ABSTRACT
The X-ray back diffraction of (1240) in a monolithic two-plate silicon cavity occurs at photon energy 14.4388 keV, at which 24 beams are simultaneously excited. Based on the dynamical theory of X-ray diffraction, a theoretical approach has been developed for solving the fundamental equation of dynamical theory to investigate this back diffraction and the interference patterns generated by the Fabry-Perot-type resonance that produces intensity undulation in both transmitted and back-reflected beams. The section of dispersion surface and its associated linear absorption coefficients, wavefield intensities and excitation of mode are calculated. The calculated intensity distribution of the transmitted beam is in a good agreement with the observed one. Details about the interaction between the multiply diffracted X-rays and cavity resonant photons are also reported. Procedures of computer programming are also provided.
ABSTRACT
Pulse jet fabric filters (PJFFs) have become an attractive option of particulate collection utilities, because they can meet stringent particulate emission limits regardless of variation in operating conditions. Despite their wide applications, the present control algorithm for PJFFs can best be described as rudimentary. In this paper, a modeling and control strategy based on the local model network (LMN) is proposed. An extended self-organizing map (ESOM) network is developed to construct the LMN model of the filtration process using the filter's input-output data. Subsequently, these ESOM local models are incorporated into the design of local generalized predictive controllers (GPC), and the proposed controller design is obtained as the weighted sum of these local controllers. Simulation results show that the proposed controller design yields a better performance than both conventional GPC and proportional plus integral (PI) controllers yield.
Subject(s)
Air Pollution/prevention & control , Models, Theoretical , Air Movements , Air Pollutants/isolation & purification , Filtration , Particle SizeABSTRACT
A new model for pulse jet fabric filtration is proposed. In contrast to the earlier model of Ravin and Humphries, which was formulated on the steady state assumption, the present study is aimed at developing a predictive capability for both transient and steady state operations, taking into account the compression effect of filter cakes. The model's relative simplicity allows frequent updating of the model parameter values, thus improving the accuracy of predictions. As a result, the model is particularly useful in developing control algorithms and designing controllers of pulse jet fabric filtration systems.
Subject(s)
Air Pollution/prevention & control , Models, Theoretical , Algorithms , Equipment Design , Filtration , Particle SizeABSTRACT
We discuss the laser deposition rate of tungsten film, which saturates with increasing light intensity during photolysis of W(CO)(6) vapor. A new method for determining the absolute deposition rate is presented, and the results obtained are found to be quite close to those determined by the absorption method. We also present data showing how the deposition rate depends on other parameters.
ABSTRACT
Linear relations have been observed between the reciprocal of the noise ratio and the reciprocal of the output power of the He-Cd laser as well as between the noise ratio and the net gain within the laser cavity. By a feedback method with an acoustooptic modulator in the laser cavity at the Brewster angle for low optical loss, a stable laser with high power output and low noise has been obtained. The noise ratio and the output power are 0.8% and 33 mW, respectively, at 4416 A
