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Resumen Actualmente las leyes ambientales son cada vez más rigurosas con los diagnósticos ambientales. Por lo anterior, es importante garantizar la confiabilidad de los resultados en los métodos de determinación de contaminantes. En el caso de los hidrocarburos, se usan métodos espectrofotométricos y cromatográficos, para los de fracción más pesada son empleadas técnicas gravimétricas Sin embargo, muchos trabajos discuten las diferencias en los resultados debido a las interacciones a matriz-contaminante. Con el fin de establecer herramientas básicas que permitan la adecuada determinación de los hidrocarburos presentes en suelo o agua, se llevó a cabo la determinación de hidrocarburos totales en distintos tipos de petróleo y destilados empleando un equipo Infracal TOG/TPH. Los diagramas de dispersión mostraron una tendencia logarítmica y se propuso un modelo de regresión lineal. Al analizar dicho modelo mediante el análisis Anova, resultó un p-valor menor a 2,2x10-16 y un coeficiente de determinación R=0,969, lo cual indica un ajuste satisfactorio del modelo potencia. Abstract Currently environmental laws are increasingly stringent with environmental diagnostics. Therefore, it is important ensure the reliability of results in the methods of determining contaminants. In the case of hydrocarbons, spectrophotometric and chromatographic methods are used, for heavier fraction are employed gravimetric techniques However, many papers discuss the differences in the results due to interactions matrix-pollutant. In order to establish basic tools that allow the proper determination of the hydrocarbons present in soil or water, was carried out the determination of total hydrocarbons in different types of oil and distillates using a computer Infracal TOG / TPH. Scatter plots and trend showed a logarithmic model linear regression was proposed. By analyzing the model by Anova analysis, it was a p-value less than 2,2x10-16 and a determination coefficient R = 0,969, indicating a satisfactory fit of the model output.

Isometric or isotonic transducers have traditionally been used to study the contractile/relaxation effects of drugs on isolated tissues. However, these mechanical sensors are expensive and delicate, and they are associated with certain disadvantages when performing experiments in the laboratory. In this paper, a method that uses an image sensor to measure the contractile effect of drugs on blood vessel rings and other luminal organs is presented. The new method is based on an image-processing algorithm, and it provides a fast, easy and non-expensive way to analyze the effects of such drugs. In our tests, we have obtained dose-response curves from rat aorta rings that are equivalent to those achieved with classical mechanic sensors.