Determinations of unsaturated soil parameters using experimental procedures are time consuming and difficult. In recent years, the soil–water characteristic curve (SWCC) has become an important tool in the interpretation of the engineering behavior of unsaturated soils. Difficulties associated with determining such parameters have justified the use of indirect determination. This paper presents the general nature of the SWCC for soils with different plasticity limits, index and gradation, in terms of gravimetric water content and degree of saturation versus soil matric suction from Anbar governorate. In order to investigate possible relationships between the plasticity limits, index, percent passing no.200 and SWCC, 7 type of soils were tested to find its SWCC experimentally and compared the result with the curves obtained from different model presented in the literature. The objectives of the paper were to check the validity of these models with the experimental results. The results shows a good agreement and to present a simple method for inferring the SWCC for soils, taking into account the liquid limit, plastic limit, plasticity index and percent of fines passing sieve no.200.
The aim of this paper is to in investigate the performance characteristics of counter flow wet cooling towers experimentally by varying air and water temperatures, fins angle, rate of air flow, rate of water flow as well as the evaporation heat transfer, along the height of the tower. The analysis of the theoretical results revealed before that the thermal performance of the cooling tower is sensitive to the degree of saturation of inlet air. Hence, the cooling capacity of the cooling tower increases with decreasing inlet air temperature whereas the overall water temperature fall is curtailed with increasing water to air mass ratio. From the experimental study the efficiency of the cooling tower and cooling tower characteristics are higher in case of low mass flow ratio due to higher contact area of water to air. Because of better contact area between airs to water the drop in performance of the cooling tower is less. The effect of fins angle on the thermal performance of counter flow wet cooling tower was predicted. The experimental study showed that the cooling range, cooling coefficient, , heat load , change in air relative humidity and cooling tower effectiveness increased with increasing fins angles and optimum fins angle obtained from this experimental work was 70 degree, at this angle all cooling tower performance has been calculated were better. While the approach increased with decreasing fins angles, the minimum approach was obtained for 70 degree fins angles and the maximum approach was obtained for 30 degree fins angles.