WorldWideScience

Sample records for medicago sativa pellets

  1. Alfalfa (Medicago sativa L.).

    Science.gov (United States)

    Fu, Chunxiang; Hernandez, Timothy; Zhou, Chuanen; Wang, Zeng-Yu

    2015-01-01

    Alfalfa (Medicago sativa L.) is a high-quality forage crop widely grown throughout the world. This chapter describes an efficient protocol that allows for the generation of large number of transgenic alfalfa plants by sonication-assisted Agrobacterium-mediated transformation. Binary vectors carrying different selectable marker genes that confer resistance to phosphinothricin (bar), kanamycin (npt II), or hygromycin (hph) were used to generate transgenic alfalfa plants. Intact trifoliates collected from clonally propagated plants in the greenhouse were sterilized with bleach and then inoculated with Agrobacterium strain EHA105. More than 80 % of infected leaf pieces could produce rooted transgenic plants in 4-5 months after Agrobacterium-mediated transformation.

  2. Identification of novel RNA viruses in alfalfa (Medicago sativa): an Alphapartitivirus, a Deltapartitivirus, and a Marafivirus.

    Science.gov (United States)

    Kim, Hyein; Park, Dongbin; Hahn, Yoonsoo

    2018-01-05

    Genomic RNA molecules of plant RNA viruses are often co-isolated with the host RNAs, and their sequences can be detected in plant transcriptome datasets. Here, an alfalfa (Medicago sativa) transcriptome dataset was analyzed and three new RNA viruses were identified, which were named Medicago sativa alphapartitivirus 1 (MsAPV1), Medicago sativa deltapartitivirus 1 (MsDPV1), and Medicago sativa marafivirus 1 (MsMV1). The RNA-dependent RNA polymerases of MsAPV1, MsDPV1, and MsMV1 showed about 68%, 58%, and 46% amino acid sequence identity, respectively, with their closest virus species. Sequence similarity and phylogenetic analyses indicated that MsAPV1, MsDPV1, and MsMV1 were novel RNA virus species that belong to the genus Alphapartitivirus of the family Partitiviridae, the genus Deltapartitivirus of the family Partitiviridae, and the genus Marafivirus of the family Tymoviridae, respectively. The bioinformatics procedure applied in this study may facilitate the identification of novel RNA viruses from plant transcriptome data. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Prediction of chemical composition of South African Medicago sativa ...

    African Journals Online (AJOL)

    The near infrared reflectance spectroscopy (NIRS) to predict chemical and digestibility parameters was investigated. Samples (n = 168) representing the spectral characteristics of the South African. Medicago sativa L. hay population were chemically analysed for the development of calibration equations. Values for r² and ...

  4. A model for assessing Medicago Sativa L. hay quality | Scholtz ...

    African Journals Online (AJOL)

    A study was conducted to identify chemical parameters and/or models for assessing. Medicago sativa L. (L) hay quality, using near infrared reflectance spectroscopy (NIRS) analysis and Cornell Net Carbohydrate and Protein System (CNCPS) milk prediction as a criterion of accuracy. Milk yield (MY) derived from the ...

  5. Sample preparation of Medicago sativa L. hay for chemical analysis ...

    African Journals Online (AJOL)

    The objective of this study was to quantify the effect of the grinding procedure on the moisture and crude protein concentration of a ground Medicago sativa L. hay sample for quality grading. An additional aim was to investigate the accuracy of electronic moisture testers (EMT). Variance of analyses revealed significant ...

  6. Accumulation of heavy metals in Medicago sativa L. and Trifolium pratense L. at the contaminated fluvisol

    Directory of Open Access Journals (Sweden)

    Jakšić Snežana P.

    2013-01-01

    Full Text Available Recently, heavy metals concentrations increased in some agricultural areas due to the consequences of anthropogenic impacts. The aim of this study was to determine the level of heavy metals (As, Cr, Ni and Pb in Medicago sativa L. and Trifolium pratense L. grown on fluvisol, in order to obtain information on safety of these nutrients. The total content of Pb, As, Cr and Ni in the samples of fluvisol was above the maximum allowable amount. The content of heavy metals in Medicago sativa L. and Trifolium pratense L. was below the critical and toxic concentrations in all samples originating from contaminated soil. It was concluded that the accumulation of heavy metals in plants did not depend only on the total content in soil, but also the affinity of the plant, and individual and interactive effects of various soil properties. No statistically significant differences in the accumulation of heavy metals between Medicago sativa L. and Trifolium pratense L were observed. It is necessary to further control of heavy metals in the investigated area, in order to prevent their entry into the food chain and provide healthy food.

  7. Lucerne (Medicago sativa) or grass-clover as cut-and-carry fertilizers in organic agriculture

    NARCIS (Netherlands)

    Burgt, van der G.J.H.M.; Eekeren, van N.J.M.; Scholberg, J.M.S.; Koopmans, C.J.

    2013-01-01

    Onfarm nitrogen fixation is a driving force in organic agriculture. The efficiency with which this nitrogen is used can be increased by using lucerne (Medicago sativa) or grassclover directly as sources of fertilizer on arable land: cutandcarry fertilizers. In two arable crops, the use of lucerne

  8. Detection of Norspermidine and Norspermine in Medicago sativa L. (Alfalfa) 1

    Science.gov (United States)

    Rodriguez-Garay, Benjamin; Phillips, Gregory C.; Kuehn, Glenn D.

    1989-01-01

    Shoot meristem tissues of alfalfa, Medicago sativa L., were found by high performance liquid chromatography analyses to contain the uncommon polyamines, norspermidine and norspermine. The chemical structures of norspermidine and norspermine, purified from alfalfa, were confirmed by comparison of mass spectra with those from authentic standards. The discovery of norspermidine and norspermine in alfalfa implicates the presence of at least two biosynthetic enzymes, a polyamine oxidase and a previously uncharacterized aminopropyltransferase. PMID:16666576

  9. Phenanthrene uptake by Medicago sativa L. under the influence of an arbuscular mycorrhizal fungus

    Energy Technology Data Exchange (ETDEWEB)

    Wu Naiying [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, PO Box 2871, Beijing 100085 (China); Department of Chemistry, Shangqiu Normal College, Shangqiu 476000 (China); Huang Honglin [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, PO Box 2871, Beijing 100085 (China); Zhang Shuzhen, E-mail: szzhang@rcees.ac.c [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, PO Box 2871, Beijing 100085 (China); Zhu Yongguan [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, PO Box 2871, Beijing 100085 (China); Christie, Peter [Agri-Environment Branch, Agriculture Food and Environmental Science Division, Agri-Food and Biosciences Institute, Newforge Lane, Belfast BT9 5PX (United Kingdom); Zhang Yong [State Key Laboratory of Marine Environmental Science, Environmental Science Research Centre, Xiamen University, Xiamen 361005 (China)

    2009-05-15

    Phenanthrene uptake by Medicago sativa L. was investigated under the influence of an arbuscular mycorrhizal fungus. Inoculation of lucerne with the arbuscular mycorrhizal fungus Glomus etunicatum L. resulted in higher phenanthrene accumulation in the roots and lower accumulation in the shoots compared to non-mycorrhizal controls. Studies on sorption and desorption of phenanthrene by roots and characterization of heterogeneity of mycorrhizal and non-mycorrhizal roots using solid-state {sup 13}C nuclear magnetic resonance spectroscopy ({sup 13}C NMR) demonstrated that increased aromatic components due to mycorrhizal inoculation resulted in enhanced phenanthrene uptake by the roots but lower translocation to the shoots. Direct visualization using two-photon excitation microscopy (TPEM) revealed higher phenanthrene accumulation in epidermal cells of roots and lower transport into the root interior and stem in mycorrhizal plants than in non-mycorrhizal controls. These results provide some insight into the mechanisms by which arbuscular mycorrhizal inoculation may influence the uptake of organic contaminants by plants. - Colonization by an arbuscular mycorrhizal fungus promoted root uptake and decreased shoot uptake of phenanthrene by Medicago sativa L.

  10. Phenanthrene uptake by Medicago sativa L. under the influence of an arbuscular mycorrhizal fungus

    International Nuclear Information System (INIS)

    Wu Naiying; Huang Honglin; Zhang Shuzhen; Zhu Yongguan; Christie, Peter; Zhang Yong

    2009-01-01

    Phenanthrene uptake by Medicago sativa L. was investigated under the influence of an arbuscular mycorrhizal fungus. Inoculation of lucerne with the arbuscular mycorrhizal fungus Glomus etunicatum L. resulted in higher phenanthrene accumulation in the roots and lower accumulation in the shoots compared to non-mycorrhizal controls. Studies on sorption and desorption of phenanthrene by roots and characterization of heterogeneity of mycorrhizal and non-mycorrhizal roots using solid-state 13 C nuclear magnetic resonance spectroscopy ( 13 C NMR) demonstrated that increased aromatic components due to mycorrhizal inoculation resulted in enhanced phenanthrene uptake by the roots but lower translocation to the shoots. Direct visualization using two-photon excitation microscopy (TPEM) revealed higher phenanthrene accumulation in epidermal cells of roots and lower transport into the root interior and stem in mycorrhizal plants than in non-mycorrhizal controls. These results provide some insight into the mechanisms by which arbuscular mycorrhizal inoculation may influence the uptake of organic contaminants by plants. - Colonization by an arbuscular mycorrhizal fungus promoted root uptake and decreased shoot uptake of phenanthrene by Medicago sativa L.

  11. Nitrogen accumulation in lucerne (Medicago sativa L.) under water deficit stress

    OpenAIRE

    Vasileva Viliana; Vasilev Emil

    2013-01-01

    In order to study nitrogen accumulation in aboveground and root dry mass in lucerne (Medicago sativa L.) under water deficit stress, a pot experiment was carried out at the Institute of Forage Crops, Pleven, Bulgaria. The plants were grown under optimum water supply (75-80% FC) and 10-days water deficit stress was simulated at the stage of budding by interrupting the irrigation until soil moisture was reduced to 37-40% FC. Mineral nitrogen fertilization (ammonium nitrate) at the doses of 40, ...

  12. First report of race 2 of Colletotrichum trifolii causing anthracnose on alfalfa (Medicago sativa) in Wisconsin

    Science.gov (United States)

    Anthracnose of alfalfa (Medicago sativa), caused by Colletotrichum trifolii, is widespread in the United States. Three physiological races have been described. Race 1 is reported to be the dominant race that is present wherever alfalfa is grown, while race 2 was reported in a limited area in the Mid...

  13. [Natural nucleotide polymorphism of the Srlk gene that determines salt stress tolerance in alfalfa (Medicago sativa L)].

    Science.gov (United States)

    Vishnevskaia, M S; Pavlov, A V; Dziubenko, E A; Dziubenko, N I; Potokina, E K

    2014-04-01

    Based on legume genome syntheny, the nucleotide sequence of Srlk gene, key role of which in response to salt stress was demonstrated for the model species Medicago truncatula, was identified in the major forage and siderate crop alfalfa (Medicago sativa). In twelve alfalfa samples originating from regions with contrasting growing conditions, 19 SNPs were revealed in the Srlk gene. For two nonsynonymous SNPs, molecular markers were designed that could be further used to analyze the association between Srlk gene nucleotide polymorphism and the variability in salt stress tolerance among alfalfa cultivars.

  14. Comparison of the phytoremediation potentials of Medicago falcata L. And Medicago sativa L. in aged oil-sludge-contaminated soil.

    Science.gov (United States)

    Panchenko, Leonid; Muratova, Anna; Turkovskaya, Olga

    2017-01-01

    Thirteen-year monitoring of the vegetation growing in the industrial and adjacent areas of an oil refinery showed the prevalence of yellow medick (Medicago falcata L.) over other plant species, including alfalfa (Medicago sativa L.). A comparative field study of the two Medicago species established that yellow medick and alfalfa exhibited similar resistance to soil petroleum hydrocarbons and that the pollutant concentration in their rhizosphere was 30% lower than that in the surrounding bulk soil. In laboratory pot experiments, yellow medick reduced the contaminant content by 18% owing to the degradation of the major heavy oil fractions, such as paraffins, naphthenes, and alcohol and benzene tars; and it was more successful than alfalfa. Both species were equally effective in stimulating the total number of soil microorganisms, but the number of hydrocarbon-oxidizing microorganisms, including polycyclic aromatic hydrocarbon degraders, was larger in the root zone of alfalfa. In turn, yellow medick provided a favorable balance of available nitrogen. Both Medicago species equally stimulated the dehydrogenase and peroxidase activities of the soil, and yellow medick increased the activity of soil polyphenol oxidase but reduced the activity of catalase. The root tissue activity of catalase, ascorbate oxidase, and tyrosinase was grater in alfalfa than in yellow medick. The peroxidase activity of plant roots was similar in both species, but nondenaturing polyacrylamide gel electrophoresis showed some differences in the peroxidase profiles of the root extracts of alfalfa and yellow medick. Overall, this study suggests that the phytoremediation potentials of yellow medick and alfalfa are similar, with some differences.

  15. Alfalfa (Medicago sativa L.) forage production, tissue and soil nutrient concentration under three N based broiler litter regimes

    Science.gov (United States)

    Alfalfa (Medicago sativa L.) is considered as most important forage legume grown in Kentucky. Alfalfa supports many livestock production systems including the beef, dairy, and horse industries in Kentucky. Being a legume, alfalfa typically meets its N requirement through symbiotic N2 fixation, but h...

  16. Resistant and susceptible responses in alfalfa (Medicago sativa) to bacterial stem blight caused by Pseudomonas syringae pv. syringae

    Science.gov (United States)

    Bacterial stem blight caused by Pseudomonas syringae pv. syringae is a common disease of alfalfa (Medicago sativa L.) in the central and western U.S. and has been reported in Australia and Europe. The disease is not always recognized because symptoms are often associated with frost damage. Two culti...

  17. The Hybridization Barrier between Herbaceous Medicago sativa and Woody M. arborea Is Weakened by Selection of Seed Parents

    Directory of Open Access Journals (Sweden)

    Edwin Bingham

    2013-05-01

    Full Text Available Medicago sativa, alfalfa or lucerne, and M. arborea were considered reproductively isolated until recently. Then, in 2003, an alfalfa genotype was identified that produced a few seeds and progeny with hybrid traits after a large number of pollinations by M. arborea. A derivative of this alfalfa genotype also produced a low frequency of progeny with hybrid traits. Thus, the hybridization barrier was weakened by selection of seed parents. Hybrids from both events expressed traits from M. arborea and M. arborea-specific DNA bands, although more of the M. sativa genome was retained, based on the DNA results. Thus, there was chromatin elimination during embryogenesis, resulting in partial hybrids (hereafter hybrids. However, more than 30 hybrids with an array of M. arborea traits have been obtained thus far, and research continues on the nature of the hybrids. Traits have been genetically transmitted in crosses, and selected traits are in use for alfalfa breeding. This paper reviews the first hybrids and then focuses on further weakening of the hybridization barrier with the discovery of a more efficient hybridizer derived from crossing Medicago sativa subspecies, sativa, coerulea and falcata. This genotype was found to have reproductive abnormalities associated with its complex subspecies origin that are best described as hybrid breakdown. In effect, this subspecies derivative is a bridge-cross parent that consistently produces hybrids. Reproductive abnormalities in the bridge-cross parent are reported and discussed.

  18. The Hybridization Barrier between Herbaceous Medicago sativa and Woody M. arborea Is Weakened by Selection of Seed Parents

    Science.gov (United States)

    Bingham, Edwin; Armour, David; Irwin, John

    2013-01-01

    Medicago sativa, alfalfa or lucerne, and M. arborea were considered reproductively isolated until recently. Then, in 2003, an alfalfa genotype was identified that produced a few seeds and progeny with hybrid traits after a large number of pollinations by M. arborea. A derivative of this alfalfa genotype also produced a low frequency of progeny with hybrid traits. Thus, the hybridization barrier was weakened by selection of seed parents. Hybrids from both events expressed traits from M. arborea and M. arborea-specific DNA bands, although more of the M. sativa genome was retained, based on the DNA results. Thus, there was chromatin elimination during embryogenesis, resulting in partial hybrids (hereafter hybrids). However, more than 30 hybrids with an array of M. arborea traits have been obtained thus far, and research continues on the nature of the hybrids. Traits have been genetically transmitted in crosses, and selected traits are in use for alfalfa breeding. This paper reviews the first hybrids and then focuses on further weakening of the hybridization barrier with the discovery of a more efficient hybridizer derived from crossing Medicago sativa subspecies, sativa, coerulea and falcata. This genotype was found to have reproductive abnormalities associated with its complex subspecies origin that are best described as hybrid breakdown. In effect, this subspecies derivative is a bridge-cross parent that consistently produces hybrids. Reproductive abnormalities in the bridge-cross parent are reported and discussed. PMID:27137379

  19. Effect of alfalfa (medicago sativa) on fermentation profile and nutritive value of switchgrass (panicum virgatum) and bermudagrass (cynodon dactylon) silages

    Science.gov (United States)

    An experiment was conducted at the University of Kentucky Spindletop Farm in Lexington, Kentucky between October and November, 2009 to evaluate the effect of different percentages of alfalfa (Medicago sativa) as mixtures in switchgrass (Panicum virgatus) and bermudagrass (Cynodon dactylon) silages. ...

  20. Influence of papermill sludge on growth of Medicago sativa, Festuca rubra and Agropyron trachycaulum in gold mine tailings: A greenhouse study

    International Nuclear Information System (INIS)

    Green, Scott; Renault, Sylvie

    2008-01-01

    A greenhouse study was undertaken to determine the suitability of adding papermill sludge to neutral/alkaline gold mine tailings to improve the establishment of Festuca rubra, Agropyron trachycaulum and Medicago sativa. Festuca rubra root and shoot biomass and A. Trachycaulum shoot biomass were increased with papermill sludge amendment. The addition of papermill sludge and fertilizer drastically increased the shoot and root biomass of M. sativa (20-30 times) while A. trachycaulum and F. rubra showed a more moderate increase in growth. Photosynthetic pigment content of the leaves was higher in papermill sludge treatments than in the treatments without papermill sludge. The organic carbon content, macro-aggregate content and field capacity of the gold mine tailings were increased while the bulk density was decreased by the addition of papermill sludge. This study suggests that addition of papermill sludge and adequate fertilization can alleviate some of the adverse conditions of neutral/alkaline gold mine tailings. - Addition of papermill sludge and adequate fertilization of neutral gold mine tailings increased growth of Medicago sativa, Festuca rubra and Agropyron trachycaulum

  1. Crystal structure of isoflavone reductase from alfalfa (Medicago sativa L.).

    Science.gov (United States)

    Wang, Xiaoqiang; He, Xianzhi; Lin, Jianqiao; Shao, Hui; Chang, Zhenzhan; Dixon, Richard A

    2006-05-19

    Isoflavonoids play important roles in plant defense and exhibit a range of mammalian health-promoting activities. Isoflavone reductase (IFR) specifically recognizes isoflavones and catalyzes a stereospecific NADPH-dependent reduction to (3R)-isoflavanone. The crystal structure of Medicago sativa IFR with deletion of residues 39-47 has been determined at 1.6A resolution. Structural analysis, molecular modeling and docking, and comparison with the structures of other NADPH-dependent enzymes, defined the putative binding sites for co-factor and substrate and potential key residues for enzyme activity and substrate specificity. Further mutagenesis has confirmed the role of Lys144 as a catalytic residue. This study provides a structural basis for understanding the enzymatic mechanism and substrate specificity of IFRs as well as the functions of IFR-like proteins.

  2. Effect of vanadium and tungsten on nitrogen fixation and the growth of Medicago sativa

    Energy Technology Data Exchange (ETDEWEB)

    Jha, K K

    1969-01-01

    In sand culture, it was found that vanadium had no stimulatory effect on nitrogen content or the growth of Medicago sativa inoculated with an effective strain of Rhizobium meliloti or supplied with ammonium nitrate. At the level of 500 ppm it reduced the plant growth, the inhibitory effect being particularly severe on the root. On the other hand tungsten increased nitrogen fixation and the dry matter yield of the inoculated plants. The results are suggestive of a direct role of tungsten in symbiotic nitrogen fixation. 4 references, 2 tables.

  3. Toxic effects of copper-based nanoparticles or compounds to lettuce (Lactuca sativa) and alfalfa (Medicago sativa).

    Science.gov (United States)

    Hong, Jie; Rico, Cyren M; Zhao, Lijuan; Adeleye, Adeyemi S; Keller, Arturo A; Peralta-Videa, Jose R; Gardea-Torresdey, Jorge L

    2015-01-01

    The increased production and use of nanoparticles (NPs) has generated concerns about their impact on living organisms. In this study, nCu, bulk Cu, nCuO, bulk CuO, Cu(OH)2 (CuPRO 2005, Kocide 3000), and CuCl2 were exposed for 15 days to 10 days-old hydroponically grown lettuce (Lactuca sativa) and alfalfa (Medicago sativa). Each compound was applied at 0, 5, 10, and 20 mg L(-1). At harvest, we measured the size of the plants and determined the concentration of Cu, macro and microelements by using ICP-OES. Catalase and ascorbate peroxidase activity was also determined. Results showed that all Cu NPs/compounds reduced the root length by 49% in both plant species. All Cu NPs/compounds increased Cu, P, and S (>100%, >50%, and >20%, respectively) in alfalfa shoots and decreased P and Fe in lettuce shoot (>50% and >50%, respectively, excluding Fe in CuCl2 treatment). Biochemical assays showed reduced catalase activity in alfalfa (root and shoot) and increased ascorbate peroxidase activity in roots of both plant species. Results suggest that Cu NPs/compounds not only reduced the size of the plants but altered nutrient content and enzyme activity in both plant species.

  4. Medicago sativa--Sinorhizobium meliloti Symbiosis Promotes the Bioaccumulation of Zinc in Nodulated Roots.

    Science.gov (United States)

    Zribi, Kais; Nouairi, Issam; Slama, Ines; Talbi-Zribi, Ons; Mhadhbi, Haythem

    2015-01-01

    In this study we investigated effects of Zn supply on germination, growth, inorganic solutes (Zn, Ca, Fe, and Mg) partitioning and nodulation of Medicago sativa This plant was cultivated with and without Zn (2 mM). Treatments were plants without (control) and with Zn tolerant strain (S532), Zn intolerant strain (S112) and 2 mM urea nitrogen fertilisation. Results showed that M. sativa germinates at rates of 50% at 2 mM Zn. For plants given nitrogen fertilisation, Zn increased plant biomass production. When grown with symbionts, Zn supply had no effect on nodulation. Moreover, plants with S112 showed a decrease of shoot and roots biomasses. However, in symbiosis with S532, an increase of roots biomass was observed. Plants in symbiosis with S. meliloti accumulated more Zn in their roots than nitrogen fertilised plants. Zn supply results in an increase of Ca concentration in roots of fertilised nitrogen plants. However, under Zn supply, Fe concentration decreased in roots and increased in nodules of plants with S112. Zn supply showed contrasting effects on Mg concentrations for plants with nitrogen fertilisation (increase) and plants with S112 (decrease). The capacity of M. sativa to accumulate Zn in their nodulated roots encouraged its use in phytostabilisation processes.

  5. Transgene silencing of sucrose synthase in alfalfa (Medicago sativa L.) stem vascular tissue suggests a role for invertase in cell wall cellulose synthesis

    Science.gov (United States)

    Alfalfa (Medicago sativa L.) plants were transformed with two constructs: (1) a truncated phosphoenolpyruvate carboxylase promoter isolated from alfalfa nodules (PEPC-4) fused to GUS; and (2) PEPC-4 fused with sucrose synthase (SUS) isolated from alfalfa nodules. Histochemical staining for GUS in st...

  6. Nitrogen accumulation in lucerne (Medicago sativa L. under water deficit stress

    Directory of Open Access Journals (Sweden)

    Vasileva Viliana

    2013-01-01

    Full Text Available In order to study nitrogen accumulation in aboveground and root dry mass in lucerne (Medicago sativa L. under water deficit stress, a pot experiment was carried out at the Institute of Forage Crops, Pleven, Bulgaria. The plants were grown under optimum water supply (75-80% FC and 10-days water deficit stress was simulated at the stage of budding by interrupting the irrigation until soil moisture was reduced to 37-40% FC. Mineral nitrogen fertilization (ammonium nitrate at the doses of 40, 80, 120 and 160 mg N kg-1 soil was applied. It was found that nitrogen accumulation in dry aboveground mass was reduced to 18.0%, and in dry root mass to 26.5% under water deficit stress. Mineral nitrogen fertilization contributed to easily overcome the stress conditions of water deficit stress in lucerne.

  7. Natural occurrence of entomophthoroid fungi of aphid pests on Medicago sativa L. in Argentina

    Directory of Open Access Journals (Sweden)

    Romina G Manfrino

    Full Text Available Four species of entomophthoroid fungi, Pandora neoaphidis (Entomophthorales: Entomophthoraceae, Zoophthora radicans (Entomophthorales: Entomophthoraceae, Entomophthora planchoniana (Entomophthorales: Entomophthoraceae and Neozygites fresenii (Neozygitales: Neozygitaceae were found to infect Aphis craccivora, Therioaphis trifolii, and Acyrthosiphon pisum and unidentified species of Acyrthosiphon on lucerne in Argentina. Samples were collected from five sites (Ceres, Rafaela, Sarmiento, Monte Vera and Bernardo de Irigoyen in the province of Santa Fe. In this study, Zoophthora radicans was the most important pathogen and was recorded mainly on Acyrthosiphon sp. Zoophthora radicans was successfully isolated and maintained in pure cultures. This study is the first report of entomophthoroid fungi infecting lucerne (Medicago sativa L. aphids in Argentina.

  8. Stress responses in alfalfa (Medicago sativa L.)

    International Nuclear Information System (INIS)

    Kessmann, H.; Edwards, R.; Dixon, R.A.; Geno, P.W.

    1990-01-01

    The isoflavonoid conjugates medicarpin-3-O-glucoside-6 double-prime-O-malonate (MGM), afrormosin-7-O-glucoside (AG), and afrormosin-7-O-glucoside-6 double-prime-O-malonate (AGM) were isolated and characterized from cell suspension cultures of alfalfa (Medicago sativa L.), where they were the major constitutive secondary metabolites. They were also found in alfalfa roots but not in other parts of the plant. The phytoalexin medicarpin accumulated rapidly in suspension cultured cells treated with elicitor from Colletotrichum lindemuthianum, and this was subsequently accompanied by an increase in the levels of MGM. In contrast, net accumulation of afrormosin conjugates was not affected by elicitor treatment. Labeling studies with [ 14 C]phenylalanine indicated that afrormosin conjugates were the major de novo synthesized isoflavonoid products in unelicited cells. During elicitation, [ 14 C]phenylalanine was incorporated predominantly into medicarpin, although a significant proportion of the newly synthesized medicarpin was also conjugated. Treatment of 14 C-labeled, elicited cells with L-α-aminooxy-β-phenylpropionic acid, a potent inhibitor of PAL activity in vivo, resulted in the initial appearance of labeled medicarpin of very low specific activity, suggesting that the phytoalexin could be released from a preformed conjugate under these conditions. Our data draw attention to the involvement of isoflavone hydroxylases during the constitutive and elicitor-induced accumulation of isoflavonoids and their conjugates in alfalfa cell cultures

  9. Production of aerial biomass and equivalent land use in alfalfa (Medicago sativa L.) intercropping

    International Nuclear Information System (INIS)

    Pereyra, T. W.; Pagliaricci, H. R.; Ohanian, A. E.; Bonvillani, M. J.

    2013-01-01

    Productivity increase has traditionally been associated to yield increase through breeding and crop management practices. Nevertheless, if production is considered per area and time unit, the intercropping system may be another way to improve cost-effectiveness. The objective of the experiment was to determine the produced biomass and the equivalent land use in alfalfa (Medicago sativa L.) monocrop and intercrops with sorghum Sudan (Sorghum sudanense L.) and oat (Avena sativa L.). The aerial biomass of all the treatments (expressed per surface unit) and the equivalent land use were determined. The design was completely randomized, arranged in blocks with two repetitions. The results were subject to an ANAVA and the means were compared through Duncan's test, by means of the statistical pack INFOSTAT. The alfalfa-sorghum intercrop triplicated the alfalfa production with regards to the monocrop, while alfalfa-oat did not exceed the production of pure alfalfa in the winter months. The alfalfa-sorghum intercrop was 57 % more efficient in land use than the respective monocrops, while alfalfa-oat did not surpass the unit. (author)

  10. How planting configuration influences plant secondary metabolites and total N in tall fescue (Festuca arundinacea Schreb.), alfalfa (Medicago sativa L.) and birdsfoot trefoil (Lotus corniculatus L.)

    Science.gov (United States)

    Theories suggest that incorporating alfalfa (Medicago sativa L.; Alf) or birdsfoot trefoil (Lotus corniculatus L.; BFT) into endophyte-infected tall fescue (Festuca arundinaceas Schreb.; E+TF) pasturelands may improve livestock production. We investigated how planting configuration might influence p...

  11. Exploring the plant-associated bacterial communities in Medicago sativa L

    Directory of Open Access Journals (Sweden)

    Pini Francesco

    2012-05-01

    Full Text Available Abstract Background Plant-associated bacterial communities caught the attention of several investigators which study the relationships between plants and soil and the potential application of selected bacterial species in crop improvement and protection. Medicago sativa L. is a legume crop of high economic importance as forage in temperate areas and one of the most popular model plants for investigations on the symbiosis with nitrogen fixing rhizobia (mainly belonging to the alphaproteobacterial species Sinorhizobium meliloti. However, despite its importance, no studies have been carried out looking at the total bacterial community associated with the plant. In this work we explored for the first time the total bacterial community associated with M. sativa plants grown in mesocosms conditions, looking at a wide taxonomic spectrum, from the class to the single species (S. meliloti level. Results Results, obtained by using Terminal-Restriction Fragment Length Polymorphism (T-RFLP analysis, quantitative PCR and sequencing of 16 S rRNA gene libraries, showed a high taxonomic diversity as well as a dominance by members of the class Alphaproteobacteria in plant tissues. Within Alphaproteobacteria the families Sphingomonadaceae and Methylobacteriaceae were abundant inside plant tissues, while soil Alphaproteobacteria were represented by the families of Hyphomicrobiaceae, Methylocystaceae, Bradyirhizobiaceae and Caulobacteraceae. At the single species level, we were able to detect the presence of S. meliloti populations in aerial tissues, nodules and soil. An analysis of population diversity on nodules and soil showed a relatively low sharing of haplotypes (30-40% between the two environments and between replicate mesocosms, suggesting drift as main force shaping S. meliloti population at least in this system. Conclusions In this work we shed some light on the bacterial communities associated with M. sativa plants, showing that Alphaproteobacteria may

  12. Uptake of oxytetracycline and its phytotoxicity to alfalfa (Medicago sativa L.)

    International Nuclear Information System (INIS)

    Kong, W.D.; Zhu, Y.G.; Liang, Y.C.; Zhang, J.; Smith, F.A.; Yang, M.

    2007-01-01

    A series of experiments were conducted in a hydroponic system to investigate the uptake of oxytetracycline (OTC) and its toxicity to alfalfa (Medicago sativa L.). OTC inhibited alfalfa shoot and root growth by up to 61% and 85%, respectively. The kinetics of OTC uptake could be well described by Michaelis-Menten equation with V max of 2.25 μmol g -1 fresh weight h -1 , and K m of 0.036 mM. The uptake of OTC by alfalfa was strongly inhibited by the metabolic inhibitor, 2,4-DNP (2,4-dinitrophenol), at pH 3.5 and 6.0, but not by the aquaporin competitors, glycerol and Ag + . OTC uptake, however, was significantly inhibited by Hg 2+ , suggesting that the inhibition of influx was due to general cellular stress rather than the specific action of Hg 2+ on aquaporins. Results from the present study suggested that OTC uptake into alfalfa is an energy-dependent process. - Plant uptake of antibiotic oxytetracycline is energy-dependent

  13. Biofertilizer in the nutritional quality of alfalfa (Medicago sativa L.

    Directory of Open Access Journals (Sweden)

    Rodrigo Luis Lemes

    2016-06-01

    Full Text Available The objective of this study was to evaluate the response of alfalfa (Medicago sativa L. in the nutritional composition to the application of biofertilizers. The experiment was conducted with increasing doses of biofertilizers in a greenhouse at the Faculty of Veterinary Medicine / UNESP, Araçatuba - Sao Paulo, Brazil, from April to October 2010. The experimental design was completely randomized with six biofertilizer doses from cattle manure (0, 25, 50, 100, 200, and 400 m3 ha-1 and five replications. Cuts were performed, on average, every 27 days, 10 cm above the ground when 10% of the plants were flowering. Biofertilization had a positive significant impact on foliar nitrogen, potassium, calcium, magnesium, sulfur, and shoot iron concentrations. The values of crude protein, acid detergent fiber, and neutral detergent fiber did not differ between doses of biofertilizers. Biofertilization is a viable alternative for nutrition of this species, showing positive results in the nutritional composition of alfalfa. However, but long-term studies are necessary to assess the environmental impact of these fertilizers.

  14. Toxic effects of arsenic on Sinorhizobium-Medicago sativa symbiotic interaction

    Energy Technology Data Exchange (ETDEWEB)

    Pajuelo, Eloisa [Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, 41012 Seville (Spain); Rodriguez-Llorente, Ignacio D. [Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, 41012 Seville (Spain)], E-mail: irodri@us.es; Dary, Mohammed; Palomares, Antonio J. [Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, 41012 Seville (Spain)

    2008-07-15

    Recently, the Rhizobium-legume symbiotic interaction has been proposed as an interesting tool in bioremediation. However, little is known about the effect of most common contaminants on this process. The phytotoxic effects of arsenic on nodulation of Medicago sativa have been examined in vitro using the highly arsenic resistant and symbiotically effective Sinorhizobium sp. strain MA11. The bacteria were able to grow on plates containing As concentrations as high as 10 mM. Nevertheless, as little as 25-35 {mu}M arsenite produced a 75% decrease in the total number of nodules, due to a 90% reduction in the number of rhizobial infections, as could be determined using the strain MA11 carrying a lacZ reporter gene. This effect was associated to root hair damage and a shorter infective root zone. However, once nodulation was established nodule development seemed to continue normally, although earlier senescence could be observed in nodules of arsenic-grown plants. - First steps of nodulation of alfalfa, in particular infection thread formation, are more sensitive to As than nitrogen fixation due to plant effects.

  15. WATER DEFICIT EFFECT ON YIELD AND FORAGE QUALITY OF MEDICAGO SATIVA POPULATIONS UNDER FIELD CONDITIONS IN MARRAKESH AREA (MOROCCO)

    OpenAIRE

    Mohamed FARISSI; Cherki GHOULAM; Abdelaziz BOUIZGAREN

    2014-01-01

    The present study focused the effect of water deficit on agronomic potential and some traits related to forage quality in plants of Moroccan Alfalfa (Medicago sativa L.) populations (Taf 1, Taf 2, Dem and Tata) originated from Oasis and High Atlas of Morocco and an introduced variety from Australia (Siriver). The experiment was conducted under field conditions in experimental station of INRA-Marrakech and under two irrigation treatments. The first treatment was normal irrigation, providing an...

  16. Phytotoxicity of three plant-based biodiesels, unmodified castor oil, and Diesel fuel to alfalfa (Medicago sativa L.), lettuce (Lactuca sativa L.), radish (Raphanus sativus), and wheatgrass (Triticum aestivum).

    Science.gov (United States)

    Bamgbose, Ifeoluwa; Anderson, Todd A

    2015-12-01

    The wide use of plant-based oils and their derivatives, in particular biodiesel, have increased extensively over the past decade to help alleviate demand for petroleum products and improve the greenhouse gas emissions profile of the transportation sector. Biodiesel is regarded as a clean burning alternative fuel produced from livestock feeds and various vegetable oils. Although in theory these animal and/or plant derived fuels should have less environmental impact in soil based on their simplified composition relative to Diesel, they pose an environmental risk like Diesel at high concentrations when disposed. The aim of the present study was to ascertain the phytotoxicity of three different plant-derived biodiesels relative to conventional Diesel. For phytotoxicological analysis, we used seeds of four crop plants, Medicago sativa, Lactuca sativa, Raphanus sativus, and Triticum aestivum to analyze the germination of seeds in contaminated soil samples. The toxicological experiment was conducted with two different soil textures: sandy loam soil and silt loam soil. The studied plant-based biodiesels were safflower methyl-ester, castor methyl ester, and castor ethyl-ester. Biodiesel toxicity was more evident at high concentrations, affecting the germination and survival of small-seeded plants to a greater extent. Tolerance of plants to the biodiesels varied between plant species and soil textures. With the exception of R. sativus, all plant species were affected and exhibited some sensitivity to the fuels, such as delayed seedling emergence and slow germination (average=10 days) at high soil concentrations (0.85% for Diesel and 1.76% for the biodiesels). Tolerance of plants to soil contamination had a species-specific nature, and on average, decreased in the following order: Raphanus sativus (0-20%)>Triticum aestivum (10-40%) ≥ Medicago sativa> Lactuca sativa (80-100%). Thus, we conclude that there is some phytotoxicity associated with plant-based biodiesels. Further

  17. Natural occurrence of entomophthoroid fungi of aphid pests on Medicago sativa L. in Argentina.

    Science.gov (United States)

    Manfrino, Romina G; Zumoffen, Leticia; Salto, César E; Lastra, Claudia C López

    2014-01-01

    Four species of entomophthoroid fungi, Pandora neoaphidis (Entomophthorales: Entomophthoraceae), Zoophthora radicans (Entomophthorales: Entomophthoraceae), Entomophthora planchoniana (Entomophthorales: Entomophthoraceae) and Neozygites fresenii (Neozygitales: Neozygitaceae) were found to infect Aphis craccivora, Therioaphis trifolii, and Acyrthosiphon pisum and unidentified species of Acyrthosiphon on lucerne in Argentina. Samples were collected from five sites (Ceres, Rafaela, Sarmiento, Monte Vera and Bernardo de Irigoyen) in the province of Santa Fe. In this study, Zoophthora radicans was the most important pathogen and was recorded mainly on Acyrthosiphon sp. Zoophthora radicans was successfully isolated and maintained in pure cultures. This study is the first report of entomophthoroid fungi infecting lucerne (Medicago sativa L.) aphids in Argentina. Copyright © 2014 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  18. A PROPOSITO DE UN ENSAYO CON ABONOS (cal y harina de huesos EN ALFALFAl (Medicago sativa

    Directory of Open Access Journals (Sweden)

    Isidoro Mogilner

    1960-01-01

    Full Text Available En este trabajo, los autores estudian el efecto que sobre el rendimiento de la alfalfa (Medicago sativa produce la incorporación de diferentes dosis de cal y harina de huesos, en un suelo pobre de P y Ca; de una textura pesada con alto contenido de arcilla en todos los horizontes, de un pH ácido (5.1 a 6.2 y que es característico de la zona donde fué hecha la experiencia.Se han obtenido resultados referentes a la influencia de la inoculación de la semilla con Rhizobium y el agregado de cal y harina de huesos sobre los rendimientos.

  19. Fotossíntese em alfafa (Medicago sativa L.) sob supressão e ressuprimento de fosfato

    OpenAIRE

    Gomes,Fernando Teixeira; Pereira,Gilmara Duarte; Borges,Arnaldo Chaer; Mosquim,Paulo Roberto

    2003-01-01

    Neste estudo, foram avaliados os efeitos da supressão e do ressuprimento de fosfato (Pi) sobre a fotossíntese e eficiência fotoquímica de plantas de Medicago sativa cv. Flórida 77, em diferentes estádios do desenvolvimento vegetativo (V3, V4) e reprodutivo (R6, R8). O ensaio foi conduzido em casa de vegetação e as plantas cultivadas na solução nutritiva de HOAGLAND & ARNON (1950), contendo 0,14mmol L-1 de Pi. A supressão de Pi por dez dias reduziu os teores de fósforo nas folhas amostrada...

  20. Uptake of oxytetracycline and its phytotoxicity to alfalfa (Medicago sativa L.)

    Energy Technology Data Exchange (ETDEWEB)

    Kong, W D [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Zhu, Y G [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Liang, Y C [Ministry of Agriculture Key Laboratory of Plant Nutrition and Nutrient Cycling, Institute of Soils and Fertilizers, Chinese Academy of Agricultural Sciences, Beijing 100081 (China); Zhang, J [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Smith, F A [Soil and Land Systems, School of Earth and Environmental Sciences, University of Adelaide, DP 636, Adelaide, SA 5005 (Australia); Yang, M [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China)

    2007-05-15

    A series of experiments were conducted in a hydroponic system to investigate the uptake of oxytetracycline (OTC) and its toxicity to alfalfa (Medicago sativa L.). OTC inhibited alfalfa shoot and root growth by up to 61% and 85%, respectively. The kinetics of OTC uptake could be well described by Michaelis-Menten equation with V {sub max} of 2.25 {mu}mol g{sup -1} fresh weight h{sup -1}, and K {sub m} of 0.036 mM. The uptake of OTC by alfalfa was strongly inhibited by the metabolic inhibitor, 2,4-DNP (2,4-dinitrophenol), at pH 3.5 and 6.0, but not by the aquaporin competitors, glycerol and Ag{sup +}. OTC uptake, however, was significantly inhibited by Hg{sup 2+}, suggesting that the inhibition of influx was due to general cellular stress rather than the specific action of Hg{sup 2+} on aquaporins. Results from the present study suggested that OTC uptake into alfalfa is an energy-dependent process. - Plant uptake of antibiotic oxytetracycline is energy-dependent.

  1. Monolignol biosynthesis in microsomal preparations from lignifying stems of alfalfa (Medicago sativa L.).

    Science.gov (United States)

    Guo, Dianjing; Chen, Fang; Dixon, Richard A

    2002-11-01

    Microsomal preparations from lignifying stems of alfalfa (Medicago sativa L.) contained coniferaldehyde 5-hydroxylase activity and immunodetectable caffeic acid 3-O-methyltransferase (COMT), and catalyzed the S-adenosyl L-methionine (SAM) dependent methylation of caffeic acid, caffeyl aldehyde and caffeyl alcohol. When supplied with NADPH and SAM, the microsomes converted caffeyl aldehyde to coniferaldehyde, 5-hydroxyconiferaldehyde, and traces of sinapaldehyde. Coniferaldehyde was a better precursor of sinapaldehyde than was 5-hydroxyconiferaldehyde. The alfalfa microsomes could not metabolize 4-coumaric acid, 4-coumaraldehyde, 4-coumaroyl CoA, or ferulic acid. No metabolism of monolignol precursors was observed in microsomal preparations from transgenic alfalfa down-regulated in COMT expression. In most microsomal preparations, the level of the metabolic conversions was independent of added recombinant COMT. Taken together, the data provide only limited support for the concept of metabolic channeling in the biosynthesis of S monolignols via coniferaldehyde.

  2. The effect of Medicago arabica, M. hybrida and M. sativa saponins on the growth and development of Fusarium oxysporum Schlecht f. sp. tulipae apt.

    Directory of Open Access Journals (Sweden)

    Anna Jarecka

    2012-12-01

    Full Text Available In the present work it was shown that total saponins originated from M. hybrida and M. sativa substantially limited mycelium growth of F. oxysporum f. sp. tulipae and symptoms of fusariosis on tulip bulbs. Out of 15 individual tested saponins originated from M. arabica, M. hybrida and M. sativa, four compounds: 3-O-[β-D-glucopyranosyl (1→2α-L-arabinopyranosyl] hederagenin, hederagenin 3-O-β-D-glucopyranoside, medicagenic acid, medicagenic acid 3-O-β-D-glucopyranoside had the strongest inhibitory effect on mycelium growth of Fusarium oxysporum f. sp. tulipae on PDA medium. The total saponins from M. arabica, M. hybrida and M. sativa inhibited the number of colony forming units of Fusarium oxysporum f. sp. tulipae in artificially infested substrate. The use of saponins originated from Medicago as a fungicide is suggested.

  3. Ractopamine up take by alfalfa (Medicago sativa) and wheat (Triticum aestivum) from soil.

    Science.gov (United States)

    Shelver, Weilin L; DeSutter, Thomas M

    2015-08-01

    Ractopamine is a beta adrenergic agonist used as a growth promoter in swine, cattle and turkeys. To test whether ractopamine has the potential to accumulate in plants grown in contaminated soil, a greenhouse study was conducted with alfalfa (Medicago sativa) and wheat (Triticum aestivum) grown in two soils having different concentrations of organic matter (1.3% and 2.1%), amended with 0, 0.5, and 10 μg/g of ractopamine. Plant growth ranged from 2.7 to 8.8 g dry weight (dw) for alfalfa, and 8.7 to 40 g dw for wheat and was generally greater in the higher organic matter content soil. The uptake of ractopamine in plant tissues ranged from non-detectable to 897 ng/g and was strongly dependent on soil ractopamine concentration across soil and plant tissue. When adjusted to the total fortified quantities, the amount of ractopamine taken up by the plant tissue was low, <0.01% for either soil. Copyright © 2015. Published by Elsevier B.V.

  4. Accumulation and residue of napropamide in alfalfa (Medicago sativa) and soil involved in toxic response.

    Science.gov (United States)

    Cui, Li E; Yang, Hong

    2011-06-15

    Napropamide belongs to the amide herbicide family and widely used to control weeds in farmland. Intensive use of the herbicide has resulted in widespread contamination to ecosystems. The present study demonstrated an analysis on accumulation of the toxic pesticide napropamide in six genotypes of alfalfa (Medicago sativa), along with biological parameters and its residues in soils. Soil was treated with napropamide at 3 mg kg(-1) dry soil and alfalfa plants were cultured for 10 or 30 d, respectively. The maximum value for napropamide accumulation is 0.426 mg kg(-1) in shoots and 2.444 mg kg(-1) in roots. The napropamide-contaminated soil with alfalfa cultivation had much lower napropamide concentrations than the control (soil without alfalfa cultivation). Also, the content of napropamide residue in the rhizosphere was significantly lower than that in the non-rhizosphere soil. M. sativa exposed to 3 mg kg(-1) napropamide showed inhibited growth. Further analysis revealed that plants treated with napropamide accumulated more reactive oxygen species (O(2)(-) and H(2)O(2)) and less amounts of chlorophyll. However, not all cultivars showed oxidative injury, suggesting that the alfalfa cultivars display different tolerance to napropamide. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Development of simple sequence repeat markers and diversity analysis in alfalfa (Medicago sativa L.).

    Science.gov (United States)

    Wang, Zan; Yan, Hongwei; Fu, Xinnian; Li, Xuehui; Gao, Hongwen

    2013-04-01

    Efficient and robust molecular markers are essential for molecular breeding in plant. Compared to dominant and bi-allelic markers, multiple alleles of simple sequence repeat (SSR) markers are particularly informative and superior in genetic linkage map and QTL mapping in autotetraploid species like alfalfa. The objective of this study was to enrich SSR markers directly from alfalfa expressed sequence tags (ESTs). A total of 12,371 alfalfa ESTs were retrieved from the National Center for Biotechnology Information. Total 774 SSR-containing ESTs were identified from 716 ESTs. On average, one SSR was found per 7.7 kb of EST sequences. Tri-nucleotide repeats (48.8 %) was the most abundant motif type, followed by di-(26.1 %), tetra-(11.5 %), penta-(9.7 %), and hexanucleotide (3.9 %). One hundred EST-SSR primer pairs were successfully designed and 29 exhibited polymorphism among 28 alfalfa accessions. The allele number per marker ranged from two to 21 with an average of 6.8. The PIC values ranged from 0.195 to 0.896 with an average of 0.608, indicating a high level of polymorphism of the EST-SSR markers. Based on the 29 EST-SSR markers, assessment of genetic diversity was conducted and found that Medicago sativa ssp. sativa was clearly different from the other subspecies. The high transferability of those EST-SSR markers was also found for relative species.

  6. Genetic transformation and analysis of rice OsAPx2 gene in Medicago sativa.

    Directory of Open Access Journals (Sweden)

    Qingjie Guan

    Full Text Available The OsAPx2 gene from rice was cloned to produce PBI121::OsAPx2 dual-expression plants, of which expression level would be increasing under stressful conditions. The enzyme ascorbate peroxidase (APX in the leaves and roots of the plants increased with increasing exposure time to different sodium chloride (NaCl and hydrogen peroxide (H(2O(2concentrations, as indicated by protein gel blot analysis. The increased enzyme yield improved the ability of the plants to resist the stress treatments. The OsAPx2 gene was localized in the cytoplasm of epidermal onion cells as indicated by the instantaneous expression of green fluorescence. An 80% regeneration rate was observed in Medicago sativa L. plants transformed with the OsAPx2 gene using Agrobacterium tumefaciens, as indicated by specific primer PCR. The OsAPx2 gene was expressed at the mRNA level and the individual M. sativa (T#1,T#2,T#5 were obtained through assaying the generation of positive T2 using RNA gel blot analysis. When the seeds of the wild type (WT and the T2 (T#1,T#5 were incubated in culture containing MS with NaCl for 7 days, the results as shown of following: the root length of transgenic plant was longer than WT plants, the H(2O(2 content in roots of WT was more than of transgenic plants, the APX activity under stresses increased by 2.89 times compared with the WT, the malondialdehyde (MDA content of the WT was higher than the transgenic plants, the leaves of the WT turned yellow, but those of the transgenic plants remained green and remained healthy. The chlorophyll content in the WT leaves was less than in the transgenic plants, after soaking in solutions of H(2O(2, sodium sulfite (Na(2SO(3, and sodium bicarbonate (NaHCO(3. Therefore, the OsAPx2 gene overexpression in transgenic M. sativa improves the removal of H(2O(2 and the salt-resistance compared with WT plants. A novel strain of M. sativa carrying a salt-resistance gene was obtained.

  7. Effects of simulated acidic rain on yields of Raphanus sativus, Lactuca sativa, Triticum aestivum and Medicago sativa

    Energy Technology Data Exchange (ETDEWEB)

    Evans, L.S.; Gmur, N.F.; Mancini, D.

    1982-01-01

    Experiments were performed to determine effects to simulated acidic rain on radishes (Raphanus sativus), lettuce (Lactuca sativa), wheat (Triticum aestivum) and alfalfa (Medicago sativa) grown under greenhouse conditions. Experimental designs allowed the detection of statistically significant differences among means that differed by less than 10%. Simulated rainfalls of 2.5, 25, 63, 398, 100 and 2512 ..mu..eq H/sup +/ 1/sup -1/ (pH 5.6, 4.6, 4.2, 3.4, 3.0 and 2.6, respectively) decreased root yields (fresh mass) of radishes 26, 42, 37, 41, 66 and 73% compared with plants not exposed to rainfalls, Similar reductions were present in radish shoot fresh mass, leaf area, and root diameter. Fresh mass yields of lettuce plants exposed to 100, 794 and 1995 ..mu..eq H/sup +/ 1/sup -1/ (pH 4.0, 3.1 and 2.7, respectively) were 11, 10 and 14%, respectively, below heads of plants not exposed to rainfalls. Yields of plants exposed to simulated rainfalls of 2.0 ..mu..eq H/sup +/ 1/sup -1/ (pH 5.7) were similar to plants not exposed to rainfalls. Although visible foliar injury occurred to lettuce, this injury was present only on wrapper leaves and would not affect marketable quality. Yields of wheat which were applied during anthesis and caryopsis development were not influenced by exposure to 46 simulated rainfalls even as high as 1996 ..mu..eq H/sup +/ 1/sup -1/ (pH 2.7). Alfalfa plants exhibited no overall differences in fresh mass of forage among treatments even after 57 simulated rainfalls of 1996 ..mu..eq H/sup +/ 1/sup -1/ (pH 2.7) over 105 days. 22 references, 2 figures, 7 tables.

  8. Molecular Diversity and Population Structure of a Worldwide Collection of Cultivated Tetraploid Alfalfa (Medicago sativa subsp. sativa L.) Germplasm as Revealed by Microsatellite Markers.

    Science.gov (United States)

    Qiang, Haiping; Chen, Zhihong; Zhang, Zhengli; Wang, Xuemin; Gao, Hongwen; Wang, Zan

    2015-01-01

    Information on genetic diversity and population structure of a tetraploid alfalfa collection might be valuable in effective use of the genetic resources. A set of 336 worldwide genotypes of tetraploid alfalfa (Medicago sativa subsp. sativa L.) was genotyped using 85 genome-wide distributed SSR markers to reveal the genetic diversity and population structure in the alfalfa. Genetic diversity analysis identified a total of 1056 alleles across 85 marker loci. The average expected heterozygosity and polymorphism information content values were 0.677 and 0.638, respectively, showing high levels of genetic diversity in the cultivated tetraploid alfalfa germplasm. Comparison of genetic characteristics across chromosomes indicated regions of chromosomes 2 and 3 had the highest genetic diversity. A higher genetic diversity was detected in alfalfa landraces than that of wild materials and cultivars. Two populations were identified by the model-based population structure, principal coordinate and neighbor-joining analyses, corresponding to China and other parts of the world. However, lack of strictly correlation between clustering and geographic origins suggested extensive germplasm exchanges of alfalfa germplasm across diverse geographic regions. The quantitative analysis of the genetic diversity and population structure in this study could be useful for genetic and genomic analysis and utilization of the genetic variation in alfalfa breeding.

  9. Micromonospora from nitrogen fixing nodules of alfalfa (Medicago sativa L.). A new promising Plant Probiotic Bacteria.

    Science.gov (United States)

    Martínez-Hidalgo, Pilar; Galindo-Villardón, Purificación; Trujillo, Martha E; Igual, José M; Martínez-Molina, Eustoquio

    2014-09-17

    Biotic interactions can improve agricultural productivity without costly and environmentally challenging inputs. Micromonospora strains have recently been reported as natural endophytes of legume nodules but their significance for plant development and productivity has not yet been established. The aim of this study was to determine the diversity and function of Micromonospora isolated from Medicago sativa root nodules. Micromonospora-like strains from field alfalfa nodules were characterized by BOX-PCR fingerprinting and 16S rRNA gene sequencing. The ecological role of the interaction of the 15 selected representative Micromonospora strains was tested in M. sativa. Nodulation, plant growth and nutrition parameters were analyzed. Alfalfa nodules naturally contain abundant and highly diverse populations of Micromonospora, both at the intra- and at interspecific level. Selected Micromonospora isolates significantly increase the nodulation of alfalfa by Ensifer meliloti 1021 and also the efficiency of the plant for nitrogen nutrition. Moreover, they promote aerial growth, the shoot-to-root ratio, and raise the level of essential nutrients. Our results indicate that Micromonospora acts as a Rhizobia Helper Bacteria (RHB) agent and has probiotic effects, promoting plant growth and increasing nutrition efficiency. Its ecological role, biotechnological potential and advantages as a plant probiotic bacterium (PPB) are also discussed.

  10. Effect of Medicago sativa L. and compost on organic and inorganic pollutant removal from a mixed contaminated soil and risk assessment using ecotoxicological tests.

    Science.gov (United States)

    Marchand, Charlotte; Hogland, William; Kaczala, Fabio; Jani, Yahya; Marchand, Lilian; Augustsson, Anna; Hijri, Mohamed

    2016-11-01

    Several Gentle Remediation Options (GRO), e.g., plant-based options (phytoremediation), singly and combined with soil amendments, can be simultaneously efficient for degrading organic pollutants and either stabilizing or extracting trace elements (TEs). Here, a 5-month greenhouse trial was performed to test the efficiency of Medicago sativa L., singly and combined with a compost addition (30% w/w), to treat soils contaminated by petroleum hydrocarbons (PHC), Co and Pb collected at an auto scrap yard. After 5 months, total soil Pb significantly decreased in the compost-amended soil planted with M. sativa, but not total soil Co. Compost incorporation into the soil promoted PHC degradation, M. sativa growth and survival, and shoot Pb concentrations [3.8 mg kg(-1) dry weight (DW)]. Residual risk assessment after the phytoremediation trial showed a positive effect of compost amendment on plant growth and earthworm development. The O2 uptake by soil microorganisms was lower in the compost-amended soil, suggesting a decrease in microbial activity. This study underlined the benefits of the phytoremediation option based on M. sativa cultivation and compost amendment for remediating PHC- and Pb-contaminated soils.

  11. Occurrence of Transgenic Feral Alfalfa (Medicago sativa subsp. sativa L.) in Alfalfa Seed Production Areas in the United States.

    Science.gov (United States)

    Greene, Stephanie L; Kesoju, Sandya R; Martin, Ruth C; Kramer, Matthew

    2015-01-01

    The potential environmental risks of transgene exposure are not clear for alfalfa (Medicago sativa subsp. sativa), a perennial crop that is cross-pollinated by insects. We gathered data on feral alfalfa in major alfalfa seed-production areas in the western United States to (1) evaluate evidence that feral transgenic plants spread transgenes and (2) determine environmental and agricultural production factors influencing the location of feral alfalfa, especially transgenic plants. Road verges in Fresno, California; Canyon, Idaho; and Walla Walla, Washington were surveyed in 2011 and 2012 for feral plants, and samples were tested for the CP4 EPSPS protein that conveys resistance to glyphosate. Of 4580 sites surveyed, feral plants were observed at 404 sites. Twenty-seven percent of these sites had transgenic plants. The frequency of sites having transgenic feral plants varied among our study areas. Transgenic plants were found in 32.7%, 21.4.7% and 8.3% of feral plant sites in Fresno, Canyon and Walla Walla, respectively. Spatial analysis suggested that feral populations started independently and tended to cluster in seed and hay production areas, places where seed tended to drop. Significant but low spatial auto correlation suggested that in some instances, plants colonized nearby locations. Neighboring feral plants were frequently within pollinator foraging range; however, further research is needed to confirm transgene flow. Locations of feral plant clusters were not well predicted by environmental and production variables. However, the likelihood of seed spillage during production and transport had predictive value in explaining the occurrence of transgenic feral populations. Our study confirms that genetically engineered alfalfa has dispersed into the environment, and suggests that minimizing seed spillage and eradicating feral alfalfa along road sides would be effective strategies to minimize transgene dispersal.

  12. Nodulation by Sinorhizobium meliloti originated from a mining soil alleviates Cd toxicity and increases Cd-phytoextraction in Medicago sativa L.

    Science.gov (United States)

    Ghnaya, Tahar; Mnassri, Majda; Ghabriche, Rim; Wali, Mariem; Poschenrieder, Charlotte; Lutts, Stanley; Abdelly, Chedly

    2015-01-01

    Besides their role in nitrogen supply to the host plants as a result of symbiotic N fixation, the association between legumes and Rhizobium could be useful for the rehabilitation of metal-contaminated soils by phytoextraction. A major limitation presents the metal-sensitivity of the bacterial strains. The aim of this work was to explore the usefulness of Sinorhizobium meliloti originated from a mining site for Cd phytoextraction by Medicago sativa. Inoculated and non-inoculated plants were cultivated for 60 d on soils containing 50 and/or 100 mg Cd kg(-1) soil. The inoculation hindered the occurrence of Cd- induced toxicity symptoms that appeared in the shoots of non-inoculated plants. This positive effect of S. meliloti colonization was accompanied by an increase in biomass production and improved nutrient acquisition comparatively to non-inoculated plants. Nodulation enhanced Cd absorption by the roots and Cd translocation to the shoots. The increase of plant biomass concomitantly with the increase of Cd shoot concentration in inoculated plants led to higher potential of Cd-phytoextraction in these plants. In the presence of 50 mg Cd kg(-1) in the soil, the amounts of Cd extracted in the shoots were 58 and 178 μg plant(-1) in non-inoculated and inoculated plants, respectively. This study demonstrates that this association M. sativa-S. meliloti may be an efficient biological system to extract Cd from contaminated soils.

  13. Enhanced salt tolerance of alfalfa (Medicago sativa) by rstB gene transformation.

    Science.gov (United States)

    Zhang, Wan-Jun; Wang, Tao

    2015-05-01

    Generating salt tolerance forage plant is essential for use of the land affected by high salinity. A salt tolerance gene rstB was used as a selectable marker gene in Agrobacterium-mediated transformation of tobacco under a selective regime of 170mM NaCl. The transgenic plants showed clear improvement in salt tolerance. To improve salt tolerance of alfalfa (Medicago sativa L.), rstB gene was introduced into alfalfa genome by Agrobacterium-mediated transformation. No abnormal phenotype was observed among the transgenic plants when compared with wild type (wt) plants. Significant enhancement of resistance to salt-shock treatment was noted on the rstB transgenic (T0) plants. Transgenic second-generation (T1) seeds showed improved germination rate and seedling growth under salt-stress condition. Hindered Na(+) accumulation, but enhanced Ca(2+) accumulation was observed on the rstB T1 plants when subjected to salt-stresses. Enhanced calcium accumulation in transgenic plants was also verified by cytohistochemical localization of calcium. Under salt-stress of 50mM NaCl, about 15% of the transgenic plants finished their life-cycle but the wt plants had no flower formation. The results demonstrated that the expression of rstB gene improved salt tolerance in transgenic alfalfa. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  14. Allelopathic interference of alfalfa (Medicago sativa L.) genotypes to annual ryegrass (Lolium rigidum).

    Science.gov (United States)

    Zubair, Hasan Muhammad; Pratley, James E; Sandral, G A; Humphries, A

    2017-07-01

    Alfalfa (Medicago sativa L.) genotypes at varying densities were investigated for allelopathic impact using annual ryegrass (Lolium rigidum) as the target species in a laboratory bioassay. Three densities (15, 30, and 50 seedlings/beaker) and 40 alfalfa genotypes were evaluated by the equal compartment agar method (ECAM). Alfalfa genotypes displayed a range of allelopathic interference in ryegrass seedlings, reducing root length from 5 to 65%. The growth of ryegrass decreased in response to increasing density of alfalfa seedlings. At the lowest density, Q75 and Titan9 were the least allelopathic genotypes. An overall inhibition index was calculated to rank each alfalfa genotype. Reduction in seed germination of annual ryegrass occurred in the presence of several alfalfa genotypes including Force 10, Haymaster7 and SARDI Five. A comprehensive metabolomic analysis using Quadruple Time of Flight (Q-TOF), was conducted to compare six alfalfa genotypes. Variation in chemical compounds was found between alfalfa root extracts and exudates and also between genotypes. Further individual compound assessments and quantitative study at greater chemical concentrations are needed to clarify the allelopathic activity. Considerable genetic variation exists among alfalfa genotypes for allelopathic activity creating the opportunity for its use in weed suppression through selection.

  15. Resistance and susceptibility of alfalfa (Medicago sativa L.) cultivars to the aphid Therioaphis maculata (Homoptera:Aphididae): insect biology and cultivar evaluation

    Institute of Scientific and Technical Information of China (English)

    ALEXANDRE DE ALMEIDA E SILVA; ELENICE MOURO VARANDA; JOS(E) RICARDO BAROSELA

    2006-01-01

    Biology of the aphid Therioaphis maculata was studied on alfalfa (Medicago sativa L.), including four resistant (Mesa-Sirsa, CUF101, Baker and Lahontan) and two susceptible (ARC and Caliverde) alfalfa cultivars, and one of the most cropped Brazilian cultivars, Crioula. Under controlled conditions, antibiosis (i.e., reduced longevity, fecundity and increased mortality of the aphid) was observed mainly on the resistant alfalfa cultivars,except on Lahontan. Crioula seemed to be tolerant to aphids. Present data support geographic limitation usage of cultivars, and we suggest Baker and Mesa-Sirsa as sources of antibiosis,and provide biological information of a tropical T. maculata biotype on alfalfa.

  16. Fotossíntese em alfafa (Medicago sativa L. sob supressão e ressuprimento de fosfato Photosynthesis in alfalfa (Medicago sativa L. under phosphate suppression and ressuply

    Directory of Open Access Journals (Sweden)

    Fernando Teixeira Gomes

    2003-10-01

    Full Text Available Neste estudo, foram avaliados os efeitos da supressão e do ressuprimento de fosfato (Pi sobre a fotossíntese e eficiência fotoquímica de plantas de Medicago sativa cv. Flórida 77, em diferentes estádios do desenvolvimento vegetativo (V3, V4 e reprodutivo (R6, R8. O ensaio foi conduzido em casa de vegetação e as plantas cultivadas na solução nutritiva de HOAGLAND & ARNON (1950, contendo 0,14mmol L-1 de Pi. A supressão de Pi por dez dias reduziu os teores de fósforo nas folhas amostradas, em todos os estádios do desenvolvimento. Entretanto, com o ressuprimento, somente nos estádios vegetativos, os valores foram semelhantes ao tratamento controle. A fotossíntese por área foliar, em todos os estádios do desenvolvimento diminuiu com a supressão de Pi. De modo geral, o ressuprimento de Pi à solução nutritiva resultou em recuperação na fotossíntese, excetuando-se as plantas no estádio V3, uma indicação de que o período de supressão não causou danos permanentes no aparato fotossintético. Os teores dos pigmentos fotossintéticos e a eficiência fotoquímica do fotossistema II (FS II, avaliada pela relação Fv/Fm, não foram alterados quando as plantas foram submetidas à supressão de Pi. Esse resultado demonstra que o transporte de elétrons através do FS II não limitou a fotossíntese nas folhas amostradas, sob supressão de Pi, sugerindo que a supressão causou efeito mais pronunciado na etapa bioquímica da fotossíntese.This work evaluated the phosphate (Pi suppression and ressupply on photosynthesis and photochemical efficiency from Medicago sativa plants cv. Florida 77, in different growth stages (V3 and V4 and reproductive (R6 and R8. The experiment was performed in a greenhouse, the plants being cultivated in HOAGLAND & ARMOND (1950 nutritive solution containing 0,14mmol L-1 of Pi. Pi suppression for ten days reduced Pi levels in sampled leaves, in all growth stages. However, with the re-supply only in the

  17. Differential response to water deficit stress in alfalfa ( Medicago ...

    African Journals Online (AJOL)

    The present study was fixed as objective to compare the response to water deficit (33% of field capacity, FC) stress of eight cultivars of Medicago sativa, originating from the Mediterranean basin. Comparison was performed on some key parameters such as growth, relative water content, leaf water potential, MDA tissue ...

  18. Stem nematode counteracts plant resistance of aphids in alfalfa, Medicago sativa.

    Science.gov (United States)

    Ramirez, Ricardo A; Spears, Lori R

    2014-10-01

    Plants are exploited by a diverse community of insect herbivores and phytopathogens that interact indirectly through plant-mediated interactions. Generally, plants are thought to respond to insects and pathogens through different defensive signaling pathways. As plants are selected for resistance to one phytophagous organism type (insect vs. pathogen) in managed systems, it is not clear how this selection may affect community interactions. This study examined the effect of nematode-resistant varieties on aphid (Acyrthosiphon pisum) suppression, and then determined how infection by the stem nematode, Ditylenchus dipsaci, mediated ecological effects on aphids and on plant defense proteins. Four alfalfa (Medicago sativa) varieties were selected with resistance to nematodes only (+,-), aphids only (-,+), nematodes and aphids (+,+), and susceptibility to nematodes and aphids (-,-). Field and greenhouse experiments were conducted to isolate the effect of nematode infection and aphid abundance on each variety. We found that varieties resistant to nematode, regardless of aphid resistance, had the lowest aphid counts, suggesting possible cross-resistance. Aphid abundance, however, increased when plants were exposed to nematodes. Resistant varieties were associated with elevated saponins but these compounds were not affected by insect or pathogen feeding. Concentrations of peroxidases and trypsin inhibitors, however, were increased in nematode resistant varieties when exposed to nematodes and aphids, respectively. The patterns of plant defense were variable, and a combination of resistance traits and changes in nutrient availability may drive positive interactions between nematodes and aphids aboveground.

  19. Nutraceutical Potential of New Alfalfa (Medicago sativa) Ingredients for Beverage Preparations.

    Science.gov (United States)

    Soto-Zarazúa, Maria Guadalupe; Bah, Moustapha; Costa, Anabela Silvia Gomes; Rodrigues, Francisca; Pimentel, Filipa Botelho; Rojas-Molina, Isela; Rojas, Alejandra; Oliveira, Maria Beatriz Prior Pinto

    2017-10-01

    Alfalfa (Medicago sativa) has been extensively used as animal feed, due to its fiber, protein, minerals, and vitamins, being also a useful source of phenolic compounds with potential therapeutic benefits. Nevertheless, its potential use as human ingredient is scarce. The aim of this work was to assess the nutritional composition, amino acid profile, and antioxidant capacity (AOC) of freeze-dried juice (FDJ) and fibrous residual material (RM), two new alfalfa-derived products (Adps) recently launched as ingredients for beverage preparations. Results demonstrated a high content of proteins (23-30 g/100 g FDJ and 13-17 g/100 g RM), crude fiber (29 g/100 g RM), and minerals (such as sodium, calcium, iron, and zinc). No significant difference was found in caloric content (4 kcal/g). Essential and nonessential amino acids were quantified in both Adps being leucine and lysine the most abundant. Total phenolic and total flavonoid contents (TPC and TFC, respectively) and their changes along the different harvesting periods of the year were also examined. FDJ presented the highest TPC in May (19 mg gallic acid equivalents/g dry weight [dw]), while in October TFC had the maximum value (4 mg catechin equivalents/g dw). Both products exhibited an interesting AOC by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power assays. This study reports the nutraceutical potential of two new types of Adps.

  20. Arbuscular mycorrhizal fungi alleviate arsenic toxicity to Medicago sativa by influencing arsenic speciation and partitioning.

    Science.gov (United States)

    Li, Jinglong; Sun, Yuqing; Jiang, Xuelian; Chen, Baodong; Zhang, Xin

    2018-08-15

    In a pot experiment, Medicago sativa inoculated with/without arbuscular mycorrhizal (AM) fungus Rhizophagus irregularis were grown in four levels (0, 10, 25, and 75 mg/kg) of arsenic (As)-polluted soil to investigate the influences of AM symbiosis on plant As tolerance. The results showed that mycorrhizal inoculation significantly increased plant biomass, while As addition decreased mycorrhizal colonization and hyphal length density. Mycorrhizal inoculation dramatically improved plant phosphorus (P) nutrition, restricted As uptake and retained more As in roots by upregulating the expression of the AM-induced P transporter gene MsPT4 and the metallothionein gene MsMT2. High soil As content downregulated MsPT4 expression. Dimethylarsenic acid (DMA) was detected only in the shoots of mycorrhizal plants, indicating that AM fungi likely play an essential role in As detoxification by biological methylation. The present investigation allowed deeper insights into the As detoxification mechanisms of AM associations and demonstrated the important role of AM fungi in plant resistance under As-contaminated conditions. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. Effects of Shepherd’s Purse (Capsella bursa pastoris (L. Medic. on the Chemical Composition of Lucerne (Medicago sativa L.

