Chart datum

In preparation for a field wide quick look correlation, all well logs need to be corrected for borehole inclination. This is done routinely with software which uses the measured depth below the derrick floor ( alonghole depth below derrick floor AHBDFor measured depth , MD) and the acquired directional surveys to calculate the true vertical depth subsea (TVSS). This is the vertical distance of a point below a common reference level, for instance chart datum (CD) or mean sea level (MSL). Figure 5.41 shows the relationship between the different depth measurements. 

Until 1910 heights of the visual tide poles were measured and, after establishment of a chart datum, recalculated. From around 1920 datum of the visual tide poles has been measured approximately every third year by the National Survey and Cadastre. 

With real-time data the main objective has changed toward primarily an operational issue Storm surge warning. Historical data are used for tidal analysis, determination of mean sea level (MSL) and long-time trends, estimation of extremes and so on, but still the redefinition of a national chart datum about every fifteenth years is an important objective. 

Most countries have a national datum level, which is often approximately equal to the MSL (for example Ordnance Datum in the UK). Chart Datum conversely, as used by the British Admiralty, represents the Lowest Astronomical Tide, which varies significantly from one place to another. 

One hundred pounds of a 73% NaOH solution at 350°F is to be diluted to give a 10% solution at 80°F. How many pounds of water at 80°F and ice at 32°F are required if there is no external source of cooling available See Fig. E4.43. Use the steam tables and the NaOH-HiO enthalpy-concentration chart in Appendix I as your source of data. (The reference conditions for the latter chart are AH = 0 at 32 for liquid water and AH = 0 for an infinitely dilute solution of NaOH, with pure caustic having an enthalpy at 68°F of 455 Btu/lb above this datum.)... 

Equation on Chart. When you click Close, the least-squares straight line and its equation appear on the graph. The line only extends from the first point to the last point. To extend the line back to jc = 0, select More Trendline Options again. Forecast Backward by 1 period. Now the trendline extends backward from the first datum at X = 1 to the y-axis at ac = 0. More Trendline Options also allows you to modify the color and style of the trendline. 

Predictable The accuracy of a radionavigation system s position solution with respect to the charted solution. Both the position solution and the chart must be based upon the same geodetic datum. Repeatable The accuracy with which a user can return to a position whose coordinates have been measured at a previous time with the same navigation system. 

For a semicrystalline polymer of your choice (other than those in Figs. 2-19-2-29), develop charts for enthalpy and entropy as functions of temperature and pressure. Use a datum of 25°C and atmospheric pressure. 

Determine the enthalpy and entropy charts as functions of temperature and pressure for a butadiene-styrene copolymer with 30% butadiene (Tg of 18 C). Use a datum of 25 C and atmospheric pressure. 

FIGURE 6.8 Enthalpy-concentration diagram for sulfuric acid-water. The datum state is zero enthalpy for pure water and for pure sulfuric acid as liquids at 32°F = 0°C, and the pure species vapor pressure. The percentage is weight percent. (The data are from the International Critical Tables, as plotted in Hougen, O. A., K. M. Watson, and R. A Ragatz, Chemical Process Principles Charts. 1960, New York Wiley. Reprinted by permission of the estate of O. A. Hougen.)... 

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