages, 13 figures, improved version, accepted by Ap

Role and acceptability of traditional birth attendants (DAIs) in a rural community in South India

Dais are the traditional birth attendants, conducting deliveries at home in the majority of villages in India. A study was planned to find out the feasibility of utilising the services of the dais in case-finding in Tuberculosis (TB) and for drug delivery to diagnosed patients. As a preliminary step, a survey was done with a view to find out the role and acceptability of the dais by the community in 5% of households in randomly selected 24 of the 48 villages in Sriperumbudur taluk in Tamil Nadu, where a voluntary organisation. "PREPARE" was delivering primary health care through dais. A total of 466 individuals, either the head of the household or any other responsible person available, were interviewed to find out the role and acceptability of the dais by the community. The salient findings of this study are that 83% mentioned that the dais reside in their respective villages. hence the services of the dais were available at ail times and 82 % had stated that the services were useful to them. This background information is essential for health planners so that this task force could be effectively utilised in health programmmes, in the rural areas in India

Thermodynamics and Kinetics of the Carbonyl process for the Refining of Nickel

The discovery by Langer and Mond in 1889 of the reaction of carbon monoxide at atmospheric pressure with active nickel at 315-353K to form gaseous Ni(C0)4 and its ready reversibility at higher temperatures paved the way for the development of the carbonyl refining process for nickel. Subsequently, to improve the kinetics, a high pressure process was developed for the carbonyl refining of Ni at somewhat higher temperatures. The carbonyl process makes it possible to produce nickel of very high purity and extr-emely fine size. This paper describes the thermodynamics and kinetics of the formation of nickel carbonyl from pure nickel and its alloys, its vapour phase transport and its decomposition.. The thermodynamic analysis includes const-ruction of Ellingham diagrams, pressure-temperature rela-tionships, partial pressuretemperature relationships and productivity function-temperature-pressure relationships for the various carbonyls. The kinetics of Ni(CO)4 forma-tion and decomposition has been analyzed based on the information available in the literature

Inflation-Produced Magnetic Fields in R^n F^2 and I F^2 models

We re-analyze the production of seed magnetic fields during Inflation in (R/m^2)^n F_{\mu \nu}F^{\mu \nu} and I F_{\mu \nu}F^{\mu \nu} models, where n is a positive integer, R the Ricci scalar, m a mass parameter, and I \propto \eta^\alpha a power-law function of the conformal time \eta, with \alpha a positive real number. If m is the electron mass, the produced fields are uninterestingly small for all n. Taking m as a free parameter we find that, for n \geq 2, the produced magnetic fields can be sufficiently strong in order to seed dynamo mechanism and then to explain galactic magnetism. For \alpha \gtrsim 2, there is always a window in the parameters defining Inflation such that the generated magnetic fields are astrophysically interesting. Moreover, if Inflation is (almost) de Sitter and the produced fields almost scale-invariant (\alpha \simeq 4), their intensity can be strong enough to directly explain the presence of microgauss galactic magnetic fields.Comment: 5 pages, 2 figures. Minor revisions. References added. Accepted for publication in Phys. Rev.

Active and driven hydrodynamic crystals

Motivated by the experimental ability to produce monodisperse particles in microfluidic devices, we study theoretically the hydrodynamic stability of driven and active crystals. We first recall the theoretical tools allowing to quantify the dynamics of elongated particles in a confined fluid. In this regime hydrodynamic interactions between particles arise from a superposition of potential dipolar singularities. We exploit this feature to derive the equations of motion for the particle positions and orientations. After showing that all five planar Bravais lattices are stationary solutions of the equations of motion, we consider separately the case where the particles are passively driven by an external force, and the situation where they are self-propelling. We first demonstrate that phonon modes propagate in driven crystals, which are always marginally stable. The spatial structure of the eigenmodes depend solely on the symmetries of the lattices, and on the orientation of the driving force. For active crystals, the stability of the particle positions and orientations depends not only on the symmetry of the crystals but also on the perturbation wavelengths and on the crystal density. Unlike unconfined fluids, the stability of active crystals is independent of the nature of the propulsion mechanism at the single particle level. The square and rectangular lattices are found to be linearly unstable at short wavelengths provided the volume fraction of the crystals is high enough. Differently, hexagonal, oblique, and face-centered crystals are always unstable. Our work provides a theoretical basis for future experimental work on flowing microfluidic crystals.Comment: 10 pages, 10 figure

Local lattice disorder in the geometrically-frustrated spin glass pyrochlore Y2Mo2O7

The geometrically-frustrated spin glass Y2Mo2O7 has been considered widely to be crystallographically ordered with a unique nearest neighbor magnetic exchange interaction, J. To test this assertion, we present x-ray-absorption fine-structure results for the Mo and Y K edges as a function of temperature and compare them to results from a well-ordered pyrochlore, Tl2Mn2O7. We find that the Mo-Mo pair distances are significantly disordered at approximately right angles to the Y-Mo pairs. These results strongly suggest that lattice disorder nucleates the spin-glass phase in this material.Comment: 9 pages, 2 Postscript figures, Phys. Rev. B: Rapid, in pres

Entropy perturbations and large-scale magnetic fields

An appropriate gauge-invariant framework for the treatment of magnetized curvature and entropy modes is developed. It is shown that large-scale magnetic fields, present after neutrino decoupling, affect curvature and entropy perturbations. The evolution of different magnetized modes is then studied across the matter-radiation transition both analytically and numerically. From the observation that, after equality (but before decoupling) the (scalar) Sachs-Wolfe contribution must be (predominantly) adiabatic, constraints on the magnetic power spectra are deduced. The present results motivate the experimental analysis of more general initial conditions of CMB anisotropies (i.e. mixtures of magnetized adiabatic and isocurvature modes during the pre-decoupling phase). The role of the possible correlations between the different components of the fluctuations is partially discussed.Comment: 43 pages, 9 figure