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In the present work the classification of dairies additives in a rapid and simple way, is proposed. Measurements were made by means of an Electronic Nose developed in our laboratories, which we named 'Patagonia E-Nose.' This E-Nose is composed of SnO2 sensors located in a thermally stabilized chamber which improves the repeatability of the measurements. Samples of various hydrolyzed dairies were measured using air as a reference gas. Then, the integrals of the signals were analyzed using a combination of different multivariate chemometric methods such as linear discriminant analysis (LDA), principal components analysis (PCA), back-propagation neural network and different classifiers. Also, different algorithms were implemented and compared by calculating the number of correctly classified samples of each method. 99.4% of correct classifications were obtained by using cross-validation and selecting the most appropriate algorithms. The results indicate that the samples were correctly classified through the implementation of a simple and low cost measurement protocol. Fil: Vorobioff, Juan. Comisión Nacional de Energía Atómica; Argentina Fil: Adaro, Mauricio Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Boggio, Norberto Gabriel. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Magallanes, J.. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Boselli, A.. Comisión Nacional de Energía Atómica; Argentina Fil: Lamagna, Federico Agustín. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; Argentina Fil: Rinaldi, Carlos Alberto. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Throughout this investigation, experiments on laser ablation with silicon (Si) wafers have been performed using silicon nitride (Si 3 N 4 ) as a sacrificial layer to find the optimal fluence capable of removing the Si 3 N 4 , which allows the subsequent anisotropic etching in Si with potassium hydroxide. As a result, an alternative to the traditional micromachining techniques that require more steps and processing times has been introduced. The effect of the pulse numbers on Si wafers has been studied and it has been observed that when increasing the pulse numbers at the same fluence, the capacity of the pyramidal cavity formed was greater than using only one pulse at higher fluences. Microcavities were performed with a floating Si 3 N 4 layer. This happens to be very useful for the development of drug delivery systems and the manufacture of microarrays. Microcavities were also used as masters for the fabrication of microionizers in polydimethyl siloxane (PDMS).

Carbon nanotubes (CNT) are valuable for their application in nanotechnology, electrical properties and high surface area, and in our particular case, for the manufacture of nanosensors. In this work the technique of Plasma Enhanced Chemical Vapor Deposition (PECVD) was used for the manufacture of CNT. The process was conducted in a horizontal tube reactor using methane as precursor gas and an R.F. discharge of 1000w output power acting as ionizing medium. Having achieved the synthesis of CNT on copper (Cu) substrates, heated with an internal electrical resistance to a process temperature of 900°C, the substrates were coated with ferric nitrate Fe(NO 3 ) 3 , which served as a catalyst and nucleation center. The heating system used differs from traditional methods by its internal heating. Growth of CNT was achieved on vertical walls on Cu substrates and perpendicular to it; a prerequisite for the manufacture of nanosensors, which is the main objective of this work, as well as to reduce as much as possible the diameter of the CNT, being its main features 5 μm average length and 7 nm average diameter.

Propulsion pellets of different metal/salt (Zn/CaCO 3 ) composition have been prepared. The impulse imparted to the pellet by the laser has been measured using two different methods: a torsion pendulum and a piezoelectric sensor. The dependence of the coupling coefficient, C m , on the composition of the solid binary propellants in ablative laser propulsion has been investigated under different experimental conditions: in vacuum and at atmospheric pressure as well as with two different wavelengths, IR and UV. The composition of the Zn/CaCO 3 propellant mixture that optimizes the coupling coefficient, C m , has been determined.

In this article a method to increase the capability of an electronic nose to discriminate between a priori similar odours is presented. Olive oil is analyzed because it is well known that the characteristics of its aroma impair in many cases the discrimination between different kinds of olive oils especially when they are from similar geographic regions. In the present work the improvement of the electronic nose performance for the above-mentioned discrimination by a non-destructive method of IR laser vaporization of the sample is studied. Laser vaporization has also been performed at two different IR wavelengths to analyze the effect of laser radiation absorption of the sample on the electronic nose selectivity.

This work shows the integration of a sensor based on carbon nanotubes using CMOS technology. A chip sensor (CS) was designed and manufactured using a 0.30 μm CMOS process, leaving a free window on the passivation layer that allowed the deposition of SWCNTs over the electrodes. We successfully investigated with the CS the effect of humidity and temperature on the electrical transport properties of SWCNTs. The possibility of a large scale integration of SWCNTs with CMOS process opens a new route in the design of more efficient, low cost sensors with high reproducibility in their manufacture.

The Riachuelo–Matanza basin area (2.240 km 2 ) is located in Buenos Aires province, Argentina. This area is affected by intensive and extensive agricultural activities, and bears almost 3,000,000 inhabitants and more than 10,000 industries, that release their effluents to the main collector of the basin, the Riachuelo River. It is a highly polluted area and the quality of water, soil and air is severely impaired causing chronic health problems. As part of an interdisciplinary study undertaken by local institutions to reach an environmental quality diagnosis and analysis of the pollutants dynamics in the basin system we have measured, with an electronic nose, the air immediately above the water in several points at the Riachuelo River mouth where the painteresque La Boca district is located. Water quality parameters simultaneously collected at the same sites were analyzed and correlated with the electronic nose response. This study is only exploratory and focuses on the viability of using an electronic nose to locate conflictive emissions throughout a given zone.

It is well know that the use of chambers with the sensors in the e‐nose improves the measurements, due to a constant gas flow and the controlled temperature sensors[1]. Normally, the chamber temperature is above room temperature due to the heat generated by the heater of sensors. Also, the chamber takes a long time to reach a stable equilibrium temperature and it depends on enviromental conditions. Besides, the temperature variations modify the humidity producing variations in resistance measurements[2]. In this work using a heater system that controls the temperature of the chamber, the desorption process on SnO2 sensor array was study[3]. Also, it was fitted the data signal sensors using a two exponential decay functions in order to determine the desorbing constant process. These constants were used to classify and identify different alcohols and their concentrations.