5,675 research outputs found
An Analytical Study for Subsonic Oblique Wing Transport Concept
The oblique wing concept has been investigated for subsonic transport application for a cruise Mach number of 0.95. Three different mission applications were considered and the concept analyzed against the selected mission requirements. Configuration studies determined the best area of applicability to be a commercial passenger transport mission. The critical parameter for the oblique wing concept was found to be aspect ratio which was limited to a value of 6.0 due to aeroelastic divergence. Comparison of the concept final configuration was made with fixed winged configurations designed to cruise at Mach 0.85 and 0.95. The crossover Mach number for the oblique wing concept was found to be Mach 0.91 for takeoff gross weight and direct operating cost. Benefits include reduced takeoff distance, installed thrust and mission block fuel and improved community noise characteristics. The variable geometry feature enables the final configuration to increase range by 10% at Mach 0.712 and to increase endurance by as much as 44%
Educational Goods Reconsidered: A Response
We gratefully reply to our five commentators, responding to their criticisms and comments under the following headings: parochialism and curriculum; rationality and truth; production and distribution; perfectionism, decisionâmaking and disagreement; adultism and parents' interests; nonâconsequential educational goods; and selfâeducation
Educational Goods: Values, Evidence, and Decision-Making-A Summary
This is a brief summary of the book Educational Goods: Values, Evidence, and DecisionâMaking by Harry Brighouse, Helen F. Ladd, Susanna Loeb and Adam Swift. It provides the introduction to the present symposium on this book, which includes the ensuing contributions from Carey Bagelman, Randall Curren, Michael Hand, John Tillson and Winston Thompson, followed by a response from the authors
Scaling of the Random-Field Ising Model at Zero Temperature
The exact determination of ground states of small systems is used in a
scaling study of the random-field Ising model. While three variants of the
model are found to be in the same universality class in 3 dimensions, the
Gaussian and bimodal models behave distinctly in 4 dimensions with the latter
apparently having a discontinuous jump in the magnetization. A finite-size
scaling analysis is presented for this transition.Comment: 14 pages Latex, 4 figure
A 12 GHz satellite video receiver: Low noise, low cost prototype model for TV reception from broadcast satellites
A 12-channel synchronous phase lock video receiver consisting of an outdoor downconverter unit and an indoor demodulator unit was developed to provide both low noise performance and low cost in production quantities of 1000 units. The prototype receiver can be mass produced at a cost under $1540 without sacrificing system performance. The receiver also has the capability of selecting any of the twelve assigned satellite broadcast channels in the frequency range 11.7 to 12.2 GHz
Lattice Boltzmann simulations of lamellar and droplet phases
Lattice Boltzmann simulations are used to investigate spinodal decomposition
in a two-dimensional binary fluid with equilibrium lamellar and droplet phases.
We emphasise the importance of hydrodynamic flow to the phase separation
kinetics. For mixtures slightly asymmetric in composition the fluid phase
separates into bulk and lamellar phases with the lamellae forming distinctive
spiral structures to minimise their elastic energy.Comment: 19 pages, 5 figure
Inelastic collapse of a randomly forced particle
We consider a randomly forced particle moving in a finite region, which
rebounds inelastically with coefficient of restitution r on collision with the
boundaries. We show that there is a transition at a critical value of r,
r_c\equiv e^{-\pi/\sqrt{3}}, above which the dynamics is ergodic but beneath
which the particle undergoes inelastic collapse, coming to rest after an
infinite number of collisions in a finite time. The value of r_c is argued to
be independent of the size of the region or the presence of a viscous damping
term in the equation of motion.Comment: 4 pages, REVTEX, 2 EPS figures, uses multicol.sty and epsf.st
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