Resistivity of water

Fig. IV-24. Effect of alkyl chain length of n-alcohols on the resistance of water evaporation at 25°C. (From Ref. 275.)...

The by-product, representing a relatively reduced form of sulfur, is a reasonable model for the sulfur impurities in the synthesis gas obtained from sulfur-rich coal. This sodium sulfide test of sulfur resistance of water gas shift catalyst systems generated in basic solutions is a very severe test since the quantities of sulfur involved are much larger than those likely to be found in synthesis gas made from any sulfur-rich coals. 

ASTM D 1125 Standard Test Method for Electrical Conductivity and Resistivity of Water. ... 

The sedimentation of particles in the water column represents an important mechanism for sediment transport and is most fundamentally controlled by gravitational setting. Gravitational forces, which act in a downward direction, are also opposed by the viscous resistance of water in an upward direction. The sinking speed for spherical, slow sinking, single particles is described by Stoke s law (Allen, 1985) ... 

As already said neither acids nor salts are suitable for lowering the specific resistance of water because of their corrosive effect. ) Therefore only sodium or... 

The electrical resistivity of water-saturated sediments depends on the resistivity of its solid and fluid constituents. However, as the sediment grains are poor conductors an electrical current mainly propagates in the pore fluid. The dominant transport mechanism is an electrolytic conduction by ions and molecules with an excess or deficiency of electrons. Hence, current propagation in water-saturated sediments actually transports material through the pore space, so that the resistivity depends on both the conductivity of the pore water and the micro structure of the sediment. The conductivity of pore water varies with its salinity, and mobility and concentration of dissolved ions and molecules. The microstructure of the sediment is controlled by the amount and distribution of pore space and its capillarity and tortuosity. Thus, the electrical resistivity cannot be considered as a bulk parameter which strictly only depends on the relative amount of solid and fluid components, but as shown below, it can be used to derive porosity and wet bulk density as bulk parameters after calibration to a typical sediment composition of a local sedimentation environment. 

Maniwa and co-workers have shown that water-SWCNTs can be used as a new type of molecular nanovalve [14]. They carried out a systematic investigation of water-SWCNTs in different gaseous environment below 0.1 MPa using electrical resistance. X-ray diffraction, NMR measurements, and MD simulations. They found that the resistivity of water-SWCNTs exhibits a significant increase in gas atmospheres below a critical temperature at which a particular type of gas molecule can enter the SWCNT in an on-and-off fashion. 

In order to improve the cooling effect of the PM motor, the water in the channel of jacket should be turbulent for the high convective heat transfer coefficient. In order to decrease the local resistance of water flow path, the section profile of the channel is designed as semielliptical type. 

Moreover, the resistivity of water changes markedly with temperature, and temperature increases with depth. Hence, for each bed under investigation, the temperature of both rock and water must be determined or closely estimated, and the calculated resistivity of the pore water at that temperature should be converted to its value at a standard temperature (i.e. 25°C). 

The electrical resistivity of water is measured in ohm centimetres, and conductivity, given by the reciprocal of resistivity, in mho/cm. In international units, 1 (imho/cm = 1 pS/cm, where S is the unit siemens. Extremely pure water is produced by deionization. This water has a conductivity of less than 1 pS/cm. 

The contact angle between formation fluid and porous rock decreased owing to the microbial action. The original contact angle between bacterial suspension and porous rock was greater than 90°, indicated that the porous rock was oleophylic initially, the capillary force was resistance of water-flooding. Combined with the data of oil-water interfacial tension, the variation of capillary... 

The electrical resistivity of water is a function of the concentration of electrically conductive ions it contains. Low resistivity waters are more corrosive generally because of the availability of ionic species to transport charge between anodic and cathodic sites. However, the magnitude of the resistivity is not the only determining factor for a water s corrosivity waters with high resistivity may be corrosive due to the presence of corrosion-causing bacteria. 

Petroleum and related products— Determination of the corrosion resistance of water-containing fire-resistant fluids for hydraulic systems Structural steels with improved atmospheric corrosion resistance Liquefied petroleum gases—Corrosiveness to copper—Copper strip test... 

Archie [5] defined a parameter known as the formation factor, F which links the resistivity of the sample at 100 % water saturation Ro with the resistivity of water R ... 

Figure 33-14. Abrasion resistance of water-repellent glass (w.r.g.).

At the same time the following measures have been proposed to increase the resistance of water source and operator s health safety, in case of which the cost-benefit efficiency is expected to be higher... 

Pioro, I.L., Duffey, R.B., 2003. Literature Survey of Heat Transfer and Hydraulic Resistance of Water, Carbon Dioxide, Helium and Other Fluids at Supercritical and Near-critical Pressures. Atomic Energy of Canada Report AECL-12137, FFC-FCT-409. 

Resistivity of water, soil, or other electrolyte solution... 

The weakness of the resistance of water, the errors which can result from the fast absorption of the dampening layer, finally the disagreement between the results above and those of the experiments with the magnetized needle with regard to the albumin and saponin solutions, hardly allow, one sees, to attribute a sufficient confidence to the process of the divided capillary tubes I thus return from there to that which I reported in my 8th series, although it gives only an approximation undoubtedly rather rough, and one cannot employ it with all liquids. 

Resistivity of water (cleaning) The electrical conductivity of water as measured between probes spaced one centimeter apart. Example 18megohm-cm. One measure of the purity of the water. See also Water, deionized (DI) Water, hard Water, soft Water, ultrapure. 

In an early paper. Brace et al. (1965) published results of a study about the influence of crack and intergramdar porosity and the effect of pressure upon the electrical resistivity of water-saturated igneous rocks. For seven rock samples from Brace et al. s (1965) paper. Fig. 8.8 shows the specific electrical resistivity of water-saturated rocks as a function of pressure. Obviously, there is a strong increase of the resistivity in the range below 400 MPa. This is caused by the reduction in the porosity, mainly by the decrease of the crack-cross section and the closure of crack parts. 

Fig. 8-34 J-Tube apparatus for measuring the hydrostatic pressure resistance of water-proofing membranes.

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