    Directory of Open Access Journals (Sweden)

    Tsvetanka Dimitrova

    2008-01-01

    Full Text Available A study was conducted in a pure stand of lucerne (variety Viktoria under natural weed infestation with shepherd’s purse (Capsella bursa pastoris (L. Medic. on a slightly leached chernozem soil under nonirrigated conditions in the experimental field of the Institute ofForage Crops – Pleven during the 2006-2007 period. The effect of shepherd’s purse Capsella bursa pastoris (L. Medic. on the chemical composition of lucerne Medicago sativa (L. was analyzed.Statistically significant (P<0.05 functional relations were found between the chemical characteristics and percentage of Capsella bursa pastoris (L. Medic. participation in the lucerne sward, and forage quality. These relations indicated a multiple practical relevance and a necessity to control Capsella bursa pastoris (L. Medic. in lucerne stands in order to decrease weed density and improve forage quality.

  2. Selective lignin downregulation leads to constitutive defense response expression in alfalfa (Medicago sativa L.).

    Science.gov (United States)

    Gallego-Giraldo, Lina; Jikumaru, Yusuke; Kamiya, Yuji; Tang, Yuhong; Dixon, Richard A

    2011-05-01

    • Downregulation of hydroxycinnamoyl CoA: shikimate hydroxycinnamoyl transferase (HCT) in alfalfa (Medicago sativa) reduces lignin levels and improves forage quality and saccharification efficiency for bioethanol production. However, the plants have reduced stature. It was previously reported that HCT-down-regulated Arabidopsis have impaired auxin transport, but this has recently been disproved. • To address the basis for the phenotypes of lignin-modified alfalfa, we measured auxin transport, profiled a range of metabolites including flavonoids and hormones, and performed in depth transcriptome analyses. • Auxin transport is unaffected in HCT antisense alfalfa despite increased flavonoid biosynthesis. The plants show increased cytokinin and reduced auxin levels, and gibberellin levels and sensitivity are both reduced. Levels of salicylic, jasmonic and abscisic acids are elevated, associated with massive upregulation of pathogenesis and abiotic stress-related genes and enhanced tolerance to fungal infection and drought. • We suggest that HCT downregulated alfalfa plants exhibit constitutive activation of defense responses, triggered by release of bioactive cell wall fragments and production of hydrogen peroxide as a result of impaired secondary cell wall integrity. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  3. Environmental impact assessment of alfalfa (Medicago sativa L.) hay production.

    Science.gov (United States)

    Bacenetti, Jacopo; Lovarelli, Daniela; Tedesco, Doriana; Pretolani, Roberto; Ferrante, Valentina

    2018-09-01

    On-farm production of hay and high-protein-content feed has several advantages such as diversification of on-farm cultivated crops, reduction of off-farm feed concentrates transported over long distances and a reduction in runoff during the winter season if grown crops are perennial. Among those crops cultivated for high-protein-content feed, alfalfa (Medicago sativa L.) is one of the most important in the Italian context. Nevertheless, up to now, only a few studies have assessed the environmental performance of alfalfa hay production. In this study, using the Life Cycle Assessment approach, the environmental impact of alfalfa hay production in Northern Italy was analyzed. More in detail, two production practices (without and with irrigation) were compared. The results show that alfalfa hay production in irrigated fields has a better environmental performance compared to non-irrigated production, mainly because of the yield increase achieved with irrigation. In particular, for the Climate Change impact category, the impact is equal to 84.54 and 80.21kgCO 2 /t of hay for the scenario without and with irrigation, respectively. However, for two impact categories (Ozone Depletion and Human Toxicity-No Cancer Effect), the impact of irrigation completely offsets the yield increase, and the cultivation practice without irrigation shows the best environmental performance. For both scenarios, the mechanization of harvest is the main environmental hotspot, mostly due to fuel consumption and related combustion emissions. Wide differences were highlighted by comparing the two scenarios with the Ecoinvent process of alfalfa hay production; these differences are mostly due to the cultivation practice and, in particular, to the more intensive fertilization in Swiss production. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. [The effect of Medicago spp. on growth of Trichophyton mentagrophytes in microculture].

    Science.gov (United States)

    Spiewak, R; Szostak, W; Jurzysta, M; Biały, Z; Maleszka, R; Rzepecka, B; Mazurek, M

    2001-01-01

    The study aimed at assessing effect of dried root and aerial parts of Medicago spp. on growth of Trichophryton mentagrophytes. Fungus strains were inoculated onto microcultures with Sabouraud agar supplemented each with 1 g of dried and pulverised roots or aerial parts of 3 species: Medicago arabica, M. sativa, and M. murex. The strongest inhibitory effect on T. mentagrophytes growth was that of aerial parts of M. arabica (median diameter 6 mm compared to 13 mm of control), followed by root of M. arabica (10 mm) and root of M. murex (10.5 mm)--in all cases p < 0.001. Slight inhibitory effect was also found in the case of aerial parts of M. murex (median diameter 12 mm, p = 0.03). In contrast, M. sativa has shown stimulating effect on growth of T. mentagrophytes (15 mm for root and 16.5 mm for aerial part, p<0.001).

  5. Sexual Polyploidization in Medicago sativa L.: Impact on the Phenotype, Gene Transcription, and Genome Methylation.

    Science.gov (United States)

    Rosellini, Daniele; Ferradini, Nicoletta; Allegrucci, Stefano; Capomaccio, Stefano; Zago, Elisa Debora; Leonetti, Paola; Balech, Bachir; Aversano, Riccardo; Carputo, Domenico; Reale, Lara; Veronesi, Fabio

    2016-04-07

    Polyploidization as the consequence of 2n gamete formation is a prominent mechanism in plant evolution. Studying its effects on the genome, and on genome expression, has both basic and applied interest. We crossed two diploid (2n = 2x = 16) Medicago sativa plants, a subsp. falcata seed parent, and a coerulea × falcata pollen parent that form a mixture of n and 2n eggs and pollen, respectively. Such a cross produced full-sib diploid and tetraploid (2n = 4x = 32) hybrids, the latter being the result of bilateral sexual polyploidization (BSP). These unique materials allowed us to investigate the effects of BSP, and to separate the effect of intraspecific hybridization from those of polyploidization by comparing 2x with 4x full sib progeny plants. Simple sequence repeat marker segregation demonstrated tetrasomic inheritance for all chromosomes but one, demonstrating that these neotetraploids are true autotetraploids. BSP brought about increased biomass, earlier flowering, higher seed set and weight, and larger leaves with larger cells. Microarray analyses with M. truncatula gene chips showed that several hundred genes, related to diverse metabolic functions, changed their expression level as a consequence of polyploidization. In addition, cytosine methylation increased in 2x, but not in 4x, hybrids. Our results indicate that sexual polyploidization induces significant transcriptional novelty, possibly mediated in part by DNA methylation, and phenotypic novelty that could underpin improved adaptation and reproductive success of tetraploid M. sativa with respect to its diploid progenitor. These polyploidy-induced changes may have promoted the adoption of tetraploid alfalfa in agriculture. Copyright © 2016 Rosellini et al.

  6. Sexual Polyploidization in Medicago sativa L.: Impact on the Phenotype, Gene Transcription, and Genome Methylation

    Directory of Open Access Journals (Sweden)

    Daniele Rosellini

    2016-04-01

    Full Text Available Polyploidization as the consequence of 2n gamete formation is a prominent mechanism in plant evolution. Studying its effects on the genome, and on genome expression, has both basic and applied interest. We crossed two diploid (2n = 2x = 16 Medicago sativa plants, a subsp. falcata seed parent, and a coerulea × falcata pollen parent that form a mixture of n and 2n eggs and pollen, respectively. Such a cross produced full-sib diploid and tetraploid (2n = 4x = 32 hybrids, the latter being the result of bilateral sexual polyploidization (BSP. These unique materials allowed us to investigate the effects of BSP, and to separate the effect of intraspecific hybridization from those of polyploidization by comparing 2x with 4x full sib progeny plants. Simple sequence repeat marker segregation demonstrated tetrasomic inheritance for all chromosomes but one, demonstrating that these neotetraploids are true autotetraploids. BSP brought about increased biomass, earlier flowering, higher seed set and weight, and larger leaves with larger cells. Microarray analyses with M. truncatula gene chips showed that several hundred genes, related to diverse metabolic functions, changed their expression level as a consequence of polyploidization. In addition, cytosine methylation increased in 2x, but not in 4x, hybrids. Our results indicate that sexual polyploidization induces significant transcriptional novelty, possibly mediated in part by DNA methylation, and phenotypic novelty that could underpin improved adaptation and reproductive success of tetraploid M. sativa with respect to its diploid progenitor. These polyploidy-induced changes may have promoted the adoption of tetraploid alfalfa in agriculture.

  7. Nonphotosynthetic CO2 fixation by alfalfa (Medicago sativa L.) roots and nodules

    International Nuclear Information System (INIS)

    Anderson, M.P.; Heichel, G.H.; Vance, C.P.

    1987-01-01

    The dependence of alfalfa (Medicago sativa L.) root and nodule nonphotosynthetic CO 2 fixation on the supply of currently produced photosynthate and nodule nitrogenase activity was examined a various times after phloem-girdling and exposure of nodules to Ar:O 2 . Phloem-girdling was effected 20 hours and exposure to Ar:O 2 was effected 2 to 3 hours before initiation of experiments. Nodule and root CO 2 fixation rates of phloem-girdled plants were reduced to 38 and 50%, respectively, of those of control plants. Exposure to Ar:O 2 decreased nodule CO 2 fixation rates to 45%, respiration rates to 55%, and nitrogenase activities to 51% of those of the controls. The products of nodule CO 2 fixation were exported through the xylem to the shoot mainly as amino acids within 30 to 60 minutes after exposure to 14 CO 2 . In contrast to nodules, roots exported very little radioactivity, and most of the 14 C was exported as organic acids. The nonphotosynthetic CO 2 fixation rate of roots and nodules averaged 26% of the gross respiration rate, i.e. the sum of net respiration and nonphotosynthetic CO 2 assimilation. Nodules fixed CO 2 at a rate 5.6 times that of roots, but since nodules comprised a small portion of root system mass, roots accounted for 76% of the nodulated roots system CO 2 fixation. The results indicate that nodule CO 2 fixation in alfalfa is associated with N assimilation

  8. Correlations between environmental factors and wild bee behavior on alfalfa (Medicago sativa) in northwestern China.

    Science.gov (United States)

    Wang, Xiaojuan; Liu, Hongping; Li, Xiaoxia; Song, Yu; Chen, Li; Jin, Liang

    2009-10-01

    To discover the effect of environmental factors on pollinator visitation to flowering Medicago sativa, several field experiments were designed to examine the diurnal movement patterns of wild bee species in the Hexi Corridor of northwestern China. Our study results showed that Megachile abluta, M. spissula, and Xylocopa valga showed unimodal diurnal foraging behavior, whereas Andrena parvula and Anthophora melanognatha showed bimodal diurnal foraging behavior. Correlation analysis indicated that diurnal foraging activities of pollinators were significantly correlated with environmental factors. Correlations of foraging activities versus environmental factors for M. abluta, M. spissula, and X. valga best fit a linear model, whereas those of A. parvula and A. melanognatha best fit a parallel quadratic model. Results of this study indicated that solitary wild bees such as M. abluta, M. spissula, X. valga, A. parvula, and A. melanognatha are potential alfalfa pollinators in the Hexi Corridor. An understanding of the environmental factors that affect the behaviors of different wild bees foraging in alfalfa are basic to the utilization of solitary wild bees in a practical way for increased, or more consistent, pollination of alfalfa for seed production.

  9. Salicornia europaea L. Na⁺/H⁺ antiporter gene improves salt tolerance in transgenic alfalfa (Medicago sativa L.).

    Science.gov (United States)

    Zhang, L Q; Niu, Y D; Huridu, H; Hao, J F; Qi, Z; Hasi, A

    2014-07-24

    In order to obtain a salt-tolerant perennial alfalfa (Medicago sativa L.), we transferred the halophyte Salicornia europaea L. Na(+)/H(+) antiporter gene, SeNHX1, to alfalfa by using the Agrobacterium-mediated transformation method. The transformants were confirmed by both PCR and RT-PCR analyses. Of 197 plants that were obtained after transformation, 36 were positive by PCR analysis using 2 primer pairs for the CaMV35S-SeNHX1 and SeNHX1-Nos fragments; 6 plants survived in a greenhouse. RT-PCR analysis revealed that SeNHX1 was expressed in 5 plants. The resultant transgenic alfalfa had better salt tolerance. After stress treatment for 21 days with 0.6% NaCl, the chlorophyll and MDA contents in transgenic plants were lower, but proline content and SOD, POD, and CAT activities were higher than those in wild-type plants. These results suggest that the salt tolerance of transgenic alfalfa was improved by the overexpression of the SeNHX1 gene.

  10. Effects of the weed density on grass yield of Alfalfa ( Medicago ...

    African Journals Online (AJOL)

    This study, in which the effects of different row spacing applications on weed density and on grass yield of Medicago sativa L. were investigated, was carried out in Van-Turkey from 2006 - 2008. Randomized blocks design was adopted with three replications. Row spacing applications of 20, 30, 40, 50, 60 and 70 cm were ...

  11. Cytotoxicity and apoptosis induced by alfalfa (Medicago sativa) leaf extracts in sensitive and multidrug-resistant tumor cells.

    Science.gov (United States)

    Gatouillat, Grégory; Magid, Abdulmagid Alabdul; Bertin, Eric; Okiemy-Akeli, Marie-Genevieve; Morjani, Hamid; Lavaud, Catherine; Madoulet, Claudie

    2014-01-01

    Alfalfa (Medicago sativa) has been used to cure a wide variety of ailments. However, only a few studies have reported its anticancer effects. In this study, extracts were obtained from alfalfa leaves and their cytotoxic effects were assessed on several sensitive and multidrug-resistant tumor cells lines. Using the mouse leukaemia P388 cell line and its doxorubicin-resistant counterpart (P388/DOX), we showed that the inhibition of cell growth induced by alfalfa leaf extracts was mediated through the induction of apoptosis, as evidenced by DNA fragmentation analysis. The execution of programmed cell death was achieved via the activation of caspase-3, leading to PARP cleavage. Fractionation of toluene extract (To-1), the most active extract obtained from crude extract, led to the identification of 3 terpene derivatives and 5 flavonoids. Among them, (-)-medicarpin, (-)-melilotocarpan E, millepurpan, tricin, and chrysoeriol showed cytotoxic effects in P388 as well as P388/DOX cells. These results demonstrate that alfalfa leaf extract may have interesting potential in cancer chemoprevention and therapy.

  12. The thiol compounds glutathione and homoglutathione differentially affect cell development in alfalfa (Medicago sativa L.).

    Science.gov (United States)

    Pasternak, Taras; Asard, Han; Potters, Geert; Jansen, Marcel A K

    2014-01-01

    Glutathione (GSH) is an important scavenger of Reactive Oxygen Species (ROS), precursor of metal chelating phytochelatins, xenobiotic defence compound and regulator of cell proliferation. Homoglutathione (hGSH) is a GSH homologue that is present in several taxa in the family of Fabaceae. It is thought that hGSH performs many of the stress-defence roles typically ascribed to GSH, yet little is known about the potential involvement of hGSH in controlling cell proliferation. Here we show that hGSH/GSH ratios vary across organs and cells and that these changes in hGSH/GSH ratio occur during dedifferentiation and/or cell cycle activation events. The use of a GSH/hGSH biosynthesis inhibitor resulted in impaired cytokinesis in isolated protoplasts, showing the critical importance of these thiol-compounds for cell division. However, exposure of isolated protoplasts to exogenous GSH accelerated cytokinesis, while exogenous hGSH was found to inhibit the same process. We conclude that GSH and hGSH have distinct functional roles in cell cycle regulation in Medicago sativa L. GSH is associated with meristemic cells, and promotes cell cycle activation and induction of somatic embryogenesis, while hGSH is associated with differentiated cells and embryo proliferation. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  13. [Determination of Hard Rate of Alfalfa (Medicago sativa L.) Seeds with Near Infrared Spectroscopy].

    Science.gov (United States)

    Wang, Xin-xun; Chen, Ling-ling; Zhang, Yun-wei; Mao, Pei-sheng

    2016-03-01

    Alfalfa (Medicago sativa L.) is the most commonly grown forage crop due to its better quality characteristics and high adaptability in China. However, there was 20%-80% hard seeds in alfalfa which could not be identified easily from non hard seeds which would cause the loss of seed utilization value and plant production. This experiment was designed for 121 samples of alfalfa. Seeds were collected according to different regions, harvested year and varieties. 31 samples were artificial matched as hard rates ranging from 20% to 80% to establish a model for hard seed rate by near infrared spectroscopy (NIRS) with Partial Least Square (PLS). The objective of this study was to establish a model and to estimate the efficiency of NIRS for determining hard rate of alfalfa seeds. The results showed that the correlation coefficient (R2(cal)) of calibration model was 0.981 6, root mean square error of cross validation (RMSECV) was 5.32, and the ratio of prediction to deviation (RPD) was 3.58. The forecast model in this experiment presented the satisfied precision. The proposed method using NIRS technology is feasible for identification and classification of hard seed in alfalfa. A new method, as nondestructive testing of hard seed rate, was provided to theoretical basis for fast nondestructive detection of hard seed rates in alfalfa.

  14. Soil bulk electrical resistivity and forage ground cover: nonlinear models in an alfalfa (Medicago sativa L. case study

    Directory of Open Access Journals (Sweden)

    Roberta Rossi

    2015-12-01

    Full Text Available Alfalfa is a highly productive and fertility-building forage crop; its performance, can be highly variable as influenced by within-field soil spatial variability. Characterising the relations between soil and forage- variation is important for optimal management. The aim of this work was to model the relationship between soil electrical resistivity (ER and plant productivity in an alfalfa (Medicago sativa L. field in Southern Italy. ER mapping was accomplished by a multi-depth automatic resistivity profiler. Plant productivity was assessed through normalised difference vegetation index (NDVI at 2 dates. A non-linear relationship between NDVI and deep soil ER was modelled within the framework of generalised additive models. The best model explained 70% of the total variability. Soil profiles at six locations selected along a gradient of ER showed differences related to texture (ranging from clay to sandy-clay loam, gravel content (0 to 55% and to the presence of a petrocalcic horizon. Our results prove that multi-depth ER can be used to localise permanent soil features that drive plant productivity.

  15. The arbuscular mycorrhizal fungus Glomus mosseae gives contradictory effects on phosphorus and arsenic acquisition by Medicago sativa Linn

    International Nuclear Information System (INIS)

    Chen Baodong; Xiao Xueyi; Zhu Yongguan; Smith, F. Andrew; Miao Xie, Z.; Smith, Sally E.

    2007-01-01

    Mycorrhizal fungi may play an important role in protecting plants against arsenic (As) contamination. However, little is known about the direct and indirect involvement of arbuscular mycorrhizal fungi (AMF) in detoxification mechanisms. A compartmented pot cultivation system ('cross-pots') is used here to investigate the roles of AMF Glomus mosseae in plant phosphorus (P) and As acquisition by Medicago sativa, and P-As interactions. The results indicate that fungal colonization dramatically increased plant dry weight by a factor of around 6, and also substantially increased both plant P and As contents (i.e. total uptake). Irrespective of P and As addition levels, AM plants had shoot and root P concentrations 2 fold higher, but As concentrations significantly lower, than corresponding uninoculated controls. The decreased shoot As concentrations were largely due to 'dilution effects' that resulted from stimulated growth of AM plants and reduced As partitioning to shoots. The study provides further evidence for the protective effects of AMF on host plants against As contamination, and have uncovered key aspects of underlying mechanisms. The possible application of AMF in remediation practices is discussed

  16. Cell suspension culture and mutants selection for resistance to PEG induced water stress in alfalfa (Medicago sativa L.)

    International Nuclear Information System (INIS)

    Zhang Xiaodong; Lin Tingan

    1994-01-01

    Elements affecting suspension cell culture in alfalfa (Medicago sativa L.) were studied and a method of rapid establishment of embryogenic suspension cell lines was introduced. Effects of γ ray irradiation on the growth of suspension cells were studied, and the optimum dose of irradiation for inducing mutants from suspension cells was about 20 ∼ 60 Gy. Effects of PEG and NaCl induced water stress on the growth of suspension cells were also investigated, and the results showed that the congregants of preliminary suspension culture were more susceptible than the established suspension cell lines. With 20 Gy of γ ray irradiation on suspension cell line (JL416), six clones were obtained with 70 days of selection on medium of 15% PEG (about-11 bar). A number of regenerated plants were obtained from these clones. One clone was also gained from medium containing 20% PEG (about-15 bar). The selected mutant cell lines (JP15 and JP20) has strong resistances to high concentration of PEG and NaCl induced water stress

  17. Concerted changes in N and C primary metabolism in alfalfa (Medicago sativa) under water restriction.

    Science.gov (United States)

    Aranjuelo, Iker; Tcherkez, Guillaume; Molero, Gemma; Gilard, Françoise; Avice, Jean-Christophe; Nogués, Salvador

    2013-02-01

    Although the mechanisms of nodule N(2) fixation in legumes are now well documented, some uncertainty remains on the metabolic consequences of water deficit. In most cases, little consideration is given to other organs and, therefore, the coordinated changes in metabolism in leaves, roots, and nodules are not well known. Here, the effect of water restriction on exclusively N(2)-fixing alfalfa (Medicago sativa L.) plants was investigated, and proteomic, metabolomic, and physiological analyses were carried out. It is shown that the inhibition of nitrogenase activity caused by water restriction was accompanied by concerted alterations in metabolic pathways in nodules, leaves, and roots. The data suggest that nodule metabolism and metabolic exchange between plant organs nearly reached homeostasis in asparagine synthesis and partitioning, as well as the N demand from leaves. Typically, there was (i) a stimulation of the anaplerotic pathway to sustain the provision of C skeletons for amino acid (e.g. glutamate and proline) synthesis; (ii) re-allocation of glycolytic products to alanine and serine/glycine; and (iii) subtle changes in redox metabolites suggesting the implication of a slight oxidative stress. Furthermore, water restriction caused little change in both photosynthetic efficiency and respiratory cost of N(2) fixation by nodules. In other words, the results suggest that under water stress, nodule metabolism follows a compromise between physiological imperatives (N demand, oxidative stress) and the lower input to sustain catabolism.

  18. Producción de biomasa aérea y uso equivalente de la tierra en intercultivos de alfalfa (Medicago sativa L.

    Directory of Open Access Journals (Sweden)

    T. W Pereyra

    Full Text Available Tradicionalmente, el incremento de la productividad se ha asociado al aumento del rendimiento a través del mejoramiento genético y las prácticas de manejo del cultivo. Sin embargo, si se considera la producción por unidad de área y de tiempo, el sistema de intercultivos puede ser otra forma de mejorar la rentabilidad. El objetivo del experimento fue determinar la biomasa producida y el uso equivalente de la tierra en monocultivo e intercultivos de alfalfa (Medicago sativa L. con sorgo sudán (Sorghum sudanense L. y avena (Avena sativa L.. Se determinó la biomasa aérea de todos los tratamientos (expresada por unidad de superficie y el uso equivalente de la tierra. El diseño fue completamente aleatorizado, dispuesto en bloques con dos repeticiones. Los resultados se sometieron a un ANOVA y las medias se compararon mediante la prueba de Duncan, a través del paquete estadístico INFOSTAT. El intercultivo alfalfa-sorgo triplicó la producción de alfalfa en relación con el monocultivo, mientras que alfalfa-avena no superó la producción de alfalfa pura en los meses de invierno. El intercultivo alfalfa-sorgo fue un 57 % más eficiente en el uso de la tierra que sus respectivos monocultivos, mientras que alfalfa-avena no logró superar la unidad.

  19. Evaluation of microbial biomass C and N content of the soils cultivated with vetch (Vicia sativa L. and alfalfa (Medicago sativa L.

    Directory of Open Access Journals (Sweden)

    İlyas Bolat

    2016-01-01

    Full Text Available Legume forage crops have the ability of retaining free nitrogen in the air through symbiotic Rhizobium bacteria found in their roots. Additionally, microbial biomass (MB–an essential living component of soil and a significant factor influencing plant nutrient dynamics–is considered to be accurate indicator of soil’s biological condition. Given the aforementioned aspects, soil MB C (Cmic and MB N (Nmic of different legume forage crops were investigated in this study. Soil samples were taken in order to identify certain physical and chemical characteristics of the soil using volume cylinders (0 – 6.5 cm depth from Vicia sativa L. (VSP and Medicago sativa L. planted (MSP areas. To determine the Cmic and Nmic contents, topsoil samples were also taken from 0 – 6.5 cm depth. Cmic and Nmic contents were identified using chloroform – fumigation – extraction method. There was no statistical significance for particle density, bulk density, electrical conductivity, CaCO3 %, and decomposition ratio (Corg/Ntotal of the VSP and MSP soil (P > 0.05. However, some other soil characteristics such as temperature, porosity, sand, silt and clay contents, pH, organic C and total N differed significantly (P < 0.05. Compared to VSP soil, the Cmic contents were determined to be 27 % higher (P < 0.05 in MSP soil. In VSP soil, the soil Nmic content ranged from 83.38 µg g-1 to 124.67 µg g-1, while it ranged from 91.62 µg g-1 to 187.07 µg g-1 in MSP soil. The Nmic content of the MSP soil was observed to be approximately 35 % higher than VSP soil, and a statistically significant difference (P < 0.05 was noticed between the two. Moreover, a significant positive correlation was found not only between the Cmic and organic C contents (r = 0.667; P < 0.05 but also between the Nmic and total N contents of MSP and VSP soil (r = 0.881; P < 0.01. The results of the study revealed that soil Cmic and Nmic values differ as the types of planted legume forage crops

  20. The arbuscular mycorrhizal fungus Glomus mosseae gives contradictory effects on phosphorus and arsenic acquisition by Medicago sativa Linn

    Energy Technology Data Exchange (ETDEWEB)

    Chen Baodong [Department of Soil Environmental Sciences/State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Xiao Xueyi [Department of Soil Environmental Sciences/State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Zhu Yongguan [Department of Soil Environmental Sciences/State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China)]. E-mail: ygzhu@rcees.ac.en; Smith, F. Andrew [Soil and Land Systems, School of Earth and Environmental Sciences, Waite Campus, University of Adelaide, South Australia 5005 (Australia); Miao Xie, Z. [Department of Environmental Science and Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Smith, Sally E. [Soil and Land Systems, School of Earth and Environmental Sciences, Waite Campus, University of Adelaide, South Australia 5005 (Australia)

    2007-07-01

    Mycorrhizal fungi may play an important role in protecting plants against arsenic (As) contamination. However, little is known about the direct and indirect involvement of arbuscular mycorrhizal fungi (AMF) in detoxification mechanisms. A compartmented pot cultivation system ('cross-pots') is used here to investigate the roles of AMF Glomus mosseae in plant phosphorus (P) and As acquisition by Medicago sativa, and P-As interactions. The results indicate that fungal colonization dramatically increased plant dry weight by a factor of around 6, and also substantially increased both plant P and As contents (i.e. total uptake). Irrespective of P and As addition levels, AM plants had shoot and root P concentrations 2 fold higher, but As concentrations significantly lower, than corresponding uninoculated controls. The decreased shoot As concentrations were largely due to 'dilution effects' that resulted from stimulated growth of AM plants and reduced As partitioning to shoots. The study provides further evidence for the protective effects of AMF on host plants against As contamination, and have uncovered key aspects of underlying mechanisms. The possible application of AMF in remediation practices is discussed.

  1. Allelopathic Potential of Switchgrass ( Panicum virgatum L.) on Perennial Ryegrass ( Lolium perenne L.) and Alfalfa ( Medicago sativa L.)

    Science.gov (United States)

    Shui, Junfeng; An, Yu; Ma, Yongqing; Ichizen, Nobumasa

    2010-10-01

    This study investigated allelopathy and its chemical basis in nine switchgrass ( Panicum virgatum L.) accessions. Perennial ryegrass ( Lolium perenne L.) and alfalfa ( Medicago sativa L.) were used as test species. Undiluted aqueous extracts (5 g plant tissue in 50 ml water) from the shoots and roots of most of the switchgrass accessions inhibited the germination and growth of the test species. However, the allelopathic effect of switchgrass declined when extracts were diluted 5- or 50-fold. Seedling growth was more sensitive than seed germination as an indicator of allelopathic effect. Allelopathic effect was related to switchgrass ecotype but not related to ploidy level. Upland accessions displayed stronger allelopathic potential than lowland accessions. The aqueous extract from one switchgrass accession was separated into phenols, organic acids, neutral chemicals, and alkaloids, and then these fractions were bioassayed to test for allelopathic potential. Alkaloids had the strongest allelopathic effect among the four chemical fractions. In summary, the results indicated that switchgrass has allelopathic potential; however, there is not enough evidence to conclude that allelopathic advantage is the main factor that has contributed to the successful establishment of switchgrass on China’s Loess Plateau.

  2. Speciation Matters: Bioavailability of Silver and Silver Sulfide Nanoparticles to Alfalfa (Medicago sativa).

    Science.gov (United States)

    Stegemeier, John P; Schwab, Fabienne; Colman, Benjamin P; Webb, Samuel M; Newville, Matthew; Lanzirotti, Antonio; Winkler, Christopher; Wiesner, Mark R; Lowry, Gregory V

    2015-07-21

    Terrestrial crops are directly exposed to silver nanoparticles (Ag-NPs) and their environmentally transformed analog silver sulfide nanoparticles (Ag2S-NPs) when wastewater treatment biosolids are applied as fertilizer to agricultural soils. This leads to a need to understand their bioavailability to plants. In the present study, the mechanisms of uptake and distribution of silver in alfalfa (Medicago sativa) were quantified and visualized upon hydroponic exposure to Ag-NPs, Ag2S-NPs, and AgNO3 at 3 mg total Ag/L. Total silver uptake was measured in dried roots and shoots, and the spatial distribution of elements was investigated using transmission electron microscopy (TEM) and synchrotron-based X-ray imaging techniques. Despite large differences in release of Ag(+) ions from the particles, Ag-NPs, Ag2S-NPs, and Ag(+) became associated with plant roots to a similar degree, and exhibited similarly limited (<1%) amounts of translocation of silver into the shoot system. X-ray fluorescence (XRF) mapping revealed differences in the distribution of Ag into roots for each treatment. Silver nanoparticles mainly accumulated in the (columella) border cells and elongation zone, whereas Ag(+) accumulated more uniformly throughout the root. In contrast, Ag2S-NPs remained largely adhered to the root exterior, and the presence of cytoplasmic nano-SixOy aggregates was observed. Exclusively in roots exposed to particulate silver, NPs smaller than the originally dosed NPs were identified by TEM in the cell walls. The apparent accumulation of Ag in the root apoplast determined by XRF, and the presence of small NPs in root cell walls suggests uptake of partially dissolved NPs and translocation along the apoplast.

  3. Development of manganese toxicity in pasture legumes under extreme climatic conditions. [Trifolium subterraneum; Medicago sativa; Brassica campestris

    Energy Technology Data Exchange (ETDEWEB)

    Siman, A; Cradock, F W; Hudson, A W

    1974-08-01

    Manganese levels and pH in soil were measured on limed and unlimed plots at bi-monthly intervals for two years at five field sites with lucerne (Medicago sativa) and subterranean clover (Trifolium subterraneum) and related to rainfall and temperature. Pot experiments with lucerne, subterranean clover and rape (Brassica campestris) were used to confirm the results of the field experiments. Manganese toxicity developed in lucerne and subterranean clover under waterlogged conditions after heavy rain on the slightly acid soils (pH 4.7-5.5). Lucerne also showed manganese toxicity on the same soils in summer after extended hot, dry conditions. The maximum available manganese was 210 ..mu..g/g in the waterlogged soil (0-15 cm) the 128 ..mu..g/g in the heat affected soil. Lime treatment of 2240 kg/ha reduced the maximum available manganese to 148 ..mu..g/g in waterlogged plots and to 47 ..mu..g/g in the heat affected plots but failed to correct manganese toxicity. However, lime corrected toxicity symptoms under less severe conditions. In the pot experiments, available manganese reached 270 ..mu..g/g after 2 weeks artificial waterlogging and 68 ..mu..g/g after 2 weeks dry heat exposure. 12 references, 4 figures, 3 tables.

  4. In vitro regeneration of some Iranian alfalfa (Medicago sativa L. genotypes via somatic embryogenesis

    Directory of Open Access Journals (Sweden)

    Majid Shokrpour

    2014-12-01

    Full Text Available An effective in vitro regeneration system is one of the prerequisites for genetic manipulation of alfalfa (Medicago sativa L. varieties and genotypes. In this research, somatic embryogenesis of four alfalfa genotypes, 6-18 (synthetic, 4-14 (Kara Yonje- Karakozlu, 3-27 (Kara Yonje Maraghe and y-6 (Regen-SY, were investigated using leaf and petiole explants. Formation of callus and somatic embryogenesis was significantly influenced by the explant type and interaction of genotype and culture medium. Petiole explants of genotype 4-14 produced the highest yield of callus (0.406 gr fresh weight of callus. Percentage of somatic embryogenesis and the number of embryos per callus in petiole explants of genotype 4-14 was higher than those of other genotypes and explants. In genotype 6-18, the highest percentage of somatic embryogenesis was achieved on MS medium containing 5 mg/L 2,4-D and 2 mg/L kinetin. There was no significant differences between genotypes and explants in terms of embryo conversion to plantlet, and on average, 58% of somatic embryos converted to plantlet on MS medium. The petiole explants of genotype 6-18 did not exhibit somatic embryogenesis response in medium containing low ratio of 2,4-D:Kinetin (5 mg/L 2,4-D and 2 mg/L kinetin. While, these explants showed somatic embryogenesis in higher ratio of 2,4-D:Kinetin (5:1. The plantlet conversion efficiency of somatic embryos produced through this study was relatively higher and therefore, the method presented in this study could be used in alfalfa genetic manipulation and molecular studies.

  5. Increase in 4-coumaryl alcohol units during lignification in alfalfa (Medicago sativa) alters the extractability and molecular weight of lignin.

    Science.gov (United States)

    Ziebell, Angela; Gracom, Kristen; Katahira, Rui; Chen, Fang; Pu, Yunqiao; Ragauskas, Art; Dixon, Richard A; Davis, Mark

    2010-12-10

    The lignin content of biomass can impact the ease and cost of biomass processing. Lignin reduction through breeding and genetic modification therefore has potential to reduce costs in biomass-processing industries (e.g. pulp and paper, forage, and lignocellulosic ethanol). We investigated compositional changes in two low-lignin alfalfa (Medicago sativa) lines with antisense down-regulation of p-coumarate 3-hydroxylase (C3H) or hydroxycinnamoyl-CoA:shikimate hydroxycinnamoyltransferase (HCT). We investigated whether the difference in reactivity during lignification of 4-coumaryl alcohol (H) monomers versus the naturally dominant sinapyl alcohol and coniferyl alcohol lignin monomers alters the lignin structure. Sequential base extraction readily reduced the H monomer content of the transgenic lines, leaving a residual lignin greatly enriched in H subunits; the extraction profile highlighted the difference between the control and transgenic lines. Gel permeation chromatography of isolated ball-milled lignin indicated significant changes in the weight average molecular weight distribution of the control versus transgenic lines (CTR1a, 6000; C3H4a, 5500; C3H9a, 4000; and HCT30a, 4000).

  6. Over-Expression of Arabidopsis EDT1 Gene Confers Drought Tolerance in Alfalfa (Medicago sativa L.

    Directory of Open Access Journals (Sweden)

    Guangshun Zheng

    2017-12-01

    Full Text Available Alfalfa (Medicago sativa L. is an important legume forage crop with great economic value. However, as the growth of alfalfa is seriously affected by an inadequate supply of water, drought is probably the major abiotic environmental factor that most severely affects alfalfa production worldwide. In an effort to enhance alfalfa drought tolerance, we transformed the Arabidopsis Enhanced Drought Tolerance 1 (AtEDT1 gene into alfalfa via Agrobacterium-mediated transformation. Compared with wild type plants, drought stress treatment resulted in higher survival rates and biomass, but reduced water loss rates in the transgenic plants. Furthermore, transgenic alfalfa plants had increased stomatal size, but reduced stomatal density, and these stomatal changes contributed greatly to reduced water loss from leaves. Importantly, transgenic alfalfa plants exhibited larger root systems with larger root lengths, root weight, and root diameters than wild type plants. The transgenic alfalfa plants had reduced membrane permeability and malondialdehyde content, but higher soluble sugar and proline content, higher superoxide dismutase activity, higher chlorophyll content, enhanced expression of drought-responsive genes, as compared with wild type plants. Notably, transgenic alfalfa plants grew better in a 2-year field trial and showed enhanced growth performance with increased biomass yield. All of our morphological, physiological, and molecular analyses demonstrated that the ectopic expression of AtEDT1 improved growth and enhanced drought tolerance in alfalfa. Our study provides alfalfa germplasm for use in forage improvement programs, and may help to increase alfalfa production in arid lands.

  7. Strontium-90 in alfalfa (Medicago sativa) around the Hanford site in southeastern Washington state: an evaluation of surveillance data

    International Nuclear Information System (INIS)

    Poston, T.M.; Jaquish, R.E.; Antonio, E.J.; Patton, G.W.

    1998-01-01

    From 1988–1994, 90 Sr concentrations in alfalfa (Medicago sativa) grown in areas receiving irrigation water from the Columbia River downstream of Hanford have exceeded concentrations observed in alfalfa grown nearby using other irrigation water sources. Surveillance data indicate that the relationship is not linked to atmospheric releases from Hanford. Attributing the apparent differences in 90 Sr concentrations to irrigation water is equivocal. Evaluations of 90 Sr in Columbia River water fail to consistently show a statistically significant (P > 0.05) contribution at locations immediately downstream of Hanford. Modeling of past 90 Sr fallout accumulation in soil indicates that the potential contribution from Hanford liquid effluents entering the Columbia River, subsequently used as irrigation water from 1972 to 1992, would account for ~ 2% of 90 Sr in soil. The remaining 98% arises from historic atomic weapons testing fallout. Radiological doses modeled for an alfalfa-cow's milk-human pathway indicate that the maximum 50 year effective dose equivalent to a standard man who consumes 270 l of milk per year was 0.9 μSv, which is < 0.03% of the 3 mSv annual dose resulting from natural sources of radiation exposure

  8. Low-fiber alfalfa (Medicago sativa L.) meal in the laying hen diet: effects on productive traits and egg quality.

    Science.gov (United States)

    Laudadio, V; Ceci, E; Lastella, N M B; Introna, M; Tufarelli, V

    2014-07-01

    This study was designed to determine the effects on laying performance and egg quality resulting from partial substitution of soybean meal (SBM) with low-fiber alfalfa (LFA; Medicago sativa L.) meal in the diet of early-phase laying hens. ISA Brown layers, 18 wk of age, were randomly allocated to 2 dietary treatments and fed for 10 wk. The hens were fed 2 wheat middling-based diets: a control diet, which contained SBM (15% of diet), and a test diet containing LFA (15% of diet) as the main protein source. Low-fiber alfalfa meal was obtained by a combination of sieving and air-classification processes. Feed intake was recorded daily, and egg production was calculated on a hen-day basis; eggs from each group were weekly collected to evaluate egg components and quality. The partial substitution of SBM with LFA had no adverse effect on growth performance of early-phase laying hens. Egg production and none of the egg-quality traits examined were influenced by dietary treatment, except for yolk color (P alfalfa meal in the laying-hen diet can positively influence yolk quality without adversely affecting productive traits. © 2014 Poultry Science Association Inc.

  9. Proteomic Identification of Differentially Expressed Proteins during Alfalfa (Medicago sativa L.) Flower Development.

    Science.gov (United States)

    Chen, Lingling; Chen, Quanzhu; Zhu, Yanqiao; Hou, Longyu; Mao, Peisheng

    2016-01-01

    Flower development, pollination, and fertilization are important stages in the sexual reproduction process of plants; they are also critical steps in the control of seed formation and development. During alfalfa ( Medicago sativa L.) seed production, some distinct phenomena such as a low seed setting ratio, serious flower falling, and seed abortion commonly occur. However, the causes of these phenomena are complicated and largely unknown. An understanding of the mechanisms that regulate alfalfa flowering is important in order to increase seed yield. Hence, proteomic technology was used to analyze changes in protein expression during the stages of alfalfa flower development. Flower samples were collected at pre-pollination (S1), pollination (S2), and the post-pollination senescence period (S3). Twenty-four differentially expressed proteins were successfully identified, including 17 down-regulated in pollinated flowers, one up-regulated in pollinated and senesced flowers, and six up-regulated in senesced flowers. The largest proportions of the identified proteins were involved in metabolism, signal transduction, defense response, oxidation reduction, cell death, and programmed cell death (PCD). Their expression profiles demonstrated that energy metabolism, carbohydrate metabolism, and amino acid metabolism provided the nutrient foundation for pollination in alfalfa. Furthermore, there were three proteins involved in multiple metabolic pathways: dual specificity kinase splA-like protein (kinase splALs), carbonic anhydrase, and NADPH: quinone oxidoreductase-like protein. Expression patterns of these proteins indicated that MAPK cascades regulated multiple processes, such as signal transduction, stress response, and cell death. PCD also played an important role in the alfalfa flower developmental process, and regulated both pollination and flower senescence. The current study sheds some light on protein expression profiles during alfalfa flower development and

  10. STUDY ON PHYTOEXTRACTION BALANCE OF ZN, CD, PB FROM MINE-WASTE POLLUTED SOILS BY USING MEDICAGO SATIVA AND TRIFOLIUM PRATENSE SPECIES

    Directory of Open Access Journals (Sweden)

    B. LIXANDRU

    2009-05-01

    Full Text Available For a term of two years was studied phytoextractive potential of Zn, Cd and Pb using successive culture of alfalfa (Medicago sativa and red clover (Trifolium pratense. In the experimental plot was incorporated a quantity of 20 kg mine waste per square meter, providing in soil 1209 mg Zn/kg d.s., 4.70 mg Cd/kg d.s. and 188.2 mg Pb/kg d.s. The metals content accumulated in plants was determined at the two moments of biomass harvesting, and through balance calculations we could establish the phytoextraction efficiency of the two forage-grasses species. The obtained results indicate that both perennial forage-legumes species have a good phytoextractive capacity and tolerance for Zn and Pb, especially Trifolium pratense specie. By using this species as phytoextractors on soil polluted with 3.76 times more Pb and 4.03 times more Zn, is provided the reduction of metallic ions concentration in soil to limits admitted by laws in a period of 3, respectively, 4 years.

  11. Identification of molecular markers associated with Verticillium wilt resistance in alfalfa (Medicago sativa L.) using high-resolution melting.

    Science.gov (United States)

    Zhang, Tiejun; Yu, Long-Xi; McCord, Per; Miller, David; Bhamidimarri, Suresh; Johnson, David; Monteros, Maria J; Ho, Julie; Reisen, Peter; Samac, Deborah A

    2014-01-01

    Verticillium wilt, caused by the soilborne fungus, Verticillium alfalfae, is one of the most serious diseases of alfalfa (Medicago sativa L.) worldwide. To identify loci associated with resistance to Verticillium wilt, a bulk segregant analysis was conducted in susceptible or resistant pools constructed from 13 synthetic alfalfa populations, followed by association mapping in two F1 populations consisted of 352 individuals. Simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) markers were used for genotyping. Phenotyping was done by manual inoculation of the pathogen to replicated cloned plants of each individual and disease severity was scored using a standard scale. Marker-trait association was analyzed by TASSEL. Seventeen SNP markers significantly associated with Verticillium wilt resistance were identified and they were located on chromosomes 1, 2, 4, 7 and 8. SNP markers identified on chromosomes 2, 4 and 7 co-locate with regions of Verticillium wilt resistance loci reported in M. truncatula. Additional markers identified on chromosomes 1 and 8 located the regions where no Verticillium resistance locus has been reported. This study highlights the value of SNP genotyping by high resolution melting to identify the disease resistance loci in tetraploid alfalfa. With further validation, the markers identified in this study could be used for improving resistance to Verticillium wilt in alfalfa breeding programs.

  12. A saturated genetic linkage map of autotetraploid alfalfa (Medicago sativa L.) developed using genotyping-by-sequencing is highly syntenous with the Medicago truncatula genome.

    Science.gov (United States)

    Li, Xuehui; Wei, Yanling; Acharya, Ananta; Jiang, Qingzhen; Kang, Junmei; Brummer, E Charles

    2014-08-21

    A genetic linkage map is a valuable tool for quantitative trait locus mapping, map-based gene cloning, comparative mapping, and whole-genome assembly. Alfalfa, one of the most important forage crops in the world, is autotetraploid, allogamous, and highly heterozygous, characteristics that have impeded the construction of a high-density linkage map using traditional genetic marker systems. Using genotyping-by-sequencing (GBS), we constructed low-cost, reasonably high-density linkage maps for both maternal and paternal parental genomes of an autotetraploid alfalfa F1 population. The resulting maps contain 3591 single-nucleotide polymorphism markers on 64 linkage groups across both parents, with an average density of one marker per 1.5 and 1.0 cM for the maternal and paternal haplotype maps, respectively. Chromosome assignments were made based on homology of markers to the M. truncatula genome. Four linkage groups representing the four haplotypes of each alfalfa chromosome were assigned to each of the eight Medicago chromosomes in both the maternal and paternal parents. The alfalfa linkage groups were highly syntenous with M. truncatula, and clearly identified the known translocation between Chromosomes 4 and 8. In addition, a small inversion on Chromosome 1 was identified between M. truncatula and M. sativa. GBS enabled us to develop a saturated linkage map for alfalfa that greatly improved genome coverage relative to previous maps and that will facilitate investigation of genome structure. GBS could be used in breeding populations to accelerate molecular breeding in alfalfa. Copyright © 2014 Li et al.

  13. Effects of compost organic amendments on chemical composition and in vitro digestibility of alfalfa (Medicago sativa L.

    Directory of Open Access Journals (Sweden)

    Francesco Montemurro

    2010-01-01

    Full Text Available The following fertiliser treatments were compared during the years 2002 and 2003 on alfalfa forage (Medicago sativa L.: compost obtained from the organic fraction of the Municipal Solid Waste (MSW; olive pomace compost (OPC; mineral fertiliser (Min. All the treatments allowed a distribution of 75kg ha-1 of P2O5. Three cuttings occurred: at 168, 206 and 351 days after compost application (DAA in 2002; 119, 152 and 320 DAA in 2003. Cumulative biomass and dry matter yields were measured during each experimental year. Furthermore, chemical composition and in vitro digestibility of dry matter (DMd, organic matter (OMd, crude protein (CPd and NDF (NDFd were determined. MSW treatment showed a significantly (P<0.01 higher content of ADL than OPC and Min (77.0, 66.0 and 65.0g kg-1 DM, respectively. Fertiliser treatments also affected (P<0.01 digestibility parameters. In fact, DMd and OMd values showed the same trend with lower percentages in MSW treatment than in the OPC and Min ones. The NDFd differed in all treatments having the highest value in OPC (40.1%. The results indicated that the soil distribution of organic materials offer the possibility to reduce the application of mineral fertilisers and production costs without decreasing alfalfa yield, forage chemical composition and in vitro digestibility.

  14. Complete nucleotide sequence of Alfalfa mosaic virus isolated from alfalfa (Medicago sativa L.) in Argentina.

    Science.gov (United States)

    Trucco, Verónica; de Breuil, Soledad; Bejerman, Nicolás; Lenardon, Sergio; Giolitti, Fabián

    2014-06-01

    The complete nucleotide sequence of an Alfalfa mosaic virus (AMV) isolate infecting alfalfa (Medicago sativa L.) in Argentina, AMV-Arg, was determined. The virus genome has the typical organization described for AMV, and comprises 3,643, 2,593, and 2,038 nucleotides for RNA1, 2 and 3, respectively. The whole genome sequence and each encoding region were compared with those of other four isolates that have been completely sequenced from China, Italy, Spain and USA. The nucleotide identity percentages ranged from 95.9 to 99.1 % for the three RNAs and from 93.7 to 99 % for the protein 1 (P1), protein 2 (P2), movement protein and coat protein (CP) encoding regions, whereas the amino acid identity percentages of these proteins ranged from 93.4 to 99.5 %, the lowest value corresponding to P2. CP sequences of AMV-Arg were compared with those of other 25 available isolates, and the phylogenetic analysis based on the CP gene was carried out. The highest percentage of nucleotide sequence identity of the CP gene was 98.3 % with a Chinese isolate and 98.6 % at the amino acid level with four isolates, two from Italy, one from Brazil and the remaining one from China. The phylogenetic analysis showed that AMV-Arg is closely related to subgroup I of AMV isolates. To our knowledge, this is the first report of a complete nucleotide sequence of AMV from South America and the first worldwide report of complete nucleotide sequence of AMV isolated from alfalfa as natural host.

  15. Alfalfa (Medicago sativa L.) shoot saponins: identification and bio-activity by the assessment of aphid feeding.

    Science.gov (United States)

    Mazahery-Laghab, H; Yazdi-Samadi, B; Bagheri, M; Bagheri, A R

    2011-01-01

    Biochemical components in alfalfa (Medicago sativa L.), such as saponins, can act as protecting factors against bio-stresses. Saponins are also antifeedants and show oral toxicity towards higher and lower animals. Changes in saponins, such as variation in the carbon skeleton, or hydrolysis of saponin glycosides and other conjugates, may change their biological effects. The aims of this research were to study saponin variation in different growth stages of alfalfa and to investigate the biological role of saponins in the spotted alfalfa aphid, Therioaphis maculata. Saponins from alfalfa shoots in different growth stages were extracted, chemically purified and analysed by TLC. Specific saponins such as soyasaponin1 from root and shoot and two bisdesmosides of medicagenic acid, one from shoot and another from root tissues, were identified using reference compounds allowing changes in saponin composition during plant development in different shoot tissues of alfalfa to be assessed. The response of the alfalfa aphid to feeding on alfalfa in different growth stages was studied. No significant difference in the survival of aphids, from neonate to adult, was observed, but due to the antibiotic effects of saponins, two differences were found in the onset of nymph production and cumulative nymph production. The results show that the saponin composition in alfalfa changes with plant development and this, in turn, can often negatively affect the development of specific insect pests such as the spotted alfalfa aphid, suggesting a possible biological role of alfalfa saponins.

  16. Genome-Wide Association Study Identifies Loci for Salt Tolerance during Germination in Autotetraploid Alfalfa (Medicago sativa L.) Using Genotyping-by-Sequencing

    Science.gov (United States)

    Yu, Long-Xi; Liu, Xinchun; Boge, William; Liu, Xiang-Ping

    2016-01-01

    Salinity is one of major abiotic stresses limiting alfalfa (Medicago sativa L.) production in the arid and semi-arid regions in US and other counties. In this study, we used a diverse panel of alfalfa accessions previously described by Zhang et al. (2015) to identify molecular markers associated with salt tolerance during germination using genome-wide association study (GWAS) and genotyping-by-sequencing (GBS). Phenotyping was done by germinating alfalfa seeds under different levels of salt stress. Phenotypic data of adjusted germination rates and SNP markers generated by GBS were used for marker-trait association. Thirty six markers were significantly associated with salt tolerance in at least one level of salt treatments. Alignment of sequence tags to the Medicago truncatula genome revealed genetic locations of the markers on all chromosomes except chromosome 3. Most significant markers were found on chromosomes 1, 2, and 4. BLAST search using the flanking sequences of significant markers identified 14 putative candidate genes linked to 23 significant markers. Most of them were repeatedly identified in two or three salt treatments. Several loci identified in the present study had similar genetic locations to the reported QTL associated with salt tolerance in M. truncatula. A locus identified on chromosome 6 by this study overlapped with that by drought in our previous study. To our knowledge, this is the first report on mapping loci associated with salt tolerance during germination in autotetraploid alfalfa. Further investigation on these loci and their linked genes would provide insight into understanding molecular mechanisms by which salt and drought stresses affect alfalfa growth. Functional markers closely linked to the resistance loci would be useful for MAS to improve alfalfa cultivars with enhanced resistance to drought and salt stresses. PMID:27446182

  17. Tolerancia experimental de las especies vegetales Nicotiana glauca, Jacaranda mimosifolia, Tecoma stans, Medicago sativa y Spinacea oleracea al boro, en Argentina

    Directory of Open Access Journals (Sweden)

    Marta L. de Viana

    2008-09-01

    Full Text Available La actividad de las industrias borateras constituye una fuente puntual y difusa de contaminación del aire, suelo y aguas superficiales y profundas. Por lo tanto, el estudio y experimentación acerca de las posibles formas de contrarrestar este impacto constituye una prioridad. Una técnica relativamente nueva para descontaminar suelos es la fitorremediación, que emplea plantas y microorganismos asociados. El primer paso es detectar las especies vegetales tolerantes, lo que constituye el objetivo de este trabajo. Se realizó un experimento en laboratorio para evaluar la germinación, la supervivencia y el crecimiento de distintas especies en diferentes concentraciones de boro. Al comienzo y al final del experimento se determinó la concentración de boro en el sustrato para cada tratamiento y para sustratos con y sin vegetación. Se encontraron diferencias significativas debidas al tratamiento, la especie y la interacción especie *tratamiento. M. sativa, N. glauca y J. mimosifolia fueron las especies de mayor tolerancia al boro. Las otras especies presentaron una disminución en todas las variables-respuesta en función de la concentración del contaminante. Todas presentaron una baja supervivencia en la máxima concentración. La disminución de boro fue máxima en el tratamiento de 30 ppm de boro con M. sativa y la menor se registró en los tratamiento de 20 ppm de boro con J. mimosifolia y de 30 ppm de boro con T. stans y S. oleraceae. Se concluye que N. glauca, M. sativa y J. mimosifolia podrían considerarse como prometedoras en remediación.Experimental tolerance to boron of the plant species Nicotiana glauca, Jacaranda mimosifolia, Tecoma stans, Medicago sativa y Spinacea oleracea in Argentina. The activity of boron industries is a punctual and diffuse source of air, soil and water pollution. Therefore, it is a priority to study possible ways of reducing this impact. A relatively new technology for reducing soil pollution is

  18. Identification of molecular markers associated with Verticillium wilt resistance in alfalfa (Medicago sativa L. using high-resolution melting.

    Directory of Open Access Journals (Sweden)

    Tiejun Zhang

    Full Text Available Verticillium wilt, caused by the soilborne fungus, Verticillium alfalfae, is one of the most serious diseases of alfalfa (Medicago sativa L. worldwide. To identify loci associated with resistance to Verticillium wilt, a bulk segregant analysis was conducted in susceptible or resistant pools constructed from 13 synthetic alfalfa populations, followed by association mapping in two F1 populations consisted of 352 individuals. Simple sequence repeat (SSR and single nucleotide polymorphism (SNP markers were used for genotyping. Phenotyping was done by manual inoculation of the pathogen to replicated cloned plants of each individual and disease severity was scored using a standard scale. Marker-trait association was analyzed by TASSEL. Seventeen SNP markers significantly associated with Verticillium wilt resistance were identified and they were located on chromosomes 1, 2, 4, 7 and 8. SNP markers identified on chromosomes 2, 4 and 7 co-locate with regions of Verticillium wilt resistance loci reported in M. truncatula. Additional markers identified on chromosomes 1 and 8 located the regions where no Verticillium resistance locus has been reported. This study highlights the value of SNP genotyping by high resolution melting to identify the disease resistance loci in tetraploid alfalfa. With further validation, the markers identified in this study could be used for improving resistance to Verticillium wilt in alfalfa breeding programs.

  19. Screening of Cd tolerant genotypes and isolation of metallothionein genes in alfalfa (Medicago sativa L.)

    International Nuclear Information System (INIS)

    Wang Xiaojuan; Song, Yu; Ma Yanhua; Zhuo Renying; Jin Liang

    2011-01-01

    In order to evaluate Cd tolerance in wide-ranging sources of alfalfa (Medicago sativa) and to identify Cd tolerant genotypes which may potentially be useful for restoring Cd-contaminated environments, thirty-six accessions of alfalfa were screened under hydroponic culture. Our results showed that the relative root growth rate varied from 0.48 to 1.0, which indicated that different alfalfa accessions had various responses to Cd stress. The candidate fragments derived from differentially expressed metallothionein (MT) genes were cloned from leaves of two Cd tolerant genotypes, YE and LZ. DNA sequence and the deduced protein sequence showed that MsMT2a and MsMT2b had high similarity to those in leguminous plants. DDRT-PCR analysis showed that MsMT2a expressed in both YE and LZ plants under control and Cd stress treatment, but MsMT2b only expressed under Cd stress treatment. This suggested that MsMT2a was universally expressed in leaves of alfalfa but expression of MsMT2b was Cadmium (Cd) inducible. - Highlights: → Evaluate Cd tolerance in wide sources of alfalfa accessions. → Identify Cd-hyperaccumulators potentially useful for restoring Cd-contaminated environments. → Cloned differentially expressed metallothionein (MT) genes. → Characteristics and deduced protein sequence of MsMT2a and MsMT2b were analyzed. → MsMT2a might be a universally gene of alfalfa but MsMT2b might be an inductive gene. - Two Cd tolerant alfalfa genotypes were screened and their metallothionein genes were cloned which showed that MsMT2a was universally expressed but MsMT2b was Cd inducible expression.

  20. Screening of Cd tolerant genotypes and isolation of metallothionein genes in alfalfa (Medicago sativa L.)

    Energy Technology Data Exchange (ETDEWEB)

    Wang Xiaojuan, E-mail: xiaojuanwang@lzu.edu.cn [School of Pastoral Agriculture Science and Technology, Lanzhou University, P.O. Box 61, Lanzhou 730020 (China); Song, Yu [School of Pastoral Agriculture Science and Technology, Lanzhou University, P.O. Box 61, Lanzhou 730020 (China); Environment Management College of China, Qinhuangdao 066004 (China); Ma Yanhua [Hebei Normal University of Science and Technology, Qinhuangdao 066004 (China); Zhuo Renying [Key Lab of Tree Genomics, Research Institute of Subtropical of Forest, Chinese Academy of Forest, Fuyang 311400 (China); Jin Liang [School of Pastoral Agriculture Science and Technology, Lanzhou University, P.O. Box 61, Lanzhou 730020 (China)

    2011-12-15

    In order to evaluate Cd tolerance in wide-ranging sources of alfalfa (Medicago sativa) and to identify Cd tolerant genotypes which may potentially be useful for restoring Cd-contaminated environments, thirty-six accessions of alfalfa were screened under hydroponic culture. Our results showed that the relative root growth rate varied from 0.48 to 1.0, which indicated that different alfalfa accessions had various responses to Cd stress. The candidate fragments derived from differentially expressed metallothionein (MT) genes were cloned from leaves of two Cd tolerant genotypes, YE and LZ. DNA sequence and the deduced protein sequence showed that MsMT2a and MsMT2b had high similarity to those in leguminous plants. DDRT-PCR analysis showed that MsMT2a expressed in both YE and LZ plants under control and Cd stress treatment, but MsMT2b only expressed under Cd stress treatment. This suggested that MsMT2a was universally expressed in leaves of alfalfa but expression of MsMT2b was Cadmium (Cd) inducible. - Highlights: > Evaluate Cd tolerance in wide sources of alfalfa accessions. > Identify Cd-hyperaccumulators potentially useful for restoring Cd-contaminated environments. > Cloned differentially expressed metallothionein (MT) genes. > Characteristics and deduced protein sequence of MsMT2a and MsMT2b were analyzed. > MsMT2a might be a universally gene of alfalfa but MsMT2b might be an inductive gene. - Two Cd tolerant alfalfa genotypes were screened and their metallothionein genes were cloned which showed that MsMT2a was universally expressed but MsMT2b was Cd inducible expression.

  1. Identification of sweet chesnut pollen in bee pollen pellet using using molecular analysis.

    Directory of Open Access Journals (Sweden)

    Jana Žiarovská

    2015-10-01

    Full Text Available Castanea sativa posses many characteristics that are used by human for different purposes, not only as a part of the food. One of them is the utilization of the sweet chesnut pollen for its pharmacological benefits. Actually, no information about the DNA based identification of the sweet chesnut exist. Here, an identification of Castanea sativa based on the specific DNA fragment amplification is described for the first time. Sweet chesnut identification was performed in the very complex sample of bee pollen pellets that were identified as to contain sweet chesnut pollen grains by morphological analysis. First, bioinformatic analysis was performed to find a Castanea sativa conservative part of galactol synthase gene. BLAST alignment of the CDS of GolS1 gene was performed by BLASTtn against plants nucleotide sequences in the NCBI database to ensure for the specifity or existing nucleotide differences. Then, specific primers were subsequently designed and PCR amplification was performed. All the PCRs have run in duplicates for pollen pellet sample and two independent samples of Castanea sativa pure pollen. Restriction cleavage of the PCR amplified fragment was performed to confirm the specifity of the obtained PCR product with the positive confirmation as the predicted three restriction fragments were obtained that fully correspond by the length to those from virtual clevage. Restriction endonuclease Hpy166II was used in restriction cleavage analysis. Castanea sativa pollen grains were confirmed reliable in multifloral pollen pellet by PCR and this approach has the potential to be used effectively for the authentication purposes of sweet chesnut.

  2. Medicago PhosphoProtein Database: a repository for Medicago truncatula phosphoprotein data

    Directory of Open Access Journals (Sweden)

    Christopher M. Rose

    2012-06-01

    Full Text Available The ability of legume crops to fix atmospheric nitrogen via a symbiotic association with soil rhizobia makes them an essential component of many agricultural systems. Initiation of this symbiosis requires protein phosphorylation-mediated signaling in response to rhizobial signals named Nod factors. Medicago truncatula (Medicago is the model system for studying legume biology, making the study of its phosphoproteome essential. Here, we describe the Medicago Phosphoprotein Database (http://phospho.medicago.wisc.edu, a repository built to house phosphoprotein, phosphopeptide, and phosphosite data specific to Medicago. Currently, the Medicago Phosphoprotein Database holds 3,457 unique phosphopeptides that contain 3,404 non-redundant sites of phosphorylation on 829 proteins. Through the web-based interface, users are allowed to browse identified proteins or search for proteins of interest. Furthermore, we allow users to conduct BLAST searches of the database using both peptide sequences and phosphorylation motifs as queries. The data contained within the database are available for download to be investigated at the user’s discretion. The Medicago Phosphoprotein Database will be updated continually with novel phosphoprotein and phosphopeptide identifications, with the intent of constructing an unparalleled compendium of large-scale Medicago phosphorylation data.

  3. USE OF PELLETED LETTUCE SEEDS IN BIOAVAILABILITY STUDIES

    Science.gov (United States)

    Lettuce (Latuca sativa L., cv. Buttercrunch) is one of the most common and sensitive test organisms, among plants, used in toxicology and bioavailability studies. Much of the available lettuce seeds in commercial channels are pelleted to allow for precision machine planting. Th...

  4. USE OF PELLETED LETTUCE SEEDS IN BIOABAILABILITY STUDIES

    Science.gov (United States)

    Lettuce (Latuca sativa L., cv. Buttercrunch) is one of the most common and sensitive test organisms, among plants, used in toxicology and bioavailability studies. Much of the available lettuce seeds in commercial channels are pelleted to allow for precision machine planting. Th...

  5. Proteomic identification of differentially expressed proteins during alfalfa (Medicago sativa L. flower development

    Directory of Open Access Journals (Sweden)

    Lingling Chen

    2016-10-01

    Full Text Available Flower development, pollination, and fertilization are important stages in the sexual reproduction process of plants; they are also critical steps in the control of seed formation and development. During alfalfa (Medicago sativa L. seed production, some distinct phenomena such as a low seed setting ratio, serious flower falling, and seed abortion commonly occur. However, the causes of these phenomena are complicated and largely unknown. An understanding of the mechanisms that regulate alfalfa flowering is important in order to increase seed yield. Hence, proteomic technology was used to analyze changes in protein expression during the stages of alfalfa flower development. Flower samples were collected at pre-pollination (S1, pollination (S2, and the post-pollination senescence period (S3. Twenty-four differentially expressed proteins were successfully identified, including 17 down-regulated in pollinated flowers, one up-regulated in pollinated and senesced flowers, and six up-regulated in senesced flowers. The largest proportions of the identified proteins were involved in metabolism, signal transduction, defense response, oxidation reduction, cell death, and programmed cell death (PCD. Their expression profiles demonstrated that energy metabolism, carbohydrate metabolism, and amino acid metabolism provided the nutrient foundation for pollination in alfalfa. Furthermore, there were three proteins involved in multiple metabolic pathways: dual specificity kinase splA-like protein (kinase splALs, carbonic anhydrase (CA, and NADPH: quinone oxidoreductase-like protein (NQOLs. Expression patterns of these proteins indicated that MAPK cascades regulated multiple processes, such as signal transduction, stress response, and cell death. PCD also played an important role in the alfalfa flower developmental process, and regulated both pollination and flower senescence. The current study sheds some light on protein expression profiles during alfalfa flower

  6. Genome-Wide Association Mapping and Genomic Selection for Alfalfa (Medicago sativa) Forage Quality Traits.

    Science.gov (United States)

    Biazzi, Elisa; Nazzicari, Nelson; Pecetti, Luciano; Brummer, E Charles; Palmonari, Alberto; Tava, Aldo; Annicchiarico, Paolo

    2017-01-01

    Genetic progress for forage quality has been poor in alfalfa (Medicago sativa L.), the most-grown forage legume worldwide. This study aimed at exploring opportunities for marker-assisted selection (MAS) and genomic selection of forage quality traits based on breeding values of parent plants. Some 154 genotypes from a broadly-based reference population were genotyped by genotyping-by-sequencing (GBS), and phenotyped for leaf-to-stem ratio, leaf and stem contents of protein, neutral detergent fiber (NDF) and acid detergent lignin (ADL), and leaf and stem NDF digestibility after 24 hours (NDFD), of their dense-planted half-sib progenies in three growing conditions (summer harvest, full irrigation; summer harvest, suspended irrigation; autumn harvest). Trait-marker analyses were performed on progeny values averaged over conditions, owing to modest germplasm × condition interaction. Genomic selection exploited 11,450 polymorphic SNP markers, whereas a subset of 8,494 M. truncatula-aligned markers were used for a genome-wide association study (GWAS). GWAS confirmed the polygenic control of quality traits and, in agreement with phenotypic correlations, indicated substantially different genetic control of a given trait in stems and leaves. It detected several SNPs in different annotated genes that were highly linked to stem protein content. Also, it identified a small genomic region on chromosome 8 with high concentration of annotated genes associated with leaf ADL, including one gene probably involved in the lignin pathway. Three genomic selection models, i.e., Ridge-regression BLUP, Bayes B and Bayesian Lasso, displayed similar prediction accuracy, whereas SVR-lin was less accurate. Accuracy values were moderate (0.3-0.4) for stem NDFD and leaf protein content, modest for leaf ADL and NDFD, and low to very low for the other traits. Along with previous results for the same germplasm set, this study indicates that GBS data can be exploited to improve both quality traits

  7. Comparative gene expression profiles between heterotic and non-heterotic hybrids of tetraploid Medicago sativa

    Directory of Open Access Journals (Sweden)

    Nettleton Dan

    2009-08-01

    Full Text Available Abstract Background Heterosis, the superior performance of hybrids relative to parents, has clear agricultural value, but its genetic control is unknown. Our objective was to test the hypotheses that hybrids expressing heterosis for biomass yield would show more gene expression levels that were different from midparental values and outside the range of parental values than hybrids that do not exhibit heterosis. Results We tested these hypotheses in three Medicago sativa (alfalfa genotypes and their three hybrids, two of which expressed heterosis for biomass yield and a third that did not, using Affymetrix M. truncatula GeneChip arrays. Alfalfa hybridized to approximately 47% of the M. truncatula probe sets. Probe set signal intensities were analyzed using MicroArray Suite v.5.0 (MAS and robust multi-array average (RMA algorithms. Based on MAS analysis, the two heterotic hybrids performed similarly, with about 27% of genes showing differential expression among the parents and their hybrid compared to 12.5% for the non-heterotic hybrid. At a false discovery rate of 0.15, 4.7% of differentially expressed genes in hybrids (~300 genes showed nonadditive expression compared to only 0.5% (16 genes in the non-heterotic hybrid. Of the nonadditively expressed genes, approximately 50% showed expression levels that fell outside the parental range in heterotic hybrids, but only one of 16 showed a similar profile in the non-heterotic hybrid. Genes whose expression differed in the parents were three times more likely to show nonadditive expression than genes whose parental transcript levels were equal. Conclusion The higher proportions of probe sets with expression level that differed from the parental midparent value and that were more extreme than either parental value in the heterotic hybrids compared to a non-heterotic hybrid were also found using RMA. We conclude that nonadditive expression of transcript levels may contribute to heterosis for biomass

  8. Expression of an alfalfa (Medicago sativa L.) peroxidase gene in transgenic Arabidopsis thaliana enhances resistance to NaCl and H2O2.

    Science.gov (United States)

    Teng, K; Xiao, G Z; Guo, W E; Yuan, J B; Li, J; Chao, Y H; Han, L B

    2016-05-23

    Peroxidases (PODs) are enzymes that play important roles in catalyzing the reduction of H2O2 and the oxidation of various substrates. They function in many different and important biological processes, such as defense mechanisms, immune responses, and pathogeny. The POD genes have been cloned and identified in many plants, but their function in alfalfa (Medicago sativa L.) is not known, to date. Based on the POD gene sequence (GenBank accession No. L36157.1), we cloned the POD gene in alfalfa, which was named MsPOD. MsPOD expression increased with increasing H2O2. The gene was expressed in all of the tissues, including the roots, stems, leaves, and flowers, particularly in stems and leaves under light/dark conditions. A subcellular analysis showed that MsPOD was localized outside the cells. Transgenic Arabidopsis with MsPOD exhibited increased resistance to H2O2 and NaCl. Moreover, POD activity in the transgenic plants was significantly higher than that in wild-type Arabidopsis. These results show that MsPOD plays an important role in resistance to H2O2 and NaCl.

  9. Mycorrhizal Glomus spp. vary in their effects on the dynamics and turnover of fine alfalfa (Medicago sativa L.) roots

    International Nuclear Information System (INIS)

    Ren, A.; Waly, N.; Chunhui, M.; Zhang, Q.; Liu, H.; Yang, J.

    2016-01-01

    The distribution of fine roots in the soil profile has important implications related to water and nutrient uptake. The Objective of this study was to compare the effects of different arbuscular mycorrhizal fungi (AMF) on the fine root dynamics of Medicago sativa L. cv. Sanditi. We used minirhizotrons to observe changes in fine root length density (FRLD, mm/cm2) and fine root surface area density (FRSAD, mm2/cm2) during the growing season. Fine root P concentrations and turnover rate were also measured. The colonization rate of fine roots varied depending on the AMF species. Colonization rates were highest when roots were inoculated with Glomus mosseae and lowest when roots were inoculated G. intraradices. Inoculation with AMF significantly increased both FRLD and FRSAD. G. versiforme increased FRLD and FRSAD most, whereas G. mosseae had the least effect. Inoculation with AMF also decreased fine root turnover rates. Inoculation with a mixture of AMF species increased fine root turnover and P concentrations more than inoculation with a single AMF species. Fine root length density increased to a maximum on Aug. 6 and then decreased. In comparison, FRSAD exhibited two peaks during the growing season. Overall, the Results indicated that inoculation with AMF can significantly promote fine root growth and P uptake by alfalfa growing on soil with low P availability. The AMF may preserve fine root function late in the growing season. (author)

  10. Co-transforming bar and CsLEA enhanced tolerance to drought and salt stress in transgenic alfalfa (Medicago sativa L.).

