NaCl at

Assume is -25 mV for a certain silica surface in contact with O.OOlAf aqueous NaCl at 25°C. Calculate, assuming simple Gouy-Chapman theory (a) at 200 A from the surface, (b) the concentrations of Na and of Cr ions 10 A from the surface, and (c) the surface charge density in electronic charges per unit area. 

Figure Bl.20.8. DLVO-type forces measured between two silica glass surfaces in aqueous solutions of NaCl at various concentrations. The inset shows the same data in the short-range regime up to D = 10 mn. The repulsive deviation at short range (<2 nm) is due to a monotonic solvation force, which seems not to depend on the salt concentration. Oscillatory surface forces are not observed. With pemiission from [73].

A saturated aqueous solution in contact with an excess of a definite solid phase at a given temperature will maintain constant humidity in an enclosed space. Table 11.4 gives a number of salts suitable for this purpose. The aqueous tension (vapor pressure, in millimeters of Hg) of a solution at a given temperature is found by multiplying the decimal fraction of the humidity by the aqueous tension at 100 percent humidity for the specific temperature. For example, the aqueous tension of a saturated solution of NaCl at 20°C is 0.757 X 17.54 = 13.28 mmHg and at 80°C it is 0.764 X 355.1 = 271.3 mmHg. 

Properties. Fluoroboric acid is stable in concentrated solutions, and hydroly2es slowly in aqueous solution to hydroxyduoroborates. For the stabihty of the duoroborate species, see Reference 3. The equiUbrium quotients (4,5) in 1 molal NaCl at 25°C show the strong affinity of boron for duo ride ... 

If this repulsion exceeds the polari2abihty attraction at the distance of closest approach, determined by vicinal fluid, the particles can be prevented from agglomerating. For example, water with =81, containing NaCl at 7 = mol/m, creates a counterion layer with = 0.15 nm. The maximum... 

Samples were tested on in a melt of salts (75% Na SO, 25% NaCl) at 950°C in an air atmosphere for 24 hours. Micro X-rays spectrum by the analysis found that the chemical composition of carbides of an alloy of the ZMI-3C and test alloys differs noticeably. In the monocarbide of phase composition of an alloy of the ZMI-3C there increased concentration of titanium and tungsten is observed in comparison with test alloys containing chemical composition tantalum. The concentration of more than 2% of tantalum in test alloys has allowed mostly to deduce tungsten from a mono carbide phase (MC) into solid solution. Thus resistance of test alloys LCD has been increased essentially, as carbide phase is mostly sensitive aggressive environments influence. The critical value of total molybdenum and tungsten concentration in MC should not exceed 15%. 

Birch, F. (1978), Finite Strain Isotherm and Velocities for Single-Crystal and Polycrystalline NaCl at High Pressures and 300 K, J. Geophys. Res. 83, 1257-1268. 

Anodes for boilers can be tested by such methods. Good-quality magnesium anodes have a mass loss rate per unit area < 30 g m d", corresponding to a current yield of >18% under galvanostatic anode loading of 50 /xA cm" in 10 M NaCl at 60°C. In 10 M NaCl at 60°C, the potential should not be more positive than t/jj = -0.9 V for the same polarization conditions [27],... 

Table 3 Dependence of Constants K and a of [T7] = KM° on Mole Fraction of Sodium Acrylate (Xsa) for Copolymer Acrylamide with Sodium Acrylate in 0.5 M NaCl at 25°C [9]...

At hydrolysis of polyacrylamide in 10 M NaCl at I00°C, the degree of hydrolysis becomes —95%, but in this case a degradation of the macromolecules is observed. Various modes of hydrolysis of polyacrylamide under basic conditions have been reviewed [2,12]. 

Suzuki, Yamake and Kitamura determined the pHs, chloride ion concentrations, metal ion concentrations and the potentials of artificial pits in Fe, Cr, Ni and Mo, and in three austenitic stainless steels during anodic polarisation in 0-5 N NaCl at 70°C. In the case of the pure metals the pH values were found to be lower than those calculated from the metal ion concentrations (Table 1.17), and the experimentally determined pHs were as follows ... 

Table 1.19 gives some critical pitting potentials collated by Uhlig for different metals in 0 -1 N NaCl at 25 °C, in which in most cases the potential was first increased incrementally and held constant at each potential for 5 min in order to obtain an approximate value of the critical pitting potential. This may be followed by a separate series of experiments in which fresh specimens are held at potentials close to b for 12 h or more and the surface... 

