Density seawater

Suppose you were marooned on a tropical island and had to use seawater (density 1.10 g-cm 3) to make a primitive barometer. What height would the water reach in your barometer when a mercury barometer would reach 73.5 cm The density of mercury is 13.6 g-cm 3. 

As demonstrated by the polynomials in the equation of state of seawater, density is not linearly related to temperature or salinity and does not exhibit conservative behavior. One of the interesting consequences of this nonconservative behavior is that an... 

The nonconservative behavior of seawater density and compressibility is caused partly by H bonding and partly by the electrostatic attractions exerted by the salt ions on their neighboring water molecules. The effect of these attractions can be estimated by trying to compute the density of seawater as a simple sum of the volumes of water and salt present in 1 kg of seawater (5 = 35%o and t = 4°C). As shown in Table 3.6, the actual density, as tabulated in the online appendix on the companion website (ct, = 27.81, so p = 1.02781 g/cm ), is about 1% higher than that predicted from summing the volumes of salt and water (1.0192 g/cm ). 

Schematic longitudinal profile through a semi-isolated basin located in a hot, arid climate and separated from the open sea by a narrow portal. The sill depth, although shallow, is still great enough to permit some two-way flow of surface water. The lines show inferred seawater density (g/cm ) and the arrows show current directions. The pattern of evaporite deposition is based on the relationships between brine density and precipitate composition as shown in Figure 17.1, assuming that salt particles accumulate on the seafloor through the process of pelagic sedimentation. Source-. From Scruton, P. C. (1953). American Association of Petroleum Geologists Bulletin, 37, 2498-2512.

Isopycnal A fine on a chart or map that connects points of constant seawater density. 

Salinity measurements are most often used in oceanography to determine seawater density. The conventional measure used by oceanographers for determining salinity is conductivity. This is feasible because the salt content of seawater is well defined, as is the temperature-related compressibility. As an alternative, the refractive index of water is a good descriptor of density when temperature is known or can be measured. Refractive index provides a high-precision method for determining the density of pure water. As various salts are added, the refractive index is a less exact predictor of density, although relative measurements can still be useful. 

How many liters of seawater (density 1.025 g/cm3) must be processed to obtain 2.0 million kg of bromine Assume the Br ion concentration listed in Table 14.3 and a recovery rate of 20%. 

Fig. 3.19. Comparison of FREZCHEM model and Feistel (2003) model estimates of seawater density as a function of temperature and pressure...

Seasonal sea level oscillations. Interannual level changes in the Black Sea are mainly defined by the variations in the water balance components, seawater density, and atmospheric pressure. 

The ranges of the steric sea level oscillations related to the changes in the seawater density are different over the Black Sea area [10]. The highest annual ranges of the steric oscillations are observed in the central (up to 20 cm) and southeastern (up to 16 cm) regions their lowest values are characteristic of the center of the eastern part of the sea. The explanation of this kind of spatial pattern may be found while assessing the phases of the annual harmonics of the total level and its temperature and salinity components. 

Salinity is a measure of the salt content of seawater. Developments in analytical chemistry have led to an historical evolution of the salinity concept. Intrinsically, it would seem to be a relatively straightforward task to measure. This is true for imprecise determinations that can be quickly performed using a hand-held refractometer. The salinity affects seawater density and thus, the impetus for high precision in salinity measurements came from physical oceanographers. 

Both temperature and salinity affect another important physical characteristic of seawater density Density is a property of matter that refers to its mass per unit volume. A cup of seawater has a higher density than a cup of freshwater because of the added mass of the dissolved salts. As the salinity of water increases, so does its density. 

Another promising option is to inject liquid CO2 into a reactor where it can react at a controlled rate with seawater to form hydrates. While it is difficult to achieve 100% reaction efficiency, laboratory and field experiments indicate that negative buoyancy, and hence sinking, can be achieved with as little as about 25% reaction efficiency. The hydrate reactor could be towed from a moving ship to encourage dilution, or attached to a fixed platform, where the large concentration of dense particles, and the increased seawater density caused by hydrate dissolution, would induce a negatively buoyant plume. 

Figure 3 shows the settling velocity as a function of particle density and diameter for a typical seawater density and viscosity value that may be encountered near a wastewater discharge site. Nonlinearity of the settling velocity contours on the semilogarithmic plot results as the... 

For polymeric PVT data, the preferred empirical representation is the relation proposed by Tait [1889] for the isothermal seawater density at high pressures. Nanda... 

The effect of salinity on pore water density and the calculation of both bulk density and grain density can be illustrated using the equation for seawater density at 1 atm presented by Millero and Poisson (1981). The results are presented in Table 6.3. A review shows that the effect is relatively small, and decreases with decreasing water content of the samples. Usually, the resulting changes are not significant for the purpose of the measurements. Extraction of pore water from a soil sample and the determination of its soluble salt content by refractometer has been standardized in ASTM D4542. 

Removal of the corrosion product or oxide layer by excessive flow velocities leads to increased corrosion rates of the metallic material. Corrosion rates 2ire often dependent on fluid flow and the availability of appropriate species required to drive electrochemical reactions. Surface shear stress is a measure of the force applied by fluid flow to the corrosion product film. For seawater, this takes into account changes in seawater density and kinematic viscosity with temperature and salinity [33]. Accelerated corrosion of copper-based alloys under velocity conditions occurs when the shear surface stress exceeds the binding force of the corrosion product film. Alloying elements such as chromium improve the adherence of the corrosion product film on copper alloys in seawater based on measurements of the surface shear stress. The critical shear stress for C72200 (297 N/m, 6.2 Ibf/ft ) far exceeds the critical shear stresses of both C70600 (43 N/m, 0.9 Ibf/ft ) and C71500 (48 N/m, 1.0 Ibf/ft ) copper-nickel alloys [33]. 

How many liters of seawater are required to produce a pound of magnesium Use a seawater density of 1.025 g/cm and assume complete precipitation and/or conversion of the relevant intermediates, (b) How many pounds of oyster shells are needed ... 

For high-precision determinations of in situ oxygen concentrations the results have to be converted into yumol/kg because the amount of oxygen defined by a volume concentration depends on the sample temperature, which changes from in situ to subsampling conditions. The conversion of /rmol/L concentrations into in situ /rmol/kg requires the application of the equations for seawater density (UNESCO, 1983 see Appendix Table 4). The sample volume at subsampling temperature (fixation) is corrected to the in situ volume and mass. Temperature or volume change after fixation do not affect the analysis. 

The hydrostatic force is generated by still or slow-moving water acting perpendicular onto planar surfaces. The hydrostatic force per unit width, Fhs, can be calculated using Eq. (11.5), where p is the seawater density, g is the gravitational acceleration, dg is the inundation depth, and Up is the normal component of flow velocity. Equation (11.5) is proposed by CCH and accounts for the velocity head. Alternatively FEMA 55 does not include the velocity head in its formulation since it is assumed to be a negligible component of the hydrostatic force ... 

Ensure calibrated pressure gauges, 0—1, 380 kPa (0—200psig), are installed on the suction and discharge of each fire pump to be tested (record calibration dates on the flow performance data sheet, with +/—3% accuracy). For pumps taking suction lift, calculate the NPSH to the level of pump discharge. Offshore installation vertical turbine lift fire pumps require a calculation of the vertical head loss to the point of pressure reading, taking into account tide levels and seawater densities. 

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