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Aluminum chemical analysis

Refs 1) US Joint Army-Navy Specification JAN-M-454 (21 Feb 1947) with Amendment 1 (15 Feb 1952), Magnesium-Aluminum Alloy, Powdered 2) N.H. Furman, Scott s Standard Methods of Chemical Analysis , 5th Ed, Vol 1, Van Nostrand, Princeton, NJ (1961), 539—53 3) US Military Specification... [Pg.26]

Fig. 6.3. Saturation indices of Amazon River water with respect to various minerals (left) calculated directly from a chemical analysis, and (right) computed assuming that equilibrium with kaolinite and hematite controls the fluid s aluminum and iron content. Fig. 6.3. Saturation indices of Amazon River water with respect to various minerals (left) calculated directly from a chemical analysis, and (right) computed assuming that equilibrium with kaolinite and hematite controls the fluid s aluminum and iron content.
In this case, a likely explanation for the apparent supersaturation is that the chemical analysis included not only dissolved aluminum and iron, but also a certain amount of aluminum and iron suspended in the water as colloids and fine sediments. Analytical error of this type occurs because the standard sampling procedure calls for passing the sample through a rather coarse filter of 0.45 tun p0re size and then adding acid to preserve it during transport and storage. [Pg.95]

In order to study he Lewis acidity of the samples, the intensity of the 1450 cm pyridine band was also measured. Sample HYUS-8 shows a high amount of Lewis centers (Fig. 4d), relative thf HYD-400 sampl (Fig. 5c). This agrees with the absence of A1 as observed by A1 MAS-NMR for HYD samples. However, chemical analysis (Table I) indicates that there is more aluminum in this sample than in that from the unit cell constant m i urements. These differences cculd be explained considering that A1 MAS-NMR does not detect octahedral EFAL because of the low symmetry of its environment (i ). If this is so, it is remarkable that this EFAL does not show Lewis acidity as measured by pyridine ad y ption. On the other hand, if indeed thej is a small amount of A1, then the EFAL should be present as Al" outside the zeolite framework. In this case it should be present as amorphous silica-alumina. [Pg.26]

Aluminum Powder Flaked, Grained and Atomized" (for use in ammunition) 2)US Spec JAN-A-512, "Aluminum Powdered" (Grained or Atomized)(from secondary metal) (for use in pyrotechnics or in incendiary "thermite") 3)US Spec JAN-A-667, "Aluminum Powder, Superfine" 4)US Spec JAN-M-454, "Magnesium-Aluminum Alloy, Powdered" 5)W.W.Scott N.H.Furman, "Standard Methods of Chemical Analysis, "Van No strand, NY(1939) 6)H.V. Churchill... [Pg.144]

R.W.Brldges, "Chemical Analysis of Aluminum," Aluminum Co of America, Pittsburgh, Pa(1941) 7)"Routine Spectrographic... [Pg.144]

Freeze-Dried Samples. Solid Materials and Tissues. These are first cut into approximately 1-inch cubes, frozen on a Teflon cookie sheet in a freezer, and placed in 1200-ml. freeze-dry flasks to capacity. The flasks are attached to the freeze-dried (lyophilizer) manifold, the valves are opened to vacuum, and the flasks are evacuated. The water from the tissues is trapped on a condenser. The dry tissues (drying time about 2-3 days) are removed from the lyophilizer and compressed into thin-walled aluminum cans with a Carver Laboratory press fitted with a special die, at about 24,000 lb. pressure (total). From 150-250 grams of the dry material, representing 500-1000 grams of fresh tissue, can be packed into a single can. The cans are sealed with a hand sealer and set aside for counting. Samples can be removed from the cans at a later date for chemical analysis or beta-emitter analyses. [Pg.232]

The compositions of samples obtained from chemical analysis are listed in Table 1. If aluminum in the samples are not lost during the boronation ( i.e., the non-framework aluminum species in the parent sample are reinserted into the framework in alkaline medium, which has been proved to be possible in our previous work [12,13]), the change in Si/Al ratios of the boronated samples as shown in Table 1 should be caused by the removal of silicon from the framework. The values of A(Si/Al) in Table 1 represent the number of dissolved silicon (expressed as Si atom/Al atom). For the boronated samples, A(Si/Al) ratios are much greater than B/Al ratios, indicating that the number of boron atoms inserted into the framework is much less than that of removed silicon atoms. In other words, a number of vacancies resulted from silicon removal are not filled by trivalent elements and remain in the framework, consistent with our observation that the masses of the samples decrease after the boronation. It can also be deduced that the vacancies and defects are more in [B]-Na(3-2 than in [B]-Na[3-1 because the A(Si/Al) value of the former is greater than that of the latter. [Pg.393]

