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Na+/K+ ratio

Based on available results, it can be summarized that the particle size of tantalum powder increases (specific charge decreases) with the increase in temperature, K2TaF7 concentration and excess sodium. In addition, an increase in the specific surface area of the melt and Na/K ratio also leads to the formation of coarser tantalum powder. The most important conclusion is that for the production of finer tantalum powders with higher specific charges, the concentration of K2TaF7 in the melt must be relatively low. This effect is the opposite of that observed in the electrochemical reduction of melts. [Pg.336]

Few data on the chemical compositions of feldspars (albite, K-feldspar) are available. Fuji (1976) indicated that K-feldspar and albite in the propylite of west Izu Peninsula, middle Honshu are of nearly end member composition. Nagayama (1992) showed that K-feldspars in the Hishikari Au-Ag vein and in the host andesitic rock have different composition Na/K ratio of K-feldspars from the vein is lower than that from the host rocks. [Pg.121]

The above discussions are based on the assumption of constant temperature. However, temperature varies widely. The chemical compositions of geothermal waters intimately relate to temperature. For example, the correlation between Na/K ratio in geothermal waters and temperature has been interpreted as indicating that this ratio is controlled by albite and K-feldspar (White, 1965 Ellis, 1969, 1970). [Pg.302]

Hemley, J.J. (1967) Aqueous Na/K ratios in the system K20-Na20-Al203-Si02-H20 (abst.). Program, 1967 Ann. Meet. Geol. Soc. Am., New Orleans, Louisiana, pp. 94-95. [Pg.398]

The other reason why the average salinity of seawater is 35%o lies in the fundamental chemistry of major ions. For example, the sevenfold increase in the Na /K ratio between river water and seawater (Table 21.8) reflects the lower affinity of marine rocks for sodium as compared to potassium. In other words, the sodium sink is not as effective as the one for potassium. Thus, more sodium remains in seawater, with its upper limit, in theory, being controlled by the solubility of halite. Likewise, the Ca /Mg ° ratio in seawater is 12-fold lower than that of river water due to the highly effective removal of calcium through the formation of biogenic calcite. [Pg.557]

Because the main reason of microcline-plagioclase sorting is to control the Na/K ratio, LIBS may be excellent separation technology. The analytical lines of Na and K are very strong and specific in order to promise confident identification (Fig. 8.6). [Pg.294]

In conclusion we showed how the optical excitation energies in isostructural cetineites, the experimental ones as well as the theoretical values, depend on the chemical composition. Based on this, in mixed phase (Na,K S) the band gap can be tuned by varying the Na K-ratio. These results give an insight into the structure/property-relation and show that the optical properties can be tuned chemically in this novel class of nanoporous semiconductors. [Pg.689]

FIGURE 5.2 STEM x-ray spectrum from a skin sample.4 Note that there is a conspicuous shift in the Na/K ratio moving from the dermis into the basal cell layer. Again, moving into the stratum spinosum, Na increases and K is lowered, a ratio shift, which suggests that the spinosum cells are incapable of entering the mitosis cycle. [Pg.47]

Adrenalectomized rats treated with DOCA or aldosterone can be utilized to test aldosterone antagonists. Spironolactone has no effect in the absence of a min-eralocorticoid, but reverses in a dose-related manner the effect of DOCA on the Na+/K+ ratio in the urine (Kagawa et al. 1957 Bicking et al. 1965). [Pg.106]

Orthorhombic or pseudotetragonal forms, found in clinkers high in alkalis. Na,/K ratio varies with that of the clinker. [Pg.10]

Data are for composition given cell parameters decrease with increasing Na/K ratio (P2). [Pg.52]

Ionic ratios and ionic proportion distributions also show clearly that all major ions, except potassium, can dominate in multiple combinations ionic ratios also range over two to three orders of magnitude, and they can be greater or less than unity for all except the Na /K ratio, in which sodium generally dominates. River compositions found in less than 1 % of analyses can be termed rare for analyses from Qi to gio and ggo to Q99,1 propose the term uncommon, from gio to Q25 and 075 to ggo, common, and between Q25 and 075, very common. An example of this terminology is shown in the next section (Figure 2) for dissolved inorganic carbon (DlC). [Pg.2462]

Because all cell culture media are carbonate-buffered systems, the pH is dependent on the CO2 in solution, which in turn is in equihbrium with the CO2 in the gas phase. This offers the opportunity of using the CO2 concentration within the gas phase for gentle, very efficient pH control (Figure 5.10.1). Alternatively, or in addition, pH control is possible by using base titration (acid titration is given by CO2 anyway). When using hydroxide, one should use a 1 M mixture of NaOH and KOH (95 5) to avoid too great a shift in Na/K ratio and osmolarity. [Pg.283]

