A three-year trial (2003-2005) was conducted under agro ecological conditions of Timočka Krajina (the experiment farm of Technological Research Center in Zaječar). Research object were six malting barley genotypes, which were top-dressed with the following amounts of nitrogen in the course of growing season: 40, 60, 80 and 100 kg ha-1. A non-fertilized variant served as a control. The obtained results indicated that the tested genotypes reacted to increased amounts of nitrogen by changing their morphological and biological characteristics as well as the technological values of grain. The effectiveness of the applied nitrogen depended significantly on the distribution of rainfall in periods of highest water uptake by malting barley

Mortar aging and deterioration are serious problem for architectural heritage conservation. The solution might be sought in advanced functional materials which could provide repair and lasting surface protection from atmospheric pollution and microbiological corrosion. In recent years, extensive studies have been conducted on the use of bacteria with biocalcification potential for self-healing effect in cements materials, but only a few publications deal with self-healing capacity of historical lime-based mortars. The main focus of our research was development of new bio-activated self-healing system and its application in laboratory conditions. The objects of the work were historical mortar samples from medieval Bač Fortress in Serbia and laboratory prepared and aged mortar models. Aiming to achieve high compatibility, laboratory models were prepared based on our previous results of historical mortars characterization. The bio-activated self-healing agent was made as two-component liquid system using bacterial cells of Sporosarcina pasteurii DSM 33 and nutrients. The components of the models were hydraulic lime, milled limestone, river sand, and crashed brick as aggregates, and water. Comparative characterization of historic mortars and aged models was performed by mechanical and colorimetric testing as well as examination of mutual interaction and cohesion between old and new material. The next step was efficiency evaluation of the external bacteria-based repair healing method in/on the laboratory samples. The detailed study of the cracks of the historical samples and the prepared models, and the bacterial suspension diffusion assessment were done by comparison of the results obtained by different complementary imaging techniques (optical and scanning electron microscopy). The experiments were performed on both samples of old and new materials treated with and without bio-activated self-healing agent. The obtained results are promising and support the development of the external bio-activated self-healing method. This solution represents functional system which could allow historical mortars and modern structures to heal themselves in the long-term, preserving their functional and aesthetic properties.

Two-year trials have been conducted in Technological Research Center in Zajecar. Research objects were six malting barley genotypes. The experimental crop was top dressed with the following amounts of nitrogen: 40, 60, 80 and 100 kg ha-1. The control variant was not top dressed. The obtained results showed that the genotypes reacted significantly to the increased amounts of nitrogen by changing their production characteristics and seed quality. In addition, the genotypes demonstrated certain varietal differences. A new genotype, Premijum, was highest yielding and it had the lowest total proteins in the grain. The genotype NS-525 had the highest 1000-grain weight (46.8 g). The effect of nitrogen on the studied characteristics depended on N quantity applied. Increasing amounts of nitrogen decrease positive effects on spike length, number of grains per spike, 1000-grain weight and yield. However, the protein content in grain kept increasing to the highest nitrogen dose, which lowered the quality of malting barley. The highest yield was obtained by applying 80 and 100 kg ha-1 of nitrogen, depending on the year of study

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