Fracture mechanics analysis of damaged turbine rotor discs using finite element method

This paper presents evaluation fracture mechanics parameters in low pressure turbine components. Critical locations such as keyway and dovetail area are experiencing stress concentration leading to crack initiation. Stress intensity factors were evaluated using the J-Integral approach available within ANSYS software code. The finite element method allowed the prediction of the point of crack initiation and the crack propagation using the orientations of the maximum principal stresses. Special attention in this investigation is focused to develop analytic expressions for stress intensity factors at critical location of low pres-sure steam turbine disc. [Projekat Ministarstva nauke Republike Srbije, br. I-174001 i br. TR-35045

The effect of water potential on accumulation of some essential elements in sugarbeet leaves, Beta vulgaris ssp. vulgaris

An investigation has been conducted on the effect of reduced water potential in nutrient solution on the accumulation of some essential macro- and micro nutrients in the aboveground pails of young sugarbeet plants. Plants of 8 different sugarbeet genotypes were exposed for 21 days to a nutrient solution whose water potential of 0.1 MPa was regulated by PEG. Contents of N, P, K Ca, Mg, Fe, Mn, Cu and Zn declined in all genotypes under water deficiency but the intensity of reduction varied among the genotypes. The results indicated that some harmful effects of water deficiency could be attributed to disturbances in plant mineral nutrition, especially the lack of N, P, and Mg, as well as to impaired ratios between the contents of particular elements, especially K/Ca

The Impact of Water Deficit on The Soybean (Glycine max L.) Reproductive Stage of Development

Experiment was conducted in 2014, 2015 and 2016 at the Institute of Field and Vegetable Crops, Novi Sad, Serbia, to study the effects of water deficit treatments during a soybean reproductive stage. Two water deficit treatments were conducted T-1 (from beginning of blossom to seed maturation) and T-2 (from beginning of seed filling to seed maturation period) and control (no water deficit). The results showed that water deficit during seed formation has a significant effect on germination energy, germination precentage and abnormal seedling. Obtained results are of great importance for farmers, because under favorable conditions, a large number of abnormal seedling has the ability to sprout, reach the reproductive stage and participate in yield formation

NPM1 gene mutations in children with Myelodysplastic syndromes

Myelodysplastic syndromes (MDS) are rare in children and only a few studies have analyzed their molecular mechanisms. The NPM1 gene encodes for nucleophosmin (NPM) which regulates hematopoiesis. Mutations in exon 12 of the NPM1 cause the nucleophosmin cytoplasmic dislocation and disrupt its functions. We have analyzed mutations of the NPM1 gene in archival bone marrow samples from 17 children with MDS and detected, in one patient, transition C to T in codon 293. To the best of our knowledge, this is the first analysis of NPM1 mutations in childhood MDS and the very first missense mutation of the NPM1 gene reported so far

Physiological and chemical characteristics of safflower (Carthamus tinctorius L.) grown in the presence of low salt concentrations

(Carthamus tinctorius L.) is highly regarded in the world as an aromatic, spicy, medicinal and oilseed crop, which can be used in all kinds of industries. It inhabits arid and semiarid areas of the world. The influence of the relatively low NaCl concentrations found in soils and irrigation waters on the growth and metabolism of saf­flower, grown under semi-controlled conditions, was examined in this work. It was found that increased concentrations of NaCl affected the number of leaves per plant and dry leaves mass/area ratio. The transpiration intensity was reduced in plants grown in the presence of NaCl and stomatal diffusive resistance increased following an increase in NaCl concentration

Effect of lead contamination of maize seed on its biological properties

Effect of treatment of seed with various lead concentrations (0, 10-5, 10-4, 10-3, and 10-2 mol/dm3) on accumulation and distribution of lead (Pb) in seedling, seed germination, seedling growth, and mobilization of mineral matter during seed germination was investigated. Content of Pb in the root and the shoot indicates that seeds imbibed in solutions of various Pb concentrations took up Pb intensively. Content of Pb in the root and the shoot increased with increase of Pb concentration and it was much larger in the root than in the shoot. Contrary to this, the accumulation coefficient was greater in the shoot than in the root. Treatment of seed with Pb did not significantly affect its biological properties. Increase of Pb concentration decreased germination ability, germination energy, and percentage of typical seedlings, while increasing the number of atypical seedlings and non-germinated seeds. Contamination of seed by Pb did not affect the dry matter mass and the growth of young plants shoots, while the length of the primary root, the mesocotyl root as well as the root mass at the highest Pb concentration, significantly decreased. Translocation of mobilized mineral matter from the seed during germination and growth of young plants into the root and shoot was specific, depending on elements. Only the implementation of the highest implemented Pb concentration affected mobilization and translocation of some elements. Based on the obtained results, it can be concluded that maize is characterized by significant tolerance to Pb contamination during seed germination and growth of seedlings

The concentration ratio of alkaline earth elements calcium, barium and strontium in grains of diploid, tetraploid and hexaploid wheat

Even though calcium (Ca), strontium (Sr) and barium (Ba) belong to the same group of the periodic table of elements, and thus have similar chemical features, their importance for plants differs greatly. Since plants do not have the ability to completely dis­criminate between essential (e.g. Ca) and non-essential elements (e.g. Sr and Ba), they read­ily take all of them up from soil solution, which is reflected in the ratios of concentrations of those elements in plant tissues, and it influences their nutritive characteristics. The ability of plant species and genotypes to take up and accumulate chemical elements in their different tissues is related to their genetic background. However, differences in chemical composition are the least reflected in their reproductive parts. Hence, the aim of this study was to evaluate ratios of concentrations of Ca, Sr and Ba in the whole grain of diploid and tetraploid wheat - ancestors of common wheat, as well as in hexaploid commercial cultivars, grown in the field, at the same location, over a period of three years. The investigated genotypes accumulated Ca, Sr and Ba at different levels, which is reflected in the ratio of their concentrations in the grain. The lowest ratio was established between Ba and Sr, followed by Ca and Ba, while the highest ratio was between Ca and Sr. Moreover, the results have shown that the year of study, genotype and the combination highly significantly affected the ratio of the concentration Ca:Sr, Ca:Ba, and Ba:Sr

Original scientific paper Chelate-assisted phytoextraction: effect of EDTA and EDDS on copper uptake by Brassica napus L.

Abstract: Chelate-assisted phytoextraction is proposed as an effective approach for the removal of heavy metals from contaminated soil through the use of high biomass plants. The aim of the present study was to compare the efficiency of the two chelators: EDTA and biodegradable EDDS in enhancing Cu uptake and translocation by Brassica napus L. grown on moderately contaminated soil and treated with increasing concentrations of EDTA or EDDS. Increasing amounts of EDDS caused serious growth suppression of B. napus and an increase in shoot metal concentrations. Growth suppression limited the actual amount of phytoextracted Cu at high concentrations of EDDS. The maximum amount of extracted Cu was achieved by the application of 8.0 and 4.0+4.0 mmol kg-1 EDDS. The shoot Cu concentrations after EDTA application were much lower than with EDDS at the same doses. According to these experiments, EDTA does not appear to be an efficient amendment if Cu phytoextraction with B. napus is considered but EDDS is