    Science.gov (United States)

    Zhang, Jiyu; Duan, Zhen; Zhang, Daiyu; Zhang, Jianquan; Di, Hongyan; Wu, Fan; Wang, Yanrong

    2016-03-25

    Drought and high salinity are two major abiotic factors that restrict alfalfa productivity. A dehydrin protein, CsLEA, from the desert grass Cleistogenes songorica was transformed into alfalfa (Medicago sativa L.) via Agrobacterium-mediated transformation using the bar gene as a selectable marker, and the drought and salt stress tolerances of the transgenic plants were assessed. Thirty-nine of 119 transformants were positive, as screened by Basta, and further molecularly authenticated using PCR and RT-PCR. Phenotype observations revealed that the transgenic plants grew better than the wild-type (WT) plants after 15d of drought stress and 10d of salt stress: the leaves of WT alfalfa turned yellow, whereas the transgenic alfalfa leaves only wilted; after rewatering, the transgenic plants returned to a normal state, though the WT plants could not be restored. Evaluation of physiologic and biochemical indices during drought and salt stresses showed a relatively lower Na(+) content in the leaves of the transgenic plants, which would reduce toxic ion effects. In addition, the transgenic plants were able to maintain a higher relative water content (RWC), higher shoot biomass, fewer photosystem changes, decreased membrane injury, and a lower level of osmotic stress injury. These results demonstrate that overexpression of the CsLEA gene can enhance the drought and salt tolerance of transgenic alfalfa; in addition, carrying the bar gene in the genome may increase herbicide resistance. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. WATER DEFICIT EFFECT ON YIELD AND FORAGE QUALITY OF MEDICAGO SATIVA POPULATIONS UNDER FIELD CONDITIONS IN MARRAKESH AREA (MOROCCO

    Directory of Open Access Journals (Sweden)

    Mohamed FARISSI

    2014-06-01

    Full Text Available The present study focused the effect of water deficit on agronomic potential and some traits related to forage quality in plants of Moroccan Alfalfa (Medicago sativa L. populations (Taf 1, Taf 2, Dem and Tata originated from Oasis and High Atlas of Morocco and an introduced variety from Australia (Siriver. The experiment was conducted under field conditions in experimental station of INRA-Marrakech and under two irrigation treatments. The first treatment was normal irrigation, providing an amount of water corresponding to the potential evapo-transpiration of the crop, and the second treatment was water deficit stress (one irrigation per cut. For each treatment, the experiment was conducted as a split plot based on a randomized complete block design with four replications. The plants were measured and analyzed over three cuts. Some agronomic traits as, plant height, fresh and dry forage yields were measured. The forage quality was evaluated by leaf:stem ratio and the contents of plants in proteins and nitrogen. The results indicated that the water deficit has negatively affected the plant height and forage yield. The decrease in leaf:stem ratio was observed under water deficit conditions. However, the proteins and nitrogen contents were unaffected. The behavior of tested alfalfa genotypes was significantly different. The Moroccan alfalfa populations were more adapted to water deficit conditions comparatively to Siriver variety and the Tata population was the most adapted one.

  12. Symbiotic Nitrogen Fixation in Alfalfa (Medicago Sativa L.) by Sinorhizobium Meliloti at Al-Qassim Regions, Saudi Arabia

    International Nuclear Information System (INIS)

    Al-Barakah, F. N.; Mridha, M. A. U.

    2016-01-01

    The nodulation status in alfalfa (Medicago sativa L.) plants by Sinorhizobium meliloti under Saudi field condition was assessed in some selected farms in four seasons for two years. In the present study, we also monitored the introduced S. meliloti strains activity under Saudi soil conditions. The samples were collected at regular seasonal intervals from the selected farms. The total number of nodules, morphology of the nodules and the effectiveness of N/sub 2/-fixation was assessed. In general, it was revealed that soils in the selected areas in Saudi Arabia have sufficient bacteria of the proper types to nodulate the alfalfa plants. These nodules are high in number, small in size and white in color. The nodules obtained from most of the selected farms are ineffective for nitrogen fixation. Inoculation of alfalfa seeds with imported S. meliloti strains failed to fix the atmospheric nitrogen sufficiently and also the growth improvement of alfalfa plants. There was a wide variation in the occurrence of number of nodules among the four seasons in two years. It was also observed that summer season severely affected the nodulation making it nearly zero. This low number of nodules exerts a very slow recovery of nodule formation in the next year. The introduced strains were always over competing with the native strains but they did not survive because of hot and dry summer. Nitrogenase activity of the nodules collected from both the inoculated and non-inoculated farms were always very low in all the collected samples, which indicates that the ability of fixing nitrogen by S. meliloti strains in alfalfa under Saudi soils conditions is very low. (author)

  13. Co-expression of bacterial aspartate kinase and adenylylsulfate reductase genes substantially increases sulfur amino acid levels in transgenic alfalfa (Medicago sativa L.).

    Science.gov (United States)

    Tong, Zongyong; Xie, Can; Ma, Lei; Liu, Liping; Jin, Yongsheng; Dong, Jiangli; Wang, Tao

    2014-01-01

    Alfalfa (Medicago sativa L.) is one of the most important forage crops used to feed livestock, such as cattle and sheep, and the sulfur amino acid (SAA) content of alfalfa is used as an index of its nutritional value. Aspartate kinase (AK) catalyzes the phosphorylation of aspartate to Asp-phosphate, the first step in the aspartate family biosynthesis pathway, and adenylylsulfate reductase (APR) catalyzes the conversion of activated sulfate to sulfite, providing reduced sulfur for the synthesis of cysteine, methionine, and other essential metabolites and secondary compounds. To reduce the feedback inhibition of other metabolites, we cloned bacterial AK and APR genes, modified AK, and introduced them into alfalfa. Compared to the wild-type alfalfa, the content of cysteine increased by 30% and that of methionine increased substantially by 60%. In addition, a substantial increase in the abundance of essential amino acids (EAAs), such as aspartate and lysine, was found. The results also indicated a close connection between amino acid metabolism and the tricarboxylic acid (TCA) cycle. The total amino acid content and the forage biomass tested showed no significant changes in the transgenic plants. This approach provides a new method for increasing SAAs and allows for the development of new genetically modified crops with enhanced nutritional value.

  14. Co-downregulation of the hydroxycinnamoyl-CoA:shikimate hydroxycinnamoyl transferase and coumarate 3-hydroxylase significantly increases cellulose content in transgenic alfalfa (Medicago sativa L.).

    Science.gov (United States)

    Tong, Zongyong; Li, Heng; Zhang, Rongxue; Ma, Lei; Dong, Jiangli; Wang, Tao

    2015-10-01

    Lignin is a component of the cell wall that is essential for growth, development, structure and pathogen resistance in plants, but high lignin is an obstacle to the conversion of cellulose to ethanol for biofuel. Genetically modifying lignin and cellulose contents can be a good approach to overcoming that obstacle. Alfalfa (Medicago sativa L.) is rich in lignocellulose biomass and used as a model plant for the genetic modification of lignin in this study. Two key enzymes in the lignin biosynthesis pathway-hydroxycinnamoyl -CoA:shikimate hydroxycinnamoyl transferase (HCT) and coumarate 3-hydroxylase (C3H)-were co-downregulated. Compared to wild-type plants, the lignin content in the modified strain was reduced by 38%, cellulose was increased by 86.1%, enzyme saccharification efficiency was increased by 10.9%, and cell wall digestibility was increased by 13.0%. The modified alfalfa exhibited a dwarf phenotype, but normal above ground biomass. This approach provides a new strategy for reducing lignin and increasing cellulose contents and creates a new genetically modified crop with enhanced value for biofuel. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  15. Comparative analysis of alfalfa (Medicago sativa L.) leaf transcriptomes reveals genotype-specific salt tolerance mechanisms.

    Science.gov (United States)

    Lei, Yunting; Xu, Yuxing; Hettenhausen, Christian; Lu, Chengkai; Shen, Guojing; Zhang, Cuiping; Li, Jing; Song, Juan; Lin, Honghui; Wu, Jianqiang

    2018-02-15

    Soil salinity is an important factor affecting growth, development, and productivity of almost all land plants, including the forage crop alfalfa (Medicago sativa). However, little is known about how alfalfa responds and adapts to salt stress, particularly among different salt-tolerant cultivars. Among seven alfalfa cultivars, we found that Zhongmu-1 (ZM) is relatively salt-tolerant and Xingjiang Daye (XJ) is salt-sensitive. Compared to XJ, ZM showed slower growth under low-salt conditions, but exhibited stronger tolerance to salt stress. RNA-seq analysis revealed 2237 and 1125 differentially expressed genes (DEGs) between ZM and XJ in the presence and absence of salt stress, among which many genes are involved in stress-related pathways. After salt treatment, compared with the controls, the number of DEGs in XJ (19373) was about four times of that in ZM (4833). We also detected specific differential gene expression patterns: In response to salt stress, compared with XJ, ZM maintained relatively more stable expression levels of genes related to the ROS and Ca 2+ pathways, phytohormone biosynthesis, and Na + /K + transport. Notably, several salt resistance-associated genes always showed greater levels of expression in ZM than in XJ, including a transcription factor. Consistent with the suppression of plant growth resulting from salt stress, the expression of numerous photosynthesis- and growth hormone-related genes decreased more dramatically in XJ than in ZM. By contrast, the expression levels of photosynthetic genes were lower in ZM under low-salt conditions. Compared with XJ, ZM is a salt-tolerant alfalfa cultivar possessing specific regulatory mechanisms conferring exceptional salt tolerance, likely by maintaining high transcript levels of abiotic and biotic stress resistance-related genes. Our results suggest that maintaining this specific physiological status and/or plant adaptation to salt stress most likely arises by inhibition of plant growth in ZM through

  16. Phytoextraction of rhenium by lucerne (Medicago sativa) and erect milkvetch (Astragalus adsurgens) from alkaline soils amended with coal fly ash.

    Science.gov (United States)

    He, Honghua; Dong, Zhigang; Pang, Jiayin; Wu, Gao-Lin; Zheng, Jiyong; Zhang, Xingchang

    2018-07-15

    Coal fly ash (CFA) is an industrial waste generated in huge amounts worldwide, and the management of CFA has become an environmental concern. Recovery of valuable metals from CFA is one of the beneficial reuse options of CFA. Rhenium (Re) is one of the rarest metals in the Earth's crust and one of the most expensive metals of strategic significance in the world market. A CFA at the Jungar Thermal Power Plant, Inner Mongolia, China, contains more Re than two alkaline soils in the surrounding region. Pot experiments were undertaken to grow lucerne (Medicago sativa) and erect milkvetch (Astragalus adsurgens) in a loessial soil and an aeolian sandy soil amended with different rates (5%, 10%, 20%, and 40%) of CFA. The results show that plant growth was considerably enhanced and Re concentration in plants was significantly increased when CFA was applied to the alkaline soils at rates of ≤20%; while in some cases plant growth was also markedly enhanced by the 40% CFA treatment, which increased plant Re concentration the most of all treatments. Both lucerne and erect milkvetch showed potential for phytoextracting Re from CFA-amended alkaline soils. Using CFA for soil amendment not only offers a potential solution for the waste disposal problem of CFA, but the phytoextraction of Re by both lucerne and erect milkvetch may also bring an economic profit in the future. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. The photosynthetic and stomatal response of Medicago sativa cv. saranac to free-air CO{sub 2} enrichment (F.A.C.E.) and nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Bridson, N.P.

    1996-08-01

    Plots of Medicago sativa cv. saranac were grown in the field at ambient (355 {mu}mol CO{sub 2} mol{sup -1} air) or elevated (600{mu}mol CO{sub 2} mol{sup -1} air) CO{sub 2} concentrations. High (200kg yr{sup -1}) or low (20kg yr{sup -1}) nitrogen levels were applied to two isogeneic lines, one able and one unable to use nitrogen fixing bacteria. Plants were in the second year of field growth. Exposure to elevated CO{sub 2} was via a Free-Air CO{sub 2} Enrichment System (FACE). Elevated CO{sub 2} increased diurnal assimilation by between 12% and 92%. Analysis of A/C{sub i} responses showed that effective nitrogen fertilisation was more important to rubisCO and RuBP activity than elevated CO{sub 2}. No acclimation was consistently observed. Leaves lower down the canopy were found to have lower Vc{sub max} and J{sub max} values, though age may be the cause of the latter effect. FACE conditions have only a small effect on these responses. There was some evidence found for the down-regulation of photosynthesis in the late afternoon. The FACE conditions had no affect on stomatal density but did increase epidermal cell density.

  18. A sequence-based genetic map of Medicago truncatula and comparison of marker colinearity with M. sativa

    NARCIS (Netherlands)

    Choi, H.K.; Kim, D.; Uhm, T.; Limpens, E.H.M.; Lim, H.; Mun, J.H.; Kalo, P.; Penmetsa, R.V.; Seres, A.; Kulikova, O.; Roe, B.A.; Bisseling, T.; Kiss, G.B.; Cook, D.R.

    2004-01-01

    A core genetic map of the legume Medicago truncatula has been established by analyzing the segregation of 288 sequence-characterized genetic markers in an E, population composed of 93 individuals. These molecular markers correspond to 141 ESTs, 80 BAC end sequence tags, and 67 resistance gene

  19. Resistant and susceptible responses in alfalfa (Medicago sativa to bacterial stem blight caused by Pseudomonas syringae pv. syringae.

    Directory of Open Access Journals (Sweden)

    Lev G Nemchinov

    Full Text Available Bacterial stem blight caused by Pseudomonas syringae pv. syringae is a common disease of alfalfa (Medicago sativa L. Little is known about host-pathogen interactions and host defense mechanisms. Here, individual resistant and susceptible plants were selected from cultivars Maverick and ZG9830 and used for transcript profiling at 24 and 72 hours after inoculation (hai with the isolate PssALF3. Bioinformatic analysis revealed a number of differentially expressed genes (DEGs in resistant and susceptible genotypes. Although resistant plants from each cultivar produced a hypersensitive response, transcriptome analyses indicated that they respond differently at the molecular level. The number of DEGs was higher in resistant plants of ZG9830 at 24 hai than in Maverick, suggesting that ZG9830 plants had a more rapid effector triggered immune response. Unique up-regulated genes in resistant ZG9830 plants included genes encoding putative nematode resistance HSPRO2-like proteins, orthologs for the rice Xa21 and soybean Rpg1-b resistance genes, and TIR-containing R genes lacking both NBS and LRR domains. The suite of R genes up-regulated in resistant Maverick plants had an over-representation of R genes in the CC-NBS-LRR family including two genes for atypical CCR domains and a putative ortholog of the Arabidopsis RPM1 gene. Resistance in both cultivars appears to be mediated primarily by WRKY family transcription factors and expression of genes involved in protein phosphorylation, regulation of transcription, defense response including synthesis of isoflavonoids, and oxidation-reduction processes. These results will further the identification of mechanisms involved in resistance to facilitate selection of parent populations and development of commercial varieties.

  20. Activity of Saponins from Medicago species Against HeLa and MCF-7 Cell Lines and their Capacity to Potentiate Cisplatin Effect.

    Science.gov (United States)

    Avato, Pinarosa; Migoni, Danilo; Argentieri, Mariapia; Fanizzi, Francesco P; Tava, Aldo

    2017-11-24

    Saponins from Medicago species display several biological activities, among them apoptotic effects against plant cells have been evidenced. In contrast, their cytotoxic and antitumor activity against animal cells have not been studied in great details. To explore the cytotoxic properties of saponin from Medicago species against animal cells and their effect in combination with the antitumoral drug cisplatin. Cytotoxic activity of saponin mixtures from M. arabica (tops and roots), M. arborea (tops) and M. sativa (tops, roots and seeds) and related prosapogenins from M. arborea and M. sativa (tops) against HeLa and MCF-7 cell lines is described. In addition, cytotoxicity of soyasaponin I and purified saponins (1-8) of hederagenin, medicagenic and zanhic acid is also presented. Combination experiments with cisplatin have been also conducted. Saponins from M. arabica tops and roots (mainly monodesmosides of hederagenin and bayogenin) were the most effective to reduce proliferation of HeLa and MCF-7 cell lines. Among the purified saponins, the most cytotoxic was saponin 1, 3-O-ß-D-glucopyranosyl(1→2)-α-L-arabinopyranosyl hederagenin. When saponins, derived prosapogenins and pure saponins were used in combination with cisplatin, they all, to different extent, were able to potentiate cisplatin activity against HeLa cells but not against MCF-7 cell lines. Moreover uptake of cisplatin in these cell lines was significantly reduced. Overall results showed that specific molecular types of saponins (hederagenin glycosides) have potential as anti-cancer agents or as leads for anti-cancer agents. Moreover saponins from Medicago species have evidenced interesting properties to mediate cisplatin effects in tumor cell lines. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  1. Fixed-Precision Sequential Sampling Plans for Estimating Alfalfa Caterpillar, Colias lesbia, Egg Density in Alfalfa, Medicago sativa, Fields in Córdoba, Argentina

    Science.gov (United States)

    Serra, Gerardo V.; Porta, Norma C. La; Avalos, Susana; Mazzuferi, Vilma

    2013-01-01

    The alfalfa caterpillar, Colias lesbia (Fabricius) (Lepidoptera: Pieridae), is a major pest of alfalfa, Medicago sativa L. (Fabales: Fabaceae), crops in Argentina. Its management is based mainly on chemical control of larvae whenever the larvae exceed the action threshold. To develop and validate fixed-precision sequential sampling plans, an intensive sampling programme for C. lesbia eggs was carried out in two alfalfa plots located in the Province of Córdoba, Argentina, from 1999 to 2002. Using Resampling for Validation of Sampling Plans software, 12 additional independent data sets were used to validate the sequential sampling plan with precision levels of 0.10 and 0.25 (SE/mean), respectively. For a range of mean densities of 0.10 to 8.35 eggs/sample, an average sample size of only 27 and 26 sample units was required to achieve a desired precision level of 0.25 for the sampling plans of Green and Kuno, respectively. As the precision level was increased to 0.10, average sample size increased to 161 and 157 sample units for the sampling plans of Green and Kuno, respectively. We recommend using Green's sequential sampling plan because it is less sensitive to changes in egg density. These sampling plans are a valuable tool for researchers to study population dynamics and to evaluate integrated pest management strategies. PMID:23909840

  2. Citric acid- and Tween(®) 80-assisted phytoremediation of a co-contaminated soil: alfalfa (Medicago sativa L.) performance and remediation potential.

    Science.gov (United States)

    Agnello, A C; Huguenot, D; van Hullebusch, E D; Esposito, G

    2016-05-01

    A pot experiment was designed to assess the phytoremediation potential of alfalfa (Medicago sativa L.) in a co-contaminated (i.e., heavy metals and petroleum hydrocarbons) soil and the influence of citric acid and Tween(®) 80 (polyethylene glycol sorbitan monooleate), applied individually and combined together, for their possible use in chemically assisted phytoremediation. The results showed that alfalfa plants could tolerate and grow in a co-contaminated soil. Over a 90-day experimental time, shoot and root biomass increased and negligible plant mortality occurred. Heavy metals were uptaken by alfalfa to a limited extent, mostly by plant roots, and their concentration in plant tissues were in the following order: Zn > Cu > Pb. Microbial population (alkane-degrading microorganisms) and activity (lipase enzyme) were enhanced in the presence of alfalfa with rhizosphere effects of 9.1 and 1.5, respectively, after 90 days. Soil amendments did not significantly enhance plant metal concentration or total uptake. In contrast, the combination of citric acid and Tween(®) 80 significantly improved alkane-degrading microorganisms (2.4-fold increase) and lipase activity (5.3-fold increase) in the rhizosphere of amended plants, after 30 days of experiment. This evidence supports a favorable response of alfalfa in terms of tolerance to a co-contaminated soil and improvement of rhizosphere microbial number and activity, additionally enhanced by the joint application of citric acid and Tween(®) 80, which could be promising for future phytoremediation applications.

  3. Silicon Priming Created an Enhanced Tolerance in Alfalfa (Medicago sativa L.) Seedlings in Response to High Alkaline Stress.

    Science.gov (United States)

    Liu, Duo; Liu, Miao; Liu, Xiao-Long; Cheng, Xian-Guo; Liang, Zheng-Wei

    2018-01-01

    Alkaline stress as a result of higher pH usually triggers more severe physiological damage to plants than that of saline stress with a neutral pH. In the present study, we demonstrated that silicon (Si) priming of alfalfa ( Medicago sativa L.) seedlings increased their tolerance to high alkaline stress situations. Gongnong No. 1 seedlings were subjected to alkaline stress simulated by 25 mM Na 2 CO 3 (pH 11.2). Alkaline stress greatly decreased the biomass and caused severe lodging or wilting of alfalfa seedlings. In contrast, the application of Si to alfalfa seedlings 36 h prior to the alkaline treatment significantly alleviated the damage symptoms and greatly increased the biomass and chlorophyll content. Because of being concomitant with increasing photosynthesis and water use efficiency, decreasing membrane injury and malondialdehyde content, and increasing peroxidase and catalase ascorbate activities in alfalfa leaves, thereby alleviating the triggered oxidative damage by alkaline stress to the plant. Furthermore, Si priming significantly decreased the accumulation of protein and proline content in alfalfa, thus reducing photosynthetic feedback repression. Si priming significantly accumulated more Na in the roots, but led to a decrease of Na accumulation and an increase of K accumulation in the leaves under alkaline stress. Meanwhile, Si priming decreased the accumulation of metal ions such as Mg, Fe, Mn, and Zn in the roots of alfalfa seedlings under alkaline stress. Collectively, these results suggested that Si is involved in the metabolic or physiological changes and has a potent priming effect on the alkaline tolerance of alfalfa seedlings. The present study indicated that Si priming is a new approach to improve the alkaline tolerance in alfalfa and provides increasing information for further exploration of the alkaline stress response at the molecular level in alfalfa.

  4. Fermentation characteristics and nutritive value of low moisture silage made from mature bermudagrass (C. dactylon) and switchgrass (P. virgatum) in mixture with alfalfa (M. sativa) or treated with urea and plantain (Musa AAB

    Science.gov (United States)

    Two experiments were conducted at the University of Kentucky Spindletop Farm in Lexington, Kentucky between October and November, 2009 to evaluate the effect of different percentages of alfalfa (Medicago sativa) as mixtures in switchgrass (Panicum virgatus) and bermudagrass (Cynodon dactylon) silage...

  5. Efecto de las arañas (Arachnida: Araneae como depredadoras de insectos plaga en cultivos de alfalfa (Medicago sativa (Fabaceae en Argentina

    Directory of Open Access Journals (Sweden)

    Andrea Armendano

    2011-12-01

    Full Text Available Effect of spiders (Arachnida: Araneae as predators of insect pest in alfalfa crops (Medicago sativa (Fabaceae in Argentina. Spiders are predators that reduce insect pest populations in agroecosystems. Trials were conducted to measure the selectivity against different insect preys, the daily consumption, effect of predators alone and together with a known number of preys, and the indirect effect of predators on vegetation. For this, experimental units (1x1m were used covered with a fine plastic mesh. Misumenops pallidus, Oxyopes salticus and Araneus sp. were used as generalist predators, and aphids, weevils, locusts, chrysomelids and Lepidoptera larvae as their potential preys. Among the preys offered, the spiders preferred Lepidoptera larvae compared to the other two pests groups (weevils and aphids. The maximum consumption rate was of 93.33% for Lepidoptera larvae, 25.33% for aphids and 11.67% for weevils. The Q Index values for the three species of spiders showed a positive selectivity only for defoliating larvae. O. salticus showed the highest values of consumption rates while Rachiplusia nu was the most consumed. The maximum value of consumption in 24 hours was showed by O. salticus on R. nu (C=2.8. The association of several species of predatory spiders increased the total number of insects captured, and also showed that the addition of spiders caused a decrease in the number of leaves damaged by the effect of lepidopterous larvae. Rev. Biol. Trop. 59 (4: 1651-1662. Epub 2011 December 01

  6. Arbuscular Mycorrhizal Colonization Alters Subcellular Distribution and Chemical Forms of Cadmium in Medicago sativa L. and Resists Cadmium Toxicity

    Science.gov (United States)

    Gao, Yanzheng

    2012-01-01

    Some plants can tolerate and even detoxify soils contaminated with heavy metals. This detoxification ability may depend on what chemical forms of metals are taken up by plants and how the plants distribute the toxins in their tissues. This, in turn, may have an important impact on phytoremediation. We investigated the impact of arbuscular mycorrhizal (AM) fungus, Glomus intraradices, on the subcellular distribution and chemical forms of cadmium (Cd) in alfalfa (Medicago sativa L.) that were grown in Cd-added soils. The fungus significantly colonized alfalfa roots by day 25 after planting. Colonization of alfalfa by G. intraradices in soils contaminated with Cd ranged from 17% to 69% after 25–60 days and then decreased to 43%. The biomass of plant shoots with AM fungi showed significant 1.7-fold increases compared to no AM fungi addition under the treatment of 20 mg·kg−1 Cd. Concentrations of Cd in the shoots of alfalfa under 0.5, 5, and 20 mg·kg−1 Cd without AM fungal inoculation are 1.87, 2.92, and 2.38 times higher, respectively, than those of fungi-inoculated plants. Fungal inoculation increased Cd (37.2–80.5%) in the cell walls of roots and shoots and decreased in membranes after 80 days of incubation compared to untreated plants. The proportion of the inactive forms of Cd in roots was higher in fungi-treated plants than in controls. Furthermore, although fungi-treated plants had less overall Cd in subcellular fragments in shoots, they had more inactive Cd in shoots than did control plants. These results provide a basis for further research on plant-microbe symbioses in soils contaminated with heavy metals, which may potentially help us develop management regimes for phytoremediation. PMID:23139811

  7. MsZEP, a novel zeaxanthin epoxidase gene from alfalfa (Medicago sativa), confers drought and salt tolerance in transgenic tobacco.

    Science.gov (United States)

    Zhang, Zhiqiang; Wang, Yafang; Chang, Leqin; Zhang, Tong; An, Jie; Liu, Yushi; Cao, Yuman; Zhao, Xia; Sha, Xuyang; Hu, Tianming; Yang, Peizhi

    2016-02-01

    The zeaxanthin epoxidase gene ( MsZEP ) was cloned and characterized from alfalfa and validated for its function of tolerance toward drought and salt stresses by heterologous expression in Nicotiana tabacum. Zeaxanthin epoxidase (ZEP) plays important roles in plant response to various environment stresses due to its functions in ABA biosynthetic and the xanthophyll cycle. To understand the expression characteristics and the biological functions of ZEP in alfalfa (Medicago sativa), a novel gene, designated as MsZEP (KM044311), was cloned, characterized and overexpressed in Nicotiana tabacum. The open reading frame of MsZEP contains 1992 bp nucleotides and encodes a 663-amino acid polypeptide. Amino acid sequence alignment indicated that deduced MsZEP protein was highly homologous to other plant ZEP sequences. Phylogenetic analysis showed that MsZEP was grouped into a branch with other legume plants. Real-time quantitative PCR revealed that MsZEP gene expression was clearly tissue-specific, and the expression levels were higher in green tissues (leaves and stems) than in roots. MsZEP expression decreased in shoots under drought, cold, heat and ABA treatment, while the expression levels in roots showed different trends. Besides, the results showed that nodules could up-regulate the MsZEP expression under non-stressful conditions and in the earlier stage of different abiotic stress. Heterologous expression of the MsZEP gene in N. tabacum could confer tolerance to drought and salt stress by affecting various physiological pathways, ABA levels and stress-responsive genes expression. Taken together, these results suggested that the MsZEP gene may be involved in alfalfa responses to different abiotic stresses and nodules, and could enhance drought and salt tolerance of transgenic tobacco by heterologous expression.

  8. Absorption of SO/sub 2/ by pecan (Carya illinoensis (Wang) K. Koch) and alfalfa (Medicago sativa L. ) and its effect on net photosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Sisson, W.B.; Booth, J.A.; Throneberry, G.O.

    1981-06-01

    Absorption rates of SO/sub 2/ by pecan (Carya illinoensis (Wang) K. Koch) leaflets exposed to 2.6, 5.2, and 7.8 mg SO/sub 2/ m/sup -3/ were measured over a 2 h period. SO/sub 2/ was rapidly absorbed by the leaflets in all treatments during the initial 30-50 min; the rate of uptake decreased to a rather constant level thereafter. Total SO/sub 2/ absorbed during the 2 h period was 15.6, 25.6, and 38.9 nmol cm/sup -2/ for the low, medium, and high SO/sub 2/ concentrations, respectively. Reductions in net photosynthetic rates were proportional to ambient SO/sub 2/ concentrations and total SO/sub 2/ absorbed. Partial photosynthetic recovery occurred in all treatments during a 2 hr post-treatment period and full recovery occurred during a 12 h dark period. Exposure to SO/sub 2/ resulted in slight increases in stomatal and boundary layer resistances to CO/sub 2/ and substantial increases in residual resistances. Absorption rates of SO/sub 2/ by alfalfa (Medicago sativa L.) exposed to 5.2 mg SO/sub 2/ m/sup -3/ for 1 h were approximately double those of pecan exposed to the same ambient SO/sub 2/ concentration. Alfalfa net photosynthetic rates were reduced 74% after 1 h exposure to 5.2 mg SO/sub 2/ m/sup -3/ while a depression of 42% occurred in pecan.

  9. Effects of four short-chain fatty acids or salts on fermentation characteristics and aerobic stability of alfalfa (Medicago sativa L.) silage.

    Science.gov (United States)

    Yuan, Xian J; Wen, Ai Y; Wang, Jian; Desta, Seare T; Dong, Zhi H; Shao, Tao

    2018-01-01

    The objective of the present study was to evaluate the effects of four chemicals on the fermentation quality and aerobic stability of alfalfa (Medicago sativa L.) silage. Wilted alfalfa was ensiled without additive (control), or with formic acid (FA), potassium diformate (KDF), sodium diacetate (SDA) or calcium propionate (CAP). After 60 days of ensiling, the pH values in FA, KDF and SDA silages were lower (P < 0.05) compared to that of control and CAP silages, and chemicals (P < 0.05) decreased butyric acid and ammonia N concentrations and populations of aerobic bacteria and yeasts compared to the control. The SDA and CAP silages had a higher (P < 0.05) lactic acid bacteria content compared to the FA and KDF silages. The SDA and CAP silages had higher (P < 0.05) acetic and propionic acid contents compared to the other silages, respectively. The ammonia N concentrations in the FA and KDF silages were lower compared to the other silages during the first 5 days of aerobic exposure, and then increased sharply to 105 and 100 g kg -1 total N, respectively, which was higher (P < 0.05) than that of the SDA and CAP silages on day 9 of aerobic exposure. Yeasts and aerobic bacteria counts in SDA silage slowly increased and remained at lower levels compared to the other silages after 7 days of aerobic exposure. Additives prolonged the aerobic stability duration compared to the control, and the SDA and CAP silages remained stable for more than 216 h, followed by the KDF and FA silages (202 and 196 h, respectively). © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  10. Transgenic alfalfa (Medicago sativa) with increased sucrose phosphate synthase activity shows enhanced growth when grown under N2-fixing conditions.

    Science.gov (United States)

    Gebril, Sayed; Seger, Mark; Villanueva, Fabiola Muro; Ortega, Jose Luis; Bagga, Suman; Sengupta-Gopalan, Champa

    2015-10-01

    Overexpression of SPS in alfalfa is accompanied by early flowering, increased plant growth and an increase in elemental N and protein content when grown under N2-fixing conditions. Sucrose phosphate synthase (SPS; EC 2.3.1.14) is the key enzyme in the synthesis of sucrose in plants. The outcome of overexpression of SPS in different plants using transgenic approaches has been quite varied, but the general consensus is that increased SPS activity is associated with the production of new sinks and increased sink strength. In legumes, the root nodule is a strong C sink and in this study our objective was to see how increasing SPS activity in a legume would affect nodule number and function. Here we have transformed alfalfa (Medicago sativa, cv. Regen SY), with a maize SPS gene driven by the constitutive CaMV35S promoter. Our results showed that overexpression of SPS in alfalfa, is accompanied by an increase in nodule number and mass and an overall increase in nitrogenase activity at the whole plant level. The nodules exhibited an increase in the level of key enzymes contributing to N assimilation including glutamine synthetase and asparagine synthetase. Moreover, the stems of the transformants showed higher level of the transport amino acids, Asx, indicating increased export of N from the nodules. The transformants exhibited a dramatic increase in growth both of the shoots and roots, and earlier flowering time, leading to increased yields. Moreover, the transformants showed an increase in elemental N and protein content. The overall conclusion is that increased SPS activity improves the N status and plant performance, suggesting that the availability of more C in the form of sucrose enhances N acquisition and assimilation in the nodules.

  11. Physiological and Proteomic Responses of Contrasting Alfalfa (Medicago sativa L.) Varieties to PEG-Induced Osmotic Stress

    Science.gov (United States)

    Zhang, Cuimei; Shi, Shangli

    2018-01-01

    Drought severely limits global plant distribution and agricultural production. Elucidating the physiological and molecular mechanisms governing alfalfa stress responses will contribute to the improvement of drought tolerance in leguminous crops. In this study, the physiological and proteomic responses of two alfalfa (Medicago sativa L.) varieties contrasting in drought tolerance, Longzhong (drought-tolerant) and Gannong No. 3 (drought-sensitive), were comparatively assayed when seedlings were exposed to -1.2 MPa polyethylene glycol (PEG-6000) treatments for 15 days. The results showed that the levels of proline, malondialdehyde (MDA), hydrogen peroxide (H2O2), hydroxyl free radical (OH•) and superoxide anion free radical (O2•-) in both varieties were significantly increased, while the root activity, the superoxide dismutase (SOD) and glutathione reductase (GR) activities, and the ratios of reduced/oxidized ascorbate (AsA/DHA) and reduced/oxidized glutathione (GSH/GSSG) were significantly decreased. The soluble protein and soluble sugar contents, the total antioxidant capability (T-AOC) and the activities of peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) first increased and then decreased with the increase in treatment days. Under osmotic stress, Longzhong exhibited lower levels of MDA, H2O2, OH• and O2•- but higher levels of SOD, CAT, APX, T-AOC and ratios of AsA/DHA and GSH/GSSG compared with Gannong No.3. Using isobaric tags for relative and absolute quantification (iTRAQ), 142 differentially accumulated proteins (DAPs) were identified from two alfalfa varieties, including 52 proteins (34 up-regulated and 18 down-regulated) in Longzhong, 71 proteins (28 up-regulated and 43 down-regulated) in Gannong No. 3, and 19 proteins (13 up-regulated and 6 down-regulated) shared by both varieties. Most of these DAPs were involved in stress and defense, protein metabolism, transmembrane transport, signal transduction, as well as cell wall and

  12. Physiological and Proteomic Responses of Contrasting Alfalfa (Medicago sativa L.) Varieties to PEG-Induced Osmotic Stress.

    Science.gov (United States)

    Zhang, Cuimei; Shi, Shangli

    2018-01-01

    Drought severely limits global plant distribution and agricultural production. Elucidating the physiological and molecular mechanisms governing alfalfa stress responses will contribute to the improvement of drought tolerance in leguminous crops. In this study, the physiological and proteomic responses of two alfalfa ( Medicago sativa L.) varieties contrasting in drought tolerance, Longzhong (drought-tolerant) and Gannong No. 3 (drought-sensitive), were comparatively assayed when seedlings were exposed to -1.2 MPa polyethylene glycol (PEG-6000) treatments for 15 days. The results showed that the levels of proline, malondialdehyde (MDA), hydrogen peroxide (H 2 O 2 ), hydroxyl free radical (OH • ) and superoxide anion free radical (O 2 •- ) in both varieties were significantly increased, while the root activity, the superoxide dismutase (SOD) and glutathione reductase (GR) activities, and the ratios of reduced/oxidized ascorbate (AsA/DHA) and reduced/oxidized glutathione (GSH/GSSG) were significantly decreased. The soluble protein and soluble sugar contents, the total antioxidant capability (T-AOC) and the activities of peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) first increased and then decreased with the increase in treatment days. Under osmotic stress, Longzhong exhibited lower levels of MDA, H 2 O 2 , OH • and O 2 •- but higher levels of SOD, CAT, APX, T-AOC and ratios of AsA/DHA and GSH/GSSG compared with Gannong No.3. Using isobaric tags for relative and absolute quantification (iTRAQ), 142 differentially accumulated proteins (DAPs) were identified from two alfalfa varieties, including 52 proteins (34 up-regulated and 18 down-regulated) in Longzhong, 71 proteins (28 up-regulated and 43 down-regulated) in Gannong No. 3, and 19 proteins (13 up-regulated and 6 down-regulated) shared by both varieties. Most of these DAPs were involved in stress and defense, protein metabolism, transmembrane transport, signal transduction, as well as cell

  13. De novo characterization of fall dormant and nondormant alfalfa (Medicago sativa L.) leaf transcriptome and identification of candidate genes related to fall dormancy.

    Science.gov (United States)

    Zhang, Senhao; Shi, Yinghua; Cheng, Ningning; Du, Hongqi; Fan, Wenna; Wang, Chengzhang

    2015-01-01

    Alfalfa (Medicago sativa L.) is one of the most widely cultivated perennial forage legumes worldwide. Fall dormancy is an adaptive character related to the biomass production and winter survival in alfalfa. The physiological, biochemical and molecular mechanisms causing fall dormancy and the related genes have not been well studied. In this study, we sequenced two standard varieties of alfalfa (dormant and non-dormant) at two time points and generated approximately 160 million high quality paired-end sequence reads using sequencing by synthesis (SBS) technology. The de novo transcriptome assembly generated a set of 192,875 transcripts with an average length of 856 bp representing about 165.1 Mb of the alfalfa leaf transcriptome. After assembly, 111,062 (57.6%) transcripts were annotated against the NCBI non-redundant database. A total of 30,165 (15.6%) transcripts were mapped to 323 Kyoto Encyclopedia of Genes and Genomes pathways. We also identified 41,973 simple sequence repeats, which can be used to generate markers for alfalfa, and 1,541 transcription factors were identified across 1,350 transcripts. Gene expression between dormant and non-dormant alfalfa at different time points were performed, and we identified several differentially expressed genes potentially related to fall dormancy. The Gene Ontology and pathways information were also identified. We sequenced and assembled the leaf transcriptome of alfalfa related to fall dormancy, and also identified some genes of interest involved in the fall dormancy mechanism. Thus, our research focused on studying fall dormancy in alfalfa through transcriptome sequencing. The sequencing and gene expression data generated in this study may be used further to elucidate the complete mechanisms governing fall dormancy in alfalfa.

  14. Co-transforming bar and CsALDH Genes Enhanced Resistance to Herbicide and Drought and Salt Stress in Transgenic Alfalfa (Medicago sativa L.)

    Science.gov (United States)

    Duan, Zhen; Zhang, Daiyu; Zhang, Jianquan; Di, Hongyan; Wu, Fan; Hu, Xiaowen; Meng, Xuanchen; Luo, Kai; Zhang, Jiyu; Wang, Yanrong

    2015-01-01

    Drought and high salinity are two major abiotic factors that restrict the productivity of alfalfa. By application of the Agrobacterium-mediated transformation method, an oxidative responsive gene, CsALDH12A1, from the desert grass Cleistogenes songorica together with the bar gene associated with herbicide resistance, were co-transformed into alfalfa (Medicago sativa L.). From the all 90 transformants, 16 were positive as screened by spraying 1 mL L-1 10% Basta solution and molecularly diagnosis using PCR. Real-time PCR analysis indicated that drought and salt stress induced high CsALDH expression in the leaves of the transgenic plants. The CsALDH expression levels under drought (15 d) and salt stress (200 mM NaCl) were 6.11 and 6.87 times higher than in the control plants, respectively. In comparison to the WT plants, no abnormal phenotypes were observed among the transgenic plants, which showed significant enhancement of tolerance to 15 d of drought and 10 d of salinity treatment. Evaluation of the physiological and biochemical indices during drought and salt stress of the transgenic plants revealed relatively lower Na+ content and higher K+ content in the leaves relative to the WT plants, a reduction of toxic on effects and maintenance of osmotic adjustment. In addition, the transgenic plants could maintain a higher relative water content level, higher shoot biomass, fewer changes in the photosystem, decreased membrane injury, and a lower level of osmotic stress. These results indicate that the co-expression of the introduced bar and CsALDH genes enhanced the herbicide, drought and salt tolerance of alfalfa and therefore can potentially be used as a novel genetic resource for the future breeding programs to develop new cultivars. PMID:26734025

  15. Impacts of coal fly ash on plant growth and accumulation of essential nutrients and trace elements by alfalfa (Medicago sativa) grown in a loessial soil.

    Science.gov (United States)

    He, Honghua; Dong, Zhigang; Peng, Qi; Wang, Xia; Fan, Chenbin; Zhang, Xingchang

    2017-07-15

    Coal fly ash (CFA) is a problematic solid waste all over the world. One distinct beneficial reuse of CFA is its utilization in land application as a soil amendment. A pot experiment was carried out to assess the feasibility of using CFA to improve plant growth and increase the supply of plant-essential elements and selenium (Se) of a loessial soil for agricultural purpose. Plants of alfalfa (Medicago sativa) were grown in a loessial soil amended with different rates (5%, 10%, 20% and 40%) of CFA for two years and subjected to four successive cuttings. Dry mass of shoots and roots, concentrations of plant-essential elements and Se in plants were measured. Shoot dry mass and root dry mass were always significantly increased by 5%, 10% and 20% CFA treatments, and by 40% CFA treatment in all harvests except the first one. The CFA had a higher supply of exchangeable phosphorus (P), magnesium (Mg), copper (Cu), zinc (Zn), molybdenum (Mo), and Se than the loessial soil. Shoot P, calcium (Ca), Mg, Mo, boron (B), and Se concentrations were generally markedly increased, but shoot potassium (K), Cu, and Zn concentrations were generally reduced. The CFA can be a promising source of some essential elements and Se for plants grown in the loessial soil, and an application rate of not higher than 5% should be safe for agricultural purpose without causing plant toxicity symptoms in the studied loessial soil and similar soils. Field trials will be carried out to confirm the results of the pot experiment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Genome sequence of Ensifer meliloti strain WSM1022; a highly effective microsymbiont of the model legume Medicago truncatula A17.

    Science.gov (United States)

    Terpolilli, Jason; Hill, Yvette; Tian, Rui; Howieson, John; Bräu, Lambert; Goodwin, Lynne; Han, James; Liolios, Konstantinos; Huntemann, Marcel; Pati, Amrita; Woyke, Tanja; Mavromatis, Konstantinos; Markowitz, Victor; Ivanova, Natalia; Kyrpides, Nikos; Reeve, Wayne

    2013-12-20

    Ensifer meliloti WSM1022 is an aerobic, motile, Gram-negative, non-spore-forming rod that can exist as a soil saprophyte or as a legume microsymbiont of Medicago. WSM1022 was isolated in 1987 from a nodule recovered from the roots of the annual Medicago orbicularis growing on the Cyclades Island of Naxos in Greece. WSM1022 is highly effective at fixing nitrogen with M. truncatula and other annual species such as M. tornata and M. littoralis and is also highly effective with the perennial M. sativa (alfalfa or lucerne). In common with other characterized E. meliloti strains, WSM1022 will nodulate but fixes poorly with M. polymorpha and M. sphaerocarpos and does not nodulate M. murex. Here we describe the features of E. meliloti WSM1022, together with genome sequence information and its annotation. The 6,649,661 bp high-quality-draft genome is arranged into 121 scaffolds of 125 contigs containing 6,323 protein-coding genes and 75 RNA-only encoding genes, and is one of 100 rhizobial genomes sequenced as part of the DOE Joint Genome Institute 2010 Genomic Encyclopedia for Bacteria and Archaea-Root Nodule Bacteria (GEBA-RNB) project.

  17. The Medicago truncatula gene expression atlas web server

    Directory of Open Access Journals (Sweden)

    Tang Yuhong

    2009-12-01

    Full Text Available Abstract Background Legumes (Leguminosae or Fabaceae play a major role in agriculture. Transcriptomics studies in the model legume species, Medicago truncatula, are instrumental in helping to formulate hypotheses about the role of legume genes. With the rapid growth of publically available Affymetrix GeneChip Medicago Genome Array GeneChip data from a great range of tissues, cell types, growth conditions, and stress treatments, the legume research community desires an effective bioinformatics system to aid efforts to interpret the Medicago genome through functional genomics. We developed the Medicago truncatula Gene Expression Atlas (MtGEA web server for this purpose. Description The Medicago truncatula Gene Expression Atlas (MtGEA web server is a centralized platform for analyzing the Medicago transcriptome. Currently, the web server hosts gene expression data from 156 Affymetrix GeneChip® Medicago genome arrays in 64 different experiments, covering a broad range of developmental and environmental conditions. The server enables flexible, multifaceted analyses of transcript data and provides a range of additional information about genes, including different types of annotation and links to the genome sequence, which help users formulate hypotheses about gene function. Transcript data can be accessed using Affymetrix probe identification number, DNA sequence, gene name, functional description in natural language, GO and KEGG annotation terms, and InterPro domain number. Transcripts can also be discovered through co-expression or differential expression analysis. Flexible tools to select a subset of experiments and to visualize and compare expression profiles of multiple genes have been implemented. Data can be downloaded, in part or full, in a tabular form compatible with common analytical and visualization software. The web server will be updated on a regular basis to incorporate new gene expression data and genome annotation, and is accessible

  18. Arbuscular mycorrhizal (Funneliformis mosseae improves alfalfa (Medicago sativa L. re-growth ability in saline soil through enhanced nitrogen remobilization and improved nutritional balance

    Directory of Open Access Journals (Sweden)

    Amin Namdari

    2018-03-01

    Full Text Available In current study, the influence of arbuscular mycorrhizal fungi (AMF on salinity tolerance in terms of root’s reserves remobilization to shoot and its relationship with re-growth ability and ionic status of alfalfa (Medicago sativa L. plants were investigated. In a pot experiment, a factorial experiment in base of randomized complete blocks design in three replications was carried out. Alfalfa plants (Iranian cultivar-Baghdadi inoculated with AMF (Funneliformis mosseae or retained as un-inoculated, were grown in soil and irrigated with three salt concentrations including 1.4 (control, 7 and 12 dS/m. Three harvests were carried out at 10% of flowering stage. AMF inoculation increased the size of root sugars and soluble N pools at harvest time. The shoot biomass production following harvest had a close correlation with nitrogen (N remobilization from root (r=0.92, P≤0.01. However salinity stress significantly reduced amount and percentage of N remobilization to re-growing shoot but AMF plants exhibited greater amount and percentage of root N pools dedicated to remobilization. AMF inoculation also affected ionic relations of plants as AM+ plants contained greater K+ within both root and shoot organs while Ca2+ and Na+ were affected by AMF only within shoot tissue. AMF plants exhibited higher K+/Na+ within shoot and Ca+2/Na+ within root organs. There was a high positive correlation coefficient between K+/Na+, Ca+2/Na+ ratios and N remobilization from root (respectively, r=0.92, 0.88; P≤0.01. To sum up, ionic status within both root and shoot organs, got more balanced by AMF inoculation so that AMF reduced limitations within both source (root and sink (re-growing shoot organs concerning N remobilization to re-growing shoot.

  19. Cloning and expression of 1-aminocyclopropane-1-carboxylate oxidase cDNA induced by thidiazuron during somatic embryogenesis of alfalfa (Medicago sativa).

    Science.gov (United States)

    Feng, Bi-Hong; Wu, Bei; Zhang, Chun-Rong; Huang, Xia; Chen, Yun-Feng; Huang, Xue-Lin

    2012-01-15

    Embryogenic callus (EC) induced from petioles of alfalfa (Medicago sativa L. cv. Jinnan) on B5h medium turned green, compact and non-embryogenic when the kinetin (KN) in the medium was replaced partially or completely by thidiazuron (TDZ). The application of CoCl₂, which is an inhibitor of 1-aminocyclopropane-1-carboxylate oxidase (ACO), counteracted the effect of TDZ. Ethylene has been shown to be involved in the modulation of TDZ-induced morphogenesis responses. However, very little is known about the genes involved in ethylene formation during somatic embryogenesis (SE). To investigate whether ethylene mediated by ACO is involved in the effect of TDZ on inhibition of embryogenic competence of the alfalfa callus. In this study we cloned full-length ACO cDNA from the alfalfa callus, named MsACO, and observed changes in this gene expression during callus formation and induction of SE under treatment with TDZ or TDZ plus CoCl₂. RNA blot analysis showed that during the EC subcultural period, the expression level of MsACO in EC was significantly increased on the 2nd day, rose to the highest level on the 8th day and remained at this high level until the 21st day. However, the ACO expression in the TDZ (0.93 μM)-treated callus was higher than in the EC especially on the 8th day. Moreover the ACO expression level increased with increasing TDZ concentration during the subcultural/maintenance period of the callus. It is worth noting that comparing the treatment with TDZ alone, the treatment with 0.93 μM TDZ plus 50 μM CoCl₂ reduced both of the ACO gene expressions and ACO activity in the treated callus. These results indicate that the effect of TDZ could be counteracted by CoCl₂ either on the ACO gene expression level or ACO activity. Thus, a TDZ inhibitory effect on embryogenic competence of alfalfa callus could be mediated by ACO gene expression. Crown Copyright © 2011. Published by Elsevier GmbH. All rights reserved.

  20. Experimental tolerance to boron of the plant species Nicotiana glauca, Jacaranda mimosifolia, Tecoma stans, Medicago sativa y Spinacea oleracea in Argentina; Tolerancia experimental de las especies vegetales Nicotiana glauca, Jacaranda mimosifolia, Tecoma stans, Medicago sativa y Spinacea oleracea al boro, en Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Viana, Marta L. de; Albarracin Franco, Silvia [Univ. Nacional de Salta, Inst. de Ecologia y Ambiente Humano, CIUNSa, Buenos Aires No. 177, 4400, Salta (Argentina)], E-mail: mldeviana@arnet.com.ar

    2008-09-15

    The activity of the borate deposits industries constitutes a point source and diffuse pollution of air, soil and water. Therefore, the study and experimentation on possible ways to offset this impact is a priority. A relatively new technique to decontaminate soils is phytoremediation, which uses plants and associated microorganisms. The first step is to identify tolerant plant species, which is the focus of this work. An experiment was conducted in the laboratory to evaluate the germination, survival and growth of different species in different concentrations of boron. At the beginning and end of the experiment was determined concentration of boron in the substrate for each treatment and for substrates with and without vegetation. Significant differences due to treatment, the species and species-treatment interaction. M. sativa, N. glauca and J. mimosifolia were the species most tolerant to boron. The other species showed a decrease in all variables-response function of the concentration of the contaminant. All had low survival in the highest concentration. The decrease of boron was highest in the treatment of 30 ppm of boron with M. sativa and the lowest was recorded in the treatment of 20 ppm of boron with J. mimosifolia and 30 ppm of boron with T. stans and S. oleracea. It is concluded that N. glauca, M. sativa and J. mimosifolia could be considered as promising remediation. (author) [Spanish] La actividad de las industrias borateras constituye una fuente puntual y difusa de contaminacion del aire, suelo y aguas superficiales y profundas. Por lo tanto, el estudio y experimentacion acerca de las posibles formas de contrarrestar este impacto constituye una prioridad. Una tecnica relativamente nueva para descontaminar suelos es la fitorremediacion, que emplea plantas y microorganismos asociados. El primer paso es detectar las especies vegetales tolerantes, lo que constituye el objetivo de este trabajo. Se realizo un experimento en laboratorio para evaluar la

  1. Characterization and genetic dissection of resistance to spotted alfalfa aphid (Therioaphis trifolii) in Medicago truncatula

    KAUST Repository

    Kamphuis, L. G.; Lichtenzveig, J.; Peng, K.; Guo, S.-M.; Klingler, John; Siddique, K. H. M.; Gao, L.-L.; Singh, K. B.

    2013-01-01

    Aphids cause significant yield losses in agricultural crops worldwide. Medicago truncatula, a model legume, cultivated pasture species in Australia and close relative of alfalfa (Medicago sativa), was used to study the defence response against Therioaphis trifolii f. maculate [spotted alfalfa aphid (SAA)]. Aphid performance and plant damage were compared among three accessions. A20 is highly susceptible, A17 has moderate resistance, and Jester is strongly resistant. Subsequent analyses using A17 and A20, reciprocal F1s and an A17×A20 recombinant inbred line (RIL) population revealed that this moderate resistance is phloem mediated and involves antibiosis and tolerance but not antixenosis. Electrical penetration graph analysis also identified a novel waveform termed extended potential drop, which occurred following SAA infestation of M. truncatula. Genetic dissection using the RIL population revealed three quantitative trait loci on chromosomes 3, 6, and 7 involved in distinct modes of aphid defence including antibiosis and tolerance. An antibiosis locus resides on linkage group 3 (LG3) and is derived from A17, whereas a plant tolerance and antibiosis locus resides on LG6 and is derived from A20, which exhibits strong temporary tolerance. The loci identified reside in regions harbouring classical resistance genes, and introgression of these loci in current medic cultivars may help provide durable resistance to SAA, while elucidation of their molecular mechanisms may provide valuable insight into other aphid–plant interactions.

  2. Characterization and genetic dissection of resistance to spotted alfalfa aphid (Therioaphis trifolii) in Medicago truncatula

    KAUST Repository

    Kamphuis, L. G.

    2013-09-21

    Aphids cause significant yield losses in agricultural crops worldwide. Medicago truncatula, a model legume, cultivated pasture species in Australia and close relative of alfalfa (Medicago sativa), was used to study the defence response against Therioaphis trifolii f. maculate [spotted alfalfa aphid (SAA)]. Aphid performance and plant damage were compared among three accessions. A20 is highly susceptible, A17 has moderate resistance, and Jester is strongly resistant. Subsequent analyses using A17 and A20, reciprocal F1s and an A17×A20 recombinant inbred line (RIL) population revealed that this moderate resistance is phloem mediated and involves antibiosis and tolerance but not antixenosis. Electrical penetration graph analysis also identified a novel waveform termed extended potential drop, which occurred following SAA infestation of M. truncatula. Genetic dissection using the RIL population revealed three quantitative trait loci on chromosomes 3, 6, and 7 involved in distinct modes of aphid defence including antibiosis and tolerance. An antibiosis locus resides on linkage group 3 (LG3) and is derived from A17, whereas a plant tolerance and antibiosis locus resides on LG6 and is derived from A20, which exhibits strong temporary tolerance. The loci identified reside in regions harbouring classical resistance genes, and introgression of these loci in current medic cultivars may help provide durable resistance to SAA, while elucidation of their molecular mechanisms may provide valuable insight into other aphid–plant interactions.

  3. Effects of Fe-chelate and iron oxide nanoparticles on some of the physiological characteristics of alfalfa (Medicago sativa L.

    Directory of Open Access Journals (Sweden)

    Mehri Askary

    2018-06-01

    Full Text Available Introduction Iron is an essential micronutrient for plant growth that plays an important role in plant metabolism. Iron deficiency is an abiotic stress that is often found in plants grown in calcareous and alkaline soils. The solubility of Fe+3 decreases dramatically with increasing pH. 30% of the arable land worldwide consists of calcareous and alkaline soils. Common iron fertilizers used to reduce deficiency syndromes contain iron(II sulfate heptahydrate (FeSO4.7H2O or iron chelates. Iron chelate (for example Fe-EDTA is absorbed by plants, which however depends on soil conditions especially soil pH. Nowadays , nano-Fe fertilizer can be used as a rich source of iron for plants ,because it gradually releases Fe in a wide pH range (pH 3– 11. Nanofertilizer usage leads to increase element efficiency, reduce soil toxicity and negative effects caused by the excessive consumption of chemical fertilizers and reduce the fertilizer’ s application . This research was carried out to determine the suitable type of iron fertilizer and to evaluate the effects of different concentrations of nano-Fe fertilizer on Medicago sativa Materials and methods In order to investigate the effects of Fe-deficiency and different levels of Fe2O3 nanoparticles compared to Fe-EDTA on leaf growth, photosynthetic pigments and antioxidative activity of alfalfa (Medicago sativa cv.Hamadani, an experiment was conducted based on completely randomized design with three replications in Arak University during 2015. After germination of sterilized seeds of alfalfa, 1-day seedlings were cultured in plastic vases contains perlite. Plants were maintained under 25/18°C day/night temperatures with 12-hr photoperiod. Irrigation was done weekly with 100ml complete Hoagland solution (containing iron chelate (Fe-EDTA for control plants or 100ml Hoagland solution without iron chelate and containing different concentrations of ironoxide nanoparticles (0, 5, 10, 20 and 25µM. Plants

  4. EFICIENCIA DEL AGUA DE RIEGO EN LA PRODUCCIÓN DE MAÍZ FORRAJERO (Zea mays L. Y ALFALFA (Medicago sativa: IMPACTO SOCIAL Y ECONÓMICO

    Directory of Open Access Journals (Sweden)

    Aurelio Pedroza Sandoval

    2014-07-01

    Full Text Available El maíz y la alfalfa, son los dos principales cultivos forrajeros en la Cuenca Lechera de la Laguna de los estados de Coahuila y Durango, México, donde el recurso hídrico es el mayor factor limitante. El objetivo de este estudio fue hacer una evaluación de la eficiencia biológica, económica y social del uso de agua de riego en los cultivos de maíz forrajero (Zea mays L. y alfalfa (Medicago sativa, mediante un análisis económico comparativo y de eficiencia de productividad. El maíz fue más eficiente que la alfalfa, puesto que un m3 de agua subterránea produjo 5.72 kg de biomasa, $0.67 de ganancia por m3 de agua usada y 100 000 m3 de agua produjeron 0.65 empleos durante el ciclo del cultivo; mientras que la alfalfa produjo 0.215 kg de biomasa, $0.90 de ganancia y se generaron 0.43 empleos con los mismos volúmenes de agua indicados en el maíz. El cultivo de maíz forrajero fue más eficiente en producción de biomasa por volumen de agua utilizado y empleos generados, pero menos eficiente en ganancias, donde la alfalfa fue mejor. Una combinación durante el año de cultivos forrajeros con calidad energética y proteica como el maíz y la alfalfa respectivamente, éstos producidos bajo un programa de rotación, habrán de redundar en un equilibrio entre calidad de forraje, productividad del mismo, un mayor beneficio social y un menor impacto ambiental.

  5. Genotype, explant, medium, light and radiation effects on the in vitro plant regeneration in alfalfa (Medicago Sativa L.)

    International Nuclear Information System (INIS)

    El-Fiki, A.A.; Abdel-Hameed, A.A.M.; Sayed, A.I.H.

    2005-01-01

    The relative importance of genotype, explants, radiation, medium and light and their interactions for in vitro plant regeneration via somatic embryogenesis in alfalfa (Medicago sativa L.) has been studied. Shoot and leaf explants of two commercially grown Egyptian cultivars, Al-Wadi Al-Gadid and Siwa Tarkibi, were used in the study. The effect of gamma radiation doses 40, 80, 120 and 160 Gy were negative on plant regeneration, in spite of increase with some treatments. The best results of plant regeneration were obtained with dose 40 Gy with control light regime (16 h) on MS + 0.5 mg NAA + 1.5 mg BAP in both shoot and leaf explants of cv. Al-Wadi. The shoot explant of cv. Siwa was sensitive for gamma radiation dose 40 Gy while affirmative effect was obtained in leaf explant on MS + 1.0 mg NAA + 0.5 mg BAP with control light regime. However, dose 80 Gy showed the best results on MS + 0.5 mg NAA + 0.5 mg BAP in shoot and leaf explants of both cultivars, with control light regime in shoot explant and dark/light (DL) and dark/dark (DD) in leaf explant of cv. Al-Wadi, while with light/dark (LD) in shoot explant and control light regime in leaf explant of cv. Siwa. On the other hand, the highest plant regeneration ratio observed with dose 120 Gy were on 1.5 mg NAA + 0.5 mg BAP with control light regime in shoot and leaf explants of cv. Al-Wadi but on 0.5 mg NAA + 0.5 mg BAP with control and dark/light (DL) light regime in shoot and leaf explants of cv. Siwa. Whereas, the radiation dose 160 Gy showed severe effect on plant regeneration in both cultivars but highest percentage was observed on MS + 0.5 mg NAA + 0.5 mg BAP with dark/light (DL) in shoot explant, MS + 0.5 mg NAA + 1.5 mg BAP with control light regime in leaf explant of cv. Al-Wadi, MS + 0.5 mg NAA + 1.5 mg BAP in shoot explant and MS + 0.5 mg NAA + 0.5 mg BAP in leaf explant with dark/light (DL) in cv. Siwa. However, the effects of the same doses on callus growth showed that the highest callus weight was

  6. Effects of sowing methods and potassium application on the performance of two Alfalfa cultivars (Medicago sativa L.)

    International Nuclear Information System (INIS)

    Elhag, B.B.M.

    2007-03-01

    A field experiment was conducted at the Demonstration Farm of the Faculty of Agriculture, Islamic University of Omdurman during the period from december 2004 to may 2006 to evaluate the effects of three sowing methods (sowing on flat, ridges and mustaba) and the tow levels of potassium fertilizer, (0 k 0 and 50 kg/ha k 1 ) on the performance of alfalfa (Medicago sativa L.). This was carried out using tow cultivars, Hegazi (local) and Alfanafa (introduced). A randomized complete block design with four applications in factorial experiment was used to layout the work field. Sowing was done in the last week of december 2004 at a seed rate of 20 kg/ha by broadcasting the seeds on flat, ridge and mustaba. The first irrigation was applied immediately and the second was done five days after sowing. Subsequent irrigations were performed at an interval of seven days between irrigations during summer and ten days during winter, depending on the weather conditions. A seedling emergence was observed 3 to 5 days after sowing. Weeding was done manually when necessary. The first cut was done 70 days after sowing, when 50% of the plants were in the bloom stage, and the subsequent ones were done monthly, using a sickle, just a above the soil surface. A After the last cut (in Feb 2006), when environmental conditions were favorable, the plants were left were for seed yield which was harvested in April, 2006. Data were collected on plant height, plant population, leaf area index, leaf to stem ratio, fresh weight, dry weight, potassium content in plant, seed-yield and its components. The results revealed that there were significant differences between cultivars, sowing methods, potassium application and all possible interactions between the different treatments for all parameters except number of pods/raceme and total seed-weight in all treatments, leaf to stem ratio, leaf area index, number of racemes/plant, number of seeds/pod and 1000-seed weight in sowing methods and potassium

  7. Transgene silencing of sucrose synthase in alfalfa (Medicago sativa L.) stem vascular tissue suggests a role for invertase in cell wall cellulose synthesis.

    Science.gov (United States)

    Samac, Deborah A; Bucciarelli, Bruna; Miller, Susan S; Yang, S Samuel; O'Rourke, Jamie A; Shin, Sanghyun; Vance, Carroll P

    2015-12-01

    Alfalfa (Medicago sativa L.) is a widely adapted perennial forage crop that has high biomass production potential. Enhanced cellulose content in alfalfa stems would increase the value of the crop as a bioenergy feedstock. We examined if increased expression of sucrose synthase (SUS; EC 2.4.1.13) would increase cellulose in stem cell walls. Alfalfa plants were transformed with a truncated alfalfa phosphoenolpyruvate carboxylase gene promoter (PEPC7-P4) fused to an alfalfa nodule-enhanced SUS cDNA (MsSUS1) or the β-glucuronidase (GUS) gene. Strong GUS expression was detected in xylem and phloem indicating that the PEPC7-P4 promoter was active in stem vascular tissue. In contrast to expectations, MsSUS1 transcript accumulation was reduced 75-90 % in alfalfa plants containing the PEPC7-P4::MsSUS1 transgene compared to controls. Enzyme assays indicated that SUS activity in stems of selected down-regulated transformants was reduced by greater than 95 % compared to the controls. Although SUS activity was detected in xylem and phloem of control plants by in situ enzyme assays, plants with the PEPC7-P4::MsSUS1 transgene lacked detectable SUS activity in post-elongation stem (PES) internodes and had very low SUS activity in elongating stem (ES) internodes. Loss of SUS protein in PES internodes of down-regulated lines was confirmed by immunoblots. Down-regulation of SUS expression and activity in stem tissue resulted in no obvious phenotype or significant change in cell wall sugar composition. However, alkaline/neutral (A/N) invertase activity increased in SUS down-regulated lines and high levels of acid invertase activity were observed. In situ enzyme assays of stem tissue showed localization of neutral invertase in vascular tissues of ES and PES internodes. These results suggest that invertases play a primary role in providing glucose for cellulose biosynthesis or compensate for the loss of SUS1 activity in stem vascular tissue.

  8. Inoculação microbiana da silagem de alfafa (Medicago sativa e seu efeito sobre o consumo de matéria seca e sobre a fermentação ruminal em bovinos - DOI: 10.4025/actascianimsci.v25i2.2074 Microbial inoculation of alfalfa silage (Medicago sativa and its effect on dry matter intake and ruminal fermentation in bovines - DOI: 10.4025/actascianimsci.v25i2.2074

    Directory of Open Access Journals (Sweden)

    Paulo Henrique Mazza Rodrigues

    2003-04-01

    Full Text Available O objetivo do presente estudo foi avaliar os efeitos da inoculação microbiana da alfafa (Medicago sativa para ensilagem sobre o consumo de matéria seca, fermentação ruminal e taxa de passagem de líquidos em bovinos. Doze vacas não-gestantes e não-lactantes foram distribuídas em um delineamento em blocos, e os tratamentos corresponderam à silagem pré-secada de alfafa (60% de MS e 19,5% de PB controle ou inoculada com o produto Silobac® (Lactobacillus plantarum e Pediococcus pentosaceus. A dieta experimental continha 50% de silagem de alfafa e 50% de concentrado. O experimento teve duração total de 21 dias, sendo o 21º dia utilizado para colheitas de líquido ruminal realizadas às 0h, 2h, 4h, 6h, 8h, 10h e 12h, após a 1a refeição. A inoculação microbiana da silagem de alfafa não alterou o consumo de MS (inoculada = 2,56 vs. controle = 2,39% PV, o pH do líquido ruminal (6,15 vs. 6,27, a concentração ruminal de N-NH3 (19,0 vs. 18,2mg/dl, a concentração total de AGVs (122,5 vs. 113,8mM ou a proporção molar de ácido acético (66,1 vs. 66,8% molar, propiônico (21,1 vs. 19,6% molar e butírico (12,8 vs. 13,6% molar. Parâmetros relativos à dinâmica líquida ruminal, como o volume líquido (59,5 vs. 63,4 litros e a taxa de passagem de líquidos (8,6 vs. 8,0%/h, também não foram alterados com a inoculação.The objective of this study was to evaluate the effects of microbial inoculation of alfalfa (Medicago sativa for ensiling on dry matter intake, ruminal fermentation and liquid passage rate in twelve non pregnant dry cows. A randomized block design was used and the treatments were alfalfa haylage control (60% DM and 19.5% CP or inoculated with Silobac® product (Lactobacillus plantarum and Pediococcus pentosaceus. Experimental diet contained 50% of alfalfa silage and 50% of concentrate. Experimental period lasted for twenty-one days; the 21st day was used for ruminal liquid sampling at 0, 2, 4, 6, 8, 10 e 12 hours

  9. Risks and benefits of compost-like materials prepared by the thermal treatment of raw scallop hepatopancreas for supplying cadmium and the growth of alfalfa (Medicago sativa L.).

    Science.gov (United States)

    Ushijima, Kensuke; Fukushima, Masami; Kanno, Shinya; Kanno, Itoko; Ohnishi, Mitsuhiro

    2016-01-01

    Scallop hepatopancreas, fishery waste, contains relatively high levels of Cd and organic nitrogen compounds, the latter of which represent a fertilizer. In this study, raw scallop hepatopancreas tissue was thermally treated with sawdust and red loam in the presence of an iron catalyst to produce compost-like materials (CLMs). Two CLM samples were prepared by varying the content of raw scallop hepatopancreas tissue: 46 wt.% for CLM-1 and 18 wt.% for CLM-2. Mixtures of control soil (CTL) and CLMs (CLM content: 10 and 25 wt.%) were examined for the growth of alfalfa (Medicago sativa L.) to evaluate the risks and benefits of using this material for fertilization. The Cd content in shoots and roots of alfalfa, that were grown in the presence of CLMs, was significantly higher than those for the plants grown in the CTL, indicating that Cd had accumulated in the plants from CLMs. The accumulation of Cd in the alfalfa roots was quite high in the case of the 25% CLM-1 sample. However, alfalfa growth was significantly promoted in the presence of 10% CLM-1. This can be attributed to the higher levels of nitrogen and humic substances, which serve as fertilizer components. Although the fertilization effect in case of CLM-1showed a potential benefit, the accumulation of Cd in alfalfa was clearly increased in the presence of both CLMs. In conclusion, the use of CLMs produced from raw scallop hepatopancreas tissue can be considered to have a desirable benefit from standpoint of its use as fertilizer, but is accompanied by a risk of the accumulation of Cd in alfalfa plants.

  10. Raw materials for pellets; Rohstoffe fuer Pellets

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, H.

    2008-01-15

    In order to keep the pellet prices stable, producers look for new raw materials. Sawdust as a former basis also competes with the manufacturers of chip boards and paper. Three classes of quality are discussed by the pellet manufacturers: (a) the DINplus pellet as a premium segment for which high-quality sawdust are used; (b) a wood pellet from natural wood with varying quality for the utilization in larger plants with filters; (c) the inexpensive industrial wood pellet which deviates from the DINplus commodity regarding to the ingredients and form and could be fired in larger power stations.

