Episodic flows

When enrichment episodes occur in the real world, but not in the laboratory under federal certification tests, real-world emissions are significantly higher than predicted. Further complicating emissions prediction is that aggressive driver behavior and complex traffic flow characteristics play a large role in enrichment occurrence. Current vehicle activity simulation models can predict average speeds and traffic volumes very well, but poorly predict the hard-accel-eration events that lead to enrichment. 

The physical transport of particles in a river occurs by two primary modes bedload and suspended load. Bedload consists of material moved along the bed of the river by the tractive force exerted by flowing water. Bedload may roll or hop along the bottom, and individual particles may remain stationary for long periods of time between episodes of movement. Suspended load consists of material suspended within the flow and that is consequently advected by flowing water. Rivers and streams are naturally turbulent, and if the upward component of turbulence is sufficient to overcome the settling velocity of a particle, then it will tend to remain in suspension because the particles become resuspended before they can settle to the bottom of the flow. Suspended load consists of the finest particles transported by a river, and in general is composed of clay- and silt-sized... 

Soil water flow is decidedly episodic. During dry times the water solutions in the soil are probably fairly concentrated and not very reactive. Time-averaged reaction rates should be roughly proportional to the fraction of time reacting minerals are in contact with thermodynamically imdersaturated (and reactive) water. In a study of the relationship between denudation rate and runoff for rivers draining igneous and metamorphic rock in Kenya, Dunne (1978) obtains the relationship of (denudation rate in tons/km per year) = 0.28 (runoff in mm/ year)°. ... 

The second case (Table 2) illustrates a hypothetic urban stream receiving both metals and nutrients mainly via urban runoff. Since urban runoff is directly linked with rainfall episodes, metal inputs and exposure will be variable under base-flow during a rainy period and very low under a situation of water scarcity (low rain and low-flow). In this case, a sudden flow increase after strong rains may cause contrasting effects on water metal transport depending on the previous situation. If previous rains have already washed the metals retained in land and sediments, the... 

Clearly, however, the flow simplification would be invalid on a small site with episodic projects, or in contexts with significant downtime due to changeover and setup activities for project-specific assays. Such simulation problems covering multiple projects and multiple assays, with use of a mix of shared and dedicated resources, can rapidly become intractable, and an early, com-monsense selection of the focus area for simulation is essential. 

Local emission to wastewater during episode U(0.0153 0.153) kg day-1 Additives by Using Substance Flow Analysis, With a Case Study in China ... 

It is now clear that the fate of chemicals in the environment is controlled by a combination of three groups of factors. First are the prevailing environmental conditions such as temperatures, flows and accumulations of air, water and solid matter and the composition of these media. Second are the properties of the chemicals which influence partitioning and reaction tendencies, i.e., the extent to which the chemical evaporates or associates with sediments, and how fast the chemical is eventually destroyed by conversion to other chemical species. Third are the patterns of use, into which compartments the substance is introduced, whether introduction is episodic or continuous and in the case of pesticides how and with which additives the active ingredient is applied. 

One of the most prominent positive symptoms in schizophrenia is the auditory hallucinations that are perceived as distinct voices emanating from outside the individual. Regional cerebral-blood-flow studies in patients experiencing auditory hallucinations reveal activation of the associational auditory cortex during the episodes of hallucinations, but not in their absence. One theory holds that auditory hallucinations occur as a consequence of the inability of individuals with schizophrenia to monitor effectively their inner speech. fMRI studies suggest that... 

Compute the availability of the level indicator system and flow shutdown system for Problem 11-2. Assume a 1-month maintenance schedule. Compute the MTBC for a high-level episode and a failure in the shutdown system, assuming that a high-level episode occurs once every 6 months. 

Diapirs rise episodically and slowly at rates of 0.1 to 1 mm/y for periods of several million years. This is roughly 100 times slower than the lateral speed of the earth s crustal plates. Some diapirs are eventually squeezed out onto the surface of the crust where they form salt islands. Some are protruding through the sides of mountains and are now flowing down slope as a type of salt glacier, called a namakier, that moves on the order of a few meters per year. 

By trapping the sediment from used alpine waters, reservoirs reduce the transport of suspended load to residual flow reaches. In these sections with a reduced channel flow, the tractive force and shear stress is drastically reduced. This additionally reduces the bed load transport, which may then result in solid matter originating from unaffected tributary streams remaiiung in the main channel, thus significantly increasing the debris-flow hazard for episodic high water discharge [36]. 

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