Changes in the mineral phases during the processing of a copper sulfide concentrate

Mineralogical, granulometric, and phase compositions of the copper sulfide concentrate of the Erdenet deposit (Mongolia) have been studied. It is shown that the concentrate has a high chemical stability against the interaction with sulfuric solutions after both a preliminary oxidizing roasting and mechanoactivation in a planetary mill (in dry and wet regimes of milling).     

Substrate uptake by Gordonia amarae in activated sludge foams by FISH-MAR.

Gordonia amarae is a right-angled branching filament belonging to the mycolic acid-containing Actinobacteria which is commonly found in many foaming activated sludge wastewater treatment plants. Although studies on different substrates as sole carbon sources by pure cultures of G. amarae have been carried out, none have examined substrate uptake by this organism in situ. Uptake of several hydrophilic and hydrophobic substrates by G. amarae was evaluated in situ using a combination of fluorescence in situ hybridization and microautoradiography. G. amarae could assimilate a range of both hydrophilic and hydrophobic substrates. From the data, G. amarae appears to be physiologically active under aerobic, anaerobic and anoxic condition (NO2 and NO3) for some substrates. This might explain why attempts to control foaming caused by G. amarae using anoxic and anaerobic selectors have been unsuccessful. This study emphasizes that bacteria can behave differently in situ to pure cultures and that it is important to evaluate the in situ physiology of these bacteria if we are to better understand their role in the wastewater treatment process.     

Testing procedure and results of tests performed on a VVÉR-1000 fuel assembly fragment in a MIR channel for a maximum anticipated accident

The testing procedure and the results of tests performed on a 19-element fragment of a VVéR-1000 fuel assembly in the channel of a MIR reactor under conditions of the second and third stage of a maximum anticipated accident are presented. The state arising in the reactor core with an uncompensated leak arising in the first cooling loop when a pipeline with the maximum diameter bursts (large leak) is studied in the experiment. In each case study, superheated steam cools the top part of the fuel elements. The main goal of the tests is to obtain data on the distortion of fuel-element cladding under tensile stresses. __________ Translated from Atomnaya énergiya, Vol. 103, No. 5, pp. 286–291, November, 2007.     

Linearization with respect to useful signal of relay control systems containing blocks with limiters

A method of linearization with respect to the useful signal of relay systems with the control plant containing blocks with limiters is proposed. Relay systems with two-position relay element are considered. The method allows studying the tracking mode of input signals in the relay system in a simple way. This is very important for synthesizing relay systems when a great number of variants need to be analyzed.     

Structure and properties of WC-Co alloys in solid-phase sintering. II. Mechanical properties of samples

The mechanical properties of hard WC-Co alloys produced by solid-phase sintering at various temperatures are discussed. It is shown that the bending strength and hardness of these alloys may be the same as those achieved in liquid-phase sintering. The difference between solid-phase and liquid-phase sintering is only in the time it takes to achieve the dense state. Excellent mechanical properties at rather low temperatures (1150–1200 °C) can be obtained by sintering under pressure. High hardness can be achieved at 1000–1100 °C by hot isostatic pressing of nanoscale powders. The excellent mechanical properties of solid-phase-sintered hard WC-Co alloys indicate that strong interphase and intercarbide boundaries occur earlier than the liquid phase.     

Statistical analysis of uniform-sampling phase-locked loops based on Volterra functional expansions

With the use of Volterra functional expansions in the domain of the multidimensional z transform, discrete uniform-sampling analogues of digital phase-locked loops of the first, second, and (N + 2)th orders with a delay of N sampling periods are analyzed.     

Combustion of boron-containing condensed systems

Moscow. Translated from Fizika Goreniya i Vzryva, Vol. 28, No. 1, pp. 51–53, January–February, 1992.