Electrolytic Corrosion of Titanium Carbonitride Composites

The corrosion properties of TiCN, TiCN – AlN, and (TiCN – AlN) – (Fe – Cr) ceramics as well as those of the individual components TiN and TiC in a 3% NaCl solution have been investigated. The kinetics and the mechanism of anode dissolution of metals and oxidation of specimens have been studied by using polarization curves, chemical and x-ray phase analyses, Auger electron spectroscopy, and scanning electron microscopy (SEM). TiCN and TiCN – AlN composites have been found to be the most corrosion-resistant. The presence of a metallic binder in the titanium carbon nitride somewhat decreases the corrosion resistance of the ceramics. On the whole, however, the ceramics developed boast a significantly higher corrosion resistance than that of structural steel.     

Determination of the length of deformation waves in the high-rate deformation of metals

A simple method has been devised for determining the length of a deformation wave in a solid. The method is based on the phenomenon of metalcutting and makes use of the interference of coherent waves. A hypothesis regarding the wave propagation of mechanical and thermal energy is proven experimentally, and it is established that the frequency of these oscillations increases with an increase in deformation rate.Translated from Problemy Prochnosti, No. 3, pp. 88–95, March, 1996.     

Swelling cottony black clays as bases of buildings and structures

Peculiarities of the material composition and physicomechanical characteristics of specific swelling soils are discussed. The authors studied processes of swelling and shrinking and quantitative changes in the soils' properties as a result of these processes in laboratory and field conditions. Dnepropetrovsk Construction Engineering Institute. Translated from Osnovaniya. Fundamenty i Mekhanika Gruntov, No. 2, pp. 24–26, March–April, 1994.     

Morphology of pores produced in <Emphasis Type="Italic">n</Emphasis>-Si {100} by etching in hydrofluoric acid solutions

Variations in the contours of pores produced in n-type silicon by electrochemical etching in hydrofluoric acid solutions are interpreted in terms of the mechanism underlying the chemical interaction of the etchant with silicon and the anisotropy of the etchant–silicon system. Mathematical expressions are proposed which describe the contours and limiting radial sizes of pores forming at the very beginning of the etching process (~10–15 s).     

Aluminum protective alloys and the outlook of organization of their production in the Ukraine

A new aluminum protective ATsKM alloy was developed in the Institute for Problems in Materials Science of the Ukrainian Academy of Sciences on the basis of industrial wastes and scrap of AMg alloys. Electrochemical polarization investigations demonstrate that the dissolution of this alloy is uniform and not accompanied by passivation both in a 3% NaCl solution and in a medium of saline soil. In addition, its stationary potential is rather high (–1.11 V in the first case and –1.07V in the second case). In the course of field tests on the body of the Fedor Erozidi ship in the Baltic Sea and Pacific Ocean, it was shown that the protective potential of ATsKM alloy is by 100 mV more negative than the potential of conventional AP3 alloy. Extensive implementation of ATsKM protectors (whose performance is proved to be quite high) produced according to new native technologies would make it possible to reduce or even eliminate our dependence on imported protectors and save costs spent for the electrochemical protection of metal structures against corrosion under operating conditions.Frantsevich Institute for Problems in Materials Science, Ukrainian Academy of Sciences, Kiev. Karpenko Physicomechanical Institute, Ukrainian Academy of Sciences, L'viv. Translated from Fiziko-Khimicheskaya Mekhanika Materialov, Vol. 31, No. 3, pp. 7–13, May–June, 1995.     

Electrochemical Behavior of ATsKM Sacrificial Anodes in the Course of Long-Term Operation on Seagoing Ships

We studied the electrochemical properties of a sacrificial-anode alloy based on aluminum and magnesium, into which calcium, along with zinc, was introduced as an antipassivator. For the production of this alloy, we used waste and scrap of aluminum-magnesium alloys. In addition to iron and silicon admixtures, it contains a significant amount of copper. Aluminum-based solid solution is the main phase of the new sacrificial-anode alloy, and its second phase represents Ca_x Zn_y Al_z intermetallic compound, which is distributed uniformly over the volume. The proposed alloy was used for the corrosion protection of seagoing ships of the Baltic Steamship Line. It was also tested successfully in waters of the Pacific and in corrosive brackish soils of Southern Ukraine and Middle Asia. These sacrificial anodes have an efficiency of ∼85% and a stationary potential in seawater of −1.10 v relative to a copper-sulfate reference electrode.__________Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 40, No. 5, pp. 95–98, September–October, 2004.     

Gornotaezhnoe geophysical system

A geophysical system has been built on the territory of the Ussuriisk astrophysical observatory of the Far East Branch, Russian Academy of Sciences. It includes a laser deformograph intended to detect variations of deformations of the Earth’s crust with an accuracy of 0.3 nm in a frequency range of 0–1000 Hz and GPS millimeter-accuracy stations.     

Designing drugs for transport into the brain

Research findings regarding general self-concept, academic self-concept, and self-awareness in students with learning disabilities have varied, and results are still inconclusive regarding the consistency between students' and teachers' judgments of academic performance. The current study focuses on students' and teachers perceptions of the students' strategy use and performance in nine different academic and organizational domains. Six hundred sixty-three students and their 57 teachers were involved in the study. Findings indicated that the students with learning disabilities considered themselves appropriately strategic and competent in the five domains of reading, writing, spelling, math, and organization. These students also rated their academic performance and organization as average to above-average in seven of nine domains, with the exception of checking and planning their work. Nevertheless, the self-ratings of the students with learning disabilities were still significantly lower than the self-ratings of average achievers in virtually all domains. The second major set of findings revealed a sharp discrepancy between the self-assessments of the students with learning disabilities and their teachers' judgments. Teachers rated the students with learning disabilities as weak in their strategy use and below-average in their performance in all nine academic and organizational domains. Finally, gender differences were not evident in eight of the nine domains. These results have added to the increasing body of literature indicating that students with learning disabilities frequently perceive themselves as capable and effective and often rate themselves as academically stronger than their teachers judge them to be.