Validation of a diatom-based index of water quality confirms its utility in monitoring of the Lake Erie's nearshore area

We conducted a validation of the Planktonic Diatom Index (PDI) to demonstrate the utility of a water quality index for the monitoring of Lake Erie's nearshore pelagial zone. Using a large, independent dataset from the Western and Central Basins of Lake Erie for validation ensures realistic assessment of the performance of the index. Diatom-based biomonitoring allows for the inference of integrative information about water quality based on diatom species composition. The PDI is based on the assumption that phosphorus, an established proxy for eutrophication, is instrumental in the structuring of diatom communities. In this study, PDI scores and measured total phosphorus were significantly correlated (r²?=?0.34, r²?=?0.63 outliers removed). However, when samples were considered on a basin-wide basis, the PDI scores were not significantly predicted by measured total phosphorus in the Western Basin. We suggest that snapshot phosphorus measurements are less likely to represent the overall condition in the highly variable, eutrophic Western Basin. When multiple phosphorus measurements were averaged over time, the relationship with the integrative PDI scores was more apparent (r²?=?0.52). Through validation with an independent dataset, we show that the PDI is likely a monitoring tool that provides a robust assessment of water quality in the pelagial zone of the nearshore waters in Lake Erie.     

Operational reliability of seals in movement joints of hydraulic structures

Poor-quality preparation of the recesses of keys is a cause of seepage. __________ Translated from Gidrotekhnicheskoe Stroitel’stvo, No. 1, January, 2007, pp. 28–34.     

Characteristics of temperature-compensator fillers in convective shafts of boiler units

Results of investigations of the physico-mechanical and aerodynamic characteristics of granular materials used as channel fillers in the temperature compensators of convective shafts of boiler units are presented. Possible causes of influxes of air into gas conduits of the boiler through a sand compensator are analyzed. A multilayer procedure is proposed for filling of the bulk compensator, and computational relationships are presented for determination of the height of each layer and its aerodynamic resistance. Results of the investigations were implemented at the Krasnoyarsk TéTs-2 thermoelectric power station (TEPS) during assembly of the No. 6 BKZ-500-140 boiler. __________ Translated from élektricheskie Stantsii, January, 2007, No. 1, pp. 31–35.     

Adapting the monitoring and control systems on the 300 MW power generation units at the Iriklinskaya GRÉS to modern operational requirements

Work done by JSC “Interavtomatika” and the Iriklinskaya GRéS (State Regional Electric Power Plant) to create automatic frequency and power control systems is reported. This involved reconstructing the turbine regulator systems and modernizing all the regulators for the power generator unit (those coupled to and those not coupled to the automatic frequency and power control systems) and the automatic burner control systems on the basis of a unified Simatic PCS7 PS controller system for the four 300 MW power generation units at the Iriklinskaya GRéS.     

Experience in connecting the power generating units of thermal power plants to automatic secondary frequency regulation within the united power system of Russia

The principles of central control of the power generating units of thermal power plants by automatic secondary frequency and active power overcurrent regulation systems, and the algorithms for interactions between automatic power control systems for the power production units in thermal power plants and centralized systems for automatic frequency and power regulation, are discussed. The order of switching the power generating units of thermal power plants over to control by a centralized system for automatic frequency and power regulation and by the Central Coordinating System for automatic frequency and power regulation is presented. The results of full-scale system tests of the control of power generating units of the Kirishskaya, Stavropol, and Perm GRéS (State Regional Electric Power Plants) by the Central Coordinating System for automatic frequency and power regulation at the United Power System of Russia on September 23–25, 2008, are reported.     

Asynchronous nonsalient-pole compensators with total air cooling1

The fundamental parameters and construction of asynchronous compensators, soon to be produced by the “Silovye Mashiny” — “élektrosila” Joint Stock Company in 2008, are considered. The compensator has a massive nonsalient-pole rotor with two excitation windings, shifted by 90° (in electrical angles), supplied from controlled reversible power sources. The compensators provide delivery-consumption of reactive power in the ±100 Mvar range with the possibility of short-term double forcing of the power output and improved dynamic characteristics compared with synchronous compensators. ¹ This paper is based on material presented at the conference “Russia Power 2008” (Moscow, April 2008). Translated from élektricheskie Stantsii, No. 11, November 2008, pp. 62–65.