Soiling mechanisms

Soiling is a natural process, because it increases overall randomness and, consequently, the entropy of the system. Therefore, an effort is needed to prevent soiling and maintain the cleanliness of a textile. This effort has been made easier by developing textile finishes that retard soiling and facilitate the removal of soil by detergency. 

A soiling process consists of two steps (1) the transport of soil to the substrate and (2) entrapment of soil in the substrate and/or adhesion of the soil to substrate. Either step can determine the rate of soiling. 

The transport of soil onto a textile can occur by one of three mechanisms (1) direct soiling (e.g., a drop of grease falling on a tablecloth or particulate soil deposited on a textile by air currents) (2) transfer of soil from a soiled surface to a cleaner one (e.g., soiling of armrests of chairs touched by hands), and (3) electrostatic soiling, caused by attraction of airborne soil by electrostatically charged textile surfaces (e.g., curtains). 

The mechanisms and kinetics of soiling with liquids differ from those of particulate soil. Soiling with liquid soils is dominated by wetting and wicking processes discussed in Chapter 11. The resistance of fabrics to soiling with a liquid is greatly enhanced by fluorochemical repellents (Section 12.7.) 

Soiling of textiles with particulate soil has been attributed to mechanical entrapment [9-13], adsorption of soil particles on an oil film covering the fiber surface [9,10,12-16], electrostatic attraction [9,10,12,13,15], and adhesion of particulate soil to the fiber surface [12,13,15,17-19]. The amount of soil that adheres to a fabric depends on the accessible fiber surface area, the topography of the fiber 

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System Soil Mechanical action Bath ratio Detergent... 

Sowers, G. B., and Sowers, G. F., Introductory Soil Mechanics and Foundations, Second Edition, MacMillan Book Co., 1961. 

Tschebotariofl, G. P, Soil Mechanics, Foundations, and Earth Structures, McGraw-Hill, New York, 1951. 

The compaction effects are the most common. According to Terzaghi s work in soil mechanics, the overburden pressure mentioned earlier, is equal to [119]... 

Terzaghi, K., 1943, Theoretical Soil Mechanics, ohn Wiley Sons, New York, NY. 

Allgood, J. R., Structures in Soil Under High Loads, Journal of Soil Mechanics and Foundations Proceedings, ASCE, Mar. 1971. 

Chlorinated anilines are produced by the hydrolysis of a range of acetanilide, urea, and carbamate herbicides, and are therefore widely distributed in agricultural soils. Mechanisms for their loss... 

The problems caused by shales in petroleum activities are not new. At the beginning of the 1950s, many soil mechanics experts were interested in the swelling of clays. It is important to maintain wellbore stability dining drilling, especially in water-sensitive shale and clay formations. The rocks within these types of formations absorb the fluid used in drilling this absorption causes the rock to swell and may lead to a wellbore collapse. The swelling of clays and the problems that may arise from these phenomena are reviewed in the literature [528,529,1788,1900]. Various additives for clay stabilization are shown in Table 3-1. 

Drought stress increases the soil mechanical impedance on plant roots, which in turn can stimulate root exudation (1,4,5). lncrea.sed release of mucilage may contribute to the maintainance of Zn uptake in dry soils by facilitating Zn transport to the root surface in mucilage-embedded soil particles (264). This effect might be supported by water transfer from the subsoil in the roots, which is... 

T. William Lambe R. V. Whitman Massachusetts Institute of Technology Civil Engineering—Soil Mechanics... 

This is similar to the analysis obtained by Ainsley and Smith (see Chhabra, 1992) using the slip line theory from soil mechanics, which results in a dimensionless group called the plasticity number ... 

Another type of reaction that responds to WD cycles is the fixation of K and NH4 ions by smectite (3-7). The fixation of K in smectite has been studied extensively by soil scientists because of its effect on the availability of plant nutrients. The reaction also decreases smectite s ability to swell, decreases its cation exchange capacity (CEC), and modifies its BrjSnsted acidity. Therefore, an understanding of this phenomenon is applicable to many fields of study that are concerned with swelling clays, fields such as soil fertility, soil mechanics, waste disposal, clay catalysis, and the geochemistry of ground and surface waters. 

