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Sample records for carex rostrata grown

  1. Methane emissions from Carex rostrata

    Science.gov (United States)

    Yelverton, C. A.; Varner, R. K.; Roddy, S.; Noyce, G. L.

    2013-12-01

    Peatlands, especially in northern regions, are known for their contribution to the increase of methane (CH4) in the atmosphere. Methane emissions from peatlands are strongly correlated with water table, temperature, and species composition. Sedges, in particular, are a conduit for the release of CH4 directly to the atmosphere. This study examines the impact of clipping and sealing sedges (Carex rostrata) on CH4 emissions from a temperate peatland (Sallie's Fen, Barrington, NH, USA). Measurements of CH4 fluxes, dissolved CH4, and environmental conditions were made over a six-year period. Data from 2008 to 2013 show that the presence of Carex rostrata in this peatland increases CH4 emissions. Clipped plots have both lower seasonal and annual CH4 emissions, compared to control plots. By studying the type of environment associated with C. rostrata through measurements of water-table depth, pore water characteristics, and the peat, surface, and air temperature of each surrounding location, further studies will show how these factors affect the rate at which CH4 is emitted into the atmosphere.

  2. Carbon-nitrogen interactions and biomass partitioning of Carex rostrata grown at three levels of nitrogen supply

    Energy Technology Data Exchange (ETDEWEB)

    Saarinen, T. [Helsinki Univ. (Finland). Dept. of Ecology and Systematics

    1996-12-31

    Biomass and production of vascular plants constitutes a major source of carbon input in peatlands. As rates of decomposition vary considerably with depth, the vertical distribution of biomass may substantially affect accumulation of carbon in peatlands. Therefore, allocation patterns between shoot and roots are particularly important when considering carbon balance of peatland ecosystems. The stimulatory effect of increasing atmospheric concentration of CO{sub 2} or photosynthesis may increase availability of carbon to most C3 plants. Availability of nitrogen may also alter both due to increased atmospheric deposition and changer in mineralisation rates associated with climate change. Most root-shoot partitioning models predict that allocation of biomass is dependent of the availability and uptake of carbon and nitrogen. A decrease in supply of carbon would favour allocation to shoots and a decrease in supply of nitrogen would increase allocation to roots. At a cellular level, non structural carbohydrates and free amino acids are thought to represent the biochemically available fraction of carbon and nitrogen, respectively. The aim of this work is study the long-term growth responses of Carex rostrata to changes in the availability of nitrogen. Special attention is paid to soluble sugars ant free amino acids, which may control partitioning of biomass. (10 refs.)

  3. Hybrid Origins of Carex rostrata var. borealis and C. stenolepis, Two Problematic Taxa in Carex Section Vesicariae (Cyperaceae)

    Science.gov (United States)

    M. Pedersen, A. Tiril; Nowak, Michael D.; Brysting, Anne K.; Elven, Reidar; Bjorå, Charlotte S.

    2016-01-01

    Hybridization is frequent in the large and ecologically significant genus Carex (Cyperaceae). In four important sections of the northern regions (Ceratocystis, Glareosae, Phacocystis and Vesicariae), the frequent occurrence of hybrids often renders the identification of “pure” species and hybrids difficult. In this study we address the origins and taxonomic rank of two taxa of section Vesicariae: Carex rostrata var. borealis and C. stenolepis. The origin and taxonomic status of C. stenolepis has been the subject of substantial debate over the years, whereas C. rostrata var. borealis has received very little attention in the years since its first description in the 19th century. By performing an extensive sampling of relevant taxa from a broad distribution range, and analyzing data from fifteen microsatellite loci developed specifically for our study together with pollen stainability measures, we resolve the hybrid origins of C. rostrata var. borealis and C. stenolepis and provide new insights into this taxonomically challenging group of sedges. Our results are in accordance with previous findings suggesting that C. stenolepis is a hybrid between C. vesicaria and C. saxatilis. They are also in accordance with a previous proposition that C. rostrata var. borealis is a hybrid between C. rostrata and C. rotundata, and furthermore suggest that both hybrids are the result of multiple, recent (i.e., postglacial) hybridization events. We found little evidence for successful sexual reproduction within C. rostrata var. borealis and C. stenolepis, but conclude that the common and recurrent, largely predictable occurrence of these taxa justifies accepting both hybrids as hybrid species with binomial names. There are, however, complications as to types and priority names, and we therefore choose to address these problems in a separate paper. PMID:27780239

  4. Effect of Carex rostrata on seasonal and interannual variability in peatland methane emissions

    Science.gov (United States)

    Noyce, Genevieve L.; Varner, Ruth K.; Bubier, Jill L.; Frolking, Steve

    2014-01-01

    are a large natural source of atmospheric methane (CH4), and the sedge Carex rostrata plays a critical role in the production, oxidation, and transport of CH4 in these systems. This 4 year clipping experiment examined the changes in CH4 emissions from a temperate peatland after removing all aboveground C. rostrata biomass. Methane fluxes, dissolved CH4, and environmental variables were measured during spring, summer, and fall from 2008 to 2011. Clipping and removing the C. rostrata leaves and stems caused an immediate decrease in CH4 emissions that persisted over 4 years of this study. There was a strong seasonal trend in CH4 flux, with the largest treatment effects occurring during the fall months when the sedges were senescing. As expected, there was a strong positive correlation between C. rostrata green-leaf area and CH4 flux, implying that the presence of C. rostrata increases CH4 emissions from this peatland. Large interannual variability in vegetation distribution and biomass, water table depth, and temperature was observed in this study, indicating the importance of multiyear studies for understanding the interactions among these factors to determine how they could be incorporated into biogeochemical models to predict CH4 emissions under changing environmental conditions.

  5. Determining the impact of Carex rostrata on methane cycling in a temperate fen

    Science.gov (United States)

    Noyce, G. L.; Varner, R. K.; Bubier, J. L.

    2010-12-01

    Northern peatlands hold ~30% of the world’s soil carbon and are the largest single natural source of atmospheric methane (CH4). Because this soil carbon is in close proximity to the atmosphere and much of it is permanently frozen, it is highly susceptible to a warming climate. Already, shifts in the dominant vegetation species have been observed in these regions as soils become wetter as a result of melting permafrost. Sedges grow well in saturated soils due to their aerenchymous tissues, which allow them to bring oxygen down to their roots. However, these tissues also act as a conduit of CH4 from peatland soils to the atmosphere. Positive correlations have been observed between sedge biomass and high CH4 emissions from a variety of wetland sites and thus an increase in sedge cover in a northern peatland could act as a positive feedback to climate change. We examined the effect that the sedge species Carex rostrata4 production, oxidation, and transport at Sallie’s Fen, Barrington, NH, through an ongoing vegetation removal experiment begun in June 2008. Originally, all plots were dominated by C. rostrata4 at 18 and 60 cm below the peat surface, sedge green area, water table depth, and peat and air temperature were measured once per week while sedges were actively growing (late March through September). On a daily basis, average CH4 flux from the control plots was usually higher than from the clipped plots and average summer CH4 flux for all years was larger from the control plots than from the clipped plots. Average CH4 flux in June, July, and August 2010 was 140 ± 67 mg CH4 m-2 day-1 for the control plots compared to 74 ± 20 mg CH4 m-2 day-1 for the experimental plots. We observed a strong positive correlation between C. rostrata4 flux. Incubations of the top 30 cm of peat conducted in 2010 show little difference in potential CH4 oxidation or potential CH4 production between treatments, but these results may be complicated by the particularly dry conditions

  6. Differences in carbohydrate profiles in batch culture grown planktonic and biofilm cells of Amphora rostrata Wm. Sm

    Digital Repository Service at National Institute of Oceanography (India)

    Khodse, V.B.; Bhosle, N.B.

    modes of growth, the concentration of total carbohydrates, carbohydrate fractions, neutral carbohydrates, uronic acids and amino sugars in planktonic and biofilm cells of Amphora rostrata were measured. The results showed that the distribution...

  7. A comparison between Carex arenaria L. and Carex ligerica GAY - sedges from the Arenariae group based on leaf characteristics

    OpenAIRE

    Lech Urbaniak

    2014-01-01

    The purpose of the study was to compare two taxonomically close species of sedges - Carex arenaria and Carex ligerica. The analysis was based on 6 characters of leaves. The populations studied were grown for the period of at least one year under the same conditions in a greenhouse. The results of statistical analysis indicate a distinctive character of each of the studied populations. Furthermore, the results show a higher interpopulational differentiation among C. ligerica populations.

  8. A comparison between Carex arenaria L. and Carex ligerica GAY - sedges from the Arenariae group based on leaf characteristics

    Directory of Open Access Journals (Sweden)

    Lech Urbaniak

    2014-01-01

    Full Text Available The purpose of the study was to compare two taxonomically close species of sedges - Carex arenaria and Carex ligerica. The analysis was based on 6 characters of leaves. The populations studied were grown for the period of at least one year under the same conditions in a greenhouse. The results of statistical analysis indicate a distinctive character of each of the studied populations. Furthermore, the results show a higher interpopulational differentiation among C. ligerica populations.

  9. Isolation, Characterization and Quantification of Stilbenes from Some Carex Species

    Directory of Open Access Journals (Sweden)

    Kamel Arraki

    2013-08-01

    Full Text Available Plants of the Carex genus (Family: Cyperaceae have attracted recent attention as potential food additives due to their high levels of potential bioactive compounds. In this study, the stilbene contents of five unexplored Carex species were investigated: Carex capillacea, Carex hirta, Carex buchananii, Carex cuprina, Carex glauca. High-performance liquid chromatography coupled to mass spectrometry (HPLC–MS and NMR spectroscopy (NMR were used to identify the structures. A novel stilbene oligomer, carexinol A, was isolated together with five previously known stilbenes: resveratrol-diglucoside, miyabenol A and C, kobophenol A and α-viniferin. Furthermore, this is the first report of resveratrol diglucoside in Carex genus.

  10. Vlozegge (Carex pulicaris L.) in Nederlandse duingebieden

    NARCIS (Netherlands)

    Weeda, E.J.

    1989-01-01

    In the Netherlands as well as in adjacent countries Carex pulicaris is a strongly declining species. It is mainly known as an inhabitant of little or not manured fen-meadows (Junco-Molinion). Besides there are a limited number of localities of C. pulicaris in the dunes, and in one of these (on the W

  11. Mycorrhizal status of the genus Carex (Cyperaceae).

    Energy Technology Data Exchange (ETDEWEB)

    Miller, R. M.; Smith, C. I.; Jastrow, J. D.; Bever, J. D.; Environmental Research; Univ. of Chicago

    1999-01-01

    The Cyperaccae have generally been considered nonmycorrhizal, although recent evidence suggests that mycotrophy may be considerably more widespread among sedges than was previously realized. This study surveyed 23 species of Carex occurring in upland and wetland habitats in northeastern Illinois. Mycorrhizal infection by arbuscular fungi was found in the roots of 16 species of Carex and appears to occur in response to many factors, both environmental and phylogenetic. While some species appear to be obligately nonmycorrhizal, edaphic influences may be responsible for infection in others. In five of the seven Carex species that were nonmycorrrhizal, a novel root character, the presence of bulbous-based root hairs, was identified. The taxonomically patchy distribution of the distinctive root hair trait suggests that these structures may have evolved several times within the genus. Evidence of multiple independent origins of the root hair trait lends support to the hypothesis that root hairs represent an adaptation to nonmycotrophy. Although taxonomic position does seem to be of importance in determining the mycorrhizal dependence of sedges, the pattern may be a patchwork of both mycorrhizal clades and clades that have adapted to the nonmycorrhizal state.

  12. Final Critical Habitat for the Navajo sedge (Carex specuicola)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — To provide the user with a general idea of areas where final critical habitat for Navajo sedge (Carex specuicola) occur based on the description provided in the...

  13. Variability characteristics and comparison of Carex arenaria L. and Carex ligerica Gay populations based on rhizome characters

    OpenAIRE

    Lech Urbaniak

    2014-01-01

    The studies included 9 populations of Carex arenaria L. and 7 populations of Carex ligerica Gay, compared with each other on grounds of variability analysis, related to rhizome characters. The sedges reach in the area of Poland their eastern range limits, with isolated populations spread along the range margins. The studied plants were placed in a greenhouse in homogenous conditions,which made possible an analysis of genetic variability in the populations. The obtained results point to the ab...

  14. Kinematics and hydrodynamics of linear acceleration in eels, Anguilla rostrata.

    Science.gov (United States)

    Tytell, Eric D

    2004-12-22

    The kinematics and hydrodynamics of routine linear accelerations were studied in American eels, Anguilla rostrata, using high-speed video and particle image velocimetry. Eels were examined both during steady swimming at speeds from 0.6 to 1.9 body lengths (L) per second and during accelerations from -1.4 to 1.3 L s(-2). Multiple regression of the acceleration and steady swimming speed on the body kinematics suggests that eels primarily change their tail-tip velocity during acceleration. By contrast, the best predictor of steady swimming speed is body wave speed, keeping tail-tip velocity an approximately constant fraction of the swimming velocity. Thus, during steady swimming, Strouhal number does not vary with speed, remaining close to 0.32, but during acceleration, it deviates from the steady value. The kinematic changes during acceleration are indicated hydrodynamically by axial fluid momentum in the wake. During steady swimming, the wake consists of lateral jets of fluid and has minimal net axial momentum, which reflects a balance between thrust and drag. During acceleration, those jets rotate to point downstream, adding axial momentum to the fluid. The amount of added momentum correlates with the acceleration, but is greater than the necessary inertial force by 2.8+/-0.6 times, indicating a substantial acceleration reaction.

  15. 76 FR 11086 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Carex lutea

    Science.gov (United States)

    2011-03-01

    ...; Designation of Critical Habitat for Carex lutea (Golden Sedge) AGENCY: Fish and Wildlife Service, Interior... for the Carex lutea (golden sedge) under the Endangered Species Act of 1973, as amended. In total... critical habitat for Carex lutea under the Act (16 U.S.C. 1531 et seq.). For more information on...

  16. 75 FR 11080 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Carex lutea

    Science.gov (United States)

    2010-03-10

    ... Critical Habitat for Carex lutea (Golden Sedge) AGENCY: Fish and Wildlife Service, Interior. ACTION... the Carex lutea (golden sedge) under the Endangered Species Act of 1973, as amended. We propose to...). Carex lutea is a perennial member of the sedge family (Cyperaceae). Fertile culms (stems) may reach...

  17. 75 FR 45592 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Carex lutea

    Science.gov (United States)

    2010-08-03

    ...; Designation of Critical Habitat for Carex lutea (Golden Sedge) AGENCY: Fish and Wildlife Service, Interior...), proposed rule to designate critical habitat for Carex lutea (golden sedge) under the Endangered Species Act... field surveys at two extant Carex lutea subpopulations indicate that the extent of the golden sedge...

  18. Human movement training with a cable driven ARm EXoskeleton (CAREX).

    Science.gov (United States)

    Mao, Ying; Jin, Xin; Gera Dutta, Geetanjali; Scholz, John P; Agrawal, Sunil K

    2015-01-01

    In recent years, the authors have proposed lightweight exoskeleton designs for upper arm rehabilitation using multi-stage cable-driven parallel mechanism. Previously, the authors have demonstrated via experiments that it is possible to apply "assist-as-needed" forces in all directions at the end-effector with such an exoskeleton acting on an anthropomorphic machine arm. A human-exoskeleton interface was also presented to show the feasibility of CAREX on human subjects. The goals of this paper are to 1) further address issues when CAREX is mounted on human subjects, e.g., generation of continuous cable tension trajectories 2) demonstrate the feasibility and effectiveness of CAREX on movement training of healthy human subjects and a stroke patient. In this research, CAREX is rigidly attached to an arm orthosis worn by human subjects. The cable routing points are optimized to achieve a relatively large "tensioned" static workspace. A new cable tension planner based on quadratic programming is used to generate continuous cable tension trajectory for smooth motion. Experiments were carried out on eight healthy subjects. The experimental results show that CAREX can help the subjects move closer to a prescribed circular path using the force fields generated by the exoskeleton. The subjects also adapt to the path shortly after training. CAREX was also evaluated on a stroke patient to test the feasibility of its use on patients with neural impairment. The results show that the patient was able to move closer to a prescribed straight line path with the "assist-as-needed" force field.

  19. Variability characteristics and comparison of Carex arenaria L. and Carex ligerica Gay populations based on rhizome characters

    Directory of Open Access Journals (Sweden)

    Lech Urbaniak

    2014-01-01

    Full Text Available The studies included 9 populations of Carex arenaria L. and 7 populations of Carex ligerica Gay, compared with each other on grounds of variability analysis, related to rhizome characters. The sedges reach in the area of Poland their eastern range limits, with isolated populations spread along the range margins. The studied plants were placed in a greenhouse in homogenous conditions,which made possible an analysis of genetic variability in the populations. The obtained results point to the absence of gene flow between the studied species and, thus, to their clearly distinct character. Genetic drift was postulated as one of the causes of the obtained variability pattern.

  20. Plant DNA barcodes and species resolution in sedges (Carex, Cyperaceae).

    Science.gov (United States)

    Starr, Julian R; Naczi, Robert F C; Chouinard, Brianna N

    2009-05-01

    We investigate the species discriminatory power of a subset of the proposed plant barcoding loci (matK, rbcL, rpoC1, rpoB, trnH-psbA) in Carex, a cosmopolitan genus that represents one of the three largest plant genera on earth (c. 2000 species). To assess the ability of barcoding loci to resolve Carex species, we focused our sampling on three of the taxonomically best-known groups in the genus, sections Deweyanae (6/8 species sampled), Griseae (18/21 species sampled), and Phyllostachyae (10/10 species sampled). Each group represents one of three major phylogenetic lineages previously identified in Carex and its tribe Cariceae, thus permitting us to evaluate the potential of DNA barcodes to broadly identify species across the tribe and to differentiate closely related sister species. Unlike some previous studies that have suggested that plant barcoding could achieve species identification rates around 90%, our results suggest that no single locus or multilocus barcode examined will resolve much greater than 60% of Carex species. In fact, no multilocus combination can significantly increase the resolution and statistical support (i.e., ≥ 70% bootstrap) for species than matK alone, even combinations involving the second most variable region, trnH-psbA. Results suggest that a matK barcode could help with species discovery as 47% of Carex taxa recently named or resolved within cryptic complexes in the past 25 years also formed unique species clusters in upgma trees. Comparisons between the nrDNA internal transcribed spacer region (ITS) and matK in sect. Phyllostachyae suggest that matK not only discriminates more species (50-60% vs. 25%), but it provides more resolved phylogenies than ITS. Given the low levels of species resolution in rpoC1 and rpoB (0-13%), and difficulties with polymerase chain reaction amplification and DNA sequencing in rbcL and trnH-psbA (alignment included), we strongly advocate that matK should be part of a universal plant barcoding system

  1. Donor life stage influences juvenile American eel Anguilla rostrata attraction to conspecific chemical cues

    Science.gov (United States)

    Galbraith, Heather S.; Blakeslee, Carrie J.; Schmucker, Andrew K.; Johnson, Nicholas; Hansen, Michael J.; Li, Weiming

    2017-01-01

    The present study investigated the potential role of conspecific chemical cues in inland juvenile American eel Anguilla rostrata migrations by assessing glass eel and 1 year old elver affinities to elver washings, and elver affinity to adult yellow eel washings. In two-choice maze assays, glass eels were attracted to elver washings, but elvers were neither attracted to nor repulsed by multiple concentrations of elver washings or to yellow eel washings. These results suggest that A. rostrata responses to chemical cues may be life-stage dependent and that glass eels moving inland may use the odour of the previous year class as information to guide migration. The role of chemical cues and olfaction in eel migrations warrants further investigation as a potential restoration tool.

  2. Characterization of the Sesbania rostrata Phytochelatin Synthase Gene: Alternative Splicing and Function of Four Isoforms

    Directory of Open Access Journals (Sweden)

    Zeng-Fu Xu

    2009-07-01

    Full Text Available Phytochelatins (PCs play an important role in detoxification of heavy metals in plants. PCs are synthesized from glutathione by phytochelatin synthase (PCS, a dipeptidyltransferase. Sesbania rostrata is a tropical legume plant that can tolerate high concentrations of Cd and Zn. In this study, the S. rostrata PCS gene (SrPCS and cDNAs were isolated and characterized. Southern blot and sequence analysis revealed that a single copy of the SrPCS gene occurs in the S. rostrata genome, and produces four different SrPCS mRNAs and proteins, SrPCS1-SrPCS4, by alternative splicing of the SrPCS pre-mRNA. The SrPCS1 and SrPCS3 proteins conferred Cd tolerance when expressed in yeast cells, whereas the SrPCS2 and SrPCS4 proteins, which lack the catalytic triad and the N-terminal domains, did not. These results suggested that SrPCS1 and SrPCS3 have potential applications in genetic engineering of plants for enhancing heavy metal tolerance and phytoremediation of contaminated soils.

  3. AGE STRUCTURES OF MODULES OF CLONAL PEATLAND SEDGE Carex middendorffii

    Institute of Scientific and Technical Information of China (English)

    BU Zhao-jun; YANG Yun-fei; H(a)kan RYDIN; LANG Hui-qing

    2005-01-01

    Age structure of a plant population carries important information on population dynamics. The traditional age classification of individuals by development phases could not explain the generation relationship neither between individuals nor between modules, and it could not accurately predict the future of population or the tendency of peatland evolution. In a peatland of the Xiao Hinggan Mountains, China, at the middle of the growth season,the age structures of 3 modules, ramets, active buds and rhizomes of a Carex middendo(fii clonal population were investigated, with the method of classifying age classes of ramets and active buds by counting generation quantity of tiller nodes, and classifying age classes of rhizomes by their real survival time. The quantity of vegetative ramets was dominant. Tiller nodes oframets can propagate vegetatively for a maximum of 3 generations. The population of ramets consisted of 3 age classes of ramets at the middle of the growth season, and showed a stable age structure. In the two sampling events, there was no significant difference between quantities and age structure of the population.The maximum age of an excavated rhizome was 12 years old. Rhizomes were classified in 8 age classes, and age classes 4-6 contributed most to the total biomass. There was no significant difference in total length and total biomass per unit area, or in biomass per unit length in rhizomes between the two samplings. Four age classes of active buds were recognized, and their number increased from July to August. The Carex middendorffii clonal population achieved regeneration by budding from the tiller nodes of ramets. The age structures of the 3 modules suggested that the Carex middendorffii clonal population could persist in the early development phase of the oligotrophic peatland in the Xiao Hinggan Mountains, but it could not be dominant. It also faces the risk to disappear from the community as the peatland develops further.

  4. Sesbania Rostrata as alternative nutrient source for the rice crop La Sesbania Rostrata como fuente alternativa de nutrientes en el cultivo del arroz A Sesbania Rostrata como fonte alternativa de nutrientes para a cultura do de arroz

    Directory of Open Access Journals (Sweden)

    Olegario Muñiz Ugarte

    2012-11-01

    Full Text Available This study evaluated the effect of using the green manure Sesbania rostrata as a preceding crop on the agricultural yield of rice. The rice was cultivated with two levels of mineral fertilizers (50 and 100% of the economical optimum level of N-P-K. Additionally, the contribution to the nitrogen nutrition of rice from the green manure previously incorporated into the soil was studied in pots using 15N stable isotope analysis. The results indicated that the Sesbania rostrata incorporation allowed the paddy rice yield to increase by at least 1 Mg ha-1 and to save 50% of the mineral fertilization employed, during two consecutive harvests. The 15N isotope analysis showed that although the N accumulation by the crop was significantly stimulated, the green manure N did not contribute directly to the growth of the rice plants, at least during their first cycle. Nevertheless, it is expected that in the medium term, the organic N derived from this green manure would restore the soil mineralized N extracted by the rice crop, thereby balancing the N losses in the system and even improving the soil nitrogen fertility.En este trabajo se evalúa el efecto del abono verde Sesbania rostrata como cultivo precedente sobre el rendimiento agrícola del arroz, cultivado con dos dosis de fertilizantes minerales (50 y 100% de la dosis N-P-K óptima económica. Adicionalmente, se estudió la contribución del abono verde previamente incorporado al suelo a la nutrición nitrogenada del arroz en macetas y empleando el isótopo 15N. Los resultados obtenidos indicaron que la incorporación de la Sesbania rostrata posibilita el incremento del rendimiento agrícola de arroz cáscara en al menos 1 Mg ha-1 y el ahorro del 50% de la fertilización mineral empleada durante dos cosechas consecutivas. Los análisis de 15N mostraron que el abono verde no contribuyó directamente con N al crecimiento de las plantas de arroz, al menos en su primer ciclo, aunque estimul

  5. Primary structure and promoter analysis of leghemoglobin genes of the stem-nodulated tropical legume Sesbania rostrata: conserved coding sequences, cis-elements and trans-acting factors

    DEFF Research Database (Denmark)

    Metz, B A; Welters, P; Hoffmann, H J;

    1988-01-01

    The primary structure of a leghemoglobin (lb) gene from the stem-nodulated, tropical legume Sesbania rostrata and two lb gene promoter regions was analysed. The S. rostrata lb gene structure and Lb amino acid composition were found to be highly conserved with previously described lb genes and Lb...

  6. Tropidia rostrata (Diptera, Syrphidae, First Recorded Genus and Species in Korea

    Directory of Open Access Journals (Sweden)

    Suk, Sang-Wook

    2014-07-01

    Full Text Available We discovered a syrphid species, Tropidia rostrata Shiraki, 1930, for the first time in Korea. This is the first member of the genus Tropidia recorded in Korea. This species can be distinguished from other Palaearctic members of Tropidia by the combination of the following characteristics: lower facial margin strongly protrudes forward; apical 3/4 of hind femur black; and tergites 2 and 3 each with a pair large yellowish brown square spots (not reached hind margin. We here provide a detailed redescription supplemented by the color photographs of external structures including genitalia. We also discussed the status of primary types associated with this taxon.

  7. Nonuniform processes of chromosome evolution in sedges (Carex: Cyperaceae).

    Science.gov (United States)

    Hipp, Andrew L

    2007-09-01

    Holocentric chromosomes-chromosomes that lack localized centromeres-occur in numerous unrelated clades of insects, flatworms, and angiosperms. Chromosome number changes in such organisms often result from fission and fusion events rather than polyploidy. In this study, I test the hypothesis that chromosome number evolves according to a uniform process in Carex section Ovales (Cyperaceae), the largest New World section of an angiosperm genus renowned for its chromosomal variability and species richness. I evaluate alternative models of chromosome evolution that allow for shifts in both stochastic and deterministic evolutionary processes and that quantify the rate of evolution and heritability/phylogenetic dependence of chromosome number. Estimates of Ornstein-Uhlenbeck model parameters and tree-scaling parameters in a generalized least squares framework demonstrate that (1) chromosome numbers evolve rapidly toward clade-specific stationary distributions that cannot be explained by constant variance (Brownian motion) evolutionary models, (2) chromosome evolution in the section is rapid and exhibits little phylogenetic inertia, and (3) explaining the phylogenetic pattern of chromosome numbers in the section entails inferring a shift in evolutionary dynamics at the root of a derived clade. The finding that chromosome evolution is not a uniform process in sedges provides a novel example of karyotypic orthoselection in an organism with holocentric chromosomes.

  8. Plasticity of nitrogen allocation in the leaves of the invasive wetland grass, Phalaris arundinacea and co-occurring Carex species determines the photosynthetic sensitivity to nitrogen availability.

    Science.gov (United States)

    Holaday, A Scott; Schwilk, Dylan W; Waring, Elizabeth F; Guvvala, Hasitha; Griffin, Chelsea M; Lewis, O Milo

    2015-04-01

    Phalaris arundinacea displaces the slower-growing, native sedge, Carex stricta, where nitrogen availability is high. Our aim was to address whether morphological and physiological traits associated with carbon gain for P. arundinacea and C. stricta responded to nitrogen supply differently and if the species exhibited different degrees of plasticity in these traits. The plants were grown in gravel and provided modified Hoagland's solution containing four nitrogen concentrations from 0.15 to 15 mM for 6 to 7 weeks. Supplied nitrogen affected the leaf nitrogen content to the same degree for both species. Increasing supplied nitrogen strongly increased CO2 assimilation (A), photosynthetic nitrogen use efficiency (PNUE), and respiration for P. arundinacea but had only a small effect on these parameters for C. stricta. Relative to growth at 15 mM nitrogen, growth at 0.15 mM for young leaves decreased carboxylation capacity and efficiency and the capacity for electron transport for P. arundinacea and a larger, stouter Carex species, Carex lacustris, by 53 to 70% but only 20 to 24% for C. stricta. Leaf nitrogen decreased approximately 50% for all species, but vacuolar nitrate did not decrease for P. arundinacea and C. stricta, suggesting that it does not serve as a nitrogen reserve for use during nitrogen deprivation in these species. After 4 months of nitrogen deprivation, P. arundinacea doubled A in 12 days after being supplied 15 mM nitrogen, whereas A for C. stricta increased only 22%. We propose that one factor linking P. arundinacea abundance to nitrogen availability involves this species' plastic response of carbon gain to nitrogen supply. C. stricta appears to be adapted to tolerate low nitrogen availability but cannot respond as rapidly and extensively as P. arundinacea when nitrogen supply is high.

  9. Genetic structure in populations of an ancient woodland sedge, carex sylvatica Hudson, at a regional and local scale.

    NARCIS (Netherlands)

    Arens, P.F.P.; Bijlsma, R.J.; Westende, van 't W.P.C.; Os, van B.; Smulders, M.J.M.; Vosman, B.J.

    2005-01-01

    Wood sedge (Carex sylvatica) is a well-known ancient woodland species with a long-term persistent seed bank and a caespitose growth habit. All thirteen isolated Carex sylvatica populations in the Dutch Rhine floodplain (including the river branches Waal and IJssel) were mapped in detail and analysed

  10. Disjunct performance and distribution in the sedge Carex prasina.

    Science.gov (United States)

    Flinn, Kathryn M; Waterway, Marcia J; Lechowicz, Martin J

    2010-05-01

    Efforts to understand species distributions and predict responses to environmental changes depend on specifying how the abiotic environment determines distributions. At landscape scales, it is critical to distinguish effects of environmental factors from other mechanisms such as competition and dispersal limitation. We examined how environmental factors affect the distribution and performance of the sedge Carex prasina across a 10-km(2) old-growth forest in southern Québec. We isolated the effects of soil characteristics by conducting a greenhouse experiment that assessed the performance of C. prasina on soils from a range of wetland habitats where it could potentially occur. This allowed us to compare how the species' performance and its distribution across the landscape relate to the same soil characteristics. In the experiment, the biomass and leaf chlorophyll content of C. prasina increased with increasing soil organic matter (OM). Across the landscape, however, the species' probability of occurrence and abundance decreased with increasing soil OM. C. prasina had similar biomass on soils from sites where it did and did not occur, but it had higher leaf chlorophyll content on soils from sites where it did not occur. We found no evidence that differential performance across environments determines the distribution of this species, as C. prasina tended to occur on soils where it showed reduced performance. Rather, other processes such as competition or dispersal limitation likely override any direct effects of the soil environment on distribution. Our results caution against the common assumption that the environments where a species tends to occur or be most abundant are the environments where it performs best. C. prasina presents a clear example of a species whose performance, at least along edaphic gradients, cannot explain its distribution. This example highlights the importance of distinguishing the relative roles of biotic and abiotic factors that shape

  11. Een nieuwe vindplaats van de Vroege zegge (Carex praecox Schreber) langs het Twentekanaal

    NARCIS (Netherlands)

    Boedeltje, G.

    1994-01-01

    In the Netherlands Carex praecox is a very rare and endangered species. Along the Twentekanaal, near the river IJssel in the province of Gelderland, a new pocket of this species was found. Here it grows at a southern slope of a sandy-clayey dike in an open grassland community.

  12. INFLUENCE OF ROOT OXYGEN DEFICIENCY ON PHOTOSYNTHESIS AND SACCHARIDE CONTENTS OF CAREX SPECIES

    NARCIS (Netherlands)

    MOOG, PR; BRUGGEMANN, W

    1993-01-01

    The responses to root oxygen deficiency concerning the photosynthesis, saccharide contents and mineral uptake have been investigated in Carex species, which were different in their anoxia-tolerance. The net rate of photosynthesis (P-N) of the anoxia-sensitive C. extensa was not affected by root anae

  13. Measurement and Analysis of Formation Conditions of Dew in Carex lasiocarpa Marsh

    Institute of Scientific and Technical Information of China (English)

    XU Ying-ying; YAN Bai-xing; GUO Yue-dong

    2009-01-01

    In order to investigate the dew amounts and analysis formation conditions of dew by examining the correlations between dew amounts and meteorological factors in Carex lasiocarpa marsh in the Sanjiang Plain, the dew amounts and several meteorological factors were monitored during the growing season from June to September in 2005 and 2008 at the Sanjiang Mire Wetland Experimental Station, Chinese Academy of Sciences. Dew was collected by woodstick made by poplar tree in Carex lasiocarpa marsh and the amounts were estimated by subtraction method. The results indicated that average daily accumulated dew amounts reached the peak in August. The highest dew amounts in Carex lasiocarpa marsh were 0.201 mm/d, and the most frequent dew volume ranged from 0.08 mm/d to 0.14 mm/d. The amounts correlated positively with relative humidity, dew point temperature, and water vapor pressure. Whereas it correlated negatively with wind speed. The dew production in Carex lasiocarpa marsh more frequently occurred under the conditions of wind speed around 2.0 m/s, the water vapor pressure above 9 hPa; the relative humidity between 90% and 95% and dew point temperature above 6 ℃.

  14. Parvilucifera rostrata sp. nov. (Perkinsozoa), a novel parasitoid that infects planktonic dinoflagellates.

    Science.gov (United States)

    Lepelletier, Frédéric; Karpov, Sergey A; Le Panse, Sophie; Bigeard, Estelle; Skovgaard, Alf; Jeanthon, Christian; Guillou, Laure

    2014-01-01

    The diversity and ecological roles of protists in marine plankton are still poorly known. In 2011, we made a substantial effort to isolate parasites into cultures during the course of blooms of the toxic microalga Alexandrium minutum (Dinophyceae) in two estuaries (the Penzé and the Rance, Brittany coast, north-west of France). In total, 99 parasitic strains were obtained. Screening of ribosomal internal transcribed spacer regions (including ITS1, 5.8S and ITS2) revealed the existence of two ribotypes. Small subunit and partial large subunit rRNA genes revealed that these two ribotypes belong to different species of the genus Parvilucifera. The first ribotype was tentatively affiliated to the species Parvilucifera infectans, whilst the second represents a new species, Parvilucifera rostrata sp. nov. The new species has several distinct morphological features in the general organization of its zoospore and in the shape and size of processes covering the sporangium. Both Parvilucifera species are generalist parasitoids with similar generation times, and this study thus raises the question of how two parasitoids exploiting similar ecological resources and infection strategies can coexist in the same ecosystem. Taxonomic relationships between Parvilucifera spp. and other closely related marine parasitoids, such as syndinians, are discussed.

  15. Sichere Nachweise der längst ausgestorbenen Seggen Carex loliacea, C. heleonastes, C. buxbaumii und C. hartmanii im westlichen Niedersachsen : Herrn Prof. Dr. Dr. Heinrich E. Weber zum 65. Geburtstag gewidmet

    OpenAIRE

    Garve, Eckhard; Kiffe, Karl

    2012-01-01

    Alten Literaturangaben aus der "Chloris Hanoverana" (Meyer 1836) und der "Flora Hanoverana Excursoria" (Meyer 1849) über das Vorkommen der boreal verbreiteten Seggen Carex loliacea, Carex heleonastes und Carex buxbaumii im westlichen Niedersachsen wurde nachgegangen. Alle drei Arten konnten anhand von Herbarbelegen bestätigt werden und sind damit erstmals sicher für Niedersachsen nachgewiesen. Carex loliacea ist sogar neu für ganz Deutschland. Zusätzlich wurde ein alter Herbarbeleg von Carex ...

  16. Efeito da sacarose, cinetina, isopentenil adenina e zeatina no desenvolvimento de embriões de Heliconia rostrata in vitro.

    OpenAIRE

    Torres,Antonio Carlos; Duval,Fernanda D.; Dalva G. Ribeiro; Barros,Ana Flavia F.; Aragão, Fernando A.D.

    2005-01-01

    Embriões provenientes de frutos maturos de Heliconia rostrata Ruiz & Pavon foram excisados e inoculados em meio de cultura contendo os sais básicos MS, vitaminas e sacarose. A adição de sacarose foi essencial para o desenvolvimento dos embriões. Em meio desprovido de sacarose os embriões morreram em cultura. Concentrações de 1%, 2% e 3% (p/v) de sacarose favoreceram o desenvolvimento dos embriões. Concentrações de 6%, 9% e 12% (p/v) de sacarose inibiram o crescimento dos embriões. A adiçã...

  17. Paralytic shellfish poisoning toxins accumulation in purple clam Hiatula rostrata and toxic effect on milkfish Chanos chanos larval fish.

    Science.gov (United States)

    Chen, C Y

    2001-11-01

    In an attempt to feed purple clams (Hiatula rostrata) with dinoglagellate Alexandrium minutum, the maximal accumulation toxicity of paralytic shellfish poisoning (PSP) toxins reached 40.6 MU/g on day 5 of feeding. Subsequently, the toxicity increased no further, although purple clams ingested more toxic algae. Furthermore, when milkfish (Chanos chanos) larvae were treated with toxic, nontoxic A. minutum or PSP toxin-containing extract in the water medium, it was found that the mortality of fish increased with the increasing concentrations of toxic algae. PSP toxin-containing extract did not show any toxic effect on milkfish larvae.

  18. Temporal variations in embryotoxicity of Lake Ontario American eel (Anguilla rostrata) extracts to developing Fundulus heteroclitus.

    Science.gov (United States)

    Rigaud, Cyril; Couillard, Catherine M; Pellerin, Jocelyne; Légaré, Benoît; Byer, Jonathan D; Alaee, Mehran; Lebeuf, Michel; Casselman, John M; Hodson, Peter V

    2016-01-15

    The recruitment of American eel (Anguilla rostrata) juveniles to Lake Ontario (LO), Canada has declined significantly since the 1980s. To investigate the possible contribution of maternally-transferred persistent organic pollutants (POPs) to this decline, this study measured temporal variations in the toxicity of complex organic mixtures extracted from LO American eels captured in 1988, 1998 and 2008 to developing Fundulus heteroclitus exposed by intravitelline (IVi) injection. The 1988 and 1998 eel extracts were most toxic, causing a pattern of sublethal embryotoxic responses similar to those previously reported in F. heteroclitus embryos exposed to single dioxin-like compounds (DLCs): stunted growth, craniofacial deformities, EROD activity induction, and reduced predatory capacities. The potency of extracts declined over time; the only significant effect of the 2008 eel extracts was EROD induction. The chemically-derived TCDD-TEQs of eel extracts, calculated using measured concentrations of some DLCs and their relative potencies for F. heteroclitus, overestimated their potency to induce EROD activity possibly due to interactions among POPs. Other POPs measured in eel extracts (non-dioxin-like PCBs, PBDEs and organochlorinated pesticides) did not appear to be important agonistic contributors to the observed toxicity. The toxicity of the complex mixtures of POPs measured in LO eels may have been underestimated as a result of several factors, including the loss of POPs during extracts preparation and a focus only on short-term effects. Based on the model species examined, our results support the hypothesis that contamination of LO with DLCs may have represented a threat to the American eel population through ecologically-relevant effects such as altered larval prey capture ability. These results prioritize the need to assess early life stage (ELS) toxicity of DLCs in Anguilla species, to investigate long-term effects of complex eel extracts to ELS of fish, and to

  19. Speciation and demographic history of Atlantic eels (Anguilla anguilla and A. rostrata) revealed by mitogenome sequencing.

    Science.gov (United States)

    Jacobsen, M W; Pujolar, J M; Gilbert, M T P; Moreno-Mayar, J V; Bernatchez, L; Als, T D; Lobon-Cervia, J; Hansen, M M

    2014-11-01

    Processes leading to speciation in oceanic environments without obvious physical barriers remain poorly known. European and American eel (Anguilla anguilla and A. rostrata) spawn in partial sympatry in the Sargasso Sea. Larvae are advected by the Gulf Stream and other currents towards the European/North African and North American coasts, respectively. We analyzed 104 mitogenomes from the two species along with mitogenomes of other Anguilla and outgroup species. We estimated divergence time between the two species to identify major events involved in speciation. We also considered two previously stated hypotheses: one where the ancestral species was present in only one continent but was advected across the Atlantic by ocean current changes and another where population declines during Pleistocene glaciations led to increasing vicariance, facilitating speciation. Divergence time was estimated to ∼3.38 Mya, coinciding with the closure of the Panama Gateway that led to reinforcement of the Gulf Stream. This could have advected larvae towards European/North African coasts, in which case American eel would be expected to be the ancestral species. This scenario could, however, not be unequivocally confirmed by analyses of dN/dS, nucleotide diversity and effective population size estimates. Extended bayesian skyline plots showed fluctuations of effective population sizes and declines during glaciations, and thus also lending support to the importance of vicariance during speciation. There was evidence for positive selection at the ATP6 and possibly ND5 genes, indicating a role in speciation. The findings suggest an important role of ocean current changes in speciation of marine organisms.

  20. Three-dimensional structure of lectin from Dioclea violacea and comparative vasorelaxant effects with Dioclea rostrata

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, B.A.M.; Bezerra, M.J.B.; Bezerra, G.A.; Alencar, K.L.L.; Nascimento, K.S.; Naganao, C.S.; Sampaio, A.H.; Cavada, B.S. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil); Delatorre, P. [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil); Rodrigues, N.V.; Pires, A.F.; Assreuy, A.M.S. [Universidade Estadual do Ceara (UECE), Fortaleza, CE (Brazil); Marins, J.L. [Universidade Federal de Pelotas (UFPel), Pelotas, RS (Brazil)

    2012-07-01

    Full text: Lectins are a structural heterogeneous group of proteins possessing at least one non-catalytic domain that binds reversibly to a specific mono or oligosaccharide. Diocleinae lectins exhibit glucose/mannose monosaccharide binding specificity and studies of their chemical and physicochemical properties revealed a high degree of identity in their amino acid sequences and three dimensional structures. This study investigated structural/functional relationships between lectins obtained from Dioclea violacea (DVL) and Dioclea rostrata (DRL). The purified lectin (DVL) was solubilized in 20 mM Tris-HCl pH 7.6 with 5 mM CaCl{sub 2} and MnCl{sub 2} buffer and incubated during one hour before the crystallization experiments with the ligand X-Man (5-bromo-4-chloro-3-indolyl-{alpha}-D-mannose) at 3 mM. Crystals of DVL grew in condition 33 of Crystal Screen I (4M Sodium formate) and belong to the orthorhombic space group I222. The structure of DVL at 2.6 resolution was obtained by molecular replacement using the coordinates of DRL (PDB code 2ZBJ), after the last refinement the structure presented R factor of 0.23 and R free of 0.27. The crystal structures reveal differences between them and could be related to relaxant activity. The conformation of residues HIS51, HIS131 and GLU205 and others positioned at CRD lead to different lectin binding activities. In fact, the pocket in DVL is small and deep and promotes weak interaction with carbohydrates, while DRL pocket is large and shallow, allowing strong interaction between CRD and sugars. This can explain why DVL and DRL elicited different degrees of aorta relaxation showing maximal effects of 43 % and 96 %, respectively. (author)

  1. Diversification rates and chromosome evolution in the most diverse angiosperm genus of the temperate zone (Carex, Cyperaceae).

    Science.gov (United States)

    Escudero, Marcial; Hipp, Andrew L; Waterway, Marcia J; Valente, Luis M

    2012-06-01

    The sedge family (Cyperaceae: Poales; ca. 5600 spp.) is a hyperdiverse cosmopolitan group with centres of species diversity in Africa, Australia, eastern Asia, North America, and the Neotropics. Carex, with ca. 40% of the species in the family, is one of the most species-rich angiosperm genera and the most diverse in temperate regions of the Northern Hemisphere, making it atypical among plants in that it inverts the latitudinal gradient of species richness. Moreover, Carex exhibits high rates of chromosome rearrangement via fission, fusion, and translocation, which distinguishes it from the rest of the Cyperaceae. Here, we use a phylogenetic framework to examine how the onset of contemporary temperate climates and the processes of chromosome evolution have influenced the diversification dynamics of Carex. We provide estimates of diversification rates and map chromosome transitions across the evolutionary history of the main four clades of Carex. We demonstrate that Carex underwent a shift in diversification rates sometime between the Late Eocene and the Oligocene, during a global cooling period, which fits with a transition in diploid chromosome number. We suggest that adaptive radiation to novel temperate climates, aided by a shift in the mode of chromosome evolution, may explain the large-scale radiation of Carex and its latitudinal pattern of species richness.

  2. Efeito da sacarose, cinetina, isopentenil adenina e zeatina no desenvolvimento de embriões de Heliconia rostrata in vitro Effect of sucrose, kinetin, isopentenyl adenine and zeatin on the development of embryos of Heliconia rostrata in vitro

    Directory of Open Access Journals (Sweden)

    Antonio Carlos Torres

    2005-07-01

    Full Text Available Embriões provenientes de frutos maturos de Heliconia rostrata Ruiz & Pavon foram excisados e inoculados em meio de cultura contendo os sais básicos MS, vitaminas e sacarose. A adição de sacarose foi essencial para o desenvolvimento dos embriões. Em meio desprovido de sacarose os embriões morreram em cultura. Concentrações de 1%, 2% e 3% (p/v de sacarose favoreceram o desenvolvimento dos embriões. Concentrações de 6%, 9% e 12% (p/v de sacarose inibiram o crescimento dos embriões. A adição de cinetina, isopentenil adenina e zeatina não favoreceram o crescimento e o desenvolvimento dos embriões.Embryos from mature fruits of Heliconia rostrata were excised and cultured in basal medium containing MS salts, vitamins and sucrose. Sucrose was essential for embryo development. In meclium without sucrose the embryos died in culture. Sucrose concentrations of 1%, 2% and 3% (w/v were beneficial for embryo development. Sucrose concentrations of 6%, 9% and 12% (w/v inhibited embryo growth. The addition of kinetin, isopentenyl adenine and zeatin did not improve embryo growth and development.

  3. Occupational exposures to carcinogens in Italy: an update of CAREX database.

    Science.gov (United States)

    Mirabelli, Dario; Kauppinen, Timo

    2005-01-01

    To update estimates of the prevalence of occupational exposures to carcinogens in Italy, the 85 CAREX agents were re-assessed. The original exposure estimates in the CAREX database were updated, taking into account changes in exposure patterns and in numbers of employees by industrial class. The 21.8 million employees in Italy, 19.4 in industry and services, 2.4 in agriculture, had 4.2 million exposures. Prevalences of exposures were highest for environmental (passive) tobacco smoke (800,000 exposures), solar radiation (700,000), diesel engine exhaust (500,000), wood dust (280,000), silica (250,000), lead and inorganic lead compounds (230,000), benzene (180 000), hexavalent chromium compounds (160,000), glass wool (140,000), and PAHs (120,000). Exposures to carcinogens at work are still an issue in Italy and do not appear to be controlled as strictly as they should be.

  4. Phenological changes in the concentration of alkaloids of Carex brevicollis in an Alpine rangeland.

    Science.gov (United States)

    Busqué, Juan; Pedrosa, Mercedes Martin; Cabellos, Blanca; Muzquiz, Mercedes

    2010-11-01

    Carex brevicollis (Cyperaceae) is a plant of mesic grasslands in calcareous mountains of southern Europe. It contains two different β-carboline alkaloids, brevicolline and brevicarine, the first of which is thought to produce abortions in mammals. In the rangeland of Aliva, within the Picos de Europa massif in northern Spain, the abundance of Carex brevicollis has been linked with the occurrence of teratogenesis in early gestating cows grazing in early summer. The concentration of alkaloids was measured in the summers of 2007 and 2008, at intervals of 2 weeks, at different altitudes within the rangeland (1,350, 1,600, and 1,850 m) and from different parts of the sedge (leaves, reproductive stems, and inflorescences). Estimated growing degree days were related to the flowering phenology of Carex brevicollis and were used to analyse its relation with the concentration of alkaloids. Brevicarine concentration was higher in inflorescences and brevicolline in leaves. Although it also depended on the zone and year, the concentrations of both alkaloids were related one to another in leaves and inflorescences but not in stems. Both alkaloids decreased with growing degree days in the inflorescences and showed no response in leaves. Our findings suggest that brevicarine, not brevicolline, could be the teratogen in pregnant cattle in this region. This hypothesis is supported by the observed frequent consumption of inflorescences and scarce consumption of leaves of Carex brevicollis by grazing livestock, and also by the coincidence of the toxicity in early pregnant cows with the flowering time of the sedge.

  5. Intraclonal variation in defence substances and palatability: a study on Carex and lemmings

    OpenAIRE

    Bråthen, KA; Agrell, Jep; Berteaux, D.; Jonsdottir, IS

    2004-01-01

    Clonal sedges consist of integrated ramets at different development stages. Many of these sedges are important food for herbivores, yet differences in herbivore preferences and defence allocation between ramet development stages have not previously been evaluated. In this study we investigated intraclonal ramet variation in level of plant defence and nutrient compounds and intraclonal ramet preferences by lemmings (Lemmus trimucronatus) in field samples of a rhizomatous sedge (Carex stans). P...

  6. Morphological variability of Carex dioica L. (Cyperaceae Juss.) in Polissya region

    OpenAIRE

    Svetlana V. Izmestieva

    2012-01-01

    Morphological variability of Carex dioica L. generative individuals in 4 habitats on the territory of Polissya has analysed. It is established that antropogenic influence and biotope heterogenity determine the highest level of morphological changeability of individuals in one of the localities on the bog Koza. The length of leaves and stems are the most variable traits which depend on the environmental conditions. Stability of such characteristics, as a width of leaves and a length of spikes ...

  7. Phytochemical, Antibacterial and Antioxidant Investigations of Sesbania rostrata Dc (Fabaceae Extracts form Leaves, Stems, Granulates, Pods and Roots

    Directory of Open Access Journals (Sweden)

    M.B. Ouattara

    2011-11-01

    Full Text Available The antibacterial, antioxidant activities and the phytochemical analysis of Sesbania rostrata used in traditional medicine in Burkina Faso were investigated. Aqueous, methanolic and hydro-acetone extracts from leaves, stems, granules, pods and roots organs have demonstrated a good polyphenolic, tannin and flavonoids with variable anti-DPPH, Iron III reduction and antibacterial capacities. Particularly methanol extract form leaves possessed 46.33 mgEGA/100 mg and 25.98 mgETA/100 mg in polyphenolic and tannin content respectively. Beside TLC analysis of this extract demonstrated the presence of quercetin, kaempferol, rutin, caffeic and gallic acids. It was presented a good possibility to inhibit bacteria growth, radical DPPH and to reduce Iron III. These biological activities could support the traditional uses of this plant.

  8. The Exotic Flowering Plant-Heliconia rostrata%姿奇色艳的垂花蝎尾蕉

    Institute of Scientific and Technical Information of China (English)

    曾宋君

    2002-01-01

    @@ 垂花蝎尾蕉(Heliconia rostrata Rui z&Pavon)又称垂花火岛蕉、垂序蝎尾蕉、垂苞蝎尾蕉、金嘴赫蕉、金嘴鹤蕉等,为旅人蕉科蝎尾蕉属植物.本属植物原生种有200多种,加上各种变种、园艺栽培种、杂交种等,数量在400种以上,均具有很高的观赏价值.其中垂花蝎尾蕉是蝎尾蕉属植物中花色最艳丽、造型最独特、最引人注目、目前也是最被人们所熟悉的蝎尾蕉种类之一.

  9. Morphological variability of Carex dioica L. (Cyperaceae Juss. in Polissya region

    Directory of Open Access Journals (Sweden)

    Svetlana V. Izmestieva

    2012-03-01

    Full Text Available Morphological variability of Carex dioica L. generative individuals in 4 habitats on the territory of Polissya has analysed. It is established that antropogenic influence and biotope heterogenity determine the highest level of morphological changeability of individuals in one of the localities on the bog Koza. The length of leaves and stems are the most variable traits which depend on the environmental conditions. Stability of such characteristics, as a width of leaves and a length of spikes are determined by their important diagnostic value and application in the systematic of sedges.

  10. Anthracoidea caricis-meadii is a new North American smut fungus on Carex sect. Paniceae.

    Science.gov (United States)

    Savchenko, Kyrylo G; Lutz, Matthias; Piatek, Marcin; Heluta, Vasyl P; Nevo, Eviatar

    2013-01-01

    The morphology and phylogeny of Anthracoidea on Carex meadii (sect. Paniceae) collected in Illinois, Iowa, Wisconsin, USA, were studied by light microscopy, scanning electron microscopy and LSU rDNA sequence analyses. As a result A. caricis-meadii sp. nov. is described. The fungus differs morphologically from Anthracoidea laxae and A. paniceae, which also occur on sedges from the section Paniceae. Molecular analyses support the placement of the latter species and Anthracoidea caricis-meadii in different phylogenetic lineages. Because of morphological discrepancies in the literature, A. laxae and A. paniceae also are described and illustrated based on re-examination of respective holotype and isotype specimens.

  11. Fatty acids composition of fruits of selected Central European sedges (Carex L. Cyperaceae)

    OpenAIRE

    Janyszek, Magdalena; Bogucka-Kocka, Anna

    2010-01-01

    Fatty acids in the fruits of 13 sedge species (Carex L., Cyperaceae) were analyzed. The oil contents in the fruits of the studied sedges ranged from 3.73 and 46.52%. In the studied fruit oils 14 different fatty acids were identified. The main unsaturated fatty acids were: linoleic, α-linolenic, oleic, oleopalmitic n-7; oleopalmitic n-9, octadecenic, and eicosenoic acids. The following acids were found in the greatest quantities: linoleic, oleic, α-linolenic and palmitic acids. Based on the fa...

  12. Stomatal behaviour and gas exchange of Sedges ( Carex spp.) under different soil moisture regimes

    Science.gov (United States)

    Busch, J.; Lösch, R.

    Sedges ( Carex spec., Cyperaceae) are important members of different vegetation types in temperate zones nearly all over the world. For this, knowledge of gas exchange and stomata behaviour of sedges is significant for understanding the exchange of water vapour and carbon dioxide between such vegetation types and the atmosphere. The gas exchange of several Carex species was studied in an experimental site of the Botanical Garden Düsseldorf (Germany). Transpiration and netassimilation rates (A), leaf conductances (g) and microclimatic parameters were measured porometrically during two vegetation periods. Patterns of dependence of leaf gas exchange on microclimatic conditions were worked out for different species and culture regimes. The sedges differ in stomatal sensitivity to changing air humidity. Water loss through transpiration is therefore decoupled from evaporation in a species-specific degree. Resulting mathematical models of g and A are presented and the importance of these species-specific differences in modelling and upscaling water vapour, carbon dioxide and trace gas fluxes are pointed out.

  13. The east-west-north colonization history of the Mediterranean and Europe by the coastal plant Carex extensa (Cyperaceae)

    NARCIS (Netherlands)

    Escudero, M.; Vargas, P.; Arens, P.; Ouborg, N.J.; Luceno, M.

    2010-01-01

    Coastal plants are ideal models for studying the colonization routes of species because of the simple linear distributions of these species. Carex extensa occurs mainly in salt marshes along the Mediterranean and European coasts. Variation in cpDNA sequences, amplified fragment length polymorphisms

  14. The Ecological Response of Carex lasiocarpa Community in the Riparian Wetlands to the Environmental Gradient of Water Depth in Sanjiang Plain, Northeast China

    Directory of Open Access Journals (Sweden)

    Zhaoqing Luan

    2013-01-01

    Full Text Available The response of Carex lasiocarpa in riparian wetlands in Sanjiang Plain to the environmental gradient of water depth was analyzed by using the Gaussian Model based on the biomass and average height data, and the ecological water-depth amplitude of Carex lasiocarpa was derived. The results indicated that the optimum ecological water-depth amplitude of Carex lasiocarpa based on biomass was [13.45 cm, 29.78 cm], while the optimum ecological water-depth amplitude of Carex lasiocarpa based on average height was [2.31 cm, 40.11 cm]. The intersection of the ecological water-depth amplitudes based on biomass and height confirmed that the optimum ecological water-depth amplitude of Carex lasiocarpa was [13.45 cm, 29.78 cm] and the optimist growing water-depth of Carex lasiocarpa was 21.4 cm. The TWINSPAN, a polythetic and divisive classification tool, was used to classify the wetland ecological series into 6 associations. Result of TWINSPAN matrix classification reflected an obvious environmental gradient in these associations: water-depth gradient. The relation of biodiversity of Carex lasiocarpa community and water depth was determined by calculating the diversity index of each association.

  15. Soil Redox Chemistry Limitation of Selenium Concentration in Carex Species Sedges

    Energy Technology Data Exchange (ETDEWEB)

    Bruce J. Mincher; John Mionczynski; Patrick A. Hnilicka

    2007-09-01

    The trace element selenium (Se) is required in the production of enzymes that protect mammalian cells from oxidative damage due to the byproducts of aerobic respiration. Its deficiency in livestock results in the nutritional muscular dystrophy called white muscle disease. This especially affects juveniles in the preweaning period. Symptoms have also been reported in wild herbivores on low-Se forage, and their appearance may be episodic, suggesting temporal variations in Se uptake by plants. Here, we report variations in selenium concentrations in Carex spp. sedges used as forage by bighorn sheep (Ovis canadensis) on summer range in the Wyoming, Wind River Mountains, and correlate those variations with soil conditions that affect the bioavailability of selenium. Variations in available Se are explained based upon the known oxidation/reduction chemistry of the element. It is concluded that water-saturated, alpine soils provide conditions suitable for the reduction of Se to the unavailable, elemental form, limiting its concentration in forage plants.

  16. A short life cycle of introduced Carex vulpina L. in the Donetsk Botanical Garden

    Directory of Open Access Journals (Sweden)

    Pavlova Marina Alexandrovna

    2015-12-01

    Full Text Available Basing on the study of a short life cycle in introduced ornamental Carex vulpina L. in the Donetsk Botanical Garden, we have revealed and described five main stages of ontogeny (plantlet, juvenile, immature, virginal, young generative and determined their time limits. It was found out that pregenerative period in this species lasts only for one growing season. This fact may be preconditioned by optimal for sapling development conditions (edaphic ones and agricultural methods. This study allowed us to formulate the following specific traits of a short life cycle in C. vulpina: a prolonged seed germination period, a long lasting relationship between a plant and its seed, an accelerated pregenerative period of ontogeny. Based on these data we suggest seed reproduction of this introduced species to be the best way to get a number of high grade planting material yet in the second year after sowing, which has implications for landscaping in our region.

  17. Isolation of 91 polymorphic microsatellite loci in the western Mediterranean endemic Carex helodes (Cyperaceae)1

    Science.gov (United States)

    Arroyo, Juan M.; Escudero, Marcial; Jordano, Pedro

    2016-01-01

    Premise of the study: Microsatellite primers were developed for Carex helodes (Cyperaceae), a western Mediterranean endemic that is locally distributed in southern Portugal and southwestern Spain and rare in northern Morocco. Methods and Results: One hundred nine nuclear microsatellite markers were developed using a shotgun pyrosequencing method, resulting in 91 polymorphic and 18 monomorphic loci when tested using 19 individuals sampled from five populations from Portugal, Spain, and Morocco. Loci averaged 3.23 alleles per locus (SD = 1.15). In a single population (Cortelha population, Portugal), the 34 most polymorphic loci showed a mean observed heterozygosity of 0.357 (SD = 0.292) and mean expected heterozygosity of 0.384 (SD = 0.255). Conclusions: Next-generation sequencing allowed us to develop a high number of genetic markers with levels of polymorphism adequate to study gene flow among populations. However, when genotyping the individuals within a population, we found low levels of variation. PMID:26819859

  18. Taxonomic revision of the tropical African group of Carex subsect. Elatae (sect. Spirostachyae, Cyperaceae

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    Escudero, Marcial

    2011-12-01

    Full Text Available The tropical African monophyletic group of Carex subsect. Elatae (sect. Spirostachyae is distributed in continental tropical Africa, Madagascar, the Mascarene archipelago, and Bioko Island (32 km off the coast of West Africa, in the Gulf of Guinea. The first monographic treatment of this Carex group, as well as of the tribe Cariceae, was published by Kükenthal (as sect. Elatae Kük.. Recently, the first molecular (nrDNA, cpDNA phylogeny of Carex sect. Elatae has been published, which also included the species of sect. Spirostachyae. In the resulting consensus trees, most species of sect. Elatae were embedded within core Spirostachyae and so this section was joined with sect. Spirostachyae as subsect. Elatae. Within subsect. Elatae, several groups were described, one of which was termed the “tropical African group”. Here we present a taxonomic revision of this group, based on more than 280 vouchers from 29 herbaria as well as in field trips in Tropical Africa. In the revision, we recognise 12 species (16 taxa within the tropical African group, and so have somewhat modified our previous view, in which 10 species, 12 taxa were listed. One new species from Tanzania is included in this treatment, C. uluguruensis Luceño & M. Escudero. Several combinations are made, C. cyrtosaccus is treated as a synonym of C. vallis-rosetto and, finally, the binomial C. greenwayi has been recognised.Las especies de la subsección Elatae (sección Spirostachyae del género Carex que se distribuyen por África tropical continental, Madagascar, el archipiélago de las Mascareñas y la isla de Bioko (a 32 km del litoral de África occidental, en el golfo de Guinea forman un grupo monofilético. El primer tratamiento taxonómico de este grupo de cárices, así como de la tribu Cariceae en su conjunto, fue elaborado por Kükenthal (sección Elatae Kük.; recientemente, se ha publicado el primer estudio de filogenia molecular (nrDNA, cpDNA de los táxones de este grupo

  19. Identification and bioactivities of resveratrol oligomers and flavonoids from Carex folliculata seeds.

    Science.gov (United States)

    Li, Liya; Henry, Geneive E; Seeram, Navindra P

    2009-08-26

    Plants of the Carex genus (Family: Cyperaceae) have attracted recent attention as potential food additives because they contain high levels of bioactive polyphenols commonly found in plant foods. Seven compounds, which included two resveratrol oligomers and five flavonoids, were isolated from seeds of Carex folliculata L. (northern long sedge), a forage prevalent in the northern United States. The compounds were identified by (1)H and (13)C nuclear magnetic resonance and mass spectrometry data. The resveratrol oligomers were pallidol (1), a resveratrol dimer reported to be present in levels equivalent to those of resveratrol in red wine, and kobophenol A (2), a resveratrol tetramer with a unique 2,3,4,5-tetraaryltetrahydrofuran skeleton. The flavonoids were isoorientin (3), luteolin (4), quercetin (5), 3-O-methylquercetin (6), and rutin (7). Compounds were evaluated for antioxidant activity in the diphenylpicrylhydrazyl (DPPH) radical scavenging assay; cytotoxicity activity against human colon (HCT116, HT29) and breast (MCF7, MDA-MB-231) tumor cell lines; and antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). The antioxidant activities of the flavonoids (3-7; IC(50) values ranging from 50 to 200 microM) were comparable to that of ascorbic acid (IC(50) = 60 microM) and superior to those of the resveratrol derivatives (1 and 2; IC(50) > 1000 microM) and butylated hydroxytoluene (BHT; IC(50) = 1500 microM), a commercial antioxidant. In the cytotoxicity and antibacterial bioassays, compounds 4 (IC(50) for HCT116 = 45 microM) and 6 (IC(50) for MRSA = 6.4 microM) were the most active, respectively. Therefore, given the wide availability and underutilization of C. folliculata, this forage may provide a source of bioactive compounds useful for nutraceutical purposes. Also, this is the first reported phytochemical investigation of C. folliculata.

