Water, residence time

Less than 0.25 years More than 0.25 years Water residence time... 

Fig. 6 Comparison of results of the AF model solved with and without streamflow trend for wet and dry years, expressed as years above and below the mean water residence time in the reservoir (0.25 years)...

In this multimedia discharge scenario the overall residence time is 59 hours, which can be viewed as 60% of the air residence time of 19.7 h, 30% of the water residence time of 140 h and 10% of the overall soil residence time of 53 h. The overall amount in the environment of 59,000 kg is thus largely controlled by the discharges to water, which account for (0.3 x 133863) or 40,000 kg. 

Figure 7.3 Comparative evolution of the concentration for a non-reactive species and a reactive species when the input concentration is doubled at t=0. In this particular case, th = 0.2 is the water residence time in time units, a,- = 4 the reactivity coefficient, equation (7.2.8), of the reactive species.

In conclusion, the processes dominating the environmental fate of non-ionic surfactants in estuaries are biodegradation in the water column, sorption/sedimentation and volatilisation, together with the dynamics of the estuary, in particular water residence times. 

Fig. 14.12 Left Intermolecular cross-relaxation rate at 600 MHz as a function of the water residence time (with permission from Ref. [39]) Right waterLOGSY experiment recorded on a ten-compound mixture with CDK2 (bottom) and reference ID spectrum (top). Spectra were collected at 19°C and 600 MHz the concentration of CDK2 was approx. 10 jj,M. The asterisks indicate signals due to a ligand binding to CDK2 (with permission from Ref. [35]).

Paramagnetic amphiphilic complexes embedded in micelles have their hydrophilic head and thus the paramagnetic ion in contact with the surrounding water. If the complex has only one hydrophobic chain, the access of water to the ion should be easy but when two hydrophobic chains are involved like in DTPA bisamides complexes, the incorporation of both chains in the micellar structure could reduce either the accessibility of water to the ion or the water exchange rate. It has been reported that micellar Gd-DOTA complexes substituted by one hydrophobic chain are characterized by a water residence time similar to that of Gd-DOTA 200 ns) and that their enhanced relax-... 

Fig. 6. Continuous extraction of w-butylamine from kerosene into water with 6-in. flat-bladed turbines. Vessel diameter = 14.75 in., 7.5 g.p.m. kerosene, 4.78 g.p.m. water, residence time = 1.08 min. Data of Overcashier et al. (03).

The mean water residence time is equal to the water volume divided by the volumetric flux ... 

Water residence time in each cell is about 1 min. 

LRL is a groundwater recharge system (no surface inlets or outlets) and receives 98-100% of its water from precipitation directly onto the lake surface. Groundwater seepage accounts for about 35% of the water output from the lake, and evaporation accounts for the remaining 65%. Water residence time, tw, is about 9-11 years. Most of LRL is situated above the regional... 

Karger (259) measured D = 2.5 x 10-7 cm2 sec-1 at -35°C for zeolite X with 12 H20 molecules per supercage, and 1.4 x 10 7cm2sec 1 for 30 molecules. This leads to jump lengths of 8 and 6 A, respectively, compared with ca. 2 A in bulk water. Residence times and jump distances in zeolites are greater than in the liquid. 

Lake Erie is the smallest and shallowest of the lakes, and it has been heavily impacted by urbanization and agriculture. Lake Erie receives runoff from agricultural areas in southwestern Ontario, northern Ohio, and southern Michigan. In addition, there are numerous metropolitan areas located in the Lake Erie basin these include Cleveland, Ohio, and Buffalo, New York. The average depth of Lake Erie is only 19 meters, and as a result, it warms rapidly in the spring and summer, and it frequently freezes over in winter. Lake Erie also has the shortest water residence time of the lakes (2.6 years), and thus, the condition of this lake can change rapidly. 

Lake Ontario is much deeper than its upstream neighbor, having an average depth of 86 meters and a water residence time of 6 years. Major Canadian urban industrial centers, such as Hamilton and Toronto, Ontario, are located on its shore. The southern (U.S.) shore of Lake Ontario is less urbanized and is not intensively farmed, except for a narrow band along the... 

SW Ontario (12 lakes) 1.0-13.7 Area catchment/lake (+) Water residence time (-) Curtis and Schindler (1997)... 

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