ECONOMIC ASPECTS ON SOYBEAN PRODUCTION IN EAST CROATIA

Tijekom dvogodišnjeg razdoblja (2004. i 2005. godine) obavljeno je istraživanje o visini prinosa i ekonomskoj isplativosti proizvodnje tri rane sorte soje (Dubravka 0, Marija 00 i Danica 000) različitih grupa dozrijevanja. Pokusi su postavljeni po split-plot shemi na poljima Zavoda za sjemenarstvo i rasadničarstvo iz Osijeka, Kutjevo d.d. i PPK Nova Gradiška uz primjenu standardne agrotehnike za soju. Jaz koji nastaje porastom broja stanovnika i istovremenim smanjenjem poljoprivrednih površina iz godine u godinu sve je veći, a soja zbog velikog postotka bjelančevina (od 35-50%) i ulja (od 18-24%) preuzima vodeće mjesto u proizvodnji i ishrani čovječanstva. Soja zbog naknadne i postrne sjetve postaje zanimljiva poljoprivrednim proizvođačima diljem svijeta. Uzimajući u obzir agrotehničke mjere koje se koriste, uz pomoć tablica i grafikona dana je analiza čimbenika i usporedba isplativosti proizvodnje pojedine sorte soje u Hrvatskoj na površini preko tri hektara, kako bi se odredila najpogodnija sorta za domaću poljoprivrednu proizvodnju.During the two vegetation years (2004 and 2005) an examination was conducted on influence of three early breeds of soybean (Dubravka 0, Marija 00 and Danica 000) belonging to different groups of ripening in terms of level of crop yield and cost effectiveness. The tests were undertaken by split-plot scheme on the crop fields originated from Institution for seed and seedlings Osijek, Kutjevo d.d. and PPK Nova Gradiška using standardized agro measures valid for soybean in The Republic of Croatia. The difference between increase of the number of inhabitants and decrease in the crop fields area has risen significantly. Soybean, because of its high percentage of proteins (35-50%) and oil (18-24%), slightly for sure overtakes the first position in agricultural production and nutrition of mankind. Soybean is becoming more and more interesting to producers worldwide because of its rich seeding capability. Taking into account the agricultural measures used the analysis and comparison of production effectiveness between each breed of soybean in Croatian on the area more than three ha are presented in tables and graphs. In this way the best breed can be ultimately determined for domestic farm production

Analysis of weld joints made of titanium alloy GRADE 2 produced by electron beam welding

Selected properties of welded joints of 2 mm thick titanium alloy Grade 2 produced by different welding parameters of electron beam welding were investigated. The visual inspection, macro and micro analysis, tensile strength test and microhardness measurements were performed. Samples manufactured by appropriate welding parameters had no internal defects, heat-affected zone (HAZ) was narrow and transformation from α phase to β phase was observed in this area. The failure occurred in the base metal during tensile test, while maximum ultimate tensile strength reached 454,3 MPa

Influence of surface roughness on the rate of corrosion penetration into the steel

This research analyses the influence of surface roughness on the rate of corrosion penetration into the steel. The test specimens were mechanically treated with fine abrasive jet to make their surface slightly rougher than it was in the initial state. The test specimens were then kept in conditions of atmospheric corrosion for 90 days to be tested afterwards by weighing, i.e. by the mass loss method. The analysis showed that a slight increase in surface roughness facilitated faster development of corrosion mechanisms, thus drastically increasing the rate of corrosion penetration into the material. Changes in surface roughness can be also caused by abrasion or erosion damage, so it is important to choose adequate surface protection technologies for prevention of unwanted wear of the steel

Axial light emission and Ar metastable densities in a parallel plate dc micro discharge in steady state and transient regimes

