4,707 research outputs found
Visualization of smoke stack plume
System consists of ultraviolet vidicon tube, interference and color filters, ultraviolet telephoto lens, monitor, and waveform analyzer to extract information from video scene, stack plume viewed against sky. System will view SO2 and any other element which absorbs light at wavelength used
TV fatigue crack monitoring system
An apparatus is disclosed for monitoring the development and growth of fatigue cracks in a test specimen subjected to a pulsating tensile load. A plurality of television cameras photograph a test specimen which is illuminated at the point of maximum tensile stress. The television cameras have a modified vidicon tube which has an increased persistence time thereby eliminating flicker in the displayed images
A four-channel portable solar radiometer for measuring particulate and/or aerosol opacity and concentration of NO2 and SO2 in stack plumes
Solar absorption radiometry has been investigated as a method of measuring stackplume effluents. A simple and inexpensive instrument was constructed for observing the sun at four wavelengths: 800, 600, 400, and 310 nm. Higher wavelength channels measured the effect of the particulates and NO2, and an ultraviolet channel measured the contribution of SO2 to the attenuation. Stack-plume measurements of opacity and concentration of NO2 and SO2 were in basic agreement with in-stack measurements. The major limitation on the use of the radiometer is the requirement for an accessible viewing position which allows the sun-plume-observer relationship to be attained. It was concluded that the solar radiometer offers an inexpensive method for monitoring plume effluents when the viewing position is not restricted
Rotating filters permit wide range of optical pyrometry
Gear-driven dual filter disks of graduated density vary linearly with respect to rotation, allowing a wide range of photographic pyrometry. this technique is applicable in metallurgy, glass, plastics and refractory research, and crystallography
Recommended from our members
Simulating Tsunami Inundation and Soil Response in a Large Centrifuge.
Tsunamis are rare, extreme events and cause significant damage to coastal infrastructure, which is often exacerbated by soil instability surrounding the structures. Simulating tsunamis in a laboratory setting is important to further understand soil instability induced by tsunami inundation processes. Laboratory simulations are difficult because the scale of such processes is very large, hence dynamic similitude cannot be achieved for small-scale models in traditional water-wave-tank facilities. The ability to control the body force in a centrifuge environment considerably reduces the mismatch in dynamic similitude. We review dynamic similitudes under a centrifuge condition for a fluid domain and a soil domain. A novel centrifuge apparatus specifically designed for exploring the physics of a tsunami-like flow on a soil bed is used to perform experiments. The present 1:40 model represents the equivalent geometric scale of a prototype soil field of 9.6 m deep, 21 m long, and 14.6 m wide. A laboratory facility capable of creating such conditions under the normal gravitational condition does not exist. With the use of a centrifuge, we are now able to simulate and measure tsunami-like loading with sufficiently high water pressure and flow velocities. The pressures and flow velocities in the model are identical to those of the prototype yielding realistic conditions of flow-soil interaction
-graded Heisenberg algebras and deformed supersymmetries
The notion of -grading on the enveloping algebra generated by products of
q-deformed Heisenberg algebras is introduced for complex number in the unit
disc. Within this formulation, we consider the extension of the notion of
supersymmetry in the enveloping algebra. We recover the ordinary
grading or Grassmann parity for associative superalgebra, and a modified
version of the usual supersymmetry. As a specific problem, we focus on the
interesting limit for which the Arik and Coon deformation of the
Heisenberg algebra allows to map fermionic modes to bosonic ones in a modified
sense. Different algebraic consequences are discussed.Comment: 2 figure
q-deformed harmonic and Clifford analysis and the q-Hermite and Laguerre polynomials
We define a q-deformation of the Dirac operator, inspired by the one
dimensional q-derivative. This implies a q-deformation of the partial
derivatives. By taking the square of this Dirac operator we find a
q-deformation of the Laplace operator. This allows to construct q-deformed
Schroedinger equations in higher dimensions. The equivalence of these
Schroedinger equations with those defined on q-Euclidean space in quantum
variables is shown. We also define the m-dimensional q-Clifford-Hermite
polynomials and show their connection with the q-Laguerre polynomials. These
polynomials are orthogonal with respect to an m-dimensional q-integration,
which is related to integration on q-Euclidean space. The q-Laguerre
polynomials are the eigenvectors of an su_q(1|1)-representation
Planar Rayleigh scattering results in helium-air mixing experiments in a Mach-6 wind tunnel
Planar Rayleigh scattering measurements with an argon—fluoride excimer laser are performed to investigate helium mixing into air at supersonic speeds. The capability of the Rayleigh scattering technique for flow visualization of a turbulent environment is demonstrated in a large-scale, Mach-6 facility. The detection limit obtained with the present setup indicates that planar, quantitative measurements of density can be made over a large cross-sectional area (5 cm × 10 cm) of the flow field in the absence of clusters
Operator Formulation of q-Deformed Dual String Model
We present an operator formulation of the q-deformed dual string model
amplitude using an infinite set of q-harmonic oscillators. The formalism
attains the crossing symmetry and factorization and allows to express the
general n-point function as a factorized product of vertices and propagators.Comment: 6pages, Late
Continuously Crossing u=z in the H3+ Boundary CFT
For AdS boundary conditions, we give a solution of the H3+ two point function
involving degenerate field with SL(2)-label b^{-2}/2, which is defined on the
full (u,z) unit square. It consists of two patches, one for z<u and one for
u<z. Along the u=z "singularity", the solutions from both patches are shown to
have finite limits and are merged continuously as suggested by the work of
Hosomichi and Ribault. From this two point function, we can derive
b^{-2}/2-shift equations for AdS_2 D-branes. We show that discrete as well as
continuous AdS_2 branes are consistent with our novel shift equations without
any new restrictions.Comment: version to appear in JHEP - 12 pages now; sign error with impact on
some parts of the interpretation fixed; material added to become more
self-contained; role of bulk-boundary OPE in section 4 more carefully
discussed; 3 references adde
- …
