The paper is devoted to the development of a non overlapping Domain Decomposition method adapted to granular dynamics. The formulation and the efficiency of such a method are well established for structural mechanics. In order to extend this approach to granular systems a so-called primal splitting of the domain is chosen because it is a less intrusive method for software development. Once the ...

There are situations where a system in mind needs to be tested before it is built. Using modeling and simulation users can apply realistic interactions with their synthetic environments representing real world. In this study, the synthetic environment is a hardware railroad model representing a miniature of the actual size railroad. Simulation software, used to test the railroad system, consist...

Neuropsychiatric symptoms in 65 welders exposed to aluminium and 217 railroad track welders were studied with the aid of a previously validated questionnaire. Semiquantitative data on exposure to the metals aluminium, chromium, lead, manganese, and nickel were also recorded by questionnaire. Logistic regression was employed to study the relation between exposure and the prevalence of symptoms. ...

I study the conversion of 13,000 miles of railroad track in the U.S. South to standard gauge on May 31 and June 1, 1886 as a large-scale natural experiment in compatibility. Using route-level freight traffic data, I find a large redistribution of traffic from steamships to railroads that declines with distance, with no effect on prices or aggregate shipments due to carriers’ anticompetitive con...

In this paper the Semi-Analytical Finite Element (SAFE) method for modeling guided wave propagation is extended to account for linear viscoelastic material damping. Linear viscoelasticity is introduced by allowing for complex stiffness constitutive matrices for the material. Dispersive characteristics of viscoelastic waveguides, such as phase velocity, attenuation, energy velocity and cross-sec...

In this article, monitoring of ballast water after its treatment by any of BWTS (Ballast Water Treatment System) on board ships has been analyzed. The efficiency of those systems has shown to be the major problem as there are no systems for tracking ship ballast operations. The overall aim of the study was to emphasize the necessity of monitoring the ballast water treatment on board ships and t...

Electronic ballasts are designed to fulfill a variety of different input and output specifications depending on their end application and performance requirements. These designs typically include non-PFC, passive PFC and active PFC input stages, and, single, dual or multi-lamp output stages. The input voltage requirements for each design can vary significantly depending on the final application...

Ballast water may, when discharged, cause the spread of nonindigenous and potentially invasive species. International ballast water treatment regulations have accelerated the development of new methods to detect, enumerate and assess the status of organisms in the water to be discharged. Flow cytometry (FCM) is a powerful technique with a broad range of applications with the possibility for mul...

CONDUCTION-MODE VOLTAGE SOURCE CHARGE-PUMP POWER FACTOR CORRECTION ELECTRONIC BALLAST * Ray-Lee Lin, Hsu-Ming Shih, National Cheng Kung University, Tainan, Taiwan Chen-Yao Liu, Kuo-Bin Liu, National Synchrotron Radiation Research Center, Hsinchu, Taiwan Abstract This paper presents the piezoelectric transformer (PT) based continuous-conduction-mode (CCM) voltage source (VS) charge-pump (CP) pow...

It is well established that cyst-forming phytoplankton species are transported in ships' ballast tanks. However, there is increasing evidence that other phytoplankton species which do not encyst are also capable of surviving ballast transit. These species have alternative modes of nutrition (hetero- or mixotrophy) and/or are able to survive long-term darkness. In our studies of no-ballast-on-bo...