Equipment set for all-seasonal processing of poultry manure

New equipment set for the processing of manure, the main waste of poultry farms, into a range of ancillary products with predetermined properties and parameters is described. This technology decreases the emission of harmful substances into the atmosphere. The method of preparation of manure for the usage as a solid fuel with decreased expenses for drying was developed; this method allows for the significant decrease of nitrogen content in the manure (resulting in the decreased nitrogen emission at burning). The method involves the preliminary mixing of the manure with a natural absorbent (3-5% of the dry matter of manure) sieved through the 0.2 mm screen; separation of the mixture (by centrifuging or pressing) to solid fraction (moisture content 45-56%) and liquid fraction; drying of the solid fraction in a cylinder drier to moisture content 12-22%; the final product can also be pelleted. A part of the product can be burned in a furnace to produce the heat for the drying of the solid fraction; liquid fraction can be further processed in a coagulator to extract protein or can be used as a liquid fertilizer or ingredient of the liquid substrates in the hydroponic greenhouses.

Learning about wave optics: the effects of combining external visualizations with extreme case reasoning

In this study we investigated whether combining external visualizations with extreme case reasoning may facilitate developing of conceptual understanding about wave optics. For purposes of answering our research question we conducted a pretest-posttest quasi-experiment which included 179 students from a first year introductory physics course at the University of Zagreb, Croatia. Students who were guided through extreme case reasoning in their wave optics seminars significantly outperformed their peers who received conventional teaching treatment. Findings from our study suggest that combining external visualizations with extreme case reasoning facilitates development of visually rich internal representations which are a good basis for performing mental simulations about wave optics phenomena. In addition, it has been also found that many students use the “closer to the source implicates greater effect” p-prim when reasoning about certain relationships, such as the relationship between fringes’ dimension and slits-screen separation.

The Research on Deproteinized Techniques of Bio-Calcium Chitin

0Objective :This study is to retain the biological calcium in the crab shell, stripped of protein, calcium biological chitin chitin that is retained characteristics have unique biological calcium carbonate mosaic structure. the traditional preparation of chitin commoly adopts acid to remove calcium carbonae,applys alkali to extract protein, while inorgaic calcium salts is mixed with it as a source of calcium or an enhancement.Methods :Superfine pulverizing technology is used to smash crab shell to D50, which is 8.05 μm to get different size of crab shell powder through screen separation. The primary element of crab shell is calcium carbonate, chitin as well as protein. The content of protein is a significant indicator of industrial application of crab shell powder. Different size of crab shell powder is processed deproteinizedly,through hot alkali methodenzyme hydrolysis methodhot alkali method assisting microwave respectively. Results: Research result shows that the lower sizes of crab shell powder induce the higher effect of deproteinized processing method. The protein residual amount in crab shell powder of particle size D50 of 8.05 μm being processed in hot alkali for 3 hours is 0.097 %, while time being processed by microwave assisting is significantly reduced, making 20 minutes possible for the same result. Conclusions: Particle size of crab shell powder after superfine pulverizing is small, and deproteinization can be achieved by various methods, while retaining original chitin and biological calcium.