  20. 垂花火鸟蕉的组织培养%Tissue Culture of Heliconia rostrata Ruiz & Pavon

    Institute of Scientific and Technical Information of China (English)

    陈伟; 李志英; 李克烈; 徐立

    2006-01-01

    @@ 1植物名称垂花火鸟蕉(Heliconia rostrata Ruiz &Pavon). 2材料类别种子长成的无菌苗茎段. 3培养条件种子萌发培养基:1/2MS培养基.芽启动培养基:(1)1/2MS+6-BA 3 mg·L-1(单位下同)+NAA 0.5+1%活性炭;(2)1/2MS+6-BA 5+NAA0.5+1%活性炭;(3)1/2MS+6-BA 10+NAA 0.5+1%活性炭.芽增殖培养基:(4)MS+6-BA 3+NAA 0.3.生根培养基:(5)MS+NAA 0.5+0.5%活性炭.以上培养基均添加7 g·L-1琼脂粉和30 g·L-1蔗糖,pH5.8,在121℃下高压灭菌20 min.培养温度为(25±2)℃,光照时间12 h·d-1,光照强度50μmol·m-2·s-1.

  1. First record of protozoan parasites, Tetrahymena rostrata and Callimastix equi from the edible oyster in Sundarbans region of West Bengal, India.

    Science.gov (United States)

    Biswas, Tanima; Bandyopadhyay, Probir Kumar

    2016-09-01

    Several protozoan parasites have been found infecting the edible oysters, hence deteriorating the meat quality. Protozoan parasites such as, Tetrahymena rostrata and Callimastix equi infested the edible oyster in Sundarbans region, West Bengal, India, are first record from this region. Due to filter feeding habit of the organisms, oysters provides excellent ecological services in regard to efficient cleaning of infectious agents from surrounding water as a potential measure to improve water quality. However, these environmental benefits are associated with public heath risks from contaminated oysters intended for human consumption.

  2. Functional analysis of the Sesbania rostrata leghemoglobin glb3 gene 5'-upstream region in transgenic Lotus corniculatus and Nicotiana tabacum plants.

    Science.gov (United States)

    Szabados, L; Ratet, P; Grunenberg, B; de Bruijn, F J

    1990-10-01

    Expression of the Sesbania rostrata leghemoglobin glb3 gene was analyzed in transgenic Lotus corniculatus and tobacco plants harboring chimeric glb3-uidA (gus) gene fusions to identify cis-acting elements involved in nodule-specific gene expression and general transcriptional control. A 1.9-kilobase fragment of the glb3 5'-upstream region was found to direct a high level of nodule-specific beta-glucuronidase (GUS) activity in L. corniculatus, restricted to the Rhizobium-infected cells of the nodules. The same fragment directed a low level of GUS activity in tobacco, restricted primarily to the roots and to phloem cells of the stem and petiole vascular system. A deletion analysis revealed that the region between coordinates -429 and -48 relative to the ATG was sufficient for nodule-specific expression. Replacement of the -161 to -48 region, containing the glb3 CAAT and TATA boxes, with the heterologous truncated promoters delta-p35S and delta-pnos resulted in a loss of nodule specificity and reduction of GUS activity in L. corniculatus but a significant increase in tobacco, primarily in the roots. The same fragment could not direct nodule-specific expression when fused to a heterologous enhancer in cis. This region contains DNA sequences required, but not sufficient, for nodule-specific expression in L. corniculatus that function poorly or may be involved in promoter silencing in tobacco. By fusing further upstream fragments to the delta-p35S and delta-pnos promoters, two positive regulatory regions were delimited between coordinates -1601 and -670, as well as -429 and -162. The former region appears to function as a general enhancer because it significantly increased promoter activity in both orientations in L. corniculatus and tobacco. The latter region could enhance gene expression in both orientations in tobacco, but only in the correct orientation in L. corniculatus. These results show that efficient expression of the S. rostrata glb3 gene in nodules is

  3. Fatty acids composition of fruits of selected Central European sedges (Carex L. Cyperaceae

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    Janyszek, Magdalena

    2010-06-01

    Full Text Available Fatty acids in the fruits of 13 sedge species (Carex L., Cyperaceae were analyzed. The oil contents in the fruits of the studied sedges ranged from 3.73 and 46.52%. In the studied fruit oils 14 different fatty acids were identified. The main unsaturated fatty acids were: linoleic, α-linolenic, oleic, oleopalmitic n-7; oleopalmitic n-9, octadecenic, and eicosenoic acids. The following acids were found in the greatest quantities: linoleic, oleic, α-linolenic and palmitic acids. Based on the fatty acid composition, studied taxa can be divided in two groups. The first group (C. flava, C. pseudocyperus, C. riparia, C. leporina is a very good source of linoleic acid. The second group, including the remaining species, is a good source of α-linolenic acid. The highest oleic acid contents were observed in C. vulpina. The studied material has shown a low concentration of saturated fatty acids, among which palmitic acid was the main one.Results of the analyses allow for the inclusion of the studied species among plants whose fruits are characterized by a high content of unsaturated fatty acids.Los ácidos grasos de frutos de 13 especies de juncos (Carex L., Cyperaceae fueron analizados. El contenido de aceite en los frutos de juncos estudiados vario desde un 3.73 a un 46.52%. En los aceites de los frutos estudiados fueron identificados 14 ácidos grasos diferentes. Los principales ácidos grasos insaturados fueron los ácidos linoleico, α-linolenico, oleico, n-7 palmitoleico, n-9 palmitoleico, octadecenoico y eicosanoico. Los siguientes ácidos grasos fueron encontrados en mayor cantidad: ácido linoleico, ácido oleico, ácido α-linolenico, y ácido palmítico. Basado en la composición de ácidos grasos, las especies estudiadas pueden ser divididas en dos grupos. El primer grupo (C. flava, C. pseudocyperus, C. riparia, C. leporina es una muy buena fuente de ácido linoleico. El segundo grupo, que incluye las especies restantes, es una buena fuente

  4. Carex flava agg. (section Ceratocystis, Cyperaceae in Poland: taxonomy, morphological variation, and soil conditions

    Directory of Open Access Journals (Sweden)

    Więcław Helena

    2014-03-01

    Full Text Available Sedges of Carex flava agg., typical of moist or wet habitats, are difficult to classify because of a lack of clear-cut morphological differences between them and the existence of numerous hybrids. This monograph presents results of research conducted in 2007-2012 in various parts of Poland. The plant material consisted of 1852 living specimens of Carex flava agg., collected from 80 localities, and dried specimens from 26 herbaria and from 7 private collections. The analysis involved 45 morphological characters (34 quantitative and 11 qualitative and 9 soil parameters. Univariate, bivariate, and multivariate statistical methods were used to process the data. The results confirm the taxonomic classification dividing the C. flava group into 4 species: C. flava s.s., C. lepidocarpa, C. demissa, and C. viridula. This classification is based on (i a high observed level of morphological separation of these taxa, resulting mostly from differences in generative characters, i.e. length of the utricle and its beak, and percentage ratio of beak length to total utricle length; (ii integrity of the taxa at the sites where they coexist, although some intermediate forms resulting from hybridization are also present; (iii habitat preferences of the taxa, especially the preference of C. lepidocarpa for calcareous sites and of C. demissa for slightly acidic soils. Thus in Poland the analysed taxa are morphologically well-defined and show clear ecological preferences. Continuous variation of morphological characters was observed among specimens of C. viridula, so it is not justifiable to distinguish its subspecies (sometimes classified even as separate species, described previously in literature. Consequently, the 2 subgroups of C. viridula were treated as local variants (i.e. varieties: var. viridula and var. pulchella, considering their different habitat requirements. Additionally, 5 hybrids were distinguished within C. flava agg.: C. ×alsatica [= C. demissa

  5. Selection and inertia in the evolution of holocentric chromosomes in sedges (Carex, Cyperaceae).

    Science.gov (United States)

    Escudero, Marcial; Hipp, Andrew L; Hansen, Thomas F; Voje, Kjetil L; Luceño, Modesto

    2012-07-01

    • Changes in chromosome number as a result of fission and fusion in holocentrics have direct and immediate effects on the recombination rate. We investigate the support for the classic hypothesis that environmental stability selects for increased recombination rates. • We employed a phylogenetic and cytogenetic data set from one of the most diverse angiosperm genera in the world, which has the largest nonpolyploid chromosome radiation (Carex, Cyperaceae; 2n = 12-124; 2100 spp.). We evaluated alternative Ornstein-Uhlenbeck models of chromosome number adaptation to the environment in an information-theoretic framework. • We found moderate support for a positive influence of lateral inflorescence unit size on chromosome number, which may be selected in a stable environment in which resources for reproductive investment are larger. We found weak support for a positive influence on chromosome number of water-saturated soils and among-month temperature constancy, which would be expected to be negatively select for pioneering species. Chromosome number showed a strong phylogenetic signal. • We argue that our finding of small but significant effects of life history and ecology is compatible with our original hypothesis regarding selection of optima in recombination rates: low recombination rate is optimal when inmediate fitness is required. By contrast, high recombination rate is optimal when stable environments allow for evolutionary innovation.

  6. Growth and Physiological Responses to Water Depths in Carex schmidtii Meinsh.

    Directory of Open Access Journals (Sweden)

    Hong Yan

    Full Text Available A greenhouse experiment was performed to investigate growth and physiological responses to water depth in completely submerged condition of a wetland plant Carex schmidtii Meinsh., one of the dominant species in the Longwan Crater Lake wetlands (China. Growth and physiological responses of C. schmidtii were investigated by growing under control (non-submerged and three submerged conditions (5 cm, 15 cm and 25 cm water level. Total biomass was highest in control, intermediate in 5 cm treatment and lowest in the other two submerged treatments. Water depth prominently affected the first-order lateral root to main root mass ratio. Alcohol dehydrogenase (ADH activity decreased but malondialdehyde (MDA content increased as water depth increased. The starch contents showed no differences among the various treatments at the end of the experiment. However, soluble sugar contents were highest in control, intermediate in 5 cm and 15 cm treatments and lowest in 25 cm treatment. Our data suggest that submergence depth affected some aspects of growth and physiology of C. schmidtii, which can reduce anoxia damage not only through maintaining the non-elongation strategy in shoot part but also by adjusting biomass allocation to different root orders rather than adjusting root-shoot biomass allocation.

  7. Rhizofiltration of a Heavy metal (lead) containing wastewater using the wetland plant carex pendula

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Brijesh K. [Environmental Hydrogeology Group, Department of Earth Sciences, Faculty of Geosciences, University of Utrecht, Utrecht (Netherlands); Indian Institute of Technology Delhi, Department of Civil Engineering, New Delhi (India); Siebel, Maarten A.; Bruggen, Johan J.A. van [Department of Environmental Resources, UNESCO-IHE Institute for Water Education, Delft (Netherlands)

    2011-05-15

    Rhizofiltration is a subset technique of phytoremediation which refers to the approach of using plant biomass for removing contaminants, primarily toxic metals, from polluted water. The effective implementation of this in situ remediation technology requires experimental as well as conceptual insight of plant-water interactions that control the extraction of targeted metal from polluted water resources. Therefore, pot and simulation experiments are used in this study to investigate the rhizofiltration of a lead containing wastewater using plants of Carex pendula, a common wetland plant found in Europe. The metal contaminant extraction along with plant growth and water uptake rates from a wastewater having varying Pb concentration is studied experimentally for 2 wk. The temporal distribution of the metal concentration in the wastewater and the accumulated metal in different compartments of C. pendula at the end are analyzed using atomic absorption spectrometry. Parameters of the metal uptake kinetics are deduced experimentally for predicting the metal removal by root biomass. Further, mass balance equations coupled with the characterized metal uptake kinetics are used for simulating the metal partitioning from the wastewater to its accumulation in the plant biomass. The simulated metal content in wastewater and plant biomass is compared with the observed data showing a good agreement with the later. Results show that C. pendula accumulates considerable amounts of lead, particularly in root biomass, and can be considered for the cleanup of lead contaminated wastewaters in combination with proper biomass disposal alternatives. Also, the findings can be used for performing further non-hydroponics experiment to mimic the real wetland conditions more closely. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Do peat amendments to oil sands wet sediments affect Carex aquatilis biomass for reclamation success?

    Science.gov (United States)

    Roy, Marie-Claude; Mollard, Federico P O; Foote, A Lee

    2014-06-15

    The oil sands industries of Alberta (Canada) have reclamation objectives to return the mined landscape to equivalent pre-disturbance land capability. Industrial operators are charged with reclaiming a vast landscape of newly exposed sediments on saline-sodic marine-shales sediments. Incorporated in these sediments are by-products resulting from bitumen extraction (consolidated tailings (CT), tailings-sand (TS), and oil sands processed water (OSPW)). A sedge community dominated by Carex aquatilis was identified as a desirable and representative late-succession community for wet-meadow zones of oil sands-created marshes. However, the physical and chemical conditions, including high salinity and low nutrient content of CT and TS sediments suppress plant growth and performance. We experimentally tested the response of C. aquatilis to amendments with peat-mineral-mix (PM) on oil sand sediments (CT and TS). In a two factorial design experiment, we also tested the effects of OSPW on C. aquatilis. We assessed survival, below- and aboveground biomass, and physiology (chlorophyll a fluorescence). We demonstrated that PM amendments to oil sands sediments significantly increased C. aquatilis survival as well as below and aboveground biomass. The use of OSPW significantly reduced C. aquatilis belowground biomass and affected its physiological performance. Due to its tolerance and performance, we verified that C. aquatilis was a good candidate for use in reclaiming the wet-meadow zones of oil sands-created marshes. Ultimately, amending CT and TS with PM expedited the reclamation of the wetland to a C. aquatilis-community which was similar in gross structure to undisturbed wetlands of the region.

  9. Interpretación de algunas cárices (Carex L.) de la Flora Anglica de W. Hudson y tipificación de tres nombres relacionados

    OpenAIRE

    Molina González, Ana María; Acedo, Carmen; Llamas García, Félix

    2007-01-01

    Se discute la identidad de once especies y seis taxones infraespecíficos del género Carex tratados por Hudson en la Flora Anglica. Se estudia la obra de este autor, comparándola con los protólogos de Linneo y otros botánicos contemporáneos y se indica en cada caso el nombre en uso actual. Cinco especies, que Hudson llamó Carex acuta, C. brizoides, C. inflata en el sentido de la segunda edición , C. muricata y C. saxatilis, corresponden a taxones sin describir en aquel momento y actualmente s...

  10. Microhabitat differences impact phylogeographic concordance of codistributed species: genomic evidence in montane sedges (Carex L.) from the Rocky Mountains.

    Science.gov (United States)

    Massatti, Rob; Knowles, L Lacey

    2014-10-01

    By selecting codistributed, closely related montane sedges from the Rocky Mountains that are similar in virtually all respects but one-their microhabitat affinities-we test predictions about how patterns of genetic variation are expected to differ between Carex nova, an inhabitant of wetlands, and Carex chalciolepis, an inhabitant of drier meadows, slopes, and ridges. Although contemporary populations of the taxa are similarly isolated, the distribution of glacial moraines suggests that their past population connectedness would have differed. Sampling of codistributed population pairs from different mountain ranges combined with the resolution provided by over 24,000 single nucleotide polymorphism loci supports microhabitat-mediated differences in the sedges' patterns of genetic variation that are consistent with their predicted differences in the degree of isolation of ancestral source populations. Our results highlight how microhabitat preferences may interact with glaciations to produce fundamental differences in the past distributions of presently codistributed species. We discuss the implications of these findings for generalizing the impacts of climate-induced distributional shifts for communities, as well as for the prospects of gaining insights about species-specific deterministic processes, not just deterministic community-level responses, from comparative phylogeographic study.

  11. Genetic structure in populations of an ancient woodland sedge, Carex sylvatica Hudson, at a regional and local scale.

    Science.gov (United States)

    Arens, P; Bijlsma, R-J; van't Westende, W; van Os, B; Smulders, M J M; Vosman, B

    2005-07-01

    Wood sedge (Carex sylvatica) is a well-known ancient woodland species with a long-term persistent seed bank and a caespitose growth habit. All thirteen isolated Carex sylvatica populations in the Dutch Rhine floodplain (including the river branches Waal and IJssel) were mapped in detail and analysed for genetic variation at a large number of AFLP loci and one microsatellite locus. Across all populations, only 40 % of the sampled individuals (n=216) represented a unique genotype. A high number of the studied patches (spatial clusters of tussocks, 2-10 m in diameter) within populations contained only one or a few genotypes. Identical plants (tussocks) were also found 20-500 m apart and in one case even 1000 m apart. Observed heterozygosity levels (H(O)=0.029) were low, indicating low levels of gene flow, which is in agreement with the selfing nature of other caespitose sedges. Although the number of genotypes in populations is low, these genotypes are genetically very distinct and variation within populations accounted for 55% of the total variation. The absence of a correlation between genetic and geographic distances among populations, and the scattered distribution of genotypes among patches within woodlands, support our hypothesis of rare establishments and subsequent local dispersal within woodlands in this forest floor species, which may benefit from and partly depend on human land use and forest management activities.

  12. Karyotype stability and predictors of chromosome number variation in sedges: a study in Carex section Spirostachyae (Cyperaceae).

    Science.gov (United States)

    Escudero, Marcial; Hipp, Andrew L; Luceño, Modesto

    2010-10-01

    Previous work on holocentric chromosomes in the angiosperm genus Carex demonstrates that many of the traditional sections are marked by different ranges of chromosome number, suggesting phylogenetic autocorrelation. It has been hypothesized that shifting constraints on chromosome rearrangements may limit the potential for hybridization among lineages, promoting speciation. In this study, we evaluated alternative evolutionary models to test for such transitions in Carex section Spirostachyae as well as the relative effects of several plausible drivers of intraspecific chromosome diversity. Chromosome number variation in section Spirostachyae shows significant phylogenetic signal, but no evidence of clade-specific shifts in chromosome number distribution. This gradual model of chromosome evolution contrasts with the shifting equilibrium model previously identified in a younger section of the same genus, suggesting that section Spirostachyae may have a more slowly evolving karyotype. Chromosome number variance, on the other hand, exhibits low phylogenetic signal. Average time of coalescence rather than geographic range or chromosome number itself predicts chromosome number variance, demonstrating a previously unreported relationship between population history and cytogenetic variation.

  13. A new species of Carex section Abditispicae (Cyperaceae from South America and additional notes on the section

    Directory of Open Access Journals (Sweden)

    Gerald A. Wheeler

    2002-01-01

    Full Text Available Se describe una nueva especie de Bolivia, Carex ruthsatzae perteneciente a la sección Abditispicae (Cyperaceae. Esta especie crece en ciénagas altoandinas, por arriba de los 4000 m s.m. y se caracteriza por sus espigas casi sésiles, escondidas en la base de la planta y por sus hojas angostas, de menos de 1,5 mm de ancho. Se agregan notas sobre distribución geográfica y hábitat de otras especies de esta sección así como también una clave. Además, debido a que algunas de las especies muestran tendencia a la dioecia, esta llamativa adaptación se discute brevemente

  14. Gas exchange and growth responses to nutrient enrichment in invasive Glyceria maxima and native New Zealand Carex species

    DEFF Research Database (Denmark)

    Sorrell, Brian Keith; Brix, Hans; Fitridge, Isla

    2012-01-01

    We compared photosynthetic gas exchange, the photosynthesis-leaf nitrogen (N) relationship, and growth response to nutrient enrichment in the invasive wetland grass Glyceria maxima (Hartman) Holmburg with two native New Zealand Carex sedges (C. virgata Boott and C. secta Boott), to explore......) in G. maxima (17 ± 6 m2 kg-1) was 1.3 times that of the sedges, leading to 1.4 times higher maximum rates of photosynthesis (350 – 400 nmol CO2 g-1 dry mass s-1) expressed on a leaf mass basis (Amaxm) when N supply was unlimited, compared to the sedges (... of Covariance (ANCOVA) revealed significant positive relationships between leaf N content and chlorophyll a:b ratios, stomatal conductance (gs), dark respiration rate (Rd), and the photosynthetic light saturation point (Ik) in G. maxima, but not in the sedges. ANCOVA also identified that, compared to G. maxima...

  15. Fe and P solubilization under limiting conditions by bacteria isolated from Carex kobomugi roots at the Hasaki coast.

    Science.gov (United States)

    Matsuoka, Hiroaki; Akiyama, Masaru; Kobayashi, Katsuichiro; Yamaji, Keiko

    2013-03-01

    Our objective was simply to report a sedge species, Carex kobomugi Ohwi that has beneficial bacterial associations under low Fe and P conditions of the Hasaki coast, Japan. C. kobomugi is the dominant species in our study area and grows closest to the sea. C. kobomugi showed higher Fe and P content, while these nutrients were less available under alkaline root-zone soil. Within the roots, mycorrhizal fungal colonization was absent, and endophytic fungal colonization was low. On the contrary, endophytic bacteria (e.g. Bacillus sp., Streptomyces luteogriseus, and Pseudomonas fluorescens) were isolated, which exhibited both siderophore production and inorganic phosphate solubilization under Fe or P limited conditions. Our results suggest that colonization of root tissue by these bacteria contribute to the Fe and P uptakes by C. kobomugi by increasing availability in the soil.

  16. 金嘴蝎尾蕉花部维管束系统的解剖学研究%Floral Vascular System Anatomy of Heliconia rostrata ( Heliconiaceae )

    Institute of Scientific and Technical Information of China (English)

    胡建竹; 邹璞; 王小宾; 廖景平

    2011-01-01

    The floral vascular system of Heliconia rostrata Ruiz & Pavon were studied using paraffin section. Results showed that the carpellary dorsal bundles (cdbs) from the prolongation base were divided into two strands. A mixture of inner strands and placental bundles ran into the style. The two abaxial outer strands generated 2 -4 branches and entered into the outer whorl at the two abaxial stamens,while the adaxial outer branch was the midrib of the staminode vasculature, which indicated its degenerate structure. After splitting into 3-5 strands at the top of the prolongation, the three parietal bundles (pbs) entered into the three stamens of the inner whorl and the remaining bundles of the ovary wall ultimately clustered into the perianth. Our results suggest that the degenerate structure with the outer androecial whorl is part of the androecium as it has the same origin of the vascular trace,Heliconiaceae is a sister family of the ginger group,different from the banana group.%利用石蜡切片技术对蝎尾蕉科代表植物金嘴蝎尾蕉(Heliconia rostrata Ruiz&Pavon)的花部维管束系统进行了解剖学研究.结果表明,心皮背束在延长部的基部分裂为内外2分支,内方分支与胎座维管束汇合后进入花柱,远轴面2枚外方分支在延长部的顶部分裂为2~4束进入远轴面2枚外轮雄蕊,而近轴面1枚外方分支则进入退化结构成为其中脉;隔膜束在延长部顶部亦分裂为3-5束,最终分别进入3枚内轮雄蕊;子房壁其它维管束最终进入花被片.本研究认为金嘴蝎尾蕉花部花瓣状退化结构与另外2枚外轮雄蕊具有完全相同的维管束系统来源,应属于雄蕊成员,且支持Kress关于蝎尾蕉科是姜群的姊妹群,区别于芭蕉群其它3科的观点.

  17. A regional approach to plant DNA barcoding provides high species resolution of sedges (Carex and Kobresia, Cyperaceae) in the Canadian Arctic Archipelago.

    Science.gov (United States)

    Clerc-Blain, Jessica L E; Starr, Julian R; Bull, Roger D; Saarela, Jeffery M

    2010-01-01

    Previous research on barcoding sedges (Carex) suggested that basic searches within a global barcoding database would probably not resolve more than 60% of the world's some 2000 species. In this study, we take an alternative approach and explore the performance of plant DNA barcoding in the Carex lineage from an explicitly regional perspective. We characterize the utility of a subset of the proposed protein-coding and noncoding plastid barcoding regions (matK, rpoB, rpoC1, rbcL, atpF-atpH, psbK-psbI) for distinguishing species of Carex and Kobresia in the Canadian Arctic Archipelago, a clearly defined eco-geographical region representing 1% of the Earth's landmass. Our results show that matK resolves the greatest number of species of any single-locus (95%), and when combined in a two-locus barcode, it provides 100% species resolution in all but one combination (matK + atpFH) during unweighted pair-group method with arithmetic mean averages (UPGMA) analyses. Noncoding regions were equally or more variable than matK, but as single markers they resolve substantially fewer taxa than matK alone. When difficulties with sequencing and alignment due to microstructural variation in noncoding regions are also considered, our results support other studies in suggesting that protein-coding regions are more practical as barcoding markers. Plastid DNA barcodes are an effective identification tool for species of Carex and Kobresia in the Canadian Arctic Archipelago, a region where the number of co-existing closely related species is limited. We suggest that if a regional approach to plant DNA barcoding was applied on a global scale, it could provide a solution to the generally poor species resolution seen in previous barcoding studies.

  18. Carex hezhouensis, a new species of Cyperaceae from Guangxi, China%广西薹草属(莎草科)一新种--贺州薹草

    Institute of Scientific and Technical Information of China (English)

    王泓; 王绍能; 宋晓军

    2005-01-01

    @@ 贺州薹草新种图版Ⅰ Carex hezhouensis Hong Wang & S.N.Wang,sp.nov.Fig.1. Species affinis C.tianmushanicae C.Z.Zheng & X.F.Jin,sed foliis angustioribus,2.5~4 mm latis,utriculis glabris,3~4 mm longis, nucibus medio non constrictis,1.5~2 mm longis,stylis basi pubescentibus differt.

  19. Non-systemic fungal endophytes in Carex brevicollis may influence the toxicity of the sedge to livestock

    Directory of Open Access Journals (Sweden)

    Rosa M. Canals

    2014-07-01

    Full Text Available The sedge Carex brevicollis is a common component of semi-natural grasslands and forests in temperate mountains of Central and Southern Europe. The consumption of this species causes a severe toxicity to livestock, associated to high plant concentrations of the β-carbolic alkaloid brevicolline. This research was started to ascertain the origin of this toxicity. An exploratory survey of alkaloid content in plants growing in contrasting habitats (grasslands/forests did not contribute to find a pattern of the variable contents of brevicolline in plants, and led us to address other possibilities, such as a potential role of fungal endophytism. Systemic, vertically-transmitted endophytes producers of herbivore-deterrent alkaloids are known to infect many known forage grasses. We did not detect systemic endophytes in C. brevicollis, but the sedge harboured a rich community of non-systemic fungi. To test experimentally whether non-systemic endophytes influenced the synthesis of the alkaloid, 24 plants were submitted to a fungicide treatment to remove the fungal assemblage, and the offspring ramets were analysed for alkaloid content. Brevicolline was the major β-carbolic alkaloid detected, and the contents were at least five times lower in the new ramets that developed from fungicide-treated plants than in the untreated plants. This result, although not conclusive about the primary source of the alkaloid (a plant or a fungal product indicates that fungal endophytes may affect the contents of the toxic brevicolline in this sedge.

  20. Effects of hydrological regime on development of Carex wet meadows in East Dongting Lake, a Ramsar Wetland for wintering waterbirds

    Science.gov (United States)

    Jing, Lei; Lu, Cai; Xia, Yan; Shi, Linlu; Zuo, Aojie; Lei, Jialing; Zhang, Hong; Lei, Guangchun; Wen, Li

    2017-01-01

    Wet meadows are one of the most important ecological components in floodplain, and are among the most dynamic ecosystems. Understanding the development of wet meadows and contributing environmental factors can provide better support for wetland management. Carex meadows in East Dongting Lake National Nature Reserve (EDLNNR) provide vital wintering ground for thousands of migratory waterbirds, and their ecological functions are under threated due to hydrological alternation. We measured wet meadow expansion in EDLNNR from 1989 to 2014, and explored its responses to hydrological and climatic factors within the generalised additive models (GAM) framework. We found an overall expansion of wet meadows over the study period. However, in contrast to many previous studies, our results showed that water level fluctuations at the hydrologic indicator site had only limited impacts on their development. Instead, sampling year, timing of water level recession, and local rainfall exerted significant effects. The effects of sampling year reflected the changes in sedimentation within Dongting Lake; and effects of timing of water withdrawal might be explained by the life history of the dominant sedge species. Our study suggested that the impacts of large scale hydrological alternation on vegetation may operate indirectly through its effects on sediment balance. PMID:28165508

  1. Impact climate change factors on the clonal sedge Carex bigelowii. Implications for population growth and vegetative spread

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, B.Aa. (Lund Univ., Dept. of Ecology, Plant Ecology, Lund (Sweden)); Callaghan, T.V. (Univ. of Manchester, Centre for Arctic Biology, School of Biological Sciences, Manchester (United Kingdom))

    1994-12-01

    Hypothesized life-cycle responses to climate change for the arctic, clonal perennial Carex bigelowii are constructed using a range of earlier observations and experiments together with new information from monitoring and an environmental perturbation study. These data suggest, that under current climate change scenarios, increases in CO[sub 2], temperature and nutrient availability would promote growth in a qualitatively similar way. The evidence suggests that both tiller size and daughter tiller production will increase, and be shifted towards production of phalanx tillers which have a greater propensity for flowering. Furthermore, age at tillering as well as tiller life span may decrease, whereas survival of younger age classes might be higher. Mathematical models using experimental data incorporating these hypotheses were used to (a) integrate the various responses and to calculate the order of magnitude of changes in population growth rate ([lambda]), and (b) to explore the implications of responses in individual demographic parameters for population growth rate. The models suggest that population growth rate following climate change might increase significantly, but not unrealistically so, with the younger, larger, guerilla tillers being the most important tiller categories in contributing to [lambda]. The rate of vegetative spread is calculated to more than double, while cyclical trends in flowering and population growth are predicted to decrease substantially. (au) (43 refs.)

  2. Consequences of Repeated Defoliation on Belowground Bud Banks of Carex brevicuspis (Cyperaceae) in the Dongting Lake Wetlands, China.

    Science.gov (United States)

    Chen, Xin-Sheng; Deng, Zheng-Miao; Xie, Yong-Hong; Li, Feng; Hou, Zhi-Yong; Wu, Chao

    2016-01-01

    Despite the predominant role of bud banks in the regeneration of clonal macrophyte populations, few studies have examined the way in which clonal macrophytes adjust the demographic features of bud banks to regulate population dynamics in response to defoliation in wetlands. We investigated the density and composition of bud banks under repeated defoliation in the wetland sedge Carex brevicuspis C. B. Clarke in the Dongting Lake wetlands, China. The density and biomass of rhizome buds and shoots did not decrease significantly in response to repeated defoliation over two consecutive years. The composition of bud banks, which consisted of long and short rhizome buds, also did not change significantly in response to repeated defoliation. Nevertheless, the ramet height and the shoot, root, and rhizome mass of C. brevicuspis declined significantly under repeated defoliation. Our findings suggest that bud banks are a conservative reproductive strategy that enables C. brevicuspis to tolerate a certain amount of defoliation. The maintenance of large bud banks after repeated defoliation may enable C. brevicuspis populations to regenerate and persist in disturbed habitats. However, bud bank density of C. brevicuspis might decline in the long term because the amount of carbon stored in rhizome buds and plants is reduced by frequent defoliation.

  3. Distribution and habitat properties of Carex pulicaris and Pedicularis sylvatica at their range margin in NW Poland

    Directory of Open Access Journals (Sweden)

    Zofia Sotek

    2016-09-01

    Full Text Available This paper presents the distribution dynamics, soil and phytocoenotical conditions of the occurrence of Carex pulicaris and Pedicularis sylvatica at the margin of their range in NW Poland. Dynamic cartograms of these species were made on the basis of our field studies and available contemporary and historical records. The studies showed that the plants grow on organic hemic-muck soils, mucky soils and typical muckous soils. The occurrence of these two species on different types of soils proves that they are able to adapt easily to varying habitat conditions of post-bog areas. Populations of C. pulicaris and P. sylvatica were most frequently not numerous and occurred in small community patches. Analyzed phytocoenoses with C. pulicaris have been classified as the community of the alliance Caricion davallianae or the alliance Molinion. Phytocoenoses with P. sylvatica are represented by the association Nardo-Juncetum squarrosi and the community of the class Molinio-Arrhenatheretea. The distribution dynamics of these species shows that they are disappearing from some parts of this region, which proves the recessive trends. This process is more intensive for P. sylvatica, which should be included in the red list of Polish plants like C. pulicaris. The disappearance of the populations of both species has been caused by worsening habitat conditions (insufficient moisture, eutrophication, expansion of competitive plant species and land abandonment.

  4. Subcellular partitioning of non-essential trace metals (Ag, As, Cd, Ni, Pb, and Tl) in livers of American (Anguilla rostrata) and European (Anguilla anguilla) yellow eels

    Energy Technology Data Exchange (ETDEWEB)

    Rosabal, Maikel [Institut national de la recherche scientifique, Centre Eau Terre et Environnement (INRS–ETE), 490 de la Couronne, Québec (Québec) G1K 9A9 (Canada); Pierron, Fabien [Université de Bordeaux, UMR EPOC CNRS 5805, F-33400 Talence (France); CNRS, EPOC, UMR 5805, F-33400 Talence (France); Couture, Patrice [Institut national de la recherche scientifique, Centre Eau Terre et Environnement (INRS–ETE), 490 de la Couronne, Québec (Québec) G1K 9A9 (Canada); Baudrimont, Magalie [Université de Bordeaux, UMR EPOC CNRS 5805, F-33400 Talence (France); CNRS, EPOC, UMR 5805, F-33400 Talence (France); Hare, Landis [Institut national de la recherche scientifique, Centre Eau Terre et Environnement (INRS–ETE), 490 de la Couronne, Québec (Québec) G1K 9A9 (Canada); Campbell, Peter G.C., E-mail: peter.campbell@ete.inrs.ca [Institut national de la recherche scientifique, Centre Eau Terre et Environnement (INRS–ETE), 490 de la Couronne, Québec (Québec) G1K 9A9 (Canada)

    2015-03-15

    Highlights: • Handling of hepatic metals consistently involved cytosolic, thermostable ligands. • Granule-like fractions are also involved in the detoxification of Ni, Pb, and Tl. • Despite these sequestration mechanisms, metal detoxification is incomplete. • Along the metal gradient, concentrations increase in metal-sensitive fractions. • This increase could represent a toxicological risk for the yellow eels. - Abstract: We determined the intracellular compartmentalization of the trace metals Ag, As, Cd, Ni, Pb, and Tl in the livers of yellow eels collected from the Saint Lawrence River system in Canada (Anguilla rostrata) and in the area of the Gironde estuary in France (Anguilla anguilla). Differential centrifugation, NaOH digestion and thermal shock were used to separate eel livers into putative “sensitive” fractions (heat-denatured proteins, mitochondria and microsomes + lysosomes) and detoxified metal fractions (heat-stable peptides/proteins and granules). The cytosolic heat-stable fraction (HSP) was consistently involved in the detoxification of all trace metals. In addition, granule-like structures played a complementary role in the detoxification of Ni, Pb, and Tl in both eel species. However, these detoxification mechanisms were not completely effective because increasing trace metal concentrations in whole livers were accompanied by significant increases in the concentrations of most trace metals in “sensitive” subcellular fractions, that is, mitochondria, heat-denatured cytosolic proteins and microsomes + lysosomes. Among these “sensitive” fractions, mitochondria were the major binding sites for As, Cd, Pb, and Tl. This accumulation of non-essential metals in “sensitive” fractions likely represents a health risk for eels inhabiting the Saint Lawrence and Gironde environments.

  5. 78 FR 37327 - Endangered and Threatened Wildlife and Plants; Proposed Designation of Critical Habitat for the...

    Science.gov (United States)

    2013-06-20

    ... dominated by beaked sedge (Carex rostrata) or reed canarygrass (Phalaris arundinacea) alliances; or (b... primarily of sedges (Carex spp. or Schoenoplectus pungens) and forbs, including, but not limited to one or more of the following associated species: Spikerush (Eleocharis macrostachya), beaked sedge...

  6. Fractal relationship between aboveground biomass and plant length or sheath height of Carex lasiocarpa population%毛果苔草种群地上生物量与株长或鞘高分形特征

    Institute of Scientific and Technical Information of China (English)

    何池全; 赵魁义

    2003-01-01

    By using the principles and methods of fractal geometry theory,the relationship between aboveground biomass and plant length or sheath height of Carex lasiocarpa population was studied,The results showed that there was a good staic fractal relationship between them.and the resulted fractal dimension was an efficient description of the accumulation of aboveground biomass in each organ.The dynamic fractal relationship showed that during the whole growing season,the increase of aboveground biomass had a self-similarity,being a fractal growth process and the pattern of its increase was the fractal dimension D.Based on these results,a fractal growth model of Carex lasiocarpa population was established ,which regarded the bigger grass as the result of the amplification of seedling growth.

  7. 三江平原毛苔草沼泽蒸散量模拟研究%Modelling Evapotranspiration of Carex lasiocarpa Marshes in Sanjiang Plain

    Institute of Scientific and Technical Information of China (English)

    贾志军; 姬兴杰

    2014-01-01

    提高湿地蒸散量估算精度对于研究湿地水分和能量平衡以及区域气候特征具有重要意义.利用Pen-man、FAO Penman-Monteith、Priestley-Taylor、Blaney-Criddle、Hargreaves、Mc-Cloud、Linacre和Makkink模型,模拟三江平原毛苔草(Carex lasiocarpa)沼泽蒸散量.结果表明,采用FAO推荐的作物系数时,各模型模拟蒸散量明显高于涡度相关系统测量值,平均高估92.8%.利用实测数据修正作物系数后,除Makkink模型外,其余模型的模拟精度都明显提高,其中,基于能量平衡的Penman、FAO Penman-Monteith和Priestley-Taylor模型的模拟结果明显优于基于温度的Blaney-Criddle、Hargreaves、McCloud和Linacre模型.在基于能量平衡的蒸散模型中,Priestley-Taylor模型的模拟结果最接近实测值;在基于温度的蒸散模型中,Hargreaves模型的模拟结果最接近实测值.

  8. Strait of Gibraltar: an effective gene-flow barrier for wind-pollinated Carex helodes (Cyperaceae) as revealed by DNA sequences, AFLP, and cytogenetic variation.

    Science.gov (United States)

    Escudero, Marcial; Vargas, Pablo; Valcárcel, Virginia; Luceño, Modesto

    2008-06-01

    The Strait of Gibraltar is the most important barrier disconnecting the landmasses of Europe and Africa on the western Mediterranean extreme. Carex helodes is a wind-pollinated species endemic to the western Mediterranean. Because molecular and cytogenetic data allow the inference of its evolutionary history, we analyzed variations in chromosome number, including meiotic chromosome behavior, amplified fragment length polymorphism (AFLP) fingerprints, and nucleotide substitutions in plastid and nuclear DNA sequences. Cytogeographic results showed that the African populations have stabilized at a single chromosome number of 2n = 74, whereas the most frequent cytotype in Iberia is 2n = 72. Phylogenetic reconstructions of 17 sequences from nine closely related species revealed that C. helodes is monophyletic and that the Moroccan populations are embedded in the Iberian lineages. The haplotype network is also consistent with a European origin of the northern African haplotype. AFLP analysis also revealed hierarchical levels of genetic variation compatible with a founder effect process responsible for the African populations. All sources of evidence support the hypothesis that the Strait of Gibraltar has been an effective gene-flow barrier, generating two isolated evolutionary lineages after their dispersal. Recent connections between the two lineages appear unlikely, whereas active gene flow occurs among populations within the two lineages.

  9. Grown on Novel Microcarriers

    Directory of Open Access Journals (Sweden)

    Torsten Falk

    2012-01-01

    Full Text Available Human retinal pigment epithelial (hRPE cells have been tested as a cell-based therapy for Parkinson’s disease but will require additional study before further clinical trials can be planned. We now show that the long-term survival and neurotrophic potential of hRPE cells can be enhanced by the use of FDA-approved plastic-based microcarriers compared to a gelatin-based microcarrier as used in failed clinical trials. The hRPE cells grown on these plastic-based microcarriers display several important characteristics of hRPE found in vivo: (1 characteristic morphological features, (2 accumulation of melanin pigment, and (3 high levels of production of the neurotrophic factors pigment epithelium-derived factor (PEDF and vascular endothelial growth factor-A (VEGF-A. Growth of hRPE cells on plastic-based microcarriers led to sustained levels (>1 ng/ml of PEDF and VEGF-A in conditioned media for two months. We also show that the expression of VEGF-A and PEDF is reciprocally regulated by activation of the GPR143 pathway. GPR143 is activated by L-DOPA (1 μM which decreased VEGF-A secretion as opposed to the previously reported increase in PEDF secretion. The hRPE microcarriers are therefore novel candidate delivery systems for achieving long-term delivery of the neuroprotective factors PEDF and VEGF-A, which could have a value in neurodegenerative conditions such as Parkinson’s disease.

  10. Noteworthy plants of Carex Linn.(Cyperaceae) from China%中国薹草属(莎草科)植物资料增补

    Institute of Scientific and Technical Information of China (English)

    赵银佳; 沈婷婷; 唐美琴; 孙莉; 金孝锋

    2011-01-01

    This paper is a supplement of the sedges (Carex-Cyperaceae) for Flora of China. Nine species were reduced to synonyms, viz. C. Schkuhriana was synonymized to C. Dimorpholepis, C. Sinomairei to C. Fedia, C. Trappistarum to C. Heterolepis, C. Paucimascula and C. Neokukenthaliana to C. Lanceolata, C. Dunniana to C. Ligulata , C. Cavaleriensis to C. Macrosandra, C. Lyi to C. Oxyphylla, C. Tricarinata to C. Planiculmis. These species were described by Franchet, Leveille and Vanoit during late 19th century and early 20th century, with the types conserved in the Paris Phanerogam Herbarium of National Museum of Natural History, but not recorded in Chinese literature. Eleven new distribution records were newly recorded in the provinces of China.%报道了作者在查阅、整理和鉴定法国巴黎自然历史博物馆显花植物标本馆中采自中国的薹革属Carex标本时,发现的9个新异名.其中C.schkuhriana归并于C.dimorpholepis,C.sinomairei归并于C.fedia,C.trappistarum归并于C.heterolepis,C.paucimascula和C.neokukenthaliana归并于C.lanceolata,C.dunniana归并于C.ligulata,C.cavaleriensis归并于C.macrosandra,C.lyi归并于C.oxyphylla,C.tricarinata归并于C.planiculmis.这些归并的名称是Franchet、Léveillé和Vanoit在19世纪末和20世纪初发表,但尚未被国内的文献所收载.同时还报道了近年来在采集和查阅标本过程中发现的中国省级薹草属植物新记录种.

  11. Differential Responses of N:P Stoichiometry of Leymus chinensis and Carex korshinskyi to N Additions in a Steppe Ecosystem in Nei Mongol

    Institute of Scientific and Technical Information of China (English)

    ZHANGLi-Xia; BAIYong-Fei; HANXing-Guo

    2004-01-01

    The typical steppe ecosystems in China are now being increasingly degraded due mainly toovergrazing. To determine the limiting nutrients is of significance in order to find out ways of successfullyrestoring the degraded steppe. In addition to field fertilization experiments, N:P stoichiometry is an alternative,but argumentative tool to study nutrient limitation. In this study, we used these two approaches to identifythe most limiting nutrient element at the species level. Furthermore, nutrient addition experimentprovides an effective means to test our hypothesis that N:P stoichiometry will remain constant becauserelatively narrow range of N:P ratio in tissues of the terrestrial plants is an important adaptive mechanismfor plants to survive on earth. For these purposes, we designed a field experiment to examine theresponses of biomass and N:P stoichiometry of the two dominant species -- Leyrnus chinensis (Trin.)Tzvel. and Carex korshinskyiKom. -- to N fertilization at rates of O, 5, 15, 30, 50 and 80 g NH4NO3.m-2.a-~in two adjacent sites, one being excluded animal grazing for 22 years (site A), and another being free ofgrazing for only two years (site B) before the experiment was carried out. No effects of N fertilization weredetected in the first year as reflected by the aboveground biomass and P concentrations of the twospecies. The regression analysis showed that N:P ratios of two species of both sites remained constant inthe second year. N fertilization significantly increased the N concentrations of two species in both years,while only significantly increased the P contents of the two species in the second year. N and P contentsof the two species were significantly correlated in all cases in 2001. Our results suggest that theL. chinensis was in short of N in site B while the growth of C. korshinskyi was limited by P in site A, andthere is a significant synergistic relationship between tissue N and P concentrations in 2001. Our hypothesiswas valid on the species

  12. A new Carex from Crete

    NARCIS (Netherlands)

    Gradstein, S.R.; Kern, J.H.

    1968-01-01

    Rhizoma caespitosum. Culmus erectus, triqueter, laevis, inferne foliatus, 15-30 cm altus. Folia culmo multo breviora, viridia vel cinereo-viridia, 1½-2½ mm lata, breviter acuminata, apice scaberula vel sublaevia, vaginis brunnescentibus; ligulae latiores quam longiores, obtusae vel subacutae. Bracte

  13. Distribution and the Correlativety of Plant Nutrient Element in Carex lasiocarpa Wetland%毛果苔草湿地植物营养元素分布及其相关性

    Institute of Scientific and Technical Information of China (English)

    何池全

    2002-01-01

    The distribution of nutrient was different for different dominant plant species in C.lasiocarpa wetland ecosystem.The distribution of nutrient was also different for different plant components in Carex lasiocarpa.The gross nutrient element distribution for N,P,K,Ca,Mg,Cu and Fe in C.lasiocarpa was in order of:redicula>rhizoma>spike>blade>sheath>inflorescence.But this rule for the gross nutrient element distribution of Zn and Mn was not obvious.The seasonal dynamic trends of nutrient element contents in dead stand were decreaseing.The liberation of general elements N,P,K and microelement Mn were continuous,and with monotone downtrend;the liberation rate of microelement Cu,Zn,Fe were faster than other elemnts,while the trend for Ca was all through incremental.There were different degrees of correlativity among different nutrient elements in C. Lasiocarpa.

  14. Self-activated Carex Meyeriana Kunth-based Porous Carbon Prepared by Direct Carbonization and Its Electrochemical Properties%自活化乌拉草基多孔碳的制备和电化学性质

    Institute of Scientific and Technical Information of China (English)

    王昀; 贲腾; 裘式纶

    2016-01-01

    Porous carbon material UlaC-950-HF( Ula stands for Carex meyeriana Kunth, C is short for carbo-nized, 950 is the optimized temperature, and HF is the etchant) was prepared through direct carbonization of Carex meyeriana Kunth after necessary impurity removal. The precursor self-activated in the process of pyroly-sis. The electrochemical measurements of the UlaC-950-HF sample and several other carbonized biomass-based porous carbon materials were carried out. The results revealed that the capacitance of UlaC-950-HF was 113 F/g. In addition, the electrode showed excellent cycling stability as its specific capacitance decreased only by 4 F/g after 4000 voltammetry cycles, showing its potential of being applied in the supercapacitor electrode material.%以乌拉草为原料,采用直接碳化方法,通过热解过程中前驱体自活化(即利用自身包含的活化剂实现分子内的化学活化),并经过必要的除杂过程制备了多孔碳材料UlaC-950-HF.测试了该多孔碳的电化学性质,并与以几种常见的生物质为原料制备的多孔碳材料及商用活性炭的电化学性质进行对比.结果表明,乌拉草基多孔碳材料UlaC-950-HF的电容值为113 F/g,经过4000次循环后,材料的电容值仅降低了4 F/g,显示出用作超级电容器电极材料的潜力.

  15. 76 FR 63093 - Endangered and Threatened Wildlife and Plants; 12-Month Finding for a Petition To List the...

    Science.gov (United States)

    2011-10-11

    ... recovery on Mulkey Creek. The study areas were differentiated by high and low coverage of Carex rostrata (beaked sedge) along the stream banks. Low coverage areas were typically associated with signs of cattle.... In both low and high sedge reaches, California golden trout more often selected undercut...

  16. Harvesting microalgae grown on wastewater.

    Science.gov (United States)

    Udom, Innocent; Zaribaf, Behnaz H; Halfhide, Trina; Gillie, Benjamin; Dalrymple, Omatoyo; Zhang, Qiong; Ergas, Sarina J

    2013-07-01

    The costs and life cycle impacts of microalgae harvesting for biofuel production were investigated. Algae were grown in semi-continuous culture in pilot-scale photobioreactors under natural light with anaerobic digester centrate as the feed source. Algae suspensions were collected and the optimal coagulant dosages for metal salts (alum, ferric chloride), cationic polymer (Zetag 8819), anionic polymer (E-38) and natural coagulants (Moringa Oleifera and Opuntia ficus-indica cactus) were determined using jar tests. The relative dewaterability of the algae cake was estimated by centrifugation. Alum, ferric chloride and cationic polymer could all achieve >91% algae recovery at optimal dosages. Life cycle assessment (LCA) and cost analysis results revealed that cationic polymer had the lowest cost but the highest environmental impacts, while ferric chloride had the highest cost and lowest environmental impacts. Based on the LCA results, belt presses are the recommended algae dewatering technology prior to oil extraction.

  17. Properties of soil and hydroponicaly grown lettuce

    OpenAIRE

    Mlakar, Mirjam

    2014-01-01

    The aim of the thesis was to examine the quality of the lettuce Lactuca sativa L., which was grown with two methods. Hydroponically grown lettuce was compared with lettuce grown in soil. The purpose of this research was to find out with which method the lettuce would look better and with which method the quality of the lettuce`s nutritiousness would be higher. We ascertained that plants grown with hydroponics did look better and were heavier. About quality results showed that the contents of ...

  18. 北京周边山地苔草属和委陵菜属植物功能性状%Plant functional traits of Carex and Potentilla around Beijing mountainous areas

    Institute of Scientific and Technical Information of China (English)

    李丹

    2013-01-01

    植物功能性状可有效反映植物代谢活动、生物化学组成以及养分吸收等特征.本研究通过分析北京周边山地苔草属和委陵菜属植物的功能性状数据,得出结论如下:(1)植株高度、叶长度、叶宽度、花长度、比叶面积和叶片氮、磷含量之间具有正相关的关系,叶厚度、叶干重与其他性状呈负相关.(2)系统进化因素是导致植株高度、叶长度和叶片总氮含量产生差异性的内在因素.(3)随着海拔升高,植株变矮小,花朵变小,叶片变窄,比叶面积更小,叶片总氮、总磷也变少,叶片变得更厚更重.综合来看,海拔和系统进化对苔草属和委陵菜属功能性状的影响基本相同,只有比叶面积与系统进化的关系在两属中出现差异.%Plant functional traits can effectively reflect the plant metabolism activities,biochemical components,and nutritional absorption.This paper analyzed the plant functional traits of Carex and Potentilla around Beijing mountainous areas,and the results showed that the plant height,leaf length,leaf width,flower length,specific leaf area (SLA),and leaf total nitrogen (TN) and total phosphorus (TP) contents had positive correlations with each other,and the leaf thickness and leaf weight had negative correlations with the other traits.Phylogenetic information affected the plant height,leaf length,and leaf TN content.With the increase of altitude,the plant height,leaf length,leaf width,flower length,SLA,and leaf TN and TP contents decreased,while the leaf thickness and leaf weight increased.Altitude and phylogenetic information had the same effects on the functional traits of Carex and Potentilla,only the relationships between SLA and phylogenetic information had differences.

  19. 毛果苔草湿地营养元素的积累、分配及其生物循环特征%The accumulation, allocation and biological cycle of the nutrient elements in Carex lasiocarpa wetland

    Institute of Scientific and Technical Information of China (English)

    何池全; 赵魁义

    2001-01-01

    毛果苔草(Carex lasiocarpa)湿地地上部分积累量小于地下部分的积累量,在地上几个构件中,叶片比叶鞘积累量大,而穗的积累量最小;地下部分中细根比根茎的积累量大.土壤分室营养元素贮量在系统的各分室中占绝对优势,毛果苔草湿地土壤中各种营养元素总贮量的顺序为:K>Fe>N>Ca>P>Mg>Mn>Zn>Cu;它们的吸收系数的排序是:Mn>N>P>Zn>Mg>Cu>Ca>Fe>K;几种营养元素的利用系数的排序是:Mn>N>P>Zn>Mg>Cu>Ca>Fe>K;几种营养元素的循环系数的排序为:Ca>K>Mg>N>P>Mn>Zn>Cu>Fe;因此,该系统中钙、钾的存留比例最小,而流动性较大,而铁则相反,存留比例大,流动性较小.

  20. Cloning and Sequence Analysis of A Heat Shock Transcription Factor Gene from Carex rigescens%白颖苔草热激转录因子基因的克隆及其序列分析

    Institute of Scientific and Technical Information of China (English)

    孙彦; 党卫玲; 杨春华; 邸超; 周禾

    2011-01-01

    The HSF gene cloned from Rigesecent Sedge (Carex rigescens (Franch. )V. Krecz. ) is an important heat-resistant candidate gene. A pair of degenerate primers designed against the conserved regions was used to amplify a cDNA segment (189 bp) from the Rigescent Sedge by RT-PCR. Based on the cDNA segment sequence, primers of 3' RACE were designed and a 902 bp cDNA segment was acquired. The primers of 5 RACE were designed from 3 end sequence of the segment and a 323 bp cDNA segment was acquired. The full-length cDNA (identified CrHSF,1226 bp) was gained by overlapping sequences. The sequence analysis indicates that it contains an open-reading frame from 103 bp to 1023 bp, encoding 306 amino acid residues, with 34. 93 kDa of predicted molecular mass and 5. 77 isoelectric points. The deduced amino acid sequence shows 59% similarity to OsHSF and it also shares significant similarities with other characterized heat shock transcription factor. In addition, the CrHSF contains no predicted signal peptide, but it contains several post-translation modification and processing sites.%白颖苔草(Carex rigescens(Franch.)V.Krecz.)的热激转录因子基因是重要的耐热候选基因.通过序列多重比对设计简并引物,扩增出白颖苔草的热击转录因子基因cDNA的中间片断,并在此基础上利用RACE技术得到3 ’端cDNA片段和5 ’端cDNA片段.结果表明:通过序列拼接获得该基因的全长cDNA(1226 bp),命名为CrHSF.序列分析表明其含有一个完整的开放阅读框(103~1023 bp),编码蛋白质含有306个氨基酸,分子量为38.75 kDa,等电点为5.85.CrHSF的氨基酸序列与OsHSF的同源性为59%,与已知的其他热激转录因子也具有较高的同源性.在CrHSF的氨基酸序列中没有预测到信号肽以及跨膜区域,但是具有多种翻译后修饰的加工位点.

  1. 白颖苔草热激转录因子(HSF1)真核表达载体的构建%Construction of eukaryotic expression vector bearing the heat shock factor in Carex rigescens

    Institute of Scientific and Technical Information of China (English)

    孙彦; 郭校民; 周禾

    2012-01-01

    Based on the characteristics of the expression vector PBI 121,and its enzyme sites,the appropriate primers were designed.Using the expression primers,we amplified the Escherichia coli bearing the cDNA with CrHsf of Rigens Sedge,and the open reading frame containing the right enzyme sites of CrHsf was got.The expression vectors and the aimed fragments were digested respectively,and then,the aimed DNA fragments were cloned into PBI 121 vector.Through PCR,double enzyme restriction analysis,it was confirmed that the PBI 121/HSF recombinant plasmid was successfully constructed.%根据表达载体PBI 121特性及酶切位点设计合适的引物,由表达引物通过PCR技术从含有白颖苔草(Carex rigescens)CrHsf全长cDNA的克隆载体的大肠杆菌上扩增出带有特定酶切位点的CrHsf完整开放阅读框。再对载体和目的片段进行酶切处理,处理后将正确的目的基因片段亚克隆至PBI 121植物表达载体。通过PCR及酶切鉴定,结果证明,目的基因片段已被正确克隆到表达载体上,载体构建成功。

  2. Luminescence from Erbium Oxide Grown on Silicon

    Science.gov (United States)

    2002-01-01

    H9.14 Luminescence from erbium oxide grown on silicon E. Nogales’, B. Mrndez , J.Piqueras’, R.Plugaru2 , J. A. Garcfa3 and T. J. Tate4 ’ Universidad ... Complutense de Madrid, Dpto. Ffsica de Materiales, 28040 Madrid, Spain.2Inst. of Microtechnology, Bucharest, Romania.3Universidad del Pais Vasco, Dpto

  3. Recrystallization phenomena of solution grown paraffin dendrites

    NARCIS (Netherlands)

    Hollander, F.F.A.; Stasse, O.; Suchtelen, van J.; Enckevort, van W.J.P.

    2001-01-01

    Paraffin crystals were grown from decane solutions using a micro-Bridgman set up for in-situ observation of the morphology at the growth front. It is shown that for large imposed velocities, dendrites are obtained. After dendritic growth, aging or recrystallization processes set in rather quickly, c

  4. Lethal photosensitization of biofilm-grown bacteria

    Science.gov (United States)

    Wilson, Michael

    1997-12-01

    Antibacterial agents are increasingly being used for the prophylaxis and treatment of oral diseases. As these agents can be rendered ineffective by resistance development in the target organisms there is a need to develop alternative antimicrobial approaches. Light-activated antimicrobial agents release singlet oxygen and free radicals which can kill adjacent bacteria and a wide range of cariogenic and periodontopathogenic bacteria has been shown to be susceptible to such agents. In the oral cavity these organisms are present as biofilms (dental plaques) which are less susceptible to traditional antimicrobial agents than bacterial suspensions. The results of these studies have shown that biofilm-grown oral bacteria are also susceptible to lethal photosensitization although the light energy doses required are grater than those needed to kill the organisms when they are grown as aqueous suspensions.

  5. Mineral composition of organically grown tomato

    Science.gov (United States)

    Ghambashidze, Giorgi

    2014-05-01

    In recent years, consumer concerns on environmental and health issues related to food products have increased and, as a result, the demand for organically grown production has grown. Results indicate that consumers concerned about healthy diet and environmental degradation are the most likely to buy organic food, and are willing to pay a high premium. Therefore, it is important to ensure the quality of the produce, especially for highly consumed products. The tomato (Lycopersicon esculentum) is one of the most widely consumed fresh vegetables in the world. It is also widely used by the food industries as a raw material for the production of derived products such as purees or ketchup. Consequently, many investigations have addressed the impact of plant nutrition on the quality of tomato fruit. The concentrations of minerals (P, Na, K, Ca and Mg) and trace elements (Cu, Zn and Mn) were determined in tomatoes grown organically in East Georgia, Marneuli District. The contents of minerals and Mn seem to be in the range as shown in literature. Cu and Zn were found in considerably high amounts in comparison to maximum permissible values established in Georgia. Some correlations were observed between the minerals and trace elements studied. K and Mg were strongly correlated with Cu and Zn. Statistically significant difference have shown also P, K and Mg based between period of sampling.

  6. The Role of Sedges in Methane Production and Emission From a Temperate Fen

    Science.gov (United States)

    Noyce, G. L.; Szarkowski, E. R.; Bubier, J. L.; Varner, R. K.

    2008-12-01

    Northern peatlands are the largest single natural source of atmospheric methane (CH4) and thus any changes in these fluxes could have global consequences. Positive correlations have been observed between sedge biomass and high CH4 emissions from peatlands. We examined the effect that Carex rostrata has on methane production and transport in Sallie's Fen, Barrington, NH. During the summer of 2008, CH4 fluxes, pore-water CH4 concentrations, and C. rostrata biomass, along with temperature, net ecosystem CO2 exchange (NEE), and water table depth, were measured from both clipped and unclipped plots. In clipped plots, all C. rostrata were clipped below the peat surface and then sealed with petroleum jelly and plastic bags. Unclipped plots were left undisturbed. We observed a strong positive correlation between C. rostrata biomass and CH4 fluxes. Initial findings suggest that sedges have a strong effect on gas transport. The average 18 cm (C. rostrata rooting depth) pore water CH4 concentrations in the clipped plots (6141 ppm CH4) were significantly higher (p<0.001) than in the unclipped plots (3912 ppm CH4). The past 20 years of data at Sallie's Fen also show that plots with more C. rostrata have higher mid-season CH4 fluxes, on average, than shrub-dominated plots. Depth to water table, however, may be a stronger control on CH4 fluxes than vegetation.

  7. Tissue grown in space in NASA Bioreactor

    Science.gov (United States)

    1998-01-01

    Dr. Lisa E. Freed of the Massachusetts Institute of Technology and her colleagues have reported that initially disc-like specimens of cartilage tend to become spherical in space, demonstrating that tissues can grow and differentiate into distinct structures in microgravity. The Mir Increment 3 (Sept. 16, 1996 - Jan. 22, 1997) samples were smaller, more spherical, and mechanically weaker than Earth-grown control samples. These results demonstrate the feasibility of microgravity tissue engineering and may have implications for long human space voyages and for treating musculoskeletal disorders on earth. Constructs grown on Mir (A) tended to become more spherical, whereas those grown on Earth (B) maintained their initial disc shape. These findings might be related to differences in cultivation conditions, i.e., videotapes showed that constructs floated freely in microgravity but settled and collided with the rotating vessel wall at 1g (Earth's gravity). In particular, on Mir the constructs were exposed to uniform shear and mass transfer at all surfaces such that the tissue grew equally in all directions, whereas on Earth the settling of discoid constructs tended to align their flat circular areas perpendicular to the direction of motion, increasing shear and mass transfer circumferentially such that the tissue grew preferentially in the radial direction. A and B are full cross sections of constructs from Mir and Earth groups shown at 10-power. C and D are representative areas at the construct surfaces enlarged to 200-power. They are stained red with safranin-O. NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). Photo credit: Proceedings of the National Academy of Sciences.

  8. Microscopy of nitride layers grown on diamond

    DEFF Research Database (Denmark)

    Pécz, B.; Tóth, L.; Barna, Á.;

    2011-01-01

    are determined by selected area electron diffraction. Besides threading dislocations a high number of inversion domains (ID) were formed in some GaN films. The preparation of the diamond surface and the growth conditions proved to affect significantly the formation of crystal defects such as threading...... dislocations and IDs. Single polarity GaN films with a low density of dislocations were achieved for the optimized growth conditions. The highest quality GaN layers were grown on AlN buffer in which two crystalline variants were nucleated, but one of them was overgrown already in the thickness of the buffer...

  9. 不同水分梯度下三江平原湿地漂筏苔草无性系株高生长特性%Ecological Attributes of Carex pseudocuraica over Different water Depth in the Sanjiang Plain

    Institute of Scientific and Technical Information of China (English)

    栾金花; 张乐; 邹元春; 吕宪国

    2006-01-01

    取三江平原沼泽湿地漂筏苔草(Carex pseudocuraica)无性系种群在生长季(5~9月)进行桶栽实验,设计了6个水分梯度,即持续干旱(土壤含水量S1和S2分别为20%和50%)和持续淹水(S3、S4、S5、和S6的淹水深度分别为0 cm、10 cm、30 cm和50 cm)6个水分处理水平,研究了漂筏苔草株高生长变化规律.结果表明:在6月末以前,各水分处理(S1~S6)下株高呈单峰曲线变化,高峰值分别出现在S3、S4和S5处理下.从7月份开始直到生长季末,随着生长时期的延续、土壤湿度的增大和水位的加深株高值不断增加,即株高在S6处理下最大,S1处理下最小.到8月末以后,深水处理S6的株高远远高于其它处理.生长季各水分处理下(S1~S5)的株高增长量均呈单峰曲线变化;在S6状态下株高增长量呈双峰曲线变化.处理S1、S2、S3和S4的植株高度绝对增长速率(HAGR)随着植物生长呈逐渐降低趋势;S5和S6状态下HAGR呈单峰曲线变化.随着水分含量的增加和水位的提高(6~9月),植株高度相对增长速率(HRGR)不断增加,S1处理下最小,S6处理下最大;5月份的HRGR值呈单峰曲线变化.随着植物的生长各水分处理下植株HRGR 5月时最大,6~9月依次减小.综合分析认为,漂筏苔草对水分条件的适应性较强,无论是缺水(土壤20%含水量)或淹水环境下均可生长,淹水50 cm时更有利于株高的增长,不同水分条件下株高及增长速率变化幅度较大.

