Colony Structure and Nest Location of Two Species of Dacetine Ants: Pyramica ohioensis (Kennedy & Schramm and Pyramica rostrata (Emery in Maryland (Hymenoptera: Formicidae

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Richard M. Duffield

2011-01-01

Full Text Available The discovery of numerous Pyramica ohioensis and P. rostrata colonies living in acorns, as well as the efficient recovery of colonies from artificial nests placed in suitable habitats, opens a new stage in the study of North American dacetine ants. Here we present detailed information, based on 42 nest collections, on the colony structure of these two species. P. ohioensis colonies are smaller than those of P. rostrata. Both species are polygynous, but nests of P. ohioensis contain fewer dealate queens than those of P. rostrata. This is the first report of multiple collections of Pyramica colonies nesting in fallen acorns, and of the use of artificial nesting cavities to sample for dacetines in the soil and leaf litter. We describe an artificial cavity nest design that may prove useful in future investigations.

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

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 Europea...

Assessing pre- and post-zygotic barriers between North Atlantic eels (Anguilla anguilla and A. rostrata)

DEFF Research Database (Denmark)

Jacobsen, M. W.; Smedegaard, L.; Sørensen, Sune Riis

2017-01-01

Elucidating barriers to gene flow is important for understanding the dynamics of speciation. Here we investigate pre- and post-zygotic mechanisms acting between the two hybridizing species of Atlantic eels: Anguilla anguilla and A. rostrata. Temporally varying hybridization was examined by analyz...... in natural hybrids.Heredity advance online publication, 9 November 2016; doi:10.1038/hdy.2016.96....

Ground Water Modelling for the Restoration of Carex Communities on a Sandy River Terrace

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Andrzej Brandyk

2016-12-01

Full Text Available Management for sustainable river valleys requires balancing their natural values against the need for agricultural and recreational development on surrounding lands. The Southern Całowanie Peatland near the city of Warsaw sits on a sandy terrace and has well preserved Carex and Molinia stands existing in part of the area, especially where water tables are less than 1.5 m below the surface. The existing drainage network in this southern part has been poorly maintained and could be reestablished to help raise water levels for restoration of the peatland. Modflow was used to look at influence of drainage channel water levels on the overall water table height in the area. By raising water levels in the drainage system by 0.5 m it was found that 29% of the area would become suitable for increasing Carex and Molinia communities.

Seasonal dynamics of biomass partitioning in a tall sedge, Carex acuta L.

Czech Academy of Sciences Publication Activity Database

Honnisová, Markéta; Hovorka, F.; Kuncová, Š.; Moulisová, L.; Vítková, J.; Plsová, M.; Čížek, J.; Čížková, H.

2015-01-01

Roč. 125, aug (2015), s. 64-71 ISSN 0304-3770 R&D Projects: GA ČR(CZ) GAP504/11/1151 Institutional support: RVO:67179843 Keywords : biomass * Carex acuta * net primary production * Ramet * retranslocation * turnover rate * Třeboň Basin Biosphere Reserve * Wetland Subject RIV: EF - Botanics Impact factor: 1.846, year: 2015

Responses of Wetland Plant Carex vulpina to Copper and Iron Nanoparticles

Czech Academy of Sciences Publication Activity Database

Cyrusová, Tereza; Petrová, Šárka; Vaněk, Tomáš; Podlipná, Radka

2017-01-01

Roč. 228, č. 7 (2017), č. článku 258. ISSN 0049-6979 R&D Projects: GA MŠk(CZ) LD14100; GA MŠk(CZ) LD13028 Institutional support: RVO:61389030 Keywords : Carex vulpina * Metal nanoparticles * Phytotoxicity Subject RIV: DJ - Water Pollution ; Quality OBOR OECD: Bioremediation, diagnostic biotechnologies (DNA chips and biosensing devices) in environmental management Impact factor: 1.702, year: 2016

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

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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.

Rediscovery of Aquilaria rostrata (Thymelaeaceae), a species thought to be extinct, and notes on Aquilaria conservation in Peninsular Malaysia

NARCIS (Netherlands)

Lee, S.Y.; Mohamed, R.

2016-01-01

After more than 100 years since the first discovery, Aquilaria rostrata, a critically endangered species listed in the IUCN Red List and presumably extinct, has been rediscovered in Terengganu State of Peninsular Malaysia. Here, we describe the history, taxonomy, ecology and conservation status of

Antitumor activity of extract and isolated compounds from Drechslera rostrata and Eurotium tonophilum

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Fatmah A.S. Alasmary

2018-02-01

Full Text Available Total extracts of Drechslera rostrata and Eurotium tonophilum in addition of two isolated compounds from their cultures [di-2-ethylhexyl phthalate (H1 and 1,8-Dihydroxy-3-methoxy-6-methyl-anthraquinone (H2] were tested for their antitumor activity using four human carcinoma cell lines. Antitumor activity was assessed by performing MTT assay to check the % cell viability. The % viability of HCT-116 (colon carcinoma, HeLa (cervical carcinoma, HEp-2 (larynx carcinoma and HepG-2 (hepatocellular carcinoma cells decreased after treatment with Drechslera rostrata and Eurotium tonophilum extracts, these effects were ranged from 059.0 ±  0.1 to 217.0  ±  0.3 µg/ml on all types of cancer cells. The best activity was recorded for Eurotium tonpholium extract (054.5 ± 0.3, 059.0 ± 0.5 and 059.0 ± 0.1 for HEp-2, Hela, and HepG-2 respectively. The isolated compounds (H1&H2 were found to be responsible about the activities because they recorded the lowest IC50 on tested cell lines with range of 9.5–20.3 μg/ml. Vinblastine sulphate was used as a reference standard and showed in vitro anticancer activity. This study demonstrated that all extracts and isolated compounds have antitumor activity against HCT-116, HeLa, HEp-2 and HepG-2 cells.

Geographic range and morphological and chromosomal variability of Carex molestiformis (Cyperaceae) east of the Mississippi River

Science.gov (United States)

Carex molestiformis (frightful sedge), described in 1997 as an endemic to the Ozark and Ouachita Mountain regions, is newly collected from Georgia, Mississippi, and Ohio. Herbarium records have also confirmed this species from North Carolina, Virginia, and West Virginia bringing the overall range of...

Traffic-emitted metal status and uptake by Carex meyeriana Kunth and Thelypteris palustris var. pubescens Fernald growing in roadside turfy swamp in the Changbai Mountain area, China.

Science.gov (United States)

Wang, Hong; Nie, Lei; Xu, Yan; Li, Miao; Lv, Yan

2018-04-26

Six traffic-emitted metals (Cr, Zn, Cu, Cd, Pb, and Ni) were determined in soil and plants for below- and aboveground parts along different distances from highway to evaluate their behavior and uptake by Carex meyeriana Kunth and Thelypteris palustris var. pubescens Fernald growing in turfy swamps. The results indicated that the different plant tissues showed significantly different levels of metal content. Nonlinear regression analysis indicated that metal contents leveled off at constant values before they decreased as the distance from the roadside increased. The high R 2 values of the regression model indicated good fit of the exponential function applied to depict the distribution pattern of the metal elements. It was deduced that Cr, Cu, and Cd in Thelypteris palustris var. pubescens Fernald were mainly derived from the soil; Carex meyeriana Kunth and Thelypteris palustris var. pubescens Fernald absorbed Pb mainly through the stomata from atmospheric depositions; Cr, Cu, and Cd in Carex meyeriana Kunth and Zn in Thelypteris palustris var. pubescens Fernald were mainly affected by soil and atmospheric depositions. After excluding the effects of traffic, only the bioaccumulation factor of Cd (1.34) in Carex meyeriana Kunth and the translocation factor of Zn (1.13) in Thelypteris palustris var. pubescens Fernald were greater than 1, suggesting that Carex meyeriana Kunth could be a good candidate for assimilating Cd from soils and Thelypteris palustris var. pubescens Fernald could be suitable for the phytoextraction of Zn.

Dynamics of chromosome number and genome size variation in a cytogenetically variable sedge (Carex scoparia var. scoparia, Cyperaceae).

Science.gov (United States)

Chung, Kyong-Sook; Weber, Jaime A; Hipp, Andrew L

2011-01-01

High intraspecific cytogenetic variation in the sedge genus Carex (Cyperaceae) is hypothesized to be due to the "diffuse" or non-localized centromeres, which facilitate chromosome fission and fusion. If chromosome number changes are dominated by fission and fusion, then chromosome evolution will result primarily in changes in the potential for recombination among populations. Chromosome duplications, on the other hand, entail consequent opportunities for divergent evolution of paralogs. In this study, we evaluate whether genome size and chromosome number covary within species. We used flow cytometry to estimate genome sizes in Carex scoparia var. scoparia, sampling 99 plants (23 populations) in the Chicago region, and we used meiotic chromosome observations to document chromosome numbers and chromosome pairing relations. Chromosome numbers range from 2n = 62 to 2n = 68, and nuclear DNA 1C content from 0.342 to 0.361 pg DNA. Regressions of DNA content on chromosome number are nonsignificant for data analyzed by individual or population, and a regression model that excludes slope is favored over a model in which chromosome number predicts genome size. Chromosome rearrangements within cytogenetically variable Carex species are more likely a consequence of fission and fusion than of duplication and deletion. Moreover, neither genome size nor chromosome number is spatially autocorrelated, which suggests the potential for rapid chromosome evolution by fission and fusion at a relatively fine geographic scale (<350 km). These findings have important implications for ecological restoration and speciation within the largest angiosperm genus of the temperate zone.

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

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. © 2009 Blackwell Publishing Ltd.

The nervus terminalis ganglion in Anguilla rostrata: an immunocytochemical and HRP histochemical analysis.

Science.gov (United States)

Grober, M S; Bass, A H; Burd, G; Marchaterre, M A; Segil, N; Scholz, K; Hodgson, T

1987-12-08

Immunocytochemistry and retrograde horseradish peroxidase (HRP) transport were used to study the ganglion of the nervus terminalis in the American eel, Anguilla rostrata. Luteinizing hormone releasing hormone (LHRH) like immunoreactivity was found in large, ganglion-like cells located ventromedially at the junction of the telencephalon and olfactory bulb and in fibers within the retina and olfactory epithelium. HRP transport from the retina demonstrated direct connections with both the ipsi- and contralateral populations of these ganglion-like cells. Given the well-documented role of both olfaction and vision during migratory and reproductive phases of the life cycle of eels, the robust nature of a nervus terminalis system in these fish may present a unique opportunity to study the behavioral correlates of structure-function organization in a discrete population of ganglion-like cells.

THE ROLE OF THE LANDSLIDE LAKES (WETLANDS IN TRANSFORMATION OF PHYSICOCHEMICAL WATER ON THE EXAMPLE VELKE OSTURNIANSKE JAZERO, SLOVAKIA

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Tadeusz Molenda

2015-03-01

Full Text Available In the article a role of the flow bog in the transformation of the physical-chemical properties of waters was described. They demonstrated that in the water flowing out of the bog a fall in the mineralization and concentrations of selected ions take place towards feedwaters. The species stated within the bog of plants, mainly Carex rostrata, Schoenoplectus lacustris, Equisetum fluviatile, Juncus effusus, Menyanthes trifoliata can be found the under construction application of sewage treatment plant on highlands of the Western Carpathians (to 900 m.n.p.m., the average annual air temperature > of 5 °C and the time of lying of the snowy lid of 90 days in the year.

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

Tolerance of photoperiod insensitive mutant of Sesbania rostrata to salinity and pH

International Nuclear Information System (INIS)

Ramani, Saradha; Joshua, D.C.; Shaikh, M.S.; Athalye, V.V.

1998-01-01

The photoperiod insensitive mutant, TSR-1 of Sesbania rostrata was compared with the parent variety for its response to soil salinity and different levels of pH in hydroponics. The plant growth and stem nodulation were not significantly affected by salinity. However, salinity in soil without farmyard manure stimulated plant growth. Radiotracer studies showed that the translocation of Na to stem and leaves was much less compared to uptake in both parent and mutant. The growth of TSR-1 was comparable to or marginally better than that of the parent variety in the pH range of 3.5-8.0. Root nodulation was less with low pH. The nitrogen content was not adversely affected by pH, but it was reduced with 200 mM NaCl. This mutant in addition to being short-day insensitive, is tolerant to low to moderate salinity levels and pH like its parent. (author)

Evaluation of three telemetry transmitter attachment methods for female silver-phase American eels ( Anguilla rostrata Lesueur)

DEFF Research Database (Denmark)

Cottrill, R.A.; Økland, F.; Aarestrup, Kim

2006-01-01

Declines in juvenile American eel (Anguilla rostrata Lesueur) abundance have led to concern about the impacts of anthropogenic structures on eel migration patterns. Telemetry provides an insightful tool for examining the movements of eels around these structures. Although there have been a number...... of studies investigating movements of Anguillid eels, using a variety of transmitter attachment techniques, there are few published evaluations of the effects of various tag attachment procedures. Hence, the effects of three telemetry attachment procedures were evaluated for female silver phase American eels...... of silver-phase American eels is not affected by the presence of telemetry transmitters or the method of transmitter attachment, even though swim performance decreases. However, transmitter retention rates varied considerably after the 12-week experimental period. Three gastric tags were regurgitated...

Cryptic Species Due to Hybridization: A Combined Approach to Describe a New Species (Carex: Cyperaceae).

Science.gov (United States)

Maguilla, Enrique; Escudero, Marcial

2016-01-01

Disappearance of diagnostic morphological characters due to hybridization is considered to be one of the causes of the complex taxonomy of the species-rich (ca. 2000 described species) genus Carex (Cyperaceae). Carex furva s.l. belongs to section Glareosae. It is an endemic species from the high mountains of the Iberian Peninsula (Spain and Portugal). Previous studies suggested the existence of two different, cryptic taxa within C. furva s.l. Intermediate morphologies found in the southern Iberian Peninsula precluded the description of a new taxa. We aimed to determine whether C. furva s.l. should be split into two different species based on the combination of morphological and molecular data. We sampled ten populations across its full range and performed a morphological study based on measurements on herbarium specimens and silica-dried inflorescences. Both morphological and phylogenetic data support the existence of two different species within C. furva s.l. Nevertheless, intermediate morphologies and sterile specimens were found in one of the southern populations (Sierra Nevada) of C. furva s.l., suggesting the presence of hybrid populations in areas where both supposed species coexist. Hybridization between these two putative species has blurred morphological and genetic limits among them in this hybrid zone. We have proved the utility of combining molecular and morphological data to discover a new cryptic species in a scenario of hybridization. We now recognize a new species, C. lucennoiberica, endemic to the Iberian Peninsula (Sierra Nevada, Central system and Cantabrian Mountains). On the other hand, C. furva s.s. is distributed only in Sierra Nevada, where it may be threatened by hybridization with C. lucennoiberica. The restricted distribution of both species and their specific habitat requirements are the main limiting factors for their conservation.

Cryopreservation studies of an artificial co-culture between the cobalamin-requiring green alga Lobomonas rostrata and the bacterium Mesorhizobium loti.

Science.gov (United States)

Ridley, Christian J A; Day, John G; Smith, Alison G

2018-01-01

Algal-bacterial co-cultures, rather than cultures of algae alone, are regarded as having the potential to enhance productivity and stability in industrial algal cultivation. As with other inocula in biotechnology, to avoid loss of production strains, it is important to develop preservation methods for the long-term storage of these cultures, and one of the most commonly used approaches is cryopreservation. However, whilst there are many reports of cryopreserved xenic algal cultures, little work has been reported on the intentional preservation of both algae and beneficial bacteria in xenic cultures. Instead, studies have focused on the development of methods to conserve the algal strain(s) present, or to avoid overgrowth of bacteria in xenic isolates during the post-thaw recovery phase. Here, we have established a co-cryopreservation method for the long-term storage of both partners in a unialgal-bacterial co-culture. This is an artificial model mutualism between the alga Lobomonas rostrata and the bacterium Mesorhizobium loti , which provides vitamin B 12 (cobalamin) to the alga in return for photosynthate. Using a Planer Kryo 360 controlled-rate cooler, post-thaw viability (PTV) values of 72% were obtained for the co-culture, compared to 91% for the axenic alga. The cultures were successfully revived after 6 months storage in liquid nitrogen, and continued to exhibit mutualism. Furthermore, the alga could be cryopreserved with non-symbiotic bacteria, without bacterial overgrowth occurring. It was also possible to use less controllable passive freezer chambers to cryopreserve the co-cultures, although the PTV was lower. Finally, we demonstrated that an optimised cryopreservation method may be used to prevent the overgrowth potential of non-symbiotic, adventitious bacteria in both axenic and co-cultures of L. rostrata after thawing.

Revegetation dynamics after 15 years of rewetting in two extracted peatlands in Sweden

Directory of Open Access Journals (Sweden)

S.A. Kozlov

2016-02-01

Full Text Available The restoration of extracted peatlands poses challenges with regard to their recolonisation by vegetation. The most significant problems are unstable water levels, destroyed propagule bank, and temperature fluctuations on bare peat surfaces. Rewetting is considered necessary for the re-establishment of peat-forming vegetation. Revegetation was investigated in a long-term field study at two rewetted extracted peatland sites in south-central Sweden, namely Västkärr (originally a lagg fen and Porla (originally a bog. Both sites were expanses of bare peat before rewetting. Rewetting procedures were applied in 1999 and strongly promoted plant colonisation. At Västkärr, colonisation started in the first year after rewetting, mostly by species that were not found during repeat vegetation surveys 15 years later. By 2014, Västkärr was a shallow lake surrounded by mesotrophic and eutrophic vegetation with species such as Carex rostrata, Lemna minor, Typha latifolia, Phalaris arundinacea and Phragmites australis. Revegetation of the Porla site was slower and started with Eriophorum vaginatum and Polytrichum spp. Sphagnum mosses appeared after six years and had established quite well after 13 years. A residual Sphagnum peat layer, inflowing surface water and groundwater provided spatially variable nutrient conditions. Sphagnum species and E. vaginatum established in nutrient-poor areas, while C. rostrata, P. australis and Eriophorum angustifolium colonised more nutrient-rich locations.

A semi-automated method of monitoring dam passage of American Eels Anguilla rostrata

Science.gov (United States)

Welsh, Stuart A.; Aldinger, Joni L.

2014-01-01

Fish passage facilities at dams have become an important focus of fishery management in riverine systems. Given the personnel and travel costs associated with physical monitoring programs, automated or semi-automated systems are an attractive alternative for monitoring fish passage facilities. We designed and tested a semi-automated system for eel ladder monitoring at Millville Dam on the lower Shenandoah River, West Virginia. A motion-activated eel ladder camera (ELC) photographed each yellow-phase American Eel Anguilla rostrata that passed through the ladder. Digital images (with date and time stamps) of American Eels allowed for total daily counts and measurements of eel TL using photogrammetric methods with digital imaging software. We compared physical counts of American Eels with camera-based counts; TLs obtained with a measuring board were compared with TLs derived from photogrammetric methods. Data from the ELC were consistent with data obtained by physical methods, thus supporting the semi-automated camera system as a viable option for monitoring American Eel passage. Time stamps on digital images allowed for the documentation of eel passage time—data that were not obtainable from physical monitoring efforts. The ELC has application to eel ladder facilities but can also be used to monitor dam passage of other taxa, such as crayfishes, lampreys, and water snakes.

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

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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 �

Methane stable isotope distribution at a Carex dominated fen in North Central Alberta

Science.gov (United States)

Popp, Trevor J.; Chanton, Jeffrey P.; Whiting, Gary J.; Grant, Nick

1999-12-01

The methane stable isotope distribution was characterized at a Carex dominated fen in boreal Alberta, Canada, over three growing seasons to examine methane production, oxidation, and transport to the atmosphere; processes which are strongly tied to emergent vegetation and the influence of the rhizosphere (upper 20 cm of peat in this system]. At times when standing floodwater was present, δ13C values of emitted methane averaged -63.6 ± 2.3, -66.3 ± 1.6, and -65.4 ± 1.3‰ for the 1994, 1995, and 1996 seasons, respectively. These emissions were significantly 13C depleted relative to the belowground methane dissolved in rhizospheric pore waters, indicating that gas transport in Carex is dominated by passive diffusion. The rhizosphere was 13CH4 enriched relative to depths below the rhizosphere, consistent with the occurrence of root associated methane oxidation, preferential mobilization of 13CH4, and a relatively greater role of acetate fermentation type methane production. Dual isotope tracers, δ13C and δD, help qualify the role of each of these processes and aid in describing the distribution of production pathways, CO2 reduction, and acetate fermentation. Inverse trends in δ13C-CH4 and δD-CH4 depth profiles are consistent with an interpretation suggesting an evolution toward methane production by CO2 reduction with increasing depth. A shift in production mechanisms appears to be the dominate process affecting the stable isotope distribution below 10 cm in the peat column, while oxidation and transport isotope effects are dominant above 10 cm. To test several hypotheses regarding the effects of transport, oxidation, and production on methane isotope distributions, we also present measurements from sites fertilized and sites devegetated (continually clipped) over the 3 year period. Removal of vegetation quickly halted rhizospheric methane oxidation and gas transport while gradually increasing the relative role of CO2 reduction in net methane production as

Plant biomass carbon store after water-level drawdown of pine mires

Energy Technology Data Exchange (ETDEWEB)

Laiho, R; Laine, J [Helsinki Univ. (Finland). Dept. of Ecology

1997-12-31

Tall-sedge pine fen is the site type most commonly drained in Finland. In their natural undrained condition sites of this type are rather wet with sparse, Scots pine dominated forest growing on hummocks and with large lawns dominated by sedges, usually Carex rostrata and/or C. lasiocarpa. Most of the primary production takes place in the field and ground layers. The major pathway for carbon accumulation in the system is via Sphagna and sedge roots, carbon accumulation by the tree stand being very slow. After drainage the situation changes radically as the sedges die out and the tree stand growth increases considerably. The aim of this study is to produce means of estimating the post-drainage dynamics of the plant biomass carbon store. The study is based on the assumption that sites similar before drainage will change in a similar manner following drainage. (5 refs.)

Plant biomass carbon store after water-level drawdown of pine mires

Energy Technology Data Exchange (ETDEWEB)

Laiho, R.; Laine, J. [Helsinki Univ. (Finland). Dept. of Ecology

1996-12-31

Tall-sedge pine fen is the site type most commonly drained in Finland. In their natural undrained condition sites of this type are rather wet with sparse, Scots pine dominated forest growing on hummocks and with large lawns dominated by sedges, usually Carex rostrata and/or C. lasiocarpa. Most of the primary production takes place in the field and ground layers. The major pathway for carbon accumulation in the system is via Sphagna and sedge roots, carbon accumulation by the tree stand being very slow. After drainage the situation changes radically as the sedges die out and the tree stand growth increases considerably. The aim of this study is to produce means of estimating the post-drainage dynamics of the plant biomass carbon store. The study is based on the assumption that sites similar before drainage will change in a similar manner following drainage. (5 refs.)

[Advenella kashmirensis subsp. methylica PK1, a facultative methylotroph from carex rhizosphere].

Science.gov (United States)

Poroshina, M N; Doronina, N V; Kaparullina, E N; Trotsenko, Iu A

2015-01-01

A strain (PK1) of facultative methylobacteria growing on methanol as a carbon and energy source was isolated from carex rhizosphere (Pamukkale National Park, Turkey). The cells were nonmotile gram-negative rods propagating by binary fission. The organism was a strict anaerobe, oxidase- and catalase-positive. Optimal growth occurred at 29°C, pH 8.0-8.5, and 0.5% NaCl; no growth occurred at 2% NaCl. The organism used the ribulose bisphosphate pathway of C1 assimilation. Predominant fatty acids were 11-octodecenoic (18:1ω7) and cis-hexadecenoic (16:1ω7c). Phosphatidylethanolamine and diphosphatidylglycerol were the dominant phospholipids. Q8 was the main ubiquinone. DNA G+C content was 55.4 mol % (mp). Sequencing of the 16S rRNA gene revealed that strain PK1 belonged to the genus Advenella with 98.8 and 99.2% similarity to the type strains A. incenata CCUG 45225T and A. kashmirensis WT001T, respectively. DNA-DNA homology of strain PK1 and A. kashmirensis WT001T was 70%. While MALDI analysis confirmed their close clusterization, RAPD analysis revealed the differences between strain PKI and other Advenella strains. Based on its geno- and phenotypic properties, the isolate PK1 was classified as A. kashmirensis subsp. methylica PK1 (VKM-B 2850 = DSM 27514), the first known methylotroph of the genus Advenella.

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...... the ecophysiological traits contributing to invasive behaviour. The photosynthesis-nitrogen relationship was uniform across all three species, and the maximum light-saturated rate of photosynthesis expressed on a leaf area basis (Amaxa) did not differ significantly between species. However, specific leaf area (SLA...... the sedges, but correlations between leaf N, gas exchange parameters (Amaxa, Amaxm, Rd and gs) and RGR were all highly significant in G. maxima, whereas they were weak or absent in the sedges. Allocation of biomass (root:shoot ratio, leaf mass ratio, root mass ratio), plant N and P content, and allocation...

Fabrication of cellulose nanocrystal from Carex meyeriana Kunth and its application in the adsorption of methylene blue.

Science.gov (United States)

Yang, Xue; Liu, Hui; Han, Fuyi; Jiang, Shuai; Liu, Lifang; Xia, Zhaopeng

2017-11-01

Cellulose nanocrystal (CNC) was extracted from Carex meyeriana Kunth (CMK) by a combination of TEMPO oxidation and mechanical homogenization method, and used to remove methylene blue (MB) from aqueous solution. After alkali-oxygen treatment, the aqueous biphasic system (polyethylene glycol/inorganic salt) was applied to further remove lignin from CMK. The characteriazation of CNC, and the effects of H 2 O 2 dosage, CNC dosage, adsorption time, and initial MB concentration on the MB removal capacity of CNC were investigated. The results showed that the removal percentage of MB by CNC was raised with the increase of H 2 O 2 and CNC dosage. The adsorption kinetics of prepared CNC followed the pseudo-second-order model, and the adsorption isotherms fitted well to the Langmuir model with a calculated maximum adsoption capacity of 217.4mg/g, which was higher than those of CNC extracted by acid hydrolysis method, indicating CNC extracted from CMK had promising potentials in the field of MB adsorption. Copyright © 2017 Elsevier Ltd. All rights reserved.

Allopatric speciation despite historical gene flow: Divergence and hybridization in Carex furva and C. lucennoiberica (Cyperaceae) inferred from plastid and nuclear RAD-seq data.

Science.gov (United States)

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

2017-10-01

Gene flow among incipient species can act as a creative or destructive force in the speciation process, generating variation on which natural selection can act while, potentially, undermining population divergence. The flowering plant genus Carex exhibits a rapid and relatively recent radiation with many species limits still unclear. This is the case with the Iberian Peninsula (Spain and Portugal)-endemic C. lucennoiberica, which lay unrecognized within Carex furva until its recent description as a new species. In this study, we test how these species were impacted by interspecific gene flow during speciation. We sampled the full range of distribution of C. furva (15 individuals sampled) and C. lucennoiberica (88 individuals), sequenced two cpDNA regions (atpI-atpH, psbA-trnH) and performed genomic sequencing of 45,100 SNPs using restriction site-associated DNA sequencing (RAD-seq). We utilized a set of partitioned D-statistic tests and demographic analyses to study the degree and direction of introgression. Additionally, we modelled species distributions to reconstruct changes in range distribution during glacial and interglacial periods. Plastid, nuclear and morphological data strongly support divergence between species with subsequent gene flow. Combined with species distribution modelling, these data support a scenario of allopatry leading to species divergence, followed by secondary contact and gene flow due to long-distance dispersal and/or range expansions and contractions in response to Quaternary glacial cycles. We conclude that this is a case of allopatric speciation despite historical secondary contacts, which could have temporally influenced the speciation process, contributing to the knowledge of forces that are driving or counteracting speciation. © 2017 John Wiley & Sons Ltd.

Water Purification Characteristic of the Actual Constructed Wetland with Carex dispalata in a Cold Area

Science.gov (United States)

Tsuji, Morio; Yamada, Kazuhiro; Hiratsuka, Akira; Tsukada, Hiroko

Carex dispalata, a native plant species applied in cold districts for water purification in constructed wetlands, has useful characteristics for landscape creation and maintenance. In this study, seasonal differences in purification ability were verified, along with comparison of frozen and non-frozen periods' performance. A wetland area was constructed using a “hydroponics method” and a “coir fiber based method”. Results show that the removal rates of BOD, SS, and Chl-a were high. On this constructed wetland reduces organic pollution, mainly phytoplankton, but the removal of nitrogen and phosphorus was insufficient. The respective mean values of influent and treated water during three years were 26.6 mg/L and 12.2 mg/L for BOD, and 27.9 mg/L and 7.5 mg/L for SS. The mean value of the BOD removal rate for the non-frozen period was 2.99 g/m2/d that for the frozen period was 1.86 g/m2/d. The removal rate followed the rise of the BOD load rate. The removal rate limits were about 4 g/m2/d during the frozen period and 15 g/m2/d during the non-frozen period. For operations, energy was unnecessary. The required working hours were about 20 h annually for all maintenance and management during operations.

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)

Participation of IPEN in the international program of information about occupational exposure to carcinogen risks; Participacion del IPEN en el programa internacional de informacion sobre exposicion ocupacional de riesgos cancerigenos (CAREX-Peru)

Energy Technology Data Exchange (ETDEWEB)

Osores, Jose; Gonzales, Susana [Direccion de Servicios, Instituto Peruano de Energia Nuclear, Lima (Peru)

2014-07-01

During 2014, the Peruvian Nuclear Energy Institute participated in the mapping of risks to carcinogens due to occupational exposure for our country through CAREX program because all radioactive substances are considered by the International Agency for Research Cancer as type 1 carcinogens (high risk) and the presence of these substances in the work environment are unknown to professionals from other institutions. This occasion allowed the incorporation of Natural Occurring Radioactive Materials (NORM) as indicators in all work activities that were not considered by the Energy and Mining Sector. (authors).

Affects N fertilization intensity and composition of root exudation from two plant species differing in their exploitation strategy?

Science.gov (United States)

Kotas, Petr; Kastovska, Eva

2017-04-01

The rhizosphere represents one of the most important hotspots of microbial activity in soil. As such, it controls soil element cycling and significantly contributes to important ecosystem processes like C and N sequestration. The close plant-microbe-soil interactions in the rhizosphere are mediated by the input of labile exudates into the surroundings of plant roots. Thus microbial performance is constrained by the intensity and composition of root exudation. However, it is poorly understood how closely root exudation corresponds with the plant metabolome and how it is related to plant traits and changing environmental conditions. To fill this gap, we determined the composition of the root metabolic pool and root exudates in two plant species differing in their exploitation type (conservative Carex acuta versus competitive Glyceria maxima) grown for two months in controlled conditions and treated weekly by two levels of foliar N fertilization. Based on previous studies, we knew that Glyceria has, compared to Carex, a lower tissue C:N ratio, higher photosynthetic rate, higher allocation belowground and also larger investment to exudation. Prior to extraction, the roots were cleaned by water and immediately frozen in liquid N2. The root exudates were collected from carefully cleaned roots of living plants encased in glass vials with water and subsequently lyophilised. Both sample types were silylated and analysed for their metabolic profiles using GC-MS/MS. Our results revealed that the metabolite content in root tissue (DW basis) of Glyceria was on average lower compared to Carex, but increased with fertilization, while the root tissue of Carex was characterized by significantly higher metabolite content in the low intensity fertilization treatment compared to both the control and high N fertilization intensity. In contrast, the amount of exuded compounds was much higher in Glyceria compared to Carex in the control plants, but decreased for Glyceria and increased

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)

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.

Flavonoid concentrations in three grass species and a sedge grown in the field and under controlled environment conditions in response to enhanced UV-B radiation.

NARCIS (Netherlands)

van de Staaij, J.W.M.; Bakker, N.; Oosthoek, A.; Broekman, R.A.; van Beem, A.P.; Stroetenga, M.J.; Aerts, R.; Rozema, J.

2002-01-01

An investigation was carried out to find whether enhanced levels of UV-B radiation induce increased concentrations of flavonoids in the leaves of the grass species Deschampsia antarctica, Deschampsia borealis and Calamagrostis epigeios and the sedge Carex arenaria. Whether the enhanced levels of

Isoprene emission from wetland sedges

Directory of Open Access Journals (Sweden)

A. Ekberg

2009-04-01

Full Text Available High latitude wetlands play an important role for the surface-atmosphere exchange of carbon dioxide (CO₂ and methane (CH₄, but fluxes of biogenic volatile organic compounds (BVOC in these ecosystems have to date not been extensively studied. This is despite BVOC representing a measurable proportion of the total gaseous C fluxes at northern locations and in the face of the high temperature sensitivity of these systems that requires a much improved process understanding to interpret and project possible changes in response to climate warming. We measured emission of isoprene and photosynthetic gas exchange over two growing seasons (2005–2006 in a subarctic wetland in northern Sweden with the objective to identify the physiological and environmental controls of these fluxes on the leaf scale. The sedge species Eriophorum angustifolium and Carex rostrata were both emitters of isoprene. Springtime emissions were first detected after an accumulated diurnal mean temperature above 0^°C of about 100 degree days. Maximum measured growing season standardized (basal emission rates (20^°C, 1000 μmol m⁻² s⁻¹ were 1075 (2005 and 1118 (2006 μg C m⁻² (leaf area h⁻¹ in E. angustifolium, and 489 (2005 and 396 (2006 μg C m⁻² h⁻¹ in C. rostrata. Over the growing season, basal isoprene emission varied in response to the temperature history of the last 48 h. Seasonal basal isoprene emission rates decreased with leaf nitrogen (N, which may be explained by the typical growth and resource allocation pattern of clonal sedges as the leaves age. The observations were used to model emissions over the growing season, accounting for effects of temperature history, links to leaf assimilation rate and the light and temperature dependencies of the cold-adapted sedges.

The distribution of {sup 137}Cs, K, Rb and Cs in plants in a Sphagnum-dominated peatland in eastern central Sweden

Energy Technology Data Exchange (ETDEWEB)

Vinichuk, M., E-mail: mykhailo.vinichuk@mark.slu.s [Department of Soil and Environment, Swedish University of Agricultural Sciences, SLU, P.O. Box 7014, SE-750 07 Uppsala (Sweden); Department of Ecology, Zhytomyr State Technological University, 103 Chernyakhovsky Street, 10005 Zhytomyr (Ukraine); Johanson, K.J. [Department of Soil and Environment, Swedish University of Agricultural Sciences, SLU, P.O. Box 7014, SE-750 07 Uppsala (Sweden); Rydin, H. [Department of Plant Ecology, Evolutionary Biology Centre, Uppsala University, Norbyvaegen 18D, SE-752 36 Uppsala (Sweden); Rosen, K. [Department of Soil and Environment, Swedish University of Agricultural Sciences, SLU, P.O. Box 7014, SE-750 07 Uppsala (Sweden)

2010-02-15

We record the distribution of {sup 137}Cs, K, Rb and Cs within individual Sphagnum plants (down to 20 cm depth) as well as {sup 137}Cs in vascular plants growing on a peatland in eastern central Sweden. In Calluna vulgaris{sup 137}Cs was mainly located within the green parts, whereas Andromeda polifolia, Eriophorum vaginatum and Vaccinium oxycoccos showed higher {sup 137}Cs activity in roots. Carex rostrata and Menyanthes trifoliata showed variable distribution of {sup 137}Cs within the plants. The patterns of {sup 137}Cs activity concentration distribution as well as K, Rb and Cs concentrations within individual Sphagnum plants were rather similar and were usually highest in the capitula and/or in the subapical segments and lowest in the lower dead segments, which suggests continuous relocation of those elements to the actively growing apical part. The {sup 137}Cs and K showed relatively weak correlations, especially in capitula and living green segments (0-10 cm) of the plant (r = 0.50). The strongest correlations were revealed between {sup 137}Cs and Rb (r = 0.89), and between {sup 137}Cs and stable Cs (r = 0.84). This suggests similarities between {sup 137}Cs and Rb in uptake and relocation within the Sphagnum, but that {sup 137}Cs differs from K.

The distribution of 137Cs, K, Rb and Cs in plants in a Sphagnum-dominated peatland in eastern central Sweden

International Nuclear Information System (INIS)

Vinichuk, M.; Johanson, K.J.; Rydin, H.; Rosen, K.

2010-01-01

We record the distribution of 137 Cs, K, Rb and Cs within individual Sphagnum plants (down to 20 cm depth) as well as 137 Cs in vascular plants growing on a peatland in eastern central Sweden. In Calluna vulgaris 137 Cs was mainly located within the green parts, whereas Andromeda polifolia, Eriophorum vaginatum and Vaccinium oxycoccos showed higher 137 Cs activity in roots. Carex rostrata and Menyanthes trifoliata showed variable distribution of 137 Cs within the plants. The patterns of 137 Cs activity concentration distribution as well as K, Rb and Cs concentrations within individual Sphagnum plants were rather similar and were usually highest in the capitula and/or in the subapical segments and lowest in the lower dead segments, which suggests continuous relocation of those elements to the actively growing apical part. The 137 Cs and K showed relatively weak correlations, especially in capitula and living green segments (0-10 cm) of the plant (r = 0.50). The strongest correlations were revealed between 137 Cs and Rb (r = 0.89), and between 137 Cs and stable Cs (r = 0.84). This suggests similarities between 137 Cs and Rb in uptake and relocation within the Sphagnum, but that 137 Cs differs from K.

The distribution of (137)Cs, K, Rb and Cs in plants in a Sphagnum-dominated peatland in eastern central Sweden.

Science.gov (United States)

Vinichuk, M; Johanson, K J; Rydin, H; Rosén, K

2010-02-01

We record the distribution of (137)Cs, K, Rb and Cs within individual Sphagnum plants (down to 20cm depth) as well as (137)Cs in vascular plants growing on a peatland in eastern central Sweden. In Calluna vulgaris(137)Cs was mainly located within the green parts, whereas Andromeda polifolia, Eriophorum vaginatum and Vaccinium oxycoccos showed higher (137)Cs activity in roots. Carex rostrata and Menyanthes trifoliata showed variable distribution of (137)Cs within the plants. The patterns of (137)Cs activity concentration distribution as well as K, Rb and Cs concentrations within individual Sphagnum plants were rather similar and were usually highest in the capitula and/or in the subapical segments and lowest in the lower dead segments, which suggests continuous relocation of those elements to the actively growing apical part. The (137)Cs and K showed relatively weak correlations, especially in capitula and living green segments (0-10cm) of the plant (r=0.50). The strongest correlations were revealed between (137)Cs and Rb (r=0.89), and between (137)Cs and stable Cs (r=0.84). This suggests similarities between (137)Cs and Rb in uptake and relocation within the Sphagnum, but that (137)Cs differs from K. Copyright 2009 Elsevier Ltd. All rights reserved.

Cut from the same cloth: The convergent evolution of dwarf morphotypes of the Carex flava group (Cyperaceae) in Circum-Mediterranean mountains

Science.gov (United States)

Benítez-Benítez, Carmen; Fernández-Mazuecos, Mario; Martín-Bravo, Santiago

2017-01-01

Plants growing in high-mountain environments may share common morphological features through convergent evolution resulting from an adaptative response to similar ecological conditions. The Carex flava species complex (sect. Ceratocystis, Cyperaceae) includes four dwarf morphotypes from Circum-Mediterranean mountains whose taxonomic status has remained obscure due to their apparent morphological resemblance. In this study we investigate whether these dwarf mountain morphotypes result from convergent evolution or common ancestry, and whether there are ecological differences promoting differentiation between the dwarf morphotypes and their taxonomically related large, well-developed counterparts. We used phylogenetic analyses of nrDNA (ITS) and ptDNA (rps16 and 5’trnK) sequences, ancestral state reconstruction, multivariate analyses of macro- and micromorphological data, and species distribution modeling. Dwarf morphotype populations were found to belong to three different genetic lineages, and several morphotype shifts from well-developed to dwarf were suggested by ancestral state reconstructions. Distribution modeling supported differences in climatic niche at regional scale between the large forms, mainly from lowland, and the dwarf mountain morphotypes. Our results suggest that dwarf mountain morphotypes within this sedge group are small forms of different lineages that have recurrently adapted to mountain habitats through convergent evolution. PMID:29281689

Ecological profiles of wetland plant species in the northern Apennines (N. Italy

Directory of Open Access Journals (Sweden)

Marcello TOMASELLI

2003-02-01

Full Text Available Eighteen selected species occurring in the wetlands of the northern Apennines were studied by the ecological profile method. By this method, it is possible to identify the ecological factors mostly influencing species distribution within a particular vegetation. Moreover, it is possible to evaluate both ecological amplitude and ecological preferences of species. Ecological profiles were built for three factors (altitude, pH and electrical conductivity from a data set of 265 phytosociological relevés, used for altitude, and from a set of 92 measures, carried out in selected sites, for idrochemical variables. By numerical classification, based on chord distance and minimum variance, the ecological species groups for each factor were individuated. Subsequently, they were ordered by correspondence analysis for detecting relationships between ecological groups and classes of factors. By applying a goodness-of-fit test to ecological profiles, the species significantly deviating from uniformity were detected. They can be regarded as indicators for the corresponding ecological factor. We found seven indicator species for altitude (Carex nigra, C. rostrata, Juncus filiformis, J. alpino-articulatus, Eriophorum latifolium, E. angustifolium and Warnstorfia exannulata, four indicator species for electrical conductivity (Campylium stellatum, Carex tumidicarpa, Eriophorum latifolium and Juncus alpino-articulatus and one indicator species for pH (Sphagnum capillifolium. The ecological profiles of the wetland species in the northern Apennines were compared with those reported in literature for the same species from the Alps (namely Dolomites. In this way, a certain degree of ecological shift in several wetland species of the northern Apennines was documented. For altitude, it is possible to explain the shift considering the reduced elevational amplitude of northern Apennine wetlands with respect to those of the Alps. For pH, Sphagnum capillifolium occurs in

Effect of clone size on submergence tolerance and post-submergence growth recovery in Carex brevicuspis (Cyperaceae

Directory of Open Access Journals (Sweden)

Zhengmiao Deng

2016-12-01

Full Text Available Clonal plants are prevalent in wetlands and play important roles in maintaining the functions of the ecosystem. In the present study, we determined the effect of clone sizes (R1, R2, and R3 comprising 1, 3, and 5clumping ramets on the tolerance of Carex brevicuspis growing under 30-cm-deep water to three different periods (one, two, and three months of submergence and its growth recovery one month after de-submergence. Our results showed that the relative growth rate (RGR of C. brevicuspis significantly declined with increasing submergence time, and was higher in R3 and R5 than in R1 plants under both submergence and post-submergence conditions. The concentration of water-soluble carbohydrates (WSCs was highest in R3, intermediate in R5, and the lowest in R1 plants during the first two months of submergence, indicating an optimal trade-off between energy investment and vegetative growth (i.e., buds and ramets production in C. brevicuspis. WSCs were significantly reduced with increasing submergence time, while the starch content was significantly reduced only during the third month of submergence, implying that WSCs were a direct energy source for C. brevicuspis during submergence. The number of buds was higher in R5 than in R3 and R1 plants after two and three months of submergence, which directly resulted in a significantly higher post-submergence ramet production in R5 plants. These results indicated that plants with relatively larger clone sizes display better tolerance to submergence stress and post-submergence growth recovery. Therefore, we speculate that the large clone size in C brevicuspis might be an effective adaptive mechanism to survive under submergence stress in floodplain wetlands.

A Laboratory of Extremophiles: Iceland Coordination Action for Research Activities on Life in Extreme Environments (CAREX Field Campaign

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Robert Hänsch

2013-02-01

Full Text Available Existence of life in extreme environments has been known for a long time, and their habitants have been investigated by different scientific disciplines for decades. However, reports of multidisciplinary research are uncommon. In this paper, we report an interdisciplinary three-day field campaign conducted in the framework of the Coordination Action for Research Activities on Life in Extreme Environments (CAREX FP7EU program, with participation of experts in the fields of life and earth sciences. In situ experiments and sampling were performed in a 20 m long hot springs system of different temperature (57 °C to 100 °C and pH (2 to 4. Abiotic factors were measured to study their influence on the diversity. The CO2 and H2S concentration varied at different sampling locations in the system, but the SO2 remained the same. Four biofilms, mainly composed by four different algae and phototrophic protists, showed differences in photosynthetic activity. Varying temperature of the sampling location affects chlorophyll fluorescence, not only in the microbial mats, but plants (Juncus, indicating selective adaptation to the environmental conditions. Quantitative polymerase chain reaction (PCR, DNA microarray and denaturing gradient gel electrophoresis (DGGE-based analysis in laboratory showed the presence of a diverse microbial population. Even a short duration (30 h deployment of a micro colonizer in this hot spring system led to colonization of microorganisms based on ribosomal intergenic spacer (RISA analysis. Polyphasic analysis of this hot spring system was possible due to the involvement of multidisciplinary approaches.

A novel recombinant bivalent outer membrane protein of Vibrio vulnificus and Aeromonas hydrophila as a vaccine antigen of American eel (Anguilla rostrata).

Science.gov (United States)

SongLin, Guo; PanPan, Lu; JianJun, Feng; JinPing, Zhao; Peng, Lin; LiHua, Duan

2015-04-01

The immogenicity of a novel vaccine antigen was evaluated after immunized American eels (Anguilla rostrata) with a recombinant bivalent expressed outer membrane protein (OMP) of Vibrio vulnificus and Aeromonas hydrophila. Three groups of eels were intraperitoneal (i.p) injected with phosphate-buffered saline (PBS group), formaline-killed-whole-cell (FKC) of A. hydrophila and V. vulnificus (FKC group) or the bivalent OMP (OMP group). On 14, 21, 28 and 42 days post-vaccination respectively, proliferation of the whole blood cells, titers of specific antibody and lysozyme activities of experimental eels were detected. On 28 day post-vaccination, eels from three groups were challenged by i.p injection of live A. hydrophila or V. vulnificus. The results showed that, compared with the PBS group, proliferation of whole blood cells in OMP group was significant enhanced on 28 days, and the serum titers of anti-A.hydrophila and anti-V. vulnificus antibody in eels of FKC and OMP group were significant increased on 14, 21 and 28d. Lysozyme Activities in serum, skin mucus, liver and kidney were significant changed between the three groups. Relative Percent Survival (RPS) after challenged A. hydrophila in KFC vs. PBS group and OMP vs. PBS group were 62.5% and 50% respectively, and the RPS challenged V. vulnificus in FKC and OMP vs. PBS group were 37.5% and 50% respectively. These results suggest that American eels immunized with the bivalent OMP would positively affect specific as well as non-specific immune parameters and protect against infection by the two pathogens in fresh water farming. Copyright © 2015 Elsevier Ltd. All rights reserved.

Azorhizobium caulinodans Transmembrane Chemoreceptor TlpA1 Involved in Host Colonization and Nodulation on Roots and Stems

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Wei Liu

2017-07-01

Full Text Available Azorhizobium caulinodans ORS571 is a motile soil bacterium that interacts symbiotically with legume host Sesbania rostrata, forming nitrogen-fixing root and stem nodules. Bacterial chemotaxis plays an important role in establishing this symbiotic relationship. To determine the contribution of chemotaxis to symbiosis in A. caulinodans ORS571-S. rostrata, we characterized the function of TlpA1 (transducer-like protein in A. caulinodans, a chemoreceptor predicted by SMART (Simple Modular Architecture Research Tool, containing two N-terminal transmembrane regions. The tlpA1 gene is located immediately upstream of the unique che gene cluster and is transcriptionally co-oriented. We found that a ΔtlpA1 mutant is severely impaired for chemotaxis to various organic acids, glycerol and proline. Furthermore, biofilm forming ability of the strain carrying the mutation is reduced under certain growth conditions. Interestingly, competitive colonization ability on S. rostrata root surfaces is impaired in the ΔtlpA1 mutant, suggesting that chemotaxis of the A. caulinodans ORS571 contributes to root colonization. We also found that TlpA1 promotes competitive nodulation not only on roots but also on stems of S. rostrata. Taken together, our data strongly suggest that TlpA1 is a transmembrane chemoreceptor involved in A. caulinodans-S. rostrata symbiosis.

Nitrogen–use efficiency in different vegetation type at Cikaniki Research Station, Halimun-Salak Mountain National Park, West Java

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SUHARNO

2007-10-01

Full Text Available A research about nitrogen–use efficiency (NUE and trees identification was conducted at different vegetation type at Cikaniki, Halimun-Salak National Park, West Java. Plot quadrate methods (20 x 50 m was used to analyze trees vegetation and Kjeldahl methods was used to analyze leaf nitrogen. The width and length of the leaf was also measured to obtain the leaf surface area. The result showed that there are 61 individual trees which consisted of 24 species was identified. The species which have 5 highest important value are Altingia excelsa (64,657, Castanopsis javanica (39,698, Platea latifolia (27,684, Garcinia rostrata (21,151, and Schima walichii (16,049. Futhermore Eugenia lineata (13,967, Melanochyla caesa (12,241, Quercus lineata (10,766, platea excelsa (10,766 have lower important value. Other trees have important value less than 10. Morphological and nitrogen content analyze were done on 4 species : Quercus lineata, G. rostrata, A. excelsa, and E. lineata. Among them, Quercus lineata has highest specific leaf area (SLA (0,01153, followed by G. rostrata (0,00821, A. excelsa (0,00579, and E. lineata (0,00984 g/cm2. The highest number of stomata was found on A. excelsa (85,10/mm2, followed by E. lineata (74,40/mm2, Q. lineata (53,70/mm2, and G. rostrata (18,4 /mm2. The emergent species (A. excelsa and Q. lineata have higher nitrogen content than the underlayer species (G. rostrata and E. lineata. A. excelsa have highest nitrogen use efficiency (28,19% compare to E. lineata (23,81% , Q. lineata (19,09%, and G. rostrata (14,87%. Although not significant, emergen species have higher NUE than underlayer species.

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.

Skin cancer full-grown from scar

International Nuclear Information System (INIS)

Zikiryakhodjaev, D.Z.; Sanginov, D.R.

2001-01-01

In this chapter authors investigate the peculiarities of skin cancer full-grown from scar, the theory of it's descent, quote some statistical data on skin cancer full-grown from scar and variety clinical forms of skin cancer full-grown from scar was shown, quote some methods of treatment

Climate change, tourism and historical grazing influence the distribution of Carex lachenalii Schkuhr - A rare arctic-alpine species in the Tatra Mts.

Science.gov (United States)

Czortek, Patryk; Delimat, Anna; Dyderski, Marcin K; Zięba, Antoni; Jagodziński, Andrzej M; Jaroszewicz, Bogdan

2018-03-15

Mountain vegetation is highly specialized to harsh climatic conditions and therefore is sensitive to any change in environment. The rarest and most vulnerable plants occurring in alpine regions are expected to respond rapidly to environmental changes. An example of such a species is Carex lachenalii subsp. lachenalii Schkuhr, which occurs in Poland on only a few isolated sites in the Tatra Mts. The aim of this study was to assess changes in distribution of C. lachenalii in the Tatra Mts over the past 50-150years and the effects of climate change, tourism and historical grazing on the ecological niche of C. lachenalii. We focused on changes in the importance of functional diversity components in shaping plant species composition. Over the past 50-150years, the elevation of the average distribution of C. lachenalii shifted about 178m upward alongside a significant prolongation of the vegetative season by approximately 20days in the last 50-60years. Species composition of plots without C. lachenalii was characterized by competition between plants, whereas on plots with C. lachenalii habitat filtering was the most important component. Our results suggest that climate change was the main factor driving upward shift of C. lachenalii. Moderate trampling enhanced horizontal spread of this plant, whereas cessation of grazing grazing caused decline of C. lachenalii. The three environmental factors studied that determined shifts in distribution of C. lachenalii may also contribute to changes in distribution of other rare mountain plant species causing changes in ecosystem functioning. Copyright © 2017 Elsevier B.V. All rights reserved.

The uptake of hydrogen fluoride by a forest

International Nuclear Information System (INIS)

Murphy, C.E. Jr.

1980-01-01

A mathematical model of hydrogen fluoride (HF) deposition and accumulation of fluoride in a Eucalyptus rostrata forest has been developed. The model is based on tree physiology and meteorological principles. The data base for the model was derived from a literature survey of the physiological characteristics of E. rostrata and similar eucalyptus species and from current knowledge of meteorological processes in plant canopies

Evidence that an internal carbonic anhydrase is present in 5% CO2-grown and air-grown Chlamydomonas

International Nuclear Information System (INIS)

Moroney, J.V.; Togasaki, R.K.; Husic, H.D.; Tolbert, N.E.

