The Isothermal Sorption Measurement and the Isosteric Heats Determinations for the South Algerian Date Varieties

Abstract

The equilibrium water content of a product to be dried is essential during a forced convection solar drying and storage operation. These values are often taken from the so-called isothermal sorption curves. The isotherms determination is an essential step to know the distribution and the intensity of the water connections in the products. They make it possible to determine the products final water content to be reached in order to optimize the drying conditions and give valuable information on the hygroscopic equilibrium. As a result, this experimental study aims to determine the physicochemical components' and the desorption isotherms curves for deferent date type L'hmira, Bamakhlouf and Tegazza from the Touat region, in SouthWest Algeria, using the saturated salt solution method. The experiment is carried out for three temperature values 40 ° C, 50 ° C and 60 ° C, to study the influence of the temperature on the equilibrium curves of the product and finally to describe the isothermal moisture desorption for deferent date types for three temperatures using known models of GAB, SMITH, LANGMUIR and OSWIN.

Design and Realization of an Air Solar Heater and Thermal Measurement

“…T amb : Ambient temperature U 1 , U 2 : Heat losses coefficients by conduction and convection in (W / (m 2 .K)) G: Solar irradiation in w/m 2 The typical 2011-2012 values for glazed and tube collectors (from the Swiss SPF (Solartechnik Prüfung Forshung) test results are as follows (for absorber surfaces):…”

“…The idea is to use solar energy to heat air and send it into a living room in order to drive out the moisture [2][3][4], used for drying of food products [5] or use it as auxiliary heating.…”

Assessment Biodiversity of Medicinal Plants Used in Treatments for Native People in Adrar, Algeria

“…Adrar is composed of three natural and cultural regions: Touat (Adrar, Zaouiet Kounta), Gourara (Aougrout, Timimoune), and Tidikelt (Aoulef) and 299 ksours. The local languages are Arabic and Zenata [8,9].…”

“…Algeria includes more than 600 species of medical plants [8]. The majority of the local people of Adrar province used the medical plants for nourishment and medical purposes.…”

Experimental Measurement of Isothermal Sorption, Microbiological and Physicochemical Analysis of Dried Tomatoes Cultivated in Adrar, Algeria

“…Indeed, the sorption isotherms are indispensable measurement before the process of drying in order to preserve the seasonal post-harvest losses [3]. The knowing of this technique permits to have an overview for the hygroscopic or hydric balance of the product under consideration, and giving the information related to the distribution and binding intensity of water molecules to ensure the physicochemical and microbiological stability during the storage [1], in addition the product shelf life can be predicted studies on sorption isotherms are carried out by mathematical modeling [8], eight mathematical models (in the literature) empirical and semi-empirical based on more or less physical bases [1,4,9], describing the correlation of water content with balance with the water activity of the products. among these models: GAB [10], modified BET [11], Henderson-Thompson [12], modified Halsey [12], modified Oswin [12], Peleg [11].…”