The term "contact aging" refers to the temporal evolution of the interface between a slider and a substrate usually resulting in increasing friction with time. Current phenomenological models for multiasperity contacts anticipate that such aging is not only the driving force behind the transition from static to sliding friction, but at the same time influences the general dynamics of the slidin...

The widespread deployment of smart meters for electricity gas and water consumption to modernise the electricity systems, has been associated with privacy concerns. In this paper, we present protocols that can be used to privately compute aggregate meter measurements, allowing for fraud and leakage detection as well as further statistical processing of meter measurements, without revealing any ...

This paper outlines the operating principles and application of ultrasonic gas flow metering for custody transfer. Basic principles and underlying equations are discussed, as are considerations for applying ultrasonic flow meter technology to station design, installation, and operation. These applications are illustrated based on operating experience with the SICK ultrasonic flow meter, however...

An inexpensive yet portable device for calibrating four different flow meters in the undergraduate fluid mechanics laboratory was designed and constructed. The apparatus contains a rotameter, a turbine-type meter, a venturi meter, and an orifice meter. All four meters are calibrated simultaneously using a volumetric measuring tank. Results obtained by undergraduate students are presented, and a...

unaccounted-for-water is a misleading term long used by water industry. unaccounted-for-water includes unmeasured volume of water that run out of access from supply to end consumer and consequently leads no revenue for supplier. examples of water losses are: meter inaccuracies, illegal connection and unauthorized usage of water, abnormal meter reading, reservoir seepage and leakage, reservoir o...

An experimental implementation of an output-feedback controller on a rotor dynamic system with set-valued friction is presented. The system exhibits coexisting stable/unstable equilibria and undesired friction-induced limit cycles. In the system, the friction and actuation are non-collocated, which prevents the application of standard friction compensation techniques. Therefore, an outputfeedba...

Abstract—This study presents a procedure for friction calculation of column electric power steering (C-EPS) system which affects handling and comfort in driving. The friction losses estimation is obtained from experimental tests and mathematical calculation. Parts in C-EPS mainly involved in friction losses are bearings and worm gear. In the theoretical approach, the gear geometry and Hertz law...

This paper describes a sliding friction model for an electro-deposited coating. Reciprocating sliding tests using ball-on-flat plate test apparatus are performed to determine an evolution of the kinetic friction coefficient. The evolution of the friction coefficient is classified into the initial running-in period, steady-state sliding, and transition to higher friction. The friction coefficien...

Friction, lubrication, and wear have a strong influence on the performance and behavior of mechanical systems. This paper deals with different friction models for sliding contacts running under different conditions. The models presented are suited to different situations, depending on the type of contact, running conditions, and the behavior of interest. The models will be discussed from simula...

Since no universal friction model exists and the practical measurement of friction is not straightforward, this paper presents an experimental method of identifying friction in mechatronic systems. Friction is perhaps the most important nonlinearity that is found in any mechatronic system of moving parts and influences the system in all regimes of operation. For the purpose of improving the per...