  11. Disponibilidade hídrica relacionada ao conteúdo de nitrogênio e à produtividade da alfafa (Medicago sativa L.

    Directory of Open Access Journals (Sweden)

    Oliveira Wladecir Salles de

    2003-01-01

    Full Text Available A variação da abundância isotópica do 13C e fixação biológica do nitrogênio podem ser utilizadas em programas de melhoramento de cultivares de alfafa (Medicago sativa L., pois contribuem para o entendimento de processos fisiológicos relacionados ao uso da água, fotossíntese, obtenção e uso do nitrogênio, bem como suas interdependências e efeitos sobre a produtividade, eficiência do uso da água e qualidade da biomassa produzida. Nesse sentido, torna-se necessária a avaliação do desempenho sob condições contrastantes em disponibilidade hídrica. Neste estudo, avaliou-se o desempenho de 12 e 6 cultivares de alfafa, respectivamente, em dois experimentos instalados em lisímetros no delineamento estatístico de parcelas subdivididas sob irrigação constante e regime de chuvas. Sob condições controladas, a alfafa responde positivamente à irrigação tanto em relação aos caracteres quantitativos quanto qualitativos e dentre os cultivares estudados, os cultivares Crioula Brasileira e Crioula Chilena apresentaram os melhores desempenhos. Na avaliação de seis meses de duração, não houve correlação entre a discriminação isotópica do carbono (DIC, fixação biológica de nitrogênio (FBN, produção de matéria seca (PMS e eficiência do uso da água (EUA. Na avaliação de um ano sob irrigação a DIC correlacionou-se negativamente com PMS (-0,92**, EUA (-0,94** e FBN (-0,79*. A FBN correlacionou-se positivamente com a PMS (0,93** e EUA (0,87*. Sob regime de chuva não houve correlação entre os parâmetros. Existe uma tendência de correlação positiva entre a PMS e DIC demonstrada em inúmeros trabalhos científicos. Essa tendência pode ser alterada sob limitação de água, limitação ao desenvolvimento radicular ou quando o conjunto de cultivares analisadas é contrastante. Se a correlação permanece de forma positiva invariável, não existe possibilidade de aumento da EUA, uma vez que o aumento da DIC

  12. Table-top pellet injector (TATOP) for impurity pellet injection

    Energy Technology Data Exchange (ETDEWEB)

    Szepesi, Tamás, E-mail: szepesi.tamas@wigner.mta.hu [Wigner RCP, RMI, Konkoly Thege 29-33, H-1121 Budapest (Hungary); Herrmann, Albrecht [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany); Kocsis, Gábor; Kovács, Ádám; Németh, József [Wigner RCP, RMI, Konkoly Thege 29-33, H-1121 Budapest (Hungary); Ploeckl, Bernhard [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany)

    2015-10-15

    Highlights: • A portable pellet injector for solid state pellets was designed. • Aims to study ELM triggering potential of impurity pellets. • Aims for multi-machine comparison of pellet–plasma interaction. • Max. pellet speed: 450 m/s, max. rate: 25 Hz. • Pellet size: 0.5–1.5 mm (diameter). - Abstract: A table-top pellet injector (TATOP) has been designed to fulfill the following scientific aims: to study the ELM triggering potential of impurity pellets, and to make pellet injection experiments comparable over several fusion machines. The TATOP is based on a centrifugal accelerator therefore the complete system is run in vacuum, ensuring the compatibility with fusion devices. The injector is able to launch any solid material (stable at room temperature) in form of balls with a diameter in the 0.5–1.5 mm range. The device hosts three individual pellet tanks that can contain e.g. pellets of different materials, and the user can select from those without opening the vacuum chamber. A key element of the accelerator is a two-stage stop cylinder that reduces the spatial scatter of pellets exiting the acceleration arm below 6°, enabling the efficient collection of all fired pellets. The injector has a maximum launch speed of 450 m/s. The launching of pellets can be done individually by providing TTL triggers for the injector, giving a high level of freedom for the experimenter when designing pellet trains. However, the (temporary) firing rate cannot be larger than 25 Hz. TATOP characterization was done in a test bed; however, the project is still in progress and before application at a fusion oriented experiment.

  13. Determination Of Simulated Pellet To Pellet Gap Using Neutron Radiography

    International Nuclear Information System (INIS)

    Kusnowo, A.

    1996-01-01

    The defect on the irradiated fuel element could be detected using neutron radiography. The defect could occurred in pellet to pellet gap, cladding, or even cladding to pellet gap. An investigations has been performed to detect pellet to pellet gap defect that might occur in an irradiated fuel element. An Al foil of 0,1; 0,2; 0,3; und 0,4 mm was inserted between pellets to simulate various pellet to pellet gap. The neutron radiography used had power of 700 kW. The result showed that this simulation represented well enough problems that irradiated fuel element may experience

  14. Wood pellet seminar

    International Nuclear Information System (INIS)

    Aarniala, M.; Puhakka, A.

    2001-01-01

    The objective of the wood pellet seminar, arranged by OPET Finland and North Karelia Polytechnic, was to deliver information on wood pellets, pellet burners and boilers, heating systems and building, as well as on the activities of wood energy advisors. The first day of the seminar consisted of presentations of equipment and products, and of advisory desks for builders. The second day of the seminar consisted of presentations held by wood pellet experts. Pellet markets, the economy and production, the development of the pellet markets and their problems (in Austria), the economy of heating of real estates by different fuel alternatives, the production, delivery and marketing of wood pellets, the utilization of wood pellet in different utilization sites, the use of wood pellets in detached houses, pellet burners and fireplaces, and conversion of communal real estate houses to use wood pellets were discussed in the presentations. The presentations held in the third day discussed the utilization of wood pellets in power plants, the regional promotion of the production and the use of pellets. The seminar consisted also of visits to pellet manufacturing plant and two pellet burning heating plants

  15. Decomposition of olive mill waste compost, goat manure and Medicago sativa in Lebanese soils using the litterbag technique

    Science.gov (United States)

    Atallah, Therese

    2014-05-01

    Organic amendments, green manure and plant residues incorporation are the main sources of nutrients in organic farming, their decomposition rate is crucial for the accumulation and long-term storage of organic matter in soils. In this study the decomposition of compost from olive mill waste (N: 29.3 g kg-1; total dissolved nitrogen or TDN: 3.82 g kg-1), goat manure (N: 31.5 g kg-1; TDN: 0.94 g kg-1), the shoots (N: 33.6 g kg-1; TDN: 17.57 g kg-1) and roots (N: 22.12 g kg-1; TDN: 8.87 g kg-1) of Medicago sativa was followed in three Lebanese soils. The nitrogen, phosphorus and potassium released were followed over one year, starting in early winter (December-January). The mild sub-humid Mediterranean conditions allowed a rapid mass loss in alfalfa shoots 30 days after incorporation. Manure and compost were more persistent. Between 80 and 90% of TDN were released, after 30 days of in-situ incubation for compost, the release was over 90% for alfalfa shoots. The movement of P was slower, as the compost (6.99 g kg-1 of P) and manure (9.81 g kg-1 of P) lost 33% and 22%, respectively, during 30 days of incubation. After one year, 15 to 35% of P remained in the soils. The manure was the richest in potassium (19.66 g kg-1) followed by the alfalfa shoots (15.56 g kg-1), the compost (8.19 g kg-1) and the roots (5.96 g kg-1). The loss of potassium was important, as over 88% had disappeared over the year. All decomposition curves followed an exponential model. The calculated coefficients of decomposition for total nitrogen (lnfinal - lninitial/days) were significantly higher for alfalfa shoots (0.00547 day-1) and similar for the compost (0.00184 day-1) and the manure (0.00175 day-1). The ANOVA test showed a difference between two of the sites (Site A: 521 g kg-1 of clay and 42 g kg-1 of calcium carbonate; Site S: 260 g kg-1 of clay and 269 g kg-1 of CaCO3) and the third one (Site L: 315 g kg-1 of clay and 591 g kg-1 of CaCO3). The relationships between the soil calcium

  16. Alfalfa (Medicago sativa L.) is tolerant to higher levels of salinity than previous guidelines indicated: Implications of field and greenhouse studies

    Science.gov (United States)

    Putnam, Daniel H.; Benes, Sharon; Galdi, Giuliano; Hutmacher, Bob; Grattan, Steve

    2017-04-01

    Alfalfa (Medicago sativa L.) is the most widely grown leguminous forage crop in North America and is valued for high productivity, quality, economic value, and for dairy productivity. Alfalfa has historically been classified as moderately sensitive to saline conditions, with yield declines predicted at >2 dS/m in the saturated soil paste extract. However, greenhouse, sand tank, and field studies over the past five years have confirmed that alfalfa can be grown with limited negative effects at much higher salinity levels. A broad collection of alfalfa varieties has exhibited a range of resistance at irrigation water salinities >5 dS/m ECw in greenhouse trials, with significant variation due to variety. USDA-ARS sand tank studies indicated similar or greater tolerances closer to 8 dS/m in the soil water, in addition to confirmation of significant varietal differences. A three-year field study on clay loam soil with applications of 5-7 dS/m ECw irrigation water indicated normal yields and excellent stand survivability. A second field study in the same soil type with levels from 8-10 dS/m ECw showed yield reductions of 10-15% but economic yields were still achieved at those levels. Field and greenhouse studies were conducted with mixed salt saline sodic waters typical of the San Joaquin Valley of California. Field evaluation of variety performance was subject to greater variation due to secondary salinity-soil interactions including water infiltration and crusting problems, not only salinity per-se. Thus, adequate irrigation water availability to the crop may be as important as salinity in impacting yields under field conditions. Once established, the deep-rooted characteristics of alfalfa enable utilization of deeper subsurface moisture, even at moderate to high salinity levels, as documented by USDA lysimeter studies. Significant advantages to salinity-tolerant varieties have been observed. It will be important to consider specific management factors which may enable

  17. Experimental tolerance to boron of the plant species Nicotiana glauca, Jacaranda mimosifolia, Tecoma stans, Medicago sativa y Spinacea oleracea in Argentina

    International Nuclear Information System (INIS)

    Viana, Marta L. de; Albarracin Franco, Silvia

    2008-01-01

    The activity of the borate deposits industries constitutes a point source and diffuse pollution of air, soil and water. Therefore, the study and experimentation on possible ways to offset this impact is a priority. A relatively new technique to decontaminate soils is phytoremediation, which uses plants and associated microorganisms. The first step is to identify tolerant plant species, which is the focus of this work. An experiment was conducted in the laboratory to evaluate the germination, survival and growth of different species in different concentrations of boron. At the beginning and end of the experiment was determined concentration of boron in the substrate for each treatment and for substrates with and without vegetation. Significant differences due to treatment, the species and species-treatment interaction. M. sativa, N. glauca and J. mimosifolia were the species most tolerant to boron. The other species showed a decrease in all variables-response function of the concentration of the contaminant. All had low survival in the highest concentration. The decrease of boron was highest in the treatment of 30 ppm of boron with M. sativa and the lowest was recorded in the treatment of 20 ppm of boron with J. mimosifolia and 30 ppm of boron with T. stans and S. oleracea. It is concluded that N. glauca, M. sativa and J. mimosifolia could be considered as promising remediation. (author) [es

  18. Pellet dimension checker

    International Nuclear Information System (INIS)

    Marmo, A.R.

    1980-01-01

    A pellet dimension checker was developed for use in making nuclear-fuel pellets. This checker eliminates operator handling of the pellet but permits remote-monitoring of the operation, and is thus suitable for mass production of green fuel pellets particularly in reprocessing plants handling irradiated uranium or plutonium. It comprises a rotatable arm for transferring a pellet from a conveyor to several dimensional measuring stations and back to the conveyor if the dimensions of the pellet are within predetermined limits. If the pellet is not within the limits, the arm removes the pellet from the process stream. (DN)

  19. PELLETS AND PELLETIZATION: EMERGING TRENDS IN THE PHARMA INDUSTRY.

    Science.gov (United States)

    Zaman, Muhammad; Saeed-Ul-Hassan, Syed; Sarfraz, Rai Muhammad; Batool, Nighat; Qureshi, Muhammad Junaid; Akram, Muhammad Abdullah; Munir, Saiqa; Danish, Zeeshan

    2016-11-01

    The present time is considered as an era of advancements in drug delivery systems. Different novel approaches are under investigation that range from uniparticulate to multi particulate system, macro to micro and nano particulate systems. Pelletization is one of the novel drug delivery technique that provides an effective way to deliver the drug in modified pattern. It is advantageous in providing site specific delivery of the drug. Drugs with unpleasant taste, poor bioavailability and short biological half-life can be delivered efficiently through pellets. Their reduced size makes them more valuable as compared to the conventional drug deliv- ery system. Different techniques are used to fabricate the pellets such as extrusion and spheronization, hot melt extrusion, powder layering, suspension or solution layering, freeze pelletization and pelletization by direct compression method. Various natural polymers including xanthan gum, guar gum, tragacanth and gum acacia, semisynthetic polymers like cellulose derivatives, synthetic polymers like derivatives of acrylamides, can be used in pellets formulation. Information provided in this review is collected from various national and intemational research articles, review articles and literature available in the books. The purpose of the current review is to discuss pellets, their characterizations, different techniques of pelletization and the polymers with potential of being suitable for pellets formulation.

  20. Effects of enhanced UVB on growth and yield of alfalfa (Medic ago Sativa L.) and soybean (Glycine max L.) under field conditions

    International Nuclear Information System (INIS)

    Al-Oudat, M.; Baydoun, S.A.; Mohamad, A.

    1997-04-01

    The effects of 20% increase of UVB on growth and yield of alfalfa (Medicago Sativa L.) and two cultivars of soybean (Glycine Max (L.) Mer) under field conditions have been investigated. The increase of UVB dose ranged between 1.746 and 7.112 J/cm 2 during experiment. The results showed that soybean yield decrease by 16% and 31% in A. 3803 and A. 2522 cultivars respectively, under UVB exposure. The dry weight and leaf area were sensitive in the A. 3803 cultivar, while they were tolerant in the A. 2522 cultivar. Alfalfa response to UVB varied during the different stages of growth, whereas the yield was 12% less in the exposed plants. (author). 21 refs., 17 tabs

  1. Energy wood. Part 2b: Wood pellets and pellet space-heating systems

    International Nuclear Information System (INIS)

    Nussbaumer, T.

    2002-01-01

    The paper gives an overview on pellet utilization including all relevant process steps: Potential and properties of saw dust as raw material, pellet production with drying and pelletizing, standardization of wood pellets, storage and handling of pellets, combustion of wood pellets in stoves and boilers and applications for residential heating. In comparison to other wood fuels, wood pellets show several advantages: Low water content and high heating value, high energy density, and homogeneous properties thus enabling stationary combustion conditions. However, quality control is needed to ensure constant properties of the pellets and to avoid the utilization of contaminated raw materials for the pellet production. Typical data of efficiencies and emissions of pellet stoves and boilers are given and a life cycle analysis (LCA) of wood pellets in comparison to log wood and wood chips is described. The LCA shows that wood pellets are advantageous thanks to relatively low emissions. Hence, the utilization of wood pellet is proposed as a complementary technology to the combustion of wood chips and log wood. Finally, typical fuel cost of wood pellets in Switzerland are given and compared with light fuel oil. (author)

  2. Evaluation of Perennial Forage Legumes and Herbs in Six Mediterranean Environments Evaluación de Leguminosas y Hierbas Forrajeras Perennes en Seis Medioambientes Mediterráneos

    Directory of Open Access Journals (Sweden)

    Daniel Real

    2011-09-01

    Full Text Available There is an absence of drought tolerant herbaceous perennial forage legume and herb options other than lucerne (Medicago sativa L. for environments with Mediterranean-like climates common in extensive areas of Southern Australia, the Mediterranean basin, and Chile. Therefore, a collection of 174 forage perennial legume and herb entries from 103 species and 32 genera was evaluated for adaptation in a diverse range of Mediterranean climatic environments in Southern Australia. The seasonal rainfall distribution varied from moderately to highly winter dominant with long term average annual rainfall ranging from 318 to 655 mm. The entries were rated for productivity and persistence over 3 yr. The 12 entries identified as the most promising for winter, summer, or all-year round production included Bituminaria bituminosa (L. C.H. Stirt. var. albomarginata; Cichorium intybus L.; Cullen australasicum (Schltdl. J.W. Grimes; Dorycnium hirsutum (L. Ser.; Kennedia prostrata R. Br.; Lotononis bainesii Baker, Lotus pedunculatus Cav.; L. corniculatus L.; L. cytisoides L.; Medicago sativa subsp. sativa L.; Medicago sativa subsp. caerulea (Less. ex Ledeb. Schmalh., and M. sativa subsp. falcata (L. Arcang. These entries maintained production and persisted for the period of the evaluation, with the exception of C. intybus and L. corniculatus that declined in persistence over time. The potential role of these species in extensive grazing systems in Mediterranean climatic zones, their attributes and limitations, and current progress in developing them as useful forage plants was discussed.Existe una escasez de leguminosas y hierbas perennes herbáceas además de alfalfa (Medicago sativa L. tolerantes a sequía para ambientes con clima mediterráneo como los que se encuentran en el Sur de Australia, el Mediterráneo y Chile. Por lo tanto, una colección de 174 leguminosas perennes y hierbas correspondientes a 103 especies y 32 géneros fue evaluada por su adaptaci

  3. Design of optimal solvent for extraction of bio–active ingredients from six varieties of Medicago sativa

    Directory of Open Access Journals (Sweden)

    Caunii Angela

    2012-10-01

    Full Text Available Abstract Background Extensive research has been performed worldwide and important evidences were collected to show the immense potential of plants used in various traditional therapeutic systems. The aim of this work is to investigate the different extracting solvents in terms of the influence of their polarity on the extracting ability of bioactive molecules (phenolic compounds from the M. sativa flowers. Results The total phenolic content of samples was determined using the Folin Ciocalteu (FC procedure and their antioxidant activity was assayed through in vitro radical decomposing activity using the radical DPPH° assay (IUPAC name for DPPH is (phenyl–(2,4,6–trinitrophenyl iminoazanium. The results showed that water was better than methanol and acetic acid for extracting bioactive compounds, in particular for total phenolic compounds from the flowers of alfalfa. The average content of bioactive molecules in methanol extract was 263.5±1.02 mg GAE/100g of dry weight lyophilized extract. The total phenolic content of the tested plant extracts was highly correlated with the radical decomposing activity. However, all extracts were free–radical inhibitors, but the water extract was more potent than the acetic and the methanol ones. The order of inhibitor effectiveness (expressed by IC50 proved to be: water extract (0.924mg/mL > acetic acid extract (0.154mg/mL > methanol (0.079mg/mL. The profiles of each extract (fingerprint were characterized by FT–MIR spectroscopy. Conclusions The present study compares the fingerprint of different extracts of the M. sativa flowers, collected from the wild flora of Romania. The total phenolic content of the tested plant extracts was highly correlated with the radical decomposing activity. The dependence of the extract composition on the solvent polarity (acetic acid vs. methanol vs. water was revealed by UV–VIS spectrometry and Infrared fingerprint.

  4. The pellet handbook: the production and thermal utilisation of pellets

    National Research Council Canada - National Science Library

    Obernberger, Ingwald; Thek, Gerold

    2010-01-01

    ...: - International overview of standards for pellets - Evaluation of raw materials and raw material potentials - Quality and properties of pellets - Technical evaluation of the pellet production process...

  5. Pellet-press-to-sintering-boat nuclear fuel pellet loading system

    International Nuclear Information System (INIS)

    Bucher, G.D.

    1988-01-01

    This patent describes a system for loading nuclear fuel pellets into a sintering boat from a pellet press which ejects newly made the pellets from a pellet press die table surface. The system consists of: (a) a bowl having an inner surface, a longitudinal axis, an open and generally circular top of larger diameter, and an open and generally circular bottom of smaller diameter; (b) means for supporting the bowl in a generally upright position such that the bowl is rotatable about its longitudinal axis; (c) means for receiving the ejected pellets proximate the die table surface of the pellet press and for discharging the received pellets into the bowl at a location proximate the inner surface towards the top of the bowl with a pellet velocity having a horizontal component which is generally tangent to the inner surface of the bowl proximate the location; (d) means for rotating the bowl about the longitudinal axis such that the bowl proximate the location has a velocity generally equal, in magnitude and direction, to the horizontal component of the pellet velocity at the location; and (e) means for moving the sintering boat generally horizontally beneath and proximate the bottom of the bowl

  6. From a single pellet press to a bench scale pellet mill - Pelletizing six different biomass feedstocks

    DEFF Research Database (Denmark)

    Puig Arnavat, Maria; Shang, Lei; Sárossy, Zsuzsa

    2016-01-01

    The increasing demand for biomass pellets requires the investigation of alternative raw materials for pelletizetion. In the present paper, the pelletization process of fescue, alfalfa, sorghum, triticale, miscanthus and willow is studied to determine if results obtained in a single pellet press (...

  7. PELLET: a computer routine for modeling pellet fueling in tokamak plasmas

    International Nuclear Information System (INIS)

    Houlberg, W.A.; Iskra, M.A.; Howe, H.C.; Attenberger, S.E.

    1979-01-01

    Recent experimental results of frozen hydrogenic pellet injection into hot tokamak plasmas and substantial agreement with theoretical predictions have led to a much greater interest in pellets as a means of refueling plasmas. The computer routine PELLET has been developed and used as an aid in assessing pellet ablation models and the effects of pellets on plasma behavior. PELLET provides particle source profiles under various options for the ablation model and can be coupled either to a fluid transport code or to a brief routine which supplies the required input parameters

  8. Opportunities for Pellet Trade - Towards a Single European Pellet Market

    International Nuclear Information System (INIS)

    Pigaht, Maurice; Janssen, Rainer; Rutz, Dominik; Boehm, Thorsten; Vasen, Norbert; Vegas, Laura; Karapanagiotis, Nicolas

    2006-01-01

    The potential for Pellets trade in Europe was researched and assessed. Such trade is of key importance for the development of a European pellet market of sufficient supply, demand, price and quality standards. Three target markets were taken as case studies for the trade assessment: Greece, Spain and Italy. All three markets stand to profit greatly from international trade. For these markets, pellet imports could supply the basis for the development of a domestic boiler market. At the same time, pellet exports would allow the planning of larger pellet production plants. Whilst these additional costs amount to some 10-20% of the Pellets price, they are financially acceptable, especially for new markets and 'peaks' in the demand/supply of established markets

  9. Neutron absorber pellets

    International Nuclear Information System (INIS)

    Radford, K.C.

    1983-01-01

    An annular burnable poison pellet of aluminium oxide - boron carbide (Al 2 O 3 - B 4 C) adapted for positioning in the annular space of concentrically disposed zircaloy tubes. Each tubular pellet is fabricated from Al 2 O 3 powders of moderate sintering activity which serves as a matrix for B 4 C medium size particle distribution. Special pellet moisture controls are incorporated in the pellet for moisture stability and the pellet is sintered in the temperature range of 1630 deg to 1650 deg C. This method of fabrication produces a pellet about 2 inch long with a wall thickness of from 0.020 inch to 0.040 inch. Fabricating each pellet to about 70% theoretical density gives an optimum compromise between fabricability, microstructure, strength and moisture absorption. (author)

  10. Medicago truncatula SOC1 Genes Are Up-regulated by Environmental Cues That Promote Flowering

    Directory of Open Access Journals (Sweden)

    Jared B. Fudge

    2018-04-01

    Full Text Available Like Arabidopsis thaliana, the flowering of the legume Medicago truncatula is promoted by long day (LD photoperiod and vernalization. However, there are differences in the molecular mechanisms involved, with orthologs of two key Arabidopsis thaliana regulators, FLOWERING LOCUS C (FLC and CONSTANS (CO, being absent or not having a role in flowering time function in Medicago. In Arabidopsis, the MADS-box transcription factor gene, SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (AtSOC1, plays a key role in integrating the photoperiodic and vernalization pathways. In this study, we set out to investigate whether the Medicago SOC1 genes play a role in regulating flowering time. Three Medicago SOC1 genes were identified and characterized (MtSOC1a–MtSOC1c. All three MtSOC1 genes, when heterologously expressed, were able to promote earlier flowering of the late-flowering Arabidopsis soc1-2 mutant. The three MtSOC1 genes have different patterns of expression. However, consistent with a potential role in flowering time regulation, all three MtSOC1 genes are expressed in the shoot apex and are up-regulated in the shoot apex of plants in response to LD photoperiods and vernalization. The up-regulation of MtSOC1 genes was reduced in Medicago fta1-1 mutants, indicating that they are downstream of MtFTa1. Insertion mutant alleles of Medicago soc1b do not flower late, suggestive of functional redundancy among Medicago SOC1 genes in promoting flowering.

  11. The lipoxygenase gene family: a genomic fossil of shared polyploidy between Glycine max and Medicago truncatula

    Directory of Open Access Journals (Sweden)

    Choi Beom-Soon

    2008-12-01

    Full Text Available Abstract Background Soybean lipoxygenases (Lxs play important roles in plant resistance and in conferring the distinct bean flavor. Lxs comprise a multi-gene family that includes GmLx1, GmLx2 and GmLx3, and many of these genes have been characterized. We were interested in investigating the relationship between the soybean lipoxygenase isozymes from an evolutionary perspective, since soybean has undergone two rounds of polyploidy. Here we report the tetrad genome structure of soybean Lx regions produced by ancient and recent polyploidy. Also, comparative genomics with Medicago truncatula was performed to estimate Lxs in the common ancestor of soybean and Medicago. Results Two Lx regions in Medicago truncatula showing synteny with soybean were analyzed. Differential evolutionary rates between soybean and Medicago were observed and the median Ks values of Mt-Mt, Gm-Mt, and Gm-Gm paralogs were determined to be 0.75, 0.62, and 0.46, respectively. Thus the comparison of Gm-Mt paralogs (Ks = 0.62 and Gm-Mt orthologs (Ks = 0.45 supports the ancient duplication of Lx regions in the common ancestor prior to the Medicago-Glycine split. After speciation, no Lx regions generated by another polyploidy were identified in Medicago. Instead tandem duplication of Lx genes was observed. On the other hand, a lineage-specific duplication occurred in soybean resulting in two pairs of Lx regions. Each pair of soybean regions was co-orthologous to one Lx region in Medicago. A total of 34 Lx genes (15 MtLxs and 19 GmLxs were divided into two groups by phylogenetic analysis. Our study shows that the Lx gene family evolved from two distinct Lx genes in the most recent common ancestor. Conclusion This study analyzed two pairs of Lx regions generated by two rounds of polyploidy in soybean. Each pair of soybean homeologous regions is co-orthologous to one region of Medicago, demonstrating the quartet structure of the soybean genome. Differential evolutionary rates between

  12. Fish pelleting

    African Journals Online (AJOL)

    PUBLICATIONS1

    fish meal pelletizing machine utilized 4kg of ingredients to produce 3.77kg pellets at an effi- ciency of .... Design and fabrication of fish meal pellet processing machine ... 53 ... horsepower for effective torque application on .... two edges were tacked with a spot weld to hold ... then welded on to the shaft making sure that the.

  13. The Medicago Genome Provides Insight into the Evolution of Rhizobial Symbioses

    Science.gov (United States)

    Young, Nevin D.; Debellé, Frédéric; Oldroyd, Giles E. D.; Geurts, Rene; Cannon, Steven B.; Udvardi, Michael K.; Benedito, Vagner A.; Mayer, Klaus F. X.; Gouzy, Jérôme; Schoof, Heiko; Van de Peer, Yves; Proost, Sebastian; Cook, Douglas R.; Meyers, Blake C.; Spannagl, Manuel; Cheung, Foo; De Mita, Stéphane; Krishnakumar, Vivek; Gundlach, Heidrun; Zhou, Shiguo; Mudge, Joann; Bharti, Arvind K.; Murray, Jeremy D.; Naoumkina, Marina A.; Rosen, Benjamin; Silverstein, Kevin A. T.; Tang, Haibao; Rombauts, Stephane; Zhao, Patrick X.; Zhou, Peng; Barbe, Valérie; Bardou, Philippe; Bechner, Michael; Bellec, Arnaud; Berger, Anne; Bergès, Hélène; Bidwell, Shelby; Bisseling, Ton; Choisne, Nathalie; Couloux, Arnaud; Denny, Roxanne; Deshpande, Shweta; Dai, Xinbin; Doyle, Jeff; Dudez, Anne-Marie; Farmer, Andrew D.; Fouteau, Stéphanie; Franken, Carolien; Gibelin, Chrystel; Gish, John; Goldstein, Steven; González, Alvaro J.; Green, Pamela J.; Hallab, Asis; Hartog, Marijke; Hua, Axin; Humphray, Sean; Jeong, Dong-Hoon; Jing, Yi; Jöcker, Anika; Kenton, Steve M.; Kim, Dong-Jin; Klee, Kathrin; Lai, Hongshing; Lang, Chunting; Lin, Shaoping; Macmil, Simone L; Magdelenat, Ghislaine; Matthews, Lucy; McCorrison, Jamison; Monaghan, Erin L.; Mun, Jeong-Hwan; Najar, Fares Z.; Nicholson, Christine; Noirot, Céline; O’Bleness, Majesta; Paule, Charles R.; Poulain, Julie; Prion, Florent; Qin, Baifang; Qu, Chunmei; Retzel, Ernest F.; Riddle, Claire; Sallet, Erika; Samain, Sylvie; Samson, Nicolas; Sanders, Iryna; Saurat, Olivier; Scarpelli, Claude; Schiex, Thomas; Segurens, Béatrice; Severin, Andrew J.; Sherrier, D. Janine; Shi, Ruihua; Sims, Sarah; Singer, Susan R.; Sinharoy, Senjuti; Sterck, Lieven; Viollet, Agnès; Wang, Bing-Bing; Wang, Keqin; Wang, Mingyi; Wang, Xiaohong; Warfsmann, Jens; Weissenbach, Jean; White, Doug D.; White, Jim D.; Wiley, Graham B.; Wincker, Patrick; Xing, Yanbo; Yang, Limei; Yao, Ziyun; Ying, Fu; Zhai, Jixian; Zhou, Liping; Zuber, Antoine; Dénarié, Jean; Dixon, Richard A.; May, Gregory D.; Schwartz, David C.; Rogers, Jane; Quétier, Francis; Town, Christopher D.; Roe, Bruce A.

    2011-01-01

    Legumes (Fabaceae or Leguminosae) are unique among cultivated plants for their ability to carry out endosymbiotic nitrogen fixation with rhizobial bacteria, a process that takes place in a specialized structure known as the nodule. Legumes belong to one of the two main groups of eurosids, the Fabidae, which includes most species capable of endosymbiotic nitrogen fixation 1. Legumes comprise several evolutionary lineages derived from a common ancestor 60 million years ago (Mya). Papilionoids are the largest clade, dating nearly to the origin of legumes and containing most cultivated species 2. Medicago truncatula (Mt) is a long-established model for the study of legume biology. Here we describe the draft sequence of the Mt euchromatin based on a recently completed BAC-assembly supplemented with Illumina-shotgun sequence, together capturing ~94% of all Mt genes. A whole-genome duplication (WGD) approximately 58 Mya played a major role in shaping the Mt genome and thereby contributed to the evolution of endosymbiotic nitrogen fixation. Subsequent to the WGD, the Mt genome experienced higher levels of rearrangement than two other sequenced legumes, Glycine max (Gm) and Lotus japonicus (Lj). Mt is a close relative of alfalfa (M. sativa), a widely cultivated crop with limited genomics tools and complex autotetraploid genetics. As such, the Mt genome sequence provides significant opportunities to expand alfalfa’s genomic toolbox. PMID:22089132

  14. The US pellet market

    International Nuclear Information System (INIS)

    Elliot, S.

    2007-01-01

    Bear Mountain is the largest producer of pellets, firelogs, animal beddings, and barbecue pellets in Western United States. The company's branded products are sold directly to more than 400 retail dealers. This presentation included a series of graphs depicting Bear Mountain's USA pellet sales in tons from 2002 to 2007; truckloads to various distribution areas; pellet stoves and insert units shipped from 1998 to 2006; and hearth appliance shipments from 1998 to 2006. It was noted that in the United States, 98 per cent of the pellets sold come in 40 pound bags and are delivered to retailers by truck. Space is needed for inventory purposes, as each customer may use 2 to 4 tons. The pellets are used in small ash capacity room heaters. The pellet producers buy sawdust from area mills. It was noted that the soft housing market combined with competition for pulp and paper has pinched the supply of pellets. Pellets were in short supply in the west coast during the winter of 2006-2007 and in eastern United States during the winters of 2004-2005 and 2005-2006, indicating that summer production of pellets is required in order to meet winter demand. The key demand factors for pellets include stove sales; pellet pricing; pricing of other fuels; and, weather. The key supply factors for pellets include availability of sawdust; logistics; competition; and cost. The greatest challenge facing pellet producers is the high cost of freight. It was concluded that 2008 will be another year of uncertainty for pellet producers, due to the abundant supply of pellets in the east and midwest, and stabilized alternative fuel pricing. tabs., figs

  15. Bioactive spirans and other constituents from the leaves of Cannabis sativa f. sativa.

    Science.gov (United States)

    Guo, Tian-Tian; Zhang, Jian-Chun; Zhang, Hai; Liu, Qing-Chao; Zhao, Yong; Hou, Yu-Fei; Bai, Lu; Zhang, Li; Liu, Xue-Qiang; Liu, Xue-Ying; Zhang, Sheng-Yong; Bai, Nai-Sheng

    2017-08-01

    In this paper, 17 compounds (1-17) were isolated from the leaves of Hemp (Cannabis sativa f. sativa). Among the isolates, two were determined to be new spirans: cannabispirketal (1), and α-cannabispiranol 4'-O-β-D-glucopyranose (2) by 1D and 2D NMR spectroscopy, LC-MS, and HRESIMS. The known compounds 7, 8, 10, 13, 15, and 16 were isolated from Hemp (C. sativa f. sativa) for the first time. Furthermore, compounds 8 and 13 were isolated from the nature for the first time. All isolated compounds were evaluated for cytotoxicity on different tissue-derived passage cancer cell lines through cell viability and apoptosis assay. Among these compounds, compounds 5, 9 and 16 exhibited a broad-spectrum antitumor effect via inhibiting cell proliferation and promoting apoptosis. These results obtained have provided valuable clues to the understanding of the cytotoxic profile for these isolated compounds from Hemp (C. sativa f. sativa).

  16. Toxicities of TNT and RDX to Terrestrial Plants in Five Soils with Contrasting Characteristics

    Science.gov (United States)

    2013-07-01

    lettuce ( Lactuca sativa (L.)) and barley (Hordeum vulgare (L.)), respectively, at analytically determined soil concentrations up to and including 3320... sativa L.), Japanese millet (J. millet; Echinochloa crus-galli L. [Beauv.]), and perennial ryegrass (Lolium perenne L.) in five natural soils that...of the test. The test species in these studies were Medicago sativa (L.) var. Canada no. 1 (alfalfa), Echinochloa crus-galli (L.) P. Beauv. var

  17. Prediction of the chemical composition and nutritive value of lucerne (Medicago sativa L. by Near Infrared Spectroscopy

    Directory of Open Access Journals (Sweden)

    M. Odoardi

    2010-01-01

    Full Text Available Lucerne is a low input energy efficient crop that improves soil fertility, and its importance is rising with the increase of public interest in sustainable agriculture. Furthermore, it occupies a significant economic position in the animal feed market (i.e. hay, dehydrated forage, pellets and silage products and deserves a particular interest in the Parmigiano-Reggiano and Grana Padano cheese production areas of Northern Italy (Torricelli et al., 2000.

  18. Production and ejection of solid hydrogen-isotope pellet (single pellet)

    International Nuclear Information System (INIS)

    Kasai, Satoshi; Hasegawa, Koichi; Miura, Yukitoshi; Ishibori, Ikuo

    1986-03-01

    The pneumatic gun type pellet injector (single pellet) has been constructed, which is basic type used at ORNL. The pellet in the carrier is 1.65 mm in diameter and 1.65 mm in length, and another is 1 mmD x 1 mmL. Hydrogen pellet velocity of about 900 m/s was observed at propellant gas (He) pressure of 14 kg/cm 2 . In the injection experiment into a plasma, typical velocity is 714 ∼ 833 m/s. These values are 80 ∼ 95 % of velocity calculated from the ideal gun model. The ejected pellet size is 71 ∼ 90 % of the hole size in the carrier disk (1.65 mmD x 1.65 mmL) and 46 ∼ 56 % (1 mmD x 1 mmL). The spread in the pellet trajectories is about 26 mm in diameter at a plasma center. (author)

  19. Effects of drought and salt stress on seed germination of three ...

    African Journals Online (AJOL)

    The seeds of Medicago sativa (L.), Astragalus adsurgens (Pall.) and Coronilla varia (L.) were evaluated at germination for tolerance to salt (NaCl) and drought conditions induced by polyethylene glycol (PEG) in an experiment of orthogonal design. The results reveal that the germination percentages of M. sativa and A.

  20. Axially alignable nuclear fuel pellets

    International Nuclear Information System (INIS)

    Johansson, E.B.; Klahn, D.H.; Marlowe, M.O.

    1978-01-01

    An axially alignable nuclear fuel pellet of the type stacked in end-to-end relationship within a tubular cladding is described. Fuel cladding failures can occur at pellet interface locations due to mechanical interaction between misaligned fuel pellets and the cladding. Mechanical interaction between the cladding and the fuel pellets loads the cladding and causes increased cladding stresses. Nuclear fuel pellets are provided with an end structure that increases plastic deformation of the pellets at the interface between pellets so that lower alignment forces are required to straighten axially misaligned pellets. Plastic deformation of the pellet ends results in less interactions beween the cladding and the fuel pellets and significantly lowers cladding stresses. The geometry of pellets constructed according to the invention also reduces alignment forces required to straighten fuel pellets that are tilted within the cladding. Plastic deformation of the pellets at the pellet interfaces is increased by providing pellets with at least one end face having a centrally-disposed raised area of convex shape so that the mean temperature and shear stress of the contact area is higher than that of prior art pellets

  1. Fuel pellet

    International Nuclear Information System (INIS)

    Hayashi, K.

    1980-01-01

    Fuel pellet for insertion into a cladding tube in order to form a fuel element or a fuel rod. The fuel pellet has got a belt-like projection around its essentially cylindrical lateral circumferential surface. The upper and lower edges in vertical direction of this belt-like projection are wave-shaped. The projection is made of the same material as the bulk pellet. Both are made in one piece. (orig.) [de

  2. Medicago sativa spp. falcata

    African Journals Online (AJOL)

    STORAGESEVER

    2009-05-18

    May 18, 2009 ... The aim of this study was to assess the genetic diversity of ... Regression analysis showed no relationship between genetic distance and phenotypic distance. ... For legumes, growth habit, flower color, leaf ..... 47.49±1.877abc.

  3. 46 CFR 148.04-21 - Coconut meal pellets (also known as copra pellets).

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Coconut meal pellets (also known as copra pellets). 148.04-21 Section 148.04-21 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DANGEROUS... § 148.04-21 Coconut meal pellets (also known as copra pellets). (a) Coconut meal pellets; (1) Must...

  4. Development of a pellet cutting and loading device for the JT-60 repetitive pellet injector

    International Nuclear Information System (INIS)

    Hiratsuka, Hajime; Ichige, Hisashi; Kizu, Kaname; Iwahashi, Takaaki; Honda, Masao

    2001-03-01

    In JT-60, a pellet injector that repetitively injects deuterium pellets is under development to supply fuel to high temperature plasmas and sustain high-density plasmas. The pellet injector generates cubic pellets and accelerates them with a straight-arm rotor by centrifugal force. In this acceleration method, it is important to supply pellets reliably and stably, to prevent pellet orbits from disordering and to stabilize the launching direction. To achieve higher performance of the injector, a pellet cutting and loading device that cuts a deuterium ice rod into cubic pellets and loads them to the pellet injector successively and stably has been developed. The pellet cutting and loading device can cut a deuterium ice rod produced at low temperature of -8 Pam 3 /s, cutting time of <3 ms, cutting frequency of 1-20 Hz and cutter stroke of 2.5 mm were confirmed in the device test. In the operation test after assembling this device to the centrifugal pellet injector, the operational performance of pellet injection frequency of ∼10 Hz, pellet speed of ∼690 m/s and pellet injection duration time of ∼3.5 s was achieved. Thus, the development of the pellet cutting and loading device contributed to the upgrade of the JT-60 pellet injector. (author)

  5. ORNL pellet acceleration program

    International Nuclear Information System (INIS)

    Foster, C.A.; Milora, S.L.

    1978-01-01

    The Oak Ridge National Laboratory (ORNL) pellet fueling program is centered around developing equipment to accelerate large pellets of solidified hydrogen to high speeds. This equipment will be used to experimentally determine pellet-plasma interaction physics on contemporary tokamaks. The pellet experiments performed on the Oak Ridge Tokamak (ORMAK) indicated that much larger, faster pellets would be advantageous. In order to produce and accelerate pellets of the order of 1 to 6 mm in diameter, two apparatuses have been designed and are being constructed. The first will make H 2 pellets by extruding a filament of hydrogen and mechanically chopping it into pellets. The pellets formed will be mechanically accelerated with a high speed arbor to a speed of 950 m/sec. This technique may be extended to speeds up to 5000 m/sec, which makes it a prime candidate for a reactor fueling device. In the second technique, a hydrogen pellet will be formed, loaded into a miniature rifle, and accelerated by means of high pressure hydrogen gas. This technique should be capable of speeds of the order of 1000 m/sec. While this technique does not offer the high performance of the mechanical accelerator, its relative simplicity makes it attractive for near-term experiments

  6. Non-enzymatic access to the plasma membrane of Medicago root hairs by laser microsurgery

    Energy Technology Data Exchange (ETDEWEB)

    Kurkdjian, A.; Leitz, G.; Manigault, P.; Harim, A.; Greulich, K. O.

    1993-07-01

    Using UV laser microsurgery, the cell walls of root hairs from Medicago sativa (alfalfa) were perforated under plasmolysing conditions, giving direct access to the plasma membrane without enzyme treatment. The opening in the cell wall of a few μm in diameter results in immediate movement of the protoplasm and partial or complete extrusion of the cell contents. The movement of the protoplasm is retarded by increases in calcium concentration. The calcium-dependency of the movement of the protoplasm allows us to obtain preferentially the extrusion of protoplasm, or to gain access to a small area of plasma membrane in situ. The complete protoplasm can be expelled, to form a protoplast. Fluorescein diacetate staining indicated esterase activity and membrane integrity of the protoplasts. Microscopic examination revealed organelle movement and the presence of a nucleus. The plasma membrane was free from cell wall fragments, as shown by Tinopal staining. Conditions for obtaining plasmolysis without disturbing the physiology of the root hairs too much were achieved by slow, stepwise and reversible plasmolysis. Cytoplasmic streaming in root hairs was maintained during plasmolysis and laser microperforation. This laser technique should be suitable for the performance of electrophysiological studies using the patch-clamp technique on plasma membrane from non-enzyme-treated cells. (author)

  7. Non-enzymatic access to the plasma membrane of Medicago root hairs by laser microsurgery

    International Nuclear Information System (INIS)

    Kurkdjian, A.; Leitz, G.; Manigault, P.; Harim, A.; Greulich, K.O.

    1993-01-01

    Using UV laser microsurgery, the cell walls of root hairs from Medicago sativa (alfalfa) were perforated under plasmolysing conditions, giving direct access to the plasma membrane without enzyme treatment. The opening in the cell wall of a few μm in diameter results in immediate movement of the protoplasm and partial or complete extrusion of the cell contents. The movement of the protoplasm is retarded by increases in calcium concentration. The calcium-dependency of the movement of the protoplasm allows us to obtain preferentially the extrusion of protoplasm, or to gain access to a small area of plasma membrane in situ. The complete protoplasm can be expelled, to form a protoplast. Fluorescein diacetate staining indicated esterase activity and membrane integrity of the protoplasts. Microscopic examination revealed organelle movement and the presence of a nucleus. The plasma membrane was free from cell wall fragments, as shown by Tinopal staining. Conditions for obtaining plasmolysis without disturbing the physiology of the root hairs too much were achieved by slow, stepwise and reversible plasmolysis. Cytoplasmic streaming in root hairs was maintained during plasmolysis and laser microperforation. This laser technique should be suitable for the performance of electrophysiological studies using the patch-clamp technique on plasma membrane from non-enzyme-treated cells. (author)

  8. Pellet injectors for JET

    International Nuclear Information System (INIS)

    Andelfinger, C.; Buechl, K.; Lang, R.S.; Schilling, H.B.; Ulrich, M.

    1981-09-01

    Pellet injection for the purpose of refuelling and diagnostic of fusion experiments is considered for the parameters of JET. The feasibility of injectors for single pellets and for quasistationary refuelling is discussed. Model calculations on pellet ablation with JET parameters show the required pellet velocity ( 3 ). For single pellet injection a light gas gun, for refuelling a centrifuge accelerator is proposed. For the latter the mechanical stress problems are discussed. Control and data acquisition systems are outlined. (orig.)

  9. Development of repetitive railgun pellet accelerator and steady-state pellet supply system

    International Nuclear Information System (INIS)

    Oda, Y.; Onozuka, M.; Azuma, K.; Kasai, S.; Hasegawa, K.

    1995-01-01

    A railgun system for repetitive high-speed pellet acceleration and steady-state pellet supply system has been developed and investigated. Using a 2m-long railgun system, the hydrogen pellet was accelerated to 2.6km/sec by the supplied energy of 1.7kJ. It is expected that the hydrogen pellet can be accelerated to 3km/sec using the present pneumatic pellet accelerator and a 2m-long augment railgun. Screw-driven hydrogen-isotope filament extruding system has been fabricated and will be tested to examine its applicability to the steady-state extrusion of the solid hydrogen-isotope filament

  10. Development of repetitive railgun pellet accelerator and steady-state pellet supply system

    Energy Technology Data Exchange (ETDEWEB)

    Oda, Y.; Onozuka, M.; Azuma, K. [Mitsubishi Heavy Industries, Ltd., Kobe (Japan); Kasai, S.; Hasegawa, K. [Japan Atomic Energy Research Inst., Naka (Japan)

    1995-12-31

    A railgun system for repetitive high-speed pellet acceleration and steady-state pellet supply system has been developed and investigated. Using a 2m-long railgun system, the hydrogen pellet was accelerated to 2.6km/sec by the supplied energy of 1.7kJ. It is expected that the hydrogen pellet can be accelerated to 3km/sec using the present pneumatic pellet accelerator and a 2m-long augment railgun. Screw-driven hydrogen-isotope filament extruding system has been fabricated and will be tested to examine its applicability to the steady-state extrusion of the solid hydrogen-isotope filament.

  11. Nuclear fuel pellet inspection system

    International Nuclear Information System (INIS)

    Ahmed, H.J.; Beatty, J.M.; Kugler, R.W.

    1992-01-01

    At least one axially extending linear portion of the peripheral surface of the pellet is optically sensed, a set of digital values representative of the pellet surface is generated, and the set is compared to a predetermined standard. Groups of adjacent locations on the surface of the pellet having values greater or less than the predetermined standard are identified, and the pellet is rejected, when a flawed area exceeds a predetermined size. During inspection, the pellet is moved axially through an inspection station by parallel support rolls, spaced by a distance less than the pellet diameter. The rolls are rotated upward and outward from each other, rotating the pellet, and chain dogs are positioned between the spaced rolls for engaging a pellet and moving it along the rolls. The pellet is rejected if its peripheral surface area is too great, and a reference pellet may be used. (author)

  12. Evaluation of the coat quality of sustained release pellets by individual pellet dissolution methodology.

    Science.gov (United States)

    Xu, Min; Liew, Celine Valeria; Heng, Paul Wan Sia

    2015-01-15

    This study explored the application of 400-DS dissolution apparatus 7 for individual pellet dissolution methodology by a design of experiment approach and compared its capability with that of the USP dissolution apparatus 1 and 2 for differentiating the coat quality of sustained release pellets. Drug loaded pellets were prepared by extrusion-spheronization from powder blends comprising 50%, w/w metformin, 25%, w/w microcrystalline cellulose and 25%, w/w lactose, and then coated with ethyl cellulose to produce sustained release pellets with 8% and 10%, w/w coat weight gains. Various pellet properties were investigated, including cumulative drug release behaviours of ensemble and individual pellets. When USP dissolution apparatus 1 and 2 were used for drug release study of the sustained release pellets prepared, floating and clumping of pellets were observed and confounded the release profiles of the ensemble pellets. Hence, the release profiles obtained did not characterize the actual drug release from individual pellet and the applicability of USP dissolution apparatus 1 and 2 to evaluate the coat quality of sustained release pellets was limited. The cumulative release profile of individual pellet using the 400-DS dissolution apparatus 7 was found to be more precise at distinguishing differences in the applied coat quality. The dip speed and dip interval of the reciprocating holder were critical operational parameters of 400-DS dissolution apparatus 7 that affected the drug release rate of a sustained release pellet during the individual dissolution study. The individual dissolution methodology using the 400-DS dissolution apparatus 7 is a promising technique to evaluate the individual pellet coat quality without the influence of confounding factors such as pellet floating and clumping observed during drug release test with dissolution apparatus 1 and 2, as well as to facilitate the elucidation of the actual drug release mechanism conferred by the applied sustained

  13. PBX/TFTR pellet program PPPL

    International Nuclear Information System (INIS)

    Schmidt, G.

    1986-01-01

    Goals, current results and plans for pellet injection work for the PBX and TFTR programs are outlined. The present PBX injector is a prototype for ORNL 4 pellet condensing injectors. It has demonstrated that pellet injection on PBX can be used to increase overall density and alter the density profile. Future PBX operation requires reliable operation in deuterium and tritium, multiple pellet capability and ability to vary the size of pellets. These goals will require the construction of a new injector similar to the TFTR DPI system. It has also been demonstrated that pellets can efficiently fuel TFTR, producing a clean, high density plasma. Issues which are still outstanding include isotope exchange effects, use of different pellet sizes, optimization of pellet density perturbations and pellet penetration at high beam power

  14. Pellet transfer apparatus and method

    International Nuclear Information System (INIS)

    DiGrande, J.T.; Huggins, T.B. Sr.; Lambert, D.V.; Roberts, E.

    1991-01-01

    This patent describes a pellet inspection system having a station for inspecting a predetermined parameter of a pellet. It comprises means for aligning and guiding pellets in a first row to be advanced along a linear path past the pellet inspecting station and in a second row previously advanced along the linear path past the pellet inspecting station; and a transfer mechanism operable for engaging at least one of the pellets in each of the first and second rows and moving from an initial position through a forward stroke to advance the first and second rows of pellets along the liner path such that the inspecting station can inspect the preselected parameter of the pellets in the first row as they are advanced successively , the transfer mechanism being operable for disengaging the pellets and moving through a return stroke relative to the stationary advanced first and second rows of pellets back to the initial position

  15. Pelletizing and combustion of wood from thinning; Pelletering och foerbraenning av gallringsvirke

    Energy Technology Data Exchange (ETDEWEB)

    Oerberg, Haakan; Thyrel, Mikael; Kalen, Gunnar; Larsson, Sylvia

    2007-12-14

    This work has been done in order to find new raw material sources for an expanding pellet industry, combined with finding a use for a forest product that has no market today. The raw material has been forest from early thinning in two typical stands in Vaesterbotten. The purpose has been to evaluate this material as a raw material for producing pellets. Two typical stands have been chosen. One stand with only pine trees and one mixed stand dominated by birch. The soil of these stands was poor. Half of the trees were delimbed by harvest and half of the trees were not delimbed. This formed four different assortments that were handled in the study. After harvesting the assortments were transported to an asphalt area to be stored. Half of the material was stored during one summer and half of the material was stored during one year and one summer. The different assortments were upgraded to pellets and test combusted in the research plant BTC at the Swedish University of Agricultural Sciences, in Umeaa. The upgrading process contains of the following steps: 1.Chipping by a mobile chipper. 2.Low temperature drying (85 deg C). 3. Coarse shredding ({phi}15 mm). 4. Fine shredding ({phi}4-6 mm) and 5. Pelletizing (Die: {phi}8). Samples for fuel analysis were taken during the chipping. Analyses shows that the net calorific value for delimbed assortments are about 0,3 MJ/kg DM higher than for limbed assortments. Pellets made of the assortments Mixed limbed and Pine limbed has shown a net calorific value comparable to stem wood pellets. Pellets made of Birch delimbed show a net calorific value 0,4 MJ/kg DM lower than stem wood pellets. Analyses show that ash contents of the assortment Mixed delimbed was 1 %-unit higher compared to stem wood pellets. The assortment Pine delimbed and Birch delimbed has showed an ash contents comparable with stem wood pellets. The ash melting characteristics can reduce the value of a raw material. Low ash melting temperature for a fuel might cause

  16. Manufacture of wood-pellets doubles. Biowatti Oy started a wood pellet plant in Turenki

    International Nuclear Information System (INIS)

    Rantanen, M.

    1999-01-01

    Wood pellets have many advantages compared to other fuels. It is longest processed biofuel with favorable energy content. It is simple to use, transport and store. Heating with wood pellets is cheaper than with light fuel oil, and approximately as cheap as utilization of heavy fuel oil, about 110 FIM/MWh. The taxable price of wood pellets is about 550 FIM/t. Stokers and American iron stoves are equally suitable for combustion of wood pellets. Chip fueled stokers are preferred in Finland, but they are also suitable for the combustion of wood pellets. Wood pellets is an environmentally friendly product, because it does not increase the CO 2 load in the atmosphere, and its sulfur and soot emissions are relatively small. The wood pelletizing plant of Biowatti Oy in Turenki was started in an old sugar mill. The Turenki sugar mill was chosen because the technology of the closed sugar factory was suitable for production of wood pellets nearly as such, and required only by slight modifications. A press, designed for briquetting of sugar beat clippings makes the pellets. The Turenki mill will double the volume of wood pellet manufacture in Finland during the next few years. At the start the annual wood pellet production will be 20 000 tons, but the environmental permit allows the production to be increased to 70 000 tons. At first the mill uses planing machine chips as a raw material in the production. It is the most suitable raw material, because it is already dry (moisture content 8-10%), and all it needs is milling and pelletizing. Another possible raw material is sawdust, which moisture content is higher than with planing machine chips. Most of the wood pellets produced are exported e.g. to Sweden, Denmark and Middle Europe. In Sweden there are over 10 000 single-family houses using wood pellets. Biowatti's largest customer is a power plant located in Stockholm, which combusts annually about 200 000 tons of wood pellets

  17. Nuclear fuel pellet loading machine

    International Nuclear Information System (INIS)

    Dazen, J.R.; Denero, J.V.

    1976-01-01

    A nuclear fuel pellet loading machine is described including an inclined rack mounted on a base and having parallel spaced grooves on its upper surface arranged to support fuel rods. A fuel pellet tray is adapted to be placed on a table spaced from the rack, the tray having columns of fuel pellets which are in alignment with the open ends of fuel rods located in the rack grooves. A transition plate is mounted between the fuel rod rack and the fuel pellet tray to receive and guide the pellets into the open ends of the fuel rods. The pellets are pushed into the fuel rods by a number of mechanical fingers mounted on a motor operated block which is moved along the pellet tray length by a drive screw driven by the motor. To facilitate movement of the pellets in the fuel rods the rack is mounted on a number of spaced vibrators which vibrate the fuel rods during fuel pellet insertion. A pellet sensing device movable into an end of each fuel rod indicates to an operator when each rod has been charged with the correct number of pellets

  18. Deuterium pellet injector gun design

    International Nuclear Information System (INIS)

    Lunsford, R.V.; Wysor, R.B.; Bryan, W.E.; Shipley, W.D.; Combs, S.K.; Foust, C.R.; Milora, S.L.; Fisher, P.W.

    1985-01-01

    The Deuterium Pellet Injector (DPI), an eight-pellet pneumatic injector, is being designed and fabricated for the Tokamak Fusion Test Reactor (TFTR). It will accelerate eight pellets, 4 by 4 mm maximum, to greater than 1500 m/s. It utilizes a unique pellet-forming mechanism, a cooled pellet storage wheel, and improved propellant gas scavenging

  19. Technology and distribution of pellets. Experience about the European network on wood pellets

    International Nuclear Information System (INIS)

    Rapp, S.W.

    1999-01-01

    Wood pellets might become the most important alternative to fossil fuels in the near future. As a bio-fuel it has the following characteristics: heat value, min 4.7 kWh/kg; ash fraction less than 1.0 vol. %; humidity less than 10 vol. %; diameter (rod shaped) min 6 mm and volumetric weight about 650 kg/m 3 . About 2.1 t pellets substitute 1000 l fuel oil. Sweden and Austria have more than 15 year experience in using wood pellets, followed by Germany. They are an environmentally friendly alternative for private houses, for district heating plants and especially suitable for densely built-up and inhabited areas. Having high energy density they can be transported to the areas with high energy requirements. Among their advantages are: low humidity, easy transport and storage, can be produced by renewable raw materials and provide new local jobs, fit for renewable energy systems with closed cycle. Disadvantages include: relatively more expensive for private houses compared to oil and gas and necessity of two times larger storage space than oil. Wood pellets are produced by all kind of paper waste and wood wastes from industry. They are especially suitable for small boiler plants and the oil burner can be replaced by a pellet burner in the same boiler. The leading producer of wood pellets is Sweden, of pellet stoves - USA. Pellet stoves, pellet burners and pellet boilers both for private houses and for heating plants are manufactured also in Sweden, Denmark,Finland, Germany, Austria and Ireland

  20. Spatio-Temporal Expression Patterns of Arabidopsis thaliana and Medicago truncatula Defensin-Like Genes

    Science.gov (United States)

    Nallu, Sumitha; Wang, Lin; Botanga, Christopher J.; Gomez, S. Karen; Costa, Liliana M.; Harrison, Maria J.; Samac, Deborah A.; Glazebrook, Jane; Katagiri, Fumiaki; Gutierrez-Marcos, Jose F.; VandenBosch, Kathryn A.

    2013-01-01

    Plant genomes contain several hundred defensin-like (DEFL) genes that encode short cysteine-rich proteins resembling defensins, which are well known antimicrobial polypeptides. Little is known about the expression patterns or functions of many DEFLs because most were discovered recently and hence are not well represented on standard microarrays. We designed a custom Affymetrix chip consisting of probe sets for 317 and 684 DEFLs from Arabidopsis thaliana and Medicago truncatula, respectively for cataloging DEFL expression in a variety of plant organs at different developmental stages and during symbiotic and pathogenic associations. The microarray analysis provided evidence for the transcription of 71% and 90% of the DEFLs identified in Arabidopsis and Medicago, respectively, including many of the recently annotated DEFL genes that previously lacked expression information. Both model plants contain a subset of DEFLs specifically expressed in seeds or fruits. A few DEFLs, including some plant defensins, were significantly up-regulated in Arabidopsis leaves inoculated with Alternaria brassicicola or Pseudomonas syringae pathogens. Among these, some were dependent on jasmonic acid signaling or were associated with specific types of immune responses. There were notable differences in DEFL gene expression patterns between Arabidopsis and Medicago, as the majority of Arabidopsis DEFLs were expressed in inflorescences, while only a few exhibited root-enhanced expression. By contrast, Medicago DEFLs were most prominently expressed in nitrogen-fixing root nodules. Thus, our data document salient differences in DEFL temporal and spatial expression between Arabidopsis and Medicago, suggesting distinct signaling routes and distinct roles for these proteins in the two plant species. PMID:23527067

  1. Spatio-temporal expression patterns of Arabidopsis thaliana and Medicago truncatula defensin-like genes.

    Directory of Open Access Journals (Sweden)

    Mesfin Tesfaye

    Full Text Available Plant genomes contain several hundred defensin-like (DEFL genes that encode short cysteine-rich proteins resembling defensins, which are well known antimicrobial polypeptides. Little is known about the expression patterns or functions of many DEFLs because most were discovered recently and hence are not well represented on standard microarrays. We designed a custom Affymetrix chip consisting of probe sets for 317 and 684 DEFLs from Arabidopsis thaliana and Medicago truncatula, respectively for cataloging DEFL expression in a variety of plant organs at different developmental stages and during symbiotic and pathogenic associations. The microarray analysis provided evidence for the transcription of 71% and 90% of the DEFLs identified in Arabidopsis and Medicago, respectively, including many of the recently annotated DEFL genes that previously lacked expression information. Both model plants contain a subset of DEFLs specifically expressed in seeds or fruits. A few DEFLs, including some plant defensins, were significantly up-regulated in Arabidopsis leaves inoculated with Alternaria brassicicola or Pseudomonas syringae pathogens. Among these, some were dependent on jasmonic acid signaling or were associated with specific types of immune responses. There were notable differences in DEFL gene expression patterns between Arabidopsis and Medicago, as the majority of Arabidopsis DEFLs were expressed in inflorescences, while only a few exhibited root-enhanced expression. By contrast, Medicago DEFLs were most prominently expressed in nitrogen-fixing root nodules. Thus, our data document salient differences in DEFL temporal and spatial expression between Arabidopsis and Medicago, suggesting distinct signaling routes and distinct roles for these proteins in the two plant species.

  2. Review of pellet fueling

    International Nuclear Information System (INIS)

    Turnbull, R.J.

    1978-01-01

    Fusion reactors based on the Tokamak concept (possibly mirrors, too) will require a low energy method of fueling. Refueling by using solid pellets of hydrogen isotopes appears to be the most promising low energy technique. The main issue in assessing the feasibility of pellet fueling is the ability of the pellet to penetrate into the central region of the reactor. A review is presented of the various theories predicting the lifetime of the pellet and their regions of applicability. Among the phenomena considered are neutral ablation of the solid, ionized ablation of the solid, shielding of the pellet by neutral molecules and electrons and ions, flow of the ablation cloud, distortion of the magnetic field by the flow of an ionized ablation cloud, and charging and electrostatic shielding of the pellet. A brief summary of results of experiments done by the University of Illinois-Oak Ridge and Riso groups is presented. The results of these experiments indicate that, at least at the low temperatures and densities used, a neutral ablation-neutral shielding model is correct. Finally, since all indications are that in order for pellet fueling to be successful, high velocity pellets will be needed, a brief discussion of possible acceleration techniques is presented

  3. Nutritive evaluation of Medicago truncutula (cv. jernalong) pasture ...

    African Journals Online (AJOL)

    Nutritive evaluation of Medicago truncutula (cv. jernalong) pasture for sheep. 1. Seasonal .... obtained by laboratory work, using in vitro techniques. (Engels et al. .... model that was used to explain 92,3% of the variance in. IVDOM content.

  4. Tritium pellet injector results

    International Nuclear Information System (INIS)

    Fisher, P.W.; Bauer, M.L.; Baylor, L.R.; Deleanu, L.E.; Fehling, D.T.; Milora, S.L.; Whitson, J.C.

    1988-01-01

    Injection of solid tritium pellets is considered to be the most promising way of fueling fusion reactors. The Tritium Proof-of- Principle (TPOP) experiment has demonstrated the feasibility of forming and accelerating tritium pellets. This injector is based on the pneumatic pipe-gun concept, in which pellets are formed in situ in the barrel and accelerated with high-pressure gas. This injector is ideal for tritium service because there are no moving parts inside the gun and because no excess tritium is required in the pellet production process. Removal of 3 He from tritium to prevent blocking of the cryopumping action by the noncondensible gas has been demonstrated with a cryogenic separator. Pellet velocities of 1280 m/s have been achieved for 4-mm-diam by 4-mm-long cylindrical tritium pellets with hydrogen propellant at 6.96 MPa (1000 psi). 10 refs., 10 figs

  5. Characterization of Cannabis sativa allergens.

    Science.gov (United States)

    Nayak, Ajay P; Green, Brett J; Sussman, Gordon; Berlin, Noam; Lata, Hemant; Chandra, Suman; ElSohly, Mahmoud A; Hettick, Justin M; Beezhold, Donald H

    2013-07-01

    Allergic sensitization to Cannabis sativa is rarely reported, but the increasing consumption of marijuana has resulted in an increase in the number of individuals who become sensitized. To date, little is known about the causal allergens associated with C sativa. To characterize marijuana allergens in different components of the C sativa plant using serum IgE from marijuana sensitized patients. Serum samples from 23 patients with a positive skin prick test result to a crude C sativa extract were evaluated. IgE reactivity was variable between patients and C sativa extracts. IgE reactivity to C sativa proteins in Western blots was heterogeneous and ranged from 10 to 70 kDa. Putative allergens derived from 2-dimensional gels were identified. Prominent IgE reactive bands included a 23-kDa oxygen-evolving enhancer protein 2 and a 50-kDa protein identified to be the photosynthetic enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase. Additional proteins were identified in the proteomic analysis, including those from adenosine triphosphate synthase, glyceraldehyde-3-phosphate dehydrogenase, phosphoglycerate kinase, and luminal binding protein (heat shock protein 70), suggesting these proteins are potential allergens. Deglycosylation studies helped refine protein allergen identification and demonstrated significant IgE antibodies against plant oligosaccharides that could help explain cross-reactivity. Identification and characterization of allergens from C sativa may be helpful in further understanding allergic sensitization to this plant species. Copyright © 2013 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  6. Fundamentals of Biomass pellet production

    DEFF Research Database (Denmark)

    Holm, Jens Kai; Henriksen, Ulrik Birk; Hustad, Johan Einar

    2005-01-01

    Pelletizing experiments along with modelling of the pelletizing process have been carried out with the aim of understanding the fundamental physico-chemical mechanisms that control the quality and durability of biomass pellets. A small-scale California pellet mill (25 kg/h) located with the Biomass...

  7. Modeling pellet impact drilling process

    Science.gov (United States)

    Kovalyov, A. V.; Ryabchikov, S. Ya; Isaev, Ye D.; Ulyanova, O. S.

    2016-03-01

    The paper describes pellet impact drilling which could be used to increase the drilling speed and the rate of penetration when drilling hard rocks. Pellet impact drilling implies rock destruction by metal pellets with high kinetic energy in the immediate vicinity of the earth formation encountered. The pellets are circulated in the bottom hole by a high velocity fluid jet, which is the principle component of the ejector pellet impact drill bit. The experiments conducted has allowed modeling the process of pellet impact drilling, which creates the scientific and methodological basis for engineering design of drilling operations under different geo-technical conditions.

  8. Multi-shot type pellet injection device

    International Nuclear Information System (INIS)

    Onozuka, Masaki; Uchikawa, Takashi; Kuribayashi, Shitomi.

    1988-01-01

    Purpose: To inject pellets at high speed without melting or sublimating not-injected pellets even at a long pellet injection interval. Constitution: In the conventional multi-shot pellet injection device, the pellet injection interval is set depending on the plasma retention time. However, as the pellet injection interval is increased, not-injected pellets are melted or sublimated due to the introduced heat of acceleration gases supplied from an acceleration gas introduction pipe to give an effect on the dimensional shape of the pellets. In view of the above, a plurality of pellet forming and injection portions each comprising a carrier, an injection pipe and a holder are disposed independently of each other and pellets are formed and injected independently to thereby prevent the thermal effects of the acceleration gases. (Kamimura, M.)

  9. Multi-shot type pellet injection device

    Energy Technology Data Exchange (ETDEWEB)

    Onozuka, Masaki; Uchikawa, Takashi; Kuribayashi, Shitomi.

    1988-07-27

    Purpose: To inject pellets at high speed without melting or sublimating not-injected pellets even at a long pellet injection interval. Constitution: In the conventional multi-shot pellet injection device, the pellet injection interval is set depending on the plasma retention time. However, as the pellet injection interval is increased, not-injected pellets are melted or sublimated due to the introduced heat of acceleration gases supplied from an acceleration gas introduction pipe to give an effect on the dimensional shape of the pellets. In view of the above, a plurality of pellet forming and injection portions each comprising a carrier, an injection pipe and a holder are disposed independently of each other and pellets are formed and injected independently to thereby prevent the thermal effects of the acceleration gases. (Kamimura, M.).

  10. Pellet imaging techniques on ASDEX

    International Nuclear Information System (INIS)

    Wurden, G.A.; Buechl, K.; Hofmann, J.; Lang, R.; Loch, R.; Rudyj, A.; Sandmann, W.

    1990-01-01

    As part of a USDOE/ASDEX collaboration, a detailed examination of pellet ablation in ASDEX with a variety of diagnostics has allowed a better understanding of a number of features of hydrogen ice pellet ablation in a plasma. In particular, fast gated photos with an intensified Xybion CCD video camera allow in-situ velocity measurements of the pellet as it penetrates the plasma. With time resolution of typically 100 nanoseconds and exposures every 50 microseconds, the evolution of each pellet in a multi-pellet ASDEX tokamak plasma discharge can be followed. When the pellet cloud track has striations, the light intensity profile through the cloud is hollow (dark near the pellet), whereas at the beginning or near the end of the pellet trajectory the track is typically smooth (without striations) and has a gaussian-peaked light emission profile. New, single pellet Stark broadened D α D β , and D γ spectra, obtained with a tangentially viewing scanning mirror/spectrometer with Reticon array readout, are consistent with cloud densities of 2 x 10 17 cm -3 or higher in the regions of strongest light emission. A spatially resolved array of D α detectors shows that the light variations during the pellet ablation are not caused solely by a modulation of the incoming energy flux as the pellet crosses rational q-surfaces, but instead are a result of a dynamic, non-stationary, ablation process. 20 refs., 4 figs

  11. Methane pellet moderator development

    International Nuclear Information System (INIS)

    Foster, C.A.; Schechter, D.E.; Carpenter, J.M.

    2004-01-01

    A methane pellet moderator assembly consisting of a pelletizer, a helium cooled sub-cooling tunnel, a liquid helium cooled cryogenic pellet storage hopper and a 1.5L moderator cell has been constructed for the purpose demonstrating a system for use in high-power spallation sources. (orig.)

  12. Nuclear fuel pellet collating system and method

    International Nuclear Information System (INIS)

    Rieben, S.L.; Kugler, R.W.; Scherpenberg, J.J.; Wiersema, D.T.

    1990-01-01

    This patent describes a method of collating nuclear fuel pellets. It comprises: supporting a plurality of pellet supply trays and a plurality of pellet storage trays at a tray positioning station. Each of the supply trays containing in at least one row thereon a plurality of nuclear fuel pellets of an enrichment different from the enrichment pellets on at least some other of the supply trays; transferring one pellet supply tray from the tray positioning station and disposing the same at an input station of a pellet collating line; transferring one pellet storage tray from the tray positioning station and disposing the same at an output station of the pellet collating line; sweeping pellets in the at least one row thereof from the one pellet supply tray onto a work station of the pellet collating line located between the input and output stations thereof; measuring a desired length of pellets in the at least one row on the work station and separating the measured desired length of pellets from the remaining pellets, if any, in the row thereof; sweeping the remaining pellets, if any, in the row from the work station back onto the one pellet supply tray; transferring the one pellet supply tray and remaining pellets, if any, back to the tray positioning station; sweeping the measured desired length of pellets from the work station onto the one pellet storage tray; and transferring the one pellet storage tray and measured desired length of pellets back to the tray positioning station

  13. Second jet workshop on pellet injection: pellet fueling program in the United States. Summary

    International Nuclear Information System (INIS)

    Milora, S.L.

