Excel as Tool for Modeling , Dynamic Simulation and Visualization ofMechanical Motion
One of the most important tasks in teaching of mechanics is to use a suitable method for developing of theoreticallyacquired knowledge. Drawing on her own experience, the author has found that the best method to be used is the system approach.System approach is closely connected to the modeling,computer simulation and dynamic visualization. Theory of the systems, modeling and computer simulation are disciplines with its own theory and research methodology. Modeling and computer simulation (M&S) can be understand as one of the most important method in teaching of mathematics and simultaneously can be use as suitable method for practical developing of theoretically acquired knowledge. Case study, described in the paper, presentspossibility of dynamic visualization of mechanical motion – trajectory of ballistic shot. The solution is demonstrated in MS Excel worksheet and chart. Key-Words:Animation, computer simulation, mathematical modeling, system approach, visualization.
Mastermind: method of the system approach in the algorithm development and computer simulation
One of the most important tasks in teaching of algorithm development and programming is to use a suitable method of developing theoretical knowledge of algorithm development and programming. Drawing on his own experience, the author has found that the best method to be used is the system approach. This method, described in the paper, is presented through the computer simulation of real process - solution of the Mastermind board game. The solution is demonstrated progressively - it starts with the mathematical analysis of the problem, then the strategy of the solution and algorithm development is presented and finally the computer simulation program in MS Excel is shown. A case study of the system approach as a suitable method of the algorithm development thinking is presented in the paper step by step; the text also emphasizes multidisciplinary learning of university students.
Denitrification of PVA-immobilized denitrifying photosynthetic bacterium, Rhodobacter sphaeroides
Abstract A newly isolated denitrifying strain, Rhodobacter sphaeroides NII2 was immobilized in polyvinyl alcohol (PVA) gel, and the properties of the cells in the gel were examined. The immobilized cells had low or almost no denitrification activity, but the cells were activated by incubation in light with culture medium for denitrification containing 0.5% nitrate and no other nitrogen source. Cells grown in the dark were activated by incubation at an earlier stage and to a higher rate than the light-grown cells. The activation was markedly enhanced in the PVA gel with a low cell concentration. The immobilized cells consumed nitrate with a temporary accumulation of NO 2 and evolved nitrogen gas. The immobilized cells could use various organic compounds as electron donors for denitrification. Thus, the immobilized cells were applied to a continuous treatment of synthetic wastewater using an aparatus devised by this laboratory. The results showed an efficient removal of NO 3 -N from the test water.