Reliable Mathematical Method Research Articles

Variability in quality of white and green beans during in-pack sterilization

Non-uniformity in process quality was investigated during in-pack thermal sterilization of food products. This was accomplished through the combined application of the Monte Carlo procedure and a reliable mathematical method for process evaluation. Despite the large coefficients of variation found, the optimum quality process could be designed. The influence of the statistical variability of heating rate index on the retention of green beans’ color was studied and an optimum temperature range was found between 125 and 135 °C. The variability in hardness of sterilized white beans, resulting from uncertainties of the combined effect of heating rate index and initial hardness of beans, was also evaluated by simulation. In this case, an optimum global temperature range between 120 and 135 °C was found, independently of the rotation, F 0 value and surface heat transfer coefficient assumed.

The nuclear region of low luminosity flat radio spectrum sources

In this work we have examined the spectroscopic properties of a sample of 19 optically bright, low luminosity Flat Radio Spectrum (LL FRS) sources. Our study focuses on the properties of their host galaxies, namely the nuclear stellar populations and dust content. In the optical – spectral region covered by our data – the objects in the sample are mainly dominated by the host galaxy starlight, which strongly dilutes the non-thermal continuum as well as possible emission-line features related to the active nucleus. We have computed the nuclear stellar populations contributing to the spectra of the objects in our sample. The stellar population synthesis has been performed by using a very reliable mathematical method, which yields a Global Principal Geometrical solution. Our results show that, for most of the objects in the sample, the populations are composed of old stars of solar metallicity, or lower; the populations are mainly composed of late-type stars, i.e. G, K and M spectral types, the young component coming thus from supergiant stars; the dust content is weak. Both the stellar populations and the dust content are in agreement with what is usually observed in “normal” elliptical galaxies. Similar stellar content has equally been found in the nuclear regions of galaxies hosting a Low Ionization Nuclear Emission Line Region, or LINER. The present work is important in illustrating the different applications of stellar population synthesis in the study of low luminosity radio sources. In fact, the synthesis allows us not only to obtain valuable information about the stellar populations and dust content of the host galaxies, therefore providing material for further studies on the connection between host galaxy and active nucleus, but also to reveal the so-far unstudied optical emission-line features present in the spectrum of our objects.

Statistical Variability of Thermal Process Lethality in Conduction Heating Food—Computerized Simulation

ABSTRACTA computerized procedure was developed for estimating the variability of process lethality when there were variations in all independent, thermal process parameters of conduction heating food packages. This was accomplished through the combined application of a Monte Carlo procedure and a reliable mathematical method for thermal process evaluation. By examining published information, statistical variations in physical and reaction kinetic parameters were represented by gamma distributions and others by normal distributions. The coefficients of variations in sterilizing values were estimated from temperature data collected by processing 211 × 300 and 307 × 409 cans of spaghetti in tomato sauce (60 cans each). They agreed well with those computed by the developed computerized procedure.