Chemical Analysis

Hammerscale is the product of high-temperature oxidation of iron alloys and it is particularly associated with the forging of iron. Due to its magnetic properties hammerscale is easily recovered from archaeological contexts. While most hammerscale consists of flakes of iron oxide, a small proportion consists of spheres. This paper presents the results of the microscopic examination and chemical analysis of both flake and spheroidal hammerscale from archaeological contexts as well as material recovered during experimental forging and welding. In addition, the experimental fire-welding of iron has been recorded using high-speed digital video. This demonstrates that spheroidal hammerscale is produced during forge welding. The chemical analysis of the experimental hammerscale shows that it isformedfrom oxidized iron with a small but significant contribution from the non-metallic inclusions in the metal.

A series of experiments were conducted to investigate the effect of activation temperature on pore development of activated carbon produced from palm shell. Activation of the samples was carried out at 800, 850 and 900°C for different durations ranging from 10 to 180min. The samples were characterized using N2 adsorption for evaluation of micropores and the mercury intrusion technique for mesopore and macropore analysis. Within the range of activation temperatures studied, high burn-off products derived from high activation temperatures tend to have larger micropore development. However, an increase in the activation temperature has no remarkable effect on mesopore and macropore development. © 2002 Society of Chemical Industry.

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Phospholipid fatty acid (PLFA) analysis of a soil microbial community was coupled with 13C isotope tracer analysis to measure the community’s response to addition of 35 μg of [13C]toluene ml of soil solution−1. After 119 h of incubation with toluene, 96% of the incorporated 13C was detected in only 16 of the total 59 PLFAs (27%) extracted from the soil. Of the total 13C-enriched PLFAs, 85% were identical to the PLFAs contained in a toluene-metabolizing bacterium isolated from the same soil. In contrast, the majority of the soil PLFAs (91%) became labeled when the same soil was incubated with [13C]glucose. Our study showed that coupling 13C tracer analysis with PLFA analysis is an effective technique for distinguishing a specific microbial population involved in metabolism of a labeled substrate in complex environments such as soil.

High-temperature creep tests were conducted on polycrystalline copper of commercial purity in order to investigate the inter-relationship between the extent and the rate of grain boundary sliding (GBS) and the development of internal cavitation. An image processing technique was used to provide quantitative information on the size and shape of the cavities formed over a range of stresses and at temperatures from 673 to 873 K. The results demonstrate that cavity development is inhomogeneous within any specimen, such that there is an increase in the level of cavitation in regions of higher local strain. It is shown by quantitative measurements that the total cavitated area increases at the faster sliding rates, but the number density of cavities decreases at the highest sliding rates because of cavity interlinkage. When interlinkage is taken into account, the results confirm that the overall level of cavitation is related to the occurrence of GBS.

Evaluation of emerging diesel-particulate emissions control technology will require analytical procedures capable of continuous measurement of transient organic and elemental carbon emissions. Procedures based on the flame ionization properties of organic carbon and ...

... Available online 12 March 2002. Abstract. The present contribution shows the results of tests on geological materials for determination of the rare-earth elements La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, as well as Y and Sc. ...