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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Light scattering off particles flowing through a two-slit interference pattern can be used to measure the shear stress of the fluid. We have designed and fabricated a miniature diffractive optic sensor based on this principle.
There is great interest in techniques that potentially enable the direct detection of light from planets orbiting nearby stars. In one technique, nulling interfer~metry, the light from two or more separate telescopes can be destructively interfered to cancel the light from the star, allowing detection of the faint off-axis light from an orbiting planet or circumstellar disc. At the Jet Propulsion Laboratory, broadband white light nulls limited by dispersion effects have been previously reported. In this paper, we investigate other limiting effects using a monochromatic laser source. We report transient laser nulls as deep as 1 part in 10^6 and stabilized nulls as deep as 1 part in 10^5 at a wavelength of 633 nm and discuss the techniques used to obtain these nulls and the residual sources of stray light. We compare the measured performance of the rotational shearing interferometer with a theoretical model.
A new technique of rotation shearing interferometry has been developed, which is optimized to reduce systematic problems when imaging through turbulence.
We present a joint cosmic shear analysis of the Dark Energy Survey (DES Y3) and the Kilo-Degree Survey (KiDS-1000) in a collaborative effort between the two survey teams. We find consistent cosmological parameter constraints between DES Y3 and KiDS-1000 which, when combined in a joint-survey analysis, constrain the parameter S 8 =σ 8 √(Ω m /0.3) with a mean value of 0.790 +0.018 −0.014. The mean marginal is lower than the maximum a posteriori estimate, S 8 =0.801, owing to skewness in the marginal distribution and projection effects in the multi-dimensional parameter space. Our results are consistent with S 8 constraints from observations of the cosmic microwave background by Planck, with agreement at the 1.7 σ level. We use a Hybrid analysis pipeline, defined from a mock survey study quantifying the impact of the different analysis choices originally adopted by each survey team. We review intrinsic alignment models, baryon feedback mitigation strategies, priors, samplers and models of the non-linear matter power spectrum.
Conformal transformation method applied to natural frequency of axial shear vibration of prismatic bars
Single plane parallel plate as lateral shearing interferometer with visible helium-neon gas laser
Radial shearing interferometer based on law of refraction
High intensity interference patterns for lateral shearing interferometer with single plane parallel plate and gaseous laser source
Modal data determination method for discontinuous, nonuniform beam with rotary inertia and shear deformation effects - application to third and fourth stage launch vehicle configuration
Shear pin coupling with plugged hollow shaft provides required load capacity for shaft protection and has no groove to induce fatigue failure.
Otolith shear and visual perception of force direction with resolution of discrepancies by tangent equation
Optimal system for automatic drive control of flying shears in metallurgical plant jobbing mill
Lateral, radial and rotational shearing interferometry
Rotatory inertia and transverse shear effects on quasi-stationary response of elastic strip plates to uniformly moving harmonic line loads
Viscosity profile and other blood flow phenomena in nonuniform shear field
Viscosity of blood at low shear rates and its relation to volume concentration and size of red cells
Shear lag effect on stress distribution in stiffened shells, and stress analysis of cone frustums and segments