The Role of the Material of Active Screen During the Plasma Nitriding Process

In this research the effect of the active screen’s material was investigated. 42CrMo4 steel was plasma nitrided with unalloyed steel, titanium and nickel active screen at 490 and 510 °C for 4h in 75 % N2 + 25 % H2 gas mixture. Scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and X-ray photoelectron spectroscopy (XPS) were used for the characterisation of the surface properties. Iron-nitride was not formed on the surface with nickel screen. The evaluation of examination results showed that most of the detected nitrogen was molecular (N2) in the formed layer.

The Influence of Pr and Mg Content on the Hydrogen Decrepitation of LaNi-Based Battery Alloys

This paper reports the results of investigations of the hydrogenation and decrepitation of some LaNi-based hydrogen storage cast ingot alloys. A decrepitation procedure for battery negative electrode alloys has been applied using a combination of hydrogen pressure and heating from room temperature to 773K. It has been shown that the Pr and Mg content have a significant influence on the microstructures of the hydrogenated alloys and decrepitation efficiency. Alloys with high concentration of Pr and Mg required an activation quenching treatment for starting the absorption of hydrogen. The decrepitated materials were characterized by scanning electron microscopy (SEM). Electrodes for alloy discharge capacity studies were produced using a nickel screen and electrochemical measurement were carried out in a standard three-electrode cell. The H content of the negative electrode, expressed as the number o H atoms (n) per formula unit, was determined using the measured storage capacity.

A simple, selective method for freeze-fracturing spherical cells.

A simple and selective method for freeze-fracturing spherical cells is described. The cells are loaded into the holes of a thin nickel screen. A metal hat is applied to the cell monolayer and the whole assembly, hat-cells-screen, is frozen and then fractured by ripping the hat off. The fractured face on the screen is replicated. By varying the size of the screen holes and by applying the hat to either side of the screen, this method can selectively expose the E face (or the outer half of plasma membrane), the P face (or the inner half of the plasma membrane), or the cytoplasm of the cells. It also provides a means to produce fractures at a preselected area on the cell, if the cells can be loaded onto the screen in an oriented fashion.