1987-01-01

Inorganic carbon (C/sub i/) uptake was measured in wild-type cells of Chlamydomonas reinhardtii, and in cia-3, a mutant strain of C. reinhardtii that cannot grow with air levels of CO 2 . Both air-grown cells, that have a CO 2 concentrating system, and 5% CO 2 -grown cells that do not have this system, were used. When the external pH was 5.1 or 7.3, air-grown, wild-type cells accumulated inorganic carbon (C/sub i/) and this accumulation was enhanced when the permeant carbonic anhydrase inhibitor, ethoxyzolamide, was added. When the external pH was 5.1, 5% CO 2 -grown cells also accumulated some C/sub i/, although not as much as air-grown cells and this accumulation was stimulated by the addition of ethoxyzolamide. At the same time, ethoxyzolamide inhibited CO 2 fixation by high CO 2 -grown, wild-type cells at both pH 5.1 and 7.3. These observations imply that 5% CO 2 -grown, wild-type cells, have a physiologically important internal carbonic anhydrase, although the major carbonic anhydrase located in the periplasmic space is only present in air-grown cells. Inorganic carbon uptake by cia-3 cells supported this conclusion. This mutant strain, which is thought to lack an internal carbonic anhydrase, was unaffected by ethoxyzolamide at pH 5.1. Other physiological characteristics of cia-3 resemble those of wild-type cells that have been treated with ethoxyzolamide. It is concluded that an internal carbonic anhydrase is under different regulatory control than the periplasmic carbonic anhydrase

Characteristics of pendent heliconia for use in landscape and as cut flower

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Vivian Loges

2016-10-01

Full Text Available The Heliconia species with pendent inflorescences and colorful bracts is a good option for landscaping in tropical gardens and cut flowers market. In Brazil only a few species of Heliconia are commercially produced eg. H. rostrata, H. rauliniana and H. chartacea. Aiming to increase the use of outstanding native plants and the knowledge of these products for enthusiasts of tropical flowers, this work was carried out to characterize H. chartacea, H. collinsiana, H. magnifica, H. pendula, H. platystachys, H. pogonantha, H. rostrata, H. rauliniana and H. vellerigera for use in landscaping and as cut flower. The evaluations were performed on plants belonging to the Germplasm Collection of the Instituto Agronômico (IAC, in Ubatuba Unit of Research and Development, located in Ubatuba, São Paulo State, growing in partial shade conditions. Qualitative and quantitative characteristics related to clump and flower stem aspects were analyzed. A point scoring system was used to determine the species most suitable as landscape plant or as cut flower. The plant height range from 2.3 (H. rostrata to 7.0 m (H. pogonantha, having inflorescence with vibrant and different colors, varying between yellow, orange, red, pink, green and two color combinations. The inflorescences from most of the species were visible in the clump and remain in good conditions for two (H. platystachys to five months (H. magnifica, H. rostrata and H. pogonantha and present six (H. platystachys and H. pendula to 40 (H. pogonantha open bracts. White wax in leaves or inflorescences were observed in H. collinsiana, H. chartacea, H. pendula and H. platystachys. On the other hand, H. magnifica, H. rostrata, H. pogonantha and H. vellerigera exhibit a hairy surface, pubescent to lanuginose. The postharvest durability longer than 10 days was observed only in H. platystachys, H. rostrata, H. chartacea, and H. rauliniana. This characterization and scoring system were important to indicate and

Adenovirus entry from the apical surface of polarized epithelia is facilitated by the host innate immune response.

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Poornima L N Kotha

2015-03-01

Full Text Available Prevention of viral-induced respiratory disease begins with an understanding of the factors that increase or decrease susceptibility to viral infection. The primary receptor for most adenoviruses is the coxsackievirus and adenovirus receptor (CAR, a cell-cell adhesion protein normally localized at the basolateral surface of polarized epithelia and involved in neutrophil transepithelial migration. Recently, an alternate isoform of CAR, CAREx8, has been identified at the apical surface of polarized airway epithelia and is implicated in viral infection from the apical surface. We hypothesized that the endogenous role of CAREx8 may be to facilitate host innate immunity. We show that IL-8, a proinflammatory cytokine and a neutrophil chemoattractant, stimulates the protein expression and apical localization of CAREx8 via activation of AKT/S6K and inhibition of GSK3β. Apical CAREx8 tethers infiltrating neutrophils at the apical surface of a polarized epithelium. Moreover, neutrophils present on the apical-epithelial surface enhance adenovirus entry into the epithelium. These findings suggest that adenovirus evolved to co-opt an innate immune response pathway that stimulates the expression of its primary receptor, apical CAREx8, to allow the initial infection the intact epithelium. In addition, CAREx8 is a new target for the development of novel therapeutics for both respiratory inflammatory disease and adenoviral infection.

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.

material in the central equatorial Pacific. Deep-Sea Res I 43:1181-1204. Hitchcock GL. 1977. The concentration of particulate carbohydrates in a region of the West Africa upwelling zone during March 1974. Deep-Sea Res 24:83-93. Hoagland KD, Rosowski JR... and Biochemistry, IIB. Academic Press, London, pp 537-568 Roszkowski W, Beuth J, Ko HL, Uhlenbruck G, Pulverer G. 1989. Blocking of lectin like adhesion molecules on pulmonary cells inhibits lung sarcoma L colonization in BALB/c-mice. Experientia 45...

Alfalfa seedlings grown outdoors are more resistant to UV-induced DNA damage than plants grown in a UV-free environmental chamber

International Nuclear Information System (INIS)

Takayanagi, Shinnosuke; Trunk, J.G.; Sutherland, J.C.; Sutherland, B.M.

1994-01-01

The relative UV sensitivities of alfalfa seedlings grown outdoors versus plants grown in a growth chamber under UV-filtered cool white fluorescent bulbs have been determined using three criteria: (1) level of endogenous DNA damage as sites for the UV endonuclease from Micrococcus luteus, (2) susceptibility to pyrimidine dimer induction by a UV challenge exposure and (3) ability to repair UV-induced damage. We find that outdoor-grown plants contain approximately equal frequencies of endogenous DNA damages, are less susceptible to dimer induction by a challenge exposure of broad-spectrum UV and photorepair dimers more rapidly than plants grown in an environmental chamber under cool white fluorescent lamps plus a filter removes most UV radiation. These data suggest that plants grown in a natural environment would be less sensitive to UVB-induced damage than would be predicted on the basis of studies on plants grown under minimum UV. (author)

Preparation, characterization, and microbial degradation of specifically radiolabeled (/sup 14/C)lignocelluloses from marine and fresh water macrophytes. [Spartina alterniflora; Juncus roemerianus; Rhizophora mangle; Carex walteriana

Energy Technology Data Exchange (ETDEWEB)

Benner, R.; Maccubbin, A.E.; Hodson, R.E.

1984-02-01

Specifically radiolabeled (/sup 14/C-lignin)lignocelluloses were prepared from the aquatic macrophytes Spartina alterniflora, Juncus roemerianus, Rhizophora mangle, and Carex walteriana by using (/sup 14/C)phenylalanine, (/sup 14/C)tyrosine, and (/sup 14/C)cinnamic acid as precursors. Specifically radiolabeled (/sup 14/C-polysaccharide)lignocelluloses were prepared by using (/sup 14/C)glucose as precursor. The rates of microbial degradation varied among (/sup 14/C-lignin)lignocelluloses labeled with different lignin precursors within the same plant species. In herbaceous plants, significant amounts (8 to 24%) of radioactivity from (/sup 14/C)phenylalanine and (/sup 14/C)tyrosine were found associated with protein. Microbial degradation of radiolabeled protein resulted in overestimation of lignin degradation rates in lignocelluloses derived from herbaceous aquatic plants. Other differences in degradation rates among (/sup 14/C-lignin)lignocelluloses from the same plant species were attributable to differences in the amount of label being associated with ester-linked subunits of peripheral lignin. After acid hydrolysis of (/sup 14/C-polysaccharide)lignocelluloses, radioactivity was detected in several sugars, although most of the radioactivity was distributed between glucose and xylose. After 576 h of incubation with salt marsh sediments, 38% of the polysaccharide component and between 6 and 16% of the lignin component (depending on the precursor) of J. roemerianus lignocellulose was mineralized to /sup 14/CO/sub 2/; during the same incubation period, 30% of the polysaccharide component and between 12 and 18% of the lignin component of S. alterniflora lignocellulose was mineralized.

Recent results in characterization of melt-grown and quench-melt- grown YBCO superconductors

International Nuclear Information System (INIS)

Balachandran, U.; Poeppel, R.B.; Gangopadhyay, A.K.

1992-02-01

From the standpoint of applications, melt-grown (MG) and quench-melt-grown (QMG) bulk YBCO superconductors are of considerable interest. In this paper, we studied the intragranular critical current density (J c ), the apparent pinning potential (U o ), and the irreversibility temperature (T irr ) of MG and QMG samples and compared the results to those for conventionally sintered YBCO. A systematic increase in U o and a slower drop in J c with temperature indicate a systematic improvement in flux-pinning properties in progressing from the sintered YBCO to QMG and MG samples. Weaker pinning is observed in the QMG YBCO than in the MG samples

Carex lepidocarpa Tausch

Czech Academy of Sciences Publication Activity Database

Štěpánková, Jitka

2016-01-01

Roč. 51, č. 1 (2016), s. 165-165 ISSN 1211-5258 R&D Projects: GA ČR GB14-36079G Institutional support: RVO:67985939 Keywords : floristics * distribution * endangered species Subject RIV: EF - Botanics

Polyphenol content and antioxidant capacity in organically and conventionally grown vegetables

Directory of Open Access Journals (Sweden)

Kevser Unal

2014-11-01

Full Text Available 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

Descrição da fêmea de Sphecozone tincta (Araneae, Linyphiidae e novas ocorrências no Brasil Description of the female of Sphecozone tincta (Araneae, Linyphiidae and news records from Brazil

Directory of Open Access Journals (Sweden)

Everton Nei Lopes Rodrigues

2005-03-01

Full Text Available A fêmea de Sphecozone tincta Millidge, 1991 é descrita e ilustrada pela primeira vez. O macho também é ilustrado. Novos registros são fornecidos para Sphecozone cristata Millidge, 1991, S. rostrata Millidge, 1991 e S. rubescens O. P.-Cambridge, 1870.The female of Sphecozone tincta Millidge, 1991 is described and illustrated for the first time. The male also is illustrated. News records are given for Sphecozone cristata Millidge, 1991, S. rostrata Millidge, 1991 and S. rubescens O. P.-Cambridge, 1870.

GREENHOUSE-GROWN CAPE GOOSEBERRY

African Journals Online (AJOL)

/2006 S 4,00. Printed in Uganda. All rights reserved O2006, African Crop Science Society. SHORT COMMINICATION. EFFECT OF GIBBERRELLIC ACID ON GROWTH AND FRUIT YIELD OF. GREENHOUSE-GROWN CAPE GOOSEBERRY.

A century of research on the larval distributions of the Atlantic eels: a re-examination of the data

DEFF Research Database (Denmark)

Miller, Michael J.; Bonhommeau, Sylvain; Munk, Peter

2015-01-01

The spawning areas of the Atlantic freshwater eels were discovered about a century ago by the Danish scientist Johannes Schmidt who after years of searching found newly hatched larvae of the European eel, Anguilla anguilla, and the American eel, Anguilla rostrata, in the southern Sargasso Sea...... comprehensive database that includes 22612 A. anguilla and 9634 A. rostrata leptocephali, which provides a detailed view of the spatial and temporal distributions and size of the larvae across the Atlantic basin and in the Mediterranean Sea. The differences in distributions, maximum sizes, and growth rates...

As-grown deep-level defects in n-GaN grown by metal-organic chemical vapor deposition on freestanding GaN

International Nuclear Information System (INIS)

Chen Shang; Ishikawa, Kenji; Hori, Masaru; Honda, Unhi; Shibata, Tatsunari; Matsumura, Toshiya; Tokuda, Yutaka; Ueda, Hiroyuki; Uesugi, Tsutomu; Kachi, Tetsu

2012-01-01

Traps of energy levels E c -0.26 and E c -0.61 eV have been identified as as-grown traps in n-GaN grown by metal-organic chemical vapor deposition by using deep level transient spectroscopy of the Schottky contacts fabricated by resistive evaporation. The additional traps of E c -0.13 and E c -0.65 eV have been observed in samples whose contacts are deposited by electron-beam evaporation. An increase in concentration of the E c -0.13 and E c -0.65 eV traps when approaching the interface between the contact and the GaN film supports our argument that these traps are induced by electron-beam irradiation. Conversely, the depth profiles of as-grown traps show different profiles between several samples with increased or uniform distribution in the near surface below 50 nm. Similar profiles are observed in GaN grown on a sapphire substrate. We conclude that the growth process causes these large concentrations of as-grown traps in the near-surface region. It is speculated that the finishing step in the growth process should be an essential issue in the investigation of the surface state of GaN.

Point defects in ZnO crystals grown by various techniques

International Nuclear Information System (INIS)

Čížek, J; Vlček, M; Hruška, P; Lukáč, F; Melikhova, O; Anwand, W; Selim, F; Hugenschmidt, Ch; Egger, W

2017-01-01

In the present work point defects in ZnO crystals were characterized by positron lifetime spectroscopy combined with back-diffusion measurement of slow positrons. Defects in ZnO crystals grown by various techniques were compared. Hydrothermally grown ZnO crystals contain defects characterized by lifetime of ≈181 ps. These defects were attributed to Zn vacancies associated with hydrogen. ZnO crystals prepared by other techniques (Bridgman, pressurized melt growth, and seeded chemical vapour transport) exhibit shorter lifetime of ≈165 ps. Positron back-diffusion studies revealed that hydrothermally grown ZnO crystals contain higher density of defects than the crystals grown by other techniques. The lowest concentration of defects was detected in the crystal grown by seeded chemical vapor transport. (paper)

The response of vegetation structure to active warming and precipitation reduction of the Sphagnum peatland

Science.gov (United States)

Łuców, Dominika; Basińska, Anna; Chojnicki, Bogdan; Gąbka, Maciej; Józefczyk, Damian; Juszczak, Radosław; Leśny, Jacek; Olejnik, Janusz; Reczuga, Monika; Samson, Mateusz; Silvennoinen, Hanna; Stróżecki, Marcin; Urbaniak, Marek; Zielińska, Małgorzata; Lamentowicz, Mariusz

2017-04-01

The recent climate change (e.g. increased temperature and decreased precipitation) is expected to affect biodiversity and vegetation structure of the European peatlands, as well as carbon fluxes. Our experimental study carried out in Western Poland, tests the hypothesis that the increased temperature, in particular in combination with rainfall reduction affects vegetation structure of the Sphagnum peatland, through changes in moss and vascular plants abundance. The innovative climate manipulation system was installed on the Rzecin peatland in 2014. The field site consists of four blocks: "drought" "warming and drought" "warming" and "control". The air and peat temperatures were increased in 2015 and 2016 by about 0.2 oC and 1.0 oC, respectively, using infrared radiators. Precipitation was reduced by automatic curtain operated only during the nights by about 37 % in both years. Data resulting from the analyses of digital pictures as well as Point Intercept method were used to identify changes in vegetation structure as a response to warming and drought. We observed increase in abundance of vascular plant and decrease in abundance of mosses during the very dry 2015 vegetation season. It appeared that Carex spp. (C. limosa and C. rostrata) abundance responded positively to warming, while Sphagnum spp. (S. angustifolium and S. teres) responded negatively. The "warming" block was characterized by an increase in abundance of Carex spp. by 8.3 % to 16.7 % and decreased abundance of Sphagnum spp. from 25 % to 19.4 %, whereas in the block of "warming and drought" 11.4 % to by 18.3 and 38 % to 26.9 %, respectively in the August 2015. However, we observed decrease in Sphagnum spp. abundance in the treatment with rainfall reduction in wetter 2016, and their increase in the control. Our results show how considerable changes in vegetation structure can be expected under the stress of warming and modified rainfall conditions, even after a short-term manipulation. However, it is

Graphic Grown Up

Science.gov (United States)

Kim, Ann

2009-01-01

It's no secret that children and YAs are clued in to graphic novels (GNs) and that comics-loving adults are positively giddy that this format is getting the recognition it deserves. Still, there is a whole swath of library card-carrying grown-up readers out there with no idea where to start. Splashy movies such as "300" and "Spider-Man" and their…

Increased occurrence of pesticide residues on crops grown in protected environments compared to crops grown in open field conditions.

Science.gov (United States)

Allen, Gina; Halsall, Crispin J; Ukpebor, Justina; Paul, Nigel D; Ridall, Gareth; Wargent, Jason J

2015-01-01

Crops grown under plastic-clad structures or in greenhouses may be prone to an increased frequency of pesticide residue detections and higher concentrations of pesticides relative to equivalent crops grown in the open field. To test this we examined pesticide data for crops selected from the quarterly reports (2004-2009) of the UK's Pesticide Residue Committee. Five comparison crop pairs were identified whereby one crop of each pair was assumed to have been grown primarily under some form of physical protection ('protected') and the other grown primarily in open field conditions ('open'). For each pair, the number of detectable pesticide residues and the proportion of crop samples containing pesticides were statistically compared (n=100 s samples for each crop). The mean concentrations of selected photolabile pesticides were also compared. For the crop pairings of cabbage ('open') vs. lettuce ('protected') and 'berries' ('open') vs. strawberries ('protected') there was a significantly higher number of pesticides and proportion of samples with multiple residues for the protected crops. Statistically higher concentrations of pesticides, including cypermethrin, cyprodinil, fenhexamid, boscalid and iprodione were also found in the protected crops compared to the open crops. The evidence here demonstrates that, in general, the protected crops possess a higher number of detectable pesticides compared to analogous crops grown in the open. This may be due to different pesticide-use regimes, but also due to slower rates of pesticide removal in protected systems. The findings of this study raise implications for pesticide management in protected-crop systems. Copyright © 2014 Elsevier Ltd. All rights reserved.

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...

Plant and microbial uptake and allocation of organic and inorganic nitrogen related to plant growth forms and soil conditions at two subarctic tundra sites in Sweden

DEFF Research Database (Denmark)

Sørensen, Pernille Lærkedal; Clemmensen, Karina Engelbrecht; Michelsen, Anders

2008-01-01

organic matter. At both sites the deciduous dwarf shrub Betula nana and the evergreen Empetrum hermaphroditum absorbed added 15N at rates in the order: NH4 + . NO3 2 . glycine, in contrast to the graminoid Carex species which took up added 15N at rates in the orderNO3 2 . NH4 + . glycine. Carex...

The Ties That Bind: Midlife Parents' Daily Experiences With Grown Children.

Science.gov (United States)

Fingerman, Karen L; Kim, Kyungmin; Birditt, Kira S; Zarit, Steven H

2016-04-01

Daily pleasant or stressful experiences with grown children may contribute to parental well-being. This diary study focused on midlife parents' ( N = 247) reports regarding grown children for 7 days. Nearly all parents (96%) had contact with a child that week via phone, text, or in person. Nearly all parents shared laughter or enjoyable interactions with grown children during the study week. More than half of parents experienced stressful encounters (e.g., child got on nerves) or stressful thoughts about grown children (e.g., worrying, fretting about a problem). Pleasant and stressful experiences with grown children were associated with parents' positive and negative daily moods. A pleasant experience with a grown child the same day as a stressful experience mitigated effects of those stressful experiences on negative mood, however. The findings have implications for understanding intergenerational ambivalence and stress buffering in this tie.

The Ties That Bind: Midlife Parents’ Daily Experiences With Grown Children

Science.gov (United States)

Fingerman, Karen L.; Kim, Kyungmin; Birditt, Kira S.; Zarit, Steven H.

2015-01-01

Daily pleasant or stressful experiences with grown children may contribute to parental well-being. This diary study focused on midlife parents’ (N = 247) reports regarding grown children for 7 days. Nearly all parents (96%) had contact with a child that week via phone, text, or in person. Nearly all parents shared laughter or enjoyable interactions with grown children during the study week. More than half of parents experienced stressful encounters (e.g., child got on nerves) or stressful thoughts about grown children (e.g., worrying, fretting about a problem). Pleasant and stressful experiences with grown children were associated with parents’ positive and negative daily moods. A pleasant experience with a grown child the same day as a stressful experience mitigated effects of those stressful experiences on negative mood, however. The findings have implications for understanding intergenerational ambivalence and stress buffering in this tie. PMID:27022198

Quality and Quantity Evaluations of Shade Grown Forages

Science.gov (United States)

K. P. Ladyman; M. S. Kerley; R. L. Kallenbach; H. E. Garrett; J. W. Van Sambeek; N. E. Navarrete-Tindall

2003-01-01

Seven legumes were grown during the summer-fall of 2000, at the Horticulture and Agroforestry Research Center (39? 01 ' N, 92? 46' W) near New Franklin, MO. The forages were grown in 7.5L white pots placed on light-colored gravel either under full sunlight, 45% sunlight, or 20% sunlight created by a shade cloth over a rectangular frame. Drip irrigation was...

Large-area, laterally-grown epitaxial semiconductor layers

Science.gov (United States)

Han, Jung; Song, Jie; Chen, Danti

2017-07-18

Structures and methods for confined lateral-guided growth of a large-area semiconductor layer on an insulating layer are described. The semiconductor layer may be formed by heteroepitaxial growth from a selective growth area in a vertically-confined, lateral-growth guiding structure. Lateral-growth guiding structures may be formed in arrays over a region of a substrate, so as to cover a majority of the substrate region with laterally-grown epitaxial semiconductor tiles. Quality regions of low-defect, stress-free GaN may be grown on silicon.

Law Enforcement Efforts to Control Domestically Grown Marijuana.

Science.gov (United States)

1984-05-25

mari- juana grown indoors , the involvement of large criminal organizations, and the patterns of domestic marijuana distribution. In response to a GAO...information is particularly important if the amount of marijuana grown indoors and the number of large-scale cultiva- tion and distribution organizations... marijuana indoors is becoming increasingly popular. A 1982 narcotics assessment by the Western States Information Network (WSIN)2 of marijuana

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.

Structural Reliability of the Nigerian Grown Abura Timber Bridge ...

African Journals Online (AJOL)

Structural reliability analysis was carried out on the Nigerian grown Abura timber, to ascertain its structural performance as timber bridge beams. Samples of the Nigerian grown Abura timber were bought from timber market, seasoned naturally and their structural/strength properties were determined at a moisture content of ...

Counting molecular-beam grown graphene layers

Energy Technology Data Exchange (ETDEWEB)

Plaut, Annette S. [School of Physics, University of Exeter, Exeter EX4 4QL (United Kingdom); Wurstbauer, Ulrich [Department of Physics, Columbia University, New York, New York 10027 (United States); Pinczuk, Aron [Department of Physics, Columbia University, New York, New York 10027 (United States); Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States); Garcia, Jorge M. [MBE Lab, IMM-Instituto de Microelectronica de Madrid (CNM-CSIC), Madrid, E-28760 (Spain); Pfeiffer, Loren N. [Electrical Engineering Department, Princeton University, New Jersey 08544 (United States)

2013-06-17

We have used the ratio of the integrated intensity of graphene's Raman G peak to that of the silicon substrate's first-order optical phonon peak, accurately to determine the number of graphene layers across our molecular-beam (MB) grown graphene films. We find that these results agree well both, with those from our own exfoliated single and few-layer graphene flakes, and with the results of Koh et al.[ACS Nano 5, 269 (2011)]. We hence distinguish regions of single-, bi-, tri-, four-layer, etc., graphene, consecutively, as we scan coarsely across our MB-grown graphene. This is the first, but crucial, step to being able to grow, by such molecular-beam-techniques, a specified number of large-area graphene layers, to order.

Hydraulics and gas exchange recover more rapidly from severe drought stress in small pot-grown grapevines than in field-grown plants.

Science.gov (United States)

Romero, Pascual; Botía, Pablo; Keller, Markus

2017-09-01

Modifications of plant hydraulics and shoot resistances (R shoot ) induced by water withholding followed by rewatering, and their relationships with plant water status, leaf gas exchange and water use efficiency at the leaf level, were investigated in pot-grown and field-grown, own-rooted Syrah grapevines in an arid climate. Water stress induced anisohydric behavior, gradually reducing stomatal conductance (g s ) and leaf photosynthesis (A) in response to decreasing midday stem water potential (Ψ s ). Water stress also rapidly increased intrinsic water-use efficiency (A/g s ); this effect persisted for many days after rewatering. Whole-plant (K plant ), canopy (K canopy ), shoot (K shoot ) and leaf (K leaf ) hydraulic conductances decreased during water stress, in tune with the gradual decrease in Ψ s , leaf gas exchange and whole plant water use. Water-stressed vines also had a lower Ψ gradient between stem and leaf (ΔΨ l ), which was correlated with lower leaf transpiration rate (E). E and ΔΨ l increased with increasing vapour pressure deficit (VPD) in non-stressed control vines but not in stressed vines. Perfusion of xylem-mobile dye showed that water flow to petioles and leaves was substantially reduced or even stopped under moderate and severe drought stress. Leaf blade hydraulic resistance accounted for most of the total shoot resistance. However, hydraulic conductance of the whole root system (K root ) was not significantly reduced until water stress became very severe in pot-grown vines. Significant correlations between K plant , K canopy and Ψ s , K canopy and leaf gas exchange, K leaf and Ψ s , and K leaf and A support a link between water supply, leaf water status and gas exchange. Upon re-watering, Ψ s recovered faster than gas exchange and leaf-shoot hydraulics. A gradual recovery of hydraulic functionality of plant organs was also observed, the leaves being the last to recover after rewatering. In pot-grown vines, K canopy recovered rather

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.

76 FR 16323 - Irish Potatoes Grown in Washington; Continuance Referendum

Science.gov (United States)

2011-03-23

...; FV11-946-1 CR] Irish Potatoes Grown in Washington; Continuance Referendum AGENCY: Agricultural... conducted among eligible Washington potato growers to determine whether they favor continuance of the marketing order regulating the handling of Irish potatoes grown in Washington. DATES: The referendum will be...

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.

Assessing Installation Ethnobotanical Resources Using Land Condition Trend Analysis (LCTA) Data: A Fort Riley, Kansas, Case Study

Science.gov (United States)

1998-07-01

incarnata S F Carya illinoensis G L Asclepias stenophylla S B Ceanothus herbaceus S B Asclepias syriaca S B Ceanothus oliganthus S L Asclepias tuberosa S...cannabinum S B Carex retroflexa G F Argemone polyanthemos S F Carex vulpinoidea S F Artemisia ludoviciana S B Carya cordiformis S B Asclepias...longipilum G B Descurainia pinnata S F Hordeum pusillum G F Descurainia sophia S F Hymenopappus scabiosaeus G B Desmanthus illinoensis S B Hypericum

VLS-grown diffusion doped ZnO nanowires and their luminescence properties

International Nuclear Information System (INIS)

Roy, Pushan Guha; Dutta, Amartya; Das, Arpita; Bhattacharyya, Anirban; Sen, Sayantani; Pramanik, Pallabi

2015-01-01

Zinc Oxide (ZnO) nanowires were deposited by vapor–liquid–solid (VLS) method on to aluminum doped ZnO (AZO) thin films grown by sol-gel technique. For various device applications, current injection into such nanowires is critical. This is expected to be more efficient for ZnO nanowires deposited on to AZO compared to those deposited on to a foreign substrate such as silicon. In this work we compare the morphological and optical properties of nanowires grown on AZO with those grown under similar conditions on silicon (Si) wafers. For nanowires grown on silicon, diameters around 44 nm with heights around 2.2 μm were obtained. For the growth on to AZO, the diameters were around 90 nm while the heights were around 520 nm. Room temperature photoluminescence (RT-PL) measurements show improved near band-edge emission for nanowires grown on to AZO, indicating higher material quality. This is further established by low temperature photoluminescence (LT-PL) measurements where excitonic transitions with width as small as 14 meV have been obtained at 4 K for such structures. Electron energy loss spectroscopy (EELS) studies indicate the presence of Al in the nanowires, indicating a new technique for introduction of dopants into these structures. These results indicate that ZnO nanowires on sol-gel grown AZO thin films show promise in the development of various optoelectronic devices. (paper)

Single layer porous gold films grown at different temperatures

International Nuclear Information System (INIS)

Zhang Renyun; Hummelgard, Magnus; Olin, Hakan

2010-01-01

Large area porous gold films can be used in several areas including electrochemical electrodes, as an essential component in sensors, or as a conducting material in electronics. Here, we report on evaporation induced crystal growth of large area porous gold films at 20, 40 and 60 deg. C. The gold films were grown on liquid surface at 20 deg. C, while the films were grown on the wall of beakers when temperature increased to 40 and 60 deg. C. The porous gold films consisted of a dense network of gold nanowires as characterized by TEM and SEM. TEM diffraction results indicated that higher temperature formed larger crystallites of gold wires. An in situ TEM imaging of the coalescence of gold nanoparticles mimicked the process of the growth of these porous films, and a plotting of the coalescence time and the neck radius showed a diffusion process. The densities of these gold films were also characterized by transmittance, and the results showed film grown at 20 deg. C had the highest density, while the film grown at 60 deg. C had the lowest consistent with SEM and TEM characterization. Electrical measurements of these gold films showed that the most conductive films were the ones grown at 40 deg. C. The conductivities of the gold films were related to the amount of contamination, density and the diameter of the gold nanowires in the films. In addition, a gold film/gold nanoparticle hybrid was made, which showed a 10% decrease in transmittance during hybridization, pointing to applications as chemical and biological sensors.

Leaf anatomy of genotypes of banana plant grown under coloured ...

African Journals Online (AJOL)

This study aimed to evaluate the effect of spectral light quality on different anatomical features of banana tree plantlets grown under coloured shade nets. Banana plants of five genotypes obtained from micropropagation, were grown under white, blue, red and black nets, with shade of 50%, in a completely randomized ...

Pullulan production by Aureobasidium pullulans grown on ethanol stillage as a nitrogen source.

Science.gov (United States)

West, T P; Strohfus, B

1996-01-01

Pullulan production by Aureobasidium pullulans strain RP-1 using thin stillage from fuel ethanol production as a nitrogen source was studied in a medium using corn syrup as a carbon source. The use of 1% thin stillage as a nitrogen source instead of ammonium sulphate elevated polysaccharide production by strain RP-1 cells when grown on a concentration of up to 7.5% corn syrup, independent of yeast extract supplementation. Dry weights of cells grown in medium containing ammonium sulphate as the nitrogen source were higher than the stillage-grown cells after 7 days of growth. The viscosity of the polysaccharide on day 7 was higher for cells grown on thin stillage rather than ammonium sulphate as a nitrogen source. The pullulan content of the polysaccharide elaborated by ammonium sulphate-grown cells on day 7 was higher than the pullulan content of polysaccharide produced by stillage-grown cells regardless of whether yeast extract was added to the culture medium.

Heteroepitaxially grown InP solar cells

International Nuclear Information System (INIS)

Weinberg, I.; Swartz, C.K.; Brinker, D.J.; Wilt, D.M.

1990-01-01

Although they are significantly more radiation resistant than either Si or GaAs solar cells, their high wafer cost presents a barrier to the widespread use of InP solar cells in space. For this reason, the authors have initiated a program aimed at producing high efficiency, radiation resistant solar cells processed from InP heteroepitaxially grown on cheaper substrates. The authors' objective is to present the most recent results emanating from this program together with the results of their initial proton irradiations on these cells. This paper reports that InP cells were processed from a 4 micron layer of InP, grown by OMCVD on a silicon substrate, with a 0.5 micron buffer layer between the InP directly grown on a GaAs substrate. Initial feasibility studies, in a Lewis sponsored program at the Spire corporation, resulted in air mass zero efficiencies of 7.1% for the former cells and 9.1% for the latter. These initial low efficiencies are attributed to the high dislocation densities caused by lattice mismatch. The authors' preirradiation analysis indicates extremely low minority carrier diffusion lengths, in both cell base and emitter, and high values of both the diffusion and recombination components of the diode reverse saturation currents. Irradiation by 10 MeV protons, to a fluence of 10 13 cm -2 , resulted in relatively low degradation in cell efficiency, short circuit current and open circuit voltage

Element distribution of the barley plant grown in an agar slice suspended culture

International Nuclear Information System (INIS)

Makino-Nakanishi, Tomoko; Matsumoto, Satoshi

1991-01-01

An agar slice suspended culture was devised for the further study of the barley root. The roots were placed into an agar covered with a nylon cloth and suspended in a water culture vessel. Barley roots grown in the agar developed hardly any root hair. The element contents of the root grown in the agar culture and that in the water culture were measured by neutron activation analysis. The concentrations of K, Mg and Cl in the root grown in the agar were about half of these grown in the water. Na and Mn concentrations were the same and Ca concentration was slightly higher when grown in the agar. The agar system is expected to provide more information to study the root hair. (author)

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...

Study on grown-in defects in CZ-Si by positron annihilation

International Nuclear Information System (INIS)

Nakagawa, S.; Hori, F.; Oshima, R.

2004-01-01

In order to study the nature of grown-in microdefects of a silicon wafer taken from a czochralski-grown single crystal (CZ-Si) in which ring oxidation-induced stacking faults (ring-OSF) are formed after oxidation heat treatment, positron annihilation coincidence Doppler broadening experiments (CDB) have been performed. Vacancy-type defects were detected in the central region of a wafer of an as-grown crystal, and they were changed with annealing. It was confirmed that different types of defects were formed in the regions of outside and inside of the ring-OSF. (orig.)

Characterization of GaN/AlGaN epitaxial layers grown

Indian Academy of Sciences (India)

GaN and AlGaN epitaxial layers are grown by a metalorganic chemical vapour deposition (MOCVD) system. The crystalline quality of these epitaxially grown layers is studied by different characterization techniques. PL measurements indicate band edge emission peak at 363.8 nm and 312 nm for GaN and AlGaN layers ...

Excavation and drying of compressed peat; Tiivistetyn turpeen nosto ja kuivaus

Energy Technology Data Exchange (ETDEWEB)

Erkkilae, A.; Frilander, P.; Hillebrand, K.; Nurmi, H.

1996-12-31

The target of this three year (1993 - 1995) project was to improve the peat product-ion efficiency by developing an energy economical excavation method for compressed peat, by which it is possible to obtain best possible degree of compression and load from the DS-production point of view. It is possible to improve the degree of utilization of solar radiation in drying from 30 % to 40 %. The main research areas were drying of the compressed peat and peat compression. The third sub-task for 1995 was demonstration of the main parts of the method in laboratory scale. Experimental compressed peat (Compeat) drying models were made for peats Carex-peat H7, Carex-peat H5 and Carex-Sphagnum-peat H7. Compeat dried without turning in best circumstances in 34 % shorter time than milled layer made of the same peat turned twice, the initial moisture content being 4 kgH2OkgDS-1. In the tests carried out in 1995 with Carex-peat the compression had not corresponding effect on intensifying of the drying of peat. Compression of Carex-Sphagnum peat H7 increased the drying speed by about 10 % compared with the drying time of uncompressed milled layer. In the sprinkling test about 30-50 % of the sprinkled water was sucked into the compressed peat layer, while about 70 % of the rain is sucked into the corresponding uncompressed milled layer. Use of vibration decreased the energy consumption of the steel-surfaced nozzles about 20 % in the maximum, but the effect depend on the rotation speed of the macerator and the vibration power. In the new Compeat method (production method for compressed peat), developed in the research, the peat is loosened from the field surface by milling 3-5 cm thick layer of peat of moisture content 75-80 %

Leaf chemical composition of twenty-one Populus hybrid clones grown under intensive culture

Science.gov (United States)

Richard E. Dickson; Philip R. Larson

1976-01-01

Leaf material from 21 nursery-grown Populus hybrid clones was analyzed for three nitrogen fractions (total N, soluble protein, and soluble amino acids) and three carbhydrate fractions (reducing sugars, total soluble sugars, and total nonstructural carbohydrates-TNC). In addition, nursery-grown green ash and silver maple, field-grown bigtooth and trembling aspen, and...

InN-based layers grown by modified HVPE

International Nuclear Information System (INIS)

Syrkin, A.; Usikov, A.; Soukhoveev, V.; Kovalenkov, O.; Ivantsov, V.; Dmitriev, V.; Collins, C.; Readinger, E.; Shmidt, N.; Davydov, V.; Nikishin, S.; Kuryatkov, V.; Song, D.; Rosenbladt, D.; Holtz, Mark

2006-01-01

This paper contains results on InN and InGaN growth by Hydride Vapor Phase Epitaxy (HVPE) on various substrates including sapphire and GaN/sapphire, AlGaN/sapphire, and AlN/sapphire templates. The growth processes are carried out at atmospheric pressure in a hot wall reactor in the temperature range from 500 to 750 and ordm;C. Continuous InN layers are grown on GaN/sapphire template substrates. Textured InN layers are deposited on AlN/sapphire and AlGaN/sapphire templates. Arrays of nano-crystalline InN rods with various shapes are grown directly on sapphire substrates. X-ray diffraction rocking curves for the (002)InN reflection have the full width at half maximum (FWHM) as narrow as 270 arcsec for the nano-rods and 460 arcsec for the continuous layers. In x Ga 1-x N layers with InN content up to 10 mol.% are grown on GaN/sapphire templates. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

EVALUATION OF ANTIBACTERIAL, ANTITUMOR, ANTIOXIDANT ACTIVITIES AND PHENOLIC CONSTITUENTS OF FIELD-GROWN AND IN VITRO-GROWN LYSIMACHIA VULGARIS L.

Science.gov (United States)

Yildirim, Arzu Birinci; Guner, Birgul; Karakas, Fatma Pehlivan; Turker, Arzu Ucar

2017-01-01

Lysimachia vulgaris L. (Yellow loosestrife) is a medicinal plant in the family Myrsinaceae. It has been used in the treatment of fever, ulcer, diarrhea and wounds in folk medicine. It has also analgesic, expectorant, astringent and anti-inflammatory activities. Two different sources of the plant (field-grown and in vitro -grown) were used to evaluate the biological activities (antibacterial, antitumor and antioxidant) of L. vulgaris. In vitro-grown plant materials were collected from L. vulgaris plants that were previously regenerated in our laboratory. Plant materials were extracted with water, ethanol and acetone. For antibacterial test, disc diffusion method and 10 different pathogenic bacteria were used. Antioxidant activity was indicated by using DPPH method. The total phenol amount by using Folin-Ciocaltaeu method and the total flavonoid amount by using aluminum chloride (AlCl 3 ) colorimetric method were determined. Generally, yellow loosestrife extracts demonstrated antibacterial activity against Gram-positive bacteria (Staphylococcus aureus, S. epidermidis and Streptococcus pyogenes) . Strong antitumor activity of yellow loosestrife was observed via potato disc diffusion bioassay. Nine different phenolics were also determined and compared by using High-Performance Liquid Chromatography (HPLC). Future investigations should be focused on fractionation of the extracts to identify active components for biological activity.

In vitro assay of the inhibitory effect of neem callus and leaf extracts on some phytopathogenes

International Nuclear Information System (INIS)

El Gaali, E.; Mukhtar, I.

2006-01-01

The effect of different concentrations of neem (Azadirachta indica) callus and leaf extracts on the radial growth of drechslera rostrata, fusarium oxysporum and alterneria alternata was assessed. Obvious inhibitory effect was observed on the mycelia radial growth of the three treated fungi. The level of inhibition increased with the increase of the extract concentration. The maximum inhibitory effect (84%) was recorded with drechslera rostrata when inoculated in media containing 20 mg/ml of neem callus extract, while the inhibition rate of the mycelial growth of the same species reached 61% when inoculated in a medium containing the same concentration of neem leaf extract. The subsequent concentrations of the callus and leaf extracts gave similar trends of inhibition on the fungi cultured on extract amended agar plates. (Author)

Zn-vacancy related defects in ZnO grown by pulsed laser deposition

Science.gov (United States)

Ling, F. C. C.; Luo, C. Q.; Wang, Z. L.; Anwand, W.; Wagner, A.

2017-02-01

Undoped and Ga-doped ZnO (002) films were grown c-sapphire using the pulsed laser deposition (PLD) method. Znvacancy related defects in the films were studied by different positron annihilation spectroscopy (PAS). These included Doppler broadening spectroscopy (DBS) employing a continuous monenergetic positron beam, and positron lifetime spectroscopy using a pulsed monoenergetic positron beam attached to an electron linear accelerator. Two kinds of Znvacancy related defects namely a monovacancy and a divacancy were identified in the films. In as-grown undoped samples grown with relatively low oxygen pressure P(O2)≤1.3 Pa, monovacancy is the dominant Zn-vacancy related defect. Annealing these samples at 900 oC induced Zn out-diffusion into the substrate and converted the monovacancy to divacancy. For the undoped samples grown with high P(O2)=5 Pa irrespective of the annealing temperature and the as-grown degenerate Ga-doped sample (n=1020 cm-3), divacancy is the dominant Zn-vacancy related defect. The clustering of vacancy will be discussed.

Polarity and microstructure in InN thin layers grown by MOVPE

International Nuclear Information System (INIS)

Kuwano, N.; Nakahara, Y.; Amano, H.

2006-01-01

Microstructures in InN grown on sapphire (0001) and yttria-stabilized zirconia (YSZ) (111) by metal-organic vapor phase epitaxy (MOVPE) were analyzed by means of transmission electron microscopy (TEM) in order to clarify the growth process. Special attention was paid to the selectivity of the crystal polarity of InN. The InN thin films grown on sapphire after nitridation has a flat surface while those grown on YSZ has hillocks on the surface. The crystal polarity was determined by comparing the experimentally observed intensity distribution in convergent beam electron diffraction (CBED) disks with those simulated by the Broch-wave method. It was found that the InN grown on the sapphire has a nitrogen-polarity and the one on YSZ has a mixture of In- and N-polarities. The effect of surface-nitridation of sapphire on the growth process is also discussed (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

All-MOCVD-grown BH laser on P-InP substrates

Science.gov (United States)

Nishimura, Tadashi; Ishimura, E.; Nakajima, Yasuo; Tada, Hitoshi; Kimura, T.; Ohkura, Y.; Goto, Katsuhiko; Omura, Etsuji; Aiga, Masao

1993-07-01

A very low cw threshold current of 2.5 mA ( 25 degree(s)C) and 8.0 mA ( 80 degree(s)C) with high reliability has been realized in the all-MOCVD grown BH lasers on p-InP substrates. A strained MQW active layer of 1.3 micrometers wavelength and the precise carrier confinement buried structure by MOCVD is employed for the BH lasers. The excellent potential of long lifetime of the all-MOCVD grown laser has also been confirmed. After the high temperature and the high current (100 degree(s)C, 200 mA) aging test, no significant degradation is observed which is comparable with the well-established LPE grown lasers. The BH laser is also operating stably over 3700 hrs under the APC condition of 50 degree(s)C, 10 mW. Finally, an extremely uniform 10-element all-MOCVD grown LD array is demonstrated, which has the threshold current uniformity of 2.4 +/- 0.1 mA ( 25 degree(s)C) and 9.2 +/- 0.2 mA ( 80 degree(s)C). The growth mechanism in the MOCVD is also described.

78 FR 28118 - Vidalia Onions Grown in Georgia; Change in Reporting and Assessment Requirements

Science.gov (United States)

2013-05-14

... onion producers in the designated production area. Small agricultural service firms, which include...; FV13-955-1 IR] Vidalia Onions Grown in Georgia; Change in Reporting and Assessment Requirements AGENCY... Vidalia onions grown in Georgia (order). The order regulates the handling of Vidalia onions grown in...

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

Energy Technology Data Exchange (ETDEWEB)

Maheswari, J. Uma, E-mail: umak.anand@gmail.com [Department of Physics, The M.D.T.Hindu College, Tirunelveli 627010, Tamilnadu (India); Krishnan, C. [Department of Physics, Arignar Anna College, Aralvoymoli 629301, Tamilnadu (India); Kalyanaraman, S. [Physics Research Centre, Sri Paramakalyani College, Alwarkurichi 627412, Tamilnadu (India); Selvarajan, P. [Department of Physics, Aditanar College of Arts and Science, Tiruchendur 628216, Tamilnadu (India)

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.

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

Science.gov (United States)

2010-07-01

... Employment or Agricultural Employees in Processing Shade-Grown Tobacco; Exemption From Minimum Wage and... 29 Labor 3 2010-07-01 2010-07-01 false Definition of âshade-grown tobacco.â 780.505 Section 780.505 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR...

Murcha de fusário em helicônia: fontes de resistência, método alternativo de detecção e defesa estrutural Heliconia’s Fusarium wilt: resistance sources, alternative method of detection and structural mechanisms

Directory of Open Access Journals (Sweden)

Neilza Reis Castro

2010-03-01

Full Text Available O cultivo das helicônias vem sendo afetado pela murcha, causada por Fusarium oxysporum f.sp. cubense. Este trabalho objetivou identificar fontes de resistência, verificar a detecção da resistência através de método alternativo e avaliar a lignificação como mecanismo de defesa do hospedeiro ao patógeno. As espécies utilizadas na identificação de resistência foram Heliconia bihai, H. psittacorum cvs. Golden Torch e Golden Torch Adrian, H. rostrata, H. stricta cvs. Capri e Fire Bird, H. psittacorum cvs. Sassy e Alan Carle, H. caribea, H. latispatha, H. wagneriana e H. chartacea cv. Sexy Pink. A avaliação dos sintomas foi realizada aos 40 dias após a inoculação baseada em escala de notas variando de 1 a 6. As espécies consideradas resistentes foram H. bihai, H. psittacorum cvs. Golden Torch e Golden Torch Adrian, H. rostrata, H. stricta cv. Capri, H. psittacorum cv. Sassy e H. caribea. O método alternativo de detecção de resistência consistiu na utilização de filtrado fúngico obtido a partir do cultivo em meio Czapek, utilizando várias concentrações do mesmo depositando em folhas destacadas das cultivares resistentes e suscetíveis H. psittacorum cvs. Golden Torch e Alan Carle, respectivamente. A avaliação foi feita após 48 horas de incubação, onde a concentração em 50% do filtrado foi a mais eficiente na distinção da resistência. O mecanismo estrutural foi observado em secções histológicas nas raízes das espécies utilizadas no estudo de resistência, inoculadas com o método de injeção e não inoculadas, que permitiram verificar a ausência de relação entre a resistência e a lignificação.Heliconia grown as a crop has been affected by wilt, caused by Fusarium oxysporum f.sp. cubense. This work aimed to identify genetic resistances sources, to evaluated the detection of resistance with an alternative method and to verify the effects of structural mechanisms in pathogen resistance. The genotypes

Acceptor Type Vacancy Complexes In As-Grown ZnO

International Nuclear Information System (INIS)

Zubiaga, A.; Tuomisto, F.; Zuniga-Perez, J.

2010-01-01

One of the many technological areas that ZnO is interesting for is the construction of opto-electronic devices working in the blue-UV range as its large band gap (∼3.4 eV at 10 K) makes them suitable for that purpose. As-grown ZnO shows generally n-type conductivity partially due to the large concentration of unintentional shallow donors, like H, but impurities can also form complexes with acceptor type defects (Zn vacancy) leading to the creation of compensating defects. Recently, Li Zn and Na Zn acceptors have been measured and H could form similar type of defects. Doppler Broadening Positron Annihilation spectroscopy experimental results on the observation of Zn related vacancy complexes in ZnO thin films, as-grown, O implanted and Al doped will be presented. Results show that as-grown ZnO film show small Zn vacancy related complexed that could be related to presence of H as a unintentional doping element.

Acceptor Type Vacancy Complexes In As-Grown ZnO

Science.gov (United States)

Zubiaga, A.; Tuomisto, F.; Zuñiga-Pérez, J.

2010-11-01

One of the many technological areas that ZnO is interesting for is the construction of opto-electronic devices working in the blue-UV range as its large band gap (˜3.4 eV at 10 K) makes them suitable for that purpose. As-grown ZnO shows generally n-type conductivity partially due to the large concentration of unintentional shallow donors, like H, but impurities can also form complexes with acceptor type defects (Zn vacancy) leading to the creation of compensating defects. Recently, LiZn and NaZn acceptors have been measured and H could form similar type of defects. Doppler Broadening Positron Annihilation spectroscopy experimental results on the observation of Zn related vacancy complexes in ZnO thin films, as-grown, O implanted and Al doped will be presented. Results show that as-grown ZnO film show small Zn vacancy related complexed that could be related to presence of H as a unintentional doping element.

Rutile TiO2 thin films grown by reactive high power impulse magnetron sputtering

International Nuclear Information System (INIS)

Agnarsson, B.; Magnus, F.; Tryggvason, T.K.; Ingason, A.S.; Leosson, K.; Olafsson, S.; Gudmundsson, J.T.

2013-01-01

Thin TiO 2 films were grown on Si(001) substrates by reactive dc magnetron sputtering (dcMS) and high power impulse magnetron sputtering (HiPIMS) at temperatures ranging from 300 to 700 °C. Optical and structural properties of films were compared both before and after post-annealing using scanning electron microscopy, low angle X-ray reflection (XRR), grazing incidence X-ray diffractometry and spectroscopic ellipsometry. Both dcMS- and HiPIMS-grown films reveal polycrystalline rutile TiO 2 , even prior to post-annealing. The HiPIMS-grown films exhibit significantly larger grains compared to that of dcMC-grown films, approaching 100% of the film thickness for films grown at 700 °C. In addition, the XRR surface roughness of HiPIMS-grown films was significantly lower than that of dcMS-grown films over the whole temperature range 300–700 °C. Dispersion curves could only be obtained for the HiPIMS-grown films, which were shown to have a refractive index in the range of 2.7–2.85 at 500 nm. The results show that thin, rutile TiO 2 films, with high refractive index, can be obtained by HiPIMS at relatively low growth temperatures, without post-annealing. Furthermore, these films are smoother and show better optical characteristics than their dcMS-grown counterparts. - Highlights: • We demonstrate growth of rutile TiO 2 on Si (111) by high power impulse magnetron sputtering. • The films exhibit significantly larger grains than dc magnetron sputtered films • TiO 2 films with high refractive index are obtained without post-growth annealing

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

Fast-grown CdS quantum dots: Single-source precursor approach vs microwave route

Energy Technology Data Exchange (ETDEWEB)

Fregnaux, Mathieu [Laboratoire de Chimie et Physique: Approche Multi-échelles des Milieux Complexes, Institut Jean Barriol, Université de Lorraine, 1 Boulevard Arago, 57070 Metz (France); Dalmasso, Stéphane, E-mail: stephane.dalmasso@univ-lorraine.fr [Laboratoire de Chimie et Physique: Approche Multi-échelles des Milieux Complexes, Institut Jean Barriol, Université de Lorraine, 1 Boulevard Arago, 57070 Metz (France); Durand, Pierrick [Laboratoire de Cristallographie, Résonance Magnétique et Modélisations, Institut Jean Barriol, Université de Lorraine, UMR CNRS 7036, Faculté des Sciences, BP 70239, 54506 Vandoeuvre lès Nancy (France); Zhang, Yudong [Laboratoire d' Etude des Microstructures et de Mécanique des Matériaux, Université de Lorraine, UMR CNRS 7239, Ile du Saulcy, 57045 Metz cedex 01 (France); Gaumet, Jean-Jacques; Laurenti, Jean-Pierre [Laboratoire de Chimie et Physique: Approche Multi-échelles des Milieux Complexes, Institut Jean Barriol, Université de Lorraine, 1 Boulevard Arago, 57070 Metz (France)

2013-10-01

A cross-disciplinary protocol of characterization by joint techniques enables one to closely compare chemical and physical properties of CdS quantum dots (QDs) grown by single source precursor methodology (SSPM) or by microwave synthetic route (MWSR). The results are discussed in relation with the synthesis protocols. The QD average sizes, reproducible as a function of the temperatures involved in the growth processes, range complementarily in 2.8–4.5 nm and 4.5–5.2 nm for SSPM and MWSR, respectively. Hexagonal and cubic structures after X-ray diffraction on SSPM and MWSR grown CdS QDs, respectively, are tentatively correlated to a better crystalline quality of the latter with respect to the further ones, suggested by (i) a remarkable stability of the MWSR grown QDs after exposure to air during several days and (ii) no evidence of their fragmentation during mass spectrometry (MS) analyses, after a fair agreement between size dispersities obtained by transmission electron microscopy (TEM) and MS, in contrast with the discrepancy found for the SSPM grown QDs. Correlatively, a better optical quality is suggested for the MWSR grown QDs by the resolution of n > 1 excitonic transitions in their absorption spectra. The QD average sizes obtained by TEM and deduced from MS are in overall agreement. This agreement is improved for the MWSR grown QDs, taking into account a prolate shape of the QDs also observed in the TEM images. For both series of samples, the excitonic responses vs the average sizes are consistent with the commonly admitted empirical energy-size correspondence. A low energy PL band is observed in the case of the SSPM grown QDs. Its decrease in intensity with QD size increase suggests a surface origin tentatively attributed to S vacancies. In the case of the MWSR grown QDs, the absence of this PL is tentatively correlated to an absence of S vacancies and therefore to the stable behavior observed when the QDs are exposed to air. - Highlights: • Single

Fabrication of in-situ grown graphene reinforced Cu matrix composites

Science.gov (United States)

Chen, Yakun; Zhang, Xiang; Liu, Enzuo; He, Chunnian; Shi, Chunsheng; Li, Jiajun; Nash, Philip; Zhao, Naiqin

2016-01-01

Graphene/Cu composites were fabricated through a graphene in-situ grown approach, which involved ball-milling of Cu powders with PMMA as solid carbon source, in-situ growth of graphene on flaky Cu powders and vacuum hot-press sintering. SEM and TEM characterization results indicated that graphene in-situ grown on Cu powders guaranteed a homogeneous dispersion and a good combination between graphene and Cu matrix, as well as the intact structure of graphene, which was beneficial to its strengthening effect. The yield strength of 244 MPa and tensile strength of 274 MPa were achieved in the composite with 0.95 wt.% graphene, which were separately 177% and 27.4% enhancement over pure Cu. Strengthening effect of in-situ grown graphene in the matrix was contributed to load transfer and dislocation strengthening. PMID:26763313

Effect Of Bird Manure On Cotton Plants Grown On Soils Sampled ...

