Fuer die Beschreibung von Trocknungsprozessen ist die Kenntnis einer Reihe von Stoffdaten, insbesondere des Wasserdampf-Sorptionsverhaltens der Trocknungsprodukte, erforderlich, da diese es gestatten, Verpackungs-, Lager-und Stabilitaetsprobleme richtig einzuschaetzen bzw. loesen zu koennen. Anhand einer umfangreichen Literaturrecherche wurde eine tabellarische Zusammenfassung der fuer den Temperaturbereich von 40 bis 80 Grad C gueltigen publizierten Sorptionsisothermen erstellt. Darueber hinaus werden zwei unterschiedliche Methoden beschrieben, die es gestatten, mit relativ einfachen Labormitteln die Wasserdampfisorptionsisothermen bei hoeherer Temperatur mit hinreichender Genauigkeit experimentell zu ermitteln.

North Africa is one of the driest regions in the world. Consequently, all countries in the region depend mainly on agricultural imports to achieve the food security. The present study endeavor to estimate: firstly, the national and the global water saving achieved through the North African international cereal trade by using the concept of virtual water trade. Secondly, the relation between the imports of cereal trade, as endogenous variable, and the available water resources availability with other important factors as exogenous variables. The results showed that, at the national level, all North African countries achieved water saves to the extent that exceed the endowment total fresh water resources in Libya, Algeria, and Tunisia. Importing of maize and wheat is the most important player of the saving national water imports of among the cereal crops. All countries in the North Africa region achieved water saving except Egypt. The model results has shown statistically significant coefficients of factors affecting the total imports of cereal crops such as, per-capita fresh water resources, the area of irrigated water, the area of Arable land . the negative sing of per-capita fresh water resources indicates that the importing cereals using intensive water is not optional decision but due to the shortage of the available of water resources . Negative signs of irrigated area and of arable land are consistent indicating that the increasing of the irrigated area and the arable land will intuitively reduce the importing of cereals.

To evaluate the base line levels of potentially toxic and essential trace metals namely, Cd, Ph, Cr, Mn, Ni, Cu and Zn in water, locally grown vegetables, cereals and vegetable ghee-oil samples of a highly industrial city Gujranwala have been measured after wet digestion by employing AAS technique. Sampling was made from selected sites in and around the city over a period of three months. The concentration of Mn, Ni, Zn, Cu and Pb was found significantly higher in vegetables ranging from 3-63, 2-81, 5-92, 7- 70 and 6-60 ppm respectively. Nickel and Cu concentration was found higher in cereals whereas, Cd was found at ppb level in all variety of samples studied. Tap water, vegetable ghee-oil have recorded lower concentration of these metals. Vegetables collected from urban area have shown elevated level of contamination than those of taken from canal irrigated farms. The overall level of trace metals with few exceptions of vegetable samples was found within the permissible limits fixed by WHO. The analytical method was checked by applying on SRM of wheat and spinach. The results were found in agreement with the certified values within experimental error. The major polluting sources of the city such as automobile, man made activities, soil and road dust, metallic corrosion and industrial activities have been indicated. The environmental impacts of pollutants on water and food quality of an industrial and non-industrial city are briefly discussed in the light of their adverse effects on human health.