In this paper, the potential of an improved electronic nose to discriminate the quality of petroleum waxes based on their volatile profile was analyzed. Two datasets at 25 and 50 °C were collected from an experiment in order to compare influence by temperature. More fine-grained levels were further labeled for classification to meet various purposes. As petroleum waxes with lower odor levels are more difficult and important to identify than those with higher odor levels, we focus on the discrimination task for low-level ones. Principal component analysis was used for dimensionality reduction and data visualization. k-nearest neighbors, support vector machine, and multilayer perceptron were employed to classify among different qualities of petroleum waxes. The leave-one-out cross-validation method was employed due to the small sample sizes. Results showed good performance on both datasets, and at a temperature of 50 °C all pattern recognition methods showed improved classification rates. The improved electronic nose can potentially be applied to discriminate the quality of petroleum wax.
The temperature recorded immediately after hypervelocity collision of microparticles comprising iron and nickel with a silver-coated piezoelectric plate was analyzed using photomultipliers of different spectral response characteristics. The conversion rate between the velocity and temperature is estimated to be ~900 K/km/s in the velocity range of 10-40 km/s. This rate is greater than that reported earlier
The propagation of transverse waves generated acoustically in a piezoelectric element by colliding it with hypervelocity microparticles was studied. The propagation times were measured by a set of multiple electrodes on the surface of the element. The coordinates that the particles struck were determined by combining the propagation times and the velocity of the waves. By using the position-sensitive element, significant deviations between the prior indicated and actually measured orbits were observed. The potential of the present element as part of a steering system is discussed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.