Physical modeling of urban air-pollutant transport

Air-pollutant transport within an urban setting is conditioned by local urban geometry, urban-modified meteorological variables, a wide variety of source characteristics and local topography. Extreme complexity and local specificity of the resulting dispersion process requires the use of physical modeling rather than numerical or analytical methods to predict concentration distributions. Serving as an analog computer the boundary-layer wind tunnel provides reliable concentration data which can be applied directly to design and/or decision making.A brief review is made of similarity criteria for simulating physical modeling of the atmospheric boundary-layer and source characteristics in a boundary-layer wind tunnel. Applications to several problems related to stack, vent and automobile emissions are described. Rudimentary portions of a data bank are presented which, with additional data acquisition, can provide a practical method for prediction of automobile exhaust concentrations that will result from proposed freeways or alternative traffic routings.     

Convergence

Convergence is the idea of merging the duties and responsibilities of physical security with that of digital security to make them part of a common reporting structure--to employ tools and techniques that are parallel if not collinear.     

Experimental study on the application of acoustic emission during the hydraulic pressurization of a reactor pressure vessel

The investigations were aimed at demonstrating the state of the art of acoustic emission testing (AET) of reactor pressure vessels. The object under investigation was the large reactor pressure vessel of the MPA in Stuttgart, a boiling-water reactor pressure vessel, which was provided with a multitude of flaws in weld seams and in the base material. Six hydrostatic tests approximately up to the working pressure of a boiling-water reactor (71 bar) were carried out. In addition to the global multichannel locating technique, also local monitoring techniques were applied. Global location permitted a large number of different indications to be detected simultaneously. Not all of the known flaws did, however, show the expected number of AE events. On the other hand, it was possible to detect flaws previously unknown to the AE staff in some weld seams; these indications were confirmed by nondestructive testing. It was demonstrated that the locating accuracy of local monitoring using signal analysis was improved by a factor of 20 to 30 compared to global monitoring.     

Parameters and Technology for Fabricating PIK Reactor Fuel Elements

The construction of the fuel elements of a high-flux PIK research reactor is described. The technological tolerances in the process of fuel-element fabrication are presented. The basic geometric and mass parameters of several standard batches of fabricated fuel elements are determined experimentally. Statistical analysis of the experimental data shows that the deviations in the main parameters fall within the limits of the indicated technological tolerances and are described by a Gaussian distribution to a high degree of accuracy.     

On the optimization of metal forming

An approach to the calculation and design of metal forming is proposed and theoretically considered. This approach can minimize the nonuniformity of a deformation distribution over the cross section of ready products, which is equal to controlling the structure and properties of forged pieces. This approach is based on the calculation of the intermediate shapes of a forged piece by solving a set of inverse forming problems using the boundary element method and by constructing a forging process that is optimal according to a given criterion using dynamic programming.