Summary of the Closing Session

Plausible costs of photovoltaic power plants of concentration are presented. Costs are based as much as possible on the recent experience of solar thermal plants. Efficiencies, on the existing world experience of PV power plants. The result is that the costs of concentrating photovoltaic plants should be of 0.08 ECUs/ kWh, about 1/3 of that of flat module plants, and of the same order of magnitude, even lower, than those attributed to solar thermal plants of present technology.

For the future, high concentration systems based on Si or tandem cells seem to be the most promising, also in the range of costs of the advanced solar thermal plants.     

海边梦想地

<正>普吉岛盛产锡矿和橡胶,早在几个世纪前,普吉岛便作为泰国南部重要的港口和来自亚欧的许多国家有着贸易往来。其中,中国和葡萄牙是主要的贸易对象。这些国家的商人常年往来,生活于普吉岛,渐渐地将各自的文化风俗融入到当地。普吉岛至今还留存有逾越一个多世纪的中国传统建筑和葡萄牙传统别墅建筑,当地甚至还延续了一些源自中国的古老节日。     

A PROLOG APPROACH TO IMAGE SEGMENTATION

Segmentation is a main problem in computer vision. It attempts to supply primitives for higher-level processes of interpretation. A multithreshold approach has already given acceptable results. This paper presents a PROLOG implementation of a multithreshold system. The system uses the technique of recursive partition of two-dimensional images in quadrants to form maximal blocks; the data structure generated by this partition algorithm is known as a quadtree. The algorithms implemented concern image representation, connected regions, identification, and contour detection. The improvement of algorithms in a logic language rather than in a procedural one appeared to be of particular interest. The main reasons for this are implementation facility and the natural use of logic programming in the field of knowledge-based systems. In fact, a knowledge-based approach seems a reasonable solution to problems of assisted image understanding processes.     

Finite element analysis of heat conduction in lasagna during thermal processing

Conductive heat transfer in lasagna during heating was computed by means of the finite element method. the thermophysical properties of the pasta and tomato sauce layers were derived from their chemical composition. Simulation results obtained with an axisymmetric 2D finite element mesh without the typical layer structure differed only slightly from results obtained with a 1D mesh in which the typical layer structure was incorporated. the predicted temperatures at various locations in the lasagna agreed well with experimentally determined temperatures during heating in a commercial medium scale oven under various operating conditions. It is shown that the temperature dependency of the thermophysical parameters has only a minor influence on the temperature near the centre of the lasagna. However, when the lasagna surface is subjected to temperatures above its boiling temperature, incorporation of the water/vapour phase change in the specific heat capacity can avoid over-estimation of the volume averaged temperature and process value.     

DISCRIMINATION OF SOME TUNISIAN OLIVE OIL VARIETIES ACCORDING TO THEIR OXIDATIVE STABILITY, VOLATILES COMPOUNDS AND CHEMOMETRIC ANALYSIS

Oxidation stability is a key property of olive oil quality and is affected by different antioxidant compounds whose levels may be influenced by several factors such as cultivar and place of production. Polyphenols, carotenoids, chlorophylls, fatty acids levels and some volatiles were correlated to oxidative stability in olive oils in five samples studied. Total polyphenols and saturated to polyunsaturated fatty acids (and/or oleic to linoleic acid ratio) ratio were shown to be the major parameters in oil antioxidant stability, according to analysis of variance and principal component analysis. The hexanal/E-2-hexenal ratio is a very important indicator of the freshness of the oils and can estimate their oxidation degree.

PRACTICAL APPLICATIONS

The present study gives information about the importance and the variability of some Tunisian olive oil varieties in both their quality (high oxidative stability) and good organoleptic properties which could be appreciated by consumers.