Absorption static method

American Society for Testing and Materials (ASTM) (2000a), ASTM I) ISIS Standard Test Method for Water Absorption (Static) ofVegetable Tanned Leather. West Conshohocken, PA, ASTM. 

Static method. In the static method, the reduction of mercury is performed as in the dynamic method. The mercury vapour is passed first through a vacuum flask, and then via a gas pipette to the absorption cuvette (Figure 93). In practice, the precision of the static method is better than that... 

Another advantage of the GSC method is its applicability for a short time of contact between adsorbate and adsorbent, which is not possible for static methods. This applies to measurements of adsorption on catalysts and studies of catalyst specific surface area at higher temperatures, close to the working temperature as well as adsorption on polymers. In this latter case static methods do not distinguish between adsorption and absorption. 

The anisotropic absorption of plane polarized light (parallel and perpendicular to the optic axis of the sample) can be recorded by inserting and rotating a plane polarizer in a "normal" spectro-photometer(3) (static method) or by converting, in a dichrograph. 

A further example of the static method of vapour pressure measurement which after teething troubles is finding increased favour is absorption spectroscopy. The method consists of heating a specimen in a closed vessel of known dimensions, usually a silica cell, maintained at a uniform temperature. A characteristic spectral source of high intensity is provided, for example, by the incorporation of the element of interest into a hollow cathode lamp. Radiation from the lamp is passed through the closed... 

Taking into consideration relations (3.2.4), expressions (3.2.6) for absorption lines allowed in infrared spectra (A/ 0) are the same as those obtained formerly by an alternative method which involves no sublattice concept.81 The determination of Davydov splittings as squared frequency differences (3.2.6) results in their independence from the static frequency renormalization. For structures with [Pg.62]

Early stages of copper electrodeposition and coadsorption of chloride on the Au(lll) electrode surface have been studied by Wu et al. [390] applying electrochemical methods and in situ X-ray absorption measurements. The results indicate a large degree of static disorder and exclude the presence of high-symmetry structures. Krznaric and Goricnik [391]... 

Gao and co-workers measured the absorption properties of an Octoliglike material [13] by a batch and a flow methods. Quantitative reaction was reported, and the absorbing ability of the PEI-silica material followed the order of Cu > Cd > Zn at a pFF of 6-7 [13]. They also measured the saturated absorption uptake and reported values for copper(II) of 25.95 mg/g and 50.01 mg/g, respectively, for static and dynamic conditions [13]. 

The opticol absorption spectra of the solvated electron have now been reported for a number of organic liquids. The chemical reactivity in the aliphatic alcohols has been studied by the pulse radiolysis method. The absorption maxima for a series of five aliphatic alcohols are in the visible to near infra-red. These maxima show a red shift with decrease in the static dielectric constant. The solvated electron undergoes reactions of electron-ion combination, electron attachment, and dissociative electron attachment. Absolute rate constants have been determined for these reactions. 

Hon et al. [34] describe a simple piece of equipment for the determination of down to 80 pg/1 of mercury by AAS using a static cold vapour procedure. In this method [35], the sample was digested with the sulfuric acid, a measured portion pipetted into the reduction vessel, and the vessel immediately capped. The reductant, comprising 1% stannous chloride, was introduced. The evolved elemental mercury in the headspace was then introduced into the absorption cell by water displacement. Maximum sensitivity is obtained when the volume of the displaced air is equal to the internal volume of the absorption cell, and the mercury solution is 9 M in sulfuric acid. The peak absorbance at 253.7 nm exhibited a marked decline for hydrochloric acid concentrations above 1.5 M and for nitric acid concentrations above 3 M. The calibration graph obtained for mercury(II) in 9M sulfuric acid is linear from 0 to 17ng/ml, and the sensitivity is 0.08 ng/ml. A windowless absorption cell can also be used with a narrower linear calibration range. 

Variable recovery is a principal cause of non-equivalence of data and there is no straightforward solution to this problem [26], Artificially made reference samples or pure compounds added to test material cannot be used for estimations of recovery of analytes. Direct speciation analysis from the solid sample [27] is not feasible at present, although analytical methods are appearing that could be useful in the future (X-ray absorption spectrometry, laser mass spectrometry, static secondary ion mass spectrometry). 

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