We are showing solutions of equations matter and energy conservation steday state for calculate thermal efíiciency of steam generators. The analysis of freedom degree show results are functions of variables chosen as input data. The results indicate chemical reactions contribute with 90 per cent of energy neccesary and expense energy share to steam and exit gas.

Se ha llevado a cabo experimentos para determinar el tiempo que demora el agua en escurrir desde un tanque de base plana conectado a tubos de vidrio de diferentes diámetros y longitudes. Los datos recolectados se utilizan para determinar los parámetros de la ecuación de Prandtl en el cálculo del factor de fricción. Los resultados muestran que el factor de fricción calculado del análisis de regresión es menor que el determinado del diagrama de Moody reproducido con la ecuación de Chen. Se considera necesario evaluar experimentalmente el factor de contracción.

Experimental data of efflux time for tank with exit pipe are comparad with values calculated by unsteady-state model(NoE) and quasi-steady-state model(SE). The time required to drain the tank calculated by boths modal give the same results when the step size is 0.1 seconds in the numerical solutlon of modal NoE. In some instances the calculations with the NoE modal glve a deviation of ±1% respect to the experimental value.

The quasi homogeneous diffusion model is used to simulate the ion exchange kinetics in batch systems. The theoretical equation predicts that rate exchange is controlled by the ratio weight of the ion exchanger to volume of solution and the resistances to mass transfer in the particle and in the liquid.

They have carried out experiments for the ion exchange reaction between ions Cr2O7 solutions and ion exchange resin in the chloride form. The concentration profile is reported in equivalent amounts of Cr +6 with time, for 0.1, 0.5 and 0.75 gram of resin. The results indicate that longer times are required at 2500 seconds to reduce the concentration to less than 1 ppm of Cr +6 in a volume of 250 ml of solution stirred at 250 rpm, with an initial concentration of 50 ppm and a weight of 0.75 grams resin.

In this paper we determine the profiles of temperature cycle of freeze drying of natural organic products, such as lucuma and garlic. The equipment used is a Freeze Dryer RIFICOR model LI-E300-CRT. This has a drying chamber, rectangular shelf, condenser and vacuum pump. The freezing temperature is -35 °C and the temperature of the condenser is -40 ºC, the vacuum pressure is 20 microns Hg.

In this first part we shall decribe several techniques which have been effectively employed to estimate nonlinear model parameter.

This reports presents the algorithm of Simplex method and two examples of computations.

In this work we examine the boiler-economizers system to determine the effect of warm water in the efficiency of steam generation system. Solving the equations balance of matter and energy (BME) provides that there is a saving in fuel consumption as it increases the temperature of water entering the boiler, and it is achieved by improving the efficiency of steam generator. The savings on fuel economy depends on the flow of water and is about 5%.

We tested biosorcion of chromium (VI) using lemon rind, citrus limonium, treated. The original lemon rind passes first through a stage of desmetoxilación with sodium hydroxide solution, 0.2M, pH 10, and in a second stage is subject to a process of crosslinking with solution diclorurm calcium, 0.2M, pH 2. The tests showed that chromium (VI) can be removed from its aqueous solutions, up to 75% of its initial concentration in twenty minutes.

Experiments were carried-out for exchange reaction between ions dichromate Cr207 2- solution and resín type DOWEX 1X4. It is reported the concentration of Cr+6 versus raaction time for resin wetghts between O.1 to 0.8 grams and for initial concentrations of 50, 100 and 200 ppm. The experimental data are correlations with the models of homogeneous quasi ditfusion and diflusion control1ed by the liquid film resistance, The experiments show that is required a weight of resin equal to O, 75 grams to reduce the Cr+6 concentration to 1 ppm in 1 hours.

We are proposing algoritms to solve problems of flow of an ideal gas in a pipe of constant section. With the compressible flow equations we have determined the pressure and velocity profile for both isothermal and adiabatic flow of air and methane.

We are showing solutions of equations matter and energy conservation steday state for calculate thermal efíiciency of steam generators. The analysis of freedom degree show results are functions of variables chosen as input data. The results indicate chemical reactions contribute with 90 per cent of energy neccesary and expense energy share to steam and exit gas.

Se ha llevado a cabo experimentos para determinar el tiempo que demora el agua en escurrir desde un tanque de base plana conectado a tubos de vidrio de diferentes diámetros y longitudes. Los datos recolectados se utilizan para determinar los parámetros de la ecuación de Prandtl en el cálculo del factor de fricción. Los resultados muestran que el factor de fricción calculado del análisis de regresión es menor que el determinado del diagrama de Moody reproducido con la ecuación de Chen. Se considera necesario evaluar experimentalmente el factor de contracción.

Experimental data of efflux time for tank with exit pipe are comparad with values calculated by unsteady-state model(NoE) and quasi-steady-state model(SE). The time required to drain the tank calculated by boths modal give the same results when the step size is 0.1 seconds in the numerical solutlon of modal NoE. In some instances the calculations with the NoE modal glve a deviation of ±1% respect to the experimental value.

The quasi homogeneous diffusion model is used to simulate the ion exchange kinetics in batch systems. The theoretical equation predicts that rate exchange is controlled by the ratio weight of the ion exchanger to volume of solution and the resistances to mass transfer in the particle and in the liquid.

They have carried out experiments for the ion exchange reaction between ions Cr2O7 solutions and ion exchange resin in the chloride form. The concentration profile is reported in equivalent amounts of Cr +6 with time, for 0.1, 0.5 and 0.75 gram of resin. The results indicate that longer times are required at 2500 seconds to reduce the concentration to less than 1 ppm of Cr +6 in a volume of 250 ml of solution stirred at 250 rpm, with an initial concentration of 50 ppm and a weight of 0.75 grams resin.

In this paper we determine the profiles of temperature cycle of freeze drying of natural organic products, such as lucuma and garlic. The equipment used is a Freeze Dryer RIFICOR model LI-E300-CRT. This has a drying chamber, rectangular shelf, condenser and vacuum pump. The freezing temperature is -35 °C and the temperature of the condenser is -40 ºC, the vacuum pressure is 20 microns Hg.

En esta primera parte se revisan las técnicas comúnmente usadas en la determinación de parámetros de modelos matemáticos no lineales.

Se presenta el algoritmo del método Simplex y dos ejemplos de cálculo.