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General Behavior

Additions of chromium to nickel impart resistance to oxidizing conditions (e.g., HNO3 and H2Cr04) by supporting the passivation process. The critical minimum chromium content [4] obtained from critical current densities for anodic passivation in sulfuric acid is 14 wt.% Cr. These alloys are more sensitive than nickel to attack by CT and by HCl, and deep pits form when the alloys are [Pg.411]

As an alloying element in nickel, tungsten behaves similarly to molybdenum, but is less effective [6]. [Pg.412]

Because the binary nickel-molybdenum alloys have poor physical properties (low ductility, poor workability), other elements, for example, iron, are added to form ternary or multicomponent alloys. These are also difficult to work, but they mark an improvement over the binary alloys. Resistance of such alloys to hydrochloric and sulfuric acids is better than that of nickel, but it is not improved with respect to oxidizing media (e.g., HNO3). Since the Ni-Mo-Fe alloys have active corrosion potentials and do not, therefore, establish passive-active cells, they do not pit in the strong acid media to which they are usually exposed in practice. [Pg.412]

By alloying nickel with both molybdenum and chromium, an alloy is obtained resistant to oxidizing media imparted by alloyed chromium, as well as to reducing media imparted by molybdenum. One such alloy, which also contains a few percent iron and tungsten (AUoy C), is immune to pitting and crevice corrosion in seawater (10-year exposure) and does not tarnish appreciably when exposed to marine atmospheres. Alloys of this kind, however, despite improved resistance to Cl, corrode more rapidly in hydrochloric acid than do the nickel-molybdenum alloys that do not contain chromium. [Pg.412]

Nominal compositions of some commercial nickel-base alloys containing copper, molybdenum, or chromium are given in Table 23.3. The Ni-Cu alloys are readily rolled and fabricated, whereas the Ni-Cr alloys are less readily, and the Ni-Mo-Fe and Ni-Mo-Cr alloys are difficult to work or fabricate. [Pg.412]


Fig. 1. Amine distribution general behavior. Converted alcohol to amine product as the ammonia to alcohol ratio increases. Fig. 1. Amine distribution general behavior. Converted alcohol to amine product as the ammonia to alcohol ratio increases.
The materials from which the system is to be fabricated are the second important consideration therefore, knowledge of the characteristics and general behavior of materials when exposed to certain environments is essential. [Pg.2417]

The above examples indicate a general behavior which roughly parallels that found in homocyclic aromatic systems. The less usual order, I >Br >C1, found for the non-activated halogenofurans is reminiscent of the similar order I > Br > Cl > F, observed by Tronov and Kruger for the halogenobenzenes. Again, it would be of interest to establish the position of fluorine in the order of reactivity of the halogenofurans. [Pg.352]

The ability of a nltro group in the substrate to bring about electron-transfer free radical chain nucleophilic subsdnidon fSpj li at a saniratedcarbon atom is well documented. Such electron transfer reacdons are one of the characterisdc feanires of nltro compounds. Komblum and Russell have established ihe Spj l reaction independently the details of the early history have been well reviewed by them. The reacdon of -nitrobenzyl chloride v/ith a salt of nitro ilkane is in sharp contrast to the general behavior of the ilkyladon of the carbanions derived from nitro ilkanes here, carbon ilkyladon is predominant. The carbon ilkyladon process proceeds via a chain reacdon involving anion radicals and free radicals, as shovmin Eq. 5.24 and Scheme 5.4 fSpj l reacdoni. [Pg.133]

Is there a more general behavioral classification scheme by which the intrinsic dynamical complexity of rules may be described ... [Pg.109]

An overview is provided by figure 4.7 plot (a) shows the numerically determined attractor sets for all 2.9 < a < 4 plot (b) - lest it be thought that the white regions in plot (a) are artifacts of the printing process - shows a blowup view of the windowed region within one of those wide white bands in plot (a). The general behavior is summarized as follows ... [Pg.182]

How does the general behavior of an integrable system, Ho, change as a small nonintegrable component, aHi (where a is some small control parameter), is added ... [Pg.189]

In their study of CMLs exhibiting a Pomeau-Manneville intermittency, Crutchfield and Kaneko [crutch87] have observed the following general behavior ... [Pg.397]

In equation 10.7, the neuronal site variables Si(t) can be updated either synchronously, where each neuron is simultaneously updated throughout the net, or asynchronously, where at each time step only one randomly chosen neuron is updated. While the first choice has the virtue of more closely resembling a conventional CA dynamical updating scheme, the second choice is more physically realistic insofar as the brain does not have an internal clock to synchronize the dynamics of its neurons. In practice, while the two updating schemes produce slightly different behavior, the general behavioral characteristics of the net are the same. [Pg.520]

For example, it is a general behavior of alcohols to undergo a reaction in which the —OH group is displaced by a halogen atom, such as —Br [as in reaction (77)]. [Pg.335]