  10. van der Waals Heterostructures Grown by MBE

    Science.gov (United States)

    Hinkle, Christopher

    In this work, we demonstrate the high-quality MBE heterostructure growth of various layered 2D materials by van der Waals epitaxy (VDWE). The coupling of different types of van der Waals materials including transition metal dichalcogenide thin films (e.g., WSe2, WTe2, HfSe2) , insulating hexagonal boron nitride (h-BN), and topological insulators (e.g., Bi2Se3) allows for the fabrication of novel electronic devices that take advantage of unique quantum confinement and spin-based characteristics. The relaxed lattice-matching criteria of van der Waals epitaxy has allowed for high-quality heterostructure growth with atomically abrupt interfaces, allowing us to couple these materials based primarily on their band alignment and electronic properties. We will discuss the impact of sample preparation, surface reactivity, and lattice mismatch of various substrates (sapphire, graphene, TMDs, Bi2Se3) on the growth mode and quality of the films and will discuss our studies of substrate temperature and flux rates on the resultant growth and grain size. Structural and chemical characterization was conducted via reflection high energy electron diffraction (RHEED, X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning tunneling microscopy/spectroscopy (STM/S), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Experimentally determined band alignments have been determined and compared with first-principles calculations allowing the design of novel low-power logic and magnetic memory devices. Initial results from the electrical characterization of these grown thin films and some simple devices will also be presented. These VDWE grown layered 2D materials show significant potential for fabricating novel heterostructures with tunable band alignments and magnetic properties for a variety of nanoelectronic and optoelectronic applications.

  11. PLD-grown thin film saturable absorbers

    Energy Technology Data Exchange (ETDEWEB)

    Tellkamp, Friedjof

    2012-11-01

    The subject of this thesis is the preparation and characterization of thin films made of oxidic dielectrics which may find their application as saturable absorber in passively Q-switched lasers. The solely process applied for fabrication of the thin films was the pulsed laser deposition (PLD) which stands out against other processes by its flexibility considering the composition of the systems to be investigated. Within the scope of this thesis the applied saturable absorbers can be divided into two fundamentally different kinds of functional principles: On the one hand, saturable absorption can be achieved by ions embedded in a host medium. Most commonly applied bulk crystals are certain garnets like YAG (Y{sub 3}Al{sub 5}O{sub 12}) or the spinel forsterite (Mg{sub 2}SiO{sub 4}), in each case with chromium as dopant. Either of these media was investigated in terms of their behavior as PLD-grown saturable absorber. Moreover, experiments with Mg{sub 2}GeO{sub 4}, Ca{sub 2}GeO{sub 4}, Sc{sub 2}O{sub 3}, and further garnets like YSAG or GSGG took place. The absorption coefficients of the grown films of Cr{sup 4+}:YAG were determined by spectroscopic investigations to be one to two orders of magnitude higher compared to commercially available saturable absorbers. For the first time, passive Q-switching of a Nd:YAG laser at 1064 nm with Cr{sup 4+}:YAG thin films could be realized as well as with Cr:Sc{sub 2}O{sub 3} thin films. On the other hand, the desirable effect of saturable absorption can also be generated by quantum well structures. For this purpose, several layer system like YAG/LuAG, Cu{sub 2}O/MgO, and ZnO/corumdum were investigated. It turned out that layer systems with indium oxide (In{sub 2}O{sub 3}) did not only grew in an excellent way but also showed up a behavior regarding their photo luminescence which cannot be explained by classical considerations. The observed luminescence at roughly 3 eV (410 nm) was assumed to be of excitonic nature and its

  12. Superconductivity in MBE grown InN

    Energy Technology Data Exchange (ETDEWEB)

    Gunes, M.; Balkan, N. [School of Computer Science and Electronic Engineering, University of Essex, Wivenhoe Park, CO4 3SQ, Colchester (United Kingdom); Tiras, E.; Ardali, S. [Department of Physics, Faculty of Science, Anadolu University, Yunus Emre Campus, 26470, Eskisehir (Turkey); Ajagunna, A.O.; Iliopoulos, E.; Georgakilas, A. [Microelectronics Research Group, IESL, FORTH and Physics Department, University of Crete, P.O. Box 1385, 71110 Heraklion, Crete (Greece)

    2011-05-15

    We present the experimental investigation of superconductivity in unintentionally doped MBE grown InN samples with various InN film thicknesses. A significant change in resistivity was observed at 3.82 K, for an 1080 nm InN layer with carrier concentration n{sub 3D}=1.185x10{sup 19} cm{sup -3}. However, no significant resistance change was observed in the case of InN samples with carrier density of 1.024x10{sup 19} cm{sup -3}, 1.38x10{sup 19} cm{sup -3}, and thicknesses of 2070 and 4700 nm, respectively. The carrier density of all investigated samples was within the range of values between the Mott transition (2x10{sup 17} cm{sup -3}) and the superconductivity to metal transition (7x10{sup 20} cm{sup -3}). We believe that at lower temperatures ({sup 3}He) which we cannot achieve with our set-up, the phase transition in other samples is likely to be observed. The origin of the observed anisotropic type-II superconductivity is discussed (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. Systemic regulation of photosynthetic function in field-grown sorghum.

    Science.gov (United States)

    Li, Tao; Liu, Yujun; Shi, Lei; Jiang, Chuangdao

    2015-09-01

    The photosynthetic characteristics of developing leaves of plants grown under artificial conditions are, to some extent, regulated systemically by mature leaves; however, whether systemic regulation of photosynthesis occurs in field-grown crops is unclear. To explore this question, we investigated the effects of planting density on growth characteristics, gas exchange, leaf nitrogen concentration and chlorophyll a fluorescence in field-grown sorghum (Sorghum bicolor L.). Our results showed that close planting resulted in a marked decline in light intensity in lower canopy. Sorghum plants grown at a high planting density had lower net photosynthetic rate (Pn), stomatal conductance (Gs), and transpiration rate (E) than plants grown at a low planting density. Moreover, in the absence of mineral deficiency, close planting induced a slight increase in leaf nitrogen concentration. The decreased photosynthesis in leaves of the lower canopy at high planting density was caused mainly by the low light. However, newly developed leaves exposed to high light in the upper canopy of plants grown at high planting density also exhibited a distinct decline in photosynthesis relative to plants grown at low planting density. Based on these results, the photosynthetic function of the newly developed leaves in the upper canopy was not determined fully by their own high light environment. Accordingly, we suggest that the photosynthetic function of newly developed leaves in the upper canopy of field-grown sorghum plants is regulated systemically by the lower canopy leaves. The differences in systemic regulation of photosynthesis were also discussed between field conditions and artificial conditions.

  14. Influence of shading on container-grown flowering dogwoods

    Science.gov (United States)

    Bare root dogwoods can be successfully grown when transplanted into a container production system. Shade treatments regardless of color or density did have an effect on the plant growth of Cherokee Brave™ and Cherokee Princess dogwood. Plants grown under 50% black and 50% white shade had more heigh...

  15. Thermal behaviour of strontium tartrate single crystals grown in gel

    Indian Academy of Sciences (India)

    M H Rahimkutty; K Rajendra Babu; K Sreedharan Pillai; M R Sudarsana Kumar; C M K Nair

    2001-04-01

    Thermal behaviour of strontium tartrate crystals grown with the aid of sodium metasilicate gel is investigated using thermogravimetry (TG) and differential thermal analysis (DTA). Effect of magnetic field and dopant (Pb)2+ on the crystal stability is also studied using thermal analysis. This study reveals that water molecules are locked up in the lattice with different strengths in the grown crystals.

  16. Bioaccumulation of copper, lead, and zinc in six macrophyte species grown in simulated stormwater bioretention systems.

    Science.gov (United States)

    Rycewicz-Borecki, Malgorzata; McLean, Joan E; Dupont, R Ryan

    2016-01-15

    Stormwater bioretention (BR) systems collect runoff containing heavy metals, which can concentrate in soil environments and potentially leach into groundwater. This greenhouse experiment evaluated differences among six plant species undergoing three varying hydraulic and pollutant loads in their bioaccumulation potential when subjected to continual application of low metal concentrations as a means of preventing copper, lead, and zinc accumulation in the BR soil. Results show that >92% of metal mass applied to the treatments via synthetic stormwater was removed from the exfiltrate within 27 cm of soil depth. Compacted soil conditions of unplanted controls retained significantly more Cu, Pb, and Zn than Carex praegracilis, and Carex microptera treatments. Differences in above and below ground plant tissue concentrations differed among species, resulting in significant differences in mass accumulation. In the above ground tissue, from highest to lowest, Phragmites australis accumulated 8 times more Cu than Scirpus acutus, and C. microptera accumulated 18 times more Pb, and 6 times more Zn than Scirpus validus. These results, and differences among species in mass distribution of the metals recovered at the end of the study, reveal various metal accumulation mechanisms.

  17. Carbon Nanotube Microarrays Grown on Nanoflake Substrates

    Science.gov (United States)

    Schmidt, Howard K.; Hauge, Robert H.; Pint, Cary; Pheasant, Sean

    2013-01-01

    This innovation consists of a new composition of matter where single-walled carbon nanotubes (SWNTs) are grown in aligned arrays from nanostructured flakes that are coated in Fe catalyst. This method of growth of aligned SWNTs, which can yield well over 400 percent SWNT mass per unit substrate mass, exceeds current yields for entangled SWNT growth. In addition, processing can be performed with minimal wet etching treatments, leaving aligned SWNTs with superior properties over those that exist in entangled mats. The alignment of the nanotubes is similar to that achieved in vertically aligned nanotubes, which are called "carpets. " Because these flakes are grown in a state where they are airborne in a reactor, these flakes, after growing SWNTs, are termed "flying carpets. " These flakes are created in a roll-to-roll evaporator system, where three subsequent evaporations are performed on a 100-ft (approx. =30-m) roll of Mylar. The first layer is composed of a water-soluble "release layer, " which can be a material such as NaCl. After depositing NaCl, the second layer involves 40 nm of supporting layer material . either Al2O3 or MgO. The thickness of the layer can be tuned to synthesize flakes that are larger or smaller than those obtained with a 40-nm deposition. Finally, the third layer consists of a thin Fe catalyst layer with a thickness of 0.5 nm. The thickness of this layer ultimately determines the diameter of SWNT growth, and a layer that is too thick will result in the growth of multiwalled carbon nanotubes instead of single-wall nanotubes. However, between a thickness of 0.5 nm to 1 nm, single-walled carbon nanotubes are known to be the primary constituent. After this three-layer deposition process, the Mylar is rolled through a bath of water, which allows catalyst-coated flakes to detach from the Mylar. The flakes are then collected and dried. The method described here for making such flakes is analogous to that which is used to make birefringent ink that is

  18. Electronic states of germanium grown under micro-gravity condition

    Energy Technology Data Exchange (ETDEWEB)

    Sugahara, A. [Department of Physics, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan)]. E-mail: sugahara@tsurugi.phys.sci.osaka-u.ac.jp; Ogawa, T. [Department of Physics, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan); Fujii, K. [Department of Physics, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan); Ohyama, T. [Liberal Arts, Fukui University of Technology, 3-6-1 Gakuen, Fukui, Fukui 910-8505 (Japan); Nakata, J. [Kyoto Semiconductor Corp. 418-9 Yodo Saime-cho, Fushimi-ku, Kyoto 613-0915 (Japan)

    2006-04-01

    Magneto-optical absorption measurements of Sb-doped germaniums grown under micro-gravity condition were carried out to investigate the influence of the gravity on crystal growth, using far-infrared laser and microwave. For comparison, we prepared two germanium crystals grown in the same conditions except the gravity conditions. In spite of the quite short growth period, the germanium grown under micro-gravity has a quite good quality. The lineshape analysis of Zeeman absorption peaks due to donor electrons indicates the existence of residual thermal acceptors.

  19. Comparative lipid composition of heterotrophically and autotrophically grown Sulfolobus acidocaldarius.

    Science.gov (United States)

    Langworthy, T A

    1977-06-01

    Complex lipids from the thermoacidophilic facultative autotroph Sulfolobus acidocaldarius, as well as a strictly autotrophic isolate, were compared between cells grown on yeast extract and elemental sulfur. Lipids from both organisms grown autotrophically were nearly identical. Each contained about 15% neutral lipids, 35% glycolipids, and 50% acidic lipids. Glycolipids and acidic lipids contained C40H82-76-derived glycerol ether residues. Major glycolipids included the glycerol ether analogues of glucosyl galactosyl diglyceride (5%) and glucosyl polyol diglyceride (75%). Acidic lipids were comprised mainly of the glycerol ether analogues of phosphatidyl inositol (7%), inositolphosphoryl glucosyl polyol diglyceride (72%), and a partially characterized sulfate- and phosphate-containing derivative of glucosyl polyol diglyceride (13%). The lipids from cells grown heterotrophically were similar to those from autotrophically grown cells, except that the partially characterized acidic lipid was absent. In addition, the two glycolipids as well as the respective inositolphosphoryl derivatives were each present in nearly equal proportions.

  20. Membrane-bound respiratory chain of Pseudomonas aeruginosa grown aerobically.

    OpenAIRE

    Matsushita, K.; Yamada, M.; Shinagawa, E; Adachi, O; Ameyama, M

    1980-01-01

    The electron transport chain of the gram-negative bacterium Pseudomonas aeruginosa, grown aerobically, contained a number of primary dehydrogenases and respiratory components (soluble flavin, bound flavin, coenzyme Q9, heme b, heme c, and cytochrome o) in membrane particles of the organism. Cytochrome o, about 50% of the b-type cytochrome, seemed to function as a terminal oxidase in the respiratory chain. The electron transport chain of P. aeruginosa grown aerobically was suggested to be line...

  1. Re-grown aligned carbon nanotubes with improved field emission.

    Science.gov (United States)

    Lim, Xiaodai; Zhu, Yanwu; Varghese, Binni; Gao, Xingyu; Wee, Andrew Thye Shen; Sow, Chorng-Haur

    2012-01-01

    In this work, a simple technique to improve the field emission property of multi-walled carbon nanotubes is presented. Re-grown multi-walled carbon nanotubes are grown on the same substrates after the as-grown multi-walled carbon nanotubes are transferred to other substrates using polydimethylsiloxane as intermediation. For the duration of the synthesis of the re-grown multi-walled carbon nanotubes, similar synthesis parameters used in growing the as-grown multi-walled carbon nanotubes are utilized. As a form of possible application, field emission studies show -2.6 times improvement in field enhancement factor and more uniform emission for the re-grown multi-walled carbon nanotubes. In addition, the turn-on field is reduced from 2.85 V/microm to 1.40 V/microm. Such significant improvements are attributed to new emission sites comprising of sharp carbonaceous impurities encompassing both tip and upper portion of the multi-walled carbon nanotubes. As such, this technique presents a viable route for the production of multi-walled carbon nanotubes with better field emission quality.

  2. Defect studies in 4H- Silicon Carbide PVT grown bulk crystals, CVD grown epilayers and devices

    Science.gov (United States)

    Byrappa, Shayan M.

    Silicon Carbide [SiC] which exists as more than 200 different polytypes is known for superior high temperature and high power applications in comparison to conventional semiconductor materials like Silicon and Germanium. The material finds plethora of applications in a diverse fields due to its unique properties like large energy bandgap, high thermal conductivity and high electric breakdown field. Though inundated with superior properties the potential of this material has not been utilized fully due to impeding factors such as defects especially the crystalline ones which limit their performance greatly. Lots of research has been going on for decades to reduce these defects and there has been subsequent improvement in the quality as the diameter of SiC commercial wafers has reached 150mm from 25mm since its inception. The main focus of this thesis has been to study yield limiting defect structures in conjunction with several leading companies and national labs using advanced characterization tools especially the Synchrotron source. The in depth analysis of SiC has led to development of strategies to reduce or eliminate the density of defects by studying how the defects nucleate, replicate and interact in the material. The strategies discussed to reduce defects were proposed after careful deliberation and analysis of PVT grown bulk crystals and CVD grown epilayers. Following are some of the results of the study: [1] Macrostep overgrowth mechanism in SiC was used to study the deflection of threading defects onto the basal plane resulting in stacking faults. Four types of stacking faults associated with deflection of c/c+a threading defects have been observed to be present in 76mm, 100mm and 150mm diameter wafers. The PVT grown bulk crystals and CVD grown epilayers in study were subjected to contrast studies using synchrotron white beam X-ray topography [SWBXT]. The SWBXT image contrast studies of these stacking faults with comparison of calculated phase shifts for

  3. Seedborne fungal contamination: consequences in space-grown wheat

    Science.gov (United States)

    Bishop, D. L.; Levine, H. G.; Kropp, B. R.; Anderson, A. J.; Hood, E. E. (Principal Investigator)

    1997-01-01

    Plants grown in microgravity are subject to many environmental stresses that may promote microbial growth and result in disease symptoms. Wheat (cv. Super Dwarf) recovered from an 8-day mission aboard a NASA (National Aeronautics and Space Administration) space shuttle showed disease symptoms, including girdling of leaf sheaths and chlorosis and necrosis of leaf and root tissues. A Neotyphodium species was isolated from the seed and leaf sheaths of symptomatic wheat used in the spaceflight mission. Certain isozymes of a peroxidase unique to extracts from the microgravity-grown plants were observed in extracts from earth-grown Neotyphodium-infected plants but were not present in noninfected wheat. The endophytic fungus was eliminated from the wheat seed by prolonged heat treatment at 50 degrees C followed by washes with water at 50 degrees C. Plants from wheat seed infected with the Neotyphodium endophyte were symptomless when grown under greenhouse conditions, whereas symptoms appeared after only 4 days of growth in closed containers. Disease spread from an infected plant to noninfected plants in closed containers. Dispersion via spores was found on asymptomatic plants at distances of 7 to 18 cm from infected plants. The size and shape of the conidia, mycelia, and phialide-bearing structures and the ability to grow rapidly on carbohydrates, especially xylose, resembled the characteristics of N. chilense, which is pathogenic on orchard grass, Doctylis glomerati. The Neotyphodium wheat isolate caused disease symptoms on other cereals (wheat cv. Malcolm, orchard grass, barley, and maize) grown in closed containers.

  4. Nanostructures of Indium Gallium Nitride Crystals Grown on Carbon Nanotubes.

    Science.gov (United States)

    Park, Ji-Yeon; Man Song, Keun; Min, Yo-Sep; Choi, Chel-Jong; Seok Kim, Yoon; Lee, Sung-Nam

    2015-11-16

    Nanostructure (NS) InGaN crystals were grown on carbon nanotubes (CNTs) using metalorganic chemical vapor deposition. The NS-InGaN crystals, grown on a ~5-μm-long CNT/Si template, were estimated to be ~100-270 nm in size. Transmission electron microscope examinations revealed that single-crystalline InGaN NSs were formed with different crystal facets. The observed green (~500 nm) cathodoluminescence (CL) emission was consistent with the surface image of the NS-InGaN crystallites, indicating excellent optical properties of the InGaN NSs on CNTs. Moreover, the CL spectrum of InGaN NSs showed a broad emission band from 490 to 600 nm. Based on these results, we believe that InGaN NSs grown on CNTs could aid in overcoming the green gap in LED technologies.

  5. SERS-applicable silver nanoisland film grown under protective coating

    Science.gov (United States)

    Reduto, I.; Chervinskii, S.; Matikainen, A.; Baklanov, A.; Kamenskii, A.; Lipovskii, A.

    2014-10-01

    We have used recently developed out-diffusion technique of growing silver nanoisland films on glass surface to grow silver nanoislands under TiO2 layer deposited on the glass. After covering the surface of silver ion-exchanged glasses with TiO2 film using atomic layer deposition technique and subsequent thermal processing of the samples in hydrogen their optical absorption spectra demonstrate the absorption peak corresponding to surface plasmon resonance in grown silver nanoislands. The spectral position of the peak is shifted relatively to the peak observed in the spectra of the nanoisland film grown on the surface of ion exchanged and annealed glass samples without dielectric cover. The applicability of the silver nanoislands grown under several nm thick protective TiO2 coating in surface-enhanced Raman scattering spectroscopy is demonstrated.

  6. 地下水位和土壤含水量对若尔盖木里苔草沼泽甲烷排放通量的影响%Effect of Water Table and Soil Water Content on Methane Emission Flux at Carex muliensis Marshes in Zoig(e) Plateau

    Institute of Scientific and Technical Information of China (English)

    李丽; 雷光春; 高俊琴; 吕偲; 周延; 贾亦飞; 杨萌; 索郎夺尔基

    2011-01-01

    This study was conducted at a typical Carex muliensis marshes in Zoige Wetland National Nature Reserve located in the eastern edge of Qinghai-Tibet Plateau of China.Four sites that characterized by different groundwater tables were selected as the sampling sites,in which mean groundwater tables from low to high during the plant growing season were 53.94 cm,31.35 cm,11.50 cm,and 4.74 cm below the surface respectively,where a set of static closed chambers had been installed to take methane gas samples each month from June to September 2009.All samples were packed and sent to laboratory for measuring methane concentration within one week,and they were measured at the same conditions with Shimadzu GC212A gas chroma-tography.The results showed methane emission flux correlated with the groundwater table exponentially (n= 16,p0.05).Further analysis indicated that soil water content at the depth of 20-30 cm was main factor regulating CH4 mission flux (n=12,p<0.01).%在若尔盖湿地国家级自然保护区典型的木里苔草(Carex muliensis)沼泽地中,选择地下水位不同的4个采样点,其植物生长季的平均地下水位分别为距离地表53.94 cm、31.35 cm、11.50 cm和4.74 cm。利用密闭式静态箱定期采集气体样品,并在实验室用ShimadzuGC212A气相色谱仪测定CH4气体浓度,分析了CH4排放通量与地下水位和土壤含水量之间的关系。研究结果表明,地下水位和土壤含水量对CH4排放通量产生明显影响,6~9月观测日中,CH4排放通量随着地下水位的升高而呈指数增加;10~40 cm土层的土壤含水量与CH4排放通量呈现显著正相关(n=36,p<0.05),而0~10 cm土壤含水量与生长季CH4排放通量不相关(n=12,p>0.05),逐步线性回归分析表明,20~30 cm土层的土壤含水量是影响CH4排放通量的主要因素(n=12,p<0.01)。

  7. Structure of shaped sapphire grown from multicapillary dies

    Science.gov (United States)

    Dobrovinskaya, E. R.; Litvinov, L. A.; Pischik, V. V.

    1990-07-01

    Peculiarities in grain structure development have been studied in sapphire crystals grown with multicapillary channels in the die to feed melt to the crystallization zone. A new mechanism of grain boundary formation based on gas-bubble collapse at the crystal-melt interface is proposed.

  8. 76 FR 67320 - Walnuts Grown in California; Increased Assessment Rate

    Science.gov (United States)

    2011-11-01

    ..., these costs are offset by the benefits derived by the operation of the marketing order. In addition, the... Agricultural Marketing Service 7 CFR Part 984 Walnuts Grown in California; Increased Assessment Rate AGENCY: Agricultural Marketing Service, USDA. ACTION: Final rule. SUMMARY: This rule increases the assessment...

  9. Shade periodicity affects growth of container grown dogwoods

    Science.gov (United States)

    Container-grown dogwoods rank third in the US in nursery sales of ornamental trees. However, Dogwoods are a challenging crop to produce in container culture, especially when bare root liners are used as the initial transplant into containers due unacceptable levels of mortality and poor growth. This...

  10. Epitaxial thin films grown by pulsed laser deposition

    NARCIS (Netherlands)

    Blank, D.H.A.

    2005-01-01

    In this paper, we present the pulsed laser deposition (PLD) technique to control the growth of metal oxide materials at atomic level using high-pressure reflective high-energy electron diffraction and ellipsometry. These developments have helped to make PLD a grown-up technique to fabricate complex

  11. Commercially Grown Short Rotation Coppice Willow in Denmark

    DEFF Research Database (Denmark)

    Nord-Larsen, Thomas; Sevel, Lisbeth; Raulund-Rasmussen, Karsten

    2015-01-01

    The objectives of this study were to estimate biomass production in commercially grown short rotation coppice willow in Denmark and to investigate effects of site and management factors on willow yield. Biomass production assessed by non-destructive sampling on 296 plots from 25 plantations...

  12. 75 FR 9536 - Olives Grown in California; Increased Assessment Rate

    Science.gov (United States)

    2010-03-03

    ... Committee for the 2010 fiscal year include $300,000 for research, $255,000 for marketing activities, and... include $300,000 for research, $255,000 for marketing activities, and $324,923 for administration...; ] DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 932 Olives Grown in California;...

  13. 77 FR 33104 - Olives Grown in California; Increased Assessment Rate

    Science.gov (United States)

    2012-06-05

    ... Committee for the 2012 fiscal year include $333,791 for research, $480,000 for marketing activities, $50,000... marketing activities, $50,000 for inspection equipment development, and $333,500 for administration...; ] DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 932 Olives Grown in California;...

  14. Phase transition of bismuth telluride thin films grown by MBE

    DEFF Research Database (Denmark)

    Fülöp, Attila; Song, Yuxin; Charpentier, Sophie

    2014-01-01

    A previously unreported phase transition between Bi2Te3 and Bi4Te3 in bismuth telluride grown by molecular beam epitaxy is recorded via XRD, AFM, and SIMS observations. This transition is found to be related to the Te/Bi beam equivalent pressure (BEP) ratio. BEP ratios below 17 favor the formation...

  15. Antioxidative properties of some phototropic microalgae grown in waste water

    DEFF Research Database (Denmark)

    Safafar, Hamed; Jacobsen, Charlotte; Møller, Peter

    for the screening and selection of the species. In this study,the potential antioxidant activities of 12 micro algal sample from Chlorella., Spirulina., Euglena, Scenedesmus and Haematococcus species grown in waste water in Kalundborg micro algal facilities were evaluated using three antioxidant assays, including...

  16. Soybean micronutrient content in irrigated plants grown in the Midsouth

    Science.gov (United States)

    Micronutrients are essential to soybean (Glycine max L. Merr.) but required in minute quantities. Concentrations and tissue contents of Fe, B, Zn, Mn and Cu were determined for two MG IV and one MG V irrigated cultivars grown in twin-rows in the Mississippi Delta on clay and sandy loam soil sites i...

  17. 78 FR 77604 - Tomatoes Grown in Florida; Increased Assessment Rate

    Science.gov (United States)

    2013-12-24

    ...; ] DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 966 Tomatoes Grown in Florida; Increased Assessment Rate AGENCY: Agricultural Marketing Service, USDA. ACTION: Proposed rule. SUMMARY: This proposed... ``order.'' The order is effective under the Agricultural Marketing Agreement Act of 1937, as amended (7...

  18. 76 FR 50703 - Walnuts Grown in California; Increased Assessment Rate

    Science.gov (United States)

    2011-08-16

    ...; ] DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 984 Walnuts Grown in California; Increased Assessment Rate AGENCY: Agricultural Marketing Service, USDA. ACTION: Proposed rule. SUMMARY: This... Agricultural Marketing Agreement Act of 1937, as amended (7 U.S.C. 601-674), hereinafter referred to as...

  19. 78 FR 77327 - Walnuts Grown in California; Increased Assessment Rate

    Science.gov (United States)

    2013-12-23

    ... Agricultural Marketing Service 7 CFR Part 984 Walnuts Grown in California; Increased Assessment Rate AGENCY: Agricultural Marketing Service, USDA. ACTION: Final rule. SUMMARY: This rule increases the assessment rate..., hereinafter referred to as the ``order.'' The order is effective under the Agricultural Marketing...

  20. 78 FR 77367 - Almonds Grown in California; Continuance Referendum

    Science.gov (United States)

    2013-12-23

    ... Agricultural Marketing Service 7 CFR Part 981 Almonds Grown in California; Continuance Referendum AGENCY: Agricultural Marketing Service, USDA. ACTION: Referendum order. SUMMARY: This document directs that a... referred to as the ``order,'' and the applicable provisions of the Agricultural Marketing Agreement Act...

  1. 75 FR 22211 - Olives Grown in California; Increased Assessment Rate

    Science.gov (United States)

    2010-04-28

    ... Agricultural Marketing Service 7 CFR Part 932 Olives Grown in California; Increased Assessment Rate AGENCY: Agricultural Marketing Service, USDA. ACTION: Final rule. SUMMARY: This rule increases the assessment rate... California, hereinafter referred to as the ``order.'' The order is effective under the Agricultural...

  2. 77 FR 51684 - Olives Grown in California; Increased Assessment Rate

    Science.gov (United States)

    2012-08-27

    ... Agricultural Marketing Service 7 CFR Part 932 Olives Grown in California; Increased Assessment Rate AGENCY: Agricultural Marketing Service, USDA. ACTION: Final rule. SUMMARY: This rule increases the assessment rate... California, hereinafter referred to as the ``order.'' The order is effective under the Agricultural...

  3. 76 FR 8871 - Walnuts Grown in California; Decreased Assessment Rate

    Science.gov (United States)

    2011-02-16

    ... Marketing Service 7 CFR Part 984 Walnuts Grown in California; Decreased Assessment Rate AGENCY: Agricultural..., hereinafter referred to as the ``order.'' The order is effective under the Agricultural Marketing Agreement... Act (RFA) (5 U.S.C. 601-612), the Agricultural Marketing Service (AMS) has considered the...

  4. Yield performance of cowpea plant introductions grown in calcareous soils

    Science.gov (United States)

    Cowpea or Southernpea [Vigna unguiculata (L.) Walp.] is an important legume crop used as a feed for livestock, as a green vegetable and for consumption of its dry beans which provide 22-25% protein. The crop is very sensitive to alkaline soil conditions. When grown at a soil pH of 7.5 or higher, co...

  5. Yield performance of cowpea genotypes grown in alkaline soils

    Science.gov (United States)

    Cowpea or Southernpea [Vigna unguiculata (L.) Walp.] is an important legume crop used as a feed for livestock, as a green vegetable and for consumption of its dry beans which provide 22-25% protein. The crop is very sensitive to alkaline soil conditions. When grown at soil pH of 7.5 or higher, cowp...

  6. Shock initiation experiments on ratchet grown PBX 9502

    Energy Technology Data Exchange (ETDEWEB)

    Gustavsen, Richard L [Los Alamos National Laboratory; Thompson, Darla G [Los Alamos National Laboratory; Olinger, Barton W [Los Alamos National Laboratory; Deluca, Racci [Los Alamos National Laboratory; Bartram, Brian D [Los Alamos National Laboratory; Pierce, Timothy H [Los Alamos National Laboratory; Sanchez, Nathaniel J [Los Alamos National Laboratory

    2010-01-01

    This study compares the shock initiation behavior of PBX 9502 pressed to less than nominal density (nominal density is 1.890 {+-} 0.005 g/cm{sup 3}) with PBX 9502 pressed to nominal density and then ''ratchet grown'' to low density. PBX 9502 is an insensitive plastic bonded explosive consisting of 95 weight % dry-aminated tri-amino-tri-nitro-benzene (TATB) and 5 weight % Kel-F 800 plastic binder. ''Ratchet growth'' - an irreversible increase in specific volume - occurs when an explosive based on TATB is temperature cycled. The design of our study is as follows: PBX 9502, all from the same lot, received the following four treatments. Samples in the first group were pressed to less than nominal density. These were not ratchet grown and used as a baseline. Samples in the second group were pressed to nominal density and then ratchet grown by temperature cycling 30 times between -54 C and +80 C. Samples in the final group were pressed to nominal density and cut into 100 mm by 25.4 mm diameter cylinders. During thermal cycling the cylinders were axially constrained by a 100 psi load. Samples for shock initiation experiments were cut perpendicular (disks) and parallel (slabs) to the axial load. The four sample groups can be summarized with the terms pressed low, ratchet grown/no load, axial load/disks, and axial load/slabs. All samples were shock initiated with nearly identical inputs in plate impact experiments carried out on a gas gun. Wave profiles were measured after propagation through 3, 4, 5, and 6 mm of explosive. Side by side comparison of wave profiles from different samples is used as a measure of relative sensitivity. All reduced density samples were more shock sensitive than nominal density PBX 9502. Differences in shock sensitivity between ratchet grown and pressed to low density PBX 9502 were small, but the low density pressings are slightly more sensitive than the ratchet grown samples.

  7. Biodiesel production from indigenous microalgae grown in wastewater.

    Science.gov (United States)

    Komolafe, Oladapo; Velasquez Orta, Sharon B; Monje-Ramirez, Ignacio; Yáñez Noguez, Isaura; Harvey, Adam P; Orta Ledesma, María T

    2014-02-01

    This paper describes a process for producing biodiesel sustainably from microalgae grown in wastewater, whilst significantly reducing the wastewater's nutrients and total coliform. Furthermore, ozone-flotation harvesting of the resultant biomass was investigated, shown to be viable, and resulted in FAMEs of greater oxidation stability. Desmodesmus sp. and two mixed cultures were successfully grown on wastewater. Desmodesmus sp. grew rapidly, to a higher maximum biomass concentration of 0.58 g/L. A native mixed culture dominated by Oscillatoria and Arthrospira, reached 0.45 g/L and exhibited the highest lipid and FAME yield. The FAME obtained from ozone-flotation exhibited the greatest oxidative stability, as the degree of saturation was high. In principle ozone could therefore be used as a combined method of harvesting and reducing FAME unsaturation. During microalgae treatment, the total nitrogen in wastewater was reduced by 55.4-83.9%. More importantly, total coliform removal was as high as 99.8%.

  8. Silicon on glass grown from indium and tin solutions

    Science.gov (United States)

    Bansen, Roman; Ehlers, Christian; Teubner, Thomas; Böttcher, Klaus; Gambaryan, Karen; Schmidtbauer, Jan; Boeck, Torsten

    2016-04-01

    A two-step process is used to grow crystalline silicon (c-Si) on glass at low temperatures. In the first step, nanocrystalline seed layers are formed at temperatures in the range of 230 to 400°C by either metal-induced crystallization or by direct deposition on heated substrates. In the second step, c-Si is grown on the seed layer by steady-state liquid phase epitaxy at a temperature range of 580 to 710°C. Microcrystalline Si layers with grain sizes of up to several tens of micrometers are grown from In and Sn solutions. Three-dimensional simulations of heat and convective flow in the crucible have been conducted and give valuable insights into the growth process. The experimental results are promising with regard to the designated use of the material in photovoltaics.

  9. Neural signal registration and analysis of axons grown in microchannels

    Science.gov (United States)

    Pigareva, Y.; Malishev, E.; Gladkov, A.; Kolpakov, V.; Bukatin, A.; Mukhina, I.; Kazantsev, V.; Pimashkin, A.

    2016-08-01

    Registration of neuronal bioelectrical signals remains one of the main physical tools to study fundamental mechanisms of signal processing in the brain. Neurons generate spiking patterns which propagate through complex map of neural network connectivity. Extracellular recording of isolated axons grown in microchannels provides amplification of the signal for detailed study of spike propagation. In this study we used neuronal hippocampal cultures grown in microfluidic devices combined with microelectrode arrays to investigate a changes of electrical activity during neural network development. We found that after 5 days in vitro after culture plating the spiking activity appears first in microchannels and on the next 2-3 days appears on the electrodes of overall neural network. We conclude that such approach provides a convenient method to study neural signal processing and functional structure development on a single cell and network level of the neuronal culture.

  10. Platinum blue staining of cells grown in electrospun scaffolds.

    Science.gov (United States)

    Yusuf, Mohammed; Millas, Ana Luiza G; Estandarte, Ana Katrina C; Bhella, Gurdeep K; McKean, Robert; Bittencourt, Edison; Robinson, Ian K

    2014-01-01

    Fibroblast cells grown in electrospun polymer scaffolds were stained with platinum blue, a heavy metal stain, and imaged using scanning electron microscopy. Good contrast on the cells was achieved compared with samples that were gold sputter coated. The cell morphology could be clearly observed, and the cells could be distinguished from the scaffold fibers. Here we optimized the required concentration of platinum blue for imaging cells grown in scaffolds and show that a higher concentration causes platinum aggregation. Overall, platinum blue is a useful stain for imaging cells because of its enhanced contrast using scanning electron microscopy (SEM). In the future it would be useful to investigate cell growth and morphology using three-dimensional imaging methods.

  11. Microprobe analysis of brine shrimp grown on meteorite extracts

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, J. [National Isotope Centre, GNS Science, 30 Gracefield Road, Lower Hutt (New Zealand)]. E-mail: j.kennedy@gns.cri.nz; Mautner, M.N. [Soil, Plant and Ecological Sciences Division, Lincoln University (New Zealand) and Department of Chemistry, University of Canterbury, Christchurch 8001 (New Zealand)]. E-mail: m.mautner@solis1.com; Barry, B. [National Isotope Centre, GNS Science, 30 Gracefield Road, Lower Hutt (New Zealand); Markwitz, A. [National Isotope Centre, GNS Science, 30 Gracefield Road, Lower Hutt (New Zealand)

    2007-07-15

    Nuclear microprobe methods have been used to investigate the uptake and distribution of various elements by brine shrimps and their unhatched eggs when grown in extracts of the Murchison and Allende carbonaceous meteorites, which were selected as model space resources. Measurements were carried out using a focussed 2 MeV proton beam raster scanned over the samples in order to obtain the average elemental concentrations. Line scans across the egg and shrimp samples show uptake of elements such as Mg, Ni, S and P which are present in the meteorites. The results confirmed that carbonaceous chondrite materials can provide nutrients, including high levels of the essential nutrient phosphate. The concentrations of these elements varied significantly between shrimp and eggs grown in extracts of the two meteorite types, which can help in identifying optimal growth media. Our results illustrate that nuclear microprobe techniques can determine elemental concentrations in organisms exposed to meteorite derived media and thus help in identifying useful future resources.

  12. Growth and Characterization of Agar Gel Grown Brushite Crystals

    Directory of Open Access Journals (Sweden)

    V. B. Suryawanshi

    2014-01-01

    Full Text Available Brushite [CaHPO4·2H2O] or calcium hydrogen phosphate dihydrate (CHPD also known as urinary crystal is a stable form of calcium phosphate. The brushite crystals were grown by single and double diffusion techniques in agar-agar gel at room temperature. Effects of different growth parameters were discussed in single diffusion and double diffusion techniques. Good quality star, needle, platy, rectangular, and prismatic shaped crystals in single diffusion and nuclei with dendritic growth were obtained in double diffusion. These grown nuclei were characterized by scanning electron microscopy (SEM, Fourier transform infrared (FTIR spectroscopy, X-ray diffraction (XRD, and thermogravimetric analysis (TGA. SEM has shown the different morphologies of crystals; FTIR has confirmed the presence of functional groups; crystalline nature was supported by XRD, whereas the TGA indicates total 24.68% loss in weight and formation of stable calcium pyrophosphate (Ca2P2O7 at 500°C.

  13. MBE-Grown Lead Tin Telluride Infrared Devices

    Directory of Open Access Journals (Sweden)

    T. Srinivasan

    1989-01-01

    Full Text Available An attempt was made to examine the performance of the Pb0.82sn0.18Te films grown by Molecular Beam Epitaxy (MBEtechnique as infrared (IR band pass filter and photoconductive IR detector. Films of required thickness for these purposes were precalculated and were grown by controlling the growth time. The fabricated band-pass filters were with Full Width at Half Maximum(FWHM of 20-25 per ent centred at 6.5, 8 and 10 microns. The measured detectivity of the film was of the order of 10 power 8 cm H Z (1/2W(-1 for 500 K black body temperature with 800 Hz chopping frequencyand 10 per cent electrical bandwidth at 77 K. All these films weregrown on freshly cleaved KC1 (100 substrates.

  14. Present and future applications of magnetic nanostructures grown by FEBID

    Energy Technology Data Exchange (ETDEWEB)

    Teresa, J.M. de [CSIC-Universidad de Zaragoza, Departamento de Fisica de la Materia Condensada, Instituto de Ciencia de Materiales de Aragon (ICMA), Saragossa (Spain); Universidad de Zaragoza, Laboratorio de Microscopias Avanzadas (LMA), Instituto de Nanociencia de Aragon (INA), Saragossa (Spain); Fernandez-Pacheco, A. [University of Cambridge, TFM Group, Cavendish Laboratory, Cambridge (United Kingdom)

    2014-12-15

    Currently, magnetic nanostructures are routinely grown by focused electron beam induced deposition (FEBID). In the present article, we review the milestones produced in the topic in the past as well as the future applications of this technology. Regarding past milestones, we highlight the achievement of high-purity cobalt and iron deposits, the high lateral resolution obtained, the growth of 3D magnetic deposits, the exploration of magnetic alloys and the application of magnetic deposits for Hall sensing and in domain-wall conduit and magnetologic devices. With respect to future perspectives of the topic, we emphasize the potential role of magnetic nanostructures grown by FEBID for applications related to highly integrated 2D arrays, 3D nanowires devices, fabrication of advanced scanning-probe systems, basic studies of magnetic structures and their dynamics, small sensors (including biosensors) and new applications brought by magnetic alloys and even exchange biased systems. (orig.)

  15. Thermally grown thin nitride films as a gate dielectric

    CERN Document Server

    Shin, H C; Hwang, T K; Lee, K R

    1998-01-01

    High-quality very thin films ( <=6 nm) of silicon nitride were thermally grown in ammonia atmosphere with an IR (Infrared) gold image furnace. As-grown nitride film was analyzed using AES(Auger Emission Spectroscopy). Using MIS (Metal-Insulator-Semiconductor) devices, the growth rate was calculated using CV (Capacitance-Voltage) measurements and various electrical characteristics were obtained using CV, IV (Current-Voltage), trapping, time-dependent breakdown, high-field stress, constant current injection stress and dielectric breakdown techniques. These characteristics showed that very thin thermal silicon nitride films can be used as gate dielectrics for future highly scaled-down ULSI (Ultra Large Scale Integrated) devices, especially for EEPROM (Electrically Erasable and Programmable ROM)'s.

  16. X-ray diffraction study of directionally grown perylene crystallites

    DEFF Research Database (Denmark)

    Breiby, Dag W.; Lemke, H. T.; Hammershøj, P.

    2008-01-01

    Using grazing incidence X-ray diffraction, perylene crystallites grown on thin highly oriented poly(tetrafluoroethylene) (PTFE) films on silicon substrates have been investigated. All the perylene crystallites are found to orient with the ab plane of the monoclinic unit cell parallel to the subst......Using grazing incidence X-ray diffraction, perylene crystallites grown on thin highly oriented poly(tetrafluoroethylene) (PTFE) films on silicon substrates have been investigated. All the perylene crystallites are found to orient with the ab plane of the monoclinic unit cell parallel...... to the substrate. The scattering data is interpreted as a trimodal texture of oriented perylene crystallites, induced by interactions between the perylene molecules and the oriented PTFE substrate. Three families of biaxial orientations are seen, with the axes (h = 1, 2, or 3) parallel to the PTFE alignment......, all having the ab-plane parallel to the substrate. About 92% of the scattered intensity corresponds to a population with highly parallel to (PTFE)....

  17. Growth and characterization of hexamethylenetetramine crystals grown from solution

    Science.gov (United States)

    Babu, B.; Chandrasekaran, J.; Balaprabhakaran, S.

    2014-06-01

    Organic nonlinear optical single crystals of hexamethylenetetramine (HMT; 10 × 10 × 5 mm3) were prepared by crystallization from methanol solution. The grown crystals were subjected to various characterization techniques such as single crystal XRD, powder XRD, UV-Vis and electrical studies. Single crystal XRD analysis confirmed the crystalline structure of the grown crystals. Their crystalline nature was also confirmed by powder XRD technique. The optical transmittance property was identified from UV-Vis spectrum. Dielectric measurements were performed as a function of frequency at different temperatures. DC conductivity and photoconductivity studies were also carried out for the crystal. The powder second harmonic generation efficiency (SHG) of the crystal was measured using Nd:YAG laser and the efficiency was found to be two times greater than that of potassium dihydrogen phosphate (KDP).

  18. Consumer sensory analysis of organically and conventionally grown vegetables.

    Science.gov (United States)

    Zhao, Xin; Chambers, Edgar; Matta, Ziad; Loughin, Thomas M; Carey, Edward E

    2007-03-01

    Consumers of organically grown fruits and vegetables often believe that these products taste better than conventional produce. However, comparison of produce from supermarket shelves does not permit adequate assessment of this consumer perception, given potentially confounding cultivar and environmental effects. We used replicated side-by-side plots to produce organic and conventional vegetables for consumer sensory studies. In one test, red loose leaf lettuce, spinach, arugula, and mustard greens, grown organically and conventionally, were evaluated for overall liking as well as for intensity of flavor and bitterness. Another consumer test was conducted comparing organically and conventionally grown tomatoes, cucumbers, and onions. Overall, organically and conventionally grown vegetables did not show significant differences in consumer liking or consumer-perceived sensory quality. The only exception was in tomatoes where the conventionally produced tomato was rated as having significantly stronger flavor than the organically produced tomato. However, overall liking was the same for both organic and conventional samples. As conventional tomatoes also were scored marginally significantly higher in ripeness and a positive correlation was found between ratings of flavor intensity and ripeness, the flavor difference observed could not be simply ascribed to the contrasting growing conditions. Consumer panelists in both tests considered organic produce to be healthier (72%) and more environmentally friendly (51%) than conventional produce, while 28% considered organic produce to have better taste. Covariance analysis indicated that consumer demographics affected sensory comparisons of organic and conventional lettuce and cucumbers. Future study is needed to substantiate the influence of segmentation of consumers on their preference for organic food.

  19. Nano transfer and nanoreplication using deterministically grown sacrificial nanotemplates

    Science.gov (United States)

    Melechko, Anatoli V [Oak Ridge, TN; McKnight, Timothy E [Greenback, TN; Guillorn, Michael A [Ithaca, NY; Ilic, Bojan [Ithaca, NY; Merkulov, Vladimir I [Knoxville, TX; Doktycz, Mitchel J [Knoxville, TN; Lowndes, Douglas H [Knoxville, TN; Simpson, Michael L [Knoxville, TN

    2012-03-27

    Methods, manufactures, machines and compositions are described for nanotransfer and nanoreplication using deterministically grown sacrificial nanotemplates. An apparatus, includes a substrate and a nanoconduit material coupled to a surface of the substrate. The substrate defines an aperture and the nanoconduit material defines a nanoconduit that is i) contiguous with the aperture and ii) aligned substantially non-parallel to a plane defined by the surface of the substrate.

  20. Spectral response of THM grown CdZnTe crystals

    DEFF Research Database (Denmark)

    Chen, H.; Awadalla, S.A.; Harris, F.

    2008-01-01

    The spectral response of several crystals grown by the Traveling Heater Method (THM) were investigated. An energy resolution of 0.98% for a Pseudo Frisch-Grid of 4 × 4 × 9 mm3 and 2.1% FWHM for a coplanar-grid of size 11 × 11 × 5 mm3 were measured using 137Cs-662 keV. In addition a 4% FWHM at 122...

  1. Glucosinolates in collard greens grown under three soil management practices.

    Science.gov (United States)

    Antonious, George F

    2015-01-01

    Glucosinolates (GSLs, β-D-thioglucoside-N-hydroxysulfates) are polar compounds present in varying amounts in members of the Brassicaceae family. They suppress soil-borne pests due to the biofumigant properties of the highly toxic isothiocyanates present in Brassica vegetables. The objectives of this investigation were to: (1) assess variation in GSLs concentrations among collard plants grown under three soil management practices: sewage sludge (SS) mixed with native soil, chicken manure (CM) mixed with native soil, and no-mulch (NM) native soil, (2) quantify GSLs concentrations in collard roots, leaves, and stems at harvest for potential use of their crude extracts in plant protection, and (3) assess myrosinase activity in soil amended with CM and SS mixed with native soil. Separation of GSLs was accomplished by adsorption on a DEAE-Sephadex ion exchange resin using disposable pipette tips filled with DEAE, a weak base, with a net positive charge when ionized and exchange anions such as GSLs (hydrophilic plant secondary metabolites). Quantification of total GSLs was based on inactivation of collard endogenous myrosinase and liberation of the glucose moiety from the GSLs molecule by addition of standardized myrosinase and colorimetric determination of the liberated glucose moiety. Across all treatments, SS and CM increased soil organic matter content from 2.2% in native soil to 4.2 and 6.5%, respectively. GSLs concentrations were significantly greater in collard leaves (30.9 µmoles g(-1) fresh weight) compared to roots and stems (7.8 and 1.2 µmoles g(-1) fresh weight), respectively. Leaves of collard grown in soil amended with SS contained the greatest concentrations of GSLs compared to leaves of plants grown in CM and NM treatments. Accordingly, leaves of collard plants grown in soil amended with SS could play a significant role in sustainable agriculture as alternative tools for soil-borne disease management in conventional and organic agriculture.

  2. Characteristics of HgCdTe epilayer grown by LPE using horizontal slider

    Indian Academy of Sciences (India)

    J K Radhakrishnan; S Sitharaman; S C Gupta

    2002-11-01

    The characteristics of HgCdTe epilayers grown in a modified horizontal slider system, are reported here. The surface morphology of the grown layers, their IR transmission characteristics, depth and lateral compositional uniformity, structural and electrical characteristics are discussed.

  3. 76 FR 69673 - Tart Cherries Grown in Michigan, New York, Pennsylvania, Oregon, Utah, Washington, and Wisconsin...

    Science.gov (United States)

    2011-11-09

    ...; ] DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 930 Tart Cherries Grown in Michigan, New... tart cherries grown in Michigan, New York, Pennsylvania, Oregon, Utah, Washington, and Wisconsin. These... handling of tart cherries grown in Michigan, New York, Pennsylvania, Oregon, Utah, Washington,...

  4. Titanium distribution in Ti-sapphire single crystals grown by Czochralski and Verneuil technique

    Science.gov (United States)

    Alombert-Goget, G.; Li, H.; Faria, J.; Labor, S.; Guignier, D.; Lebbou, K.

    2016-01-01

    The distributions of Ti3+ and Ti4+ ions were evaluated by photoluminescence measurement in the wafers cut from different positions of the ingots grown by Czochralski and Verneuil techniques. Particular radial distributions of Ti4+ as function of the position in the ingot were observed in the crystals grown by Verneuil technique different than the crystals grown by Czochralski method.

  5. 29 CFR 780.505 - Definition of “shade-grown tobacco.”

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Definition of âshade-grown tobacco.â 780.505 Section 780... Employment or Agricultural Employees in Processing Shade-Grown Tobacco; Exemption From Minimum Wage and Overtime Pay Requirements Under Section 13(a)(14) Shade-Grown Tobacco § 780.505 Definition of...

  6. Response of container-grown flowering dogwood cultivars to sun/shade production regime, 2015

    Science.gov (United States)

    Flowering dogwood, Cornus florida, ‘Cherokee Brave™’ and ‘Cherokee Princess’ were grown in #5 nursery containers in an amended 100% bark substrate. Treatments were assigned based on exposure time to a full sun/shade condition during the growing season: 1) plants grown in full sun, 2) plants grown in...

  7. 鄱阳湖湿地灰化苔草群落物种多度分布格局沿水分梯度的变化%The change of species-abundance distribution patterns of Carex cinerascens community along a hydrological gradient in the Poyanghu wetland

    Institute of Scientific and Technical Information of China (English)

    刘扬; 施建敏; 边子星; 邓绍勇; 裘利洪; 张微微; 缪伸义

    2016-01-01

    为揭示鄱阳湖湿地苔草群落的构建机制,选择灰化苔草(Carex cinerascens)群落作为研究对象,通过设立3条样带调查不同水分梯度的群落物种多度,选用断棍模型(BSM)、生态位优先占领模型(NPM)、优势优先模型(DPM)、随机分配模型(RAM)和生态位重叠模型(ONM)5个生态位模型对群落种-多度关系进行拟合,结果表明,1)灰化苔草群落可按土壤水分划分为高湿度、中湿度和低湿度3组,分别对应从湖边、湿地中间和湿地边缘的梯度分布;2)从高到低的水分梯度上,灰化苔草群落的物种数先增加后降低,优势种多度逐渐增加,物种多度分布曲线由相对平缓变为陡峭;3)高湿度灰化苔草群落物种多度分布格局的最佳拟合模型为BSM,中、低湿度的理想模型转变为NPM.研究认为,水分条件的变化是灰化苔草群落物种多度分布格局改变的主因,随着水分梯度降低,群落构建的生态学过程由随机生态位变为生态位优先占领.研究为鄱阳湖湿地多样性保育和生态功能管理提供了理论参考.

  8. Ретроспективные и текущие представления о микоризности видов рода Carex L

    OpenAIRE

    Конопленко, М.; Веселкин, Д.; Бетехтина, А.

    2013-01-01

    Ретроспективно проанализированы сведения из 60 публикаций 1926–2012 гг. о наличии или отсутствии арбускулярных микориз у видов рода Carex L. (Cyperaceae). Из 173 видов осок, в отношении которых имеется информация о микоризном статусе, у 98 видов (57%) микориза не найдена, у 23 видов (13%) микоризы обнаруживались всегда; 52 вида (30%) могут как образовывать, так и не образовывать микоризы. По мере увеличения числа исследований растет доля видов Carex, в отношении которых показана способность к...

  9. Polyphenol content and antioxidant capacity in organically and conventionally grown vegetables

    Institute of Scientific and Technical Information of China (English)

    Kevser Unal; Deny Susanti; Muhammad Taher

    2014-01-01

    Objective: To evaluate the polyphenol content and antioxidant capacity of ethanol extracts of some organically and conventionally grown leafy vegetables. Methods:The ethanol extracts of kailan (Brassica alboglabra), bayam (Amaranthus spp.) and sawi (Brassica parachinensis) were tested for total phenolic content (TPC), total flavonoid content (TFC), and total anthocyanin content (TAC) and the antioxidant capacity of the extracts measured using 2,2-diphenyl-1-picrylhydrazyl assay. Results:In TPC test, sawi extract showed the highest phenolic content while bayam contained the least phenolic content for both organically and conventionally grown types. In TFC test, organically grown sawi extract showed the highest flavonoid content, while organically grown kailan extract showed the least flavonoid content among all types of vegetables. The flavonoid content of the conventionally grown types of vegetable extracts was the highest in kalian and the least in sawi. For 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, the activity increased with the increasing concentration of each extract. All conventionally grown vegetable extracts showed higher antioxidant activity compared to their organically grown counterparts. Extracts of conventionally grown sawi showed the highest percentage inhibition followed by conventionally grown kailan and organically grown sawi. There were no correlation between TPC, TFC, TAC and IC25 of both organically and conventionally grown vegetables. However, there was a correlation between TAC and IC25 of conventionally grown vegetable extracts. The results showed relatively similar polyphenol content between organically and conventionally grown vegetable extracts. However, the conventionally grown vegetables extracts generally have higher antioxidant activity compared to the organically grown extracts. Conclusions:These results suggested that the different types of agricultural practice had a significant contribution to the polyphenol

  10. Annealing to reduce scattering centers in Czochralski-grown beta-BaB2O4.

    Science.gov (United States)

    Kouta, H; Kuwano, Y

    1999-02-20

    When a visible laser beam passes through beta-BaB(2)O(4) (BBO), scattered light can be observed along the beam within the crystal. Scattering centers caused by structural defects in Czochralski-grown BBO can be reduced by 95% by annealing at 920 degrees C. In the flux-grown BBO, centers actually increase by the same annealing because the process causes microcracks and/or secondary inclusions. It is shown that annealed Czochralski-grown BBO is superior to flux-grown BBO (annealed or as-grown) in terms of optical loss.

  11. Comparison Of Energy Sources Grown On Agricultural Land

    Directory of Open Access Journals (Sweden)

    Jureková Zuzana

    2015-11-01

    Full Text Available The aim of the paper is to compare biomass production of energy plants and selected crops grown on arable land in the south-western Slovakia in 2007–2014, its energy value and the influence of decisive climatic factors on the size of the production. The data on yields of dominant crops grown in the agricultural farm were obtained from the statistical data of the farm. Aboveground biomass of willows and poplars was harvested at the end of the harvest cycle. Aboveground biomass of Miscanthus sinensis was harvested in 2010–2014, always in early spring period of the following year. Winter wheat, spring barley and maize grown for silage during the period 2007–2014 provided the lowest yields in 2010 and the highest in 2011 and 2014. The highest energy value was obtained from maize in 2014 (400.66 GJ ha−1. The short rotation coppice poplars of Italian provenance yielded biomass with energy value of 951.68 GJ ha−1 year−1 at the end of the first three-year harvest cycle in 2012. The analysis of variance confirmed that there are highly significant statistical differences in the poplar biomass yield among the varieties and individual experimental years. The fast growing willows of Swedish provenance provided aboveground biomass energy value of 868.88 GJ ha−1 year−1 at the end of the first four-year harvest cycle in 2011. The biomass production of the perennial grass Miscanthus sinensis, depending on the growing period, can be expressed by a polynomial trend function. The highest biomass production was obtained in the third growing period (2012. At the end of the fifth growing period (2014, the yield amounted to 28.60 t ha−1 of the dry aboveground biomass. The energy value of the aboveground biomass of Miscanthus reached 486.20 GJ ha−1 in 2014. Differences in the biomass yield of the Miscanthus genotypes are statistically highly significant in each of the monitored growing periods. The growth and production process of the selected energy

  12. Uptake of /sup 131/I by some hydroponically grown crops

    Energy Technology Data Exchange (ETDEWEB)

    Asprer, G.A.; Lansangan, L.M.; de la Paz, L.R. (Philippine Atomic Energy Commission, Diliman, Quezon City)

    Biologically labelled vegetables which include kangkong and sweet potato tops were grown hydroponically in a modified Hoagland-Arnon nutrient solution containing radioiodine with 0.5% non-radioactive Nal solution as the medium. The crops considered in this study are commonly eaten by Filipinos. The concentration of the solution as well as the uptake in the plant system were determined at various time intervals. The extent of radioiodine uptake through air-water-plant pathway is one of the parameters needed for calculating the dose that the general populace could be exposed to, due to radioactivity in the environment.

  13. Effects of irrigation strategies and soils on field grown potatoes

    DEFF Research Database (Denmark)

    Ahmadi, Seyed Hamid; Plauborg, Finn; Andersen, Mathias Neumann;

    2011-01-01

    Root distribution of field grown potatoes (cv. Folva) was studied in 4.32m2 lysimeters and subjected to full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation strategies. Drip irrigation was applied for all irrigations. Irrigations were run in three different soils: coarse sand......, loamy sand, and sandy loam. Irrigation treatments started after tuber bulking and lasted until final harvest with PRD and DI receiving 65% of FI. Potatoes irrigated with water-saving irrigation techniques (PRD and DI) did not show statistically different dry root mass and root length density (RLD, cm...... in practice for efficient use of water and nutrients in the field....

  14. Progress in MBE grown type-II superlattice photodiodes

    Science.gov (United States)

    Hill, Cory J.; Li, Jian V.; Mumolo, Jason M.; Gunapala, Sarath D.

    2006-01-01

    We report on the status of GaSb/InAs type-II superlattice diodes grown and fabricated at the Jet Propulsion Laboratory designed for infrared absorption in the 8-12(mu)m range. Recent devices have produced detectivities as high as 8x10 to the tenth power Jones with a differential resistance-area product greater than 6 Ohmcm(sup 2) at 80K with a long wavelength cutoff of approximately 12(mu)m. The measured quantum efficiency of these front-side illuminated devices is close to 30% in the 10-11(mu)m range without antireflection coatings.

  15. Inversion domains in AlN grown on (0001) sapphire

    Energy Technology Data Exchange (ETDEWEB)

    Jasinski, J.; Liliental-Weber, Z.; Paduano, Q.S.; Weyburne, D.W.

    2003-08-25

    Al-polarity inversion domains formed during AlN layer growth on (0001) sapphire were identified using transmission electron microscopy (TEM). They resemble columnar inversion domains reported for GaN films grown on (0001) sapphire. However, for AlN, these columns have a V-like shape with boundaries that deviate by 2 {+-} 0.5{sup o} from the c-axis. TEM identification of these defects agrees with the post-growth surface morphology as well as with the microstructure revealed by etching in hot aqueous KOH.

  16. Fabrication of metal nanoclusters on graphene grown on Ru(0001)

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hui; FU Qiang; CUI Yi; TAN DaLi; BAO XinHe

    2009-01-01

    Monolayer graphene was epitaxially grown on Ru(0001) through exposure of the Ru(0001) to ethylene at room temperature followed by annealing in ultrahigh vacuum at elevated temperatures. The resulting graphene structures were studied by scanning tunneling microscopy (STM), X-ray photoelectron spec-troscopy (XPS), and ultraviolet photoelectron spectroscopy (UPS). The graphene/Ru(0001) surface was used as a periodic template for growth of metal nanoclusters. Highly dispersed Pt clusters with well controlled size and spatial distribution were fabricated on the surface.

  17. Lipid profiling of some authotrophic microalgae grown on waste water

    DEFF Research Database (Denmark)

    Safafar, Hamed; Jacobsen, Charlotte; Møller, Per

    the most suitable microalgae and downstream processing for food and feed production. The present study is part of a big project funded by GUDP (green development and demonstration program of ministry of agriculture and fisheries of Denmark) which aims at developing new processing technologies, so...... that microalgae-biomass can be used as an alternative valuable resource in fish feed. In this work, 10 fresh water and marine microalgae from Chlorella, Scenedesmus, Haematococcus, Nannochloropsis, Nannochloropsis and Dunialiella species grown in waste water in Kalundborg micro algal facility were harvested...

  18. InSb thin films grown by electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Joginder, E-mail: joginderchauhan82@gmail.com; Rajaram, P., E-mail: joginderchauhan82@gmail.com [School of Studies in Physics, Jiwaji University, Gwalior-474011 (India)

    2014-04-24

    We have grown InSb thin films on Cu substrates using the electrodeposition technique. The electrochemical bath from which the InSb thin films were grown was made up of a mixture of aqueous solutions of 0.05 M InCl{sub 3} and 0.03M SbCl{sub 3}, 0 .20M citric acid and 0.30M sodium citrate. Citric acid and sodium citrate were used as complexing agents to bring the reduction potential of In and Sb closer to maintain binary growth. The electrodeposited films were characterized by structural, morphological and optical studies. X-ray diffraction studies show that the films are polycrystalline InSb having the zinc blende structure. Scanning electron microscopy (SEM) studies reveal that the surface of the films is uniformly covered with submicron sized spherical particles. FTIR spectra of InSb thin films show a sharp absorption peak at wave number 1022 cm{sup −1} corresponding to the band gap. Hot probe analysis shows that the InSb thin films have p type conductivity.