    1983-01-01

    S. Milora described the US programme on pellet injection. It has four parts: (1) a confinement experimental program; (2) pellet injector development; (3) theoretical support; and (4) tritium pellet study for TFTR

  14. Sequence divergence of microsatellites for phylogeographic assessment of Moroccan Medicago species.

    Science.gov (United States)

    Zitouna, N; Marghali, S; Gharbi, M; Haddioui, A; Trifi-Farah, N

    2014-03-12

    Six Medicago species were investigated to characterize and valorize plant genetic resources of pastoral interest in Morocco. Samples were obtained from the core collection of the South Australian Research and Development Institute (SARDI). The transferability of single sequence repeat markers of Medicago truncatula was successful with 97.6% efficiency across the five species. A total of 283 alleles and 243 genotypes were generated using seven SSR markers, confirming the high level of polymorphism that is characteristic of the Medicago genus, despite a heterozygosity deficit (HO = 0.378; HE = 0.705). In addition, a high level of gene flow was revealed among the species analyzed with significant intra-specific variation. The unweighted pair group method with arithmetic mean dendrogram generated by the dissimilarity matrix revealed that M. polymorpha and M. orbicularis are closely related, and that M. truncatula is likely the ancestral species. The Pearson correlation index revealed no significant correlations between the geographic distribution of the Moroccan species and genetic similarities, indicating local adaptation of these species to different ecological environments independent of their topographical proximities. The substantial genetic variation observed was likely due to the predominance of selfing species, the relative proximity of prospected sites, human impacts, and the nature of the SARDI core collections, which are selected for their high genetic diversity. The results of this first report on Moroccan Medicago species will be of great interest for establishing strategies aiming at reasonable management and selection programs for local and Mediterranean germplasm in the face of increasing environmental change.

  15. Steam-treated wood pellets: Environmental and financial implications relative to fossil fuels and conventional pellets for electricity generation

    International Nuclear Information System (INIS)

    McKechnie, Jon; Saville, Brad; MacLean, Heather L.

    2016-01-01

    Highlights: • Steam-treated pellets can greatly reduce greenhouse gas emissions relative to coal. • Cost advantage is seen relative to conventional pellets. • Higher pellet cost is more than balanced by reduced retrofit capital requirements. • Low capacity factors further favour steam-treated pellets over conventional pellets. - Abstract: Steam-treated pellets can help to address technical barriers that limit the uptake of pellets as a fuel for electricity generation, but there is limited understanding of the cost and environmental impacts of their production and use. This study investigates life cycle environmental (greenhouse gas (GHG) and air pollutant emissions) and financial implications of electricity generation from steam-treated pellets, including fuel cycle activities (biomass supply, pellet production, and combustion) and retrofit infrastructure to enable 100% pellet firing at a generating station that previously used coal. Models are informed by operating experience of pellet manufacturers and generating stations utilising coal, steam-treated and conventional pellets. Results are compared with conventional pellets and fossil fuels in a case study of electricity generation in northwestern Ontario, Canada. Steam-treated pellet production has similar GHG impacts to conventional pellets as their higher biomass feedstock requirement is balanced by reduced process electricity consumption. GHG reductions of more than 90% relative to coal and ∼85% relative to natural gas (excluding retrofit infrastructure) could be obtained with both pellet options. Pellets can also reduce fuel cycle air pollutant emissions relative to coal by 30% (NOx), 97% (SOx), and 75% (PM 10 ). Lesser retrofit requirements for steam-treated pellets more than compensate for marginally higher pellet production costs, resulting in lower electricity production cost compared to conventional pellets ($0.14/kW h vs. $0.16/kW h). Impacts of retrofit infrastructure become increasingly

  16. Cloning and characterization of a heme oxygenase-2 gene from alfalfa (Medicago sativa L.).

    Science.gov (United States)

    Fu, Guang-Qing; Jin, Qi-Jiang; Lin, Yu-Ting; Feng, Jian-Fei; Nie, Li; Shen, Wen-Biao; Zheng, Tian-Qing

    2011-11-01

    Heme oxygenase (HO, EC 1.14.99.3) catalyzes the oxidation of heme and performs vital roles in plant development and stress responses. Two HO isozymes exist in plants. Between these, HO-1 is an oxidative stress-response protein, and HO-2 usually exhibited constitutive expression. Although alfalfa HO-1 gene (MsHO1) has been investigated previously, HO2 is still poorly understood. In this study, we report the cloning and characterization of HO2 gene, MsHO2, from alfalfa (Medica sativa L.). The full-length cDNA of MsHO2 contains an ORF of 870 bp and encodes for 290 amino acid residues with a predicted molecular mass of 33.3 kDa. Similar to MsHO1, MsHO2 also appears to have an N-terminal transit peptide sequence for chloroplast import. Many conserved residues in plant HO were also conserved in MsHO2. However, unlike HO-1, the conserved histidine (His) required for heme-iron binding and HO activity was replaced by tyrosine (Tyr) in MsHO2. Further biochemical activity analysis of purified mature MsHO2 showed no HO activity, suggesting that MsHO2 may not be a true HO in nature. Semi-quantitative RT-PCR confirmed its maximum expression in the germinating seeds. Importantly, the expression levels of MsHO2 were up-regulated under sodium nitroprusside (SNP) and H(2)O(2) (especially) treatment, respectively.

  17. Wood pellets in a power plant - mixed combustion of coal and wood pellets

    International Nuclear Information System (INIS)

    Nupponen, M.

    2001-01-01

    The author reviews in his presentation the development of Turku Energia, the organization of the company, the key figures of the company in 2000, as well as the purchase of energy in 2000. He also presents the purchase of basic heat load, the energy production plants of the company, the sales of heat in 2000, the emissions of the plants, and the fuel consumption of the plants in 2000. The operating experiences of the plants are also presented. The experiences gained in Turku Energia on mixed combustion of coal and wood pellets show that the mixing ratios, used at the plants, have no effect on the burning properties of the boiler, and the use of wood pellets with coal reduce the SO 2 and NO x emissions slightly. Simultaneously the CO 2 share of the wood pellets is removed from the emissions calculations. Several positive effects were observed, including the disappearance of the coal smell of the bunker, positive publicity of the utilization of wood pellets, and the subsidies for utilization of indigenous fuels in power generation. The problems seen include the tendency of wood pellets to arc the silos, especially when the pellets include high quantities of dust, and the loading of the trucks and the pneumatic unloading of the trucks break the pellets. Additionally the wood pellets bounce on the conveyor so they drop easily from the conveyor, the screw conveyors designed for conveying grain are too weak and they get stuck easily, and static electricity is easily generated in the plastic pipe used as the discharge pipe for wood pellet (sparkling tendency). This disadvantage has been overcome by using metal net and grounding

  18. The promotive effect of N 2 fixers, Bacillus circulans and ...

    African Journals Online (AJOL)

    The promotive effect of N 2 fixers, Bacillus circulans and Saccharomyces cerevisiae on the viability of native arbuscular mycorrhizal fungi and the impact on the productivity of alfalfa ( Medicago sativa l.)

  19. Pellet injector development at ORNL

    International Nuclear Information System (INIS)

    Milora, S.L.; Argo, B.E.; Baylor, L.R.; Cole, M.J.; Combs, S.K.; Dyer, G.R.; Fehling, D.T.; Fisher, P.W.; Foster, C.A.; Foust, C.R.; Gouge, M.J.; Jernigan, T.C.; Langley, R.A.; Qualls, A.L.; Schechter, D.E.; Sparks, D.O.; Tsai, C.C.; Whealton, J.H.; Wilgen, J.B.; Schmidt, G.L.

    1992-01-01

    Plasma fueling systems for magnetic confinement experiments are under development at Oak Ridge National Laboratory (ORNL). ORNL has recently provided a four-shot tritium pellet injector with up to 4-mm-diam capability for the Tokamak Fusion Test Reactor (TFTR). This injector, which is based on the in situ condensation technique for pellet formation, features three single-stage gas guns that have been qualified in deuterium at up to 1.7 km/s and a two-stage light gas gun driver that has been operated at 2.8-km/s pellet speeds for deep penetration in the high-temperature TFTR supershot regime. Performance improvements to the centrifugal pellet injector for the Tore Supra tokamak are being made by modifying the storage-type pellet feed system, which has been redesigned to improve the reliability of delivery of pellets and to extend operation to longer pulse durations (up to 400 pellets). Two-stage light gas guns and electron-beam (e-beam) rocket accelerators for speeds in the range from 2 to 10 km/s are also under development. A repeating, two-stage light gas gun that has been developed can accelerate low-density plastic pellets at a 1-Hz repetition rate to speeds of 3 km/s. In a collaboration with ENEA-Frascati, a test facility has been prepared to study repetitive operation of a two-stage gas gun driver equipped with an extrusion-type deuterium pellet source. Extensive testing of the e-beam accelerator has demonstrated a parametric dependence of propellant burn velocity and pellet speed, in accordance with a model derived from the neutral gas shielding theory for pellet ablation in a magnetized plasma

  20. Pellets standard on the way

    International Nuclear Information System (INIS)

    Laeng, H.-P.

    2001-01-01

    This short article introduces the Swiss standard that has been adapted from the German standard for heating pellets made of untreated wood. The various requirements placed on the materials used in the manufacture of the pellets and their influence on the pollution emissions produced by boilers and ovens using the pellets as a heating fuel are listed. Further points in the standard referring to declarations to be made by the manufacturer, size and specific weight of the pellets and instructions for the storage and burning of the pellets are discussed

  1. Pneumatic pellet injector for JET

    International Nuclear Information System (INIS)

    Andelfinger, C.; Buechl, K.; Jacobi, D.; Sandmann, W.; Schiedeck, J.; Schilling, H.B.; Weber, G.

    1983-07-01

    Pellet injection is a useful tool for plasma diagnostics of tokamaks. Pellets can be applied for investigation of particle, energy and impurity transport, fueling efficiency and magnetic surfaces. Design, operation and control of a single shot pneumatic pellet gun is described in detail including all supplies, the vacuum system and the diagnostics of the pellet. The arrangement of this injector in the torus hall and the interfaces to the JET system and CODAS are considered. A guide tube system for pellet injection is discussed but it will not be recommended for JET. (orig.)

  2. Sinorhizobium meliloti can protect Medicago truncatula against Phoma medicaginis attack

    Directory of Open Access Journals (Sweden)

    Moncef MRABET

    2011-09-01

    Full Text Available The Sinorhizobium meliloti microsymbiont of Medicago spp. was used in an antibiosis test against Phoma medicaginis and in bioprotection assays of Medicago truncatula JA17 from the pathogen. Among 17 S. meliloti strains isolated from root nodules of M. truncatula and Medicago laciniata grown in Tunisian soils, six showed up to 60% growth inhibition of five P. medicaginis strains isolated from infected field-grown M. truncatula. Two S. meliloti strains with differing in vitro effects on P. medicaginis, 10.16/R6 antagonist and 5M6 non antagonist, were used in a bioprotection assay of M. truncatula JA17 from the pathogen. The inoculation of P. medicaginis caused complete root and stem rotting, and the mortality of all treated plantlets. Inoculation of the antagonist S. meliloti strain 10.16/R6 to M. truncatula JA17 infected with P. medicaginis was associated with a significant 65% decrease of vegetative rotting length, an 80% decrease of plant mortality, an increase of root length, and enhancement of root and shoot biomass comparatively to control plantlets treated with P. medicaginis. The inoculation of the non antagonistic S. meliloti strain 5M6 slightly decreased disease and slightly increased plant growth parameters.

  3. Pellet injection in WVIIA

    International Nuclear Information System (INIS)

    Renner, H.; Wuersohing, E.; Weller, A.; Jaeckel, H.; Hartfuss, H.; Hacker, H.; Ringler, H.; Buechl, K.

    1986-01-01

    The results of pellet injection experiments in the Wendelstein VII A stellarator are presented. The injector was a single shot pneumatic gun using deuterium pellets. Experiments were carried out in both ECRH and NI plasmas. Data is shown for plasma density, energy confinement, penetration depth and pellet ablation. Results are compared to a neutral gas shielding model

  4. Nuclear fuel pellet loading machine

    International Nuclear Information System (INIS)

    Kee, R.W.; Denero, J.V.

    1975-01-01

    An apparatus for loading nuclear fuel pellets on trays for transfer in a system is described. A conveyor supplies pellets from a source to a loading station. When the pellets reach a predetermined position at the loading station, a manual or automatically operated arm pushes the pellets into slots on a tray and this process is repeated until pellet sensing switches detect that the tray is full. Thereupon, the tray is lowered onto a belt or other type conveyor and transferred to other apparatus in the system, such as a furnace for sintering, and in some cases, reduction of UO 2 . 2 to UO 2 . The pellets are retained on the tray and subsequently loaded directly into fuel rods to be used in the reactor core. (auth)

  5. Fuel rod pellet loading head

    International Nuclear Information System (INIS)

    Howell, T.E.

    1975-01-01

    An assembly for loading nuclear fuel pellets into a fuel rod comprising a loading head for feeding pellets into the open end of the rod is described. The pellets rest in a perforated substantially V-shaped seat through which air may be drawn for removal of chips and dust. The rod is held in place in an adjustable notched locator which permits alignment with the pellets

  6. Wood pellets : a worldwide fuel commodity

    International Nuclear Information System (INIS)

    Melin, S.

    2005-01-01

    Aspects of the wood pellet industry were discussed in this PowerPoint presentation. Details of wood pellets specifications were presented, and the wood pellet manufacturing process was outlined. An overview of research and development activities for wood pellets was presented, and issues concerning quality control were discussed. A chart of the effective calorific value of various fuels was provided. Data for wood pellet mill production in Canada, the United States and the European Union were provided, and various markets for Canadian wood pellets were evaluated. Residential sales as well as Canadian overseas exports were reviewed. Production revenues for British Columbia and Alberta were provided. Wood pellet heat and electricity production were discussed with reference to prefabricated boilers, stoves and fireplaces. Consumption rates, greenhouse gas (GHG) emissions, and fuel ratios for wood pellets and fossil fuels were compared. Price regulating policies for electricity and fossil fuels have prevented the domestic expansion of the wood pellet industry. There are currently no incentives for advanced biomass combustion to enter British Columbia markets, and this has led to the export of wood pellets. It was concluded that climate change mitigation policies will be a driving force behind market expansion for wood pellets. tabs., figs

  7. Quality wood chips - an alternative to pellets; Alternative zu Pellets. Qualischnitzel

    Energy Technology Data Exchange (ETDEWEB)

    Keel, A.

    2008-07-01

    This article takes a look at a new wood-chip product that features wood-chips that are dryer than traditional ones. The new 'quality chips' are also of a calibrated size and are supplied dust-free. Their low water content permits their use in the same areas as wood pellets, where, especially in summer, low water-content is important. The increasing use of pellets and the growing shortages of clean sawdust and shavings for their production is commented on, as is the use of forestry wastes in pellet production. The new wood-chip product is further discussed as being a direct alternative to pellets. The low 'grey energy' content for tree-felling, hacking, transport and the drying of the chips is quoted as being less than 5% of the energy in the chippings.

  8. Review: study of single-pellet injection experiments and development of pellet injector in JFT-2M

    International Nuclear Information System (INIS)

    Kasai, Satoshi; Miura, Yukitoshi; Hasegawa, Kouichi; Sengoku, Seio

    1987-10-01

    The single pellet injector developed for JFT-2M and the improvement of plasma characteristics in the auxiliary-heated discharges by single-pellet injection are reviewed for the period 1982 - 1986. The pellet injector is a pneumatic type and the designed pellet size is 1.65 mmD x 1.65 mmL and 1 mmD x 1 mmL. The hydrogen, deuterium and mixed (H 2 + D 2 ) pellets can be produced with good reproducibility. Maximum pellet velocity is about 970 m/s (pellet is deuterium and propellant gas is hydrogen). In the pellet injection experiments into auxiliary-heated (NB, ICRF) divertor or limiter discharges, the plasma confinement time is improved by a factor of 1.4 - 1.7 compared with the confinement time in the Ohmic discharges. The achieved confinement time is longer than that on the high confinement mode (H-mode) in gas fueled discharges, although the phenomena are transient. (author)

  9. Pellet injection into ASDEX upgrade plasmas

    International Nuclear Information System (INIS)

    Lang, P.T.; Zohm, H.; Buechl, K.; Fuchs, J.C.; Gehre, O.; Gruber, O.; Lang, R.S.; Mertens, V.; Neuhauser, J.; Salzmann, H.

    1996-04-01

    This work comprises results obtained using the new centrifuge injection system for the two first years of pellet injection experiments at Asdex Upgrade until the end of the 1995 experimental campaign. The main aim of the pellet injection investigation is to develop scenarios allowing for a more flexible plasma density control means of injection of cryogenic solid hydrogen pellets. Efforts have been made to develop scenarios allowing more flexible plasma density control by injecting cryogenic solid hydrogen pellets. While the injection of pellets during ohmic discharges was found to be most efficient and also improves the plasma performance, increasing the auxiliary heating power causes a detoriation of the pellet fuelling efficiency. A further strong reduction of the pellet fuelling efficiency by an additional process was observed for the more reactor-relevant conditions of shallow particle deposition during H-mode phases. With injection during type I ELMy H-mode phases, each pellet was found to trigger the release of an ELM and therefore cause particle losses mainly from the edge region. In the type I ELMy H-mode, only sufficient pellet penetration allowed noticeable, persistent particle deposition in the plasma by the pellets. Applying adequate pellet injection conditions and favourable scenarios using combined pellet/gas puff refuelling, significant density ramp-up to densities exceeding the empirical Greenwald limit by up to a factor of two was achieved even for strongly heated H-mode plasmas. (orig.)

  10. Pelletizing using forest fuels and Salix as raw materials. A study of the pelletizing properties; Pelletering med skogsbraensle och Salix som raavara. En undersoekning av pelleterbarheten

    Energy Technology Data Exchange (ETDEWEB)

    Martinsson, Lars; Oesterberg, Stefan [Swedish National Testing and Research Inst., Boraas (Sweden)

    2004-08-01

    Three common forest fuels: light thinning material, cull tree and logging residues as well as energy forest fuel (Salix) has been used as fuel pellet materials. Logging residues and Salix were stacked for approximately 6 and 10 months respectively. Parameters varied for each raw material have been the moisture content and the press length of the die. These parameters have been changed to obtain best possible quality, mainly concerning mechanical durability. Pellets were also produced from bark free shavings in order to use as a reference in this study. Physical as well as chemical properties have been compared. It was comparatively easy to press logging residues and Salix into durable pellets and, even with larger press length, the production of pellets was higher than it was for the other raw materials. The density was equal for all pellets while the mechanical durability was better for all tested raw materials compared with the reference material. The fact that all raw materials besides the reference material contains bark which has an improving effect on the degree of hardness. The quality properties were mainly about the same or better for pellets made of light thinning material and cull tree respectively, compared with the reference pellets. However, the ash content was approximately twice as high compared with the reference pellets. The pellets made of logging residues and Salix respectively were of very good quality concerning duration and density but the ash content was approximately 10 times higher than in the reference pellets. Additionally, the nitrogen content was 6-9 times higher compared with the reference pellets.

  11. Initial deuterium pellet experiments on FTU

    International Nuclear Information System (INIS)

    Snipes, J.A.

    1993-01-01

    Initial experiments have been performed with the Single Pellet INjector (SPIN) on FTU. SPIN is a two-stage cryogenic deuterium pellet injector capable of injection,a pellets with velocities up to 2.5 km/s. The nominal pellet mass for these experiments was approximately 1 x 10 20 atoms. These initial pellet experiments concentrated on studying pellet penetration under a variety of plasma conditions to compare with code predictions and to examine toroidal particle transport. The principal diagnostics used were two fast (∼1 μsec) photomultiplier tubes at nearly opposite toroidal locations with H α (D α ) interference filters (λ = 656 nm), a microwave cavity for pellet mass and velocity, a vertical array of soft x ray diodes without filters looking down onto the pellet, a DCN interferometer for electron density profiles, and a Michelson ECE system for electron temperature profiles. The time integral of the absolutely calibrated fast H α signal appears to give reasonable agreement with the expected pellet mass. Toroidal transport of deuterium ions from the pellet to nearly the opposite side of the tokamak agrees with calculated thermal deuterium velocities near the plasma edge. Comparison of the experimental results with code calculations using the Neutral Gas Shielding model show good agreement for the post-pellet electron temperature and density profiles and the H α profiles in some cases. Calculated penetration distances agree within 20%

  12. Fuel Pellets from Wheat Straw: The Effect of Lignin Glass Transition and Surface Waxes on Pelletizing Properties

    DEFF Research Database (Denmark)

    Stelte, Wolfgang; Clemons, Craig; Holm, Jens K.

    2012-01-01

    and a high concentration of hydrophobic waxes on its outer surface that may limit the pellet strength. The present work studies the impact of the lignin glass transition on the pelletizing properties of wheat straw. Furthermore, the effect of surface waxes on the pelletizing process and pellet strength...... are investigated by comparing wheat straw before and after organic solvent extraction. The lignin glass transition temperature for wheat straw and extracted wheat straw is determined by dynamic mechanical thermal analysis. At a moisture content of 8%, transitions are identified at 53°C and 63°C, respectively....... Pellets are pressed from wheat straw and straw where the waxes have been extracted from. Two pelletizing temperatures were chosen—one below and one above the glass transition temperature of lignin. The pellets compression strength, density, and fracture surface were compared to each other. Pellets pressed...

  13. The JET multi-pellet injector launcher

    International Nuclear Information System (INIS)

    Kupschus, P.; Bailey, W.; Gadeberg, M.; Hedley, L.; Twyman, P.; Szabo, T.; Evans, D.

    1987-01-01

    Under a collaborative agreement between the Joint European Torus JET and the United States Department of Energy US DOE, JET and Oak Ridge National Laboratory (ORNL) jointly built a multi-pellet injector for fuelling and re-fuelling of the JET plasma. A three-barrel repetitive pneumatic pellet Launcher - built by ORNL - is attached to a JET pellet launcher-machine interface (in short: Pellet Interface) which is the subject of this paper. The present Launcher-Interface combination provides deuterium or hydrogen injection at moderate pellet speeds for the next two operational periods on JET. The Pellet Interface, however, takes into account the future requirements of JET. It was designed to allow the attachment of the high speed pellet launchers now under development at JET and complies with the requirements of remote handling and tritium operation. In addition, the use of tritium pellets is being considered

  14. Reciprocating pellet press

    Science.gov (United States)

    Jones, Charles W.

    1981-04-07

    A machine for pressing loose powder into pellets using a series of reciprocating motions has an interchangeable punch and die as its only accurately machines parts. The machine reciprocates horizontally between powder receiving and pressing positions. It reciprocates vertically to press, strip and release a pellet.

  15. In silico identification of known osmotic stress responsive genes from Arabidopsis in soybean and Medicago

    Directory of Open Access Journals (Sweden)

    Nina M. Soares-Cavalcanti

    2012-01-01

    Full Text Available Plants experience various environmental stresses, but tolerance to these adverse conditions is a very complex phenomenon. The present research aimed to evaluate a set of genes involved in osmotic response, comparing soybean and medicago with the well-described Arabidopsis thaliana model plant. Based on 103 Arabidopsis proteins from 27 categories of osmotic stress response, comparative analyses against Genosoja and Medicago truncatula databases allowed the identification of 1,088 soybean and 1,210 Medicago sequences. The analysis showed a high number of sequences and high diversity, comprising genes from all categories in both organisms. Genes with unknown function were among the most representative, followed by transcription factors, ion transport proteins, water channel, plant defense, protein degradation, cellular structure, organization & biogenesis and senescence. An analysis of sequences with unknown function allowed the annotation of 174 soybean and 217 Medicago sequences, most of them concerning transcription factors. However, for about 30% of the sequences no function could be attributed using in silico procedures. The establishment of a gene set involved in osmotic stress responses in soybean and barrel medic will help to better understand the survival mechanisms for this type of stress condition in legumes.

  16. Manufacture, delivery and marketing of wood pellets

    International Nuclear Information System (INIS)

    Huhtanen, T.

    2001-01-01

    Wood pellet is a cheap fuel, the use of which can easily bee automated. Pellet heating can be carried out with a stoker or a pellet burner, which can be mounted to oil and solid fuels boiler or to solid fuel boilers. Vapo Oy delivers wood pellet to farms and detached houses via Agrimarket stores. Vapo Oy delivers pellets to large real estates, municipalities, industry, greenhouses and power plants directly as bulk. The pellets are delivered either by trailers or lorries equipped with fan-operated unloaders. The use of wood pellets is a suitable fuel especially for real estates, the boiler output of which is 20 - 1000 kW. Vapo Oy manufactures wood pellets of cutter chips, grinding dust and sawdust. The raw material for Ilomantsi pellet plant is purchased from the province of North Karelia. The capacity of pelletizing plant is 45 000 t of pellets per year, half of which is exported mainly to Sweden and Denmark

  17. Tritium pellet injector for TFTR

    International Nuclear Information System (INIS)

    Gouge, M.J.; Baylor, L.R.; Cole, M.J.; Combs, S.K.; Dyer, G.R.; Fehling, D.T.; Fisher, P.W.; Foust, C.R.; Langley, R.A.; Milora, S.L.; Qualls, A.L.; Wilgen, J.B.; Schmidt, G.L.; Barnes, G.W.; Persing, R.G.

    1992-01-01

    The tritium pellet injector (TPI) for the Tokamak Fusion Test Reactor (TFTR) will provide a tritium pellet fueling capability with pellet speeds in the 1- to 3-km/s range for the TFTR deuterium-tritium (D-T) phase. The existing TFTR deuterium pellet injector (DPI) has been modified at Oak Ridge National Laboratory (ORNL) to provide a four-shot, tritium-compatible, pipe-gun configuration with three upgraded single-stage pneumatic guns and a two-stage light gas gun driver. The TPI was designed to provide pellets ranging from 3.3 to 4.5 mm in diameter in arbitrarily programmable firing sequences at speeds up to approximately 1.5 km/s for the three single-stage drivers and 2.5 to 3 km/s for the two-stage driver. Injector operation is controlled by a programmable logic controller. The new pipe-gun injector assembly was installed in the modified DPI guard vacuum box, and modifications were made to the internals of the DPI vacuum injection line, including a new pellet diagnostics package. Assembly of these modified parts with existing DPI components was then completed, and the TPI was tested at ORNL with deuterium pellet. Results of the limited testing program at ORNL are described. The TPI is being installed on TFTR to support the D-D run period in 1992. In 1993, the tritium pellet injector will be retrofitted with a D-T fuel manifold and secondary tritium containment systems and integrated into TFTR tritium processing systems to provide full tritium pellet capability

  18. Nuclear fuel pellet loading apparatus

    International Nuclear Information System (INIS)

    Gerkey, K.S.

    1979-01-01

    An automatic apparatus for loading a predetermined amount of nuclear fuel pellets into a nuclear fuel element to be used in a nuclear reactor is described. The apparatus consists of a vibratory bed capable of supporting corrugated trays containing rows of nuclear fuel pellets and arranged in alignment with the open ends of several nuclear fuel elements. A sweep mechanism is arranged above the trays and serves to sweep the rows of fuel pellets onto the vibratory bed and into the fuel element. A length detecting system, in conjunction with a pellet stopping mechanism, is also provided to assure that a predetermined amount of nuclear fuel pellets are loaded into each fuel element

  19. Numerical analysis of the influence of the fuel pellet shape on the pellet-cladding contact condition

    International Nuclear Information System (INIS)

    Marajofsky, Adolfo; Denis, Alicia C.; Soba, Alejandro

    2004-01-01

    One of the problems of greater concern in nuclear fuels operation is that of pellet-cladding interaction (PCI), since it may be cause of fuel failure. In unfailed claddings, the occurrence of contact with the pellet is generally evidenced by a typical deformation pattern known as bamboo effect. In the present work different pellets' shapes are proposed, all of them with a chamfer next to the top and bottom surfaces. The performance of these pellets design is simulated with a numerical code, DIONISIO, previously developed in this working group, which makes use of the finite elements method. It provides the temperature, stress and strain distribution and the inventory of fission gases by analyzing phenomena like thermal expansion, elasticity, plasticity, creep, irradiation growth, PCI, swelling and densification. The pellets' design tested are grouped into two types: those with a straight chamfer running from the central pellet plane to both extremes (R-type pellets) and those with the chamfer occupying one quarter of the pellet's height leaving a central ring of the standard, cylindrical shape (M-type pellets). Different chamfer depths were numerically tested. It was found that the gap increase associated with the introduction of a deep chamfer is responsible for a significant temperature increment. But chamfers which leave a gap of 110 to 150 μm (assuming a normal fuel element with a gap 90 μm thick) gave place to pellets with an adequate thermal response and, moreover, the disappearance of the bamboo effect or even the appearance of an inverse effect, that is, pellets which make contact with the cladding in the region around its middle plane. (author) [es

  20. The molecular genetic linkage map of the model legume Medicago truncatula: an essential tool for comparative legume genomics and the isolation of agronomically important genes

    Directory of Open Access Journals (Sweden)

    Ané Jean-Michel

    2002-01-01

    Full Text Available Abstract Background The legume Medicago truncatula has emerged as a model plant for the molecular and genetic dissection of various plant processes involved in rhizobial, mycorrhizal and pathogenic plant-microbe interactions. Aiming to develop essential tools for such genetic approaches, we have established the first genetic map of this species. Two parental homozygous lines were selected from the cultivar Jemalong and from the Algerian natural population (DZA315 on the basis of their molecular and phenotypic polymorphism. Results An F2 segregating population of 124 individuals between these two lines was obtained using an efficient manual crossing technique established for M. truncatula and was used to construct a genetic map. This map spans 1225 cM (average 470 kb/cM and comprises 289 markers including RAPD, AFLP, known genes and isoenzymes arranged in 8 linkage groups (2n = 16. Markers are uniformly distributed throughout the map and segregation distortion is limited to only 3 linkage groups. By mapping a number of common markers, the eight linkage groups are shown to be homologous to those of diploid alfalfa (M. sativa, implying a good level of macrosynteny between the two genomes. Using this M. truncatula map and the derived F3 populations, we were able to map the Mtsym6 symbiotic gene on linkage group 8 and the SPC gene, responsible for the direction of pod coiling, on linkage group 7. Conclusions These results demonstrate that Medicago truncatula is amenable to diploid genetic analysis and they open the way to map-based cloning of symbiotic or other agronomically-important genes using this model plant.

  1. Impurity pellet injection experiments at TFTR

    International Nuclear Information System (INIS)

    Marmar, E.S.

    1992-01-01

    Impurity (Li and C) pellet injection experiments on TFTR have produced a number of new and significant results. (1) We observe reproducible improvements of TFTR supershots after wall-conditioning by Li pellet injection ('lithiumization'). (2) We have made accurate measurements of the pitch angle profiles of the internal magnetic field using two novel techniques. The first measures the internal field pitch from the polarization angles of Li + line emission from the pellet ablation cloud, while the second measures the pitch angle profiles by observing the tilt of the cigar-shaped Li + emission region of the ablation cloud. (3) Extensive measurements of impurity pellet penetration into plasmas with central temperatures ranging from ∼0.3 to ∼7 keV have been made and compared with available theoretical models. Other aspects of pellet cloud physics have been investigated. (4) Using pellets as a well defined perturbation has allowed study of transport phenomena. In the case of small pellet perturbations, the characteristics of the background plasmas are probed, while with large pellets, pellet induced effects are clearly observed. These main results are discussed in more detail in this paper

  2. Effects of Sludge Compost on EC value of Saline Soil and Plant Height of Medicago

    Science.gov (United States)

    Sun, Chongyang; Zhao, Ke; Chen, Xing; Wang, Xiaohui

    2017-12-01

    In this study, the effects of sludge composting on the EC value of saline soil and the response to Medicago plant height were studied by planting Medicago with pots for 45 days in different proportions as sludge composting with saline soil. The results showed that the EC value of saline soil did not change obviously with the increase of fertilization ratio,which indicated that the EC value of saline soil was close to that of the original soil. The EC decreased by 31.45% at fertilization ratio of 40%. The height of Medicago reached the highest at 40% fertilization ratio, and that was close to 60% fertilization ratio, and the difference was significant with other treatments. By comprehensive analyse and compare,the optimum application rate of sludge compost was 40% under this test condition.

  3. Introducing wood pellet fuel to the UK

    Energy Technology Data Exchange (ETDEWEB)

    Cotton, R A; Giffard, A

    2001-07-01

    Technical and non-technical issues affecting the introduction of wood pellet-fired heating to the UK were investigated with the aim of helping to establish a wood pellet industry in the UK. The project examined the growth and status of the industry in continental Europe and North America, reviewed relevant UK standards and legislation, identified markets for pellet heating in the UK, organised workshops and seminars to demonstrate pellet burning appliances, carried out a trial pelletisation of a range of biomass fuels, helped to set up demonstration installations of pellet-fired appliances, undertook a promotional campaign for wood pellet fuel and compiled resource directories for pellet fuel and pellet burning appliances in the UK. The work was completed in three phases - review, identification and commercialisation. Project outputs include UK voluntary standards for wood pellet fuel and combustion appliances, and a database of individuals with an interest in wood pellet fuel.

  4. Root developmental programs shape the Medicago truncatula nodule meristem

    NARCIS (Netherlands)

    Franssen, H.; Xiao, T.T.; Kulikova, O.; Wan, X.; Bisseling, T.; Scheres, B.; Heidstra, R.

    2015-01-01

    Nodules on the roots of legume plants host nitrogen-fixing Rhizobium bacteria. Several lines of evidence indicate that nodules are evolutionarily related to roots. We determined whether developmental control of the Medicago truncatula nodule meristem bears resemblance to that in root meristems

  5. Observations of foliar injury to plants by sulfur dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, A.K.; Chaphekar, S.B.

    1978-01-01

    Morphological and anatomical changes in mature leaves indicated that Raphanus sativus, Commelina benghalensis and Medicago sativa were injured and Pennisetum typhoideum, Alternanthere ficoidea and Mangifera indica (seedlings) were not injured by sulfur dioxide fumigation. The highly susceptible plants like Raphanus, Medicago, and Commelina can be used for monitoring air quality in a polluted atmosphere. Uninjured species like Pennisetum on the other hand, may be grown in polluted areas for maintaining agricultural production. 9 references, 1 table.

  6. Apparatus for unloading more particularly for nuclear fuel pellets, and to fill tubes with these pellets

    International Nuclear Information System (INIS)

    Fort, C.; Masson, S.

    1985-01-01

    The device allows to discharge the nuclear fuel pellets arranged in trays, and to introduce them to form stacks of pellets of determined length in storage tubes of associated diameter. It comprises a carriage to make the pellets slip from each tray on a guide vibrating bowl to a shute and then on a conveyor which loads the pellets into an intermediate tube to form a stack of the said length. A lift moves the intermediate tube transversally to its length between a loading position and a transfer position. Means allow to move a storage tube bundle to put each tube in its turn face to the transfer position. The stack of pellets contained in the intermediate tube which is in the transfer position is thus sent back to the storage tube facing it. The invention applies to pellets which have been sintered in the trays in inert atmosphere. These pellets have to be stored before several examinations and grinding, and finally loading into the cans to constitute fuel rods. These sintered pellets have a cylindrical shape and the invention spares them hard handling which would damage them [fr

  7. Method of manufacturing nuclear fuel pellet

    International Nuclear Information System (INIS)

    Oguma, Masaomi; Masuda, Hiroshi; Hirai, Mutsumi; Tanabe, Isami; Yuda, Ryoichi.

    1989-01-01

    In a method of manufacturing nuclear fuel pellets by compression molding an oxide powder of nuclear fuel material followed by sintering, a metal nuclear material is mixed with an oxide powder of the nuclear fuel material. As the metal nuclear fuel material, whisker or wire-like fine wire or granules of metal uranium can be used effectively. As a result, a fuel pellet in which the metal nuclear fuel is disposed in a network-like manner can be obtained. The pellet shows a great effect of preventing thermal stress destruction of pellets upon increase of fuel rod power as compared with conventional pellets. Further, the metal nuclear fuel material acts as an oxygen getter to suppress the increase of O/M ratio of the pellets. Further, it is possible to reduce the swelling of pellet at high burn-up degree. (T.M.)

  8. Fuel pellet loading apparatus

    International Nuclear Information System (INIS)

    1980-01-01

    Apparatus is described for loading a predetermined amount of nuclear fuel pellets into nuclear fuel elements and particularly for the automatic loading of fuel pellets from within a sealed compartment. (author)

  9. cell- and tissue-specific transcriptome analyses of Medicago truncatula root nodules.

    Directory of Open Access Journals (Sweden)

    Erik Limpens

    Full Text Available Legumes have the unique ability to host nitrogen-fixing Rhizobium bacteria as symbiosomes inside root nodule cells. To get insight into this key process, which forms the heart of the endosymbiosis, we isolated specific cells/tissues at different stages of symbiosome formation from nodules of the model legume Medicago truncatula using laser-capture microdissection. Next, we determined their associated expression profiles using Affymetrix Medicago GeneChips. Cells were collected from the nodule infection zone divided into a distal (where symbiosome formation and division occur and proximal region (where symbiosomes are mainly differentiating, as well as infected cells from the fixation zone containing mature nitrogen fixing symbiosomes. As non-infected cells/tissue we included nodule meristem cells and uninfected cells from the fixation zone. Here, we present a comprehensive gene expression map of an indeterminate Medicago nodule and selected genes that show specific enriched expression in the different cells or tissues. Validation of the obtained expression profiles, by comparison to published gene expression profiles and experimental verification, indicates that the data can be used as digital "in situ". This digital "in situ" offers a genome-wide insight into genes specifically associated with subsequent stages of symbiosome and nodule cell development, and can serve to guide future functional studies.

  10. Pneumatic pellet injector for JT-60

    International Nuclear Information System (INIS)

    Onozuka, Masanori; Hiratsuka, Hajime; Kawasaki, Kouzo.

    1990-01-01

    The pneumatic 4-shot pellet injector has been installed and operated for JT-60 (JAERI Tokamak-60). The performance tests have proven that the device provides high speed pellets as planned. The maximum pellet velocity obtained in the hydrogen pellet tests is greater than 2.3km/s at 100 bar propellant gas. (author)

  11. Pneumatic pellet injector for JT-60

    Energy Technology Data Exchange (ETDEWEB)

    Onozuka, Masanori (Mitsubishi Heavy Industries Ltd., Tokyo (Japan)); Hiratsuka, Hajime; Kawasaki, Kouzo

    1990-11-01

    The pneumatic 4-shot pellet injector has been installed and operated for JT-60 (JAERI Tokamak-60). The performance tests have proven that the device provides high speed pellets as planned. The maximum pellet velocity obtained in the hydrogen pellet tests is greater than 2.3km/s at 100 bar propellant gas. (author).

  12. Degradation of copepod fecal pellets

    DEFF Research Database (Denmark)

    Poulsen, Louise K.; Iversen, Morten

    2008-01-01

    amount of fecal pellets. The total degradation rate of pellets by the natural plankton community of Oresund followed the phytoplankton biomass, with maximum degradation rate during the spring bloom (2.5 +/- 0.49 d(-1)) and minimum (0.52 +/- 0.14 d(-1)) during late winter. Total pellet removal rate ranged...

  13. Uranium dioxide pellets

    International Nuclear Information System (INIS)

    Zawidzki, T.W.

    1979-01-01

    Sintered uranium dioxide pellets composed of particles of size > 50 microns suitable for power reactor use are made by incorporating a small amount of sulphur into the uranium dioxide before sintering. The increase in grain size achieved results in an improvement in overall efficiency when such pellets are used in a power reactor. (author)

  14. New pellet production and acceleration technologies for high speed pellet injection system 'HIPEL' in large helical device

    International Nuclear Information System (INIS)

    Viniar, I.; Sudo, S.

    1994-12-01

    New technologies of pellet production and acceleration for fueling and diagnostics purposes in large thermonuclear reactors are proposed. The technologies are intended to apply to the multiple-pellet injection system 'HIPEL' for Large Helical Device of NIFS in Japan. The pellet production technology has already been tested in a pipe-gun type pellet injector. It will realize the repeating pellet injection by means of decreasing of the pellet formation time into the pipe-gun barrel. The acceleration technology is based upon a new pump tube operation in two-stage gas gun and also upon a new conception of the allowable pressure acting on a pellet into a barrel. Some preliminary estimations have been made, and principles of a pump tube construction providing for a reliable long term operation in the repeating mode without any troubles from a piston are proposed. (author)

  15. Optimization of bentonite pellet properties

    International Nuclear Information System (INIS)

    Sanden, Torbjoern; Andersson, Linus; Jonsson, Esther; Fritzell, Anni

    2012-01-01

    Document available in extended abstract form only. SKB in Sweden is developing and implementing concepts for the final disposal of spent nuclear fuel. A KBS-3V repository consists of a deposition tunnel with copper canisters containing spent fuel placed in vertical deposition holes. The canisters are embedded in highly compacted bentonite. After emplacement of canisters and bentonite blocks, the tunnels will be backfilled and sealed with an in-situ cast plug at the entrance. The main concept for backfilling the deposition tunnels imply pre compacted blocks of bentonite stacked on a bed of bentonite pellet. The remaining slot between blocks and rock will be filled with bentonite pellets. The work described in this abstract is a part of the ASKAR-project which main goal is to make a system design based on the selected concept for backfilling. Immediately after starting the backfill installation, inflowing water from the rock will come in contact with the pellet filling and thereby influence the characteristics of the pellet filling. The pellet filling helps to increase the average density of the backfill, but one of the most important properties beside this is the water storing capacity which will prevent water from reaching the backfill front where it would disturb and influence the quality of the installation. If water flows through the pellet filling out to the backfilling front, there will be erosion of material which also will affect the quality of the installed backfill. In order to optimize the properties regarding water storing capacity and sensitivity for erosion a number of tests have been made with different pellet types. The tests were made in different scales and with equipment specially designed for the purpose. The performed tests can be divided in four parts: 1. Standard tests (determining water content and density of pellet fillings and individual pellets, compressibility of the pellet fillings and strength of the individual pellets); 2. Erosion

  16. Ranking of lignocellulosic biomass pellets through multicriteria modeling

    Energy Technology Data Exchange (ETDEWEB)

    Sultana, A.; Kumar, A. [Alberta Univ., Edmonton, AB (Canada). Dept. of Mechanical Engineering

    2009-07-01

    A study was conducted in which pellets from different lignocellulosic biomass sources were ranked using a multicriteria assessment model. Five different pellet alternatives were compared based on 10 criteria. The pair-wise comparison was done in order to develop preference indices for various alternatives. The methodology used in this study was the Preference Ranking Organization Method for Enrichment and Evaluation (PROMETHEE). The biomass included wood pellets, straw pellets, switchgrass pellets, alfalfa pellets and poultry pellets. The study considered both quantitative and qualitative criteria such as energy consumption to produce the pellets, production cost, bulk density, NOx emissions, SOx emissions, deposit formation, net calorific value, moisture content, maturity of technology, and quality of material. A sensitivity analysis was performed by changing weights of criteria and threshold values of the criteria. Different scenarios were developed for ranking cost and environmental impacts. According to preliminary results, the wood pellet is the best energy source, followed by switchgrass pellets, straw pellets, alfalfa pellets and poultry pellets.

  17. Development of railgun pellet injector using a laser-induced plasma armature. Results of dummy pellet acceleration tests

    International Nuclear Information System (INIS)

    Onozuka, Masanori; Oda, Yasushi; Azuma, Kingo; Ogino, Mutsuo

    1995-01-01

    Using the low electric energy railgun system, dummy pellet acceleration tests have been conducted to investigate the application of the electromagnetic railgun system for high-speed pellet injection into fusion plasmas. The primary objective of the development is to improve the pellet acceleration efficiency and durability of the rail materials. In the system, the pellet is pre-accelerated before railgun acceleration. A laser beam is used to induce plasma armature. The ignited plasma armature is accelerated by an electromagnetic force that accelerates the pellet. As low electric energy was used, rail materials were used for multiple operations. Tungsten-alloy rail provided longer durability and slightly higher energy conversion coefficient than copper rail. The energy conversion coefficient was from 0.3 to 0.5% using a plastic insulator. A ceramic insulator improved the energy conversion coefficient by 80%. The highest pellet velocity was 1.7 km/s using wooden pellets accelerated by 1m-long railgun. Based on the findings, it is estimated that the hydrogen pellet has the potential to be accelerated to 5 km/s using a 3m-long railgun. (author)

  18. Development of railgun pellet injector using a laser-induced plasma armature. Results of dummy pellet acceleration tests

    Energy Technology Data Exchange (ETDEWEB)

    Onozuka, Masanori; Oda, Yasushi; Azuma, Kingo; Ogino, Mutsuo [Mitsubishi Heavy Industries Ltd., Yokohama (Japan). Nuclear Energy Systems Engineering Center

    1995-03-01

    Using the low electric energy railgun system, dummy pellet acceleration tests have been conducted to investigate the application of the electromagnetic railgun system for high-speed pellet injection into fusion plasmas. The primary objective of the development is to improve the pellet acceleration efficiency and durability of the rail materials. In the system, the pellet is pre-accelerated before railgun acceleration. A laser beam is used to induce plasma armature. The ignited plasma armature is accelerated by an electromagnetic force that accelerates the pellet. As low electric energy was used, rail materials were used for multiple operations. Tungsten-alloy rail provided longer durability and slightly higher energy conversion coefficient than copper rail. The energy conversion coefficient was from 0.3 to 0.5% using a plastic insulator. A ceramic insulator improved the energy conversion coefficient by 80%. The highest pellet velocity was 1.7 km/s using wooden pellets accelerated by 1m-long railgun. Based on the findings, it is estimated that the hydrogen pellet has the potential to be accelerated to 5 km/s using a 3m-long railgun. (author).

  19. Pellets - A fuel with a future

    International Nuclear Information System (INIS)

    2004-01-01

    This special brochure presents a series of articles on the topic of wood pellets as a fuel of the future. Dr. Walter Steinmann, director of the Swiss Federal Office of Energy (SFOE) introduces the topic, stressing that the Swiss Confederation and the Cantons are supporting efforts to increase the sustainable use of wood fuels. Further articles take a closer look at pellets and their form. Pellets-fired heating units are introduced as a viable alternative to traditional oil-fired units. Tips are presented on the various ways of storing pellets. Quality-assurance aspects are examined and manufacturers and distributors of wood pellets are listed. A further article takes a closer look at a large Swiss manufacturer of pellets and describes the production process used as well as the logistics necessary for the transportation of raw materials and finished products. The brochure also presents a selection of pellet ovens and heating systems from various manufacturers. A further article illustrates the use of pellets as a means of heating apartment blocks built to the MINERGIE low-energy-consumption standard. In the example quoted, the classic combination of solar energy for the pre-heating of hot water and pellets for the central heating and hot water supply is used. The use of a buried spherical tank to store pellets - and thus the saving of space inside the building - is described in a further article that takes a look at the refurbishment of the heating system in a single-family home. Finally, various contributions presented at the Pellets Forum held in Berne in November 2003 are summarised in a short article

  20. Power from Pellets Technology and Applications

    CERN Document Server

    Döring, Stefan

    2013-01-01

    This book provides a practical description of the technology of pellet production on the basis of renewable sources as well as the utilization of pellets. The author explains what kinds of biomass are usable in addition to wood, how to produce pellets and how to use pellets to produce energy. Starting with the basics of combustion, gasification and the pelletizing process, several different technologies are described. The design, planning, construction and economic efficiency are discussed as well. The appendix gives useful advice about plant concepts, calculations, addresses, conversion tables and formulas.

  1. Solid deuterium centrifuge pellet injector

    International Nuclear Information System (INIS)

    Foster, C.A.

    1982-01-01

    Pellet injectors are needed to fuel long pulse tokamak plasmas and other magnetic confinement devices. For this purpose, an apparatus has been developed that forms 1.3-mm-diam pellets of frozen deuterium at a rate of 40 pellets per second and accelerates them to a speed of 1 km/s. Pellets are formed by extruding a billet of solidified deuterium through a 1.3-mm-diam nozzle at a speed of 5 cm/s. The extruding deuterium is chopped with a razor knife, forming 1.3-mm right circular cylinders of solid deuterium. The pellets are accelerated by synchronously injecting them into a high speed rotating arbor containing a guide track, which carries them from a point near the center of rotation to the periphery. The pellets leave the wheel after 150 0 of rotation at double the tip speed. The centrifuge is formed in the shape of a centrifugal catenary and is constructed of high strength KEVLAR/epoxy composite. This arbon has been spin-tested to a tip speed of 1 km/s

  2. Nuclear fuel pellet charging device

    International Nuclear Information System (INIS)

    Komuro, Kojiro.

    1990-01-01

    The present invention concerns a nuclear fuel pellet loading device, in which nuclear fuel pellets are successively charged from an open end of a fuel can while rotating the can. That is, a fuel can sealed at one end with an end plug and opened at the other end is rotated around its pipe axis as the center on a rotationally diriving table. During rotation of the fuel can, nuclear fuel pellets are successively charged by means of a feed rod of a feeding device to the inside of the fuel can. The fuel can is rotated while being supported horizontally and the fuel pellets are charged from the open end thereof. Alternatively, the fuel can is rotated while being supported obliquely and the fuel pellets are charged gravitationally into the fuel can. In this way, the damages to the barrier of the fuel can can be reduce. Further, since the fuel pellets can be charged gravitationally by rotating the fuel can while being supported obliquely, the damages to the barrier can be reduced remarkably. (I.S.)

  3. Solid deuterium centrifuge pellet injector

    International Nuclear Information System (INIS)

    Foster, C.A.

    1983-01-01

    Pellet injectors are needed to fuel long pulse tokamak plasmas and other magnetic confinement devices. For this purpose, an apparatus has been developed that forms 1.3-mm-diam pellets of frozen deuterium at a rate of 40 pellets per second and accelerates them to a speed of 1 km/s. Pellets are formed by extruding a billet of solidified deuterium through a 1.3-mm-diam nozzle at a speed of 5 cm/s. The extruding deuterium is chopped with a razor knife, forming 1.3-mm right circular cylinders of solid deuterium. The pellets are accelerated by synchronously injecting them into a high speed rotating arbor containing a guide track, which carries them from a point near the center of rotation to the periphery. The pellets leave the wheel after 150 0 of rotation at double the tip speed. The centrifuge is formed in the shape of a centrifugal catenary and is constructed of high strength Kevlar/epoxy composite. This arbor has been spin-tested to a tip speed of 1 km/s

  4. Automatic pellet density checking machine using vision technique

    International Nuclear Information System (INIS)

    Kumar, Suman; Raju, Y.S.; Raj Kumar, J.V.; Sairam, S.; Sheela; Hemantha Rao, G.V.S.

    2012-01-01

    Uranium di-oxide powder prepared through chemical process is converted to green pellets through the powder metallurgy route of precompaction and final compaction operations. These green pellets are kept in a molybdenum boat, which consists of a molybdenum base and a shroud. The boats are passed through the high temperature sintering furnaces to achieve required density of pellets. At present MIL standard 105 E is followed for measuring density of sintered pellets in the boat. As per AQL 2.5 of MIL standard, five pellets are collected from each boat, which contains approximately 800 nos of pellets. The densities of these collected pellets are measured. If anyone pellet density is less than the required value, the entire boat of pellets are rejected and sent back for dissolution for further processing. An Automatic Pellet Density Checking Machine (APDCM) was developed to salvage the acceptable density pellets from the rejected boat of pellets

  5. Cover crops for managing weeds, soil chemical fertility and nutritional status of organically grown orange orchard in Sicily

    Directory of Open Access Journals (Sweden)

    Rosario Paolo Mauro

    2015-06-01

    Full Text Available Cover crops can offer significant advantages in the agronomic management of citrus orchards in Mediterranean environments. Therefore, a three-year research was conducted in eastern Sicily aimed at studying the effects of four cover crop sequences (Sinapis arvensis-Trigonella foenum-graecum-T. foenum-graecum; Medicago scutellata-Avena sativa-Lolium perenne; Vicia faba minor-A. sativa-A. sativa; A. sativa-V. faba. minor-L. perenne on weeds, major soil chemical properties and nutritional status of an organically grown orange orchard. The results highlighted that, among the studied cover crop sequences, Vicia faba-Avena-Avena was the most beneficial for weeds control within the orchard (92%, of cover crop cover, and 586 and 89 g DW m–2 of cover crop aboveground biomass and weeds aboveground biomass, respectively. Overall, the chemical fertility of the soil was positively influenced. In particular, it was observed an increase of the content of total nitrogen and available phosphorus in the soil by both Sinapis-Trigonella-Trigonella (0.75 g kg–1 and 59.0 mg kg–1, respectively and Vicia faba-Avena-Avena (0.70 g kg–1 and 56.0 mg kg–1, respectively cover crop sequences. Medicago-Avena-Lolium sequence seemed to be the most useful to ensure a better nutritional status of the orange orchard.

  6. Emissions from burning of softwood pellets

    International Nuclear Information System (INIS)

    Olsson, Maria; Kjaellstrand, Jennica

    2004-01-01

    Softwood pellets from three different Swedish manufacturers were burnt in laboratory scale to determine compounds emitted. The emissions were sampled on Tenax cartridges and assessed by gas chromatography and mass spectrometry. No large differences in the emissions from pellets from different manufacturers were observed. The major primary semi-volatile compounds released during flaming burning were 2-methoxyphenols from lignin. The methoxyphenols are of interest due to their antioxidant effect, which may counteract health hazards of aromatic hydrocarbons. Glowing combustion released the carcinogenic benzene as the predominant aromatic compound. However, the benzene emissions were lower than from flaming burning. To relate the results from the laboratory burnings to emissions from pellet burners and pellet stoves, chimney emissions were determined for different burning equipments. The pellet burner emitted benzene as the major aromatic compound, whereas the stove and boiler emitted phenolic antioxidants together with benzene. As the demand for pellets increases, different biomass wastes will be considered as raw materials. Ecological aspects and pollution hazards indicate that wood pellets should be used primarily for residential heating, whereas controlled large-scale combustion should be preferred for pellets made of most other types of biomass waste. (Author)

  7. Electrothermal plasma gun as a pellet injector

    International Nuclear Information System (INIS)

    Kincaid, R.W.; Bourham, M.A.

    1994-01-01

    The NCSU electrothermal plasma gun SIRENS has been used to accelerate plastic (Lexan polycarbonate) pellets, to determine the feasibility of the use of electrothermal guns as pellet injectors. The use of an electrothermal gun to inject frozen hydrogenic pellets requires a mechanism to provide protective shells (sabots) for shielding the pellet from ablation during acceleration into and through the barrel of the gun. The gun has been modified to accommodate acceleration of the plastic pellets using special acceleration barrels equipped with diagnostics for velocity and position of the pellet, and targets to absorb the pellet's energy on impact. The length of the acceleration path could be varied between 15 and 45 cm. The discharge energy of the electrothermal gun ranged from 2 to 6 kJ. The pellet velocities have been measured via a set of break wires. Pellet masses were varied between 0.5 and 1.0 grams. Preliminary results on 0.5 and 1.0 g pellets show that the exit velocity reaches 0.9 km/s at 6 kJ input energy to the source. Higher velocities of 1.5 and 2.7 km/s have been achieved using 0.5 and 1.0 gm pellets in 30 cm long barrel, without cleaning the barrel between the shots

  8. Pellet-plasma interactions in tokamaks

    DEFF Research Database (Denmark)

    Chang, C.T.

    1991-01-01

    confinement time, offset by the accumulation of impurities at the plasma core is brought into focus. A possible remedy is suggested to diminish the effect of the impurities. Plausible arguments are presented to explain the apparent controversial observations on the propagation of a fast cooling front ahead......The ablation of a refuelling pellet of solid hydrogen isotopes is governed by the plasma state, especially the density and energy distribution of the electrons. On the other hand, the cryogenic pellet gives rise to perturbations of the plasma temperature and density. Based on extensive experimental...... data, the interaction between the pellet and the plasma is reviewed. Among the subjects discussed are the MHD activity, evolution of temperature and density profiles, and the behaviour of impurities following the injection of a pellet (or pellets). The beneficial effect of density peaking on the energy...

  9. Uranium uptake and accumulation in plants from soil contaminated with uranium in different concentrations

    International Nuclear Information System (INIS)

    Zhao Luxue; Tang Yongjin; Luo Xuegang

    2014-01-01

    The plants of Medicago sativa L., Hibiscus esulentus L, Waterspinach, Amaranthus retroflexus and Abutilon theophrasti Medic were employed as the indicator to investigate the uranium uptake and accumulation from soils contaminated with uranium (UO_2 (CH_3COO)_2 · 2H_2O) of 25 mg · kg"-"l, 75 mg · kg"-"1, 125 mg · kg"-"l, 175 mg · kg"-"l respectively, in a pot experiment. The result shows that, U concentration in the aerial part and underground part of the whole plant increased with the rise of uranium concentration in the soils. In the contaminated soils with 25∼125 mg · kg"-"l concentrations of uranium, U content of Medicago sativa L is the highset (6.78 mg · kg"-"l, 61.53 mg · kg"-"l, 74.06 mg · kg"-"l separately). While in the 175 mg · kg"-"l concentration of uranium contaminated soils, U content of Hibiscus esulentus L is the highest (86.72 mg · kg"-"1), which is mainly because of U concentration in its roots have higher level of uranium (388.16 mg · kg"-"l). Comprehensive analysis shows that Medicago sativa L. is a good plant for phytoextraction and Hibiscus esulentus L is a good immobilizing plant for phytoremediation. The results can provide some theoretical basis and technical support for remedying U-contaminated soils in different areas of our country. (authors)

  10. High-rate behaviour of iron ore pellet

    Science.gov (United States)

    Gustafsson, Gustaf; Häggblad, Hans-Åke; Jonsén, Pär; Nishida, Masahiro

    2015-09-01

    Iron ore pellets are sintered, centimetre-sized spheres of ore with high iron content. Together with carbonized coal, iron ore pellets are used in the production of steel. In the transportation from the pelletizing plants to the customers, the iron ore pellets are exposed to different loading situations, resulting in degradation of strength and in some cases fragmentation. For future reliable numerical simulations of the handling and transportation of iron ore pellets, knowledge about their mechanical properties is needed. This paper describes the experimental work to investigate the dynamic mechanical properties of blast furnace iron ore pellets. To study the dynamic fracture of iron ore pellets a number of split Hopkinson pressure bar tests are carried out and analysed.

  11. Fuel pellets from biomass: The importance of the pelletizing pressure and its dependency on the processing conditions

    DEFF Research Database (Denmark)

    Stelte, Wolfgang; Holm, Jens K.; Sanadi, Anand R.

    2011-01-01

    The aim of the present study was to identify the key factors affecting the pelletizing pressure in biomass pelletization processes. The impact of raw material type, pellet length, temperature, moisture content and particle size on the pressure build up in the press channel of a pellet mill...... act as lubricants, lowering the friction between the biomass and the press channel walls. The effect of moisture content on the pelletizing pressure was dependent on the raw material species. Different particle size fractions, from below 0.5 mm up to 2.8 mm diameter, were tested, and it was shown...

  12. Efecto de las arañas (Arachnida: Araneae como depredadoras de insectos plaga en cultivos de alfalfa (Medicago sativa (Fabaceae en Argentina

    Directory of Open Access Journals (Sweden)

    Andrea Armendano

    2011-12-01

    Full Text Available Effect of spiders (Arachnida: Araneae as predators of insect pest in alfalfa crops (Medicago sativa (Fabaceae in Argentina. Spiders are predators that reduce insect pest populations in agroecosystems. Trials were conducted to measure the selectivity against different insect preys, the daily consumption, effect of predators alone and together with a known number of preys, and the indirect effect of predators on vegetation. For this, experimental units (1x1m were used covered with a fine plastic mesh. Misumenops pallidus, Oxyopes salticus and Araneus sp. were used as generalist predators, and aphids, weevils, locusts, chrysomelids and Lepidoptera larvae as their potential preys. Among the preys offered, the spiders preferred Lepidoptera larvae compared to the other two pests groups (weevils and aphids. The maximum consumption rate was of 93.33% for Lepidoptera larvae, 25.33% for aphids and 11.67% for weevils. The Q Index values for the three species of spiders showed a positive selectivity only for defoliating larvae. O. salticus showed the highest values of consumption rates while Rachiplusia nu was the most consumed. The maximum value of consumption in 24 hours was showed by O. salticus on R. nu (C=2.8. The association of several species of predatory spiders increased the total number of insects captured, and also showed that the addition of spiders caused a decrease in the number of leaves damaged by the effect of lepidopterous larvae. Rev. Biol. Trop. 59 (4: 1651-1662. Epub 2011 December 01Las arañas son depredadoras capaces de reducir las poblaciones de insectos plaga en agroecosistemas. Para medir la selectividad frente a distintas presas, se realizaron ensayos de consumo diario, efecto de los depredadores aisladamente y en conjunto sobre el número de presas y efecto indirecto de los depredadores sobre la vegetación; se utilizaron jaulas experimentales de 1x1m cubiertas con una fina malla plástica. Misumenops pallidus, Oxyopes salticus y

  13. Intelligent Automated Nuclear Fuel Pellet Inspection System

    International Nuclear Information System (INIS)

    Keyvan, S.

    1999-01-01

    At the present time, nuclear pellet inspection is performed manually using naked eyes for judgment and decisionmaking on accepting or rejecting pellets. This current practice of pellet inspection is tedious and subject to inconsistencies and error. Furthermore, unnecessary re-fabrication of pellets is costly and the presence of low quality pellets in a fuel assembly is unacceptable. To improve the quality control in nuclear fuel fabrication plants, an automated pellet inspection system based on advanced techniques is needed. Such a system addresses the following concerns of the current manual inspection method: (1) the reliability of inspection due to typical human errors, (2) radiation exposure to the workers, and (3) speed of inspection and its economical impact. The goal of this research is to develop an automated nuclear fuel pellet inspection system which is based on pellet video (photographic) images and uses artificial intelligence techniques

  14. FBR pellet fabrication - density and dimensional control

    International Nuclear Information System (INIS)

    Rasmussen, D.E.; Schaus, P.S.

    1982-01-01

    The fuel pellet fabricating experience described in this paper involved pellet processing tests using mixed oxide (PuO 2 -UO 2 ) powders to produce fast breeder reactor (FBR) fuel pellets. Objectives of the pellet processing tests were to establish processing parameters for sintered-to-size fuel pellets to be used in an irradiation test in the Fast Flux Test Facility and to establish baseline fabrication control information. 26 figures, 7 tables

  15. Alfalfa stem tissues: Cell wall deposition, composition, and degradability

    NARCIS (Netherlands)

    Jung, H.G.; Engels, F.M.

    2002-01-01

    Declining cell wall degradability of alfalfa (Medicago sativa L.) stems with maturation limits the nutritional value of alfalfa for ruminants. This study characterized changes in cell wall concentration, composition, and degradability by rumen microbes resulting from alfalfa stem tissue

  16. Cover crop-based ecological weed management: exploration and optimization

    NARCIS (Netherlands)

    Kruidhof, H.M.

    2008-01-01

    Keywords: organic farming, ecologically-based weed management, cover crops, green manure, allelopathy, Secale cereale, Brassica napus, Medicago sativa

    Cover crop-based ecological weed management: exploration and optimization. In organic farming systems, weed control is recognized as one

  17. Cardiovascular benefits of black cumin (Nigella sativa).

    Science.gov (United States)

    Shabana, Adel; El-Menyar, Ayman; Asim, Mohammad; Al-Azzeh, Hiba; Al Thani, Hassan

    2013-03-01

    Black Cumin (Nigella sativa), which belongs to the botanical family of Ranunculaceae, commonly grows in Eastern Europe, the Middle East, and Western Asia. Its ripe fruit contains tiny black seeds, known as "Al-Habba Al-Sauda" and "Al-Habba Al-Barakah" in Arabic and black seed or black cumin in English. Seeds of Nigella sativa are frequently used in folk medicine in the Middle East and some Asian countries for the promotion of good health and the treatment of many ailments. However, data for the cardiovascular benefits of black cumin are not well-established. We reviewed the literature from 1960 to March 2012 by using the following key words: "Nigella sativa," "black seeds," and "thymoquinone." Herein, we discussed the most relevant articles to find out the role of Nigella sativa in the cardiovascular diseases spectrum especially when there is a paucity of information and need of further studies in human to establish the utility of Nigella sativa in cardiovascular system protection.

  18. Uranium dioxide pellets

    International Nuclear Information System (INIS)

    Zawidzki, T.W.

    1982-01-01

    A process for the preparation of a sintered, high density, large crystal grain size uranium dioxide pellet is described which involves: (i) reacting a uranyl nitrate of formula UO 2 (NO 3 ) 2 .6H 2 O with a sulphur source, at a temperature of from about 300 deg. C to provide a sulphur-containing uranium trioxide; (ii) reacting the thus-obtained modified uranium trioxide with ammonium nitrate to form an insoluble sulphur-containing ammonium uranate; (iii) neutralizing the thus-formed slurry with ammonium hydroxide to precipitate out as an insoluble ammonium uranate the remaining dissolved uranium; (iv) recovering the thus-formed precipitates in a dry state; (v) reducing the dry precipitate to UO 2 , and forming it into 'green' pellets; and (vi) sintering the pellets in a hydrogen atmosphere at an elevated temperature

  19. SAF line pellet gaging

    International Nuclear Information System (INIS)

    Jedlovec, D.R.; Bowen, W.W.; Brown, R.L.

    1983-10-01

    Automated and remotely controlled pellet inspection operations will be utilized in the Secure Automated Fabrication (SAF) line. A prototypic pellet gage was designed and tested to verify conformance to the functions and requirements for measurement of diameter, surface flaws and weight-per-unit length

  20. Development and problems of pellet markets in Austria

    International Nuclear Information System (INIS)

    Nemestothy, K.P.; Rakos, C.

    2001-01-01

    Wood pellets became into Austrian markets in 1994. Up to then the Austrian industry had manufactured pellet fireplaces for export, but none was sold into Austria, because there were not pellets available in the Austrian markets. In spite of significant problems in the beginning and unfavourable economic conditions (decrease of oil prices) the pellet markets in Austria have increased since 1996 dynamically. Annual pellet deliveries have increased from 15 000 t/a to present 45 000 t/a. Customers and Austrian industry are interested in pellets and they believe in the future. The pellet manufacturing capacity increases continuously. In 1999 the capacity of 12 companies was 120 000 t. In 2003 the annual pellet consumption is estimated to over 100 000 tons and in 2010 about 200 000 tons. Main portion of the pellet manufactures in Austria is also used in the country by detached houses and small real estate houses. The pellet markets for large real estates are developing after the boiler manufacturers have started to produce pellet-fired equipment. The number of pellet-fired devices in 1997, sold to detached houses was 425, and in 2000 the number was 3500

  1. A centrifuge CO2 pellet cleaning system

    International Nuclear Information System (INIS)

    Foster, C.A.; Fisher, P.W.; Nelson, W.D.; Schechter, D.E.

    1993-01-01

    Centrifuge-based cryogenic pellet accelerator technology, originally developed at Oak Ridge National Laboratory (ORNL) for the purpose of refueling fusion reactors with high-speed pellets of frozen deuterium/tritium,is now being developed as a method of cleaning without the use of conventional solvents. In these applications large quantities of pellets made of frozen CO 2 or argon are accelerated in a high-speed rotor. The accelerated pellet stream is used to clean or etch surfaces. The advantage of this system is that the spent pellets and debris resulting from the cleaning process can be filtered leaving only the debris for disposal. This paper discusses the centrifuge CO 2 pellet cleaning system, the physics model of the pellet impacting the surface, the centrifuge apparatus, and some initial cleaning and etching tests

  2. Nuclear fuel pellet transfer escalator

    International Nuclear Information System (INIS)

    Huggins, T.B. Sr.; Roberts, E.; Edmunds, M.O.

    1991-01-01

    This patent describes a nuclear fuel pellet escalator for loading nuclear fuel pellets into a sintering boat. It comprises a generally horizontally-disposed pellet transfer conveyor for moving pellets in single file fashion from a receiving end to a discharge end thereof, the conveyor being mounted about an axis at its receiving end for pivotal movement to generally vertically move its discharge end toward and away from a sintering boat when placed below the discharge end of the conveyor, the conveyor including an elongated arm swingable vertically about the axis and having an elongated channel recessed below an upper side of the arm and extending between the receiving and discharge ends of the conveyor; a pellet dispensing chute mounted to the arm of the conveyor at the discharge end thereof and extending therebelow such that the chute is carried at the discharge end of the conveyor for generally vertical movement therewith toward and away from the sintering boat

  3. A community resource for high-throughput quantitative RT-PCR analysis of transcription factor gene expression in Medicago truncatula

    Directory of Open Access Journals (Sweden)

    Redman Julia C

    2008-07-01

    Full Text Available Abstract Background Medicago truncatula is a model legume species that is currently the focus of an international genome sequencing effort. Although several different oligonucleotide and cDNA arrays have been produced for genome-wide transcript analysis of this species, intrinsic limitations in the sensitivity of hybridization-based technologies mean that transcripts of genes expressed at low-levels cannot be measured accurately with these tools. Amongst such genes are many encoding transcription factors (TFs, which are arguably the most important class of regulatory proteins. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR is the most sensitive method currently available for transcript quantification, and one that can be scaled up to analyze transcripts of thousands of genes in parallel. Thus, qRT-PCR is an ideal method to tackle the problem of TF transcript quantification in Medicago and other plants. Results We established a bioinformatics pipeline to identify putative TF genes in Medicago truncatula and to design gene-specific oligonucleotide primers for qRT-PCR analysis of TF transcripts. We validated the efficacy and gene-specificity of over 1000 TF primer pairs and utilized these to identify sets of organ-enhanced TF genes that may play important roles in organ development or differentiation in this species. This community resource will be developed further as more genome sequence becomes available, with the ultimate goal of producing validated, gene-specific primers for all Medicago TF genes. Conclusion High-throughput qRT-PCR using a 384-well plate format enables rapid, flexible, and sensitive quantification of all predicted Medicago transcription factor mRNAs. This resource has been utilized recently by several groups in Europe, Australia, and the USA, and we expect that it will become the 'gold-standard' for TF transcript profiling in Medicago truncatula.

  4. Pellet injector development and experiments at ORNL

    International Nuclear Information System (INIS)

    Baylor, L.R.; Argo, B.E.; Barber, G.C.; Combs, S.K.; Cole, M.J.; Dyer, G.R.; Fehling, D.T.; Fisher, P.W.; Foster, C.A.; Foust, C.R.; Gouge, M.J.; Jernigan, T.C.; Langley, R.A.; Milora, S.L.; Qualls, A.L.; Schechter, D.E.; Sparks, D.O.; Tsai, C.C.; Wilgen, J.B.; Whealton, J.H.