Pfaffian Differential Expressions With Two Variables Before we undertake the arguments generalized for three or more variables, we digress to consider some examples involving only two variables. These do not provide the generality we must have to treat thermodynamic systems of three or more variables, but will provide concrete illustrations of the general behavior we will invoke in the development. [Pg.64]

In Chapter 6, we considered the more general behavior of the activity with temperature and showed with equations (6.163) to (6,166) how to integrate the right hand of equation (8,28) when the enthalpy of fusion is not constant over the temperature range of interest. Those same considerations apply directly here and they will not be repeated, except to give the final result ... [Pg.419]

Figure 20 shows the plot of the surface tension vs. the logarithm of the concentration (or-lg c-isotherms) of sodium alkanesulfonates C,0-C15 at 45°C. In accordance with the general behavior of surfactants, the interfacial activity increases with growing chain length. The critical micelle concentration (cM) is shifted to lower concentration values. The typical surface tension at cM is between 38 and 33 mN/m. The ammonium alkanesulfonates show similar behavior, though their solubility is much better. The impact of the counterions is twofold First, a more polarizable counterion lowers the cM value (Fig. 21), while the aggregation number of the micelles rises. Second, polarizable and hydrophobic counterions, such as n-propyl- or isopropylammonium and n-butylammonium ions, enhance the interfacial activity as well (Fig. 22). Hydrophilic counterions such as 2-hydroxyethylammonium have the opposite effect. Table 14 summarizes some data for the dodecane 1-sulfonates. Figure 20 shows the plot of the surface tension vs. the logarithm of the concentration (or-lg c-isotherms) of sodium alkanesulfonates C,0-C15 at 45°C. In accordance with the general behavior of surfactants, the interfacial activity increases with growing chain length. The critical micelle concentration (cM) is shifted to lower concentration values. The typical surface tension at cM is between 38 and 33 mN/m. The ammonium alkanesulfonates show similar behavior, though their solubility is much better. The impact of the counterions is twofold First, a more polarizable counterion lowers the cM value (Fig. 21), while the aggregation number of the micelles rises. Second, polarizable and hydrophobic counterions, such as n-propyl- or isopropylammonium and n-butylammonium ions, enhance the interfacial activity as well (Fig. 22). Hydrophilic counterions such as 2-hydroxyethylammonium have the opposite effect. Table 14 summarizes some data for the dodecane 1-sulfonates.
One exception to this general behavior is the system p(2x2) 0.25 0/Pt( 111), where, due to the high tendency of coadsorbed CO and O for C02 formation on Pt(lll), the value of S0 for CO adsorption is the same to the one for the clean surface, although on other substrates oxygen behaves as a typical electronegative modifier of CO adsorption. [Pg.61]

The objectives of this presentation are to discuss the general behavior of non isothermal chain-addition polymerizations and copolymerizations and to propose dimensionless criteria for estimating non isothermal reactor performance, in particular thermal runaway and instability, and its effect upon polymer properties. Most of the results presented are based upon work (i"8), both theoretical and experimental, conducted in the author s laboratories at Stevens Institute of Technology. Analytical methods include a Semenov-type theoretical approach (1,2,9) as well as computer simulations similar to those used by Barkelew LS) ... [Pg.15]

Moreover, as a general behavior and indirect effect of solubilizate/micelle interactions, incorporation of additives influences the stability and the phase diagram of the system [48,119,124]. [Pg.484]

In this section, we will investigate the surface structure of the electrode in the potential range before a surface or bulk oxide starts forming, and will restrict ourselves to the adsorption of atomic oxygen only (not OH ) [Jacob and Scheffler, 2007]. Furthermore, in our simulations, we assume a single-crystal Pt(lll) electrode, which will be compared with the experimental CV curve (Fig. 5.9) for poly crystalline Pt. This simplification is motivated by the fact that our interest here is to describe the general behavior of the system only. [Pg.150]

Behavior of Ra in groundwater. The general behavior of Ra has been examined under laboratory conditions and in various environments (see Osmond and Cowart 1992). A major goal of field studies of Ra isotopes have aimed at obtaining bulk, in situ values of adsorption rates and so the retardation factors. Note that Ba serves as a very close chemical analogue to Ra but is typically 10 times more abundant, and so its behavior is related to that of Ra. [Pg.334]

The dominant processes are apparently sediment deposition, sediment burial, volatilization,and deposition with air particles (i.e. dry dustfall and scavenging by rain). It is believed that the concentrations and process rates may be broadly consistent with average conditions in Lake Michigan in the early 1970s. No claim is made that the model simulates Lake Michigan precisely since the Lake has complex heterogeneous water movement and sedimentation. But the general behavior is believed to be correct and, with adjustment of the parameters, a better fit could be obtained. [Pg.194]


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