Nelson diagram

Fig. 4.3-12. Resistance limits for the attack of pressurized hydrogen on steels ( Nelson Diagram).

F ure 9.2 Nelson diagram showing the limits for use of different Cr-Mo steels in the chemical process industry[2]. 

Figure 2-54. Nelson diagram showing the susceptibility of steels to hydrogen attack based on long-term investigations. The curves give the maximum allowable temperatures for service (Nelson, 1966).

The hardness and strength of a steel depends on its carbon content. A loss of carbon (decarburization) lowers the tensile strength of steels and can be caused by moist hydrogen at high pressures and temperatures. Figure 3.6 shows the Nelson diagram that depicts the limit of service conditions for carbon and alloy steels in hydrogen services. 

Fig. 9.1 (a) Block diagram of a gas chromatograph. (b) Typical chart record. Reproduced by permission from R. C. Denney, The Truth about Breath Tests, Nelson, London, 1970. 

Figure 47-10. Schematic diagram of the structure of human L-selectin. The extracellular portion contains an amino terminal domain homologous to C-type lectins and an adjacent epidermal growth factor-like domain. These are followed by a variable number of complement regulatory-like modules (numbered circles) and a transmembrane sequence (blackdiamond). A short cytoplasmic sequence (open rectangle) is at the carboxyl terminal. The structures of P- and E-selectin are similar to that shown except that they contain more complement-regulatory modules.The numbers of amino acids in L-, P-, and E- selectins, as deduced from the cDNA sequences, are 385,789, and 589, respectively. (Reproduced, with permission, from Bevilacqua MP, Nelson RM Selectins. J Clin Invest 1993 91 370.)...

Figure 3.21 Conceptual diagram of a two-dimensional (2D) NMR experiment. (Adapted with permission of Nelson Thornes Ltd. from Figure 8.1 of Akitt, J. W. NMR and Chemistry, 3rd ed., 1992.)...

Figure 3.1. Schematic diagram of a Soxhlet apparatus. (Reproduced from Ref. 93, with permission from Nelson Thornes Ltd.)...

Figure 4.8. (a) Schematic diagram of a typical purge and trap-GC system. (Reprinted with permission from Nelson Thornes, Ref. 27.) (b) Needle sparger for purge and trap. 

Overall effect. A procedure for evaluating the overall effect (combining the direct and indirect effects on tray efficiency) was developed by Nelson, Olson, and Sandler (156). This method is based on the Fenske, Underwood, and Gilliland (Eduljee version) shortcut relationships (Secs. 3.2.1 to 3.2.5) and was shown to work well when comparing to a more rigorous procedure. An example (using an x-y diagram) in Sec. 7.3.6 demonstrates how differences between true and apparent volatility affect efficiencies calculated from test data. 

Figures 9 and 10 show phase-behavior diagrams for David Lloydminster crude oil and the surfactant Neodol 25-3S in the presence of 1 wt% sodium carbonate. Phase-behavior measurements were carried out according to the method of Nelson et al. (52). The David Lloydminster oil field is near the Alberta-Saskatchewan border directly east of Edmonton. The oil has a density of 0.922 g/mL and a viscosity of 144 MPa s at 23 °C. The region of optimal phase behavior is shown at a surfactant concentration of 0.1 wt% in Figure 9. The region of optimal phase behavior is shaded. Above this region, type II +) behavior occurs, and type II(-) behavior occurs below the region of optimal phase behavior. Volume percent oil refers to the amount of oil present in the phase-behavior tube used. For a given oil-to-water ratio, a transition from type II(-) to type III to type II(+) occurs as salinity increases. As the amount of oil increases relative to the amount of aqueous phase, the same trend in phase behavior is seen.

Nelson P., Bloom I., Amine K., Henriksen G., J. of Power Sources, (2002) 110, 437-444. Suzuki J., Yoshida M., Nakahara C., Sekine K., Kikuchi M., Takamura T., Li mass hansfer through a metallic copper film on a carbon fiber during the electrochemical insertion/exhaction reaction, Elechochem. and Solid State Lett., (2001), 4 (1), A1-A4. Klemm W., Volavsek, B. Z. Anorg. Chem. (1958) 296, 184-187, or Bull. Alloy Phase Diagrams, (1986) 7 (2), or Binary Alloy Phase Diagrams (1990), Vol. 2, 2 Ed., ASM International, Materials Park, Ohio, Editor-in-chief, Massalski T. B., pg. 1430. 

To follow the preceding section s discussion of the ternary diagram and Hand s rule, this section discnsses how to calculate phase compositions Cy. The general approach is to represent the binodal and distribution curves (tie lines) as a fnnction of the total concentration of water, oil, and surfactant (i.e., Ci, C2, C3—of which only two are independent) with the electrolyte concentration as a parameter, based on an idea outlined by Lake (1989). A similar approach was proposed by Pope and Nelson (1978) and Camilleri (1983). 

Nelson, R.C., 1982. The salinity-requirement diagram—a useful tool in chemical flooding research and development. SPEJ (April), 259-270. 

---