    1993-01-01

    The development of pellet injectors for plasma fueling of magnetic confinement fusion experiments has been under way at Oak Ridge National Laboratory (ORNL) for the past 15 years. Recently, ORNL provided a tritium-compatible four-shot pneumatic injector for the Tokamak Fusion Test Reactor (TFTR) based on the in situ condensation technique that features three single-stage gas guns and an advanced two-stage light gas gun driver. In another application, ORNL supplied the Tore Supra tokamak with a centrifuge pellet injector in 1989 for pellet fueling experiments that has achieved record numbers of injected pellets into a discharge. Work is progressing on an upgrade to that injector to extend the number of pellets to 400 and improve pellet repeatability. In a new application, the ORNL three barrel repeating pneumatic injector has been returned from JET and is being readied for installation on the DIII-D device for fueling and enhanced plasma performance experiments. In addition to these experimental applications, ORNL is developing advanced injector technologies, including high-velocity pellet injectors, tritium pellet injectors, and long-pulse feed systems. The two-stage light gas gun and electron-beam-driven rocket are the acceleration techniques under investigation for achieving high velocity. A tritium proof-of-principle (TPOP) experiment has demonstrated the feasibility of tritium pellet production and acceleration. A new tritium-compatible, extruder-based, repeating pneumatic injector is being fabricated to replace the pipe gun in the TPOP experiment and will explore issues related to the extrudability of tritium and acceleration of large tritium pellets. The tritium pellet formation experiments and development of long-pulse pellet feed systems are especially relevant to the International Tokamak Engineering Reactor (ITER)

  5. Production of 2nd generation Bioethanol from Lucerne - Optimization of Hydrothermal Pretreatment

    DEFF Research Database (Denmark)

    Thomsen, Sune Tjalfe; Jensen, Morten; Schmidt, Jens Ejbye

    2012-01-01

    Lucerne (Medicago sativa) has many qualities associated with sustainable agriculture such as nitrogen fixation and high biomass yield. Therefore, there is interest in whether lucerne is a suitable biomass substrate for bioethanol production, and if hydrothermal pretreatment (HTT) of lucerne impro...

  6. Arabidopsis CDS blastp result: AK062499 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK062499 001-104-A06 At4g27250.1 dihydroflavonol 4-reductase family / dihydrokaempferol... 4-reductase family similar to dihydrokaempferol 4-reductase, Ipomoea purpurea (GI:4239849), Medicago sativa, PIR2:S61416 8e-45 ...

  7. Arabidopsis CDS blastp result: AK067272 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK067272 J013098D22 At4g27250.1 dihydroflavonol 4-reductase family / dihydrokaempferol... 4-reductase family similar to dihydrokaempferol 4-reductase, Ipomoea purpurea (GI:4239849), Medicago sativa, PIR2:S61416 7e-40 ...

  8. Arabidopsis CDS blastp result: AK099340 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK099340 J033024N22 At4g27250.1 dihydroflavonol 4-reductase family / dihydrokaempferol... 4-reductase family similar to dihydrokaempferol 4-reductase, Ipomoea purpurea (GI:4239849), Medicago sativa, PIR2:S61416 2e-40 ...

  9. NCBI nr-aa BLAST: CBRC-CJAC-01-0155 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-CJAC-01-0155 sp|Q09134|GRPA_MEDFA Abscisic acid and environmental stress-induc...ible protein emb|CAA42554.1| environmental stress and abscisic acid inducible protein [Medicago sativa subsp. falcata] Q09134 2e-05 35% ...

  10. Pellets - the advance of refined bioenergy

    International Nuclear Information System (INIS)

    Dahlstroem, J.E.

    1997-01-01

    This conference paper discusses the role of pellets in the use of bioenergy in Sweden. Pellets (P) have many advantages: (1) P are dry and can be stored, (2) P create local jobs, (3) P burn without seriously polluting the environment, (4) P are made from domestic and renewable resources, (5) P have high energy density, (6) P fit well in an energy system adapted to nature, (6) P are an economical alternative, both on a small scale and on a large scale. Pellets are more laborious to use than oil or electricity and require about three times as much storage space as oil. The Swedish pellets manufacturers per 1997 are listed. Locally pellets are most conveniently transported as bulk cargo and delivered to a silo by means of pressurized air. Long-distance transport use train or ship. At present, pellets are most often used in large or medium-sized heat plants, but equipment exists for use from private houses and up to the size of MW. Pellets may become the most important alternative to the fossil fuels which along with electricity today are dominating the small scale market. 1 fig., 1 table

  11. Pellet-plasma interaction studies at ASDEX Upgrade

    International Nuclear Information System (INIS)

    Kocsis, G.; Belonohy, E.; Gal, K.; Kalvin, S.; Veres, G.; Lang, P.T.

    2005-01-01

    Pellets produced from cryogenic hydrogen isotopes are used for efficient plasma refueling. Beyond this 'classical' application, pellets pacing the frequency of Edge Localized Modes (ELMs) turned out to be a suitable technique to mitigate the power load on plasma facing components. Although pellet pacing is already integrated in the toolkit for plasma control, its underlying physics is still poorly understood. For investigations aiming to resolve where and how an ELM is triggered by the pellet imposed local perturbation precise knowledge of the ablation profile is required. This renewed and even boosted the interest to understand the interaction of pellets with the hot ambient plasma. Both the investigation of the pellet ablation and also its impact on the target plasma were highlighted. Dedicated investigations require precise information both in the space and time domain. E. g. it is necessary to determine the localization of the pellet at the moment it triggers the ELM as well as the actual imposed 3D distribution of the pellet cloud and its mass deposition profile. By these means, a spatial distribution can be mapped out for a local perturbation of the plasma sufficient to release ELMs. High resolution ablation profile and pellet path measurements at different pellet parameters (mass and velocity) could also help to understand the mechanism of the ELM triggering. Recently pellet-plasma interaction is intensively investigated both experimentally at ASDEX Upgrade tokamak and theoretically based on the obtained experimental data. To gain detailed information an observation system was developed at ASDEX Upgrade consisting of digital cameras that detect the pellet cloud distribution and photo diodes that measure the time evolution of the light emission. The great variety of possible combinations of different images, timings and wavelength selections makes the detection sophisticated. Combination of triggered fast camera images and photo diode signals also enables us

  12. Circular economy in drinking water treatment: reuse of ground pellets as seeding material in the pellet softening process.

    Science.gov (United States)

    Schetters, M J A; van der Hoek, J P; Kramer, O J I; Kors, L J; Palmen, L J; Hofs, B; Koppers, H

    2015-01-01

    Calcium carbonate pellets are produced as a by-product in the pellet softening process. In the Netherlands, these pellets are applied as a raw material in several industrial and agricultural processes. The sand grain inside the pellet hinders the application in some high-potential market segments such as paper and glass. Substitution of the sand grain with a calcite grain (100% calcium carbonate) is in principle possible, and could significantly improve the pellet quality. In this study, the grinding and sieving of pellets, and the subsequent reuse as seeding material in pellet softening were tested with two pilot reactors in parallel. In one reactor, garnet sand was used as seeding material, in the other ground calcite. Garnet sand and ground calcite performed equally well. An economic comparison and a life-cycle assessment were made as well. The results show that the reuse of ground calcite as seeding material in pellet softening is technologically possible, reduces the operational costs by €38,000 (1%) and reduces the environmental impact by 5%. Therefore, at the drinking water facility, Weesperkarspel of Waternet, the transition from garnet sand to ground calcite will be made at full scale, based on this pilot plant research.

  13. Injection of pellets into the TCA tokamak

    International Nuclear Information System (INIS)

    Martin, Y.

    1993-05-01

    This thesis presents experimental results from the analysis of the ablation process of pellets injected into the TCA tokamak. The determination of scaling laws relating the pellet penetration to the pellet and plasma parameters preceding injection, were used to improve the understanding of the interaction of the pellet with the plasma since a) the pellet and plasma conditions preceding injection were varied over a large range, and b) the estimation of the penetration depth takes into account the influence of striations in the deposition profile. Over 400 pellets with a range of sizes and speeds were injected into a range of plasma parameters in order to create a database from which the scaling laws could be deduced. The ablation characteristics were principally measured with two CCD video cameras, which provided good spatial resolution, and two filtered photomultiplier tubes, which provided good temporal resolution of the light emitted from the pellet ablation cloud. In the text, the traditional methods of analysing these diagnostics are examined with special reference to the presumptions that a) the pellet velocity is constant in the plasma, and b) the light intensity determined from the ablation cloud is proportional to the ablation rate. After successive data reduction from the database, in order to separate the effects of varying different parameters, the main observations were that, a) the pellet penetration varies as the square root of the pellet velocity, b) the scaling laws for the other parameters strongly depend on whether the pellet has sufficient velocity to reach the q=1 rational magnetic surface in the tokamak. (author) 45 refs

  14. Handling of Deuterium Pellets for Plasma Refuelling

    DEFF Research Database (Denmark)

    Jensen, Peter Bjødstrup; Andersen, Verner

    1982-01-01

    The use of a guide tube technique to inject pellets in pellet-plasma experiments is described. The effect of the guide tube on the mass and speed of a slowly moving pellet ( nu approximately 150 m s-1) is negligible. To improve the divergence in trajectories of the pellets on leaving the guide tube...

  15. Capabilities of nitrogen admixed cryogenic deuterium pellets

    Energy Technology Data Exchange (ETDEWEB)

    Sharov, Igor; Sergeev, Vladimir [SPU, Saint-Petersburg (Russian Federation); Lang, Peter; Ploeckl, Bernhard; Cavedon, Marco [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Kocsis, Gabor; Szepesi, Tamas [Wigner RCP RMI, Budapest (Hungary); Collaboration: ASDEX Upgrade Team

    2015-05-01

    Operation at high core density with high energy confinement - as foreseen in a future fusion reactor like DEMO - is being investigated at ASDEX Upgrade tokamak. The efficiency of pellet fuelling from the high-field side usually increases with increasing injection speed. Due to the fragile nature of the deuterium ice, however, the increment of pellet mass losses and subsequent pellet fragmentations take place when the speed is increased. Studies show, that admixing of a small amount of nitrogen (N{sub 2}) into D{sub 2} gas can be favorable for the mechanical stability of pellets. This might be helpful for deeper pellet penetration. Besides, seeding by N{sub 2} can enhance plasma performance due to both increasing the energy confinement time and reducing the divertor heat load in the envisaged ELMy H-mode plasma scenario. Fuelling efficiency of N{sub 2}-admixed solid D{sub 2} pellets and their nitrogen seeding capabilities were investigated. It was found that both the overall plasma density increase and the measured averaged pellet penetration depth were smaller in case of the admixed (1% mol. in the gas resulting in about 0.8% in the ice) pellet fuelling. Possibility of the N{sub 2}-seeding by admixed pellets was confirmed by CXRS measurements of N{sup 7+} content in plasma.

  16. Wood pellets for stoker burner

    International Nuclear Information System (INIS)

    Nykaenen, S.

    2000-01-01

    The author of this article has had a stoker for several years. Wood chips and sod peat has been used as fuels in the stoker, either separately or mixed. Last winter there occurred problems with the sod peat due to poor quality. Wood pellets, delivered by Vapo Oy were tested in the stoker. The price of the pellets seemed to be a little high 400 FIM/500 kg large sack. If the sack is returned in good condition 50 FIM deposit will be repaid to the customer. However, Vapo Oy informed that the calorific value of wood pellets is three times higher than that of sod peat so it should not be more expensive than sod peat. When testing the wood pellets in the stoker, the silo of the stoker was filled with wood pellets. The adjustments were first left to position used for sod peat. However, after the fire had ignited well, the adjustments had to be decreased. The content of the silo was combusted totally. The combustion of the content of the 400 litter silo took 4 days and 22 hours. Respectively combustion of 400 l silo of good quality sod peat took 2 days. The water temperature with wood pellets remained at 80 deg C, while with sod peat it dropped to 70 deg C. The main disadvantage of peat with small loads is the unhomogenous composition of the peat. The results of this test showed that wood pellets will give better efficiency than peat, especially when using small burner heads. The utilization of them is easier, and the amount of ash formed in combustion is significantly smaller than with peat. Wood pellets are always homogenous and dry if you do not spoil it with unproper storage. Pellets do not require large storages, the storage volume needed being less than a half of the volume needed for sod peat. When using large sacks the amount needed can even be transported at the trunk of a passenger car. Depending on the area to be heated, a large sack is sufficient for heating for 2-3 weeks. Filling of stoker every 2-5 day is not an enormous task

  17. Railgun pellet injection system for fusion experimental devices

    International Nuclear Information System (INIS)

    Onozuka, M.; Hasegawa, K.

    1995-01-01

    A railgun pellet injection system has been developed for fusion experimental devices. Using a low electric energy railgun system, hydrogen pellet acceleration tests have been conducted to investigate the application of the electromagnetic railgun system for high speed pellet injection into fusion plasmas. In the system, the pellet is pre-accelerated before railgun acceleration. A laser beam is used to induce plasma armature. The ignited plasma armature is accelerated by an electromagnetic force that accelerates the pellet. Under the same operational conditions, the energy conversion coefficient for the dummy pellets was around 0.4%, while that for the hydrogen pellets was around 0.12%. The highest hydrogen pellet velocity was 1.4 km s -1 using a 1 m long railgun. Based on the findings, it is estimated that the hydrogen pellet has the potential to be accelerated to 5 km s -1 using a 3 m long railgun. (orig.)

  18. A novel gene whose expression in Medicago truncatula roots is suppressed in response to colonization by vesicular-arbuscular mycorrhizal (VAM) fungi and to phosphate nutrition.

    Science.gov (United States)

    Burleigh, S H; Harrison, M J

    1997-05-01

    A cDNA clone (Mt4) was isolated as a result of a differential screen to identify genes showing altered expression during the interaction between Medicago truncatula and the vesicular-arbuscular mycorrhizal (VAM) fungus Glomus versiforme. Mt4 represents a M. truncatula mRNA that contains numerous short open reading frames, the two longest of which are predicted to encode polypeptides of 51 amino acids each. One of these open reading frames shares a short region of identity with a phosphate starvation-inducible gene from tomato. Mt4 gene expression is regulated in response to colonization by mycorrhizal fungi: transcripts were detected in non-colonized roots and levels decreased in both M. truncatula and M. sativa (alfalfa) roots after colonization by G. versiforme. Transcript levels also decreased during the incomplete interaction between G. versiforme and a M. sativa mycorrhizal minus (myc-) line, indicating that the down-regulation of this gene occurs early during the interaction between the fungus and its host plant. Phosphate levels in the nutrient media also affected the expression of the Mt4 gene: transcripts were present in the roots of plants grown under phosphate-deficient conditions, but were undetectable in the roots of plants grown under phosphate sufficient conditions. Furthermore, expression was only observed when plants were grown under nitrogen-sufficient conditions. Northern blot analyses indicate that Mt4 transcripts are present primarily in roots and barely detectable in stems or leaves. Thus, Mt4 represents a M. truncatula gene whose expression is regulated in response to both colonization by mycorrhizal fungi and to the phosphate status of the plant.

  19. Pellets direct from the forest

    International Nuclear Information System (INIS)

    Keel, A.

    2006-01-01

    This article takes a look at developments in the market for wood pellets and their production from forest wood. The general situation in the booming pellets market is reviewed and the potential of this climate-neutral form of heating is discussed. Figures and prognoses on the use of wood pellets are presented. In particular, the potential for the use of forestry wood supplies to augment the use of wood wastes and sawdust from sawmills is looked at

  20. Description of pelletizing facility

    Energy Technology Data Exchange (ETDEWEB)

    Vojin Cokorilo; Dinko Knezevic; Vladimir Milisavljevic [University of Belgrade, Belgrade (Serbia). Faculty of Mining and Geology

    2006-07-01

    A lot of electrical energy in Serbia was used for heating, mainly for domestics. As it is the most expensive source for heating the government announced a National Program of Energy Efficiency with only one aim, to reduce the consumption of electric energy for the heating. One of the contributions to mentioned reduction is production of coal pellets from the fine coal and its use for domestic heating but also for heating of schools, hospitals, military barracks etc. Annual production of fine coal in Serbia is 300,000 tons. The stacks of fine coal present difficulties at each deep mine because of environmental pollution, spontaneous combustion, low price, smaller market etc. To overcome the difficulties and to give the contribution to National Program of Energy Efficiency researchers from the Department of Mining Engineering, the University of Belgrade designed and realized the project of fine coal pelletizing. This paper describes technical aspect of this project. Using a CPM machine Model 7900, a laboratory facility, then a semi-industrial pelletizing facility followed by an industrial facility was set up and produced good quality pellets. The plant comprised a coal fines hopper, conveyor belt, hopper for screw conveyor, screw conveyor, continuous mixer conditioner, binder reservoir, pump and pipelines, pellet mill, product conveyor belt and product hopper. 4 refs., 3 figs., 1 tab.

  1. IAEA technical committee meeting on pellet injection

    International Nuclear Information System (INIS)

    1993-01-01

    The IAEA Technical Committee Meeting on Pellet Injection, May 10-12, 1993, at the Japan Atomic Energy Research Institute, Naka, Ibaraki-ken, Japan, was held to review the latest results on pellet injection and its effects on plasma confinement. In particular, topics included in the meeting include (i) pellet ablation and particle fueling results, (ii) pellet injection effects on confinement, including improved confinement modes, edge effects, magnetohydrodynamic activity and impurity transport, and (iii) injector technology and diagnostics using pellets. About 30 experts attended and 23 papers were presented. Refs, figs and tabs

  2. Pelletization of fine coals. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Sastry, K.V.S.

    1995-12-31

    Coal is one of the most abundant energy resources in the US with nearly 800 million tons of it being mined annually. Process and environmental demands for low-ash, low-sulfur coals and economic constraints for high productivity are leading the coal industry to use such modern mining methods as longwall mining and such newer coal processing techniques as froth flotation, oil agglomeration, chemical cleaning and synthetic fuel production. All these processes are faced with one common problem area--fine coals. Dealing effectively with these fine coals during handling, storage, transportation, and/or processing continues to be a challenge facing the industry. Agglomeration by the unit operation of pelletization consists of tumbling moist fines in drums or discs. Past experimental work and limited commercial practice have shown that pelletization can alleviate the problems associated with fine coals. However, it was recognized that there exists a serious need for delineating the fundamental principles of fine coal pelletization. Accordingly, a research program has been carried involving four specific topics: (i) experimental investigation of coal pelletization kinetics, (ii) understanding the surface principles of coal pelletization, (iii) modeling of coal pelletization processes, and (iv) simulation of fine coal pelletization circuits. This report summarizes the major findings and provides relevant details of the research effort.

  3. Arabidopsis CDS blastp result: AK241480 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241480 J065165O08 At4g27250.1 68417.m03912 dihydroflavonol 4-reductase family / dihydrokaempferol... 4-reductase family similar to dihydrokaempferol 4-reductase, Ipomoea purpurea (GI:4239849), Medicago sativa, PIR2:S61416 4e-31 ...

  4. Arabidopsis CDS blastp result: AK242505 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242505 J080309P03 At4g27250.1 68417.m03912 dihydroflavonol 4-reductase family / dihydrokaempferol... 4-reductase family similar to dihydrokaempferol 4-reductase, Ipomoea purpurea (GI:4239849), Medicago sativa, PIR2:S61416 3e-38 ...

  5. Identification of loci Associated with Resistance to Root-Rot Diseases in Autotetraploid Alfalfa using Genome-Wide Sequencing and Association Mapping

    Science.gov (United States)

    Alfalfa (Medicago sativa L.) is the world-wide forage crop. Changing trends to multipurpose uses increases demand for alfalfa. However, the production of alfalfa is challenged by endemic and emerging diseases. Identification of genes/loci controlling disease resistance will facilitate breeding for i...

  6. First report of Fusarium wilt of alfalfa caused by Fusarium oxysporum f. sp. medicaginis in Wisconsin

    Science.gov (United States)

    Fusarium wilt, caused by Fusarium oxysporum f. sp. medicaginis, is an economically important vascular disease of alfalfa (Medicago sativa) throughout the world. Alfalfa plants with foliar wilt symptoms and reddish-brown arcs in roots consistent with Fusarium wilt were observed in disease assessment ...

  7. Storage characteristics, nutritive value, energy content, and in-vivo digestibility of moist large-rectangular bales of alfalfa-orchardgrass hay treated with a propionic-acid-based preservative

    Science.gov (United States)

    Unstable weather, poor drying conditions, and unpredictable rainfall events often place valuable hay crops at risk. Recent research with large-round bales comprised of alfalfa (Medicago sativa L.) and orchardgrass (Dactylis glomerata L.) has shown that these large-bale packages are particularly sens...

  8. Railgun pellet injection system for fusion experimental devices

    Energy Technology Data Exchange (ETDEWEB)

    Onozuka, M. [Mitsubishi Heavy Industries Ltd., Yokohama (Japan). Adv. Tech. Dev. Dept.; Oda, Y. [Mitsubishi Heavy Industries Ltd., Yokohama (Japan). Adv. Tech. Dev. Dept.; Azuma, K. [Mitsubishi Heavy Industries Ltd., Yokohama (Japan). Adv. Tech. Dev. Dept.; Satake, K. [Mitsubishi Heavy Industries Ltd., Yokohama (Japan). Adv. Tech. Dev. Dept.; Kasai, S. [Japan Atomic Energy Research Institute, Tokai-mura, Naka-gun 319-11 (Japan); Hasegawa, K. [Japan Atomic Energy Research Institute, Tokai-mura, Naka-gun 319-11 (Japan)

    1995-11-01

    A railgun pellet injection system has been developed for fusion experimental devices. Using a low electric energy railgun system, hydrogen pellet acceleration tests have been conducted to investigate the application of the electromagnetic railgun system for high speed pellet injection into fusion plasmas. In the system, the pellet is pre-accelerated before railgun acceleration. A laser beam is used to induce plasma armature. The ignited plasma armature is accelerated by an electromagnetic force that accelerates the pellet. Under the same operational conditions, the energy conversion coefficient for the dummy pellets was around 0.4%, while that for the hydrogen pellets was around 0.12%. The highest hydrogen pellet velocity was 1.4 km s{sup -1} using a 1 m long railgun. Based on the findings, it is estimated that the hydrogen pellet has the potential to be accelerated to 5 km s{sup -1} using a 3 m long railgun. (orig.).

  9. Three way interactions between Thymus vulgaris, Medicago truncatula and Sinorhizobium meliloti

    DEFF Research Database (Denmark)

    Grøndahl, Eva; Ehlers, Bodil Kirstine

    2012-01-01

    Thymus vulgaris is a dominating component of the Mediterranean garrigue vegetation. It produces aromatic oil, containing monoterpenes, which affects the performance (growth, survival) of other plants, and microorganisms. Annual plant species of the genus Medicago are commonly found in Mediterranean...... shows patterns of adaptation to its thyme neighbor, and 2) if any adaptive response was dependent on the rhizobium, and whether the rhizobium was either "experienced" or "naive" with respect to thyme monoterpenes. Using a G*G*E design, the fitness of 13 genotypes of Medicago truncatula was tested....... Of these genotypes, 7 were ”experienced”, and 6 were ”naive” to thyme. All genotypes were grown on soil either amended with thyme monoterpene or not. In addition, each plant received a rhizobium treatment, which was either: no rhizobium, a mix of thyme experienced Sinorhizobium genotypes, or a mix of thyme naive...

  10. Vertical pellet injection in FTU discharges

    International Nuclear Information System (INIS)

    Giovannozzi, E.; Annibaldi, S.V.; Buratti, P.

    2005-01-01

    Central fuelling and pellet enhanced performance modes have been obtained with pellets injected vertically from the high field side on the FTU tokamak. Four phases have been recognized: ablation of the pellets, drifting plasmoids, MHD modes which take the density to the centre of the discharge and finally an anomalous drift which further increases the density peaking. Pellet ablation data have been compared with values from a pellet ablation and deposition code. Comparison between 0.8 and 1.1 MA discharges at a high magnetic field (B T = 7 T) has been carried out: a higher performance has been obtained with the latter due to the higher target density and the larger inversion radius which would increase the effects of m = 1 modes to take the density to the plasma centre

  11. Factors Affecting the Sintering of UO2 Pellets

    International Nuclear Information System (INIS)

    El-Hakim, E.; Afifi, Y.K.

    1999-01-01

    Sintering of UO 2 pellets is affected by many parameters such as; UO 2 powder parameters, the conditions followed for preparing the green UO 2 pellets and the sintering scheme(heating and cooling rate, soaking time and temperature). The aim of this work is to study the effect of some these parameters on the characteristics of the sintered UO 2 pellets were qualified according to the technical specifications of Candu fuel. Pressed green pellets at different pressing force (15 to 50 k N) were sintered at 1650 ±20 degree for two hours to study the effect of pressing force on the sintered pellets characteristics; visual inspection, pellet dimensions, density and shrinkage ratio. Compacted green pellets at a pressing force of 48 k N were sintered at different sintering temperature (1600± 20 degree, 1650 ±20 degree, 1700± 20 degree) for two hours to study the effect of sintering temperature on the sintered pellets characteristics. The effect of the heating rate (200,300 and 400 degree per hour) on the sintered pellets characteristics was also investigated. It was found that the pressing force used to compact the green pellets had an effect on the density of the sintered pellets. Pellets pressed at 15 k N have a density of 10.3 g/cm 3 while, those pressed at 50 k N have a density of 10.6 g/cm 3. It was observed that increasing the heating rate to 400 degree /h lead to cracked pellets

  12. Pellet injector research and development at ORNL

    International Nuclear Information System (INIS)

    Combs, S.K.; Argo, B.E.; Baylor, L.R.; Cole, M.J.; Dyer, G.R.; Fehling, D.T.; Fisher, P.W.; Foster, C.A.; Foust, C.R.; Gouge, M.J.; Jernigan, T.C.; Langley, R.A.; Milora, S.L.; Qualls, A.L.; Schechter, E.; Sparks, D.O.; Tsai, C.C.; Wilgen, J.B.; Whealton, J.W.

    1993-01-01

    A variety of pellet injector designs have been developed at ORNL including single-shot guns that inject one pellet, multiple-shot guns that inject four and eight pellets, machine gun-types (single- and multiple-barrel) that can inject up to >100 pellets, and centrifugal accelerators (mechanical devices that are inherently capable of high repetition rates and long-pulse operation). With these devices, macroscopic pellets (1--6 mm in diameter) composed of hydrogen isotopes are typically accelerated to speeds of ∼1.0 to 2.0 km/s for injection into plasmas of experimental fusion devices. In the past few years, steady progress has been made at ORNL in the development and application of pellet injectors for fueling present-day and future fusion devices. In this paper, we briefly describe some research and development activities at ORNL, including: (1) two recent applications and a new one on large experimental fusion devices, (2) high-velocity pellet injector development, and (3) tritium injector research

  13. Power matching for pellet fusion

    International Nuclear Information System (INIS)

    Martin, R.L.; Arnold, R.C.

    1976-01-01

    The number of beams required for optimum power transfer from a given power source to the surface of a pellet is derived. The result is valid for linear optical systems, hence, for pellet fusion by laser or high energy ion beams. The optimum number of beams turns out to be inconceivably large for any practical system. Practical pellet fusion by lasers or high energy heavy ion beams must thus compromise physical principles in favor of reduced cost and optical complexity

  14. Production of hydrogen, nitrogen and argon pellets with the Moscow-Juelich pellet target

    International Nuclear Information System (INIS)

    Buescher, M.; Boukharov, A.; Semenov, A.; Gerasimov, A.; Chernetsky, V.; Fedorets, P.

    2009-01-01

    Targets of frozen droplets ("pellets") from various liquefiable gases like H 2 , D 2 , N 2 , Ne, Ar, Kr and Xe are very promising for high luminosity experiments with a 4π detector geometry at storage-rings. High effective target densities (> 10 15 atoms/cm 2 ), a small target size (⊘ ≈ 20–30 μm), a low gas load and a narrow pellet beam are the main advantages of such targets. Pioneering work on pellet targets has been made at Uppsala, Sweden. A next generation target has been built at the IKP of FZJ in collaboration with two institutes (ITEP and MPEI) from Moscow, Russia. It is a prototype for the future pellet target at the PANDA experiment at FAIR/HESR (supported by INTAS 06-1000012-8787, 2007/08) and makes use of a new cooling and liquefaction method, based on cryogenic liquids instead of cooling machines. The main advantages of this method are the vibration-free cooling and the possibility for cryogenic jet production from various gases in a wide range of temperatures. Different regimes of pellet production from H 2 , N 2 and Ar have been observed and their parameters have been measured. For the first time, mono-disperse and satellite-free droplet production was achieved for cryogenic liquids from H 2 , N 2 and Ar. (author)

  15. Wood pellets. The cost-effective fuel

    International Nuclear Information System (INIS)

    Anon.

    2001-01-01

    The article is based on an interview with Juhani Hakkarainen of Vapo Oy. Wood pellets are used in Finland primarily to heat buildings such as schools and offices and in the home. They are equally suitable for use in larger installations such as district heating plants and power stations. According to him wood pellets are suitable for use in coal-fired units generating heat, power, and steam. Price-wise, wood pellets are a particularly competitive alternative for small coal-fired plants away from the coast. Price is not the only factor on their side, however. Wood pellets also offer a good environmental profile, as they burn cleanly and generate virtually no dust, an important plus in urban locations. The fact that pellets are a domestically produced fuel is an added benefit, as their price does not fluctuate in the same way that the prices of electricity, oil, coal, and natural gas do. The price of pellets is largely based on direct raw material and labour costs, which are much less subject to ups and downs

  16. Optimization of a multi-parameter model for biomass pelletization to investigate temperature dependence and to facilitate fast testing of pelletization behavior

    DEFF Research Database (Denmark)

    Holm, Jens Kai; Stelte, Wolfgang; Posselt, Dorthe

    2011-01-01

    Pelletization of biomass residues increases the energy density, reduces storage and transportation costs and results in a homogeneous product with well-defined physical properties. However, raw materials for fuel pellet production consist of ligno-cellulosic biomass from various resources...... and error” experiments and personal experience. However in recent years the utilization of single pellet press units for testing the biomass pelletizing properties has attracted more attention. The present study outlines an approach where single pellet press testing is combined with modeling to mimic...... the pelletizing behavior of new types of biomass in a large scale pellet mill. This enables a fast estimation of key process parameters such as optimal press channel length and moisture content. Secondly, the study addresses the question of the origin of the observed relationship between pelletizing pressure...

  17. Nuclear fuel pellet production method and nuclear fuel pellet

    International Nuclear Information System (INIS)

    Yuda, Ryoichi; Ito, Ken-ichi; Masuda, Hiroshi.

    1993-01-01

    In a method of manufacturing nuclear fuel pellets by compression-molding UO 2 powders followed by sintering, a sintering agent having a composition of about 40 to 80 wt% of SiO 2 and the balance of Al 2 O 3 , a sintering agent at a ratio of 10 to 500 ppm based on the total amount of UO 2 and UO 2 powders are mixed, compression molded and then sintered at a sintering temperature of about 1500 of 1800degC. The UO 2 particles have an average grain size of about 20 to 60μm, most of the crystal grain boundary thereof is coated with a glassy or crystalline alumina silicate phase, and the porosity is about 1 to 4 vol%. With such a constitution, the sintering agent forms a single liquid phase eutectic mixture during sintering, to promote a surface reaction between nuclear fuel powders by a liquid phase sintering mechanism, increase their density and promote the crystal growth. Accordingly, it is possible to lower the softening temperature, improve the creep velocity of the pellets and improve the resistance against pellet-clad interaction. (T.M.)

  18. Solidification of radioactive waste solutions by pelletization technique

    International Nuclear Information System (INIS)

    Akbar, A.H.; Koester, R.; Rudolph, G.

    1980-04-01

    A possible way of performing the cement fixation of radioactive wastes is the incorporation into cement pellets on a pan pelletizer, followed by embedding the pellets into an inactive cement matrix. This procedure is suitable for various types of waste, particularly for medium level liquid wastes, and can be used both at drum disposal and at in-situ solidification. This report describes some initial studies on the pelletization technique using a laboratory pelletizer. Formation and size of the pellets have been found to be determined by speed, angle, and load of the pan, ratio and mode of addition of the liquid and solid components, ect. Pellets in various compositions have been produced from cement and water or simulated waste solution, in some cases with the addition of bentonite for improving cesium retention. Some mechanical properties of the pellets such as fall height of fresh pellets, development of hardness (crush test), impact and abrasion resistance, have been determined. Some preliminary experiments were done on backfilling the void space between the pellets - about 40 per cent of the bulk volume - with cement grouts of appropriate compositions. (orig.) [de

  19. Linear resonance acceleration of pellets

    International Nuclear Information System (INIS)

    Mills, R.G.

    1978-01-01

    A possible requirement for the acceleration of macroscopic pellets to velocities exceeding 10 4 meters per second implies the development of new apparatus. A satisfactory approach might be the linear resonance accelerator. Such apparatus would require the charging of pellets to very high values not yet demonstrated. The incompatibility of phase stability with radial stability in these machines may require abandoning phase stability and adopting feedback control of the accelerating voltage to accommodate statistical fluctuations in the charge to mass ratio of successive pellets

  20. An advanced cold moderator using solid methane pellets

    International Nuclear Information System (INIS)

    Foster, C.A.; Carpenter, J.M.

    2001-01-01

    This paper reports developments of the pellet formation and transport technologies required for producing a liquid helium or hydrogen cooled methane pellet moderator. The Phase I US DOE SBIR project, already completed, demonstrated the production of 3 mm transparent pellets of frozen methane and ammonia and transport of the pellets into a 40 cc observation cell cooled with liquid helium. The methane pellets, formed at 72 K, stuck together during the loading of the cell. Ammonia pellets did not stick and fell readily under vibration into a packed bed with a 60% fill fraction. A 60% fill fraction should produce a very significant increase in long-wavelength neutron production and advantages in shorter pulse widths as compared to a liquid hydrogen moderator. The work also demonstrated a method of rapidly changing the pellets in the moderator cell. The Phase II project, just now underway, will develop a full-scale pellet source and transport system with a 1.5 L 'moderator' cell. The Phase II effort will also produce an apparatus to sub-cool the methane pellets to below 20 K, which should prevent the methane pellets from sticking together. In addition to results of the phase I experiments, the presentation includes a short video of the pellets, and a description of plans for the Phase II project. (author)

  1. Apparatus for feeding nuclear fuel pellets to a loading tray

    International Nuclear Information System (INIS)

    Huggins, T.B.

    1979-01-01

    Apparatus for feeding nuclear fuel pellets at a uniform predetermined rate between pellet centering and grinding apparatus and a tray for loading pellets into nuclear fuel rod. Pellets discharged from the grinding apparatus are conveyed by a belt to a drive wheel forcing the pellets in engagement with the belt. The pellets under the drive wheel are capable of pushing a line of about 36 pellets onto a pellet dumping mechanism. As the dumping mechanism is actuated to dump the pellets on to a loading tray, the pellets moving toward the mechanism are stopped and the drive wheel is simultaneously lifted off the pellets until the pellet dumping process is completed. (U.K.)

  2. Wood pellets offer a competitive energy option in Sweden

    International Nuclear Information System (INIS)

    2001-01-01

    The market for wood pellets in Sweden grew rapidly during the 1990s and production now stands at around 550,000 tonnes/year. More efficient combustion technology, pellet transportation, pellet storage and pellet delivery have also been developed. The pellets, which are produced by some 25 plants, are used in family houses, large-scale district heating plants, and combined heat and power (CHP) plants. Most of the pellets are made from biomass resources such as forest residues and sawdust and shavings from wood mills. Pellet production, the energy content of saw mill by-products, the current market and its potential for future expansion, the way in which the pellets are used in different combustion systems, the theoretical market potential for wood pellet heating installations in small houses and the Swedish P-certificate system for the certification of pellet stoves and burners are described

  3. Elicitor-induced transcription factors for metabolic reprogramming of secondary metabolism in Medicago truncatula

    Directory of Open Access Journals (Sweden)

    Dixon Richard A

    2008-12-01

    Full Text Available Abstract Background Exposure of Medicago truncatula cell suspension cultures to pathogen or wound signals leads to accumulation of various classes of flavonoid and/or triterpene defense molecules, orchestrated via a complex signalling network in which transcription factors (TFs are essential components. Results In this study, we analyzed TFs responding to yeast elicitor (YE or methyl jasmonate (MJ. From 502 differentially expressed TFs, WRKY and AP2/EREBP gene families were over-represented among YE-induced genes whereas Basic Helix-Loop-Helix (bHLH family members were more over-represented among the MJ-induced genes. Jasmonate ZIM-domain (JAZ transcriptional regulators were highly induced by MJ treatment. To investigate potential involvement of WRKY TFs in signalling, we expressed four Medicago WRKY genes in tobacco. Levels of soluble and wall bound phenolic compounds and lignin were increased in all cases. WRKY W109669 also induced tobacco endo-1,3-β-glucanase (NtPR2 and enhanced the systemic defense response to tobacco mosaic virus in transgenic tobacco plants. Conclusion These results confirm that Medicago WRKY TFs have broad roles in orchestrating metabolic responses to biotic stress, and that they also represent potentially valuable reagents for engineering metabolic changes that impact pathogen resistance.

  4. Present status of laser fusion fuel pellet

    International Nuclear Information System (INIS)

    Nakai, Sadao; Mima, Kunioki; Norimatsu, Takayoshi; Takagi, Masaru.

    1986-01-01

    Accompanying the advance of pellet implosion experiment, the data base required for fuel pellet design has been steadily accumulated. The clarification of the physics related to the process of absorbing laser beam, energy transport, the generation of ablative pressure, the hydrodynamic mechanism of implosion, the energy transmission to fuel core and so on progressed, and the design data supported by these results are prepared. Based on the data base like this, the design of fuel pellets taking the optimization of implosion in consideration is carried out. The various fuel pellets designed in this way are tested for their effectiveness by implosion experiment. For this purpose, the high performance measurement of implosion and the high accuracy manufacture of fuel pellets become very important. In this paper, the present state of the research on the method of laser implosion, the example of pellet design and the law of proportion, the manufacturing techniques of the fuel pellets having various structures, the techniques dealing with tritium and so on is summarized, and the direction of future research and development is ascertained. At present, implosion experiment is carried out mostly by hanging a pellet target with a fiber of several μm diameter, but the fiber impairs the symmetry of implosion. The levitation techniques without contact is required. (Kako, I.)

  5. A centrifuge CO2 pellet cleaning system

    Science.gov (United States)

    Foster, C. A.; Fisher, P. W.; Nelson, W. D.; Schechter, D. E.

    1995-01-01

    An advanced turbine/CO2 pellet accelerator is being evaluated as a depaint technology at Oak Ridge National Laboratory (ORNL). The program, sponsored by Warner Robins Air Logistics Center (ALC), Robins Air Force Base, Georgia, has developed a robot-compatible apparatus that efficiently accelerates pellets of dry ice with a high-speed rotating wheel. In comparison to the more conventional compressed air 'sandblast' pellet accelerators, the turbine system can achieve higher pellet speeds, has precise speed control, and is more than ten times as efficient. A preliminary study of the apparatus as a depaint technology has been undertaken. Depaint rates of military epoxy/urethane paint systems on 2024 and 7075 aluminum panels as a function of pellet speed and throughput have been measured. In addition, methods of enhancing the strip rate by combining infra-red heat lamps with pellet blasting and by combining the use of environmentally benign solvents with the pellet blasting have also been studied. The design and operation of the apparatus will be discussed along with data obtained from the depaint studies.

  6. Pellet fired appliances. Market survey. 7. rev. ed.; Pelletheizungen. Marktuebersicht

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-01-15

    The market survey under consideration reports on pellet central heating systems and pellet fired appliances. The main chapters of this market survey are concerned to: (1) Information on wood pellets and pellet fired appliances; (2) Information about the interpretation of the market survey; (3) Survey of all compared pellet fired appliances with respect to the nominal power; (4) Price lists of pellet fired appliances and pellet central heating systems; (5) Type sheets of the compared pellet fired appliances and pellet central heating systems. Finally, this brochure contains the addresses of the produces and distribution partners of pellet fired appliances and pellet central heating systems.

  7. Comparative investigation of physiological responses of field-grown ...

    African Journals Online (AJOL)

    An important consideration in designing and managing forage systems is the knowledge of the physiological response mechanisms to cutting, especially when water deficit conditions are prevailing. The objective of this study was to determine the physiological response of Medicago sativa and Festuca arundinacea to ...

  8. Arabidopsis CDS blastp result: AK288497 [KOME

    Lifescience Database Archive (English)

    Full Text Available H3 from Zea mays SP|P05203, Medicago sativa GI:166384, Encephalartos altensteinii SP|P08903, Pisum sativum SP|P02300; contains Pfam profile PF00125 Core histone H2A/H2B/H3/H4 4e-57 ...

  9. Molecular cloning of a novel GSK3/shaggy-like gene from Triticum ...

    African Journals Online (AJOL)

    The deduced amino acid sequence showed a high homology with shaggy-like kinases from Triticum aestivum, Zea mays, Trifolium repens, Nicotine tabacum, Medicago sativa and Arabidopsis thaliana; therefore, the gene was named TmGSK1 (Triticum monococcum Glycogen Synthase Kinase 1,GenBank Accession No.

  10. Alfalfa contains substantial 9-hydroperoxide lyase activity and a 3Z:2E-enal isomerase

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Noordermeer, M.A.; Veldink, G.A.

    1999-01-01

    Fatty acid hydroperoxides formed by lipoxygenase can be cleaved by hydroperoxide lyase resulting in the formation of short-chain aldehydes and omega-oxo acids. Plant hydroperoxide lyases use 13- or 9-hydroperoxy linoleic and linolenic acid as substrates. Alfalfa (Medicago sativa L.) has been

  11. Forage accumulation and nutritive value of reduced lignin and reference alfalfa cultivars

    Science.gov (United States)

    Reduced lignin alfalfa (Medicago sativa L.) cultivars have the potential to increase the feeding value of alfalfa for livestock by improving the forage fiber digestibility and to increase harvest management flexibility. The objectives were to compare the yield and forage nutritive value of reduced ...

  12. Enhancing pollination by attracting & retaining leaf cutting bees (Megachile rotundata) in alfalfa seed production fields

    Science.gov (United States)

    The alfalfa leafcutting bee, Megachile rotundata (F.), has become an important managed pollinator of alfalfa, Medicago sativa L. One problem when using alfalfa leafcutting bees as managed pollinator, is the dispersal of many females upon release, even when adequate nesting sites are present. While d...

  13. Soil quality effects on regeneration of annual Medicago pastures in ...

    African Journals Online (AJOL)

    Annual medic (Medicago spp.) pastures are widely used as the forage component of crop rotation systems in the Mediterranean region of South Africa. Reliable establishment of medics can be challenging. This may be related to poor soil quality, an inherent problem of soils in the region often aggravated by poor ...

  14. Pellet injection and toroidal confinement

    International Nuclear Information System (INIS)

    1989-12-01

    The proceedings of a technical committee meeting on pellet injection and toroidal confinement, held in Gut Ising, Federal Republic of Germany, 24-26 October, 1988, are given in this report. Most of the major fusion experiments are using pellet injectors; these were reported at this meeting. Studies of confinement, which is favorably affected, impurity transport, radiative energy losses, and affects on the ion temperature gradient instability were given. Studies of pellet ablation and effects on plasma profiles were presented. Finally, several papers described present and proposed injection guns. Refs, figs and tabs

  15. Monterey Peninsula Water Supply Project Supplemental Draft Environmental Impact Report/Statement. Appendices. Monterey Peninsula Water Management District

    Science.gov (United States)

    1991-08-01

    device and trapping facility near the face cf the 8 3 88089 A3-7 FIGURE 3-3 -7/ .7-U mv I 1 . - a Cach agua Creek Site Are a V 0 2.5 5 I I 1L KilometersI...succulentus succulent annual lupine Madia gracilis gumweed Madia madioides woodland madia Madia sativa Chile tarweed Marah fabaceus manroot Medicago...Lupinus nanus ssp. nanus sky lupine Lupinus succulentus succulent annual lupine Madia gracilis gumweed Madia sativa Chile tarweed I Marah fabaceus

  16. Advanced turbine/CO2 pellet accelerator

    International Nuclear Information System (INIS)

    Foster, C.A.; Fisher, P.W.

    1994-01-01

    An advanced turbine/CO 2 pellet accelerator is being evaluated as a depaint technology at Oak Ridge National Laboratory. The program, sponsored by Warner Robins Air Logistics Center, Robins Air Force Base, Georgia, has developed a robot-compatible apparatus that efficiently accelerates pellets of dry ice with a high-speed rotating wheel. In comparison to the more conventional compressed air sandblast pellet accelerators, the turbine system can achieve higher pellet speeds, has precise speed control, and is more than ten times as efficient. A preliminary study of the apparatus as a depaint technology has been undertaken. Depaint rates of military epoxy/urethane paint systems on 2024 and 7075 aluminum panels as a function of pellet speed and throughput have been measured. In addition, methods of enhancing the strip rate by combining infra-red heat lamps with pellet blasting have also been studied. The design and operation of the apparatus will be discussed along with data obtained from the depaint studies. Applications include removal of epoxy-based points from aircraft and the cleaning of surfaces contaminated with toxic, hazardous, or radioactive substances. The lack of a secondary contaminated waste stream is of great benefit

  17. Tritium proof-of-principle pellet injector

    International Nuclear Information System (INIS)

    Fisher, P.W.

    1991-07-01

    The tritium proof-of-principle (TPOP) experiment was designed and built by Oak Ridge National Laboratory (ORNL) to demonstrate the formation and acceleration of the world's first tritium pellets for fueling of future fusion reactors. The experiment was first used to produce hydrogen and deuterium pellets at ORNL. It was then moved to the Tritium Systems Test Assembly at Los Alamos National Laboratory for the production of tritium pellets. The injector used in situ condensation to produce cylindrical pellets in a 1-m-long, 4-mm-ID barrel. A cryogenic 3 He separator, which was an integral part of the gun assembly, was capable of lowering 3 He levels in the feed gas to <0.005%. The experiment was housed to a glovebox for tritium containment. Nearly 1500 pellets were produced during the course of the experiment, and about a third of these were pure tritium or mixtures of deuterium and tritium. Over 100 kCi of tritium was processed through the experiment without incident. Tritium pellet velocities of 1400 m/s were achieved with high-pressure hydrogen propellant. The design, operation, and results of this experiment are summarized. 34 refs., 44 figs., 3 tabs

  18. Quality properties of fuel pellets from forest biomass

    Energy Technology Data Exchange (ETDEWEB)

    Lehtikangas, P.

    1999-07-01

    Nine pellet assortments, made of fresh and stored sawdust, bark and logging residues (a mixture of Norway spruce and Scots pine) were tested directly after production and after 5 months of storage in large bags (volume about 1 m{sup 3} loose pellets) for moisture content, heating value and ash content. Dimensions, bulk density, density of individual pellets and durability were also determined. Moreover, sintering risk and contents of sulphur, chlorine, and lignin of fresh pellets were determined. It is concluded that bark and logging residues are suitable raw materials for pellets production, especially regarding durability and if the ash content is controlled. Pellets density had no effect on its durability, unlike lignin content which was positively correlated. The pellets had higher ash content and lower calorific heating value than the raw materials, probably due to loss of volatiles during drying. In general, the quality changes during storage were not large, but notable. The results showed that storage led to negative effects on durability, especially on pellets made of fresh materials. The average length of pellets was decreased due to breakage during storage. Microbial growth was noticed in some of the pellet assortments. Pellets made out of fresh logging residues were found to be weakest after storage. The tendency to reach the equilibrium with the ambient moisture content should be taken into consideration during production due to the risk of decreasing durability.

  19. Fuel Pellets from Wheat Straw: The Effect of Lignin Glass Transition and Surface Waxes on Pelletizing Properties

    Science.gov (United States)

    Wolfgang Stelte; Craig Clemons; Jens K. Holm; Jesper Ahrenfeldt; Ulrik B. Henriksen; Anand R. Sanadi

    2012-01-01

    The utilization of wheat straw as a renewable energy resource is limited due to its low bulk density. Pelletizing wheat straw into fuel pellets of high density increases its handling properties but is more challenging compared to pelletizing wood biomass. Straw has a lower lignin content and a high concentration of hydrophobic waxes on its outer surface that may limit...

  20. Apparatus and method for loading pellets into fuel rods

    International Nuclear Information System (INIS)

    Widener, W.H.

    1991-01-01

    An apparatus for feeding a column of aligned cylindrical pellets along a longitudinal path of travel and while identifying a pellet of improper size. It comprises guide surface means adapted for supporting a plurality of serially arranged and longitudinally oriented cylindrical pellets, and such that the pellets are adapted to be slidably and longitudinally advanced along the guide surface means to define an advancing column of pellets, and pellet segregation means positioned adjacent one end of the guide surface means for permitting each advancing pellet having a cross-sectional diameter equal to a predetermined minimum diameter to advance thereacross while permitting each advancing pellet having a cross-sectional diameter less than the predetermined minimum diameter to drop to a level below the level of the remaining pellets in the advancing column

  1. Application of EMILAC to pellet injection

    International Nuclear Information System (INIS)

    Iwamura, Yasuhiro; Yamasaki, Takao; Nakamura, Hirone; Hashimoto, Mitsuo; Miya, Kenzo

    1987-01-01

    A new type of electromagnetic accelerator for pellet injection is proposed. Projectile of cylinder shape is accelerated with the repulsive force generated by a combination of two coils, which are different in purpose. And the accelerator is named EMILAC (Electro-Magnetic Inductive Linear Accelerator). In this paper, we investigate the method of applying EMILAC to pellet injection, and calculate the ablation rate of pellet. (author)

  2. Fuel pellets from biomass - Processing, bonding, raw materials

    Energy Technology Data Exchange (ETDEWEB)

    Stelte, W.

    2011-12-15

    The present study investigates several important aspects of biomass pelletization. Seven individual studies have been conducted and linked together, in order to push forward the research frontier of biomass pelletization processes. The first study was to investigate influence of the different processing parameters on the pressure built up in the press channel of a pellet mill. It showed that the major factor was the press channel length as well as temperature, moisture content, particle size and extractive content. Furthermore, extractive migration to the pellet surface at an elevated temperature played an important role. The second study presented a method of how key processing parameters can be estimated, based on a pellet model and a small number of fast and simple laboratory trials using a single pellet press. The third study investigated the bonding mechanisms within a biomass pellet, which indicate that different mechanisms are involved depending on biomass type and pelletizing conditions. Interpenetration of polymer chains and close intermolecular distance resulting in better secondary bonding were assumed to be the key factors for high mechanical properties of the formed pellets. The outcome of this study resulted in study four and five investigating the role of lignin glass transition for biomass pelletization. It was demonstrated that the softening temperature of lignin was dependent on species and moisture content. In typical processing conditions and at 8% (wt) moisture content, transitions were identified to be at approximately 53-63 deg. C for wheat straw and about 91 deg. C for spruce lignin. Furthermore, the effects of wheat straw extractives on the pelletizing properties and pellet stability were investigated. The sixth and seventh study applied the developed methodology to test the pelletizing properties of thermally pre-treated (torrefied) biomass from spruce and wheat straw. The results indicated that high torrefaction temperatures above 275 deg

  3. Dissolution test for homogeneity of mixed oxide fuel pellets

    International Nuclear Information System (INIS)

    Lerch, R.E.

    1979-08-01

    Experiments were performed to determine the relationship between fuel pellet homogeneity and pellet dissolubility. Although, in general, the amount of pellet residue decreased with increased homogeneity, as measured by the pellet figure of merit, the relationship was not absolute. Thus, all pellets with high figure of merit (excellent homogeneity) do not necessarily dissolve completely and all samples that dissolve completely do not necessarily have excellent homogeneity. It was therefore concluded that pellet dissolubility measurements could not be substituted for figure of merit determinations as a measurement of pellet homogeneity. 8 figures, 3 tables

  4. Trapping of pellet cloud radiation in thermonuclear plasmas

    International Nuclear Information System (INIS)

    Sergeev, V.Yu.; Miroshinikov, I.V.; Sudo, Shigeru; Namba, C.; Lisitsa, V.S.

    2001-01-01

    The experimental and theoretical data on radiation trapping in clouds of pellets injected into thermonuclear plasmas are presented. The theoretical modeling is performed in terms of equivalent Stark spectral line widths under condition of LTE (Sakha-Boltzman) in pellet cloud plasmas. It is shown that a domain of blackbody radiation could exist in hydrogen pellet clouds resulting in ''pellet disappearance'' effect which is absent in a case of impurity pellet clouds. Reasons for this difference are discussed. (author)

  5. Fabrication of chamfered uranium-plutonium mixed carbide pellets

    International Nuclear Information System (INIS)

    Arai, Yasuo; Iwai, Takashi; Shiozawa, Kenichi; Handa, Muneo

    1985-10-01

    Chamfered uranium-plutonium mixed carbide pellets for high burnup irradiation test in JMTR were fabricated in glove boxes with purified argon gas. The size of die and punch in a press was decided from pellet densities and dimensions including the angle of chamfered parts. No chip or crack caused by adopting chamfered pellets was found in both pressing and sintering stages. In addition to mixed carbide pellets, uranium carbide pellets used as insulators were also successfully fabricated. (author)

  6. Lab and Bench-Scale Pelletization of Torrefied Wood Chips

    DEFF Research Database (Denmark)

    Shang, Lei; Nielsen, Niels Peter K.; Stelte, Wolfgang

    2013-01-01

    Combined torrefaction and pelletization is used to increase the fuel value of biomass by increasing its energy density and improving its handling and combustion properties. In the present study, a single-pellet press tool was used to screen for the effects of pellet die temperature, moisture cont...... of the torrefied pellets was higher and the particle size distribution after grinding the pellets was more uniform compared to conventional wood pellets....

  7. Manufacture of Regularly Shaped Sol-Gel Pellets

    Science.gov (United States)

    Leventis, Nicholas; Johnston, James C.; Kinder, James D.

    2006-01-01

    An extrusion batch process for manufacturing regularly shaped sol-gel pellets has been devised as an improved alternative to a spray process that yields irregularly shaped pellets. The aspect ratio of regularly shaped pellets can be controlled more easily, while regularly shaped pellets pack more efficiently. In the extrusion process, a wet gel is pushed out of a mold and chopped repetitively into short, cylindrical pieces as it emerges from the mold. The pieces are collected and can be either (1) dried at ambient pressure to xerogel, (2) solvent exchanged and dried under ambient pressure to ambigels, or (3) supercritically dried to aerogel. Advantageously, the extruded pellets can be dropped directly in a cross-linking bath, where they develop a conformal polymer coating around the skeletal framework of the wet gel via reaction with the cross linker. These pellets can be dried to mechanically robust X-Aerogel.

  8. Fuel pellets from lodge pole pine first thinnings

    Energy Technology Data Exchange (ETDEWEB)

    Hoegqvist, Olof; Larsson, Sylvia H.; Samuelsson, Robert; Lestander, Torbjoern A. [Swedish Univ. of Agricultural Sciences, Unit of Biomass Technology and Chemistry, Umeaa (Sweden)], e-mail: sylvia.larsson@slu.se

    2012-11-01

    Stemwood and whole trees of lodgepole pine (Pinus contorta Dougl. var. latifolia L.) were evaluated as raw materials for fuel pellets in a pilot scale pelletizing study. Pellet and pelletizing properties were measured and modeled in an experimental design where raw material moisture content (%), die channel length (mm), and storage time (days) were varied. Additionally, ash contents (%), extractive contents (%), and ash melting temperatures (deg C) were analyzed. For both assortments, raw material moisture content was positively correlated to pellet bulk density and durability (range 9-13%, wet base). Both assortments had ash contents below 0.7%, and thus, fulfilled the demands for class A1 pellets.

  9. Electron-beam rocket acceleration of hydrogen pellets

    International Nuclear Information System (INIS)

    Tsai, C.C.; Foster, C.A.; Milora, S.L.; Schechter, D.E.; Whealton, J.H.

    1992-01-01

    A proof-of-principle device for characterizing electron-beam rocket pellet acceleration has been developed and operated during the last few years. Experimental data have been collected for thousands of accelerated hydrogen pellets under a variety of beam conditions. One intact hydrogen pellet was accelerated to a speed of 578 m/s by an electron beam of 10 kV, 0.8 A, and I ms. The collected data reveal the significant finding that the measured bum velocity of bare hydrogen pellets increases with the square of the beam voltage in a way that is qualitatively consistent with the theoretical prediction based on the neutral gas shielding (NGS) model. The measured bum velocity increases with the beam current or power and then saturates at values two to three times greater than that predicted by the NGS model. The discrepancy may result from low pellet strength and large beam-pellet interaction areas. Moreover, this feature may be the cause of the low measured exhaust velocity, which often exceeds the sonic velocity of the ablated gas. Consistent with the NGS model, the measured exhaust velocity increases in direct proportion to the beam current and in inverse proportion to the beam voltage. To alleviate the pellet strength problem, experiments have been performed with the hydrogen ice contained in a lightweight rocket casing or shell. Pellets in such sabots have the potential to withstand higher beam powers and achieve higher thrust-coupling efficiency. Some experimental results are reported and ways of accelerating pellets to higher velocity are discussed

  10. Influences on particle shape in underwater pelletizing processes

    Energy Technology Data Exchange (ETDEWEB)

    Kast, O., E-mail: oliver.kast@ikt.uni-stuttgart.de, E-mail: matthias.musialek@ikt.uni-stuttgart.de, E-mail: kalman.geiger@ikt.uni-stuttgart.de, E-mail: christian.bonten@ikt.uni-stuttgart.de; Musialek, M., E-mail: oliver.kast@ikt.uni-stuttgart.de, E-mail: matthias.musialek@ikt.uni-stuttgart.de, E-mail: kalman.geiger@ikt.uni-stuttgart.de, E-mail: christian.bonten@ikt.uni-stuttgart.de; Geiger, K., E-mail: oliver.kast@ikt.uni-stuttgart.de, E-mail: matthias.musialek@ikt.uni-stuttgart.de, E-mail: kalman.geiger@ikt.uni-stuttgart.de, E-mail: christian.bonten@ikt.uni-stuttgart.de; Bonten, C., E-mail: oliver.kast@ikt.uni-stuttgart.de, E-mail: matthias.musialek@ikt.uni-stuttgart.de, E-mail: kalman.geiger@ikt.uni-stuttgart.de, E-mail: christian.bonten@ikt.uni-stuttgart.de [Institut für Kunststofftechnik, University of Stuttgart (Germany)

    2014-05-15

    Underwater pelletizing has gained high importance within the last years among the different pelletizing technologies, due to its advantages in terms of throughput, automation, pellet quality and applicability to a large variety of thermoplastics. The resulting shape and quality of pellets, however, differ widely, depending on material characteristics and effects not fully understood yet. In an experimental set-up, pellets of different volumes and shapes were produced and the medium pellet mass, the pellet surface and the bulk density were analyzed in order to identify the influence of material properties and process parameters. Additionally, the shaping kinetics at the die opening were watched with a specially developed camera system. It was found that rheological material properties correlate with process parameters and resulting particle form in a complex way. Higher cutting speeds were shown to have a deforming influence on the pellets, leading to less spherical s and lower bulk densities. More viscous materials, however, showed a better resistance against this. Generally, the viscous properties of polypropylene proofed to be dominant over the elastic ones in regard to their influence on pellet shape. It was also shown that the shapes filmed at the die opening and the actual form of the pellets after a cooling track do not always correlate, indicating a significant influence of thermodynamic properties during the cooling.

  11. Customized bentonite pellets. Manufacturing, performance and gap filling properties

    Energy Technology Data Exchange (ETDEWEB)

    Marjavaara, P.; Holt, E.; Sjoeblom, V. [VTT Technical Research Centre of Finland, Espoo (Finland)

    2013-12-15

    The goal of this work was to provide knowledge about how to manufacture customized bentonite pellets and how customized bentonite pellets perform in practice during the nuclear repository construction process. The project was mainly focused on laboratory experimental tests to optimize the pellet filling by customizing the raw materials and pellet manufacturing. Bentonite pellets were made using both extrusion and roller compaction methods. The pellets were intended for use in gaps between compacted bentonite and the rock walls in both buffer deposition holes and tunnel backfilling. Performance of different types of custom-made pellets were evaluated with regard to their ease of manufacturing, density, crush strength, abrasion resistance, water holding capacity, free swelling and also their thermal conductivity. These evaluations were done in both Finland (by VTT) and Canada (by AECL). Over 50 different varieties of pellets were roller-compaction manufactured at AECL in Canada and 20 types of extrusion pellets at VTT in Finland. The parameters that were varied during manufacturing included: bentonite raw material type, water content, pellet sizes, bentonite compaction machine parameters, use of recycled pellets, and addition of two different types of filler (illite or granitic sand) at varying addition percentages. By examining the pellets produced with these methods and materials the performance and behaviour of the bentonite pellets were evaluated in laboratory with selected tests. The work done using extrusion pellets showed that it was possible to manufacture pellets with higher water contents, up to 21 % from MX-80. This water content value was higher than what was typically possible using roller-compaction method in this study. Higher water content values allow closer compatibility with the designed bentonite buffer water content. The extrusion tests also showed that the required production simulation runs could be made successfully with reference type of MX

  12. Method of manufacturing nuclear fuel pellet

    International Nuclear Information System (INIS)

    Oguma, Masaomi; Masuda, Hiroshi.

    1988-01-01

    Purpose: To prevent pellet destruction due to thermal stresses and reduce the swelling or issue of corrosive gaseous fission products. Method: Raw material powder for nuclear fuel pellets constitute so-called secondary particles in which a plurality of primary particles are coagulated. The degree of coagulation of the secondary particles can be determined as the bulk density of the powder. In view of the above, when pellets are sintered by using a powder mixture comprising a powder having the same constitution and different bulk density from the main raw powder as the sub-raw material powder incorporated to the main raw material powder, the pellet tissue provides such a fine porous structure that fine gaps are present a the periphery of high density secondary particles, since there is a difference in the shrinkage factor (sintering-shrinkage degree) between powders of different secondary particle densities in the course of the sintering. Thus, pellets can be prevented from thermal impact destruction and cause no destructive cracks. (Takahashi, M.)

  13. Assessment of pelletized biofuels

    International Nuclear Information System (INIS)

    Samson, R.; Duxbury, P.; Drisdelle, M.; Lapointe, C.

    2000-04-01

    There has been an increased interest in the development of economical and convenient renewable energy fuels, resulting from concerns about climate change and rising oil prices. An opportunity to use agricultural land as a means of producing renewable fuels in large quantities, relying on wood and agricultural residues only has come up with recent advances in biomass feedstock development and conversion technologies. Increasing carbon storage in the landscape and displacing fossil fuels in combustion applications can be accomplished by using switchgrass and short rotation willow which abate greenhouse gas emissions. The potential of switchgrass and short rotation willow, as well as other biomass residues as new feedstocks for the pellet industry is studied in this document. Higher throughput rates are facilitated by using switchgrass, which shows potential as a pelleting feedstock. In addition, crop drying requires less energy than wood. By taking into consideration energy for switchgrass production, transportation to the conversion facility, preprocessing, pelleting, and marketing, the overall energy balance of switchgrass is 14.5:1. Research on alfalfa pelleting can be applied to switchgrass, as both exhibit a similar behaviour. The length of chop, the application of high temperature steam and the use of a die with a suitable length/diameter ratio are all factors that contribute to the successful pelleting of switchgrass. Switchgrass has a similar combustion efficiency (82 to 84 per cent) to wood (84 to 86 per cent), as determined by combustion trials conducted by the Canada Centre for Mineral and Energy Technology (CANMET) in the Dell-Point close coupled gasifier. The energy content is 96 per cent of the energy of wood pellets on a per tonne basis. Clinker formation was observed, which necessitated some adjustments of the cleaner grate settings. While stimulating rural development and export market opportunities, the high yielding closed loop biofuels show

  14. Design of in situ dispersible and calcium cross-linked alginate pellets as intestinal-specific drug carrier by melt pelletization technique.

    Science.gov (United States)

    Nurulaini, Harjoh; Wong, Tin Wui

    2011-06-01

    Conventional alginate pellets underwent rapid drug dissolution and loss of multiparticulate characteristics such as aggregation in acidic medium, thereby promoting oral dose dumping. This study aimed to design sustained-release dispersible alginate pellets through rapid in situ matrix dispersion and cross-linking by calcium salts during dissolution. Pellets made of alginate and calcium salts were prepared using a solvent-free melt pelletization technique that prevented reaction between processing materials during agglomeration and allowed such a reaction to occur only in dissolution phase. Drug release was remarkably retarded in acidic medium when pellets were formulated with water-soluble calcium acetate instead of acid-soluble calcium carbonate. Different from calcium salt-free and calcium carbonate-loaded matrices that aggregated or underwent gradual erosion, rapid in situ solvation of calcium acetate in pellets during dissolution resulted in burst of gas bubbles, fast pellet breakup, and dispersion. The dispersed fragments, though exhibiting a larger specific surface area for drug dissolution than intact matrix, were rapidly cross-linked by Ca(2+) from calcium acetate and had drug release retarded till a change in medium pH from 1.2 to 6.8. Being dispersible and pH-dependent in drug dissolution, these pellets are useful as multiparticulate intestinal-specific drug carrier without exhibiting dose dumping tendency of a "single-unit-like" system via pellet aggregation. Copyright © 2011 Wiley-Liss, Inc.

  15. Operation of the lithium pellet injector

    International Nuclear Information System (INIS)

    Khlopenkov, K.V.; Sudo, S.; Sergeev, V.Yu.

    1996-05-01

    A lithium pellet injection requires an accurate handling with lithium and special technique of loading the pellets. Thus, the technology for this has been developed based on the following conditions: 1) Because of chemical activity of lithium it is necessary to operate in a glove-box with the noble gas atmosphere (He, Ar, etc.). 2) A special procedure of replacing the glove-box atmosphere allows to achieve high purity of the noble gas. 3) When making the pellets it is better to keep the clean lithium in the liquid hexane so as to maintain lithium purity. 4) The pressure of the accelerating gas for Li pellets should be not less than 30 atm. (author)

  16. Wood pellets : is it a reliable, sustainable, green energy option?

    International Nuclear Information System (INIS)

    Swaan, J.

    2006-01-01

    The Wood Pellet Association of Canada was formerly called the BC Pellet Fuel Manufacturers Association, and was renamed and re-organized in January 2006. The association serves as an advocate for the wood pellet industry in addition to conducting research projects. This power point presentation presented an overview of the wood pellet industry in North America and Europe. Canada's 23 pellet plants currently produce just over 1,000,000 tons of wood pellets annually. Pellet producers in the United States produce approximately 800,000 tons annually for the residential bagged market. There are currently 240 pellet plants in Europe, and district heating is the largest growth market for wood pellets in Europe. British Columbia (BC) pellet producers will ship 450,000 tons to European power plants in 2005. Wood pellet specifications were presented, with details of calorific values, moisture and ash contents. An outline of wood pellet production processes was provided. New pellet plants currently under construction were reviewed. Domestic, North American and overseas exports were discussed, along with production estimates for BC for the next 5 years. A chart of world production and consumption of wood pellets between 2000 to 2010 was presented. North American wood pellet technologies were described. The impact of the pine beetle infestation in BC on the wood pellet industry was evaluated, and a worldwide wood pellet production growth forecast was presented. Issues concerning off-gassing, emissions, and torrifracation were also discussed. tabs., figs

  17. Production of zinc pellets

    Science.gov (United States)

    Cooper, J.F.

    1996-11-26

    Uniform zinc pellets are formed for use in batteries having a stationary or moving slurry zinc particle electrode. The process involves the cathodic deposition of zinc in a finely divided morphology from battery reaction product onto a non-adhering electrode substrate. The mossy zinc is removed from the electrode substrate by the action of gravity, entrainment in a flowing electrolyte, or by mechanical action. The finely divided zinc particles are collected and pressed into pellets by a mechanical device such as an extruder, a roller and chopper, or a punch and die. The pure zinc pellets are returned to the zinc battery in a pumped slurry and have uniform size, density and reactivity. Applications include zinc-air fuel batteries, zinc-ferricyanide storage batteries, and zinc-nickel-oxide secondary batteries. 6 figs.

  18. Repetitive fueling pellet injection in large helical device

    International Nuclear Information System (INIS)

    Yamada, H.; Sakamoto, R.; Viniar, I.; Oda, Y.; Kikuchi, K.; Lukin, A.; Skoblikov, S.; Umov, A.; Takaura, K.; Onozuka, M.; Kato, S.; Sudo, S.

    2003-01-01

    A repetitive pellet injector has been developed for investigation of fueling issues towards the steady-state operation in Large Helical Device (LHD). The goal of this approach is achievement of the plasma operation for longer than 1000 s. A principal technical element of the pellet injector is solidification of hydrogen and extrusion of a solid hydrogen rod through a cryogenic screw extruder cooled by Giffard-McMahon (GM) cryo-coolers. Continuous operation of more than 10000 pellet launches at 10 Hz has been demonstrated. The reliability of pellet launch exceeds 99%. The pellet mass and velocity, the consumption of propellant gas and quality of pellets have been successfully tested to fit the experimental requirement in LHD

  19. Repetitive fueling pellet injection in large helical device

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, H. E-mail: hyamada@lhd.nifs.ac.jp; Sakamoto, R.; Viniar, I.; Oda, Y.; Kikuchi, K.; Lukin, A.; Skoblikov, S.; Umov, A.; Takaura, K.; Onozuka, M.; Kato, S.; Sudo, S

    2003-09-01

    A repetitive pellet injector has been developed for investigation of fueling issues towards the steady-state operation in Large Helical Device (LHD). The goal of this approach is achievement of the plasma operation for longer than 1000 s. A principal technical element of the pellet injector is solidification of hydrogen and extrusion of a solid hydrogen rod through a cryogenic screw extruder cooled by Giffard-McMahon (GM) cryo-coolers. Continuous operation of more than 10000 pellet launches at 10 Hz has been demonstrated. The reliability of pellet launch exceeds 99%. The pellet mass and velocity, the consumption of propellant gas and quality of pellets have been successfully tested to fit the experimental requirement in LHD.

  20. Pelletized waste form demonstration program, October 1980-March 1981

    International Nuclear Information System (INIS)

    Lewis, E.L.; Herbert, R.F. Jr.

    1981-01-01

    During the last six months, performance testing of waste/cement pellets was continued. These evaluations included leachability tests and compressive strength tests of cold soil/cement pellets of various compositions. Fractional leach rates (g/cm 2 /day) after 21 months of testing were, in all cases -5 g/cm 2 /day (Mound Acceptance Value). Based upon these recent data, the pressed waste/cement pellets appeared to be a suitable matrix for the immobilization of low-level transuranic wastes. The installation of the Carver custom pellet press was completed. Plutonium-238 contaminated (< 100 nCi/g) ash/cement pellets were produced at a rate of 360 pellets/hr. Pellets of two different compositions were produced, 50% ash/50% cement and 65% ash/35% cement. The compressive strength of sample pellets was slightly lower than expected. Static MCC-1 leachability testing as well as long-term radiolysis testing of sample pellets are scheduled

  1. Voluntary intake and digestibility by sheep of alfalfa ensiled at different moisture concentrations following fertilization with dairy slurry

    Science.gov (United States)

    Dairy slurry is used commonly as an animal-sourced fertilizer in agronomic production. However, residual effects of slurry application on intake and digestibility of alfalfa (Medicago sativa L.) silage from subsequent harvests are not well known. The objective of this study was to determine if mois...

  2. Degradation of lucerne stem cell walls by five rumen bacterial species

    NARCIS (Netherlands)

    Jung, H.G.; Engels, F.M.; Weimer, P.J.