The composition, pH, and volume of salivary excretion for different salivary glands vary. Usually 1-2 L of saliva are secreted per day. Saliva is a hypotonic solution with a pH of about 7.0 principal cations are Na" and K+, and anions are Cl andHCOj. Aldosterone (a steroid hormone of the adrenal cortex) modulates Na+ and K levels in saliva as it does in the kidney (Chapter 32). Aldosterone increases reabsorption of Na+ and secretion of K+ by direct action on the salivary gland ducts. In hypoaldosteronism (e.g., Addison s disease), the salivary Na" /K+ ratio is high. [Pg.197]

The variation in Na-K ATPase activity with pH and with Na K ratio is shown in Figures 3 and 4. Although some differences are apparent in the curves obtained with the various divalent cations, the qualitative behavior is the same for all. However, the relative activating effect is pH dependent. The patterns of activity variation in Figures 3 and 4 could be duplicated using controls that contained choline acetate instead of Na+-K+ acetate and ouabain, and so they do not reflect variations in degree of ouabain inhibition. No activating effect under the conditions studied could be found for Ba2+, Ca2+, Cd2+, Cu2+, Fe2+, Pb2+, or Sr2+. [Pg.244]

Other hand, Lezzi and Friegg (1971) claim that the action of juvenile hormones results in an increase of the intracellular Na/K ratio. [Pg.192]

Recently, studies have shown that excess sodium is not the sole consideration in the control of blood pressure. More important is the sodium ion/potassium ion (Na+/K+) ratio. That ratio should be about 0.6 in other words, our diet should contain about 67% more potassium than sodium. Does the typical American diet fall within this limit Definitely not Young American males (25-30 years old) consume a diet with a Na+/K+ = 1.07, and the diet of females of the same age range has a Na+/K+ = 1.04. It is little wonder that so many Americans suffer from hypertension. [Pg.97]

A high intake of table salt, sodium chloride, the major source of sodium in the diet, is one factor that may cause high blood pressure, hypertension, in susceptible individuals. There has been considerable emphasis on "low-salt" diets as a means of avoiding hypertension. However, it appears that sodium is not the only culprit. It is the sodium ion-to-potassium ion ratio that appears to be important in controlling blood pressure. Ideally, the Na+/K+ ratio should be about 0.6, but the Na+/K+ ratio consumed by the average American is greater than 1.0. To avoid h)rperten-sion in later life, it is important to reduce the amount of sodium in the diet and increase the amount of potassium. [Pg.790]

Both Na and K are involved in various electrophysio-logical functions in higher animals. The [Na ] [K ] ratio is different in intra- and extra-cellular fluids, and the concentration gradients of these ions across cell membranes are the origin of the trans-membrane potential difference that, in nerve and muscle cells, is responsible for the transmission of nerve impulses. A balanced diet therefore includes both Na and salts. Potassium is also an essential plant nutrient, and salts are widely used as fertilizers. Uses of Li and Na in batteries are highlighted in Box 10.3, and the use of KO2 in breathing masks is described in Section 10.6. [Pg.259]

T-effects The effects of T on white mica compositions are most clearly seen in terms of the Na/(Na+K) ratios of the phases Ms and Pg. Temperature also impacts the substitutions in the VI and IV sites, but with the exception of Ti substituting into VI sites, the VI and IV substitutions are also significantly controlled by P. Consequently, they will be considered mainly below in the context of the effects of P on white mica composition. [Pg.419]

Figure 4 Effects of (7) on Ms + Pg Na/(Na+K) ratio. Based on Figure 22 of Guidotti (1984). Figure 4 Effects of (7) on Ms + Pg Na/(Na+K) ratio. Based on Figure 22 of Guidotti (1984).
V-EFFECTS. The effects of P on the composition of Pg are observed to be minor at most. In contrast, the effects of P on the composition of Ms are extensive, affecting mainly the VI and IV sites but also the interlayer site. As discussed above, the effect of P on the Na/(Na+K) ratio of Ms is mainly a response to the effects of the VI and IV substitutions on the degree of non-ideality for the Na-K substitution in Ms. This effect is large but not yet calibrated. Hence, at this point, nothing can be said about it serving as a geobarometer. [Pg.421]


See other pages where Na+/K+ ratio is mentioned: [Pg.336]    [Pg.242]    [Pg.34]    [Pg.34]    [Pg.176]    [Pg.335]    [Pg.40]    [Pg.237]    [Pg.490]    [Pg.683]    [Pg.1363]    [Pg.11]    [Pg.58]    [Pg.58]    [Pg.336]    [Pg.55]    [Pg.54]    [Pg.1833]    [Pg.590]    [Pg.591]    [Pg.99]    [Pg.419]    [Pg.419]    [Pg.421]    [Pg.421]    [Pg.425]   
See also in sourсe #XX -- [ Pg.106 ]




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K-ratios

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