Fig. 1.63 Effect of stirring rate on the aluminium-mild steel couple in 1 - 0 n NaCl at 25°C. Equal areas (20 cm ) of aluminium and steel coupled together for 24 h (after Pryor and...

Fig. 1.65 Potential/time curves for cathodically polarised and unpolarised iron in 1 0 n NaCl at 25 C. Curve a unpolarised Fe curve b Fe polarised cathodically at 20 nA/cm, pFt = 6 2 curve c Fe polarised cathodically at 20/iA/cm, pFt = 8-9 and curve d Fe polarised cathodically at 40/iA/cm, pFt = 6-2 (potentials vs. S.H.E.) (after Pryor )...

Fig. 1.67 Effect of mild-steel cathode on the weight loss of aluminium and zinc anodes (100 cm area) and on the number of coulombs flowing in the aluminium-mild steel and zinc-mild steel couples over a 96 h period in 1 -0 n NaCl at 25°C (after Pryor and Keir )...

Table 3.47 Breakdown potentials evaluated from E-i curves in 3% NaCl at 60°C...

Fig. 8.90 Load relaxation curves for a maraging steel stress corroded in 0.6 m NaCl at pH 2...

A recent evaluation of HSCI anodes in different soil conditions has been conducted by Jakobs and Hewes . They report a consumption rate for different HSCI alloys in 3% NaCl, at a current density of 21-5 Am , of between 0-32 and 0- 87 kg A y" depending upon the alloy composition ... 

Fig. 63. Heat of solution of HC1 and NaCl at 25°C (Slansky) and of NaCI at 20° (Moss and Wolfenden). Abscissas give the mole fraction of methanol in the inethanol-water mixture. [It. L. Moss and J. H. Wolfenden, J. Chem. Soc., 1939, 118 C. M. Slansky, J. Am. Chem. Soc., 62, 2433 (1940).]...

Fig. 3.1.6 Effects of pH on the activity and stability of Cypridina luciferase (solid lines) and the quantum yield of Cypridina luciferin (dashed line). In the measurements of activity and quantum yield, luciferin (1 pg/ml) was luminesced in the presence of luciferase (a trace amount for the activity measurement 20 pg/ml for the quantum yield) in 20 mM buffer solutions of various pH containing 0.1M NaCl, at 20°C. In the stability measurement, luciferase (a trace amount) was left standing in 0.1 ml of the buffer solutions of various pH for 30 min at 20°C, then the activity was measured by adding 1 ml of 50 mM sodium phosphate buffer, pH 6.5, containing 0.1 M NaCl and 1 pg of luciferin, at 20°C. The activity and stability data are taken from Shimomura et al., 1961, with permission from John Wiley 8c Sons Ltd.

Fig. 3.2.2 Influence of pH on the initial light intensity of euphausiid luminescence when the fluorescent compound F and protein P are mixed in 25 mM sodium phosphate buffers of various pH values, each containing 1M NaCl, at near 0°C. Both F and P were obtained from Meganyctiphanes norvegica. From Shimomura and Johnson, 1967, with permission from the American Chemical Society.

The bioluminescence reaction of Oplophorus is a typical luciferin-luciferase reaction that requires only three components luciferin (coelenterazine), luciferase and molecular oxygen. The luminescence spectrum shows a peak at about 454nm (Fig. 3.3.1). The luminescence is significantly affected by pH, salt concentration, and temperature. A certain level of ionic strength (salt) is necessary for the activity of the luciferase. In the case of NaCl, at least 0.05-0.1 M of the salt is needed for a moderate rate of light emission, and about 0.5 M for the maximum light intensity. 

Quantum yield and luciferase activity The quantum yield of coelenterazine in the luminescence reaction catalyzed by Oplophorus luciferase was 0.34 when measured in 15 mM Tris-HCl buffer, pH 8.3, containing 0.05 M NaCl at 22°C (Shimomura et al., 1978). The specific activity of pure luciferase in the presence of a large excess of coelenterazine (0.9pg/ml) in the same buffer at 23°C was 1.75 x 1015 photons s 1 mg-1 (Shimomura et al., 1978). Based on these data and the molecular weight of luciferase (106,000), the turnover number of luciferase is calculated at 55/min. 

