Moisture infiltration

The soil treated with the tallow fatty acid-DETA reaction product retarded moisture infiltration on both soils. The partially hydrogenated and completely hydrogenated tallow fatty acid-DETA derivatives also displayed hydrophobic properties on both soils. Although the completely hydrogenated tallow fatty acid-DETA reaction product (m.p. 90°C) had optimum hydrophobic properties on all three soils, it was difficult to dissolve in most organic solvents. Even the partially hydrogenated tallow fatty acid-DETA reaction product, m.p. 45°-50°C, was not readily soluble. 

McCarthy et al. (1999) studied CCB diagenesis in core material recovered from four disposal landfills or civil engineering works. In three of the sites, where sufficient moisture infiltration occurred, ash materials experienced significant... 

A closed carbonate system is defined as one in which the carbon dioxide (carbonic acid) initially present in the water is not replenished as it is consumed in carbonate mineral dissolution. This may simply reflect that soil moisture/infiltration is charged with CO2 chiefly in the A horizon of the soil, whereas carbonate mineral dissolution by H2CO3 takes place at greater depths in the soil C horizon or below the water table in the absence of further sources of carbon dioxide. (There may be, however, sources of additional CO2 at depth, including pollution. See Chap. 5.)... 

Know how and why the rate and character of chemical weathering is dependent on temperature, soil or-ganic/biological activity, and moisture infiltration rate. 

Abstract This paper examines the hydraulic interaction between emplaced engineered clay buffers and host rock formations. This has been achieved via the analysis of the re-saturation behaviour of a large scale in-situ experiment. Experimental results from a testing programme performed by Atomic Energy of Canada Limited, (AECL), are examined via both direct interpretation of the experimental results and numerical simulations of the test. Analysis of seepage rates into an open borehole indicate the presence of an EDZ prior to the emplacement and some healing of the EDZ after buffer placement. It is also found that correct representation of moisture infiltration into the buffer is essential to capture the variations in pore water pressure in the host rock. 

Simulation of the second phase of the test, when the buffer is in-situ, showed that correctly representing moisture infiltration into the buffer was essential to capture the variations in pore water pressure in the host rock. In particular when an effective conductivity for the buffer was used, in comparison to a conventional relationship, an improved correlation with experimental in-flow within the buffer was found. Correspondingly the pore water pressure variations in the rock correctly followed the trends observed in the experimental results. 

Plastic film is used as an envelope for the electrode element which constitutes an insuperable barrier against solvent vapor permeation and moisture infiltration. 

Filter compartments Number 5 and 6 and the spare filter compartment are no longer stored on the roof. The compartment doors have been sealed closed. Blanks are installed in the inlet and outlet ducts to help prevoit insect and animal infestation and moisture infiltration. Provisions will not be made to fluther seal junction boxes or the fire detection box. Stainless steel pipe plugs have been replaced rith an acceptable plastic plug to prevent galling. The drain lines on the compartment and on the roof have been capped. 

It was found, however, that an envelope of aluminum-laminated polymer film could not sufficiently stop moisture infiltration. A significant amount of moisture penetrated through adhesive for a margin of the envelope rather than through the aluminum-laminated film (Figure 8). To make this adhesive... 

Figure 8. Schematic drawing of LPB envelope and path of ambient moisture infiltration...

Residential Construction. Owing to rising energy costs, the cost and low thermal conductivity are of prime importance in wall and ceiling insulation of residential buildings. The combination of insulation efficiency, desirable stmctural properties, ease of appHcation, abiHty to reduce air infiltration, and moisture resistance has led to use of extmded polymeric foam in residential constmction as sheathing, as perimeter and floor insulation under concrete, and as a combined plaster base and insulation for walls. 

Example 5 Cooling and Dehumidification Find the cooling load per pound of dry air resulting from infiltration of room air at 80 F dry-bulb temperature and 67 F wet-bulb temperature into a cooler maintained at. 30 F dry-bulb and 28 F wet-bulb temperature, where moisture freezes on the coil, which is maintained at 20 F. 

The hunnidity ratio oJ a rotjm at any given time is given by a Jatent heat balance equation including the water vapor flows due to infiltration to ventilation to moisture transport through envelope elements... 

Subsurface runoff. When precipitation hits the land surface, the vast majority does not go directly into the network of streams and rivers in fact, it may be cycled several times before ever reaching a river and the ocean. Instead, most precipitation that is not intercepted by the vegetation canopy and re-evaporated infiltrates into the soil, where it may reside as soil moisture, percolate down to ground-water, or be transpired by plants. 

The harmful liquid that collects at the bottom of a landfill is known as leachate. The generation of leachate is a result of uncontrolled runoff, and percolation of precipitation and irrigation water into the landfill. Leachate can also include the moisture content initially contained in the waste, as well as infiltrating groundwater. Leachate contains a variety of chemical constituents derived from the solubilization of the materials deposited in the landfill and from the products of the chemical and biochemical reactions occurring within the landfill under the anaerobic conditions. 

It was observed that the factors contributing to the variation of leachate data are solid waste characteristics, for example, the composition and size of the waste and degree of compaction, the moisture content and degree of rainwater infiltration, temperature, sampling, and analytical methods.47... 

It is assumed that the moisture content of the soil has been determined to be approximately 50% under worst-case conditions. Using this information and the results from vendor tests, it has been determined that a minimum dose of one part solidification reagent to two parts soil is required for the migration control of lead. Testing has shown that the optimum solidification reagent mixture would comprise ca. 50% fly ash and ca. 50% kiln dust. Thus, ca. 7000 t (6364 T) each of fly ash and cement kiln dust would be required. The reagents would be added in situ with a backhoe. As one area of the soil is fixed, the equipment could be moved onto the fixed soil to blend the next section. It may be anticipated that the soil volume would expand by ca. 20% as a result of the fixation process. This additional volume would be used to achieve the required slope for the cap. An RCRA soil/clay cap placed over the solidified material is necessary to prevent infiltration and additional hydraulic stress on the fixed soil. It is estimated that the fixation would reduce lead migration by 40% and that the fixed soil may pass the U.S. EPA levels for lead. 

Subsurface formations can be divided into the overburden (unconsolidated) and bedrock according to its solidarity. The upper subsurface can be further divided into the unsaturated zone and the saturated zone depending on pore structure and moisture saturation. The saturated zone is the zone in which the voids in the rock or soil are filled with water at a pressure greater than atmospheric. The water table is at the top of a saturated zone in an unconfined aquifer. The unsaturated zone is the zone between the land surface and the water table, and is also called the zone of aeration or the vadose zone. The pore spaces contain water at less than atmospheric pressure, air, and other gases. This zone is unsaturated except during periods of heavy infiltration. 

The movement of free product is dependent on soil permeability and moisture. The released gasoline first infiltrates downward vertically, mainly governed by the gravity force, into and through the unsaturated zone, then reaches the water table. If there is an impermeable layer above the water table, the free product will be purged and may not reach the water table directly. In the... 

The hydrologic cycle, or moisture cycle — that may encompass the processes of rain infiltration in the soil, exfiltration from the soil to the air, surface runoff, evaporation, moisture behavior, groundwater recharge and capillary rise from the groundwater. All these processes are interconnected and are frequently referred to as the hydrologic cycle components. 

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... 

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. 

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