Artificial soils

As with the case of energy input, detergency generally reaches a plateau after a certain wash time as would be expected from a kinetic analysis. In a practical system, each of its numerous components has a different rate constant, hence its rate behavior generally does not exhibit any simple pattern. Many attempts have been made to fit soil removal (50) rates in practical systems to the usual rate equations of physical chemistry. The rate of soil removal in the Launder-Ometer could be reasonably well described by the equation of a first-order chemical reaction, ie, the rate was proportional to the amount of removable soil remaining on the fabric (51,52). In a study of soil removal rates from artificially soiled fabrics in the Terg-O-Tometer, the percent soil removal increased linearly with the log of cumulative wash time. 

Examples of artificially soiled test pieces used to test the performance of amylases include cocoa /milk/sugar, cocoa/sugar/potato starch, cocoa /milk/sugar/potato starch, and starch/carbon black, all on cotton or polyester/cotton. 

Artificial soil solution [24] (MgSq, cacq CaSq) x-x ... 

Fig. 3-7 Electrochemical depolarization after switching off the protection current for different recording speeds (polarization of steel in artificial soil solution for 200 h).

Detergency was ascertained as the quotient of the whiteness obtained and the whiteness which is theoretically possible, expressed as a percentage. Samples of artificial soiled fabrics are washed under given conditions. Aqueous solutions of alkanephosphonic acid bisdiisopropanolamides show a notable detergency without addition of a builder, e.g., sodium triphosphate [190] see Table 12. 

Addition of suitable builders, such as sodium silicates or sodium tripolyphosphate, could increase the detergency of soap-LSDA blend even further. A systematic investigation of three-component systems, soap-LSDA builder, showed that a detergency maximum could be attained which corresponded to a certain fixed ratio of components. Maximum detergency corresponded to an approximate composition of 75% soap, 10% MES, and 15% metasilicate. The tests were carried out at 50°C and at 300 ppm water hardness which is well above that of U.S. municipal water supplies. The principle of detergency potentiation of soap by an LSDA and builder was always evident, even when using other artificially soiled cloths, such as those supplied by U.S. Testing Co. or Testfabrics Inc. 

Materials and methods. Each species studied was grown in the greenhouse in a growth unit constructed from 10 cm PVC drain pipe and T-fittings, as described previously. The growth units were filled with an artificial soil mix of perlite/coarse sand/coarse vermlculite 3/2/1 by volume. On the second and fifth day of each week four liters of a full strength Peter s Hydro-sol solution plus calcium nitrate (36.7 g/37.8 liters plus 17.0 g Ca(N03 )2 /37.8 liters) were added to each growth... 

Soybean bloassays of root exudates. Four soybean seeds ( Bragg ) were planted In each of 100 12.5 cm plastic pots filled with an artificial soil mix consisting of perlite/coarse sand/coarse vermiculite 3/2/1 by volume. After one week the plants were thinned to two per pot and the treatments were begun. The experimental design was a completely randomized design with 10 replications (pots) per treatment. On the first day of each week each pot was watered with 300 ml effluent from the appropriate growth units. On the fifth day of each week all pots were watered with Peter s Hydro-sol solution with CaCNOj. At other times the pots were watered as needed with tap water. On the second and fifth day of each week the height of the soybeans (base to apical bud) was measured. 

Earthworm, Eisenia foetida 10-12 pg Zn/cm2 applied to epidermis 662 mg Zn/kg artificial soil (95% confidence interval 574-674)... 

Insulation of refrigerators, refrigerated coaches and boats. Artificial soil for horticulture. 

Dror et al. (2000a, 2000b) report an experiment dealing with the effect of type and concentration of electrolytes, in an artificial soil aqueous solution, on the... 

Kammenga, J.E. Koert, P. Riksen, J. Korthals, G.W. Bakker, J. A toxicity test in artificial soil based on the life-history strategy of the nematode Plectus acuminatys. Environ. Toxicol. Chem. 1996,15, 722-727. 