Fig. 6.3.11 Chromatography of an extract of the eye light organs of Symplecto-teuthis luminosa on a column of Superdex 200 Prep (1x27.5 cm) in 20 mM phosphate buffer, pH 6.0, containing 0.6 M NaCl, at 0°C (monitored at 280 nm). Each fraction (0.5 ml) is measured for the initial intensity of H202/catalase-triggered luminescence and the content of dehydrocoelenterazine measured as coelenterazine after NaBH4-reduction 1LU = 6 x 108 photons.

Assay of photoprotein. The activity of the photoprotein was measured in 1ml of 20 mM Tris-HCl buffer, pH 8.0, containing 0.6 M NaCl at room temperature. The intensity and total amount of light emitted were recorded. The luminescence intensity is markedly intensified by adding 5 il of catalase solution (crystalline bovine liver catalase 1.5 mg/ml) and 10 pi of 3% H2O2. 

An affinity sorbent based on WPA-PG carrying immobilized human IgG was applied to the isolation of the first component of the complement (Cl) from human serum and for its separation into subcomponents Clr, Cls and Clq by the one-step procedure [126,127]. Cl was quantitatively bound to the sorbent at 0 °C. The activities of subcomponents Clq and Clr2r2 in the unbound part of the serum were found to be 0.8% and 3.3% of the initial activities in serum. This fraction, therefore, could be used as a R1 reagent for determining the hemolytic activity of Cl. Apparently, the neighboring macromolecules of immobilized IgG resemble to some extent an immune complex, whereas Cl formation is facilitated due to the mobility of polymer chains with the attached IgG macromolecules (Cl is usually dissociated in serum by 30%). After activation of bound Cl by heating (30 °C, 40 min) the activated subcomponent Clr is eluted from the sorbent. Stepwise elution with 0.05 mol/1 EDTA at pH 7.4 or with 0.05 mol/1 EDTA + 1 mol/1 NaCl at pH 8.5 results in a selective and quantitative elution of the activated subcomponent Cls and subcomponent Clq. 

E5.5 The following equation has been found to represent the volume of aqueous solutions of NaCl at T= 298.15 K and p = 0.101 MPa that contains 1.000 kg of water... 

The Pyrex tube was suspended, with capillary down, in a small-holed rubber stopper which, in turn, was fastened to a goniometer head by a length of stout copper wire. The solid material within the capillary was photographed in a cold room (4°C.) using copper x-radiation, a camera with radius 5 cm., and oscillation range 30°. The effective camera radius was established by superimposing a powder spectrum of NaCl during an exposure of the sample the lattice constant for NaCl at 4°C. was taken to be 5.634 A. 

The feasibility of strategies B and C has been demonstrated particularly for the synthesis of the so-called pericyclinosilanes (previously also named cyclo-silethynes [20]) 70-72 (Fig. 3). Historically, an approach of type C was the first one ever, in that [4]pericyclinosilane 70 was prepared by simple pyrolysis of a mixture of calcium carbide and dichlorodimethylsilane in a molten salt mixture of KCl/NaCl at 400°C, albeit in low yield (actual yield not reported) [21]. A... 

Table 1. Cations and pH Affects PE Flux and Permeability Permeability and Flux with NaCl at pH 8.0 Cone., M JigQ Pjgo...

PE permeability was enhanced by CaCl2 at lower concentrations than effective for NaCl. Pi8o in O.IM CaCL was approximately 0.33, and similar to the permeability in 0.4M NaCl at pH 3.8. There seems to be a unique cation effect rather than ionic strength effect. At equivalent ionic strength (0.3M NaCl and O.IM CaCl2, pH 3.8), Pjso of PE with CaCl2, was approximately four fold higher. 

Fig. 1. Separation of two exopolygalacturonase groups (Fraction A, Fraction B) on CM-Sephadex C-50. Column size, 20x250 mm. Stepwise elution with 0.05 M acetate buffer, pH 3.8 (starting at arrow marked a), 0.10 M acetate buffer, pH 4.8 (at arrow marked b), 0.15 M acetate, pH 5.6 (at arrow marked c) and the latter buffer plus 1.0 M NaCl (at arrow marked d). Fraction size 6 ml per half hr. Exopolygalacturonase activity determined with sodium pectate, pH 5.0 (o—O) 2nd expressed as A,, .

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