African Journals Online (AJOL)

Cotton plant had a better development and growth when bird manure was only applied to soil or combined with mineral fertilizer and when cotton was grown on a soil where the previous crops were cereals (maize or sorghum). Planting cotton on a soil where the previous crop grown was maize or sorghum had no significant ...

InN layers grown by the HVPE

International Nuclear Information System (INIS)

Syrkin, A.L.; Ivantsov, V.; Usikov, A.; Dmitriev, V.A.; Chambard, G.; Ruterana, P.; Davydov, A.V.; Sundaresan, S.G.; Lutsenko, E.; Mudryi, A.V.; Readinger, E.D.; Chern-Metcalfe, G.D.; Wraback, M.

2008-01-01

We report on the properties of high quality HVPE InN and on successful subsequent MBE growth of InN layers with improved characteristics on HVPE InN template substrates. InN layers were grown by HVPE on GaN/sapphire HVPE templates. The (00.2) XRD rocking curve of the best InN layer (RC) had the FWHM of about 375 arc sec, being the narrowest XRD RCs ever reported for HVPE InN. Transmission Electron Microscopy (TEM) revealed that at the GaN/InN interface, the threading dislocations that come from GaN were transmitted into the InN layer. We estimated the dislocation density in HVPE grown InN to be in the low 10 9 cm -2 range. Reflection high energy electron diffraction (RHEED) confirmed monocrystalline structure of the InN layers surface. Layers photoluminescence (PL) showed edge emission around 0.8 eV. Hall measured free electron concentration was in the range of 10 19 -10 20 cm -3 and electron mobility was ∝200 cm 2 /V s. MBE growth of InN was performed on the HVPE grown InN template substrate demonstrating the improvement of material quality in the case of homo-epitaxial growth of InN. Demonstration of the high quality HVPE InN materials opens a new way for InN substrate development. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Small-scale shifting mosaics of two dominant grassland species: the possible role of soil-borne pathogens.

Science.gov (United States)

Olff, H; Hoorens, B; de Goede, R G M; van der Putten, W H; Gleichman, J M

2000-10-01

We analyzed the dynamics of dominant plant species in a grazed grassland over 17 years, and investigated whether local shifts in these dominant species, leading to vegetation mosaics, could be attributed to interactions between plants and soil-borne pathogens. We found that Festuca rubra and Carex arenaria locally alternated in abundance, with different sites close together behaving out of phase, resulting in a shifting mosaic. The net effect of killing all soil biota on the growth of these two species was investigated in a greenhouse experiment using gamma radiation, controlling for possible effects of sterilization on soil chemistry. Both plant species showed a strong net positive response to soil sterilization, indicating that pathogens (e.g., nematodes, pathogenic fungi) outweighed the effect of mutualists (e.g., mycorrhizae). This positive growth response towards soil sterilization appeared not be due to effects of sterilization on soil chemistry. Growth of Carex was strongly reduced by soil-borne pathogens (86% reduction relative to its growth on sterilized soil) on soil from a site where this species decreased during the last decade (and Festuca increased), while it was reduced much less (50%) on soil from a nearby site where it increased in abundance during the last decade. Similarly, Festuca was reduced more (67%) on soil from the site where it decreased (and Carex increased) than on soil from the site where it increased (55%, the site where Carex decreased). Plant-feeding nematodes showed high small-scale variation in densities, and we related this variation to the observed growth reductions in both plant species. Carex growth on unsterilized soil was significantly more reduced at higher densities of plant-feeding nematodes, while the growth reduction in Festuca was independent of plant-feeding nematode densities. At high plant-feeding nematode densities, growth of Carex was reduced more than Festuca, while at low nematode densities the opposite was found

Photoemission electronic states of epitaxially grown magnetite films

International Nuclear Information System (INIS)

Zalecki, R.; Kolodziejczyk, A.; Korecki, J.; Spiridis, N.; Zajac, M.; Kozlowski, A.; Kakol, Z.; Antolak, D.

2007-01-01

The valence band photoemission spectra of epitaxially grown 300 A single crystalline magnetite films were measured by the angle-resolved ultraviolet photoemission spectroscopy (ARUPS) at 300 K. The samples were grown either on MgO(0 0 1) (B termination) or on (0 0 1) Fe (iron-rich A termination), thus intentionally presenting different surface stoichiometry, i.e. also different surface electronic states. Four main features of the electron photoemission at about -1.0, -3.0, -5.5 and -10.0 eV below a chemical potential show systematic differences for two terminations; this difference depends on the electron outgoing angle. Our studies confirm sensitivity of angle resolved PES technique on subtleties of surface states

Nucleoli from growing oocytes support the development of enucleolated full-grown oocytes in the pig.

Science.gov (United States)

Kyogoku, Hirohisa; Ogushi, Sugako; Miyano, Takashi

2010-02-01

Recent research has shown that the maternal nucleolus is essential for embryonic development. The morphology of the nucleolus in growing oocytes differs from that in full-grown oocytes. We determined the ability of nucleoli from growing oocytes to substitute for nucleoli of full-grown oocytes in terms of supporting embryonic development in this study. Growing (around 100 microm in diameter) and full-grown porcine oocytes (120 microm) were collected from small (0.6-1.0 mm) and large antral follicles (4-5 mm), respectively. The nucleolus was aspirated from full-grown oocytes by micromanipulation, and the resulting enucleolated oocytes were matured to metaphase II; the nucleoli originating from full-grown and growing oocytes were then injected into the oocytes. The Chromatin of growing oocytes was aspirated with the nucleolus during the enucleolation process. Growing oocytes were thus treated with actinomycin D to release the chromatin from their nucleoli, and the nucleoli were collected and transferred to the enucleolated and matured full-grown oocytes. After activation by electro-stimulation, nucleoli were formed in pronuclei of sham-operated oocytes. Enucleolated oocytes that had been injected with nucleoli from either full-grown or growing, however, did not form any nucleoli in the pronuclei. No enucleolated oocytes developed to blastocysts, whereas enucleolated oocytes injected with nucleoli from full-grown oocytes (15%) or growing oocytes (18%) developed to blastocysts. These results indicate that the nucleoli from growing oocytes can substitute for nucleoli from full-grown oocytes during early embryonic development. (c) 2009 Wiley-Liss, Inc.

Study of grown-in and radiation-induced defects in indium phosphide

International Nuclear Information System (INIS)

Shaban, E.H.

1986-01-01

This research is focused on (1) conducting detailed theoretical and experimental study of grown-in and radiation-induced defects in liquid encapsulated Czohralski (LEC) grown, Zn-doped P-type indium phosphide (InP), (2) identifying the physical origin of the defects detected using Deep Level Transient Spectroscopy (DLTS) method, and (3) and developing a second-order model to interpret the presence of nonexponential capacitance transients in DLTS method. Analysis of grown-in and radiation-induced defects in P-type InP is undertaken. The main research results are summarized as follows: (1) DLTS analysis of grown-in defects in liquid LEC-grown, Zn-doped, P-type InP is made in this study. A single-hole trap of E/sub v/ + 0.52 eV is detected with a trap density of 1.8 x 10 15 cm -3 . The physical origin of this hole trap is attributed to a phosphorus vacancy or phosphorus interstitial-related defect. (2) One-MeV electron-irradiated P-type InP introduced two new hole traps, namely E/sub v/ + 0.34 and E/sub v/ + 0.58 eV with introduction rates (dN/sub T/d phi) of 0.4 and 1.2 per electron-cm, respectively. (3) A theoretical model is developed to interpret nonexponential capacitance transients in a deep-level transient spectroscopy method when the capture process competes with the dominant thermal-emission process

Characterization of Si(100) homoepitaxy grown in the STM at low temperatures

Energy Technology Data Exchange (ETDEWEB)

Grube, H. (Holger); Brown, G. W. (Geoffrey W.); Pomeroy, J. M. (Joshua M.); Hawley, M. E. (Marilyn E.)

2002-01-01

We explore the growth of low-temperature bulk-like Si(100) homoepitaxy with regard to microscopic surface roughness and defects We characterize films grown at different temperatures up to 500K in-situ by means of an effusion cell added to our UHVSTM. The development of novel architectures for future generation computers calls for high-quality homoepitaxial (WOO) grown at low temperature. Even though Si(100) can be grown crystalline up to a limited thickness: the microstructure reveals significant small-scale surface roughness and defects specific to low-temperature growth. Both can he detrimental to fabrication and operation of small-scale electronic devices.

Investigation of ZnTe thin films grown by Pulsed Laser Deposition method

International Nuclear Information System (INIS)

Kotlyarchuk, B.; Savchuk, V.

2007-01-01

This paper is devoted to optimization of the Pulsed Laser Deposition (PLD) growth condition of ZnTe films on various substrates and subsequent investigation of relevant parameters of growth process, structural, optical and electrical properties of grown films. Studies of the effect of growth parameters on the structural quality and properties of grown films were carried out. X-ray diffraction measurements showed that the ZnTe films, which have been deposited at optimal substrate temperatures, were characterized by a (111) preferred orientation with large average grain size. The optical transmission and reflectance in the energy range 1.5-5.5 eV for films grown at various substrate temperatures were measured. We calculated the variation in the absorption coefficient with the photon energy from the transmittance spectrum for samples grown at various substrate temperatures. Obtained data were analyzed and the value of the absorption coefficient, for allowed direct transitions, has been determined as a function of photon energy. We found that the undoped ZnTe films, which were grown by the PLD method, are typically p-type and possess resistivity in the range of 10 3 Ωcm at room temperature. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Phytochemical phenolics in organically grown vegetables.

Science.gov (United States)

Young, Janice E; Zhao, Xin; Carey, Edward E; Welti, Ruth; Yang, Shie-Shien; Wang, Weiqun

2005-12-01

Fruit and vegetable intake is inversely correlated with risks for several chronic diseases in humans. Phytochemicals, and in particular, phenolic compounds, present in plant foods may be partly responsible for these health benefits through a variety of mechanisms. Since environmental factors play a role in a plant's production of secondary metabolites, it was hypothesized that an organic agricultural production system would increase phenolic levels. Cultivars of leaf lettuce, collards, and pac choi were grown either on organically certified plots or on adjacent conventional plots. Nine prominent phenolic agents were quantified by HPLC, including phenolic acids (e. g. caffeic acid and gallic acid) and aglycone or glycoside flavonoids (e. g. apigenin, kaempferol, luteolin, and quercetin). Statistically, we did not find significant higher levels of phenolic agents in lettuce and collard samples grown organically. The total phenolic content of organic pac choi samples as measured by the Folin-Ciocalteu assay, however, was significantly higher than conventional samples (p lettuce and collards, the organic system provided an increased opportunity for insect attack, resulting in a higher level of total phenolic agents in pac choi.

Violaxanthin is an abscisic acid precursor in water-stressed dark-grown bean leaves

International Nuclear Information System (INIS)

Li, Yi; Walton, D.C.

1990-01-01

The leaves a dark-grown bean (Phaseolus vulgaris L.) seedlings accumulate considerably lower quantities of xanthophylls and carotenes than do leaves of light-grown seedlings, but they synthesize at least comparable amounts of abscisic acid (ABA) and its metabolites when water stressed. We observed a 1:1 relationship on a molar basis between the reduction in levels of ciolaxanthin, 9'-cis-neoxanthin, and 9-cis-violaxanthin and the accumulation of ABA, phaseic acid, and dihydrophaseic acid, when leaves from dark-grown plants were stressed for 7 hours. Early in the stress period, reductions in xanthophylls were greater than the accumulation of ABA and its metabolites, suggesting the accumulation of an intermediate which was subsequently converted to ABA. Leaves which were detached, but no stressed, did not accumulate ABA nor were their xanthophyll levels reduced. Leaves from plants that had been sprayed with cycloheximido did not accumulate ABA when stressed, nor were their xanthophyll levels reduced significantly. Incubation of dark-grown stressed leaves in an 18 O 2 -containing atmosphere resulted in the synthesis of ABA with levels of 18 O in the carboxyl group that were virtually identical to those observed in light-grown leaves. The results of these experiments indicate that violaxanthin is an ABA precursor in stressed dark-grown leaves, and they are used to suggest several possible pathways from violaxanthin to ABA

Violaxanthin is an abscisic acid precursor in water-stressed dark-grown bean leaves

Energy Technology Data Exchange (ETDEWEB)

Li, Yi; Walton, D.C. (State Univ. of New York, Syracuse (USA))

1990-03-01

The leaves a dark-grown bean (Phaseolus vulgaris L.) seedlings accumulate considerably lower quantities of xanthophylls and carotenes than do leaves of light-grown seedlings, but they synthesize at least comparable amounts of abscisic acid (ABA) and its metabolites when water stressed. We observed a 1:1 relationship on a molar basis between the reduction in levels of ciolaxanthin, 9{prime}-cis-neoxanthin, and 9-cis-violaxanthin and the accumulation of ABA, phaseic acid, and dihydrophaseic acid, when leaves from dark-grown plants were stressed for 7 hours. Early in the stress period, reductions in xanthophylls were greater than the accumulation of ABA and its metabolites, suggesting the accumulation of an intermediate which was subsequently converted to ABA. Leaves which were detached, but no stressed, did not accumulate ABA nor were their xanthophyll levels reduced. Leaves from plants that had been sprayed with cycloheximido did not accumulate ABA when stressed, nor were their xanthophyll levels reduced significantly. Incubation of dark-grown stressed leaves in an {sup 18}O{sub 2}-containing atmosphere resulted in the synthesis of ABA with levels of {sup 18}O in the carboxyl group that were virtually identical to those observed in light-grown leaves. The results of these experiments indicate that violaxanthin is an ABA precursor in stressed dark-grown leaves, and they are used to suggest several possible pathways from violaxanthin to ABA.

TEM EDS analysis of epitaxially-grown self-assembled indium islands

Directory of Open Access Journals (Sweden)

Jasmine Sears

2017-05-01

Full Text Available Epitaxially-grown self-assembled indium nanostructures, or islands, show promise as nanoantennas. The elemental composition and internal structure of indium islands grown on gallium arsenide are explored using Transmission Electron Microscopy (TEM Energy Dispersive Spectroscopy (EDS. Several sizes of islands are examined, with larger islands exhibiting high (>94% average indium purity and smaller islands containing inhomogeneous gallium and arsenic contamination. These results enable more accurate predictions of indium nanoantenna behavior as a function of growth parameters.

High-quality GaN nanowires grown on Si and porous silicon by thermal evaporation

Energy Technology Data Exchange (ETDEWEB)

Shekari, L., E-mail: lsg09_phy089@student.usm.my [Nano-Optoelectronics Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Ramizy, A.; Omar, K.; Hassan, H. Abu; Hassan, Z. [Nano-Optoelectronics Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia)

2012-12-15

Highlights: Black-Right-Pointing-Pointer A new kind of substrate (porous silicon) was used. Black-Right-Pointing-Pointer Also this research introduces an easy and safe method to grow high quality GaN NWs. Black-Right-Pointing-Pointer This is a new growth process to decrease the cost, complexity of growth of GaN NWs. Black-Right-Pointing-Pointer It is a controllable method to synthesize GaN NWs by thermal evaporation. - Abstract: Nanowires (NWs) of GaN thin films were prepared on as-grown Si (1 1 1) and porous silicon (PS) substrates using thermal evaporation method. The film growth produced high-quality wurtzite GaN NWs. The size, morphology, and nanostructures of the crystals were investigated through scanning electron microscopy, high-resolution X-ray diffraction and photoluminescence spectroscopy. The NWs grown on porous silicon were thinner, longer and denser compared with those on as-grown Si. The energy band gap of the NWs grown on PS was larger than that of NWs on as-grown Si. This is due to the greater quantum confinement effects of the crystalline structure of the NWs grown on PS.

Quantification of the growth response of light quantity of greenhouse grown crops

NARCIS (Netherlands)

Marcelis, L.F.M.; Broekhuijsen, A.G.M.; Nijs, E.M.F.M.; Raaphorst, M.G.M.

2006-01-01

Growers have often assumed that a 1% increment in light results in a 1% yield increase. In this study, this rule of thumb has been evaluated for a number of greenhouse grown crops: fruit vegetables (cucumber, tomato, sweet pepper), soil grown vegetables (lettuce, radish), cut flowers (rose,

Influence of Si-doping on heteroepitaxially grown a-plane GaN

Energy Technology Data Exchange (ETDEWEB)

Wieneke, Matthias; Bastek, Barbara; Noltemeyer, Martin; Hempel, Thomas; Rohrbeck, Antje; Witte, Hartmut; Veit, Peter; Blaesing, Juergen; Dadgar, Armin; Christen, Juergen; Krost, Alois [Otto-von-Guericke-Universitaet Magdeburg, FNW/IEP, Universitaetsplatz 2, 39106 Magdeburg (Germany)

2011-07-01

Si-doped a-plane GaN samples with nominal doping levels up to 10{sup 20} cm{sup -3} were grown on r-plane sapphire by metal organic vapor phase epitaxy. Silane flow rates higher than 59 nmol/min lead to three dimensional grown crystallites as revealed by scanning electron microscopy. High resolution X-ray diffraction, photoluminescence and cathodoluminescence suggest considerably reduced defect densities in the large micrometer-sized GaN crystallites. Especially, transmission electron microscopy images verify a very low density of basal plane stacking faults less than 10{sup 4} cm{sup -1} in these crystallites consisting of heteroepitaxially grown a-plane GaN. In our presentation the influence of the Si doping on the basal plane stacking faults will be discussed.

InGaAs Quantum Well Grown on High-Index Surfaces for Superluminescent Diode Applications

Directory of Open Access Journals (Sweden)

Wu Jiang

2010-01-01

Full Text Available Abstract The morphological and optical properties of In0.2Ga0.8As/GaAs quantum wells grown on various substrates are investigated for possible application to superluminescent diodes. The In0.2Ga0.8As/GaAs quantum wells are grown by molecular beam epitaxy on GaAs (100, (210, (311, and (731 substrates. A broad photoluminescence emission peak (~950 nm with a full width at half maximum (FWHM of 48 nm is obtained from the sample grown on (210 substrate at room temperature, which is over four times wider than the quantum well simultaneously grown on (100 substrate. On the other hand, a very narrow photoluminescence spectrum is observed from the sample grown on (311 with FWHM = 7.8 nm. The results presented in this article demonstrate the potential of high-index GaAs substrates for superluminescent diode applications.

Postharvest evaluation of soilless-grown table grape during storage in modified atmosphere.

Science.gov (United States)

Cefola, Maria; Pace, Bernardo; Buttaro, Donato; Santamaria, Pietro; Serio, Francesco

2011-09-01

Soilless growth systems, developed mainly for vegetables and ornamental crops, have also been used recently as an alternative to soil culture for table grape in order to achieve optimal production performance. In this study, sensory, physical and chemical parameters were analysed in table grapes obtained from soil and soilless growth systems at harvest and during storage in air or modified atmosphere. At harvest, soilless-grown berries were 30% firmer than those grown in soil. Moreover, they showed 60% higher antioxidant activity and total phenol content than soil-grown fruits. Modified atmosphere storage resulted in a better quality of table grapes compared with those stored in air. Furthermore, soilless growth was more suitable than soil growth for preserving visual quality and controlling rachis browning and weight loss. Since the soilless system produces berries that are cleaner and of higher quality than those grown in soil, the implementation of soilless growth for the production of health-promoting and convenience fruits is suggested. Copyright © 2011 Society of Chemical Industry.

CONSUMER ATTITUDES TOWARD ORGANICALLY GROWN LETTUCE

OpenAIRE

Wolf, Marianne McGarry; Johnson, Bradey; Cochran, Kerry; Hamilton, Lynn L.

2002-01-01

This research shows that approximately 29 percent of lettuce purchases in California expect to purchase an organically grown lettuce product in the future. Organic lettuce purchasers are more likely to be female, have a higher household income and a higher level of education. Consumers are concerned with the freshness, quality, price, and environmental impact of the lettuce they purchase.

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 13(a...

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.

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.

Nucleoli from growing oocytes inhibit the maturation of enucleolated, full-grown oocytes in the pig.

Science.gov (United States)

Kyogoku, Hirohisa; Ogushi, Sugako; Miyano, Takashi; Fulka, Josef

2011-06-01

In mammals, the nucleolus of full-grown oocyte is essential for embryonic development but not for oocyte maturation. In our study, the role of the growing oocyte nucleolus in oocyte maturation was examined by nucleolus removal and/or transfer into previously enucleolated, growing (around 100 µm in diameter) or full-grown (120 µm) pig oocytes. In the first experiment, the nucleoli were aspirated from growing oocytes whose nucleoli had been compacted by actinomycin D treatment, and the enucleolated oocytes were matured in vitro. Most of non-treated or actinomycin D-treated oocytes did not undergo germinal vesicle breakdown (GVBD; 13% and 12%, respectively). However, the GVBD rate of enucleolated, growing oocytes significantly increased to 46%. The low GVBD rate of enucleolated, growing oocytes was restored again by the re-injection of nucleoli from growing oocytes (23%), but not when nucleoli from full-grown oocytes were re-injected into enucleolated, growing oocytes (49%). When enucleolated, full-grown oocytes were injected with nucleoli from growing or full-grown oocytes, the nucleolus in the germinal vesicle was reassembled (73% and 60%, respectively). After maturation, the enucleolated, full-grown oocytes injected with nucleoli from full-grown oocytes matured to metaphase II (56%), whereas injection with growing-oocyte nucleoli reduced this maturation to 21%. These results suggest that the growing-oocyte nucleolus is involved in the oocyte's meiotic arrest, and that the full-grown oocyte nucleolus has lost the ability. Copyright © 2011 Wiley-Liss, Inc.

Vascular plant biodiversity of the lower Coppermine River valley and vicinity (Nunavut, Canada: an annotated checklist of an Arctic flora

Directory of Open Access Journals (Sweden)

Jeffery M. Saarela

2017-01-01

Full Text Available The Coppermine River in western Nunavut is one of Canada’s great Arctic rivers, yet its vascular plant flora is poorly known. Here, we report the results of a floristic inventory of the lower Coppermine River valley and vicinity, including Kugluk (Bloody Falls Territorial Park and the hamlet of Kugluktuk. The study area is approximately 1,200 km2, extending from the forest-tundra south of the treeline to the Arctic coast. Vascular plant floristic data are based on a review of all previous collections from the area and more than 1,200 new collections made in 2014. Results are presented in an annotated checklist, including citation of all specimens examined, comments on taxonomy and distribution, and photographs for a subset of taxa. The vascular plant flora comprises 300 species (311 taxa, a 36.6% increase from the 190 species documented by previous collections made in the area over the last century, and is considerably more diverse than other local floras on mainland Nunavut. We document 207 taxa for Kugluk (Bloody Falls Territorial Park, an important protected area for plants on mainland Nunavut. A total of 190 taxa are newly recorded for the study area. Of these, 14 taxa (13 species and one additional variety are newly recorded for Nunavut (Allium schoenoprasum, Carex capitata, Draba lonchocarpa, Eremogone capillaris subsp. capillaris, Sabulina elegans, Eleocharis quinqueflora, Epilobium cf. anagallidifolium, Botrychium neolunaria, Botrychium tunux, Festuca altaica, Polygonum aviculare, Salix ovalifolia var. arctolitoralis, Salix ovalifolia var. ovalifolia and Stuckenia pectinata, seven species are newly recorded for mainland Nunavut (Carex gynocrates, Carex livida, Cryptogramma stelleri, Draba simmonsii, Festuca viviparoidea subsp. viviparoidea, Juncus alpinoarticulatus subsp. americanus and Salix pseudomyrsinites and 56 range extensions are reported. The psbA-trnH and rbcL DNA sequence data were used to help identify the three Botrychium

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.

Electrical properties of ZnO thin films grown by MOCVD

International Nuclear Information System (INIS)

Pagni, O.; Somhlahlo, N.N.; Weichsel, C.; Leitch, A.W.R.

2006-01-01

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

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.)

Conformity and structure of titanium oxide films grown by atomic layer deposition on silicon substrates

Energy Technology Data Exchange (ETDEWEB)

Jogi, Indrek [University of Tartu, Institute of Experimental Physics and Technology, Taehe 4, 51010, Tartu (Estonia)], E-mail: indrek.jogi@ut.ee; Paers, Martti; Aarik, Jaan; Aidla, Aleks [University of Tartu, Institute of Physics, Riia 142, 51014, Tartu (Estonia); Laan, Matti [University of Tartu, Institute of Experimental Physics and Technology, Taehe 4, 51010, Tartu (Estonia); Sundqvist, Jonas; Oberbeck, Lars; Heitmann, Johannes [Qimonda Dresden GmbH and Co. OHG, Koenigsbruecker Strasse 180, 01099, Dresden (Germany); Kukli, Kaupo [University of Tartu, Institute of Experimental Physics and Technology, Taehe 4, 51010, Tartu (Estonia)

2008-06-02

Conformity and phase structure of atomic layer deposited TiO{sub 2} thin films grown on silicon substrates were studied. The films were grown using TiCl{sub 4} and Ti(OC{sub 2}H{sub 5}){sub 4} as titanium precursors in the temperature range from 125 to 500 {sup o}C. In all cases perfect conformal growth was achieved on patterned substrates with elliptical holes of 7.5 {mu}m depth and aspect ratio of about 1:40. Conformal growth was achieved with process parameters similar to those optimized for the growth on planar wafers. The dominant crystalline phase in the as-grown films was anatase, with some contribution from rutile at relatively higher temperatures. Annealing in the oxygen ambient resulted in (re)crystallization whereas the effect of annealing depended markedly on the precursors used in the deposition process. Compared to films grown from TiCl{sub 4}, the films grown from Ti(OC{sub 2}H{sub 5}){sub 4} were transformed into rutile in somewhat greater extent, whereas in terms of step coverage the films grown from Ti(OC{sub 2}H{sub 5}){sub 4} remained somewhat inferior compared to the films grown from TiCl{sub 4}.

Anisotropic Friction of Wrinkled Graphene Grown by Chemical Vapor Deposition.

Science.gov (United States)

Long, Fei; Yasaei, Poya; Yao, Wentao; Salehi-Khojin, Amin; Shahbazian-Yassar, Reza

2017-06-21

Wrinkle structures are commonly seen on graphene grown by the chemical vapor deposition (CVD) method due to the different thermal expansion coefficient between graphene and its substrate. Despite the intensive investigations focusing on the electrical properties, the nanotribological properties of wrinkles and the influence of wrinkle structures on the wrinkle-free graphene remain less understood. Here, we report the observation of anisotropic nanoscale frictional characteristics depending on the orientation of wrinkles in CVD-grown graphene. Using friction force microscopy, we found that the coefficient of friction perpendicular to the wrinkle direction was ∼194% compare to that of the parallel direction. Our systematic investigation shows that the ripples and "puckering" mechanism, which dominates the friction of exfoliated graphene, plays even a more significant role in the friction of wrinkled graphene grown by CVD. The anisotropic friction of wrinkled graphene suggests a new way to tune the graphene friction property by nano/microstructure engineering such as introducing wrinkles.

Residual carrier density in GaSb grown on Si substrates

International Nuclear Information System (INIS)

Akahane, Kouichi; Yamamoto, Naokatsu; Gozu, Shin-ichiro; Ueta, Akio; Ohtani, Naoki

2006-01-01

The relationships between the densities of residual carriers and those of dislocation in GaSb films grown on Si substrates were investigated. Dislocation density was evaluated by cross-sectional transmission electron microscopy (TEM). The TEM images indicated that the dislocation density after a 5-μm-thick GaSb film was grown was below 1 x 10 8 /cm 2 although the density near the interface between the Si substrate and the GaSb film was about 3 x 10 9 /cm 2 . Forming a dislocation loop by growing a thick GaSb layer may decrease the dislocation density. The density and mobility of the residual carrier were investigated by Hall measurement using the van der Pauw method. The residual carriers in GaSb grown on Si substrates were holes, and their densities decreased significantly from 4.2 x 10 18 to 1.4 x 10 17 /cm 3 as GaSb thickness was increased from 500 to 5500 nm

Loblolly pine grown under elevated CO2 affects early instar pine sawfly performance.

Science.gov (United States)

Williams, R S; Lincoln, D E; Thomas, R B

1994-06-01

Seedlings of loblolly pine Pinus taeda (L.), were grown in open-topped field chambers under three CO 2 regimes: ambient, 150 μl l -1 CO 2 above ambient, and 300 μl l -1 CO 2 above ambient. A fourth, non-chambered ambient treatment was included to assess chamber effects. Needles were used in 96 h feeding trials to determine the performance of young, second instar larvae of loblolly pine's principal leaf herbivore, red-headed pine sawfly, Neodiprion lecontei (Fitch). The relative consumption rate of larvae significantly increased on plants grown under elevated CO 2 , and needles grown in the highest CO 2 regime were consumed 21% more rapidly than needles grown in ambient CO 2 . Both the significant decline in leaf nitrogen content and the substantial increase in leaf starch content contributed to a significant increase in the starch:nitrogen ratio in plants grown in elevated CO 2 . Insect consumption rate was negatively related to leaf nitrogen content and positively related to the starch:nitrogen ratio. Of the four volatile leaf monoterpenes measured, only β-pinene exhibited a significant CO 2 effect and declined in plants grown in elevated CO 2 . Although consumption changed, the relative growth rates of larvae were not different among CO 2 treatments. Despite lower nitrogen consumption rates by larvae feeding on the plants grown in elevated CO 2 , nitrogen accumulation rates were the same for all treatments due to a significant increase in nitrogen utilization efficiency. The ability of this insect to respond at an early, potentially susceptible larval stage to poorer food quality and declining levels of a leaf monoterpene suggest that changes in needle quality within pines in future elevated-CO 2 atmospheres may not especially affect young insects and that tree-feeding sawflies may respond in a manner similar to herb-feeding lepidopterans.

Surface characterization of ZnO nanorods grown by chemical bath deposition

Energy Technology Data Exchange (ETDEWEB)

Mbulanga, C.M., E-mail: crispin.mbulanga@nmmu.ac.za [Department of Physics, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031 (South Africa); Urgessa, Z.N.; Tankio Djiokap, S.R.; Botha, J.R. [Department of Physics, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031 (South Africa); Duvenhage, M.M.; Swart, H.C. [Department of Physics, University of the Free State, P.O Box 77000, Bloemfontein ZA9300 (South Africa)

2016-01-01

The surface composition of as-grown and annealed ZnO nanorods (ZNs) grown by a two-step chemical bath deposition method is investigated by the following surface-sensitive techniques: Time-of-Flight Secondary Ion Mass Spectroscopy (TOF-SIMS), X-ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES). The presence of H on the surface and throughout the entire thickness of ZNs is confirmed by TOF-SIMS. Based on TOF-SIMS results, the O2 XPS peak mostly observable at ~531.5 is assigned to O bound to H. Furthermore, it is found that the near surface region of as-grown ZNs is Zn-rich, and annealing at high temperature (~850 °C) removes H-related defects from the surface of ZNs and affect the balance of zinc and oxygen concentrations.

Growth and electrical properties of AlOx grown by mist chemical vapor deposition

Directory of Open Access Journals (Sweden)

Toshiyuki Kawaharamura

2013-03-01

Full Text Available Aluminum oxide (AlOx thin films were grown using aluminum acetylacetonate (Al(acac3 as a source solute by mist chemical vapor deposition (mist CVD. The AlOx thin films grown at temperatures above 400°C exhibited a breakdown field (EBD over 6 MV/cm and a dielectric constant (κ over 6. It is suggested that residual OH bonding in the AlOx thin films grown at temperatures below 375°C caused degradation of the breakdown field (EBD. With FC type mist CVD, the reaction proceeded efficiently (Ea = 22–24 kJ/mol because the solvent, especially H2O, worked as a stronger oxygen source. The AlOx film could be grown at 450°C with a high deposition rate (23 nm/min and smooth surface (RMS = 1.5 nm. Moreover, the AlOx thin films grown by mist CVD had excellent practicality as insulators because the gate leakage current (IG of the oxide thin film transistor (TFT with an IGZO/AlOx stack was suppressed below 1 pA at a gate voltage (VG of 20 V.

High-efficiency supercapacitor electrodes of CVD-grown graphenes hybridized with multiwalled carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Kalam, Amir Abul; Bae, Joon Ho [Dept. of Nano-physics, Gachon University, Seongnam (Korea, Republic of); Park, Soo Bin; Seo, Yong Ho [Nanotechnology and Advanced Material Engineering, HMC, and GRI, Sejong University, Seoul (Korea, Republic of)

2015-08-15

We demonstrate, for the first time, high-efficiency supercapacitors by utilizing chemical vapor deposition (CVD)-grown graphenes hybridized with multiwalled carbon nanotubes (CNTs). A single-layer graphene was grown by simple CVD growth method, and transferred to polyethylene terephthalate substrates. The bare graphenes were further hybridized with multiwalled CNTs by drop-coating CNTs on graphenes. The supercapacitors using bare graphenes and graphenes with CNTs revealed that graphenes with CNTs resulted in enhanced supercapacitor performances of 2.2- (the mass-specific capacitance) and 4.4-fold (the area-specific capacitance) of those of bare graphenes. Our strategy to improve electrochemical performance of CVD-grown graphenes is advantageous for large-scale graphene electrodes due to high electrical conductivity of CVD-grown graphenes and cost-effectiveness of using multiwalled CNTs as compared to conventional employment of single-walled CNTs.

High-efficiency supercapacitor electrodes of CVD-grown graphenes hybridized with multiwalled carbon nanotubes

International Nuclear Information System (INIS)

Kalam, Amir Abul; Bae, Joon Ho; Park, Soo Bin; Seo, Yong Ho

2015-01-01

We demonstrate, for the first time, high-efficiency supercapacitors by utilizing chemical vapor deposition (CVD)-grown graphenes hybridized with multiwalled carbon nanotubes (CNTs). A single-layer graphene was grown by simple CVD growth method, and transferred to polyethylene terephthalate substrates. The bare graphenes were further hybridized with multiwalled CNTs by drop-coating CNTs on graphenes. The supercapacitors using bare graphenes and graphenes with CNTs revealed that graphenes with CNTs resulted in enhanced supercapacitor performances of 2.2- (the mass-specific capacitance) and 4.4-fold (the area-specific capacitance) of those of bare graphenes. Our strategy to improve electrochemical performance of CVD-grown graphenes is advantageous for large-scale graphene electrodes due to high electrical conductivity of CVD-grown graphenes and cost-effectiveness of using multiwalled CNTs as compared to conventional employment of single-walled CNTs

Study of CdTe quantum dots grown using a two-step annealing method

Science.gov (United States)

Sharma, Kriti; Pandey, Praveen K.; Nagpal, Swati; Bhatnagar, P. K.; Mathur, P. C.

2006-02-01

High size dispersion, large average radius of quantum dot and low-volume ratio has been a major hurdle in the development of quantum dot based devices. In the present paper, we have grown CdTe quantum dots in a borosilicate glass matrix using a two-step annealing method. Results of optical characterization and the theoretical model of absorption spectra have shown that quantum dots grown using two-step annealing have lower average radius, lesser size dispersion, higher volume ratio and higher decrease in bulk free energy as compared to quantum dots grown conventionally.

Developmental, nutritional and hormonal anomalies of weightlessness-grown wheat

Science.gov (United States)

Carman, J. G.; Hole, P.; Salisbury, F. B.; Bingham, G. E.

2015-07-01

The behavior of water in weightlessness, as occurs in orbiting spacecraft, presents multiple challenges for plant growth. Soils remain saturated, impeding aeration, and leaf surfaces remain wet, impeding gas exchange. Herein we report developmental and biochemical anomalies of "Super Dwarf" wheat (Triticum aestivum L.) grown aboard Space Station Mir during the 1996-97 "Greenhouse 2" experiment. Leaves of Mir-grown wheat were hyperhydric, senesced precociously and accumulated aromatic and branched-chain amino acids typical of tissues experiencing oxidative stress. The highest levels of stress-specific amino acids occurred in precociously-senescing leaves. Our results suggest that the leaf ventilation system of the Svet Greenhouse failed to remove sufficient boundary layer water, thus leading to poor gas exchange and onset of oxidative stress. As oxidative stress in plants has been observed in recent space-flight experiments, we recommend that percentage water content in apoplast free-spaces of leaves be used to evaluate leaf ventilation effectiveness. Mir-grown plants also tillered excessively. Crowns and culms of these plants contained low levels of abscisic acid but high levels of cytokinins. High ethylene levels may have suppressed abscisic acid synthesis, thus permitting cytokinins to accumulate and tillering to occur.

Recrystallization phenomena of solution grown paraffin dendrites

NARCIS (Netherlands)

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

Contamination level in vegetables grown around Peshawar using sewerage and canal water

International Nuclear Information System (INIS)

Mahmood, S.

2001-01-01

The level of contamination in vegetables grown around Peshawar using sewerage/canal water is reported. The vegetable samples were collected from three representative locations. The results indicated that vegetables grown with sewerage water contained higher levels of Cd, Cu and Pb than those with irrigation water. Maximum amount of Cd was in Qulfa (3.68 mu g/ g) followed by sponge gourd leaves (3.38 mu g/ g) the tomato leaves (93.32 mu g/ g). while Pb in tomato leaves (4.88 mu g / g), Cu content ranged between 2.08 and 7.5 mu g/g in these vegetables. In the vegetables grown with canal water the Cd ranged 0.82 - 2.88 mu g/g, Cu 2.38 mu g /g and Pb 0.84 - 1.88 mu g/ g. The concentration of Fe and P in the vegetables of sewerage water ranged 9.0-25.0 and 5.6-14.8 mg/100g respectively while those grown with canal water 9.0-11.0 mg/ 100 g and 8.4-12.8 mg/ 100 g respectively. (author)

Observation of Zn vacancies in ZnO grown by chemical vapor transport

Energy Technology Data Exchange (ETDEWEB)

Tuomisto, F.; Saarinen, K. [Laboratory of Physics, Helsinki University of Technology, P.O. Box 1100, 02015 TKK (Finland); Grasza, K.; Mycielski, A. [Institute of Physics, Polish Academy of Sciences, Lotnikow 32/46, 02-668 Warsaw (Poland)

2006-03-15

We have used positron annihilation spectroscopy to study the vacancy defects in ZnO crystals grown by both the conventional and contactless chemical vapor transport (CVT and CCVT). Our results show that Zn vacancies or Zn vacancy related defects are present in as-grown ZnO, irrespective of the growth method. Zn vacancies are observed in CVT-grown undoped ZnO and (Zn,Mn)O. The Zn vacancies present in undoped CCVT-ZnO are the dominant negatively charged point defect in the material. Doping the material with As introduces also Zn vacancy-related defect complexes with larger open volume. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Thermal stability of amorphous carbon films grown by pulsed laser deposition

Science.gov (United States)

Friedmann, T. A.; McCarty, K. F.; Barbour, J. C.; Siegal, M. P.; Dibble, Dean C.

1996-03-01

The thermal stability in vacuum of amorphous tetrahedrally coordinated carbon (a-tC) films grown on Si has been assessed by in situ Raman spectroscopy. Films were grown in vacuum on room-temperature substrates using laser fluences of 12, 22, and 45 J/cm2 and in a background gas of either hydrogen or nitrogen using a laser fluence of 45 J/cm2. The films grown in vacuum at high fluence (≳20J/cm2) show little change in the a-tC Raman spectra with temperature up to 800 °C. Above this temperature the films convert to glassy carbon (nanocrystalline graphite). Samples grown in vacuum at lower fluence or in a background gas (H2 or N2) at high fluence are not nearly as stable. For all samples, the Raman signal from the Si substrate (observed through the a-tC film) decreases in intensity with annealing temperature indicating that the transparency of the a-tC films is decreasing with temperature. These changes in transparency begin at much lower temperatures (˜200 °C) than the changes in the a-tC Raman band shape and indicate that subtle changes are occurring in the a-tC films at lower temperatures.

Epitaxial Ge Solar Cells Directly Grown on Si (001) by MOCVD Using Isobutylgermane

Science.gov (United States)

Kim, Youngjo; Kim, Kangho; Lee, Jaejin; Kim, Chang Zoo; Kang, Ho Kwan; Park, Won-Kyu

2018-03-01

Epitaxial Ge layers have been grown on Si (001) substrates by metalorganic chemical vapor deposition (MOCVD) using an isobutylgermane (IBuGe) metalorganic source. Low and high temperature two-step growth and post annealing techniques are employed to overcome the lattice mismatch problem between Ge and Si. It is demonstrated that high quality Ge epitaxial layers can be grown on Si (001) by using IBuGe with surface RMS roughness of 2 nm and an estimated threading dislocation density of 4.9 × 107 cm -2. Furthermore, single-junction Ge solar cells have been directly grown on Si substrates with an in situ MOCVD growth. The epitaxial Ge p- n junction structures are investigated with transmission electron microscopy and electrochemical C- V measurements. As a result, a power conversion efficiency of 1.69% was achieved for the Ge solar cell directly grown on Si substrate under AM1.5G condition.

Uptake of Radium by Grass and Shrubs Grown on Mineral Heaps: A Preliminary Study

International Nuclear Information System (INIS)

Laili, Z.; Omar, M.; Yusof, M.A. Wahab; Ibrahim, M.Z.

2015-01-01

A preliminary study of the uptake of 226 Ra and 228 Ra by grass and shrubs grown on mineral heaps was carried out. Activity concentrations of 226 Ra and 228 Ra in grass and shrubs were measured using gamma spectrometry. The result showed that grass and shrubs grown on mineral heaps contained elevated levels of radium compared to grass and shrubs grown on normal soils. Thus, these plants might be used for phytoremediation of radium contaminated soil. (author)

Helicopter Parents and Landing Pad Kids: Intense Parental Support of Grown Children

Science.gov (United States)

Fingerman, Karen L.; Cheng, Yen-Pi; Wesselmann, Eric D.; Zarit, Steven; Furstenberg, Frank; Birditt, Kira S.

2012-01-01

Popular media describe adverse effects of helicopter parents who provide intense support to grown children, but few studies have examined implications of such intense support. Grown children (N = 592, M age = 23.82 years, 53% female, 35% members of racial/ethnic minority groups) and their parents (N = 399, M age = 50.67 years, 52% female; 34%…

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.

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

International Nuclear Information System (INIS)

Shukrullah, S.; Mohamed, N. M.; Shaharun, M. S.; Yasar, M.

2014-01-01

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

The calcareous mires in South-East Poland are home to two rare Anthracoidea species

Directory of Open Access Journals (Sweden)

Marcin Piątek

2013-12-01

Full Text Available The new collections of Anthracoidea buxbaumii Kukkonen on Carex buxbaumii Wahlenb. and Anthracoidea hostianae B.Lindeb. ex Nannf. on Carex lepidocarpa Tausch recorded in the calcareous mires in South-East Poland are described, illustrated and discussed. The holotype of the latter smut is also re-examined, described and illustrated in detail. Anthracoidea buxbaumii is reported for the second time from Poland on a new host plant. Anthracoidea hostianae is new to Poland. The variability of spore sizes of both species is discussed. The conspecificity of Anthracoidea buxbaumii and A. hostianae suggested in the literature is analyzed.

Determination of Vitamin C, b-carotene and Riboflavin Contents in Five Green Vegetables Organically and Conventionally Grown.

Science.gov (United States)

Ismail, Amin; Cheah, Sook Fun

2003-03-01

As consumer interest in organically grown vegetables is increasing in Malaysia, there is a need to answer whether the vegetables are more nutritious than those conventionally grown. This study investigates commercially available vegetables grown organically and conventionally, purchased from retailers to analyse β-carotene, vitamin C and riboflavin contents. Five types of green vegetables were selected, namely Chinese mustard (sawi) (Brassica juncea), Chinese kale (kai-lan) (Brassica alboglabra), lettuce (daun salad) (Lactuca sativa), spinach (bayam putih) (Amaranthus viridis) and swamp cabbage (kangkung) (Ipomoea aquatica). For vitamin analysis, a reverse-phase high performance liquid chromatography was used to identify and quantify β -carotene, vitamin C and riboflavin. The findings showed that not all of the organically grown vegetables were higher in vitamins than that conventionally grown. This study found that only swamp cabbage grown organically was highest in β -carotene, vitamin C and riboflavin contents among the entire samples studied. The various nutrients in organically grown vegetables need to be analysed for the generation of a database on nutritional value which is important for future research.

Characteristics evaluation of stilbene single crystal grown by vertical bridgman technique

International Nuclear Information System (INIS)

Jo, Kwang Ho

2012-02-01

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 Φ 30 mm x 15 mm, and Φ 40 mm x 17 mm from the first ample, and size of Φ 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

Structural and morphological characterizations of ZnO films grown on GaAs substrates by MOCVD

Energy Technology Data Exchange (ETDEWEB)

Agouram, S.; Zuniga Perez, J.; Munoz-Sanjose, V. [Universitat de Valencia, Departamento de Fisica Aplicada y Electromagnetismo, Burjassot (Spain)

2007-07-15

ZnO films were grown on GaAs(100), GaAs(111)A and GaAs(111)B substrates by metal organic chemical vapour deposition (MOCVD). Diethylzinc (DEZn) and tertiarybutanol (t-butanol) were used as Zn and O precursors, respectively. The influence of the growth temperature and GaAs substrate orientation on the crystalline orientation and morphology of the ZnO grown films has been analysed. Crystallinity of grown films was studied by X-ray diffraction (XRD); thickness and morphology of ZnO films were investigated by scanning electron microscopy (SEM). SEM results reveal significant differences between morphologies depending on growth temperature but not significant differences were detected on the texture of grown films. (orig.)

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

Science.gov (United States)

2010-10-20

... Service 7 CFR Part 983 [Doc. No. AMS-FV-10-0077; FV10-983-3 CR] Pistachios Grown in California, Arizona..., 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: The...

Annealing behavior of solution grown polyethylene single crystals

NARCIS (Netherlands)

Loos, J.; Tian, M.

2006-01-01

The morphology evolution of solution grown polyethylene single crystals has been studied upon annealing below their melting temperature by using atomic force microscopy (AFM). AFM investigations have been performed ex situ, which means AFM investigations at room temperature after the annealing

Tissue grown in space in NASA Bioreactor

Science.gov (United States)

2001-01-01

Dr. Lisa E. Freed of the Massachusetts Institute of Technology and her colleagues have reported that initially disc-like specimens 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. Final samples from Mir and Earth appeared histologically cartilaginous throughout their entire cross sections (5-8 mm thick), with the exception of fibrous outer capsules. Constructs grown on Earth (A) appeared to have a more organized extracellular matrix with more uniform collagen orientation as compared with constructs grown on Mir (B), but the average collagen fiber diameter was similar in the two groups (22 +- 2 nm) and comparable to that previously reported for developing articular cartilage. Randomly oriented collagen in Mir samples would be consistent with previous reports that microgravity disrupts fibrillogenesis. These are transmission electron micrographs of constructs from Mir (A) and Earth (B) groups at magnifications of x3,500 and x120,000 (Inset). 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). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Credit: Proceedings of the National Academy of Sciences.

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…

Wrinkle-Free Single-Crystal Graphene Wafer Grown on Strain-Engineered Substrates.

Science.gov (United States)

Deng, Bing; Pang, Zhenqian; Chen, Shulin; Li, Xin; Meng, Caixia; Li, Jiayu; Liu, Mengxi; Wu, Juanxia; Qi, Yue; Dang, Wenhui; Yang, Hao; Zhang, Yanfeng; Zhang, Jin; Kang, Ning; Xu, Hongqi; Fu, Qiang; Qiu, Xiaohui; Gao, Peng; Wei, Yujie; Liu, Zhongfan; Peng, Hailin

2017-12-26

Wrinkles are ubiquitous for graphene films grown on various substrates by chemical vapor deposition at high temperature due to the strain induced by thermal mismatch between the graphene and substrates, which greatly degrades the extraordinary properties of graphene. Here we show that the wrinkle formation of graphene grown on Cu substrates is strongly dependent on the crystallographic orientations. Wrinkle-free single-crystal graphene was grown on a wafer-scale twin-boundary-free single-crystal Cu(111) thin film fabricated on sapphire substrate through strain engineering. The wrinkle-free feature of graphene originated from the relatively small thermal expansion of the Cu(111) thin film substrate and the relatively strong interfacial coupling between Cu(111) and graphene, based on the strain analyses as well as molecular dynamics simulations. Moreover, we demonstrated the transfer of an ultraflat graphene film onto target substrates from the reusable single-crystal Cu(111)/sapphire growth substrate. The wrinkle-free graphene shows enhanced electrical mobility compared to graphene with wrinkles.

Characterization of carbon nanotubes grown on Fe70Pd30 film

International Nuclear Information System (INIS)

Khan, Zishan H.; Islam, S.S.; Kung, S.C.; Perng, T.P.; Khan, Samina; Tripathi, K.N.; Agarwal, Monika; Zulfequar, M.; Husain, M.

2006-01-01

Carbon nanotubes have been synthesized by a LPCVD on nanocrystalline Fe-Pd film. CNTs are grown for 30min and 1h respectively. From the SEM images, the diameter of these nanotubes varies from 40-80nm and the length is several micro-meter approximately. TEM observations suggest that the CNTs are multi-walled and the structure changes from ordinary geometry of CNTs to bamboo shaped. We have observed sharp G and D bands in the Raman spectra of these carbon nanotubes. Higher D-band is observed for the carbon nanotubes grown for longer time (1h), showing that these nanotubes contain more amorphous carbon. The field emission measurements for these CNTs are also performed. For CNTs grown for longer time (1h), a superior turn-on field of 4.88V/μm (when the current density achieves 10μA/cm 2 ) is obtained and a current density of 29.36mA/cm 2 can be generated at 9.59V/μm

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.

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

Energy Technology Data Exchange (ETDEWEB)

Li, Detian; Cheng, Yongjun [Science and Technology on Vacuum Technology and Physics Laboratory, Lanzhou Institute of Physics, Lanzhou 730000 (China); Wang, Yongjun, E-mail: wyjlxlz@163.com [Science and Technology on Vacuum Technology and Physics Laboratory, Lanzhou Institute of Physics, Lanzhou 730000 (China); Zhang, Huzhong [Science and Technology on Vacuum Technology and Physics Laboratory, Lanzhou Institute of Physics, Lanzhou 730000 (China); Dong, Changkun [Institute of Micro-Nano Structures and Optoelectronics, Wenzhou University, Wenzhou 325035 (China); Li, Da [Division of Advanced Nanomaterials, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215125 (China)

2016-03-01

Graphical abstract: - Highlights: • The high quality CNT arrays were successfully grown on conductive stainless steel substrates. • The CNT array grown on stainless steel substrate exhibited superior field emission properties. • A high vacuum level about 10–8 Pa was measured by resultant CNT-based ionization gauge. • The ionization gauge with CNT cathode demonstrated a high stability. - Abstract: 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{sup −8} Pa, which is one order of magnitude lower than the result reported for the same of gauge with CNT cathode.

Composition of MBE-grown iron oxide films

NARCIS (Netherlands)

Voogt, F.C; Hibma, T; Smulders, P.J M; Niesen, L

A wide range of iron oxides have been grown epitaxially on MgO(100) substrates using a dual beam technique in which the deposited iron is oxidised by a beam of NO2 particles. At high fluxes magnetite (Fe3-deltaO4) phases with compositions between near-stoichiometric magnetite (Fe3O4, delta = 0) and

Low temperature grown GaNAsSb: A promising material for photoconductive switch application

Energy Technology Data Exchange (ETDEWEB)

Tan, K. H.; Yoon, S. F.; Wicaksono, S.; Loke, W. K.; Li, D. S. [School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798 (Singapore); Saadsaoud, N.; Tripon-Canseliet, C. [Laboratoire d' Electronique et Electromagnétisme, Pierre and Marie Curie University, 4 Place Jussieu, 75005 Paris (France); Lampin, J. F.; Decoster, D. [Institute of Electronics, Microelectronics and Nanotechnology (IEMN), UMR CNRS 8520, Universite des Sciences et Technologies de Lille, BP 60069, 59652 Villeneuve d' Ascq Cedex (France); Chazelas, J. [Thales Airborne Systems, 2 Avenue Gay Lussac, 78852 Elancourt (France)

2013-09-09

We report a photoconductive switch using low temperature grown GaNAsSb as the active material. The GaNAsSb layer was grown at 200 °C by molecular beam epitaxy in conjunction with a radio frequency plasma-assisted nitrogen source and a valved antimony cracker source. The low temperature growth of the GaNAsSb layer increased the dark resistivity of the switch and shortened the carrier lifetime. The switch exhibited a dark resistivity of 10{sup 7} Ω cm, a photo-absorption of up to 2.1 μm, and a carrier lifetime of ∼1.3 ps. These results strongly support the suitability of low temperature grown GaNAsSb in the photoconductive switch application.

Phyllosphere Microbiota Composition and Microbial Community Transplantation on Lettuce Plants Grown Indoors

Science.gov (United States)

Williams, Thomas R.

