http://ktisis.cut.ac.cy/handle/10488/32 Search the Channel search http://ktisis.cut.ac.cy/simple-search http://ktisis.cut.ac.cy/handle/10488/2434 Title: Modelling of a Parabolic Trough Collector System for Hot Water Production<br/><br/>Authors: Kalogirou, Soteris A.; Lloyd, S.; Ward, J.<br/><br/>Abstract: The modelling of a Parabolic Trough Collector System for the hot water production is presented. This is followed by an experimental verification of the model and analysis of the experimental results. The difference between the predicted and actual results is about 7%. This variation is attributed to the difference of the actual weather during the tests compared to standard data taken from a "reference yea" and the convection losses from the collector receiver which were not constant as accounted by the program. http://ktisis.cut.ac.cy/handle/10488/2419 Title: A tracking mechanism for medium and high concentration ratio parabolic trough solar collectors<br/><br/>Authors: Kalogirou, Soteris A.; Lloyd, S.; Ward, J.<br/><br/>Abstract: This paper describes a tracking system for use with solar parabolic trough collectors. The position and "status" of the Sun are detected by three Light Dependent Resistors (LDRs), one of which detects whether the collector is focused, whilst a second resistor determines if there is cloud cover, and the third senses whether it is day or night. The resultant signals are fed to an electronic control system which operates a low speed 12 V d.c. motor which rotates the collector via a speed reduction gearbox. The system provides a tracking accuracy of 0.2 wich solar radiation of 100 W/m2 and 0.05 for solar radiation of 600 W/m2. http://ktisis.cut.ac.cy/handle/10488/1593 Title: Reducing Atmospheric Emissions from Land Application of Manure<br/><br/>Authors: Kathijotes, Nicholas; Marinova, Svetla<br/><br/>Abstract: In view of the extreme climatic changes that are occurring, all gas inputs into the atmosphere should be investigated, especially carbon dioxide, nitrogen and ammonia. When raising animals, and nearby these farms, large amounts of animal liquid wastes are accumulated. These are used for irrigating and fertilizing nearby fields. During surface application, and in the process of bacterial hydrolysis, considerable quantities of nitrogen, after passing through ammonification, and are liberated into the atmosphere as atmospheric nitrogen. The aim of this paper is to evaluate the quantities of nitrogen loss during application of these liquid wastes, as well as the principle parameters which influence these losses. Model plant under natural conditions was used where using an aspirator unit, the quantity of gaseous nitrogen loss was determined. Series of factors were investigated, as state of soil surface, amount of fertilizer, extent of fertilizer dilution with water, air temperature, soil type, etc. These results show that the largest amount of ammonia nitrogen is evolved in the atmosphere, at surface sprinkling of liquid manure on meadows, pasture-grounds and lawn and at a less degree on fallow land. Some recommendations were made for decreasing atmospheric nitrogen losses up to 25% if immediately after sprinkling the fertilizer or manure plow down or cultivation in 8-10-cm depth is carried out. The nitrogen losses are practically insignificant at larger depth. http://ktisis.cut.ac.cy/handle/10488/1311 Title: Testing of Sewage Sludge Produced in a Model Installation for Water Purification for Antibiotics-Fertilization Products<br/><br/>Authors: Marinova, Svetla; Zlatareva, E.; Kathijotes, Nicholas<br/><br/>Abstract: Research is carried to establish the effectiveness of the sewage sludge from antibiotic production as an organic fertilizer. Sludge was assessed high to total nitrogen and phosphorus, but with low values of potassium. Data received in a precise short term pot experiment on a grey forest soil showed that different plant species react to the treating with this agent in a different way.The stabilized primary sludge from the I and II bio basins is suitable for cereals under our chemical conditions and agricultural treatment. Increasing the sludge rate proportionally increases the yield of rye-grass and oat. The highest yields are achieved at rates of 40% of the soil weight. In the case of maize the results do not seem satisfactory.