A complete vehicle-ballasted track-bridge coupling dynamic model is established. A program to analyze dynamic characteristics is also invented, which is the first time to systematically analyze the dynamic characteristics of vehicles, tracks and bridges when using mats under ballast on the rigid foundation of bridge, in China. The results show that:(1) The mats under ballast are able to reduce ...

Class E Resonant Inverters are theoretically capable of delivering any power to a load and achieve 100% efficiency at any frequency of operation. In practice efficiency in the “high 90's” can be achieved into megahertz frequencies regardless of inverter output powers. The topology also allows the manipulation of output power through sub-optimal operation, with a negligible efficiency penalty. T...

Ballast water treatment consists of the elimination of exotic species. Currently, the development of alternative methods for this process is directed toward treatment onboard ships. However, we present onshore treatment as a viable alternative for ballast water treatment. We investigated onshore treatment in two iron ore ports with movement capacities of 25 and 90 million tons annually (Mta) th...

The human mediated transfer of harmful organisms via shipping, specifically via ballast water transport, leading to the loss of biodiversity, alteration of ecosystems, negative impacts on human health and in some regions economic loss, has raised considerable attention especially in the last decade. Ballast water sampling is very important for biological invasions risk management. The complexit...

Railway ballast tamping operation is employed in order to restore the geometry of railway track distorted by train traffics. In this paper, based on analysis of tamping principle, the discrete element analysis model of railway ballast is created using the discrete element method, numerical simulations are performed to study the change of railway ballast compactness during tamping process. This ...

In this paper will be reported the study and implementation of a single stage High Power Factor (HPF) electronic ballast for High Pressure Sodium (HPS) lamps using a LCC filter. In the recent years many authors are working to obtain single stage HPF electronic ballast for fluorescent lamps [1][2]. Normally to obtain HPF in electronic ballast for high pressure sodium lamps a Power Factor Preregu...

In this paper will be reported the study and implementation of a single stage High Power Factor (HPF) electronic ballast for High Pressure Sodium (HPS) lamps using a Half-Bridge Boost Rectifier integrated with an Electronic Ballast based in a LCC filter. In the recent years many authors are working to obtain single stage HPF electronic ballast for fluorescent lamps [1-3]. Normally to obtain HPF...

This paper presents findings of a railroad ballast Discrete Element Modeling (DEM) research study focused on investigating ballast settlement under repeated wheel loading. In this approach, the ballast layer is modeled as an assembly of aggregate particles, AREMA No. 24 ballast gradation with different shapes and angularities and rough surface textures. The study matrix considered three differe...