2014-01-01

ABSTRACT The aerial surfaces of plants, or phyllosphere, are microbial habitats important to plant and human health. In order to accurately investigate microbial interactions in the phyllosphere under laboratory conditions, the composition of the phyllosphere microbiota should be representative of the diversity of microorganisms residing on plants in nature. We found that Romaine lettuce grown in the laboratory contained 10- to 100-fold lower numbers of bacteria than age-matched, field-grown lettuce. The bacterial diversity on laboratory-grown plants was also significantly lower and contained relatively higher proportions of Betaproteobacteria as opposed to the Gammaproteobacteria-enriched communities on field lettuce. Incubation of field-grown Romaine lettuce plants in environmental growth chambers for 2 weeks resulted in bacterial cell densities and taxa similar to those on plants in the field but with less diverse bacterial populations overall. In comparison, the inoculation of laboratory-grown Romaine lettuce plants with either freshly collected or cryopreserved microorganisms recovered from field lettuce resulted in the development of a field-like microbiota on the lettuce within 2 days of application. The survival of an inoculated strain of Escherichia coli O157:H7 was unchanged by microbial community transfer; however, the inoculation of E. coli O157:H7 onto those plants resulted in significant shifts in the abundance of certain taxa. This finding was strictly dependent on the presence of a field-associated as opposed to a laboratory-associated microbiota on the plants. Phyllosphere microbiota transplantation in the laboratory will be useful for elucidating microbial interactions on plants that are important to agriculture and microbial food safety. PMID:25118240

Assessing biodiesel quality parameters for wastewater grown Chlorella sp.

Science.gov (United States)

Bagul, Samadhan Yuvraj; K Bharti, Randhir; Dhar, Dolly Wattal

2017-07-01

Microalgae are reported as the efficient source of renewable biodiesel which should be able to meet the global demand of transport fuels. Present study is focused on assessment of wastewater grown indigenous microalga Chlorella sp. for fuel quality parameters. This was successfully grown in secondary treated waste water diluted with tap water (25% dilution) in glass house. The microalga showed a dry weight of 0.849 g L -1 with lipid content of 27.1% on dry weight basis on 21st day of incubation. After transesterification, the yield of fatty acid methyl ester was 80.64% with major fatty acids as palmitic, linoleic, oleic and linolenic. The physical parameters predicted from empirical equations in the biodiesel showed cetane number as 56.5, iodine value of 75.5 g I 2 100 g -1 , high heating value 40.1 MJ kg -1 , flash point 135 °C, kinematic viscosity 4.05 mm 2 s -1 with density of 0.86 g cm 3 and cold filter plugging point as 0.7 °C. Fourier transform infra-red (FTIR), 1 H, 13 C NMR spectrum confirmed the chemical nature of biodiesel. The results indicated that the quality of biodiesel was almost as per the criterion of ASTM standards; hence, wastewater grown Chlorella sp. can be used as a promising strain for biodiesel production.

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.

76 FR 33967 - Irish Potatoes Grown in Southeastern States; Suspension of Marketing Order Provisions

Science.gov (United States)

2011-06-10

... IR] Irish Potatoes Grown in Southeastern States; Suspension of Marketing Order Provisions AGENCY... suspends the marketing order for Irish potatoes grown in Southeastern states (order), and the rules and regulations implemented thereunder, through March 1, 2014. The order regulates the handling of Irish potatoes...

Cuprous oxide thin films grown by hydrothermal electrochemical deposition technique

International Nuclear Information System (INIS)

Majumder, M.; Biswas, I.; Pujaru, S.; Chakraborty, A.K.

2015-01-01

Semiconducting cuprous oxide films were grown by a hydrothermal electro-deposition technique on metal (Cu) and glass (ITO) substrates between 60 °C and 100 °C. X-ray diffraction studies reveal the formation of cubic cuprous oxide films in different preferred orientations depending upon the deposition technique used. Film growth, uniformity, grain size, optical band gap and photoelectrochemical response were found to improve in the hydrothermal electrochemical deposition technique. - Highlights: • Cu 2 O thin films were grown on Cu and glass substrates. • Conventional and hydrothermal electrochemical deposition techniques were used. • Hydrothermal electrochemical growth showed improved morphology, thickness and optical band gap

Increased sensitivity of the respiratory system of plants grown in Gibberellic acid toward fluoride

Energy Technology Data Exchange (ETDEWEB)

Lustinec, J; Pokorna, V; Ruzicka, J

1962-01-01

Gibberellic acid in concentrations between 2 and 80 mg/l does not affect the ratio of radioactivities of /sup 14/CO/sub 2/ liberated from glucose-6-/sup 14/C and -1-/sup 14/C(C/sub 6//C/sub 1/) when acting for several hours on sliced wheat leaves, and that at a concentration of 10 mg/l it does not alter the degree of inhibition of respiration due to fluoride, iodoacetate and malonate or the consumption of oxygen. A linear relationship was established between the decrease in /sup 14/CO/sub 2/ liberation from glucose-/sup 14/C and the concentration of gibberellic acid. The C/sub 6//C/sub 1/ ratio as well as the absolute values of radioactivity decrease more rapidly in the course of several days after the germination of plants grown in a solution of gibberellic acid (10-20 mg/l) than in the water-grown controls. Fluoride inhibits the respiration of plants grown in gibberellic acid more than of those grown in water, its tissue concentration being either equal or less in the gibberellic -grown plants; the effect of iodoacetate and malonate is the same with plants of equal age (4 days) in both variants. 11 references, 1 figure, 4 tables.

Direct effects of warming increase woody plant abundance in a subarctic wetland.

Science.gov (United States)

Carlson, Lindsay G; Beard, Karen H; Adler, Peter B

2018-03-01

Both the direct effects of warming on a species' vital rates and indirect effects of warming caused by interactions with neighboring species can influence plant populations. Furthermore, herbivory mediates the effects of warming on plant community composition in many systems. Thus, determining the importance of direct and indirect effects of warming, while considering the role of herbivory, can help predict long-term plant community dynamics. We conducted a field experiment in the coastal wetlands of western Alaska to investigate how warming and herbivory influence the interactions and abundances of two common plant species, a sedge, Carex ramenskii , and a dwarf shrub, Salix ovalifolia . We used results from the experiment to model the equilibrium abundances of the species under different warming and grazing scenarios and to determine the contribution of direct and indirect effects to predict population changes. Consistent with the current composition of the landscape, model predictions suggest that Carex is more abundant than Salix under ambient temperatures with grazing (53% and 27% cover, respectively). However, with warming and grazing, Salix becomes more abundant than Carex (57% and 41% cover, respectively), reflecting both a negative response of Carex and a positive response of Salix to warming. While grazing reduced the cover of both species, herbivory did not prevent a shift in dominance from sedges to the dwarf shrub. Direct effects of climate change explained about 97% of the total predicted change in species cover, whereas indirect effects explained only 3% of the predicted change. Thus, indirect effects, mediated by interactions between Carex and Salix, were negligible, likely due to use of different niches and weak interspecific interactions. Results suggest that a 2°C increase could cause a shift in dominance from sedges to woody plants on the coast of western Alaska over decadal timescales, and this shift was largely a result of the direct effects

Heavy metals in Australian grown and imported rice and vegetables on sale in Australia: health hazard.

Science.gov (United States)

Rahman, M Azizur; Rahman, Mohammad Mahmudur; Reichman, Suzie M; Lim, Richard P; Naidu, Ravi

2014-02-01

Dietary exposure to heavy metals is a matter of concern for human health risk through the consumption of rice, vegetables and other major foodstuffs. In the present study, we investigated concentrations of cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn) in Australian grown and imported rice and vegetables on sale in Australia. The mean concentrations of Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn in Australian grown rice were 7.5 µg kg(-1), 21 µg kg(-1), 144 µg kg(-1), 2.9 mg kg(-1), 24.4 mg kg(-1), 166 µg kg(-1), 375 µg kg(-1), and 17.1 mg kg(-1) dry weight (d. wt.), respectively. Except Cd, heavy metal concentrations in Australian grown rice were higher than Bangladeshi rice on sale in Australia. However, the concentrations of Cd, Cr, Cu, and Ni in Indian rice on sale in Australia were higher than Australian grown rice. The concentrations of Cu and Ni in Vietnamese rice, and that of Cd, Cr, Cu, Ni, and Pb in Thai rice on sale in Australia were also higher than Australian grown rice. Heavy metal concentrations in Pakistani rice on sale in Australia were substantially lower than that in Australian grown rice. In Australian grown rice varieties, the concentrations of heavy metals were considerably higher in brown rice varieties than white rice varieties, indicating Australian brown rice as a potential source of dietary heavy metals for Australian consumers. The mean concentrations of heavy metals in Australian grown and Bangladeshi vegetables on sale in Australia were also determined. Some of the Australian grown and Bangladeshi vegetables contained heavy metals higher than Australian standard maximum limits indicating them as potential sources of dietary heavy metals for Australian consumers. Further investigation is required to estimate health risks of heavy metals from rice and vegetables consumption for Australian consumers. © 2013 Published by Elsevier Inc.

Comparative study for antibacterial potential of in vitro and in vivo grown Ocimum basilicum L. plant extracts

Energy Technology Data Exchange (ETDEWEB)

Shafique, M; Khan, S J [Pakistan Councile of Scientific and Industrial Research, Lahore (Pakistan). Dept. of Food and Biotechnology

2011-09-15

The antimicrobial activities of in vitro grown callus extract and in vivo grown Ocimum basilicum L. plant leaves extracts were studied and compared. Effect of extraction solvent was also assessed. These extracts were tested in vitro against eight bacterial strains following disc diffusion method. The results indicated that in vitro grown callus extracts of O. basilicum exhibited higher antimicrobial activity against tested Gram positive microorganisms as compared to in vivo grown plant material extract. These findings indicate towards potential use of biotechnology for natural therapeutic agent production. (author)

Comparative study for antibacterial potential of in vitro and in vivo grown Ocimum basilicum L. plant extracts

International Nuclear Information System (INIS)

Shafique, M.; Khan, S.J.

2011-01-01

The antimicrobial activities of in vitro grown callus extract and in vivo grown Ocimum basilicum L. plant leaves extracts were studied and compared. Effect of extraction solvent was also assessed. These extracts were tested in vitro against eight bacterial strains following disc diffusion method. The results indicated that in vitro grown callus extracts of O. basilicum exhibited higher antimicrobial activity against tested Gram positive microorganisms as compared to in vivo grown plant material extract. These findings indicate towards potential use of biotechnology for natural therapeutic agent production. (author)

Response of Plant Height, Species Richness and Aboveground Biomass to Flooding Gradient along Vegetation Zones in Floodplain Wetlands, Northeast China.

Science.gov (United States)

Lou, Yanjing; Pan, Yanwen; Gao, Chuanyu; Jiang, Ming; Lu, Xianguo; Xu, Y Jun

2016-01-01

Flooding regime changes resulting from natural and human activity have been projected to affect wetland plant community structures and functions. It is therefore important to conduct investigations across a range of flooding gradients to assess the impact of flooding depth on wetland vegetation. We conducted this study to identify the pattern of plant height, species richness and aboveground biomass variation along the flooding gradient in floodplain wetlands located in Northeast China. We found that the response of dominant species height to the flooding gradient depends on specific species, i.e., a quadratic response for Carex lasiocarpa, a negative correlation for Calamagrostis angustifolia, and no response for Carex appendiculata. Species richness showed an intermediate effect along the vegetation zone from marsh to wet meadow while aboveground biomass increased. When the communities were analysed separately, only the water table depth had significant impact on species richness for two Carex communities and no variable for C. angustifolia community, while height of dominant species influenced aboveground biomass. When the three above-mentioned communities were grouped together, variations in species richness were mainly determined by community type, water table depth and community mean height, while variations in aboveground biomass were driven by community type and the height of dominant species. These findings indicate that if habitat drying of these herbaceous wetlands in this region continues, then two Carex marshes would be replaced gradually by C. angustifolia wet meadow in the near future. This will lead to a reduction in biodiversity and an increase in productivity and carbon budget. Meanwhile, functional traits must be considered, and should be a focus of attention in future studies on the species diversity and ecosystem function in this region.

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.

Anisotropy of electrical resistivity in PVT grown WSe2-x crystals

Science.gov (United States)

Solanki, G. K.; Patel, Y. A.; Agarwal, M. K.

2018-05-01

Single crystals of p-type WSe2 and WSe1.9 were grown by a physical vapour transport technique. The anisotropy in d.c. electrical resistivity was investigated in these grown crystals. The off-stoichiometric WSe1.9 exhibited a higher anisotropy ratio as compared to WSe2 crystals. The electron microscopic examination revealed the presence of a large number of stacking faults in these crystals. The resistivity enhancement along the c-axis and anisotropic effective mass ratio explained on the basis of structural disorder introduced due to off-stoichiometry.

78 FR 76031 - Sweet Cherries Grown in Designated Counties in Washington; Decreased Assessment Rate

Science.gov (United States)

2013-12-16

... FIR] Sweet Cherries Grown in Designated Counties in Washington; Decreased Assessment Rate AGENCY... subsequent fiscal periods from $0.18 to $0.15 per ton of sweet cherries handled. The Committee locally administers the marketing order for sweet cherries grown in designated counties in Washington. The Committee's...

Responses of soilless grown tomato plants to arbuscular ...

African Journals Online (AJOL)

STORAGESEVER

2008-10-20

Oct 20, 2008 ... Full Length Research Paper. Responses of soilless grown tomato plants to arbuscular mycorrhizal fungal (Glomus fasciculatum) colonization in re-cycling and open systems. H. Yildiz Dasgan1*, Sebnem Kusvuran1 and Ibrahim Ortas2. 1Cukurova University, Faculty of Agriculture, Department of Horticulture ...

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...

Nanophotonic integrated circuits from nanoresonators grown on silicon.

Science.gov (United States)

Chen, Roger; Ng, Kar Wei; Ko, Wai Son; Parekh, Devang; Lu, Fanglu; Tran, Thai-Truong D; Li, Kun; Chang-Hasnain, Connie

2014-07-07

Harnessing light with photonic circuits promises to catalyse powerful new technologies much like electronic circuits have in the past. Analogous to Moore's law, complexity and functionality of photonic integrated circuits depend on device size and performance scale. Semiconductor nanostructures offer an attractive approach to miniaturize photonics. However, shrinking photonics has come at great cost to performance, and assembling such devices into functional photonic circuits has remained an unfulfilled feat. Here we demonstrate an on-chip optical link constructed from InGaAs nanoresonators grown directly on a silicon substrate. Using nanoresonators, we show a complete toolkit of circuit elements including light emitters, photodetectors and a photovoltaic power supply. Devices operate with gigahertz bandwidths while consuming subpicojoule energy per bit, vastly eclipsing performance of prior nanostructure-based optoelectronics. Additionally, electrically driven stimulated emission from an as-grown nanostructure is presented for the first time. These results reveal a roadmap towards future ultradense nanophotonic integrated circuits.

78 FR 21520 - Sweet Cherries Grown in Designated Counties in Washington; Decreased Assessment Rate

Science.gov (United States)

2013-04-11

...; FV12-923-1 FIR] Sweet Cherries Grown in Designated Counties in Washington; Decreased Assessment Rate... 2012-2013 and subsequent fiscal periods from $0.40 to $0.18 per ton of sweet cherries handled. The Committee locally administers the marketing order for sweet cherries grown in designated counties in...

Helicopter Parents and Landing Pad Kids: Intense Parental Support of Grown Children

OpenAIRE

Fingerman, Karen L.; Cheng, Yen-Pi; Wesselmann, Eric D.; Zarit, Steven; Furstenberg, Frank; Birditt, Kira S.

2012-01-01

Popular media describe adverse effects of helicopter parents who provide intense support to grown children, but few studies have examined implications of such intense support. Grown children (N = 592, M age = 23.82 years, 53% female, 35% members of racial/ethnic minority groups) and their parents (n = 399, M age = 50.67 years, 52% female; 34% members of racial/ethnic minority groups) reported on the support they exchanged with one another. Intense support involved parents’ providing several t...

Mineral Analysis of Pine Nuts (Pinus spp.) Grown in New Zealand.

Science.gov (United States)

Vanhanen, Leo P; Savage, Geoffrey P

2013-04-03

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.

Estimation of N2-fixation in cowpea grown in monoculture or in mixture with maize using 15 N

International Nuclear Information System (INIS)

Shammaa, Mouhammad; Kurd Ali, Fawaz

1994-01-01

A pot experiment was carried out under natural climatic conditions to determine the proportion of different nitrogen sources (air, soil, fertilizer) in cowpea and maize grown alone or in mixture using 15 N isotope dilution technique. On average, the proportion of N derived from fixation by cowpea grown in mixed culture was 55% lower than that derived by the sole cropped cowpea (77%). Dry matter produced by one plant of maize grown in mixed culture was twice as much as that produced by a plant grown in mono culture. Moreover, total nitrogen content in one maize plant grown in mixed culture was 213 mg higher than that determined by two plant of maize grown in mono culture (171 mg). However, the amount of nitrogen derived from soil by maize grown in mixed culture was equal or even higher than that taken up by two plants of maize grown in mono culture. This indicates a better utilization of soil N by the maize in mixed culture. This data emphasize the crucial role of interspecific competition in soil N uptake. Data from this study do not support the hypothesis of N transfer from the legume to the cereal because no significant differences were found between mixed and pure maize in terms of 15 N in excess content. (author). 9 refs., 1 tab

Cyan laser diode grown by plasma-assisted molecular beam epitaxy

International Nuclear Information System (INIS)

Turski, H.; Muziol, G.; Wolny, P.; Cywiński, G.; Grzanka, S.; Sawicka, M.; Perlin, P.; Skierbiszewski, C.

2014-01-01

We demonstrate AlGaN-cladding-free laser diodes (LDs), operating in continuous wave (CW) mode at 482 nm grown by plasma-assisted molecular beam epitaxy (PAMBE). The maximum CW output power was 230 mW. LDs were grown on c-plane GaN substrates obtained by hydride vapor phase epitaxy. The PAMBE process was carried out in metal-rich conditions, supplying high nitrogen flux (Φ N ) during quantum wells (QWs) growth. We found that high Φ N improves quality of high In content InGaN QWs. The role of nitrogen in the growth of InGaN on (0001) GaN surface as well as the influence of LDs design on threshold current density are discussed

Translocation of aluminum to grain crops grown in different agricultural systems

International Nuclear Information System (INIS)

Khan, S.; Kazi, T.G.; Kolachi, N.F.; Afridi, H.I.

2012-01-01

The aim of this study was to evaluate the mobility and transport of Aluminum (AI) by shoot and grain crops (wheat and maize) grown on two different agricultural soil irrigated with water have high (lake water) and low levels (canal water) of AI. The total and bio available fractions (deionized water, 0.11 M CH/sub 3/COOH, 0.05 M ethylenediaminetetraacetic acid (EDT A) and 0.1 M HCl extractable) of Al in both understudied agricultural soils and correlate with respective total Al in the edible parts (grains) and non edible parts (Shoots) of wheat and maize. The All content in lake and canal water samples was found in the range of 750 - 1340 and 90 - 50 micro g/L respectively. The total and extractable Al in both agricultural soil samples, edible and non edible parts of wheat and maize were analysed by atomic absorption spectrometry after acid digestion in microwave oven. The edible and non edible part of both crops absorbed significantly high levels of Al grown on agricultural soil irrigated with lake water (SILW) as compared to those grown on soil irrigated with can water (SICW) had low level of A] (p< O.OI). The transfer factor of Al from soils to edible and non edible parts of wheat and maize were also evaluated. It was observed that the bioaccumulation of Al was found to be high in non edible parts of both crops grown in SILW. This study highlights the increased danger of growing food crops in the agricultural land continuously irrigated by A] contaminated lake water. (author)

78 FR 30737 - Irish Potatoes Grown in Colorado; Reestablishment of Membership on the Colorado Potato...

Science.gov (United States)

2013-05-23

... FR] Irish Potatoes Grown in Colorado; Reestablishment of Membership on the Colorado Potato...: This final rule reestablishes the membership on the Colorado Potato Administrative Committee, Area No... Irish potatoes grown in Colorado. This action modifies the Committee membership structure by amending...

Synthesis and Secretion of Isoflavones by Field-Grown Soybean.

Science.gov (United States)

Sugiyama, Akifumi; Yamazaki, Yumi; Hamamoto, Shoichiro; Takase, Hisabumi; Yazaki, Kazufumi

2017-09-01

Isoflavones play important roles in rhizosphere plant-microbe interactions. Daidzein and genistein secreted by soybean roots induce the symbiotic interaction with rhizobia and may modulate rhizosphere interactions with microbes. Yet despite their important roles, little is known about the biosynthesis, secretion and fate of isoflavones in field-grown soybeans. Here, we analyzed isoflavone contents and the expression of isoflavone biosynthesis genes in field-grown soybeans. In roots, isoflavone contents and composition did not change with crop growth, but the expression of UGT4, an isoflavone-specific 7-O-glucosyltransferase, and of ICHG (isoflavone conjugates hydrolyzing beta-glucosidase) was decreased during the reproductive stages. Isoflavone contents were higher in rhizosphere soil than in bulk soil during both vegetative and reproductive stages, and were comparable in the rhizosphere soil between these two stages. We analyzed the degradation dynamics of daidzein and its glucosides to develop a model for predicting rhizosphere isoflavone contents from the amount of isoflavones secreted in hydroponic culture. Conjugates of daidzein were degraded much faster than daidzein, with degradation rate constants of 8.51 d-1 for malonyldaidzin and 11.6 d-1 for daidzin, vs. 9.15 × 10-2 d-1 for daidzein. The model suggested that secretion of isoflavones into the rhizosphere is higher during vegetative stages than during reproductive stages in field-grown soybean. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Carex hostiana - ostřice Hostova

Czech Academy of Sciences Publication Activity Database

Štěpánková, Jitka; Paulič, R.

2015-01-01

Roč. 55, č. 1 (2015), s. 15-15 ISSN 0139-8172 R&D Projects: GA ČR GB14-36079G Institutional support: RVO:67985939 Keywords : floristics * distribution * endangered species Subject RIV: EF - Botanics

Thermoelectric properties of ZnSb films grown by MOCVD

Energy Technology Data Exchange (ETDEWEB)

Venkatasubramanian, R; Watko, E; Colpitts, T

1997-07-01

The thermoelectric properties of ZnSb films grown by metallorganic chemical vapor deposition (MOCVD) are reported. The growth conditions necessary to obtain stoichiometric ZnSb films and the effects of various growth parameters on the electrical conductivity and Seebeck coefficients of the films are described. The as-grown ZnSb films are p-type. It was observed that the thicker ZnSb films offer improved carrier mobilities and lower free-carrier concentration levels. The Seebeck coefficient of ZnSb films was found to rise rapidly at approximately 160 C. The thicker films, due to the lower doping levels, indicate higher Seebeck coefficients between 25 to 200 C. A short annealing of the ZnSb film at temperatures of {approximately}200 C results in reduced free-carrier level. Thermal conductivity measurements of ZnSb films using the 3-{omega} method are also presented.

Chalcone Synthase Gene Lineage Diversification confirms allopolyploid evolutionary relationships of European Rostrate Violets

NARCIS (Netherlands)

Hof, van den K.; Berg, van den R.G.; Gravendeel, B.

2008-01-01

Phylogenetic relationships among and within the subsections of the genus Viola are still far from resolved. We present the first organismal phylogeny of predominantly western European species of subsection Rostratae based on the plastid trnS¿trnG intron and intergenic spacer and the nuclear low-copy

Susceptibility of chemostat-grown Yersinia enterocolitica and Klebsiella pneumoniae to chlorine dioxide.

Science.gov (United States)

Harakeh, M S; Berg, J D; Hoff, J C; Matin, A

1985-01-01

The resistance of bacteria to antimicrobial agents could be influenced by growth environment. The susceptibility of two enteric bacteria, Yersinia enterocolitica and Klebsiella pneumoniae, to chlorine dioxide was investigated. These organisms were grown in a defined medium in a chemostat and the influence of growth rate, temperature, and cell density on the susceptibility was studied. All inactivation experiments were conducted with a dose of 0.25 mg of chlorine dioxide per liter in phosphate-buffered saline at pH 7.0 and 23 degrees C. The results indicated that populations grown under conditions that more closely approximate natural aquatic environments, e.g., low temperatures and growth at submaximal rates caused by nutrient limitation, were most resistant. The conclusion from this study is that antecedent growth conditions have a profound effect on the susceptibility of bacteria to disinfectants, and it is more appropriate to use the chemostat-grown bacteria as test organisms to evaluate the efficacy of a certain disinfectant.

Electron irradiation induced deep centers in hydrothermally grown ZnO

International Nuclear Information System (INIS)

Fang, Z.-Q.; Claflin, B.; Look, D. C.; Farlow, G. C.

2007-01-01

An n-type hydrothermally grown ZnO sample becomes semi-insulating (ρ∼10 8 Ω cm) after 1-MeV electron-irradiation. Deep traps produced by the irradiation were studied by thermally stimulated current spectroscopy. The dominant trap in the as-grown sample has an activation energy of 0.24 eV and is possibly related to Li Zn acceptors. However, the electron irradiation introduces a new trap with an activation energy of 0.15 eV, and other traps of energy 0.30 and 0.80 eV, respectively. From a comparison of these results with positron annihilation experiments and density functional theory, we conclude that the 0.15-eV trap may be related to V Zn

Neutralization of Hydroxide Ion in Melt-Grown NaCl Crystals

Science.gov (United States)

Otterson, Dumas A.

1961-01-01

Many recent studies of solid-state phenomena, particularly in the area of crystal imperfections, have involved the use of melt-grown NaCl single crystals. Quite often trace impurities in these materials have had a prominent effect on these phenomena. Trace amounts of hydroxide ion have been found in melt-grown NaCl crystals. This paper describes a nondestructive method of neutralizing the hydroxide ion in such crystals. Crystals of similar hydroxide content are maintained at an elevated temperature below the melting point of NaCl in a flowing atmosphere containing. dry hydrogen chloride. Heat treatment is continued until an analysis of the test specimens shows no excess hydroxide ion. A colorimetric method previously described4 is used for this analysis.

Positron annihilation studies of defects in molecular beam epitaxy grown III-V layers

International Nuclear Information System (INIS)

Umlor, M.T.; Keeble, D.J.; Cooke, P.W.

1994-01-01

A summary of recent positron annihilation experiments on molecular beam epitaxy (MBE) grown III-V layers is Presented. Variable energy positron beam measurements on Al 0.32 Ga 0.68 As undoped and Si doped have been completed. Positron trapping at a open volume defect in Al 0.32 Ga 0.68 :Si for temperatures from 300 to 25 K in the dark was observed. The positron trap was lost after 1.3 eV illumination at 25K. These results indicate an open volume defect is associated with the local structure of the deep donor state of the DX center. Stability of MBE GaAs to thermal annealing war, investigated over the temperature range of 230 to 700 degrees C, Proximity wafer furnace anneals in flowing argon were used, Samples grown above 450 degrees C were shown to be stable but for sample below this temperature an anneal induced vacancy related defect was produced for anneals between 400 and 500 degrees C. The nature of the defect was shown to be different for material grown at 350 and 230 degrees C. Activation energies of 2.5 eV to 2.3 eV were obtained from isochronal anneal experiments for samples grown at 350 and 230 degrees C, respectively

Scanning tunneling microscopy of hexagonal BN grown on graphite

International Nuclear Information System (INIS)

Fukumoto, H.; Hamada, T.; Endo, T.; Osaka, Y.

1991-01-01

The microscopic surface topography of thin BN x films grown on graphite by electron cyclotron resonance plasma chemical vapor deposition have been imaged with scanning tunneling microscopy in air. The scanning tunneling microscope has generated images of hexagonal BN with atomic resolution

78 FR 77367 - Almonds Grown in California; Continuance Referendum

Science.gov (United States)

2013-12-23

... 20250-0237, or internet: regulations.gov . FOR FURTHER INFORMATION CONTACT: Maria Stobbe, Marketing... DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 981 [Doc. No. AMS-FV-13-0082; FV14-981-1 CR] Almonds Grown in California; Continuance Referendum AGENCY: Agricultural Marketing...

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.

Origin of green luminescence in hydrothermally grown ZnO single crystals

Energy Technology Data Exchange (ETDEWEB)

Čížek, J., E-mail: jakub.cizek@mff.cuni.cz; Hruška, P.; Melikhova, O.; Procházka, I. [Department of Low-Temperature Physics, Charles University in Prague, V Holešovičkách 2, CZ-180 00, Prague 8 (Czech Republic); Valenta, J. [Department of Chemical Physics and Optics, Charles University in Prague, Ke Karlovu 3, CZ-121 16, Prague 2 (Czech Republic); Novotný, M.; Bulíř, J. [Academy of Science of the Czech Republic, Institute of Physics, Na Slovance 2, CZ-182 21 Praha 8 (Czech Republic)

2015-06-22

Combining photoluminescence and positron annihilation studies of hydrothermally grown ZnO crystals with stoichiometry varied by controlled annealing enabled us to clarify the origin of green luminescence. It was found that green luminescence in ZnO has multiple origins and consists of a band at 2.3(1) eV due to recombination of electrons of the conduction band by zinc vacancy acceptors coupled with hydrogen and a band at 2.47(2) eV related to oxygen vacancies. The as-grown ZnO crystals contain zinc vacancies associated with hydrogen and exhibit a green luminescence at 2.3(1) eV. Annealing in Zn vapor removed zinc vacancies and introduced oxygen vacancies. This led to disappearance of the green luminescence band at 2.3(1) eV and appearance of a green emission at higher energy of 2.47(2) eV. Moreover, the color of the crystal was changed from colorless to dark red. In contrast, annealing of the as-grown crystal in Cd vapor did not remove zinc vacancies and did not cause any significant change of green luminescence nor change in coloration.

Origin of green luminescence in hydrothermally grown ZnO single crystals

International Nuclear Information System (INIS)

Čížek, J.; Hruška, P.; Melikhova, O.; Procházka, I.; Valenta, J.; Novotný, M.; Bulíř, J.

2015-01-01

Combining photoluminescence and positron annihilation studies of hydrothermally grown ZnO crystals with stoichiometry varied by controlled annealing enabled us to clarify the origin of green luminescence. It was found that green luminescence in ZnO has multiple origins and consists of a band at 2.3(1) eV due to recombination of electrons of the conduction band by zinc vacancy acceptors coupled with hydrogen and a band at 2.47(2) eV related to oxygen vacancies. The as-grown ZnO crystals contain zinc vacancies associated with hydrogen and exhibit a green luminescence at 2.3(1) eV. Annealing in Zn vapor removed zinc vacancies and introduced oxygen vacancies. This led to disappearance of the green luminescence band at 2.3(1) eV and appearance of a green emission at higher energy of 2.47(2) eV. Moreover, the color of the crystal was changed from colorless to dark red. In contrast, annealing of the as-grown crystal in Cd vapor did not remove zinc vacancies and did not cause any significant change of green luminescence nor change in coloration

Origin of green luminescence in hydrothermally grown ZnO single crystals

Science.gov (United States)

Čížek, J.; Valenta, J.; Hruška, P.; Melikhova, O.; Procházka, I.; Novotný, M.; Bulíř, J.

2015-06-01

Combining photoluminescence and positron annihilation studies of hydrothermally grown ZnO crystals with stoichiometry varied by controlled annealing enabled us to clarify the origin of green luminescence. It was found that green luminescence in ZnO has multiple origins and consists of a band at 2.3(1) eV due to recombination of electrons of the conduction band by zinc vacancy acceptors coupled with hydrogen and a band at 2.47(2) eV related to oxygen vacancies. The as-grown ZnO crystals contain zinc vacancies associated with hydrogen and exhibit a green luminescence at 2.3(1) eV. Annealing in Zn vapor removed zinc vacancies and introduced oxygen vacancies. This led to disappearance of the green luminescence band at 2.3(1) eV and appearance of a green emission at higher energy of 2.47(2) eV. Moreover, the color of the crystal was changed from colorless to dark red. In contrast, annealing of the as-grown crystal in Cd vapor did not remove zinc vacancies and did not cause any significant change of green luminescence nor change in coloration.

Oil and fatty acid composition of peanut cultivars grown in Pakistan

International Nuclear Information System (INIS)

Hassan, F.; Ahmed, M.

2012-01-01

Quality and flavor of edible peanuts and its products are affected by fatty acid composition of oil. The information related to chemical composition of Peanut grown in the country are scarce, therefore, the present investigation was designed to determine the oil and fatty acid composition of some commonly grown peanut cultivars in Pakistan. Seven Peanut cultivars were grown during 2008 in randomized complete block design replicated thrice. The tested cultivars differed significantly for oil content which ranged from 49.83 to 53.06% on dry weight basis, thus showing differences of 7% among cultivars. The saturated fatty acids (Palmetic and Stearic acid) in different cultivars ranged between 9.95 to 10.79% and 1.63 to 2.19%, respectively. Differences among cultivars for oleic acid exhibited significance which ranged between 49.34 to 54.83%. Similarly, cultivars differed statistically for linoleic ac id which showed a range of 28.99 to 34.23%, thus depicted difference of 7%. Significant differences among tested cultivars may be attributed to the place of origin of particular cultivar. An inverse relationship was exhibited between oleic and linoleic acid, similar to other edible oils. (author)

Influences of Different Halophyte Vegetation on Soil Microbial Community at Temperate Salt Marsh.

Science.gov (United States)

Chaudhary, Doongar R; Kim, Jinhyun; Kang, Hojeong

2018-04-01

Salt marshes are transitional zone between terrestrial and aquatic ecosystems, occupied mainly by halophytic vegetation which provides numerous ecological services to coastal ecosystem. Halophyte-associated microbial community plays an important role in the adaptation of plants to adverse condition and also affected habitat characteristics. To explore the relationship between halophytes and soil microbial community, we studied the soil enzyme activities, soil microbial community structure, and functional gene abundance in halophytes- (Carex scabrifolia, Phragmites australis, and Suaeda japonica) covered and un-vegetated (mud flat) soils at Suncheon Bay, South Korea. Higher concentrations of total, Gram-positive, Gram-negative, total bacterial, and actinomycetes PLFAs (phospholipid fatty acids) were observed in the soil underneath the halophytes compared with mud flat soil and were highest in Carex soil. Halophyte-covered soils had different microbial community composition due to higher abundance of Gram-negative bacteria than mud flat soil. Similar to PLFA concentrations, the increased activities of β-glucosidase, cellulase, phosphatase, and sulfatase enzymes were observed under halophyte soil compared to mud flat soil and Carex exhibited highest activities. The abundance of archaeal 16S rRNA, fungal ITS, and denitrifying genes (nirK, nirS, and nosZ) were not influenced by the halophytes. Abundance bacterial 16S rRNA and dissimilatory (bi)sulfite (dsrA) genes were highest in Carex-covered soil. The abundance of functional genes involved in methane cycle (mcrA and pmoA) was not affected by the halophytes. However, the ratios of mcrA/pmoA and mcrA/dsrA increased in halophyte-covered soils which indicate higher methanogenesis activities. The finding of the study also suggests that halophytes had increased the microbial and enzyme activities, and played a pivotal role in shaping microbial community structure.

Response of Plant Height, Species Richness and Aboveground Biomass to Flooding Gradient along Vegetation Zones in Floodplain Wetlands, Northeast China

Science.gov (United States)

Lou, Yanjing; Pan, Yanwen; Gao, Chuanyu; Jiang, Ming; Lu, Xianguo; Xu, Y. Jun

2016-01-01

Flooding regime changes resulting from natural and human activity have been projected to affect wetland plant community structures and functions. It is therefore important to conduct investigations across a range of flooding gradients to assess the impact of flooding depth on wetland vegetation. We conducted this study to identify the pattern of plant height, species richness and aboveground biomass variation along the flooding gradient in floodplain wetlands located in Northeast China. We found that the response of dominant species height to the flooding gradient depends on specific species, i.e., a quadratic response for Carex lasiocarpa, a negative correlation for Calamagrostis angustifolia, and no response for Carex appendiculata. Species richness showed an intermediate effect along the vegetation zone from marsh to wet meadow while aboveground biomass increased. When the communities were analysed separately, only the water table depth had significant impact on species richness for two Carex communities and no variable for C. angustifolia community, while height of dominant species influenced aboveground biomass. When the three above-mentioned communities were grouped together, variations in species richness were mainly determined by community type, water table depth and community mean height, while variations in aboveground biomass were driven by community type and the height of dominant species. These findings indicate that if habitat drying of these herbaceous wetlands in this region continues, then two Carex marshes would be replaced gradually by C. angustifolia wet meadow in the near future. This will lead to a reduction in biodiversity and an increase in productivity and carbon budget. Meanwhile, functional traits must be considered, and should be a focus of attention in future studies on the species diversity and ecosystem function in this region. PMID:27097325

Effect of amaranth dye on the growth and properties of conventional and SR method grown KAP single crystals

Science.gov (United States)

Babu Rao, G.; P., Rajesh; Ramasamy, P.

2018-04-01

The 0.1 mol% amaranth added KAP single crystals were grown from aqueous solutions by both slow evaporation solution technique and Sankaranarayanan-Ramasamy method. The single crystal having dimension of 45 mm length and 12 mm diameter was grown with growth rate of 1.5 mm/day using SR method. 87 % transmittance is obtained for SR method grown amaranth added KAP single crystal. The high intense luminescence at 661 nm is obtained from amaranth added conventional and SR method grown KAP single crystal. The amaranth added KAP single crystal possesses good mechanical and laser damage threshold stability.

assessment of cadmium and lead in soil and tomatoes grown

African Journals Online (AJOL)

MAHMUD IMAM

Transfer of Heavy Metals from Soil to Lettuce (Lactuca sativa) grown in irrigated farmlands of ... respectively being the highest elements absorbed by the lettuce samples from the irrigated .... radioactive elements and organic chemicals,.

Accelerated carrier recombination by grain boundary/edge defects in MBE grown transition metal dichalcogenides

Science.gov (United States)

Chen, Ke; Roy, Anupam; Rai, Amritesh; Movva, Hema C. P.; Meng, Xianghai; He, Feng; Banerjee, Sanjay K.; Wang, Yaguo

2018-05-01

Defect-carrier interaction in transition metal dichalcogenides (TMDs) plays important roles in carrier relaxation dynamics and carrier transport, which determines the performance of electronic devices. With femtosecond laser time-resolved spectroscopy, we investigated the effect of grain boundary/edge defects on the ultrafast dynamics of photoexcited carrier in molecular beam epitaxy (MBE)-grown MoTe2 and MoSe2. We found that, comparing with exfoliated samples, the carrier recombination rate in MBE-grown samples accelerates by about 50 times. We attribute this striking difference to the existence of abundant grain boundary/edge defects in MBE-grown samples, which can serve as effective recombination centers for the photoexcited carriers. We also observed coherent acoustic phonons in both exfoliated and MBE-grown MoTe2, indicating strong electron-phonon coupling in this materials. Our measured sound velocity agrees well with the previously reported result of theoretical calculation. Our findings provide a useful reference for the fundamental parameters: carrier lifetime and sound velocity and reveal the undiscovered carrier recombination effect of grain boundary/edge defects, both of which will facilitate the defect engineering in TMD materials for high speed opto-electronics.

Accelerated carrier recombination by grain boundary/edge defects in MBE grown transition metal dichalcogenides

Directory of Open Access Journals (Sweden)

Ke Chen

2018-05-01

Full Text Available Defect-carrier interaction in transition metal dichalcogenides (TMDs plays important roles in carrier relaxation dynamics and carrier transport, which determines the performance of electronic devices. With femtosecond laser time-resolved spectroscopy, we investigated the effect of grain boundary/edge defects on the ultrafast dynamics of photoexcited carrier in molecular beam epitaxy (MBE-grown MoTe2 and MoSe2. We found that, comparing with exfoliated samples, the carrier recombination rate in MBE-grown samples accelerates by about 50 times. We attribute this striking difference to the existence of abundant grain boundary/edge defects in MBE-grown samples, which can serve as effective recombination centers for the photoexcited carriers. We also observed coherent acoustic phonons in both exfoliated and MBE-grown MoTe2, indicating strong electron-phonon coupling in this materials. Our measured sound velocity agrees well with the previously reported result of theoretical calculation. Our findings provide a useful reference for the fundamental parameters: carrier lifetime and sound velocity and reveal the undiscovered carrier recombination effect of grain boundary/edge defects, both of which will facilitate the defect engineering in TMD materials for high speed opto-electronics.

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.

Locally Grown Foods and Farmers Markets: Consumer Attitudes and Behaviors

Directory of Open Access Journals (Sweden)

Susan B. Smalley

2010-03-01

Full Text Available Farm viability poses a grave challenge to the sustainability of agriculture and food systems: the number of acres in production continues to decline as the majority of farms earn negative net income. Two related and often overlapping marketing strategies, (i locally grown foods and (ii distribution at farmers markets, can directly enhance food system sustainability by improving farm profitability and long-term viability, as well as contributing to an array of ancillary benefits. We present results of a representative Michigan telephone survey, which measured consumers’ perceptions and behaviors around local foods and farmers markets. We discuss the implications of our findings on greater farm profitability. We conclude with suggestions for future research to enhance the contributions of locally grown foods and farmers markets to overall food system sustainability.

The genesis, stratigraphy and age of Finnish peat deposits. Soiden syntvy, rakenne ja ikae Suomessa

Energy Technology Data Exchange (ETDEWEB)

Glueckert, G [Turun yliopisto (Finland). Maaperaegeologian osasto

1986-01-01

The genesis, stratigraphy and age of Finnish peat deposits are briefly described. Finnish peats are classified according to their botanical composition to Sphagnum, sedge (Carex) and wood peats. They form complex types of peat land: the ombrotrophic raised bogs in southern Finland and the minerotrophic open sedge (aapa) bogs in northern Finland. The structural bog types in the geological classification are mainly composed of Sphagnum and Carex peats. The raised bogs are predominantly built up of Sphagnum peat, the aapa bogs of Carex peat. The bogs are formed by paludification of lakes, of rising coasts or of low-lying forests. The thickness of peat varies from 3 to 8 m in southern Finland and from 1 to 3 m in northern Finland. The age of the bogs varies according to the uplift of land and the altitude of the bog gasin above sea level. The oldest bogs are 9500-10000 years old and formed in southern and eastern Finland on high-lying upland tracts just after the retreat of the ice at the end of the last glaciation. The geological and palaeontological development of bogs and the history of climate and vegetation can be studied and dated pollenanalytically and with the radiocarbon method.

Surface oxidation phenomena of boride coatings grown on iron

International Nuclear Information System (INIS)

Carbucicchio, M.; Palombarini, G.; Sambogna, G.

1992-01-01

Very hard boride coatings are grown on various metals using thermochemical as well as chemical vapour deposition techniques. In this way many surface properties, and in particular the wear resistance, can be considerably improved. Usually, also the corrosion behaviour of the treated components is important. In particular, oxidizing atmospheres are involved in many applications where, therefore, coating-environment interactions can play a relevant role. In a previous work, the early stages of the oxidation of iron borides were studied by treating single phase compacted powders in flowing oxygen at low temperatures (300-450deg C). In the present paper, the attention is addressed to the oxidation of both single phase and polyphase boride coatings thermochemically grown on iron. The single phase boride coatings were constituted by Fe 2 B, while the polyphase coatings were constituted by an inner Fe 2 B layer and an outer FeB-base layer. All the boride layers displayed strong (002) preferred crystallographic orientations. (orig.)

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)....

Atomically flat platinum films grown on synthetic mica

Science.gov (United States)

Tanaka, Hiroyuki; Taniguchi, Masateru

2018-04-01

Atomically flat platinum thin films were heteroepitaxially grown on synthetic fluorophlogopite mica [KMg3(AlSi3O10)F2] by van der Waals epitaxy. Platinum films deposited on a fluorophlogopite mica substrate by inductively coupled plasma-assisted sputtering with oxygen introduction on a synthetic mica substrate resulted in the growth of twin single-crystalline epitaxial Pt(111) films.

Light-emission from in-situ grown organic nanostructures

DEFF Research Database (Denmark)

Oliveira Hansen, Roana Melina de; Kjelstrup-Hansen, Jakob; Rubahn, Horst-Günter

2011-01-01

Organic crystalline nanofibers made from phenylene-based molecules exhibit a wide range of extraordinary optical properties such as intense, anisotropic and polarized luminescence that can be stimulated either optically or electrically, waveguiding and random lasing. For lighting and display...... of morphological characterization and demonstrate how appropriate biasing with an AC gate voltage enables electroluminescence from these in-situ grown organic nanostructures....

Studies of antifungal activity of forsskalea tenacissima

International Nuclear Information System (INIS)

Qaisar, M.; Ahmad, V.U.; Nisar, M.; Gilani, S.N.; Pervez, S.

2011-01-01

Antifungal activity of different extracts from Forsskalea tenacissima prepared by solvent-solvent extraction and vacuum liquid chromatography (VLC) was determined. Extracts were found to be active against Candida albicans, Trichophyton mentagrophyte, Allescheria boydii, Microsporum canis, Aspergillus niger, Drechslera rostrata, Nigrospora oryzae, Stachybotrys atra, Curvularia lunata, Trichophyton semii and Trichophyton schoenleinii. (author)

Metals in leafy vegetables grown in Addis Ababa and toxicological ...

African Journals Online (AJOL)

Metals in leafy vegetables grown in Addis Ababa and toxicological implications. ... the leafy vegetables is attributed to plant differences in tolerance to heavy metals. ... Treatment of industrial effluents and phyto-extraction of excess metals from ...

Field emission from carbon nanotube bundle arrays grown on self-aligned ZnO nanorods

International Nuclear Information System (INIS)

Li Chun; Fang Guojia; Yuan Longyan; Liu Nishuang; Ai Lei; Xiang Qi; Zhao Dongshan; Pan Chunxu; Zhao Xingzhong

2007-01-01

The field emission (FE) properties of carbon nanotube (CNT) bundle arrays grown on vertically self-aligned ZnO nanorods (ZNRs) are reported. The ZNRs were first synthesized on ZnO-seed-coated Si substrate by the vapour phase transport method, and then the radically grown CNTs were grown directly on the surface of the ZNRs from ethanol flames. The CNT/ZNR composite showed a turn-on field of 1.5 V μm -1 (at 0.1 μA cm -2 ), a threshold field of 4.5 V μm -1 (at 1 mA cm -2 ) and a stable emission current with fluctuations of 5%, demonstrating significantly enhanced FE of ZNRs due to the low work function and high aspect ratio of the CNTs, and large surface-to-volume ratio of the underlying ZNRs

Locally Grown, Natural Ingredients? The Isotope Ratio Can Reveal a Lot!

Science.gov (United States)

Rossier, Joël S; Maury, Valérie; Pfammatter, Elmar

2016-01-01

This communication gives an overview of selected isotope analyses applied to food authenticity assessment. Different isotope ratio detection technologies such as isotope ratio mass spectrometry (IRMS) and cavity ring down spectroscopy (CRDS) are briefly described. It will be explained how δ(18)O of water contained in fruits and vegetables can be used to assess their country of production. It will be explained why asparagus grown in Valais, in the centre of the Alps carries much less heavy water than asparagus grown closer to the sea coast. On the other hand, the use of δ(13)C can reveal whether a product is natural or adulterated. Applications including honey or sparkling wine adulteration detection will be briefly presented.

D-penicillamine exhibits a higher radioprotective effect in suckling mice than in grown-up animals

International Nuclear Information System (INIS)

Oroszlan, Gy.; Lakatos, L.; Dezsi, Z.; Hatvani, I.; Pintye, E.; Karmazsin, L.; Orvostudomanyi Egyetem, Debrecen; Orvostudomanyi Egyetem, Debrecen

1982-01-01

Grown-up and suckling mice were exposed to whole-body 60 Co-irradiation of 6-10 Gy. The survival time was significantly increased in suckling animals by 3000 mg per kg body weight D-penicillamine applied intraperitoneally 60 min before irradiation, whereas the same treatment had no significant effect in grown-up animals. (L.E.)

Growth and antimicrobial studies of γ-glycine crystal grown using CuSO4

Science.gov (United States)

Vijayalakshmi, V.; Dhanasekaran, P.

2018-05-01

In the current work single crystals of pure and 1M of CuSO4-added glycine were grown by slow evaporation method and its optical and antimicrobial properties were studied. The Polymorph of glycine transforms from a-glycine to γ-glycine due to the incorporation of CuSO4 on glycine was affirmed by the PXRD and FTIR studies. The impact of CuSO4 on the antimicrobial action of the grown samples was deliberate by utilizing the agar diffusion method.

Annihilation characteristics in as-grown and electron irradiated Zn II-VI semiconductors

International Nuclear Information System (INIS)

Moser, P.; La Cruz, R.M. de; Pareja, R.

1991-01-01

The temperature dependence of the positron lifetime has been investigated in as-grown crystals of Zns, ZnSe and ZnTe over the temperature range 8-320 K. Also, isochronal annealing experiments up to 1175 K have been performed on these crystals. Zns and ZnSe crystals have been electron irradiated at room temperature and at 77 K. From the results in as-grown and annealed crystals, the values of (230±3), (240±5) and (266±3) ps are attributed to the positron lifetime in the bulk of Zns, ZnSe and ZnTe, respectively. 8 refs., 3 figs

Annihilation characteristics in As-grown and electron irradiated Zn II-VI semiconductors

International Nuclear Information System (INIS)

Cruz, R.M. de la; Pareja, R.; Moser, P.

1992-01-01

The temperature dependence of the positron lifetime has been investigated in as-grown crystals of ZnS, ZnSe and ZnTe over the temperature range 8-320 K. Also, isochronal annealing experiments up to 1175 K have been performed on these crystals. ZnS and ZnSe crystals have been electron irradiated at room temperature and at 77 K. From the results in as-grown and annealed crystals, the values of (230±3), (240±5) and (266±3) ps are attributed to the positron lifetime in the bulk of ZnS, ZnSe and ZnTe, respectively

Auger electron spectroscopy analysis of high metal content micro-structures grown by electron beam induced deposition

International Nuclear Information System (INIS)

Cicoira, F.; Hoffmann, P.; Olsson, C.O.A.; Xanthopoulos, N.; Mathieu, H.J.; Doppelt, P.

2005-01-01

An auger electron spectroscopy study was carried out on Rh-containing micro-structures grown by electron beam induced deposition (EBID) of the iso-structural and iso-electronic precursors [RhCl(PF 3 ) 2 ] 2 and [RhCl(CO) 2 ] 2 . A material containing between 55 and 60 at.% Rh was obtained from both precursors. The chemical composition of structures grown from the two different precursors indicates a similar decomposition mechanism. Deposits grown from [RhCl(PF 3 ) 2 ] 2 showed a chemical composition independent of electron energy and electron dose in the investigated range of conditions

Thermal evolution of defects in undoped zinc oxide grown by pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Wang, Zilan; Su, Shichen; Ling, Francis Chi-Chung, E-mail: ccling@hku.hk [Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong (China); Anwand, W.; Wagner, A. [Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden (Germany)

2014-07-21

Undoped ZnO films are grown by pulsed laser deposition on c-plane sapphire with different oxygen pressures. Thermal evolutions of defects in the ZnO films are studied by secondary ion mass spectroscopy (SIMS), Raman spectroscopy, and positron annihilation spectroscopy (PAS), and with the electrical properties characterized by the room temperature Hall measurement. Oxygen deficient defect related Raman lines 560 cm{sup −1} and 584 cm{sup −1} are identified and their origins are discussed. Thermal annealing induces extensive Zn out-diffusion at the ZnO/sapphire interface and leaves out Zn-vacancy in the ZnO film. Two types of Zn-vacancy related defects with different microstructures are identified in the films. One of them dominates in the samples grown without oxygen. Annealing the sample grown without oxygen or growing the samples in oxygen would favor the Zn-vacancy with another microstructure, and this Zn-vacancy defect persists after 1100 °C annealing.

Thermal evolution of defects in undoped zinc oxide grown by pulsed laser deposition

Science.gov (United States)

Wang, Zilan; Su, Shichen; Ling, Francis Chi-Chung; Anwand, W.; Wagner, A.

2014-07-01

Undoped ZnO films are grown by pulsed laser deposition on c-plane sapphire with different oxygen pressures. Thermal evolutions of defects in the ZnO films are studied by secondary ion mass spectroscopy (SIMS), Raman spectroscopy, and positron annihilation spectroscopy (PAS), and with the electrical properties characterized by the room temperature Hall measurement. Oxygen deficient defect related Raman lines 560 cm-1 and 584 cm-1 are identified and their origins are discussed. Thermal annealing induces extensive Zn out-diffusion at the ZnO/sapphire interface and leaves out Zn-vacancy in the ZnO film. Two types of Zn-vacancy related defects with different microstructures are identified in the films. One of them dominates in the samples grown without oxygen. Annealing the sample grown without oxygen or growing the samples in oxygen would favor the Zn-vacancy with another microstructure, and this Zn-vacancy defect persists after 1100 °C annealing.

Thermal evolution of defects in undoped zinc oxide grown by pulsed laser deposition

International Nuclear Information System (INIS)

Wang, Zilan; Su, Shichen; Ling, Francis Chi-Chung; Anwand, W.; Wagner, A.

2014-01-01

Undoped ZnO films are grown by pulsed laser deposition on c-plane sapphire with different oxygen pressures. Thermal evolutions of defects in the ZnO films are studied by secondary ion mass spectroscopy (SIMS), Raman spectroscopy, and positron annihilation spectroscopy (PAS), and with the electrical properties characterized by the room temperature Hall measurement. Oxygen deficient defect related Raman lines 560 cm −1 and 584 cm −1 are identified and their origins are discussed. Thermal annealing induces extensive Zn out-diffusion at the ZnO/sapphire interface and leaves out Zn-vacancy in the ZnO film. Two types of Zn-vacancy related defects with different microstructures are identified in the films. One of them dominates in the samples grown without oxygen. Annealing the sample grown without oxygen or growing the samples in oxygen would favor the Zn-vacancy with another microstructure, and this Zn-vacancy defect persists after 1100 °C annealing.

