Use of econometric models for predicting the lifetime of steam pipelines in the power industry

The object of the research were bends of steam pipelines 10CrMo9-10, in which the highest frequency of failures caused by material cracks occurs. The forecast of pipeline operation time was determined on the basis of results Rm. Applying the principles of statistical inference to forecast the trouble-free operation time of steam pipelines, mathematical models were selected that in a highly statistically significant way most reflect the actual reduction in Rm over time and determine the limit value of material exhaustion to avoid failure

Convergent patterns of tissue-level distribution of elements in different tropical woody nickel hyperaccumulator species from Borneo Island

Abstract The Malaysian state of Sabah on the Island of Borneo has recently emerged as a global hotspot of nickel hyperaccumulator plants. This study focuses on the tissue-level distribution of nickel and other physiologically relevant elements in hyperaccumulator plants with distinct phylogenetical affinities. The roots, old stems, young stems and leaves of Flacourtia kinabaluensis (Salicaceae), Actephila alanbakeri (Phyllanthaceae), Psychotria sarmentosa (Rubiaceae) and young stems and leaves of Glochidion brunneum (Phyllanthaceae) were studied using nuclear microprobe (micro-PIXE and micro-BS) analysis. The tissue-level distribution of nickel found in these species has the same overall pattern as in most other hyperaccumulator plants studied previously, with substantial enrichment in the epidermal cells and in the phloem. This study also revealed enrichment of potassium in the spongy and palisade mesophyll of the studied species. Calcium, chlorine, manganese and cobalt were found to be enriched in the phloem and also concentrated in the epidermis and cortex of the studied species. Although hyperaccumulation ostensibly evolved numerous times independently, the basic mechanisms inferred from tissue elemental localization are convergent in these tropical woody species from Borneo Island

Nickel biopathways in tropical nickel hyperaccumulating trees from Sabah (Malaysia)

The extraordinary level of accumulation of nickel (Ni) in hyperaccumulator plants is a consequence of specific metal sequestering and transport mechanisms, and knowledge of these processes is critical for advancing an understanding of transition element metabolic regulation in these plants. The Ni biopathways were elucidated in three plant species, Phyllanthus balgooyi, Phyllanthus securinegioides (Phyllanthaceae) and Rinorea bengalensis (Violaceae), that occur in Sabah (Malaysia) on the Island of Borneo. This study showed that Ni is mainly concentrated in the phloem in roots and stems (up to 16.9% Ni in phloem sap in Phyllanthus balgooyi) in all three species. However, the species differ in their leaves - in P. balgooyi the highest Ni concentration is in the phloem, but in P. securinegioides and R. bengalensis in the epidermis and in the spongy mesophyll (R. bengalensis). The chemical speciation of Ni(2+) does not substantially differ between the species nor between the plant tissues and transport fluids, and is unambiguously associated with citrate. This study combines ion microbeam (PIXE and RBS) and metabolomics techniques (GC-MS, LC-MS) with synchrotron methods (XAS) to overcome the drawbacks of the individual techniques to quantitatively determine Ni distribution and Ni(2+) chemical speciation in hyperaccumulator plants.Antony van der Ent, Damien L. Callahan, Barry N. Noller, Jolanta Mesjasz-Przybylowicz, Wojciech J. Przybylowicz, Alban Barnabas and Hugh H. Harri

Iron and ferritin accumulate in separate cellular locations in Phaseolus seeds

<p>Abstract</p> <p>Background</p> <p>Iron is an important micronutrient for all living organisms. Almost 25% of the world population is affected by iron deficiency, a leading cause of anemia. In plants, iron deficiency leads to chlorosis and reduced yield. Both animals and plants may suffer from iron deficiency when their diet or environment lacks bioavailable iron. A sustainable way to reduce iron malnutrition in humans is to develop staple crops with increased content of bioavailable iron. Knowledge of where and how iron accumulates in seeds of crop plants will increase the understanding of plant iron metabolism and will assist in the production of staples with increased bioavailable iron.</p> <p>Results</p> <p>Here we reveal the distribution of iron in seeds of three <it>Phaseolus </it>species including thirteen genotypes of <it>P. vulgaris</it>, <it>P. coccineus</it>, and <it>P. lunatus</it>. We showed that high concentrations of iron accumulate in cells surrounding the provascular tissue of <it>P. vulgaris </it>and <it>P. coccineus </it>seeds. Using the Perls' Prussian blue method, we were able to detect iron in the cytoplasm of epidermal cells, cells near the epidermis, and cells surrounding the provascular tissue. In contrast, the protein ferritin that has been suggested as the major iron storage protein in legumes was only detected in the amyloplasts of the seed embryo. Using the non-destructive micro-PIXE (Particle Induced X-ray Emission) technique we show that the tissue in the proximity of the provascular bundles holds up to 500 μg g^-1of iron, depending on the genotype. In contrast to <it>P. vulgaris </it>and <it>P. coccineus</it>, we did not observe iron accumulation in the cells surrounding the provascular tissues of <it>P. lunatus </it>cotyledons. A novel iron-rich genotype, NUA35, with a high concentration of iron both in the seed coat and cotyledons was bred from a cross between an Andean and a Mesoamerican genotype.</p> <p>Conclusions</p> <p>The presented results emphasize the importance of complementing research in model organisms with analysis in crop plants and they suggest that iron distribution criteria should be integrated into selection strategies for bean biofortification.</p

