Determination of the melting point of ice in porous glass in relation to the size of the pores

The method of proton magnetic resonance is used to determine the melting point of ice particles in the pores of monodisperse porous glasses ranging from 10 to 1000 Å in radius.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 48, No. 3, pp. 461–466, March, 1985.     

Effects of arylthio-and arylseleno(methoxy)methanes on acid corrosion of CT 3 steel

The effects of various arylthio-and arylseleno(methoxy)methanes on corrosion of CT3 steel in sulfuric and hydrochloric acid solutions were studied by gravimetric and voltammetric methods. Some compounds of theses classes were found to be effective inhibitors of the acid corrosion of CT3 steel. The presence of the-X-CH₂-O-CH₃ groups (X = S or Se) in aromatic amines and their derivatives enhanced their inhibitive properties. However, because these groups are highly hydrophobic, the molecules of inhibitors should contain other fragments that ensure sufficient solubility. Original Russian Text ? I.N. Chernyad’ev, A.B. Shein, A.N. Nedugov, 2007, published in Zashchita Metallov, 2007, Vol. 43, No. 3, pp. 285–289.     

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Investigation of helix-shaped and transverse crack propagation in rotor shafts based on disk shrunk technology

It is known from international feedback that the rotor shafts of the turbo-generators with disk shrunk technology may have transverse cracks located near the keys which maintain the bond between the core of the shaft and the surrounding disks in case of over speed. It was understood that the cracks were initiated by fretting between the keys and the shaft and that they propagated due to a fatigue mechanism generated by the rotational flexion of the shafts under gravity. The destructive observation now correlated to the service history of the shaft shows different mixed modes propagation phases and a stopped circumferential crack evolution during the last months of service of the shaft. Mechanical studies based on the determination of the stress intensity factors provide the evolution of the stress intensity factors during the crack propagation. They give access to information not available otherwise to explain the observed crack profiles. Finally, experimental investigations are needed to obtain the kinetics as a function of the stress intensity factors. The information provided is helpful in determining the possible crack profiles to be detected by the most suitable vibratory surveillance systems before failure in service of the shaft line.     

Vegetation Change in Great Lakes Coastal Wetlands: Deviation from the Historical Cycle

Water-level change is integral to the structure and function of Great Lakes coastal wetlands, and many studies document predictable relationships between vegetation and water level. However, anthropogenic stressors, such as invasive species, land-use change, and water-level stabilization, interact to shift the historical cycle (of native vegetation migration up- and down-slope) toward dominance by invasive Typha species. Knowing from earlier studies that water-level stabilization alters the historical vegetation cycle, we asked if similar shifts can occur where water levels are not stabilized. Using historical aerial photographs of three coastal wetlands (in Lake Michigan's Green Bay, Wisconsin), we determined that habitat dominated by Typha species has expanded to eliminate wet meadow habitat. Between 1974 and 1992, linear regressions showed strong, significant relationships of both meadow area (R² ≥ 0.894; p < 0.02) and marsh area (R² ≥ 0.784; p < 0.05) to water level in all three wetlands. In 2000, meadow area was below that predicted by the historical pattern due to the landward advance of marsh habitat during a year of decreasing water levels. In the same period, land use in the wetland watersheds converted from agriculture to urban. Urbanization and the replacement of native Typha latifolia by the invasive hybrid Typha xglauca may have overwhelmed the beneficial impact of water-level fluctuation. The documentation of vegetation shifts, as herein, is an essential step in the process of preserving and restoring ecological integrity.     

Analytical prediction of structural response to fire

In this paper, general methods for analytical prediction of thermal and structural responses of building subassemblies exposed to any specified fire exposure are summarized and validity and application of these methods to design for structural fire safety of buildings are discussed.     

A system for quality control of mineral-processing products

In this paper, consideration is given to a quality control system for mineral-processing products that provides a concentrate of optimal quality in a required quantity with minimum acceptable losses of the useful component. Operation of a new type of a specialized teslameter adapted to the conditions of an ore-mining enterprise is considered. Teslameters in an operable state are used in the quality control system for mineral-processing products of dry and liquid magnetic separation at the processing mill of OAO Vanadii and dozens of other enterprises in Russia.