The cause of the uneven carbonization process in wet coal charging in coke oven chamber

In the case of the wet coal charging process in coke oven chamber, it is known that the coking process is uneven and a local carbonization delay occurs. The reason was investigated through a laboratory-scale experiment and a quantitative estimation. A partial carbonization test in a test coke oven replicated the uneven plastic layer and local carbonization delay. It was revealed that most of the gas generated in the uncarbonized coal layer results from the evaporation of condensed water and that steam can break through the plastic layer in a test coke oven. Moreover, the order estimation implied that steam that generates in the uncarbonized coal layer and breaks through the plastic layer has sufficient heat capacity to cool the heating wall and delay the carbonization. It was also shown that the steam pressure peak measured in a commercial coke oven is much lower than the estimated steam pressure in this study assuming steam not breaking through the plastic layer. The above-mentioned results and quantitative investigation strongly support the ‘steam breaking through the plastic layer’ theory proposed by Dr. Rohde that an uneven carbonization process is caused by vaporized coal moisture breaking through the plastic layer at definite, unforeseeable points, which results in cooling of the wall by the steam flow.     

The behavior of a cloud of emissions of high moisture content in the surface layer of the atmosphere

The propagation in the atmosphere of instantaneous emissions which largely consist of water vapor is treated in a three-dimensional formulation. The regularities are studied of the evolution of the hydrodynamic, concentration, and temperature fields depending on the parameters which define the state of the atmosphere (temperature and humidity), as well as on the temperature and moisture content of the cloud of emissions.     

Simulation of the slug flow of a gas-liquid system in capillaries

A mathematical model for the gas-liquid slug flow in a capillary is developed. The velocity profiles in the bubble, film, and interbubble liquid are calculated. The calculated results are in good agreement with the experimental data of other researchers. The experimentally found bifurcational behavior of the slip velocity of bubbles relative to the two-phase mixture reported in the literature is described and supported by the theory. The reasons for which the bubble can stop in a small-diameter dead-end capillary are discussed.     

Continuous hydrogen evolution from cyclohexanes over platinum catalysts supported on activated carbon fibers

The continuous production of hydrogen from cyclohexanes is achieved effectively using Pt/ACF (ACF = activated carbon fiber) catalysts in a fixed-bed flow reactor. The Pt catalysts are more effective than a Pd/ACF catalyst for the reaction. Besides cyclohexane, methylcyclohexane, 1,4-dimethylcyclohexane, and p-menthane can also be employed as hydrogen source in the reaction system.     

Cadmium telluride thin-film detectors of nuclear radiation

Semiconductor detectors for X-ray and γ radiation are developed based on thin cadmium telluride (p-n-CdTe) films possessing a columnar structure. The detector structures are formed on molybdenum substrates by CdTe sublimation and magnetron sputtering of cadmium. The p-CdTe films have a thickness of d=30–150 μm and a resistivity of ρ≥10³–10⁷ Ω cm. The single crystal grains in the films have an average size of 50–100 μm and are oriented perpendicularly with respect to the Mo substrate. In comparison to the usual single crystal CdTe detectors, the proposed thin-film single crystal CdTe detectors possess a more perfect structure, since the grain boundaries act as effective sinks for defects. The energy resolution of the new generation of CdTe detectors reaches ∼5 keV for the 59.6 keV line of ²⁴¹Am at room temperature.     

Integration of knowledge-based systems with data processing

Transaction Oriented Prolog-Online Environment is a multi-user, mainframe implementation of the logic programming language Prolog, specially designed and developed for the data processing environment. This article describes the background, functionality, implementation and use of TOP-ONE, stressing that applications of knowledge-based systems technology to data processing environments will achieve full success only when existing systems and existing conventional data are incorporated within the applications.     

Structure and processes of formation of oxide electrocatalysts

Translated from Khimicheskoe i Neftyanoe Mashinostroenie, No. 10, pp. 27–29, October, 1991.     

Parametric and structural optimization of the queuing network throughput

Consideration was given to the parametric and structural optimization of the throughput of various queuing systems. Solutions of these problems rely on a combination of the decomposition methods for optimization of the nonsmooth functions and search of the admissible solutions of the transportation problem, as well as on the majorant estimates of the efficiency of the integrated queuing systems.     

The band formula for A.N. Krylov’s problem

A new formula for solving the Krylov problem on the basis of band matrices is proposed. Properties of the obtained formula are studied for problems of analysis and synthesis of linear controlled systems.