Energy variable monoenergetic positron beam study of oxygen atoms in Czochralski grown Si

International Nuclear Information System (INIS)

Tanigawa, S.; Wei, L.; Tabuki, Y.; Nagai, R.; Takeda, E.

1992-01-01

A monoenergetic positron beam has been used to investigate the state of interstitial oxygen in Czochralski-grown Si with the coverage of SiO 2 (100 nm) and poly-Si (200 nm)/SiO 2 (100 nm), respectively. It was found that (i) the growth of SiO 2 gives rise to a strong Doppler broadening of positron annihilation radiations in the bulk of Si, (ii) such a broadening can be recovered to the original level by annealing at 450degC, by the removal of overlayers using chemical etching and long-term aging at room temperature, (iii) the film stress over the CZ-grown Si is responsible for the rearrangement of oxygen atoms in S and (iv) only tensile stress gives rise to the clustering of oxygen atoms. The observed broadening was assigned to arise from the positron trapping by oxygen interstitial clusters. It was concluded that film stress is responsible for the rearrangement of oxygen atoms in CZ-grown Si. (author)

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.

The performance studies of DKDP crystals grown by a rapid horizontal growth method

Science.gov (United States)

Xie, Xiaoyi; Qi, Hongji; Wang, Bin; Wang, Hu; Chen, Duanyang; Shao, Jianda

2018-04-01

A deuterated potassium dihydrogen phosphate (DKDP) crystal with about 70% deuterium level was grown by a rapid horizontal growth method with independent design equipment, which includes a continuous filtration system. The cooling program during crystal growth was designed according to a self-developed software to catch the size of growing crystal in real time. The crystal structure, optical performance and laser induced damage threshold (LIDT) of this DKDP crystal were investigated in this paper. The deuterium concentration of the crystal was confirmed by the neutron diffraction technique, which was effective and available in determining a complete range of deuteration level. The dielectric property was measured to evaluate the perfection of the lattice. The transmittance and LIDT were carried out further to evaluate the optical and functional properties of this DKDP crystal grown in the rapid horizontal growth technique. All of the detailed characterization for DKDP figured out that the 70% deuterated KDP crystal grown in this way had relatively good qualities.

Optical and electrical properties of ZrSe3 single crystals grown by chemical vapour transport technique

International Nuclear Information System (INIS)

Patel, Kaushik; Prajapati, Jagdish; Vaidya, Rajiv; Patel, S.G.

2005-01-01

Single crystals of the lamellar compound, ZrSe 3 , were grown by chemical vapour transport technique using iodine as a transporting agent. The grown crystals were characterized with the help of energy dispersive analysis by X-ray (EDAX), which gave confirmation about the stoichiometry. The optical band gap measurement of as grown crystals was carried out with the help of optical absorption spectra in the range 700-1450 nm. The indirect as well as direct band gap of ZrSe 3 were found to be 1.1 eV and 1.47 eV, respectively. The resistivity of the as grown crystals was measured using van der Pauw method. The Hall parameters of the grown crystals were determined at room temperature from Hall effect measurements. Electrical resistivity measurements were performed on this crystal in the temperature range 303-423 K. The crystals were found to exhibit semiconducting nature in this range. The activation energy and anisotropy measurements were carried out for this crystal. Pressure dependence of electrical resistance was studied using Bridgman opposed anvils set up up to 8 GPa. The semiconducting nature of ZrSe 3 single crystal was inferred from the graph of resistance vs pressure. The results obtained are discussed in detail. (author)

ZnO homoepitaxy on the O polar face of hydrothermal and melt-grown substrates by pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Rogers, D.J. [Nanovation SARL, Orsay (France); Technical Univ. of Troyes (France); CNRS, Troyes (France); Hosseini Teherani, F. [Nanovation SARL, Orsay (France); Largeteau, A.; Demazeau, G. [ICMCB-CNRS, Bordeaux 1 University (Science and Technology), Pessac (France); Moisson, C.; Turover, D. [Novasic, Savoie Technolac, Arche Bat. 4, BP 267, Le Bourget du Lac (France); Nause, J. [Cermet Inc., Atlanta, GA (United States); Garry, G. [Thales Research, Domaine de Corbeville, Orsay (France); Kling, R.; Gruber, T. [Ulm University, Department of Semiconductor Physics, Ulm (Germany); Waag, A. [Braunschweig Technical University, Institute of Semiconductor Technology, Braunschweig (Germany); Jomard, F.; Galtier, P.; Lusson, A. [LPSC-CNRS, Meudon (France); Monteiro, T.; Soares, M.J.; Neves, A.; Carmo, M.C.; Peres, M. [University of Aveiro, Physics Department, Aveiro (Portugal); Lerondel, G.; Hubert, C. [Technical University of Troyes-CNRS (FRE2671), 12 rue Marie Curie, BP 2060, Troyes (France)

2007-07-15

2 cm diameter hydrothermal ZnO crystals were grown and then made into substrates using both mechanical and chemical-mechanical polishing (CMP). CMP polishing showed superior results with an (0002) {omega} scan full width half maximum (FWHM) of 67 arcsec and an root mean square (RMS) roughness of 2 Aa. In comparison, commercial melt-grown substrates exhibited broader X-ray diffraction (XRD) linewidths with evidence of sub-surface crystal damage due to polishing, including a downward shift of c-lattice parameter. Secondary ion mass spectroscopy revealed strong Li, Fe, Co, Al and Si contamination in the hydrothermal crystals as opposed to the melt-grown substrates, for which glow discharge mass spectroscopy studies had reported high levels of Pb, Fe, Cd and Si. Low temperature photoluminescence (PL) studies indicated that the hydrothermal crystal had high defect and/or impurity concentrations compared with the melt-grown substrate. The dominant bound exciton for the melt-grown substrate was indexed to Al. ZnO films were grown using pulsed laser deposition. The melt-grown substrates gave superior results with XRD (0002) {omega} and 2{theta}/{omega} WHM of 124 and 34 arcsec, respectively. Atomic force microscope measurements indicated a low RMS roughness (1.9 nm) as confirmed by fringes in the XRD 2{theta}/{omega} scan. It was suggested that the improvement in XRD response relative to the substrate might be due to ''healing'' of sub-surface polishing damage due to the elevated T{sub s} used for the growth. Indeed the c-lattice parameter for the homoepitaxial layer on the melt-grown substrate had become that which would be expected for strain-free ZnO. Furthermore, the stability of the PL peak positions relative to bulk ZnO, confirmed that the films appear practically strain free. (orig.)

Accumulation of heavy metals by vegetables grown in mine wastes

Energy Technology Data Exchange (ETDEWEB)

Cobb, G.P.; Sands, K.; Waters, M.; Wixson, B.G.; Dorward-King, E.

2000-03-01

Lead, cadmium, arsenic, and zinc were quantified in mine wastes and in soils mixed with mine wastes. Metal concentrations were found to be heterogeneous in the wastes. Iceberg lettuce, Cherry Belle radishes, Roma bush beans, and Better Boy tomatoes were cultivated in mine wastes and in waste-amended soils. Lettuce and radishes had 100% survival in the 100% mine waste treatments compared to 0% and 25% survival for tomatoes and beans, respectively. Metal concentrations were determined in plant tissues to determine uptake and distribution of metals in the edible plant parts. Individual soil samples were collected beneath each plant to assess metal content in the immediate plant environment. This analysis verified heterogeneous metal content of the mine wastes. The four plant species effectively accumulated and translocated lead, cadmium, arsenic, and zinc. Tomato and bean plants contained the four metals mainly in the roots and little was translocated to the fruits. Radish roots accumulated less metals compared to the leaves, whereas lettuce roots and leaves accumulated similar concentrations of the four metals. Lettuce leaves and radish roots accumulated significantly more metals than bean and tomato fruits. This accumulation pattern suggests that consumption of lettuce leaves or radish roots from plants grown in mine wastes would pose greater risks to humans and wildlife than would consumption of beans or tomatoes grown in the same area. The potential risk may be mitigated somewhat in humans, as vegetables grown in mine wastes exhibited stunted growth and chlorosis.

Expression of virulence factors by Staphylococcus aureus grown in serum.

Science.gov (United States)

Oogai, Yuichi; Matsuo, Miki; Hashimoto, Masahito; Kato, Fuminori; Sugai, Motoyuki; Komatsuzawa, Hitoshi

2011-11-01

Staphylococcus aureus produces many virulence factors, including toxins, immune-modulatory factors, and exoenzymes. Previous studies involving the analysis of virulence expression were mainly performed by in vitro experiments using bacterial medium. However, when S. aureus infects a host, the bacterial growth conditions are quite different from those in a medium, which may be related to the different expression of virulence factors in the host. In this study, we investigated the expression of virulence factors in S. aureus grown in calf serum. The expression of many virulence factors, including hemolysins, enterotoxins, proteases, and iron acquisition factors, was significantly increased compared with that in bacterial medium. In addition, the expression of RNA III, a global regulon for virulence expression, was significantly increased. This effect was partially restored by the addition of 300 μM FeCl₃ into serum, suggesting that iron depletion is associated with the increased expression of virulence factors in serum. In chemically defined medium without iron, a similar effect was observed. In a mutant with agr inactivated grown in serum, the expression of RNA III, psm, and sec4 was not increased, while other factors were still induced in the mutant, suggesting that another regulatory factor(s) is involved. In addition, we found that serum albumin is a major factor for the capture of free iron to prevent the supply of iron to bacteria grown in serum. These results indicate that S. aureus expresses virulence factors in adaptation to the host environment.

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)

Acclimation of photosynthesis, H2O2 content and antioxidants in maiza(Zea mays) grown at sub-optimal temperatures.

NARCIS (Netherlands)

Kingston-Smith, A.H.; Harbinson, J.; Foyer, C.H.

1999-01-01

Maize plants were grown at 14, 18 and 20 °C until the fourth leaf had emerged. Leaves from plants grown at 14 and 18 °C had less chlorophyll than those grown at 20 °C. Maximal extractable ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity was decreased at 14 °C compared with 20 °C,

Nutritional diversity of leafy amaranth species grown in Kenya ...

African Journals Online (AJOL)

Objectives: Despite the availability of many species of amaranth in Kenya, there is inadequate information on their nutritional diversity and how they can be best used in mitigation of malnutrition. Hence, this study was aimed at investigating the nutritional diversity of five leafy amaranth species grown in Kenya. Methodology ...

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

Science.gov (United States)

2011-06-13

...; FV11-983-1 PR] Pistachios Grown in California, Arizona, and New Mexico; Proposed Amendments to... amendments to Marketing Agreement and Order No. 983, which regulates the handling of pistachios grown in California, Arizona, and New Mexico, were proposed by the Administrative Committee for Pistachios (Committee...

Fabrication of radiation detectors with HgI2 crystals grown from a solution

International Nuclear Information System (INIS)

Friant, Alain; Mellet, Jean; Saliou, Charles; Mohammed Brahim, Tayeb.

1979-01-01

Mercuric Iodide crystals grown from a solution of molecular complexes with dimethylsulfoxide have been evaluated as γ-ray and X-ray room temperature detectors. Compared with materials grown from the vapor phase these crystals are characterized by a larger size, a lower level of native defects, but a higher impurity level. Detector technology, X-ray and γ-ray (up to 662 keV) detection properties and characterization measurements (T.S.C., photoconductivity, photovoltaic effect) are described. The effect of light on crystal properties is briefly discussed [fr

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...

Microscopic characterisation of suspended graphene grown by chemical vapour deposition

NARCIS (Netherlands)

Bignardi, L.; Dorp, W.F. van; Gottardi, S.; Ivashenko, O.; Dudin, P.; Barinov, A.; de Hosson, J.T.M.; Stöhr, M.; Rudolf, P.

2013-01-01

We present a multi-technique characterisation of graphene grown by chemical vapour deposition (CVD) and thereafter transferred to and suspended on a grid for transmission electron microscopy (TEM). The properties of the electronic band structure are investigated by angle-resolved photoelectron

Defect-induced polytype transformations in LPE grown SiC epilayers on (1 1 1) 3C-SiC seeds grown by VLS on 6H-SiC

International Nuclear Information System (INIS)

Marinova, Maya; Zoulis, Georgios; Robert, Teddy; Mercier, Frederic; Mantzari, Alkioni; Galben, Irina; Kim-Hak, Olivier; Lorenzzi, Jean; Juillaguet, Sandrine; Chaussende, Didier; Ferro, Gabriel; Camassel, Jean; Polychroniadis, Efstathios K.

2009-01-01

The results of transmission electron microscopy (TEM) with low-temperature photoluminescence (LTPL) and Raman studies of liquid phase grown epilayers on top of a vapor liquid solid (VLS) grown 3C-SiC buffer layer are compared. While the 6H-SiC substrate was completely covered by the 3C-SiC seed after the first VLS process, degradation occurred during the early stage of the liquid phase epitaxy process. This resulted in polytype instabilities, such that several rhombohedral forms stabilized one after the other. These (21R-SiC, 57R-SiC) eventually led after few microns to a final transition back to 6H-SiC. This interplay of polytypes resulted in a complex optical signature, with specific LTPL and Raman features.

New records of Vertigo moulinsiana (Gastropoda: Vertiginidae and notes on its distribution and habitats in the Czech Republic

Directory of Open Access Journals (Sweden)

Luboš Beran

2006-04-01

Full Text Available Vertigo moulinsiana (Dupuy, 1849 was found in 2003–2005 in Northern Bohemia (Czech Republic at 11 sites. All these sites are situated on floodplains of smaller streams in a sandstone area. The known occurrence of this endangered relict in the Czech Republic is concentrated in three areas – a large area of Bohemian Cretaceous Basin, a floodplain near villages Břežany and Božice (Dyje River Basin in Southern Moravia and small, isolated, treeless fens in the White Carpathians (Bílé Karpaty Mts.. The principal habitats where V. moulinsiana lives in the Czech Republic are sedge marshes, Typha swamps, reed swamps (with Carex spp., alder carrs (also with Carex spp. and tufa-forming spring fens.

Characterization and growth mechanism of nonpolar and semipolar GaN layers grown on patterned sapphire substrates

International Nuclear Information System (INIS)

Okada, Narihito; Tadatomo, Kazuyuki

2012-01-01

Nonpolar and semipolar GaN layers with markedly improved crystalline quality can be obtained by selective-area growth from the sapphire sidewalls of patterned sapphire substrates (PSSs). In this paper, we review the crystalline qualities of GaN layers grown on PSSs and their growth mechanism. We grew semipolar {1 1 −2 2} and {1 0 −1 1} GaN layers on r- and n-PSSs. The crystalline qualities of the GaN layers grown on the PSSs were higher than those of GaN layers grown directly on heteroepitaxial substrates. To reveal the growth mechanism of GaN layers grown on PSSs, we also grew various nonpolar and semipolar GaN layers such as m-GaN on a-PSS, {1 1 −2 2} GaN on r-PSS, {1 0 − 1  1} GaN on n-PSS, m-GaN on c-PSS and a-GaN on m-PSS. It was found that the nucleation of GaN on the c-plane-like sapphire sidewall results in selective growth from the sapphire sidewall, and nonpolar or semipolar GaN can be obtained. Finally, we demonstrated a light-emitting diode fabricated on a {1 1 −2 2} GaN layer grown on an r-PSS. (paper)

Investigation on nonlinear optical properties of MoS2 nanoflakes grown on silicon and quartz substrates

Science.gov (United States)

Bayesteh, Samaneh; Zahra Mortazavi, Seyedeh; Reyhani, Ali

2018-05-01

In this study, MoS2 nanoflakes were directly grown on different substrates—Si/SiO2 and quartz—by one-step thermal chemical vapor deposition using MoO3 and sulfide powders as precursors. Scanning electron microscopy and x-ray diffraction patterns demonstrated the formation of MoS2 structures on both substrates. Moreover, UV-visible and photoluminescence analysis confirmed the formation of MoS2 few-layer structures. According to Raman spectroscopy, by assessment of the line width and frequency shift differences between the and A 1g, it was inferred that the MoS2 grown on the silicon substrate was monolayer and that grown on the quartz substrate was multilayer. In addition, open-aperture and close-aperture Z-scan techniques were employed to study the nonlinear optical properties including nonlinear absorption and nonlinear refraction of the grown MoS2. All experiments were performed using a diode laser with a wavelength of 532 nm as the light source. It is noticeable that both samples demonstrate obvious self-defocusing behavior. The monolayer MoS2 grown on the silicon substrate displayed considerable two-photon absorption while, the multilayer MoS2 synthesized on the quartz exhibited saturable absorption. In general, few-layered MoS2 would be useful for the development of nanophotonic devices like optical limiters, optical switchers, etc.

RAPD-PCR analysis of some species of Euphorbia grown in ...

African Journals Online (AJOL)

family ^____^

2013-12-04

Dec 4, 2013 ... This study attempts to identify species of Euphorbia (Euphorbia peplus, Euphorbia helioscopia,. Euphorbia granulata and Euphorbia hirta) grown in University of Baghdad Campus in Jadiriyah and determine the genetic polymorphism among them by using DNA markers generated by polymerase.

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,

Large local lattice expansion in graphene adlayers grown on copper

Science.gov (United States)

Chen, Chaoyu; Avila, José; Arezki, Hakim; Nguyen, Van Luan; Shen, Jiahong; Mucha-Kruczyński, Marcin; Yao, Fei; Boutchich, Mohamed; Chen, Yue; Lee, Young Hee; Asensio, Maria C.

2018-05-01

Variations of the lattice parameter can significantly change the properties of a material, and, in particular, its electronic behaviour. In the case of graphene, however, variations of the lattice constant with respect to graphite have been limited to less than 2.5% due to its well-established high in-plane stiffness. Here, through systematic electronic and lattice structure studies, we report regions where the lattice constant of graphene monolayers grown on copper by chemical vapour deposition increases up to 7.5% of its relaxed value. Density functional theory calculations confirm that this expanded phase is energetically metastable and driven by the enhanced interaction between the substrate and the graphene adlayer. We also prove that this phase possesses distinctive chemical and electronic properties. The inherent phase complexity of graphene grown on copper foils revealed in this study may inspire the investigation of possible metastable phases in other seemingly simple heterostructure systems.

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.)

Effect of growth temperature on defects in epitaxial GaN film grown by plasma assisted molecular beam epitaxy

Directory of Open Access Journals (Sweden)

S. S. Kushvaha

2014-02-01

Full Text Available We report the effect of growth temperature on defect states of GaN epitaxial layers grown on 3.5 μm thick GaN epi-layer on sapphire (0001 substrates using plasma assisted molecular beam epitaxy. The GaN samples grown at three different substrate temperatures at 730, 740 and 750 °C were characterized using atomic force microscopy and photoluminescence spectroscopy. The atomic force microscopy images of these samples show the presence of small surface and large hexagonal pits on the GaN film surfaces. The surface defect density of high temperature grown sample is smaller (4.0 × 108 cm−2 at 750 °C than that of the low temperature grown sample (1.1 × 109 cm−2 at 730 °C. A correlation between growth temperature and concentration of deep centre defect states from photoluminescence spectra is also presented. The GaN film grown at 750 °C exhibits the lowest defect concentration which confirms that the growth temperature strongly influences the surface morphology and affects the optical properties of the GaN epitaxial films.

Uptake and translocation of sulfamethazine by alfalfa grown under hydroponic conditions.

Science.gov (United States)

Kurwadkar, Sudarshan; Struckhoff, Garrett; Pugh, Kameron; Singh, Om

2017-03-01

Antibiotics are routinely used in intensive animal agriculture operations collectively known as Concentrated Animal Feed Operations (CAFO) which include dairy, poultry and swine farms. Wastewater generated by CAFOs often contains low levels of antibiotics and is typically managed in an anaerobic lagoon. The objective of this research is to investigate the uptake and fate of aqueous sulfamethazine (SMN) antibiotic by alfalfa (Medicago sativa) grass grown under hydroponic conditions. Uptake studies were conducted using hydroponically grown alfalfa in a commercially available nutrient solution supplemented with 10mg/L of SMN antibiotic. Analysis of alfalfa sap, root zone, middle one-third, and top portion of the foliage showed varying uptake rate and translocation of SMN. The highest average amount of SMN (8.58μg/kg) was detected in the root zone, followed by the top portion (1.89μg/kg), middle one-third (1.30μg/kg), and sap (0.38μg/kg) samples, indicating a clear distribution of SMN within the sampled regions. The ultraviolet (UV) spectra of parent SMN and translocated SMN identified in different parts of the plant present the possibility of metabolization during the uptake process. Uptake of SMN using alfalfa grown under hydroponic conditions has potential as a promising remediation technology for removal of similar antibiotics from wastewater lagoons. Copyright © 2016. Published by Elsevier B.V.

76 FR 4254 - Irish Potatoes Grown in Certain Designated Counties in Idaho, and Malheur County, Oregon...

Science.gov (United States)

2011-01-25

... Service 7 CFR Part 945 [Doc. No. AMS-FV-10-0109; FV11-945-1] Irish Potatoes Grown in Certain Designated... among eligible producers of Irish potatoes in certain designated counties in Idaho, and Malheur County... Irish potatoes grown in the production area. DATES: The referendum will be conducted from March 5 to...

Locally Grown: Examining Attitudes and Perceptions About Organic Cotton Production and Manufacturing Between Mississippi Cotton Growers and Consumers

Directory of Open Access Journals (Sweden)

Charles Freeman

2016-06-01

Full Text Available The purpose of this study is to examine attitudes and perceptions about organic cotton of Mississippi cotton growers and producers in comparison to fashion-conscious consumers, including advantages/disadvantages of growing and production processes, quality control, consumer preferences, and competitive price structures/profit margins. A sample size of 16 local Mississippi growers and/or producers and 44 undergraduate students at a mid-major Southeastern university were chosen to participate in the study. Instruments were developed based on current research and the definition of organic cotton production defined by the United States Department of Agriculture. Results indicate 75% of growers and producers do not perceive a quality difference between organic and conventionally grown cotton, while 72.7% of the consumers report organically grown cotton is capable of producing a higher quality product compared to conventionally grown cotton. Even with an increase in organic cotton prices (25- 40% higher premium, only 25% of growers and producers would be willing to convert, while a majority (52.3% of consumers would not be willing to spend more than 25% extra for an organically grown cotton product. Consumers indicate the negative effects of conventionally grown cotton, yet many report little knowledge about organic cotton production, while growers/producers immediately dismiss organically grown cotton as a retail marketing strategy.

The relationship between growth and soluble sugar concentration of Aloe vera plants grown under three levels of irradiance

Energy Technology Data Exchange (ETDEWEB)

Paez, A.; Gebre, G.M.; Tschaplinski, T.J. (Universidad del Zulia (Venezuela))

1994-06-01

The CAM plant Aloe vera was vegetatively propagated and grown under three irradiances: full sun, partial and deep shade (30% and 10% of ambient light, respectively) to determine the effect on growth, biomass allocation, and sugar concentration. After one year, the plants were harvested to determine final dry weight and the sugar concentration of the leaf mucilaginous gel. Plants grown under full sun produced twice the total dry weight of those grown under partial shade, with the difference equally partitioned between the shoot and root. Plants grown under full sun also produced thicker leaves, and more numerous and large auxiliary shoots. The dry weight of plants grown under deep shade was 8.6% that of plants grown under full sun, which was directly proportional to the irradiance received. Partial shade increased the number and length of leaves produced on the primary shoot, but the allocation of carbon to roots was the lowest of all treatments. Partial shade reduced the total sugar concentration of the leaf gel matrix to 34% that of plants under full sun, due to reductions in all sugars measured. Glucose was the most abundant soluble sugar, with its relative contribution to the total pool increasing under shade. In summary, the proportional effects of partial shading were greater on soluble sugar concentrations than on the total plant biomass produced.

Electrical and structural characterization of as-grown and annealed hydrothermal bulk ZnO

International Nuclear Information System (INIS)

Kassier, G. H.; Hayes, M.; Auret, F. D.; Mamor, M.; Bouziane, K.

2007-01-01

Hall effect measurements in the range 20-370 K on as-grown and annealed hydrothermal bulk ZnO have been performed. The bulk conductivity in the highly resistive as-grown sample was found to decrease and then increase after annealing at 550 deg. C and 930 deg. C, respectively. The conduction in the as-grown material is attributed to a deep donor which is replaced by a much shallower donor after annealing at 930 deg. C. Annealing at both temperatures also produced strong surface conduction effects. Nondegenerate low-mobility surface conduction dominated the electrical properties of the sample annealed at 550 deg. C, while a degenerate surface channel was formed after annealing at 930 deg. C. In addition, Rutherford backscattering and channeling spectrometry (RBS/C) was used to assess the effect of annealing on the crystalline quality of the samples. RBS/C measurements reveal that annealing at 930 deg. C leads to significant improvement of the crystalline quality of the material, while annealing at 550 deg. C results in the segregation of a nonchanneling impurity at the surface

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...

pH-sensor properties of electrochemically grown iridium oxide

NARCIS (Netherlands)

Olthuis, Wouter; Robben, M.A.M.; Bergveld, Piet; Bos, M.; van der Linden, W.E.

1990-01-01

The open-circuit potential of an electrochemically grown iridium oxide film is measured and shows a pH sensitivity between −60 and −80 mV/pH. This sensitivity is found to depend on the state of oxidation of the iridium oxide film; for a higher state of oxidation (or more of the oxide in the high

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.

Molecular Dynamic Simulation of Space and Earth-Grown Crystal Structures of Thermostable T1 Lipase Geobacillus zalihae Revealed a Better Structure.

Science.gov (United States)

Ishak, Siti Nor Hasmah; Aris, Sayangku Nor Ariati Mohamad; Halim, Khairul Bariyyah Abd; Ali, Mohd Shukuri Mohamad; Leow, Thean Chor; Kamarudin, Nor Hafizah Ahmad; Masomian, Malihe; Rahman, Raja Noor Zaliha Raja Abd

2017-09-25

Less sedimentation and convection in a microgravity environment has become a well-suited condition for growing high quality protein crystals. Thermostable T1 lipase derived from bacterium Geobacillus zalihae has been crystallized using the counter diffusion method under space and earth conditions. Preliminary study using YASARA molecular modeling structure program for both structures showed differences in number of hydrogen bond, ionic interaction, and conformation. The space-grown crystal structure contains more hydrogen bonds as compared with the earth-grown crystal structure. A molecular dynamics simulation study was used to provide insight on the fluctuations and conformational changes of both T1 lipase structures. The analysis of root mean square deviation (RMSD), radius of gyration, and root mean square fluctuation (RMSF) showed that space-grown structure is more stable than the earth-grown structure. Space-structure also showed more hydrogen bonds and ion interactions compared to the earth-grown structure. Further analysis also revealed that the space-grown structure has long-lived interactions, hence it is considered as the more stable structure. This study provides the conformational dynamics of T1 lipase crystal structure grown in space and earth condition.

Root exudation of phytosiderophores from soil-grown wheat

Science.gov (United States)

Oburger, Eva; Gruber, Barbara; Schindlegger, Yvonne; Schenkeveld, Walter D C; Hann, Stephan; Kraemer, Stephan M; Wenzel, Walter W; Puschenreiter, Markus

2014-01-01

For the first time, phytosiderophore (PS) release of wheat (Triticum aestivum cv Tamaro) grown on a calcareous soil was repeatedly and nondestructively sampled using rhizoboxes combined with a recently developed root exudate collecting tool. As in nutrient solution culture, we observed a distinct diurnal release rhythm; however, the measured PS efflux was c. 50 times lower than PS exudation from the same cultivar grown in zero iron (Fe)-hydroponic culture. Phytosiderophore rhizosphere soil solution concentrations and PS release of the Tamaro cultivar were soil-dependent, suggesting complex interactions of soil characteristics (salinity, trace metal availability) and the physiological status of the plant and the related regulation (amount and timing) of PS release. Our results demonstrate that carbon and energy investment into Fe acquisition under natural growth conditions is significantly smaller than previously derived from zero Fe-hydroponic studies. Based on experimental data, we calculated that during the investigated period (21–47 d after germination), PS release initially exceeded Fe plant uptake 10-fold, but significantly declined after c. 5 wk after germination. Phytosiderophore exudation observed under natural growth conditions is a prerequisite for a more accurate and realistic assessment of Fe mobilization processes in the rhizosphere using both experimental and modeling approaches. PMID:24890330

Relations of enzymes inAspergillus repens grown under sodium chloride stress.

Science.gov (United States)

Kelavkar, U P; Chhatpar, H S

1993-09-01

Aspergillus repens, a salt-pan isolate, was halotolerant. When grown for 72 h (log phase) and 144 h (beginning of stationary phase) in a medium containing 2M sodium chloride, the activities of invertase, malate dehydrogenase (MDH), glucose-6-phosphate dehydrogenase (G6PDH), and glutamate dehydrogenase (GDH) were found to have increased. Control cultures grown in a medium devoid of 2M NaCl failed to show such changes. The activities of MDH, G6PDH, and GDH increased with rising concentrations of Na(+) (as NaCl) when added up to 100MM in vitro. At higher concentrations they decreased. Changes in kinetic constants, Km and Vmax of these enzymes, as well as their de novo synthesis, were found to be some of the responses to NaCl stress-mediated changes.

Influence of electron irradiation on hydrothermally grown zinc oxide single crystals

Science.gov (United States)

Lu, L. W.; So, C. K.; Zhu, C. Y.; Gu, Q. L.; Li, C. J.; Fung, S.; Brauer, G.; Anwand, W.; Skorupa, W.; Ling, C. C.

2008-09-01

The resistivity of hydrothermally grown ZnO single crystals increased from ~103 Ω cm to ~106 Ω cm after 1.8 MeV electron irradiation with a fluence of ~1016 cm-2, and to ~109 Ω cm as the fluence increased to ~1018 cm-2. Defects in samples were studied by thermally stimulated current (TSC) spectroscopy and positron lifetime spectroscopy (PLS). After the electron irradiation with a fluence of 1018 cm-2, the normalized TSC signal increased by a factor of ~100. A Zn vacancy was also introduced by the electron irradiation, though with a concentration lower than expected. After annealing in air at 400 °C, the resistivity and the deep traps concentrations recovered to the levels of the as-grown sample, and the Zn vacancy was removed.

Photoluminescence investigation of thick GaN films grown on Si substrates by hydride vapor phase epitaxy

International Nuclear Information System (INIS)

Yang, M.; Ahn, H. S.; Chang, J. H.; Yi, S. N.; Kim, K. H.; Kim, H.; Kim, S. W.

2003-01-01

The optical properties of thick GaN films grown by hydried vapor phase epitaxy (HVPE) using a low-temperature intermediate GaN buffer layer grown on a (111) Si substrate with a ZnO thin film were investigated by using photoluminescence (PL) measurement at 300 K and 77 K. The strong donor bound exciton (DBE) at 357 nm with a full width at half maximum (FWHM) of 15 meV was observed at 77 K. The value of 15 meV is extremely narrow for GaN grown on Si substrate by HVPE. An impurity-related peak was also observed at 367 nm. The origin of impurity was investigated using Auger spectroscopy.

Post-annealing effects on pulsed laser deposition-grown GaN thin films

International Nuclear Information System (INIS)

Cheng, Yu-Wen; Wu, Hao-Yu; Lin, Yu-Zhong; Lee, Cheng-Che; Lin, Ching-Fuh

2015-01-01

In this work, the post-annealing effects on gallium nitride (GaN) thin films grown from pulsed laser deposition (PLD) are investigated. The as-deposited GaN thin films grown from PLD are annealed at different temperatures in nitrogen ambient. Significant changes of the GaN crystal properties are observed. Raman spectroscopy is used to observe the crystallinity, the change of residual stress, and the thermal decomposition of the annealed GaN thin films. X-ray diffraction is also applied to identify the crystal phase of GaN thin films, and the surface morphology of GaN thin films annealed at different temperatures is observed by scanning electron microscopy. Through the above analyses, the GaN thin films grown by PLD undergo three stages: phase transition, stress alteration, and thermal decomposition. At a low annealing temperature, the rock salt GaN in GaN films is transformed into wurtzite. The rock salt GaN diminishes with increasing annealing temperature. At a medium annealing temperature, the residual stress of the film changes significantly from compressive strain to tensile strain. As the annealing temperature further increases, the GaN undergoes thermal decomposition and the surface becomes granular. By investigating the annealing temperature effects and controlling the optimized annealing temperature of the GaN thin films, we are able to obtain highly crystalline and strain-free GaN thin films by PLD. - Highlights: • The GaN thin film is grown on sapphire by pulsed laser deposition. • The GaN film undergoes three stages with increasing annealing temperature. • In the first stage, the film transfers from rock salt to wurtzite phase. • In the second stage, the stress in film changes from compressive to tensile. • In the final stage, the film thermally decomposes and becomes granular

Optical and Electrical Characterization of Melt-Grown Bulk Indium Gallium Arsenide and Indium Arsenic Phosphide Alloys

Science.gov (United States)

2011-03-01

spectrum, photoluminescence (PL), and refractive index measurements. Other methods such as infrared imagery and micro probe wavelength dispersing ...States. AFIT/DS/ENP/11-M02 OPTICAL AND ELECTRICAL CHARACTERIZATION OF MELT- GROWN BULK INDIUM GALLIUM ARSENIDE AND INDIUM ARSENIC PHOSPHIDE ...CHARACTERIZATION OF MELT-GROWN BULK INDIUM GALLIUM ARSENIDE AND INDIUM ARSENIC PHOSPHIDE ALLOYS Jean Wei, BS, MS Approved

75 FR 3333 - Irish Potatoes Grown in Colorado; Modification of the Handling Regulation for Area No. 2

Science.gov (United States)

2010-01-21

... FR] Irish Potatoes Grown in Colorado; Modification of the Handling Regulation for Area No. 2 AGENCY... requirement under the Colorado potato marketing order, Area No. 2. The marketing order regulates the handling of Irish potatoes grown in Colorado, and is administered locally by the Colorado Potato...

78 FR 35743 - Irish Potatoes Grown in Colorado; Modification of the General Cull and Handling Regulation for...

Science.gov (United States)

2013-06-14

... IR] Irish Potatoes Grown in Colorado; Modification of the General Cull and Handling Regulation for.... SUMMARY: This interim rule modifies the size requirements for potatoes handled under the Colorado potato marketing order, Area No. 2 (order). The order regulates the handling of Irish potatoes grown in Colorado...

77 FR 36119 - Pistachios Grown in California, Arizona, and New Mexico; Order Amending Marketing Order No. 983

Science.gov (United States)

2012-06-18

...; FV11-983-1 FR] Pistachios Grown in California, Arizona, and New Mexico; Order Amending Marketing Order... amends Marketing Agreement and Order No. 983 (order), which regulates the handling of pistachios grown in... Committee for Pistachios (Committee), which is responsible for local administration of the order. The...

78 FR 57101 - Walnuts Grown in California; Increased Assessment Rate

Science.gov (United States)

2013-09-17

... rate currently in effect. The quantity of assessable walnuts for the 2013-14 marketing year is... DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 984 [Doc. No. AMS-FV-13-0056; FV13-984-1 PR] Walnuts Grown in California; Increased Assessment Rate AGENCY: Agricultural Marketing...

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

Science.gov (United States)

2010-04-28

... Executive Order 12988, Civil Justice Reform. Under the marketing order now in effect, California olive... DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 932 [Doc. No. AMS-FV-09-0089; FV10-932-1 FR] Olives Grown in California; Increased Assessment Rate AGENCY: Agricultural Marketing...

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

Science.gov (United States)

2011-11-01

... Justice Reform. Under the marketing order now in effect, California walnut handlers are subject to... DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 984 [Doc. No. AMS-FV-11-0062; FV11-984-1 FR] Walnuts Grown in California; Increased Assessment Rate AGENCY: Agricultural Marketing...

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

Science.gov (United States)

2012-08-27

... 12988, Civil Justice Reform. Under the marketing order now in effect, California olive handlers are... DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 932 [Doc. No. AMS-FV-11-0093; FV12-932-1 FR] Olives Grown in California; Increased Assessment Rate AGENCY: Agricultural Marketing...

Cryopreservation of in vitro -grown shoot tips of apricot ( Prunus ...

African Journals Online (AJOL)

In vitro grown apricot (Prunus armeniaca L.) cv. El-Hamawey shoot tips were successfully cryopreserved using an encapsulation-dehydration procedure. Shoot tips were encapsulated in calcium-alginate beads before preculture on woody plant (WP) medium supplemented with different sucrose concentrations; 0.1, 0.3, 0.5, ...

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...

Functional diversity of macrophyte communities within and between Pyrenean lakes

Directory of Open Access Journals (Sweden)

Enric BALLESTEROS

2009-02-01

Full Text Available Submersed vegetation is a common feature in about 70% Pyrenean high mountain (>1500 m a.s.l. lakes. Isoetids and soft-water elodeids are common elements of this underwater flora and can form distinct vegetation units (i.e. patches of vegetation dominated by different species within complex mosaics of vegetation in shallow waters (<7 m. Since isoetids exert a strong influence on sediment biogeochemistry due to high radial oxygen loss, we examined the small scale characteristics of the lake environment (water and sediment associated to vegetation patches in order to ascertain potential functional differences among them. To do so, we characterised the species composition and biomass of the main vegetation units from 11 lakes, defined plant communities based on biomass data, and then related each community with sediment properties (redox and dissolved nutrient concentration in the pore water and water nutrient concentration within plant canopy. We also characterised lake water and sediment in areas without vegetation as a reference. A total of twenty-one vegetation units were identified, ranging from one to five per lake. A cluster analysis on biomass species composition suggested seven different macrophyte communities that were named after the most dominant species: Nitella sp., Potamogeton praelongus, Myriophyllum alterniflorum, Sparganium angustifolium, Isoetes echinospora, Isoetes lacustris and Carex rostrata. Coupling between macrophyte communities and their immediate environment (overlying water and sediment was manifested mainly as variation in sediment redox conditions and the dominant form of inorganic nitrogen in pore-water. These effects depended on the specific composition of the community, and on the allocation between above- and belowground biomass, and could be predicted with a model relating the average and standard deviation of sediment redox potential from 0 down to -20 cm, across macrophyte communities. Differences in pore

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.

Hydroxyapatite growth on multiwall carbon nanotubes grown on titanium fibers from a titanium sheet

KAUST Repository

Chetibi, Loubna; Achour, Amine; Peszke, Jerzy; Hamana, Djamel; Achour, Slimane

2013-01-01

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.

P-N junction solar cell grown by molecular beam epitaxy

International Nuclear Information System (INIS)

Hazrati Fard, M.

2001-01-01

Growth of GaAs epilayers by Molecular Beam Epitaxy was accomplished for the first time in Iran. The layers were grown on GaAs (001) substrates (p+ wafer) with Si impurity for p n junction solar cell fabrication at a rate of nearly one micron per hour and 0.25 micron per quarter. Crystalline quality of grown layers had been monitored during growth by Reflection High Energy Electron Diffraction system. Doping profile and layer thickness was assessed by electrochemical C-V profiling method. Then Hall measurements were conducted on small samples both in room temperature and liquid nitrogen temperature so giving average carrier concentration and compensation ratio. The results as like: V oc , I sc , F F, η were comparable with other laboratory reports. information for obtaining good and repeatable growths was collected. Therefore, the conditions of repeatable quality growth p n junction solar cells onto GaAs (001) substrates were determined

Phosphorus reduces the zinc concentration in cereals pot-grown on calcareous Vertisols from southern Spain.

Science.gov (United States)

Sánchez-Rodríguez, Antonio Rafael; Del Campillo, María Carmen; Torrent, José

2017-08-01

Zinc deficiency, a major problem in crops grown on soils low in available Zn, is even more important in phosphorus-rich soils. This work aimed to elucidate the effects of soil P and Zn levels, and of fertilizer application, on yield and Zn concentration in cereal grains. Wheat and barley were successively pot-grown on 20 calcareous Vertisols low in available Zn and ranging widely in available P. Grain yield in the plants grown on the native soils was positively correlated with Olsen P but not with diethylenetriaminepentaacetic acid (DTPA)-extractable Zn except for wheat on P-rich soils. Grain Zn concentration was negatively correlated with Olsen P. Grain Zn uptake differed little among soils. Application of P to the soils increased grain yield insignificantly and P concentration significantly; however, it reduced grain Zn concentration (particularly at low Olsen P values). Applying Zn alone only increased grain Zn concentration, whereas applying P and Zn in combination increased yield and grain Zn concentration at low and high Olsen P values, respectively. Applying P alone to plants grown on calcareous Vertisols low in available P and Zn may in practice reduce grain Zn concentrations while not increasing grain yield significantly. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

75 FR 17034 - Irish Potatoes Grown in Colorado; Relaxation of the Handling Regulation for Area No. 3

Science.gov (United States)

2010-04-05

...; FV09-948-2 IFR] Irish Potatoes Grown in Colorado; Relaxation of the Handling Regulation for Area No. 3...: This rule relaxes the size requirement prescribed under the Colorado potato marketing order. The marketing order regulates the handling of Irish potatoes grown in Colorado, and is administered locally by...

Phytochemical profiles and antioxidant potential of four Arctic vascular plants from Svalbard

Digital Repository Service at National Institute of Oceanography (India)

Singh, P.; Singh, S.M.; DeSouza, L.; Wahidullah, S.

the chemical composition and antioxidative activities of four Arctic flowering plant species (Dryas octopetala, Carex rupestris, Silene uralensis and Deschampsia alpina.) through in vitro measurements of the free radical scavenging activities (FRS), inhibition...

Nitrogen and amino acids content in lake Drukshyaj plancton organisms biocenoses grown in model experiments

International Nuclear Information System (INIS)

Krevsh, A.V.; Budrene, S.F.; Yankyavichyus, K.K.

1989-01-01

Biocenoses growth in lake Drukshyaj (from 1984 water reservoir of the Ignalina NPP) collected in July 1985 and grown in 2 various in composition culture media: in medium close in composition of main minerals to water of high capacity reservoir (medium 1) and in medium Fitzjarld (medium 2), has shown that the medium affects the component composition of plancton, as well as dominating types of algae. Phytoplancton was dominating component in biomass in both media. In medium 1 dominate green and diatoms, in medium 2 - blue-green algae. Content of proteins and amino acids in biomass changed depending on duration of biocenoses growth when dominating green and diatoms in biocenoses mass grown in medium 1, it reached maximum on the 15th day, and when dominating blue-green algae in biocenoses biomass grown in medium 2 - on the 30th day

Enhancement of optical properties of InAs quantum dots grown by using periodic arsine interruption

International Nuclear Information System (INIS)

Kim, Jungsub; Yang, Changjae; Sim, Uk; Lee, Jaeyel; Yoon, Euijoon; Lee, Youngsoo

2009-01-01

We investigated the morphological and optical properties of InAs quantum dots (QDs) grown by using periodic arsine interruption (PAI) and compared them with QDs grown conventionally. In the conventional growth, the formation of large islands was observed, which suppresses the nucleation and growth of QDs. Furthermore, the growth of capping layers was significantly degraded by these large islands. On the other hand, in the PAI growth, the formation of large islands was completely suppressed, resulting in the increase of the density and aspect ratio of QDs and the uniform growth of capping layers. As a result of photoluminescence (PL) measurements, we found that the emission efficiency was enhanced and the full-width-half-maximum was reduced to 32 meV. The temperature dependence of these optical properties also revealed the enhancement of the uniformity of QDs grown by the PAI method.

Ag-catalyzed InAs nanowires grown on transferable graphite flakes

DEFF Research Database (Denmark)

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

2016-01-01

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...

Copper and lead levels in two popular leafy vegetables grown ...

African Journals Online (AJOL)

A study was carried out to determine the levels of two heavy metals, Lead (Pb) and Copper (Cu), in two popular leafy vegetables grown around Morogoro Municipality in Tanzania. Vegetable samples of Pumpkin leaves ( Cucurbita moschata) and Chinese cabbage ( Brassica chinensis) were collected from three sites and ...

Crystalline perfection and mechanical investigations on vertical Bridgman grown Bismuth telluride (Bi_2Te_3) single crystals for thermoelectric applications

International Nuclear Information System (INIS)

Krishna, Anuj; Vijayan, N.; Singh, Budhendra; Thukral, Kanika; Maurya, K.K.

2016-01-01

High efficiency thermoelectric materials plays a vital role in power generation and refrigeration applications. Bismuth telluride (Bi_2Te_3) is one among them. In the present work single crystal of bismuth telluride was grown using vertical Bridgman technique. The phase of grown crystals was analysed using a powder X-ray diffractometer. Quality of the grown crystal was assessed by using high resolution X-ray diffractometer and observed that it is fairly good. Further mechanical investigations on grown crystal was carried out using nano-indentation technique and various mechanical properties like hardness, stiffness and Young’s modulus were evaluated. Observed results clearly indicate its suitability for thermoelectric applications.

78 FR 3 - Irish Potatoes Grown in Colorado; Modification of the Handling Regulation for Area No. 2

Science.gov (United States)

2013-01-02

...; FV12-948-1 IR] Irish Potatoes Grown in Colorado; Modification of the Handling Regulation for Area No. 2...: This rule modifies the grade requirements for potatoes handled under the Colorado potato marketing order, Area No. 2 (order). The order regulates the handling of Irish potatoes grown in Colorado and is...

Effects of migratory geese on plant communities of an Alaskan salt marsh

Science.gov (United States)

Zacheis, Amy B.; Hupp, Jerry W.; Ruess, Roger W.

2001-01-01

1. We studied the effects of lesser snow geese (Anser caerulescens caerulescens) and Canada geese (Branta canadensis) on two salt marsh plant communities in Cook Inlet, Alaska, a stopover area used during spring migration. From 1995 to 1997 we compared plant species composition and biomass on plots where geese were excluded from feeding with paired plots where foraging could occur. 2. Foraging intensity was low (650-1930 goose-days km-2) compared to other goose-grazing systems. 3. Canada geese fed mainly on above-ground shoots of Triglochin maritimum, Puccinellia spp. and Carex ramenskii, whereas the majority of the snow goose diet consisted of below-ground tissues of Plantago maritima and Triglochin maritimum. 4. Plant communities responded differently to goose herbivory. In the sedge meadow community, where feeding was primarily on above-ground shoots, there was no effect of grazing on the dominant species Carex ramenskii and Triglochin maritimum. In the herb meadow community, where snow geese fed on Plantago maritima roots and other below-ground tissues, there was a difference in the relative abundance of plant species between treatments. Biomass of Plantago maritima and Potentilla egedii was lower on grazed plots compared with exclosed, whereas biomass of Carex ramenskii was greater on grazed plots. There was no effect of herbivory on total standing crop biomass in either community. The variable effect of herbivory on Carex ramenskii between communities suggests that plant neighbours and competitive interactions are important factors in a species' response to herbivory. In addition, the type of herbivory (above- or below-ground) was important in determining plant community response to herbivory. 5. Litter accumulation was reduced in grazed areas compared with exclosed in both communities. Trampling of the previous year's litter into the soil surface by geese incorporated more litter into soils in grazed areas. 6. This study illustrates that even light herbivore

Photocatalytic properties of chemically grown vanadium oxide at 65 °C

International Nuclear Information System (INIS)

Vernardou, D.; Drosos, H.; Fasoulas, J.; Koudoumas, E.; Katsarakis, N.

2014-01-01

In this paper, the photocatalytic response of amorphous V 2 O 5 coatings prepared by hydrothermal growth at 65 °C is presented. The position of the substrate during the deposition and the pH of the solution were found to affect the coverage and the response of the coatings upon catalysis. The photocatalytic activity of the coatings was tested using stearic acid as a pollutant for an illumination time of 480 min. The materials grown on microscope glass positioned at an angle of 0° with respect to the bottom of the bottle exhibit the best photocatalytic activity, degrading stearic acid by 64% due to the enhanced surface coverage. - Highlights: • Hydrothermally grown amorphous V 2 O 5 coatings at 65 °C • Their properties are dependent on the substrate arrangement. • Their photocatalytic activity is correlated with the oxide coverage

Stress engineering in GaN structures grown on Si(111) substrates by SiN masking layer application

Energy Technology Data Exchange (ETDEWEB)

Szymański, Tomasz, E-mail: tomasz.szymanski@pwr.edu.pl; Wośko, Mateusz; Paszkiewicz, Bogdan; Paszkiewicz, Regina [The Faculty of Microsystem Electronics and Photonics, Wrocaw University of Technology, Janiszewskiego 11/17, 50-372 Wroclaw (Poland); Drzik, Milan [International Laser Center, Ilkovicova 3, 841-04 Bratislava 4 (Slovakia)

2015-07-15

GaN layers without and with an in-situ SiN mask were grown by using metal organic vapor phase epitaxy for three different approaches used in GaN on silicon(111) growth, and the physical and optical properties of the GaN layers were studied. For each approach applied, GaN layers of 1.4 μm total thickness were grown, using silan SiH{sub 4} as Si source in order to grow Si{sub x}N{sub x} masking layer. The optical micrographs, scanning electron microscope images, and atomic force microscope images of the grown samples revealed cracks for samples without SiN mask, and micropits, which were characteristic for the samples grown with SiN mask. In situ reflectance signal traces were studied showing a decrease of layer coalescence time and higher degree of 3D growth mode for samples with SiN masking layer. Stress measurements were conducted by two methods—by recording micro-Raman spectra and ex-situ curvature radius measurement—additionally PLs spectra were obtained revealing blueshift of PL peak positions with increasing stress. The authors have shown that a SiN mask significantly improves physical and optical properties of GaN multilayer systems reducing stress in comparison to samples grown applying the same approaches but without SiN masking layer.

Loose smut of barley grown in three types of farming

Directory of Open Access Journals (Sweden)

T. Nedelcheva

2016-09-01

Full Text Available Abstract. Over the period of 2014-2015, on the experimental field of the Institute of Agriculture in Karnobat, Bulgaria, was set a field trial with twenty cultivars of barley – 15 two-row: Obzor, Emon, Perun, Orfey, Lardeya, Asparuh, Kuber, Zagorets, Imeon, Sayra, Devinya, Sitara, Krami, Vicky, Potok; 3 four-row: Veslets, Aheloy 2, Tamaris; and 2 six-row cultivars – IZ Bori and Bozhin. All the cultivars were grown in three types of farming: conventional, organic and biodynamic. In conventional farming were applied pesticides and nitrogen fertilization. In the organic production were not used pesticides, mineral and organic fertilizers; and in biodynamic farming was applied biodynamic compost prepared from manure and biodynamic preparations (also organic. In conventional farming, the seeds were disinfected before sowing with Kinto plus (Triticonazole 20 g/l + Prochloraz 60 g/l, at a rate of 150 ml/100 kg seeds. In organic and biodynamic farming were used nondisinfected seeds. In the phenophase of full maturity of barley was conducted monitoring survey for plants infected with loose smut in all 2 the trial variants, the number of infected plants per m were counted and the infection rates were calculated. Infected plants of Tamaris grown in the three types of farming underwent microscopic analysis and measurement of 100 teliospores from each variant. The aim of this experiment was to investigate varietal susceptibility of barley to Ustilago nuda, grown in three types of farming, and to establish if the growing method affects the size of the teliospores of the pathogen. With two-row barley were found plants of Lardeya, Kuber, Devinya, Krami and Vicky infected with Ustilago nuda. Krami manifested the lowest resistance in the three types of farming. With four-row barley, Tamaris was found to be highly susceptible and Veslets was poorly resistant. Both cultivars expressed weaker susceptibility in conventional and biodynamic farming and stronger in

Thermal behaviour of strontium tartrate single crystals grown in gel

Indian Academy of Sciences (India)

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 ...

Growth and development of wetland-grown taro under different plant ...

African Journals Online (AJOL)

It is widely grown in Uganda but the extent of its production and consumption is not known, partly because it has been ignored as legitimate crop for research and development (R&D), and it is managed outside the conventional agricultural production, marketing and economic channels. Therefore, there is limited information ...

Pb-210 in beans grown in normal background environments

International Nuclear Information System (INIS)

Mingote, Raquel M.; Nogueira, Regina A.

2013-01-01

A survey was carried out on the activity concentration of 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 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 210 Pb activity concentration in beans was estimated by using robust ROS, a censored data analysis method. The value 0.047 Bq kg -1 fresh wt. obtained here is according to 210 Pb activity concentration in grains reported by UNSCEAR 0.05 Bq kg -1 . (author)

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)

Topographic and spectroscopic characterization of electronic edge states in CVD grown graphene nanoribbons.

