3,562 research outputs found
Mach 5 inlet CFD and experimental results
An experimental research program was conducted in the NASA Lewis Research Center 10 x 10 ft supersonic wind tunnel. The 2-D inlet model was designed to study the Mach 3.0 to 5.0 speed range for an over-under turbojet plus ramjet propulsion system. The model was extensively instrumented to provide both analytical code validation data as well as inlet performance information. Support studies for the program include flow field predictions with both 3-D parabolized Navier-Stokes (PNS) and 3-D full Navier-Stokes (FNS) analytical codes. Analytical predictions and experimental results are compared
Interplay between the Reactions to Light and to Gravity in Phycomyces
Sporangiophores of Phycomyces do not grow directly towards a horizontal beam of light, but equilibrate at an angle of about 30° above the horizontal. After describing several related observations, this paper suggests that the dioptric properties of an obliquely illuminated cylindrical lens, illustrated by a dummy cell, as well as a negative geotropic response, play major roles in determining the direction of growth. The shift of the equilibrium direction of growth towards the vertical, or a purely geotropic response, over a tenfold range of very low intensities (around 10^6 quanta/cm^2 sec., or 10^-13 watt/cm^2) has been studied, and an action spectrum made, measuring the quantum fluxes producing a standard intermediate equilibrium direction of growth at different wavelengths. This may differ from the action spectra at higher intensities in lacking conspicuous maxima from 370 to 490 mµ. However, in the ultraviolet it parallels the other spectra, although without showing the much higher quantum efficiency of ultraviolet relative to visible light previously noted. Possible interpretations are discussed
The jamming transition and new percolation universality classes in particulate systems with attraction
We numerically study the jamming transition in particulate systems with
attraction by investigating their mechanical response at zero temperature. We
find three regimes of mechanical behavior separated by two critical
transitions--connectivity and rigidity percolation. The transitions belong to
different universality classes than their lattice counterparts, due to force
balance constraints. We also find that these transitions are unchanged at low
temperatures and resemble gelation transitions in experiments on colloidal and
silica gels.Comment: 4 pages, 2 figures, 2 table
A summary of research relating to first grade reading, 1932-1963
Thesis (Ed.M.)--Boston UniversityProblem: An attempt to compare the rate of learning of colorful and abstract words of children in grade one.
Materials:
1. Thirty words were selected to be used in three groups of ten words each. Each list consisted of five colorful and five abstract words. Colorful words are those which have much meaning for children and abstract words are those with little meaning. The words were printed on 3 x 11 inch flash cards in lower case letters.
2. Check sheets were made with spaces for checking the retention of words at three different times and pictures were made to enrich the colorful words.
3. Directions were prepared and given to each teacher who participated in the study.
4. Kuhlmann-Anderson Intelligence Test: Battery A.
5. Detroit Word Recognition Test: Form A [TRUNCATED
Divalent ions tune the kinetics of a bacterial GTPase center rRNA folding transition from secondary to tertiary structure
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