Klasifikacija i pravci razvoja traktora

Classification of tractors according to using field, purpose, nominal of force, strength and design conception was presented in this paper. Afterwards, directions of development of tractors were given through general development and development of components, engine, power train, hydraulic, wheels, etc.U radu je data klasifikacija traktora prema području korišćenja, nameni, nominalnoj sili, snazi i koncepciji gradnje. Potom su dati pravci razvoja traktora preko opšteg razvoja i razvoja komponenata, motora, prenosnika snage, hidraulika, hodnog sistema i dr

Teorija vuče i koeficijent korisnosti gumene gusenice

The pull theory of rubber track was shown in this paper. The mathematics model for analyzing a pull balance and balance of tractive power of crawler tractor, anticipating draw bar pull characteristics of tractor, tractive balance and power balance of rubber track and tractor crawler and rubber track efficiency coefficient were given.U radu je prikazana teorija vuče gumene gusenice. Dat je matematički model za analizu vučnog bilansa i bilansa snage traktora guseničara, predviđanje vučnih pokazatelja traktora, vučni bilans i bilans snage gumene gusenice i koeficijent korisnosti traktora guseničara i gumene gusenice

Značaj korišćenja blokade diferencijala traktora pri oranju

The results of research of tractor behavior during ploughing and movement in furrow and out of furrow were presented in this paper. Afterwards the importance of usage of tractor differential lock during movement in the furrow was defined. The financial advantages of usage of tractor differential lock during ploughing and movement of right wheel in furrow were presented in the end.U radu su izloženi rezltati istraživanja ponašanja traktora pri oranju i kretanju u brazdi i van brazde. Potom je definisan značaj blokade diferencijala pri kretanju traktora u brazdi. Prikazana je i finansijska prednost korišćenja blokade diferencijala pri oranju i kretanju desnih točkova u brazdi

Reversible Oxidation of Myometrial Voltage-Gated Potassium Channels with Hydrogen Peroxide

The uteri, spontaneously active or Ca2+ (6 mM) induced, were allowed to equilibrate, and to inhibit voltage-gated potassium () channels 1 mM 4-amino pyridine (4-AP) was applied for 15 min before adding H2O2 .  H2O2 was added cumulatively: 2 μM, 20 μM, 200 μM, 400 μM, and 3 mM. Average time for H2O2 concentrations (2, 20, 200, and 400) μM to reach its full effect was 15 min. H2O2 3 mM had a prolonged effect and therefore was left to act for 30 min. Two-way ANOVA showed significant differences in time dependency between spontaneous and Ca2+-induced rat uteri after applying 3 mM H2O2 (type of contraction, ), but not 400 μM H2O2 (). Our results indicate that H2O2 oxidises channel intracellular thiol groups and activates the channel, inducing relaxation. Cell antioxidative defence system quickly activates glutathione peroxidase (GSHPx) defence mechanism but not catalase (CAT) defence mechanism. Intracellular redox mechanisms repair the oxidised sites and again establish deactivation of channels, recuperating contractility. In conclusion, our results demonstrate that channels can be altered in a time-dependent manner by reversible redox-dependent intracellular alterations

Stanje i potrebe za mehanizacijom u 2007 u Republici Srbiji

The results of research of state and needs for mechanization in Serbian agriculture in 2007 were presented in this paper. The included fields were: power machines and tractors, mechanization in field crops production, mechanization in vegetable crops production, mechanization in perennial planted fields and plant protection, mechanization in cattle breeding, thermo technique and process technique.U radu su izloženi rezultati istraživanja stanja i potreba mehanizacije u poljoprivredi Srbije za 2007. godinu. Obuhvaćene su oblasti: pogonske mašine i traktori, mehanizacija u ratarstvu, mehanizacija u povrtarstvu, mehanizacija višegodišnjih zasada i zaštita bilja, mehanizacija u stočarstvu i termotehnika i procesna tehnika