ABSTRACT
The EPA proposed regulations for municipal waste combustors (MWCs) on December 20, 1989. The regulations include (1) performance standards under Section 111(b) of the Clean Air Act (CAA) for new, modified, or reconstructed MWCs and (2) draft emission guidelines and compliance schedules for the states to use to develop control requirements from existing MWCs under Section 111(d). This paper will outline the proposed air emission standards and guidelines, as well as the basis for the prescribed emission limits. The schedule for the remainder of the regulations development will also be discussed.
Subject(s)
Air Pollution/legislation & jurisprudence , Refuse Disposal/standards , United States , United States Environmental Protection AgencyABSTRACT
The unique properties of Gaussian beams must be considered when designing and using laser Doppler anemometer systems. This paper presents an analysis of Gaussian beam effects in LDA systems in order to quantify their influence on the Doppler signal. The analytical results, which are verified by experiment, show that both axial and lateral frequency gradients can exist in the probe volume of improperly aligned LDA systems. The effects of lens aberrations and of optical path changes due to the insertion of planar optical elements in the beam are also considered.
ABSTRACT
A generalized method for determining the properties of a Gaussian laser beam focus including waist radius, position, and intensity distribution is presented. Of significance to in situ laser diagnostic methods is a unique analysis of illuminated area as a function of intensity in a plane of the laser beam. The results apply for nontruncating diffraction-limited optical systems and are important in determination of the optical sampling volume of laser instruments for particulate and gaseous species analysis.
ABSTRACT
This report describes the employment of moiré patterns to model visually interference phenomena in general and laser Doppler anemometer signals in particular. The modeling includes signals created in dual beam and reference beam anemometers by both single particles and particle pairs. The considerations are extended to visual modeling of multiparticle signals and the decay of signal quality in the presence of many particles. The fringe model of the laser Doppler anemometer is also considered, and moiré patterns are employed to demonstrate the interference fringes in the crossover region of two intersecting laser beams. Gaussian beam properties are taken into account to allow the effects of improperly designed optical systems to be studied. Instructions for using computer generated transparencies to produce the different moiré patterns are provided to allow the reader to study in detail the various interference phenomena described.
ABSTRACT
This paper presents an analysis describing the thermal behavior of a thin film subjected to a spatially modulated irradiation field. The analysis shows that it is possible using a cw laser to establish a temperature field in such a film that maps the irradiation pattern with a resolution adequate for recording high quality holograms. Effects of the thermal properties of the film and substrate on such recording characteristics as linearity, sensitivity, and resolution are examined. A high diffraction efficiency recording technique based on the sublimation of a thin film situated on a constant temperature substrate is proposed as an example of the application of the analysis.
ABSTRACT
Approximate methods for calculating the error introduced by the deflection of the light beam or refractive error in schlieren, shadowgraph, interferometric, and holographic measurements of transport phenomena are investigated. Relative error is reported for the well-known correction parabola and paraxial approximations as well as for a new first-order approximation in both a linear and nonlinear refractive index field. The first-order approximation is exact in a linear field but is in about the same error as the other approximations in the nonlinear field of a boundary layer. In many cases, actual optical data can be corrected for refractive errors by using the results presented.
ABSTRACT
The doppler frequency shift produced in the various diffraction orders of a rotating radial diffraction grating allows such a device to be used as an optical modulator. The theory and performance of such devices is presented.