Science.gov (United States)

Pan, Minghu; Girão, E Costa; Jia, Xiaoting; Bhaviripudi, Sreekar; Li, Qing; Kong, Jing; Meunier, V; Dresselhaus, Mildred S

2012-04-11

We used scanning tunneling microscopy and spectroscopy (STM/S) techniques to analyze the relationships between the edge shapes and the electronic structures in as-grown chemical vapor deposition (CVD) graphene nanoribbons (GNRs). A rich variety of single-layered graphene nanoribbons exhibiting a width of several to 100 nm and up to 1 μm long were studied. High-resolution STM images highlight highly crystalline nanoribbon structures with well-defined and clean edges. Theoretical calculations indicate clear spin-split edge states induced by electron-electron Coulomb repulsion. The edge defects can significantly modify these edge states, and different edge structures for both sides of a single ribbon produce asymmetric electronic edge states, which reflect the more realistic features of CVD grown GNRs. Three structural models are proposed and analyzed to explain the observations. By comparing the models with an atomic resolution image at the edge, a pristine (2,1) structure was ruled out in favor of a reconstructed edge structure composed of 5-7 member rings, showing a better match with experimental results, and thereby suggesting the possibility of a defective morphology at the edge of CVD grown nanoribbons. © 2012 American Chemical Society

76 FR 57001 - Pistachios Grown in California, Arizona, and New Mexico; Proposed Amendment of Marketing Order No...

Science.gov (United States)

2011-09-15

... Service 7 CFR Part 983 [Doc. No. AMS-FV-10-0099; FV11-983-1 PR] Pistachios Grown in California, Arizona... pistachios grown in California, Arizona, and New Mexico, and provides growers with the opportunity to vote in... Administrative Committee for Pistachios (Committee), which is responsible for local administration of the order...

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.

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.

Novel scanning procedure enabling the vectorization of entire rhizotron-grown root systems.

Science.gov (United States)

Lobet, Guillaume; Draye, Xavier

2013-01-04

: 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.

Phase-separated CsI-NaCl scintillator grown by the Czochralski method

Science.gov (United States)

Yasui, Nobuhiro; Kobayashi, Tamaki; Ohashi, Yoshihiro; Den, Toru

2014-08-01

A phase-separated CsI-NaCl scintillator with light-guiding properties was grown by the Czochralski method. The CsI-NaCl eutectic phase usually consists of NaCl cylinders in a CsI matrix and contains grain boundaries. However, we have grown composites without grain boundaries by creating a convex solid/liquid interface, selecting a single grain by Dash's neck method, and increasing the diameter of the composite moderately. The good continuous convection flow required for these conditions was achieved by suppressing the drop in the aspect ratio of the melt height to the crucible radius with a double crucible setup. We successfully obtained a CsI-NaCl:Tl composite that was uniform with no grain boundaries greater than 30 mm in diameter.

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

Malt quality of 4 barley ( Hordeum vulgare L.) grain varieties grown ...

African Journals Online (AJOL)

propiconazole) spray intervals (7, 14, 21 day) and no spray control were arranged in a RCBD in 4 replications to assess net blotch (Pyrenophora teres) effect on malt quality. The varieties were grown at Holetta agricultural research center in 2005, ...

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.

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...

Effects of irrigation strategies and soils on field grown potatoes

DEFF Research Database (Denmark)

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

2010-01-01

Yield and water productivity of potatoes grown in 4.32 m2 lysimeters were measured in coarse sand, loamy sand, and sandy loam and imposed to full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation strategies. PRD and DI as water-saving irrigation treatments received 65% of FI after...

Atomic force microscopy studies of homoepitaxial GaN layers grown on GaN template by laser MBE

Energy Technology Data Exchange (ETDEWEB)

Choudhary, B. S. [CSIR-National Physical Laboratory, Dr K.S. Krishnan Road, New Delhi 110012 (India); Rajasthan Technical University, Rawatbhata Road, Kota 324010 (India); Singh, A.; Tyagi, P. K. [Department of Applied Physics, Delhi Technological University, Delhi 110042 (India); Tanwar, S. [Rajasthan Technical University, Rawatbhata Road, Kota 324010 (India); Kumar, M. Senthil; Kushvaha, S. S., E-mail: kushvahas@nplindia.org [CSIR-National Physical Laboratory, Dr K.S. Krishnan Road, New Delhi 110012 (India)

2016-04-13

We have grown homoepitaxial GaN films on metal organic chemical vapor deposition (MOCVD) grown 3.5 µm thick GaN on sapphire (0001) substrate (GaN template) using an ultra-high vacuum (UHV) laser assisted molecular beam epitaxy (LMBE) system. The GaN films were grown by laser ablating a polycrystalline solid GaN target in the presence of active r.f. nitrogen plasma. The influence of laser repetition rates (10-30 Hz) on the surface morphology of homoepitaxial GaN layers have been studied using atomic force microscopy. It was found that GaN layer grown at 10 Hz shows a smooth surface with uniform grain size compared to the rough surface with irregular shape grains obtained at 30 Hz. The variation of surface roughness of the homoepitaxial GaN layer with and without wet chemical etching has been also studied and it was observed that the roughness of the film decreased after wet etching due to the curved structure/rough surface.

Reduced phenylalanine ammonia-lyase and tyrosine ammonia-lyase activities and lignin synthesis in wheat grown under low pressure sodium lamps

Science.gov (United States)

Guerra, D.; Anderson, A. J.; Salisbury, F. B.

1985-01-01

Wheat (Triticum aestivum L. cv Fremont) grown in hydroponic culture under 24-hour continuous irradiation at 560 to 580 micromoles per square meter per second from either metalhalide (MH), high pressure sodium (HPS), or low pressure sodium (LPS) lamps reached maturity in 70 days. Grain yields were similar under all three lamps, although LPS-grown plants lodged at maturity. Phenylalanine ammonia-lyase (PAL) and a tyrosine ammonia lyase (TAL) with lesser activity were detected in all extracts of leaf, inflorescence, and stem. Ammonia-lyase activities increased with age of the plant, and plants grown under the LPS lamp displayed PAL and TAL activities lower than wheat cultured under MH and HPS radiation. Greenhouse solar-grown wheat had the highest PAL and TAL activities. Lignin content of LPS-grown wheat was also significantly reduced from that of plants grown under MH or HPS lamps or in the greenhouse, showing a correlation with the reduced PAL and TAL activities. Ratios of far red-absorbing phytochrome to total phytochrome were similar for all three lamps, but the data do not yet warrant a conclusion about specific wavelengths missing from the LPS lamps that might have induced PAL and TAL activities in plants under the other lamps.

Structure and magnetism of ultrathin Co and Fe films epitaxially grown on Pd/Cu(0 0 1)

International Nuclear Information System (INIS)

Lu, Y.F.; Przybylski, M.; Yan, L.; Barthel, J.; Meyerheim, H.L.; Kirschner, J.

2005-01-01

A contribution originating from the Co/Pd and Fe/Pd interfaces to the magneto-optical Kerr effect (MOKE) rotation is analyzed for Co and/or Fe films grown on a Pd-buffer-monolayer on Cu(0 0 1). A clear increase of the MOKE signal in comparison to the Co(Fe) films grown directly on Cu(0 0 1) is detected. An interpretation is supported by similar observations for Co films grown on Pd(1 1 0) and Pd(0 0 1). In particular, the sign reversal of the Kerr loops with increasing thickness of the Co(Fe) films is discussed. Magneto-optical effects are separated from the real magnetization and its dependence on the film thickness

Apocrustacyanin C(1) crystals grown in space and on earth using vapour-diffusion geometry: protein structure refinements and electron-density map comparisons.

Science.gov (United States)

Habash, Jarjis; Boggon, Titus J; Raftery, James; Chayen, Naomi E; Zagalsky, Peter F; Helliwell, John R

2003-07-01

Models of apocrustacyanin C(1) were refined against X-ray data recorded on Bending Magnet 14 at the ESRF to resolutions of 1.85 and 2 A from a space-grown and an earth-grown crystal, respectively, both using vapour-diffusion crystal-growth geometry. The space crystals were grown in the APCF on the NASA Space Shuttle. The microgravity crystal growth showed a cyclic nature attributed to Marangoni convection, thus reducing the benefits of the microgravity environment, as reported previously [Chayen et al. (1996), Q. Rev. Biophys. 29, 227-278]. A subsequent mosaicity evaluation, also reported previously, showed only a partial improvement in the space-grown crystals over the earth-grown crystals [Snell et al. (1997), Acta Cryst. D53, 231-239], contrary to the case for lysozyme crystals grown in space with liquid-liquid diffusion, i.e. without any major motion during growth [Snell et al. (1995), Acta Cryst. D52, 1099-1102]. In this paper, apocrustacyanin C(1) electron-density maps from the two refined models are now compared. It is concluded that the electron-density maps of the protein and the bound waters are found to be better overall for the structures of apocrustacyanin C(1) studied from the space-grown crystal compared with those from the earth-grown crystal, even though both crystals were grown using vapour-diffusion crystal-growth geometry. The improved residues are on the surface of the protein, with two involved in or nearby crystal lattice-forming interactions, thus linking an improved crystal-growth mechanism to the molecular level. The structural comparison procedures developed should themselves be valuable for evaluating crystal-growth procedures in the future.

Electrolytic coloration of air-grown sodium fluoride crystals

International Nuclear Information System (INIS)

Gu Hongen; Han Li; Song Cuiying; Guo Meili; Wang Na

2007-01-01

Air-grown sodium fluoride crystals were colored electrolytically by using a pointed cathode at various temperatures and electric field strengths, which should mainly benefit appropriate coloration temperatures and electric field strengths. O 2 - , F, M, N 1 , N 2 color centers and O 2- -F + complexes were produced in the colored crystals. Current-time curves for the electrolytic colorations were given, and activation energy for the V color center migration was determined. The formation of the color centers was explained

The biotechnology of hydrogen production by Nostoc flagelliforme grown under chemostat conditions

Energy Technology Data Exchange (ETDEWEB)

Lichtl, R.R.; Bazin, M.J.; Hall, D.O. [Div. of Life Sciences, King`s College, London Univ. (United Kingdom)

1997-11-01

The potential of using N{sub 2}-fixing cyanobacteria to produce hydrogen photobiologically has stimulated research on the physiology and biotechnology of species exhibiting high H{sub 2} production rates over long periods of time. In this work Nostoc flagelliforme, a terrestrial N{sub 2}-fixing cyanobacterium, has been examined to establish its physiology and potential for H{sub 2} production under controlled conditions. Cell filaments of N. flagelliforme were purified and grown in liquid culture to optimize its H{sub 2} metabolism. In batch-grown cultures the activity of nitrogenase, the key enzyme for H{sub 2} production in N{sub 2}-fixing organisms, was found to be high only during a short phase of exponential growth. A chemostat system was thus constructed for long-term experiments using continuous cultures, with the aim of exploiting the exponential growth phase. The dilution rate (D) and environmental factors, such as N{sub 2} concentration in the gas phase and temperature, significantly influenced H{sub 2} production. Cells grown continuously under the optimized conditions of D=0.022 h{sup -1}, 34 C and 5.1 kPa N{sub 2} in the gas phase exhibited H{sub 2} production rates that were more than four times higher than the maximal rates under standard batch growth conditions. (orig.)

High quality long-wavelength lasers grown by atmospheric organometallic vapor phase epitaxy using tertiarybutylarsine

International Nuclear Information System (INIS)

Miller, B.I.; Young, M.G.; Oron, M.; Koren, U.; Kisker, D.

1990-01-01

High quality long-wavelength InGaAsP/InP lasers were grown by atmospheric organometallic vapor phase epitaxy using tertiarybutylarsine (TBA) as a substitute for AsH 3 . Electrical and photoluminescence measurements on InGaAs and InGaAsP showed that TBA-grown material was at least as good as AsH 3 material in terms of suitability for lasers. From two wafers grown by TBA, current thresholds I th as low as 11 mA were obtained for a 2-μm-wide semi-insulating blocking planar buried heterostructure laser lasing near 1.3 μm wavelength. The differential quantum efficiencies η D were as high as 21%/facet with a low internal loss α=21 cm -1 . In addition I th as low as 18 mA and η D as high as 18% have been obtained for multiplequantum well lasers at 1.54 μm wavelength. These results show that TBA might be used to replace AsH 3 without compromising on laser performance

Reliability of Czochralski-grown {beta}-BaB{sub 2}O{sub 4}(BBO) devices

Energy Technology Data Exchange (ETDEWEB)

Umezu, Nobuhiko; Fukui, Tatsuo; Okamoto, Tsutomu; Wada, Hiroyuki; Tatsuki, Kouichi; Kondo, Kenji; Kubota, Shigeo [Sony Corp., Tokyo (Japan)

1998-03-01

We have achieved more than 1000 hours-operation in 266 nm-continuous wave (CW), 100 mW-generation of all-solid-state-UV laser system using Czochralski (Cz)-grown {beta}-BaB{sub 2}O{sub 4}(BBO) crystal devices. Absorption of the Cz-grown crystal for e-ray at 266 nm was improved to 1%/cm, which is one-third lower than that of the crystal grown by top seeded solution growth (TSSG) method. Degradation rate of 266 nm generation, using 7 kHz repetition rate laser diode pumped Q switched Nd:YAG laser as a fundamental light source, was one order of magnitude lower than that of TSSG-crystal. Surface roughness of the crystal was better than 0.3 rms.-nm. HfO{sub 2} film with extremely high adhesion was deposited on the surfaces using reactive low voltage ion plating method. Our devices can be put to practical use in areas of photolithography, micro fabrication, material processing and ultra high density optical disk mastering. (author)

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.

Photocatalytic properties of chemically grown vanadium oxide at 65 °C

Energy Technology Data Exchange (ETDEWEB)

Vernardou, D., E-mail: dimitra@iesl.forth.gr [Center of Materials Technology and Photonics, School of Applied Technology, Technological Educational Institute of Crete, 710 04 Heraklion, Crete (Greece); Science Department, School of Applied Technology, Technological Educational Institute of Crete, 710 04 Heraklion, Crete (Greece); Drosos, H.; Fasoulas, J. [Mechanical Engineering Department, School of Applied Technology, Technological Educational Institute of Crete, 710 04 Heraklion, Crete (Greece); Koudoumas, E. [Center of Materials Technology and Photonics, School of Applied Technology, Technological Educational Institute of Crete, 710 04 Heraklion, Crete (Greece); Electrical Engineering Department, School of Applied Technology, Technological Educational Institute of Crete, 710 04 Heraklion, Crete (Greece); Katsarakis, N. [Center of Materials Technology and Photonics, School of Applied Technology, Technological Educational Institute of Crete, 710 04 Heraklion, Crete (Greece); Science Department, School of Applied Technology, Technological Educational Institute of Crete, 710 04 Heraklion, Crete (Greece); Institute of Electronic Structure and Laser, Foundation for Research and Technology—Hellas, P.O. Box 1527, Vassilika Vouton, 711 10 Heraklion, Crete (Greece)

2014-03-31

In this paper, the photocatalytic response of amorphous V{sub 2}O{sub 5} coatings prepared by hydrothermal growth at 65 °C is presented. The position of the substrate during the deposition and the pH of the solution were found to affect the coverage and the response of the coatings upon catalysis. The photocatalytic activity of the coatings was tested using stearic acid as a pollutant for an illumination time of 480 min. The materials grown on microscope glass positioned at an angle of 0° with respect to the bottom of the bottle exhibit the best photocatalytic activity, degrading stearic acid by 64% due to the enhanced surface coverage. - Highlights: • Hydrothermally grown amorphous V{sub 2}O{sub 5} coatings at 65 °C • Their properties are dependent on the substrate arrangement. • Their photocatalytic activity is correlated with the oxide coverage.

Influence of electron irradiation on hydrothermally grown zinc oxide single crystals

International Nuclear Information System (INIS)

Lu, L W; So, C K; Zhu, C Y; Gu, Q L; Fung, S; Ling, C C; Li, C J; Brauer, G; Anwand, W; Skorupa, W

2008-01-01

The resistivity of hydrothermally grown ZnO single crystals increased from ∼10 3 Ω cm to ∼10 6 Ω cm after 1.8 MeV electron irradiation with a fluence of ∼10 16 cm −2 , and to ∼10 9 Ω cm as the fluence increased to ∼10 18 cm −2 . Defects in samples were studied by thermally stimulated current (TSC) spectroscopy and positron lifetime spectroscopy (PLS). After the electron irradiation with a fluence of 10 18 cm −2 , the normalized TSC signal increased by a factor of ∼100. A Zn vacancy was also introduced by the electron irradiation, though with a concentration lower than expected. After annealing in air at 400 °C, the resistivity and the deep traps concentrations recovered to the levels of the as-grown sample, and the Zn vacancy was removed

Weed Growth and Efficacy of Pre-Applied Herbicides in Alternative Rooting Substrates Used in Container-Grown Nursery Crops

Science.gov (United States)

Container-grown nursery crops in the Southeastern United States are typically grown in a rooting substrate comprised primarily of the ground bark of pine trees. However pine bark is becoming less available and more costly due to changes in production and marketed practices within Southeastern pine f...

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...

Vertically grown Ge nanowire Schottky diodes on Si and Ge substrates

Science.gov (United States)

Chandra, Nishant; Tracy, Clarence J.; Cho, Jeong-Hyun; Picraux, S. T.; Hathwar, Raghuraj; Goodnick, Stephen M.

2015-07-01

The processing and performance of Schottky diodes formed from arrays of vertical Ge nanowires (NWs) grown on Ge and Si substrates are reported. The goal of this work is to investigate CMOS compatible processes for integrating NWs as components of vertically scaled integrated circuits, and elucidate transport in vertical Schottky NWs. Vertical phosphorus (P) doped Ge NWs were grown using vapor-liquid-solid epitaxy, and nickel (Ni)-Ge Schottky contacts were made to the tops of the NWs. Current-voltage (I-V) characteristics were measured for variable ranges of NW diameters and numbers of nanowires in the arrays, and the I-V characteristics were fit using modified thermionic emission theory to extract the barrier height and ideality factor. As grown NWs did not show rectifying behavior due to the presence of heavy P side-wall doping during growth, resulting in a tunnel contact. After sidewall etching using a dilute peroxide solution, rectifying behavior was obtained. Schottky barrier heights of 0.3-0.4 V and ideality factors close to 2 were extracted using thermionic emission theory, although the model does not give an accurate fit across the whole bias range. Attempts to account for enhanced side-wall conduction due to non-uniform P doping profile during growth through a simple shunt resistance improve the fit, but are still insufficient to provide a good fit. Full three-dimensional numerical modeling using Silvaco Atlas indicates that at least part of this effect is due to the presence of fixed charge and acceptor like traps on the NW surface, which leads to effectively high ideality factors.

Superconducting proximity effect in MBE grown Nb-InAs junctions

Science.gov (United States)

Kan, Carolyn; Xue, Chi; Law, Stephanie; Eckstein, James

2013-03-01

Several proposals for the realization of Majorana fermions rely on excellent quality proximity coupling between a superconductor and a high-mobility semiconductor. We examine the long-range proximity coupling between MBE-grown InAs and in situ grown superconducting overlayers by fabricating transport devices, and investigate the effect of substrate choice and growth conditions on the quality of the MBE InAs. GaAs is commonly available as a high quality insulating substrate. Overcoming its lattice mismatch with InAs using GaSb and AlSb layers results in locally smooth terraced surfaces, but global spiral dislocation structures also appear and have a negative impact on the InAs mobility. Growing InAs on homoepitaxial GaSb results in improved morphology and increases the mean free path. We compare the proximity effect in devices made both ways. This material is based upon work supported by the U.S. Department of Energy, Division of Materials Sciences under Award No. DE-FG02 07ER46453, through the Frederick Seitz Materials Research Laboratory at the University of Illinois at Urbana-Champaign.

Yield of lettuce grown in aquaponic system using different substrates

Directory of Open Access Journals (Sweden)

Rodrigo A. Jordan

Full Text Available ABSTRACT In the aquaponic system, the characteristics of the materials used as substrate directly affect plant development, because besides acting as a support base, they must present a surface to fix microorganisms, responsible for the conversion of nutrients into forms more easily available to plants. Thus, the objective of this study was to evaluate the effect of four growing substrates on the yield of lettuce grown in aquaponic system. The experimental design was randomized blocks with four treatments, which corresponded to the substrates, and six replicates. Plants were grown using the nutrient film technique (NFT system. The substrates used in the experiment were: coconut shell fiber with crushed stone #3, expanded vermiculite, zeolite and phenolic foam. The treatment with phenolic foam was considered as the least suitable for lettuce cultivation in aquaponic system, because it caused lower yield (20.8 t ha-1. The treatment using coconut shell fiber with crushed stone #3 was considered as the most adequate, since it led to higher yield (39.9 t ha-1 compared with the other substrates analyzed.

Draft genome of the American Eel (Anguilla rostrata).

Science.gov (United States)

Pavey, Scott A; Laporte, Martin; Normandeau, Eric; Gaudin, Jérémy; Letourneau, Louis; Boisvert, Sébastien; Corbeil, Jacques; Audet, Céline; Bernatchez, Louis

2017-07-01

Freshwater eels (Anguilla sp.) have large economic, cultural, ecological and aesthetic importance worldwide, but they suffered more than 90% decline in global stocks over the past few decades. Proper genetic resources, such as sequenced, assembled and annotated genomes, are essential to help plan sustainable recoveries by identifying physiological, biochemical and genetic mechanisms that caused the declines or that may lead to recoveries. Here, we present the first sequenced genome of the American eel. This genome contained 305 043 contigs (N50 = 7397) and 79 209 scaffolds (N50 = 86 641) for a total size of 1.41 Gb, which is in the middle of the range of previous estimations for this species. In addition, protein-coding regions, including introns and flanking regions, are very well represented in the genome, as 95.2% of the 458 core eukaryotic genes and 98.8% of the 248 ultra-conserved subset were represented in the assembly and a total of 26 564 genes were annotated for future functional genomics studies. We performed a candidate gene analysis to compare three genes among all three freshwater eel species and, congruent with the phylogenetic relationships, Japanese eel (A. japanica) exhibited the most divergence. Overall, the sequenced genome presented in this study is a crucial addition to the presently available genetic tools to help guide future conservation efforts of freshwater eels. © 2016 John Wiley & Sons Ltd.

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

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.

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.

76 FR 18001 - Irish Potatoes Grown in Washington; Decreased Assessment Rate

Science.gov (United States)

2011-04-01

... IR] Irish Potatoes Grown in Washington; Decreased Assessment Rate AGENCY: Agricultural Marketing... rate established for the State of Washington Potato Committee (Committee) for the 2011-2012 and subsequent fiscal periods from $0.0035 to $0.003 per hundredweight of potatoes handled. The Committee locally...

76 FR 41589 - Irish Potatoes Grown in Washington; Decreased Assessment Rate

Science.gov (United States)

2011-07-15

... FIR] Irish Potatoes Grown in Washington; Decreased Assessment Rate AGENCY: Agricultural Marketing... established for the State of Washington Potato Committee (Committee) for the 2011-2012 and subsequent fiscal periods from $0.0035 to $0.003 per hundredweight of potatoes handled. The Committee locally administers...

76 FR 7095 - Avocados Grown in South Florida; Increased Assessment Rate

Science.gov (United States)

2011-02-09

... FIR] Avocados Grown in South Florida; Increased Assessment Rate AGENCY: Agricultural Marketing Service... established for the Avocado Administrative Committee (Committee), for the 2010-11 and subsequent fiscal periods from $0.27 to $0.37 per 55-pound bushel container of Florida avocados handled. The Committee...

Transcriptional, proteomic, and metabolic responses to lithium in galactose-grown yeast cells

DEFF Research Database (Denmark)

Bro, Christoffer; Regenberg, Birgitte; Lagniel, G.

2003-01-01

Lithium is highly toxic to yeast when grown in galactose medium mainly because phosphoglucomutase, a key enzyme of galactose metabolism, is inhibited. We studied the global protein and gene expression profiles of Saccharomyces cerevisiae grown in galactose in different time intervals after addition...... of lithium. These results were related to physiological studies where both secreted and intracellular metabolites were determined. Microarray analysis showed that 664 open reading frames were down-regulated and 725 up-regulated in response to addition of lithium. Genes involved in transcription, translation......-regulated proteins were also identified as being changed on the mRNA level. Functional clusters obtained from proteome data were coincident with transcriptional clusters. Physiological studies showed that acetate, glycerol, and glycogen accumulate in response to lithium, as reflected in expression data, whereas...

Epitaxially Grown Ultra-Flat Self-Assembling Monolayers with Dendrimers

Directory of Open Access Journals (Sweden)

Takane Imaoka

2018-02-01

Full Text Available Mono-molecular films formed by physical adsorption and dendrimer self-assembly were prepared on various substrate surfaces. It was demonstrated that a uniform dendrimer-based monolayer on the subnanometer scale can be easily constructed via simple dip coating. Furthermore, it was shown that an epitaxially grown monolayer film reflecting the crystal structure of the substrate (highly ordered pyrolytic graphite (HOPG can also be formed by aligning specific conditions.

Photoluminescence characteristics of InAs quantum dots grown by STM/MBE site-control technique

Energy Technology Data Exchange (ETDEWEB)

Nishikawa, S.; Kohmoto, S.; Nakamura, H.; Ishikawa, T.; Asakawa, K.; Wada, O. [Femtosecond Technology Research Association, Tsukuba, Ibaraki (Japan). FESTA Lab.

2001-03-08

This paper describes micro-photoluminescence (PL) analysis of site-controlled QDs (SCQDs) grown using a novel in-situ MBE growth technique in which sites of self-assembled InAs QDs are controlled by forming nanometer deposits using a scanning tunneling microscope (STM) probe. We found from the temperature dependence of PL that the carrier collection at QDs at low temperature is limited by carrier diffusion in the wetting layer. The analysis of PL data considering this effect has indicated that individual QDs grown have high crystalline quality in spite of the addition of an artificial STM process during growth. (orig.)

Fly-ash-induced oxidative stress and tolerance in Prosopis juliflora L. grown on different amended substrates.

Science.gov (United States)

Sinha, S; Rai, U N; Bhatt, K; Pandey, K; Gupta, A K

2005-03-01

Field experiments were conducted to study the impact of metal accumulation on malondialdehyde (MDA), cysteine and non-protein thiol (NPSH) contents in the plants of Prosopis juliflora grown on the fly ash (FA) amended with soil, blue green algae (BGA) biofertilizer, farm yard manure, press mud and Rhizobium inoculation. The analysis of data revealed that the level of MDA, cysteine and NPSH was higher in the roots of the plant than leaves, which was found positively correlated with metal accumulation. An increase of 361.14, 64.25 and 305.62% in MDA, cysteine and NPSH contents, respectively was observed after 45 days in the roots of the plants grown in 100% FA as compared to 100% garden soil (GS). The level of MDA, cysteine and NPSH was found less in the plants grown on various amendments of FA showing ameliorating effect on the toxicity induced due to the accumulation of metals. The decrease in MDA, cysteine and NPSH contents was higher in Rhizobium-inoculated plants as compared to uninoculated plants grown on 100% FA. The results showed a high tolerance potential of the plant, which is further increased by inoculating the plant with FA-tolerant Rhizobium showing feasibility of using P. julifilora in environmental monitoring of FA landfills.

MOVPE of InN films on GaN templates grown on sapphire and silicon(111) substrates

International Nuclear Information System (INIS)

Jamil, Muhammad; Arif, Ronald A.; Ee, Yik-Khoon; Tong, Hua; Tansu, Nelson; Higgins, John B.

2008-01-01

This paper reports the study of MOVPE of InN on GaN templates grown on sapphire and silicon(111) substrates. Thermodynamic analysis of MOVPE of InN performed using NH 3 as nitrogen source and the experimental findings support the droplet-free epitaxial growth of InN under high V/III ratios of input precursors. At a growth pressure of 500 Torr, the optimum growth temperature and V/III ratio of the InN film are 575-650 C and >3 x 10 5 , respectively. The surface RMS roughness of InN film grown GaN/sapphire template is ∝0.3 nm on 2 μm x 2 μm area, while the RMS roughness of the InN film grown on GaN/Si(111) templates is found as ∝0.7 nm. The X-ray diffraction (XRD) measurement reveals the (0002) texture of the InN film on GaN/sapphire template with a FWHM of 281 arcsec of the InN(0002) ω rocking curve. For the film grown on GaN/Si template under identical growth conditions, the XRD measurements show the presence of metallic In, in addition to the (0002) orientation of InN layer. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Photoluminescence characteristics of Pb-doped, molecular-beam-epitaxy grown ZnSe crystal layers

International Nuclear Information System (INIS)

Mita, Yoh; Kuronuma, Ryoichi; Inoue, Masanori; Sasaki, Shoichiro; Miyamoto, Yoshinobu

2004-01-01

The characteristic green photoluminescence emission and related phenomena in Pb-doped, molecular-beam-epitaxy (MBE)-grown ZnSe crystal layers were investigated to explore the nature of the center responsible for the green emission. The intensity of the green emission showed a distinct nonlinear dependence on excitation intensity. Pb-diffused polycrystalline ZnSe was similarly examined for comparison. The characteristic green emission has been observed only in MBE-grown ZnSe crystal layers with moderate Pb doping. The results of the investigations on the growth conditions, luminescence, and related properties of the ZnSe crystal layers suggest that the green emission is due to isolated Pb replacing Zn and surrounded with regular ZnSe lattice with a high perfection

Thermal behaviour of strontium tartrate single crystals grown in gel

Indian Academy of Sciences (India)

Unknown

Keywords. Strontium tartrate; dopant; effect of magnetic field; thermal behaviour. 1. Introduction ... tals of such type of compounds cannot be grown by either slow evaporation or ... is observed under a stereo binocular microscope (Carl. Zeiss) and ... a depth of 1⋅8 cm due to the diffusion of the top solution. After about a week ...

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...

Growth and yield models for Eucalyptus grandis grown in Swaziland ...

African Journals Online (AJOL)

The aim of this study was to develop a stand-level growth and yield model for short-rotationEucalyptus grandis grown for pulp wood production at Piggs Peak in Swaziland. The data were derived from a Nelder 1a spacing trial established with E. grandis clonal cuttings in 1998 and terminated in 2005. Planting density ...

Electrical, photoelectrical and morphological properties of ZnO nanofiber networks grown on SiO{sub 2} and on Si nanowires

Energy Technology Data Exchange (ETDEWEB)

Vega, Nadia Celeste; Comedi, David [Universidad Nacional de Tucuman (FACET/UNT), (Argentina). Facultad de Ciencias Exactas y Tecnologia. Dept. de Fisica. Lab. de Fisica del Solido; Audebert, Fernando [Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Tirado, Monica, E-mail: mtirado@herrera.unt.edu.ar [Universidad Nacional de Tucuman (FACET/UNT), (Argentina). Facultad de Ciencias Exactas y Tecnologia. Dept. de Fisica. Lab. de Nanomateriales y de Propiedades Dielectricas; Rodriguez, Andres; Rodriguez, Tomas [Universidad Politecnica de Madrid (ETSIT/UPM), Madrid (Spain). Escuela Tecnica Superior de Ingenieros de Telecomucacion. Tecnologia Electronica; Hughes, Gareth M.; Grovenor, Chris R.M. [University of Oxford, Parks Road, OX (United Kingdom). Dept. of Materials

2013-11-01

ZnO nanofibre networks (NFNs) were grown by vapour transport method on Si-based substrates. One type of substrate was SiO{sub 2} thermally grown on Si and another consisted of a Si wafer onto which Si nanowires (NWs) had been grown having Au nanoparticles catalysts. The ZnO-NFN morphology was observed by scanning electron microscopy on samples grown at 600 Degree-Sign C and 720 Degree-Sign C substrate temperature, while an focused ion beam was used to study the ZnO NFN/Si NWs/Si and ZnO NFN/SiO{sub 2} interfaces. Photoluminescence, electrical conductance and photo conductance of ZnO-NFN was studied for the sample grown on SiO{sub 2}. The photoluminescence spectra show strong peaks due to exciton recombination and lattice defects. The ZnO-NFN presents quasi-persistent photoconductivity effects and ohmic I-V characteristics which become nonlinear and hysteretic as the applied voltage is increased. The electrical conductance as a function of temperature can be described by a modified three dimensional variable hopping model with nanometer-ranged typical hopping distances. (author)

Paramagnetic resonance of LaGaO3: Mn single crystals grown by floating zone melting

Science.gov (United States)

Vazhenin, V. A.; Potapov, A. P.; Artyomov, M. Yu.; Salosin, M. A.; Fokin, A. V.; Gil'mutdinov, I. F.; Mukhamedshin, I. R.

2016-02-01

The EPR spectrum of Mn-doped lanthanum gallate single crystals grown by floating zone melting with optical heating has been studied. In contrast to the crystals grown according to the Czochralski method, no manganese is found in these crystals even after high-temperature annealing in air. The spectral characteristics of Fe3+ and Gd3+ centers in crystals prepared by various methods have been compared in the rhombohedral phase, and the fourth-rank nondiagonal parameters of the Fe3+ trigonal centers have been determined, as well.

Evaluation of Diverse Microalgal Species as Potential Biofuel Feedstocks Grown Using Municipal Wastewater

Energy Technology Data Exchange (ETDEWEB)

Hiibel, Sage R. [Department of Biochemistry and Molecular Biology, University of Nevada Reno, Reno, NV (United States); Department of Civil and Environmental Engineering, University of Nevada Reno, Reno, NV (United States); Lemos, Mark S.; Kelly, Brian P.; Cushman, John C., E-mail: jcushman@unr.edu [Department of Biochemistry and Molecular Biology, University of Nevada Reno, Reno, NV (United States)

2015-05-11

Microalgae offer great potential as a third-generation biofuel feedstock, especially when grown on wastewater, as they have the dual application for wastewater treatment and as a biomass feedstock for biofuel production. The potential for growth on wastewater centrate was evaluated for forty microalgae strains from fresh (11), brackish (11), or saltwater (18) genera. Generally, freshwater strains were able to grow at high concentrations of centrate, with two strains, Neochloris pseudostigmata and Neochloris conjuncta, demonstrating growth at up to 40% v/v centrate. Fourteen of 18 salt water Dunaliella strains also demonstrated growth in centrate concentrations at or above 40% v/v. Lipid profiles of freshwater strains with high-centrate tolerance were determined using gas chromatography–mass spectrometry and compared against those obtained on cells grown on defined maintenance media. The major lipid compounds were found to be palmitic (16:0), oleic (18:1), and linoleic (18:2) acids for all freshwater strains grown on either centrate or their respective maintenance medium. These results demonstrate the highly concentrated wastewater can be used to grow microalgae, which limits the need to dilute wastewater prior to algal production. In addition, the algae produced generate lipids suitable for biodiesel or green diesel production.

Electrical characterization of 6H-SiC grown by physical vapor transport method

Energy Technology Data Exchange (ETDEWEB)

Zaremba, G., E-mail: gzaremba@ite.waw.p [Institute of Electron Technology, Department of Analysis of Semiconductor Nanostructures, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Kaniewska, M.; Jung, W. [Institute of Electron Technology, Department of Analysis of Semiconductor Nanostructures, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Guziewicz, M. [Institute of Electron Technology, Department of Semiconductor Processing for Photonics, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Grasza, K. [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Institute of Electronic Materials Technology, ul. Wolczynska 133, 01-919 Warsaw (Poland)

2009-11-25

Deep level transient spectroscopy (DLTS) and capacitance versus voltage (C-V) measurements have been used to study the electrical properties of electron traps in n-type 6H-silicon carbide (SiC) grown by physical vapor transport (PVT) technique, designed as Schottky diodes. Ir Schottky- and Ni ohmic-contacts were deposited by sputtering. Current versus voltage (I-V) measurements showed that sputter deposition of the Schottky contact yields diodes with a reduced barrier height and poor rectification characteristics. Four main electron traps revealed in DLTS spectra have activation energies at 0. 39, 0.41, 0,66, and 0.74 eV below the conduction band. Based on a comparison made with electron traps reported in the literature, we conclude that three of them are well-known traps found in the as-grown or irradiated material. There was no emission signature in the literature to make such a correspondence for the trap at 0.74 eV. Strongly nonhomogenous spatial distribution with a tendency of the trap to accumulation at the surface was found by DLTS and C-V profiling. This together with the fact that the trap at 0.74 eV has not been previously reported in as-grown or processed material makes it possible that the trap is sputter deposition induced defect.

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.

Tailoring the optical characteristics of microsized InP nanoneedles directly grown on silicon.

Science.gov (United States)

Li, Kun; Sun, Hao; Ren, Fan; Ng, Kar Wei; Tran, Thai-Truong D; Chen, Roger; Chang-Hasnain, Connie J

2014-01-08

Nanoscale self-assembly offers a pathway to realize heterogeneous integration of III-V materials on silicon. However, for III-V nanowires directly grown on silicon, dislocation-free single-crystal quality could only be attained below certain critical dimensions. We recently reported a new approach that overcomes this size constraint, demonstrating the growth of single-crystal InGaAs/GaAs and InP nanoneedles with the base diameters exceeding 1 μm. Here, we report distinct optical characteristics of InP nanoneedles which are varied from mostly zincblende, zincblende/wurtzite-mixed, to pure wurtzite crystalline phase. We achieved, for the first time, pure single-crystal wurtzite-phase InP nanoneedles grown on silicon with bandgaps of 80 meV larger than that of zincblende-phase InP. Being able to attain excellent material quality while scaling up in size promises outstanding device performance of these nanoneedles. At room temperature, a high internal quantum efficiency of 25% and optically pumped lasing are demonstrated for single nanoneedle as-grown on silicon substrate. Recombination dynamics proves the excellent surface quality of the InP nanoneedles, which paves the way toward achieving multijunction photovoltaic cells, long-wavelength heterostructure lasers, and advanced photonic integrated circuits.

Advancements in Root Growth Measurement Technologies and Observation Capabilities for Container-Grown Plants.

Science.gov (United States)

Judd, Lesley A; Jackson, Brian E; Fonteno, William C

2015-07-03

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.

Evaluation of diverse microalgal species as potential biofuel feedstocks grown using municipal wastewater

Directory of Open Access Journals (Sweden)

Sage R Hiibel

2015-05-01

Full Text Available Microalgae offer great potential as a third-generation biofuel feedstock, especially when grown on wastewater, as they have the dual application for wastewater treatment and as a biomass feedstock for biofuel production. The potential for growth on wastewater centrate was evaluated for forty microalgae strains from fresh (11, brackish (11, or saltwater (18 genera. Generally, freshwater strains were able to grow at high concentrations of centrate, with two strains, Neochloris pseudostigmata and N. conjuncta, demonstrating growth at up to 40% v/v centrate. Fourteen of eighteen salt water Dunaliella strains also demonstrated growth in centrate concentrations at or above 40% v/v. Lipid profiles of freshwater strains with high-centrate tolerance were determined using gas chromatography-mass spectrometry (GC-MS and compared against those obtained on cells grown on defined maintenance media. The major lipid compounds were found to be palmitic (16:0, oleic (18:1, and linoleic (18:2 acids for all freshwater strains grown on either centrate or their respective maintenance medium. These results demonstrate the highly concentrated wastewater can be used to grow microalgae, which limits the need to dilute wastewater prior to algal production. In addition, the algae produced generate lipids suitable for biodiesel or green diesel production.

Comparison of the microbiological quality of environmentally friendly and conventionally grown vegetables sold at retail markets in Korea.

Science.gov (United States)

Ryu, Jee-Hoon; Kim, Minju; Kim, Eun-Gyeong; Beuchat, Larry R; Kim, Hoikyung

2014-09-01

Fresh produce is usually eaten raw without cooking or heating, which may increase the probability of foodborne infection. The microbiological quality of 11 types of fresh, raw vegetables (romaine lettuce, sesame leaves, crown daisy, garlic chives, iceberg lettuce, cabbage, broccoli, leek, chili pepper, capsicum, and zucchini) purchased at retail markets in Iksan, Korea as affected by cultivation method (environmentally friendly vegetables [organic, pesticide-free, and low-pesticide vegetables] and conventionally grown vegetables) and harvest season was determined. Escherichia coli O157:H7 and Salmonella were not detected in all samples of vegetables tested. Aerobic mesophiles (>6 log cfu/g) were detected in environmentally friendly romaine lettuce and crown daisy and environmentally friendly and conventionally grown garlic chives, which also contained coliforms (>3 log cfu/g). Sesame leaf and crown daisy (regardless of cultivation method), as well as conventionally grown romaine lettuce and leek, contained >1 log cfu/g of E. coli. The overall microbiological quality of environmentally friendly and conventionally grown vegetables was not significantly different (P > 0.05). However, there were seasonal effects on populations of coliforms and generic E. coli on vegetables. The greatest numbers of microorganisms were isolated from environmentally friendly or conventionally grown vegetables purchased in winter. The vegetables, regardless of cultivation method or season, should be subjected to appropriate antimicrobial treatment to enhance their microbial safety. © 2014 Institute of Food Technologists®

Performance of cowpea grown as an intercrop with maize of different ...

African Journals Online (AJOL)

The negative effects of shade were more pronounced in the semi-determinate cowpea than in the indeterminate. Therefore, in high maize populations, indeterminate spreading cowpeas should be grown; while semi-determinate cowpeas should be planted in low to moderate maize populations because of their intolerance ...

78 FR 23671 - Onions Grown in South Texas; Increased Assessment Rate

Science.gov (United States)

2013-04-22

... behalf. There are approximately 85 producers of onions in the production area and approximately 30... FR] Onions Grown in South Texas; Increased Assessment Rate AGENCY: Agricultural Marketing Service... Texas Onion Committee (Committee) for the 2012-13 and subsequent fiscal periods from $0.025 to $0.03 per...

77 FR 71688 - Avocados Grown in South Florida; Decreased Assessment Rate

Science.gov (United States)

2012-12-04

...; FV12-915-1 FIR] Avocados Grown in South Florida; Decreased Assessment Rate AGENCY: Agricultural... 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 avocados handled. The...

Uptake of perfluorinated alkyl acids by hydroponically grown lettuce (Lactuca sativa)

NARCIS (Netherlands)

Felizeter, S.; McLachlan, M.; de Voogt, P.

2012-01-01

An uptake study was carried out to assess the potential human exposure to perfluorinated alkyl acids (PFAAs) through the ingestion of vegetables. Lettuce (Lactuca sativa) was grown in PFAA-spiked nutrient solutions at four different concentrations, ranging from 10 ng/L to 10 μg/L. Eleven

2-undecanone and 2-tridecanone in field-grown onion.

Science.gov (United States)

Antonious, George F

2013-01-01

A field study was conducted to investigate the impact of soil amendments on concentrations of two volatile organic compounds, 2-undecanone and 2-tridecanone, in onion bulbs. The soil in five plots was mixed with sewage sludge, five plots were mixed with yard waste compost, five plots were mixed with laying hen manure each at 15 t acre(-1), and five unamended plots that never received soil amendments were used for comparison purposes. Plots (n = 20) were planted with onion, Allium cepa L. var. Super Star-F1 bulbs. Gas chromatographic/mass spetrometric (GC/MS) analyses of mature onion bulbs crude extracts revealed the presence of two major fragment ions that correspond to 2-undecanone and 2-tridecanone. Soil amended with yard waste compost enhanced 2-undecanone and 2-tridecanone production by 31 and 59%, respectively. Soil amended with chicken manure enhanced 2-undecanone and 2-tridecanone production by 28 and 43%, respectively. Concentrations of 2-undecanone and 2-tridecanone were lowest in onion bulbs of plants grown in sewage sludge and unamended soil, respectively. The increased concentrations of 2-undecanone and 2-tridecanone in onion bulbs may provide a protective character against insect and spider mite attack in field grown onions.

Anatomical features of pepper plants (Capsicum annuum L.) grown under red light-emitting diodes supplemented with blue or far-red light

Science.gov (United States)

Schuerger, A. C.; Brown, C. S.; Stryjewski, E. C.

1997-01-01

Pepper plants (Capsicum annuum L. cv., Hungarian Wax) were grown under metal halide (MH) lamps or light-emitting diode (LED) arrays with different spectra to determine the effects of light quality on plant anatomy of leaves and stems. One LED (660) array supplied 90% red light at 660 nm (25nm band-width at half-peak height) and 1% far-red light between 700-800nm. A second LED (660/735) array supplied 83% red light at 660nm and 17% far-red light at 735nm (25nm band-width at half-peak height). A third LED (660/blue) array supplied 98% red light at 660nm, 1% blue light between 350-550nm, and 1% far-red light between 700-800nm. Control plants were grown under broad spectrum metal halide lamps. Plants were gron at a mean photon flux (300-800nm) of 330 micromol m-2 s-1 under a 12 h day-night photoperiod. Significant anatomical changes in stem and leaf morphologies were observed in plants grown under the LED arrays compared to plants grown under the broad-spectrum MH lamp. Cross-sectional areas of pepper stems, thickness of secondary xylem, numbers of intraxylary phloem bundles in the periphery of stem pith tissues, leaf thickness, numbers of choloplasts per palisade mesophyll cell, and thickness of palisade and spongy mesophyll tissues were greatest in peppers grown under MH lamps, intermediate in plants grown under the 660/blue LED array, and lowest in peppers grown under the 660 or 660/735 LED arrays. Most anatomical features of pepper stems and leaves were similar among plants grown under 660 or 660/735 LED arrays. The effects of spectral quality on anatomical changes in stem and leaf tissues of peppers generally correlate to the amount of blue light present in the primary light source.

Investigation of in-pile grown corrosion films on zirconium-based alloys

International Nuclear Information System (INIS)

Gebhardt, O.; Hermann, A.; Bart, G.; Blank, H.; Ray, I.L.F.

1996-01-01

In-pile grown corrosion films on different fuel rod claddings (standard Zircaloy-4, extra low tin Zircaloy (ELS), and Zr2.5Nb) have been studied using a variety of experimental techniques. The aim of the investigations was to find out common features and differences between the corrosion layers grown on zirconium alloys having different composition. Methods applied were scanning and transmission electron microscopy (SEM, TEM), electrochemical impedance spectroscopy (EIS), and electrochemical anodization. The morphological differences have been observed between the specimens that could explain the irradiation enhancement of corrosion of Zircaloy-4. The features of the compact oxide close to the oxide/metal interface have been characterized by electrochemical methods. The relationship between the thickness of this protective oxide and the overall oxide thickness has been investigated by EIS. It was found that this relation is dependent on the location of the oxide along the fuel rod and on the corrosion rate

78 FR 43827 - Irish Potatoes Grown in Modoc and Siskiyou Counties, California, and in All Counties in Oregon...

Science.gov (United States)

2013-07-22

... Service 7 CFR Part 947 [Doc. No. AMS-FV-13-0036; FV13-947-1 PR] Irish Potatoes Grown in Modoc and Siskiyou... handling of Irish potatoes grown in Modoc and Siskiyou Counties, California, and in all counties in Oregon... by the Oregon-California Potato Committee (Committee), which recommended termination of the marketing...

Structural characterization of AgGaTe{sub 2} layers grown on a- and c-sapphire substrates by a closed space sublimation method

Energy Technology Data Exchange (ETDEWEB)

Uruno, Aya; Usui, Ayaka [Department of Electrical Engineering and Bioscience, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan); Kobayashi, Masakazu [Department of Electrical Engineering and Bioscience, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan); Kagami Memorial Research Institute for Materials Science and Technology, Waseda University, 2-8-26 Nishiwaseda, Shinjuku, Tokyo 169-0051 (Japan)

2014-07-15

AgGaTe{sub 2} layers were grown on a- and c-plane sapphire substrates by a closed space sublimation method with varying the source temperature. Grown films were evaluated by θ -2θ and pole figure measurements of X-ray diffraction. AgGaTe{sub 2} layers were grown to have strong preference for the (103) orientation. However, it was cleared the Ag{sub 5}Te{sub 3} was formed along with the AgGaTe{sub 2} when the layer was grown on c-plane sapphire. The orientation of the film was analyzed by using the pole figure, and resulted in AgGaTe{sub 2} without Ag{sub 5}Te{sub 3} layers could be grown on a-plane sapphire. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Characterization of as-grown and heavily irradiated GaN epitaxial structures by photoconductivity and photoluminescence

International Nuclear Information System (INIS)

Gaubas, E.; Jurs e-dot nas, S.; Tomasiunas, R.; Vaitkus, J.; Zukauskas, A.; Blue, A.; Rahman, M.; Smith, K.M.

2005-01-01

The influence of radiation defects on photoconductivity transients and photoluminescence (PL) spectra have been examined in semi-insulating GaN epitaxial layers grown on bulk n-GaN/sapphire substrates. Defects induced by 10-keV X-ray irradiation with a dose of 600Mrad and 100-keV neutrons with fluences of 5x10 14 and 10 16 cm -2 have been revealed through contact photoconductivity and microwave absorption transients. The amplitude of the initial photoconductivity decay is significantly reduced by the radiation defect density. A simultaneous decrease with radiation-induced defect density is also observed in the steady-state PL intensity of yellow, blue and ultraviolet bands peaked at 2.18, 2.85, and 3.42eV, respectively. The decrease of the PL intensity is accompanied by an increase of asymptotic decay lifetime, which is due to excess carrier multi-trapping. The decay can be described by the stretched exponential approximation exp[-(t/τ) α ] with different values of α in as-grown material (α∼0.7) and irradiated samples (α∼0.3). The value of the fracton dimension d s of the disordered structure, evaluated as d s =2α/(1-α), changes from 4.7 to 0.86 for as-grown and irradiated material, respectively, implying percolative carrier motion on an infinite cluster of dislocations net in the as-grown material and cluster fragmentation into finite fractons after irradiation

Lignocellulose mineralization by Arctic lake sediments in response to nutrient manipulation

International Nuclear Information System (INIS)

Federle, T.W.; Vestal, J.R.

1980-01-01

Mineralization of specifically labeled 14 C-cellulose- and 14 C-lignin-labeled lignocelluloses by Toolik Lake, Alaska, sediments was examined in response to manipulation of various environmental factors. Mineralization was measured by quantifying the amount of labeled CO 2 released from the specifically labeled substrates. Nitrogen (NH 4 NO 3 ) and, to a greater degree, phosphorus (PO 4 -3 ) additions enhanced the mineralization of white pine (Pinus strobus) cellulose during the summer of 1978. Nitrogen and phosphorus together had no cumulative effect. During the summer of 1979, nitrogen or phosphorus alone had only a slight stimulatory effect on the mineralization of a sedge (Carex aquatilis) cellulose; however, together, they had a dramatic effect. This variable response of mineralization to nutrient addition between 1978 and 1979 was probably attributable to year-to-year variation in nutrient availability within the lake. Cellobiose addition and oxygen depletion inhibited the amount of pine cellulose mineralized. Whereas addition of nitrogen to oxygen-depleted treatments had limited effect, addition of phosphorus resulted in mineralizations equal to or greater than that of the controls. Nitrogen had no effect on mineralization of pine or Carex lignins. Phosphorus, however, inhibited mineralization of both lignins. With Carex lignin, the phosphorus inhibition occurred at a concentration as low as 0.1 μM. The antagonistic role of phosphorus in cellulose and lignin mineralizations may be of significance in understanding the increased proportion of lignin relative to cellulose in decomposing litter

Polyol concentrations in Aspergillus repens grown under salt stress.

Science.gov (United States)

Kelavkar, U P; Chhatpar, H S

1993-09-01

Na(+), K(+) and the ratio of Na(+)/K(+) were higher in cells of the halotolerant Aspergillus repens grown with 2 M NaCl than without NaCl. The osmolytes, proline, glycerol, betaine and glutamate, did not affect the Na(+)/K(+) ratio, nor the polyol content of cells under any conditions. The concentrations of polyols, consisting of glycerol, arabitol, erythritol and mannitol, changed markedly during growth, indicating that they have a crucial role in osmotic adaptation.

Mountain cloud forest and grown-shade coffee plantations: A comparison of tree biodiversity in central Veracruz, Mexico

Energy Technology Data Exchange (ETDEWEB)

González-Zamora, A.; Esperón-Rodríguez, M.; Barradas, V.L.

2016-07-01

Aim of study: The objective of this work is to compare tree diversity and richness among one grown-shade coffee plantation (CAE) and two sites of montane cloud forests, one preserved (MCF1) and other perturbed (MCF2). We also develop an analysis of the importance of coffee plantations as a refuge of tree species, holding a potential role for conservation. Area of study: Our study area is the coffee region of Coatepec-Xico, in the state of Veracruz, Mexico. Material and methods: We compiled a list of all tree species in each site to determine tree diversity and floristic similarity (dissimilarity). We used different similarity indices and a cluster analysis to show relations among sites. Main results: 2721 individuals from 154 species were registered in the montane cloud forests as a whole. In the grown-shade coffee plantation we registered 2947 individuals from 64 species. The most similar sites were the perturbed montane cloud forest and the grown-shade coffee plantation and the least similar were the preserved montane cloud forest and the grown-shade coffee plantation. The high biodiversity found in all sites and the differences in tree composition between the two montane cloud forests supports evidence of the ecosystems richness in the region. Research highlight: Diversity differences among sites determine that the grown-shade coffee plantation is not substitute for montane cloud forest. CAE’s are developed under similar environmental conditions than the MCF; therefore, coexistence and recombination (replacement) of species make them particularly complementary. CAE’s in Veracruz have a potential role as refuge for biodiversity. (Author)

Atomic structure of defects in GaN:Mg grown with Ga polarity

International Nuclear Information System (INIS)

Liliental-Weber, Z.; Tomaszewicz, T.; Zakharov, D.; Jasinski, J.; O'Keefe, M.A.; Hautakangas, S.; Laakso, A.; Saarinen, K.