    2004-01-01

    The rumen bacterial strains Butyrivibrio fibrisolvens H17c, Fibrobacter succinogenes S85, Lachnospira multiparus 40, Ruminococcus albus 7 and R. flavefaciens FD-1 were compared individually and as a five-species mixture with a rumen inoculum for their ability to degrade lucerne (Medicago sativa L.)

  3. Meat goat kids finished on alfalfa, red clover, or orchardgrass pastures: Carcass merit and meat quality

    Science.gov (United States)

    This experiment was conducted in 2005-2007 to evaluate carcass and meat quality parameters when meat goat kids were finished on alfalfa (Medicago sativa L; ALF); red clover (Trifolium pretense L.; RCG); or orchardgrass (Dactylis glomerata L; OGR) pastures. Final shrunk body weights were similar whe...

  4. Development and characterization of the first infectious clone of alfalfa latent virus, a strain of Pea streak virus

    Science.gov (United States)

    Alfalfa (Medicago sativa) is a natural host plant for many plant pathogens including fungi, bacteria, nematodes and viruses. Alfalfa latent virus (ALV) is a member of the carlavirus group and occurs symptomlessly in alfalfa. The first complete genomic sequence of the ALV that was recently obtained i...

  5. Pelletizing properties of torrefied spruce

    DEFF Research Database (Denmark)

    Stelte, Wolfgang; Clemons, Craig; Holm, Jens K.

    2011-01-01

    analysis revealed a cohesive failure mechanism due to strong inter-particle bonding in spruce pellets as a resulting from a plastic flow of the amorphous wood polymers, forming solid polymer bridges between adjacent particles. Fracture surfaces of pellets made from torrefied spruce possessed gaps and voids...

  6. Performance characterization of pneumatic single pellet injection system

    International Nuclear Information System (INIS)

    Schuresko, D.D.; Milora, S.L.; Hogan, J.T.; Foster, C.A.; Combs, S.K.

    1982-01-01

    The Oak Ridge National Laboratory single-shot pellet injector, which has been used in plasma fueling experiments on ISX and PDX, has been upgraded and extensively instrumented in order to study the gas dynamics of pneumatic pellet injection. An improved pellet transport line was developed which utilizes a 0.3-cm-diam by 100-cm-long guide tube. Pellet gun performance was characterized by measurements of breech and muzzle dynamic pressures and by pellet velocity and mass determinations. Velocities up to 1.4 km/s were achieved for intact hydrogen pellets using hydrogen propellant at 5-MPa breech pressure. These data have been compared with new pellet acceleration calculations which include the effects of propellant friction, heat transfer, time-dependent boundary conditions, and finite gun geometry. These results provide a basis for the extrapolation of present-day pneumatic injection system performance to velocities in excess of 2 km/s

  7. Performance characterization of pneumatic single pellet injection system

    International Nuclear Information System (INIS)

    Schuresko, D.D.; Milora, S.L.; Hogan, J.T.; Foster, C.A.; Combs, S.K.

    1983-01-01

    The Oak Ridge National Laboratory single-shot pellet injector, which has been used in plasma fueling experiments on ISX and PDX, has been upgraded and extensively instrumented in order to study the gas dyamics of pneumatic pellet injection. An improved pellet transport line was developed which utilizes a 0.3-cm-diam by 100-cm-long guide tube. Pellet gun performance was characterized by measurements of breech and muzzle dynamic pressures and by pellet velocity and mass determinations. Velocities of up to 1.4 km/s were achieved for intact hydrogen pellets using hydrogen propellant at 5-MPa breech pressure. These data have been compared with new pellet acceleration calculations which include the effects of propellant friction, heat transfer, time-dependent boundary conditions, and finite gun geometry. These results provide a basis for the extrapolation of present-day pneumatic injection system performance to velocities in excess of 2 km/s

  8. Discovery AP2/ERF family genes in silico in Medicago truncatula

    African Journals Online (AJOL)

    aghomotsegin

    Medicago truncatula is a legume model plant due to its small genome and it has been used to study the molecular events of legume ... molecular mechanism of stress responses of AP2/EREBPs. ..... comprehensive profiling of developmental, hormonal or ... interactions with other organisms, plant development and stress.

  9. [Molecular identification of astragali radix and its adulterants by ITS sequences].

    Science.gov (United States)

    Cui, Zhan-Hu; Li, Yue; Yuan, Qing-Jun; Zhou, Li-She; Li, Min-Hui

    2012-12-01

    To explore a new method for identification Astragali Radix from its adulterants by using ITS sequence. Thirteen samples of the different Astragali Radix materials and 6 samples of the adulterants of the roots of Hedysarum polybotrys, Medicago sativa and Althaea rosea were collected. ITS sequence was amplified by PCR and sequenced unidirectionally. The interspecific K-2-P distances of Astragali Radix and its adulterants were calculated, and NJ tree and UPGMA tree were constructed by MEGA 4. ITS sequences were obtained from 19 samples respectively, there were Astragali Radix 646-650 bp, H. polybotrys 664 bp, Medicago sativa 659 bp, Althaea rosea 728 bp, which were registered in the GenBank. Phylogeny trees reconstruction using NJ and UPGMA analysis based on ITS nucleotide sequences can effectively distinguish Astragali Radix from adulterants. ITS sequence can be used to identify Astragali Radix from its adulterants successfully and is an efficient molecular marker for authentication of Astragali Radix and its adulterants.

  10. Pellet fueling development at ORNL

    International Nuclear Information System (INIS)

    Combs, S.K.; Milora, S.L.; Foster, C.A.; Schuresko, D.D.; Foust, C.R.; Simmons, D.W.; Beard, D.S.

    1986-09-01

    Advanced plasma fueling systems for magnetic confinement devices are being developed at the Oak Ridge National Laboratory (ORNL). The general approach is that of producing and accelerating frozen hydrogenic pellets at speeds in the range of 1-2 km/s and higher. Two specific concepts are under development: (1) high-speed pneumatic acceleration; and (2) mechanical (centrifugal) acceleration. Both approaches are being pursued to meet the projected pellet size and delivery rates for major near-term plasma confinement devices, such as the Tokamak Fusion Test Reactor (TFTR), Tore Supra, the Joint European Torus (JET), JT-60, and Doublet III-D (DIII-D), as well as future applications. In addition to these confinement physics related activities, ORNL is pursuing advanced technologies to achieve pellet velocities significantly in excess of the 2-km/s range already attained with pneumatic injectors and has embarked on a development program designed to explore the feasibility of fabricating and accelerating tritium pellets. This paper describes these ongoing activities

  11. Current generation by phased injection of pellets

    International Nuclear Information System (INIS)

    Fisch, N.J.

    1983-08-01

    By phasing the injection of frozen pellets into a tokamak plasma, it is possible to generate current. The current occurs when the electron flux to individual members of an array of pellets is asymmetric with respect to the magnetic field. The utility of this method for tokamak reactors, however, is unclear; the current, even though free in a pellet-fueled reactor, may not be large enough to be worth the trouble. Uncertainty as to the utility of this method is, in part, due to uncertainty as to proper modeling of the one-pellet problem

  12. Modelling the role of pellet crack motion in the (r-θ) plane upon pellet-clad interaction in advanced gas reactor fuel

    Energy Technology Data Exchange (ETDEWEB)

    Haynes, T.A. [Centre for Nuclear Engineering & Department of Materials, Imperial College London, Exhibition Rd., London SW7 2AZ (United Kingdom); Ball, J.A. [EDF Energy, Barnett Way, Gloucester GL4 3RS (United Kingdom); Wenman, M.R., E-mail: m.wenman@imperial.ac.uk [Centre for Nuclear Engineering & Department of Materials, Imperial College London, Exhibition Rd., London SW7 2AZ (United Kingdom)

    2017-04-01

    Highlights: • Finite element modelling of pellet relocation in the (r-θ) plane of nuclear fuel. • ‘Soft’ and ‘hard’ PCI have been predicted in a cracked nuclear fuel pellet. • Stress concentration in the cladding ahead of radial pellet cracks is predicted. • The model is very sensitive to the coefficient of friction and power ramp duration. • The model is less sensitive to the number of cracks assumed. - Abstract: A finite element model of pellet fragment relocation in the r-θ plane of advanced gas-cooled reactor (AGR) fuel is presented under conditions of both ‘hard’ and ‘soft’ pellet-clad interaction. The model was able to predict the additional radial displacement of fuel fragments towards the cladding as well as the stress concentration on the inner surface resulting from the azimuthal motion of pellet fragments. The model was subjected to a severe ramp in power from both full power and after a period of reduced power operation; in the former, the maximum hoop stress in the cladding was found to be increased by a factor of 1.6 as a result of modelling the pellet fragment motion. The pellet-clad interaction was found to be relatively insensitive to the number of radial pellet crack. However, it was very sensitive to both the coefficient of friction used between the clad and pellet fragments and power ramp duration.

  13. Tritium recovery from lithium oxide pellets

    International Nuclear Information System (INIS)

    Bertone, P.C.; Jassby, D.L.

    1984-01-01

    The TFTR Lithium Blanket Module is an assembly containing 650 kg of lithium oxide that will be used to test the ability of neutronics codes to model the tritium breeding characteristics of limited-coverage breeding zones in a tokamak. It is required that tritium concentrations as low as 0.1 nCi/g bred in both metallic lithium samples and lithium oxide pellets be measured with an uncertainty not exceeding +- 6%. A tritium assay technique for the metallic samples which meets this criterion has been developed. Two assay techniques for the lithium oxide pellets are being investigated. In one, the pellets are heated in a flowing stream of hydrogen, while in the other, the pellets are dissolved in 12 M hydrochloric acid

  14. Suprathermal fusion reactions in laser-imploded D-T pellets. Applicability to pellet diagnosis and necessity of nuclear data

    International Nuclear Information System (INIS)

    Tabaru, Y.; Nakao, Y.; Kudo, K.; Nakashima, H.

    1995-01-01

    The suprathermal fusion reaction is examined on the basis of coupled transport/hydrodynamic calculation. We also calculate the energy spectrum of neutrons bursting from DT pellet. Because of suprathermal fusion and rapid pellet expansion, these neutrons contain fast components whose maximum energy reachs about 40 MeV. The pellet ρR diagnosis by the detection of suprathermal fusion neutrons is discussed. (author)

  15. The complete chloroplast genomes of Cannabis sativa and Humulus lupulus.

    Science.gov (United States)

    Vergara, Daniela; White, Kristin H; Keepers, Kyle G; Kane, Nolan C

    2016-09-01

    Cannabis and Humulus are sister genera comprising the entirety of the Cannabaceae sensu stricto, including C. sativa L. (marijuana, hemp), and H. lupulus L. (hops) as two economically important crops. These two plants have been used by humans for many purposes including as a fiber, food, medicine, or inebriant in the case of C. sativa, and as a flavoring component in beer brewing in the case of H. lupulus. In this study, we report the complete chloroplast genomes for two distinct hemp varieties of C. sativa, Italian "Carmagnola" and Russian "Dagestani", and one Czech variety of H. lupulus "Saazer". Both C. sativa genomes are 153 871 bp in length, while the H. lupulus genome is 153 751 bp. The genomes from the two C. sativa varieties differ in 16 single nucleotide polymorphisms (SNPs), while the H. lupulus genome differs in 1722 SNPs from both C. sativa cultivars.

  16. NaCl - Changes stem morphology, anatomy and phloem structure in Lucerne (Medicago sativa cv. Gabès): Comparison of upper and lower internodes.

    Science.gov (United States)

    Nja, Riheb Ben; Merceron, Bruno; Faucher, Mireille; Fleurat-Lessard, Pierrette; Béré, Emile

    2018-02-01

    In M. sativa cv. Gabès plants treated with 150mM NaCl, the height of the stem is decreased and the internode number, length and diameter are reduced. This depressive effect on growth, but also on photosynthetic activity and water balance, is accompanied by structural changes. In the upper internodes, NaCl treatment increases cambium development, so that the vascular ring is initiated earlier than in controls. In the lower internodes, the number of lignified phloem fibers is increased by NaCl, and their wall thickness is augmented, compared to controls; in the phloem complex, the nacreous layer is enlarged, the number of internal wall ingrowths is increased, but companion cells are damaged. In the treated lower internodes, few vessels occur in the secondary xylem, which is by contrast rich in lignified fibers and in wide vessels grouped in the metaxylem area; protoxylem parenchyma and adjacent pith are also lignified. In addition, in treated lower internodes, starch grains are less abundant than in controls, and this variation might be related to the decrease of photosynthesis. When taken together, qualitative and quantitative results indicate that the saline stress has a marked morpho-anatomical impact on the M. sativa Gabès stem. In particular, variations of secondary derivative distribution, increased wall thickening, lignification of phloem and xylem fibers and damage in the phloem complex are NaCl-induced responses, and are more expressed in the lower than in the upper internodes. The reinforcement of the stem lignified vasculature is thus a positive response to stress, but it has a negative impact on the quality of the forage. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Influence of pellet diameter and length on the quality of pellets and performance, nutrient utilisation and digestive tract development of broilers fed on wheat-based diets.

    Science.gov (United States)

    Abdollahi, M R; Ravindran, V; Wester, T J; Ravindran, G; Thomas, D V

    2013-06-01

    1. The influence of pellet diameter and length on the quality of pellets and performance, nutrient utilisation and digestive tract development of broilers given wheat-based diets was examined from 10 to 42 d of age. The experimental design was a 2 × 2 factorial arrangement of treatments evaluating two pellet diameters (3 and 4.76 mm) and two pellet lengths (3 and 6 mm). From 0 to 9 d of age, all birds were offered a common starter diet pelleted with a 3-mm diameter die and 3-mm length. Broiler grower (d 10 to 21) and finisher (d 22 to 42) diets, based on wheat, were formulated and then subjected to the 4 different treatments. 2. In grower diets, increasing pellet diameter and pellet length reduced the gelatinised starch (GS) content of the diets. In finisher diets, GS content of 3-mm diameter pellets did not change with increasing pellet length but decreased in 4.76-mm diameter pellets. 3. In grower and finisher diets, increments in intact pellet weight, pellet durability index and pellet hardness with increasing pellet length were greater in 3-mm diameter pellets than those with 4.76-mm diameter. 4. Increasing pellet length from 3 to 6 mm increased apparent metabolisable energy values. Neither the interaction nor main effects were significant for the ileal digestibility of nitrogen and starch. 5. During the grower period (d 10 to 21), birds given pellets of 6-mm length had greater body-weight gain than those given 3-mm length pellets. Feeding 6-mm length pellets decreased feed per body-weight gain compared to 3-mm length pellets. During the finisher (d 22 to 42) and whole grow-out (d 10 to 42) periods, while different pellet lengths had no effect on feed per body-weight gain values at 3-mm pellet diameter, increasing the pellet length decreased feed per body-weight gain at 4.76-mm pellet diameter. 6. Increasing pellet diameter and pellet length reduced the relative length of duodenum. Birds given 3-mm diameter pellets had heavier proventriculus compared to

  18. Development of the centrifugal pellet injector for JT-60U

    Energy Technology Data Exchange (ETDEWEB)

    Kizu, Kaname; Hiratsuka, Hajime; Ichige, Hisashi [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment] [and others

    2001-03-01

    For core fueling of JT-60U plasmas, a repetitive pellet injector which centrifugally accelerates D{sub 2} cubic pellets using a straight rod has been developed. This centrifugal pellet injector can eject trains of up to 40 cubic pellets at frequencies of 1-10 Hz and velocities of 0.3-1.0 km/s. The average pellet mass is 3.6x10{sup 20} atoms/pellet below 0.7 m/s. Key techniques for the development were a mesh structured acceleration component for removing gas sublimated from the pellet and a funnel with an appropriate angle connected just behind the acceleration chamber for introducing the pellet to plasma without destruction. Using the mesh structured components, the horizontal angular distribution of pellets ejected became narrow, because irregular pellet motion caused by sublimated gas was reduced. To investigate the performance of the injector, pellet injection experiments from the low magnetic field side (LFS) were conducted using ohmic heating plasmas. Central fueling and enhanced fueling rate have been observed. D{alpha} intensity around the divertor region was reduced in a pellet injection plasma compared to gas puffing, indicating low recycling rate was maintained with the pellet injection. (author)

  19. Development of the centrifugal pellet injector for JT-60U

    International Nuclear Information System (INIS)

    Kizu, Kaname; Hiratsuka, Hajime; Ichige, Hisashi

    2001-03-01

    For core fueling of JT-60U plasmas, a repetitive pellet injector which centrifugally accelerates D 2 cubic pellets using a straight rod has been developed. This centrifugal pellet injector can eject trains of up to 40 cubic pellets at frequencies of 1-10 Hz and velocities of 0.3-1.0 km/s. The average pellet mass is 3.6x10 20 atoms/pellet below 0.7 m/s. Key techniques for the development were a mesh structured acceleration component for removing gas sublimated from the pellet and a funnel with an appropriate angle connected just behind the acceleration chamber for introducing the pellet to plasma without destruction. Using the mesh structured components, the horizontal angular distribution of pellets ejected became narrow, because irregular pellet motion caused by sublimated gas was reduced. To investigate the performance of the injector, pellet injection experiments from the low magnetic field side (LFS) were conducted using ohmic heating plasmas. Central fueling and enhanced fueling rate have been observed. Dα intensity around the divertor region was reduced in a pellet injection plasma compared to gas puffing, indicating low recycling rate was maintained with the pellet injection. (author)

  20. Apoptotic Effect of Nigella sativa on Human Lymphoma U937 Cells.

    Science.gov (United States)

    Arslan, Belkis Atasever; Isik, Fatma Busra; Gur, Hazal; Ozen, Fatih; Catal, Tunc

    2017-10-01

    Nigella sativa is from botanical Ranunculaceae family and commonly known as black seed. Apoptotic effect of N. sativa and its apoptotic signaling pathways on U937 lymphoma cells are unknown. In this study, we investigated selective cytotoxic and apoptotic effects of N. sativa extract and its apoptotic mechanisms on U937 cells. In addition, we also studied selective cytotoxic activity of thymoquinone that is the most active essential oil of N. sativa . Our results showed that N. sativa extract has selective cytotoxicity and apoptotic effects on U937 cells but not ECV304 control cells. However, thymoquinone had no significant cytotoxicity against on both cells. N. sativa extract increased significantly caspase-3, BAD, and p53 gene expressions in U937 cells. N. sativa may have anticancer drug potential and trigger p53-induced apoptosis in U937 lymphoma cells. This is the first study showing the apoptotic effect of Nigella sativa extract on U937 cells. Abbreviations used: CI: Cytotoxicity index, DMEM: Dulbecco's Modified Eagle Medium, HL: Hodgkin's lymphoma, MTT: 3-(4,5-dimethy lthiazol-2yl)-2,5-diphenyl tetrazolium bromide, RPMI: Roswell Park Memorial Institute medium.

  1. Modeling drying of iron ore pellets

    OpenAIRE

    Ljung, Anna-Lena

    2010-01-01

    Iron ore pellets are a highly refined product supplied to the steel making industry for use in blast furnaces or direct reduction processes. The use of pellets offers many advantages such as customer adopted products, transportability and mechanical strength yet the production is time and energy consuming. Being such, there is a natural driving force to enhance the pelletization in order to optimize production and improve quality. The aim with this thesis is to develop numerical models with w...

  2. Sintering of wax for controlling release from pellets.

    Science.gov (United States)

    Singh, Reena; Poddar, S S; Chivate, Amit

    2007-09-14

    The purpose of the present study was to investigate incorporation of hydrophobic (ie, waxy) material into pellets using a thermal sintering technique and to evaluate the pellets in vitro for controlled release. Pellets prepared by extrusion-spheronization technology were formulated with a water-soluble drug, microcrystalline cellulose, and carnauba wax. Powdered carnauba wax (4%-20%) prepared by grinding or by emulsification was studied with an attempt to retard the drug release. The inclusion of ground or emulsified carnauba wax did not sustain the release of theophylline for more than 3 hours. Matrix pellets of theophylline prepared with various concentrations of carnauba wax were sintered thermally at various times and temperatures. In vitro drug release profiles indicated an increase in drug release retardation with increasing carnauba wax concentration. Pellets prepared with ground wax showed a higher standard deviation than did those prepared with emulsified wax. There was incomplete release at the end of 12 hours for pellets prepared with 20% ground or emulsified wax. The sintering temperature and duration were optimized to allow for a sustained release lasting at least 12 hours. The optimized temperature and duration were found to be 100 degrees C and 140 seconds, respectively. The sintered pellets had a higher hydrophobicity than did the unsintered pellets. Scanning electron micrographs indicated that the carnauba wax moved internally, thereby increasing the surface area of wax within the pellets.

  3. Microsynteny between pea and Medicago truncatula in the SYM2 region

    NARCIS (Netherlands)

    Gualtieri, G.; Kulikova, O.; Limpens, E.; Kim, D.J.; Cook, D.R.; Bisseling, T.; Geurts, R.

    2002-01-01

    The crop legume pea (Pisum sativum) is genetically well characterized. However, due to its large genome it is not amenable to efficient positional cloning strategies. The purpose of this study was to determine if the model legume Medicago truncatula, which is a close relative of pea, could be used

  4. Lithium Pellet Injector Development for NSTX

    International Nuclear Information System (INIS)

    Gettelfinger, G.; Dong, J.; Gernhardt, R.; Kugel, H.; Sichta, P.; Timberlake, J.

    2003-01-01

    A pellet injector suitable for the injection of lithium and other low-Z pellets of varying mass into plasmas at precise velocities from 5 to 500 m/s is being developed for use on NSTX (National Spherical Torus Experiment). The ability to inject low-Z impurities will significantly expand NSTX experimental capability for a broad range of diagnostic and operational applications. The architecture employs a pellet-carrying cartridge propelled through a guide tube by deuterium gas. Abrupt deceleration of the cartridge at the end of the guide tube results in the pellet continuing along its intended path, thereby giving controlled reproducible velocities for a variety of pellets materials and a reduced gas load to the torus. The planned injector assembly has four hundred guide tubes contained in a rotating magazine with eight tubes provided for injection into plasmas. A PC-based control system is being developed as well and will be described elsewhere in these Proceedings. The development path and mechanical performance of the injector will be described

  5. Hydrogen Pellet-Rotating Plasma Interaction

    DEFF Research Database (Denmark)

    Jørgensen, L. W.; Sillesen, Alfred Hegaard; Øster, Flemming

    1977-01-01

    Spectroscopic measurements on the interaction between solid hydrogen pellets and rotating plasmas are reported. It was found that the light emitted is specific to the pellet material, and that the velocity of the ablated H-atoms is of the order of l0^4 m/s. The investigation was carried out...

  6. Tritium proof-of-principle pellet injector results

    International Nuclear Information System (INIS)

    Fisher, P.W.; Fehling, D.T.; Gouge, M.J.; Milora, S.L.

    1989-01-01

    The tritium proof-of-principle (TPOP) experiment was built by Oak Ridge National Laboratory (ORNL) to demonstrate the feasibility of forming solid tritium pellets and accelerating them to high velocities for fueling future fusion reactors. TPOP used a pneumatic pipe-gun with a 4-mm-i.d. by 1-m-long barrel. Nearly 1500 pellets were fired by the gun during the course of the experiment; about a third of these were tritium or mixtures of deuterium and tritium. The system also contained a cryogenic 3 He separator that reduced the 3 He level to <0.005%. Pure tritium pellets were accelerated to 1400 m/s. Experiments evaluated the effect of cryostat temperature and fill pressure on pellet size, the production of pellets from mixtures of tritium and deuterium, and the effect of aging on pellet integrity. The tritium phase of these experiments was performed at the Tritium Systems Test Assembly (TSTA) at Los Alamos National Laboratory. About 100 kCi of tritium was processed through the apparatus without incident. 8 refs., 7 figs

  7. Pellet-plasma interaction: Local disturbances caused by pellet ablation in tokamaks

    International Nuclear Information System (INIS)

    Lengyel, L.L.

    1989-01-01

    The local disturbance amplitudes caused by ablating pellets in tokamaks are computed in the framework of a magnetohydrodynamic model supplemented by the neutral gas plasma shielding ablation model. The model computes, for a given number of pellet particles locally deposited, the time histories of the ablatant cloud parameters, such as cloud radius, cloud length, electron density, temperature and cloud beta, at a succession of magnetic flux surfaces. The cloud radius thus determined may be fed back into the ablation model, thus adjusting the effect of the shielding cloud on the ablation rate. The model is applied to typical plasma parameter ranges of existing and planned tokamaks. The results show that the ablating pellets may cause massive local disturbances in tokamaks, depending upon the number of particles locally deposited. The peaks of these disturbances are of a spike nature, lasting only a few microseconds (Alfven time-scale). The characteristic decay time of the 'quasi-steady' disturbance values that characterize the after-spike period is of the order of several milliseconds (hydrodynamic time-scale). The peak electron density values may be as high as 10 23 to 10 25 m -3 , with the associated beta peaks exceeding unity. The 'quasi-steady' values of the electron density and the ablatant beta may be of the order of 10 22 to 10 24 m -3 and unity, respectively. Furthermore, the results show the strong dependence of the ablation rate on the dynamic characteristics of the ablatant cloud surrounding the pellet. (author). 25 refs, 6 figs, 2 tabs

  8. Simulation of peeling-ballooning modes with pellet injection

    Energy Technology Data Exchange (ETDEWEB)

    Chen, S. Y. [College of Physical Science and Technology, Sichuan University, 610064 Chengdu (China); Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); Southwestern Institute of Physics, Chengdu 610041 (China); Huang, J.; Sun, T. T.; Tang, C. J. [College of Physical Science and Technology, Sichuan University, 610064 Chengdu (China); Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); Wang, Z. H. [Southwestern Institute of Physics, Chengdu 610041 (China)

    2014-11-15

    The influence of pellet ablation on the evolution of peeling-ballooning (P-B) modes is studied with BOUT++ code. The atoms coming from pellet ablation can significantly reshape the plasma pressure profile, so the behaviors of P-B modes and edge localized mode (ELM) are modified dramatically. This paper shows that the energy loss associated with an ELM increases substantially over that without the pellet, if the pellet is deposited at the top of the pedestal. On the contrary, for pellet deposition in the middle of the pedestal region the ELM energy loss can be less.

  9. Numerical investigations of the WASA pellet target operation and proposal of a new technique for the PANDA pellet target

    International Nuclear Information System (INIS)

    Varentsov, Victor L.

    2011-01-01

    The conventional nozzle vibration technique of the hydrogen micro-droplet generation that is supposed to be used for internal pellet target production for the future PANDA experiment at the international FAIR facility in Darmstadtfor is described. The operation of this technique has been investigated by means of detailed computer simulations. Results of calculations for the geometry and operation conditions of the WASA pellet generator are presented and discussed. We have found that for every given pellet size, there is a set of operation parameters where the efficiency of the WASA hydrogen pellet target operation is considerably increased. Moreover, the results of presented computer simulations clearly show that the future PANDA pellet target setup can be realized with the use of much smaller (and cheaper) vacuum pumps than those used at present in the WASA hydrogen pellet target. To qualitatively improve the PANDA hydrogen pellet target performance we have proposed the use of a novel flow focusing method of Ganan-Calvo and Barreto (1997,1999) combined with the use of conventional vacuum injection capillary. Possibilities of this approach for the PANDA pellet target production have been also explored by means of computer simulations. The results of these simulations show that the use of this new approach looks very promising and in particular, there is no need here to use of expensive ultra-pure hydrogen to prevent nozzle clogging or freezing up due to impurities and it will allow simple, fast, smooth and a wide range of change of pellet sizes in accordance with requirements of different experiments at the PANDA detector. In this article we also propose and describe the idea of a new technique to break up a liquid microjet into microdroplets using a process of liquid jet evaporation under pulsed laser beam irradiation. This technique should be experimentally checked before it may be used in the design of the future PANDA pellet target setup.

  10. Numerical investigations of the WASA pellet target operation and proposal of a new technique for the PANDA pellet target

    Energy Technology Data Exchange (ETDEWEB)

    Varentsov, Victor L., E-mail: v.varentsov@gsi.de [Institute for Theoretical and Experimental Physics, B. Cheremushkinskaya 25, 117218 Moscow (Russian Federation)

    2011-08-01

    The conventional nozzle vibration technique of the hydrogen micro-droplet generation that is supposed to be used for internal pellet target production for the future PANDA experiment at the international FAIR facility in Darmstadtfor is described. The operation of this technique has been investigated by means of detailed computer simulations. Results of calculations for the geometry and operation conditions of the WASA pellet generator are presented and discussed. We have found that for every given pellet size, there is a set of operation parameters where the efficiency of the WASA hydrogen pellet target operation is considerably increased. Moreover, the results of presented computer simulations clearly show that the future PANDA pellet target setup can be realized with the use of much smaller (and cheaper) vacuum pumps than those used at present in the WASA hydrogen pellet target. To qualitatively improve the PANDA hydrogen pellet target performance we have proposed the use of a novel flow focusing method of Ganan-Calvo and Barreto (1997,1999) combined with the use of conventional vacuum injection capillary. Possibilities of this approach for the PANDA pellet target production have been also explored by means of computer simulations. The results of these simulations show that the use of this new approach looks very promising and in particular, there is no need here to use of expensive ultra-pure hydrogen to prevent nozzle clogging or freezing up due to impurities and it will allow simple, fast, smooth and a wide range of change of pellet sizes in accordance with requirements of different experiments at the PANDA detector. In this article we also propose and describe the idea of a new technique to break up a liquid microjet into microdroplets using a process of liquid jet evaporation under pulsed laser beam irradiation. This technique should be experimentally checked before it may be used in the design of the future PANDA pellet target setup.

  11. Pellet injectors for the tokamak fusion test reactor

    International Nuclear Information System (INIS)

    Combs, S.K.

    1986-01-01

    The repeating pneumatic injector is a device from the ORNL development program. A new eight-shot deuterium pellet injector has been designed and constructed specifically for the TFTR application and is scheduled to replace the repeating injector this year. The new device combines a cryogenic extruder and a cold wheel rotary mechanism to form and chamber eight pellets in a batch operation; the eight pellets can then be delivered in any time sequence. Another unique feature of the device is the variable pellet size with three pellets each of 3.0 and 3.5 mm diam and two each of 4.0 mm diam. The experience and technology that have been developed on previous injectors at ORNL have been utilized in the design of this latest pellet injection system

  12. ECONOMIC VALUE OF SOME LEGUMINOUS PLANT SPECIES OF THE COLLECTIONS FROM THE BOTANICAL GARDEN (INSTITUTE OF THE ACADEMY OF SCIENCES OF MOLDOVA

    Directory of Open Access Journals (Sweden)

    Alexandru TELEUTA

    2016-12-01

    Full Text Available The results of the evaluation of the growth and development rates, the seed productivity, the green mass yield, the biochemical composition and the content of amino acids, phosphorous and calcium, the nutritive and energy value of the forage, as well as the biomethane productivity of local ecotypes of the leguminous species maintained in monoculture, in the collection of the Botanical Garden (Institute of the Academy of Sciences of Moldova (BG ASM: Astragalus ponticus, Coronilla varia, Lotus corniculatus, Medicago falcata, Onobrychis arenaria and Trifolium repens are presented in this article. Control variants – the traditional forage crops: Medicago sativa and Onobrychis viciifolia. The local ecotypes of the studied leguminous species were characterized by different growth and development rates. Coronilla varia and Lotus corniculatus, in the 2nd-3rd years, could be harvested, for the first time, 5 days earlier than Medicago sativa, but Medicago falcata and Onobrychis viciifolia – 18 days later. The green mass yield varied from 0.83 kg/m2 to 4.08 kg/m2. The studied ecotypes reached amounts of 0.60-0.89 nutritive units/kg and metabolizable energy 8.05-9.90 MJ/kg of dry matter, the content of digestible protein, of 106.28-225.09 g/nutritive unit, met the zootechnical standards; seed production: 19.12-83.00 g/m2; the biomethane yield ranged from 692 to 3197 m3/ha. Higher yield of natural forage, dry matter and biomethane was produced by Onobrychis arenaria and Coronilla varia.

  13. Changes in mycorrhiza development in maize induced by crop management practices

    DEFF Research Database (Denmark)

    Gavito, M.E.; Miller, M.H.

    1998-01-01

    (Zea mays L.) or with the original plant species in the field site, bromegrass (Bromus inermis Leys.) and alfalfa (Medicago sativa L.). The delay in mycorrhiza development after cropping with canola was also observed in samples taken from the field and in a bioassay, both conducted at the beginning...

  14. Reduced Lignin Alfalfa - Update

    Science.gov (United States)

    U.S. farmers harvested alfalfa (Medicago sativa) for hay or haylage from 24.5million acres in 2009. Midwestern states harvested 57 % of 2009 acreage for hay and haylage. However, acreage is stable to declining. Alfalfa provides an excellent source of fiber, protein, minerals and vitamins that partia...

  15. Mechanisms of qualitative and quantitative resistance to Aphanomyces root rot in alfalfa

    Science.gov (United States)

    Aphanomyces root rot (ARR), caused by Aphanomyces euteiches, is one of the most important diseases of alfalfa (Medicago sativa) in the United States. Two races of the pathogen are currently recognized. Most modern alfalfa cultivars have high levels of resistance to race 1 but few cultivars have resi...

  16. Dynamics of predation on Lygus hesperus (Hemiptera: Miridae) in alfalfa trap cropped organic strawberry

    Science.gov (United States)

    Alfalfa (Medicago sativa L.) can be strategically planted as a trap crop for Lygus spp. in California’s organic strawberry fields. Alfalfa has been shown to attract both Lygus spp. and, in turn, a Lygus-specific parasitoid, Peristenus relictus (Ruthe). However, the impact of alfalfa trap-cropped st...

  17. Establishing vegetation on Kimberlite mine tailings: 2. Field trials. | N ...

    African Journals Online (AJOL)

    A series of field experiments were carried out on Kimberlite mine tailing located at Cullinan in the Transvaal. The most successful species in pure sward were Chloris gayana, Cynodon aethiopicus, Eragrostis curvula, E. tef, Pennisetum purpureum, Melilotus alban and Medicago sativa. Growth of grasses in the absence of ...

  18. Optimization of backfill pellet properties AASKAR DP2 - Laboratory tests

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Linus; Sanden, Torbjoern [Clay Technology AB, Lund (Sweden)

    2012-12-15

    Bentonite pellets are planned to be used as a part of the backfill in the Swedish spent nuclear fuel deep repository concept KBS-3. This report describes testing and evaluation of different backfill pellet candidates. The work completed included testing of both pellet material and pellet type. The materials tested were sourced from India (ASHA), Greece (IBECO, 2 products) and Wyoming USA (MX-80 clay). The majority of the tests were completed on the ASHA clay as well as the IBECO-RWC-BF products, with only limited testing of the others. The pellets tested were manufactured using both extrusion and roller compaction techniques and had different sizes and geometries. The following tests have been performed and are presented in this report: 1. General tests. Water content, bulk density and dry density have been determined for both the pellet filling and the individual pellets. The compressibility of the pellet filling was tested with CRS-tests and the strength of the individual pellets was tested with a special compression test. The water content varied from 11.3% to 18.7% and was highest for the extruded pellets. The dry density was somewhat higher for the roller-compacted pellets and their compressibility was lower. The strength of the individual pellets was generally higher for the extruded pellets. 2. Erosion. The pellet filling will be exposed to groundwater inflow when installed in the tunnel. This flow could possibly cause significant erosion on the pellet filling. Erosion tests have been performed with comparisons in erosion resistance made on the various material- and pellet-types. The influence of variations in water salinity and flow rates was also tested. The IBECO extruded 6- and 10- mm diameter rods and the compacted Posiva spec.-A pellet filling seem to have the lowest tendency to erode. It is also the IBECO extruded pellet filling that withstands variations in water salinity and flow rates best. 3. Water storing capacity. The pellet filling

  19. Development of advanced LWR fuel pellet technology

    International Nuclear Information System (INIS)

    Song, Kun Woo; Kang, K.W.; Kim, K. S.; Yang, J. H.; Kim, Y. M.; Kim, J. H.; Bang, J. B.; Kim, D. H.; Bae, S. O.; Jung, Y. H.; Lee, Y. S.; Kim, B. G.; Kim, S. H.

    2000-03-01

    A UO 2 pellet was designed to have a grain size of larger than 12 μm, and a new duplex design that UO 2 -Gd 2 O 3 is in the core and UO 2 -Er 2 O 3 in the periphery was proposed. A master mixing method was developed to make a uniform mixture of UO 2 and additives. The open porosity of UO 2 pellet was reduced by only mixing AUC-UO 2 powder with ADU-UO 2 or milled powder. Duplex compaction tools (die and punch) were designed and fabricated, and duplex compacting procedures were developed to fabricate the duplex BA pellet. In UO 2 sintering, the relations between sintering variables (additive, sintering gas, sintering temperature) and pellet properties (density, grain size, pore size) were experimentally found. The UO 2 -U 3 O 8 powder which is inherently not sinterable to high density could be sintered well with the aid of additives. U 3 O 8 single crystals were added to UO 2 powder, and homogeneous powder mixture was pressed and sintered in a reducing atmosphere. This technology leads to a large-grained pellet of 12-20 μm. In UO 2 -Gd 2 O 3 sintering, the relations between sintering variables (additives, sintering gas) and pellet properties (density, grain size) were experimentally found. The developed technology of fabricating a large-grained UO 2 pellet has been optimized in a lab scale. Pellet properties were investigated in the fields of (1) creep properties, (2) thermal properties, (3) O/M ratios and (4) unit cell lattice. (author)

  20. A four-pellet pneumatic injection system in the JT-60

    International Nuclear Information System (INIS)

    Hiratsuka, Hajime; Kawasaki, Kouzo; Miyo, Yasuhiko; Yoshioka, Yuji; Ohta, Kazuya; Shimizu, Masatsugu; Kondo, Ikuo; Onozuka, Masanori; Shimomura, Tomoyoshi; Iwamoto, Syuichi; Hashiri, Noboru

    1991-01-01

    A four-pellet pneumatic injection system has been developed for plasma fueling of the JT-60. The JT-60 pellet injector is capable of accelerating separately four cylindrical pellets 3.0 mm in diameter x 3.0 mm long for two pellets and 4.0 mm in diameter x 4.0 mm long for the remaining two. The JT-60 pellet injector was installed on the JT-60 tokamak machine at the end of 1988. Obtained pellet velocity was higher than 2300 m/s by propellant gases of up to 100 bar and the pellet fueling efficiency achieved was around 70% for both dimensions of pellets. This paper describes the design, injection operation and performance test results of the JT-60 pellet injector. (orig.)

  1. A four-pellet pneumatic injection system in the JT-60

    Energy Technology Data Exchange (ETDEWEB)

    Hiratsuka, Hajime; Kawasaki, Kouzo; Miyo, Yasuhiko; Yoshioka, Yuji; Ohta, Kazuya; Shimizu, Masatsugu; Kondo, Ikuo (Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan)); Onozuka, Masanori; Shimomura, Tomoyoshi; Iwamoto, Syuichi; Hashiri, Noboru (Mitsubishi Heavy Industries Ltd., Kobe (Japan))

    1991-05-01

    A four-pellet pneumatic injection system has been developed for plasma fueling of the JT-60. The JT-60 pellet injector is capable of accelerating separately four cylindrical pellets 3.0 mm in diameter x 3.0 mm long for two pellets and 4.0 mm in diameter x 4.0 mm long for the remaining two. The JT-60 pellet injector was installed on the JT-60 tokamak machine at the end of 1988. Obtained pellet velocity was higher than 2300 m/s by propellant gases of up to 100 bar and the pellet fueling efficiency achieved was around 70% for both dimensions of pellets. This paper describes the design, injection operation and performance test results of the JT-60 pellet injector. (orig.).

  2. Complete mitochondrial genome of Eruca sativa Mill. (Garden rocket.

    Directory of Open Access Journals (Sweden)

    Yankun Wang

    Full Text Available Eruca sativa (Cruciferae family is an ancient crop of great economic and agronomic importance. Here, the complete mitochondrial genome of Eruca sativa was sequenced and annotated. The circular molecule is 247,696 bp long, with a G+C content of 45.07%, containing 33 protein-coding genes, three rRNA genes, and 18 tRNA genes. The Eruca sativa mitochondrial genome may be divided into six master circles and four subgenomic molecules via three pairwise large repeats, resulting in a more dynamic structure of the Eruca sativa mtDNA compared with other cruciferous mitotypes. Comparison with the Brassica napus MtDNA revealed that most of the genes with known function are conserved between these two mitotypes except for the ccmFN2 and rrn18 genes, and 27 point mutations were scattered in the 14 protein-coding genes. Evolutionary relationships analysis suggested that Eruca sativa is more closely related to the Brassica species and to Raphanus sativus than to Arabidopsis thaliana.

  3. Fuel pellet fracture and relocation

    International Nuclear Information System (INIS)

    Walton, L.A.; Husser, D.L.

    1983-01-01

    The model used to describe fuel pellet fracture and relocation is an important feature of a fuel performance computer code. This model becomes especially important if the computer code is principally to be used for the evaluation of pellet clad interaction. The fracture and relocation model being developed for the B and W fuel performance code FUMAC was derived from an extensive data base. Cross sections of irradiated fuel rods were photographically magnified and measured to determine the configuration of the fragments of the fractured fuel pellets. Data, representing a wide range of LWR fuel designs and as-manufactured mechanical configurations, were catalogued and systematically reduced and then correlated as a function of the likely independent variables. These correlations define the key phenomenological behavior patterns which the relocation model must duplicate and indicate which mechanistic approaches are viable explanations of this behavior. The data base covers the burnup range from approximately one to 35 GWd/mtU and linear heat rates from less than 100 to nearly 700 W/Cm. This paper presents the correlated data base and the methods used to derive and interpret it. It was determined from this data base that pellet cracking is initially both power level and burnup dependent but tends to saturate eventually with continued steady irradiation. Fuel pellet relocation was found to be much more extensive than would be deduced from thermal considerations alone. Even at very low burnups fuel fragments were found to move outward until restrained by the cladding. The results also suggest that changes in internal resistance to heat flow within the pellets due to the opening of cracks may be as important as peripheral gap changes to the thermal modeler. The transient response and thermal implications of this model are recommended as primary areas for future investigation

  4. Particle density determination of pellets and briquettes

    Energy Technology Data Exchange (ETDEWEB)

    Rabier, Fabienne; Temmerman, Michaeel [Centre wallon de Recherches agronomiques, Departement de Genie rural, CRA-W, Chaussee de Namur, 146, B 5030 Gembloux (Belgium); Boehm, Thorsten; Hartmann, Hans [Technologie und Foerderzentrum fuer Nachwachsende Rohstoffe, TFZ, Schulgasse 18, D 94315 Straubing (Germany); Daugbjerg Jensen, Peter [Forest and Landscape, The Royal Veterinary and Agricultural University, Rolighedsvej 23, DK 1958 Frederiksberg C (Denmark); Rathbauer, Josef [Bundesanstalt fuer Landtechnik, BLT, Rottenhauer Strasse,1 A 3250 Wieselburg (Austria); Carrasco, Juan; Fernandez, Miguel [Centro de investigaciones Energeticas, Medioambientales y Tecnologicas, CIEMAT, Avenida Complutense, 22 E 28040 Madrid (Spain)

    2006-11-15

    Several methods and procedures for the determination of particle density of pellets and briquettes were tested and evaluated. Round robin trials were organized involving five European laboratories, which measured the particle densities of 15 pellet and five briquette types. The test included stereometric methods, methods based on liquid displacement (hydrostatic and buoyancy) applying different procedures and one method based on solid displacement. From the results for both pellets and briquettes, it became clear that the application of a method based on either liquid or solid displacement (only tested on pellet samples) leads to an improved reproducibility compared to a stereometric method. For both, pellets and briquettes, the variability of measurements strongly depends on the fuel type itself. For briquettes, the three methods tested based on liquid displacement lead to similar results. A coating of the samples with paraffin did not improve the repeatability and the reproducibility. Determinations with pellets proved to be most reliable when the buoyancy method was applied using a wetting agent to reduce surface tensions without sample coating. This method gave the best values for repeatability and reproducibility, thus less replications are required to reach a given accuracy level. For wood pellets, the method based on solid displacement gave better values of repeatability, however, this instrument was tested at only one laboratory. (author)

  5. Pellet injector research at ORNL

    International Nuclear Information System (INIS)

    Combs, S.K.; Foster, C.A.; Milora, S.L.

    1988-01-01

    Advanced plasma fueling systems for magnetic confinement devices are under development a the Oak Ridge National Laboratory (ORNL). The general approach is that of producing and accelerating frozen hydrogen isotope pellets at speeds in the range 1-2 km/s and higher. Recently, ORNL provided pneumataic-based pellet fueling systems for two of the world's largest tokamak experiments, the Tokamak Fusion Test Reactor (TFTR) and the Joint European Torus (JET). A new versatile centrifuge type injector is being readied at ORNL for use on the Tore Supra tokamak. Also, a new simplified eight-shot injector design has been developed for use on the Princeton Beta Experiment (PBX) and the Advanced Toroidal Facility (ATF). In addition to these confinement physics related activities, ORNL is pursuing advanced technologies to achieve pellet velocities significantly in excess of 2 km/s and is carrying out a Tritium Proof-of-Principle (TPOP) experiment in which the fabrication and acceleration of tritium pellets have already been demonstrated. This paper describes these ongoing activities. 25 refs., 9 figs

  6. Fuel Pellets from Biomass. Processing, Bonding, Raw Materials

    DEFF Research Database (Denmark)

    Stelte, Wolfgang

    in an increasing interest in biomass densification technologies, such as pelletization and briquetting. The global pellet market has developed quickly, and strong growth is to be expected for the coming years. Due to an increasing demand for biomass, the traditionally used wood residues from sawmills and pulp...... influence of the different processing parameters on the pressure built up in the press channel of a pellet mill. It showed that the major factor was the press channel length as well as temperature, moisture content, particle size and extractive content. Furthermore, extractive migration to the pellet...... surface at an elevated temperature played an important role. The second study presented a method of how key processing parameters can be estimated, based on a pellet model and a small number of fast and simple laboratory trials using a single pellet press. The third study investigated the bonding...

  7. Development of railgun pellet injector for nuclear fusion fueling

    International Nuclear Information System (INIS)

    Azuma, Kingo; Oda, Yasushi; Onozuka, Masanori.

    1996-01-01

    Recent fusion plasmas have become larger as fusion research progresses. This requires high-velocity solid-hydrogen pellet injection that is the most efficient fueling method. The application of the electro-magnetic railgun system for pellet injection is one of the most feasible technologies for accelerating a pellet to a high speed. The system consists of a pneumatic pre-accelerator for the first acceleration stage and a railgun for the second stage. The railgun is operated by a low voltage discharged from a pulse-forming-network power supply to accelerate a plasma armature between the rail electrodes. The plasma is induced by high-power laser beam irradiation. The highest velocity of a solid-hydrogen pellet obtained using the railgun was 2.6 km/s. This velocity is higher than the maximum pellet velocity of 2.3 km/s achieved by MHI's pneumatic pellet injector. It was also found that the pellet velocity could be controlled easily using railgun pellet injection. (author)

  8. Development of railgun pellet injector for nuclear fusion fueling

    Energy Technology Data Exchange (ETDEWEB)

    Azuma, Kingo [Mitsubishi Heavy Industries Ltd., Takasago, Hyogo Takasago Research and Development Center (Japan); Oda, Yasushi; Onozuka, Masanori

    1996-03-01

    Recent fusion plasmas have become larger as fusion research progresses. This requires high-velocity solid-hydrogen pellet injection that is the most efficient fueling method. The application of the electro-magnetic railgun system for pellet injection is one of the most feasible technologies for accelerating a pellet to a high speed. The system consists of a pneumatic pre-accelerator for the first acceleration stage and a railgun for the second stage. The railgun is operated by a low voltage discharged from a pulse-forming-network power supply to accelerate a plasma armature between the rail electrodes. The plasma is induced by high-power laser beam irradiation. The highest velocity of a solid-hydrogen pellet obtained using the railgun was 2.6 km/s. This velocity is higher than the maximum pellet velocity of 2.3 km/s achieved by MHI`s pneumatic pellet injector. It was also found that the pellet velocity could be controlled easily using railgun pellet injection. (author).

  9. Acceleration of solid pellets using a plasma gun

    International Nuclear Information System (INIS)

    Buller, T.L.; Turnbull, R.J.; Kim, K.

    1979-01-01

    The use of solid pellets of hydrogen isotopes to refuel thermonuclear fusion reactors based on the tokamak configuration will require that the pellets be accelerated to high velocities. One possible method of acceleration is to interact a fast plasma from a plasma gun with the pellets. In this paper preliminary results are given on the acceleration of solid pellets with a plasma gun. The plasma-gun requirements for successful acceleration to high velocities are discussed

  10. Backfilling of deposition tunnels: Use of bentonite pellets

    International Nuclear Information System (INIS)

    Dixon, David; Sanden, Torbjoern; Jonsson, Esther; Hansen, Johanna

    2011-02-01

    The state of knowledge related to use of bentonite pellets as part of backfill or other gap filling components in repository applications is reviewed. How the pellets interact with adjacent sealing materials and the surrounding rock mass is a critical aspect in determining backfill behaviour. The key features and processes that determine how the pellet component of the KBS-3V deposition tunnel backfill will behave are discussed and recommendations related to what additional information needs to be developed are provided. Experiences related to pellet material composition, size, shape, placement options and more importantly, the density to which they can be placed all indicate that there are significant limitations to the achievable as-placed density of bentonite pellet fill. Low as-placed density of the pellet fill component of the backfill is potentially problematic as the outermost regions of tunnel backfill will be the first region of the backfill to be contacted by water entering the tunnels. It is also through this region that initial water movement along the length of the deposition tunnels will occur. This will greatly influence the operations in a tunnel, especially with respect to situations where water is exiting the downstream face of still open deposition tunnels. Pellet-filled regions are also sensitive to groundwater salinity, susceptible to development of piping features and subsequent mechanical erosion by through flowing water, particularly in the period preceding deposition tunnel closure. A review of the experiences of various organisations considering use of bentonite-pellet materials as part of buffer or backfill barriers is provided in this document. From this information, potential options and limitations to use of pellets or pellet-granule mixtures in backfill are identified. Of particular importance is identification of the apparent upper-limits of dry density to which such materials can to be placed in the field. These bounds will

  11. Backfilling of deposition tunnels: Use of bentonite pellets

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, David (Atomic Energy of Canada Limited (Canada)); Sanden, Torbjoern (Clay Technology AB (Sweden)); Jonsson, Esther (Swedish Nuclear Fuel and Waste Mangaement Co. (Sweden)); Hansen, Johanna (Posiva Oy (Finland))

    2011-02-15

    The state of knowledge related to use of bentonite pellets as part of backfill or other gap filling components in repository applications is reviewed. How the pellets interact with adjacent sealing materials and the surrounding rock mass is a critical aspect in determining backfill behaviour. The key features and processes that determine how the pellet component of the KBS-3V deposition tunnel backfill will behave are discussed and recommendations related to what additional information needs to be developed are provided. Experiences related to pellet material composition, size, shape, placement options and more importantly, the density to which they can be placed all indicate that there are significant limitations to the achievable as-placed density of bentonite pellet fill. Low as-placed density of the pellet fill component of the backfill is potentially problematic as the outermost regions of tunnel backfill will be the first region of the backfill to be contacted by water entering the tunnels. It is also through this region that initial water movement along the length of the deposition tunnels will occur. This will greatly influence the operations in a tunnel, especially with respect to situations where water is exiting the downstream face of still open deposition tunnels. Pellet-filled regions are also sensitive to groundwater salinity, susceptible to development of piping features and subsequent mechanical erosion by through flowing water, particularly in the period preceding deposition tunnel closure. A review of the experiences of various organisations considering use of bentonite-pellet materials as part of buffer or backfill barriers is provided in this document. From this information, potential options and limitations to use of pellets or pellet-granule mixtures in backfill are identified. Of particular importance is identification of the apparent upper-limits of dry density to which such materials can to be placed in the field. These bounds will

  12. On the Drag Effect of a Refuelling Pellet

    DEFF Research Database (Denmark)

    Chang, Tinghong; Michelsen, Poul

    1981-01-01

    A refueling pellet is subjected mainly to two kinds of drags: (1) inertial drag caused by the motion of the pellet relative to the surrounding plasma, and (2) ablation drag caused by an uneven ablation rate of the front and the rear surface of the pellet in an inhomogeneous plasma. Computational ...... results showed that for reasonable combinations of pellet size and injection speed, the drag effect is hardly detectable for plasma conditions prevailing in current large tokamaks....

  13. Spin-polarized fuel in ICF pellets

    International Nuclear Information System (INIS)

    Wakuta, Yoshihisa; Emoto, Nobuya; Nakao, Yasuyuki; Honda, Takuro; Honda, Yoshinori; Nakashima, Hideki.

    1990-01-01

    The use of parallel spin-polarized DT or D 3 He fuel increases the fusion cross-section by 50%. By implosion-burn simulation for inertially confined fusion (ICF) pellets of the spin-polarized fuels, we found that the input energy requirement could be reduced by nearly a fact of two. These pellets taken up here include large-high-aspect-ratio DT target proposed in ILE Osaka University and DT ignitor/D 3 He fuel pellet proposed by our group. We also found that the polarized state could survive during the implosion-burn phase. (author)

  14. Repeating pneumatic pellet injector in JAERI

    Energy Technology Data Exchange (ETDEWEB)

    Kasai, Satoshi; Hasegawa, Kouichi; Suzuki, Sadaaki; Miura, Yukitoshi (Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment); Oda, Yasushi; Onozuka, Masanori; Tsujimura, Seiichi.

    1992-09-01

    A repeating pneumatic pellet injector has been developed and constructed at Japan Atomic Energy Research Institute. This injector can provide repetitive pellet injection to fuel tokamak plasmas for an extended period of time, aiming at the improvement of plasma performance. The pellets with nearly identical speed and mass can be repeatedly injected with a repetition rate of 2-3.3 Hz and a speed of up to 1.7 km/s by controlling the temperature of the cryogenic system, the piston speed and the pressure of the propellant gas. (author).

  15. Repeating pneumatic pellet injector in JAERI

    International Nuclear Information System (INIS)

    Kasai, Satoshi; Hasegawa, Kouichi; Suzuki, Sadaaki; Miura, Yukitoshi; Oda, Yasushi; Onozuka, Masanori; Tsujimura, Seiichi.

    1992-09-01

    A repeating pneumatic pellet injector has been developed and constructed at Japan Atomic Energy Research Institute. This injector can provide repetitive pellet injection to fuel tokamak plasmas for an extended period of time, aiming at the improvement of plasma performance. The pellets with nearly identical speed and mass can be repeatedly injected with a repetition rate of 2-3.3 Hz and a speed of up to 1.7 km/s by controlling the temperature of the cryogenic system, the piston speed and the pressure of the propellant gas. (author)

  16. Mox pellet reference material

    International Nuclear Information System (INIS)

    Perolat, J.P.

    1991-01-01

    A first batch of MOX pellets certified in plutonium and uranium has been prepared and characterised in France to meet the needs of laboratories which are engaged upon destructive analysis for safeguards purposes especially in fuel fabrication plants. The pellets sintering has been obtained in a special fabrication to achieve an homogeneity better than 0.1%. The plutonium and uranium characterisation by chemical analysis has been carried out by two laboratories using at least two different methods. 1 fig., 5 refs

  17. Pellet injectors for steady state plasma fuelling

    International Nuclear Information System (INIS)

    Vinyar, I.; Geraud, A.; Yamada, H.; Lukin, A.; Sakamoto, R.; Skoblikov, S.; Umov, A.; Oda, Y.; Gros, G.; Krasilnikov, I.; Reznichenko, P.; Panchenko, V.

    2005-01-01

    Successful steady state operation of a fusion reactor should be supported by repetitive pellet injection of solidified hydrogen isotopes in order to produce high performance plasmas. This paper presents pneumatic pellet injectors and its implementation for long discharge on the LHD and TORE SUPRA, and a new centrifuge pellet injector test results. All injectors are fitted with screw extruders well suited for steady state operation

  18. The long-term effects of alfalfa on soil water content in the Loess ...

    African Journals Online (AJOL)

    Administrator

    2011-05-23

    May 23, 2011 ... affect the water content in deep soil and continuous growing alfalfa ... Wasteland, wheat field and six seeded alfalfa (Medicago sativa L.) grasslands with ... The crops (wheat, maize, potato, beans and millet) had been rainfed on all ..... Productivity dynamic of alfalfa and its effects on water eco-environment.

  19. Effects of a propionic acid-based preservative on storage characteristics, nutritive value, and energy content for alfalfa hays packaged in large, round bales

    Science.gov (United States)

    During 2009 and 2010, alfalfa (Medicago sativa L.) hays from two cuttings that were harvested from the same field site were used to evaluate the effects of a propionic acid-based preservative on the storage characteristics and nutritive value of hays stored as large, round bales. A total of 87 large...

  20. Do soil tests help forecast nitrogen response in first-year corn following alfalfa on fine-textured soils?

    Science.gov (United States)

    Improved methods of predicting grain yield response to fertilizer N for first-year corn (Zea mays L.) following alfalfa (Medicago sativa L.) on fine-textured soils are needed. Data from 21 site-years in the North Central Region were used to (i) determine how Illinois soil nitrogen test (ISNT) and pr...

  1. Experimental study of curved guide tubes for pellet injection

    International Nuclear Information System (INIS)

    Combs, S.K.; Baylor, L.R.; Foust, C.R.; Gouge, M.J.; Jernigan, T.C.; Milora, S.L.

    1997-01-01

    The use of curved guide tubes for transporting frozen hydrogen pellets offers great flexibility for pellet injection into plasma devices. While this technique has been previously employed, an increased interest in its applicability has been generated with the recent ASDEX Upgrade experimental data for magnetic high-field side (HFS) pellet injection. In these innovative experiments, the pellet penetration appeared to be significantly deeper than for the standard magnetic low-field side injection scheme, along with corresponding greater fueling efficiencies. Thus, some of the major experimental fusion devices are planning experiments with HFS pellet injection. Because of the complex geometries of experimental fusion devices, installations with multiple curved guide tube sections will be required for HFS pellet injection. To more thoroughly understand and document the capability of curved guide tubes, an experimental study is under way at the Oak Ridge National Laboratory (ORNL). In particular, configurations and pellet parameters applicable for the DIII-D tokamak and the International Thermonuclear Experimental Reactor (ITER) were simulated in laboratory experiments. Initial test results with nominal 2.7- and 10-mm-diam deuterium pellets are presented and discussed

  2. Consolidated waste forms: glass marbles and ceramic pellets

    International Nuclear Information System (INIS)

    Treat, R.L.; Rusin, J.M.

    1982-05-01

    Glass marbles and ceramic pellets have been developed at Pacific Northwest Laboratory as part of the multibarrier concept for immobilizing high-level radioactive waste. These consolidated waste forms served as substrates for the application of various inert coatings and as ideal-sized particles for encapsulation in protective matrices. Marble and pellet formulations were based on existing defense wastes at Savannah River Plant and proposed commercial wastes. To produce marbles, glass is poured from a melter in a continuous stream into a marble-making device. Marbles were produced at PNL on a vibratory marble machine at rates as high as 60 kg/h. Other marble-making concepts were also investigated. The marble process, including a lead-encapsulation step, was judged as one of the more feasible processes for immobilizing high-level wastes. To produce ceramic pellets, a series of processing steps are required, which include: spray calcining - to dry liquid wastes to a powder; disc pelletizing - to convert waste powders to spherical pellets; sintering - to densify pellets and cause desired crystal formation. These processing steps are quite complex, and thereby render the ceramic pellet process as one of the least feasible processes for immobilizing high-level wastes

  3. Apparatus for loading fuel pellets in fuel rods

    International Nuclear Information System (INIS)

    Tedesco, R.J.

    1976-01-01

    An apparatus is disclosed for loading fuel pellets into fuel rods for a nuclear reactor including a base supporting a table having grooves therein for holding a multiplicity of pellets. Multiple fuel rods are placed in alignment with grooves in the pellet table and a guide member channels pellets from the table into the corresponding fuel rods. To effect movement of pellets inside the fuel rods without jamming, a number of electromechanical devices mounted on the base have arms connected to the lower surface of the fuel rod table which cyclically imparts a reciprocating arc motion to the table for moving the fuel pellets longitudinally of and inside the fuel rods. These electromechanical devices include a solenoid having a plunger therein connected to a leaf type spring, the arrangement being such that upon energization of the solenoid coil, the leaf spring moves the fuel rod table rearwardly and downwardly, and upon deenergization of the coil, the spring imparts an upward-forward movement to the table which results in physical displacement of fuel pellets in the fuel rods clamped to the table surface. 8 claims, 6 drawing figures

  4. Nigella sativa L.

    African Journals Online (AJOL)

    ajl yemi

    2011-10-26

    Oct 26, 2011 ... and agro-biodiversity in black cumin (Nigella sativa L.) genotypes from ... analysis. INTRODUCTION. Among the medicinal plants in use from prehistoric times, .... AA240 FS Fast sequential atomic absorption spectrophotometer) ... Lead (Pb) mg kg- ..... for herbal, pharmaceutical, neutraceutical and cosmetic.

  5. Geometric dimensioning of UO2 pellets for PWR

    International Nuclear Information System (INIS)

    Teixeira e Silva, A.

    1988-01-01

    The finite element structural program SAP-IV is used to calculate UO 2 pellet strains developed under thermal gradients in pressurized water reactors. The applied procedure allows to analyse the influence of various aspects of pellet geometry on cladding strains and can be utilized for the dimensioning of UO 2 pellets. Pellets purchased with flat ends, with dishes pressed into both ends, shouders, and a 45-deg edge chamfer are analysed. The analyse results are compared with experimental data.(autor) [pt

  6. Two complete chloroplast genome sequences of Cannabis sativa varieties.

    Science.gov (United States)

    Oh, Hyehyun; Seo, Boyoung; Lee, Seunghwan; Ahn, Dong-Ha; Jo, Euna; Park, Jin-Kyoung; Min, Gi-Sik

    2016-07-01

    In this study, we determined the complete chloroplast (cp) genomes from two varieties of Cannabis sativa. The genome sizes were 153,848 bp (the Korean non-drug variety, Cheungsam) and 153,854 bp (the African variety, Yoruba Nigeria). The genome structures were identical with 131 individual genes [86 protein-coding genes (PCGs), eight rRNA, and 37 tRNA genes]. Further, except for the presence of an intron in the rps3 genes of two C. sativa varieties, the cp genomes of C. sativa had conservative features similar to that of all known species in the order Rosales. To verify the position of C. sativa within the order Rosales, we conducted phylogenetic analysis by using concatenated sequences of all PCGs from 17 complete cp genomes. The resulting tree strongly supported monophyly of Rosales. Further, the family Cannabaceae, represented by C. sativa, showed close relationship with the family Moraceae. The phylogenetic relationship outlined in our study is well congruent with those previously shown for the order Rosales.

  7. [Ttextual research of Cannabis sativa varieties and medicinal part].

    Science.gov (United States)

    Wei, Yingfang; Wang, Huadong; Guo, Shanshan; Yan, Jie; Long, Fei

    2010-07-01

    To determine the medicinal part and varieties of Cannabis Sativa through herbal textual research to Provide bibliographic reference for clinical application. Herbal textual research of C. Sativa from ancient herbal works and modern data analysis. Through the herbal textual research, the plant of the C. sativa, for Fructus Cannabis used now is identical with that described in ancient herbal literatures. People did not make a sharp distinction on medicinal part of C. sativa in the early stage literatures, female inflorescence and unripe fruit, fruit and kernel of seed were all used. Since Taohongjing realized the toxicity ofpericarp, all the herbal and prescription works indicate that the pericarp shall be removed before usage and only the kernel can be used. However, in modem literatures, both fruit and kernel can be used as medicinal part. The plants for Fructus Cannabis described in modern and ancient literatures are identical. The base of the original plant is the same either in ancient or modern. And the toxicity of the fruit is more than that of the kernel. The kernel is the exact medicinal part of C. Sativa.

  8. Translational genomics from model species Medicago truncatula to crop legume Trifolium pratense

    NARCIS (Netherlands)

    Lang Chunting, Chunting

    2012-01-01

    The legume Trifolium pratense (red clover) is an important fodder crop and produces important secondary metabolites. This makes red clover an interesting species. In this thesis, the red clover genome is compared to the legume model species Medicago truncatula, of which the

  9. Measurement of Persistent Organic Pollutants (POPs) in plastic resin pellets from remote islands : Toward establishment of baseline level for International Pellet Watch

    Science.gov (United States)

    Takada, H.; Heskett, M.; Yamashita, R.; Yuyama, M.; Itoh, M.; Geok, Y. B.; Ogata, Y.

    2011-12-01

    Plastic resin pellets collected from remote islands in open oceans (Canary, St. Helena, Cocos, Hawaii, Maui Islands and Barbados) were sorted and yellowing polyethylene (PE) pellets were measured for polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and the degradation products (DDTs), and hexachlorocyclohexanes (HCHs) by gas chromatograph equipped with mass spectrometer (GC-MS) and with electron capture detector (GC-ECD). PCBs were detected from all the pellet samples, confirming the global dispersion of PCBs. Median concentrations of PCBs (sum of 13 congeners : CB-66, CB-101, CB-110, CB-118, CB-105, CB-149, CB-153, CB-138, CB-128, CB-187, CB-180, CB-170, CB-206) in the remote island pellets ranged from 0.1 to 10 ng/g-pellet. These were one to three orders of magnitude lower than those observed for pellets from industrialized coastal zones (hundreds ng/g in Los Angeles, Boston, Tokyo; Ogata et al., 2009). Because these remote islands are far (>100 km) from industrialized zones, these concentrations (i.e., 0.1 to 10 ng/g-pellet) can be regarded as global "baseline" level of PCB pollution. Concentrations of DDTs in the remote island pellets ranged from 0.2 to 5.5 ng/g-pellet. At some locations, DDT was dominant over the degradation products (DDE and DDD), suggesting current usage of the pesticides in the islands. HCHs concentrations were 0.4 - 1.8 ng/g-pellet and lower than PCBs and DDTs, except for St. Helena Island at 18.8 ng/g-pellet where the current usage of the pesticides are of concern. The analyses of pellets from the remote islands provided "baseline" level of POPs (PCBs effects of global distillation, pellet samples from remote islands in higher latitude regions are necessary. From the eco-toxicological point of view, the fact that sporadic high concentrations of POPs were detected in some pellet samples from the remote islands is underscored. Some plastic debris which were contaminated in industrialized coastal zones may have rapidly

  10. Repeating pneumatic hydrogen pellet injector for plasma fueling

    International Nuclear Information System (INIS)

    Combs, S.K.; Milora, S.L.; Foust, C.R.; Foster, C.A.; Schuresko, D.D.

    1985-01-01

    A repeating pneumatic pellet injector has been developed for plasma fueling applications. The repetitive device extends pneumatic injector operation to steady state. The active mechanism consists of an extruder and a gun assembly that are cooled by flowing liquid-helium refrigerant. The extruder provides a continuous supply of solid hydrogen to the gun assembly, where a reciprocating gun barrel forms and chambers cylindrical pellet from the extrusion; pellets are then accelerated with compressed hydrogen gas (pressures up to 125 bar) to velocities -1 have been obtained with 2.1- , 3.4- , and 4.0-mm-diameter pellets. The present apparatus operates at higher firing rates in short bursts; for example, a rate of 6 s -1 for 2 s with the larger pellets. These pellet parameters are in the range applicable for fueling large present-day fusion devices such as the Tokamak Fusion Test Reactor (TFTR). Experimental results are presented, including effects of propellant pressure and barrel length on gun performance

  11. Development of advanced LWR fuel pellet technology

    Energy Technology Data Exchange (ETDEWEB)

    Song, Kun Woo; Kang, K.W.; Kim, K. S.; Yang, J. H.; Kim, Y. M.; Kim, J. H.; Bang, J. B.; Kim, D. H.; Bae, S. O.; Jung, Y. H.; Lee, Y. S.; Kim, B. G.; Kim, S. H

    2000-03-01

    A UO{sub 2} pellet was designed to have a grain size of larger than 12 {mu}m, and a new duplex design that UO{sub 2}-Gd{sub 2}O{sub 3} is in the core and UO{sub 2}-Er{sub 2}O{sub 3} in the periphery was proposed. A master mixing method was developed to make a uniform mixture of UO{sub 2} and additives. The open porosity of UO{sub 2} pellet was reduced by only mixing AUC-UO{sub 2} powder with ADU-UO{sub 2} or milled powder. Duplex compaction tools (die and punch) were designed and fabricated, and duplex compacting procedures were developed to fabricate the duplex BA pellet. In UO{sub 2} sintering, the relations between sintering variables (additive, sintering gas, sintering temperature) and pellet properties (density, grain size, pore size) were experimentally found. The UO{sub 2}-U{sub 3}O{sub 8} powder which is inherently not sinterable to high density could be sintered well with the aid of additives. U{sub 3}O{sub 8} single crystals were added to UO{sub 2} powder, and homogeneous powder mixture was pressed and sintered in a reducing atmosphere. This technology leads to a large-grained pellet of 12-20 {mu}m. In UO{sub 2}-Gd{sub 2}O{sub 3} sintering, the relations between sintering variables (additives, sintering gas) and pellet properties (density, grain size) were experimentally found. The developed technology of fabricating a large-grained UO{sub 2} pellet has been optimized in a lab scale. Pellet properties were investigated in the fields of (1) creep properties, (2) thermal properties, (3) O/M ratios and (4) unit cell lattice. (author)

  12. Novel SINEs families in Medicago truncatula and Lotus japonicus: bioinformatic analysis.

    Science.gov (United States)

    Gadzalski, Marek; Sakowicz, Tomasz

    2011-07-01

    Although short interspersed elements (SINEs) were discovered nearly 30 years ago, the studies of these genomic repeats were mostly limited to animal genomes. Very little is known about SINEs in legumes--one of the most important plant families. Here we report identification, genomic distribution and molecular features of six novel SINE elements in Lotus japonicus (named LJ_SINE-1, -2, -3) and Medicago truncatula (MT_SINE-1, -2, -3), model species of legume. They possess all the structural features commonly found in short interspersed elements including RNA polymerase III promoter, polyA tail and flanking repeats. SINEs described here are present in low to moderate copy numbers from 150 to 3000. Bioinformatic analyses were used to searched public databases, we have shown that three of new SINE elements from M. truncatula seem to be characteristic of Medicago and Trifolium genera. Two SINE families have been found in L. japonicus and one is present in both M. truncatula and L. japonicus. In addition, we are discussing potential activities of the described elements. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. Method of manufacturing UO2 pellet

    International Nuclear Information System (INIS)

    Harada, Yuhei; Asami, Yasuji.