Unfortunately, cannot be easily determined analytically, and is often either estimated using methods from the field of soil mechanics (from the normal stress ratio, K, or simply adjusted to a value which produces good fits for the experimental data. The forwarding force f, at the barrel wall is positioned in the plane of the barrel surface. This force is adjusted using as found in Eq. A5.1 and results in Eq. A5.2. This is because is the local pressure in the channel. Referring to Fig. A5.4, the forces are defined as follow ... 

Jury WA, Fluhler H (1992) Transport of chemicals through soil Mechanisms, models and field applications. Adv Agron 47 142-202... 

A generalized three-dimensional resin flow model has been developed that employs soil mechanics consolidation theory to predict profiles of resin pressure, resin flow velocity, laminate consolidation, and resin content in a curing laminate. 

Taylor, D.W. Fundamentals of Soil Mechanics (1948) New York, John Wiley and Sons... 

Munkholm, L.J., Schjonning, P. and Petersen, C.T. 2001a. Soil mechanical behaviour of sandy loams in a temperate climate case studies on long-term effects of fertilization and crop rotation. Soil Use and Management 17 269-277. 

Cheng, H.H. 1990. Organic residues in soils Mechanisms of retention and extractability. Intern. J. Environ. Anal. Chem. 39(2) 165-171. 

Source Adapted from von Ltitzow, M., Kogel-Knabner, I., Ekschmitt, K., et al. (2006). Stabilization of organic matter in temperate soils mechanisms and their relevance under different soil conditions—a review. Eur. J. Soil Sci. 57,426-445, with permission from Wiley-Blackwell. 

Cornelissen, G., Gustafsson, O., Bucheli, T.D., Jonker, M.T.O., Koelmans, A.A., van No-ort, P.C.M., 2005. Extensive sorption of organic compounds to black carbon, coal, and kerogen in sediments and soils Mechanisms and consequences for distribution, bioaccumulation, and biodegradation. Environ. Sci. Technol. 39, 6881-6895. 

Casagrande, L. (1952) Electro-osmotic stabilization of soils, Journal of the Boston Society of Civil Engineers, Vol. XXXIX, no. 1 reprinted in Contributions to Soil Mechanics, 1941-1953... 

It is well known that the permeability of a clay soil is not only a function of its porosity, but also of the concentration of ions in the pore fluid, and the permittivity of the pore fluid. While this may be well known, an explanation for the behaviour is not well known. In fact, in a recent paper Hueckel identified the explanation for this behaviour as one of the outstanding problems in soil mechanics ([4]) The controversy over these two inconsistent data sets (i.e., increased... 

The principles outlined in Section 3.6.6 apply to both the removal and anti-redeposi-tion of soils, and to detergency in both industrial and personal care situations. There are, however, some differences between the application of detergency in an industrial setting (Section 12.2.1) and in a household setting. For example, whereas industrial cleaning usually involves hard surfaces that cannot mechanically hold soil, fabrics can hold soil mechanically, even after the soil has been removed from the fibre surfaces. In addition, fabrics can usually swell in aqueous solution, are permeable to small molecules, and may contain charged or polar surface groups that can interact with soil. An effective shampoo or skin cleaner needs to displace dirt and keep it dispersed so it does not redeposit before the hair or skin can be rinsed. 

Lambe, T. W., and Whitman, R. V. (1979). Soil Mechanics, SI Version. John Wiley Sons, New York. 

The study of problems concerning the flow of fluids through beds of granular material has many applications. It is indispensable to the theory of industrial filtration and water purification. The flow of ground water is controlled by soil structure and the most elementary phases of granular bed structure are fundamental to soil mechanics and soil physics. 

Discussion of paper, Practical application of soil mechanics (Charles Terzaghi)Trans. A.S.C.E., 103 1461-1469. 

Theoretical soil mechanics. New York Wiley Sons, Inc. 

DYNAMICS OF FLUIDS IN POROUS MEDIA. Jacob Bear. For advanced students of ground water hydrology, soil mechanics and physics, drainage and irrigation engineering and more. 335 illustrations. Exercises, with answers. 784pp. 6b x 9b. 65675-6 Pa. 19.95... 

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