Annals of „Constantin Brâncuşi” University of Târgu Jiu ENGINEERING SERIES

4

Authors: S.S.Stoyanova

There is proposed an approximate formula to determine the induction in pneumatic interspace of not branching magnetic circuit with constant magnet. The formula can be used in case when it is not dispose of the constant magnet histeresis curve, but only the residual induction and the coercive magnetic intensity are known.

8

Authors: Mihai Cruceru

In drawing up the balance sheet for thermal power boilers energy, specific heat loss through convection and radiation to the environment are calculated by statistical relationship or are chosen from diagrams depending on boiler load. If these values are close to reality for new or upgraded boilers, to boilers whose isolation was not maintained the values chosen are far undersized. By using thermography one can calculate the insulation outer surface temperature, the heat flux using specific relations and the actual loss of heat by convection and radiation.

10

Authors: CĂPĂŢÎNĂ Camelia, ŞCHIOPU Emil Cătălin

Dangerous wastes jeopardize human health, by short or long term exposure. In the paper it is presented the capitalization by incorporation in the vitreous matrix of some galvanic wastes with nickel content and obtaining some bottles that can be used in an industrial manner. Melting proofs was realized at the temperature of 610°C, for 30 minutes, and their cooling once with the oven. To the tests that resulted have been determined the hydrolytic stability through the conductometric method. The experimental results show a good chemical stability of the bottles obtained from wastes.

12

Authors: S. GROUDEV, I. SPASOVA, M. NICOLOVA

acid drainage waters generated in the uranium deposit curilo, bulgaria, were treated by means of a passive system consisting of two constructed wetlands connected in a series. The waters had a ph in the range of about 2 – 4 and were heavily polluted by radionuclides, several heavy metals, arsenic and sulphates. The first wetland was characterized by a subsurface water flow, a very dense water and emergent vegetation and a large anaerobic zone in which different sulphate-reducing bacteria and some metabolically interdependent species were the prevalent microorganisms. The second wetland was a predominantly aerobic system due to the cascade-type construction of its bottom and the surface water flow. The water flow through the wetlands varied in the range of about 0.2 – 0.75 l/s, reflecting total residence times of about 90 to 25 hours. An efficient removal of pollutants was achieved by this system during the different climatic seasons, even during the cold winter months at water temperatures close to the freezing point.