2003-01-01

Electron microscope phase images, produced by direct reconstruction of the scattered electron wave from a focal series of high-resolution images, were used to determine the nature of defects formed in GaN:Mg crystals. We studied bulk crystals grown from dilute solutions of atomic nitrogen in liquid gallium at high pressure and thin films grown by the MOCVD method. All the crystals were grown with Ga-polarity. In both types of samples the majority of defects were three dimensional Mg-rich hexagonal pyramids with bases on the (0001) plane and six walls on {11(und 2)3} planes seen in cross-section as triangulars. Some other defects appear in cross-section as trapezoidal (rectangular) defects as a result of presence of truncated pyramids. Both type of defects have hollow centers. They are decorated by Mg on all six side walls and a base. The GaN which grows inside on the defect walls shows polarity inversion. It is shown that change of polarity starts from the defect tip and propagates to the base, and that the stacking sequence changes from ab in the matrix to bc inside the defect. Exchange of the Ga sublattice with the N sublattice within the defect leads to 0.6 ± 0.2(angstrom) displacement between Ga sublattices outside and inside the defects. It is proposed that lateral overgrowth of the cavities formed within the defect takes place to restore matrix polarity on the defect base

Inflorescence and leaves essential oil composition of hydroponically grown Ocimum basilicum L

Directory of Open Access Journals (Sweden)

MOHAMMAD BAGHER HASSANPOURAGHDAM

2010-10-01

Full Text Available In order to characterize the essential oils of leaves and inflorescences, water distilled volatile oils of hydroponically grown Ocimum basilicum L. were analyzed by GC/EI-MS. Fifty components were identified in the inflorescence and leaf essential oils of the basil plants, accounting for 98.8 and 99.9 % of the total quantified components respectively. Phenylpropanoids (37.7 % for the inflorescence vs. 58.3 % for the leaves were the predominant class of oil constituents, followed by sesquiterpenes (33.3 vs. 19.4 % and monoterpenes (27.7 vs. 22.1 %. Of the monoterpenoid compounds, oxygenated monoterpenes (25.2 vs. 18.9 % were the main subclass. Sesquiterpene hydrocarbons (25 vs. 15.9 % were the main subclass of sesquiterpenoidal compounds. Methyl chavicol, a phenylpropane derivative, (37.2 vs. 56.7 % was the principle component of both organ oils, with up to 38 and 57 % of the total identified components of the inflorescence and leaf essential oils, respectively. Linalool (21.1 vs. 13.1 % was the second common major component followed by α-cadinol (6.1 vs. 3 %, germacrene D (6.1 vs. 2.7 % and 1,8-cineole (2.4 vs. 3.5 %. There were significant quantitative but very small qualitative differences between the two oils. In total, considering the previous reports, it seems that essential oil composition of hydroponically grown O. basilicum L. had volatile constituents comparable with field grown counterparts, probably with potential applicability in the pharmaceutical and food industries.

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

Science.gov (United States)

2011-05-31

... forms to collect information related to the Federal marketing orders for nectarines and peaches grown in... FURTHER INFORMATION CONTACT: Andrew Hatch, Supervisory Marketing Specialist, Marketing Order... Email: [email protected] . SUPPLEMENTARY INFORMATION: Marketing Order Nos. 916 and 917...

Characterization of GaN/AlGaN epitaxial layers grown by ...

Indian Academy of Sciences (India)

GaN and AlGaN epitaxial layers are grown by a metalorganic chemical ... reported by introducing annealing of the GaN layer in nitrogen [5], Fe doping [6], .... [2] Y F Wu, S M Wood, R P Smith, S Sheppard, S T Allen, P Parikh and J Milligan,.

78 FR 48285 - Irish Potatoes Grown in Washington; Decreased Assessment Rate

Science.gov (United States)

2013-08-08

...; FV13-946-1 FIR] Irish Potatoes Grown in Washington; Decreased Assessment Rate AGENCY: Agricultural... established for the State of Washington Potato Committee (Committee) for the 2013-2014 fiscal year and all subsequent fiscal periods from $0.003 to $0.0025 per hundredweight of potatoes handled. The Committee locally...

Trace gas emissions from a sun and shade grown ornamental crop

Science.gov (United States)

Previous work has begun to establish baseline approximations for greenhouse gas (GHG) (CO2, CH4, and N2O) emissions of several horticultural crops, though much work is still needed to expand contingencies for multiple best management practices. In this study, GHG emissions from one shade-grown speci...

78 FR 57099 - Avocados Grown in South Florida; Increased Assessment Rate

Science.gov (United States)

2013-09-17

... Service 7 CFR Part 915 [Doc. No. AMS-FV-13-0054; FV13-915-2 PR] Avocados Grown in South Florida; Increased... rule would increase the assessment rate established for the Avocado Administrative Committee (Committee... Florida avocados handled. The Committee locally administers the marketing order, which regulates the...

78 FR 8047 - Onions Grown in South Texas; Increased Assessment Rate

Science.gov (United States)

2013-02-05

... Executive Order 12988, Civil Justice Reform. Under the marketing order now in effect, South Texas onion... DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 959 [Doc. No. AMS-FV-12-0039; FV12-959-1 PR] Onions Grown in South Texas; Increased Assessment Rate AGENCY: Agricultural Marketing...

Biogeochemical spatio-temporal transformation of copper in Aspergillus niger colonies grown on malachite with different inorganic nitrogen sources.

Science.gov (United States)

Fomina, Marina; Bowen, Andrew D; Charnock, John M; Podgorsky, Valentin S; Gadd, Geoffrey M

2017-03-01

This work elucidates spatio-temporal aspects of the biogeochemical transformation of copper mobilized from malachite (Cu 2 (CO 3 )(OH) 2 ) and bioaccumulated within Aspergillus niger colonies when grown on different inorganic nitrogen sources. It was shown that the use of either ammonium or nitrate determined how copper was distributed within the colony and its microenvironment and the copper oxidation state and succession of copper coordinating ligands within the biomass. Nitrate-grown colonies yielded ∼1.7× more biomass, bioaccumulated ∼7× less copper, excreted ∼1.9× more oxalate and produced ∼1.75× less water-soluble copper in the medium in contrast to ammonium-grown colonies. Microfocus X-ray absorption spectroscopy revealed that as the mycelium matured, bioaccumulated copper was transformed from less stable and more toxic Cu(I) into less toxic Cu(II) which was coordinated predominantly by phosphate/malate ligands. With time, a shift to oxalate coordination of bioaccumulated copper occurred in the central older region of ammonium-grown colonies. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

Flat-Top and Stacking-Fault-Free GaAs-Related Nanopillars Grown on Si Substrates

Directory of Open Access Journals (Sweden)

Kouta Tateno

2012-01-01

Full Text Available The VLS (vapor-liquid-solid method is one of the promising techniques for growing vertical III-V compound semiconductor nanowires on Si for application to optoelectronic circuits. Heterostructures grown in the axial direction by the VLS method and in the radial direction by the general layer-by-layer growth method make it possible to fabricate complicated and functional three-dimensional structures in a bottom-up manner. We can grow some vertical heterostructure nanopillars with flat tops on Si(111 substrates, and we have obtained core-multishell Ga(InP/GaAs/GaP nanowires with flat tops and their air-gap structures by using selective wet etching. Simulations indicate that a high- factor of over 2000 can be achieved for this air-gap structure. From the GaAs growth experiments, we found that zincblende GaAs without any stacking faults can be grown after the GaP nanowire growth. Pillars containing a quantum dot and without stacking faults can be grown by using this method. We can also obtain flat-top pillars without removing the Au catalysts when using small Au particles.

Microarray Data Analysis of Space Grown Arabidopsis Leaves for Genes Important in Vascular Patterning

Science.gov (United States)

Weitzeal, A. J.; Wyatt, S. E.; Parsons-Wingerter, P.

2016-01-01

Venation patterning in leaves is a major determinant of photosynthesis efficiency because of its dependency on vascular transport of photoassimilates, water, and minerals. Arabidopsis thaliana grown in microgravity show delayed growth and leaf maturation. Gene expression data from the roots, hypocotyl, and leaves of A. thaliana grown during spaceflight vs. ground control analyzed by Affymetrix microarray are available through NASAs GeneLab (GLDS-7). We analyzed the data for differential expression of genes in leaves resulting from the effects of spaceflight on vascular patterning. Two genes were found by preliminary analysis to be upregulated during spaceflight that may be related to vascular formation. The genes are responsible for coding an ARGOS like protein (potentially affecting cell elongation in the leaves), and an F-boxkelch-repeat protein (possibly contributing to protoxylem specification). Further analysis that will focus on raw data quality assessment and a moderated t-test may further confirm upregulation of the two genes and/or identify other gene candidates. Plants defective in these genes will then be assessed for phenotype by the mapping and quantification of leaf vascular patterning by NASAs VESsel GENeration (VESGEN) software to model specific vascular differences of plants grown in spaceflight.

Gentamicin-Eluting Titanium Dioxide Nanotubes Grown on the Ultrafine-Grained Titanium.

Science.gov (United States)

Nemati, Sima Hashemi; Hadjizadeh, Afra

2017-08-01

Titanium (Ti)-based materials is the most appropriate choices for the applications as orthopedic and dental implants. In this regard, ultrafine-grained (UFG) titanium with an enhanced mechanical properties and surface energy has attracted more attention. Titanium dioxide (TiO 2 ) nanotubes grown on the titanium could enhance bone bonding, cellular response and are good reservoirs for loading drugs and antibacterial agents. This article investigates gentamicin loading into and release from the TiO 2 nanotubes, grown on the UFG compared to coarse-grained (CG) titanium substrate surfaces. Equal Channel Angular Pressing (ECAP) was employed to produce the UFG structure titanium. TiO 2 nanotubes were grown by the anodizing technique on both UFG and CG titanium substrate surfaces. Scanning electron microscopy (SEM) imaging confirmed TiO 2 nanotube growth on the surface. The UV-vis spectroscopy analysis results show that the amount of gentamicin load-release in the anodized UFG titanium sample is higher than that of CG one which can be explained in terms of thicker TiO 2 nanotube arrays layer formed on UFG sample. Moreover, the anodized UFG titanium samples released the drug in a longer time than CG (1 day for the UFG titanium vs. 3 h for the CG one). Regarding wettability analysis, anodized UFG titanium sample showed more enhanced hydrophilicity than CG counterpart. Therefore, the significantly smaller grain size of pure titanium provided by the ECAP technique coupled with appropriate subsequent anodization treatment not only offers a good combination of biocompatibility and adequate mechanical properties but also it provides a delayed release condition for gentamicin.

Comparison of defence responses to Botrytis cinerea infection in tomato plants propagated in vitro and grown in vivo

Directory of Open Access Journals (Sweden)

Jacek Patykowski

2013-12-01

Full Text Available Defence reactions: O2 - generation, superoxide dismutase, catalase, guaiacol peroxidase and ascorbate peroxidase activities after B. cinerea infection in tomato plants propagated in vitro and grown in vivo have been compared. Infection resulted in rapid O2 - generation. Superoxide dismutase activity increase was slower than O2 - response. In plants propagated in vitro catalase and guaiacol peroxidase activities after infection were induced less strongly than in plants grown in vivo. K2HPO4 pretreatment of plants grown in vitro enhanced significantly the activities of catalase and guaiacol peroxidase after infection. Slight restriction of B. cinerea infection development in in vitro propagated plants pretreated with K2HP04 was observed.

Thermally oxidized formation of new Ge dots over as-grown Ge dots in the Si capping layer

International Nuclear Information System (INIS)

Nie Tianxiao; Lin Jinhui; Shao Yuanmin; Wu Yueqin; Yang Xinju; Fan Yongliang; Jiang Zuimin; Chen Zhigang; Zou Jin

2011-01-01

A Si-capped Ge quantum dot sample was self-assembly grown via Stranski-Krastanov mode in a molecular beam epitaxy system with the Si capping layer deposited at 300 deg. C. After annealing the sample in an oxygen atmosphere at 1000 deg. C, a structure, namely two layers of quantum dots, was formed with the newly formed Ge-rich quantum dots embedded in the oxidized matrix with the position accurately located upon the as-grown quantum dots. It has been found that the formation of such nanostructures strongly depends upon the growth temperature and oxygen atmosphere. A growth mechanism was proposed to explain the formation of the nanostructure based on the Ge diffusion from the as-grown quantum dots, Ge segregation from the growing oxide, and subsequent migration/agglomeration.

Photoluminescence properties of ZnO thin films grown by using the hydrothermal technique

International Nuclear Information System (INIS)

Sahoo, Trilochan; Jang, Leewoon; Jeon, Juwon; Kim, Myoung; Kim, Jinsoo; Lee, Inhwan; Kwak, Joonseop; Lee, Jaejin

2010-01-01

The photoluminescence properties of zinc-oxide thin films grown by using the hydrothermal technique have been investigated. Zinc-oxide thin films with a wurtzite symmetry and c-axis orientation were grown in aqueous solution at 90 .deg. C on sapphire substrates with a p-GaN buffer layer by using the hydrothermal technique. The low-temperature photoluminescence analysis revealed a sharp bound-exciton-related luminescence peak at 3.366 eV with a very narrow peak width. The temperature-dependent variations of the emission energy and of the integrated intensity were studied. The activation energy of the bound exciton complex was calculated to be 7.35 ± 0.5 meV from the temperature dependent quenching of the integral intensities.

Radioactivity in tomatoes grown on mine tailings from Oka, a niobium mining region

International Nuclear Information System (INIS)

Boulet, M.; Boudreau, A.; Roy, J.C.

1983-01-01

The radioactivity contained in the tailings of a niobium mine in the Oka region, Quebec, was the object of concern for the population of the area in 1979. To find the impact of these tailings on fruit and vegetables grown in this environment, an investigation of the radioactivity found on tomatoes grown in green houses in niobium tailings and in vermiculites was undertaken. The tailings contained a high level of natural radioactivity and a small amount of 137 Cs while the vermiculites had a very low level of natural radioactivity and an appreciable amount of 137 Cs. Cesium-137 was the only nuclide detected in tomato ashes in measurable quantity. Absence of natural radioactivity is explained by its presence as insoluble minerals

Enhanced electrochemical activity using vertically aligned carbon nanotube electrodes grown on carbon fiber

Directory of Open Access Journals (Sweden)

Evandro Augusto de Morais

2011-09-01

Full Text Available Vertically aligned carbon nanotubes were successfully grown on flexible carbon fibers by plasma enhanced chemical vapor deposition. The diameter of the CNT is controllable by adjusting the thickness of the catalyst Ni layer deposited on the fiber. Vertically aligned nanotubes were grown in a Plasma Enhanced Chemical Deposition system (PECVD at a temperature of 630 ºC, d.c. bias of -600 V and 160 and 68 sccm flow of ammonia and acetylene, respectively. Using cyclic voltammetry measurements, an increase of the surface area of our electrodes, up to 50 times higher, was observed in our samples with CNT. The combination of VACNTs with flexible carbon fibers can have a significant impact on applications ranging from sensors to electrodes for fuel cells.

A comparison of nitrate level in spinach grown both under different densities in aquaponic system and under natural growth conditions

Directory of Open Access Journals (Sweden)

Ştefan Mihai PETREA

2013-12-01

Full Text Available As bio-integrated systems that link both plants and fish culture, inside aquaponic systems, the processes of ammonia-oxidizing and nitrification in nitrite and nitrate are essential for growth and development of both fish and plants culture biomass. Plants with nearly the same nutritional requirements during their life cycle, like spinach in our case, are recommended to be grown under aquaponic conditions. Although nitrates concentrations up to 200 – 250mg/l are reported to be acceptable for fish growth, in the last years the toxic effect of long term exposure to high nitrate levels on fish and plants cultured biomass were highlighted. The main goal of the present study is to compare the nitrate level of spinach, grown in an aquaponic system, under three plant densities (V1 - 59 plants/m2, V2 - 48plants/m2 and V3 – 39 plants/m2. The second objective is to compare the results obtained, in term of nitrate content, for spinach grown in the integrated rainbow trout – spinach aquaponic system with those of marketable spinach, grown under conventional condition, in the field. The experimental design consists in a recirculating aquaculture system with 12 growing units, mechanical and biological water treatment units and four aquaponic units. Fish were fed with two types of feed with 41% and 50% protein, using 3 different feeding regimes. The results show a higher nitrate level on spinach grown in aquaponic system, compared to the one derived from field culture. Differences were observed also among the three variants grown in aquaponic conditions, under different plant densities. As a conclusion, it can be said that considering the nitrate level, spinach grown in aquaponic system is marketable.

Crystalline perfection and mechanical investigations on vertical Bridgman grown Bismuth telluride (Bi{sub 2}Te{sub 3}) single crystals for thermoelectric applications

Energy Technology Data Exchange (ETDEWEB)

Krishna, Anuj [Academy of Scientific and Innovative Research, CSIR- National Physical Laboratory, New Delhi 110012 (India); X-ray Analysis and Crystal Growth Section, CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012 (India); Vijayan, N., E-mail: nvijayan@nplindia.org [X-ray Analysis and Crystal Growth Section, CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012 (India); Singh, Budhendra [TEMA-NRD, Mechanical Engineering Department and Aveiro Institute of Nanotechnology (AIN), University of Aveiro, 3810-193 Aveiro (Portugal); Thukral, Kanika [Academy of Scientific and Innovative Research, CSIR- National Physical Laboratory, New Delhi 110012 (India); X-ray Analysis and Crystal Growth Section, CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012 (India); Maurya, K.K. [X-ray Analysis and Crystal Growth Section, CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012 (India)

2016-03-07

High efficiency thermoelectric materials plays a vital role in power generation and refrigeration applications. Bismuth telluride (Bi{sub 2}Te{sub 3}) is one among them. In the present work single crystal of bismuth telluride was grown using vertical Bridgman technique. The phase of grown crystals was analysed using a powder X-ray diffractometer. Quality of the grown crystal was assessed by using high resolution X-ray diffractometer and observed that it is fairly good. Further mechanical investigations on grown crystal was carried out using nano-indentation technique and various mechanical properties like hardness, stiffness and Young’s modulus were evaluated. Observed results clearly indicate its suitability for thermoelectric applications.

Alkane-grown Beauveria bassiana produce mycelial pellets displaying peroxisome proliferation, oxidative stress, and cell surface alterations.

Science.gov (United States)

Huarte-Bonnet, Carla; Paixão, Flávia R S; Ponce, Juan C; Santana, Marianela; Prieto, Eduardo D; Pedrini, Nicolás

2018-06-01

The entomopathogenic fungus Beauveria bassiana is able to grow on insect cuticle hydrocarbons, inducing alkane assimilation pathways and concomitantly increasing virulence against insect hosts. In this study, we describe some physiological and molecular processes implicated in growth, nutritional stress response, and cellular alterations found in alkane-grown fungi. The fungal cytology was investigated using light and transmission electron microscopy while the surface topography was examined using atomic force microscopy. Additionally, the expression pattern of several genes associated with oxidative stress, peroxisome biogenesis, and hydrophobicity were analysed by qPCR. We found a novel type of growth in alkane-cultured B. bassiana similar to mycelial pellets described in other alkane-free fungi, which were able to produce viable conidia and to be pathogenic against larvae of the beetles Tenebrio molitor and Tribolium castaneum. Mycelial pellets were formed by hyphae cumulates with high peroxidase activity, exhibiting peroxisome proliferation and an apparent surface thickening. Alkane-grown conidia appeared to be more hydrophobic and cell surfaces displayed different topography than glucose-grown cells. We also found a significant induction in several genes encoding for peroxins, catalases, superoxide dismutases, and hydrophobins. These results show that both morphological and metabolic changes are triggered in mycelial pellets derived from alkane-grown B. bassiana. Copyright © 2017 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

EXAFS investigations on PbMoO4 single crystals grown under ...

Indian Academy of Sciences (India)

Abstract. Extended X-ray absorption fine structure (EXAFS) measurements on PbMoO4 (LMO) crystals have been performed at the recently-commissioned dispersive EXAFS beamline (BL-8) of INDUS-2 Synchrotron facility at Indore, India. The LMO samples were prepared under three different conditions viz. (i) grown from ...

Stress evolution of GaN/AlN heterostructure grown on 6H-SiC substrate by plasma assisted molecular beam epitaxy

Science.gov (United States)

Agrawal, M.; Ravikiran, L.; Dharmarasu, N.; Radhakrishnan, K.; Karthikeyan, G. S.; Zheng, Y.

2017-01-01

The stress evolution of GaN/AlN heterostructure grown on 6H-SiC substrate by plasma assisted molecular beam epitaxy (PA-MBE) has been studied. AlN nucleation layer and GaN layer were grown as a function of III/V ratio. GaN/AlN structure is found to form buried cracks when AlN is grown in the intermediate growth regime(III/V˜1)and GaN is grown under N-rich growth regime (III/VHEMT) heterostructure was demonstrated on 2-inch SiC that showed good two dimensional electron gas (2DEG) properties with a sheet resistance of 480 Ω/sq, mobility of 1280 cm2/V.s and sheet carrier density of 1×1013 cm-2.

Characterization of ZnO thin films grown on different p-Si substrate elaborated by solgel spin-coating method

Energy Technology Data Exchange (ETDEWEB)

Chebil, W., E-mail: Chbil.widad@live.fr [Laboratoire Physico-chimie des Matériaux, Unité de Service Commun de Recherche “High resolution X-ray diffractometer”, Département de Physique, Université de Monastir, Faculté des Sciences de Monastir, Avenue de l’Environnement, 5019 Monastir (Tunisia); Fouzri, A. [Laboratoire Physico-chimie des Matériaux, Unité de Service Commun de Recherche “High resolution X-ray diffractometer”, Département de Physique, Université de Monastir, Faculté des Sciences de Monastir, Avenue de l’Environnement, 5019 Monastir (Tunisia); Institut Supérieur des Sciences Appliquées et de Technologie de Sousse, Université de Sousse (Tunisia); Fargi, A. [Laboratoire de Microélectronique et Instrumentation, Faculté des Sciences de Monastir, Université de Monastir, Avenue de l’environnement, 5019 Monastir (Tunisia); Azeza, B.; Zaaboub, Z. [Laboratoire Micro-Optoélectroniques et Nanostructures, Faculté des Sciences de Monastir, Université de Monastir, Avenue de l' environnement, 5019 Monastir (Tunisia); and others

2015-10-15

Highlights: • High quality ZnO thin films grown on different p-Si substrates were successful obtained by sol–gel process. • PL measurement revealed that ZnO thin film grown on porous Si has the better optical quality. • I–V characteristics for all heterojunctions exhibit successful diode formation. • The diode ZnO/PSi shows a better photovoltaic effect under illumination with a maximum {sub Voc} of 0.2 V. - Abstract: In this study, ZnO thin films are deposited by sol–gel technique on p-type crystalline silicon (Si) with [100] orientation, etched silicon and porous silicon. The structural analyses showed that the obtained thin films were polycrystalline with a hexagonal wurtzite structure and preferentially oriented along the c-axis direction. Morphological study revealed the presence of rounded and facetted grains irregularly distributed on the surface of all samples. PL spectra at room temperature revealed that ZnO thin film grown on porous Si has a strong UV emission with low defects in the visible region comparing with ZnO grown on plat Si and etched Si surface. The heterojunction parameters were evaluated from the (I–V) under dark and illumination at room temperature. The ideality factor, barrier height and series resistance of heterojunction grown on different p-Si substrates are determined by using different methods. Best electrical properties are obtained for ZnO layer deposited on porous silicon.

Sb-related defects in Sb-doped ZnO thin film grown by pulsed laser deposition

Science.gov (United States)

Luo, Caiqin; Ho, Lok-Ping; Azad, Fahad; Anwand, Wolfgang; Butterling, Maik; Wagner, Andreas; Kuznetsov, Andrej; Zhu, Hai; Su, Shichen; Ling, Francis Chi-Chung

2018-04-01

Sb-doped ZnO films were fabricated on c-plane sapphire using the pulsed laser deposition method and characterized by Hall effect measurement, X-ray photoelectron spectroscopy, X-ray diffraction, photoluminescence, and positron annihilation spectroscopy. Systematic studies on the growth conditions with different Sb composition, oxygen pressure, and post-growth annealing were conducted. If the Sb doping concentration is lower than the threshold ˜8 × 1020 cm-3, the as-grown films grown with an appropriate oxygen pressure could be n˜4 × 1020 cm-3. The shallow donor was attributed to the SbZn related defect. Annealing these samples led to the formation of the SbZn-2VZn shallow acceptor which subsequently compensated for the free carrier. For samples with Sb concentration exceeding the threshold, the yielded as-grown samples were highly resistive. X-ray diffraction results showed that the Sb dopant occupied the O site rather than the Zn site as the Sb doping exceeded the threshold, whereas the SbO related deep acceptor was responsible for the high resistivity of the samples.

Factors Affecting Isoflavone Content in Soybean Seeds Grown in Thailand

Directory of Open Access Journals (Sweden)

Supanimit Teekachunhatean

2013-01-01

Full Text Available Soybeans are the most common source of isoflavones in human foods. The objectives of this study were to determine the effects of Thai soybean variety, planting date, physical seed quality, storage condition, planting location, and crop year on isoflavone content, as well as to analyze the relationship between seed viability and isoflavone content in soybean seeds grown in Thailand. Isoflavone content in Thai soybeans varied considerably depending on such factors as variety, physical seed quality, crop year, planting date (even in the same crop year, and planting location. Most varieties (except for Nakhon Sawan 1 and Sukhothai 1 had significantly higher isoflavone content when planted in early rather than in late dry season. Additionally, seed viability as well as long-term storage at 10∘C or at ambient condition seemed unlikely to affect isoflavone content in Thai soybean varieties. Isoflavone content in soybean seeds grown in Thailand depends on multiple genetic and environmental factors. Some varieties (Nakhon Sawan 1 and Sukhothai 1 exhibited moderately high isoflavone content regardless of sowing date. Soybeans with decreased seed viability still retained their isoflavone content.

Weak localization behavior observed in graphene grown on germanium substrate

Directory of Open Access Journals (Sweden)

Yinbo Sun

2018-04-01

Full Text Available Two dimensional electron systems (2DES usually show the weak localization behavior in consequence of electron interaction in the limited dimension. Distinct from other 2DES, the monolayer graphene, due to the chirality, exhibits unique weak localization behavior sensitive to not only inelastic but also elastic carrier scattering. Grain boundaries, which usually exist in monolayer graphene, are apparently related to the elastic carrier scattering process, thus affecting the weak localization behavior. However, their effect is scarcely studied due to the lack of an ideal platform. Here, a complementary system consisting of both single-crystalline graphene grown on Ge (110 and poly-crystalline graphene grown on Ge (111 is constructed. From the comparison of magnetoresistivity measurements, the weak localization effect is found to be greatly enhanced for the poly-crystalline graphene on Ge(111 compared to the single-crystalline graphene on Ge(110. The degraded transport performance in graphene/Ge(111 is due to the presence of grain boundary in poly-crystalline graphene, which results in the enhanced elastic intervalley scattering. In addition, the inelastic scattering originating from the strong electron-electron interaction at low temperature also contributes to weak localization of poly-crystalline graphene/Ge(111.

Creep properties of a thermally grown alumina

Energy Technology Data Exchange (ETDEWEB)

Kang, K.J. [Department of Mechanical Engineering, Chonnam National University, Kwangju 500-757 (Korea, Republic of)], E-mail: kjkang@chonnam.ac.kr; Mercer, C. [Materials Department, University of California, Santa Barbara, CA 93106-5050 (United States)

2008-04-15

A unique test system has been developed to measure creep properties of actual thermally grown oxides (TGO) formed on a metal foil. The thickness of TGO, load and displacement can be monitored in situ at high temperature. Two batches of FeCrAlY alloys which differ from each other in contents of yttrium and titanium were selected as the {alpha}-Al{sub 2}O{sub 3} TGO forming materials. The creep tests were performed on {alpha}-Al{sub 2}O{sub 3} of thickness 1-4 {mu}m, thermally grown at 1200 deg. C in air. The strength of the substrate was found to be negligible, provided that the TGO and substrate thickness satisfy: h{sub TGO} > 1 {mu}m and H{sub sub} {<=} 400 {mu}m. The steady-state creep results for all four TGO thicknesses obtained on batch I reside within a narrow range, characterized by a parabolic creep relation. It is nevertheless clear that the steady-state creep rates vary with TGO thickness: decreasing as the thickness increases. For batch II, the steady-state creep rates are higher and now influenced more significantly by TGO thickness. In comparison with previous results of the creep properties for bulk polycrystalline {alpha}-Al{sub 2}O{sub 3} at a grain size of {approx}2 {mu}m, the creep rates for the TGO were apparently higher, but both were significantly affected by yttrium content. The higher creep rate and dependency on the TGO thickness led to a hypothesis that the deformation of the TGO under tensile stress at high temperature was not a result of typical creep mechanisms such as diffusion of vacancies or intra-granular motion of dislocations, but a result of inter-grain growth of TGO. Results also indicate that the amount of yttrium may influence the growth strain as well as the creep rate.

Microarray Data Analysis of Space Grown Arabidopsis Leaves for Genes Important in Vascular Patterning. Analysis of Space Grown Arabidopsis with Microarray Data from GeneLab: Identification of Genes Important in Vascular Patterning

Science.gov (United States)

Weitzel, A. J.; Wyatt, S. E.; Parsons-Wingerter, P.

2016-01-01

Venation patterning in leaves is a major determinant of photosynthesis efficiency because of its dependency on vascular transport of photo-assimilates, water, and minerals. Arabidopsis thaliana grown in microgravity show delayed growth and leaf maturation. Gene expression data from the roots, hypocotyl, and leaves of A. thaliana grown during spaceflight vs. ground control analyzed by Affymetrix microarray are available through NASA's GeneLab (GLDS-7). We analyzed the data for differential expression of genes in leaves resulting from the effects of spaceflight on vascular patterning. Two genes were found by preliminary analysis to be up-regulated during spaceflight that may be related to vascular formation. The genes are responsible for coding an ARGOS (Auxin-Regulated Gene Involved in Organ Size)-like protein (potentially affecting cell elongation in the leaves), and an F-box/kelch-repeat protein (possibly contributing to protoxylem specification). Further analysis that will focus on raw data quality assessment and a moderated t-test may further confirm up-regulation of the two genes and/or identify other gene candidates. Plants defective in these genes will then be assessed for phenotype by the mapping and quantification of leaf vascular patterning by NASA's VESsel GENeration (VESGEN) software to model specific vascular differences of plants grown in spaceflight.

Complex impedance spectroscopy of alkali impurities in as-grown, irradiated and annealed quartz

International Nuclear Information System (INIS)

Devautour-Vinot, S.; Cambon, O.; Prud'homme, N.; Giuntini, J. C.; Boy, J.-J.; Cibiel, G.

2007-01-01

This work compares the dielectric relaxation properties of different crystalline quartz materials, according to their source (natural or synthetics). It is shown that these relaxation properties are due to a hopping process of alkaline (Li + , Na + , and K + ) impurities located near [Al-O 4 ] 5- tetrahedra. A detailed analysis, in terms of the distribution function of the dielectric loss peak, allowed us to perfectly distinguish the different types of as-grown quartz. We show that (i) the natural quartz has less stable M + charge carriers than the synthetic materials and that (ii) the homogeneity of the M + trapping sites, created by the [Al-O 4 ] 5- tetrahedra, strongly depends on the crystal growth conditions. These features were then studied using quartz samples with different treatment conditions: as-grown, irradiated, or annealed at high temperature. We propose that the irradiation greatly facilitates the M + relaxation, by creating additional low energy M + hosting sites, whose number depends on the source of the quartz crystals. We also show that for 100 krad irradiation, the saturation state of the defects is already reached for all the materials under consideration. Finally, we propose that the irradiation followed by annealing at 450 deg. C improves the M + stability and homogeneity in quartz materials, compared with the as-grown materials, this trend being much more relevant for the natural than for the synthetic quartz

Biological Control of Diseases of Vegetables Grown Hydroponically in Thailand: Challenge and Opportunity.

Science.gov (United States)

Kanjanamaneesathian, Mana

2015-01-01

In Thailand, yield loss due to plant diseases in vegetables grown hydroponically is very high as a result of the growers` lack of knowledge for controlling diseases and their un- willingness to invest in setting-up the proper hydroponic system from the beginning. Severe root rot disease caused by Pythium spp. is frequent and can be anticipated in the hot climate in Thailand. This review focuses on the diseases in temperate lettuces which have been produced hydroponically and have been attacked by plant pathogens, particularly Pythium spp. Biological control of vegetable diseases grown hydroponically has been investigated in Thailand. Research is being carried out to identify effective strains of the antagonists, formulating the applicable products and delivering them appropriately to control the disease. Products of Bacillus subtilis, Chaetomium globosom and Trichoderma harzianum have been recommended for use to control diseases in vegetables grown hydroponically. Control efficacy of these products is varied as the biological products have been used by the growers in the paradigm of using chemical fungicide for disease control in hydroponic production system, overlooking the intrinsic characteristics of the biological control products. The recent patent, which minimizes the effects of sunlight and heat on the nutrient solution without the use of an external energy for cooling the nutrient, should be applied in producing hydroponic vegetables to mitigate poor plant growth and root rot disease outbreak in Thailand.

Acclimation of aerobic-activated sludge degrading benzene derivatives and co-metabolic degradation activities of trichloroethylene by benzene derivative-grown aerobic sludge.

Science.gov (United States)

Wang, Shizong; Yang, Qi; Bai, Zhiyong; Wang, Shidong; Wang, Yeyao; Nowak, Karolina M

2015-01-01

The acclimation of aerobic-activated sludge for degradation of benzene derivatives was investigated in batch experiments. Phenol, benzoic acid, toluene, aniline and chlorobenzene were concurrently added to five different bioreactors which contained the aerobic-activated sludge. After the acclimation process ended, the acclimated phenol-, benzoic acid-, toluene-, aniline- and chlorobenzene-grown aerobic-activated sludge were used to explore the co-metabolic degradation activities of trichloroethylene (TCE). Monod equation was employed to simulate the kinetics of co-metabolic degradation of TCE by benzene derivative-grown sludge. At the end of experiments, the mixed microbial communities grown under different conditions were identified. The results showed that the acclimation periods of microorganisms for different benzene derivatives varied. The maximum degradation rates of TCE for phenol-, benzoic acid-, toluene-, aniline- and chlorobenzene-grown aerobic sludge were 0.020, 0.017, 0.016, 0.0089 and 0.0047 mg g SS(-1) h(-1), respectively. The kinetic of TCE degradation in the absence of benzene derivative followed Monod equation well. Also, eight phyla were observed in the acclimated benzene derivative-grown aerobic sludge. Each of benzene derivative-grown aerobic sludge had different microbial community composition. This study can hopefully add new knowledge to the area of TCE co-metabolic by mixed microbial communities, and further the understanding on the function and applicability of aerobic-activated sludge.

A mutation (radA100) in Escherichia coli that selectively sensitizes cells grown in rich medium to X- or U.V.-radiation, or methyl methanesulphonate

International Nuclear Information System (INIS)

Diver, W.P.; Sargentini, N.J.; Smith, K.C.

1982-01-01

The radA100 mutant was isolated from Escherichia coli K-12 after mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine and selection for gamma radiation sensitivity. The radA100 mutation sensitized stationary phase cells to X-rays if they had been grown in glucose-supplemented rich medium, but not if they had been grown in nonsupplemented rich medium (indicating a defect in glucose-induced resistance). Similarly, logarithmic phase cells were sensitized to X-rays, U.V. radiation and methyl methanesulphonate if they had been grown in rich medium, but not if they had been grown in minimal medium (indicating a defect in medium-dependent resistance). Relative to the wild-type strain, the radA100 mutant was deficient in the repair of X-ray-induced DNA single-strand breaks when grown to logarithmic phase in rich medium, but not when grown in minimal medium. This is a novel mutation amongst the known DNA repair defects in that it did not sensitize logarithmic phase cells, grown in minimal medium, to either X- or U.V.-radiation. (author)

Comparison of antimicrobial resistant genes in chicken gut microbiome grown on organic and conventional diet

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Narasimha V. Hegde

2016-12-01

Full Text Available Antibiotics are widely used in chicken production for therapeutic purposes, disease prevention and growth promotion, and this may select for drug resistant microorganisms known to spread to humans through consumption of contaminated food. Raising chickens on an organic feed regimen, without the use of antibiotics, is increasingly popular with the consumers. In order to determine the effects of diet regimen on antibiotic resistant genes in the gut microbiome, we analyzed the phylotypes and identified the antimicrobial resistant genes in chicken, grown under conventional and organic dietary regimens. Phylotypes were analyzed from DNA extracted from fecal samples from chickens grown under these dietary conditions. While gut microbiota of chicken raised in both conventional and organic diet exhibited the presence of DNA from members of Proteobacteria and Bacteroidetes, organic diet favored the growth of members of Fusobacteria. Antimicrobial resistance genes were identified from metagenomic libraries following cloning and sequencing of DNA fragments from fecal samples and selecting for the resistant clones (n=340 on media containing different concentrations of eight antibiotics. The antimicrobial resistant genes exhibited diversity in their host distribution among the microbial population and expressed more in samples from chicken grown on a conventional diet at higher concentrations of certain antimicrobials than samples from chicken grown on organic diet. Further studies will elucidate if this phenomena is widespread and whether the antimicrobial resistance is indeed modulated by diet. This may potentially assist in defining strategies for intervention to reduce the prevalence and dissemination of antibiotic resistance genes in the production environment.

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.

The wood quality of Pinus chiapensis (Mart.) Andresen grown in the ...

African Journals Online (AJOL)

The wood quality of Pinus chiapensis (Mart.) Andresen grown in the Mpumalanga forest region: scientific paper. ... When present, the amounts of included resin, pieces of bark and other debris at the occluded pruning cuts, were small and of little practical significance. The wood machined without any difficulty in the wet and ...

The α-particle excited scintillation response of YAG:Ce thin films grown by liquid phase epitaxy

International Nuclear Information System (INIS)

Prusa, Petr; Nikl, Martin; Mares, Jiri A.; Nitsch, Karel; Beitlerova, Alena; Kucera, Miroslav

2009-01-01

Y 3 Al 5 O 12 :Ce (YAG:Ce) thin films were grown from PbO-,BaO-, and MoO 3 -based fluxes using the liquid phase epitaxy (LPE) method. Photoelectron yield, its time dependence within 0.5-10 μs shaping time, and energy resolution of these samples were measured under α-particle excitation. For comparison a sample of the Czochralski grown bulk YAG:Ce single crystal was measured as well. Photoelectron yield values of samples grown from the BaO-based flux were found superior to other LPE films and comparable with that of the bulk single crystal. The same is valid also for the time dependence of photoelectron yield. Obtained results are discussed taking into account the influence of the flux and technology used. Additionally, α particle energy deposition in very thin films is modelled and discussed. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Mountain cloud forest and grown-shade coffee plantations: A comparison of tree biodiversity in central Veracruz, Mexico

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Alfredo González-Zamora

2016-04-01

Full Text Available Aim of the study: The objective of this work is to compare tree diversity and richness among one grown-shade coffee plantation (CAE and two sites of montane cloud forests, one preserved (MCF1 and other perturbed (MCF2. We also develop an analysis of the importance of coffee plantations as a refuge of tree species, holding a potential role for conservation.Area of study: Our study area is the coffee region of Coatepec-Xico, in the state of Veracruz, Mexico.Material and methods: We compiled a list of all tree species in each site to determine tree diversity and floristic similarity (dissimilarity. We used different similarity indices and a cluster analysis to show relations among sites.Main results: 2721 individuals from 154 species were registered in the montane cloud forests as a whole. In the grown-shade coffee plantation we registered 2947 individuals from 64 species. The most similar sites were the perturbed montane cloud forest and the grown-shade coffee plantation and the least similar were the preserved montane cloud forest and the grown-shade coffee plantation. The high biodiversity found in all sites and the differences in tree composition between the two montane cloud forests supports evidence of the ecosystems richness in the region.Research highlight: Diversity differences among sites determine that the grown-shade coffee plantation is not substitute for montane cloud forest. CAE’s are developed under similar environmental conditions than the MCF; therefore, coexistence and recombination (replacement of species make them particularly complementary. CAE’s in Veracruz have a potential role as refuge for biodiversity.

Co2FeAl Heusler thin films grown on Si and MgO substrates: Annealing temperature effect

International Nuclear Information System (INIS)

Belmeguenai, M.; Tuzcuoglu, H.; Zighem, F.; Chérif, S. M.; Moch, P.; Gabor, M. S.; Petrisor, T.; Tiusan, C.

2014-01-01

10 nm and 50 nm Co 2 FeAl (CFA) thin films have been deposited on MgO(001) and Si(001) substrates by magnetron sputtering and annealed at different temperatures. X-rays diffraction revealed polycrystalline or epitaxial growth (according to CFA(001)[110]//MgO(001)[100] epitaxial relation) for CFA films grown on a Si and on a MgO substrate, respectively. For these later, the chemical order varies from the A2 phase to the B2 phase when increasing the annealing temperature (T a ), while only the A2 disorder type has been observed for CFA grown on Si. Microstrip ferromagnetic resonance (MS-FMR) measurements revealed that the in-plane anisotropy results from the superposition of a uniaxial and a fourfold symmetry term for CFA grown on MgO substrates. This fourfold anisotropy, which disappears completely for samples grown on Si, is in accord with the crystal structure of the samples. The fourfold anisotropy field decreases when increasing T a , while the uniaxial anisotropy field is nearly unaffected by T a within the investigated range. The MS-FMR data also allow for concluding that the gyromagnetic factor remains constant and that the exchange stiffness constant increases with T a . Finally, the FMR linewidth decreases when increasing T a , due to the enhancement of the chemical order. We derive a very low intrinsic damping parameter (1.1×10 −3 and 1.3×10 −3 for films of 50 nm thickness annealed at 615 °C grown on MgO and on Si, respectively)

Commercial potential of rambutan cultivars grown at two locations in Puerto Rico

Science.gov (United States)

Eight rambutan (Nephelium lappaceum) cultivars grown on an Oxisol and Ultisol were evaluated for four years under intensive management at Isabela and Corozal, Puerto Rico, respectively. There were significant differences in number and weight of fruits per hectare between locations and years. Signif...

Antioxidant activity screening of extracts from Sideritis species (Labiatae) grown in Bulgaria

NARCIS (Netherlands)

Koleva, I.; Linssen, J.P.H.; Beek, van T.A.; Evstatieva, L.N.; Kortenska, V.; Handjieva, N.

2003-01-01

Plant samples from several species and populations of the genus Sideritis (Labiatae) grown in Bulgaria (S scardica, S syriaca and S montana) were extracted with different solvents. Their antioxidant activities were determined by the -carotene bleaching test (BCBT), 2,2-diphenyl-1-picrylhydrazyl

Low temperature step-graded InAlAs/GaAs metamorphic buffer layers grown by molecular beam epitaxy

International Nuclear Information System (INIS)

Shang, X Z; Wu, S D; Liu, C; Wang, W X; Guo, L W; Huang, Q; Zhou, J M

2006-01-01

Low-temperature step-graded InAlAs metamorphic buffer layers on GaAs substrate grown by molecular beam epitaxy were investigated. The strain relaxation and the composition of the top InAlAs layer were determined by high-resolution triple-axis x-ray diffraction measurements, which show that the top InAlAs layer is nearly fully relaxed. Surface morphology was observed by reflection high-energy electron diffraction pattern and atomic force microscopy. Under a selected range of growth parameters, the root mean square surface roughness of the sample grown at 380 deg. C is 0.802 nm, which has the smallest value compared with those of other samples. Furthermore, The ω-2θ and ω scans of the triple-axis x-ray diffraction, and photoluminescence show the sample grown at 380 deg. C has better crystalline quality. With decreasing As overpressure at this growth temperature, crystalline quality became poor and could not maintain two dimensional growth with increasing overpressure. The carrier concentrations and Hall mobilities of the InAlAs/ InGaAs/GaAs MM-HEMT structure on low-temperature step-graded InAlAs metamorphic buffer layers grown in optimized conditions are high enough to make devices

Observation of the in-plane spin-dephasing anisotropy in [111]-grown GaAs/AlGaAs quantum well

International Nuclear Information System (INIS)

Zhao, Chunbo; Li, Junbin; Yu, Ying; Ni, Haiqiao; Niu, Zhichuan; Zhang, Xinhui

2014-01-01

The electron density and temperature dependent in-plane spin-dephasing anisotropy in [111]-grown GaAs quantum well (QW) has been investigated by time-resolved magneto-Kerr rotation technique. Due to the specific symmetry of [111]-grown quantum well, the in-plane Rashba and linear Dresselhaus effective spin-orbit magnetic field is parallel to each other for electron wave vectors in all directions. However, an obvious in-plane spin-dephasing anisotropy comparing [2 ¯ 11] with [01 ¯ 1] crystalline orientations has been observed and discussed in this work. Our results demonstrate the innegligible spin dephasing channel through inhomogeneous broadening induced by the out-of-plane non-linear Dresselhaus field, which arises naturally from the C 3 symmetry of [111]-grown GaAs QW

High-quality single crystalline NiO with twin phases grown on sapphire substrate by metalorganic vapor phase epitaxy

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Kazuo Uchida

2012-12-01

Full Text Available High-quality single crystalline twin phase NiO grown on sapphire substrates by metalorganic vapor phase epitaxy is reported. X-ray rocking curve analysis of NiO films grown at different temperatures indicates a minimum full width at half maximum of the cubic (111 diffraction peak of 0.107° for NiO film grown at as low as 550 °C. Detailed microstructural analysis by Φ scan X-ray diffraction and transmission electron microscopy reveal that the NiO film consists of large single crystalline domains with two different crystallographic orientations which are rotated relative to each other along the [111] axis by 60°. These single crystal domains are divided by the twin phase boundaries.

Clean and polymer-free transfer of CVD-grown graphene films on hexagonal boron nitride substrates

Science.gov (United States)

Fujihara, Miho; Ogawa, Shun; Yoshimura, Shintaro; Inoue, Ryosuke; Maniwa, Yutaka; Taniguchi, Takashi; Watanabe, Kenji; Shinohara, Hisanori; Miyata, Yasumitsu

2017-05-01

This report describes the development of a solution-assisted, polymer-free transfer method and the characterization of chemical vapor deposition (CVD)-grown graphene on hexagonal boron nitride. Raman analysis reveals that polymer-free samples have small variations in G- and 2D-mode Raman frequencies and are minimally affected by charge doping as observed for clean exfoliated graphene. Electrical measurements indicate that charge doping, hysteresis, and carrier scattering are suppressed in polymer-free samples. The results demonstrate that this method provides a simple and effective way to prepare clean heterostructures of CVD-grown, large-area graphene and other two-dimensional materials.

Lead, arsenic, and copper content of crops grown on lead arsenate-treated and untreated soils

Energy Technology Data Exchange (ETDEWEB)

Chisholm, D

1972-01-01

Increased lead and arsenic concentrations in the surface soil (0-15 cm), resulting from applications of lead arsenate (PbHAs0/sub 1/), increased both lead and arsenic levels in crops grown on treated plots. The lead levels in some crops approached or exceeded the Canadian residue tolerance of 2.0 ppM. Lead arsenate soil treatments did not affect copper absorption by crops. On areas such as old orchard land contaminated with lead arsenate residues it may be advisable to ascertain crops, and also to determine the lead affinity and arsenic sensitivity of the plants to be grown.

Influence of Common Bean (Phaseolus vulgaris) Grown in Elevated CO2 on Apatite Dissolution

Science.gov (United States)

Olsen, A. A.; Morra, B.

2016-12-01

We ran a series of experiments to test the hypothesis that release of plant nutrients contained in apatite will be accelerated by the growth of Langstrath Stringless green bean in the presence of atmospheric CO2 meant to simulate possible future atmospheric conditions due a higher demand of nutrients and growth rate caused by elevated CO2. We hypothesize that elevated atmospheric CO2 will lead to both increased root growth and organic acid exudation. These two traits will lead to improved acquisition of P derived from apatite. Experiments were designed to investigate the effect of these changes on soil mineral weathering using plants grown under two conditions, ambient CO2 (400ppm) and elevated CO2 (1000ppm). Plants were grown in flow-through microcosms consisting of a mixture of quartz and apatite sands. Mini-greenhouses were utilized to control CO2 levels. Plant growth was sustained by a nutrient solution lacking in Ca and P. Calcium and P content of the leachate and plant tissue served as a proxy for apatite dissolution. Plants were harvested biweekly during the eight-week experiment and analyzed for Ca and P to calculate apatite dissolution kinetics. Preliminary results suggest that approximately four times more P and Ca are present in the leachate from experiments containing plants under both ambient and elevated CO2 levels than in abiotic experiments; however, the amounts of both P and Ca released in experiments conducted under both ambient and elevated CO2 levels are similar. Additionally, the amount of P in plant tissue grown under ambient and elevated CO2 conditions is similar. Plants grown in elevated CO2 had a greater root to shoot ratio. The planted microcosms were found to have a lower pH than abiotic controls most likely due to root respiration and exudation of organic acids.

Characterization of Cellulolytic Bacterial Cultures Grown in Different Substrates

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Mohamed Idris Alshelmani

2013-01-01

Full Text Available Nine aerobic cellulolytic bacterial cultures were obtained from the Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Culture (DSMZ and the American Type Culture Collection (ATCC. The objectives of this study were to characterize the cellulolytic bacteria and to determine the optimum moisture ratio required for solid state fermentation (SSF of palm kernel cake (PKC. The bacteria cultures were grown on reconstituted nutrient broth, incubated at 30∘C and agitated at 200 rpm. Carboxymethyl cellulase, xylanase, and mannanase activities were determined using different substrates and after SSF of PKC. The SSF was conducted for 4 and 7 days with inoculum size of 10% (v/w on different PKC concentration-to-moisture ratios: 1 : 0.2, 1 : 0.3, 1 : 0.4, and 1 : 0.5. Results showed that Bacillus amyloliquefaciens 1067 DSMZ, Bacillus megaterium 9885 ATCC, Paenibacillus curdlanolyticus 10248 DSMZ, and Paenibacillus polymyxa 842 ATCC produced higher enzyme activities as compared to other bacterial cultures grown on different substrates. The cultures mentioned above also produced higher enzyme activities when they were incubated under SSF using PKC as a substrate in different PKC-to-moisture ratios after 4 days of incubation, indicating that these cellulolytic bacteria can be used to degrade and improve the nutrient quality of PKC.

A new species of Dalbergia (Leguminosae from Malay Peninsula

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Bambang - Sunarno

2003-12-01

Full Text Available SUNARNO, BAMBANG & OHASHI, HIROSHI. 2002. A new species of Dalbergia (Leguminosae from Malay Peninsula. Reinwardtia 12(1: 117–119. ⎯ A new species, Dalbergia johoriensis from the Malay Peninsula is described. It is close to D. rostrata and D. havilandii but readily distinguished by the grooved midrib beneath, flowers with narrower standard and wings and style hairy in the lower part.

Giant current-perpendicular-to-plane magnetoresistance in multilayer graphene as grown on nickel.

Science.gov (United States)

Bodepudi, S C; Singh, A P; Pramanik, S

2014-05-14

Strong magnetoresistance effects are often observed in ferromagnet-nonmagnet multilayers, which are exploited in state-of-the-art magnetic field sensing and data storage technologies. In this work we report a novel current-perpendicular-to-plane magnetoresistance effect in multilayer graphene as grown on a catalytic nickel surface by chemical vapor deposition. A negative magnetoresistance effect of ∼10(4)% has been observed, which persists even at room temperature. This effect is correlated with the shape of the 2D peak as well as with the occurrence of D peak in the Raman spectrum of the as-grown multilayer graphene. The observed magnetoresistance is extremely high as compared to other known materials systems for similar temperature and field range and can be qualitatively explained within the framework of "interlayer magnetoresistance" (ILMR).

COMPOSITIONAL PROPERTIES OF THREE FRESHWATER CARP SPECIES GROWN IN BRACKISH WATER

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Muhammad Ismail Chughtai

2015-06-01

Full Text Available Three freshwater fish species viz. Labeo rohita, Cirrhinus mrigala and Gibelion catla, grown in brackish water ponds were analyzed for compositional properties to assess the potential of this habitat to produce nutritionally adequate fish for human consumption. Overall, the unsaturated fatty acids were lower in L. rohita (46.6% than saturated fatty acids; while in C. mrigala and G. catla, the unsaturated fatty acids were 50.4% and 58.2%, respectively. The most abundant saturated fatty acid in examined species was palmitic acid (C16:0, 23.7 to 34.1%; mono-unsaturated fatty acid was oleic acid (C18:1 19.6 to 31.7% and poly-unsaturated fatty acid linoleic acid (C18:2 9.46 to 13.3%. A reasonable amount of essential fatty acids ω-3 (5.80 to 9.26% and ω-6 (9.46 to 13.3% was also found in these species while growing in brackish water on salt tolerant forages like Leptochloa fusca, Brachiaria mutica and Kochia indica as supplemental feed. The ω-3/ω-6 ratio was calculated as 0.46, 0.80 and 0.69 in L. rohita, C. mrigala and G. catla, respectively. The maximum EPA (eicosapentaenoic acid, C20:5 was observed in C. mrigala (2.23%, followed by G. catla (1.62% and L. rohita (0.98%. While the DHA (docosahexanenoic acids, C22:6 was found maximum in G. catla (1.97% and minimum in C. mrigala (0.95%. The results of body composition indicated that L. rohita found maximum protein contents (19.2% with minimum total fats (1.28% while C. mrigala found maximum total fats (2.11% but minimum protein contents (18.3%. Overall results indicated that the Indian carps grown in brackish water have comparable chemical composition and nutritive value with the same species grown in freshwater medium.

