The use of ethanol as fuel in Brazil stimulated the competition between distribution companies and resellers, which aggravated the practice of adulteration of fuels, aiming for illicit gains and tax evasion. The most common practice of adulteration in fuel alcohol is the addition of water. The classic techniques for measuring the water content in ethanol offer good precision and good detailing as to the presence of water. However, they present disadvantages such as the need for sample collection, long analysis time, in addition to the need for specialized laboratory and labor. This work aims to propose digital signal processing techniques to analyze and quantify the presence of water in ethanol fuel using a combination of Principal Component Analysis (PCA), and Singular Spectrum Analysis (SSA) applied on ultrasonic signals. This method resulted in the proposal of a new score, which relates to the ethanol/water ratio information present in the mixture. The results were promising when relating the proposed score to the presence of moisture in ethanol to a greater or lesser degree. Experiments performed prove the technique's feasibility and pave the way for a new method for real-time monitoring.INDEX TERMS Acoustic signature, ethanol, principal component analysis (PCA), singular spectrum analysis (SSA), singular value decomposition (SVD), ultrasound.
Abstract. Due to the large diffusion of ultrasonic technique in medicine, use of tissue mimicking materials to understand physical interaction of ultrasound has grown in importance. From this view measuring acoustic properties of such materials is crucial. This work shows the settlement at INRIM laboratory of a simple system for acoustic properties measurements with particular interest in attenuation of ultrasound. The system is based on substitution method and Fourier analysis and allow the evaluation of speed of sound, impedance and attenuation in the frequency range between 3 MHz and 12 MHz.
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.