Nitrogen saturation

Fig. 3.56 Potentiodynamic polarisation curves for high-chromium white irons in nitrogen-saturated solution containing 800mg/l Cl , pH 3.5. 25°C...

Figure 19.21 shows the types of crevices used by Wilde " for studying crevice corrosion and pitting of Cr-Ni-Fe alloys in the laboratory and in the field. Types 1 and 5 were used for anodic polarisation studies in nitrogen-saturated 1 mol dm NaCl and in aerated 3-5 mass% NaCl, respectively, and it can be seen that attachment to the conducting lead is by means of a Stern-Makrides pressure gasket Types 3 and 4 were used for field tests... 

On the surface it would seem that global nitrogen fertilization is beneficial in that it reduces the concentration of CO2 in the atmosphere and thus its radiative forcing. However, it raises the question of how long global biomass can continue to respond in this way. Should the northern forests switch over from nitrogen fertilization to nitrogen saturation, or if other nutri-... 

TPD of the nitrogen-saturated Fe(lOO) surface shows a symmetric feature with a peak maximum at 740 K if we use a heating ramp of 2 K s . Estimate the activation energy for desorption assuming second-order desorption. 

Volta potentials are measured by means of voltaic cells, i.e., systems composed of conducting, condensed phases in series, with a gas, liquid dielectric (e.g., decane) or a vacuum (in the case of solid conductors such as metals) gap situated between two condensed phases. The gap, g, may contain a gas such as pure air or nitrogen, saturated with vapors of the liquids present. Owing to the presence of a dielectric, special methods are necessary for the investigation of voltaic cells (see Section IV). 

The reaction vessel is then packed in ice and the reaction mixture is neutralized to pH 6.5 to 7.0 with aqueous hydrochloric acid. The neutral solution was dialyzed against nitrogen-saturated, distilled water for two days. The polymer solution is precipitated in a 5- to... 

FIGURE 1.13 Absorbance measurement of 2, 7 -dichlorodihydrofluorescein (DCDHF), a peroxynitrite-sensitive dye, as a function of nitrite (1 mM) and NADH (1 mM) introduction to a solution containing 100 pM DCDHF and 30mU/mL NR under ambient (a) and nitrogen saturated conditions (b). As can be seen, die absorbance of DCDHF increases upon nitrite and NADH introduction only under an oxygen atmosphere, indicative of peroxynitrite production. (Reprinted with permission from Elsevier Publishing [117].)... 

Laser Flash Photolysis at 248 nm of TDI-PU. MDI-PUE. and Model Compounds. Figures 1 and 2 show the transient absorption spectra of MDI-PUE (5.5 X lO-3 g/dL) and TDI-PU (2.3 X 10 3 g/dL) in THF at a 2.0 ns delay after pulsing with a krypton fluoride excimer laser (Xex=248 nm) in air and nitrogen saturated samples. Both spectra have common peaks in nitrogen saturated solutions (shown by arrows) at 310 nm, 330-360 nm (broad), and above 400 nm (broad, diffuse absorbance).. The MDI-PUE sample has an additional and quite distinctive peak at 370 nm. In the presence of air, the peak at 370 nm for MDI-PUE is completely extinguished, while the sharp peaks at 310 nm for TDI-PU and MDI-PUE and the broad band above 400 nm are only marginally quenched by oxygen. 

Figure 1. Transient absorption spectra (2.0 ms) of 5.5 X 10 3 MDI-PUE in THF (a) Nitrogen saturated (b) Air saturated (xex 248 nm) (Reproduced from Ref. 13. Copyright 1988 ACS).

After electrodeposition, the electrodes were rinsed with distilled water saturated with hydrogen and transferred to a three-compartment cell filled with a nitrogen saturated electrolyte for electrochemical studies. 

