Wind-tunnel studies of advanced cargo aircraft concepts

Accomplishments in vortex flap research are summarized. A singular feature of the vortex flap is that, throughout the range of angle of attack range, the flow type remains qualitatively unchanged. Accordingly, no large or sudden change in the aerodynamic characteristics, as happens when forcibly maintained attached flow suddenly reverts to separation, will occur with the vortex flap. Typical wind tunnel test data are presented which show the drag reduction potential of the vortex flap concept applied to a supersonic cruise airplane configuration. The new technology offers a means of aerodynamically augmenting roll-control effectiveness on slender wings at higher angles of attack by manipulating the vortex flow generated from leading edge separation. The proposed manipulator takes the form of a flap hinged at or close to the leading edge, normally retracted flush with the wing upper surface to conform to the airfoil shape

Correlations of projectile like fragments in heavy ion reactions at Fermi energy

Correlations between pairs of projectile-like fragments, emitted by the system ${^{16}O}+{^{197}Au}$ at the laboratory bombarding energy of 515 MeV, have been studied under two stipulated conditions: (1) at least one member of the pair is emitted at an angle less than the grazing angle for the system, (2) both the members of the pair are emitted at angles larger than the grazing angle. A surprisingly large difference, by more than an order of magnitude, is found between the correlations for the two cases. This observation could be explained on the basis of a simple semi-classical break up model. Further analysis of the variation of the charge correlation function with the difference in the nuclear charges of the correlated pair showed trends which are consistent with an "inelastic break up process", in which the projectile breaks up at the radius of contact, in such a way that, one fragment (preferably the lighter) is emitted to one side within the grazing angle, while the other orbits around the target nucleus for a while and emerges on the other side, at a negative scattering angle, much like in a deep inelastic scattering.Comment: 19 pages, 12 figures accepted by Eurp. Physics Journal

Pressure Drop Across Woven Screens Under Uniform and Nonuniform Flow Conditions

Tests were conducted to determine the experimental pressure drop and velocity data for water flowing through woven screens. The types of materials used are dutch twill and square weave fabrics. Pressure drop measures were made at four locations in a rectangular channel. The data are presented as change in pressure compared with the average entry velocity and the numerical relationship is determined by dividing the volumetric flow rate by the screen area open to flow. The equations of continuity and momentum are presented. A computer program listing an extension of a theoretical model and data from that computer program are included

Geometry of good sets in n-fold Cartesian product

We propose here a multidimensional generalisation of the notion of link introduced in our previous papers and we discuss some consequences for simplicial measures and sums of function algebras.Comment: 17 pages, no figures, no table

Droplet Fluctuations in the Morphology and Kinetics of Martensites

We derive a coarse grained, free-energy functional which describes droplet configurations arising on nucleation of a product crystal within a parent. This involves a new `slow' vacancy mode that lives at the parent-product interface. A mode-coupling theory suggests that a {\it slow} quench from the parent phase produces an equilibrium product, while a {\it fast} quench produces a metastable martensite. In two dimensions, the martensite nuclei grow as `lens-shaped' strips having alternating twin domains, with well-defined front velocities. Several empirically known structural and kinetic relations drop out naturally from our theory.Comment: 4 pages, REVTEX, and 3 .eps figures, compressed and uuencoded, Submitted to Phys. Rev. Let

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R-PEKS: RBAC Enabled PEKS for Secure Access of Cloud Data

In the recent past, few works have been done by combining attribute-based access control with multi-user PEKS, i.e., public key encryption with keyword search. Such attribute enabled searchable encryption is most suitable for applications where the changing of privileges is done once in a while. However, to date, no efficient and secure scheme is available in the literature that is suitable for these applications where changing privileges are done frequently. In this paper our contributions are twofold. Firstly, we propose a new PEKS scheme for string search, which, unlike the previous constructions, is free from bi-linear mapping and is efficient by 97% compared to PEKS for string search proposed by Ray et.al in TrustCom 2017. Secondly, we introduce role based access control (RBAC) to multi-user PEKS, where an arbitrary group of users can search and access the encrypted files depending upon roles. We termed this integrated scheme as R-PEKS. The efficiency of R-PEKS over the PEKS scheme is up to 90%. We provide formal security proofs for the different components of R-PEKS and validate these schemes using a commercial dataset