    1989-01-01

    The present invention concerns a method of manufacturing UO 2 pellets with less FP gas release and having fine structure for moderating PCMI. At first, oxide nuclear fuel pellets are placed in a sintering furnance and preliminarily sintered in a H 2 gas atmosphere at 1400 - 1600 degC. In this step, sintering is progressed to about 90 % TD, by which closed cells are formed substantially completely. Then, when sintering is further advanced at an identical temperature in a CO 2 gas atmosphere, growth of the crystal grains is advanced at the central portion of the pellets. Then, reductive heat treatment is applied at the identical temperature in a H 2 gas atmosphere. As a result, pellets having a fine double structure with the larger grain size region being in the central portion and smaller grain size region in the outer periphery can be obtained. (I.J.)

  14. Kinetic depletion model for pellet ablation

    International Nuclear Information System (INIS)

    Kuteev, Boris V.

    2001-11-01

    A kinetic model for depletion effect, which determines pellet ablation when the pellet passes a rational magnetic surface, is formulated. The model predicts a moderate decrease of the ablation rate compared with the earlier considered monoenergy versions [1, 2]. For typical T-10 conditions the ablation rate reduces by a reactor of 2.5 when the 1-mm pellet penetrates through the plasma center. A substantial deceleration of pellets -about 15% per centimeter of low shire rational q region; is predicted. Penetration for Low Field Side and High Field Side injections is considered taking into account modification of the electron distribution function by toroidal magnetic field. It is shown that Shafranov shift and toroidal effects yield the penetration length for HFS injection higher by a factor of 1.5. This fact should be taken into account when plasma-shielding effects on penetration are considered. (author)

  15. UO2 pellet and manufacturing method

    International Nuclear Information System (INIS)

    Komada, Kiichi; Nishinaka, Keiji; Adachi, Kazunori; Fujiwara, Shuji.

    1995-01-01

    The present invention concerns an uranium dioxide pellet having a large crystal grain size. The grain size of the pellet is enlarged to increase the distance of an FP gas generated in the crystal grain to reach the grain boundary and, as a result, decrease the releasing speed of the FP gas. A UO 2 powder having a specific surface area of from 5 to 50m 2 /g is used as a starting powder in a step of forming a molding product, and chlorine or a chlorine compound is added in such an amount that the chlorine content in the UO 2 pellet is from 3 to 25ppm, in one of a production step, a molding step or a sintering step for UO 2 powder. With such procedures, a UO 2 pellet having a large crystal grain size can be prepared with good reproducibility. (T.M.)

  16. Development of the pellet injector for JT-60

    International Nuclear Information System (INIS)

    Kawasaki, Kouzo; Hiratsuka, Hajimo; Takatsu, Hideyuki; Shimizu, Masatsugu; Onozuka, Masanori; Uchikawa, Takashi; Iwamoto, Syuichi; Hashiri, Nobuo

    1989-01-01

    The pneumatic 4-shot pellet injector has been installed and operated for JT-60 (JAERI Tokamak-60). The performance tests have proved that the device provides high speed hydrogen pellets just as planned. The maximum pellet velocity obtained in the hydrogen pellet tests is greater than 1.6 km/sec at 50 bar propellant gas. The device is now in use for JT-60 contributing to plasma study. In this paper the outline of features and performance of the device is presented. (author). 4 refs.; 8 figs

  17. Characteristics of pellet injuries to the orbit.

    Science.gov (United States)

    Kükner, A Sahap; Yilmaz, Turgut; Celebi, Serdal; Karslioğlu, Safak; Alagöz, Gürsoy; Serin, Didem; Acar, M Akif; Ozveren, M Faik

    2009-01-01

    To investigate the features of orbital injuries by pellets fired from the front. Retrospective, 4 cases of pellet injuries. Five orbits of 4 patients who sustained pellet injuries received from the front were reviewed retrospectively. The course of injury and results were assessed. Radiological examinations were reviewed. The patients were evaluated between December 1996 and June 2004. Five orbits of 4 patients sustained injuries caused by pellets fired from an anterior direction. The globe in the injured orbit was intact in 2 cases. Severe loss of vision was also present in these 2 globes due to optic nerve involvement. Final visual acuity was down to no light perception in 4 eyes and limited to light perception in 1 eye. The prognosis of orbital pellet injuries is, unfortunately, poor. A pellet passing through the floor of the orbit often causes double perforation of the globe and, once in the orbital aperture, it travels towards the apex as a result of the conical shape of the orbit and lodges in the optic canal or its entrance, severely damaging the optic nerve. Surgery or other treatments are usually unsuccessful. Even if the globe is intact, vision is usually severely impaired. Copyright 2009 S. Karger AG, Basel.

  18. Studies on a burner used biomass pellets as fuel. Performance of a spiral vortex pellet burner

    Energy Technology Data Exchange (ETDEWEB)

    Iwao, Toshio

    1987-12-21

    In order to develop a small size burner with high performance using biomass pellets fuel substitute for fuel oil, the burning performance of a spiral vortex pallet burner has been studied. An experimental equipment for the pellet burning is made up of a fuel supply unit, combustion chamber and a furnace. The used woody pellet is made of mixed sawdust and bark; with water content of 10.29%, particle diameter of 5.5-9mm, length of 5-50mm, and, apparent and real specific gravities are 0.59 and 1.334 respectively. The pellets are sent to bottom of the combustion chamber, spiral vortex combustion are carried out with blown air, the ashes and unburnt residues are discharged to out of combustion chamber with spiral vortex hot gases. As the result, it was clarified that the formation of the burning layers in a burner is required to be in order of the layers of ash, oxidation, reduction and carbonization up to the upper layer for high burning performance, and the formation of the layer is influenced by the condition of sedimentation of pellets in the combustion chamber. In the meanwhile the burning performance of the burner is influenced by the quantity of blast, the rate of feeding, and by the time of pre-heating in the combustion chamber. (23 figs, 5 refs)

  19. Development of repeating pneumatic pellet injector

    International Nuclear Information System (INIS)

    Oda, Y.; Onozuka, M.; Shimomura, T.

    1990-01-01

    A repeating pneumatic pellet injector has been constructed to experiment with the technique of continuous injection for fueling fusion reactors. This device is composed of a cryogenic extruder and a gun assembly in (among others) a high-vacuum vessel, diagnostic vessels, LHe, fuel-gas and propellant-gas supply systems, control and data acquisition systems, etc. The performance tests, using hydrogen, have proved that the device provides the function of extruding frozen hydrogen ribbons at the speed of 6 mm s -1 , chambering pellet at the rate of 5 Hz, and injecting pellet at the speed of 900 m s -1 , as planned. (author)

  20. Impurity pellet injection experiments at TFTR

    International Nuclear Information System (INIS)

    Marmar, E.S.

    1991-01-01

    Impurity (Li and C) pellet experiments, which began at TFTR in 1989, and are expected to continue at least through 1991, have continued to produce new and significant results. The most significant of these are: (1) improvements in TFTR supershots after wall-conditioning by Li pellet injection; (2) accurate measurements of the pitch angle profiles of the internal magnetic field using the polarization angles of line emission from Li + in the pellet ablation cloud; and (3) initial measurements of pitch angle profiles using the tilt of the LI + emission region of the ablation cloud which is stretched out along the field lines

  1. Tracking alien chromosome in sativa background by genomic in situ hybridization

    International Nuclear Information System (INIS)

    Abbasi, F.M.; Iqbal, M.; Salim, M.

    2004-01-01

    Genomic in situ hybridization (GISH) was used to look into the genomic constitution of monosomic alien -addition line derived from O. sativa x O. brachyantha. Biotin label genomic DNA from O. brachyantha was used as probe. The probe hybridized to the brachyantha chromosome. No detectable hybridization signal was observed on sativa chromosomes. This differential painting of chromosome enables us to unequivocally discriminate brachyantha chromosome from those of sativa. Results showed the usefulness of GISH in the identification of a single alien chromosome in the sativa background. (author)

  2. Particle fueling experiments with a series of pellets in LHD

    Science.gov (United States)

    Baldzuhn, J.; Damm, H.; Dinklage, A.; Sakamoto, R.; Motojima, G.; Yasuhara, R.; Ida, K.; Yamada, H.; LHD Experiment Group; Wendelstein 7-X Team

    2018-03-01

    Ice pellet injection is performed in the heliotron Large Helical Device (LHD). The pellets are injected in short series, with up to eight individual pellets. Parameter variations are performed for the pellet ice isotopes, the LHD magnetic configurations, the heating scenario, and some others. These experiments are performed in order to find out whether deeper fueling can be achieved with a series of pellets compared to single pellets. An increase of the fueling efficiency is expected since pre-cooling of the plasma by the first pellets within a series could aid deeper penetration of later pellets in the same series. In addition, these experiments show which boundary conditions must be fulfilled to optimize the technique. The high-field side injection of pellets, as proposed for deep fueling in a tokamak, will not be feasible with the same efficiency in a stellarator or heliotron because there the magnetic field gradient is smaller than in a tokamak of comparable size. Hence, too shallow pellet fueling, in particular in a large device or a fusion reactor, will be an issue that can be overcome only by extremely high pellet velocities, or other techniques that will have to be developed in the future. It turned out by our investigations that the fueling efficiency can be enhanced by the injection of a series of pellets to some extent. However, further investigations will be needed in order to optimize this approach for deep particle fueling.

  3. Centrifuge pellet injector for JET

    International Nuclear Information System (INIS)

    Andelfinger, C.; Buchelt, E.; Jacobi, D.; Lackner, E.; Schilling, H.B.; Ulrich, M.; Weber, G.

    1983-08-01

    An engineering design of a centrifuge pellet injector for JET is reported as part of the Phase I contract number JE 2/9016. A rather detailed design is presented for the mechanical and electronic features. Stress calculations, dynamic behaviour and life estimates are considered. The interfaces to the JET vacuum system and CODAS are discussed. Proposals for the pellet diagnostics (velocity, mass and shape) are presented. (orig.)

  4. Investigation of pellet acceleration by an arc heated gas gun

    International Nuclear Information System (INIS)

    Andersen, P.; Andersen, S.A.; Bundgaard, J.; Baekmark, L.; Hansen, B.H.; Jensen, V.O.; Kossek, H.; Michelsen, P.K.; Nordskov, A.; Sass, B.; Soerensen, H.; Weisberg, K.V.

    1987-06-01

    This report describes work on pellet acceleration by means of an arc heated gas gun. The work is a continuation of the work described in RISO-M-2536. The aim of the work is to obtain velocities well above 2 km/s for 3.2 mm diameter deuterium pellets. By means of a cryogenic arc chamber in which the hydrogen propellant is pre-condensed, extruded deutetrium pellets are accelerated up to a maximum velocity of 1.93 km/s. When increasing the energy input to the arc in order to increase the pellet velocity further the heat input to the extrusion/punching pellet loading mechanism was found to be critical: preparation of pellets became difficult and cooling times between shots became inconveniently long. In order to circumvent this problems the concept of a room temperature hydrogen propellant pellet fed arc chamber was proposed. Preliminary results from acceleration of polyurethane pellets with this arc chamber are described as well as the work of developing of feed pellet guns for this chamber. Finally the report describes design consideration for a high pressure propellant pellet fed arc chamber together with preliminary results obtained with a proto-type arc chamber. (author)

  5. Global Wood Pellet Industry and Trade Study 2017

    NARCIS (Netherlands)

    Thrän, D.; Peetz, D.; Schaubach, K.; Mai-Moulin, T.; Junginger, H.M.; Lamers, P.; Visser, L.

    2017-01-01

    The report Global Wood Pellet Industry Market published in 2011 has always been the most downloaded document of IEA Bioenergy Task 40. We have decided to update the report and bring new insights on market trends and trade of the global wood pellets. The global wood pellet market has increased

  6. Effects of legume species introduction on vegetation and soil nutrient development on abandoned croplands in a semi-arid environment on the Loess Plateau, China.

    Science.gov (United States)

    Yuan, Zi-Qiang; Yu, Kai-Liang; Epstein, Howard; Fang, Chao; Li, Jun-Ting; Liu, Qian-Qian; Liu, Xue-Wei; Gao, Wen-Juan; Li, Feng-Min

    2016-01-15

    Revegetation facilitated by legume species introduction has been used for soil erosion control on the Loess Plateau, China. However, it is still unclear how vegetation and soil resources develop during this restoration process, especially over the longer term. In this study, we investigated the changes of plant aboveground biomass, vegetation cover, species richness and density of all individuals, and soil total nitrogen, mineral nitrogen, total phosphorus and available phosphorus over 11 years from 2003 to 2013 in three treatments (natural revegetation, Medicago sativa L. introduction and Melilotus suaveolens L. introduction) on the semi-arid Loess Plateau. Medicago significantly increased aboveground biomass and vegetation cover, and soil total nitrogen and mineral nitrogen contents. The Medicago treatment had lower species richness and density of all individuals, lower soil moisture in the deep soil (i.e., 1.4-5m), and lower soil available phosphorus. Melilotus introduction significantly increased aboveground biomass in only the first two years, and it was not an effective approach to improve vegetation biomass and cover, and soil nutrients, especially in later stages of revegetation. Overall, our study suggests that M. sativa can be the preferred plant species for revegetation of degraded ecosystems on the Loess Plateau, although phosphorus fertilizer should be applied for the sustainability of the revegetation. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Study of the boron distribution in pea and alfalfa plants using SSNTD

    International Nuclear Information System (INIS)

    Li Jianming; Inst. for Application of Atomic Energy)" data-affiliation=" (Chinese Academy of Agricultural Sciences, Beijing, BJ (China)> Inst. for Application of Atomic Energy)" >Deng Hongmin

    1988-01-01

    The distribution of boron in pea (Pisum sativum L.) and alfalfa (Medicago sativa L.) was determined by using SSNTD. The results show that boron concentrations in leaves are highest, furthermore boron concentrations of the base leaves are higher than those of the top leaves. Among flower tissues, calyx has the highest boron concentration

  8. Prohexadione-calcium rate and timing effects on alfalfa interseeded into silage corn

    Science.gov (United States)

    Prohexadione-Ca (PHD) can enhance establishment of alfalfa (Medicago sativa, L.) interseeded into silage corn (Zea mays, L.), but optimal application rates and timing for this growth regulator are unknown. Two experiments examined how single or split applications of 0.25 to 1.0 kg a.i. ha-1 of PHD o...

  9. Preparation and characterization of a self-emulsifying pellet formulation.

    Science.gov (United States)

    Abdalla, Ahmed; Mäder, Karsten

    2007-05-01

    The purpose of the current study is to investigate the feasibility of producing solid self-emulsifying pellets using the extrusion/spheronization technique. Pellets were made from a mixture of C18 partial glycerides, Solutol HS15 and microcrystalline cellulose. Pellets with good physical properties (size, shape, friability) and self-emulsifying properties were produced. The pellets were, in contrast to pellets lacking Solutol, able to transfer a lipophilic dye and a spin probe into the aqueous media. The release kinetics and the microenvironment of the pellets during the release process were assessed using electron spin resonance (ESR) spectroscopy. The ESR results showed that the hydrophobic spin probe was localized mainly in the lipid environment all over the release time. Furthermore, the formulation was capable of accelerating the release of the drug diazepam and achieving a diazepam concentration above its saturation solubility. In conclusion, spherical pellets with low friability and self-emulsifying properties can be produced by the standard extrusion/spheronization technique. The pellets are capable of transfering lipophilic compounds into the aqueous phase and have a high potential to increase the bioavailability of lipophilic drugs.

  10. Automatic control system for uniformly paving iron ore pellets

    Science.gov (United States)

    Wang, Bowen; Qian, Xiaolong

    2014-05-01

    In iron and steelmaking industry, iron ore pellet qualities are crucial to end-product properties, manufacturing costs and waste emissions. Uniform pellet pavements on the grate machine are a fundamental prerequisite to ensure even heat-transfer and pellet induration successively influences performance of the following metallurgical processes. This article presents an automatic control system for uniformly paving green pellets on the grate, via a mechanism mainly constituted of a mechanical linkage, a swinging belt, a conveyance belt and a grate. Mechanism analysis illustrates that uniform pellet pavements demand the frontend of the swinging belt oscillate at a constant angular velocity. Subsequently, kinetic models are formulated to relate oscillatory movements of the swinging belt's frontend to rotations of a crank link driven by a motor. On basis of kinetic analysis of the pellet feeding mechanism, a cubic B-spline model is built for numerically computing discrete frequencies to be modulated during a motor rotation. Subsequently, the pellet feeding control system is presented in terms of compositional hardware and software components, and their functional relationships. Finally, pellet feeding experiments are carried out to demonstrate that the control system is effective, reliable and superior to conventional methods.

  11. The wood pellet market in Austria: A structural market model analysis

    International Nuclear Information System (INIS)

    Kristöfel, Christa; Strasser, Christoph; Schmid, Erwin; Morawetz, Ulrich B.

    2016-01-01

    EU bioenergy policies and oil price hikes have resulted in a significant increase of installed pellet boilers for residential heating. Hence, European demand for wood pellets has been growing faster and more steadily than supply leading to rising market prices in recent years. This article presents an econometric analysis of demand and supply of wood pellets in the residential heating sector in Austria, one of the most dynamic markets for residential pellets. Annual and monthly time series data between 2000 and 2014 are used in a two-stage least-squares (2SLS) regression to estimate supply and demand elasticities of wood pellets. In all model specifications, pellets demand is found to be inelastic (from −0.66 to −0.76) and pellets supply unit-elastic (from 1.03 to 1.18). Thus, consumers are highly exposed to price changes resulting from supply shocks. Policies which support investments in pellet boilers will shift the demand of wood pellets and likely leading to higher prices for consumers. - Highlights: • Characterisation of the European pellet market. • A structural market model for wood pellets in Austria. • Estimation of supply and demand price elasticities using a two-stage least-squares (2SLS) regression. • Pellets demand is found to be inelastic and pellets supply unit-elastic in the short run. • Policies stimulating demand will likely increase pellet and sawmill by-product prices.

  12. Alfalfa breeding benefits from genomics of Medicago truncatula

    Directory of Open Access Journals (Sweden)

    Žilije Bernadet

    2010-01-01

    Full Text Available International programs aim at developing knowledge and tools in the model species Medicago truncatula. Genetic resources, DNA sequences, markers, genetic and physical maps are now publicly available. These efforts contribute to improve breeding schemes of crop species such as alfalfa. However, transfer of information from M. truncatula to alfalfa is not straightforward. The article reviews the gain given by the model species to better analyze genetic determinism of breeding traits in alfalfa. It also shows that investments in alfalfa genomics (DNA sequences, SNP development are needed to benefit from the model species.

  13. Production and Innovative Applications of Cryogenic Solid Pellets

    International Nuclear Information System (INIS)

    Baylor, L.R.; Combs, S.K.; Fisher, P.W.; Foster, C.A.; Foust, C.R.; Gouge, M.J.; Milora, S.L.

    1999-01-01

    For over two decades Oak Ridge National Laboratory has been developing cryogenic pellet injectors for fueling hot, magnetic fusion plasmas. Cryogenic solid pellets of all three hydrogen isotopes have been produced in a size range of 1- to 10-mm diameter and accelerated to speeds from <100 to ∼3000 m/s. The pellets have been formed discretely by cryocondensation in gun barrels and also by extrusion of cryogenic solids at mass flow rates up to ∼0.26 g/s and production rates up to ten pellets per second. The pellets traverse the hot plasma in a fraction of a millisecond and continuously ablate, providing fresh hydrogenic fuel to the interior of the plasma. From this initial application, uses of this technology have expanded to include (1) cryogenic xenon drops or solids for use as a debris-less target in a laser plasma source of X-rays for advanced lithography systems, (2) solid argon and carbon dioxide pellets for surface cleaning or decontamination, and (3) methane pellets in a liquid hydrogen bath for use as an innovative moderator of cold neutrons. Methods of production and acceleration/transport of these cryogenic solids will be described, and examples will be given of their use in prototype systems

  14. Pellet injection in the RFP (Reversed Field Pinch)

    Science.gov (United States)

    Wurden, G. A.; Weber, P. G.; Munson, C. P.; Cayton, T. E.; Bunting, C. A.; Carolan, P. G.

    Observation of pellets injected into the ZT-40M Reversed Field Pinch has allowed a new twist on the usual tokamak ablation physics modeling. The RFP provides a strong ohmic heating regime with relatively high electron drift parameter (xi sub drift approx. 0.2), in the presence of a highly sheared magnetic field geometry. In situ photos of the pellet ablation cloud using a grated-intensified CCD camera, as well as two-view integrated photos of the pellet trajectory show substantial modification of the original pellet trajectory, in both direction and speed. Depending on the launch geometry, increases in the initial 500 m/s pellet speed by 50 percent were observed, and a ski jump deflector plate in the launch port has been used to counteract strong poloidal curvature. In contrast to the tokamak, the D sub alpha light signature is strongest near the edge, and weaker in the plasma center. Additional information on ion temperature response to pellet injection with 20 microsec time resolution has been obtained using a 5-channel neutral particle analyzer (NPA). The energy confinement is transiently degraded while the beta is largely unchanged. This may be indicative of pellet injection into a high-beta plasma operating at fixed beta.

  15. Pellet injection in the RFP [Reversed Field Pinch

    International Nuclear Information System (INIS)

    Wurden, G.A.; Weber, P.G.; Munson, C.P.; Cayton, T.E.; Bunting, C.A.; Carolan, P.G.

    1988-01-01

    Observation of pellets injected into the ZT-40M Reversed Field Pinch has allowed a new twist on the usual tokamak ablation physics modeling. The RFP provides a strong ohmic heating regime with relatively high electron drift parameter (ξ/sub drift/ /approximately/ 0.2), in the presence of a highly sheared magnetic field geometry. In situ photos of the pellet ablation cloud using a grated-intensified CCD camera, as well as two-view integrated photos of the pellet trajectory show substantial modification of the original pellet trajectory, in both direction and speed. Depending on the launch geometry, increases in the initial 500 m/s pellet speed by 50% have been observed, and a ski jump deflector plate in the launch port has been used to counteract strong poloidal curvature. In contrast to the tokamak, the D/sub α/ light signature is strongest near the edge, and weaker in the plasma center. Additional information on ion temperature response to pellet injection with 20 μsec time resolution has been obtained using a 5-channel neutral particle analyzer (NPA). The energy confinement is transiently degraded while the beta is largely unchanged. This may be indicative of pellet injection into a high-beta plasma operating at fixed beta. 10 refs., 6 figs

  16. Westinghouse Advanced Doped Pellet - Characteristics and irradiation behavior

    International Nuclear Information System (INIS)

    Backman, K.; Hallstadius, L.; Roennberg, G.

    2009-01-01

    Full text: There are a number of trends in the nuclear power industry, which put additional requirements on the operational flexibility and reliability of nuclear fuel, for example power uprates and longer cycles in order to increase production, higher burnup levels in order to reduce the backend cost of the fuel cycle, and lower goals for activity release from power plant operation. These additional requirements can be addressed by increasing the fuel density, improving the FG retention, improving the PCI resistance and improving the post-failure performance. In order to achieve that, Westinghouse has developed ADOPT (Advanced Doped Pellet Technology) UO 2 fuel containing additions of chromium and aluminium oxides. The additives facilitate pellet densification during sintering, enlarge the pellet grain size, and increase the creep rate. The final manufactured doped pellets reach about 0.5 % higher density within a shorter sintering time and a five times larger grain size compared with standard UO 2 fuel pellets. Fuel rods with ADOPT pellets have been irradiated in several light water reactors (LWRs) since 1999, including two full SVEA Optima2 reloads in 2005. ADOPT pellets has been investigated in pool-side and hot cell Post Irradiation Examinations (PIEs), as well as in a ramp test and a fuel washout test in the Studsvik R2 test reactor. The investigations have identified three areas of improved operational behaviour: Reduced Fission Gas Release (FGR), improved Pellet Cladding Interaction (PCI) performance thanks to increased pellet plasticity and higher resistance against post-failure degradation. The better FGR behaviour of ADOPT has been verified with a pool side FGR gamma measurement performed at 55 MWd/kgU, as well as transient tests in the Studsvik R2 reactor. Creep measurements performed on fresh pellets show that ADOPT has a higher creep rate which is beneficial for the PCI performance. ADOPT has also been part of a high power Halden test (IFA-677). The

  17. Tritium pellet injector for the Tokamak Fusion Test Reactor

    International Nuclear Information System (INIS)

    Gouge, M.J.; Baylor, L.R.; Combs, S.K.; Fisher, P.W.; Foust, C.R.; Milora, S.L.

    1992-01-01

    The tritium pellet injector (TPI) for the Tokamak Fusion Test Reactor (TFTR) will provide a tritium pellet fueling capability with pellet speeds in the 1- to 3-km/s range for the TFTR deuterium-tritium (D-T) plasma phase. An existing deuterium pellet injector (DPI) was modified at Oak Ridge National Laboratory (ORNL) to provide a four-shot, tritium-compatible, pipe-gun configuration with three upgraded single-stage pneumatic guns and a two-stage light gas gun driver. The TPI was designed for frozen pellets ranging in size from 3 to 4 mm in diameter in arbitrarily programmable firing sequences at tritium pellet speeds up to approximately 1.5 km/s for the three single-stage drivers and 2.5 to 3 km/s for the two-stage driver. Injector operation is controlled by a programmable logic controller (PLC). The new pipe-gun injector assembly was installed in the modified DPI guard vacuum box, and modifications were also made to the internals of the DPI vacuum injection line, including a new pellet diagnostics package. Assembly of these modified parts with existing DPI components was then completed and the TPI was tested at ORNL with deuterium pellets. Results of the testing program at ORNL are described. The TPI has been installed and operated on TFTR in support of the CY-92 deuterium plasma run period. In 1993, the tritium pellet injector will be retrofitted with a D-T fuel manifold and tritium gloveboxes and integrated into TFTR tritium processing systems to provide full tritium pellet capability

  18. Development of a two-state pellet injector for Heliotron-E

    International Nuclear Information System (INIS)

    Sudo, S.; Baba, T.; Kanno, M.; Saka, S.

    1991-01-01

    This paper reports on a two-stage pellet injector for Heliotron-E that is constructed and tested. The aim is to increase pellet velocity for more flexible density profile control of the Heliotron-E plasma and also to conduct a pellet ablation study using a wider range of pellet velocity. The pellet velocity is limited to ∼1.4 km/s in the current six-pellet injector at Heliotron-E. The fundamental operation is simulated with the Quickgun code. The experimental results generally agree well (within 80 to 90%) with the code calculations. By using a newly developed high-pressure fast valve, a hydrogen pellet velocity of 3.2 km/s has been achieved, without a supportive shell or sabot to protect the pellet, although more tests are needed to confirm whether pellets can reliably be accelerated to this high speed without fracturing. The dependence of the pellet velocity and breech pressure on the pump tube fill pressure is studied. The results show that the fill pressure is an important parameter. The effect of the clearance between the piston and the pump tube wall on the pellet velocity is also investigated. The wear and damage of the piston caused by the compressing propellant gas are investigated. It is shown that changes on the piston surface when hydrogen is used for fill gas are different from the case of helium

  19. Pellet injection and plasma behavior simulation code PEPSI

    International Nuclear Information System (INIS)

    Takase, Haruhiko; Tobita, Kenji; Nishio, Satoshi

    2003-08-01

    Fueling is one of the major issues on design of nuclear fusion reactor and the injection of solid hydrogen pellet to the core plasma is a useful method. On the design of a nuclear fusion reactor, it is necessary to determine requirements on the pellet size, the number of pellets, the injection speed and the injection cycle. PEllet injection and Plasma behavior SImulation code PEPSI has been developed to assess these parameters. PEPSI has two special features: 1) Adopting two numerical pellet models, Parks model and Strauss model, 2) Calculating fusion power and other plasma parameters in combination with a time-dependent one-dimensional transport model. This report describes the numerical models, numerical scheme, sequence of calculation, list of subroutines, list of variables and an example of calculation. (author)

  20. Assessment of genomic relationship between Oryza sativa and ...

    African Journals Online (AJOL)

    The hybrid was produced between these two species at the International Rice Research Institute using embryo rescue technique. The chromosome pairing was examined in pollen mother cells of O. australinesis, O. sativa and the hybrid between O. sativa and O. australinesis. The hybrid was highly sterile with pollen stain ...

  1. Genome-Wide Association Mapping of Loci Associated with Plant Growth and Forage Production under Salt Stress in Alfalfa (Medicago sativa L.

    Directory of Open Access Journals (Sweden)

    Xiang-Ping Liu

    2017-05-01

    Full Text Available Salinity tolerance is highly desirable to sustain alfalfa production in marginal lands that have been rendered saline. In this study, we used a diverse panel of 198 alfalfa accessions for mapping loci associated with plant growth and forage production under salt stress using genome-wide association studies (GWAS. The plants were genotyped using genotyping-by-sequencing (GBS. A greenhouse procedure was used for phenotyping four agronomic and physiological traits affected by salt stress, including dry weight (DW, plant height (PH, leaf chlorophyll content (LCC, and stomatal conductance (SC. For each trait, a stress susceptibility index (SSI was used to evaluate plant performance under stressed and non-stressed conditions. Marker-trait association identified a total of 42 markers significantly associated with salt tolerance. They were located on all chromosomes except chromosome 2 based on the alignment of their flanking sequences to the reference genome (Medicago truncatula. Of those identified, 13 were associated with multiple traits. Several loci identified in the present study were also identified in previous reports. BLAST search revealed that 19 putative candidate genes linked to 24 significant markers. Among them, B3 DNA-binding protein, Thiaminepyrophosphokinase and IQ calmodulin-binding motif protein were identified among multiple traits in the present and previous studies. With further investigation, these markers and candidates would be useful for developing markers for marker-assisted selection in breeding programs to improve alfalfa cultivars with enhanced tolerance to salt stress.

  2. Porosity influence on UO2 pellet fracture

    International Nuclear Information System (INIS)

    Quadros, N.F. de; Abreu Aires, M. de; Gentile, E.F.

    1976-01-01

    Compression tests were made with UO 2 pellets with grain size of 0,01 mm, approximately the same for all pellets, and with different porosities. The strain rate was 5,5 X 10 -5 sec -1 at room temperature. From fractographic studies and observations made during the compression tests, it was suggested that the pores and flaws resulting from sintering at 1650 0 C, play a fundamental role on the fracture mechanism of the UO 2 pellets [pt

  3. Measurement of shadowgraph of flying solid-hydrogen pellets

    International Nuclear Information System (INIS)

    Hasegawa, Kouichi; Kasai, Satoshi; Suzuki, Sadaaki; Oda, Yasushi.

    1992-11-01

    The measurement system of shadowgraphs of flying pellets for the high-speed multi-pellet injector is described. Shadowgraphs of pellets ejected repeatedly with 1-5 Hz could be taken with about 100 % probability by using the system, which is composed of a intense pulse-lamp with a video-camera and a timing control system. (author)

  4. Design of a tritium pellet injector for TFTR

    International Nuclear Information System (INIS)

    Milora, S.L.; Gouge, M.J.; Fisher, P.W.; Combs, S.K.; Cole, M.J.; Wysor, R.B.; Fehling, D.T.; Foust, C.R.; Baylor, L.R.; Schmidt, G.L.; Barnes, G.W.; Persing, R.G.

    1991-01-01

    The TFTR tritium pellet injector (TPI) is designed to provide a tritium pellet fueling capability with pellet speeds in the 1- to 3 km/s-range for the TFTR D-T phase. The existing TFTR deuterium pellet injector is being modified at Oak Ridge National Laboratory to provide a fourshot, tritium-compatible, pipe-gun configuration with three upgraded single-stage pneumatic guns a two -stage light gas gun driver. The pipe gun concept has been qualified for tritium operation by the tritium proof-of-principle injector experiments conducted on the Tritium Systems Test Assembly at Los Alamos National Laboratory. In these experiments, tritium and D-T pellets were accelerated to speeds near 1.5 km/s. The TPI is being designed for pellet sizes in the range from 3.43 to 4.0 mm in diameter in arbitrarily programmable firing sequences at speeds up to approximately 1.5 km/s for the three single-stage drivers and 2.5 to 3 km/s for the two-stage driver. Injector operation will be controlled by a programmable logic controller. 7 refs., 4 figs

  5. Radiation-induced grafting of styrene on polypropylene pellets

    International Nuclear Information System (INIS)

    Souza, Camila P.; Ferreira, Henrique P.; Parra, Duclerc F.; Lugao, Ademar B.

    2009-01-01

    The changes of radiation-induced in polypropylene (PP) pellets exposed to gamma irradiation in inert atmosphere were investigated in correlation with the applied doses (10 and 50 kGy). Also, results from the grafting of styrene onto PP pellets using simultaneous irradiation at the same doses are presented. The grafting reaction was carried out using toluene as solvent, under nitrogen atmosphere and at room temperature. The properties of the irradiated and grafted PP pellets were studied using Melt Flow Index, thermal analysis (TG and DSC), and ATR-IR. The degree of grafting (DOG) for the grafted pellets was gravimetrically determined. The results showed that radiation-induced graft polymerization on pellets were successfully obtained and the influence of dose irradiated did not change the thermal properties in spite of the increase in the MFI and consequently this increase in the viscosity results an decrease the molecular mass. The MFI for grafted pellets was not achievable because the high degree of viscosity of polymer, even arising the test temperature, the polymer was not flow enough. (author)

  6. Physics of inertial confinement pellets

    International Nuclear Information System (INIS)

    Mead, W.C.

    1979-01-01

    An overview of inertial confinement fusion pellet physics is given. A discussion is presented of current estimated ICF driver requirements and a couple of pellet examples. The physics of driver/plasma coupling for two drivers which are being considered, namely a laser driver and a heavy ion accelerator driver, is described. Progress towards inertial confinement fusion that has been made using laser drivers in target experiments to date is discussed

  7. Fuel Pellets Production from Biodiesel Waste

    Directory of Open Access Journals (Sweden)

    Kawalin Chaiyaomporn

    2010-01-01

    Full Text Available This research palm fiber and palm shell were used as raw materials to produce pelletised fuel, and waste glycerol were used as adhesive to reduce biodiesel production waste. The aim of this research is to find optimum ratio of raw material (ratio of palm fiber and palm shell, raw material size distribution, adhesive temperature, and ratio of ingredients (ratio of raw material, waste glycerol, and water. The optimum ratio of pelletized fuel made only by palm fiber was 50:10:40; palm fiber, water, and waste glycerol respectively. In the best practice condition; particle size was smaller than 2 mm, adhesive glycerol was heated. From the explained optimum ratio and ingredient, pelletizing ratio was 62.6%, specific density was 982.2 kg/m3, heating value was 22.5 MJ/kg, moisture content was 5.9194%, volatile matter was 88.2573%, fix carbon content was 1.5894%, and ash content was 4.2339% which was higher than the standard. Mixing palm shell into palm fiber raw material reduced ash content of the pellets. The optimum raw material ratio, which minimizes ash content, was 80 to 20 palm fiber and palm shell respectively. Adding palm shell reduced ash content to be 2.5247% which was higher than pelletized fuel standard but followed cubed fuel standard. At this raw material ratio, pelletizing ratio was 70.5%, specific density was 774.8 kg/m3, heating value was 19.71 MJ/kg, moisture content was 9.8137%, volatile matter was 86.2259%, fix carbon content was 1.4356%, and compressive force was 4.83 N. Pelletized fuel cost at optimum condition was 1.14 baht/kg.

  8. Decay rate of reindeer pellet-groups

    Directory of Open Access Journals (Sweden)

    Anna Skarin

    2008-06-01

    Full Text Available Counting of animal faecal pellet groups to estimate habitat use and population densities is a well known method in wildlife research. Using pellet-group counts often require knowledge about the decay rate of the faeces. The decay rate of a faecal pellet group may be different depending on e.g. substrate, size of the pellet group and species. Pellet-group decay rates has been estimated for a number of wildlife species but never before for reindeer (Rangifer tarandus. During 2001 to 2005 a field experiment estimating the decay rate of reindeer pellet groups was performed in the Swedish mountains close to Ammarnäs. In total the decay rate of 382 pellet groups in three different habitat types (alpine heath, birch forest and spruce forest was estimated. The slowest decay rate was found in alpine heath and there the pellet groups persisted for at least four years. If decay was assumed to take place only during the bare ground season, the estimated exponential decay rate was -0.027 pellet groups/week in the same habitat. In the forest, the decay was faster and the pellet groups did not persist more than two years. Performing pellet group counts to estimate habitat use in dry habitats, such as alpine heath, I will recommend using the faecal standing crop method. Using this method makes it possible to catch the animals’ general habitat use over several years. Abstract in Swedish / Sammanfattning:Nedbrytningshastighet av renspillningInom viltforskningen har spillningsinventeringar använts under flera årtionden för att uppskatta habitatval och populationstäthet hos olika djurslag. För att kunna använda data från spillningsinventeringar krävs ofta att man vet hur lång tid det tar för spillningen att brytas ner. Nedbrytningshastigheten är olika beroende på marktyp och djurslag. Nedbrytningshastighet på spillning har studerats för bland annat olika typer av hjortdjur, men det har inte studerats på ren (Rangifer tarandus tidigare. I omr

  9. Direct dissolution and supercritical fluid extraction of uranium from UO2 powder, granule, green pellet and sintered pellet

    International Nuclear Information System (INIS)

    Rao, Ankita; Kumar, Pradeep; Ramakumar, K.L.

    2009-01-01

    In the present work, direct dissolution and extraction of UO 2 from the solid rejects various stages of fuel fabrication viz. powder granules green pellet and, sintered pellet has been studied. Powder and granules could be easily dissolved in TBP-HNO 3 complex at 50 deg C., whereas in case of green and sintered pellets at elevated temperature at raised to 80 deg C in TBP-HNO 3 complex. With supercritical (SC) CO 2 alone the efficiency was ∼70%. But with SC CO 2 +2.5% TBP, the efficiency was ∼95% for powder and granules, and ∼60% for green and sintered pellets. Nearly complete extraction (∼99%) was achievable for SC CO 2 + 2.5 % TTA in all cases. The method has distinct advantage of elimination of acid usage and minimization of liquid waste generation. (author)

  10. Are owl pellets good estimators of prey abundance?

    Directory of Open Access Journals (Sweden)

    Analia Andrade

    2016-07-01

    Full Text Available Some ecologists have been skeptics about the use of owl pellets to estimate small mammal’s fauna. This is due to the assumptions required by this method: (a that owls hunt at random, and (b that pellets represent a random sample from the environment. We performed statistical analysis to test these assumptions and to assess the effectiveness of Barn owl pellets as a useful estimator of field abundances of its preys. We used samples collected in the arid Extra-Andean Patagonia along an altitudinal environmental gradient from lower Monte ecoregion to upper Patagonian steppe ecoregion, with a mid-elevation ecotone. To test if owls hunt at random, we estimated expected pellet frequency by creating a distribution of random pellets, which we compared with data using a simulated chi-square. To test if pellets represent a random sample from the environment, differences between ecoregions were evaluated by PERMANOVAs with Bray–Curtis dissimilarities. We did not find evidence that owls foraged non-randomly. Therefore, we can assume that the proportions of the small mammal’s species in the diet are representative of the proportions of the species in their communities. Only Monte is different from other ecoregions. The ecotone samples are grouped with those of Patagonian steppes. There are no real differences between localities in the small mammal’s abundances in each of these ecoregions and/or Barn owl pellets cannot detect patterns at a smaller spatial scale. Therefore, we have no evidence to invalidate the use of owl pellets at an ecoregional scale.

  11. Development of repeating pneumatic pellet injector

    Energy Technology Data Exchange (ETDEWEB)

    Oda, Y.; Onozuka, M.; Shimomura, T. (Mitsubishi Heavy Industries Ltd., Kobe (Japan)) (and others)

    1990-01-01

    A repeating pneumatic pellet injector has been constructed to experiment with the technique of continuous injection for fueling fusion reactors. This device is composed of a cryogenic extruder and a gun assembly in (among others) a high-vacuum vessel, diagnostic vessels, LHe, fuel-gas and propellant-gas supply systems, control and data acquisition systems, etc. The performance tests, using hydrogen, have proved that the device provides the function of extruding frozen hydrogen ribbons at the speed of 6 mm s{sup -1}, chambering pellet at the rate of 5 Hz, and injecting pellet at the speed of 900 m s{sup -1}, as planned. (author).

  12. Identification of the large subunit of Ribulose 1,5-bisphosphate carboxylase/oxygenase as a substrate for transglutaminase in Medicageo sativa L. (alfalfa)

    International Nuclear Information System (INIS)

    Margosiak, S.A.; Dharma, A.; Carver, M.R.B.; Gonzales, A.P.; Louie, D.; Kuehn, G.D.

    1990-01-01

    Extract prepared from floral meristematic tissue of alfalfa (Medicago sativa L.) were investigated for expression of the enzyme transglutaminase in order to identify the major protein substrate for transglutaminase-directed modifications among plant proteins. The large polymorphic subunits of ribulose 1,5-bisphosphate carboxylase/oxygenase in alfalfa, with molecular weights of 52,700 and 57,600, are major substrates for transglutaminase in these extracts. This was established by: (a) covalent conjugation of monodansylcadaverine to the large subunit followed by fluorescent detection in SDS-polyacrylamide gels; (b) covalent conjugation of [ 14 C]putrescine to the large subunit with detection by autoradiography; (c) covalent conjugation of monodansylcadaverine to the large subunit and demonstration of immunocross-reactivity on nitrocellulose transblot of the modified large subunit with antibody prepared in rabbits against dansylated-ovalbumin; (d) demonstration of a direct dependence of the rate of transglutaminase-mediated, [ 14 C]putresciene incorporation upon the concentration of ribulose, 1,5-bisphosphate carboxylase/oxygenase from alfalfa or spinach; and (e) presumptive evidence from size exclusion chromatography that transglutaminase may cofractionate with native molecules of ribulose 1,5-bisphosphate carboxylase/oxygenase in crude extracts

  13. Hot-melt extrusion of sugar-starch-pellets.

    Science.gov (United States)

    Yeung, Chi-Wah; Rein, Hubert

    2015-09-30

    Sugar-starch-pellets (syn. sugar spheres) are usually manufactured through fluidized bed granulation or wet extrusion techniques. This paper introduces hot-melt extrusion (HME) as an alternative method to manufacture sugar-starch-pellets. A twin-screw extruder coupled with a Leistritz Micro Pelletizer (LMP) cutting machine was utilized for the extrusion of different types (normal-, waxy-, and high-amlyose) of corn starch, blended with varying amounts of sucrose. Pellets were characterized for their physicochemical properties including crystallinity, particle size distribution, tensile strength, and swelling expansion. Furthermore, the influence of sugar content and humidity on the product was investigated. Both sucrose and water lowered the Tg of the starch system allowing a convenient extrusion process. Mechanical strength and swelling behavior could be associated with varying amylose and amylopectin. X-ray powder diffractometric (XRPD) peaks of increasing sucrose contents appeared above 30%. This signified the oversaturation of the extruded starch matrix system with sucrose. Otherwise, had the dissolved sucrose been embedded into the molten starch matrix, no crystalline peak could have been recognized. The replacement of starch with sucrose reduced the starch pellets' swelling effect, which resulted in less sectional expansion (SEI) and changed the surface appearance. Further, a nearly equal tensile strength could be detected for sugar spheres with more than 40% sucrose. This observation stands in good relation with the analyzed values of the commercial pellets. Both techniques (fluidized bed and HME) allowed a high yield of spherical pellets (less friability) for further layering processes. Thermal influence on the sugar-starch system is still an obstacle to be controlled. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Experimental setting for assessing mechanical strength of gas hydrate pellet

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, S.J.; Choi, J.H.; Koh, B.H. [Dongguk Univ., Phil-dong, Chung-gu, Seoul (Korea, Republic of). Dept. of Mechanical Engineering

    2008-07-01

    Due to the constant increase in global demand for clean energy, natural gas production from stranded medium and small size gas wells has drawn significant interest. Because the ocean transport of natural gas in the form of solid hydrate pellets (NGHP) has been estimated to be economically feasible, several efforts have been made to develop a total NGHP ocean transport chain. The investigation of mechanical strength of solid-form hydrate pellet has been an important task in fully exploiting the benefit of gas hydrate in the perspective of mass transportation and storage. This paper provided the results of a preliminary study regarding the assessment of mechanical properties of the gas hydrate pellet. The preliminary study suggested some of the key issues regarding formation and strength of gas hydrate pellets. Instead of utilizing the gas hydrate pellet, the study focused on a preliminary test setup for developing the ice pellet which was readily applied to the gas hydrate pellet in the future. The paper described the pelletization of ice powder as well as the experimental setup. Several photographs were illustrated, including samples of ice pellets; compression test for ice pellet using air press and load cell; and the initiation of crack in the cross section of an ice pellet. It was found that mechanical strength, especially, compression strength was not significantly affected by different level of press-forming force up to a certain level. 4 refs., 1 tab., 4 figs.

  15. Characteristics of an electron-beam rocket pellet accelerator

    International Nuclear Information System (INIS)

    Tsai, C.C.; Foster, C.A.; Schechter, D.E.

    1989-01-01

    An electron-beam rocket pellet accelerator has been designed, built, assembled, and tested as a proof-of-principle (POP) apparatus. The main goal of accelerators based on this concept is to use intense electron-beam heating and ablation of a hydrogen propellant stick to accelerate deuterium and/or tritium pellets to ultrahigh speeds (10 to 20 km/s) for plasma fueling of next-generation fusion devices such as the International Thermonuclear Engineering Reactor (ITER). The POP apparatus is described and initial results of pellet acceleration experiments are presented. Conceptual ultrahigh-speed pellet accelerators are discussed. 14 refs., 8 figs

  16. Pellet fueling development at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Foster, C.A.; Milora, S.L.; Schuresko, D.D.; Combs, S.K.; Lunsford, R.V.

    1982-01-01

    A pellet injector development program has been under way at the Oak Ridge National Laboratory (ORNL) since 1976 with the goals of developing D 2 , T 2 pellet fuel injectors capable of reliable repetitive fueling of reactors and of continued experimentation on contemporary plasma devices. The development has focused primarily on two types of injectors that show promise. One of these injectors is the centrifuge-type injector, which accelerates pellets in a high speed rotating track. The other is the gas or pneumatic gun, which accelerates pellets in a gun barrel using compressed helium of H 2 gas

  17. Standard specification for nuclear-grade aluminum oxide pellets

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This specification applies to pellets of aluminum oxide that may be ultimately used in a reactor core, for example, as filler or spacers within fuel, burnable poison, or control rods. In order to distinguish between the subject pellets and “burnable poison” pellets, it is established that the subject pellets are not intended to be used as neutron-absorbing material. 1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

  18. Geometrical dimensioning of PWR UO2 pellets

    International Nuclear Information System (INIS)

    Silva, A.T.

    1988-08-01

    The finite element structural program SAP-IV is used to calculate UO 2 pellet strains developed under thermal gradients in pressurized water reactors. The applied procedure allows to analyse the influence of various aspects of pelet geometry on cladding strains and can be utilized for the dimensioning of UO 2 pellets. Pellets purchased with flat ends, with dishes pressed into both ends, shouders, and a 45-deg edge chamfer are analysed. The analyse results are compared with experiemtnal data. (author) [pt

  19. Laser driven pellet refuelling for JET (and reactor) uses

    International Nuclear Information System (INIS)

    Spalding, I.J.

    1978-11-01

    Published estimates of pellet sizes and velocities required to refuel JET and post-JET experiments are summarized. Possible advantages and difficulties of accelerating solid, unconstrained hydrogenic (and also jacketed) pellets to these velocities using laser techniques are then discussed. An essential problem to be solved is adequate axial guidance of the pellet during its acceleration, since laser pulse durations of many sound-transit times (in the solid D 2 ) are necessary to avoid shock-heating the pellet. It is shown that Culham's multikilojoule CO 2 TROJAN laser facility is well suited to testing many of the concepts proposed. In particular it is shown that successful verification, and subsequent optimization, of such (novel) techniques would permit single shot tests of contemporary pellet ablation theories by the injection of approximately 1 mm diameter D 2 pellets at velocities 6 cm s -1 into the JET plasma. Means for scaling these techniques to repetition rates of order 10 Hz, and to the 1 cm pellet diameters possibly required in a working Tokamak reactor, are also discussed. (author)

  20. Lead shot pellets dispersed by hunters: ingested by ducks

    Energy Technology Data Exchange (ETDEWEB)

    Danell, K [Univ. of Umea, Sweden; Andersson, A; Marcstrom, V

    1977-01-01

    Many of the lead pellets shot by waterfowl hunters over shores and waters fall on the feeding grounds of ducks and geese. These pellets, picked up and ingested by the birds, can remain in the gizzard where they are eroded by mechanical and chemical action. In some cases the bird absorbs enough lead to cause lead poisoning. This report describes the incidence of ingested lead shot pellets found in 928 ducks collected in Sweden during hunting season. Pellets were found in both dabbling and diving ducks and were present in birds from six of the eight localities sampled. Usually one or two pellets were found but some ducks contained up to 62 pellets. As the incidence of ingested pellets in the present study is approximately the same as that found in North America, where the annual duck loss due to lead poisoning is estimated to be 2 to 3 percent of the population, it may be assumed that lead poisoning is a mortality factor for Swedish ducks also.

  1. Studies of hydrogen pellet acceleration with fuseless electromagnetic railgun

    International Nuclear Information System (INIS)

    Kim, K.

    1986-01-01

    A fuseless circular-bore electromagnetic railgun specifically designed for injection of high-velocity hydrogen pellets was constructed and tested. Hydrogen pellets were first accelerated to medium velocities (∼ 500 m/s) using a gas gun and then injected into the railgun. Once a pellet entered the railgun, a plasma arc was initiated by electrically breaking down the propellant gas which followed the pellet from the gas gun into the railgun. Utilizing the propulsive force of this plasma arc armature, further acceleration of the hydrogen pellet was achieved. Using a 60 cm long railgun, proof-of-principle experiments were performed on hydrogen pellets, 1.6 mm, in diameter and 2.15 mm in length, producing velocities exceeding 1.5 km/s. Encouraged by this preliminary success, more extensive studies are in progress to further improve the performance and capabilities of the current system

  2. Influence of burner form and pellet type on domestic pellet boiler performance

    Science.gov (United States)

    Rastvorov, D. V.; Osintsev, K. V.; Toropov, E. V.

    2017-10-01

    The study presents combustion and emission results obtained using two serial pellet boilers of the same heating capacity 40 kW. These boilers have been designed by producers for domestic conditions of exploitation. The principal difference between boilers was the type of the burner. The study concerns the efficiency and ecological performance difference between burners of circular and rectangular forms. The features of the combustion process in both types of burners were studied when boiler operated with different sorts of pellets. The results suggest that the burner of circular form excels the rectangular form burner. However, there is some difference of NOx emission between circular and rectangular burners.

  3. Building giant plant for pellets; Bygger gigantanlegg for pellets

    Energy Technology Data Exchange (ETDEWEB)

    Nylund, Hilde Kari

    2008-07-01

    At Averoey outside of Kristiansund, Norway, one of the biggest pellet factories in the world is going to be built. The Norwegian companies Hafslund and Moere og Romsdal Biobrensel are together making an effort in bio energy. A brief presentation of the planned plant is provided

  4. Portuguese pellets market: Analysis of the production and utilization constrains

    International Nuclear Information System (INIS)

    Monteiro, Eliseu; Mantha, Vishveshwar; Rouboa, Abel

    2012-01-01

    As opposite in Portugal, the wood pellets market is booming in Europe. In this work, possible reasons for this market behavior are foreseen according to the key indicators of biomass availability, costs and legal framework. Two major constrains are found in the Portuguese pellets market: the first one is the lack of an internal consumption, being the market based on exportations. The second one is the shortage of raw material mainly due to the competition with the biomass power plants. Therefore, the combination of the biomass power plants with pellet production plants seems to be the best option for the pellets production in the actual Portuguese scenario. The main constrains for pellets market has been to convince small-scale customers that pellets are a good alternative fuel, mainly due to the investment needed and the strong competition with natural gas. Besides some benefits in the acquisition of new equipment for renewable energy, they are insufficient to cover the huge discrepancy of the investment in pellets heating. However, pellets are already economic interesting for large utilizations. In order cover a large amount of households, additional public support is needed to cover the supplementary costs of the pellets heating systems. - Highlights: ► There is a lack of internal consumption being the pellets market based on exportation. ► The shortage of raw material is mainly due to the biomass power plants. ► Combining pellet plants with biomass power plants seems to be a wise solution. ► The tax benefits of renewable energy equipments are not enough to cover the higher investment. ► Pellets are already economic interesting for large utilizations in the Portuguese scenario.

  5. proximate and ultimate analysis of fuel pellets from oil palm residues

    African Journals Online (AJOL)

    HOD

    Keywords: Oil Palm Residues, Fuel Pellets, Proximate Analysis, Ultimate Analysis. 1. INTRODUCTION ... Pelletizing of this biomass resources into pellets is a way of ensuring a ... demand for pellets [3], and alternative feed-stocks such as palm kernel ... agro-residues, selection of the best pellets has to be made based on ...

  6. Modeling Dynamic Fracture of Cryogenic Pellets

    Energy Technology Data Exchange (ETDEWEB)

    Parks, Paul [General Atomics, San Diego, CA (United States)

    2016-06-30

    This work is part of an investigation with the long-range objective of predicting the size distribution function and velocity dispersion of shattered pellet fragments after a large cryogenic pellet impacts a solid surface at high velocity. The study is vitally important for the shattered pellet injection (SPI) technique, one of the leading technologies being implemented at ORNL for the mitigation of disruption damage on current tokamaks and ITER. The report contains three parts that are somewhat interwoven. In Part I we formulated a self-similar model for the expansion dynamics and velocity dispersion of the debris cloud following pellet impact against a thick (rigid) target plate. Also presented in Part I is an analytical fracture model that predicts the nominal or mean size of the fragments in the debris cloud and agrees well with known SPI data. The aim of Part II is to gain an understanding of the pellet fracturing process when a pellet is shattered inside a miter tube with a sharp bend. Because miter tubes have a thin stainless steel (SS) wall a permanent deformation (dishing) of the wall is produced at the site of the impact. A review of the literature indicates that most projectile impact on thin plates are those for which the target is deformed and the projectile is perfectly rigid. Such impacts result in “projectile embedding” where the projectile speed is reduced to zero during the interaction so that all the kinetic energy (KE) of the projectile goes into the energy stored in plastic deformation. Much of the literature deals with perforation of the target. The problem here is quite different; the softer pellet easily undergoes complete material failure causing only a small transfer of KE to stored energy of wall deformation. For the real miter tube, we derived a strain energy function for the wall deflection using a non-linear (plastic) stress-strain relation for 304 SS. Using a dishing profile identical to the linear Kirchkoff-Love profile (for lack

  7. Inspecting fuel pellets for nuclear reactor

    International Nuclear Information System (INIS)

    Wilks, R.S.; Sternheim, E.; Breakey, G.A.; Sturges, R.H.; Taleff, A.; Castner, R.P.

    1982-01-01

    An improved method of controlling the inspection, sorting and classifying of nuclear reactor fuel pellets, including a mechanical handling system and a computer controlled data processing system, is described. Having investigated the diameter, length, surface flaws and weights of the pellets, they are sorted accordingly and the relevant data are stored. (U.K.)

  8. Soil sulfur amendments suppress Selenium uptake by alfalfa and western wheatgrass

    Science.gov (United States)

    C. L. Mackowiak; M. C. Amacher

    2008-01-01

    Selenium (Se) is a potential soil contaminant in many parts of the world where it can pose a health risk to livestock and wildlife. Phosphate ore mining in Southeast Idaho has resulted in numerous waste rock dumps revegetated with forages to stabilize the dumps and support grazing. Alfalfa (Medicago sativa L.), smooth brome (Bromus inermis...

  9. Mycelial pellet formation by edible ascomycete filamentous fungi, Neurospora intermedia.

    Science.gov (United States)

    Nair, Ramkumar B; Lennartsson, Patrik R; Taherzadeh, Mohammad J

    2016-12-01

    Pellet formation of filamentous fungi in submerged culture is an imperative topic of fermentation research. In this study, we report for the first time the growth of filamentous ascomycete fungus, Neurospora intermedia in its mycelial pellet form. In submerged culture, the growth morphology of the fungus was successfully manipulated into growing as pellets by modifying various cultivation conditions. Factors such as pH (2.0-10.0), agitation rate (100-150 rpm), carbon source (glucose, arabinose, sucrose, and galactose), the presence of additive agents (glycerol and calcium chloride) and trace metals were investigated for their effect on the pellet formation. Of the various factors screened, uniform pellets were formed only at pH range 3.0-4.0, signifying it as the most influential factor for N. intermedia pellet formation. The average pellet size ranged from 2.38 ± 0.12 to 2.86 ± 0.38 mm. The pellet formation remained unaffected by the inoculum type used and its size showed an inverse correlation with the agitation rate of the culture. Efficient glucose utilization was observed with fungal pellets, as opposed to the freely suspended mycelium, proving its viability for fast-fermentation processes. Scale up of the pelletization process was also carried out in bench-scale airlift and bubble column reactors (4.5 L).

  10. Geographically structured genetic variation in the Medicago lupulina-Ensifer mutualism.

    Science.gov (United States)

    Harrison, Tia L; Wood, Corlett W; Heath, Katy D; Stinchcombe, John R

    2017-07-01

    Gene flow between genetically differentiated populations can maintain variation in species interactions, especially when population structure is congruent between interacting species. However, large-scale empirical comparisons of the population structure of interacting species are rare, particularly in positive interspecific interactions (mutualisms). One agriculturally and ecologically important mutualism is the partnership between legume plants and rhizobia. Through characterizing and comparing the population genomic structure of the legume Medicago lupulina and two rhizobial species (Ensifer medicae and E. meliloti), we explored the spatial scale of population differentiation between interacting partners in their introduced range in North America. We found high proportions of E. meliloti in southeastern populations and high proportions of E. medicae in northwestern populations. Medicago lupulina and the Ensifer genus showed similar patterns of spatial genetic structure (isolation by distance). However, we detected no evidence of isolation by distance or population structure within either species of bacteria. Genome-wide nucleotide diversity within each of the two Ensifer species was low, suggesting limited introduction of strains, founder events, or severe bottlenecks. Our results suggest that there is potential for geographically structured coevolution between M. lupulina and the Ensifer genus, but not between M. lupulina and either Ensifer species. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

  11. Wood pellets and work environment; Traepiller og arbejdsmiljoe

    Energy Technology Data Exchange (ETDEWEB)

    Skov, S.

    2012-07-01

    The project aim was to evaluate the working environment in the production, transport and use of wood pellets. Furthermore, obtained knowledge and guidelines should be disseminated to relevant audiences. The first aim was achieved by making dust measurements at various relevant locations and analyze the results. Several technical problems regarding the measurements occurred during the project. In general, the manual handling of pellets often is a short-term task, which limits the amount of dust that can be collected on the sampling filter. The solution to this problem could be the use of in situ monitoring equipment, however, this technic did not work well for wood dust. Dissemination is mainly done by publishing the findings and guidelines on the webpage www.fyrmedpiller.dk. The result shows that there are widespread dust problems associated with the use and handling of pellets. The result may have been expected in the wood pellet industry, which has been reluctant to support this project. Legislation on the working environment has set a threshold limit for the dust concentration in the air on max 1 mg of dust per cubic meters of air over a working day and in over shorter periods this limit may be doubled. These threshold values were exceeded in many cases. Brief overview: The production of pellets takes place in a very dusty working environment, but the specific pelletizing and bagging processes only produce limited amounts of dust. The dust problems are major in the large warehouses where the handling of the raw material for the pellets increases the dust concentration in the air to levels that by far exceeds the legal threshold values. The work is mainly carried out from the cabin of different machines e.g. loaders and bobcats. It turns out that the average dust concentration in these cabins with filters also exceeds the threshold values. The transports of wood pellets include loading, unloading and delivery of loose pellets, all situations that are critical

  12. Impacto de una intervención alimentaria con un concentrado proteico de Medicago sativa L (alfalfa, en niños pre escolares con desnutrición crónica

    Directory of Open Access Journals (Sweden)

    María Soberón

    2009-09-01

    Full Text Available Introducción: Estudios realizados a nivel preclínico han demostrado el valor biológico del concentrado proteico obtenido de Medicago sativa L, alfalfa (CPA, por lo que este producto puede ser una alternativa para reducir la desnutrición. Objetivo: Evaluar el efecto del consumo de CPA por niños preescolares con desnutrición crónica, mediante indicadores bioquímicos y hematológicos. Diseño: Estudio analítico de intervención, de tipo longitudinal y prospectivo. Institución: Centro de Investigación de Bioquímica y Nutrición, Facultad de Medicina, Universidad Nacional Mayor de San Marcos. Participantes: Niños preescolares con desnutrición crónica, provenientes de una comunidad de Pampas, Huancavelica, Perú. Intervenciones: Previo consentimiento informado de los padres, se evaluó el estado alimentario-nutricional, bioquímico y hematológico de 23 niños menores de seis años, para establecer la condición de desnutrición. Luego, se desarrolló una intervención alimentario nutricional con el CPA como complemento alimenticio, por 25 días, en niños seleccionados. Finalmente, se repitió la evaluación una vez concluido el período de intervención. Las determinaciones bioquímicas fueron hemoglobina, proteínas totales, albúmina y globulina, creatinina, transaminasas, y las hematológicas, hematocrito, recuento de reticulocitos. Se utilizó el programa Excel y t-student, a fin de obtener la inferencia en los resultados. Resultados: Para el indicador talla/edad, 84,5% de los niños padecía desnutrición crónica; respecto a calorías y nutrientes consumidos por los niños, los valores de energía estuvieron entre 563 kcal y 2 597 kcal; de proteína, 9,7 g a 78 g; de grasas, 5,1 g a 53,8 g; carbohidratos, 79,8 g a 495,1 g; calcio, entre 180,9 mg y 986 mg; y hierro, 1,9 mg y 21,5 mg. Los valores de hemoglobina, proteínas totales, globulinas, creatinina, transaminasas y hematocrito obtenidos antes y después de la ingesta de

  13. Results of hydrogen pellet injection into ISX-B

    International Nuclear Information System (INIS)

    Milora, S.L.; Foster, C.A.; Thomas, C.E.

    1980-09-01

    High speed pellet fueling experiments have been performed on the ISX-B device in a new regime characterized by large global density rise in both ohmic and neutral beam heated discharges. Hydrogen pellets of 1 mm in diameter were injected in the plasma midplane at velocities exceeding 1 km/s. In low temperature ohmic discharges, pellets penetrate beyond the magnetic axis, and in such cases a sharp decrease in ablation is observed as the pellet passes the plasma center. Density increases of approx. 300% have been observed without degrading plasma stability or confinement. Energy confinement time increases in agreement with the empirical scaling tau/sub E/ approx. n/sub e/ and central ion temperature increases as a result of improved ion-electron coupling. Laser-Thomson scattering and radiometer measurements indicate that the pellet interaction with the plasma is adiabatic. Penetration to r/a approx. 0.15 is optimal, in which case large amplitude sawtooth oscillations are observed and the density remains elevated. Gross plasma stability is dependent roughly on the amount of pellet penetration and can be correlated with the expected temporal evolution of the current density profile

  14. Emissions from small scale combustion of pelletized wood fuels

    International Nuclear Information System (INIS)

    Bachs, A.

    1998-01-01

    Combustion of wood pellets in small scale heating systems with an effect below 20 kW has increased. During the winter season 1995/96 1500 small plants for heating houses are estimated to be in operation. Stack emissions from three pellet burners and two pellet stoves have been studied at laboratory. Different pellet qualities were tested. When the fraction of fines increased also the NO x emissions increased with about 10 %. As reference fuel 8 mm pellets was used. Tests with 6 mm pellets gave, in most cases, significant lower emissions of CO and THC. Eleven stoves, burners and boilers were studied in a field test. The results show that all the plants generally have higher emissions in the field than during conditions when the plants are adjusted with a stack gas monitoring instrument. A conclusion is that it is difficult for the operator to adjust the plant without a monitoring instrument. The emissions from the tested plants give an estimation of stack gas emissions from small scale pellet plants. The difference between the 'best' and 'worst' technologies is big. The span of emissions with the best technology to the worst is given below. The interval is concerning normal combustion . During abnormal conditions the emissions are on a significant higher level: * CO 80-1 000 mg/MJ; * Tar 0,3-19 mg/MJ; * THC (as methane equivalents) 2-100 mg/MJ; * NO x 50-70 mg/W;, and * Dust emissions 20-40 mg/MJ. Emissions from pellets heating are lower than from wood combustion and the best technology is close to the emission from oil burners. Wood and pellets have the same origin but the conditions to burn them in an environmental friendly way differ. Combustion of pellets could be improved through improved control of the air and fuel ratio that will create more stable conditions for the combustion

  15. Hydrogen pellet injection into Alcator C

    International Nuclear Information System (INIS)

    Greenwald, M.

    1983-09-01

    A four-shot pneumatic pellet injector, based on an ORNL design, has been built and operated on the Alcator C tokamak at MIT. The injector fires four independently-timed frozen hydrogen pellets with velocities in the range 8 x 10 4 - 1 x 10 5 cm/sec. Each contains 6 x 10 19 particles which corresponds to = 2 x 10 14 /cm 3 . The objectives of this experiment are to study pellet fueling and penetration, particle confinement, dependence of energy confinement on density profile and fueling mode, and edge physics and recycling as a function of fueling mode. Typical pre-injection plasmas have had anti n/sub e/ = 2 - 3 x 10 14 , Bt = 80 - 100 kG, Ip = 400 - 500 kA, T/sub e/(0) = 1200 - 1500 ev. A single pellet injected into this plasma will roughly double the electron density. Record plasma densities have been obtained by multiple injections. Line average densities in excess of 8 x 10 14 have been achieved, with highly peaked profiles. Central densities of 1.5 - 2 x 10 15 have been measured

  16. Modelling of pellet-clad interaction during power ramps

    International Nuclear Information System (INIS)

    Zhou, G.; Lindback, J.E.; Schutte, H.C.; Jernkvist, L.O.; Massih, A.R.; Massih, A.R.

    2005-01-01

    A computational method to describe the pellet-clad interaction phenomenon is presented. The method accounts for the mechanical contact between fragmented pellets and the zircaloy clad, as well as for chemical reaction of fission products with zircaloy during power ramps. Possible pellet-clad contact states, soft, hard and friction, are taken into account in the computational algorithm. The clad is treated as an elastic-plastic-viscoplastic material with irradiation hardening. Iodine-induced stress corrosion cracking is described by using a fracture mechanics-based model for crack propagation. This integrated approach is used to evaluate two power ramp experiments made on boiling water reactor fuel rods in test reactors. The influence of the pellet-clad coefficient of friction on clad deformation is evaluated and discussed. Also, clad deformations, pellet-clad gap size and fission product gas release for one of the ramped rods are calculated and compared with measured data. (authors)

  17. Reuse potential of low-calcium bottom ash as aggregate through pelletization.

    Science.gov (United States)

    Geetha, S; Ramamurthy, K

    2010-01-01

    Coal combustion residues which include fly ash, bottom ash and boiler slag is one of the major pollutants as these residues require large land area for their disposal. Among these residues, utilization of bottom ash in the construction industry is very low. This paper explains the use of bottom ash through pelletization. Raw bottom ash could not be pelletized as such due to its coarseness. Though pulverized bottom ash could be pelletized, the pelletization efficiency was low, and the aggregates were too weak to withstand the handling stresses. To improve the pelletization efficiency, different clay and cementitious binders were used with bottom ash. The influence of different factors and their interaction effects were studied on the duration of pelletization process and the pelletization efficiency through fractional factorial design. Addition of binders facilitated conversion of low-calcium bottom ash into aggregates. To achieve maximum pelletization efficiency, the binder content and moisture requirements vary with type of binder. Addition of Ca(OH)(2) improved the (i) pelletization efficiency, (ii) reduced the duration of pelletization process from an average of 14-7 min, and (iii) reduced the binder dosage for a given pelletization efficiency. For aggregate with clay binders and cementitious binder, Ca(OH)(2) and binder dosage have significant effect in reducing the duration of pelletization process. 2010 Elsevier Ltd. All rights reserved.

  18. Fuel compliance model for pellet-cladding mechanical interaction

    International Nuclear Information System (INIS)

    Shah, V.N.; Carlson, E.R.

    1985-01-01

    This paper describes two aspects of fuel pellet deformation that play significant roles in determining maximum cladding hoop strains during pellet-cladding mechanical interaction: compliance of fragmented fuel pellets and influence of the pellet end-face design on the transmission of axial compressive force in the fuel stack. The latter aspect affects cladding ridge formation and explains several related observations that cannot be explained by the hourglassing model. An empirical model, called the fuel compliance model and representing the above aspects of fuel deformation, has been developed using the results from two Halden experiments and incorporated into the FRAP-T6 fuel performance code

  19. Pellet injector research and development at ORNL

    International Nuclear Information System (INIS)

    Combs, S.K.; Barber, G.C.; Baylor, L.R.

    1994-01-01

    Oak Ridge National Laboratory has been developing pellet injectors for plasma fueling experiments on magnetic confinement devices for more than 15 years. Recent major applications of the ORNL development program include (1) a tritium-compatible four-shot pneumatic injector for the Tokamak Fusion Test Reactor, (2) a centrifuge pellet injector for the Tore Supra tokamak, and most recently (3) a three-barrel repeating pneumatic injector for the DIII-D tokamak. In addition to applications, ORNL is developing advanced technologies, including high-speed pellet injectors, tritium injectors, and long-pulse pellet feed systems. The high-speed research involves a collaboration between ORNL and ENEA-Frascati in the development of a repeating two-stage light gas gun based on an extrusion-type pellet feed system. Construction of a new tritium-compatible, extruder-based repeating pneumatic injector (8-mm-diam) is complete and will replace the pipe gun in the original tritium proof-of-principle experiment. The development of a steady-state feed system in which three standard extruders operate in tandem is under way. These research and development activities are relevant to the International Thermonuclear Experimental Reactor and are briefly described in this paper

  20. Performance and emission of CI engine fuelled with camelina sativa oil

    International Nuclear Information System (INIS)

    Kruczyński, Stanisław W.

    2013-01-01

    Highlights: ► Camelina sativa as a potential source of alternative fuel. ► Neat camelina sativa oil as a fuel for CI engine. ► The engine performance and emissions of CI engine fuelled with neat camelina sativa oil. ► Comparison of rate of heat release for camelina sativa oil and diesel oil. - Abstract: The paper describes the results of the tests of CI Perkins 1104C-44 engine fuelled with camelina sativa oil. The engine was not especially calibrated for fuelling with the vegetable fuel. During the test the engine performance and emissions were analysed. For comparison the same speed characteristic was examined for standard fuelling of the engine with diesel oil. In order to understand the engine performance and emission the mass fraction burnt and the rate of heat release was calculated and compared for the same energy provided to the engine cylinder with the injected fuels. The results show that there is possible to receive relatively good engine performance for fuelling the engine with camelina sativa oil but there is a need to change the calibration parameters of the engine fuel system when the engine is fuelled with this fuel.