  19. GaAsP Nanowires Grown by Aerotaxy.

    Science.gov (United States)

    Metaferia, Wondwosen; Persson, Axel R; Mergenthaler, Kilian; Yang, Fangfang; Zhang, Wei; Yartsev, Arkady; Wallenberg, Reine; Pistol, Mats-Erik; Deppert, Knut; Samuelson, Lars; Magnusson, Martin H

    2016-09-14

    We have grown GaAsP nanowires with high optical and structural quality by Aerotaxy, a new continuous gas phase mass production process to grow III-V semiconductor based nanowires. By varying the PH3/AsH3 ratio and growth temperature, size selected GaAs1-xPx nanowires (80 nm diameter) with pure zinc-blende structure and with direct band gap energies ranging from 1.42 to 1.90 eV (at 300 K), (i.e., 0 ≤ x ≤ 0.43) were grown, which is the energy range needed for creating tandem III-V solar cells on silicon. The phosphorus content in the NWs is shown to be controlled by both growth temperature and input gas phase ratio. The distribution of P in the wires is uniform over the length of the wires and among the wires. This proves the feasibility of growing GaAsP nanowires by Aerotaxy and results indicate that it is a generic process that can be applied to the growth of other III-V semiconductor based ternary nanowires.

  20. Pb-210 in beans grown in normal background environments

    Energy Technology Data Exchange (ETDEWEB)

    Mingote, Raquel M.; Nogueira, Regina A., E-mail: mingote@cnen.gov.br, E-mail: rnogueira@cnen.gov.br [Centro Regional de Ciencias Nucleares do Centro-Oeste (CRCN-CO/CNEN-GO), Abadia de Goias, GO (Brazil)

    2013-07-01

    A survey was carried out on the activity concentration of {sup 210}Pb in common beans (Phaseolus vulgaris L.) grown in normal background environments in Brazil. The Carioca beans and the black type were analyzed, which contribute with 90% of the Brazilian market share of the common beans. To this study 18 bean samples sowing in the Middle-Western and Southern regions of Brazil during the years 2010-2011 were analyzed. The proportion per bean type was similar to the national production: most of the Carioca beans (n=13; 72%) and black beans (n=5; 28%). Other 17 values of {sup 210}Pb activity concentration in beans grown in Southeastern region available in the GEORAD, a dataset of radioactivity in Brazil, were added to the statistic analysis of the data. Considering the information contained in censored observations (60%), representative value of {sup 210}Pb activity concentration in beans was estimated by using robust ROS, a censored data analysis method. The value 0.047 Bq kg{sup -1} fresh wt. obtained here is according to {sup 210}Pb activity concentration in grains reported by UNSCEAR 0.05 Bq kg{sup -1}. (author)

  1. Orthodox etching of HVPE-grown GaN

    Energy Technology Data Exchange (ETDEWEB)

    Weyher, J.L.; Lazar, S.; Macht, L.; Liliental-Weber, Z.; Molnar,R.J.; Muller, S.; Nowak, G.; Grzegory, I.

    2006-08-10

    Orthodox etching of HVPE-grown GaN in molten eutectic of KOH + NaOH (E etch) and in hot sulfuric and phosphoric acids (HH etch) is discussed in detail. Three size grades of pits are formed by the preferential E etching at the outcrops of threading dislocations on the Ga-polar surface of GaN. Using transmission electron microscopy (TEM) as the calibration tool it is shown that the largest pits are formed on screw, intermediate on mixed and the smallest on edge dislocations. This sequence of size does not follow the sequence of the Burgers values (and thus the magnitude of the elastic energy) of corresponding dislocations. This discrepancy is explained taking into account the effect of decoration of dislocations, the degree of which is expected to be different depending on the lattice deformation around the dislocations, i.e. on the edge component of the Burgers vector. It is argued that the large scatter of optimal etching temperatures required for revealing all three types of dislocations in HVPE-grown samples from different sources also depends upon the energetic status of dislocations. The role of kinetics for reliability of etching in both etches is discussed and the way of optimization of the etching parameters is shown.

  2. Quality characteristics of the radish grown under reduced atmospheric pressure

    Science.gov (United States)

    Levine, Lanfang H.; Bisbee, Patricia A.; Richards, Jeffrey T.; Birmele, Michele N.; Prior, Ronald L.; Perchonok, Michele; Dixon, Mike; Yorio, Neil C.; Stutte, Gary W.; Wheeler, Raymond M.

    This study addresses whether reduced atmospheric pressure (hypobaria) affects the quality traits of radish grown under such environments. Radish (Raphanus sativus L. cv. Cherry Bomb Hybrid II) plants were grown hydroponically in specially designed hypobaric plant growth chambers at three atmospheric pressures; 33, 66, and 96 kPa (control). Oxygen and carbon dioxide partial pressures were maintained constant at 21 and 0.12 kPa, respectively. Plants were harvested at 21 days after planting, with aerial shoots and swollen hypocotyls (edible portion of the radish referred to as the “root” hereafter) separated immediately upon removal from the chambers. Samples were subsequently evaluated for their sensory characteristics (color, taste, overall appearance, and texture), taste-determining factors (glucosinolate and soluble carbohydrate content and myrosinase activity), proximate nutrients (protein, dietary fiber, and carbohydrate) and potential health benefit attributes (antioxidant capacity). In roots of control plants, concentrations of glucosinolate, total soluble sugar, and nitrate, as well as myrosinase activity and total antioxidant capacity (measured as ORACFL), were 2.9, 20, 5.1, 9.4, and 1.9 times greater than the amount in leaves, respectively. There was no significant difference in total antioxidant capacity, sensory characteristics, carbohydrate composition, or proximate nutrient content among the three pressure treatments. However, glucosinolate content in the root and nitrate concentration in the leaf declined as the atmospheric pressure decreased, suggesting perturbation to some nitrogen-related metabolism.

  3. Automorphogenesis and gravitropism of plant seedlings grown under microgravity conditions.

    Science.gov (United States)

    Hoson, T; Saiki, M; Kamisaka, S; Yamashita, M

    2001-01-01

    Plant seedlings exhibit automorphogenesis on clinostats. The occurrence of automorphogenesis was confirmed under microgravity in Space Shuttle STS-95 flight. Rice coleoptiles showed an inclination toward the caryopsis in the basal region and a spontaneous curvature in the same adaxial direction in the elongating region both on a three-dimensional (3-D) clinostat and in space. Both rice roots and Arabidopsis hypocotyls also showed a similar morphology in space and on the 3-D clinostat. In rice coleoptiles, the mechanisms inducing such an automorphic curvature were studied. The faster-expanding convex side of rice coleoptiles showed a higher extensibility of the cell wall than the opposite side. Also, in the convex side, the cell wall thickness was smaller, the turnover of the matrix polysaccharides was more active, and the microtubules oriented more transversely than the concave side, and these differences appear to be causes of the curvature. When rice coleoptiles grown on the 3-D clinostat were placed horizontally, the gravitropic curvature was delayed as compared with control coleoptiles. In clinostatted coleoptiles, the corresponding suppression of the amyloplast development was also observed. Similar results were obtained in Arabidopsis hypocotyls. Thus, the induction of automorphogenesis and a concomitant decrease in graviresponsiveness occurred in plant shoots grown under microgravity conditions.

  4. Synthesis and characterization of gel-grown cobalt tartrate crystals

    Indian Academy of Sciences (India)

    V M Athivanan; M Haris; T Prasanyaa; M Amgalan

    2014-03-01

    Crystals of cobalt tartrate are grown from the gel using chemical reaction method. The functional groups are found from Fourier transform infrared spectroscopy (FTIR). The OH stretching mode owing to water, carbonyl group, CH stretching modes and metal–oxygen stretching are identified. The unit cell dimensions, interaxial angles and unit cell volume are found from powder X-ray diffraction studies (XRD) which show the orthorhombic nature of the crystal. The magnetic study is used to find the magnetic susceptibility and magnetic moment of the grown crystal. It reveals the magnetic nature of the crystal. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) are done to find the thermal properties of the crystal which manifest the water of hydration in the crystal. The variation of dielectric constant with respect to the applied frequency shows the polarization property of the crystal. The AC conductivity is increased proportionally with increase in frequency. The reverse nature is found for the AC resistivity. The nature of the composition of the crystals affects the dielectric properties.

  5. Gallium Nitride Nanowires Grown by Hydride Vapor Phase Epitaxy

    Institute of Scientific and Technical Information of China (English)

    LIU Zhan-Hui; XIU Xiang-Qan; YAN Huai-Yue; ZHANG Rong; XIE Zi-Li; HAN Ping; SHI Yi; ZHENG You-Dou

    2011-01-01

    @@ GaN nanowires are grown by hydride vapor phase epitaxy using nickel as a catalyst.The properties of the obtained GaN nanowires are characterized by scanning and transmission electron microscopy,electron diffraction,roomtemperature photoluminescence and energy dispersive spectroscopy.The results show that the nanowires are wurtzite single crystals growing along the[0001]direction and a redshift in the photoluminescence is observed due to a superposition of several effects.The Raman spectra are close to those of the bulk GaN and the significantly broadening of those modes indicates the phonon confinement effects associated with the nanoscale dimensions of the system.%GaN nanowires are grown by hydride vapor phase epitaxy using nickel as a catalyst. The properties of the obtained GaN nanowires are characterized by scanning and transmission electron microscopy, electron diffraction, room-temperature photoluminescence and energy dispersive spectroscopy. The results show that the nanowires are wurtzite single crystals growing along the [0001] direction and a redshift in the photoluminescence is observed due to a superposition of several effects. The Raman spectra are close to those of the bulk GaN and the significantly broadening of those modes indicates the phonon confinement effects associated with the nanoscale dimensions of the system.

  6. Food Value of Mealworm Grown on Acrocomia aculeata Pulp Flour.

    Directory of Open Access Journals (Sweden)

    Ariana Vieira Alves

    Full Text Available Insects have played an important role as human food throughout history, especially in Africa, Asia and Latin America. A good example of edible insects is the mealworm, Tenebrio molitor Linnaeus, 1758 (Coleoptera, Tenebrionidae, which are eaten in Africa, Asia, the Americas and Australia. This species is easily bred in captivity, requiring simple management. The bocaiuva (Acrocomia aculeata (Jacq. Lodd is an abundant palm tree found in the Brazilian Cerrado, providing fruits with high nutritional value. The aim of this work was to determine the chemical composition of T. molitor grown in different artificial diets with bocaiuva pulp flour. The nutritional composition, fatty acid composition, antioxidant activity, trypsin activity and anti-nutritional factors of larvae were analyzed. The results showed that mealworms grown on artificial diet with bocaiuva are a good source of protein (44.83% and lipid (40.45%, with significant levels of unsaturated fatty acids (65.99%, antioxidant activity (4.5 μM Trolox/g of oil extracted from larvae and absence of anti-nutritional factors. This study indicates a new source of biomass for growing mealworms and shows that it is possible to breed mealworms in artificial diet with bocaiuva flour without compromising the nutritional quality of the larvae.

  7. Organically grown food provides health benefits to Drosophila melanogaster.

    Science.gov (United States)

    Chhabra, Ria; Kolli, Santharam; Bauer, Johannes H

    2013-01-01

    The "organic food" market is the fastest growing food sector, yet it is unclear whether organically raised food is nutritionally superior to conventionally grown food and whether consuming organic food bestows health benefits. In order to evaluate potential health benefits of organic foods, we used the well-characterized fruit fly Drosophila melanogaster as a model system. Fruit flies were raised on a diets consisting of extracts of either conventionally or organically raised produce (bananas, potatoes, raisins, soy beans). Flies were then subjected to a variety of tests designed to assess overall fly health. Flies raised on diets made from organically grown produce had greater fertility and longevity. On certain food sources, greater activity and greater stress resistance was additionally observed, suggesting that organic food bestows positive effects on fly health. Our data show that Drosophila can be used as a convenient model system to experimentally test potential health effects of dietary components. Using this system, we provide evidence that organically raised food may provide animals with tangible benefits to overall health.

  8. Organically grown food provides health benefits to Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Ria Chhabra

    Full Text Available The "organic food" market is the fastest growing food sector, yet it is unclear whether organically raised food is nutritionally superior to conventionally grown food and whether consuming organic food bestows health benefits. In order to evaluate potential health benefits of organic foods, we used the well-characterized fruit fly Drosophila melanogaster as a model system. Fruit flies were raised on a diets consisting of extracts of either conventionally or organically raised produce (bananas, potatoes, raisins, soy beans. Flies were then subjected to a variety of tests designed to assess overall fly health. Flies raised on diets made from organically grown produce had greater fertility and longevity. On certain food sources, greater activity and greater stress resistance was additionally observed, suggesting that organic food bestows positive effects on fly health. Our data show that Drosophila can be used as a convenient model system to experimentally test potential health effects of dietary components. Using this system, we provide evidence that organically raised food may provide animals with tangible benefits to overall health.

  9. Food Value of Mealworm Grown on Acrocomia aculeata Pulp Flour.

    Science.gov (United States)

    Alves, Ariana Vieira; Sanjinez-Argandoña, Eliana Janet; Linzmeier, Adelita Maria; Cardoso, Claudia Andrea Lima; Macedo, Maria Lígia Rodrigues

    2016-01-01

    Insects have played an important role as human food throughout history, especially in Africa, Asia and Latin America. A good example of edible insects is the mealworm, Tenebrio molitor Linnaeus, 1758 (Coleoptera, Tenebrionidae), which are eaten in Africa, Asia, the Americas and Australia. This species is easily bred in captivity, requiring simple management. The bocaiuva (Acrocomia aculeata (Jacq.) Lodd) is an abundant palm tree found in the Brazilian Cerrado, providing fruits with high nutritional value. The aim of this work was to determine the chemical composition of T. molitor grown in different artificial diets with bocaiuva pulp flour. The nutritional composition, fatty acid composition, antioxidant activity, trypsin activity and anti-nutritional factors of larvae were analyzed. The results showed that mealworms grown on artificial diet with bocaiuva are a good source of protein (44.83%) and lipid (40.45%), with significant levels of unsaturated fatty acids (65.99%), antioxidant activity (4.5 μM Trolox/g of oil extracted from larvae) and absence of anti-nutritional factors. This study indicates a new source of biomass for growing mealworms and shows that it is possible to breed mealworms in artificial diet with bocaiuva flour without compromising the nutritional quality of the larvae.

  10. Mechanoresponses of human primary osteoblasts grown on carbon nanotubes.

    Science.gov (United States)

    Kroustalli, A; Kotsikoris, V; Karamitri, A; Topouzis, S; Deligianni, D

    2015-03-01

    Bone mechanotransduction is strongly influenced by the biomaterial properties. A good understanding of these mechanosensory mechanisms in bone has the potential to provide new strategies in the highly evolving field of bone tissue engineering. The aim of the present investigation was to study the interactive effects of local mechanical stimuli on multiwalled carbon nanotubes (MWCNTs)/osteoblast interface, using an in vitro model that allows the study of cell growth, attachment and differentiation. Strain was applied at physiological levels [strain magnitudes 500 microstrain (μɛ), at frequency of load application 0.5 Hz]. The effect of mechanical strain and substrate was thus studied by measuring the messenger RNA expression of alkaline phosphatase, vinculin, collagen 1A, and integrins β1, β3, α4, and αv, using real-time quantitative polymerase chain reaction. The osteoblasts grown on MWCNTs displayed quick adaptation to the new environment by modulating the expression of key adhesion integrins. Furthermore, the addition of mechanical strain interplayed with the extracellular matrix and was efficiently transduced by cells grown on MWCNTs, providing stronger adhesion and survival. MWCNTs are therefore a material perfectly compatible with osteoblast differentiation, adhesion, and growth, and should be further evaluated, to derive new-generation biomaterial scaffolds for the treatment of skeletal defects which require bone reconstruction.

  11. Characteristics of Preferentially Attached Network Grown from Small World

    CERN Document Server

    Lee, Seungyoung

    2015-01-01

    We introduce a model for a preferentially attached network which has grown from a small world network. Here, the average path length and the clustering coefficient are estimated, and the topological properties of modeled networks are compared as the initial conditions are changed. As a result, it is shown that the topological properties of the initial network remain even after the network growth. However, the vulnerability of each to preferentially attached nodes being added is not the same. It is found that the average path length rapidly decreases as the ratio of preferentially attached nodes increases and that the characteristics of the initial network can be easily disappeared. On the other hand, the clustering coefficient of the initial network slowly decreases with the ratio of preferentially attached nodes and its clustering characteristic remains much longer.

  12. Carbon nanotubes grown on bulk materials and methods for fabrication

    Science.gov (United States)

    Menchhofer, Paul A.; Montgomery, Frederick C.; Baker, Frederick S.

    2011-11-08

    Disclosed are structures formed as bulk support media having carbon nanotubes formed therewith. The bulk support media may comprise fibers or particles and the fibers or particles may be formed from such materials as quartz, carbon, or activated carbon. Metal catalyst species are formed adjacent the surfaces of the bulk support material, and carbon nanotubes are grown adjacent the surfaces of the metal catalyst species. Methods employ metal salt solutions that may comprise iron salts such as iron chloride, aluminum salts such as aluminum chloride, or nickel salts such as nickel chloride. Carbon nanotubes may be separated from the carbon-based bulk support media and the metal catalyst species by using concentrated acids to oxidize the carbon-based bulk support media and the metal catalyst species.

  13. Grown Up Congenital Heart Diseases (GUCH: A Review

    Directory of Open Access Journals (Sweden)

    Ajmer Singh

    2013-10-01

    Full Text Available The survival of children with congenital heart disease into adulthood has increased. These patients may require primary cardiac surgical repair, repair after prior palliation, revision of repair for residual lesion, or non-cardiac surgery. Preoperative cardiac evaluation consists of review of laboratory data, echocardiography, cardiac MRI, CT, cardiopulmonary exercise testing, arrhythmia monitoring, and cardiac catheterization. Perioperative complications are more frequently seen in high-risk patients i.e. those with pulmonary hypertension, cyanosis, heart failure, and poor general health. Guidelines for the management of patients with grown up congenital heart (GUCH diseases suggest that such patients are best treated in dedicated tertiary care centres by a multidisciplinary team, knowledgeable about the anatomy and pathophysiology of the lesion.

  14. Photoluminescence of ingaas/inp grown by molecular beam epitaxy

    Directory of Open Access Journals (Sweden)

    Harmand Jean Christophe

    2004-01-01

    Full Text Available Photoluminescence (PL measurements due to temperature and excitation power were carried out in as function of sample containing a In0,53Ga0,47. As layer, grown by Molecular Beam Epitaxy on an InP substrate. The origins of the several luminescence processes observed at low temperature were determined by studying their different behaviors with increasing temperature and excitation power and by comparing the results with the data found in the literature. The following transitions have been identified: one transition involving localized excitons and two transitions involving acceptor impurities. A review of the main works published in the literature related to the optical transitions observed at low temperature in InGaAs/InP is also presented.

  15. Nitrides optoelectronic devices grown by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Kauer, M.; Bousquet, V.; Hooper, S.E.; Barnes, J.M.; Windle, J.; Tan, W.S.; Heffernan, J. [Sharp Laboratories of Europe, Edmund Halley Road, Oxford Science Park, Oxford OX4 4GB (United Kingdom)

    2007-01-15

    We report on the characteristics of our recent room temperature continuous-wave InGaN quantum well laser diodes grown by by molecular beam epitaxy (MBE). Uncoated ridge waveguide lasers fabricated on freestanding GaN substrates have a continuous-wave (cw) threshold current of 110 mA, corresponding to a threshold current density of 5.5 kA cm{sup -2}. We report on our steps taken to reduce threshold voltage to 7 V. Lasers with uncoated facets have a maximum cw output power of 14 mW and a cw characteristic temperature T{sub 0} of 123 K. Cw laser lifetime vs. power dissipation data is presented, with a maximum lifetime of 2.6 hours for the best laser. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. Transport properties of polymer-vapour grown carbon fibre composites

    Science.gov (United States)

    Gordeyev, S. A.; Macedo, F. J.; Ferreira, J. A.; van Hattum, F. W. J.; Bernardo, C. A.

    2000-04-01

    DC electrical resistivity and thermal conductivity of polypropylene (PP) filled with vapour grown carbon fibre (VGCF) was studied. This was done for a wide range of fibre content and compared to systems produced under the same conditions in which a conventional carbon fibre was used as filler. The composites studied exhibit characteristic percolating behaviour. Because of the low degree of graphite perfection in the VGCF used in this work, the fraction of VGCF required to achieve percolation was higher than expected. Non-linear I- V characteristics and time dependent electrical resistivity effects are only observed in PP filled with VGCF. Several mechanisms must be called upon to explain the observed electrical behaviour of the PP/VGCF composite. The thermal conductivity of the composites is in agreement with the effective medium theories.

  17. Stress determination in thermally grown alumina scales using ruby luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Renusch, D.; Veal, B.W.; Koshelev, I.; Natesan, K.; Grimsditch [Argonne National Lab., IL (United States); Hou, P.Y. [Lawrence Berkeley Lab., CA (United States)

    1996-06-01

    By exploiting the strain dependence of the ruby luminescence line, we have measured the strain in alumina scales thermally grown on Fe-Cr- Al alloys. Results are compared and found to be reasonably consistent with strains determined using x rays. Oxidation studies were carried out on alloys Fe - 5Cr - 28Al and Fe - 18Cr - 10Al (at.%). Significantly different levels of strain buildup were observed in scales on these alloys. Results on similar alloys containing a ``reactive element`` (Zr or Hf) in dilute quantity are also presented. Scales on alloys containing a reactive element (RE) can support significantly higher strains than scales on RE-free alloys. With the luminescence technique, strain relief associated with spallation thresholds is readily observed.

  18. Sustainability and economic evaluation of microalgae grown in brewery wastewater.

    Science.gov (United States)

    Mata, Teresa M; Mendes, Adélio M; Caetano, Nídia S; Martins, António A

    2014-09-01

    This article evaluates the sustainability and economic potential of microalgae grown in brewery wastewater for biodiesel and biomass production. Three sustainability and two economic indicators were considered in the evaluation within a life cycle perspective. For the production system the most efficient process units were selected. Results show that harvesting and oil separation are the main process bottlenecks. Microalgae with higher lipid content and productivity are desirable for biodiesel production, although comparable to other biofuel's feedstock concerning sustainability. However, improvements are still needed to reach the performance level of fossil diesel. Profitability reaches a limit for larger cultivation areas, being higher when extracted biomass is sold together with microalgae oil, in which case the influence of lipid content and areal productivity is smaller. The values of oil and/or biomass prices calculated to ensure that the process is economically sound are still very high compared with other fuel options, especially biodiesel.

  19. Anisotropic magnetothermopower in ferromagnetic thin films grown on macroscopic substrates

    Energy Technology Data Exchange (ETDEWEB)

    Jayathilaka, P.B. [Department of Physical Sciences, Faculty of Applied Sciences, Rajarata University of Sri Lanka, Mihintale (Sri Lanka); Belyea, D.D. [Department of Physics, University of South Florida, 4202 East Fowler Avenue, Tampa, FL 33620 (United States); Fawcett, T.J. [College of Engineering, University of South Florida, 4202 East Fowler Avenue, Tampa, FL 33620 (United States); Miller, Casey W. [School of Chemistry and Materials Science, Rochester Institute of Technology, 85 Lomb Memorial Drive, Rochester, NY 14623 (United States)

    2015-05-15

    We report observing the anisotropic magnetothermopower in a variety of ferromagnetic thin films grown on macroscopic substrates. These measurements were enabled by eliminating spurious signals related to the Anomalous Nernst Effect by butt-mounting the sample to the heat source and sink, and appropriate positioning of electrical contacts to avoid unwanted thermal gradients. This protocol enabled detailed measurements of the magnetothermopower in the transverse and longitudinal configurations. This may enable Spin Seebeck Effect studies in the in-plane geometry. - Highlights: • Unintentional thermal gradients along surface normal mitigated via butt-mounting. • Longitudinal/transverse magnetothermopower measured on many systems. • Anomalous Nernst Effect reduced. • Importance of magnetic anisotropy identified with angle-dependent measurements.

  20. InP Bulk Crystals Grown from Various Stoichiometric Melt

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    InP crystal was grown from stoichiometric or non-stoichiometric melt, including P-rich and In-rich condition by the P-injection synthesis LEC method. Owing to the non-stoichiometric condition, there are many pores in the tail of the P-rich ingot. Samples were characterized by high speed photoluminescence mapping and E.P.D. mapping. The perfection (dislocation, stoichiometry and uniformity) of these samples were studied and compared. The PL peak intensity standard deviation of the 4-inch InP wafer is higher. The EPDs around the pores are higher than the other regions. Besides the stress releasing, the pores and the high concentration of dislocations around them are the leading factors causing the inhomogeneity of the wafer. By adjusting the thermal field and ensuring the chemical stoichiometry, InP crystals of larger diameters and better performance can be developed.

  1. Glycoalkaloids in potato tubers grown under controlled environments

    Science.gov (United States)

    Nitithamyong, A.; Vonelbe, J. H.; Wheeler, R. M.; Tibbitts, T. W.

    1999-01-01

    Tuber content of alpha-solanine, alpha-chaconine, and total glycoalkaloids (TGA) was determined for the potato cultivars, Norland, Russet Burbank, and Denali grown under different environmental conditions in growth chambers. The lowest TGA concentrations (0.30 to 0.35 mg g-1 dry tissue) were found in the cv. Norland with 400 micromoles m-2 s-1 photosynthetic photon flux (PPF), 12 h day length, 16 C temperature, and 350 micromoles mol-1 carbon dioxide. The ratio of alpha-chaconine to alpha-solanine was close to 60:40 under all growing conditions, except that it was 50:50 under the low temperature of 12 C. Cultivars responded similarly to environmental conditions although TGA was about 20% greater in cv. Russet Burbank and about 30% greater in Denali compared to Norland. The largest changes in TGA occurred with changes in temperature. In comparison to 16 C, TGA were 40% greater at 12 C, 80% greater at 20 C, and 125% greater at 24 C (0.70 mg g-1 dry weight). The TGA concentration increased from 10 to 25% with an increase in light from 400 to 800 micromoles m-2 s-1 PPF for all three cultivars. TGA increased 20% with extension of the day length from 12 to 24 hr and also increased 20% when carbon dioxide was increased from 350 to 1000 micromoles mol-1. TGA concentrations were not influenced by changes in relative humidity from 50 to 80%. TGA concentrations decreased only slightly in harvests made from 9 to 21 weeks after planting. Variations in TGA among the different growing conditions and cultivars were below 20 mg/100 g fresh weight (approximately 1.0 mg g-1 dry weight) recognized as the upper concentration for food safety. However the results suggest that TGA should be considered when potatoes are grown at temperatures above 20 C.

  2. Epitaxially Grown Layered MFI–Bulk MFI Hybrid Zeolitic Materials

    KAUST Repository

    Kim, Wun-gwi

    2012-11-27

    The synthesis of hybrid zeolitic materials with complex micropore-mesopore structures and morphologies is an expanding area of recent interest for a number of applications. Here we report a new type of hybrid zeolite material, composed of a layered zeolite material grown epitaxially on the surface of a bulk zeolite material. Specifically, layered (2-D) MFI sheets were grown on the surface of bulk MFI crystals of different sizes (300 nm and 10 μm), thereby resulting in a hybrid material containing a unique morphology of interconnected micropores (∼0.55 nm) and mesopores (∼3 nm). The structure and morphology of this material, referred to as a "bulk MFI-layered MFI" (BMLM) material, was elucidated by a combination of XRD, TEM, HRTEM, SEM, TGA, and N2 physisorption techniques. It is conclusively shown that epitaxial growth of the 2-D layered MFI sheets occurs in at least two principal crystallographic directions of the bulk MFI crystal and possibly in the third direction as well. The BMLM material combines the properties of bulk MFI (micropore network and mechanical support) and 2-D layered MFI (large surface roughness, external surface area, and mesoporosity). As an example of the uses of the BMLM material, it was incorporated into a polyimide and fabricated into a composite membrane with enhanced permeability for CO2 and good CO2/CH4 selectivity for gas separations. SEM-EDX imaging and composition analysis showed that the polyimide and the BMLM interpenetrate into each other, thereby forming a well-adhered polymer/particle microstructure, in contrast with the defective interfacial microstructure obtained using bare MFI particles. Analysis of the gas permeation data with the modified Maxwell model also allows the estimation of the effective volume of the BMLM particles, as well as the CO2 and CH4 gas permeabilities of the interpenetrated layer at the BMLM/polyimide interface. © 2012 American Chemical Society.

  3. Metallic impurities in gallium nitride grown by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    McHugo, S.A.; Krueger, J.; Kisielowski, C. [Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    Transition metals are often encountered in trace amounts in semiconductors. They have been extensively studied in most elemental and compound systems, since they form deep donor and/or acceptor levels which usually degrade the electronic and optical material properties. Only very little is known about transition metals in recent III-V semiconducting materials, such as GaN, AlN and InN. These few studies have been done exclusively on Metal-Organic Chemical Vapor Deposition (MOCVD) or Hybrid Vapor Phase Epitaxy HVPE-grown GaN. Preliminary x-ray fluorescence studies at the Advanced Light Source, beamline 10.3.1, Lawrence Berkeley National Laboratory have revealed that GaN materials grown by Molecular Beam Epitaxy (MBE) have Fe, Ni and Cr as the dominant transition metal contaminants. This finding is commensurate with the extremely high concentrations of hydrogen, carbon and oxygen (up to 10{sup 20} cm{sup {minus}3}) measured by Secondary Ion Mass Spectroscopy (SIMS). Preliminary work using the mapping capabilities of the x-ray fluorescence microprobe revealed the metal impurities were inhomogeneously distributed over the film. Future work of this collaboration will be to find a correlation between the existence of transition metals in MBE films, as revealed by x-ray fluorescence, and Photoluminescence (PL) spectra taken in the infrared region. Also, the authors will make use of the 1 {mu}m spatial resolution of x-ray microprobe to locate the contaminants in relation to structural defects in the GaN films. Because of the large strain caused by the lattice mismatch between the GaN films and the substrates, the films grow in a columnar order with high densities of grain boundaries and dislocations. These structural defects offer preferential sites for metal precipitation or agglomeration which could degrade the optical properties of this material more so than if the impurities were left dissolved in the GaN.

  4. Confocal Raman studies in determining crystalline nature of PECVD grown Si nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Nafis; Bhargav, P. Balaji; Ramasamy, P. [SSN Research Centre, Kalavakkam-603110, Tamilnadu (India); Department of Physics, SSN College of Engineering, Kalavakkam-603110, Tamilnadu (India); Sivadasan, A. K.; Tyagi, A. K.; Dhara, S., E-mail: dhara@igcar.gov.in [Surface and Nanoscience Division, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102 (India); Amirthapandian, S.; Panigrahi, B. K. [Materials Physics Division, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102 (India); Bhattacharya, S. [SSN Research Centre, Kalavakkam-603110, Tamilnadu (India)

    2015-06-24

    Silicon nanowires of diameter ∼200 nm and length of 2-4 µm are grown in the plasma enhanced chemical vapour deposition technique using nanoclustered Au catalyst assisted vapour-liquid-solid process. The crystallinity in the as-grown and annealed samples is studied using confocal Raman spectroscopic studies. Amorphous phase is formed in the as-grown samples. Structural studies using high resolution transmission electron microscopy confirm the polycrystalline nature in the annealed sample.

  5. Defect studies in low-temperature-grown GaAs

    Energy Technology Data Exchange (ETDEWEB)

    Bliss, D.E.

    1992-11-01

    High content of excess As is incorporated in GaAs grown by low-temperature molecular-beam-epitaxy (LTMBE). The excess As exists primarily as As antisite defects AsGa and a lesser extent of gallium vacancies V[sub Ga]. The neutral AsGa-related defects were measured by infrared absorption at 1[mu]m. Gallium vacancies, V[sub Ga], was investigated by slow positron annihilation. Dependence of defect contents on doping was studied by Si and Be dopants. No free carriers are generated by n-type or p-type doping up to 10[sup 19] cm[sup [minus]3] Si or Be. Raman data indicate Be occupies Ga substitutional sites but Si atom is not substitutional. Si induces more As[sub Ga] in the layer. As As[sub Ga] increases, photoquenchable As[sub Ga] decreases. Fraction of photoquenchable defects correlates to defects within 3 nearest neighbor separations disrupting the metastability. Annealing reduces neutral As[sub Ga] content around 500C, similar to irradiation damaged and plastically deformed Ga[sub As], as opposed to bulk grown GaAs in which As[sub Ga]-related defects are stable up to 1100C. The lower temperature defect removal is due to V[sub Ga] enhanced diffusion of As[sub Ga] to As precipitates. The supersaturated V[sub GA] and also decreases during annealing. Annealing kinetics for As[sub Ga]-related defects gives 2.0 [plus minus] 0.3 eV and 1.5 [plus minus] 0.3 eV migration enthalpies for the As[sub Ga] and V[sub Ga]. This represents the difference between Ga and As atoms hopping into the vacancy. The non-photoquenchable As[sub Ga]-related defects anneal with an activation energy of 1.1 [plus minus] 0.3eV. Be acceptors can be activated by 800C annealing. Temperature difference between defect annealing and Be activation formation of As[sub Ga]-Be[sub Ga] pairs. Si donors can only be partially activated.

  6. Defect studies in low-temperature-grown GaAs

    Energy Technology Data Exchange (ETDEWEB)

    Bliss, D.E.

    1992-11-01

    High content of excess As is incorporated in GaAs grown by low-temperature molecular-beam-epitaxy (LTMBE). The excess As exists primarily as As antisite defects AsGa and a lesser extent of gallium vacancies V{sub Ga}. The neutral AsGa-related defects were measured by infrared absorption at 1{mu}m. Gallium vacancies, V{sub Ga}, was investigated by slow positron annihilation. Dependence of defect contents on doping was studied by Si and Be dopants. No free carriers are generated by n-type or p-type doping up to 10{sup 19} cm{sup {minus}3} Si or Be. Raman data indicate Be occupies Ga substitutional sites but Si atom is not substitutional. Si induces more As{sub Ga} in the layer. As As{sub Ga} increases, photoquenchable As{sub Ga} decreases. Fraction of photoquenchable defects correlates to defects within 3 nearest neighbor separations disrupting the metastability. Annealing reduces neutral As{sub Ga} content around 500C, similar to irradiation damaged and plastically deformed Ga{sub As}, as opposed to bulk grown GaAs in which As{sub Ga}-related defects are stable up to 1100C. The lower temperature defect removal is due to V{sub Ga} enhanced diffusion of As{sub Ga} to As precipitates. The supersaturated V{sub GA} and also decreases during annealing. Annealing kinetics for As{sub Ga}-related defects gives 2.0 {plus_minus} 0.3 eV and 1.5 {plus_minus} 0.3 eV migration enthalpies for the As{sub Ga} and V{sub Ga}. This represents the difference between Ga and As atoms hopping into the vacancy. The non-photoquenchable As{sub Ga}-related defects anneal with an activation energy of 1.1 {plus_minus} 0.3eV. Be acceptors can be activated by 800C annealing. Temperature difference between defect annealing and Be activation formation of As{sub Ga}-Be{sub Ga} pairs. Si donors can only be partially activated.

  7. The Environmental Assessment and Management (TEAM) Guide: New York Supplement

    Science.gov (United States)

    2010-03-01

    Carex aggregata Glomerate Sedge Carex amphibola var. amphibola Narrow-leaved Sedge Carex ...arcta Northern Clustered Sedge Carex atherodes Awned Sedge Carex atratiformis Black Sedge Carex barrattii Barratt’s Sedge Carex bullata Button Sedge ... Carex capillaris Hair-like Sedge Carex caroliniana Carolina Sedge Carex collinsii Collins’ Sedge

  8. Epitaxial yttrium iron garnet films grown by pulsed laser deposition

    Science.gov (United States)

    Dorsey, P. C.; Bushnell, S. E.; Seed, R. G.; Vittoria, C.

    1993-07-01

    Epitaxial Y3Fe5O12 (YIG) films have been grown by the pulsed laser deposition (PLD) technique on (111) gadolinium gallium garnet substrates. The effect of substrate temperature and oxygen partial pressure on the structure, composition, and magnetic properties of the films was investigated and compared to liquid phase epitaxy YIG films. The results demonstrated that epitaxial YIG films could be prepared under a wide range of deposition conditions, but narrow linewidth (ΔH≂1 Oe) films were producible only at low oxygen partial pressures (O2temperatures (Ts≳800 °C). Since the linewidth of single-crystal YIG is dominated by surface and volume defects and/or impurities, the narrow linewidth indicated that PLD is a viable technique for producing high-quality ferrite films for microwave device applications. In addition, under all deposition conditions (50-1000 mTorr and 700-850 °C) there is a uniaxial axis perpendicular to the film plane. However, at low oxygen pressure the uniaxial anisotropy energy constant Ku is negative while at high oxygen pressure Ku is positive.

  9. Purification of carbon nanotubes grown by thermal CVD

    Science.gov (United States)

    Porro, S.; Musso, S.; Vinante, M.; Vanzetti, L.; Anderle, M.; Trotta, F.; Tagliaferro, A.

    2007-03-01

    We show the results of a set of purifications on carbon nanotubes (CNT) by acid and basic treatments. CNTs were obtained by thermal decomposition of camphor at 850 °C in a CVD growth system, by means of a growth process catalyzed by iron clusters originating from the addition of ferrocene in the precursors mixture. The purification procedures involved HNO 3, H 2SO 4, HSO 3Cl and NaOH for different process temperatures. As-grown CNTs showed a consistent presence of metal catalyst (about 6 wt%), evidenced by TGA. The purification treatments led to a certain amount of opening of the CNT tips, with a consequent loss of metal catalyst encapsulated in tips. This is also confirmed by BET analysis, which showed an increase of the surface area density of CNT after the purification. FT-IR and XPS revealed the presence of carboxylic groups on the CNT surface chemically modified by the harsh environment of the purification process. Among the various treatments that have been tested, the 1:3 solution of nitric and sulphuric acid was the most effective in modifying the CNT surface and inducing the formation of functional groups.

  10. Polyphenol and glycoalkaloid contents in potato cultivars grown in Luxembourg.

    Science.gov (United States)

    Deusser, Hannah; Guignard, Cédric; Hoffmann, Lucien; Evers, Danièle

    2012-12-15

    The polyphenol (phenolic acids, flavanols and flavonols) and glycoalkaloid (α-chaconine and α-solanine) contents of potato tubers grown in Luxembourg were analyzed by UPLC-DAD and HPLC-MS/MS separately in peel (approx. 2mm), outer (approx. 1cm) and inner flesh. Polyphenol contents decreased from the peel via the outer to the inner flesh and differed among the cultivars. The cultivars Vitelotte and Luminella had the highest polyphenol contents (5202 and 572 μg/g dry weight (DW) in the outer flesh), whereas Charlotte and Bintje had the lowest contents (19.5 and 48.0 μg/g DW). Chlorogenic acid and its isomers (neo- and cryptochlorogenic acid) were the major polyphenols. Glycoalkaloid contents were highest in the peel and lowest in the inner flesh, values in the flesh were below guideline limits in all cultivars. In conclusion, potatoes contribute to the daily intake of polyphenols and their consumption, thereby, may have positive effects on health.

  11. Arsenic uptake and speciation in vegetables grown under greenhouse conditions.

    Science.gov (United States)

    Smith, E; Juhasz, A L; Weber, J

    2009-04-01

    The accumulation of arsenic (As) by vegetables is a potential human exposure pathway. The speciation of As in vegetables is an important consideration due to the varying toxicity of different As species. In this study, common Australian garden vegetables were hydroponically grown with As-contaminated irrigation water to determine the uptake and species of As present in vegetable tissue. The highest concentrations of total As were observed in the roots of all vegetables and declined in the aerial portions of the plants. Total As accumulation in the edible portions of the vegetables decreased in the order radish > mung bean > lettuce = chard. Arsenic was present in the roots of radish, chard, and lettuce as arsenate (As(V)) and comprised between 77 and 92% of the total As present, whereas in mung beans, arsenite (As(III)) comprised 90% of the total As present. In aerial portions of the vegetables, As was distributed equally between both As(V) and As(III) in radish and chard but was present mainly as As(V) in lettuce. The presence of elevated As in vegetable roots suggests that As species may be complexed by phytochelatins, which limits As translocation to aerial portions of the plant.

  12. Possible Internalization of an Enterovirus in Hydroponically Grown Lettuce.

    Science.gov (United States)

    Carducci, Annalaura; Caponi, Elisa; Ciurli, Adriana; Verani, Marco

    2015-07-17

    Several studies have shown that enteric viruses can be transferred onto the surface of vegetables and fruits through spray irrigation, but, recently, reports have suggested viral contamination of vegetables sub-irrigated with reused wastewater. Hydroponic cultures, used to grow ready to eat fresh lettuce, have also been used to study the possibility of viral absorption through roots. This study was conducted to assess a possible risk of viral contamination in lettuce from contaminated water. The leaves of lettuce plants grown in hydroponic cultures where the roots were exposed to water containing Coxsakievirus B2, were analysed for evidence of the virus. The plants and water were sampled at different times and virus was measured using quantitative RT-PCR and infectivity assay. In leaf samples, the lowest observed infective data were lower than the qRT-PCR detection limits, suggesting that free viral RNA or damaged viruses are eliminated rapidly while infectious particles remain stable for a longer time. The obtained data revealed that the leaves were contaminated at a water concentration of 4.11 ± 1 Log Most Probable Number/L (8.03 ± 1 Log GC/L) a concentration observed in contaminated untreated water of wastewater treatment plants. However, the absorption dynamics and whether the virus is inactive in the leaves still remains to be clarified. Nevertheless, this work has practical implications for risk management in using reclaimed water for agricultural use; when irrigated vegetables are destined for raw consumption, virological contamination in water sources should be evaluated.

  13. Tensile stress and creep in thermally grown oxide.

    Science.gov (United States)

    Veal, Boyd W; Paulikas, Arvydas P; Hou, Peggy Y

    2006-05-01

    Structural components that operate at high temperatures (for example, turbine blades) rely on thermally grown oxide (TGO), commonly alumina, for corrosion protection. Strains that develop in TGOs during operation can reduce the protectiveness of the TGO. However, the occurrence of growth strains in TGOs, and mechanisms that cause them, are poorly understood. It is accepted that compressive strains can develop as oxygen and metal atoms meet to form new growth within constrained oxide. More controversial is the experimental finding that large tensile stresses, close to 1 GPa, develop during isothermal growth conditions in alumina TGO formed on a FeCrAlY alloy. Using a novel technique based on synchrotron radiation, we have confirmed these previous results, and show that the tensile strain develops as the early oxide, (Fe,Cr,Al)(2)O(3), converts to alpha-Al2O3 during the growth process. This allows us to model the strain behaviour by including creep and this diffusion-controlled phase change.

  14. Modeling uptake kinetics of cadmium by field-grown lettuce

    Energy Technology Data Exchange (ETDEWEB)

    Chen Weiping [Department of Environmental Sciences, University of California, 900 University Avenue, Riverside, CA 92521 (United States)], E-mail: chenweip@yahoo.com.cn; Li Lianqing [Institute of Resources, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, Nanjing 210095 (China); Chang, Andrew C.; Wu Laosheng [Department of Environmental Sciences, University of California, 900 University Avenue, Riverside, CA 92521 (United States); Kwon, Soon-Ik [Agricultural Environmental and Ecology Division, National Institute of Agricultural Science and Technology, Suwon 441-707 (Korea, Republic of); Bottoms, Rick [Desert Research and Extension Center, 1004 East Holton Road, El Centro, CA 92243 (United States)

    2008-03-15

    Cadmium uptake by field grown Romaine lettuce treated with P-fertilizers of different Cd levels was investigated over an entire growing season. Results indicated that the rate of Cd uptake at a given time of the season can be satisfactorily described by the Michaelis-Menten kinetics, that is, plant uptake increases as the Cd concentration in soil solution increases, and it gradually approaches a saturation level. However, the rate constant of the Michaelis-Menten kinetics changes over the growing season. Under a given soil Cd level, the cadmium content in plant tissue decreases exponentially with time. To account for the dynamic nature of Cd uptake, a kinetic model integrating the time factor was developed to simulate Cd plant uptake over the growing season: C{sub Plant} = C{sub Solution} . PUF{sub max} . exp[-b . t], where C{sub Plant} and C{sub Solution} refer to the Cd content in plant tissue and soil solution, respectively, PUF{sub max} and b are kinetic constants. - A kinetic model was developed to evaluate the uptake of Cd under field conditions.

  15. Evaluation of endosulfan residues in vegetables grown in greenhouses.

    Science.gov (United States)

    Arrebola, F J; Egea-González, F J; Moreno, M; Fernández-Gutiérrez, A; Hernández-Torres, M E; Martínez-Vidal, J L

    2001-07-01

    The reduction in residue levels of endosulfan with time after treatment of tomatoes, green beans, peppers and cucumbers grown in different types of commercial greenhouses (flat- and asymmetric-roof greenhouses) in Almería (Spain) was investigated. A study of the major and minor degradation products of endosulfan in peppers and cucumbers (endosulfan-sulfate, -ether and -lactone) was carried out using gas chromatography-tandem mass spectrometry (GC-MS/MS). To establish the influence of environmental conditions on the degradation of endosulfan, several field trials have been carried out in which crops were sprayed at different rates (full, half- and quarter- of those rates recommended) during two seasons (spring and winter). For statistical purposes, the disappearance of endosulfan with time was considered to follow a pseudo-first-order reaction. Analysis of variance (ANOVA) has been applied to the results obtained. Half-lives of residue disappearance were 4.03-4.68 days in green beans, 4.03-4.20 days in tomatoes, 8.22 days in peppers and 7.97 days in cucumbers. Half-lives in spring were shorter than in the winter season. The application rate and the type of greenhouse did not influence the half-lives.

  16. Characteristics of purple nonsulfur bacteria grown under Stevia residue extractions.

    Science.gov (United States)

    Xu, J; Feng, Y; Wang, Y; Lin, X

    2013-11-01

    As a consequence of the large-scale cultivation of Stevia plants, releases of plant residues, the byproduct after sweetener extraction, to the environment are inevitable. Stevia residue and its effluent after batching up contain large amounts of organic matters with small molecular weight, which therefore are a potential pollution source. Meanwhile, they are favourite substrates for micro-organism growths. This investigation was aimed to utilize the simulated effluent of Stevia residue to enrich the representative purple nonsulfur bacterium (PNSB), Rhodopseudomonas palustris (Rps. palustris), which has important economic values. The growth profile and quality of Rps. palustris were characterized by spectrophotometry, compared to those grown in common PNSB mineral synthetic medium. Our results revealed that the simulated effluent of Stevia residue not only stimulated Rps. palustris growth to a greater extent, but also increased its physiologically active cytochrome concentrations and excreted indole-3-acetic acid (IAA) content. This variation in phenotype of Rps. palustris could result from the shift in its genotype, further revealed by the repetitive sequence-based PCR (rep-PCR) fingerprinting analysis. Our results showed that the effluent of Stevia residue was a promising substrate for microbial growth.

  17. Insitu CCVD grown bilayer graphene transistors for applications in nanoelectronics

    Science.gov (United States)

    Wessely, Pia Juliane; Schwalke, Udo

    2014-02-01

    We invented a method to fabricate graphene field effect transistors (GFETs) on oxidized silicon wafers in a Silicon CMOS compatible process. The graphene layers needed are grown in situ by means of a transfer-free catalytic chemical vapor deposition (CCVD) process directly on silicon dioxide. Depending on the process parameters the fabrication of single, double or multi-layer graphene FETs (GFETs) is possible. The produced graphene layers have been characterized by SEM, TEM, TEM-lattice analysis as well as Raman-Spectroscopy. Directly after growth, the fabricated GFETs are electrically functional and can be electrically characterized via the catalyst metals which are used as contact electrodes. In contrast to monolayer graphene FETs, the fabricated bilayer graphene FETs (BiLGFETs) exhibit unipolar p-type MOSFET behavior. Furthermore, the on/off current-ratio of 104 up to several 107 at room temperature of the fabricated BiLGFETs allows their use in digital logic applications [1]. In addition, a stable hysteresis of the GFETs enables their use as memory devices without the need of storage capacitors and therefore very high memory device-densities are possible. The whole fabrication process is fully Si-CMOS compatible, enabling the use of hybrid silicon/graphene electronics.

  18. Insitu CCVD grown bilayer graphene transistors for applications in nanoelectronics

    Energy Technology Data Exchange (ETDEWEB)

    Wessely, Pia Juliane, E-mail: pj.wessely@iht.tu-darmstadt.de; Schwalke, Udo

    2014-02-01

    We invented a method to fabricate graphene field effect transistors (GFETs) on oxidized silicon wafers in a Silicon CMOS compatible process. The graphene layers needed are grown in situ by means of a transfer-free catalytic chemical vapor deposition (CCVD) process directly on silicon dioxide. Depending on the process parameters the fabrication of single, double or multi-layer graphene FETs (GFETs) is possible. The produced graphene layers have been characterized by SEM, TEM, TEM-lattice analysis as well as Raman-Spectroscopy. Directly after growth, the fabricated GFETs are electrically functional and can be electrically characterized via the catalyst metals which are used as contact electrodes. In contrast to monolayer graphene FETs, the fabricated bilayer graphene FETs (BiLGFETs) exhibit unipolar p-type MOSFET behavior. Furthermore, the on/off current-ratio of 10{sup 4} up to several 10{sup 7} at room temperature of the fabricated BiLGFETs allows their use in digital logic applications [1]. In addition, a stable hysteresis of the GFETs enables their use as memory devices without the need of storage capacitors and therefore very high memory device-densities are possible. The whole fabrication process is fully Si-CMOS compatible, enabling the use of hybrid silicon/graphene electronics.

  19. Succinic Acid Synthesis by Ethanol-Grown Yeasts

    Directory of Open Access Journals (Sweden)

    Svetlana V. Kamzolova

    2009-01-01

    Full Text Available The synthesis of succinic acid in ethanol-containing media has been tested in 32 yeasts of different genera (Debaryomyces, Candida, Pichia, Saccharomyces, Torulopsis. The capability of succinic acid synthesis was revealed in 29 strains, from which two most effective producers were selected. When grown in a fermentor under high aeration in mineral medium with pulsed addition of ethanol, the strain Candida catenulata VKM Y-5 produced succinic acid up to 5.2 g/L with mass yield of 32.6 % and energy yield of 14.8 %; the other strain, Candida zeylanoides VKM Y-2324, excreted 9.4 g/L of succinic acid with mass and energy yields of 39 and 17.8 %, respectively. It was indicated that succinic acid formation in the yeasts was accompanied by the synthesis of considerable amounts of malic acid, which was apparently due to a high activity of the glyoxylate cycle. Growth characteristics of both strains were studied in dependence on the concentrations of ethanol, zinc ions and nitrogen in the medium.

  20. Extended defects in as-grown CdZnTe

    Energy Technology Data Exchange (ETDEWEB)

    Xu, L.; Bolotnikov, A.E.; Hossain, A.; Kim, K-H.; Gul, R.; Yang, G.; Camarda, G.S.; Marchini, L.; Cui, Y.; James, R.B.; Xu, Y.; Wang, T.; Jie, W.

    2010-08-01

    We characterized samples cut from different locations in as-grown CdZnTe (CZT) ingots, using Automated Infrared (IR) Transmission Microscopy and White Beam X-ray Diffraction Topography (WBXDT), to locate and identify the extended defects in them. Our goal was to define the distribution of these defects throughout the entire ingot and their effects on detectors’ performance as revealed by the pulse-height spectrum. We found the highest- and the lowest- concentration of Te inclusions, respectively, in the head and middle part of the ingot, which could serve as guidance in selecting samples. Crystals with high concentration of Te inclusions showed high leakage current and poor performance, because the accumulated charge loss around trapping centers associated with Te inclusions distorts the internal electric field, affects the carrier transport properties inside the crystal, and finally degrades the detector’s performance. In addition, other extended defects revealed by the WBXDT measurements severely reduced the detector’s performance, since they trap large numbers of electrons, leading to a low signal for the pulse-height spectrum, or none whatsoever. Finally, we fully correlated the detector’s performance with our information on the extended defects gained from both the IR- and the WBXDT-measurements.

  1. Performance of rapid-grown KDP crystals with continuous filtration

    Institute of Scientific and Technical Information of China (English)

    Guohang Hu; Yueliang Wang; Junxiu Chang; Xiaoyi Xie; Yuanan Zhao; Hongji Qi; Jianda Shao

    2015-01-01

    Rapid growth processing of KDP crystals was improved by employing continuous filtration to eliminate bulk defects.The performances of the KDP crystals, including scattering defects, laser damage resistance and transmittance, were measured and analyzed. Compared with rapid-grown KDP without continuous filtration, the transmittance in the nearinfrared was increased by at least 2%, almost all of ‘micron size’ defects were eliminated and ‘sub-micron size’ defects were decreased by approximately 90%. Laser damage testing revealed that the laser-induced damage thresholds(LIDTs),as well as the consistency of the LIDTs from sample to sample, were improved greatly. Moreover, it identified that‘micron size’ defects were the precursors which initiated laser damage at relative lower laser fluence(4–6 J cm-2),and there was a lower correlation between smaller size scattering defects and laser damage initiation. The improved consistency in the LIDTs, attributed to elimination of ‘micron size’ defects, and LIDT enhancement originated from the decreased absorption of the KDP crystals.

  2. Stoichiometric magnetite grown by infrared nanosecond pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Sanz, Mikel, E-mail: mikel.sanz@iqfr.csic.es [Instituto de Química Física Rocasolano, CSIC, 28006 Madrid (Spain); Oujja, Mohamed; Rebollar, Esther; Marco, José F.; Figuera, Juan de la; Monti, Matteo [Instituto de Química Física Rocasolano, CSIC, 28006 Madrid (Spain); Bollero, Alberto [IMDEA Nanoscience, Instituto Madrileño de Estudios Avanzados en Nanociencia, Campus Universidad Autónoma de Madrid, 28049 Madrid (Spain); Camarero, Julio [IMDEA Nanoscience, Instituto Madrileño de Estudios Avanzados en Nanociencia, Campus Universidad Autónoma de Madrid, 28049 Madrid (Spain); Departamento de Física de la Materia Condensada, Instituto Nicolás Cabrera, Campus Universidad Autónoma de Madrid, 28049 Madrid (Spain); Pedrosa, Francisco J. [IMDEA Nanoscience, Instituto Madrileño de Estudios Avanzados en Nanociencia, Campus Universidad Autónoma de Madrid, 28049 Madrid (Spain); García-Hernández, Mar [Instituto de Ciencias Materiales de Madrid, CSIC, 28049 Madrid (Spain); Castillejo, Marta [Instituto de Química Física Rocasolano, CSIC, 28006 Madrid (Spain)

    2013-10-01

    Pulsed laser deposition (PLD) is a versatile technique for the fabrication of nanostructures due to the possibilities it offers to control size and shape of nanostructured deposits by varying the laser parameters. Magnetite nanostructures are currently promising materials to be used in computing, electronic devices and spintronic applications. For all these uses the fabrication of uniform nanostructured pure magnetite thin films is highly advantageous. In PLD of magnetite, the laser irradiation wavelength and substrate temperature crucially affect the composition, crystallinity, surface structure and the magnetic properties of the grown samples. This work shows that the use of nanosecond IR laser at 1064 nm enhances the quality of the resulting magnetite thin films, compared to the extensively used UV wavelengths. Deposition at 1064 nm, upon heating the substrate at 750 K, produces thin films constituted by stoichiometric magnetite nanoparticles with sharp edges and sizes ranging from 80 to 150 nm, with a Verwey transition at 119 K and a coercivity of 232 Oe at room temperature, close to those of pure bulk magnetite. Thus, IR-PLD of self-prepared hematite sintered targets constitutes a low-cost procedure of fabrication of pure magnetite nanostructured thin films.

  3. Characterization of traditional tomato varieties grown in organic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Cebrino, F.; Lozano, M.; Ayuso, M. C.; Bernalte, M. J.; Vidal-Aragon, M. C.; Gonzalez-Gomez, D.

    2011-07-01

    Organic horticulture is a sustainable agricultural model that can provide high quality products and allows conservation of genetic diversity. Traditional tomato varieties are well adapted to organic production and they have the organoleptic characteristics demanded by consumers. Seven traditional tomato varieties were studied: BGV-001020, BGV-000998, BGV-001000, BGV-004123, CIDA-44-A, CIDA-62, CIDA-59-A, and they were compared with a tomato Marmandetype commercial cv. Baghera, all them grown under organic production. Several quality variables were measured to establish whether any of the traditional varieties might be suitable for commercial production. CIDA-62 was shown to be the most promising variety. It produces tomatoes of very high quality under organic conditions. It excels in terms of bioactive compounds such as vitamin C (459.22 mg kg{sup -}1 fw) and lycopene (62.25 mg kg{sup -}1 fw) and in its total antioxidant activity (43.58 mg Trolox/100 g fw). It is also outstanding in terms of its sugar content (4.56% fructose and glucose combined) and of its total soluble solids content (6.22 degree centigrade Brix). All of these variables are associated with both sensory quality and health benefits. Other varieties that emerged with relatively high levels of total soluble solids content, lycopene, vitamin C and total antioxidant activity were BGV-004123 and BGV-001020. (Author) 41 refs.

  4. Pyrolysis kinetics of algal consortia grown using swine manure wastewater.

    Science.gov (United States)

    Sharara, Mahmoud A; Holeman, Nathan; Sadaka, Sammy S; Costello, Thomas A

    2014-10-01

    In this study, pyrolysis kinetics of periphytic microalgae consortia grown using swine manure slurry in two seasonal climatic patterns in northwest Arkansas were investigated. Four heating rates (5, 10, 20 and 40 °C min(-1)) were used to determine the pyrolysis kinetics. Differences in proximate, ultimate, and heating value analyses reflected variability in growing substrate conditions, i.e., flocculant use, manure slurry dilution, and differences in diurnal solar radiation and air temperature regimes. Peak decomposition temperature in algal harvests varied with changing the heating rate. Analyzing pyrolysis kinetics using differential and integral isoconversional methods (Friedman, Flynn-Wall-Ozawa, and Kissinger-Akahira-Sunose) showed strong dependency of apparent activation energy on the degree of conversion suggesting parallel reaction scheme. Consequently, the weight loss data in each thermogravimetric test was modeled using independent parallel reactions (IPR). The quality of fit (QOF) for the model ranged between 2.09% and 3.31% indicating a good agreement with the experimental data.

  5. Screw dislocations in GaN grown by different methods

    Energy Technology Data Exchange (ETDEWEB)

    Liliental-Weber, Z.; Zakharov, D.; Jasinski, J.; O' Keefe, M.A.; Morkoc, H.

    2003-05-27

    A study of screw dislocations in Hydride-Vapor-Phase-Epitaxy (HVPE) template and Molecular-Beam-Epitaxy (MBE) over-layers was performed using Transmission Electron Microscopy (TEM) in plan-view and in cross-section. It was observed that screw dislocations in the HVPE layers were decorated by small voids arranged along the screw axis. However, no voids were observed along screw dislocations in MBE overlayers. This was true both for MBE samples grown under Ga-lean and Ga-rich conditions. Dislocation core structures have been studied in these samples in the plan-view configuration. These experiments were supported by image simulation using the most recent models. A direct reconstruction of the phase and amplitude of the scattered electron wave from a focal series of high-resolution images was applied. It was shown that the core structures of screw dislocations in the studied materials were filled. The filed dislocation cores in an MBE samples were stoichiometric. However, in HVPE materials, single atomic columns show substantial differences in intensities and might indicate the possibility of higher Ga concentration in the core than in the matrix. A much lower intensity of the atomic column at the tip of the void was observed. This might suggest presence of lighter elements, such as oxygen, responsible for their formation.

  6. Lattice constant and hardness of InSb:Bi bulk crystals grown by vertical directional solidification

    Science.gov (United States)

    Maske, Dilip; Deshpande, Manisha; Choudhary, Rashmi; Gadkari, Dattatray

    2016-05-01

    Ingots of the Bi doped InSb (InSb1-xBix) bulk semiconductor crystals were grown by specially designed Vertical Directional Solidification (VDS) technique. Substrates of seven crystals grown with various composition values of x (0 ≤ x 0.05.

  7. 76 FR 65357 - Tart Cherries Grown in Michigan, New York, Pennsylvania, Oregon, Utah, Washington, and Wisconsin...

    Science.gov (United States)

    2011-10-21

    ... Service 7 CFR Part 930 Tart Cherries Grown in Michigan, New York, Pennsylvania, Oregon, Utah, Washington... prescribed under the marketing order for tart cherries (order). The order regulates the handling of tart... amended (7 CFR part 930), regulating the handling of tart cherries grown in Michigan, New...

  8. 75 FR 77564 - Tart Cherries Grown in the States of Michigan, et al.;

    Science.gov (United States)

    2010-12-13

    ... Agricultural Marketing Service 7 CFR Part 930 Tart Cherries Grown in the States of Michigan, et al.; Final Free and Restricted Percentages for the 2010-2011 Crop Year for Tart Cherries AGENCY: Agricultural... handling of tart cherries grown in the States of Michigan, New York, Pennsylvania, Oregon, Utah,...

  9. 76 FR 42072 - Tart Cherries Grown in Michigan, New York, Pennsylvania, Oregon, Utah, Washington, and Wisconsin...

    Science.gov (United States)

    2011-07-18

    ... Agricultural Marketing Service 7 CFR Part 930 Tart Cherries Grown in Michigan, New York, Pennsylvania, Oregon... changes to the grower diversion regulations prescribed under the marketing order for tart cherries (order). The order regulates the handling of tart cherries grown in the States of Michigan, New...

  10. 77 FR 13015 - Tart Cherries Grown in Michigan, New York, Pennsylvania, Oregon, Utah, Washington, and Wisconsin...

    Science.gov (United States)

    2012-03-05

    ... Agricultural Marketing Service 7 CFR Part 930 Tart Cherries Grown in Michigan, New York, Pennsylvania, Oregon... the handling of tart cherries grown in Michigan, New York, Pennsylvania, Oregon, Utah, Washington, and... 40 handlers of tart cherries subject to regulation under the order and approximately 600 producers...

  11. 7 CFR 30.43 - Class 8; Foreign-grown cigar-leaf types.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Class 8; Foreign-grown cigar-leaf types. 30.43 Section... CONTAINER REGULATIONS TOBACCO STOCKS AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.43 Class 8; Foreign-grown cigar-leaf types. No group divisions...

  12. 7 CFR 30.44 - Class 9; foreign-grown types other than cigar leaf.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Class 9; foreign-grown types other than cigar leaf. 30... STANDARD CONTAINER REGULATIONS TOBACCO STOCKS AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.44 Class 9; foreign-grown types other than cigar leaf. No...

  13. Major Proteins of the Amyloplast of Agar and Soil - Grown Potato Tubers

    DEFF Research Database (Denmark)

    Hald, Simon; Blennow, Andreas; Stensballe, Allan;

    In potato (Solanum tuberosum) tuber starch is synthesized and stored in amyloplasts. Amyloplasts were prepared from in vitro or agar-grown micro tubers and from soil-grown mini tubers and subjected to proteome analysis. The quality of amyloplasts was assessed by comparing amyloplast fractions...

