Water equivalent

Hs0 = Head at no flow, or shutoff, ft I4ms = Head of viscous fluid, ft Hw = Water equivalent head, ft hd = Discharge head on a pump, ft of fluid hs = Suction head (or suction lift) on a pump, ft of fluid hSL, hDL = Friction losses in pipe and fittings , subscript SL for suction line and DL for discharge line, ft of fluid hv = Velocity head, ft of fluid L = S = Static head, suction side, ft (Figure 3-38)... 

A stirred reactor contains a batch of 700 kg reactants of specific heat 3.8 kJ/kg K initially at 290 K, which is heated by dry saturated steam at 170 kN/m2 fed to a helical coil. During the heating period the steam supply rate is constant at 0.1 kg/s and condensate leaves at the temperature of the steam. If heat losses arc neglected, calculate the true temperature of the reactants when a thermometer immersed in the material reads 360 K. The bulb of the thermometer is approximately cylindrical and is 100 mm long by 10 mm diameter with a water equivalent of 15 g, and the overall heat transfer coefficient to the thermometer is 300 W/m2 K. What would a thermometer with a similar bulb of half the length and half the heat capacity indicate under these conditions ... 

An open bowl, 0.3 m in diameter, contains water at 350 K evaporating into the atmosphere, if the air currents are sufficiently strong to remove the water vapour as it is formed and if the resistance to its mass transfer in air is equivalent to that of a 1 mm layer for conditions of molecular diffusion, what will be the rate of cooling due to evaporation The water can be considered as well mixed and the water equivalent of the system is equal to 10 kg. The diffusivity of water vapour in air may be taken as 0.20 ctn2/s and the kilogram molecular volume at NTP as 22.4 in3. 

AAC = acceptable ambient concentration ACGIH = American Conference of Governmental Industrial Hygienists ADEQ = Arizona Department of Environmental Quality SNA = Bureau of National Affairs CDC = Center for Disease Control CERCLA = Comprehensive Environmental Response, Compensation, and Liability Act CFR = Code of Federal Regulations DNR = Department of Natural Resources DWEL = drinking water equivalent level ... 

Mass of water equivalent to the mass of the Dewar vessel (kg) Mass of the sample (kg)... 

NAS Drinking Water Equivalent Level SNARL 0.26 mg/L ERA 1987c... 

Estimates of THg loading (pg/m ) can be determined for a dated snowpack interval by the product of the interval Hg concentration and the snow water equivalent, which is determined from the interval density and thickness. Seasonal and, at many sites, near annual (-90%) loadings can then be estimated by summing the interval loadings (USEPA 2003). 

EPA = Environmental Protection Agency DWEL = Drinking Water Equivalent Level ODW = Office of Drinking Water RfD = reference dose USAMBRDL = United States Army Medical Bioengineering Research and Development Laboratory... 

This is precisely the Zwanzig perturbation free energy formula (12.4), with Uuv as the perturbation. Thus, AW(X) turns out to be the free energy to turn on the interactions between the solute (biomolecule) and the solvent (water). Equivalently, it is the free energy to transfer the solute from the gas phase into solution, i.e., AW(X) is the solvation free energy of the solute, artificially maintained in the conformation X. 

Drinking water equivalent of 42.5 mg/kg BW daily as copper glutamate lifetime exposure... 

In mice, nickel chloride produces a dose-dependent increase in abnormal lymphoma cells (WHO 1991). Mice given high concentrations of nickel in drinking water, equivalent to 23 mg Ni/kg BW daily and higher, have an increased incidence of micronuclei in bone marrow (USPHS 1993). However, mice injected once with 50 mg Ni/kg BW as nickel chloride show no evidence of mutagenicity (USPHS 1977). 

A ubiquitous co-catalyst is water. This can be effective in extremely small quantities, as was first shown by Evans and Meadows [18] for the polymerisation of isobutene by boron fluoride at low temperatures, although they could give no quantitative estimate of the amount of water required to co-catalyse this reaction. Later [11, 13] it was shown that in methylene dichloride solution at temperatures below about -60° a few micromoles of water are sufficient to polymerise completely some decimoles of isobutene in the presence of millimolar quantities of titanium tetrachloride. With stannic chloride at -78° the maximum reaction rate is obtained with quantities of water equivalent to that of stannic chloride [31]. As far as aluminium chloride is concerned, there is no rigorous proof that it does require a co-catalyst in order to polymerise isobutene. However, the need for a co-catalyst in isomerisations and alkylations catalysed by aluminium bromide (which is more active than the chloride) has been proved [34-37], so that there is little doubt that even the polymerisations carried out by Kennedy and Thomas with aluminium chloride (see Section 5, iii, (a)) under fairly rigorous conditions depended critically on the presence of a co-catalyst - though whether this was water, or hydrogen chloride, or some other substance, cannot be decided at present. 

With ethylene oxide the situation is complicated. Worsfold and Eastham [63] showed that under anhydrous conditions in ethylene dichloride solution boron fluoride reacts slowly with the monomer to form a co-catalyst and that after the induction period during which this occurs the polymerization proceeds smoothly and that the induction period can be eliminated if water, equivalent to the boron fluoride, is added to the system. 

Tidal-current (or stream) power is derived from water turbines submerged in the wide expanse of a tidal flow or current there is no constructed barrier. Such a turbine is, therefore, the water-equivalent of a wind turbine. As yet, there are no commercial tidal-current power plants. 

The minimum water equivalent is 3.5 mg of water per ml of Karl Fischer reagent. Hence, the percentage of water w/w in the given sample may be calculated by the following expression ... 

The water equivalent of Karl Fischer reagent should always be determined before use. 

English degree chem A unit of water hardness, equal to 1 part calcium carbonate to 70,000 parts water equivalent to 1 grain of calcium carbonate per gallon of water. Also known as Clark degree, ir -glish di.gre ... 

Also reported are drinking water equivalent levels (DWELs). The DWEL is defined by the U.S. EPA as a lifetime exposure concentration protective of adverse, noncancer health effects that assumes all exposure to a contaminant is derived from drinking water. 

Fig. 4 Depth-age relationship of the ice cores from Fiescherhom glacier [12] and Colle Gnifetti [13, 14], Besides annual layer counting and radiocarbon ( C) dating, two types of time markers were used Saharan dust events (labeled by the year only) and volcanic eruptions (labeled by year and name of volcano). Depth is given in water equivalent. This is the amount of water contained in the ice core which is calculated using fim and ice density, respectively, both increasing with depth...

NATIONAL tOont i 1-day (child) 10-day (child) Longer term (child) Longer term (adult) Lifetime (adult) DWEL (Drinking Water Equivalent Level) 1.0 mg/L 1.0 mg/L 0.5 mg/L 1.7 mg/L 0.1 mg/L 0.6 mg/L ... 

Knowing the so-called " water equivalent factor of the calorimeter, it is possible to determine the heat of combustion at constant volume with an accuracy better than 1%... 

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