Staint-Dernis, M. Narbonne, J.F. Amaud, C. Ribera, D. Biochemical responses of the earthworm Eisenia fetida andrei exposed to contaminated artificial soil effects of lead acetate. Soil Biol. Biochem. 2001, 33, 395-404. 

Lee, P.K. and Touray, J.C. (1998) Characteristics of a polluted artificial soil located along a motorway and effects of acidification on the leaching behaviour of heavy metals (Pb, Zn, Cd). Water Res., 32, 3425-3435. 

Acute toxicity using artificial soil substrate... 

Oomen et al. (2003) defined 4 steps in the oral bioavailability of chemicals present in contaminated soils to man soil ingestion, mobilization from soil during digestion (i.e., bioaccessibility), absorption from the intestinal lumen, and first-pass effect. An in vitro model of the human digestive system was used to study the uptake of chemicals from ingested soil. When an artificial soil, spiked... 

Bielska, L., Smidova, K., Hofman, J. Supercritical fluid extraction of persistent organic pollutants from natural and artificial soil and comparison with hioaccumulation in earthworms. Environ. Pollut. 176, 48-54 (2013)... 

Grayness of a fabric swatch is not directly proportional to its content of black pigment (or artificial soil). A basic formula relating reflectance to the pigment content or concentration can be applied to the evaluation of detergency test swatches (64, 125-127). In simple form, an adaptation of the Kubelka-Munk equation, it states that the quantity (1 R) /2R (where R is the fraction of fight reflected... 

Applications of Fiexible Urethane Foams. Cushioning materials are the major applicatioii of flexible urethane foams. In 1980, the worldwide consumption of urethane foams was as follows (48) furniture and mattress applications, 37% and automotive applications, 18%. In addition to these applications, a wide variety of additional applications have been reported, including transportation, textiles, packaging, appliances, household materials, medical supplies, sound absorbents, sporting goods, cosmetics, agricultural applications such as artificial soil, and toys. 

International Organization for Standardization. 1992. Soil quality. Effects of pollutants on earthworms (Eisenia foetida). Part 1 Method for the determination of acute toxicity using artificial soil substrate. BSI, London. Draft International Standard ISO/DIS 11268-1. 

Tests with three soil invertebrate groups, lumbricid earthworms, enchytraeids and springtails, have been ratified. All three tests were developed originally for testing the toxicity of plant protection products in an artificial soil consisting of 10% peat,... 

Saint-Denis, M., Pfohl-Leszkowicz, A., Narbonne, J.F. and Ribera, D. (2000) Dose-response and kinetics of the formation of DNA adducts in the earthworm Eisenia fetidaiandrei exposed to B(a)P-contaminated artificial soil. Polycyclic Aromatic Compounds, 18, 117-127. 

For terrestrial organisms, there remains the choice of natural or artificial soil. The former is clearly more directly relevant, but suffers from the lack of repeatability. The problem with artificial soils is the range of types that may be required, varying critically in their organic content that is a primary determinant of bioavailability and toxicity. 

Values of EC50 were substantially higher using an artificial soil than in using a natural loam. 

A comparison of ECS0 using concentrations in pore water showed that values for the artificial soil were highest followed by values for the nutrient solution. 

It was concluded that, on the basis of the desirability for comparison and standardization, the artificial soil recommended by OECD was preferable. 

A preponderance of toxicity data reported to date was generated in studies using artificial soil (similarly formulated Organization for Economic Cooperation and Development [OECD] artificial soil or U.S. Environmental Protection Agency [USEPA] standard artificial soil). These investigations did not consider the effects of soil physical and chemical properties, which can vary widely at contaminated sites, on the bioavailability and subsequent toxicity of EM. Ecotoxicological data established in such studies may have limited relevance for site-specific ERAs. Therefore,... 

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