Abstract
Fractional calculus (FC) was originally developed in a pure mathematical viewpoint. However, nowadays FC is applied in many emerging fields of physics and engineering. This paper studies the fractional electrical impedance of vegetables and fruits having FC modelling in mind. In this line of thought, are developed several experiments for measuring the impedance of botanical elements, based in the Bode and polar diagrams. An electrical circuit that models these systems is presented and conclusions are drawn. Copyright © 2006 IFAC.

Abstract
This paper analyses the performance of a Genetic Algorithm (GA) in the synthesis of digital circuits using a new approach. The novel concept extends the classical fitness function by introducing a fractional-order dynamical evaluation. The dynamic fitness function results from an analogy with control systems where it is possible to benefit the proportional algorithm by including a differential component. For this purpose the non integer derivative is approximated through Padé fractions. The experiments reveal superior results when comparing with the classical fitness method. Copyright © 2006 IFAC.

Abstract
This paper presents a motion planning and control method with application in the field of legged robots. The general aim is to explore a set of simple underlying principles that govern balance of posture and gait of biped robots, and to develop control methodologies for such a highly unstable and non linear plants. The proposed controller reflects a hierarchical structure based on the interaction forces between the foot and ground and simple feedback rules used online. The algorithms are applied to a simulated 3-D leg model with five degrees of freedom (DOF). The simulation analyses demonstrate the capability of the control system to keep balance when the leg executes different tasks. To validate the proposed method several aspects are investigated, such as the posture robustness on the level ground when subject to external perturbations, the adaptation when standing in a moving platform and the improvements introduced by the compensation of the tangential reaction forces.

Abstract
Fifty-one quince jams from several different brands, commercialised in three consecutive years, traditionally prepared and industrially manufactured, were studied. Principal component analysis (PCA) was performed, in order to assess the correlations between the different components of quince jam phenolics, organic acids and free amino acids. Phenolics determination was the most interesting. The differences between phenolic profiles of traditional and industrial quince jams were emphasised during PCA. Two main PC characterise the quince jam phenolic composition (54.4% of all variance): PCl (37.4%) and PC2 (17.0%). The PCl describes the differences between the contents of 3-0- and 5-0-caffeoylquinic acids and all flavonoids and the PC2 relates the contents of 4-0- and 5-0-caffeoylquinic acids against 3-0-caffeoylquinic and 3,5-dicaffeoylquinic acids. The results indicate that many industrial manufacturers usually use unpeeled fruits in the preparation of the jams. The PCA of phenolic compounds enabled clear discrimination between quince jams prepared with peeled and unpeeled fruits.

Abstract
The aim of the present study was to compare the accuracy and reproducibility of six statistical models for the calculation of olive (Olea europeae L.) heat requirements to trigger the onset of flowering in three Portuguese regions: Reguengos de Monsaraz, Valenca do Douro, and Braga. Other aims were to ascertain the date on which the heat-accumulation period started and the threshold temperatures above which the development of reproductive structures starts in olives. The starting and peak dates for the regional O. europeae flowering season were estimated by monitoring airborne pollen from 1998 to 2004 using "Cour" type samplers. The threshold temperature values calculated for the three regions were very similar (9.0 degrees C for Valenca do Douro, 9.2 degrees C for Reguengos de Monsaraz, and 9.7 degrees C for Braga). The accumulated daily mean temperature model had less interannual and inter-regional variation, showing best predictive results for 2004, with absolute differences between the observed and predicted dates of 4 d in Reguengos de Monsaraz and 2 d in Valenca do Douro and Braga for the onset of flowering date and of 2 d in Reguengos de Monsaraz, 7 d in Valenca do Douro, and 4 d in Braga for peak flowering dates. This model was the most accurate, reproducible, and operational to calculate heat requirements for olives to flower, with an average mean temperature accumulation of 1 446 degrees C in Reguengos, 1 642 degrees C in Valenca do Douro, and 1 703 degrees C in Braga to reach the onset of flowering. The best initial date for this accumulation was 1 January.

Abstract
For calculating the total annual Olea pollen concentration, the onset of the main pollen season and the peak pollen concentration dates, using data from 1998 to 2004, predictive models were developed using multiple regression analysis. Four Portuguese regions were studied: Reguengos de Monsaraz, Valenca do Douro, Braga and Elvas. The effect of some meteorological parameters such as temperature and precipitation on Olea spatial and temporal airborne pollen distribution was studied. The best correlations were found when only the pre-peak period was used, with thermal parameters (maximum temperature) showing the highest correlation with airborne pollen distribution. Independent variables, selected by regression analysis for the predictive models, with the greatest influence on the Olea main pollen season features were accumulated number of days with rain and rainfall in the previous autumn, and temperatures (average and minimum) from January through March. The models predict 59 to 99% of the total airborne pollen concentration recorded and the initial and peak concentration dates of the main Olea pollen season.