Nodules from fynbos legume Virgilia divaricata have high functional plasticity under variable P supply levels

Legumes have the unique ability to fix atmospheric nitrogen (N2) via symbiotic bacteria in their nodules but depend heavily on phosphorus (P), which affects nodulation, and the carbon costs and energy costs of N2 fixation. Consequently, legumes growing in nutrient-poor ecosystems (e.g., sandstone-derived soils) have to enhance P recycling and/or acquisition in order to maintain N2 fixation. In this study, we investigated the flexibility of P recycling and distribution within the nodules and their effect on N nutrition in Virgilia divaricata Adamson, Fabaceae, an indigenous legume in the Cape Floristic Region of South Africa. Specifically, we assessed tissue elemental localization using micro-particle-induced X-ray emission (PIXE), measured N fixation using nutrient concentrations derived from inductively coupled mass-spectrometry (ICP-MS), calculated nutrient costs, and determined P recycling from enzyme activity assays. Morphological and physiological features characteristic of adaptation to P deprivation were observed for V. divaricata. Decreased plant growth and nodule production with parallel increased root:shoot ratios are some of the plastic features exhibited in response to P deficiency. Plants resupplied with P resembled those supplied with optimal P levels in terms of growth and nutrient acquisition. Under low P conditions, plants maintained an increase in N2-fixing efficiency despite lower levels of orthophosphate (Pi) in the nodules. This can be attributed to two factors: (i) an increase in Fe concentration under low P, and (ii) greater APase activity in both the roots and nodules under low P. These findings suggest that V. divaricata is well adapted to acquire N under P deficiency, owing to the plasticity of its nodule physiologyDST-NRF Centre of Excellence in Tree Health Biotechnology(CTHB).http://www.elsevier.com/locate/jplpham201

\u3ci\u3eSenecio Conrathii\u3c/i\u3e N.E.Br. (Asteraceae), a New Hyperaccumulator of Nickel from Serpentinite Outcrops of the Barberton Greenstone Belt, South Africa

Five nickel hyperaccumulators belonging to the Asteraceae are known from ultramafic outcrops in South Africa. Phytoremediation applications of the known hyperaccumulators in the Asteraceae, such as the indigenous Berkheya coddii Roessler, are well reported and necessitate further exploration to find additional species with such traits. This study targeted the most frequently occurring species of the Asteraceae on eight randomly selected serpentinite outcrops of the Barberton Greenstone Belt. Twenty species were sampled, including 12 that were tested for nickel accumulation for the first time. Although the majority of the species were excluders, the known hyperaccumulators Berkheya nivea N.E.Br. and B. zeyheri (Sond. & Harv.) Oliv. & Hiern subsp. rehmannii (Thell.) Roessler var. rogersiana (Thell.) Roessler hyperaccumulated nickel in the leaves at expected levels. A new hyperaccumulator of nickel was discovered, Senecio conrathii N.E.Br., which accumulated the element in its leaves at 1695 ± 637 µg g−1 on soil with a total and exchangeable nickel content of 503 mg kg−1 and 0.095 µg g−1, respectively. This makes it the third known species in the Senecioneae of South Africa to hyperaccumulate nickel after Senecio anomalochrous Hilliard and Senecio coronatus (Thunb.) Harv., albeit it being a weak accumulator compared with the latter. Seven tribes in the Asteraceae have now been screened for hyperaccumulation in South Africa, with hyperaccumulators only recorded for the Arctoteae and Senecioneae. This suggests that further exploration for hyperaccumulators should focus on these tribes as they comprise all six species (of 68 Asteraceae taxa screened thus far) to hyperaccumulate nickel

The Nuclear Microprobe - a Challenging Tool in Plant Sciences

The nuclear microprobe is a microanalytical tool capable of quantitative studies of elemental distribution at the ppm level with a spatial resolution of the order of 1μm. This sensitivity is adequate for most elements of interest, and the spatial resolution is acceptable for studies of elemental distribution in organs, tissues, and cells. The main techniques used in plant science are particle induced X-ray emission using protons, proton backscattering, scanning transmission ion microscopy, and particle induced gamma-ray emission. Specimen preparation is the most difficult part of analysis, and only cryotechniques are recommended presently for all types of microanalytical studies