On the supposition that the total number of unit cells keeps invariable and no aluminum atoms are lost during the boronation, the composition of unit cell and the population of vacancies can be estimated as listed in composition of unit cell (I) in Table 2. It can be seen that the vacancies occupy about 30-50% of total T sites after the boronation. However, it should be noted that the population of vacancies thus obtained by chemical analysis is only a bulk average result. The composition on the surface of crystallites is actually different from that in the bulk because the dissolution of silicon starts first from the outer surface, so that the vacancies on the surface are much more than those in the interior of crystallites. Such a large number of vacancies on the surface will result in corrosion and dissolution of the surface parts of crystal particles. Therefore, the number of unit cells in the sample after the boronation is actually less than that before the boronation, whereas boron atoms in each unit cell should be more than those shown in composition of unit cell (1) in Table 2. On the other hand, if all the 64 T sites are occupied by silicon and trivalent atoms, we can give another set of compositions as shown in composition of unit cell (II) in Table 2. The real composition of a unit cell should be between these two sets of compositions, that is, the 64 T sites are neither occupied completely nor vacated so severely that the collapse of the framework occurs. It can also be seen that the introduction of boron atoms is so limited that there are no more than 1.5 atoms per unit cell even though the repeated boronation is performed. [Pg.394]

Equation (IS) provides the zeolite chemist with a powerful quantitative method for the determination of framework composition of zeolites. By comparing (Si/A1)NMR values with the results of chemical analysis, which gives bulk composition, the amount of nonframework (six-coordinated) aluminum can be calculated. This is of particular value in the study of chemically modified zeolites (see Sections III,J-III,M). [Pg.228]

When aluminum-silicon (Al-Si) metallization was deposited on wafers by evaporation, wet chemical analysis was used to study the changes in concentrations of Al to Si in the single evaporating cup. Wet chemical analysis was also used to determine the uniformity of silicon in aluminum and the evaporation patterns on the wafers in a rotating evaporator. The results revealed an accumulation of silicon in the cup and clearly showed the total lack of uniformity within a wafer and from wafer to wafer. The study showed why metallization problems were occurring and how to stop them. [Pg.527]

R.W.Bridges, "Chemical Analysis of Aluminum," Aluminum Co of America, Pittsburgh, Pa(1941) 7)"Routine Spectrographic Analysis of Aluminum and Magnesium and Their Alloys, Aluminum Co of.America, Pittsburgh, Pa(1944) 8)Kirk Othmer 1 (1947), 595 8a)American Research Insti-... [Pg.144]

At present, no biomarkers of exposure and effect other than the parent compounds are available for aluminum. There are no data to indicate whether other biomarkers, if available, would be preferred over chemical analysis for monitoring exposure to aluminum. [Pg.269]

Calculated from FAL (1) and total aluminum by chemical analysis. [Pg.20]

Sometimes the nucleus can be changed by bombarding it with another type of particle. This is referred to as induced radioactivity. In 1934, Irene Curie, the daughter of Pierre and Marie Curie, and her husband, Frederic Joliot, announced the first synthesis of an artificial radioactive isotope. They bombarded a thin piece of aluminum foil with ot-particles produced by the decay of polonium and found that the aluminum target became radioactive. Chemical analysis showed that the product of this reaction was an isotope of phosphorus. [Pg.101]

Particles of ZSM-5 with different Si Al ratio may have different chemical profiles across the particle. Small (0.3ym) particles of low Si Al may either be composed of 30nm crystals stacked together or be a single crystal with more aluminum in the center. Large 2pm particles of higher Si Al exhibit a chemical profile showing more aluminum near the particle surface than in the interior. Therefore, the overall Si Al ratio from bulk chemical analysis should not be taken as the analysis at each point in each particle. [Pg.216]

The results of total chemical analysis are usually expressed in oxides. For example, the percent of silicon dioxide, aluminum oxide, ferrous and ferric oxides, etc., is given in Chapter 1, Section I.3.2.2. A special use of chemical analysis is the determination of cation- or anion-exchange capacity (Chapter 1, Section 1.3.3.2). [Pg.208]


See other pages where Aluminum chemical analysis is mentioned: [Pg.173]    [Pg.407]    [Pg.208]    [Pg.23]    [Pg.20]    [Pg.148]    [Pg.173]    [Pg.354]    [Pg.135]    [Pg.390]    [Pg.56]    [Pg.17]    [Pg.321]    [Pg.154]    [Pg.468]    [Pg.130]    [Pg.173]    [Pg.58]    [Pg.161]    [Pg.624]    [Pg.32]    [Pg.197]    [Pg.519]    [Pg.225]    [Pg.194]    [Pg.508]    [Pg.135]    [Pg.200]    [Pg.393]    [Pg.105]   
See also in sourсe #XX -- [ Pg.320 ]




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Aluminum analysis

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