Understanding the wear behaviour of non-doped and Si,O-doped diamond-like carbon films

Two diamond-like carbon coatings have been examined, both prior to, and post tribotesting. Physical–chemical characterisation allows the elucidation of both the physical and tribochemical mechanisms underpinning the respective wear behaviours. The wear of the undoped a-C:H DLC coating is far lower than that of the Si,O-doped DLC. Both coatings show formation of protective tribofilms with tribochemically-relevant elements derived from the lubricant additives; however the tribofilms on the two coatings exhibit key differences, with one containing pyrophosphate. The undoped a-C:H DLC coating shows an increase in non-planar sp2 carbon content during wear testing which appears to be at the expense of sp3-hybridised carbon. In comparison, the Si,O-doped DLC undergoes comparatively little change in carbon hybridisation state

Algo500 – a New Approach to the Joint Analysis of Algorithms and Computers

The described project is aimed at a complete solution to the problem of jointanalysis of the properties of algorithms and features of the architecture of computing systems. This problem arose in the mid-70s of the last century, and over time, its importance in the practice of using computer systems is constantly growing. The main reason is a significant complication of the architecture of computers, which determines a strong dependence of the efficiency of their work on the properties of algorithms and programs. Exactly this dependence leads in practice to a huge gap between real and peak performance indicators, which is typical for all classes of computers from mobile devices to supercomputers of the highest performance range. It is this dependence that leads to a decrease in the quality of work of supercomputer centers and a drop in the efficiency of computer systems below a fraction of a percent. And at the same time, the fundamental nature of the problem itself determines two important facts. First, it is characteristic of all computer systems and centers of the world without exception. Second, practically all scientific groups of the world in all science areas, conducting research using high-performance computing systems, face this problem

A Laboratory Investigation of the Probable Mechanisms of the Action of an Artificial Thunderstorm Cell on Model Aircraft Radomes

The results of experimental laboratory investigations of possible mechanisms of the impact of lightning and thunderclouds on aircraft radomes and equipment inside them are presented. An artificial thunderstorm cell of negative polarity and model aircraft radomes with lightning diverter strips have been used. Experiments have shown that the discharge processes in a radome model significantly depend on the magnitude of the charge that accumulates on the inner and outer surfaces of the radome shell. It is established that the accumulation of large-magnitude charges of different signs on the outer and/or inner surface of the radome (up to hundreds of µC/m2) shell leads to a multivariance of the mechanisms of development of discharge processes inside the radome model, along its surface, and in the space near it. Significant influence of the “reverse” discharge from the antenna model under the radome on the types of current impulses recorded on the antennas under impact of the artificial thunderstorm cell is established. Peculiarities of the discharge formation in the radome model when using solid and segmented diverter strips for its protection are revealed. Parameters of the current impulses registered on the diverter strips and the antennas have been determined. Based on the conducted research, the possible mechanisms of the impact of thunderclouds and lightning discharges on radio-transparent aircraft radomes and the equipment inside them are considered