Infiltration rate

Alternatively, tows of fibers can be passed through a Hquid metal bath, where the individual fibers are wet by the molten metal, wiped of excess metal, and a composite wine is produced. A bundle of such wines can be consoHdated by extmsion to make a composite. Another pressureless Hquid metal infiltration process of making MMCs is the Prim ex process (Lanxide), which can be used with certain reactive metal alloys such as Al—Mg to iafiltrate ceramic preforms. For an Al—Mg alloy, the process takes place between 750—1000°C ia a nitrogen-rich atmosphere (2). Typical infiltration rates are less than 25 cm/h. 

Because many pesticides are appHed to the soil surface, the transport of pesticide during water infiltration is important. Water infiltration is characterized by high initial infiltration rates which decrease rapidly to a nearly constant rate. Dry soils have greater rates of infiltration than wet soils during the initial appHcation of water. Thus, perfluridone movement after appHcation of 3.8 cm of water was considerably greater in soil at a water content of <1% of field capacity than at 50% of field capacity (62). Fluometuron moved deeper into the soil in response to greater rainfall intensity or after rainfall onto a dry rather than a moist soil (63). 

Infiltration rate The rate at which outdoor air enters into a room through the imperfections in the building structure, expressed in air changes per hour or L s. ... 

Infiltration rate. This is the rate at which air moves through a window system as a result of pressure differences between the inside and the outside. Infiltration rates are expressed as airflow rates—cubic meters per hour or cubic feet per minute per square foot of window. An infiltration rate below 0.3 cfm/sq ft is recommended in all applications. 

Where there is no mechanical supply or extract, factors are used to estimate possible natural infiltration rates. Empirical values may be found in several standard references, and the CIBSE Guide ([2], A4) covers this ground adequately. 

Under water scarcity, the two factors, salinity and sodicity of the irrigation water must be considered together for a proper evaluation of the ultimate effect of the water on the infiltration rate that generally increases with increasing salinity of the irrigation water and decreases with either decreasing salinity or increasing sodicity. 

Infiltration rate Water content Particle size distribution Frozen soil Bulk density Clay mineralogy Macro porosity... 

Surface runoff can begin only after (1) rainfall or snowmelt fills storage by plant interception and surface ponding and (2) the rainfall or snowmelt rate exceeds the soil infiltration rate. Excellent sources for technical details include Chow et al.,50 ASCE Manual 28,53 and Linsley et al.56 Factors affecting Q are listed in Table 25.1. 

The investigators also installed 60 1-ft diameter rings in the surface of the liner, so that they could measure independently 60 different infiltration rates on the surface of the liner. Each of the 3-ft2 blocks was assigned an average hydraulic conductivity based on many months of testing and observation. The conductivity for the rest of the liner varies between 10 and 10-8 cm/s, a 100-fold variation of hydraulic conductivity. 

The tests do not directly measure the hydraulic conductivity k of the soil. Instead they measure the infiltration rate / for the soil. Since hydraulic conductivity is the infiltration rate divided by the hydraulic gradient i (see equations in Figure 26.14), it is necessary to determine the hydraulic gradient before k can be calculated. The following equation (with terms defined in Figure 26.14) can be used to estimate the hydraulic gradient ... 

From the hydrologic cycle temporal resolution of soil moisture surface, runoff, and groundwater recharge components, by inputting to the model the net infiltration rate into the soil column and... 

Crust formation thus is attributed to the disaggregation of the uppermost soil layer, initiated by the mechanical impact of the rain drops, and the subsequent dispersion of the clay fraction facilitated by the high ESR of the soil and by the low electrolyte content of rain water (Shainberg, 1990). Upon drying, the dispersed clay is responsible for the formation of the hard crust and decreases in infiltration rate. 

Nero, A.V., M.L. Baegel, C.D. Hollowell, J.G. Ingersoll, and W.W. Nazaroff, Radon Concentrations and Infiltration Rates Measured in Conventional and Energy-efficient Houses, Health Phys. 45 401 (1983). 

Even though only a small proportion of the non-harvested biomass returned to soil ends up in soil humus, SOC is needed to improve water infiltration rates and reduce erosion. SOC contents can be increased by adding more non-harvested biomass to soil or by slowing the mineralization rate of fresh biomass. 

In watersheds where surface runoff is limited by infiltration rate rather than soil-water storage capacity, areas of the watershed can alternate between sources and sinks of surface flow. This again will be a function of soil properties, rainfall intensity and duration, and antecedent moisture condition. As surface runoff is the main mechanism by which phosphorus is exported from most watersheds, it is clear that, if surface runoff does not occur, phosphorus export can be small. Thus, consideration of hydro-logic pathways and variable source areas is critical to a more detailed understanding of phosphorus export from agricultural watersheds. 

The order Aridisol is, as its name suggests, typical of arid climate conditions and found in the southwest deserts. The Aridisol for this project is of the Sagehill series and was collected from Gilliam County, Oregon. The soil is an alkaline coarse-grained soil with free CaC03. It has low infiltration rates and capacities. 

The industrial fatty acid-DETA derivatives were evaluated for application to soil. Water infiltrated soil coated with the BETA derivative of tallow more rapidly than the controls. This was due to the high unsaturation content and also in part to the glycerine retained in the product as discussed below. We were unable to find a solvent system which would readily separate the glycerine, formed from the triglyceride, from the BETA reaction product. If the glycerine were removed, the infiltration rates for the tallow-DETA derivative should be identical with the rates obtained for tallow fatty acid-DETA reaction product. 

Overland runoff may be expressed as a conservation of mass in a flow domain, where the excess rainfall or irrigation rate, R, is equal to the difference between the rainfall and infiltration rates ... 

Viscosity Effect The infiltration and redistribution of two hydrocarbons in moist silt loam and loamy sand soils, with viscosities of 4.7 (soltrol) and 77 (mineral oil) times greater than that of water, was reported by Cary et al. (1989). The spatial distribution of the two hydrocarbons and water is presented Fig. 12.12 the infiltration rate of... 

Finally studies have reported the penetration factor which describes penetration and not decay. Penetration factors are not directly observable and they are usually calculated from infiltration rates and decay rates [11],... 

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