Corrosion Behavior in Saline Medium for a Cu-Zn Casting Alloy

The paper present aspects about the structural modification of CuZn alloy obtained by casting and used to manufacture the housing which works in corrosive liquid mediums. The analyzed alloy has a chemical composition determine by spectral quantitative analysis, with an optic spectrometer type Foundry Masters, using cooper analysis base. The structural modifications, both in cast state, also after corrosion studies, have highlighted by SEM, at 500x and 2000x magnitude. The experiments were made on samples, with specific dimensions for each analysis.

Development and Evaluation of Dedicated Bench-Type near Infrared Spectrometers to Estimate the Flavour of Green Soybeans from Single Pod Measurements

Green soybeans are now an economically important and popular food product in Japan. We have been studying the determination of the eating quality-related constituents of green soybean (edamame) such as sucrose and NRQ (defined by ninhydrine reaction, which has a high positive correlation with total free amino acids) using a commercial near infrared (NIR) transmission analyser since 2002. In order to shorten the breeding time and to decide an optimal harvest time, we have been developing a dedicated NIR transmission spectrometer for the determination of constituent content of green soybeans in a single pod since 2004. We developed two bench-type transmission NIR spectrometers, one employs a new sample presentation with the existing light source and spectrometer (Type 1) and the other employs a new sample presentation with modifications to both the light source and the spectrometer (Type 2). Spectra, obtained using the Type 2 transmission NIR, processed using partial least squares (PLS) regression modelling with full cross-validation methods achieved the following parameters: R2 = 0.69 and SECV = 0.21% for free amino acid and R2 = 0.74 and SECV = 0.39% for sucrose. These findings indicate that reasonably accurate models could be obtained.

Partial Pressure Analysis in Space Testing

For vacuum-system or test-article analysis, it is often desirable to know the species and partial pressures of the vacuum gases. Residual gas or partial pressure analyzers (PPAs) are commonly used for this purpose. These are mass spectrometer-type instruments, most commonly employing quadrupole filters. These instruments can be extremely useful, but they should be used with care. Depending on the instrument design, calibration procedures, and conditions of use, measurements made with these instruments can be accurate to within a few percent, or in error by two or more orders of magnitude. Significant sources of error can include relative gas sensitivities that differ from handbook values by an order of magnitude, changes in sensitivity with pressure by as much as two orders of magnitude, changes in sensitivity with time after exposure to chemically active gases, and the dependence of the sensitivity for one gas on the pressures of other gases. However, for most instruments, these errors can be greatly reduced with proper operating procedures and conditions of use. In this paper, data are presented illustrating performance characteristics for different instruments and gases. Operating parameters are recommended to minimize some errors. Calibrations procedures are described that can detect and correct other errors.