Brass, analysis

Gluodenis describes the use of ICP to analyze samples containing Pb and Ni in brass. The analysis for Pb uses external standards prepared from brass samples containing known amounts of lead. Results are shown in the following table. ... 

What is the %w/w Pb in a sample of brass that gives an emission intensity of 9.25 X lO" The analysis for Ni uses an internal standard. Results for a typical calibration are shown in the following table. ... 

Other example of the application of described method may give analysis of copper in brass. It is well known that for the analytical line of copper CuKa the strong absorption takes place in Fe, Mn, Sn, Pb. These elements have the similar effect on ZnKa. It is possible to suppose that the ratio IcuKb IznKa less effected by the named elements. The analysis that was realized has confirmed that the variation of the named above ratio is about 25 less then variation of L. ... 

The pole has a eharaeteristie dimension of 8 mm from the rear of the bobbin to the reeess faee and has a toleranee assigned to it of 0.02 mm. From the pole reeess faee, the tube base toleranee is the last eomponent to make up the toleranee staek. The brass tube has been given a dimensional toleranee on its base of 0.2 0.025 mm. Note, the dimensional toleranee on the plunger is 28 0.05 mm, but the analysis will eoneentrate on the silieone rubber seal length of 6 mm beeause this is moulded onto the plunger and again is a mould related dimension. 

Figure 2.42 shows the variability risks analysis based on the toleranees assigned to meet the 0.2 mm toleranee for the assembly. Given that an FMEA Severity Rating (S) = 5 has been determined, whieh relates to a definite return to manufaeturer , both impaet extruded eomponents are in the unaeeeptable design region, as well as the bobbin and plunger end seal as shown on the Conformability Matrix in Figure 2.43. The toleranee for the brass tube base thiekness has no risk and is an aeeeptable design.

An analysis of the brass tube is performed to assess the likely eapability using CA. Referring to the proeess eapability map for deep drawing shown in Figure 2, and determining the material, m, and geometry, g, variability risks gives ... 

Measurements of the characteristic X-ray line spectra of a number of elements were first reported by H. G. J. Moseley in 1913. He found that the square root of the frequency of the various X-ray lines exhibited a linear relationship with the atomic number of the element emitting the lines. This fundamental Moseley law shows that each element has a characteristic X-ray spectrum and that the wavelengths vary in a regular fiishion form one element to another. The wavelengths decrease as the atomic numbers of the elements increase. In addition to the spectra of pure elements, Moseley obtained the spectrum of brass, which showed strong Cu and weak Zn X-ray lines this was the first XRF analysis. The use of XRF for routine spectrochemical analysis of materials was not carried out, however, until the introduction of modern X-ray equipment in the late 1940s. 

Leidheiser, H. and Kissinger, R., Chemical Analysis of the Liquid Within a Propagating Stress Corrosion Crack in 70 30 Brass Immersed in Concentrated NH4OH , Corrosion, 28, 218... 

To gain experience in qualitative analysis, full details will be given for the analysis of brass and an artificial seven-radical inorganic mixture. 

Tungsten ores often contain traces of molybdenum that need to be determined before the ore is processed. When the tungsten content is known, as it usually is, that element can serve as a built-in standard for the determination of molybdenum. In the work to be described, the intensity ratio was measured for molybdenum Ka and tungsten Lyl. The general approach thus resembles that of Eddy and Laby to the analysis of brass (7.10), but conditions are less favorable in the present instance. The background corrections necessary were somewhat involved, and they will be discussed in Chapter 8. See Figure 8-1 c. 

An inscribed thick plate of brass attributed to the landing, in 1579, of Francis Drake on the coast of California, is retained in safekeeping at the University of California, Berkeley. Since its discovery, in the San Francisco Bay area in 1936, however, there have been doubts about the authenticity of the plate, although an early chemical study had apparently confirmed its authenticity. Regardless of this initial study, doubts about the origin of the plate persisted, and a new study, based on the composition of the brass as determined by neutron activation, X-rays fluorescence, and atomic absorption analysis was initiated to reevaluate the earlier authentication of the plate. The results of this study were then compared with the composition typical of brass from Drake s time as well as from modem brass, and it was then concluded that the plate was probably made during the latter part of the nineteenth century or the early years of the twentieth century (Hedges 1979). 

Hedges, R. E. M. (1979), Analysis of the Drake plate Comparison with the composition of Elizabethan brass, Archaeometry 21, 21-26. 

Figure 13.8. The image of a fingerprint after contact with As203 taken from a brass sheet surface (500x500p,m). (Reprinted from Szynkowska, M. I. et al., 2007. Preliminary Studies Using Scanning Mass Spectrometry (TOF-SIMS) in the Visualisation and Analysis of Fingerprints, Imaging Sci. J., 55 180-187. With permission from Maney Publishing.) (See color insert.)...

Pollard, A.M. (1983a). Authenticity of brass objects by major element analysis Paper presented at Symposium on Archaeometry, Castel Dell Ovo, Naples, 18th-23rd April 1983. 

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