  14. Mid-Atlantic Consumer Purchasing Behavior and Knowledge of Locally Grown and Seasonal Produce

    Science.gov (United States)

    Chamberlain, Amy J.; Kelley, Kathleen M.; Hyde, Jeffrey

    2013-01-01

    Mid-Atlantic urban consumers were surveyed on their fruit and vegetable purchasing behaviors and their knowledge of produce grown in the region. Consumers were generally unaware of what produce is grown in the mid-Atlantic and during what months they are harvested. Additionally, differences pertaining to number of produce items purchased were…

  15. 29 CFR 780.506 - Dependence of exemption on shade-grown tobacco operations.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Dependence of exemption on shade-grown tobacco operations. 780.506 Section 780.506 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION....506 Dependence of exemption on shade-grown tobacco operations. The exemption provided by section...

  16. 75 FR 64681 - Pistachios Grown in California, Arizona, and New Mexico; Continuance Referendum

    Science.gov (United States)

    2010-10-20

    ...; ] DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 983 Pistachios Grown in California..., Arizona, and New Mexico pistachio producers to determine whether they favor continuance of the marketing order regulating the handling of pistachios grown in California, Arizona, and New Mexico. DATES:...

  17. Yield and Oil Composition of Thirty-Eight Basil (Ocimum basilicum L.) Accessions Grown in Mississippi

    Science.gov (United States)

    Sweet basil (Ocimum basilicum L.) has been grown as an essential oil crop in many countries; however, the herbage yield, oil content, composition, and bioactivity of basil grown in Mississippi and other Southern U.S. states has not been explored. The hypothesis of this study was that certain basil ...

  18. 78 FR 30782 - Avocados Grown in South Florida; Change in Minimum Grade Requirements

    Science.gov (United States)

    2013-05-23

    ...; ] DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 915 Avocados Grown in South Florida... prescribed under the Florida avocado marketing order (order). The order regulates the handling of avocados grown in South Florida, and is administered locally by the Avocado Administrative Committee...

  19. Scintillation properties of solution-grown trans-stilbene single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Zaitseva, Natalia, E-mail: zaitseva1@llnl.gov [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94551 (United States); Glenn, Andrew; Carman, Leslie; Paul Martinez, H.; Hatarik, Robert [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94551 (United States); Klapper, Helmut [Institut für Kristallographie, Jägerstraße 17-19, D-52066 Aachen (Germany); Payne, Stephen [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94551 (United States)

    2015-07-21

    The scintillation properties of trans-stilbene crystals grown for the first time by application of the solution growth technique to the scale of 10 cm are reported. Measurements of the scintillation light output, pulse shape discrimination, and neutron detection efficiency were made with sets of crystals cut as 50 cm diameter cylinders of different lengths from 0.3 to 10 cm. Comparison to liquid scintillators and traditional melt-grown stilbene showed that at increasing sizes new solution-grown crystals exhibit better scintillation performance that makes them promising for use in large scale neutron detectors. Results are discussed in relation to structural imperfections attributed to different methods of growth. - Highlights: • 10-cm-scale trans-stilbene single crystals grown from organic solutions. • Crystals have high optical quality required for fast neutron detection. • Scintillation performance superior to liquids and melt-grown stilbene demonstrated.

  20. Outer space grown semi-insulating GaAs and its applications

    Institute of Scientific and Technical Information of China (English)

    林兰英; 张绵; 钟兴儒; 陈诺夫; Masayoshi; Yamada

    1999-01-01

    GaAs single crystal has been grown in recoverable satellite. Hall measurements indicate that the GaAs shows semi-insulating behavior. The structural properties of the crystal have been improved obviously, and their uniformity has been improved as well. The stoichiometry and its distribution in space-grown GaAs are improved greatly compared with the GaAs single crystal grown terrestrially. The properties of integrated circuits made by direct ion-implantation on space-grown GaAs are better than those made on ground-grown materials. These results show that the stoichiometry in semi-insulating GaAs seriously affects the properties of related devices.

  1. Characterization of potassium bromide crystals grown in the aqueous solution of picric acid

    Science.gov (United States)

    Maheswari, J. Uma; Krishnan, C.; Kalyanaraman, S.; Selvarajan, P.

    2016-12-01

    Potassium bromide crystals were grown in the aqueous solution of picric acid by slow evaporation technique at room temperature. X-ray Diffraction (XRD) analysis ensures that the grown sample is in Fm3m space group and FCC structure. Energy Dispersive X-ray Spectroscopy (EDX) reveals the presence of elements in the title compound. UV-Vis-NIR spectrum reveals that the grown sample is a promising nonlinear optical (NLO) material. FTIR analysis confirms the functional groups present in the sample. The thermogravimetric (TG) and differential thermogravimetric (DTA) analyses ensure that the sample material is thermally stable up to 160 °C. The second harmonic efficiency of the sample is 1.3 times greater than that of standard KDP. The mechanical strength of the grown sample is estimated by Vickers microhardness tester. The electrical properties were investigated by impedance analysis and the results of various studies of the grown crystals are discussed.

  2. Glycemic index of American-grown jasmine rice classified as high.

    Science.gov (United States)

    Truong, Teresa H; Yuet, Wei Cheng; Hall, Micki D

    2014-06-01

    The primary objective was to determine the glycemic index (GI) of jasmine rice grown in the United States (US). Secondary objective was to compare the GI of US grown jasmine rice to those grown in Thailand. Twelve healthy subjects were served all four brands of jasmine rice and a reference food (glucose), each containing 50 g of available carbohydrate. Fingerstick blood glucose was measured at 0, 15, 30, 45, 60, 90, and 120 min after consumption following a fasting state. The GI was calculated using the standard equation. The GI values for test foods ranged from 96 to 116 and were all classified as high GI foods. No difference in GI was found between American-grown and Thailand-grown jasmine rice. Although not statistically significant, observations show glycemic response among Asian American participants may be different. GI should be considered when planning meals with jasmine rice as the main source carbohydrate.

  3. The fertilization ability and developmental competence of bovine oocytes grown in vitro.

    Science.gov (United States)

    Makita, Miho; Ueda, Mayuko; Miyano, Takashi

    2016-08-25

    In vitro growth culture systems for oocytes are being developed in several mammalian species. In these growth culture systems, in vitro grown oocytes usually have lower blastocyst formation than in vivo grown oocytes after in vitro fertilization. Furthermore, there have been a few reports that investigated the fertilization ability of in vitro grown oocytes in large animals. The purpose of this study was to investigate the fertilization process and developmental competence of bovine oocytes grown in vitro. Oocyte-granulosa cell complexes collected from bovine early antral follicles (0.4-0.7 mm in diameter) were cultured for growth with 17β-estradiol and androstenedione for 14 days and matured in vitro. These oocytes were then inseminated for 6 or 12 h, and further cultured for development up to 8 days in vitro. After growth culture, oocytes grew from 95 µm to around 120 µm and acquired maturation competence (79%). Although fertilization rates of in vitro grown oocytes were low after 6 h of insemination, 34% of in vitro grown oocytes fertilized normally after 12 h of insemination, having two polar bodies and two pronuclei with a sperm tail, and 22% of these oocytes developed into blastocysts after 8 days of culture. The fertilization and blastocyst formation rates were similar to those of in vivo grown oocytes. In addition, blastocyst cell numbers were also similar between in vitro and in vivo grown oocytes. In conclusion, in vitro grown bovine oocytes are similar to in vivo grown oocytes in fertilization ability and can develop into blastocysts.

  4. Cadmium distribution in field-grown fruit trees

    Energy Technology Data Exchange (ETDEWEB)

    Korcak, R.F. (Dept. of Agriculture, Beltsville, MD (United States))

    The effect of soil applied Cd on Cd distribution in and growth of five species of fruit trees was investigated. Cadmium was applied at three rates (0, 5, and 10 mg kg{sup {minus}1} soil) as CdSO{sub 4} to orchard plots established at two pH levels, low (5.5) and high (6.5). Five fruit tree types were planted: Gala apple (Malus domestica Borkh.) budded on M.26 (dwarfing) or MM.111 (semistandard) rootstocks, Redskin peach (Prunus persica L.) on Lovell rootstock, Stanley plum (Prunus domestica L.) on Myrobalon rootstock, and Seckel pear (Pyrus communis L.) on seedling rootstock. The trees were grown for 6 yr, 7 yr in the case of pear, and leaf, bark, wood, fruit, and root Cd concentrations were monitored. Gala apple on both rootstocks accumulated very small concentrations of Cd, usually 0.1 mg kg{sup {minus}1} dry wt. in all tissues tested. Peach and plum were intermediate in Cd accumulation, but both still relatively low. Seckel pear had high Cd concentrations in all tissues including fruit flesh and peel. Pear leaf Cd concentrations were 2.0 mg kg{sup {minus}1} from the 10 mg kg{sup {minus}1} soil Cd application after 5 yr. Pear fruit peel and flesh showed elevated, although nonsignificant, Cd concentrations with increased Cd applied. There was little difference between bark and wood tissue Cd concentrations independent of tree type. Root Cd concentrations were highest for pear followed by peach and plum, and lowest in apple.

  5. Some analytical characters of cottonseed varieties grown in Turkey

    Directory of Open Access Journals (Sweden)

    Nergiz, Cevdet

    1997-12-01

    Full Text Available Sixteen cottonseed varieties grown in Turkey were analysed. The average oil content in varieties ranged from 309.7g Kg-1 to 379.5g Kg-1 whereas the range in values of gossypol content for glanded varieties was 7.4-12.8g Kg-1. One glandless variety contained gossypol as 0.2g Kg-1. The samples contained 337.2- 466.5g Kg-1 protein. Fatty acid composition of the oils obtained from cottonseed varieties were also determined. Generally total gossypol content of cottonseed varieties were below the limits established by the some nations for human food or animal feed.

    Se han analizado dieciséis variedades de semillas de algodón cultivadas en Turquía. El contenido medio de aceite en las distintas variedades osciló entre 309,7g Kg-1 y 379,5g Kg-1 mientras que el contenido en gosipol para variedades con glándulas fue desde 7,4 a 12,8g Kg-1. Una variedad sin glándula tuvo un valor en gosipol de 0, Kg-1. El valor en proteínas de las muestras osciló entre 337,2 y 466,5g Kg-1. También se determinó la composición en ácidos grasos de los aceites obtenidos de las distintas variedades de semilla de algodón. Por lo general el contenido total en gosipol en las distintas variedades fue inferior a los límites establecidos por algunas naciones para su consumo humano o para alimentación animal.

  6. Growth and Quality of Chinese Kale Grown Under Different LEDs

    Institute of Scientific and Technical Information of China (English)

    Jintong XlN; Houcheng LlU; Shiwei SONG; Riyuan CHEN; Guangwen SUN

    2015-01-01

    Objective] This study was conducted to investigate the effects of light quality on growth and quality of Chinese kale (Brassica alboglabra Bailey). [Method] Chinese kale was grown in hydroponic under three different Light Emitting Diode (LEDs) conditions [red:blue=8:1 (8R1B), red:blue=6:3 (6R3B) and red:green:blue=6:2:1 (6R2G1B), 12 h light, 50 μmol/(m2·s)]. Then its growth and quality indices including root and shoot fresh weight and dry weight, concentrations of soluble protein, vita-min C, nitrate, soluble phenols, flavonoids, soluble sugar, free amino acids, and ac-tivity of nitrate reductase were measured. [Result] There was no significant differ-ence in plant height, diameter of flower stalk and leaf number among three LED treatments. The fresh weight of shoot, root and plant in 8R1B and 6R2G1B was significantly higher than in 6R3B. The dry weight of shoot and plant in 8R1B was significantly higher than in 6R3B. The concentrations of vitamin C, soluble protein and soluble sugar in flower stalk of 6R3B treatment were significantly higher than those in 8R1B and 6R2G1B, while there was no remarkable difference in concen-trations of reducing sugar, soluble phenol, flavonoids and free amino acid among the three treatments. The nitrate concentration in flower stalk of 6R3B was signifi-cantly lower than in the other two treatments, and the activity of nitrate reductase in 6R3B was significantly higher than in the other two treatments. [Conclusion] The LED treatment of red:blue=6:3 was more suitable for the growth of Chinese kale.

  7. Heterogeneously grown tunable group-IV laser on silicon

    Science.gov (United States)

    Hudait, Mantu; Clavel, M.; Lester, L.; Saladukha, D.; Ochalski, T.; Murphy-Armando, F.

    2016-02-01

    Tunable tensile-strained germanium (epsilon-Ge) thin films on GaAs and heterogeneously integrated on silicon (Si) have been demonstrated using graded III-V buffer architectures grown by molecular beam epitaxy (MBE). epsilon-Ge epilayers with tunable strain from 0% to 1.95% on GaAs and 0% to 1.11% on Si were realized utilizing MBE. The detailed structural, morphological, band alignment and optical properties of these highly tensile-strained Ge materials were characterized to establish a pathway for wavelength-tunable laser emission from 1.55 μm to 2.1 μm. High-resolution X-ray analysis confirmed pseudomorphic epsilon-Ge epitaxy in which the amount of strain varied linearly as a function of indium alloy composition in the InxGa1-xAs buffer. Cross-sectional transmission electron microscopic analysis demonstrated a sharp heterointerface between the epsilon-Ge and the InxGa1-xAs layer and confirmed the strain state of the epsilon-Ge epilayer. Lowtemperature micro-photoluminescence measurements confirmed both direct and indirect bandgap radiative recombination between the Γ and L valleys of Ge to the light-hole valence band, with L-lh bandgaps of 0.68 eV and 0.65 eV demonstrated for the 0.82% and 1.11% epsilon-Ge on Si, respectively. The highly epsilon-Ge exhibited a direct bandgap, and wavelength-tunable emission was observed for all samples on both GaAs and Si. Successful heterogeneous integration of tunable epsilon-Ge quantum wells on Si paves the way for the implementation of monolithic heterogeneous devices on Si.

  8. Short-Term Effects of Fire Disturbance on Carbon Storage of Larix gmelinii-Carex schmidtii Forested Wetlands Ecosystem in Daxing'an Mountain%火干扰对大兴安岭兴安落叶松瘤囊苔草湿地生态系统碳储量的短期影响

    Institute of Scientific and Technical Information of China (English)

    牟长城; 包旭; 卢慧翠; 王彪; 崔巍

    2013-01-01

    In this study, we investigated vegetation carbon storage, litter carbon storage and soil carbon storage of Larix gmelinii-Carex schmidtii forested wetlands ecosystem under the unburned site, lightly burned site and heavily burned site in Daxing'an Mountain, in order to reveal the short-term effects of fire disturbance on carbon storage of forested wetlands ecosystem. Results showed that the vegetation carbon storage of heavily burned site (0.26 kg·m-2 ) significantly (P 0. 05 ) . The litter carbon storage of the lightly burned site (0. 23kg·m-2 ) and heavily burned site (0. 15 kg·m-2) decreased respectively by 32.4% and 55. 9% than that of the unburned site (0. 34kg·m-2) , but only the latter existed significant difference with unburned site ( P < 0. 05). The soil carbon storage of the lightly burned site (15. 46 kg·m-2) and heavily burned site (16.33 kg·m-2) was both significantly lower than that of the unburned site (23. 07 kg·m-2) ( decreased by 33. 0% and 29. 2% , P < 0. 05). The ecosystem carbon storage of the lightly burned site (22. 04kg·m-2) and heavily burned site (16. 74 kg·m-2) decreased by 27. 8% and 45. 2% (8.49 or 13. 79 kg·m-2) than that of the unburned site (30. 53 kg·m-2) , but only the latter existed significant difference with the unburned site (P<0. 05) , and there were decreased trends with the fire disturbance intensity increased. Therefore, the heavily fire disturbance should be prevented in order to maintain or increase the carbon sink of the forested wetlands ecosystem.%对比分析大兴安岭未火烧、轻度火烧与重度火烧兴安落叶松瘤囊苔草湿地的植被碳储量、凋落物碳储量及土壤碳储量,揭示火烧干扰对寒温带森林湿地生态系统碳储量的短期影响规律.结果表明:兴安落叶松瘤囊苔草湿地轻度与重度火烧样地的植被碳储量(6.35和0.26 kg·m-2)较未火烧样地(7.12 kg·m-2)降低了10.8%和96.3%,重度火烧使其显著降低(P<0.05);轻度与重

  9. Comparison of fluence-response relationships of phototropism in light- and dark-grown buckwheat.

    Science.gov (United States)

    Ellis, R J

    1987-11-01

    Fluence-response relationships of phototropism in light- and dark-grown buckwheat (Fagopyrum esculentum Moench.) were compared using systematically varied fluence rates and irradiation times of unilateral monochromatic blue light. Etiolated seedlings respond to most fluence rates in a tri-phasic manner. Phase one differs from classic first positive in that reciprocity is not observed and the peak occurs at a wide variety of fluences, often orders of magnitude less than those characteristic of first positive. Light-grown plants display this pattern only when stimulated by low fluence rates. Phase three is an ascending arm directly related to irradiance time and is comparable to classic second positive. Phase two is a nearly indifferent zone separating phases one and three. At the lowest fluence rates, the maximal observed curvature is greater for dark-grown than for light-grown plants and the former curve more in response to short (2-second) exposures than do the latter. At the highest fluence rates, the maximal observed curvature is much greater for light-grown than for dark-grown seedlings, particularly at irradiation times of 2 to 3 minutes or more. Tropic curvatures correlate positively with increasing fluence rate up to some inflection range, above which the relationship becomes negative. This inflection range is approximately two orders of magnitude higher for light-grown plants.

  10. Differential carotenoid production and gene expression in Xanthophyllomyces dendrorhous grown in a nonfermentable carbon source.

    Science.gov (United States)

    Wozniak, Aniela; Lozano, Carla; Barahona, Salvador; Niklitschek, Mauricio; Marcoleta, Andrés; Alcaíno, Jennifer; Sepulveda, Dionisia; Baeza, Marcelo; Cifuentes, Víctor

    2011-05-01

    Xanthophyllomyces dendrorhous is a basidiomycetous yeast of considerable biotechnological interest because it synthesizes astaxanthin as its main carotenoid. The carotenoid production increases when it is grown using nonfermentable compounds as the sole carbon source. This work analyzes the expression of the carotenogenic genes and their relationship with the amount and types of carotenoids produced when X. dendrorhous is grown using a nonfermentable (succinate) or a fermentable carbon source (glucose). When X. dendrorhous is grown in succinate, carotenoid production is approximately three times higher than when it is grown in glucose. Moreover, carotenoid biosynthesis occurs at the start of the growth cycle when X. dendrorhous is grown in succinate, whereas when it is grown in glucose, carotenoids are produced at the end of the exponential phase. Additionally, we observed that some carotenogenic genes, such as alternative transcripts of crtYB and crtI, are differentially expressed when the yeast is grown in these carbon sources; other genes, such as crtS, exhibit a similar pattern of expression. Our data indicate that transcriptional regulation is not sufficient to explain the differences in carotenoid production between the two culture conditions, indicating that additional regulatory mechanisms may be operating in the carotenogenic pathway of X. dendrorhous.

  11. Ultrafast carrier dynamics in purified and as-grown single-walled carbon nanotube films

    Institute of Scientific and Technical Information of China (English)

    Long Yong-Bing; Song Li; Zhang Chun-Yu; Wang Li; Fu Pan-Ming; Zhang Zhi-Guo; Xie Si-Shen; Wang Guo-Ping

    2005-01-01

    Ultrafast time-resolved optical transmissions in purified and as-grown single-walled carbon nanotube films are measured at a temperature of 200K. The signal of the purified sample shows a crossover from photobleaching to photoabsorption. The former and the latter are interpreted as the state filling and the red shift of the π-plasmon,respectively. The signal of the as-grown sample can be perfectly fitted by a single-exponential with a time constant of 232fs. The disappearance of the negative component in the as-grown sample is attributed to the charge transfer between the semiconducting nanotubes and the impurities.

  12. Microstructural development of melt-grown mullite fibrils

    Science.gov (United States)

    Baer, Amanda

    The crystallization behavior of mullite growing from the melt within a siliceous glassy phase has been investigated. Initial studies examined single crystal, nominally continuous mullite fibers grown in bundles by directional solidification using a modified version of the Edge-Defined Film-Fed Growth (EFG) process (GE-AE/Saphikon, Inc.). These fibers are intended to be recovered by dissolution of the glass matrix and used as reinforcements of ceramic matrix composites. Subsequent experiments employed small-scale crucible-based solidification experiments conducted at the UCSB Materials Processing Lab. The EFG approach yielded ribbons containing bundles of aligned single-crystal mullite with relatively small diameters embedded in a silicate glass matrix. Because of interactions between the growing crystals, however, the fibers recovered are actually discontinous crystals and hence termed "fibrils." Ribbons were produced from SiOsb2-Alsb2Osb3-MgO melts at solidification rates ranging from 2.5 to 61 cm/h. Typically, mullite fibers grew in the (001) direction and had distinct facets on the \\{110)-type planes. The mullite fibrils exhibited a variety of cross-sectional profiles-including various forms of glass-filled hollows, internal splintering, and lateral dendritic growth-which resulted largely from morphological instability during growth, and thus depended on the alloy composition and solidification parameters. Morphological instabilities became more pronounced with increasing growth velocity. Increasing the MgO content or the Alsb2Osb3/SiOsb2 ratio reduced these instabilities, indicating the role of alloy chemistry in modifying the transport properties in the melt, and hence the ease of solute redistribution. The crucible experiments examined the role of melt chemistry further, paying particular attention to the effects of various modifying additions to the SiOsb2-Alsb2Osb3 melt (MgO, BaO, Nasb2O, and Ksb2O). The choice of modifying oxide had a significant effect

  13. Preliminary investigations of the rhizosphere nature of hydroponically grown lettuces

    Science.gov (United States)

    Antunes, Inês; Paille, Christel; Lasseur, Christophe

    Due to capabilities of current launchers, future manned exploration beyond the Earth orbit will imply long journeys and extended stays on planet surfaces. For this reason, it is of a great importance to develop a Regenerative Life Support System that enables the crew to be, to a very large extent, metabolic consumables self-sufficient. In this context, the European Space Agency, associated with a scientific and engineering con-sortium, initiated in 1989 the Micro-Ecological Life Support System Alternative (MELiSSA) project. This concept, inspired on a terrestrial ecosystem (i.e. a lake), comprises five intercon-nected compartments inhabited by micro-organisms and higher-plants aiming to produce food, fresh water, and oxygen from organic waste, carbon dioxide, and minerals. Given the important role of the higher-plant compartment for the consumption of carbon dioxide and the production of oxygen, potable water, and food, it was decided to study the microbial communities present in the root zone of the plants (i.e. the rhizosphere), and their synergistic and antagonistic influences in the plant growth. This understanding is important for later investigations concerning the technology involved in the higher plant compartment, since the final goal is to integrate this compartment inside the MELiSSA loop and to guarantee a healthy and controlled environment for the plants to grow under reduced-gravity conditions. To perform a preliminary assessment of the microbial populations of the root zone, lettuces were grown in a hydroponic system and their growth was characterized in terms of nutrient uptake, plant diameter, and plant wet and dry weights. In parallel, the microbial population, bacteria and fungi, present in the hydroponic medium and also inside and outside the roots were analyzed in terms of quantity and nature. The goal of this presentation is to give a preliminary review in the plant root zone of the micro-organisms communities and as well their proportions

  14. 7 CFR 982.467 - Report of receipts and dispositions of hazelnuts grown outside the United States.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Report of receipts and dispositions of hazelnuts grown..., Nuts), DEPARTMENT OF AGRICULTURE HAZELNUTS GROWN IN OREGON AND WASHINGTON Administrative Rules and Regulations § 982.467 Report of receipts and dispositions of hazelnuts grown outside the United States....

  15. 75 FR 29647 - Tart Cherries Grown in the States of Michigan, et al.; Final Free and Restricted Percentages for...

    Science.gov (United States)

    2010-05-27

    ... Service 7 CFR Part 930 Tart Cherries Grown in the States of Michigan, et al.; Final Free and Restricted... Federal marketing order regulating tart cherries grown in seven States (order). The percentages are 32... tart cherries grown in the States of Michigan, New York, Pennsylvania, Oregon, Utah, Washington,...

  16. 76 FR 13528 - Tart Cherries Grown in the States of Michigan, New York, Pennsylvania, Oregon, Utah, Washington...

    Science.gov (United States)

    2011-03-14

    ... Agricultural Marketing Service 7 CFR Part 930 Tart Cherries Grown in the States of Michigan, New York... Marketing Agreement and Order No. 930 (order), which regulate the handling of tart cherries grown in... agreements, Reporting and recordkeeping requirements, Tart cherries. PART 930--TART CHERRIES GROWN IN...

  17. 75 FR 33736 - Tart Cherries Grown in the States of Michigan, New York, Pennsylvania, Oregon, Utah, Washington...

    Science.gov (United States)

    2010-06-15

    ... Agricultural Marketing Service 7 CFR Part 930 Tart Cherries Grown in the States of Michigan, New York... regulates the handling of tart cherries grown in Michigan, New York, Pennsylvania, Oregon, Utah, Washington... amend Marketing Agreement and Order No. 930 (order) regulating the handling of tart cherries grown...

  18. 78 FR 46494 - Tart Cherries Grown in the States of Michigan, New York, Pennsylvania, Oregon, Utah, Washington...

    Science.gov (United States)

    2013-08-01

    ... Agricultural Marketing Service 7 CFR Part 930 Tart Cherries Grown in the States of Michigan, New York... prescribed under the marketing order for tart cherries grown in the States of Michigan, New York... tart cherries grown in the States of Michigan, New York, Pennsylvania, Oregon, Utah, Washington,...

  19. Reduced virulence of Pseudomonas aeruginosa grown in the presence of benzalkonium chloride.

    Science.gov (United States)

    Adair, F W; Liauw, H L; Geftic, S G; Gelzer, J

    1975-01-01

    Resistant cells of Pseudomonas aeruginosa ATCC 9027 which were grown in the presence of 1 mg of benzalkonium chloride (BC) per ml caused only a mild conjunctivitis when they were dropped onto the scratched corneas of rabbits. In contrast, cells of the BC-sensitive parent strain induced a severe keratoconjunctivitis. In addition, the BC-grown cells also had a reduced capacity to produce kidney infections in mice as compared to the parent strain. BC-grown cells acted as weak complex antigens which conferred slight protection against lethal doses of BC-grown cells. No cross-protection to cells of the parent strain occurred. The data indicate that growth in the presence of BC results in cells with reduced virulence. Images PMID:809470

  20. Room temperature direct band gap emission characteristics of surfactant mediated grown compressively strained Ge films

    Science.gov (United States)

    Katiyar, Ajit K.; Grimm, Andreas; Bar, R.; Schmidt, Jan; Wietler, Tobias; Joerg Osten, H.; Ray, Samit K.

    2016-10-01

    Compressively strained Ge films have been grown on relaxed Si0.45Ge0.55 virtual substrates using molecular beam epitaxy in the presence of Sb as a surfactant. Structural characterization has shown that films grown in the presence of surfactant exhibit very smooth surfaces with a relatively higher strain value in comparison to those grown without any surfactant. The variation of strain with increasing Ge layer thickness was analyzed using Raman spectroscopy. The strain is found to be reduced with increasing film thickness due to the onset of island nucleation following Stranski-Krastanov growth mechanism. No phonon assisted direct band gap photoluminescence from compressively strained Ge films grown on relaxed Si0.45Ge0.55 has been achieved up to room temperature. Excitation power and temperature dependent photoluminescence have been studied in details to investigate the origin of different emission sub-bands.

  1. Study of surface morphology and alignment of MWCNTs grown by chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Shukrullah, S., E-mail: zshukrullah@gmail.com, E-mail: noranimuti-mohamed@petronas.com.my, E-mail: maizats@petronas.com.my; Mohamed, N. M., E-mail: zshukrullah@gmail.com, E-mail: noranimuti-mohamed@petronas.com.my, E-mail: maizats@petronas.com.my; Shaharun, M. S., E-mail: zshukrullah@gmail.com, E-mail: noranimuti-mohamed@petronas.com.my, E-mail: maizats@petronas.com.my [Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS, 31750 Tronoh, Perak (Malaysia); Yasar, M., E-mail: Muhammad.yasar@ieee.org [Department of Electrical and Electronic Engineering, Universiti Teknologi PETRONAS, 31750 Tronoh, Perak (Malaysia)

    2014-10-24

    In this research work, Multiwalled Carbon Nanotubes (MWCNTs) have been synthesized successfully by using floating catalytic chemical vapor deposition (FCCVD) method. Different ferrocene amounts (0.1, 0.125 and 0.15 g) were used as catalyst and ethylene was used as a carbon precursor at reaction temperature of 800°C. Characterization of the grown MWCNTs was carried out by using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The obtained data showed that the catalyst weight affects the nanotubes diameter, alignment, crystallinity and growth significantly, whereas negligible influence was noticed on CNTs forest length. The dense, uniform and meadow like patterns of grown CNTs were observed for 0.15 g ferrocene. The average diameter of the grown CNTs was found in the range of 32 to 75 nm. Close inspection of the TEM images also confirmed the defects in some of the grown CNTs, where few black spots were evident in CNTs structure.

  2. MBE and ALD grown High k Dielectrics Gate Stacks on GaN

    Science.gov (United States)

    Chang, Y. C.; Lee, K. Y.; Lee, W. C.; Lin, T. D.; Lee, Y. J.; Huang, M. L.; Hong, M.; Kwo, J.; Wang, Y. H.

    2007-03-01

    III-nitride compound semiconductors are attractive for high-temperature and high-power MOSFET applications due to their intrinsic properties of wide band gap, high breakdown field, and high saturation velocity under high fields. In this work GaN-based high k MOS diodes were fabricated using MBE-grown Ga2O3(Gd2O3), MBE-grown HfO2 and ALD-grown HfO2 as the gate dielectrics with dielectric constants of 14.7, 17.4 and 16.5, respectively. All MOS diodes exhibited low leakage (XPS and with the bandgaps of the oxides. For example, the ALD-grown HfO2-GaN at the interfaces gave approximately δEC and δEV of 1.2 eV and 1.1 eV, respectively.

  3. Mapping QTLs for Yield Stability in Durum Wheat Grown under Different Water Regimes

    Institute of Scientific and Technical Information of China (English)

    M.C. Sanguineti; A. E1-Ahmed; I. Elouafi; F. Maalouf; V. Martos; M.M. Nachit; N.Nserallah; H. Ouabbou; Y. Rharrabti; S. Rhouma; C. Royo; M. Maccaferri; A. Slama; D. Villegas; R. Tuberosa; E. Natoli; J.L. Araus-Ortega; M.B. Salem; J.Bort; E. de Ambrogio; L.F.G. del Moral; A. de Montis

    2007-01-01

    @@ Among the most important Mediterranean annual crops, durum wheat is widely grown in drought-prone areas. Therefore, improving water-use efficiency (WUE) of durum wheat represents a major breeding goal.

  4. Narrow size distributed Ag nanoparticles grown by spin coating and thermal reduction: effect of processing parameters

    Science.gov (United States)

    Ansari, A. A.; Sartale, S. D.

    2016-08-01

    A simple method to grow uniform sized Ag nanoparticles with narrow size distribution on flat support (glass and Si substrates) via spin coating of Ag+ ions (AgNO3) solution followed by thermal reduction in H2 is presented. These grown nanoparticles can be used as model catalytic system to study size dependent oxygen reduction reaction (ORR) activity. Ag nanoparticles formation was confirmed by local surface plasmon resonance and x-ray photoelectron spectroscopy measurements. Influences of process parameters (revolution per minute (rpm), ramp and salt concentration) on grown Ag nanoparticles size, density and size uniformity are studied. With increase in rpm and ramp the size decreases and the particle number density increases, whereas the size dispersion improves. The catalytic activity of the grown Ag particles for ORR is studied and it is found that the catalytic performance is dependent on the size as well as the number density of the grown Ag nanoparticles.

  5. Electrical and Optical Properties of Bulk ZnO Single Crystal Grown by Flux Bridgman Method

    Institute of Scientific and Technical Information of China (English)

    LI Xin-Hua; XU Jia-Yue; JIN Min; SHEN Hui; LI Xiao-Min

    2006-01-01

    Zinc oxide (ZnO) single crystals are grown by the modified vertical Bridgman method using a PbF2 flux. Themaximum size of the as-grown ZnO crystal is about φ25 mm× 5mm. The transmittance of the as-grown ZnOcrystal is more than 70% in the range of 600-800nm and the optical band gap is estimated to be 3.21 eV. Thephotoluminescence spectrum indicates that the as-grown ZnO crystal has a very low concentration of nativedefects and is much closed to its stoichiometry. The electrical measurement exhibits that the ZnO crystal haslow electrical resistivity of 0.02394Ωcm-1 and a high carrier concentration of 2.10 × 1018 cm-3

  6. 76 FR 31295 - Nectarines and Peaches Grown in California; Notice of Withdrawal

    Science.gov (United States)

    2011-05-31

    ...; ] DEPARTMENT OF AGRICULTURE Agricultural Marketing Service Nectarines and Peaches Grown in California; Notice of Withdrawal AGENCY: Agricultural Marketing Service, USDA. ACTION: Notice; withdrawal. SUMMARY: The Agricultural Marketing Service (AMS) is withdrawing the notice soliciting comments on its request for...

  7. Microbiological Quality and Food Safety of Plants Grown on ISS Project

    Science.gov (United States)

    Wheeler, Raymond M. (Compiler)

    2014-01-01

    The goal of this project is to select and advance methods to enable real-time sampling, microbiological analysis, and sanitation of crops grown on the International Space Station (ISS). These methods would validate the microbiological quality of crops grown for consumption to ensure safe and palatable fresh foods. This would be achieved through the development / advancement of microbiological sample collection, rapid pathogen detection and effective sanitation methods that are compatible with a microgravity environment.

  8. ZnO layers grown by Atomic Layer Deposition: A new material for transparent conductive oxide

    Energy Technology Data Exchange (ETDEWEB)

    Godlewski, M., E-mail: godlew@ifpan.edu.p [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, Warsaw (Poland); Department of Mathematics and Natural Sciences, College of Science, Cardinal Stefan Wyszynski University, Warsaw (Poland); Guziewicz, E.; Luka, G.; Krajewski, T. [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, Warsaw (Poland); Lukasiewicz, M.; Wachnicki, L.; Wachnicka, A. [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, Warsaw (Poland); Department of Mathematics and Natural Sciences, College of Science, Cardinal Stefan Wyszynski University, Warsaw (Poland); Kopalko, K. [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, Warsaw (Poland); Sarem, A.; Dalati, B. [Department of Physics, Faculty of Science, Tishreen University, Latakia (Syrian Arab Republic)

    2009-12-15

    We demonstrate possibility of a control (by selection of zinc precursors and variation of a growth temperature) of electrical properties of ZnO films grown by Atomic Layer Deposition (ALD). ZnO films grown by ALD are used in test photovoltaic devices (solar cells) as transparent conductive oxides for upper, transparent layer in inorganic and organic solar cells, and as n-type partners of p-type CdTe.

  9. Carbon Nanotubes Grown on Metal Microelectrodes for the Detection of Dopamine

    OpenAIRE

    Yang, Cheng; Jacobs, Christopher B.; Nguyen, Michael D.; Ganesana, Mallikarjunarao; Zestos, Alexander G.; Ivanov, Ilia N.; Puretzky, Alexander A.; Rouleau, Christopher M.; Geohegan, David B.; Venton, B. Jill

    2015-01-01

    Microelectrodes modified with carbon nanotubes (CNTs) are useful for the detection of neurotransmitters because the CNTs enhance sensitivity and have electrocatalytic effects. CNTs can be grown on carbon fiber microelectrodes (CFMEs) but the intrinsic electrochemical activity of carbon fibers makes evaluating the effect of CNT enhancement difficult. Metal wires are highly conductive and many metals have no intrinsic electrochemical activity for dopamine, so we investigated CNTs grown on metal...

  10. Effects of CZSi furnace modification on density of grown-in defects

    Institute of Scientific and Technical Information of China (English)

    REN; Bingyan(任丙彦); ZHANG; Zhicheng(张志成); LIU; Caichi(刘彩池); HAO; Qiuyan(郝秋燕); WANG; Meng(王猛)

    2002-01-01

    During large diameter Czochralski silicon growth, heat zone and argon flow influence the formation of defects in silicon crystal by changing the distribution of temperature. Different silicon crys tals with various density of grown-in defects were grown by replacing the popular heater with the com posite heater and changing the popular argon flow into a controlled flow. The experimental results have been explained well by the numeric simulation of argon flow.

  11. Zintl and intermetallic phases grown from calcium/lithium flux

    Science.gov (United States)

    Blankenship, Trevor

    , (Im-3, a = 9.6055(8)A) which contains C 34- units. A very similar phase, Ba12InC 18H4 (Im-3,a = 11.1415(8) A), was grown from the reaction of indium, carbon, and LiH in Ba/Li flux. This compound also includes C34- units. Preliminary Ca/Li flux reactions of aluminum with other main group elements have produced several new phases: a hydride clathrate Ca31Al2H25 in cubic Fd-3m (a=18.0835(15) A), Ca24Al2(C 1-xHx)N2H16 in tetragonal P42/nmc (a=15.9069(12) A, c=13.7323(10) A, and Ca 4Al2N5 in orthorhombic Pna21 (a = 11.2331(1) A, b=9.0768(8) A, c=6.0093(5) A.

  12. Yield and quality of tomato (Lycopersicon esculentum Mill. fruit harvested from plants grown in mulched soil

    Directory of Open Access Journals (Sweden)

    Joanna Majkowska-Gadomska

    2012-12-01

    Full Text Available A study investigating the yield of field-grown tomatoes was conducted in 2007–2009 in the Garden of the Research and Experimental Station of the University of Warmia and Mazury in Olsztyn. The experimental materials comprised two tomato cultivars, 'Bawole Serce' and 'Złoty Ożarowski'. Tomato plants were grown in bare soil and in soil mulched with black non-woven PP 50 fabric. Cultivar selection had a significant effect only on average early yield of 'Bawole Serce'. The highest average early yield for three years of the study was recorded for 'Bawole Serce' grown in mulched soil, while the lowest one for 'Złoty Ożarowski' grown in mulched plots. Tomato marketable yield was significantly higher in both treatments where 'Bawole Serce' plants were grown. Fruits harvested from tomato plants 'Złoty Ożarowski' had a higher dry matter content. Soil mulching significantly increased the dry matter content of 'Złoty Ożarowski' tomato fruit. The experimental factors had no influence on the concentrations of L-ascorbic acid, total sugars, and organic acids. Nitrate levels in tomato fruit were within permissible limits, and they were significantly affected by the cultivation method and the method x cultivar interaction. Nitrate accumulation was reduced in tomato plants 'Złoty Ożarowski' grown in mulched soil.

  13. Flux-Grown Piezoelectric Materials: Application to α-Quartz Analogues

    Directory of Open Access Journals (Sweden)

    Pascale Armand

    2014-06-01

    Full Text Available Using the slow-cooling method in selected MoO3-based fluxes, single-crystals of GeO2 and GaPO4 materials with an α-quartz-like structure were grown at high temperatures (T ≥ 950 °C. These piezoelectric materials were obtained in millimeter-size as well-faceted, visually colorless and transparent crystals. Compared to crystals grown by hydrothermal methods, infrared and Raman measurements revealed flux-grown samples without significant hydroxyl group contamination and thermal analyses demonstrated a total reversibility of the α-quartz ↔ β-cristobalite phase transition for GaPO4 and an absence of phase transition before melting for α-GeO2. The elastic constants CIJ (with I, J indices from 1 to 6 of these flux-grown piezoelectric crystals were experimentally determined at room and high temperatures. The ambient results for as-grown α-GaPO4 were in good agreement with those obtained from hydrothermally-grown samples and the two longitudinal elastic constants measured versus temperature up to 850 °C showed a monotonous evolution. The extraction of the ambient piezoelectric stress contribution e11 from the CD11 to CE11 difference gave for the piezoelectric strain coefficient d11 of flux-grown α-GeO2 crystal a value of 5.7(2 pC/N, which is more than twice that of α-quartz. As the α-quartz structure of GeO2 remained stable up to melting, a piezoelectric activity was observed up to 1000 °C.

  14. Analysis of peg formation in cucumber seedlings grown on clinostats and in a microgravity (space) environment

    Science.gov (United States)

    Link, B. M.; Cosgrove, D. J.

    1999-01-01

    In young cucumber seedlings, the peg is a polar out-growth of tissue that functions by snagging the seed coat, thereby freeing the cotyledons. Previous studies have indicated that peg formation is gravity dependent. In this study we analyzed peg formation in cucumber seedlings (Cucumis sativus L. cv Burpee Hybrid II) grown under conditions of normal gravity, microgravity, and simulated microgravity (clinostat rotation). Seeds were germinated on the ground, in clinostats and on board the space shuttle (STS 95) for 1-2 days, frozen and subsequently examined for their stage of development, degree of hook formation, number of pegs formed, and peg morphology. The frequency of peg formation in space grown seedlings was found to be nearly identical to that of clinostat grown seedlings and to differ from that of seedlings germinated under normal gravity only in a minority of cases; approximately 6% of the seedlings formed two pegs and nearly 2% of the seedlings lacked pegs, whereas such abnormalities did not occur in ground controls. The degree of hook formation was found to be less pronounced for space grown seedlings, compared to clinostat grown seedlings, indicating a greater degree of decoupling between peg formation and hook formation in space. Nonetheless, in all seedlings having single pegs and a hook, the peg was found to be positioned correctly on the inside of the hook, showing that there is coordinate development even in microgravity environments. Peg morphologies were altered in space grown samples, with the pegs having a blunt appearance and many pegs showing alterations in expansion, with the peg extending out over the edges of the seed coat and downwards. These phenotypes were not observed in clinostat or ground grown seedlings.

  15. Shark predation on migrating adult American eels (Anguilla rostrata in the Gulf of St. Lawrence.

    Directory of Open Access Journals (Sweden)

    Mélanie Béguer-Pon

    Full Text Available In an attempt to document the migratory pathways and the environmental conditions encountered by American eels during their oceanic migration to the Sargasso Sea, we tagged eight silver eels with miniature satellite pop-up tags during their migration from the St. Lawrence River in Québec, Canada. Surprisingly, of the seven tags that successfully transmitted archived data, six were ingested by warm-gutted predators, as observed by a sudden increase in water temperature. Gut temperatures were in the range of 20 to 25°C-too cold for marine mammals but within the range of endothermic fish. In order to identify the eel predators, we compared their vertical migratory behavior with those of satellite-tagged porbeagle shark and bluefin tuna, the only endothermic fishes occurring non-marginally in the Gulf of St. Lawrence. We accurately distinguished between tuna and shark by using the behavioral criteria generated by comparing the diving behavior of these two species with those of our unknown predators. Depth profile characteristics of most eel predators more closely resembled those of sharks than those of tuna. During the first days following tagging, all eels remained in surface waters and did not exhibit diel vertical migrations. Three eels were eaten at this time. Two eels exhibited inverse diel vertical migrations (at surface during the day during several days prior to predation. Four eels were eaten during daytime, whereas the two night-predation events occurred at full moon. Although tagging itself may contribute to increasing the eel's susceptibility to predation, we discuss evidence suggesting that predation of silver-stage American eels by porbeagle sharks may represent a significant source of mortality inside the Gulf of St. Lawrence and raises the possibility that eels may represent a reliable, predictable food resource for porbeagle sharks.

  16. Speciation and demographic history of Atlantic eels (Anguilla anguilla and A. rostrata) revealed by mitogenome sequencing

    DEFF Research Database (Denmark)

    Jacobsen, M.W.; Pujolar, J.M.; Gilbert, M.T.P.

    2014-01-01

    , coinciding with the closure of the Panama Gateway that led to reinforcement of the Gulf Stream. This could have advected larvae towards European/North African coasts, in which case American eel would be expected to be the ancestral species. This scenario could, however, not be unequivocally confirmed...... for positive selection at the ATP6 and possibly ND5 genes, indicating a role in speciation. The findings suggest an important role of ocean current changes in speciation of marine organisms...

  17. Extracellular polymeric substances of the marine fouling diatom Amphora rostrata Wm. Sm.

    Digital Repository Service at National Institute of Oceanography (India)

    Khandeparker, R.; Bhosle, N.B.

    the presence of a single peak. Capillary gas chromatographic analysis of both planktonic and biofilm EPS showed that fucose (36.7%) and galactose (27.6%) were the most abundant monosaccharides, with small quantities of rhamnose, xylose, arabinose, mannose...

  18. Low PCB concentrations observed in American eel (Anguilla rostrata) in six Hudson River tributaries

    Science.gov (United States)

    Limburg, K.E.; Machut, L.S.; Jeffers, P.; Schmidt, R.E.

    2008-01-01

    We analyzed 73 eels, collected in 2004 and 2005 above the head of tide in six Hudson River tributaries, for total PCBs, length, weight, age, and nitrogen stable isotope ratios (??15N). Mean total PCB concentration (wet weight basis) was 0.23 ppm ?? 0.08 (standard error), with a range of 0.008 to 5.4 ppm. A majority of eels (84) had concentrations below 0.25 ppm, and only seven eels (10%) had concentrations exceeding 0.5 ppm. Those eels with higher PCB concentrations were ???12 yr; there was a weak correlation of PCB concentration with ??15N and also with weight. Compared to recent (2003) data from the mainstem of the Hudson River estuary, these results indicate that tributaries are generally much less contaminated with PCBs. We hypothesize that those tributary eels with high PCB concentrations were relatively recent immigrants from the mainstem. Given concern over the possible adverse effects of PCBs on eel reproduction, these tributaries may serve as refugia. Therefore, providing improved access to upland tributaries may be critically important to this species. ?? 2008 Northeastern Naturalist.

  19. Growth observations on European (Anguilla anguilla L. and American (Anguilla rostrata Le Sueur glass eels

    Directory of Open Access Journals (Sweden)

    APPELBAUM S.

    1998-04-01

    (x = 0.167 ± 0.006 g. After 45 days of rearing, the weight differences between the species became insignificant. Except for the different transportation mortalities on arrival, the European and the American eels demonstrated similar mortality rates during the experiment ( 1 2 . 5 % , food conversion rate (2.3 and specific growth rate (0.90 and 0.99 respectively. No parasites or diseases were detected. No differences were observed in general behaviour and feeding between the two species.

  20. Shark predation on migrating adult american eels (Anguilla rostrata) in the Gulf of St. Lawrence

    DEFF Research Database (Denmark)

    Béguer-Pon, Mélanie; Benchetrit, José; Castonguay, Martin;

    2012-01-01

    to identify the eel predators, we compared their vertical migratory behavior with those of satellite-tagged porbeagle shark and bluefin tuna, the only endothermic fishes occurring non-marginally in the Gulf of St. Lawrence. We accurately distinguished between tuna and shark by using the behavioral criteria...... generated by comparing the diving behavior of these two species with those of our unknown predators. Depth profile characteristics of most eel predators more closely resembled those of sharks than those of tuna. During the first days following tagging, all eels remained in surface waters and did not exhibit...... itself may contribute to increasing the eel's susceptibility to predation, we discuss evidence suggesting that predation of silver-stage American eels by porbeagle sharks may represent a significant source of mortality inside the Gulf of St. Lawrence and raises the possibility that eels may represent...

  1. Spectral quality affects disease development of three pathogens on hydroponically grown plants

    Science.gov (United States)

    Schuerger, A. C.; Brown, C. S.; Sager, J. C. (Principal Investigator)

    1997-01-01

    Plants were grown under light-emitting diode (LED) arrays with various spectra to determine the effects of light quality on the development of diseases caused by tomato mosaic virus (ToMV) on pepper (Capsicum annuum L.), powdery mildew [Sphaerotheca fuliginea (Schlectend:Fr.) Pollaci] on cucumber (Cucumis sativus L.), and bacterial wilt (Pseudomonas solanacearum Smith) on tomato (Lycopersicon esculentum Mill.). One LED (660) array supplied 99% red light at 660 nm (25 nm bandwidth at half-peak height) and 1% far-red light between 700 to 800 nm. A second LED (660/735) array supplied 83% red light at 660 nm and 17% far-red light at 735 nm (25 nm bandwidth at half-peak height). A third LED (660/BF) array supplied 98% red light at 660 nm, 1% blue light (BF) between 350 to 550 nm, and 1% far-red light between 700 to 800 nm. Control plants were grown under broad-spectrum metal halide (MH) lamps. Plants were grown at a mean photon flux (300 to 800 nm) of 330 micromoles m-2 s-1 under a 12-h day/night photoperiod. Spectral quality affected each pathosystem differently. In the ToMV/pepper pathosystem, disease symptoms developed slower and were less severe in plants grown under light sources that contained blue and UV-A wavelengths (MH and 660/BF treatments) compared to plants grown under light sources that lacked blue and UV-A wavelengths (660 and 660/735 LED arrays). In contrast, the number of colonies per leaf was highest and the mean colony diameters of S. fuliginea on cucumber plants were largest on leaves grown under the MH lamp (highest amount of blue and UV-A light) and least on leaves grown under the 660 LED array (no blue or UV-A light). The addition of far-red irradiation to the primary light source in the 660/735 LED array increased the colony counts per leaf in the S. fuliginea/cucumber pathosystem compared to the red-only (660) LED array. In the P. solanacearum/tomato pathosystem, disease symptoms were less severe in plants grown under the 660 LED array, but the

  2. Growth and Flowering Responses of Cut Chrysanthemum Grown under Restricted Root Volume to Irrigation Frequency

    Directory of Open Access Journals (Sweden)

    Viyachai Taweesak

    2014-01-01

    Full Text Available Influences of irrigation frequency on the growth and flowering of chrysanthemum grown under restricted root volume were tested. Chrysanthemum cuttings (Chrysanthemum morifolium “Reagan White” were grown in seedling tray which contained coconut peat in volumes of 73 and 140 cm3. Plants were irrigated with drip irrigation at irrigation frequencies of 4 (266 mL, 6 (400 mL, and 8 (533 mL times/day to observe their growth and flowering performances. There was interaction between irrigation frequency and substrate volume on plant height of chrysanthemum. Plants grown in 140 cm3 substrates and irrigated 6 times/day produced the tallest plant of 109.25 cm. Plants irrigated 6 and 8 times/day had significantly higher level of phosphorus content in their leaves than those plants irrigated 4 times/day. The total leaf area, number of internodes, leaf length, and leaf width of chrysanthemums grown in 140 cm3 substrate were significantly higher than those grown in 73 cm3 substrate. The numbers of flowers were affected by both irrigation frequencies and substrate volumes. Chrysanthemums irrigated 8 times/day had an average of 19.56 flowers while those irrigated 4 times/day had an average of 16.63 flowers. Increasing irrigation frequency can improve the growth and flowering of chrysanthemums in small substrate volumes.

  3. Photoresponse properties of BaSi2 film grown on Si (100) by vacuum evaporation

    Science.gov (United States)

    Thi Trinh, Cham; Nakagawa, Yoshihiko; Hara, Kosuke O.; Takabe, Ryota; Suemasu, Takashi; Usami, Noritaka

    2016-07-01

    We have succeeded in the observation of high photoresponsivity of orthorhombic BaSi2 film grown on crystalline Si by a vacuum evaporation method, raising the prospect of its promising application in high-efficiency thin-film solar cells. Photocurrent was observed at photon energies larger than 1.28 eV, which corresponds to the band gap of evaporated BaSi2 film, indicating that the photoresponsivity originates from the BaSi2 film. The effect of the substrate temperature on the film’s properties was also investigated. The films grown at a substrate temperature larger than 500 °C are single-phase polycrystalline BaSi2 films, while those grown at a substrate temperature of 400 °C is a mixture of phases. We confirmed that undoped evaporated BaSi2 films are an n-type material with high carrier concentration. High carrier lifetime of 4.8 and 2.7 μs can be found for the films grown at 500 °C and 400 °C, respectively. BaSi2 film grown at a substrate temperature of 500 °C, which is crack-free and single-phase, shows the best photoresponsivity. The maximum value of photocurrent was obtained at photon energy of 1.9 eV, corresponding to an external quantum efficiency of 22% under reverse applied voltage of 2 V.

  4. Procyanidins in Lotus L. genotypes grown in soil with different saturations of aluminum

    Directory of Open Access Journals (Sweden)

    Sílvia Ortiz Chini

    2016-02-01

    Full Text Available Condensed tannins are formed by monomers of procyanidins and prodelfinidins, where the proportion and concentration of their monomers varies according to the plant species and environmental conditions. In Lotus spp., condensed tannins prevent tympanism in ruminants that feed on them. This study aimed to evaluate the concentration of procyanidins and their monomers, catechin and epicatechin in the genotypes of Lotus L. grown in soil with different saturations of aluminum. A two-factor (genotype × Al saturation assay was performed, where the genotypes São Gabriel, Ganador, and UFRGS (Lotus corniculatus L.; Serrano (Lotus uliginosus; and El Rincón (Lotus subbiflorus were cultivated in soil with an Al saturation of 0-20%. The procyanidins were evaluated using high-performance liquid chromatography, which was previously validated for catechin and epicatechin. The concentration of procyanidins and the proportion of epicatechin:catechin were affected by the genotype × environment interaction. In L. corniculatus and L. subbiflorus, the concentration of procyanidin was significantly higher when they were grown in the soil with an Al saturation of 20% compared to that when they were grown in the soil with 0% Al saturation, but the opposite effect was observed in L. uliginosus. The proportion of epicatechin:catechin decreased in plants grown in soil without Al, and only the UFRGS genotype maintained a similar proportion under both the soil acidity conditions. The predominant monomer was epicatechin, which varied from 57% to 75% according to the soil in which the plants were grown.

  5. Multilayer porous structures of HVPE and MOCVD grown GaN for photonic applications

    Science.gov (United States)

    Braniste, T.; Ciers, Joachim; Monaico, Ed.; Martin, D.; Carlin, J.-F.; Ursaki, V. V.; Sergentu, V. V.; Tiginyanu, I. M.; Grandjean, N.

    2017-02-01

    In this paper we report on a comparative study of electrochemical processes for the preparation of multilayer porous structures in hydride vapor phase epitaxy (HVPE) and metal organic chemical vapor phase deposition (MOCVD) grown GaN. It was found that in HVPE-grown GaN, multilayer porous structures are obtained due to self-organization processes leading to a fine modulation of doping during the crystal growth. However, these processes are not totally under control. Multilayer porous structures with a controlled design have been produced by optimizing the technological process of electrochemical etching in MOCVD-grown samples, consisting of five pairs of thin layers with alternating-doping profiles. The samples have been characterized by SEM imaging, photoluminescence spectroscopy, and micro-reflectivity measurements, accompanied by transfer matrix analysis and simulations by a method developed for the calculation of optical reflection spectra. We demonstrate the applicability of the produced structures for the design of Bragg reflectors.

  6. Characterization of 1064nm laser-induced damage on antireflection coatings grown by atomic layer deposition

    Science.gov (United States)

    Liu, Zhichao; Wei, Yaowei; Chen, Songlin; Luo, Jin; Ma, Ping

    2011-12-01

    Damage tests were carried out to measure the laser resistance of Al2O3/TiO2 and Al2O3/HfO2 antireflection coatings at 1064nm grown by atomic layer deposition (ALD). The S-on-1 and R-on-1 damage results are given. It's interesting to find that ALD coatings damage performance seems closed to those grown by conventional e-beam evaporation process. For Al2O3/TiO2 coatings, the grown temperature will impact the damage resistance of thin films. Crystallization of TiO2 layer at higher temperature could play an importance role as absorption defects that reduced the LIDT of coatings. In addition, it is found that using inorganic compound instead of organic compound as precursors for ALD process can effective prevent residual carbon in films and will increase the LIDT of coatings.

  7. Improved optical performance of GaN grown on pattered sapphire substrate

    Institute of Scientific and Technical Information of China (English)

    Yao Guangrui; Fan Guanghan; Li Shuti; Zhang Yong; Zhou Tianmin

    2009-01-01

    An improved GaN film with low dislocation density was grown on a C-face patterned sapphire substrate (PSS) by metalorganic chemical vapor deposition (MOCVD). The vapor phase epitaxy starts from the regions with no etched pits and then spreads laterally to form a continuous GaN film. The properties of the GaN film have been investigated by double crystal X-ray diffraction (DCXRD), atomic force microscopy (AFM) and photoluminescence (PL), respectively. The full-width at half-maximum (FWHM) of the X-ray diffraction curves (XRCs) for the GaN film grown on PSS in the (0002) plane and the (10(1)2) plane are as low as 312.80 arcsec and 298.08 acrsec, respec-tively. The root mean square (RMS) of the GaN film grown on PSS is 0.233 nm and the intensity of the PL peak is comparatively strong.

  8. AlN Nanowall Structures Grown on Si (111) Substrate by Molecular Beam Epitaxy.

    Science.gov (United States)

    Tamura, Yosuke; Hane, Kazuhiro

    2015-12-01

    AlN nanowall structures were grown on Si (111) substrate using molecular beam epitaxy at substrate temperature of 700 °C with N/Al flux ratios ranging from 50 to 660. A few types of other AlN nanostructures were also grown under the nitrogen-rich conditions. The AlN nanowalls were ranged typically 60-120 nm in width and from 190 to 470 nm in length by changing N/Al flux ratio. The AlN nanowall structures grown along the c-plane consisted of AlN (0002) crystal with full-width at half maximum of the rocking curve about 5000 arcsec.

  9. Active protein and calcium hydroxyapatite bilayers grown by laser techniques for therapeutic applications.

    Science.gov (United States)

    Motoc, M M; Axente, E; Popescu, C; Sima, L E; Petrescu, S M; Mihailescu, I N; Gyorgy, E

    2013-09-01

    Active protein and bioceramic calcium hydroxyapatite (HA) bilayers were grown by combining conventional pulsed laser deposition (PLD) and matrix-assisted pulsed laser evaporation (MAPLE) techniques. A pulsed UV KrF* excimer laser was used for the irradiations. The HA layers were grown by PLD. Proteins with antimicrobial action were attached to the bioceramic layers using MAPLE. The composite MAPLE targets were obtained by dissolving the proteins powder in distilled water. The crystalline status and chemical composition of the obtained structures were studied by X-ray diffractometry and Fourier transform infrared spectroscopy. The layers were grown for the design of advanced future metal implants coatings, ensuring both enhanced bone formation and localized antimicrobial therapy. Our results demonstrated that protein coatings improve bone cell proliferation in vitro. Immunofluorescence experiments show that actin filaments stretch throughout bone cells and sustain their optimal spreading.

  10. Ag-catalyzed InAs nanowires grown on transferable graphite flakes

    Science.gov (United States)

    Meyer-Holdt, Jakob; Kanne, Thomas; Sestoft, Joachim E.; Gejl, Aske; Zeng, Lunjie; Johnson, Erik; Olsson, Eva; Nygård, Jesper; Krogstrup, Peter

    2016-09-01

    Semiconducting nanowires grown by quasi-van-der-Waals epitaxy on graphite flakes are a new class of hybrid materials that hold promise for scalable nanostructured devices within opto-electronics. Here we report on high aspect ratio and stacking fault free Ag-seeded InAs nanowires grown on exfoliated graphite flakes by molecular beam epitaxy. Ag catalyzes the InAs nanowire growth selectively on the graphite flakes and not on the underlying InAs substrates. This allows for easy transfer of the flexible graphite flakes with as-grown nanowire ensembles to arbitrary substrates by a micro-needle manipulator. Besides the possibilities for fabricating novel nanostructure device designs, we show how this method is used to study the parasitic growth and bicrystal match between the graphite flake and the nanowires by transmission electron microscopy.

  11. Growth, characterization and dielectric property studies of gel grown barium succinate single crystals

    Indian Academy of Sciences (India)

    M P Binitha; P P Pradyumnan

    2014-05-01

    Single crystals of barium succinate (BaC4H4O4) were grown in silica gel medium using controlled chemical reaction method. Plate-like single crystals of size up to 3 × 2 × 0.2 mm3 was obtained. Single crystal X-ray diffraction (XRD) studies confirmed that structure of the title compound is tetragonal. Powder X-ray diffraction (PXRD) pattern of the grown crystal and the Fourier transform infrared (FT–IR) spectrum in the range 400–4000 cm-1 are recorded. The vibrational bands corresponding to different functional groups are assigned. Thermal stability of the grown crystals is confirmed by differential scanning calorimetry (DSC). Dielectric constant and dielectric loss have been calculated and discussed as a function of frequency at different temperatures.

  12. Biochemical and physiological responses of rice (Oryza sativa L.) grown on different sewage sludge amendments rates.

    Science.gov (United States)

    Singh, R P; Agrawal, M

    2010-05-01

    Using sewage sludge, a biological residue from sewage treatment processes, in agriculture is an alternative disposal technique of waste. To study the biochemical and physiological responses of Rice (Oryza sativa L.) grown on different sewage sludge amendments (SSA) rates a field experiment was conducted by mixing sewage sludge at 0, 3, 4.5, 6, 9, 12 kg m(-2) rate to the agricultural soil. Rate of photosynthesis and stomatal conductance increased in plants grown at different SSA rate. Chlorophyll and protein contents also increased due to different SSA rates. Lipid peroxidation, ascorbic acid, peroxidase activity and proline content increased, however, thiol and phenol content decreased in plants grown at different SSA rates. The study concludes that for rice plant sewage sludge amendment in soil may be a good option as plant has adequate heavy metal tolerance mechanism showed by increased rate of photosynthesis and chlorophyll content and various antioxidant levels.

  13. Bioethanol Production from Sugarcane Grown in Heavy Metal-Contaminated Soils

    Directory of Open Access Journals (Sweden)

    Jun Xie

    2014-03-01

    Full Text Available Field and laboratory experiments were conducted to evaluate the feasibility of bioethanol production using the juice of sugarcane grown in heavy metal-contaminated soils. The results suggest that the sugar concentration was not adversely affected when the sugarcane was grown in the heavy metal-contaminated soil. Although the juice of sugarcane grown in contaminated soil contained elevated levels of heavy metals, sugar fermentation and ethanol production were not adversely affected when five selected yeast species were used to mediate the processes. The preliminary research findings obtained from this study have implications for developing cost-effective technologies for simultaneous bioethanol production and soil clean-up using heavy metal-contaminated soils for energy sugarcane farming.

  14. Structural characterization of one-dimensional ZnO-based nanostructures grown by MOCVD

    Energy Technology Data Exchange (ETDEWEB)

    Sallet, Vincent; Falyouni, Farid; Marzouki, Ali; Haneche, Nadia; Sartel, Corinne; Lusson, Alain; Galtier, Pierre [Groupe d' Etude de la Matiere Condensee (GEMAC), CNRS-Universite de Versailles St-Quentin, Meudon (France); Agouram, Said [SCSIE, Universitat de Valencia, Burjassot (Spain); Enouz-Vedrenne, Shaima [Thales Research and Technology France, Palaiseau (France); Munoz-Sanjose, Vicente [Departamento de Fisica Aplicada y Electromagnetismo, Universitat de Valencia, Burjassot (Spain)

    2010-07-15

    Various one-dimensional (1D) ZnO-based nanostructures, including ZnO nano-wires (NWs) grown using vapour-liquid-solid (VLS) process, ZnO/ZnSe core/shell, nitrogen-doped ZnO and ZnMgO NWs were grown by metalorganic chemical vapour deposition (MOCVD). Transmission electron microscopy (TEM) analysis is presented. For all the samples, a high crystalline quality is observed. Some features are emphasized such as the gold contamination of ZnO wires grown under the metal droplets in the VLS process. It is concluded that MOCVD is a suitable technique for the realization of original ZnO nanodevices. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  15. LEDs on HVPE grown GaN substrates: Influence of macroscopic surface features

    Directory of Open Access Journals (Sweden)

    SK. S. Rahman

    2014-07-01

    Full Text Available We demonstrate the strong influence of GaN substrate surface morphology on optical properties and performance of light emitting devices grown on freestanding GaN. As-grown freestanding HVPE GaN substrates show excellent AFM RMS and XRD FWHM values over the whole area, but distinctive features were observed on the surface, such as macro-pits, hillocks and facets extending over several millimeters. Electroluminescence measurements reveal a strong correlation of the performance and peak emission wavelength of LEDs with each of these observed surface features. This results in multiple peaks and non-uniform optical output power for LEDs on as-grown freestanding GaN substrates. Removal of these surface features by chemical mechanical polishing results in highly uniform peak wavelength and improved output power over the whole wafer area.