A similar polymer, composed of osmium complexed with bis-dichlorobipyridine, chloride, and PVI in a PVI—poly(acrylamide) copolymer (Table 2, compound 3), demonstrated a lower redox potential, 0.57 V vs SHE, at 37.5 °C in a nitrogen-saturated buffer, pH 5 109,156 adduct of this polymer with bilirubin oxidase, an oxygen-reducing enzyme, was immobilized on a carbon paper RDE and generated a current density exceeding 9 mA/cm at 4000 rpm in an O2-saturated PBS buffer, pH 7, 37.5 °C. Current decayed at a rate of 10% per day for 6 days on an RDE at 300 rpm. The performance characteristics of electrodes made with this polymer are compared to other reported results in Table 2. 

Anodic polarization nitrogen-saturated 5% aq. NaCl IQOfik anodic current imposed for 7 days. 

The electron spin resonance spectra were run in nitrogen-saturated solutions of aromatic compound ca. 10" m) and nucleophile (0-05-0-1 M) in the solvent(s) indicated. Irradiation in the cavity was effected with a high pressure mercury arc. Electrolysis was performed with the platinum cathode in the cavity, tetraethyl-ammonium perchlorate as electrolyte and electric currents of 10-250 /lA. 

Figure 1 Differential absorption spectrum obtained upon nanosecond flash photolysis (532 nm) of 7.2 X 10M solutions of Fc-ZnP-H2P-C6o triad in nitrogen saturated benzonitrile with a time delay of 50 nsec at 298 K. (From Ref. 47.)...

Photochemistry. For photochemical experiments, each MPe complex was dissolved in nitrogen-saturated dichloromethane, which contained 10 M CBr4 as the electron acceptor. The solutions were irradiated with light from a 300 W tungsten-halogen projector lamp and excitation into the... 

X-ray diffraction powder patterns were recorded on a CGR Theta 60 instrument, using monochromated CuKa radiation. The adsorption capacities for several adsorbates were measured at room temperature by gravimetry, using a Cahn RH microbalance as proposed by Vaughan and Lussier (3 ). The samples were first treated in air for 5 hours at 480°C. The experiment was performed by passing, over the sample, a stream of nitrogen saturated by the vapor pressure of the sorbate at room temperature, the relative pressure P/Po was then equal to 1. 

Aminocarbene complexes usually are less sensitive towards oxygen than the corresponding alkoxycarbene complexes, but nevertheless should be handled in an inert atmosphere. Their preparation is carried out under nitrogen free from oxygen and moisture, using dry, nitrogen-saturated solvents. 

Polonium tetrabromide is a bright red solid which melts, in bromine vapor, at about 330°C (7, 75), and boils at 360°C/200 mm 75). It is prepared by heating polonium metal in bromine vapor at 200 mm pressure for 1 hour at 250°C (7, 75) or, more rapidly, in a stream of nitrogen saturated with bromine vapor at 200°-250°C, and by heating polonium dioxide in hydrogen bromide or by evaporating a solution of polonium(IV) in hydro-... 

In order to avoid oxidation of PhTRAP, nitrogen-saturated solvent was used for the extraction and the chromatography. These manipulations should be done as quickly as possible. 

The formulation was applied with a calibrated wire wound applicator onto a quartz or sodium chloride plate the thickness of the uniform layer was typically between 5 and 10 . Samples were exposed to the laser beam for various durations up to a maximum absorbed dose of 100 mJ cm-2. Except for some specific experiments carried out in a nitrogen saturated reactor, all the irradiations were performed in the presence of air, at room temperature. 

Figure 4. Intrinsic viscosity of polystyrene samples irradiated in benzene solution under various conditions. Polystyrene concentration 7.69x 10-2 M and initiator I concentration 3.12x 10-3 M. vacuum nitrogen saturated air saturated V oxygen saturated 3.12 3 / 3-tert-butyl-4-hydroxyanisole 3.12x 10-3 M 1.4-diazobicyclo(2.2.2)-octane (DABCO).

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