Axial emission profiles in a parallel plate dc micro discharge (feedgas: argon; discharge gap d=1mm; pressure p=10Torr) were studied by means of time resolved imaging with a fast ICCD camera. Additionally, volt-ampere (V-A) characteristics were recorded and Ar* metastable densities were measured by tunable diode laser absorption spectroscopy (TDLAS). Axial emission profiles in the steady state regime are similar to corresponding profiles in standard size discharges (d=1cm, p=1Torr). For some discharge conditions relaxation oscillations are present when the micro discharge switches periodically between low current Townsend-like mode and normal glow. At the same time the axial emission profile shows transient behavior, starting with peak distribution at the anode, which gradually moves towards the cathode during the normal glow. The development of argon metastable densities highly correlates with the oscillating discharge current. Gas temperatures in the low current Townsend-like mode (T= 320-400K) and the high current glow mode (T=469-526K) were determined by the broadening of the recorded spectral profiles as a function of the discharge current.Comment: submitted to Plasma Sources Sci. Techno

Analysis of the vehicle exhaust system corrosion and its effect on the ECO-test result

This paper deals with analysis of the vehicle exhaust system quality and its influence on the results of measuring exhaust emissions of the Otto and Diesel motor vehicles. Results of eco-tests obtained from correct and faulty vehicle exhaust systems were compared to conclude that damages caused by corrosion had significant influence on the pass rate of vehicles at eco-test. Referring to vehicles with the Otto engine, damages in the exhaust system increase the oxygen level, which results in the increased λ factor and in failure at the eco-test. On the contrary, vehicles with the damaged Diesel engine exhaust system allow the gas to leak through the damage, so the measurement of blackening is lower, i.e. the eco-test result is better than that of the exhaust system without damage

Testing of the shopprimer’s influence on the quality of welded joint

This paper presents the process of preparing the surface of construction material and applying the temporary protection that refers to the two-component epoxy workshop primer (shopprimer) in order to perform testing of its influence on mechanical properties of the weld. Testing of mechanical properties of welds after welding proved that there were no negative influences of the protective coating on the quality of welded joint

Corrosion resistance of the X6CrNiTi18-10 material exposed to a salt spray test

The research was focused on testing the corrosion resistance of the X6CrNiTi18-10 material. This material exhibits good corrosion resistance in the humid atmosphere, but with the occurrence of chloride inclusion in the same atmosphere, its corrosion resistance is drastically reduced. The X6CrNiTi18-10 material is austenitic stainless steel susceptible to pitting corrosion and this can cause problems during exploitation of the construction made of this material. In order to determine the likelihood of pitting corrosion occurrence, a light microscopy was performed on test samples that were exposed to the salt spray test chamber atmosphere, i.e. sprayed with a 5% sodium chloride solution (NaCl) at different time intervals

Analysis of interconnection between physical and protective properties of two-component epoxy primer

This paper presents the research into protective properties of two-component epoxy primer obtained by measurements of the notch corrosion and by testing of the gloss as a physical property. In order to obtain different values of measured response, the first experiment was done by applying the primer in various amounts of the dry film thickness, while the second experiment was based on combining various contents of anti-corrosion pigment. Analysis of the obtained research results proved the interconnection between the two observed properties. It was confirmed that the obtained results were inversely proportional for both experiments. Protective properties of coating could be assessed by measuring the gloss value, which is simpler and faster than measuring the notch corrosion

Influence of surface roughness on the rate of corrosion penetration into the steel

This research analyses the influence of surface roughness on the rate of corrosion penetration into the steel. The test specimens were mechanically treated with fine abrasive jet to make their surface slightly rougher than it was in the initial state. The test specimens were then kept in conditions of atmospheric corrosion for 90 days to be tested afterwards by weighing, i.e. by the mass loss method. The analysis showed that a slight increase in surface roughness facilitated faster development of corrosion mechanisms, thus drastically increasing the rate of corrosion penetration into the material. Changes in surface roughness can be also caused by abrasion or erosion damage, so it is important to choose adequate surface protection technologies for prevention of unwanted wear of the steel