  16. Carbon Nanotubes Grown on Metal Microelectrodes for the Detection of Dopamine.

    Science.gov (United States)

    Yang, Cheng; Jacobs, Christopher B; Nguyen, Michael D; Ganesana, Mallikarjunarao; Zestos, Alexander G; Ivanov, Ilia N; Puretzky, Alexander A; Rouleau, Christopher M; Geohegan, David B; Venton, B Jill

    2016-01-05

    Microelectrodes modified with carbon nanotubes (CNTs) are useful for the detection of neurotransmitters because the CNTs enhance sensitivity and have electrocatalytic effects. CNTs can be grown on carbon fiber microelectrodes (CFMEs) but the intrinsic electrochemical activity of carbon fibers makes evaluating the effect of CNT enhancement difficult. Metal wires are highly conductive and many metals have no intrinsic electrochemical activity for dopamine, so we investigated CNTs grown on metal wires as microelectrodes for neurotransmitter detection. In this work, we successfully grew CNTs on niobium substrates for the first time. Instead of planar metal surfaces, metal wires with a diameter of only 25 μm were used as CNT substrates; these have potential in tissue applications due to their minimal tissue damage and high spatial resolution. Scanning electron microscopy shows that aligned CNTs are grown on metal wires after chemical vapor deposition. By use of fast-scan cyclic voltammetry, CNT-coated niobium (CNT-Nb) microelectrodes exhibit higher sensitivity and lower ΔEp value compared to CNTs grown on carbon fibers or other metal wires. The limit of detection for dopamine at CNT-Nb microelectrodes is 11 ± 1 nM, which is approximately 2-fold lower than that of bare CFMEs. Adsorption processes were modeled with a Langmuir isotherm, and detection of other neurochemicals was also characterized, including ascorbic acid, 3,4-dihydroxyphenylacetic acid, serotonin, adenosine, and histamine. CNT-Nb microelectrodes were used to monitor stimulated dopamine release in anesthetized rats with high sensitivity. This study demonstrates that CNT-grown metal microelectrodes, especially CNTs grown on Nb microelectrodes, are useful for monitoring neurotransmitters.

  17. A Comparison between AlN Films Grown by MOCVD Using Dimethylethylamine Alane and Trimethylaluminium as the Aluminium Precursors

    Institute of Scientific and Technical Information of China (English)

    HU Wei-Guo; PAN Yi; LIU Xiang-Lin; ZHANG Pan-Feng; ZHAO Feng-Ai; JIAO Chun-Mei; WEI Hong-Yuan; ZHANG Ri-Qing; WU Jie-Jun; CONG Guang-Wei

    2007-01-01

    Aluminium nitride (AlN) films grown with dimethylethylamine alane (DMEAA) are compared with the ones grown with trimethylaluminium (TMA). In the high-resolution x-ray diffraction Ω scans, the full width at half maximum (FWHM) of (0002) AlN films grown with DMEAA is about 0.70 deg, while the FWHM of (0002)AlN films grown with TMA is only 0.11 deg. The surface morphologies of the films are different, and the rms roughnesses of the surface are approximately identical. The rms roughness of AlN films grown with DMEAA is 47.4 nm, and grown with TMA is 69.4 nm. Although using DMEAA as the aluminium precursor cannot improve the AlN crystal quality, AlN growth can be reached at low temperature of 673 K. Thus, DMEAA is an alternative aluminium precursor to deposit AlN film at low growth temperatures.

  18. Preparation, structural and electrical properties of zinc oxide grown on silicon nanoporous pillar array

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Polycrystalline thick film of zinc oxide (ZnO) is grown on a unique silicon substrate with a hierarchical structure,silicon nanoporous pillar array (Si-NPA), by using a vapour phase transport method. It is found that as-grown ZnO film is composed of closely packed ZnO crystallites with an average size of ~10 μm. The film resistivity of ZnO/Siheterostructure is measured. Theoretical analysis shows that the carrier transport across ZnO/Si-NPA heterojunction is dominated by two mechanisms, i.e. a thermionic process at high voltages and a quantum tunnelling process at low voltages.

  19. GaSb grown from Sn solvent at low temperatures by LPE

    Energy Technology Data Exchange (ETDEWEB)

    Compean, V H; Anda, F de; Mishurnyi, V A; Gorbatchev, A Yu, E-mail: fdeanda@cactus.iico.uaslp.m [Universidad Autonoma de San Luis Potosi, Instituto de Investigacion en Comunicacion Optica, Av. Karakorum 1470, Col. Lomas 4a Sec., San Luis Potosi, SLP, CP 78210 (Mexico)

    2009-05-01

    The LPE growth of GaSb using Sn as a solvent has been studied in the temperature range 250-370 C and using liquid solutions covering a wide range of compositions. In order to find the growth conditions the phase diagram has been determined experimentally around the same temperature region. It is shown the Sn incorporates into the grown layers and that it behaves as an acceptor. The photoluminescence spectra of the grown layers with different Sn contents show characteristic peaks that can be attributed to different recombination processes.

  20. Surface studies on as-grown (111) faces of sodium bromate crystals

    Indian Academy of Sciences (India)

    K Kishan Rao; V Surender

    2001-12-01

    Single crystals of sodium bromate are grown at various supersaturations ranging from 3% to 8%. Surface studies have been carried out on as-grown and etched (111) faces of these crystals. Typical and systematically oriented growth hillocks are observed almost on all the faces. Further dislocation studies are made to understand the growth history of these crystals. These studies suggest that the crystals grow by 2D-growth mechanism. In addition to this, studies are also conducted on the formation of overgrowths and inclusions in these crystals.

  1. InAlAs/InGaAs/InP sub-micron HEMTs grown by CBE

    Science.gov (United States)

    Munns, G. O.; Sherwin, M. E.; Brock, T.; Haddad, G. I.; Kwon, Y.; Ng, G. I.; Pavlidis, D.

    1992-05-01

    The paper describes the growth of InGaAs/InAlAs and InP/InAlAs high-electron-mobility transistors (HEMTs), using InAlAs grown by chemical beam epitaxy (CBE) with trimethyl amine alane (TMAA). The InAlAs bulk layers showed background carrier concentrations of 2 x 10 exp 14/cu cm, with 15 K photoluminescence FWHM of only 18.5 meV. Planar doped InAlAs/InGaAS HEMTs grown by CBE showed f(t) values of 150 GHz and f(max) values of 160 GHz.

  2. Cathodoluminescence studies of GaAs nano-wires grown on shallow-trench-patterned Si

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ling; Fan, Wen-Chung; Ku, Jui-Tai; Chang, Wen-Hao; Chen, Wei-Kuo; Chou, Wu-Ching [Department of Electrophysics, National Chiao Tung University, Hsinchu 300, Taiwan (China); Ko, Chih-Hsin; Wu, Cheng-Hsien; Lin, You-Ru; Wann, Clement H [Taiwan Semiconductor Manufacturing Co., Ltd, Hsinchu 300, Taiwan (China); Hsu, Chao-Wei; Chen, Yung-Feng; Su, Yan-Kuin, E-mail: acceptor.ep89g@nctu.edu.tw, E-mail: wuchingchou@mail.nctu.edu.tw [Institute of Microelectronics and Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 701, Taiwan (China)

    2010-11-19

    The optical properties of GaAs nano-wires grown on shallow-trench-patterned Si(001) substrates were investigated by cathodoluminescence. The results showed that when the trench width ranges from 80 to 100 nm, the emission efficiency of GaAs can be enhanced and is stronger than that of a homogeneously grown epilayer. The suppression of non-radiative centers is attributed to the trapping of both threading dislocations and planar defects at the trench sidewalls. This approach demonstrates the feasibility of growing nano-scaled GaAs-based optoelectronic devices on Si substrates.

  3. Characterization of GaN Buffer Layers and Its Epitaxial Layers Grown by MOCVD

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Low-pressure MOCVD has been used to investigate the properties of low-temperature buffer layer deposition conditions and their influence on the properties of high-temperature GaN epilayers grown subsequently. It is found that the surface morphology of the as-grown buffer layer after thermal annealing at 1030℃ and 1050℃ depends strongly on the thickness of the buffer layer. In particular when a thick buffer layer is used, large trapezoidal nuclei are formed after annealing.

  4. Bulk crystals of L-Histidinium dihydrogen phosphate orthophosphoric acid grown by Sankaranarayanan-Ramasamy method

    Science.gov (United States)

    Ittyachan, Reena; Arunkumar, A.

    2017-01-01

    L-Histidinium dihydrogen phosphate orthophosphoric acid (LHDP) crystal of length 80 mm long and 20 mm diameter has been grown from aqueous solution along c-axis using Sankaranarayanan-Ramasamy method. The unit cell parameters were confirmed by single crystal X-ray diffraction analysis and it belongs to orthorhombic system. The UV-vis-NIR spectrum showed that the grown crystal is transparent in the entire visible region. The lower optical cut-off wavelength for this crystal was observed at 240 nm. Fluorescence studies were carried out in range of 200-700 nm. SHG efficiency was analyzed using Kurtz-Perry powder technique.

  5. Misorientation dependent epilayer tilting and stress distribution in heteroepitaxially grown silicon carbide on silicon (111) substrate

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Li, E-mail: l.wang@griffith.edu.au [Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan, QLD 4111 (Australia); Iacopi, Alan; Dimitrijev, Sima; Walker, Glenn [Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan, QLD 4111 (Australia); Fernandes, Alanna [Bluglass Ltd., 74 Asquith Street, Silverwater, NSW 2128 (Australia); Hold, Leonie; Chai, Jessica [Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan, QLD 4111 (Australia)

    2014-08-01

    The advantages and disadvantages of using off-axis substrates for heteroepitaxial growth of 3C-SiC on Si(111) substrates are investigated in this paper. 3C-SiC is deposited on on-axis and 4° off-axis 150 mm Si(111) substrates using low pressure chemical vapour deposition. The dependence of surface morphology, roughness, crystallinity, alignment between the epilayer and the substrate, and film stress are evaluated using atomic force microscopy, X-ray diffraction, and wafer curvature measurement. Highly parallel steps are observed on both on-axis and off-axis Si substrates after surface preparation, yet step density is doubled and step height is much larger (> 21 times of single step height) for 4° off-cut Si compared to on-axis Si. X-ray diffraction results indicate that SiC grown on on-axis Si substrates are well-aligned with the Si substrates, while the SiC grown on off-axis substrates are tilted positively by as large angle as 1.66°. The well-aligned SiC grown on on-axis Si substrate exhibits lower and uniform residual stress compared to the film grown on off-axis Si substrates, which exhibits a nonuniform distribution of higher stress. The stress distribution is found to be dependent on Si surface step direction and height. These misorientation dependent tilting and stress distribution mechanisms are expected to be applicable to other hetero-epitaxial growth systems with similar mismatch magnitude. - Highlights: • SiC grown on on-axis Si substrates are well-aligned with the Si substrates. • The well-aligned SiC grown on on-axis Si exhibits lower and uniform stress. • SiC grown on off-axis substrate has a positive tilting of 1.66°. • SiC grown on off-axis Si exhibits a nonuniform distribution of higher stress. • The stress and tilting are dependent on Si surface step direction and height.

  6. Optical anisotropy and light extraction efficiency of MBE grown GaN nanowires epilayers.

    Science.gov (United States)

    Henneghien, Anne-Line; Tourbot, Gabriel; Daudin, Bruno; Lartigue, Olivier; Désières, Yohan; Gérard, Jean-Michel

    2011-01-17

    The use of nanowires as active medium seems very promising for the development of high brightness LEDs. With a lower effective refractive index than bulk, semiconductor nanowire layers may lead to a high light extraction efficiency. We hereafter discuss the anisotropic properties of dense arrays of molecular beam epitaxy (MBE) grown gallium nitride (GaN) nanowires and the consequences on the optical design of nanowire based LEDs. In particular we show numerically that light extraction efficiency as high as 72% can be expected for GaN nanowires layer grown on a low cost Si substrate.

  7. ZnO nanostructured microspheres and grown structures by thermal treatment

    Indian Academy of Sciences (India)

    Jun Wang; Shunxiao Zhang; Jia You; Huijun Yan; Zhanshuang Li; Xiaoyan Jing; Milin Zhang

    2008-08-01

    Synthesis of flower-shaped ZnO nanostructures composed of ZnO nanosticks was achieved by the solution process using zinc acetate dihydrate, sodium hydroxide and polyethylene glycol-20000 (PEG-20000) at 180°C for 4 h. The diameter of individual nanosticks was about 100 nm. Detailed structure characterizations demonstrate that the synthesized products are wurtzite hexagonal phase, grown along the [001] direction. The infrared (IR) spectrum shows the standard peak of zinc oxide at 571 cm-1. Raman scattering exhibits a sharp and strong 2 mode at 441 cm-1 which further confirms the good crystal and wurtzite hexagonal phase of the grown nanostructures.

  8. Structural instability of N-acceptors in homo- and heteroepitaxially grown ZnO by MBE

    Energy Technology Data Exchange (ETDEWEB)

    Ando, K.; Abe, T.; Taya, T.; Ishihara, Y.; Enomoto, K.; Yamazaki, Y.; Yoshikawa, J.; Fujino, K.; Nakamura, H.; Ohno, T.; Kasada, H. [Department of Information and Electronic Engineering, Graduate School of Engineering, Tottori University, 4-1-1 Koyama-Minami, Tottori 680-8550 (Japan)

    2010-06-15

    Unique properties of the N-acceptor in homo- and heteroepitaxially grown ZnO by molecular beam epitaxy (MBE) are studied by means of microproving of surface sheet-resistance, Hall-effect measurement, persistent photoconduction (PPC) and thermally stimulated current (TSC). Rapid postanneal of N-doped ZnO is found to induce the change in the conduction type from n-type (as-grown) to p/n-type mixed conduction, forming island structure, and these properties are related to a structural instability of the N-acceptor. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  9. Effect of Mulch Surface Color on Root-knot of Tomato Grown in Simulated Planting Beds

    OpenAIRE

    Fortnum, B. A.; Kasperbauer, M. J.; Decoteau, D. R.

    2000-01-01

    The effect of different-colored polyethylene mulches on quantity and spectra of reflected light, plant morphology, and root-knot disease was studied in tomato (Lycopersicon esculentum) grown in simulated planting beds. Tomato plants were inoculated with Meloidogyne incognita at initial populations (Pi) of 0, 1,000, 10,000, or 50,000 eggs/plant, and grown in a greenhouse for 50 days over white, red, or black mulch. Soil temperature was kept constant among the mulch treatments by placing an ins...

  10. Effective annealing of ZnO thin films grown by three different SILAR processes

    OpenAIRE

    2015-01-01

    In the present work, zinc oxide (ZnO) thin films have been grown three different cation solution on glass substrates by a simple and economic successive ionic layer absorption and reaction method (SILAR). One of each grown different solution films was annealed to investigate to effective annealing at 473 K for 30 minutes. Absorption measurements showed that the optical band-gaps of all ZnO thin films were wide and were about 3.08-3.31 eV. All films’ band gap increased with annealing. Energy-D...

  11. Electrical properties of ZnO thin films grown by MOCVD

    Energy Technology Data Exchange (ETDEWEB)

    Pagni, O. [Department of Physics, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031 (South Africa); Somhlahlo, N.N. [Department of Physics, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031 (South Africa); Weichsel, C. [Department of Physics, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031 (South Africa); Leitch, A.W.R. [Department of Physics, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031 (South Africa)]. E-mail: andrew.leitch@nmmu.ac.za

    2006-04-01

    We report on the electrical characterization of ZnO films grown by MOCVD on glass and sapphire substrates. After correcting our temperature variable Hall measurements by applying the standard two-layer model, which takes into account an interfacial layer, scattering mechanisms in the ZnO films were studied as well as donor activation energies determined. ZnO films grown at different oxygen partial pressures indicated the importance of growth conditions on the defect structure by means of their conductivities and conductivity activation energies.

  12. Extraction of absorption coefficients from GaN nanowires grown on opaque substrates

    CERN Document Server

    Jayaprakash, Rahul; Germanis, Savvas; Androulidaki, Maria; Tsagaraki, Katerina; Georgakilas, Alexandros; Pelekanos, Nikos T

    2014-01-01

    We demonstrate a new method to measure absorption coefficients in any family of nanowires, provided they are grown on a substrate having considerable difference in permittivity with the nanowire-air matrix. In the case of high crystal quality, strain-free GaN nanowires, grown on Si (111) substrates with a density of ~1010 cm-2, the extracted absorption coefficients do not exhibit any enhancement compared to bulk GaN values, unlike relevant claims in the literature. This may be attributed to the relatively small diameters, short heights, and high densities of our nanowire arrays.

  13. Micro-porous TiO2 thin films grown on surface of Ti substrate

    Institute of Scientific and Technical Information of China (English)

    WU Xiao-hong; QIN Wei; JIANG Zhao-hua; HU Xin-guo; Li Qing-fen

    2004-01-01

    Microporous titanium dioxide thin films have been grown on titanium plates by the micro-plasma oxidation method with different current densities (4, 6, 10 and 14 A/dm2). X-ray diffraction, scanning electronic microscopy and UV-Vis spectrophotometry were used to characterize the films. It is found that the films grown are microporous and consist of crystalline titanium dioxide. The micropore size and the content of anatase and rutile TiO2 phase increase with the applied voltage. The relatively higher degradation efficiency for rhodamine B is obtained in the film produced with a current density of 10 A/dm2.

  14. Ag-catalyzed InAs nanowires grown on transferable graphite flakes

    DEFF Research Database (Denmark)

    Meyer-Holdt, Jakob; Kanne, Thomas; Sestoft, Joachim E.;

    2016-01-01

    Semiconducting nanowires grown by quasi-van-der-Waals epitaxy on graphite flakes are a new class of hybrid materials that hold promise for scalable nanostructured devices within opto-electronics. Here we report on high aspect ratio and stacking fault free Ag-seeded InAs nanowires grown......-needle manipulator. Besides the possibilities for fabricating novel nanostructure device designs, we show how this method is used to study the parasitic growth and bicrystal match between the graphite flake and the nanowires by transmission electron microscopy....

  15. Zinc segregation in CdZnTe grown under Cd/Zn partial pressure control

    Science.gov (United States)

    Azoulay, M.; Rotter, S.; Gafni, G.; Tenne, R.; Roth, M.

    1992-02-01

    CdZnTe crystals have been grown by the modified vertical gradient freeze (VGF) method. Growth atmosphere control has been introduced to compensate for the Zn depletion in the melt during solidification. The axial Zn concentration in the grown crystals is found to be uniform within ±3%, as evaluated by X-ray diffraction and electron microprobe analysis. The radial segregation of Zn is minimal and does not exceed the experimental error due to the nearly planar interface achieved. Zinc microsegregation has been studied as well and is discussed in terms of the temporal variations of the solute concentration at the growth interface.

  16. Improved field emission properties of carbon nanotubes grown on stainless steel substrate and its application in ionization gauge

    Science.gov (United States)

    Li, Detian; Cheng, Yongjun; Wang, Yongjun; Zhang, Huzhong; Dong, Changkun; Li, Da

    2016-03-01

    Vertically aligned carbon nanotube (CNT) arrays were fabricated by chemical vapor deposition (CVD) technique on different substrates. Microstructures and field emission characteristics of the as-grown CNT arrays were investigated systematically, and its application in ionization gauge was also evaluated preliminarily. The results indicate that the as-grown CNT arrays are vertically well-aligned relating to the substrate surfaces, but the CNTs grown on stainless steel substrate are longer and more crystalline than the ones grown on silicon wafer substrate. The field emission behaviors of the as-grown CNT arrays are strongly dependent upon substrate properties. Namely, the CNT array grown on stainless steel substrate has better field emission properties, including lower turn on and threshold fields, better emission stability and repeatability, compared with the one grown on silicon wafer substrate. The superior field emission properties of the CNT array grown on stainless steel substrate are mainly attributed to low contact resistance, high thermal conductivity, good adhesion strength, etc. In addition, the metrological behaviors of ionization gauge with the CNT array grown on stainless steel substrate as an electron source were investigated, and this novel cathode ionization gauge extends the lower limit of linear pressure measurement to 10-8 Pa, which is one order of magnitude lower than the result reported for the same of gauge with CNT cathode.

  17. Observation of As-Grown Defects in Zn-Doped GaAs by Positron Lifetime Spectra

    Institute of Scientific and Technical Information of China (English)

    WANG Zhu; WANG Shao-Jie; CHEN Zhi-Quan

    2000-01-01

    Positron lifetime spectra were measured for the Zn-doped p-type GaAs. In comparing the horizontal-Bridgman-method-grown and the floating-zone-method grown p-type GaAs with the liquid-encapsulation-Czochvalski-grown p-type GaAs samples, positron trapping into vacancy type defects was observed in the former two grown p-type GaAs. Shallow positron traps were detected, and the dominant ones were attributed to acceptor the in p-type GaAs.

  18. Cytochemical Localization of Catalase Activity in Methanol-Grown Hansenula polymorpha

    NARCIS (Netherlands)

    Dijken, J.P. van; Veenhuis, M.; Vermeulen, C.A.; Harder, W.

    1975-01-01

    The localization of peroxidase activity in methanol-grown cells of the yeast Hansenula polymorpha has been studied by a method based on cytochemical staining with diaminobenzidine (DAB). The oxidation product of DAB occurred in microbodies, which characteristically develop during growth on methanol,

  19. GaIn As Quantum Dots (QD) grown by Liquid Phase Epitaxy (LPE)

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz Vazquez, F E; Mishurnyi, V A; Gorbatchev, A Yu; De Anda, F [Universidad Autonoma de San Luis Potosi, Instituto de Investigation en Comunicacion Optica, Av. Karakorum 1470, Col. Lomas 4a Sec., San Luis Potosi, SLP, CP 78210 (Mexico); Elyukhin, V A, E-mail: fcoe_ov@prodigy.net.m, E-mail: andre@cactus.iico.uaslp.m [CINVESTAV-IPN, Av. IPN 2508, Col. San Pedro Zacatenco, Mexico D.F., CP 07360 (Mexico)

    2009-05-01

    The majority of the semiconductor structures with QD today are grown by MBE and MOCVD. It is known that the best material quality can be achieved by LPE because, in contrast to MBE and MOCVD, this method is realized at near-equilibrium conditions. To develop QD LPE technology first of all it is necessary to find out a growth technique allowing the crystallization of epitaxial materials with very small volume. This can be done by means of different techniques. In this work we apply a low temperature short-time growth method, which allows the production not only of single, but also of multilayer heterostructures. We have grown Ga{sub x}In{sub 1-z}As QD on GaAs (100) substrates at 450 C. The details of the QD formation, depending on composition of the Ga{sub x}In{sub -x} As solid solutions, have been studied by atom-force microscopy. The photoluminescence spectra of investigated samples show, in addition to a short-wave GaAs related peak, a longer wavelength line, which disappears after removal of the grown GaInAs material using an etching solution. This fact, together with atom-force microscopy results can be interpreted as a proof that QD heterostructures were grown successfully by LPE.

  20. Photosynthetic induction responses of Pinus koraiensis seedlings grown in different light environments

    Institute of Scientific and Technical Information of China (English)

    ZHOUYong-bin; YINYou; LIUXing-shuang; WANGQing-li

    2004-01-01

    The time processes of photosynthetic induction responses to various irradiances in Korean pine (Pinus koraiensis) seedlings grown in open-light environments and in understory of forest were studied in an area near the Research Station of Changbai Mountain Forest Ecosystems, Jilin Province, China from July 15 to August 5, 1997. The results showed that at 200 IJmol·m-2·s-1 photosynthetic photon flux density (PPFD) and 500 pmol·m-2·s-1 PPFD, the induction time for the photosynthetic rates of understory-grown seedlings to reach 50% and 90% steady-state net photosynthetic rates was longer than that of the open-grown seedlings. The induction responses of open-growth seedlings at 500 pmol·m-2·s-1 PPFD were slower than those at 200 pmol·m-2·s-1 PPFD, but it was the very reverse for understory-growth seedlings, which indicates that the photosynthetic induction times of Korean pine seedlings grown in the understory depended on the sunfleck intensity.

  1. Proximate composition of CELSS crops grown in NASA's Biomass Production Chamber

    Science.gov (United States)

    Wheeler, R. M.; Mackowiak, C. L.; Sager, J. C.; Knott, W. M.; Berry, W. L.

    1996-01-01

    Edible biomass from four crops of wheat (Triticum aestivum L.), four crops of lettuce (Lactuca sativa L.), four crops of potato (Solanum tuberosum L.), and three crops of soybean (Glycine max (L.) Merr.) grown in NASA's CELSS Biomass Production Chamber were analyzed for proximate composition. All plants were grown using recirculating nutrient (hydroponic) film culture with pH and electrical conductivity automatically controlled. Temperature and humidity were controlled to near optimal levels for each species and atmospheric carbon dioxide partial pressures were maintained near 100 Pa during the light cycles. Soybean seed contained the highest percentage of protein and fat, potato tubers and wheat seed contained the highest levels of carbohydrate, and lettuce leaves contained the highest level of ash. Analyses showed values close to data published for field-grown plants with several exceptions: In comparison with field-grown plants, wheat seed had higher protein levels; soybean seed had higher ash and crude fiber levels; and potato tubers and lettuce leaves had higher protein and ash levels. The higher ash and protein levels may have been a result of the continuous supply of nutrients (e.g., potassium and nitrogen) to the plants by the recirculating hydroponic culture.

  2. 76 FR 34181 - Pistachios Grown in California, Arizona, and New Mexico; Proposed Amendments to Marketing Order

    Science.gov (United States)

    2011-06-13

    ... provide an additional tool to aid in the marketing of pistachios covered under the order. In the event the... Agricultural Marketing Service 7 CFR Part 983 Pistachios Grown in California, Arizona, and New Mexico; Proposed Amendments to Marketing Order AGENCY: Agricultural Marketing Service, USDA. ACTION: Proposed rule....

  3. Controlling hyperhydration of carnations (Dianthus caryophyllus L.) grown in a mist reactor.

    Science.gov (United States)

    Correll, M J; Wu, Y; Weathers, P J

    Carnations (Dianthus caryophyllus L.) grown in vitro often develop physiological abnormalities such as hyperhydration. The amount of hyperhydration and growth was compared between carnations grown in mist reactors and conventional semisolid micropropagation systems (vented or unvented GA7 culture boxes). Plants grown in the mist reactor with long misting times (10 min h(-1)) produced more dry mass than those grown with <10 min h(-1); however, more misting also produced more hyperhydrated plants (70% hyperhydration). Control of hyperhydration in the mist reactor involved either reducing the overall nutrient mist supply or altering the mist supply throughout the culturing period. Stepped decreases in the mist supply throughout the 3-week period or an overall decrease in the duration of misting reduced hyperhydration to 13% and 5%, respectively. However, for both misting regimes, the biomass of normal (healthy) plants (fresh and dry weights) was limited. Further analysis suggested that, although normal plant biomass increased with longer mist exposure, hyperhydration levels also increased while the water content, based on percent dry weight, approached that of hyperhydrated plants. Sufficient normal plant development (fresh weight, leaf and shoot numbers, height, and rooting) with < 50% hyperhydration was obtained by weekly, stepped increases in the nutrient mist supply.

  4. Irrigation and nitrogen use efficiency of Thuja occidentalis grown on sandy soils

    NARCIS (Netherlands)

    Pronk, A.A.

    2004-01-01

    A combined conifer growth - soil water and nitrogen balance model was calibrated to simulate dry mass production and partitioning, water and nitrogen demand and nitrogen losses for Thuja occidentalis grown for two years on a sandy soil. Light interception was successfully described by the row-of-cub

  5. 76 FR 60361 - Pistachios Grown in California, Arizona, and New Mexico; Decreased Assessment Rate

    Science.gov (United States)

    2011-09-29

    ... Internet at the address provided above. FOR FURTHER INFORMATION CONTACT: Andrea Ricci, Marketing Specialist... Agricultural Marketing Service 7 CFR Part 983 Pistachios Grown in California, Arizona, and New Mexico; Decreased Assessment Rate AGENCY: Agricultural Marketing Service, USDA. ACTION: Interim rule with...

  6. Are Grown-ups with Congenital Heart Disease Willing to Participate in an Exercise Program?

    NARCIS (Netherlands)

    Dontje, Manon L.; Feenstra, Marlies; de Greef, Mathieu H. G.; Nieuwland, Wybe; Hoendermis, Elke S.

    2014-01-01

    ObjectiveTo examine the willingness of grown-ups with congenital heart disease (GUCH) to participate in the GUCH Training Program-Individualised (GTI), an exercise program specifically designed for GUCH, and to identify factors affecting their willingness to participate. Design and SettingIn this cr

  7. Ferromagnetism and increased ionicity in epitaxially grown TbMnO3 films

    NARCIS (Netherlands)

    Rubi, D.; de Graaf, C.; Daumont, C. J. M.; Mannix, D.; Broer, R; Noheda, B

    2009-01-01

    Thin films of TbMnO3 have been grown on SrTiO3 substrates. The films grow under compressive strain and are only partially clamped to the substrate. This produces remarkable changes in the magnetic properties and, unlike the bulk material, the films display ferromagnetic interactions below the orderi

  8. Influence of Annealing on Properties of ZnO Films Grown via Plasma-enhanced MOCVD

    Institute of Scientific and Technical Information of China (English)

    ZHAO Bai-jun; LIU Da-li; LI Wan-cheng; FANG Xiu-jun; DU Guo-tong; YANG Hong-jun; WANG Jinz-hong; ZHANG Yuan-tao; YANG Xiao-tian; LIU Bo-yang; MA Yan; YANG Tian-peng

    2003-01-01

    The structural and the optical properties of ZnO films with high quality grown via plasma-enhanced metal-organic chemical vapour deposition(MOCVD) on C-plane sapphire substrate were studied. The crystallinity and the optical properties of the films are greatly improved having been annealed in oxygen plasma atmosphere. The structure, the band gap and the binding energy of O1s electrons, and the molar ratio of O to Zn were determined by X-ray diffraction(XRD), photoluminescence(PL) and X-ray photoelectron scan methods. For both the annealed and the as-grown films, the exciton peak features were observed at room temperature. The band-edge photoluminescence of the annealed film is much stronger than that of the as-grown film, and the exciton peak relating to the deep level at 439 nm disappears. The molar ratio of O to Zn in the annealed film is 0.91, while it is 0.78 for the as-grown film.

  9. Growth and characterization of solution-grown tetra glycine barium chloride (TGBC) single crystals

    Science.gov (United States)

    Senthil Pandian, M.; Ramasamy, P.

    2008-05-01

    The single crystals of tetra glycine barium chloride (TGBC), a semi-organic material, were grown by the solvent evaporation technique from an aqueous solution of glycine and barium chloride at ambient temperature. Good optical quality single crystals of size 11×13×7 mm 3 were grown in a period of 2 weeks. Powder X-ray diffraction (XRD) and Fourier transform infrared transmission (FTIR) have confirmed the formation of the new crystal. The grown crystals were characterized by single-crystal XRD analysis to study the crystal structure. The crystalline perfection was evaluated by high-resolution X-ray diffractometry (HRXRD). From this analysis we found that the quality of the crystal was quite good. The full-width at half-maximum (FWHM) of the diffraction curves is 8.5 arcsec, which is very close to that expected from the plane wave dynamical theory of XRD showing that the crystalline perfection is excellent. UV-Vis-NIR spectrum was recorded to study the optical transparency of the grown crystals. Thermal properties of the crystal have been investigated using thermo gravimetric (TG), differential thermal analysis (DTA). The mechanical strength of the crystal is estimated by Vicker's hardness test.

  10. The potential, variety, and nutrient content of natural vegetation as feedstuffs grown under cashewnut plantation

    Directory of Open Access Journals (Sweden)

    E Sutedi

    2001-06-01

    Full Text Available Ruminant production is limited by the quality, the sufficiency and the continuation of feed supply, especially during the dry season. The objective of the study was to find out the potency, type and quality of natural vegetation grown under cashewnut plantation. The study was carried out by exploration of existing natural vegetation resources in cashewnut plantation area. Results showed that native pasture growing under cashewnut plantation area comprised of dry-tolerant grasses and legumes, such as Setaria sp., Themeda sp., Calopogonium mucunoides, and Desmodium sp. The fresh yield and the dry matter production of natural vegetation grown under less than eight years old of cashewnut plantation was lower compared to those grown under cashewnut plantation of more than eight years old. This may be due to shading by the tree crop, which is known to reduce the photosynthetically active radiation reaching the ground of vegetation. It seems that, light is the critical factor affecting the growth of vegetation underneath tree canopies. Carrying capacity of native forages grown under cashewnut plantation was only 0.5 animal unit of ruminant/ha/year.

  11. Genetic analysis of biomass and photosynthetic parameters in wheat grown in different light intensities

    Institute of Scientific and Technical Information of China (English)

    Hongwei Li; Gui Wang; Qi Zheng; Bin Li; Ruilian Jing; Zhensheng Li

    2014-01-01

    Growth light intensities largely determine photo-synthesis, biomass, and grain yield of cereal crops. To explore the genetic basis of light responses of biomass and photosynthetic parameters in wheat (Triticum aestivum L.), a quantitative trait locus (QTL) analysis was carried out in a doubled haploid (DH) population grown in low light (LL), medium light (ML), and high light (HL), respectively. The results showed that the wheat seedlings grown in HL produced more biomass with lower total chlorophyll content (Chl), carotenoid content, and maximum photochemical efficiency of photosystem II (Fv/Fm) while the wheat seed-lings grown in LL produced less biomass with higher Chl compared with those grown in ML. In total, 48 QTLs were identified to be associated with the investigated parameters in relation to growth light intensities. These QTLs were mapped to 15 chromosomes which individually explained 6.3%-36.0% of the phenotypic variance, of which chromo-somes 3A, 1D, and 6B were specifically involved in LL response, 5D and 7A specifically involved in ML response, and 4B specifically involved in HL response. Several light-responsive QTLs were co-located with QTLs for photosyn-thetic parameters, biomass, and grain weight under various conditions which may provide new hints to uncover the genetic control of photosynthesis, biomass, and grain weight.

  12. Superior Thermal Interface via Vertically Aligned Carbon Nanotubes Grown on Graphite Foils

    Science.gov (United States)

    2012-01-01

    L.L. Zhang, Z. Xiong, and X.S. Zhao: Pillaring chemically exfoliated graphene oxide with carbon nanotubes for photocatalytic degrada- tion of dyes...and V.T. Renard: Few graphene layers/carbon nanotube composites grown at complimentary-metal-oxide- semiconductor compatible temper- ature. Appl

  13. Mortality of container-grown blueberry plants inoculated with Phytophthora cinnamomi Rands

    Science.gov (United States)

    We conducted four studies to evaluate the effect of Phytophthora cinnamomi isolates and inoculum delivery methods on root rot development and mortality of container-grown blueberry plants. Phytophthora cinnamomi isolates were obtained from the root zone of symptomatic blueberry plants and identifie...

  14. Effects of simulated acidic rainfalls on yields of field-grown radishes and garden beets

    Energy Technology Data Exchange (ETDEWEB)

    Evans, L S; Cunningham, E A; Lewin, K F

    1981-01-01

    The effects of small additions of simulated acidic rain on radishes and garden beets grown under standard agronomic practices was determined. Only the foliage of plants was sprayed with simulated rain. The composition of the simulated rainfall approximated that of rain falling in the Long Island, NY area. (ACR)

  15. The Identification and Interpretation of Differences in the Transcriptomes of Organically and Conventionally Grown Potato Tubers

    NARCIS (Netherlands)

    Dijk, van J.P.; Cankar, K.; Hendriksen, P.J.M.; Beenen, H.G.; Zhu, M.; Scheffer, S.J.; Shepherd, L.V.T.; Steward, D.; Davies, H.V.; Leifert, C.; Wilkockson, S.J.; Gruden, K.; Kok, E.J.

    2012-01-01

    In the European integrated research project SAFEFOODS, one of the aims was to further establish the potential of transcriptomics for the assessment of differences between plant varieties grown under different environmental conditions. Making use of the knowledge of cellular processes and interaction

  16. Scanning Tunneling Microscopy Studies of Topological Insulators Grown by Molecular Beam Epitaxy

    Directory of Open Access Journals (Sweden)

    Xue Qikun

    2012-03-01

    Full Text Available We summarize our recent scanning tunneling microscopy (STM study of topological insulator thin films grown by molecular beam epitaxy (MBE, which includes the observation of electron standing waves on topological insulator surface and the Landau quantization of topological surface states. The work has provided valuable information to the understanding of intriguing properties of topological insulators, as predicted by theory.

  17. COMPARATIVE EVALUATION OF QUALITATIVE VALUES IN GERMINATED AND UNGERMINATED WHEAT GRAIN GROWN IN DIFFERENT TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    Ingrida Kraujutiene

    2010-01-01

    Full Text Available To estimate an influence of different growing technologies (organical and conventional, separate cultivars of wheat (Širvinta-1 and Zentos and germinating time upon wheat grain nutritive composition (dry matter, ash, protein, fat and fibre, activity of enzymes (α- and β-amylase, xylanase, cellulose, catalase and protease. It was established that the amount of dry matters reduced in germinated wheat and the content of mineral substances, protein and activity of ferments  and β-amylases, cellulase, proteases and maltase was greater than in ungerminated wheat. Furthermore, the amount of cellulase reduced due to growing conditions and the distribution of fat amount was ambiguous regarding wheat species. (Širvinta-1: germinated > ungerminated and Zentos: germinated < ungerminated. The amounts of cellulase and the activity of ferments in ecologically grown wheat, both germinated and ungerminated were greater than in those conventionally grown, with exception of ferments of cellulase and protease. The activity of cellulase in ecologically grown grain was 39 % less and the content of protease was almost the same as in those conventionally grown.

  18. Cardiac surgery in grown-up congenital heart patients. Will the surgical workload increase?

    DEFF Research Database (Denmark)

    Klcovansky, J.; Søndergård, Lars; Helvind, M.;

    2008-01-01

    The number of patients with grown-up congenital heart (GUCH) disease is steadily increasing. Although there is agreement that the medical service for GUCH patients should be expanded in coming years, it is still unknown whether this should also include the surgical service. In an attempt...

  19. Origin of Spontaneous Core-Shell AIGaAs Nanowires Grown by Molecular Beam Epitaxy

    DEFF Research Database (Denmark)

    Dubrovskii, V. G.; Shtrom, I. V.; Reznik, R. R.;

    2016-01-01

    Based on the high-angle annular dark-field scanning transmission electron microscopy and energy dispersive X-ray spectroscopy studies, we unravel the origin of spontaneous core shell AlGaAs nanowires grown by gold-assisted molecular beam epitaxy. Our AlGaAs nanowires have a cylindrical core...

  20. Inactivation by ionizing radiation of Salmonella enteritidis serotype montevideo grown in composed sewage sludge

    Energy Technology Data Exchange (ETDEWEB)

    Brandon, J.R.; Burge, W.D.; Enkiri, N.K.

    1977-04-01

    S. enteritidis ser. montevideo were grown in composted sewage sludge to levels of approximately 10/sup 9//g. These bacteria were found to be inactivated by ionizing radiation (with Co/sub 60/) at approximately the same rate (30 krads/log) as Salmonella species in liquid digested sludge.

  1. Phenolic compounds and fatty acid composition of organic and conventional grown pecan kernels

    Science.gov (United States)

    In this study, differences in contents of phenolic compounds and fatty acids in pecan kernels of organically versus conventionally grown pecan cultivars (‘Desirable’, ‘Cheyenne’, and ‘Wichita’) were evaluated. Although we were able to identify nine phenolic compounds (gallic acid, catechol, catechin...

  2. The effects of Fe-chelate type and PH on substrate grown roses

    NARCIS (Netherlands)

    Voogt, W.; Sonneveld, C.

    2009-01-01

    Substrate grown roses appear to be susceptible to chlorosis, which indicates problems with Fe or Mn uptake and hence yield reduction. In common practice this problem is often treated by the addition of extra Fe-chelate, or the use of Fe-EDDHA instead of Fe-DTPA. In previous tests, it was shown that

  3. Winter triticale response to nitrogen fertilization when grown after corn or soybean

    Science.gov (United States)

    Winter triticale (XTriticosecale Wittmack) could be more widely grown as a forage, grain, or cover crop in the U.S. Corn and Soybean Belt, but research needed to establish best management practices is limited. This study was conducted to determine the amount of nitrogen (N) fertilizer needed to opti...

  4. High-efficiency AlGaInP solar cells grown by molecular beam epitaxy

    Science.gov (United States)

    Faucher, J.; Sun, Y.; Jung, D.; Martin, D.; Masuda, T.; Lee, M. L.

    2016-10-01

    AlGaInP is an ideal material for ultra-high efficiency, lattice-matched multi-junction solar cells grown by molecular beam epitaxy (MBE) because it can be grown lattice-matched to GaAs with a wide 1.9-2.2 eV bandgap. Despite this potential, AlGaInP grown by molecular beam epitaxy (MBE) has yet to be fully explored, with the initial 2.0 eV devices suffering from poor performance due to low minority carrier diffusion lengths in both the emitter and base regions of the solar cell. In this work, we show that implementing an AlGaInP graded layer to introduce a drift field near the front surface of the device enabled greatly improved internal quantum efficiency (IQE) across all wavelengths. In addition, optimizing growth conditions and post-growth annealing improved the long-wavelength IQE and the open-circuit voltage of the cells, corresponding to a 3× increase in diffusion length in the base. Taken together, this work demonstrates greatly improved IQE, attaining peak values of 95%, combined with an uncoated AM1.5G efficiency of 10.9%, double that of previously reported MBE-grown devices.

  5. Passivation of MBE grown InGaSb/InAs superlattice photodiodes

    Science.gov (United States)

    Hill, Cory J.; Keo, Sam S.; Mumolo, Jason M.; Gunapala, Sarath D.

    2005-01-01

    We have performed wet chemical passivation tests on InGaSb/InAs superlattice photodiode structures grown molecular beam epitaxy. The details of the devices growth and characterization as well as the results of chemical passivation involving RuCl3 and H2SO4 with SiO2 dielectric depositions are presented.

  6. Perfluoroalkyl acid distribution in various plant compartments of edible crops grown in biosolids-amended soils

    Science.gov (United States)

    Crop uptake of perfluoroalkyl acids (PFAAs) from biosolids-amended soil has been identified as a potential pathway for PFAA entry into the terrestrial food chain. This study compared the uptake of PFAAs in greenhouse-grown radish (Raphanus sativus), celery (Apium graveolens var.d...

  7. Yield and Composition of Ocimum basilicum L. and Ocimum sanctum L. Grown at Four Locations

    Science.gov (United States)

    Sweet basil (Ocimum basilicum L.) and holy basil (Ocimum sanctum L.) are the most widely grown basil species in the world, either for the fresh market or for essential oil production. Both species are considered as promising essential oil crops in the Southeastern US, however, research on oil produ...

  8. 75 FR 43042 - Irish Potatoes Grown in Washington; Temporary Change to the Handling Regulations and Reporting...

    Science.gov (United States)

    2010-07-23

    ... will be required for the purpose of obtaining information necessary to administer the marketing order... Agricultural Marketing Service 7 CFR Part 946 Irish Potatoes Grown in Washington; Temporary Change to the Handling Regulations and Reporting Requirements AGENCY: Agricultural Marketing Service, USDA....

  9. In-Situ Grown Erbium-Doped Dielectric Nanoparticles in Silica-Based Transparent Optical Fibers

    CERN Document Server

    Dussardier, Bernard; Mauroy, Valérie; Ude, Michèle; Trzesien, Stanislaw; Mady, Franck; Benabdesselam, Mourad; Monnom, Gérard

    2011-01-01

    An efficient method to fabricate transparent glass ceramic fibers containing in-situ grown Er3+-doped oxide nanoparticles is presented. Characterization of the drawn fibers exhibits low loss (0.4 dB/m) and broadened Er3+ emission spectrum. This attractive method offers new scopes for fiber amplifiers.

  10. Chloroplast avoidance movement is not functional in plants grown under strong sunlight.

    Science.gov (United States)

    Higa, Takeshi; Wada, Masamitsu

    2016-04-01

    Chloroplast movement in nine climbing plant species was investigated. It is thought that chloroplasts generally escape from strong light to avoid photodamage but accumulate towards weak light to perform photosynthesis effectively. Unexpectedly, however, the leaves of climbing plants grown under strong sunlight showed very low or no chloroplast photorelocation responses to either weak or strong blue light when detected by red light transmittance through leaves. Direct observations of Cayratia japonica leaves, for example, revealed that the average number of chloroplasts in upper periclinal walls of palisade tissue cells was only 1.2 after weak blue-light irradiation and almost all of the chloroplasts remained at the anticlinal wall, the state of chloroplast avoidance response. The leaves grown under strong light have thin and columnar palisade tissue cells comparing with the leaves grown under low light. Depending on our analyses and our schematic model, the thinner cells in a unit leaf area have a wider total plasma membrane area, such that more chloroplasts can exist on the plasma membrane in the thinner cells than in the thicker cells in a unit leaf-area basis. The same strategy might be used in other plant leaves grown under direct sunlight.

  11. Optical characteristics of ZnO single crystal grown by the hydrothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Chen, G. Z.; Yin, J. G., E-mail: gzhchen@siom.ac.cn, E-mail: yjg@siom.ac.cn; Zhang, L. H.; Zhang, P. X.; Wang, X. Y.; Liu, Y. C. [Chinese Academy of Sciences, Key Laboratory of High Power Laser Materials, Shanghai Institute of Optics and Fine Mechanics (China); Zhang, C. L. [Guilin Research Institute of Geology for Mineral Resources (China); Gu, S. L. [Nanjing University, Department of Physics (China); Hang, Y., E-mail: yhang@siom.ac.cn [Chinese Academy of Sciences, Key Laboratory of High Power Laser Materials, Shanghai Institute of Optics and Fine Mechanics (China)

    2015-12-15

    ZnO single crystals have been grown by the hydrothermal method. Raman scattering and Photoluminescence spectroscopy (PL) have been used to study samples of ZnO that were unannealed or annealed in different ambient gases. It is suggested that the green emission may originate from defects related to copper in our samples.

  12. Oxygen uptake kinetics of Pseudomonas chlororaphis grown in glucose- or glutamate-limited continuous cultures

    NARCIS (Netherlands)

    Bodelier, P.L.E.; Laanbroek, H.J.

    1997-01-01

    Oxygen uptake and glucose and glutamate oxidation kinetics of the heterotrophic bacterium Pseudomonas chlororaphis grown in glucose- or glutamate-limited cultures under oxygen-saturating or oxygen-limiting conditions were determined. Km values for oxygen were 1.4– 5.6 UM. Only in the case of glucose

  13. Effects of mutual shading on the regulation of photosynthesis in field-grown sorghum.

    Science.gov (United States)

    Li, Tao; Liu, Li-Na; Jiang, Chuang-Dao; Liu, Yu-Jun; Shi, Lei

    2014-08-01

    In the field, close planting inevitably causes mutual shading and depression of leaf photosynthesis. To clarify the regulative mechanisms of photosynthesis under these conditions, the effects of planting density on leaf structure, gas exchange and proteomics were carefully studied in field-grown sorghum. In the absence of mineral deficiency, (1) close planting induced a significant decrease in light intensity within populations, which further resulted in much lower stomatal density and other anatomical characteristics associated with shaded leaves; (2) sorghum grown at high planting density had a lower net photosynthetic rate and stomatal conductance than those grown at low planting density; (3) approximately 62 protein spots changed their expression levels under the high planting density conditions, and 22 proteins associated with photosynthesis were identified by mass spectrometry. Further analysis revealed the depression of photosynthesis caused by mutual shading involves the regulation of leaf structure, absorption and transportation of CO2, photosynthetic electron transport, production of assimilatory power, and levels of enzymes related to the Calvin cycle. Additionally, heat shock protein and oxygen-evolving enhancer protein play important roles in photoprotection in field-grown sorghum. A model for the regulation of photosynthesis under mutual shading was suggested based on our results.

  14. Weather-Based forecasting of Rhizoctonia web blight development on container-grown azalea

    Science.gov (United States)

    Fungicides are the only approach currently used to control Rhizoctonia web blight on container-grown azalea. The most reliable criterion for timing fungicides has been a fixed calendar date with adjustment for year-to-year differences in disease progression made by monitoring early-season increase o...

  15. Effects of zinc toxicity on sugar beet (Beta vulgaris L.) plants grown in hydroponics.

    Science.gov (United States)

    Sagardoy, R; Morales, F; López-Millán, A-F; Abadía, A; Abadía, J

    2009-05-01

    The effects of high Zn concentration were investigated in sugar beet (Beta vulgaris L.) plants grown in a controlled environment in hydroponics. High concentrations of Zn sulphate in the nutrient solution (50, 100 and 300 microm) decreased root and shoot fresh and dry mass, and increased root/shoot ratios, when compared to control conditions (1.2 microm Zn). Plants grown with excess Zn had inward-rolled leaf edges and a damaged and brownish root system, with short lateral roots. High Zn decreased N, Mg, K and Mn concentrations in all plant parts, whereas P and Ca concentrations increased, but only in shoots. Leaves of plants treated with 50 and 100 microm Zn developed symptoms of Fe deficiency, including decreases in Fe, chlorophyll and carotenoid concentrations, increases in carotenoid/chlorophyll and chlorophyll a/b ratios and de-epoxidation of violaxanthin cycle pigments. Plants grown with 300 microm Zn had decreased photosystem II efficiency and further growth decreases but did not have leaf Fe deficiency symptoms. Leaf Zn concentrations of plants grown with excess Zn were high but fairly constant (230-260 microg.g(-1) dry weight), whereas total Zn uptake per plant decreased markedly with high Zn supply. These data indicate that sugar beet could be a good model to investigate Zn homeostasis mechanisms in plants, but is not an efficient species for Zn phytoremediation.

  16. Carbon Nanofibers Grown on Large Woven Cloths: Morphology and Properties of Growth

    NARCIS (Netherlands)

    Koissin, Vitaly; Bor, Ton; Kotanjac, Zeljko; Lefferts, Leon; Warnet, Laurent; Akkerman, Remko

    2016-01-01

    The morphology and chemical composition of carbon nanofibers in situ grown on a large carbon-fiber woven fabric are studied using SEM measurements, X-ray Diffraction, X-ray Flourescence, and X-ray Photoelectron Spectroscopy. Results show that nanofibers can have a density and a morphology potentiall

  17. 75 FR 55942 - Avocados Grown in South Florida; Increased Assessment Rate

    Science.gov (United States)

    2010-09-15

    ... Agricultural Marketing Service 7 CFR Part 915 Avocados Grown in South Florida; Increased Assessment Rate AGENCY... increases the assessment rate established for the Avocado Administrative Committee (Committee) for the 2010... avocados handled. The Committee locally administers the marketing order which regulates the handling...

  18. 77 FR 71688 - Avocados Grown in South Florida; Decreased Assessment Rate

    Science.gov (United States)

    2012-12-04

    ... Agricultural Marketing Service 7 CFR Part 915 Avocados Grown in South Florida; Decreased Assessment Rate AGENCY... the assessment rate established for the Avocado Administrative Committee (Committee) for the 2012-13 and subsequent fiscal periods from $0.37 to $0.25 per 55-pound bushel container of Florida...

  19. 76 FR 48742 - Kiwifruit Grown in California; Change in Reporting Requirements and New Information Collection

    Science.gov (United States)

    2011-08-09

    ... definition. In addition, based on kiwifruit production and price information, as well as the total number of...; ] DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 920 Kiwifruit Grown in California; Change in Reporting Requirements and New Information Collection AGENCY: Agricultural Marketing Service,...

  20. Valorisation of discharge water from substrate-grown crops in greenhouses

    NARCIS (Netherlands)

    Balendonck, J.; Os, van E.A.; Ruijven, van J.P.M.; Lans, van der C.J.M.; Beerling, E.A.M.; Feenstra, L.

    2014-01-01

    Due to mismatch of nutrients, high sodium concentration, growth inhibition or system failures, greenhouse growers with substrate-grown crops tend to discharge their drain water. To comply with Water Framework regulations, in future, they must re-use drain water streams as much as possible. With memb

  1. 76 FR 18003 - Raisins Produced From Grapes Grown in California; Increased Assessment Rate

    Science.gov (United States)

    2011-04-01

    ... Industry Marketing Promotion Fund (IMPF). Other expenses which have been reduced include: travel for... hauling costs ($65,000), and 2011-2012 export marketing promotion costs. These costs would be unnecessary... Agricultural Marketing Service 7 CFR Part 989 Raisins Produced From Grapes Grown in California;...

  2. 75 FR 7981 - Kiwifruit Grown in California; Secretary's Decision and Referendum Order on Proposed Amendments...

    Science.gov (United States)

    2010-02-23

    ..., a State marketing program, is authorized to conduct research and promotion projects for the industry... Agricultural Marketing Service 7 CFR Part 920 Kiwifruit Grown in California; Secretary's Decision and Referendum Order on Proposed Amendments to Marketing Order No. 920 AGENCY: Agricultural Marketing...

  3. 75 FR 77563 - Nectarines, Pears, and Peaches Grown in California; Continuance Referenda

    Science.gov (United States)

    2010-12-13

    ... an effective means for determining whether growers favor the continuation of marketing order programs... Agricultural Marketing Service 7 CFR Parts 916 and 917 Nectarines, Pears, and Peaches Grown in California; Continuance Referenda AGENCY: Agricultural Marketing Service, USDA. ACTION: Referenda order. SUMMARY:...

  4. 75 FR 37288 - Kiwifruit Grown in California; Order Amending Marketing Order No. 920

    Science.gov (United States)

    2010-06-29

    ... absence of a signed marketing agreement, the issuance of this amendatory order is the only practical means... Agricultural Marketing Service 7 CFR Part 920 Kiwifruit Grown in California; Order Amending Marketing Order No. 920 AGENCY: Agricultural Marketing Service, USDA. ACTION: Final rule. SUMMARY: This rule...

  5. Strain relaxation in thin films of Cu grown on Ni(001)

    DEFF Research Database (Denmark)

    Rasmussen, F.B.; Baker, J.; Nielsen, M.;

    1998-01-01

    Surface X-ray diffraction and kinematical model calculations are used to determine the strain relaxation of embedded wedges with internal (111) facets formed in thin Cu films when grown on Ni(001). We show the wedges to be inhomogenously strained with a large lateral relaxation near the Cu...

  6. Location of catalase in crystalline peroxisomes of methanol-grown Hansenula polymorpha

    NARCIS (Netherlands)

    Keizer, Ineke; Roggenkamp, Rainer; Harder, Willem; Veenhuis, Marten

    1992-01-01

    We have studied the intraperoxisomal location of catalase in peroxisomes of methanol-grown Hansenula polymorpha by (immuno)cytochemical means. In completely crystalline peroxisomes, in which the crystalline matrix is composed of octameric alcohol oxidase (AO) molecules, most of the catalase protein

  7. 76 FR 4202 - Pears Grown in Oregon and Washington; Amendment To Allow Additional Exemptions

    Science.gov (United States)

    2011-01-25

    ... order regulates the handling of pears grown in Oregon and Washington. Local administration of the... action is intended to provide regulatory flexibility to small pear handlers, while facilitating the sale... INFORMATION: This rule is issued under Marketing Order No. 927, as amended (7 CFR part 927), regulating...

  8. 75 FR 34950 - Walnuts Grown in California; Changes to the Quality Regulations for Shelled Walnuts

    Science.gov (United States)

    2010-06-21

    ...; ] DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 984 Walnuts Grown in California; Changes to the Quality Regulations for Shelled Walnuts AGENCY: Agricultural Marketing Service, USDA. ACTION....'' The order is effective under the Agricultural Marketing Agreement Act of 1937, as amended (7...

  9. 76 FR 8917 - Pears Grown in Oregon and Washington; Continuance Referendum

    Science.gov (United States)

    2011-02-16

    ...; ] DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 927 Pears Grown in Oregon and Washington; Continuance Referendum AGENCY: Agricultural Marketing Service, USDA. ACTION: Referendum order. SUMMARY: This... referred to as the ``order,'' and the applicable provisions of the Agricultural Marketing Agreement Act...

  10. 78 FR 62961 - Apricots Grown in Designated Counties in Washington; Increased Assessment Rate

    Science.gov (United States)

    2013-10-23

    ... Agricultural Marketing Service 7 CFR Part 922 Apricots Grown in Designated Counties in Washington; Increased Assessment Rate AGENCY: Agricultural Marketing Service, USDA. ACTION: Final rule. SUMMARY: This rule... referred to as the ``order.'' The order is effective under the Agricultural Marketing Agreement Act of...

  11. 78 FR 1715 - Grapes Grown in Designated Area of Southeastern California; Increased Assessment Rate

    Science.gov (United States)

    2013-01-09

    ... Agricultural Marketing Service 7 CFR Part 925 Grapes Grown in Designated Area of Southeastern California; Increased Assessment Rate AGENCY: Agricultural Marketing Service, USDA. ACTION: Final rule. SUMMARY: This... to as the ``order.'' The order is effective under the Agricultural Marketing Agreement Act of...

  12. 77 FR 72245 - Pears Grown in Oregon and Washington; Committee Membership Reapportionment for Processed Pears

    Science.gov (United States)

    2012-12-05

    ...; ] DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 927 Pears Grown in Oregon and Washington; Committee Membership Reapportionment for Processed Pears AGENCY: Agricultural Marketing Service, USDA... under the Agricultural Marketing Agreement Act of 1937, as amended (7 U.S.C. 601-674),...

  13. Phenotypic Characteristics Of Ten Garlic Cultivars Grown At Different North American Locations

    Science.gov (United States)

    Garlic (Allium sativum L.) bulbs are marketed for their health and culinary values. It is difficult to identify garlic cultivars or classes grown under diverse conditions as a result of their highly elastic environmental responses, particularly relating to skin color and clove arrangement of bulbs....

  14. 76 FR 7095 - Avocados Grown in South Florida; Increased Assessment Rate

    Science.gov (United States)

    2011-02-09

    ... / Wednesday, February 9, 2011 / Rules and Regulations#0;#0; ] DEPARTMENT OF AGRICULTURE Agricultural Marketing... Marketing Service, USDA. ACTION: Affirmation of interim rule as final rule. SUMMARY: The Department of... Committee locally administers the marketing order which regulates the handling of avocados grown in...

  15. 76 FR 41589 - Irish Potatoes Grown in Washington; Decreased Assessment Rate

    Science.gov (United States)

    2011-07-15

    ... / Friday, July 15, 2011 / Rules and Regulations#0;#0; ] DEPARTMENT OF AGRICULTURE Agricultural Marketing... Marketing Service, USDA. ACTION: Affirmation of interim rule as final rule. SUMMARY: The Department of... administers the marketing order for Irish potatoes grown in Washington. The interim rule was necessary...

  16. Growth Dynamics of Celosia cristata Grown in Cocopeat, Burnt Rice Hull and Kenaf Core Fiber Mixtures

    Directory of Open Access Journals (Sweden)

    Yahya Awang

    2010-01-01

    Full Text Available Problem statement: Understanding the growth dynamics of short-lived plant could be critical as it would complete its life cycle in a short time period. It does not normally has much time to adjust to hostile environmental condition. This study provides a detail account on growth dynamics of Celosia cristata grown in five growing media for the production of high quality flowers. Approach: Celosia cristata plants were grown on five growing media (v/v: 100% Cocopeat (CP; 70% CP: 30% Burnt Rice Hull (BRH; 70% CP: 30% perlite; 70% CP: 30% Kenaf Core Fiber (KCF and 40% CP: 60% KCF. To explore the dynamics of plant growth and development, data on plant height and canopy diameter were regressed against Days After Transplanting (DAT by using the equation y = A/(1+be-cx while its derivative [dy/dx = (Abce-cx/(1+be-cx2] was used to estimate the growth rate of the parameter. The variation in leaf number, flower length and flower diameter were modeled using an exponential function of y = Aebx and their rate of change was derived using dx/dy = Abebx. Results: The growth rates of plant height, canopy diameter and leaf number of plants grown in media containing 100% CP, 70% CP: 30% BRH, 70% CP: 30% perlite, 70% CP: 30% KCF were higher than those grown on media containing 40% CP: 60% KCF. The growth rates of stem and canopy of the plants grown in the later media tended to be higher at the end of the growth cycle. This, however would not be sufficient to compensate their early losses, since the rate of growth in leaf number did not increase concurrently. Negative effects of media containing KCF were also detected in flower size. Conclusion: Overall results showed that CP is an excellent growing media for the production of Celosia cristata. Replacing 30% of CP with BRH, perlite and KCF did not affect the growth and flowering of the plants.

  17. Characteristics evaluation of stilbene single crystal grown by vertical bridgman technique

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Kwang Ho

    2012-02-15

    As the nature of organic scintillator, stilbene single crystal's decay time is only a couple of nano seconds, which makes it suitable for fast neutron detection. However, the entire amount of stilbene single crystal being used relies on import currently. As the necessity of fast neutron detection equipment such as KSTAR and Sodium-cooled Fast Reactor system increases, the goal is to have our own domestic technology through the growth of stilbene single crystal. The emission wavelength of grown stilbene single crystal is confirmed, and the property of grown stilbene single crystal is assessed compared to commercial stilbene (Ukraine ISMA research center) through gamma ray and neutron tests. In this research, we have grown stilbenes through Bridgman technique, and obtained three stilbenes out of two amples. (Two ones of {Phi} 30 mm x 15 mm, and {Phi} 40 mm x 17 mm from the first ample, and size of {Phi} 25 mm x 13 mm from the other) The grown stilbene's emission wavelength and inherent property of stilbene are confirmed. As the result of gamma ray test, we have confirmed linearity of grown stilbene's scintillator, and the relative light yield ratio is proven 101% efficiency to reference stilbene. Neutron detection efficiency of the three stilbenes amounts to 80% of reference stilbene, and FOM of them is 108% efficiency to reference stilbene's one. Although Ukraine ISMA research center still holds a dominant position with world-class efficiency and performance of its stilbene, we expect to produce a better stilbene with our domestic technology development. Through this, fast neutron detection technique can be obtained, which opens up an opportunity to be used not only in neutron monitoring system in nuclear fusion reactor, but also in alternative measurement technique as the unit price of He-3 increases recently

  18. 77 FR 24640 - Tart Cherries Grown in the State of Michigan, et al.; Increasing the Primary Reserve Capacity and...

    Science.gov (United States)

    2012-04-25

    ...; ] DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 930 Tart Cherries Grown in the State of... diversion activities prescribed under the marketing order for tart cherries (order). The order regulates the handling of tart cherries grown in the States of Michigan, New York, Pennsylvania, Oregon, Utah,...

  19. 77 FR 33303 - Tart Cherries Grown in the States of Michigan, New York, Pennsylvania, Oregon, Utah, Washington...

