Determination of boron in nickel-base alloys by the dianthrimide method.
The dianthrimide method for the determination of boron in iron and low-alloy steels may be applied to nickel-base materials. The sample is dissolved, without any loss of boron, by hydrochloric and sulphuric acids and the resulting boric acid determined spectrophotometrically with dianthrimide. Background corrections are necessary to compensate for the absorbance from ions such as nickel and iron.
The effect of foreign ions on the spectrophotometric determination of boron with 1,1'-dianthrimide
Abstract The effects of about 40 inorganic ions and reducing and oxidizing agents on the determination of boron with 1,1'-dianthrimide were studied spectrophotometrically. The separate foreign ions were added both to solutions containing boron and 1,1'-dianthrimide and to solutions containing only 1,1'-dianthrimide. From the two series of extinction measurements conclusions were drawn as to the type of interference present. With the use of hydrazine sulphate as reducing agent, the only ions interfering were: germanium (IV), tellurium(IV), cobalt(II), nickel(II), copper(II), chromium-(III), bromide, iodide, fluoride, vanadate and high concentrations of orthophosphate. A new method of indicating spectrophotometric interference was introduced.
Computer-Aided System of Virtual Testing of Gas Turbine Engines
The article describes the concept of a virtual lab that includes subsystem of gas turbine engine simulation, subsystem of experiment planning, subsystem of measurement errors simulation, subsystem of simulator identification and others. The basis for virtual lab development is the computer-aided system of thermogasdynamic research and analysis “ASTRA”. The features of gas turbine engine transient modes simulator are described. The principal difference between the simulators of transient and stationary modes of gas turbine engines is that the energy balance of the compressor and turbine becomes not applicable. The computer-aided system of virtual gas turbine engine testing was created using the developed transient modes simulator. This system solves the tasks of operational (throttling, speed, climatic, altitude) characteristics calculation, analysis of transient dynamics and selection of optimal control laws. Besides, the system of virtual gas turbine engine testing is a clear demonstration of gas turbine engine working process and the regularities of engine elements collaboration. The interface of the system of virtual gas turbine engine testing is described in the article and some screenshots of the interface elements are provided. The developed system of virtual gas turbine engine testing provides means for reducing the laboriousness of gas turbine engines testing. Besides, the implementation of this system in the learning process allows the diversification of lab works and therefore improve the quality of training.