Existing quality controlmethods for railway ballast are arduous and expensive since they are based onmanual material inspections. Thus, test intervals are typically fairly wide. As a consequence, short-term andmid-term fluctuations of ballast quality may not be detected. This results in increased costs for maintenance work such as tamping. To make test intervals shorter and even allow for conti...

The impact of NaOH as a ballast water treatment (BWT) on microbial community diversity was assessed using the 16S rRNA gene based Ion Torrent sequencing with its new 400 base chemistry. Ballast water samples from a Great Lakes ship were collected from the intake and discharge of both control and NaOH (pH 12) treated tanks and were analyzed in duplicates. One set of duplicates was treated with t...

ballast as a part of the railway system plays an important role in the operation of the railways and also has a great impact on repair and maintenance activities. hence most of the repair and maintenance activities in traditional railway systems are due to the defections in the ballast layer and therefore most of the maintenance budget is spent on repairing these defects. these repair and maint...

This paper describes a stochastic model used to characterize the probability/risk of NIS establishment from ships’ ballast water discharges. Establishment is defined as the existence of a sufficient number of individuals of a species to provide for a sustained population of the organism. The inherent variability in population dynamics of organisms in their native or established environments is ...

The observed rates and deleterious impacts of biological invasions have caused significant alarm in recent years, driving efforts to reduce the risk (establishment) of new introductions. Characterizing the supply of propagules is key to understanding invasion risk and developing effective management strategies. In coastal ecosystems, ships' ballast water is an important transfer mechanism (vect...

Transition zones in railway tracks are locations with considerable changes in the vertical stiffness of the rail support. Typically they are located near engineering structures, such as bridges, culverts, tunnels and level crossings. In such locations, the differential settlement always exists and continually grows without proper maintenance. Due to the effect of the differential settlement and...

The unintentional introduction of nonindigenous species by ballast water discharge is one of the greatest threats to biodiversity in freshwater systems. Proposed international regulations for ballast water management will require enumeration of viable plankton in ballast water. In this study we analyze the efficacy of vital stains in determining viability of freshwater taxa. The efficacy of vit...

To minimize the dispersal of aquatic nuisance species through shipping, ballast water can be treated to kill, remove, or inactivate organisms. Ultraviolet (UV) radiation is used in some ballast water management systems to address this goal. Because UV treatment renders cells nonviable (by sterilizing them, preventing reproduction) and does not necessarily kill organisms instantaneously, the eff...