16,806 research outputs found
SOME MORE IDEAS ON SMARANDACHE FACTOR PARTITIONS
We define here the SMARANDACHE FACTOR PARTITION FUNCTION (SFP)
Calculation of sidewall boundary-layer parameters from rake measurements for the Langley 0.3-meter transonic cryogenic tunnel
Correction of airfoil data for sidewall boundary-layer effects requires a knowledge of the boundary-layer displacement thickness and the shape factor with the tunnel empty. To facilitate calculation of these quantities under various test conditions for the Langley 0.3 m Transonic Cryogenic Tunnel, a computer program was written. This program reads the various tunnel parameters and the boundary-layer rake total head pressure measurements directly from the Engineering Unit tapes to calculate the required sidewall boundary-layer parameters. Details of the method along with the results for a sample case are presented
Corrections for attached sidewall boundary-layer effects in 2-dimensional airfoil testing
The problems of sidewall boundary-layer effects in airfoil testing is treated by considering the changes in the flow area due to boundary-layer thinning under the influence of the airfoil flowfield. Using von Karman's momentum integral equation, it is shown that the sidewall boundary-layer thickness in the region of the airfoil can reduce to about half the undisturbed value under the conditions prevailing in testing of supercritical airfoils. A Mach number correction due to this increased width of the flow passage is proposed. Using the small disturbance approximation, the effect of the sidewall boundary-layers is shown to be equivalent to a change in the test Mach number and also in the airfoil thickness. Comparison of the results of this approach with other similarity rules and correlation of the experimental data demonstrate the applicability of the analysis presented from low speeds to transonic speeds
EXPLORING SOME NEW IDEAS ON SMARANDACHE TYPE SETS, FUNCTIONS AND SEQUENCES
In this article I have defined a number of SMARANDACHE type sets ,sequences which I found very interesting. The problems and conjectures proposed would give
food for thought and would pave ways for more work in this field
Modifications to Langley 0.3-m TCT adaptive wall software for heavy gas test medium, phase 1 studies
The scheme for two-dimensional wall adaptation with sulfur hexafluoride (SF6) as test gas in the NASA Langley Research Center 0.3-m Transonic Cryogenic Tunnel (0.3-m TCT) is presented. A unified version of the wall adaptation software has been developed to function in a dual gas operation mode (nitrogen or SF6). The feature of ideal gas calculations for nitrogen operation is retained. For SF6 operation, real gas properties have been computed using the departure function technique. Installation of the software on the 0.3-m TCT ModComp-A computer and preliminary validation with nitrogen operation were found to be satisfactory. Further validation and improvements to the software will be undertaken when the 0.3-m TCT is ready for operation with SF6 gas
Reentrant cluster glass behavior in La2CoMnO6 nanoparticles
Magnetic study on La2CoMnO6 nanoparticles revealed multiple magnetic
transitions at 218 K, 135 K and below 38 K and the nature of the low
temperature transition was unclear [J Appl Phys 111, 024102 2012]. Presence of
mixed valance states of Co and Mn has been confirmed from the XPS measurement
and its presence along with antisite disorder affects in reducing the
saturation magnetization of the nanoparticles. The zero field cooled and field
cooled bifurcation in dc magnetization, relaxation in zero field cooled
magnetization and large enhancement in coercive field below the glassy
temperature has been discussed. Frequency dependence of ac susceptibility using
power law has revealed cluster glass behavior. Further, the dc field
superimposed on ac susceptibility and absence of memory effect in ac
susceptibility has suggested the existence of non interacting clusters
comprising of competing interactions below 38 K. Competing magnetic
interactions due to the presence of mixed valances and antisite disorder found
to establish a reentered cluster glassy state in the nanoparticles.Comment: 13 pages 6 fig
Collective Edge Modes near the onset of a graphene quantum spin Hall state
Graphene subject to a strong, tilted magnetic field exhibits an
insulator-metal transition tunable by tilt-angle, attributed to the transition
from a canted antiferromagnetic (CAF) to a ferromagnetic (FM) bulk state at
filling factor zero. We develop a theoretical description for the spin and
valley edge textures in the two phases, and the implied evolution in the nature
of edge modes through the transition. In particular, we show that the CAF has
gapless neutral modes in the bulk, but supports gapped charged edge modes. At
the transition to the FM state the charged edge modes become gapless and are
smoothly connected to the helical edge modes of the FM state. Possible
experimental consequences are discussed.Comment: 5 pages, 2 figure
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