Characterization of multiphase gas–solid flow and accuracy of turbulence models for lower stage cyclones used in suspension preheaters

This study involved the analysis and characterization of the multiphase flow phenomenon inside the lower stage cyclone separator used in the clinker burning process. The analysis was performed using both CFD and experimental research methods. Very few studies are devoted to such types of cyclone separators, which in addition to their basic functions are also responsible for the technological process. Due to the atypical working conditions of these cyclone separators, they are characterized with a complex geometry, which significantly differs from that of the traditional separators.Furthermore, the evaluation of the accuracy and level of reliability of the two models of turbulence closure—k-e RNG and RSM(RANS), and the LES. The results obtained led to the conclusion that for the lower stage cyclone separators, the LES model proved to be the most accurate(both in the case of forecasting the separation efficiency and pressure drop). The performance parameter(in particular the separation efficiency) values obtained for the RSM model were also characterized by high accuracy. The k-e RNG model was characterized by significantly larger deviations.     

Partial-SOI isolation structure for reduced bipolar transistorparasitics

A bipolar isolation structure with the capability of significantly reducing collector-base capacitance and base resistance is presented. Partial SOI, with SOI surrounding the collector opening, can be used to reduce the collector window width in combination with any emitter-base self-aligned bipolar device structure, and in particular for device structures that feature sublithographic emitter width. Near-ideal transistor Gummel characteristics and a minimum ECL gate delay of 24 ps have been achieved with a nonoptimized lateral device layout, and simulations suggest that sub-20-ps delay at reduced switch current will be possible by using the optimized partial-SOI isolation structure     

P-wave ekg averaging technique--a new method of selecting patients with paroxysmal atrial fibrillation

The aim of study was to assess the value of signal averaged ecg for detection of patients (pts) at risk for paroxysmal atrial fibrillation (paf). We examined three groups of pts: group I-41 pts with nonvalvular paf, group II-20 pts with hypertension and/or ischemic heart disease without paf and group 3-26 health persons, without organic heart disease. In all pts the signal-averaged electrocardiogram triggered by P waves was recorded. Seven parameters of the spatial magnitude of filtered P wave were measured. Significant difference between group I and group II or III was found in most parameters. Using the method of multidimensional variance analysis we constructed "the diagnostic vector" in multidimensional parameters space, which was used to determine patients belonging to group. Total percent of right decision was 85%. These findings suggest that pts at risk for paf could be detected while in sinus rhythm by using the P wave-triggered signal-averaged ecg.     

Thermal Mass and Thermal Inertia in Fluids — A Comparison of Hypotheses

Thermal inertia and thermal mass are concepts that offer means to describe transport of heat in nonequilibrium fluids. However there are options regarding how to separate the part of the total flow that caries entropy from the "mechanical", nonentropy-bearing part. Some hypotheses are examined and compared for constructing such a field theory of thermal mass in the energy representation. A global intrinsic symmetry and a finite thermal momentum imply that any formulation which hypothesizes a constant ratio of thermal mass to the entropy must tie the thermal mass to the so-called bare mass of particles, to preserve the global conservation of matter. However, in any formulation consistent with the Grad-Boltzmann theory, where must be variable, the thermal mass behaves as a separate variable governed by the entropy and the second law. Nonetheless, in this case has a reasonably broad plateau of values within which entropy is a measure of the thermal mass associated with changes of state. Nonlinear transformations linking usual thermodynamic variables with those of the thermal mass frame preserve the components of the tensor of matter, including Nöther's energy and pressure. A formula is given for the fraction of the observed mass assignable as thermal mass, in accordance with Grad's solution of the Boltzmann equation.     

Workflow management system with smart procedures

Supervision of repair and diagnostic works aimed at improving the safety of maintenance crews is one of the key objectives of the distributed INRED system. Working in a real industrial environment, the INRED system includes, among others, the so-called INRED-Workflow, which provides an infrastructure for process automation. Participants of the service processes, managed by the INRED-Workflow, are controlled at each stage of the performed service procedures, both by the system and other process participants, such as quality managers and technologists. All data collected from the service processes is stored in the System Knowledge Repository (SKR) for further processing by using advanced algorithms, and the so-called Smart Procedures merge services supplied by other INRED system modules. The applicability of workflow management systems in conjunction with image recognition and machine learning methods has not yet been thoroughly explored. The presented paper shows the innovative usage of such systems in the supervision of the repair and diagnostic works.

     

Various Charge-Ordered States in the Extended Hubbard Model with On-Site Attraction in the Zero-Bandwidth Limit

The extended Hubbard model in the zero-bandwidth limit with intersite density–density interactions (nearest- and next-nearest-neighbor) is analyzed in the site-dependent mean-field approximation. In this paper, we investigate a case of on-site attraction U<0 for arbitrary values of intersite interactions as well as chemical potential (or electron density). We present ground state and finite temperature phase diagrams obtained in the four-sublattice assumption (e.g., 1D chain, 2D square, or 3D body-centered cubic lattices). Our results for U<0 show that in the system various phases emerge: three different types of charge-ordered phases (checkerboard, laminar/stripe, and four-subllatice-type) and non-ordered phases.     

On 2D integro-differential systems. Stability and sensitivity analysis

Multidimensional Systems and Signal Processing - In the paper a two-dimensional integro-differential system is considered. Using some variational methods we give sufficient conditions for the...     

Determination of the impact indicators of electromagnetic interferences on computer information systems

The present article covers an influence of the impact of electromagnetic interferences on computer information systems whose purpose is to control transport supervision systems. The primary objective of transport supervision systems is to detect hazards to human life and health that occur in the process of transport: traveling of people and/or cargos. This process needs to be characterized by a high level of reliability and safety. The measure of the transport safety is the confidence that the elements of a transport process will remain intact during its realization with the exception of those changes that are the result of the natural processes of aging and wear. The railway environment is one of the most difficult environments concerning the provision of electromagnetic compatibility. Those electromagnetic interferences that are intended and not intended being generated in a rail area have an impact on the operation process of a transport supervision system.