International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The paper presents summarized results of lysimetric experiments intended to determine the impact of green manure crops and straw on chemical elements leaching (N, K, Ca, Corg) and of atmospheric precipitation infiltration in sandy loam Luvisol. Lysimeter surface area is 1.75 m2, the test soil layer is 0.60 m. It was determined that under climatic conditions of Lithuania, cover crops for green manure reduce atmospheric precipitation infiltration in sandy loam soil during autumn, and the effects of nutrient leaching depend on the plant species. Fabaceae plants clover (Trifolium pratense L.) stimulate nitrogen leaching, while Poaceae orchard grass (Dactylis glomerata L.) and Brassicaceae fodder radish (Raphanus sativus L.) lessen it. Incorporation of green manure biomass does not alter potassium and calcium leaching, but substantially reduces the organic carbon leaching.

This practical research work is devoted to the adaptation of technology for ion plasma nitriding of mechanical parts (pins and gears). Formerly these parts were inductive hardened, and requirement of the purchaser was to replace inductive hardening technology with the chemical-heat treatment i.e. ion plasma nit riding.

Procedure for ion plasma nitriding of pin hammers and gears made of 4M2CrMo4 steel was described. Starting from the heat treatment of the parts, their cleaning and charging of the parts in the chamber. Description of the chamber and complete installation for nitride in is described. Experimental nitriding parameters are given too. Finally, accuracy of obtained results was checked using hardness measured of nitrided parts. Hardness values were in accordance with purchaser requirement.

TiAl6V (ELI) has the low density, low elastic modulus and high strength. Biocompatibility of this material allows one to adapt it to human implant production and successfully use in the manufacture of surgical implants. Spherical argon-atomized Ti6Al4V (ELI) (45µm) powder from TLS Technik was used for study. The chemical composition complies with the ASTM F-136 (grade 5), ASTM B348 (grade 23) standard for surgical implant applications. Two machines from two scientific centers (Russia and South Africa) were used for the manufacturing of the alloys. Analysis of the oxygen and nitrogen contamination in SLM alloys was done with Van de Graaff accelerator with 2 Mega Volts. It is found that the oxygen concentration in both samples is about 0.2 wt. % and decreases with the increasing of the sample depth; the nitrogen concentration is about 0,02 wt%. X-Ray results show an absence of beta (BCC) phase in both samples. TEM studies found the metastable martensitic structure and silicon nitride Si3N4.

X-ray diffraction, optical and electron microscopy were used to analyze microstructural variations in the surface layers of martensite chromium containing steels after low-energy, high-current-density ion implantation. These data show that nitrogen implantation produces solid solutions and precipitates of new phases in surface layers that are several micrometers thick. Phases formed are controlled by the virgin microstructure of blocks, the temperature of implantation and the ion fluence. The influence of processing length and ion beam current density are also considered.

The objective of this study was to compare the effects of previous crop residue (wheat vs. lentil), tillage (reduced tillage vs. no-tillage) and nitrogen source (rhizobial inoculant and fertilizer-N application) on nodul formation, dry matter accumulation and seed yield of double crop soybean. The experiment was laid out as split-split plot with three replications. According to results obtained from the study, previous crop residue affected seed yield, and seed yield after cultivation of lentil was higher than after wheat. Nodul nitrogen content decreased at the reduced tillage, while nodule dry matter and seed yield increased compared to no-tillage system. Rhizobium inoculation alone produced the highest seed yield. However, the addition of N-fertilizer to inoculated soybean did not improve seed yields when compared with inoculated only treatment. This research demonstrates that applying rhizobium inoculation in no-tillage system under lentil residue has the potential in increase nodulation and seed yield of soybean grown double-cropping system.

This paper presents a research of a controlled nitrogen application on 10 ha grassland. The experiment consists of 2 years of periodical application of manure and mineral fertilizer. Before each cutting of the grass the surface is scanned with a N-sensor.