Background Measuring physical activity (PA) and sedentary time (ST) by self-report or device as well as assessing related health factors may alter those behaviors. Thus, in intervention trials assessments may bias intervention effects. The aim of our study was to examine whether leisure-time PA, transport-related PA, and overall ST measured via self-report vary after assessments and whether a b...

The flow in sewers is a complete three phase flow (air, water and sediment). The mechanism of sediment transport in sewers is very important. In other words, the passing flow must able to wash deposited sediments and the design should be done in an economic and optimized way. In this study, the sediment transport process in sewers is simulated using a hybrid model. In other words, using the Ada...

Understanding the mechanics of bed load at the flood scale is necessary to link hydrology to landscape evolution. Here we report on observations of the transport of coarse sediment tracer particles in a cobblebedded alluvial river and a step-pool bedrock tributary, at the individual flood and multi-annual timescales. Tracer particle data for each survey are composed of measured displacement len...

a two-dimensional two-phase numerical model is developed to predict transport and fate of oil slicks which resulted the concentration distribution of oil on the water surface. two dimensional governing equation of fluid flow which consists mass and momentum conservation was solved using the finite difference method on the structured staggered grid system. the resulted algebric equations were so...

In this paper, longshore sediment transport in littoral zones is investigated. For investigation of sediment transport in the nearshore zone, the effects of waves, currents and topographical conditions of coast are considered. Linear wave theory was used for the investigation of the wave behaviour. Governing equations of littoral current are continuity and momentum ones. For calculating concent...

Sediment transport along the surface drives geophysical phenomena as diverse as wind erosion and dune formation. The main length scale controlling the dynamics of sediment erosion and deposition is the saturation length Ls, which characterizes the flux response to a change in transport conditions. Here we derive, for the first time, an expression predicting Ls as a function of the average sedim...

Naturally occurring clay colloidal particles are heavily involved in sediment processes in the subsurface soil. Due to the importance of these processes in the subsurface environment, the transport of clay colloidal particles has been studied in several disciplines, including soil sciences, petrology, hydrology, etc. Specifically, in environmental engineering, clay colloid release and transport...