Hydrocarbon impurities in SiF<Subscript>4</Subscript> and SiH<Subscript>4</Subscript> prepared from it

Using gas chromatography and high-resolution Fourier-transform IR spectroscopy, we have determined the concentrations of C₁–C₄ hydrocarbon impurities in isotopically unmodified silicon tetrafluoride before and after fine purification and in ²⁸Si-enriched SiF₄. The concentrations of C₁–C₄ hydrocarbon impurities in silicon tetrafluoride for SiH₄ synthesis have been shown to correlate with those in the synthesized silane.     

The effect of medium on the corrosion and electrochemical behavior of nickel

Electrochemical and corrosion properties of nickel in neutral, alkaline, and acidic solutions are studied. Chemical and phase composition of surface films and surface morphology are examined. The effect of electrolyte composition and concentration on the metal removal rate in the course of broaching is determined. Optical, electrochemical, and gravimetrical methods, x-ray diffraction analysis, and thermogravimetry were used in the work. Original Russian Text ? V.V. Parshutin, N.L. Bogdashkina, G.P. Chernova, 2007, published in Zashchita Metallov, 2007, Vol. 43, No. 1, pp. 64–70.     

From Autonomy to Cooperative Traded Control of Humanoid Manipulation Tasks with Unreliable Communication

In this paper, we present our system design, operational procedure, testing process, field results, and lessons learned for the valve-turning task of the DARPA Robotics Challenge (DRC). We present a software framework for cooperative traded control that enables a team of operators to control a remote humanoid robot over an unreliable communication link. Our system, composed of software modules running on-board the robot and on a remote workstation, allows the operators to specify the manipulation task in a straightforward manner. In addition, we have defined an operational procedure for the operators to manage the teleoperation task, designed to improve situation awareness and expedite task completion. Our testing process, consisting of hands-on intensive testing, remote testing, and remote practice runs , demonstrates that our framework is able to perform reliably and is resilient to unreliable network conditions. We analyze our approach, field tests, and experience at the DRC Trials and discuss lessons learned which may be useful for others when designing similar systems.     

Preparation of weakly agglomerated yttrium aluminum garnet powders by burning a mixture of yttrium aluminum hydroxynitrates, urea, and acetic acid

We have optimized the composition of a mixture of aluminum yttrium hydroxynitrates, urea, and acetic acid for the self-propagating high-temperature synthesis of yttrium aluminum garnet (YAG) powder. The powder prepared in this way offers a low degree of agglomeration, and the ceramic produced from it has a low carbon content. A technique has been proposed for carbon determination in YAG ceramics through gas chromatographic analysis of the gaseous products of carbide hydrolysis after the dissolution of the ceramic in pyrophosphoric acid.     

Energy-power conditions for drawing bimetal blanks

A procedure for determining the optimal geometry of a drawing tool for drawing a bimetal blank is proposed. The optimum cone angles of the drawing tool, which offers the minimum drawing stress and minimum energy consumption during the manufacture of bimetal articles, were found from the condition of minimum of the drawing stress.     

Purification of undergound waters of manganese compounds using a natural sorbent-catalyst

Natural underground waters often contain manganese ions in such amount that the water becomes hazardous for human health. We have developed the technology of obtaining sorbent-catalyst based on oxide-carbonate ore of the Nikopol Deposit (Ukraine). We have also determined conditions for using the given material for purification of underground water with a high content of manganese.     

Obtaining of a finely dispersed powder of gadolinium hydroxide

Finely dispersed powders of gadolinium hydroxide are obtained by chemical deposition (dispersing). The influence of various factors on the powder characteristics such as dispersity, morphology, and chemical composition is investigated. The dependence that the mentioned characteristics have on the character of the anion of the gadolinium salt, the concentration and acidity of its solution, and the concentration of the precipitant and pH of precipitation, is established. The optimal results are observed with the use of diluted chloride solutions of gadolinium and a 5–10 wt % precipitant in the form of the NH₃ solution.     

Formation of nanoporous anodic films on pure aluminum in sulfuric acid

The effect of the duration of electrochemical anodic oxidation on the formation of nanoporous anodic oxide films on high-purity aluminum (99.99%) in a sulfuric acid solution is studied. The resulting oxide film is analyzed using an atomic force microscope. The method of photoelectric polarization (PEP) and X-ray analysis revealed that these films are sesquioxides of aluminum with variable compositions, nonstoichiometry due to a metal deficiency, and p-type conductivity. The mechanism of the formation of a regular nanoporous oxide structure that results from the nonstoichiometry relation and the intrinsic formation of defects in the oxide is proposed.     

The Effect of Potassium Phosphate on the Corrosion of АМг6 Alloy in Water-Acetate Solutions

Corrosion-electrochemical investigation of an 6 type alloy was carried out in aqueous solutions of potassium acetate and phosphate. The corroded surface was examined by IR spectroscopy. The alloy is shown to corrode in the passive state at a rate of no more than 0.0002 mm/year. A small addition of potassium phosphate (1%) noticeably impedes, and a large (10%)—accelerates the alloy's corrosion. An explanation of these effects was suggested.