    Science.gov (United States)

    2012-06-06

    ... Agricultural Marketing Service 7 CFR Part 930 Tart Cherries Grown in the States of Michigan, New York.... 930 (order), which regulates the handling of tart cherries grown in Michigan, New York, Pennsylvania... (77 FR 13015). This document directed that a referendum among tart cherry growers and processors...

  20. 75 FR 31719 - Tart Cherries Grown in the States of Michigan, New York, Pennsylvania, Oregon, Utah, Washington...

    Science.gov (United States)

    2010-06-04

    ...; ] DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 930 Tart Cherries Grown in the States of... handling of tart cherries grown in Michigan, New York, Pennsylvania, Oregon, Utah, Washington, and... with respect to the proposed amendments to Marketing Order 930 regulating the handling of tart...

  1. 77 FR 40250 - Tart Cherries Grown in the States of Michigan, et al.; Increasing the Primary Reserve Capacity...

    Science.gov (United States)

    2012-07-09

    ... Agricultural Marketing Service 7 CFR Part 930 Tart Cherries Grown in the States of Michigan, et al.; Increasing... order for tart cherries (order). The order regulates the handling of tart cherries grown in the States... locally by the Cherry Industry Administrative Board (Board). This action increases the volume of...

  2. 77 FR 36115 - Tart Cherries Grown in the States of Michigan, et al.; Final Free and Restricted Percentages for...

    Science.gov (United States)

    2012-06-18

    ... Service 7 CFR Part 930 Tart Cherries Grown in the States of Michigan, et al.; Final Free and Restricted Percentages for the 2011-12 Crop Year for Tart Cherries AGENCY: Agricultural Marketing Service, USDA. ACTION... year under the marketing order for tart cherries grown in the states of Michigan, New...

  3. 75 FR 12702 - Tart Cherries Grown in the States of Michigan, et al.; Final Free and Restricted Percentages for...

    Science.gov (United States)

    2010-03-17

    ...; ] DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 930 Tart Cherries Grown in the States of Michigan, et al.; Final Free and Restricted Percentages for the 2009-2010 Crop Year for Tart Cherries... order regulates the handling of tart cherries grown in the States of Michigan, New York,...

  4. 75 FR 33673 - Tart Cherries Grown in the States of Michigan, New York, Pennsylvania, Oregon, Utah, Washington...

    Science.gov (United States)

    2010-06-15

    ... Service 7 CFR Part 930 Tart Cherries Grown in the States of Michigan, New York, Pennsylvania, Oregon, Utah... regulates the handling of tart cherries grown in Michigan, New York, Pennsylvania, Oregon, Utah, Washington... referendum among tart cherry growers and processors be conducted during the period February 1, 2010,...

  5. 77 FR 12748 - Tart Cherries Grown in the States of Michigan, et al.; Final Free and Restricted Percentages for...

    Science.gov (United States)

    2012-03-02

    ...; ] DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 930 Tart Cherries Grown in the States of Michigan, et al.; Final Free and Restricted Percentages for the 2011-12 Crop Year for Tart Cherries AGENCY... tart cherries grown in the states of Michigan, New York, Pennsylvania, Oregon, Utah, Washington,...

  6. Thermal conductivity of low temperature grown vertical carbon nanotube bundles measured using the three-ω method

    NARCIS (Netherlands)

    Vollebregt, S.; Banerjee, S.; Beenakker, K.; Ishihara, R.

    2013-01-01

    The thermal conductivity of as-grown vertical multi-walled carbon nanotubes (CNT) bundles fabricated at low temperature (500 °C) was measured using a vertical 3ω-method. For this, CNT were selectively grown inside an oxide opening and sandwiched between two metal electrodes. The validity of the meth

  7. Whole-genome sequences of 13 endophytic bacteria isolated from shrub willow (salix) grown in geneva, new york.

    Science.gov (United States)

    Gan, Huan You; Gan, Han Ming; Savka, Michael A; Triassi, Alexander J; Wheatley, Matthew S; Smart, Lawrence B; Fabio, Eric S; Hudson, André O

    2014-05-08

    Shrub willow, Salix spp. and hybrids, is an important bioenergy crop. Here we report the whole-genome sequences and annotation of 13 endophytic bacteria from stem tissues of Salix purpurea grown in nature and from commercial cultivars and Salix viminalis × Salix miyabeana grown in bioenergy fields in Geneva, New York.

  8. Genetic variation in yield and chemical composition of wide range of sorghum accessions grown in north-west China

    NARCIS (Netherlands)

    Wang, J.S.; Wang, M.L.; Spiertz, J.H.J.; Liu, Z.; Han, L.; Xie, G.H.

    2013-01-01

    Sorghum can be grown on marginal and waste lands as a versatile feedstock for biofuel production in the vast areas of north-west China. Fifty-six sorghum accessions were grown in 2009 at the experimental station of Xinjiang Agricultural University, located at Urumchi, Xinjiang, China. A total of 31

  9. Leaf temperature of soybean grown under elevated CO2 increases Aphis glycines (Hemiptera: Aphididae)population growth

    Institute of Scientific and Technical Information of China (English)

    Bridget F. O'Neill; Arthur R. Zangerl; Evan H. DeLucia; Clare Casteel; Jorge A. Zavala; May R. Berenbaum

    2011-01-01

    Plants grown under elevated carbon dioxide (CO2) experience physiological changes that influence their suitability as food for insects.To determine the effects of living on soybean (Glycine max Linnaeus) grown under elevated CO2,population growth of the soybean aphid (Aphis glycines Matsumura) was determined at the SoyFACE research site at the University of Illinois,Urbana-Champaign,Illinois,USA,grown under elevated (550μL/L) and ambient (370μL/L) levels of CO2.Growth of aphid populations under elevated CO2 was significantly greater after 1 week,with populations attaining twice the size of those on plants grown under ambient levels of CO2.Soybean leaves grown under elevated levels of CO2 were previously demonstrated at SoyFACE to have increased leaf temperature caused by reduced stomatal conductance.To separate the increased leaf temperature from other effects of elevated CO2,air temperature was lowered while the CO2 level was increased,which lowered overall leaf temperatures to those measured for leaves grown under ambient levels of CO2.Aphid population growth on plants grown under elevated CO2 and reduced air temperature was not significantly greater than on plants grown under ambient levels of CO2.By increasing Glycine max leaf temperature,elevated CO2 may increase populations of Aphis glycines and their impact on crop productivity.

  10. Spectral, optical and mechanical studies on L-histidine hydrochloride monohydrate (LHC) single crystals grown by unidirectional growth technique

    Energy Technology Data Exchange (ETDEWEB)

    Robert, R. [Department of Physics, Government Arts College (Men), Krishnagiri (India); Justin Raj, C. [Department of Physics, Loyola College, Chennai 600 034 (India); Krishnan, S. [Department of Physics, R.M.K. Engineering College, Kavaripettai 601 206 (India); Uthrakumar, R.; Dinakaran, S. [Department of Physics, Loyola College, Chennai 600 034 (India); Jerome Das, S., E-mail: sjeromedas2004@yahoo.co [Department of Physics, Loyola College, Chennai 600 034 (India)

    2010-08-15

    Single crystals of nonlinear optical L-histidine hydrochloride monohydrate (LHC) were grown in an aqueous solution by the unidirectional crystal growth method within a period of 45 days along (1 0 1) plane. The grown crystals were subjected to single crystal X-ray diffraction analysis to confirm their orthorhombic structure having space group P2{sub 1}2{sub 1}2{sub 1}. Values of several physical parameters were determined for the grown crystal. Optical transmission studies revealed very low absorption and band gap energy was calculated for the LHC crystals. Further, some optical constant were also determined for the grown crystals. Anisotropy in Vicker's microhardness led to the assessment of fracture toughness, brittleness index and yield strength for the synthesized crystals. Nonlinear optical studies were carried out for the grown crystal and second harmonic generation (SHG) efficiency was found to be three times that of KDP crystals.

  11. Characteristics of cannabinoids composition of Cannabis plants grown in Northern Thailand and its forensic application.

    Science.gov (United States)

    Tipparat, Prapatsorn; Natakankitkul, Surapol; Chamnivikaipong, Pipop; Chutiwat, Sirot

    2012-02-10

    The Thai government has recognized the possibility for legitimate cultivation of hemp. Further study of certain cannabinoid characteristics is necessary in establishing criteria for regulation of cannabis cultivation in Thailand. For this purpose, factors affecting characteristics of cannabinoids composition of Thai-grown cannabis were investigated. Plants were cultivated from seeds derived from the previous studies under the same conditions. 372 cannabis samples from landraces, three different trial fields and seized marijuana were collected. 100g of each sample was dried, ground and quantitatively analyzed for THC, CBD and CBN contents by GC-FID. The results showed that cannabis grown during March-June which had longer vegetative stages and longer photoperiod exposure, had higher cannabinoids contents than those grown in August. The male plants grown in trial fields had the range of THC contents from 0.722% to 0.848% d.w. and average THC/CBD ratio of 1.9. Cannabis in landraces at traditional harvest time of 75 days had a range of THC contents from 0.874% to 1.480% d.w. and an average THC/CBD ratio of 2.6. The THC contents and THC/CBD ratios of cannabis in second generation crops grown in the same growing season were found to be lower than those grown in the first generation, unless fairly high temperatures and a lesser amount of rainfall were present. The average THC content in seized fresh marijuana was 2.068% d.w. while THC/CBD ratios were between 12.6 and 84.09, which is 10-45 times greater than those of similar studied cannabis samples from the previous study. However, most Thai cannabis in landraces and in trial fields giving a low log(10) value of THC/CBD ratio at below 1 may be classified as intermediate type, whereas seized marijuana giving a higher log(10) value at above 1 could be classified as drug type. Therefore, the expanded information provided by the current study will assist in the development of criteria for regulation of hemp cultivation in

  12. The effect of electrical lighting power and irradiance on indoor-grown cannabis potency and yield.

    Science.gov (United States)

    Potter, David J; Duncombe, Paul

    2012-05-01

    The floral development and potencies [Δ(9) -tetrahydrocannabinol (THC) contents] of cannabis plants were compared when grown indoors under high-pressure sodium lamps consuming electrical power at three densities (270, 400, and 600 W/m(2)). After a 3-week vegetative phase, plants were grown for 8 weeks, with lamps maintaining an artificial day length of 12 h. Foliar and floral yields were measured. Gas chromatography was used to measure the content of the psychoactive cannabinoid THC. Mean yields per unit of electrical power in each lighting regime ranged from 0.9 to 1.6 g/W, the highest being achieved in the lowest irradiance regime. The individual potencies of the separated leaf and flower materials were not affected by increasing irradiance. However, there was a corresponding increase in the overall potency of the aerial plant tissue. This was because of the plants in brighter conditions producing a higher proportion of floral material.

  13. Novel scanning procedure enabling the vectorization of entire rhizotron-grown root systems

    Directory of Open Access Journals (Sweden)

    Lobet Guillaume

    2013-01-01

    Full Text Available Abstract This paper presents an original spit-and-combine imaging procedure that enables the complete vectorization of complex root systems grown in rhizotrons. The general principle of the method is to (1 separate the root system into a small number of large pieces to reduce root overlap, (2 scan these pieces one by one, (3 analyze separate images with a root tracing software and (4 combine all tracings into a single vectorized root system. This method generates a rich dataset containing morphological, topological and geometrical information of entire root systems grown in rhizotrons. The utility of the method is illustrated with a detailed architectural analysis of a 20-day old maize root system, coupled with a spatial analysis of water uptake patterns.

  14. Increased Biomass of Nursery-Grown Douglas-Fir Seedlings upon Inoculation with Diazotrophic Endophytic Consortia

    Directory of Open Access Journals (Sweden)

    Zareen Khan

    2015-10-01

    Full Text Available Douglas-fir (Pseudotsuga menziesii seedlings are periodically challenged by biotic and abiotic stresses. The ability of endophytes to colonize the interior of plants could confer benefits to host plants that may play an important role in plant adaptation to environmental changes. In this greenhouse study, nursery-grown Douglas-fir seedlings were inoculated with diazotrophic endophytes previously isolated from poplar and willow trees and grown for fifteen months in nutrient-poor conditions. Inoculated seedlings had significant increases in biomass (48%, root length (13% and shoot height (16% compared to the control seedlings. Characterization of these endophytes for symbiotic traits in addition to nitrogen fixation revealed that they can also solubilize phosphate and produce siderophores. Colonization was observed through fluorescent microscopy in seedlings inoculated with gfp- and mkate-tagged strains. Inoculation with beneficial endophytes could prove to be valuable for increasing the production of planting stocks in forest nurseries.

  15. Characterization of large cadmium zinc telluride crystals grown by traveling heater method

    DEFF Research Database (Denmark)

    Chen, H.; Awadalla, S.A.; Iniewski, K.

    2008-01-01

    The focus of this paper is to evaluate thick, 20 X 20 X 10 and 10 X 10 X 10 mm(3), cadmium zinc telluride (CZT), Cd0.9Zn0.1Te, crystals grown using the traveling heater method (THIM). The phenomenal spectral performance and small size and low concentration of Te inclusions/precipitates of these c......The focus of this paper is to evaluate thick, 20 X 20 X 10 and 10 X 10 X 10 mm(3), cadmium zinc telluride (CZT), Cd0.9Zn0.1Te, crystals grown using the traveling heater method (THIM). The phenomenal spectral performance and small size and low concentration of Te inclusions...

  16. Synthesis and Photoluminescence Studies on Catalytically Grown Zn1 – xMnxS Nanowires

    Directory of Open Access Journals (Sweden)

    R. Venugopal

    2011-01-01

    Full Text Available Zn1 – xMnxS alloy nanowires with composition (x = 0.0, 0.1 and 0.3 have been successfully synthesized by a simple thermal evaporation on the silicon substrate coated with a gold film of 2 nm thickness. X-ray powder diffraction measurements reveal that as synthesized products were hexagonal wurtzite structure. The as grown nanowires have been investigated by Scanning Electron Microscopy (SEM, Transmission Electron Microscopy (TEM, Energy Dispersive Analysis of X-rays (EDAX and photoluminescence studies. The results reveal that the as grown nanowires consist of Zn, Mn, and S material and diameter ranging from 70 - 150 nm with lengths up to several tens of micrometers. Photoluminescence studies on Zn1 – xMnxS exhibited peaks at 600 and 613 nm for x = 0.1 and 0.3 respectively.

  17. Second harmonic generation studies in L-alanine single crystals grown from solution

    Science.gov (United States)

    Boomadevi, Shanmugam; Pandiyan, Krishnamoorthy

    2014-01-01

    Single crystals of L-alanine of dimensions 2×1.1×0.5 cm3 were grown by evaporation method using deionised water as a solvent. The morphology of the grown crystals had (1 2 0) and (0 1 1) as their prominent faces. UV-vis-near IR spectrum shows the transparency range of L-alanine crystal available for frequency doubling from 250 to 1400 nm. Phase-matched second harmonic generation was observed in L-alanine sample by using 7 ns Q-switched Nd:YAG laser with OPO set up. In the present work, phase matching was achieved by angle and wavelength tuning. The angular and spectral phase-matching bandwidths were determined experimentally for a 1.5 mm thick L-alanine crystal and the results have been compared with their theoretical results. Further the possible reasons for the broadening of SHG spectrum have been discussed.

  18. Second harmonic generation studies in L-alanine single crystals grown from solution

    Energy Technology Data Exchange (ETDEWEB)

    Boomadevi, Shanmugam, E-mail: sboomi@gmail.com [Department of Physics, Periyar Maniammai University, Thanjavur-613 403, Tamil Nadu (India); Pandiyan, Krishnamoorthy [School of Electrical and Electronics Engineering, SASTRA University, Thanjavur-613 401, Tamil Nadu (India)

    2014-01-01

    Single crystals of L-alanine of dimensions 2×1.1×0.5 cm{sup 3} were grown by evaporation method using deionised water as a solvent. The morphology of the grown crystals had (1 2 0) and (0 1 1) as their prominent faces. UV–vis-near IR spectrum shows the transparency range of L-alanine crystal available for frequency doubling from 250 to 1400 nm. Phase-matched second harmonic generation was observed in L-alanine sample by using 7 ns Q-switched Nd:YAG laser with OPO set up. In the present work, phase matching was achieved by angle and wavelength tuning. The angular and spectral phase-matching bandwidths were determined experimentally for a 1.5 mm thick L-alanine crystal and the results have been compared with their theoretical results. Further the possible reasons for the broadening of SHG spectrum have been discussed.

  19. Bond strength of individual carbon nanotubes grown directly on carbon fibers

    Science.gov (United States)

    Kim, Kyoung Ju; Lee, Geunsung; Kim, Sung-Dae; Kim, Seong-Il; Youk, Ji Ho; Lee, Jinyong; Kim, Young-Woon; Yu, Woong-Ryeol

    2016-10-01

    The performance of carbon nanotube (CNT)-based devices strongly depends on the adhesion of CNTs to the substrate on which they were directly grown. We report on the bond strength of CNTs grown on a carbon fiber (T700SC Toray), measured via in situ pulling of individual CNTs inside a transmission electron microscope. The bond strength of an individual CNT, obtained from the measured pulling force and CNT cross-section, was very high (˜200 MPa), 8-10 times higher than that of an adhesion model assuming only van der Waals interactions (25 MPa), presumably due to carbon-carbon interactions between the CNT (its bottom atoms) and the carbon substrate.

  20. Stress, structural and electrical properties of Si-doped GaN film grown by MOCVD

    Energy Technology Data Exchange (ETDEWEB)

    Xu Zhihao; Zhang Jincheng; Duan Huantao; Zhang Zhongfen; Zhu Qingwei; Xu Hao; Hao Yue, E-mail: forman1115@163.co [Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices, School of Microelectronics, Xidian University, Xi' an 710071 (China)

    2009-12-15

    The stresses, structural and electrical properties of n-type Si-doped GaN films grown by metalorganic chemical vapor deposition (MOCVD) are systemically studied. It is suggested that the main stress relaxation is induced by bending dislocations in low doping samples. But for higher doping samples, as the Si doping concentration increases, the in-plane stresses in the grown films are quickly relaxed due to the rapid increase of the edge dislocation densities. Hall effect measurements reveal that the carrier mobility first increases rapidly and then decreases with increasing Si doping concentration. This phenomenon is attributed to the interaction between various scattering process. It is suggested that the dominant scattering process is defect scattering for low doping samples and ionized impurity scattering for high doping samples. (semiconductor materials)

  1. Shock-produced vapor-grown crystals in the Yanzhuang meteorite

    Institute of Scientific and Technical Information of China (English)

    谢先德; 陈鸣

    1997-01-01

    Vapor-grown crystals intimately related to shock metamorphism of meteorites were found in the Yanzhuang (H6) chondrite which had been heavily impacted in the space. These crystals include: (i) subhedral low-Ca pyroxene occurring on the wall of the pores within a silicate melt pocket that experienced a shock temperature higher than 1 500℃, (ii)Fe-Ni needle-whiskers (taenite) occurring in the cracks in the partially melted chondritic facies that experienced a shock temperature of 850-1 300℃ , (iii) troilite with abundant microholes occurring in the cracks in the brecciated facies and the lightly deformed chondritic facies that experienced a shock temperature lower than 850℃ . The occurrence and mineralogical features of vapor-grown crystals show that vaporization of minerals could be produced in heavily impacted meteorites and that a small amount of crystals could be deposited in situ from vapor plus-

  2. Effects of heat-treatment and hydrogen adsorption on Graphene grown on Cu foil

    Science.gov (United States)

    Cho, Jongweon; Gao, Li; Tian, Jifa; Cao, Helin; Yu, Qingkai; Guest, Jeffrey; Chen, Yong; Guisinger, Nathan

    2011-03-01

    Graphene has recently been a subject of intense research efforts due to its remarkable physical properties as an ideal two-dimensional material. While numerous different methods for graphene synthesis are being explored, CVD-grown graphene on Cu foil presents the possibility of a large-scale and high-quality synthesis of graphene.[1] To improve the quality of graphene films on Cu foil prepared by CVD and better understand its microscopic growth, atomic-scale characterization becomes of great importance. We have investigated the effects of thermal annealing and hydrogen adsorption/desorption on ex-situ CVD-grown monolayer graphene on polycrystalline Cu foil at the atomic-scale using ultrahigh vacuum scanning tunneling microscopy, and we will report on these studies.

  3. Homojunction GaAs solar cells grown by close space vapor transport

    Energy Technology Data Exchange (ETDEWEB)

    Boucher, Jason W. [University of Oregon; Ritenour, Andrew J. [University of Oregon; Greenaway, Ann L. [University of Oregon; Aloni, Shaul [Lawrence Berkeley National Laboratory; Boettcher, Shannon W. [University of Oregon

    2014-06-08

    We report on the first pn junction solar cells grown by homoepitaxy of GaAs using close space vapor transport (CSVT). Cells were grown both on commercial wafer substrates and on a CSVT absorber film, and had efficiencies reaching 8.1%, open circuit voltages reaching 909 mV, and internal quantum efficiency of 90%. The performance of these cells is partly limited by the electron diffusion lengths in the wafer substrates, as evidenced by the improved peak internal quantum efficiency in devices fabricated on a CSVT absorber film. Unoptimized highly-doped n-type emitters also limit the photocurrent, indicating that thinner emitters with reduced doping, and ultimately wider band gap window or surface passivation layers, are required to increase the efficiency.

  4. Adaptive changes in cardiolipin content of Staphylococcus aureus grown in different salt concentrations

    Directory of Open Access Journals (Sweden)

    Takatsu,Tieko

    1975-12-01

    Full Text Available Adaptive changes in cardiolipin content were examined in Staphylococcus aureus 209P using the 32P pulse-labelling method. Cardiolipin synthesis showed increased adaptation when cells grown in normal medium were transferred into high NaCl containing medium. When S. aureus cultured in 10% NaCl medium was transferred back to normal medium, cardiolipin concentration decreased to the normal level within 3 hours. The catabolic rate of cardiolipin in the cells was much slower in the 5% NaCl medium than in normal medium. The cardiolipin synthetase activity was examined by isolated membrane fraction from S. aureus grown both in normal and 10% NaCl medium. The activity was higher by two-fold in membrane fractions from cells cultured in 10% NaCl-containing medium than in membranes from cells cultured in normal medium.

  5. Nontargeted metabolite profiles and sensory properties of strawberry cultivars grown both organically and conventionally.

    Science.gov (United States)

    Kårlund, Anna; Hanhineva, Kati; Lehtonen, Marko; Karjalainen, Reijo O; Sandell, Mari

    2015-01-28

    Strawberry (Fragaria × ananassa Duch.) contains many secondary metabolites potentially beneficial for human health, and several of these compounds contribute to strawberry sensory properties, as well. In this study, three strawberry cultivars grown both conventionally and organically were subjected to nontargeted metabolite profiling analysis with LC-qTOF-ESI-MS and to descriptive sensory evaluation by a trained panel. Combined metabolome and sensory data (PLS model) revealed that 79% variation in the metabolome explained 88% variation in the sensory profiles. Flavonoids and condensed and hydrolyzable tannins determined the orosensory properties, and fatty acids contributed to the odor attributes of strawberry. Overall, the results indicated that the chemical composition and sensory quality of strawberries grown in different cultivation systems vary mostly according to cultivar. Organic farming practices may enhance the accumulation of some plant metabolites in specific strawberry genotypes. Careful cultivar selection is a key factor for the improvement of nutritional quality and marketing value of organic strawberries.

  6. Integrated management tactics for Frankliniella thrips (Thysanoptera: Thripidae) in field-grown pepper.

    Science.gov (United States)

    Reitz, Stuart R; Yearby, Erika L; Funderburk, Joseph E; Stavisky, Julianne; Momol, M Timur; Olson, Steve M

    2003-08-01

    In a 2-yr study, the impacts of different plastic soil mulches, insecticides, and predator releases on Frankliniella thrips and their natural enemies were investigated in field-grown peppers. Ultraviolet light (UV)-reflective mulch significantly reduced early season abundance of adult thrips compared with standard black plastic mulch. This difference diminished as the growing seasons progressed. Late season abundance of thrips larvae was higher in UV reflective mulch compared with black mulch plots. The abundance of the predator Orius insidiosus (Say) was significantly lower in UV-reflective mulch compared with black mulch treatments. Infection of plants with tomato spotted wilt virus, a pathogen vectored by Frankliniella occidentalis (Pergande), was Geocoris punctipes (Say) reduced populations of thrips immediately after releases; naturally occurring predators probably provided late season control of thrips. Our results suggest that UV-reflective mulch, combined with early season applications of spinosad, can effectively reduce abundance of thrips in field-grown pepper.

  7. Atomic structure of "multilayer silicene" grown on Ag(111): Dynamical low energy electron diffraction analysis

    Science.gov (United States)

    Kawahara, Kazuaki; Shirasawa, Tetsuroh; Lin, Chun-Liang; Nagao, Ryo; Tsukahara, Noriyuki; Takahashi, Toshio; Arafune, Ryuichi; Kawai, Maki; Takagi, Noriaki

    2016-09-01

    We have investigated the atomic structure of the "multilayer silicene" grown on the Ag(111) single crystal surface by using low energy electron diffraction (LEED) and scanning tunneling microscopy (STM). We measured the intensity of the LEED spot as a function of the incident electron energy (I-V curve) and analyzed the I-V curve using a dynamical LEED theory. We have found that the Si(111)(√{ 3} ×√{ 3})-Ag model well reproduces the I-V curve whereas the models consisting of the honeycomb structure of Si do not. The bias dependence of the STM image of multilayer silicene agrees with that of the Si(111)(√{ 3} ×√{ 3})-Ag reconstructed surface. Consequently, we have concluded that the multilayer silicene grown on Ag(111) is identical to the Si(111)(√{ 3} ×√{ 3})-Ag reconstructed structure.

  8. Photoluminescence excitation spectroscopy of MBE grown InGaN quantum wells and quantum boxes

    Energy Technology Data Exchange (ETDEWEB)

    White, M.E.; O' Donnell, K.P.; Martin, R.W.; Deatcher, C.J. [Strathclyde Univ., Glasgow (United Kingdom). Dept. of Physics and Applied Physics; Damilano, B.; Grandjean, N.; Massies, J. [CRHEA/CNRS, Sophia Antipolis, Valbonne (France)

    2001-11-01

    Photoluminescence excitation (PLE) spectroscopy was carried out to investigate the excitation/emission cycle of MBE grown InGaN quantum structures. Quantum well and Stranski-Krastanov type quantum box samples were chosen that emit from blue to red. The bandgap energy (E{sub g}), determined from the PLE spectrum, was found to decrease concurrently with the detection energy. This indicates that the emission spectrum from the sample is inhomogeneously broadened. A plot of the resultant Stokes shift against detection energy shows a linear trend. Our results agree with those from independent measurements of thermally detected optical absorption (TDOA) in some of the samples. On comparison with absorption and PLE measurements on MOCVD grown InGaN, a difference in the bandgap energies obtained becomes apparent for detection energies below {approx}2.6 eV. (orig.)

  9. Some biomedical applications of Balanites aegyptiaca grown naturally in radioactive area, Southeastern Desert, Egypt

    Energy Technology Data Exchange (ETDEWEB)

    Morsy, A.M.A., E-mail: Ghostvolca@hotmail.com [Nuclear Materials Authority, P.O. Box 530, El Maadi, Cairo (Egypt); Ahmad, I.A. [Chemistry Department, Faculty of Science, Cairo University (Egypt); Kamel, A.M. [Labeled Compounds Department, Radioisotopes Production Division, Hot Labs Center, Atomic Energy Authority, Abou-Zaabal 13759 (Egypt)

    2010-06-15

    Balanites aegyptiaca is a naturally grown desert plant at some radioactive places in Wadi El-Gemal area, Southeastern Desert. The aim of the present study was to highlight on the B. aegyptiaca species grown naturally at radioactive places in Wadi El-Gemal area (fruit part) on the ability of using the fruit in some biomedical application (glucose, cholesterol, triglycerides, HDL-cholesterol, LDL-cholesterol and diabetes). The investigated plant was collected from different location at Wadi El-Gemal area. The uranium content was determined previously and different concentrations from the fruit with highest uranium content were used to examine the effect of B. aegyptiaca (fruit part) on the glucose, triglycerides, total cholesterol (HDL and LDL-cholesterol) levels using experimental rats. Different analysis techniques were used in order to determine different parameters. The obtained data suggest the beneficial role of B. aegyptiaca fruit as an anti-diabetic and hypo-lipidimic agent.

  10. Photoluminescence studies of ZnO nanorods grown by plasma-assisted molecular beam epitaxy.

    Science.gov (United States)

    Kim, Min Su; Nam, Giwoong; Leem, Jae-Young

    2013-05-01

    Metal catalyst-free ZnO nanorods were grown on PS with buffer layers grown at 450 degrees C by plasma-assisted molecular beam epitaxy. Room temperature and temperature-dependent photoluminescence were carried out to investigate the optical properties of the ZnO nanorods with the average diameter of 120 nm and length of 300 nm. Three emission peaks, free excition, neutral-donor exciton, and free electron-to-neutral acceptor, were observed at 10 K. Huang-Rhys factor S of the ZnO nanorods was 0.978, which is much higher than that of ZnO thin films. The values of Varshni's empirical equation fitting parameters were alpha = 4 x 10(-3) eV/K, beta = 4.1 x 10(4) K, and E9(0) = 3.388 eV and the activation energy was about 96 meV.

  11. Controlling crystal phases in GaAs nanowires grown by Au-assisted molecular beam epitaxy.

    Science.gov (United States)

    Dheeraj, D L; Munshi, A M; Scheffler, M; van Helvoort, A T J; Weman, H; Fimland, B O

    2013-01-11

    Control of the crystal phases of GaAs nanowires (NWs) is essential to eliminate the formation of stacking faults which deteriorate the optical and electronic properties of the NWs. In addition, the ability to control the crystal phase of NWs provides an opportunity to engineer the band gap without changing the crystal material. We show that the crystal phase of GaAs NWs grown on GaAs(111)B substrates by molecular beam epitaxy using the Au-assisted vapor-liquid-solid growth mechanism can be tuned between wurtzite (WZ) and zinc blende (ZB) by changing the V/III flux ratio. As an example we demonstrate the realization of WZ GaAs NWs with a ZB GaAs insert that has been grown without changing the substrate temperature.

  12. Enhancement of the Electrical Properties of CVD-Grown Graphene with Ascorbic Acid Treatment

    Science.gov (United States)

    Tang, Chunmiao; Chen, Zhiying; Zhang, Haoran; Zhang, Yaqian; Zhang, Yanhui; Sui, Yanping; Yu, Guanghui; Cao, Yijiang

    2016-02-01

    Ascorbic acid was used to modify to chemical vapor deposition (CVD)-grown graphene films transferred onto SiO2 substrate. Residual polymer (polymethyl methacrylate), Fe3+, Cl-, H2O, and O2 affected the electrical and thermal properties on graphene during the transfer or device fabrication processes. Exposure of transferred graphene to ascorbic acid resulted in significantly enhanced electrical properties with increased charge carrier mobility. All devices exhibited more than 30% improvement in room temperature carrier mobility in air. The carrier mobility of the treated graphene did not significantly decrease in 21 days. This result can be attributed to electron donation to graphene through the -OH functional group in ascorbic acid that is absorbed in graphene. This work provides a method to enhance the electrical properties of CVD-grown graphene.

  13. ZnS:N and ZnS:N,Ag grown by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Ichino, K.; Kotani, A.; Tanaka, H.; Kawai, T. [Department of Information and Electronics, Tottori University, 4-101 Koyama-minami, Tottori 680-8552 (Japan)

    2010-06-15

    The N-doping conditions have been investigated in the growth of ZnS:N by molecular beam epitaxy using RF plasma of N{sub 2} gas. As a result, high growth temperatures are found to be suitable for the effective incorporation and the activation of N acceptors. The capacitance versus voltage data of the ZnS:N layers grown at around 350 C exhibit p-type behavior, while the undoped layers show an n-type characteristic due to residual donors. ZnS:N,Ag epitaxial layers were also grown to investigate the effect of Ag-co-doping. It is shown that the p-type behavior of the N-doped layers is enhanced by the Ag-co-doping. This suggests the formation of Ag-related complex centers compensating residual donors (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. Optical characteristics of silicon nanowires grown from tin catalyst layers on silicon coated glass

    KAUST Repository

    Ball, Jeremy

    2012-08-20

    The optical characteristics of silicon nanowires grown on Si layers on glass have been modeled using the FDTD (Finite Difference Time Domain) technique and compared with experimental results. The wires were grown by the VLS (vapour-liquid-solid) method using Sn catalyst layers and exhibit a conical shape. The resulting measured and modeled absorption, reflectance and transmittance spectra have been investigated as a function of the thickness of the underlying Si layer and the initial catalyst layer, the latter having a strong influence on wire density. High levels of absorption (>90% in the visible wavelength range) and good agreement between the modeling and experiment have been observed when the nanowires have a relatively high density of ∼4 wires/μ m2. The experimental and modeled results diverge for samples with a lower density of wire growth. The results are discussed along with some implications for solar cell fabrication. © 2012 Optical Society of America.

  15. SiC nanowires grown on activated carbon in a polymer pyrolysis route

    Energy Technology Data Exchange (ETDEWEB)

    Li Gongyi, E-mail: nudtlgy@gmail.co [State Key Laboratory of Advanced Ceramic Fibers and Composites, College of Aerospace and Materials Engineering, National University of Defense Technology, No. 109 Deya Road, Shangdalong Street, Kaifu District, Changsha 410073 (China); Li Xiaodong, E-mail: xdli0153@sina.co [State Key Laboratory of Advanced Ceramic Fibers and Composites, College of Aerospace and Materials Engineering, National University of Defense Technology, No. 109 Deya Road, Shangdalong Street, Kaifu District, Changsha 410073 (China); Wang Hao; Xing Xin; Yang Yong [State Key Laboratory of Advanced Ceramic Fibers and Composites, College of Aerospace and Materials Engineering, National University of Defense Technology, No. 109 Deya Road, Shangdalong Street, Kaifu District, Changsha 410073 (China)

    2010-01-15

    beta-SiC nanowires are a novel type of photocatalysts. However, they tend to be entangled together especially at high concentrations when dispersed in water, which may reduce the photocatalytic activity. It is reasonable to expect that beta-SiC nanowires would provide better photocatalytic activity if they are grown on activated carbon. In the letter we report the successful synthesis of quantities of beta-SiC nanowires grown on the surfaces of the activated carbon by pyrolysis of polycarbosilane at 1300 deg. C. The nanowires, with the diameters of 50-100 nm and the length of tens of micrometers, are composed of single crystal beta-SiC along the <1 1 1> direction. Both the VLS and the VS mechanisms were employed to interpret the nanowires growth.

  16. Roughness of CdTe thin films grown on glass by hot wall epitaxy.

    Science.gov (United States)

    Leal, F F; Ferreira, S O; Menezes-Sobrinho, I L; Faria, T E

    2005-01-12

    Cadmium telluride films were grown on glass substrates using the hot wall epitaxy (HWE) technique. The samples were polycrystalline with a preferential (111) orientation. Scanning electron micrographs reveal a grain size between 0.1 and 0.5 µm. The surface morphology of the samples was studied by measuring the roughness profile using a stylus profiler. The roughness as a function of growth time and scale size were investigated to determine the growth and roughness exponents, β and α, respectively. From the results we can conclude that the growth surface has a self-affine character with a roughness exponent α equal to 0.69 ± 0.03 and almost independent of growth time. The growth exponent β was equal to 0.38 ± 0.06. These values agree with that determined previously for CdTe(111) films grown on GaAs(100).

  17. Electronic properties and strain sensitivity of CVD-grown graphene with acetylene

    Science.gov (United States)

    Yang, Meng; Sasaki, Shinichirou; Ohnishi, Masato; Suzuki, Ken; Miura, Hideo

    2016-04-01

    Although many studies have shown that large-area monolayer graphene can be formed by chemical vapor deposition (CVD) using methane gas, the growth of monolayer graphene using highly reactive acetylene gas remains a big challenge. In this study, we synthesized a uniform monolayer graphene film by low-pressure CVD (LPCVD) with acetylene gas. On the base of Raman spectroscopy measurements, it was found that up to 95% of the as-grown graphene is monolayer. The electronic properties and strain sensitivity of the LPCVD-grown graphene with acetylene were also evaluated by testing the fabricated field-effect transistors (FETs) and strain sensors. The derived carrier mobility and gauge factor are 862-1150 cm2/(V·s) and 3.4, respectively, revealing the potential for high-speed FETs and strain sensor applications. We also investigated the relationship between the electronic properties and the graphene domain size.

  18. Flexible supercapacitor electrodes with vertically aligned carbon nanotubes grown on aluminum foils

    Directory of Open Access Journals (Sweden)

    Itir Bakis Dogru

    2016-06-01

    Full Text Available In this work, vertically aligned carbon nanotubes (VACNTs grown on aluminum foils were used as flexible supercapacitor electrodes. Aluminum foils were used as readily available, cheap and conductive substrates, and VACNTs were grown directly on these foils through chemical vapor deposition (CVD method. Solution based ultrasonic spray pyrolysis (USP method was used for the deposition of the CNT catalyst. Direct growth of VACNTs on aluminum foils ruled out both the internal resistance of the supercapacitor electrodes and the charge transfer resistance between the electrode and electrolyte. A specific capacitance of 2.61 mF/cm2 at a scan rate of 800 mV/s was obtained from the fabricated electrodes, which is further improved through the bending cycles.

  19. Self-organized dots of GaN:Mn grown by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Kuroda, S.; Marcet, S. [CEA-CNRS Group ' ' Nanophysique et Semiconducteurs' ' , Laboratoire de Spectrometrie Physique, Universite Joseph Fourier, Grenoble I and CEA/DRFMC/SP2M, 17 avenue des Martyrs, 38054 Grenoble, Cedex 9 (France); Institute of Materials Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); Halley, D.; Ferrand, D.; Mariette, H. [CEA-CNRS Group ' ' Nanophysique et Semiconducteurs' ' , Laboratoire de Spectrometrie Physique, Universite Joseph Fourier, Grenoble I and CEA/DRFMC/SP2M, 17 avenue des Martyrs, 38054 Grenoble, Cedex 9 (France); Cibert, J. [Laboratoire Louis Neel, CNRS, BP 166, 38042 Grenoble (France); Yamamoto, S.; Sakai, T.; Ohshima, T.; Itoh, H. [Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gumma 370-1292 (Japan)

    2006-07-01

    Self-organized dots of Mn-doped GaN were grown on AlN by plasma-assisted molecular beam epitaxy. The growth was performed in the nitrogen-rich growth regime with the addition of small amount of Mn flux. The in-situ surface observation using reflection high energy electron diffraction (RHEED) and the ex-situ examination using atomic force microscope (AFM) revealed that the dot formation was observed only in the case where the amount of Mn flux was small. The estimate of Mn composition using particle induced X-ray emission (PIXE) experiment showed that the Mn composition in the dots layer was much higher than in thick (Ga,Mn)N layers grown with the same amount of Mn flux. The maximum Mn composition for the high-density dot formation was about x=0.01. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  20. Annealing effects of sapphire substrate on properties of ZnO films grown by magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y.Z. [South China Normal University, School of Physics and Telecommunication Engineering, Guangzhou (China); Xu, J. [Chinese Academy of Sciences, Shanghai Institute of Optics and Fine Mechanics, P.O. Box 800-211, Shanghai (China)

    2007-09-15

    The annealing effects of sapphire substrates on the quality of epitaxial ZnO films grown by dc reactive magnetron sputtering were studied. The atomic steps formed on (0001) sapphire ({alpha}-Al{sub 2}O{sub 3}) substrates surface by annealing at high temperature were analyzed by atomic force microscopy. Their influence on the growth of ZnO films was examined by X-ray diffraction and photoluminescence measurements. Experimental results indicate that the film quality is strongly affected by annealing treatment of the sapphire substrate surface. The optimum annealing temperature of sapphire substrates for ZnO grown by magnetron sputtering is 1400 C for 1 h in air. (orig.)

  1. Diamond films grown without seeding treatment and bias by hot-filament CVD system

    Science.gov (United States)

    Ali, M.; Ürgen, M.

    2012-04-01

    Diamond film growth without seeding treatment has been the subject of numerous studies. In the present study, diamond films with/without seeding treatment were grown on silicon using hot-filament chemical vapour deposition. An inexpensive and simple approach, namely, "dry ultrasonic treatment", was introduced in which full coverage of diamond film was achieved on unseeded substrate. For comparison, one substrate was seeded with 5 μm diamond particles, prior to deposition. The resulting diamond films were examined through standard characterization tools and distinct features were observed in each film. Here we present the results of uniform and high purity diamond film, free from nano-sized grains, which is grown without seeding treatment and is expected to be potential candidate for electro-optical applications, particularly as heat sinks.

  2. Some biomedical applications of Balanites aegyptiaca grown naturally in radioactive area, Southeastern Desert, Egypt.

    Science.gov (United States)

    Morsy, A M A; Ahmad, I A; Kamel, A M

    2010-06-15

    Balanites aegyptiaca is a naturally grown desert plant at some radioactive places in Wadi El-Gemal area, Southeastern Desert. The aim of the present study was to highlight on the B. aegyptiaca species grown naturally at radioactive places in Wadi El-Gemal area (fruit part) on the ability of using the fruit in some biomedical application (glucose, cholesterol, triglycerides, HDL-cholesterol, LDL-cholesterol and diabetes). The investigated plant was collected from different location at Wadi El-Gemal area. The uranium content was determined previously and different concentrations from the fruit with highest uranium content were used to examine the effect of B. aegyptiaca (fruit part) on the glucose, triglycerides, total cholesterol (HDL and LDL-cholesterol) levels using experimental rats. Different analysis techniques were used in order to determine different parameters. The obtained data suggest the beneficial role of B. aegyptiaca fruit as an anti-diabetic and hypo-lipidimic agent.

  3. Health biomarkers in a rat model after intake of organically grown carrots

    DEFF Research Database (Denmark)

    Melballe Jensen, Maja; Jørgensen, Henry; Halekoh, Ulrich

    2012-01-01

    BACKGROUND:Organic foodis perceived as beingofbetter quality andhealthier than conventional foods although the scientific research on organic foodstuffs is highly contradictory. The aim of the present study was to investigate if intake of carrots from four different cultivation systems grown in two...... consecutive years would influence various biomarkers of health in a rat model. All rats were fed a diet with 40% carrot content. The carrots were grown under conventional (C), ‘minimalistic’ organic (O1), organic (O2), or ‘very’ organic cultivation systems (O3). A control group (CO) being fed standard rat......: This well-controlled field study demonstrated no clear influence of cultivation methods or harvest year on the nutritional quality of carrots or effect of cultivation methods on health-related biomarkers in a sensitive rat model. However, the experimental set-up and selected biomarkers could be used...

  4. Edge states of graphene wrinkles in single-layer graphene grown on Ni(111)

    Science.gov (United States)

    Liu, Liwei; Xiao, Wende; Wang, Dongfei; Yang, Kai; Tao, Lei; Gao, Hong-Jun

    2016-10-01

    As quasi-one-dimensional (1D) structures with characteristic widths of nanometer scale, graphene wrinkles (GWs) have been widely observed in graphene grown by chemical vapor deposition. Similar to conventional 1D graphene-based nanostructures, e.g., carbon nanotubes and graphene nanoribbons, 1D electron confinement has been observed in the GWs. However, it remains an open question whether the GWs have effective edges and exhibit corresponding edge states. Here, we report on the edge states of the GWs in single-layer graphene grown on Ni(111) by means of low temperature scanning tunneling microscopy and spectroscopy. We show that the GWs are decoupled from the substrate, while the surrounding planar graphene are strongly coupled with the substrate. The different graphene-substrate coupling leads to effective edges and 1D character of the GWs. The chiral edges of the GWs give rise to pronounced edge states around the Fermi level in the density of states.

  5. Electrochemical properties of seamless three-dimensional carbon nanotubes-grown graphene modified with horseradish peroxidase.

    Science.gov (United States)

    Komori, Kikuo; Terse-Thakoor, Trupti; Mulchandani, Ashok

    2016-10-01

    Horseradish peroxidase (HRP) was immobilized through sodium dodecyl sulfate (SDS) on the surface of a seamless three-dimensional hybrid of carbon nanotubes grown at the graphene surface (HRP-SDS/CNTs/G) and its electrochemical properties were investigated. Compared with graphene alone electrode modified with HRP via SDS (HRP-SDS/G electrode), the surface coverage of electroactive HRP at the CNTs/G electrode surface was approximately 2-fold greater because of CNTs grown at the graphene surface. Based on the increase in the surface coverage of electroactive HRP, the sensitivity to H2O2 at the HRP-SDS/CNTs/G electrode was higher than that at the HRP-SDS/G electrode. The kinetics of the direct electron transfer from the CNTs/G electrode to compound I and II of modified HRP was also analyzed.

  6. Uranium immobilization by sulfate-reducing biofilms grown on hematite, dolomite, and calcite.

    Science.gov (United States)

    Marsili, Enrico; Beyenal, Haluk; Di Palma, Luca; Merli, Carlo; Dohnalkova, Alice; Amonette, James E; Lewandowski, Zbigniew

    2007-12-15

    Biofilms of sulfate-reducing bacteria Desulfovibrio desulfuricans G20 were used to reduce dissolved U(VI) and subsequently immobilize U(IV) in the presence of uranium-complexing carbonates. The biofilms were grown in three identically operated fixed bed reactors, filled with three types of minerals: one noncarbonate-bearing mineral (hematite) and two carbonate-bearing minerals (calcite and dolomite). The source of carbonates in the reactors filled with calcite and dolomite were the minerals, while in the reactor filled with hematite it was a 10 mM carbonate buffer, pH 7.2, which we added to the growth medium. Our five-month study demonstrated that the sulfate-reducing biofilms grown in all reactors were able to immobilize/reduce uranium efficiently, despite the presence of uranium-complexing carbonates.

  7. Do CVD grown graphene films have antibacterial activity on metallic substrates?

    CERN Document Server

    Dellieu, Louis; Reckinger, Nicolas; Didembourg, Christian; Letesson, Jean-Jacques; Sarrazin, Michael; Deparis, Olivier; Matroule, Jean-Yves; Colomer, Jean-François

    2014-01-01

    Accurate assessment of the antibacterial activity of graphene requires consideration of both the graphene fabrication method and, for supported films, the properties of the substrate. Large-area graphene films produced by chemical vapor deposition were grown directly on copper substrates or transferred on a gold substrate and their effect on the viability and proliferation of the Gram-positive bacteria Staphylococcus aureus and the Gram-negative bacteria Escherichia coli were assessed. The viability and the proliferation of both bacterial species were not affected when they were grown on a graphene film entirely covering the gold substrate, indicating that conductivity plays no role on bacterial viability and graphene has no antibacterial activity against S. aureus and E. coli. On the other hand, antibacterial activity was observed when graphene coated the copper substrates, resulting from the release of bactericidal cupric ions in inverse proportion to the graphene surface coverage.

  8. Bioaccumulations of heavy metals in Ipomoea aquatica grown in bottom ash recycling wastewater.

    Science.gov (United States)

    Milla, Odette Varela; Rivera, Eva B; Huang, Wu-Jang

    2014-05-01

    A plant bioassay using hydroponically grown Ipomoea aquatica (water spinach) was applied to assess the phytotoxicity of untreated and treated wastewaters from a municipal solid waste incineration bottom ash recycling facility. The 50%-diluted, untreated wastewater exhibited acute toxicity (plants died within 24 hours). Highly diluted doses (3 and 6%) of both wastewater types displayed no significant differences when compared with the control. Treating the wastewater through sequential physical filtration and chemical precipitation processes decreased not only the dissolved solids content but also the pH and salt content. In addition, significant accumulations of Sr, Cr, and Sn were observed in the hydroponically grown I. aquatica plant tissues; in particular, the bioaccumulation of Sr in the leaves and roots was unexpectedly high.

  9. Stress, structural and electrical properties of Si-doped GaN film grown by MOCVD

    Institute of Scientific and Technical Information of China (English)

    Xu Zhihao; Zhang Jincheng; Duan Huantao; Zhang Zhongfen; Zhu Qingwei; Xu Hao; Hao Yue

    2009-01-01

    The stresses, structural and electrical properties of n-type Si-doped GaN films grown by metalorganic chemical vapor deposition (MOCVD) are systemically studied. It is suggested that the main stress relaxation is induced by bending dislocations in low doping samples. But for higher doping samples, as the Si doping concentration increases, the in-plane stresses in the grown films are quickly relaxed due to the rapid increase of the edge dislocation densities. Hall effect measurements reveal that the carrier mobility first increases rapidly and then decreases with increasing Si doping concentration. This phenomenon is attributed to the interaction between various scattering process. It is suggested that the dominant scattering process is defect scattering for low doping samples and ionized impurity scattering for high doping samples.

  10. Functionalizing single crystals: incorporation of nanoparticles inside gel-grown calcite crystals.

    Science.gov (United States)

    Liu, Yujing; Yuan, Wentao; Shi, Ye; Chen, Xiaoqiang; Wang, Yong; Chen, Hongzheng; Li, Hanying

    2014-04-14

    Synthetic single crystals are usually homogeneous solids. Biogenic single crystals, however, can incorporate biomacromolecules and become inhomogeneous solids so that their properties are also extrinsically regulated by the incorporated materials. The discrepancy between the properties of synthetic and biogenic single crystals leads to the idea to modify the internal structure of synthetic crystals to achieve nonintrinsic properties by incorporation of foreign material. Intrinsically colorless and diamagnetic calcite single crystals are turned into colored and paramagnetic solids, through incorporation of Au and Fe3O4 nanoparticles without significantly disrupting the crystalline lattice of calcite. The crystals incorporate the nanoparticles and gel fibers when grown in agarose gel media containing the nanoparticles, whereas the solution-grown crystals do not. As such, our work extends the long-history gel method for crystallization into a platform to functionalize single-crystalline materials.

  11. Ordered silicon microwire arrays grown from substrates patterned using imprint lithography and electrodeposition.

    Science.gov (United States)

    Audesirk, Heather A; Warren, Emily L; Ku, Jessie; Lewis, Nathan S

    2015-01-28

    Silicon microwires grown by the vapor-liquid-solid process have attracted a great deal of interest as potential light absorbers for solar energy conversion. However, the research-scale techniques that have been demonstrated to produce ordered arrays of micro and nanowires may not be optimal for use as high-throughput processes needed for large-scale manufacturing. Herein we demonstrate the use of microimprint lithography to fabricate patterned templates for the confinement of an electrodeposited Cu catalyst for the vapor-liquid-solid (VLS) growth of Si microwires. A reusable polydimethylsiloxane stamp was used to pattern holes in silica sol-gels on silicon substrates, and the Cu catalyst was electrodeposited into the holes. Ordered arrays of crystalline p-type Si microwires were grown across the sol-gel-patterned substrates with materials quality and performance comparable to microwires fabricated with high-purity metal catalysts and cleanroom processing.

  12. Selenium Accumulation and Antioxidant Status of Rice Plants Grown on Seleniferous Soil from Northwestern India

    Institute of Scientific and Technical Information of China (English)

    Sucheta SHARMA; Reeti GOYAL; Upkar Singh SADANA

    2014-01-01

    Greenhouse experiment was conducted to investigate selenium accumulation and its antioxidant response in two rice varieties (PR116 and Pusa Basmati 1121) grown on normal and seleniferous soils. The plant growth was reduced at early developmental stages and flowering was delayed by a period of 10 d on seleniferous soil. Selenium accumulation increased by 3–20 and 13–14 folds in leaves, 18 and 3 folds in grains from Pusa Basmati 1121 and PR116 varieties, respectively. Selenium accumulation in leaves from rice plants grown on seleniferous soil resulted in significant increase in chlorophyll content, hydrogen peroxide, proline, free amino acids, total phenol and tannin contents. Lipid peroxidation levels and peroxidase activities in leaves increased whereas catalase activity showed a reverse trend. It is concluded that selenium accumulation decreased dry matter content in rice during crop development but these plants were able to combat selenium toxicity by inducing alterations in their defense system.

  13. Bond strength of individual carbon nanotubes grown directly on carbon fibers.

    Science.gov (United States)

    Kim, Kyoung Ju; Lee, Geunsung; Kim, Sung-Dae; Kim, Seong-Il; Youk, Ji Ho; Lee, Jinyong; Kim, Young-Woon; Yu, Woong-Ryeol

    2016-10-07

    The performance of carbon nanotube (CNT)-based devices strongly depends on the adhesion of CNTs to the substrate on which they were directly grown. We report on the bond strength of CNTs grown on a carbon fiber (T700SC Toray), measured via in situ pulling of individual CNTs inside a transmission electron microscope. The bond strength of an individual CNT, obtained from the measured pulling force and CNT cross-section, was very high (∼200 MPa), 8-10 times higher than that of an adhesion model assuming only van der Waals interactions (25 MPa), presumably due to carbon-carbon interactions between the CNT (its bottom atoms) and the carbon substrate.

  14. Double acceptor in p-type GaAsN grown by chemical beam epitaxy

    Science.gov (United States)

    Elleuch, Omar; Wang, Li; Lee, Kan-Hua; Ikeda, Kazuma; Kojima, Nobuaki; Ohshita, Yoshio; Yamaguchi, Masafumi

    2015-12-01

    The properties of the acceptor states in GaAsN grown by chemical beam epitaxy (CBE) are studied by analyzing their charges based on the Poole-Frenkel model. Deep level transient spectroscopy (DLTS) shows two acceptor levels at 0.11 and 0.19 eV above the valence band maximum. The emission rates of carriers from these states are enhanced with increasing the electric field during the DLTS measurement, which indicates that the energies required for the emission are decreased. By analyzing this field-enhanced emission process, the polarizabilities of the levels at 0.11 and 0.19 eV are found to be -1 (±0.1) and -2 (±0.1), respectively. In addition, these states have almost the same concentration. Therefore, we conclude that they originate from the same defect, acting as a double acceptor in GaAsN film grown by CBE.

  15. Thermoelectric properties of Tl-doped PbTeSe crystals grown by directional solidification

    Science.gov (United States)

    Su, Ching-Hua

    2016-04-01

    Three Tl-doped PbTe and two Tl-doped PbTeSe crystals were grown by vertical un-seeded directional solidification method. Among them, two Tl-doped PbTe ingots, with starting composition of (Pb0.99Tl0.01)Te, were grown under Pb or Te pressure over the melt provided by a Pb or Te reservoir, respectively, whereas another ingot, with starting composition of (Pb0.98Tl0.02)Te, was grown under Te overpressure. Two Tl-doped PbTeSe crystals, with starting composition of (Pb0.98Tl0.02)(Te0.85Se0.15) and (Pb0.96Tl0.04)(Te0.85Se0.15), were grown without any over-pressure. Disk-shaped samples were sliced at different locations along the growth axis and their thermal conductivities were determined from thermal diffusivity, density, and heat capacity measurements. The electrical conductivity and Seebeck coefficient were simultaneously measured as a function of temperature for each disk sample. The Figure of Merit for the thermoelectric application, zT, was calculated from these properties from room temperature to about 640 °C. The Tl-doped PbTeSe samples have the highest zT value of 1.63 at temperature range of 425 to 475 °C, comparing to 1.13 at 410 °C for the Tl-doped PbTe samples. By substituting 15% of the Te atoms in the Tl-doped PbTe by Se atoms, the Figure of Merit of PbTeSe was enhanced by reducing the thermal conductivity about 26% and, at the same time, increasing the electrical conductivity by 43%.

  16. The effects of nutrient solution sterilization on the growth and yield of hydroponically grown lettuce

    Science.gov (United States)

    Schwartzkopf, S. H.; Dudzinski, D.; Minners, R. S.

    1987-01-01

    Two methods of removing bacteria from hydroponic nutrient solution [ultraviolet (UV) radiation and submicronic filter] were evaluated for efficiency and for their effects on lettuce (Lactuca sativa L.) production. Both methods were effective in removing bacteria; but, at high intensity, the ultraviolet sterilizer significantly inhibited the production of plants grown in the treated solution. Bacterial removal by lower intensity UV or a submicronic filter seemed to promote plant growth slightly, but showed no consistent, statistically significant effect.

  17. Nutritional properties of cherry tomatoes harvested at different times and grown in an organic cropping.

    OpenAIRE

    Pinho, L.; Almeida, A. C.; Costa, C.A.; PAES, M. C. D.; M.B.A. Glória; Souza, R. M.

    2011-01-01

    The physicochemical characteristics of the cherry tomato cultivated in organic and conventional production systems and harvested at either 30 or 45 days of cropping were evaluated using a randomized, 2x2 factorial design (2 cropping systems x 2 harvesting times) with five repetitions. The parameters analyzed were color, centesimal composition, total energetic value, carotenoids and bioactive amine content. Tomatoes harvested at 30 days had higher total soluble solid (TSS) content when grown c...

  18. An Investigation into Factors Influencing the Sensory Properties of Selected Irish Grown Organic and Conventional Vegetables

    OpenAIRE

    Gilsenan, Clare

    2010-01-01

    Research studies conducted on organic produce have given conflicting results whether they have superior sensory qualities when compared to conventionally cultivated produce. The development and implementation of a reliable testing system is therefore required. In this study Irish grown organic and conventional carrots (cv. Nairobi), potatoes (cv. Orla) and tomatoes (cv. Amoroso) were selected for physicochemical (size, colour, dry matter, texture, sugars, oBrix & pH), volatile emissions and s...

  19. The characteristics of carbon nanotubes grown at low temperature for electronic device application

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yong Seob [Department of Photoelectronics Information, Chosun College of Science and Technology, Gwangju (Korea, Republic of); Yi, Junsin [School of Information and Communications Engineering, Sungkyunkwan University, Suwon, 440–746 (Korea, Republic of); Lee, Jaehyeong, E-mail: jaehyeong@skku.edu [School of Information and Communications Engineering, Sungkyunkwan University, Suwon, 440–746 (Korea, Republic of)

    2013-11-01

    For the application of carbon nanotubes (CNTs) in flexible electronic devices, the CNTs were grown on Corning 1737 glass substrate by microwave plasma enhanced chemical vapor deposition (MPECVD) method. To deposit the catalyst layer, TiN buffer layer of 200 nm thickness and Ni catalyst layer of 60 nm were first deposited on the glass by r.f. magnetron sputtering method. The CH{sub 4} and H{sub 2} gases are used as the synthesis gas of CNTs and the working pressure was about 2.13 kPa, and the substrate bias was about − 200 V. The growth time was from 2 min to 5 min and the microwave power was about 800 W. The substrate temperature as the main parameter was changed from 400 °C to 550 °C. The structural properties of CNTs synthesized with the substrate temperature were investigated using Raman, field emission scanning electron microscopy, and transmission electron microscopy methods. The surface and electrical properties of CNTs grown by MPECVD method were studied by scanning probe microscopy and four-point probe methods. We obtained the multi-walled CNTs (MW-CNTs). Multi-walled CNTs were vertically grown on Ni/TiN/glass substrates below 500 °C without any glass deformations. As the substrate temperature was increased, the crystallinity of CNTs was improved. Ni catalyst was found at the tip of CNT by the TEM observation and the grown CNTs were found to have a multi-walled with bamboo like structure. - Highlights: • Synthesis of vertically aligned carbon nanotubes. • Effects of substrate temperature on carbon nanotubes properties. • Improvement of the crystallinity with increasing substrate temperature. • Reduction of sheet resistance with increasing substrate temperature.

  20. Sublimation process and physical properties of vapor grown γ-In2Se3 platelet crystals

    Science.gov (United States)

    Ajayakumar, C. J.; Kunjomana, A. G.

    2016-11-01

    Indium selenide (γ-In2Se3) crystals have been grown by the closed tube sublimation process in the absence of seed crystals and chemical transporting agents. The composition, structure and morphology of the samples grown under different vacuum conditions were examined by energy dispersive analysis, X-ray diffraction, and scanning electron microscope. Structural features of the crystals obtained in a vacuum of 10-3 mbar exhibited a few reflections not belonging to γ phase, whereas X-ray diffraction spectra of the crystals deposited under a vacuum of 10-6 mbar revealed evidence of sharp peaks with high intensities of γ-In2Se3 crystalline phase. When growth runs were performed for 72 h, voids were observed on the surface whereas for a duration of 120 h, platelet crystals were obtained. Optical properties of these samples were investigated using the FT-IR and photoluminescence spectroscopy. The average transmittance of the platelets in the visible and near infrared region of solar spectrum was found to be ∼81% and an optical band gap of ∼2.05 eV was computed from the transmission spectrum. Photoluminescence spectra of the grown In2Se3 crystals recorded at room temperature using an excitation laser of wavelength 355 nm showed a peak in the near band edge emission (NBE) corresponding to an energy of 2.01 eV. Under an illumination power of 12 mW/cm2, the photocurrent increased linearly with applied voltage and the dark current was found to be 2.5×10-9 A for 10 V. These results suggest that the as-grown γ-In2Se3 platelets crystallized from vapor deposition, possess superior optoelectronic properties than the other phases for solar cell applications.

  1. Epitaxial gamma-iron silicide grown on single-crystal Si. A summary of Moessbauer results

    Energy Technology Data Exchange (ETDEWEB)

    Desimoni, J.; Sanchez, F.H

    1998-08-15

    Metastable {gamma}-FeSi{sub 2} grown on or into single-crystals of silicon can be produced by different techniques as molecular beam epitaxy, and ion implantation followed by ion beam induced epitaxial crystallisation. In these investigations, Moessbauer effect has been used to provide short range order information about the system. We present here a summary of these results, which will be compared and discussed.

  2. Properties of boron-doped epitaxial diamond layers grown on (110) oriented single crystal substrates

    OpenAIRE

    Mortet, Vincent; Pernot, J.; Jomard, F.; Soltani, A; Remes, Zdenek; Barjon, Julien; D'Haen, J; Haenen, Ken

    2015-01-01

    Boron doped diamond layers have been grown on (110) single crystal diamond substrates with B/C ratios up to 20 ppm in the gas phase. The surface of the diamond layers observed by scanning electron microscopy consists of (100) and (113) micro-facets. Fourier Transform Photocurrent Spectroscopy indicates substitutional boron incorporation. Electrical properties were measured using Hall effect from 150 to 1000 K. Secondary ion mass spectrometry analyses are consistent with the high incorporation...

  3. Plasma-mediated inactivation of Pseudomonas aeruginosa biofilms grown on borosilicate surfaces under continuous culture system.

    Science.gov (United States)

    Vandervoort, Kurt G; Brelles-Mariño, Graciela

    2014-01-01

    Biofilms are microbial communities attached to a surface and embedded in a matrix composed of exopolysaccharides and excreted nucleic acids. Bacterial biofilms are responsible for undesirable effects such as disease, prostheses colonization, biofouling, equipment damage, and pipe plugging. Biofilms are also more resilient than free-living cells to regular sterilization methods and therefore it is indispensable to develop better ways to control and remove them. The use of gas discharge plasmas is a good alternative since plasmas contain a mixture of reactive agents well-known for their decontamination potential against free microorganisms. We have previously reported that Pseudomonas aeruginosa biofilms were inactivated after a 1-min plasma exposure. We determined that the adhesiveness and the thickness of Pseudomonas biofilms grown on borosilicate were reduced. We also reported sequential morphological changes and loss of viability upon plasma treatment. However, the studies were carried out in batch cultures. The use of a continuous culture results in a more homogenous environment ensuring reproducible biofilm growth. The aim of this work was to study plasma-mediated inactivation of P. aeruginosa biofilms grown on borosilicate in a continuous culture system. In this paper we show that biofilms grown on glass under continuous culture can be inactivated by using gas discharge plasma. Both biofilm architecture and cell culturability are impacted by the plasma treatment. The inactivation kinetics is similar to previously described ones and cells go through sequential changes ranging from minimal modification without loss of viability at short plasma exposure times, to major structure and viability loss at longer exposure times. We report that changes in biofilm structure leading to the loss of culturability and viability are related to a decrease of the biofilm matrix adhesiveness. To our knowledge, there has been no attempt to evaluate the inactivation

  4. High Luminescence Efficiency in MoS2 Grown by Chemical Vapor Deposition.

    Science.gov (United States)

    Amani, Matin; Burke, Robert A; Ji, Xiang; Zhao, Peida; Lien, Der-Hsien; Taheri, Peyman; Ahn, Geun Ho; Kirya, Daisuke; Ager, Joel W; Yablonovitch, Eli; Kong, Jing; Dubey, Madan; Javey, Ali

    2016-07-26

    One of the major challenges facing the rapidly growing field of two-dimensional (2D) transition metal dichalcogenides (TMDCs) is the development of growth techniques to enable large-area synthesis of high-quality materials. Chemical vapor deposition (CVD) is one of the leading techniques for the synthesis of TMDCs; however, the quality of the material produced is limited by defects formed during the growth process. A very useful nondestructive technique that can be utilized to probe defects in semiconductors is the room-temperature photoluminescence (PL) quantum yield (QY). It was recently demonstrated that a PL QY near 100% can be obtained in MoS2 and WS2 monolayers prepared by micromechanical exfoliation by treating samples with an organic superacid: bis(trifluoromethane)sulfonimide (TFSI). Here we have performed a thorough exploration of this chemical treatment on CVD-grown MoS2 samples. We find that the as-grown monolayers must be transferred to a secondary substrate, which releases strain, to obtain high QY by TFSI treatment. Furthermore, we find that the sulfur precursor temperature during synthesis of the MoS2 plays a critical role in the effectiveness of the treatment. By satisfying the aforementioned conditions we show that the PL QY of CVD-grown monolayers can be improved from ∼0.1% in the as-grown case to ∼30% after treatment, with enhancement factors ranging from 100 to 1500× depending on the initial monolayer quality. We also found that after TFSI treatment the PL emission from MoS2 films was visible by eye despite the low absorption (5-10%). The discovery of an effective passivation strategy will speed the development of scalable high-performance optoelectronic and electronic devices based on MoS2.

  5. Change in dry matter and nutritive composition of Brachiaria humidicola grown in Ban Thon soil series

    OpenAIRE

    2008-01-01

    This experiment was conducted to determine the change in dry matter and nutritive composition of Humidicola grass (Brachiaria humidicola) grown in Ban Thon soil series (infertility soil) as a function of growth age. One rai (0.16 ha) of two-year-old pasture of fertilised Humidicola grass was uniformly cut and the regrowth samples were collected every twenty days. The samples were subjected to analysis for dry matter content and nutritive composition, i.e. crude protein, ash, calcium, phosphor...

  6. Structural and magnetic properties of Gd/Fe multilayers grown by pulsed laser deposition

    DEFF Research Database (Denmark)

    Kant, K. Mohan; Bahl, Christian Robert Haffenden; Pryds, Nini

    2010-01-01

    This work investigates the structural and the magnetic properties of Gd/Fe multilayered thin films grown by pulsed laser deposition onto Si (001) substrates at room temperature. he Fe layer thickness is varied from 70 to 150 nm and its effect on the structural and magnetic properties of Fe....../Gd/Fe sandwich multilayers has been explored. Gd films were found to change from amorphous to polycrystalline at a critical thickness of 20 nm....

  7. Effect of Crucibles on Qualities of Self-Seeded Aluminium Nitride Crystals Grown by Sublimation

    Institute of Scientific and Technical Information of China (English)

    HAN Qi-Feng; WANG Yu-Qi; DUAN Cheng-Hong; QIU Kai; JI Chang-Jian; LI Xin-Hua; ZHONG Fei; YIN Zhi-Jun; CAO Xian-Cun; ZHOU Xiu-Ju

    2007-01-01

    Self-seeded aluminium nitride (AIN)crystals are grown in tungsten and hot pressed boron nitride(HPBN)crucibles With different shapes by a sublimation method.The qualities of the AIN crystals are characterized by high-resolution transmission electronic microscopy(HRTEM),scanning electron microscopy(SEM)and MicroRaman spectroscopy.The results indicate that the better quality crystals can be collected in.conical tungsten crucible.

  8. Thermal efficiency and particulate pollution estimation of four biomass fuels grown on wasteland

    Energy Technology Data Exchange (ETDEWEB)

    Kandpal, J.B.; Madan, M. [Indian Inst. of Tech., New Delhi (India). Centre for Rural Development and Technology

    1996-10-01

    The thermal performance and concentration of suspended particulate matter were studied for 1-hour combustion of four biomass fuels, namely Acacia nilotica, Leucaena leucocepholea, Jatropha curcus, and Morus alba grown in wasteland. Among the four biomass fuels, the highest thermal efficiency was achieved with Acacia nilotica. The suspended particulate matter concentration for 1-hour combustion of four biomass fuels ranged between 850 and 2,360 {micro}g/m{sup 3}.

  9. Pure electron-electron dephasing in percolative aluminum ultrathin film grown by molecular beam epitaxy.

    Science.gov (United States)

    Lin, Shih-Wei; Wu, Yue-Han; Chang, Li; Liang, Chi-Te; Lin, Sheng-Di

    2015-01-01

    We have successfully grown ultrathin continuous aluminum film by molecular beam epitaxy. This percolative aluminum film is single crystalline and strain free as characterized by transmission electron microscopy and atomic force microscopy. The weak anti-localization effect is observed in the temperature range of 1.4 to 10 K with this sample, and it reveals that, for the first time, the dephasing is purely caused by electron-electron inelastic scattering in aluminum.

  10. Mn2Au: body-centered-tetragonal bimetallic antiferromagnets grown by molecular beam epitaxy.

    Science.gov (United States)

    Wu, Han-Chun; Liao, Zhi-Min; Sofin, R G Sumesh; Feng, Gen; Ma, Xiu-Mei; Shick, Alexander B; Mryasov, Oleg N; Shvets, Igor V

    2012-12-11

    Mn(2)Au, a layered bimetal, is successfully grown using molecular beam epitaxy (MBE). The experiments and theoretical calculations presented suggest that Mn(2)Au film is antiferromagnetic with a very low critical temperature. The antiferromagnetic nature is demonstrated by measuring the exchange-bias effect of Mn(2)Au/Fe bilayers. This study establishes a primary basis for further research of this new antiferromagnet in spin-electronic device applications.

  11. Usability value and heavy metals accumulation in forage grasses grown on power station ash deposit

    Directory of Open Access Journals (Sweden)

    Simić Aleksandar S.

    2015-01-01

    Full Text Available The study of five forage grasses (Lolium multiflorum, Festuca rubra, Festuca arundinacea, Arrhenatherum elatius and Dactylis glomerata was conducted on an uncontaminated cultivated land, of leached chernozem type, and on “Nikola Tesla A” (TENT A thermal power station ash deposit. The concentrations of: As, Pb, Cd, Zn, Ni, Fe i Cu in grasses grown on two media were compared. Grass samples have been collected in tillering stage, when they were in full development. During the vegetative period three replications cut was conducted at about 3-5 cm height, imitating mowing and grazing. The concentrations of As and Ni were elevated in media samples collected from TENT A ash deposit, while the level of all studied elements in soil samples collected from cultivated land were within allowed limits. The variance of certain elements amounts in plant material collected from TENT A ash deposit was less homogeneous; the concentrations of As, Fe and Ni were higher in grasses collected from ash deposit, but Pb and Cu concentrations were higher in grasses grown on cultivated land. The concentrations of Zn were approximately the same in plants collected from the sites, whereas Cd concentrations were slightly increased in grasses grown on ash deposit. In general, it can be concluded from the results of this study that the concentrations of heavy metals in plants collected from both sites do not exceed maximal tolerant levels for fodder. The use of grasses grown on ash deposit for forage production should be taken with reserve. [Projekat Ministarstva nauke Republike Srbije, br. TR 31016: Unapređenje tehnologije gajenja krmnih biljaka na oranicama i travnjacima

  12. Trace element toxicity in VA mycorrhizal cucumber grown on weathered coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Dosskey, M.G.; Adriano, D.C. (University of Georgia, Aiken, SC (United States). Savannah River Ecology Lab.)

    1993-11-01

    Mycorrhizal colonization is widely recognized as enhancing plant growth on severely disturbed sites. A greenhouse pot experiment was conducted to determine if inoculation with vesicular-arbuscular mycorrhizal (VAM) fungi will enhance vegetation establishment on abandoned coal fly ash basinss, Spores of Glomus intraradices (Schenck and Smith) and Glomus etunicatum (Becker and Gerdemann) were added to weathered precipitator ash (EC-0.91 dSm[sup -1], pH 5.0) and to a pasteurized soils of the same pH (Grossarenic Paleudult, 92% sand, 1% organic matter). Some soil and ash were left unamended as non-mycorrhizal controls. Cucumber (Cucumis sativus L. cv. Poinsette 76) seeds were sown, watered regularly, and fertilized periodically with macronutrient solution. By 8 weeks all ash-grown plants exhibited smaller leaves with leaf margin curl and necrosis, and plant biomass was significantly less (0.75x) than soil-grown plants. Based on analysis of 18 elements in plant tissues, toxicity to B, Mn, or Zn could have caused growth suppression, confirming trace element problems for plant growth on fly ash. For plants grown on fly ash, G. etunicatum was the only fungus that colonized roots (20% of root length reduced from 67% on soil) and it suppressed plant growth to 0.80 x that of uninoculated ash-grown plants. Correspondingly, shoot Zn concentration in G. etunicatum-inoculated plants was 3.5 x higher than in uninoculated plants and at generally toxic levels (273 mg kg[sup -1]). Glomus etunicatum had no other significant effects on elemental concentrations. These results indicate that VAM colonization in acid, weathered fly ash suppressed plant growth by facilitating uptake of Zn to toxic levels, and implies a limitation to successful use of VAM for vegetation establishment on abandoned coal fly ash basins.

  13. Sensory quality of turnip greens and turnip tops grown in northwestern Spain

    OpenAIRE

    Francisco Candeira, Marta; Velasco Pazos, Pablo; Romero, Ángeles; Vázquez, Lourdes; Cartea González, María Elena

    2009-01-01

    In Galicia (northwestern Spain), Brassica rapa var. rapa L. includes turnip greens and turnip tops as vegetable products. They are characterized by a particular sulfurous aroma, pungent flavor, and a bitter taste. In this work twelve local varieties grown as turnip greens and turnip tops were evaluated to define the sensory attributes, to relate them with secondary metabolites, and to select those sensorial traits that better describe these crops. Results showed differences in the sensory pro...

  14. Plasma-mediated inactivation of Pseudomonas aeruginosa biofilms grown on borosilicate surfaces under continuous culture system.

    Directory of Open Access Journals (Sweden)

    Kurt G Vandervoort

    Full Text Available Biofilms are microbial communities attached to a surface and embedded in a matrix composed of exopolysaccharides and excreted nucleic acids. Bacterial biofilms are responsible for undesirable effects such as disease, prostheses colonization, biofouling, equipment damage, and pipe plugging. Biofilms are also more resilient than free-living cells to regular sterilization methods and therefore it is indispensable to develop better ways to control and remove them. The use of gas discharge plasmas is a good alternative since plasmas contain a mixture of reactive agents well-known for their decontamination potential against free microorganisms. We have previously reported that Pseudomonas aeruginosa biofilms were inactivated after a 1-min plasma exposure. We determined that the adhesiveness and the thickness of Pseudomonas biofilms grown on borosilicate were reduced. We also reported sequential morphological changes and loss of viability upon plasma treatment. However, the studies were carried out in batch cultures. The use of a continuous culture results in a more homogenous environment ensuring reproducible biofilm growth. The aim of this work was to study plasma-mediated inactivation of P. aeruginosa biofilms grown on borosilicate in a continuous culture system. In this paper we show that biofilms grown on glass under continuous culture can be inactivated by using gas discharge plasma. Both biofilm architecture and cell culturability are impacted by the plasma treatment. The inactivation kinetics is similar to previously described ones and cells go through sequential changes ranging from minimal modification without loss of viability at short plasma exposure times, to major structure and viability loss at longer exposure times. We report that changes in biofilm structure leading to the loss of culturability and viability are related to a decrease of the biofilm matrix adhesiveness. To our knowledge, there has been no attempt to evaluate the

  15. Purification of Single-walled Carbon Nanotubes Grown by a Chemical Vapour Deposition (CVD) Method

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A procedure for purification of single-walled carbon nanotubes(SWNTs) grown by the chemical vapour deposition (CVD) of carbon monooxide has been developed. Based on the result from TGA/DTA of as-prepared sample, the oxidation temperature was determined. The process included sonication, oxidation and acid washing steps. The purity and yield after purification were determined and estimated by TEM. Moreover, for the first time, a loop structure for CVD SWNTs has been observed.

  16. Characterization of Femtosecond Low-Temperature-Grown GaAs Photoconductive Switch

    Institute of Scientific and Technical Information of China (English)

    林位株; 刘智刚; 廖睿; 张海潮; 郭冰; 文锦辉; 赖天树

    2002-01-01

    A photoconductive response time, as short as 350 fs, of a low-temperature-grown GaAs (LT-GaAs) micro-coplanar photoconductive switch has been measured and modelled to the ultrafast trapping of the photoexcited carriers in LT-GaAs. The coherent interference of the pump and probe pulses results in a narrow spike photocurrent autocorrelation signal which maps the femtosecond optical pulses.

  17. Single crystals of bismuth silicon oxide grown by the Czochralski technique and their characterisation

    Directory of Open Access Journals (Sweden)

    ANDREJA VALCIC

    1999-09-01

    Full Text Available Single crystals of Bi12SiO20 were grown by the Czochralski technique. The critical diameter and the critical rate of rotation were calculated. Suitable polishing and etching solutions were determined. X-Ray measurements were performed on powdered samples to obtain the lattice parameters. The optical properties of the bismuth silicon oxide single crystals were investigated. The obtained results are discussed and compared with published data.

  18. Physico-Chemical Properties, Antioxidant Activity and Mineral Contents of Pineapple Genotypes Grown in China

    OpenAIRE

    Xin-Hua Lu; De-Quan Sun; Qing-Song Wu; Sheng-Hui Liu; Guang-Ming Sun

    2014-01-01

    The fruit physico-chemical properties, antioxidant activity and mineral contents of 26 pineapple [Ananas comosus (L.) Merr.] genotypes grown in China were measured. The results showed great quantitative differences in the composition of these pineapple genotypes. Sucrose was the dominant sugar in all 26 genotypes, while citric acid was the principal organic acid. Potassium, calcium and magnesium were the major mineral constituents. The ascorbic acid (AsA) content ranged from 5.08 to 33.57 mg/...

  19. Microhardness Indentation Size Effect in Flux-grown Crystals of Rare Earth Aluminates

    Institute of Scientific and Technical Information of China (English)

    Jianghong GONG; Zhenduo GUAN

    2001-01-01

    The previously reported results of microhardness measurements on flux-grown crystals of rare earth aluminates were re-examined in this paper to explore the applicability of the proportional specimen resistance (PSR) model to describe the indentation size effect. It was found that the PSR model is insufficient for describing the experimental data and a modified form of this model was proposed based on the consideration of the effect of surface stress state on hardness testing.

  20. Dislocation reduction in HgCdTe grown on CdTe/Si

    Science.gov (United States)

    Wijewarnasuriya, Priyalal S.

    2016-05-01

    Bulk-grown CdZnTe (Zn = 3%) substrates are the natural choice for HgCdTe epitaxy since it is lattice matched to long wave LW-HgCdTe alloy. However, lack of large area CdZnTe substrates, high production costs, and more importantly, the difference in thermal expansion coefficients between CdZnTe and silicon Read out Integrated Circuits (ROIC) are some of the inherent drawbacks of CdZnTe substrates. Consequently, Hg1-xCdxTe detectors fabricated on silicon substrates are an attractive alternative. Recent developments in the molecular beam epitaxy (MBE) buffer layer growth technology on Si substrates has revolutionized the HgCdTe research and offered a new dimension to HgCdTe-based IR technology. Si substrates provide advantages in terms of relatively large area (3 to 6-inch diameter is easily obtained) compared to CZT substrate materials, durability during processing, and reliability to thermal cycling. Innovations in Si-based composite substrates made it possible to fabricate very large-format IR arrays that offer higher resolution, low-cost arrays and more dies per wafer. Between Si substrates and HgCdTe has large lattice mismatch of 19%. This leads to dislocation densities of low-107 cm-2 for optimal growth of HgCdTe on silicon-based substrates as compared to the mid-104 cm-2 dislocation density of HgCdTe grown on CdZnTe. This paper present dislocation reduction by two orders of magnitude using thermal cycle anneal under Hg environment on HgCdTe grown on Si substrates and as well as defect reduction in Cd(Se)Te buffer layers grown on Si Substrates.

  1. Properties of Ga1-xMnxN Epilayers Grown by Molecular Beam Epitaxy

    Science.gov (United States)

    Marcet, S.; Bellet, E.; Biquard, X.; Bougerol, C.; Cibert, J.; Ferrand, D.; Giraud, R.; Halley, D.; Kulatov, E.; Kuroda, S.; Mariette, H.; Titov, A.

    2005-06-01

    Wurtzite (Ga,Mn)N epilayers were grown by plasma-assisted molecular beam epitaxy. Mn incorporation strongly depends on growth conditions. Infrared optical absorption shows absorption bands related to neutral Mn acceptor A0 at 1.412 eV and 1.43 eV. Magnetic circular dichroism spectroscopyat the band gap edge, in agreement with magnetization data, exhibits temperature and magnetic field dependence revealing paramagnetic properties of Mn-doped GaN.

  2. Observation of the Intrinsic Bandgap Behavior in As-Grown Epitaxial Twisted Graphene (Postprint)

    Science.gov (United States)

    2015-01-06

    technology . Here, we present evidence that direct growth by carbon source molecular beam epitaxy (CMBE) with C60 molecular on pre grown template graphene...sp3 C C bonding carbon . Discussion The sp3 C C interlayer bonding has been experimentally observed in graphite and carbon nanotubes modified by... carbon nanotube fibers. ACS Nano 5, 1921 1927 (2011). 19. Hass, J. et al. Structural properties of the multilayer graphene/4H-SiC ð0001Þ system as

  3. A NORMATIVE STUDY OF NIGERIAN GROWN MAHA-TITA (KING OF BITTERS) - ANDROGRAPHIS PANICULATA NEES

    OpenAIRE

    Ameh, Sunday; Obodozie, Obiageri; Inyang, Uford; Abubakar, Mujitaba; Garba, Magaji

    2010-01-01

    The aim of the study is to characterize the aerial parts of Andrographis paniculata - an intensely bitter herb grown in Nigeria from seeds obtained in India. The ultimate aim is to develop a suitable dosage form from the herb for use in Nigeria. The bitterness value; various physicochemical characteristics; tests for key phytochemicals; and thin layer chromatography (TLC) were carried out on the air-dried herb as prescribed in relevant standard texts. The mean bitterness value for both men an...

  4. Effective-mass theory for coupled quantum dots grown on (11N)-oriented substrates

    Institute of Scientific and Technical Information of China (English)

    Li Shu-Shen; Xia Jian-Bai

    2007-01-01

    The electronic structures of coupled quantum dots grown on (11N)-oriented substrates are studied in the framework of effective-mass envelope-function theory. The results show that the all-hole subbands have the smallest widths and the optical properties are best for the (113), (114), and (115) growth directions. Our theoretical results agree with the available experimental data. Our calculated results are useful for the application of coupled quantum dots in photoelectric devices.

  5. High-Level Production of Heterologous Protein by Engineered Yeasts Grown in Cottage Cheese Whey

    OpenAIRE

    Maullu, Carlo; Lampis, Giorgio; Desogus, Alessandra; Ingianni, Angela; Rossolini, Gian Maria; Pompei, Raffaello

    1999-01-01

    Cottage cheese whey is a cheese industry by-product still rich in proteins and lactose. Its recycling is seldom cost-effective. In this work we show that the lactose-utilizing yeast Kluyveromyces lactis, engineered for production of recombinant human lysozyme, can be grown in cottage cheese whey, resulting in high-level production of the heterologous protein (125 μg/ml).

  6. Electrical conductivity measurements on gel grown KDP crystals added with urea and thiourea

    Indian Academy of Sciences (India)

    M Priya; C M Padma; T H Freeda; C Mahadevan; C Balasingh

    2001-10-01

    Pure and impurity added (with urea and thiourea) KDP single crystals were grown by the gel method using silica gels. Electrical conductivity measurements were carried out along both the unique axis and perpendicular directions at various temperatures ranging from 30 to 140°C by the conventional two-probe method. The present study shows that the conductivity in KDP crystals, for both the impurities considered, increases with the increase in impurity concentration and temperature. Activation energies were also determined and reported.

  7. Amylolytic enzyme production byRhizopus oryzae grown on agricultural commodities.

    Science.gov (United States)

    Yu, R C; Hang, Y D

    1990-03-01

    The amylolytic enzyme production byRhizopus oryzae NRRL 395 grown on different agricultural commodities was datermined. The mould produced much higher enzyme activity from barley, corn, bats, and rice than from cassava. The optimal temperature for enzyme production was 30°C. Neutralization with CaCO3 greatly enhanced the rate of enzyme production. Nitrogen supplementation of cassava resulted in higher enzyme yields.

  8. Ordered Silicon Microwire Arrays Grown from Substrates Patterned Using Imprint Lithography and Electrodeposition

    OpenAIRE

    Audesirk, Heather A.; Warren, Emily L.; Ku, Jessie; Lewis, Nathan S.

    2015-01-01

    Silicon microwires grown by the vapor–liquid–solid process have attracted a great deal of interest as potential light absorbers for solar energy conversion. However, the research-scale techniques that have been demonstrated to produce ordered arrays of micro and nanowires may not be optimal for use as high-throughput processes needed for large-scale manufacturing. Herein we demonstrate the use of microimprint lithography to fabricate patterned templates for the confinement of an electrodeposi...

  9. Effects of drought on cadmium accumulation in peanuts grown in a contaminated calcareous soil.

    Science.gov (United States)

    Xia, Shenglan; Wang, Xvming; Su, Genqiang; Shi, Gangrong

    2015-12-01

    This study aimed to investigate the effects of drought stress on cadmium (Cd) accumulation in peanut (Arachis hypogaea L.) grown in contaminated calcareous soils. Five peanut cultivars were grown in a calcareous soil spiked with 4 mg Cd kg(-1) soil (dry weight) under well-watered, mild drought, and severe drought conditions. The biomass production, gas exchange, spectral reflectance, and Cd accumulation in plant tissues were determined. The five cultivars significantly differed from each other in biomass production, gas exchange, spectral reflectance, and Cd accumulation. The effect of drought on Cd accumulation in peanuts varies with plant tissues, cultivars, and developmental stages. Drought decreased root Cd concentrations in seedlings of the two high Cd-accumulating cultivars (Haihua 1 and Zhenghong 3), which is associated with increasing leaf active Fe content. However, for the mature plants, drought stress caused an increase in Cd accumulation in roots, pod walls, and seeds depending on peanut cultivars. Negative correlations were found between seed Cd concentration and biomasses in both preflowering seedlings and mature plants. The seed Cd concentration in mature plants was also observed to be positively correlated with the shoot Cd concentration in preflowering seedlings. The increased Cd concentration in seeds of drought-stressed peanut plants grown in Cd-contaminated calcareous soils might be attributed to the drought-induced decrease of biomass production.

  10. Phenolic Profile of Dark-Grown and Photoperiod-Exposed Hypericum perforatum L. Hairy Root Cultures

    Directory of Open Access Journals (Sweden)

    Oliver Tusevski

    2013-01-01

    Full Text Available Hypericum perforatum L. is a medicinal plant considered as an important natural source of secondary metabolites with a wide range of pharmacological attributes. Hairy roots (HR were induced from root segments of in vitro grown seedlings from H. perforatum after cocultivation with Agrobacterium rhizogenes A4. Investigations have been made to study the production of phenolic compounds in dark-grown (HR1 and photoperiod-exposed (HR2 cultures. The chromatographic analysis of phenolic acids, flavonols, flavan-3-ols, and xanthones revealed marked differences between HR1 and HR2 cultures. The production of quinic acid, kaempferol, and seven identified xanthones was increased in HR2. Moreover, HR2 showed a capability for de novo biosynthesis of two phenolic acids (3-p-coumaroylquinic acid and 3-feruloylquinic acid, three flavonol glycosides (kaempferol hexoside, hyperoside, and quercetin acetylglycoside, and five xanthones (tetrahydroxy-one-methoxyxanthone, 1,3,5-trihydroxy-6-methoxyxanthone, 1,3,5,6-tetrahydroxy-2-prenylxanthone, paxanthone, and banaxanthone E. On the other side, HR1 cultures were better producers of flavan-3-ols (catechin, epicatechin, and proanthocyanidin dimers than HR2. This is the first comparative study on phenolic profile of H. perforatum HR cultures grown under dark and photoperiod conditions.

  11. Structural characterization of InSb thin films grown by electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Joginder, E-mail: joginderchauhan82@gmail.com; Rajaram, P. [School of Studies in Physics, Jiwaji University, Gwalior-474011 (India)

    2015-06-24

    In the present work we have grown InSb thin films on brass substrates, using the electrodeposition technique. The electrochemical baths used in the growth were made up of aqueous solutions of InCl{sub 3} and SbCl{sub 3} mixed together in various proportions. The films grown were characterized by X-Ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive Analysis of X-rays (EDAX). Compositional studies show that stoichiometric InSb films can be prepared from a bath containing 0.05M InCl{sub 3} and 0.04M SbCl{sub 3}. XRD studies reveal that the films grown are polycrystalline having the zinc blende structure with (111) orientation. Crystallite size, dislocation density and strain were calculated using the XRD results. Optical transmission spectra were recorded using an FTIR spectrophotometer. The value of direct band gap was found to be around 0.20 eV for the thin films having the best stoichiometry.

  12. Structural and optical properties of ZnS thin film grown by pulsed electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Hennayaka, H.M.M.N.; Lee, Ho Seong, E-mail: hs.lee@knu.ac.kr

    2013-12-02

    ZnS thin films were grown on indium–tin-oxide coated glass substrates using pulsed electrodeposition and the effect of the deposition temperature on the structural and optical properties of the ZnS films was investigated. Polycrystalline cubic ZnS films were obtained at all the deposition temperatures. At temperatures below 70 °C, less dense films were obtained and particle agglomeration was visible. On the other hand, at temperatures above 70 °C, more dense films with well-defined grains were obtained. With increasing deposition temperatures, the optical transmittance and bandgap of the ZnS films decreased. These results are attributed to the increase in the thickness of ZnS films and their particle size. The ZnS films grown at 90 °C exhibited the highly (200) preferred orientation and n-type conductivity with a wide bandgap of 3.75 eV. - Highlights: • This study describes the effect of the deposition temperature on the growth of the ZnS thin films. • ZnS thin films were grown using pulsed electrodeposition. • ZnS thin films exhibited the good crystal quality and chemical composition. • ZnS thin films exhibited n-type conductivity with a wide bandgap of 3.75 eV.

  13. Evaluation of holocellulase production by plant-degrading fungi grown on agro-industrial residues.

    Science.gov (United States)

    de Siqueira, Félix Gonçalves; de Siqueira, Aline Gonçalves; de Siqueira, Eliane Gonçalves; Carvalho, Marly Azevedo; Peretti, Beatriz Magalhães Pinto; Jaramillo, Paula Marcela Duque; Teixeira, Ricardo Sposina Sobral; Dias, Eustáquio Souza; Félix, Carlos Roberto; Filho, Edivaldo Ximenes Ferreira

    2010-09-01

    Agaricus brasiliensis CS1, Pleurotus ostreatus H1 and Aspergillus flavus produced holocellulases when grown in solid and submerged liquid cultures containing agro-industrial residues, including sugar cane bagasse and dirty cotton residue, as substrates. These isolates proved to be efficient producers of holocellulases under the conditions used in this screening. Bromatological analysis of agro-industrial residues showed differences in protein, fiber, hemicellulose, cellulose and lignin content. Maximal holocellulase activity (hemicellulase, cellulase and pectinase) was obtained using solid-state cultivation with 10% substrate concentration. In this case, remarkably high levels of xylanase and polygalacturonase activity (4,008 and 4,548 IU/l, respectively) were produced by A. flavus when grown in media containing corn residue, followed by P. ostreatus H1 with IU/l values of 1,900 and 3,965 when cultivated on 5% and 10% sugar cane bagasse, respectively. A. brasiliensis CS1 showed the highest reducing sugar yield (11.640 mg/ml) when grown on medium containing sugar cane bagasse. A. brasiliensis was also the most efficient producer of protein, except when cultivated on dirty cotton residue, which induced maximal production in A. flavus. Comparison of enzymatic hydrolysis of sugar cane bagasse and dirty cotton residue by crude extracts of A. brasiliensis CS1, P. ostreatus H1 and A. flavus showed that the best reducing sugar yield was achieved using sugar cane bagasse as a substrate.

  14. Aging impairs osteoblast differentiation of mesenchymal stem cells grown on titanium by favoring adipogenesis

    Science.gov (United States)

    ABUNA, Rodrigo Paolo Flores; STRINGHETTA-GARCIA, Camila Tami; FIORI, Leonardo Pimentel; DORNELLES, Rita Cassia Menegati; ROSA, Adalberto Luiz; BELOTI, Marcio Mateus

    2016-01-01

    ABSTRACT Aging negatively affects bone/titanium implant interactions. Our hypothesis is that the unbalance between osteogenesis and adipogenesis induced by aging may be involved in this phenomenon. Objective We investigated the osteoblast and adipocyte differentiation of mesenchymal stem cells (MSCs) from young and aged rats cultured on Ti. Material and Methods Bone marrow MSCs derived from 1-month and 21-month rats were cultured on Ti discs under osteogenic conditions for periods of up to 21 days and osteoblast and adipocyte markers were evaluated. Results Cell proliferation, alkaline phosphatase (ALP) activity, extracellular matrix mineralization and gene expression of RUNX2, osterix, ALP, bone sialoprotein, osteopontin, and osteocalcin were reduced in cultures of 21-month rats compared with 1-month rats grown on Ti. Gene expression of PPAR-γ , adipocyte protein 2, and resistin and lipid accumulation were increased in cultures of 21-month rats compared with 1-month rats grown on the same conditions. Conclusions These results indicate that the lower osteogenic potential of MSCs derived from aged rats compared with young rats goes along with the higher adipogenic potential in cultures grown on Ti surface. This unbalance between osteoblast and adipocyte differentiation should be considered in dental implant therapy to the elderly population. PMID:27556209

  15. Direct transfer of multilayer graphene grown on a rough metal surface using PDMS adhesion engineering

    Science.gov (United States)

    Jang, Heejun; Kang, Il-Suk; Lee, Youngbok; Cha, Yun Jeong; Yoon, Dong Ki; Ahn, Chi Won; Lee, Wonhee

    2016-09-01

    The direct transfer of graphene using polydimethylsiloxane (PDMS) stamping has advantages such as a ‘pick-and-place’ capability and no chemical residue problems. However, it is not easy to apply direct PDMS stamping to graphene grown via chemical vapor deposition on rough, grainy metal surfaces due to poor contact between the PDMS and graphene. In this study, graphene consisting of a mixture of monolayers and multiple layers grown on a rough Ni surface was directly transferred without the use of an adhesive layer. Liquid PDMS was cured on graphene to effect a conformal contact with the graphene. A fast release of graphene from substrate was achieved by carrying out wet-etching-assisted mechanical peeling. We also carried out a thermal post-curing of PDMS to control the level of adhesion between PDMS and graphene and hence facilitate a damage-free release of the graphene. Characterization of the transferred graphene by micro-Raman spectroscopy, SEM/EDS and optical microscopy showed neither cracks nor contamination from the transfer. This technique allows a fast and simple transfer of graphene, even for multilayer graphene grown on a rough surface.

  16. Microstructural evolution in multiseeded YBCO bulk samples grown by the TSMG process

    Science.gov (United States)

    Goodfellow, A.; Shi, Y.-H.; Durrell, J. H.; Dennis, A. R.; Cardwell, D. A.; Grovenor, C. R. M.; Speller, S. C.

    2016-11-01

    Superconducting single-grain YBCO bulk samples with the ability to trap high magnetic fields can be grown using the top-seeded melt-growth process. Multiseeding techniques have the potential to enable larger diameter bulks to be grown, but the performance of these materials is not yet comparable to the single-seeded bulks. Here we carry out detailed three-dimensional microstructural characterisation on a multiseeded sample grown with the seeds aligned in the 0°-0° geometry using high resolution microanalysis techniques. Chemical and structural variations have been correlated with the trapped field distribution in three separate slices of the sample. The top slice of the sample shows four peaks in trapped field, indicating that the current flows in four separate loops rather than in one large loop within the sample. This has been explained by the build-up in insulating Y-211 particles where the growth fronts from the two seeds meet, forming a barrier to current flow, as well as the low Y-211 content (and hence low J c) of the large c-axis growth sector.

  17. Carbon assimilation in Eucalyptus urophylla grown under high atmospheric CO2 concentrations: A proteomics perspective.

    Science.gov (United States)

    Santos, Bruna Marques Dos; Balbuena, Tiago Santana

    2017-01-06

    Photosynthetic organisms may be drastically affected by the future climate projections of a considerable increase in CO2 concentrations. Growth under a high concentration of CO2 could stimulate carbon assimilation-especially in C3-type plants. We used a proteomics approach to test the hypothesis of an increase in the abundance of the enzymes involved in carbon assimilation in Eucalyptus urophylla plants grown under conditions of high atmospheric CO2. Our strategy allowed the profiling of all Calvin-Benson cycle enzymes and associated protein species. Among the 816 isolated proteins, those involved in carbon fixation were found to be the most abundant ones. An increase in the abundance of six key enzymes out of the eleven core enzymes involved in carbon fixation was detected in plants grown at a high CO2 concentration. Proteome changes were corroborated by the detection of a decrease in the stomatal aperture and in the vascular bundle area in Eucalyptus urophylla plantlets grown in an environment of high atmospheric CO2. Our proteomics approach indicates a positive metabolic response regarding carbon fixation in a CO2-enriched atmosphere. The slight but significant increase in the abundance of the Calvin enzymes suggests that stomatal closure did not prevent an increase in the carbon assimilation rates.

  18. Columnar structured FePt films epitaxially grown on large lattice mismatched intermediate layer

    Science.gov (United States)

    Dong, K. F.; Deng, J. Y.; Peng, Y. G.; Ju, G.; Chow, G. M.; Chen, J. S.

    2016-09-01

    The microstructure and magnetic properties of the FePt films grown on large mismatched ZrN (15.7%) intermediate layer were investigated. With using ZrN intermediate layer, FePt 10 nm films exhibited (001) texture except for some weaker FePt (110) texture. Good epitaxial relationships of FePt (001) //ZrN (001) //TiN (001) among FePt and ZrN/TiN were revealed from the transmission electron microscopy (TEM) results. As compared with TiN intermediate layer, although FePt-SiO2-C films grown on ZrN/TiN intermediate layer showed isotropic magnetic properties, the large interfacial energy and lattice mismatch between FePt and ZrN would lead to form columnar structural FePt films with smaller grain size and improved isolation. By doping ZrN into the TiN layer, solid solution of ZrTiN was formed and the lattice constant is increased comparing with TiN and decreased comparing with ZrN. Moreover, FePt-SiO2-C films grown on TiN 2 nm-20 vol.% ZrN/TiN 3 nm intermediate layer showed an improved perpendicular magnetic anisotropy. Simultaneously, columnar structure with smaller grain size retained.

  19. HPLC profiles and biomarker contents of Australian-grown Salvia miltiorrhiza f. alba roots.

    Science.gov (United States)

    Li, Chun Guang; Sheng, Shu Jun; Pang, Edwin C K; May, Brian; Xue, Charlie Chang Li

    2009-07-01

    Salvia miltiorrhiza f. alba (Baihua Danshen) is a Chinese medicinal herb commonly used for treating cardiovascular disease. It has been grown in Australia, although the quality of its main medicinal part (dried root) has not been assessed. In this study, we investigated HPLC profiles and biomarker contents of Australian-grown S. miltiorrhiza f. alba roots. Patterns of HPLC profiles were established in MeOH, and aqueous extracts in terms of number of common characteristic peaks and their relative retention times. The contents of three tanshinone biomarkers (cryptotanshinone (3), tanshinone I (1), and tanshinone IIA (2)) were significantly higher (pplants than those of two-year-old plants. In contrast, salvianolic acid B (4) content was significantly higher in the roots of two-year-old plants than in those of one-year-old plants. The findings suggest that the biomarker contents in Australian-grown S. miltiorrhiza f. alba roots vary with the growth periods of the plants, which may be important in determining the optimal harvest time for the plant roots with targeted levels of tanshinones and salvianolic acid B (4).

  20. Comparison of total polyphenol contents And antioxidant activity in cruciferous vegetables grown in diversified ecological conditions

    Directory of Open Access Journals (Sweden)

    Joanna Kapusta-Duch

    2012-12-01

    Full Text Available Background.The aim of this study was to compare total polyphenol contents and antioxidant activity of three species of cruciferous vegetables grown under diversified ecological conditions for three consecutive years. Material and methods. Methanol extracts were prepared to be used to determine (spectrometrically the content of total phenolics, using the Folin-Ciocalteau reagent and antioxidant activity by identifying the sam- ple’s ability to extinguish an ABTS•+free radical. Results.All these species of cruciferous vegetables contained similar total polyphenols amounts regardless of its origin. Only red cabbage from organic farms was characterized by significantly higher antioxidant activity compared to vegetables purchased from local retailers in Cracow and similar or those cultivated near the steelworks. In white cabbage from farms located in a former steelworks protection zone a higher antioxidant activity was found than in organically grown vegetables and similar to that in vegetables available in retail. Brussels sprouts was characterised by a similar antioxidant activity regardless of its origin. Conclusions. On the basis of the present study, it cannot be concluded that organically grown cruciferous vegetables generally have higher contents of health-promoting secondary metabolites in comparison with the conventionally cultivated ones.

  1. Transcriptome profiling of Xanthomonas campestris pv. campestris grown in minimal medium MMX and rich medium NYG.

    Science.gov (United States)

    Liu, Wei; Yu, Yan-Hua; Cao, Shi-Yuan; Niu, Xiang-Na; Jiang, Wei; Liu, Guo-Fang; Jiang, Bo-Le; Tang, Dong-Jie; Lu, Guang-Tao; He, Yong-Qiang; Tang, Ji-Liang

    2013-06-01

    Xanthomonas campestris pathovar campestris (Xcc) is the causal agent of black rot disease in cruciferous plants worldwide. Although the complete genomes of several Xcc strains have been determined, the gene expression and regulation mechanisms in this pathogen are far from clear. In this work, transcriptome profiling of Xcc 8004 grown in MMX medium (minimal medium for Xanthomonas campestris) and NYG medium (peptone yeast glycerol medium) were investigated by RNA-Seq. Using the Illumina HiSeq 2000 platform, a total of 26,514,630 reads (90 nt in average) were generated, of which 15,708,478 reads mapped uniquely to coding regions of Xcc 8004 genome. Of the 4273 annotated protein-coding genes of Xcc 8004, 629 were found differentially expressed in Xcc grown in MMX and NYG. Of the differentially expressed genes, 495 were up-regulated and 134 were down-regulated in MMX. The MMX-induced genes are mainly involved in amino acid metabolism, transport systems, atypical condition adaptation and pathogenicity, especially the type III secretion system, while the MMX-repressed genes are mainly involved in chemotaxis and degradation of small molecules. The global transcriptome analyzes of Xcc 8004 grown in MMX and NYG might facilitate the gene functional characterization of this phytopathogenic bacterium.

  2. Low temperature synthesis and field emission characteristics of single to few layered graphene grown using PECVD

    Science.gov (United States)

    Kumar, Avshish; Khan, Sunny; Zulfequar, M.; Harsh; Husain, Mushahid

    2017-04-01

    In this work, high-quality graphene has successfully been synthesized on copper (Cu) coated Silicon (Si) substrate at very large-area by plasma enhanced chemical vapor deposition system. This method is low cost and highly effective for synthesizing graphene relatively at low temperature of 600 °C. Electron microscopy images have shown that surface morphology of the grown samples is quite uniform consisting of single layered graphene (SLG) to few layered graphene (FLG). Raman spectra reveal that graphene has been grown with high-quality having negligible defects and the observation of G and G' peaks is also an indicative of stokes phonon energy shift caused due to laser excitation. Scanning probe microscopy image also depicts the synthesis of single to few layered graphene. The field emission characteristics of as-grown graphene samples were studied in a planar diode configuration at room temperature. The graphene samples were observed to be a good field emitter having low turn-on field, higher field amplification factor and long term emission current stability.

  3. Morpho-anatomical study of Stevia rebaudiana roots grown in vitro and in vivo

    Directory of Open Access Journals (Sweden)

    Rafael V. Reis

    Full Text Available ABSTRACT Stevia rebaudiana (Bertoni Bertoni, Asteraceae, is used as a food additive because its leaves are a source of steviol glycosides. There are examples of tissue culture based on micropropagation and phytochemical production of S. rebaudiana leaves but there are few studies on adventitious root culture of S. rebaudiana. More than 90% of the plants used in industry are harvested indiscriminately. In order to overcome this situation, the development of methodologies that employ biotechnology, such as root culture, provides suitable alternatives for the sustainable use of plants. The aim of this study was to compare morpho-anatomical transverse sections of S. rebaudiana roots grown in vitro and in vivo. The in vitro system used to maintain root cultures consisted of a gyratory shaker under dark and light conditions and a roller bottle system. Transverse sections of S. rebaudiana roots grown in vitro were structurally and morphologically different when compared to the control plant; roots artificially maintained in culture media can have their development affected by the degree of media aeration, sugar concentration, and light. GC–MS and TLC confirmed that S. rebaudiana roots grown in vitro have the ability to produce metabolites, which can be similar to those produced by wild plants.

  4. Extended defects in MBE-grown CdTe-based solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Wichrowska, Karolina; Wosinski, Tadeusz; Kret, Slawomir; Chusnutdinow, Sergij; Karczewski, Grzegorz [Institute of Physics, Polish Academy of Sciences, Warsaw (Poland); Rawski, Michal [Analytical Laboratory, Maria Curie-Sklodowska University, Lublin (Poland); Yastrubchak, Oksana [Institute of Physics, Maria Curie-Sklodowska University, Lublin (Poland)

    2015-08-15

    Extended defects in the p -ZnTe/n -CdTe heterojunctions grown by the molecular-beam epitaxy technique on two different substrates, GaAs and CdTe, have been investigated by deep-level transient spectroscopy (DLTS) and transmission electron microscopy (TEM). Four hole traps, called H1 to H4, and one electron trap, called E3, have been revealed in the DLTS spectra measured for the heterojunctions grown on the GaAs substrates. The H1, H3, H4 and E3 traps have been attributed to the electronic states of dislocations on the ground of their logarithmic capture kinetics. The DLTS peaks associated with the H1 and E3 traps were not observed in the DLTS spectra measured for the heterojunction grown on the CdTe substrate. They are most likely associated with threading dislocations generated at the mismatched interface with the GaAs substrate. Cross-sectional TEM images point out that they are dislocations of the 60 -type. In both the types of heterojunctions the H4 trap was observed only under forward-bias filling pulse, suggesting that this trap is associated with the CdTe/ZnTe interface. In addition, TEM images revealed also the presence of intrinsic and extrinsic stacking faults in the CdTe layers, which may considerably affect their electronic properties. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Compost Grown Agaricus bisporus Lacks the Ability to Degrade and Consume Highly Substituted Xylan Fragments.

    Science.gov (United States)

    Jurak, Edita; Patyshakuliyeva, Aleksandrina; de Vries, Ronald P; Gruppen, Harry; Kabel, Mirjam A

    2015-01-01

    The fungus Agaricus bisporus is commercially grown for the production of edible mushrooms. This cultivation occurs on compost, but not all of this substrate is consumed by the fungus. To determine why certain fractions remain unused, carbohydrate degrading enzymes, water-extracted from mushroom-grown compost at different stages of mycelium growth and fruiting body formation, were analyzed for their ability to degrade a range of polysaccharides. Mainly endo-xylanase, endo-glucanase, β-xylosidase and β-glucanase activities were determined in the compost extracts obtained during mushroom growth. Interestingly, arabinofuranosidase activity able to remove arabinosyl residues from doubly substituted xylose residues and α-glucuronidase activity were not detected in the compost enzyme extracts. This correlates with the observed accumulation of arabinosyl and glucuronic acid substituents on the xylan backbone in the compost towards the end of the cultivation. Hence, it was concluded that compost grown A. bisporus lacks the ability to degrade and consume highly substituted xylan fragments.

  6. Electrical properties of in-situ grown and transferred organic nanofibers

    DEFF Research Database (Denmark)

    Oliveira Hansen, Roana Melina de; Madsen, Morten; Kjelstrup-Hansen, Jakob;

    2010-01-01

    Para-hexaphenylene (p6P) molecules have the ability to self-assemble into organic nanofibers, which exhibit a range of interesting optical and optoelectronic properties such as intense, polarized luminescence, waveguiding and lasing. The nanofibers are typically grown on specific single-crystalli......Para-hexaphenylene (p6P) molecules have the ability to self-assemble into organic nanofibers, which exhibit a range of interesting optical and optoelectronic properties such as intense, polarized luminescence, waveguiding and lasing. The nanofibers are typically grown on specific single......-crystalline templates, such as muscovite mica, on which mutually parallel nanofibers are self-assembled upon vapor deposition of the organic material under high vacuum conditions. Besides such single-crystalline templates, the nanofibers can also be grown on non-crystalline gold surfaces, on which the orientation...... of the nanofibers can be manipulated by structuring the gold surface prior to parahexaphenylene (p6P) deposition. In this work it is demonstrated, how such organic nanofiber growth can be controlled by modifying the design of the underlying gold structures prior to growth. Here, the investigated designs include...

  7. Characterizations of microwave plasma CVD grown polycrystalline diamond coatings for advanced technological applications

    Directory of Open Access Journals (Sweden)

    Awadesh Kumar Mallik

    2014-06-01

    Full Text Available Polycrystalline diamond (PCD coatings ranging from few microns to several hundred microns thickness have been grown by 915 MHz microwave plasma reactor with 9000 W power. The coatings were deposited on 100 mm diameter silicon (Si substrate from few hours to several days of continuous runs. PCD coatings were made freestanding by wet chemical etching technique. The deposited PCDs were evaluated by X-ray diffraction (XRD, scanning electron microscopy (SEM, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS for physical characterization and compared with authors’ earlier work. Refractive index of 2.41 was obtained at 633 nm wavelength and a maximum of 6.6 W·cm-1K-1 value for thermal conductivity could be achieved with the grown coatings. The values are well above the existing non-diamond heat spreading substrates, which makes the grown PCDs as candidates for heat spreaders in different technological applications. High refractive index along with translucent nature of the white freestanding PCDs, make them potential candidate for optical windows.

  8. InGaN violet laser diodes grown by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Heffernan, J.; Kauer, M.; Hooper, S.E.; Bousquet, V.; Johnson, K. [Sharp Laboratories of Europe Ltd, Edmund Halley Road, Oxford Science Park, Oxford, OX4 4GB (United Kingdom)

    2004-09-01

    We report on the first InGaN quantum well laser diodes grown by molecular beam epitaxy (MBE). Devices were grown by gas-source MBE using ammonia as a source of nitrogen and elemental group III sources. The devices were grown on commercially available GaN template substrates. The lasers consist of a separate confinement heterostructure including an active region consisting of three In{sub 0.1}Ga{sub 0.9}N quantum wells with a nominal thickness of 2 nm. P-type doping of GaN and AlGaN cladding regions was obtained without the use of post-growth thermal annealing. The lasers were fabricated into a ridge-stripe geometry with ridge width of 5 {mu}m and length of 500-1500 {mu}m. Electron cyclotron resonance (ECR) dry-etching was used to fabricate the laser facets. Under pulsed current injection conditions, the lasers exhibit a room temperature threshold current density of 22 kA cm{sup -2} emitting at 400 nm. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. ZnO Nanorods Grown Electrochemically on Different Metal Oxide Underlays

    Science.gov (United States)

    Gromyko, I.; Dedova, T.; Krunks, M.; Syritski, V.; Mere, A.; Mikli, V.; Unt, T.; Oja Acik, I.

    2015-03-01

    In this study we present results on electrochemically grown ZnO nanorods on different metal oxide underlays, such as ZnO seed layers with different morphologies, ZnS and TiO2 compact thin films produced by spray pyrolysis on transparent conductive oxide (TCO) substrates. Also in this work we present results on ZnO nanorods directly deposited on some chosen TCO substrates. The relationship between nanorod formation and substrate properties were studied. All ZnO nanorod layers were grown electrochemically using ZnCl2 aqueous solutions (c=0.2 mmol/L) at the bath temperature of 80 °C during one hour. The structural properties and morphology of metal oxide underlays and ZnO nanorods grown on them were studied by scanning electron microscopy (SEM), x-ray diffraction spectroscopy (XRD). Depending on the substrate morphology, ZnO rods with different dimension, orientation, shape and density were obtained. For instance, larger rods (d~200 nm, l~700 nm) were obtained on substrates, such as ITO/glass, FTO/glass and ZnO:In/ITO/glass. Smaller rods (d~60 nm, l~350 nm) were obtained on smooth, uniform and fine-grained underlays, such as ZnS and TiO2.

  10. Effect of surface treatment on hot-filament chemical vapour deposition grown diamond films

    Science.gov (United States)

    Ali, M.; Ürgen, M.; Atta, M. A.

    2012-02-01

    Diamond film growth without seeding treatment has been the subject of numerous studies. In this study, diamond films with/without seeding treatment were grown on silicon using hot-filament chemical vapour deposition. An inexpensive and simple approach, namely ‘dry ultrasonic treatment’, was introduced in which full coverage of the diamond film was achieved over the substrate having no prior seeding treatment. For comparison purposes, two substrates were seeded with different sizes of diamond particles, 5 µm by hand and 30-40 µm by ultrasonic agitation, prior to deposition. The produced diamond films were examined through standard characterization tools and distinct features were observed in each film. The diamond film grown without the seeding treatment shows slightly lower growth rate (1 µm h-1) but bigger grain size up to 8 µm compared with seeded films. Here we show the growth of uniform and high-purity diamond films free from nano-sized grains, which are grown without any seeding treatment.

  11. Nanogenerators consisting of direct-grown piezoelectrics on multi-walled carbon nanotubes using flexoelectric effects

    Science.gov (United States)

    Han, Jin Kyu; Jeon, Do Hyun; Cho, Sam Yeon; Kang, Sin Wook; Yang, Sun A.; Bu, Sang Don; Myung, Sung; Lim, Jongsun; Choi, Moonkang; Lee, Minbaek; Lee, Min Ku

    2016-07-01

    We report the first attempt to prepare a flexoelectric nanogenerator consisting of direct-grown piezoelectrics on multi-walled carbon nanotubes (mwCNT). Direct-grown piezoelectrics on mwCNTs are formed by a stirring and heating method using a Pb(Zr0.52Ti0.48)O3 (PZT)-mwCNT precursor solution. We studied the unit cell mismatch and strain distribution of epitaxial PZT nanoparticles, and found that lattice strain is relaxed along the growth direction. A PZT-mwCNT nanogenerator was found to produce a peak output voltage of 8.6 V and an output current of 47 nA when a force of 20 N is applied. Direct-grown piezoelectric nanogenerators generate a higher voltage and current than simple mixtures of PZT and CNTs resulting from the stronger connection between PZT crystals and mwCNTs and an enhanced flexoelectric effect caused by the strain gradient. These experiments represent a significant step toward the application of nanogenerators using piezoelectric nanocomposite materials.

  12. Hydroxyapatite growth on multiwall carbon nanotubes grown on titanium fibers from a titanium sheet

    KAUST Repository

    Chetibi, Loubna

    2013-09-27

    Nano-hydroxyapatite (HA) was grown on functionalized multiwalled carbon nanotubes (MWCNTs) deposited on TiO2 nanofibers (NFs) that were hydrothermally grown on Ti metal sheets. The HA was electrochemically grown on the MWCNTs/TiO2 porous layer. It was found that the HA grows on the MWCNTs/TiO2 NFs in the form of dense coating with nanorice grain-shaped. The incorporation of MWCNTs between HA and TiO2 NFs has led to higher adhesion strength as measured by micro-scratching test indicating the benefit of MWCNTs on the improving the bonding strength of HA layer. The obtained coatings exhibit excellent corrosion resistance in simulated body fluid. It is expected that this simple route for preparing the new HA/MWCNTs/TiO2/Ti-layered structure might be used not only in the biomedical field, but also in catalysis and biological sensing among others. © 2013 Springer Science+Business Media New York.

  13. Electrical properties of as-grown and proton-irradiated high purity silicon

    Energy Technology Data Exchange (ETDEWEB)

    Krupka, Jerzy, E-mail: krupka@imio.pw.edu.pl [Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland); Karcz, Waldemar [Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna (Russian Federation); Kamiński, Paweł [Institute of Electronic Materials Technology, Wólczyńska 13, 301-919 Warsaw (Poland); Jensen, Leif [Topsil Semiconductor Materials A/S, Siliciumvej 1, DK-3600 Frederikssund (Denmark)

    2016-08-01

    The complex permittivity of as-grown and proton-irradiated samples of high purity silicon obtained by the floating zone method was measured as a function of temperature at a few frequencies in microwave spectrum by employing the quasi TE{sub 011} and whispering gallery modes excited in the samples under test. The resistivity of the samples was determined from the measured imaginary part of the permittivity. The resistivity was additionally measured at RF frequencies employing capacitive spectroscopy as well as in a standard direct current experiment. The sample of as-grown material had the resistivity of ∼85 kΩ cm at room temperature. The sample irradiated with 23-MeV protons had the resistivity of ∼500 kΩ cm at 295 K and its behavior was typical of the intrinsic material at room and at elevated temperatures. For the irradiated sample, the extrinsic conductivity region is missing and at temperatures below 250 K hopping conductivity occurs. Thermal cycle hysteresis of the resistivity for the sample of as-grown material is observed. After heating and subsequent cooling of the sample, its resistivity decreases and then slowly (∼50 h) returns to the initial value.

  14. Nonstoichiometry and luminescent properties of ZnSe crystals grown from the melt at high pressures

    Science.gov (United States)

    Khanh, Tran; Mozhevitina, Elena; Khomyakov, Andrew; Avetisov, Roman; Davydov, Albert; Chegnov, Vladimir; Antonov, Vladimir; Kobeleva, Svetlana; Zhavoronkov, Nikolai; Avetissov, Igor

    2017-01-01

    50 mm diameter ZnSe crystals have been grown from the melt by a vertical Bridgman technique at 100 atm argon pressure in a graphite crucible. 3D impurities concentration and nonstoichiometry mappings of the grown crystals have been defined by ICP-MS and a direct physic-chemical method, correspondingly. Photoluminescence mapping of the analyzed crystal has been done. It was found out that along the crystal height the nonstoichiometry changed from Se excess over stoichiometrical composition in the cone (bottom) part to Zn excess in the tail (upper) part passing through the stoichiometrical composition in the cylindrical part of the crystal. Metal impurities concentrated in the upper part of the crystal. The gas-forming impurities (H, C, O, N, F) had stochastic distribution but Cl impurity concentrated in the crystal peripheral part (near the crucible walls). It was found out that the as-grown crystal had a single wide PL peal with maximum of 583 nm. A proposal about complex structure luminescent center based on Cl dopant an overstoichiometric Se has been made.

  15. Laplace DLTS of molecular beam epitaxy GaAs grown on (100) and (211)B substrates

    Energy Technology Data Exchange (ETDEWEB)

    Mari, R.H.; Shafi, M.; Henini, M. [School of Physics and Astronomy, Nottingham Nanotechnology and Nanoscience Centre University of Nottingham, Nottingham NG7 2RD (United Kingdom)

    2009-12-15

    Deep Level Transient Spectroscopy (DLTS) and Laplace DLTS (LDLTS) techniques have been employed to study defects in n-type GaAs grown by MBE on (100) and (211)B GaAs planes. The DLTS spectra were different for the two GaAs substrate orientations. Five and four defect states are found in samples grown on (100) and (211)B GaAs planes, respectively with activation energies ranging from 0.054 eV to 0.570 eV. For all of the traps observed in our samples we obtained small activation energies as compared to the previous data published in literature on n-GaAs samples grown by MBE. This can be explained by the fact that the emission of the carriers depends on the applied electric field and temperature dependence of the carrier concentration. These two phenomena seem to explain the small trap energies seen in our samples. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. Advancements in Root Growth Measurement Technologies and Observation Capabilities for Container-Grown Plants

    Directory of Open Access Journals (Sweden)

    Lesley A. Judd

    2015-07-01

    Full Text Available The study, characterization, observation, and quantification of plant root growth and root systems (Rhizometrics has been and remains an important area of research in all disciplines of plant science. In the horticultural industry, a large portion of the crops grown annually are grown in pot culture. Root growth is a critical component in overall plant performance during production in containers, and therefore it is important to understand the factors that influence and/or possible enhance it. Quantifying root growth has varied over the last several decades with each method of quantification changing in its reliability of measurement and variation among the results. Methods such as root drawings, pin boards, rhizotrons, and minirhizotrons initiated the aptitude to measure roots with field crops, and have been expanded to container-grown plants. However, many of the published research methods are monotonous and time-consuming. More recently, computer programs have increased in use as technology advances and measuring characteristics of root growth becomes easier. These programs are instrumental in analyzing various root growth characteristics, from root diameter and length of individual roots to branching angle and topological depth of the root architecture. This review delves into the expanding technologies involved with expertly measuring root growth of plants in containers, and the advantages and disadvantages that remain.

  17. Optical properties of InN grown on Si(111) substrate

    Energy Technology Data Exchange (ETDEWEB)

    Sakalauskas, E.; Schley, P.; Raethel, J.; Klar, T.A.; Mueller, R.; Pezoldt, J.; Tonisch, K.; Goldhahn, R. [Institut fuer Mikro- und Nanotechnologien, Technische Universitaet Ilmenau (Germany); Grandal, J.; Sanchez-Garcia, M.A.; Calleja, E. [ISOM y Departamento de Ingenieria Electronica, ETSI Telecomunicacion, Universidad Politecnica de Madrid, Ciudad Universitaria (Spain); Vilalta-Clemente, A.; Ruterana, P. [CIMAP UMR 6252 CNRS-ENSICAEN-CEA-UCBN, Caen (France)

    2010-05-15

    A comprehensive characterization of the optical properties of wurtzite InN films grown by molecular beam epitaxy on Si(111) substrates is presented. Two types of films are investigated in this work: InN on AlN/Si(111) and InN on GaN/AlN/Si(111). Their properties are compared to a layer deposited on GaN/sapphire substrate. The dielectric function (DF) is obtained from spectroscopic ellipsometry (SE). The infrared studies yield the plasma frequency and thus the electron density, while the interband absorption is probed between 0.56 and 9.8 eV. For InN grown on Si(111) substrate, the absorption onset is slightly shifted to higher energies with respect to the InN film grown on GaN/sapphire which can be attributed to higher electron concentrations. Despite this, strongly pronounced optical transitions due to critical points of the band structure are found in the high-energy part of the DF. It emphasizes the already promising quality of the InN films on silicon. Band-gap renormalization (BGR), band filling, and strain are taken into account in order to estimate the intrinsic band gap of wurtzite InN. For the InN layers on silicon, we get a band gap between 0.66 and 0.685 eV. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  18. Morphology and photoresponse of crystalline antimony film grown on mica by physical vapor deposition

    Directory of Open Access Journals (Sweden)

    Shafa Muhammad

    2016-09-01

    Full Text Available Antimony is a promising material for the fabrication of photodetectors. This study deals with the growth of a photosensitive thin film by the physical vapor deposition (PVD of antimony onto mica surface in a furnace tube. The geometry of the grown structures was studied via scanning electron microscopy (SEM, X-ray diffraction (XRD, energy-dispersive X-ray spectroscopy (EDX and elemental diffraction analysis. XRD peaks of the antimony film grown on mica mostly matched with JCPDF Card. The formation of rhombohedral crystal structures in the film was further confirmed by SEM micrographs and chemical composition analysis. The Hall measurements revealed good electrical conductivity of the film with bulk carrier concentration of the order of 1022 Ω·cm-3 and mobility of 9.034 cm2/Vs. The grown film was successfully tested for radiation detection. The photoresponse of the film was evaluated using its current-voltage characteristics. These investigations revealed that the photosensitivity of the antimony film was 20 times higher than that of crystalline germanium.

  19. Mineral Analysis of Pine Nuts (Pinus spp. Grown in New Zealand

    Directory of Open Access Journals (Sweden)

    Leo P. Vanhanen

    2013-04-01

    Full Text Available Mineral analysis of seven Pinus species grown in different regions of New Zealand; Armand pine (Pinus armandii Franch, Swiss stone pine (Pinus cembra L., Mexican pinyon (Pinus cembroides Zucc. var. bicolor Little, Coulter pine (Pinus coulteri D. Don, Johann’s pine (Pinus johannis M.F. Robert, Italian stone pine (Pinus pinea L. and Torrey pine (Pinus torreyana Parry ex Carrière, was carried out using an inductively coupled plasma optical emission spectrophotometer (ICP-OES analysis. Fourteen different minerals (Al, B, Ca, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, S and Zn were identified in all seven varieties, except that no Al or Na was found in Pinus coulteri D. Don. New Zealand grown pine nuts are a good source of Cu, Mg, Mn, P and Zn, meeting or exceeding the recommended RDI for these minerals (based on an intake of 50 g nuts/day while they supplied between 39%–89% of the New Zealand RDI for Fe. Compared to other commonly eaten tree-nuts New Zealand grown pine nuts are an excellent source of essential minerals.

  20. Pyroelectric and piezoelectric responses of thin AlN films epitaxy-grown on a SiC/Si substrate

    Science.gov (United States)

    Kukushkin, S. A.; Osipov, A. V.; Sergeeva, O. N.; Kiselev, D. A.; Bogomolov, A. A.; Solnyshkin, A. V.; Kaptelov, E. Yu.; Senkevich, S. V.; Pronin, I. P.

    2016-05-01

    This paper presents the results of pyroelectric and piezoelectric studies of AlN films formed by chloride-hydride epitaxy (CHE) and molecular beam epitaxy (MBE) on epitaxial SiC nanolayers grown on Si by the atom substitution method. The surface topography and piezoelectric and pyroelecrtric responses of AlN films have been analyzed. The results of the study have shown that the vertical component of the piezoresponse in CHE-grown AlN films is more homogeneous over the film area than that in MBE-grown AlN films. However, the signal from the MBE-synthesized AlN films proved to be stronger. The inversion of the polar axis (polarization vector) on passage from MBE-grown AlN films to CHE-grown AlN films has been found experimentally. It has been shown that the polar axis in MBE-grown films is directed from the free surface of the film toward the Si substrate while, in CHE-grown films, the polarization vector is directed toward the free surface.