Hydrothermally grown zeolite crystals

International Nuclear Information System (INIS)

Durrani, S.K.; Qureshi, A.H.; Hussain, M.A.; Qazi, N.K.

2009-01-01

The aluminium-deficient and ferrosilicate zeolite-type materials were synthesized by hydrothermal process at 150-170 degree C for various periods of time from the mixtures containing colloidal reactive silica, sodium aluminate, sodium hydroxide, iron nitrate and organic templates. Organic polycation templates were used as zeolite crystal shape modifiers to enhance relative growth rates. The template was almost completely removed from the zeolite specimens by calcination at 550 degree C for 8h in air. Simultaneous thermogravimetric (TG) and differential thermal analysis (DTA) was performed to study the removal of water molecules and the amount of organic template cations occluded inside the crystal pore of zeolite framework. The 12-13% weight loss in the range of (140-560 degree C) was associated with removal of the (C/sub 3/H/sub 7/)/sub 4/ N+ cation and water molecules. X-ray diffraction (XRD) analysis and scanning electron microscope (SEM) techniques were employed to study the structure, morphology and surface features of hydrothermally grown aluminium-deficient and ferrosilicate zeolite-type crystals. In order to elucidate the mode of zeolite crystallization the crystallinity and unit cell parameters of the materials were determined by XRD, which are the function of Al and Fe contents of zeolites. (author)

Incorporation of transuranics into vegetable and field crops grown at the Nevada Test Site

International Nuclear Information System (INIS)

Au, F.H.F.; Leavitt, V.D.; Beckert, W.F.; McFarlane, J.C.

1977-01-01

Radish, lettuce, barley, and alfalfa plants were grown from seeds in undisturbed soil in Area 13 of the Nevada Test Site to determine the uptake of transuranics under field conditions. The plants were grown in small greenhouses erected over the soil to preclude aerial deposition of resuspended transuranics on the growing plants. The crops were irrigated during the growing season with either distilled water, diethylenetriaminepentaacetic acid (DTPA) in distilled water, fertilizer in distilled water, or a combination of DTPA and fertilizer in distilled water. The plutonium and americium contents of the harvested plants showed differences which are mostly attributable to the effects of the treatments and the resulting changes in soil pH during the experiment

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....

Modeling osmotic salinity effects on yield characteristics of substrate-grown greenhouse crops

NARCIS (Netherlands)

Sonneveld, C.; Bos, van den A.L.; Voogt, W.

2004-01-01

In a series of experiments with different osmotic potentials in the root environment, various vegetables, and ornamentals were grown in a substrate system. The osmotic potential was varied by addition of nutrients. Yield characteristics of the crop were related to the osmotic potential of the

Reproductive characteristics of citrus rootstocks grown under greenhouse and field environments

Directory of Open Access Journals (Sweden)

Divanilde Guerra

2013-01-01

Full Text Available The aim of the present study was to evaluate the possible effect of environmental factors on meiosis, meiotic index, pollenviability and in vitro germination of pollen from stock plants of the rootstocks Trifoliate, ‘Swingle’, ‘Troyer’, ‘Fepagro C13’, ‘FepagroC37’ and ‘Fepagro C41’ grown in a protected environment in comparison with stock plants grown in the field. The results showed thatvalues for the characteristics analyzed in 2008, 2009 and 2010 were always higher in the field than in the greenhouse conditions. Inthe field, the average of normal meiotic cells was 60.05%, 44.44% and 60.12%, respectively, and in the greenhouse, 52.75%, 30.95%and 52.82%, respectively. Mean pollen viability in the field was 90.28%, 56.23% and 74.74%, and, in the greenhouse, 64.25%, 41.41%and 66.71%, respectively. As temperature oscillations were higher in the greenhouse than in the field, we suggest that this negativelyaffects the reproductive characteristics analyzed.

Effects of annealing on the recombination dynamics of low-temperature grown ZnO nanorods

Energy Technology Data Exchange (ETDEWEB)

Hilker, B.; Bekeny, C.; Voss, T.; Gutowski, J. [IFP, Universitaet Bremen, 28334 Bremen (Germany); Hauschild, R.; Kalt, H. [Universitaet Karlsruhe, 76128 Karlsruhe (Germany); Postels, B.; Bakin, Andrey; Waag, A. [IHT, TU Braunschweig, 38023 Braunschweig (Germany)

2007-07-01

We present systematic temperature and excitation density dependent time-resolved photoluminescence (TRPL) measurements of as-grown and annealed ZnO nanorods fabricated by an aqueous chemical growth (ACG) technique at {proportional_to}90 C. The as-grown nanorods show strong nearband-edge and rather weak deep-level emission indicating their already good optical quality. At 4K, we find a broad emission line at 3.36 eV (line width 30 meV) which we attribute to recombination from a donor band formed through the high donor concentration. After annealing in oxygen and nitrogen atmospheres at 600-800 C well-resolved and sharper excitonic transitions are observed. To understand the recombination dynamics in the nanorods we carried out TRPL measurements using a frequency-doubled femtosecond laser and a streak camera. The as-grown sample shows a very fast monoexponential decay time of {proportional_to}10ps independent of temperature and excitation density. In contrast, the annealed samples exhibit a biexponential decay. Each a fast {tau}1 and a slow {tau}2 time constant have been determined for all annealed samples both of them significantly varying depending on the annealing atmosphere and temperature. This will be discussed on the basis of a phenomenological rate-equation model.

Correlation of Etch Pits and Dislocations in As-grown and Thermal Cycle-Annealed HgCdTe(211) Films

Science.gov (United States)

Vaghayenegar, M.; Jacobs, R. N.; Benson, J. D.; Stoltz, A. J.; Almeida, L. A.; Smith, David J.

2017-08-01

This paper reports observations of the different types of etch pits and dislocations present in thick HgCdTe (211) layers grown by molecular beam epitaxy on CdTe/Si (211) composite substrates. Dislocation analysis for as-grown and thermal cycle-annealed samples has been carried out using bright-field transmission electron microscopy. Triangular pits present in as-grown material are associated with a mixture of Frank partials and perfect dislocations, while pits with fish-eye shapes have perfect dislocations with 1/2[0\\bar{1}1] Burgers vector. The dislocations beneath skew pits are more complex as they have two different crystallographic directions, and are associated with a mixture of Shockley partials and perfect dislocations. Dislocation analysis of samples after thermal cycle annealing (TCA) shows that the majority of dislocations under the etch pits are short segments of perfect dislocations with 1/2[0\\bar{1}1] Burgers vector while the remainder are Shockley partials. The absence of fish-eye shape pits in TCA samples suggests that they are associated with mobile dislocations that have reacted during annealing, causing the overall etch pit density to be reduced. Very large pits with a density ˜2×103 cm-2 are observed in as-grown and TCA samples. These defects thread from within the CdTe buffer layer into the upper regions of the HgCdTe layers. Their depth in as-grown material is so large that it is not possible to locate and identify the underlying defects.

Low temperature synthesis and field emission characteristics of single to few layered graphene grown using PECVD

Energy Technology Data Exchange (ETDEWEB)

Kumar, Avshish; Khan, Sunny; Zulfequar, M.; Harsh; Husain, Mushahid, E-mail: mush_reslab@rediffmail.com

2017-04-30

Highlights: • Graphene was synthesized by PECVD system at a low temperature of 600 °C. • From different characterization techniques, the presence of single and few layered graphene was confirmed. • X-ray diffraction pattern of the graphene showed single crystalline nature of the film. • The as-grown graphene films were observed extremely good field emitters with long term emission current stability. - Abstract: 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.

Optical properties of m-plane GaN grown on patterned Si(112) substrates by MOCVD using a two-step approach

Science.gov (United States)

Izyumskaya, N.; Okur, S.; Zhang, F.; Monavarian, M.; Avrutin, V.; Özgür, Ü.; Metzner, S.; Karbaum, C.; Bertram, F.; Christen, J.; Morkoç, H.

2014-03-01

Nonpolar m-plane GaN layers were grown on patterned Si (112) substrates by metal-organic chemical vapor deposition (MOCVD). A two-step growth procedure involving a low-pressure (30 Torr) first step to ensure formation of the m-plane facet and a high-pressure step (200 Torr) for improvement of optical quality was employed. The layers grown in two steps show improvement of the optical quality: the near-bandedge photoluminescence (PL) intensity is about 3 times higher than that for the layers grown at low pressure, and deep emission is considerably weaker. However, emission intensity from m-GaN is still lower than that of polar and semipolar (1 100 ) reference samples grown under the same conditions. To shed light on this problem, spatial distribution of optical emission over the c+ and c- wings of the nonpolar GaN/Si was studied by spatially resolved cathodoluminescence and near-field scanning optical microscopy.

Charge collection efficiency in SI GaAs grown from melts with variable composition as a material for solar neutrino detection

CERN Document Server

Verbitskaya, E; Ivanov, A; Strokan, N; Vasilev, V; Markov, A; Polyakov, A; Gavrin, V; Kozlova, Y; Veretenkin, E; Bowles, T J

2000-01-01

The results on electrical characteristics and charge collection efficiency in the detectors from bulk SI GaAs developed as a material for solar neutrino spectroscopy are presented. SI GaAs crystals were grown by the Czochralski method. The changes in the stoichiometric components are permanently controlled. It is shown that the performance of GaAs p sup + -i-n sup + structures provided the range of operational reverse voltage up to 1 kV. Measurement of deep level spectra and their analysis reveal the dominant deep levels - hole traps E sub v +0.51 and +0.075 eV in GaAs grown from stoichiometric and nonstoichiometric melts, respectively. Investigation of carrier transport properties and bulk homogeneity evinced in charge collection efficiency has shown advantageous results for SI GaAs grown from stoichiometric melt. The reduction of carrier transport parameters and charge collection efficiency in GaAs grown from nonstoichiometric melt is analyzed taking into consideration formation of the hole trap E sub v +0....

Electronic and surface properties of pentacene films deposited on SiO2 prepared by the sol–gel and thermally grown methods

International Nuclear Information System (INIS)

Dai, Chi-Jie; Tsao, Hou-Yen; Lin, Yow-Jon; Liu, Day-Shan

2014-01-01

This study investigates the effect of different types of SiO 2 on the electronic and surface properties of pentacene films. Developing better contacts on dielectrics is one of the main challenges for pentacene-based transistor technology. The water contact angle variation indicates more hydrophobic thermally grown SiO 2 surfaces than sol–gel SiO 2 surfaces, suggesting that the thermally grown SiO 2 dielectric enables a better molecular arrangement as the pentacene layer is deposited. It is found that the carrier mobility in pentacene on thermally grown SiO 2 dielectrics is higher than that in pentacene on sol–gel SiO 2 dielectrics. The Hall-effect analysis by using the polaron theory revealed that the enhanced carrier mobility is due to the increased spacing between molecules. - Highlights: • The carrier mobility of pentacene on thermally grown and sol–gel SiO 2 was researched. • The enhanced carrier mobility of pentacene on thermally grown SiO2 was observed. • The dominance of tunneling (hopping) at low (high) temperatures was observed. • The carrier mobility is correlated with the morphology of pentacene films

DETERMINATION OF VICKERS MICROHARDNESS IN β-Ga2O3 SINGLE CRYSTALS GROWN FROM THEIR OWN MELT

Directory of Open Access Journals (Sweden)

L. I. Guzilova

2015-05-01

Full Text Available The results of microhardness measurements of β-Ga2O3 single crystals for (001 crystallographic face are reported. The crystals were grown by the free crystallization with the "Garnet-2M" equipment. Microhardness values ​​ were determined by the Vickers method at varying loads. A four-sided diamond pyramid was used as an indenter. The average value of gallium oxide microhardness was equal to 8.91 GPa. We have carried out comparison of the values ​​obtained with the microhardness for the other wide bandgap semiconductors - epitaxial GaN layers grown on 6H-SiC and GaP layers grown on GaP:S. The findings are usable for machining process development of β-Ga2O3 single crystal substrates. In particular, silicon carbide and electrocorundum may be recommended for β-Ga2O3 machine processing.

Heterojunction oxide thin-film transistors with unprecedented electron mobility grown from solution

KAUST Repository

Faber, Hendrik; Das, Satyajit; Lin, Yen-Hung; Pliatsikas, Nikos; Zhao, Kui; Kehagias, Thomas; Dimitrakopulos, George; Amassian, Aram; Patsalas, Panos A.; Anthopoulos, Thomas D.

2017-01-01

with the extrinsic electron transport properties of the often defect-prone oxides. We overcome this limitation by replacing the single-layer semiconductor channel with a low-dimensional, solution-grown In2O3/ZnO heterojunction. We find that In2O3/ZnO transistors

Epitaxial (100)-oriented Mo/V superlattice grown on MgO(100) by dcMS and HiPIMS

International Nuclear Information System (INIS)

Shayestehaminzadeh, S.; Magnusson, R.L.; Gislason, H.P.; Olafsson, S.

2013-01-01

Epitaxial (100)-oriented Mo/V superlattices have been grown by High Power Impulse Magnetron Sputtering (HiPIMS) and dc Magnetron Sputtering (dcMS) on single-crystalline MgO(100) substrates at growth temperatures ranging from 30 °C to 600 °C. Superlattice bilayer period of Mo/V around 12/12 monolayers and 15 repeat periods was studied. This study aims to investigate the effect of the HiPIMS process on reducing the growth temperature of Mo/V superlattices using the high energy ionized Mo, V species in the HiPIMS plasma. In one case, the Mo layer was only grown with the HiPIMS process and V layer grown using the dcMS process while in another both layers were grown with the HiPIMS process. The as-deposited films were characterized by X-ray reflection and diffraction techniques. The dcMS process was found to give superior superlattice growth at high growth temperatures while a mixed Mo HiPIMS and V dcMS process gives better result at lower growth temperatures (300 °C). Room temperature growth reveals that neither the mixed Mo HiPIMS and V dcMS process nor the pure HiPIMS for both materials can produce better result compared to the pure dcMS process, which gives a relatively better result. - Highlights: • Epitaxial (100)-oriented Mo/V superlattices have been grown by HiPIMS and dcMS on MgO(100) for various temperatures. • The study was aimed to investigate the effect of ionized HiPIMS process onlowering the growth temperature. • The dcMS process was found to give superior superlattice growth at high growth temperature. • The mixed Mo HiPIMS and V dcMS process gives best result at lower growth temperatures

Yttria and ceria doped zirconia thin films grown by pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Saporiti, F.; Juarez, R. E., E-mail: cididi@fi.uba.ar [Grupo de Materiales Avanzados, Facultad de Ingenieria, Universidad de Buenos Aires (Argentina); Audebert, F. [Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Boudard, M. [Laboratoire des Materiaux et du Genie Physique (CNRS), Grenoble (France)

2013-11-01

The Yttria stabilized Zirconia (YSZ) is a standard electrolyte for solid oxide fuel cells (SOFCs), which are potential candidates for next generation portable and mobile power sources. YSZ electrolyte thin films having a cubic single phase allow reducing the SOFC operating temperature without diminishing the electrochemical power density. Films of 8 mol% Yttria stabilized Zirconia (8YSZ) and films with addition of 4 weight% Ceria (8YSZ + 4CeO{sub 2}) were grown by pulsed laser deposition (PLD) technique using 8YSZ and 8YSZ + 4CeO{sub 2} targets and a Nd-YAG laser (355 nm). Films have been deposited on Soda-Calcia-Silica glass and Si(100) substrates at room temperature. The morphology and structural characteristics of the samples have been studied by means of X-ray diffraction and scanning electron microscopy. Films of a cubic-YSZ single phase with thickness in the range of 1-3 Micro-Sign m were grown on different substrates (author)

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

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.

Germanium nanoislands grown by radio frequency magnetron sputtering: Annealing time dependent surface morphology and photoluminescence

International Nuclear Information System (INIS)

Samavati, Alireza; Othaman, Z.; Ghoshal, S. K.; Amjad, R. J.

2013-01-01

Structural and optical properties of ∼ 20 nm Ge nanoislands grown on Si(100) by radio frequency (rf) magnetron sputtering under varying annealing conditions are reported. Rapid thermal annealing at a temperature of 600°C for 30 s, 90 s, and 120 s are performed to examine the influence of annealing time on the surface morphology and photoluminescence properties. X-ray diffraction spectra reveal prominent Ge and GeO 2 peaks highly sensitive to the annealing time. Atomic force microscope micrographs of the as-grown sample show pyramidal nanoislands with relatively high-density 10 11 cm −2) ). The nanoislands become dome-shaped upon annealing through a coarsening process mediated by Oswald ripening. The room temperature photoluminescence peaks for both as-grown 3.29 eV) and annealed 3.19 eV) samples consist of high intensity and broad emission, attributed to the effect of quantum confinement. The red shift (∼0.10 eV) of the emission peak is attributed to the change in the size of the Ge nanoislands caused by annealing. Our easy fabrication method may contribute to the development of Ge nanostructure-based optoelectronics. (interdisciplinary physics and related areas of science and technology)

Doping characteristics of iodine on as-grown chemical vapor deposited graphene on Pt

Energy Technology Data Exchange (ETDEWEB)

Kim, HoKwon, E-mail: hknano@gmail.com [Université Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, 17 rue des Martyrs, F-38054 Grenoble (France); Renault, Olivier [Université Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, 17 rue des Martyrs, F-38054 Grenoble (France); Tyurnina, Anastasia; Guillet, Jean-François; Simonato, Jean-Pierre [Université Grenoble Alpes, F-38000 Grenoble (France); CEA, LITEN/DTMN, F-38054 Grenoble (France); Rouchon, Denis; Mariolle, Denis; Chevalier, Nicolas [Université Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, 17 rue des Martyrs, F-38054 Grenoble (France); Dijon, Jean [Université Grenoble Alpes, F-38000 Grenoble (France); CEA, LITEN/DTMN, F-38054 Grenoble (France)

2015-12-15

Using laboratory X-ray photoelectron emission microscopy (XPEEM), we investigated the doping efficiency and thermal stability of iodine on as-grown graphene on Pt. After iodine adsorption of graphene in saturated vapor of I{sub 2,} monolayer and bilayer graphene exhibited work function of 4.93 eV and 4.87 eV, respectively. Annealing of the doped monolayer graphene at 100 °C led to desorption of hydrocarbons, which increased the work function of monolayer graphene by ~0.2 eV. The composition of the polyiodide complexes evolved upon a step-by-step annealing at temperatures from 100 °C to 300 °C while the work-function non-monotonically changed with decreasing iodine content. The iodine dopant was stable at relatively high temperature as a significant amount of iodine remained up to the annealing temperature of 350 °C. - Highlights: • Laboratory XPEEM demonstrates that iodine can effectively p-dope as-grown graphene on Pt with a work-function value up to 5.1 eV. • On the other hand, residual hydrocarbon contamination decreases the work function by up to ~0.2 eV. • The spontaneous intercalation of as-grown few-layered graphene is not easily feasible. • The iodine dopant was not completely removed up to the annealing temperature of 350 °C. • The I{sub 3}{sup −} and I{sub 5}{sup −} polyiodide content ratio of I-doped Gr/Pt decreases with annealing temperature.

Defects in zinc oxide grown by pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Ling, Francis C.C., E-mail: ccling@hku.hk [Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong (China); Wang, Zilan; Ping Ho, Lok; Younas, M. [Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong (China); Anwand, W.; Wagner, A. [Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden (Germany); Su, S.C. [Institute of Optoelectronic Material and Technology, South China Normal University, Guangzhou 510631 (China); Shan, C.X. [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China)

2016-01-01

ZnO films are grown on c-plane sapphire using the pulsed laser deposition method. Systematic studies on the effects of annealing are performed to understand the thermal evolutions of the defects in the films. Particular attention is paid to the discussions of the ZnO/sapphire interface thermal stability, the Zn-vacancy related defects having different microstructures, the origins of the green luminescence (∼2.4–2.5 eV) and the near band edge (NBE) emission at 3.23 eV.

Submicron beam X-ray diffraction of nanoheteroepitaxily grown GaN: Experimental challenges and calibration procedures

Energy Technology Data Exchange (ETDEWEB)

Bonanno, P.L., E-mail: PeterBonanno@gatech.ed [Georgia Institute of Technology/GTL, UMI 2958 Georgia Tech-CNRS, 57070 Metz (France); Gautier, S. [Laboratoire Materiaux Optiques, Photonique et Micro-Nano Systemes, UMR CNRS 7132, Universite de Metz et SUPELEC, 2 rue E. Belin, 57070 Metz (France); Sirenko, A.A. [Department of Physics, New Jersey Institute of Technology, Newark, NJ 07102 (United States); Kazimirov, A. [Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, New York 14853 (United States); Cai, Z.-H. [Advanced Photon Source, 9700 S. Cass Avenue, Argonne, IL 60439 (United States); Goh, W.H. [Georgia Institute of Technology/GTL, UMI 2958 Georgia Tech-CNRS, 57070 Metz (France); Martin, J. [Laboratoire Materiaux Optiques, Photonique et Micro-Nano Systemes, UMR CNRS 7132, Universite de Metz et SUPELEC, 2 rue E. Belin, 57070 Metz (France); Martinez, A. [Laboratoire de Photonique et de Nanostructures, UPR CNRS 20, Route de Nozay, 91460 Marcoussis (France); Moudakir, T. [Laboratoire Materiaux Optiques, Photonique et Micro-Nano Systemes, UMR CNRS 7132, Universite de Metz et SUPELEC, 2 rue E. Belin, 57070 Metz (France); Maloufi, N. [Laboratoire d' Etude des Textures et Application aux Materiaux, UMR CNRS 7078, Ile du Saulcy, 57045 Metz Cedex 1 (France); Assouar, M.B. [Laboratoire de Physique des Milieux Ionises et Applications, Nancy University, CNRS, BP 239, F-54506 Vandoeuvre-les-Nancy Cedex (France); Ramdane, A.; Gratiet, L. Le [Laboratoire de Photonique et de Nanostructures, UPR CNRS 20, Route de Nozay, 91460 Marcoussis (France); Ougazzaden, A. [Georgia Institute of Technology/GTL, UMI 2958 Georgia Tech-CNRS, 57070 Metz (France)

2010-02-15

Highly relaxed GaN nanodots and submicron ridges have been selectively grown in the NSAG regime using MOVPE on lattice mismatched 6H-SiC and AlN substrates. 2D real space and 3D reciprocal space mapping was performed with a CCD detector using 10.4 keV synchrotron X-ray radiation at the 2-ID-D micro-diffraction beamline at Advanced Photon Source (APS). Calibration procedures have been developed to overcome the unique challenges of analyzing NSAG structures grown on highly mismatched substrates. We studied crystallographic planar bending on the submicron scale and found its correlation with strain relaxation in the NSAG ridges.

Formation mechanism of PbTe dendritic nanostructures grown by electrodeposition

Energy Technology Data Exchange (ETDEWEB)

Bae, Sangwoo; Kim, Hyunghoon; Lee, Ho Seong, E-mail: hs.lee@knu.ac.kr

2017-02-01

The formation mechanism of PbTe dendritic nanostructures grown at room temperature by electrodeposition in nitric acid electrolytes containing Pb and Te was investigated. Scanning electron microscopy and transmission electron microscopy analyses indicated that the PbTe dendritic nanostructures were composed of triangular-shaped units surrounded by {111} and {110} planes. Because of the interfacial energy anisotropy of the {111} and {110} planes and the difference in the current density gradient, the growth rate in the vertical direction of the (111) basal plane was slower than that in the direction of the tip of the triangular shape, leading to growth in the tip direction. In contrast to the general growth direction of fcc dendrites, namely <100>, the tip direction of the {111} basal plane for our samples was <112>, and the PbTe dendritic nanostructures grew in the tip direction. The angles formed by the main trunk and first branches were regular and approximately 60°, and those between the first and second branches were also approximately 60°. Finally, the nanostructures grew in single-crystalline dendritic form. - Highlights: • PbTe dendrite nanostructures were grown by electrodeposition. • PbTe dendritic nanostructures were composed of triangular-shaped units. • The formation mechanism of PbTe dendrite nanostructures was characterized.

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. PMID:26974840

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.

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.

Microstructure of nitrides grown on inclined c-plane sapphire and SiC substrate

International Nuclear Information System (INIS)

Imura, M.; Honshio, A.; Miyake, Y.; Nakano, K.; Tsuchiya, N.; Tsuda, M.; Okadome, Y.; Balakrishnan, K.; Iwaya, M.; Kamiyama, S.; Amano, H.; Akasaki, I.

2006-01-01

High-quality (112-bar 0) GaN layers with atomically flat surface have been grown on a precisely offset-angle-controlled (11-bar 02) sapphire substrate by metal-organic vapor phase epitaxy (MOVPE). Insertion of AlGaN layer between underlying AlN layer and GaN was found to improve crystalline quality of upper GaN layer. In addition, a combination of high growth condition followed and epitaxial lateral overgrowth has been employed for the growth of GaN and this helped in reducing the dislocation density in the resultant layers. GaN and AlN were grown on (303-bar 8) SiC substrates by MOVPE and sublimation methods, respectively. The crystal orientation of GaN and AlN could be just aligned to that of the substrate. Microstructure analysis of the layers was also carried out by transmission electron microscopy

[Plant communities in the terrestrial-aquatic transition zone in the paramo of Chingaza, Colombia].

Science.gov (United States)

Schmidt-Mumm, Udo; Vargas Ríos, Orlando

2012-03-01

Plant communities in the terrestrial-aquatic transition zone in the paramo of Chingaza, Colombia. High Andean paramo ecosystems are an important water resource for many towns, and major cities in this region. The aquatic and wetland vegetation of different paramo lakes, pond, swamps and bogs was studied according to the classical phytosociological approach, which is based on homogenous stands, but excludes any border phenomena or transitional zone. The present research aimed at determining the aquatic and wetland vegetation along different moisture gradients. A total of 89 species in 30 transects were reported, of which Crassula venezuelensis, Carex honplandii, Callitriche nubigena, Eleocharis macrostachya, Ranunculus flagelliformis, R. nubigenus, Eleocharis stenocarpa, Galium ascendens y Alopecurus aequalis were present in more than one third of the transects. Numerical classification and indicator species analysis resulted in the definition of the next 18 communities: 1) Calamagrostis effusa, 2) Sphagnum cuspidatum, 3) Cyperus rufus, 4) Eleocharis stenocarpa, 5) Carex acutata, 6) Poa annua,7) Valeriana sp., 8) Ranunculus flagelliformis, 9) Carex bonplandii, 10) Festuca andicola. 11) Muhlenbergia fustigiata, 12) Elatine paramoana, 13) Isoëtes palmeri, 14) Crassula venezuelensis, 15) Lilaeopsis macloviana, 16) Callitriche nubigena, 17) Potamogeton paramoanus and 18) Potamogeton illinoensis. The ordination of communities reveals the presence of three different aquatic-terrestrial gradients which are related to the life form structure of species that characterized the various communities. We concluded that patchiness and heterogeneity of the vegetation is mainly the result of alterations caused by human activities (burning, cattle raise and material extraction for road and dam construction).

Multi-Polarization ASAR Backscattering from Herbaceous Wetlands in Poyang Lake Region, China

Directory of Open Access Journals (Sweden)

Huiyong Sang

2014-05-01

Full Text Available Wetlands are one of the most important ecosystems on Earth. There is an urgent need to quantify the biophysical parameters (e.g., plant height, aboveground biomass and map total remaining areas of wetlands in order to evaluate the ecological status of wetlands. In this study, Environmental Satellite/Advanced Synthetic Aperture Radar (ENVISAT/ASAR dual-polarization C-band data acquired in 2005 is tested to investigate radar backscattering mechanisms with the variation of hydrological conditions during the growing cycle of two types of herbaceous wetland species, which colonize lake borders with different elevation in Poyang Lake region, China. Phragmites communis (L. Trin. is semi-aquatic emergent vegetation with vertical stem and blade-like leaves, and the emergent Carex spp. has rhizome and long leaves. In this study, the potential of ASAR data in HH-, HV-, and VV-polarization in mapping different wetland types is examined, by observing their dynamic variations throughout the whole flooding cycle. The sensitivity of ASAR backscattering coefficients to vegetation parameters of plant height, fresh and dry biomass, and vegetation water content is also analyzed for Phragmites communis (L. Trin. and Carex spp. The research for Phragmites communis (L. Trin. shows that HH polarization is more sensitive to plant height and dry biomass than HV polarization. ASAR backscattering coefficients are relatively less sensitive to fresh biomass, especially in HV polarization. However, both are highly dependent on canopy water content. In contrast, the dependence of HH- and HV- backscattering from Carex community on vegetation parameters is poor, and the radar backscattering mechanism is controlled by ground water level.

Enhanced Productivity of a Lutein-Enriched Novel Acidophile Microalga Grown on Urea

Directory of Open Access Journals (Sweden)

Carlos Vilchez

2010-12-01

Full Text Available Coccomyxa acidophila is an extremophile eukaryotic microalga isolated from the Tinto River mining area in Huelva, Spain. Coccomyxa acidophila accumulates relevant amounts of b-carotene and lutein, well-known carotenoids with many biotechnological applications, especially in food and health-related industries. The acidic culture medium (pH < 2.5 that prevents outdoor cultivation from non-desired microorganism growth is one of the main advantages of acidophile microalgae production. Conversely, acidophile microalgae growth rates are usually very low compared to common microalgae growth rates. In this work, we show that mixotrophic cultivation on urea efficiently enhances growth and productivity of an acidophile microalga up to typical values for common microalgae, therefore approaching acidophile algal production towards suitable conditions for feasible outdoor production. Algal productivity and potential for carotenoid accumulation were analyzed as a function of the nitrogen source supplied. Several nitrogen conditions were assayed: nitrogen starvation, nitrate and/or nitrite, ammonia and urea. Among them, urea clearly led to the best cell growth (~4 ´ 108 cells/mL at the end of log phase. Ammonium led to the maximum chlorophyll and carotenoid content per volume unit (220 mg·mL-1 and 35 mg·mL-1, respectively. Interestingly, no significant differences in growth rates were found in cultures grown on urea as C and N source, with respect to those cultures grown on nitrate and CO2 as nitrogen and carbon sources (control cultures. Lutein accumulated up to 3.55 mg·g-1 in the mixotrophic cultures grown on urea. In addition, algal growth in a shaded culture revealed the first evidence for an active xanthophylls cycle operative in acidophile microalgae.

Factors Affecting Isoflavone Content in Soybean Seeds Grown in Thailand

OpenAIRE

Teekachunhatean, Supanimit; Hanprasertpong, Nutthiya; Teekachunhatean, Thawatchai

2013-01-01

Soybeans are the most common source of isoflavones in human foods. The objectives of this study were to determine the effects of Thai soybean variety, planting date, physical seed quality, storage condition, planting location, and crop year on isoflavone content, as well as to analyze the relationship between seed viability and isoflavone content in soybean seeds grown in Thailand. Isoflavone content in Thai soybeans varied considerably depending on such factors as variety, physical seed qual...

Effects of growth duration on the structural and optical properties of ZnO nanorods grown on seed-layer ZnO/polyethylene terephthalate substrates

Energy Technology Data Exchange (ETDEWEB)

Jeong, Y.I.; Shin, C.M.; Heo, J.H. [Department of Nano Systems Engineering, Center for Nano Manufacturing Inje University, Gimhae, Gyeongnam 621-749 (Korea, Republic of); Ryu, H., E-mail: hhryu@inje.ac.kr [Department of Nano Systems Engineering, Center for Nano Manufacturing Inje University, Gimhae, Gyeongnam 621-749 (Korea, Republic of); Lee, W.J. [Department of Nano Engineering, Dong-Eui University, Busan 614-714 (Korea, Republic of); Chang, J.H. [Major of Nano Semiconductor, Korea Maritime University, Busan 606-791 (Korea, Republic of); Son, C.S. [Department of Electronic Materials Engineering, Silla University, Busan 617-736 (Korea, Republic of); Yun, J. [Department of Nano Science and Engineering, Institute of Advanced Materials Kyungnam University, Changwon, Gyeongnam 631-701 (Korea, Republic of)

2011-10-01

Well-aligned single crystalline zinc oxide (ZnO) nanorods were successfully grown, by hydrothermal synthesis at a low temperature, on flexible polyethylene terephthalate (PET) substrates with a seed layer. Photoluminescence (PL), field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) measurements were used to analyze the optical and structural properties of ZnO nanorods grown for various durations from 0.5 h to 10 h. Regular and well-aligned ZnO nanorods with diameters ranging from 62 nm to 127 nm and lengths from 0.3 {mu}m to 1.65 {mu}m were formed after almost 5 h of growth. The growth rate of ZnO grown on PET substrates is lower than that grown on Si (1 0 0) substrates. Enlarged TEM images show that the tips of the ZnO nanorods grown for 6 h have a round shape, whereas the tips grown for 10 h are sharpened. The crystal properties of ZnO nanorods can be tuned by using the growth duration as a growth condition. The XRD and PL results indicate that the structural and optical properties of the ZnO nanorods are most improved after 5 h and 6 h of growth, respectively.

Effect of SHI irradiation on structural, surface morphological and optical studies of CVT grown ZnSSe single crystals

International Nuclear Information System (INIS)

Kannappan, P.; Asokan, K.; Krishna, J.B.M.; Dhanasekaran, R.

2013-01-01

Highlights: •CVT grown ZnSSe single crystals were irradiated with 120 MeV Au ion. •The GIXRD results show the FWHM increases with increasing ion fluency. •The AFM study show the surface roughness increases with ion fluency. •The optical band gap energy vary with increasing ion fluency. •The PL emission decreases with increasing ion fluency. -- Abstract: The ZnSSe single crystals grown by chemical vapour transport (CVT) method have been irradiated by 120 MeV Au 9+ ions at room temperature with fluences of 1 × 10 12 and 5 × 10 12 ions/cm 2 . The grazing incidence X-ray diffraction (GIXRD) results show that the full width at half maximum (FWHM) value for the as grown ZnSSe crystal is 0.215°; and for the irradiated samples, the FWHM values are 0.413° and 0.625°, with the increase of ion fluences. The atomic force microscopy (AFM) studies reveal the formation of the pits and islands due to irradiation. The optical absorption cut off wavelength is found to be 441 nm for as grown ZnSSe crystal. The cut off values are increased to 447 nm and 457 nm for the irradiated samples with increasing ion fluency. The photoluminescence studies show the emission for the as grown ZnSSe is 590 nm whereas for the irradiated samples in the emission range it is 580–590 nm and 575–595 nm due to SHI irradiation. FT-Raman spectra analysis has been made for the ZnSSe single crystals and irradiated samples. The results are discussed in detail

Effect of SHI irradiation on structural, surface morphological and optical studies of CVT grown ZnSSe single crystals

Energy Technology Data Exchange (ETDEWEB)

Kannappan, P. [Crystal Growth Centre, Anna University, Chennai 600 025 (India); Asokan, K. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110 067 (India); Krishna, J.B.M. [UGC-DAE Consortium for Scientific Research, III-/LB-8, Bidhan nagar, Kolkata 700 098 (India); Dhanasekaran, R., E-mail: rdcgc@yahoo.com [Crystal Growth Centre, Anna University, Chennai 600 025 (India)

2013-12-15

Highlights: •CVT grown ZnSSe single crystals were irradiated with 120 MeV Au ion. •The GIXRD results show the FWHM increases with increasing ion fluency. •The AFM study show the surface roughness increases with ion fluency. •The optical band gap energy vary with increasing ion fluency. •The PL emission decreases with increasing ion fluency. -- Abstract: The ZnSSe single crystals grown by chemical vapour transport (CVT) method have been irradiated by 120 MeV Au{sup 9+} ions at room temperature with fluences of 1 × 10{sup 12} and 5 × 10{sup 12} ions/cm{sup 2}. The grazing incidence X-ray diffraction (GIXRD) results show that the full width at half maximum (FWHM) value for the as grown ZnSSe crystal is 0.215°; and for the irradiated samples, the FWHM values are 0.413° and 0.625°, with the increase of ion fluences. The atomic force microscopy (AFM) studies reveal the formation of the pits and islands due to irradiation. The optical absorption cut off wavelength is found to be 441 nm for as grown ZnSSe crystal. The cut off values are increased to 447 nm and 457 nm for the irradiated samples with increasing ion fluency. The photoluminescence studies show the emission for the as grown ZnSSe is 590 nm whereas for the irradiated samples in the emission range it is 580–590 nm and 575–595 nm due to SHI irradiation. FT-Raman spectra analysis has been made for the ZnSSe single crystals and irradiated samples. The results are discussed in detail.

Co{sub 2}FeAl Heusler thin films grown on Si and MgO substrates: Annealing temperature effect

Energy Technology Data Exchange (ETDEWEB)

Belmeguenai, M., E-mail: belmeguenai.mohamed@univ-paris13.fr; Tuzcuoglu, H.; Zighem, F.; Chérif, S. M.; Moch, P. [LSPM (CNRS-UPR 3407), 99 avenue Jean-Baptiste Clément, Université Paris 13, 93430 Villetaneuse (France); Gabor, M. S., E-mail: mihai.gabor@phys.utcluj.ro; Petrisor, T. [Center for Superconductivity, Spintronics and Surface Science, Technical University of Cluj-Napoca, Str. Memorandumului No. 28 RO-400114 Cluj-Napoca (Romania); Tiusan, C. [Center for Superconductivity, Spintronics and Surface Science, Technical University of Cluj-Napoca, Str. Memorandumului No. 28 RO-400114 Cluj-Napoca (Romania); Institut Jean Lamour, CNRS, Université de Nancy, BP 70239, F–54506 Vandoeuvre (France)

2014-01-28

10 nm and 50 nm Co{sub 2}FeAl (CFA) thin films have been deposited on MgO(001) and Si(001) substrates by magnetron sputtering and annealed at different temperatures. X-rays diffraction revealed polycrystalline or epitaxial growth (according to CFA(001)[110]//MgO(001)[100] epitaxial relation) for CFA films grown on a Si and on a MgO substrate, respectively. For these later, the chemical order varies from the A2 phase to the B2 phase when increasing the annealing temperature (T{sub a}), while only the A2 disorder type has been observed for CFA grown on Si. Microstrip ferromagnetic resonance (MS-FMR) measurements revealed that the in-plane anisotropy results from the superposition of a uniaxial and a fourfold symmetry term for CFA grown on MgO substrates. This fourfold anisotropy, which disappears completely for samples grown on Si, is in accord with the crystal structure of the samples. The fourfold anisotropy field decreases when increasing T{sub a}, while the uniaxial anisotropy field is nearly unaffected by T{sub a} within the investigated range. The MS-FMR data also allow for concluding that the gyromagnetic factor remains constant and that the exchange stiffness constant increases with T{sub a}. Finally, the FMR linewidth decreases when increasing T{sub a}, due to the enhancement of the chemical order. We derive a very low intrinsic damping parameter (1.1×10{sup −3} and 1.3×10{sup −3} for films of 50 nm thickness annealed at 615 °C grown on MgO and on Si, respectively)

Understanding the defect structure of solution grown zinc oxide

Energy Technology Data Exchange (ETDEWEB)

Liew, Laura-Lynn [Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A-STAR), 3 Research Link, Singapore 117602 (Singapore); School of Materials Science and Engineering, Nanyang Technological University, Block N4.1 Nanyang Avenue, Singapore 639798 (Singapore); Sankar, Gopinathan, E-mail: g.sankar@ucl.ac.uk [Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ (United Kingdom); Handoko, Albertus D. [Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A-STAR), 3 Research Link, Singapore 117602 (Singapore); Goh, Gregory K.L., E-mail: g-goh@imre.a-star.edu.sg [Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A-STAR), 3 Research Link, Singapore 117602 (Singapore); School of Materials Science and Engineering, Nanyang Technological University, Block N4.1 Nanyang Avenue, Singapore 639798 (Singapore); Kohara, Shinji [Japan Synchrotron Radiation Research Institute (JASRI), Mikazuki, Sayo, Hyogo 679-5198 (Japan)

2012-05-15

Zinc oxide (ZnO) is a wide bandgap semiconducting oxide with many potential applications in various optoelectronic devices such as light emitting diodes (LEDs) and field effect transistors (FETs). Much effort has been made to understand the ZnO structure and its defects. However, one major issue in determining whether it is Zn or O deficiency that provides ZnO its unique properties remains. X-ray absorption spectroscopy (XAS) is an ideal, atom specific characterization technique that is able to probe defect structure in many materials, including ZnO. In this paper, comparative studies of bulk and aqueous solution grown ({<=}90 Degree-Sign C) ZnO powders using XAS and x-ray pair distribution function (XPDF) techniques are described. The XAS Zn-Zn correlation and XPDF results undoubtedly point out that the solution grown ZnO contains Zn deficiency, rather than the O deficiency that were commonly reported. This understanding of ZnO short range order and structure will be invaluable for further development of solid state lighting and other optoelectronic device applications. - Graphical abstract: Highlights: Black-Right-Pointing-Pointer ZnO powders have been synthesized through an aqueous solution method. Black-Right-Pointing-Pointer Defect structure studied using XAS and XPDF. Black-Right-Pointing-Pointer Zn-Zn correlations are less in the ZnO powders synthesized in solution than bulk. Black-Right-Pointing-Pointer Zn vacancies are present in the powders synthesized. Black-Right-Pointing-Pointer EXAFS and XPDF, when used complementary, are useful characterization techniques.

Single crystal diamond detectors grown by chemical vapor deposition

International Nuclear Information System (INIS)

Tuve, C.; Angelone, M.; Bellini, V.; Balducci, A.; Donato, M.G.; Faggio, G.; Marinelli, M.; Messina, G.; Milani, E.; Morgada, M.E.; Pillon, M.; Potenza, R.; Pucella, G.; Russo, G.; Santangelo, S.; Scoccia, M.; Sutera, C.; Tucciarone, A.; Verona-Rinati, G.

2007-01-01

The detection properties of heteropitaxial (polycrystalline, pCVD) and homoepitaxial (single crystal, scCVD) diamond films grown by microwave chemical vapor deposition (CVD) in the Laboratories of Roma 'Tor Vergata' University are reported. The pCVD diamond detectors were tested with α-particles from different sources and 12 C ions produced by 15MV Tandem accelerator at Southern National Laboratories (LNS) in Catania (Italy). pCVDs were also used to monitor 14MeV neutrons produced by the D-T plasma at Joint European Torus (JET), Culham, U.K. The limit of pCVDs is the poor energy resolution. To overcome this problem, we developed scCVD diamonds using the same reactor parameters that optimized pCVD diamonds. scCVD were grown on a low cost (100) HPHT single crystal substrate. A detector 110μm thick was tested under α-particles and under 14MeV neutron irradiation. The charge collection efficiency spectrum measured under irradiation with a triple α-particle source shows three clearly resolved peaks, with an energy resolution of about 1.1%. The measured spectra under neutron irradiation show a well separated C(n,α 0 ) 9 Be12 reaction peak with an energy spread of 0.5MeV for 14.8MeV neutrons and 0.3MeV for 14.1MeV neutrons, which are fully compatible with the energy spread of the incident neutron beams

Seed yield and quality of pepper plants grown under salt stress ...

African Journals Online (AJOL)

The effect of salinity on seed yield and quality of pepper plants were evaluated. Plants were grown in five salt levels (electrical conductivity, EC): 1.0, 1.5, 2.0, 4.0 to 6.0 dSm-1 in glasshouse. Seed yield was assessed by seed weight/fruit, seed weight/plant and individual seed weight. Seed quality was measured by ...

contents of sweet cherry ( Prunus avium L. ) type grown in Konya ...

African Journals Online (AJOL)

In this research, several physico-chemical properties and mineral contents of one earliest (May 19) sweet cherry type grown in Konya region were determined. The results in terms of chemical properties were total soluble solids, 18.33 mg/100 g; pH, 3.86; color, S41P50E41; texture, 0.25 kg/cm2; and juice yield, 66.28%.

Seed yield and quality of pepper plants grown under salt stress

African Journals Online (AJOL)

İbrahim Demir

2013-12-04

Dec 4, 2013 ... The effect of salinity on seed yield and quality of pepper plants were evaluated. Plants were grown in five salt levels (electrical conductivity, EC): 1.0, 1.5, 2.0, 4.0 to 6.0 dSm-1 in glasshouse. Seed yield was assessed by seed weight/fruit, seed weight/plant and individual seed weight. Seed quality was.

Low-Temperature, Chemically Grown Titanium Oxide Thin Films with a High Hole Tunneling Rate for Si Solar Cells

Directory of Open Access Journals (Sweden)

Yu-Tsu Lee

2016-05-01

Full Text Available In this paper, we propose a chemically grown titanium oxide (TiO2 on Si to form a heterojunction for photovoltaic devices. The chemically grown TiO2 does not block hole transport. Ultraviolet photoemission spectroscopy was used to study the band alignment. A substantial band offset at the TiO2/Si interface was observed. X-ray photoemission spectroscopy (XPS revealed that the chemically grown TiO2 is oxygen-deficient and contains numerous gap states. A multiple-trap-assisted tunneling (TAT model was used to explain the high hole injection rate. According to this model, the tunneling rate can be 105 orders of magnitude higher for holes passing through TiO2 than for flow through SiO2. With 24-nm-thick TiO2, a Si solar cell achieves a 33.2 mA/cm2 photocurrent on a planar substrate, with a 9.4% power conversion efficiency. Plan-view scanning electron microscopy images indicate that a moth-eye-like structure formed during TiO2 deposition. This structure enables light harvesting for a high photocurrent. The high photocurrent and ease of production of chemically grown TiO2 imply that it is a suitable candidate for future low-cost, high-efficiency solar cell applications.

Acetylcholinesterase inhibition and antibacterial activity of Mondia whitei adventitious roots and ex vitro-grown somatic embryogenic-biomass

Directory of Open Access Journals (Sweden)

Ponnusamy Baskaran

2016-10-01

Full Text Available Mondia whitei (Hook.f. Skeels is an important endangered medicinal and commercial plant in South Africa. In vitro propagation systems are required for biomass production and bioactivity analysis to supplement wild resources/stocks. Adventitious roots from somatic embryogenic explants using suspension culture and ex vitro-grown plants produced via somatic embryogenesis were established using different plant growth regulator treatments. The adventitious root biomass and different parts of ex vitro-grown and mother plants were used to investigate the potential for acetylcholinesterase (AChE and antibacterial activities. Adventitious roots derived from 2.5 µM indole-3-acetic acid (IAA treatments and ex vitro-grown plants derived from meta-topolin riboside (mTR and IAA treatments gave the best AChE and antibacterial activities. The in vitro-established M. whitei and ex vitro biomass have comparable ability to function as inhibitors of acetylcholinesterase and antibacterial agents, and can be used as potent bioresources in traditional medicine

Structural and optical properties of ZnO films grown on silicon and ...

Indian Academy of Sciences (India)

TECS

Abstract. Photoluminescence (PL) properties of undoped ZnO thin films grown by rf magnetron sputtering on silicon .... voluted O1 s and (c) typical Zr 3d spectra of ZrO2/ZnO/Si film. .... strate doping concentration (NB) of ≈ 2⋅5 × 1015 cm–3 is.

A study of 1/f noise in InP grown by CBE

NARCIS (Netherlands)

Chen, X.Y.; Leijs, M.R.

1996-01-01

The origin of low-frequency noise in InP was studied experimentally by measuring the noise of InP layers grown by chemical beam epitaxy (CBE). Such InP layers are unintentionally doped, but of varying purity and always of n-type conductivity. We performed noise measurements at temperatures from 77

Optimization of CVD parameters for long ZnO NWs grown on ITO

Indian Academy of Sciences (India)

The optimization of chemical vapour deposition (CVD) parameters for long and vertically aligned (VA) ZnO nanowires (NWs) were investigated. Typical ZnO NWs as a single crystal grown on indium tin oxide (ITO)-coated glass substrate were successfully synthesized. First, the conducted side of ITO–glass substrate was ...

Modeling of soil CO2 efflux during water table fluctuation based on in situ measured data from a sedge-grass marsh

Czech Academy of Sciences Publication Activity Database

Pavelka, Marian; Dařenová, Eva; Dušek, Jiří

2016-01-01

Roč. 14, č. 3 (2016), s. 423-437 ISSN 1589-1623 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:67179843 Keywords : carex acuta * fen * soil chamber * soil respiration * wetland Subject RIV: EH - Ecology, Behaviour Impact factor: 0.681, year: 2016

454-sequencing reveals stochastic local reassembly and high disturbance tolerance within arbuscular mycorrhizal fungal communities

DEFF Research Database (Denmark)

Lekberg, Karin Ylva Margareta; Schnoor, Tim; Kjøller, Rasmus

2012-01-01

unpredictable, with approximately 40%of all sequences within a sample belonging to a single OTU of varying identity. The distribution of two plant species that are often poorly colonized by AMfungi (Dianthus deltoides and Carex arenaria) correlated significantly with the OTU composition, which may indicate...

Nieuwe plantesoorten voor Vlieland

NARCIS (Netherlands)

Roos, de G.Th.

1977-01-01

The author mentions the records of a number of taxa new for the Wadden island of Vlieland, viz. Thalictrum dunense L. subsp. dunense (Dum.) Rouy et Fouc., Ruppia cirrhosa (Petagna) Grande, Carex acutiformis Ehrh., C. paniculata L., Phalaris canariensis L., and Orchis praetermissa Druce.

Assessment of Total Phenolic and Flavonoid Content, Antioxidant Properties, and Yield of Aeroponically and Conventionally Grown Leafy Vegetables and Fruit Crops: A Comparative Study

Directory of Open Access Journals (Sweden)

Suman Chandra

2014-01-01

Full Text Available A comparison of the product yield, total phenolics, total flavonoids, and antioxidant properties was done in different leafy vegetables/herbs (basil, chard, parsley, and red kale and fruit crops (bell pepper, cherry tomatoes, cucumber, and squash grown in aeroponic growing systems (AG and in the field (FG. An average increase of about 19%, 8%, 65%, 21%, 53%, 35%, 7%, and 50% in the yield was recorded for basil, chard, red kale, parsley, bell pepper, cherry tomatoes, cucumber, and squash, respectively, when grown in aeroponic systems, compared to that grown in the soil. Antioxidant properties of AG and FG crops were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DDPH and cellular antioxidant (CAA assays. In general, the study shows that the plants grown in the aeroponic system had a higher yield and comparable phenolics, flavonoids, and antioxidant properties as compared to those grown in the soil.

Dislocations limited electronic transport in hydride vapour phase epitaxy grown GaN templates: A word of caution for the epitaxial growers

Energy Technology Data Exchange (ETDEWEB)

Chatterjee, Abhishek, E-mail: cabhishek@rrcat.gov.in; Khamari, Shailesh K.; Kumar, R.; Dixit, V. K.; Oak, S. M.; Sharma, T. K., E-mail: tarun@rrcat.gov.in [Semiconductor Physics and Devices Laboratory, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India)

2015-01-12

GaN templates grown by hydride vapour phase epitaxy (HVPE) and metal organic vapour phase epitaxy (MOVPE) techniques are compared through electronic transport measurements. Carrier concentration measured by Hall technique is about two orders larger than the values estimated by capacitance voltage method for HVPE templates. It is learnt that there exists a critical thickness of HVPE templates below which the transport properties of epitaxial layers grown on top of them are going to be severely limited by the density of charged dislocations lying at layer-substrate interface. On the contrary MOVPE grown templates are found to be free from such limitations.

Characteristics of threading dislocations in ZnO grown on facet-controlled epitaxial overgrown GaN templates

International Nuclear Information System (INIS)

Zhou, H L; Chua, S J; Chow, S Y; Pan, H; Zhu, Y W; Feng, Y P; Wang, L S; Zang, K Y; Liu, W; Tripathy, S

2007-01-01

Using transmission electron microscopy (TEM), the authors have investigated the behavior of threading dislocations in ZnO selectively grown on a facet-controlled epitaxial overgrown GaN template. In this case, the ZnO is grown by a vapor transport method. The TEM study in the overgrown regions shows that all the pure-edge type dislocations in ZnO are parallel toward the mask area and vertical propagation of dislocation to the ZnO surface is minimized. Using such a selective growth technique on a faceted semi-polar GaN surface, a reduction of threading dislocation density in ZnO could be achieved

Defects in silicon carbide grown by fluorinated chemical vapor deposition chemistry

Science.gov (United States)

Stenberg, Pontus; Booker, Ian D.; Karhu, Robin; Pedersen, Henrik; Janzén, Erik; Ivanov, Ivan G.

2018-04-01

Point defects in n- and p-type 4H-SiC grown by fluorinated chemical vapor deposition (CVD) have been characterized optically by photoluminescence (PL) and electrically by deep-level transient spectroscopy (DLTS) and minority carrier transient spectroscopy (MCTS). The results are considered in comparison with defects observed in non-fluorinated CVD growth (e.g., using SiH4 instead of SiF4 as silicon precursor), in order to investigate whether specific fluorine-related defects form during the fluorinated CVD growth, which might prohibit the use of fluorinated chemistry for device-manufacturing purposes. Several new peaks identifying new defects appear in the PL of fluorinated-grown samples, which are not commonly observed neither in other halogenated chemistries, nor in the standard CVD chemistry using silane (SiH4). However, further investigation is needed in order to determine their origin and whether they are related to incorporation of F in the SiC lattice, or not. The electric characterization does not find any new electrically-active defects that can be related to F incorporation. Thus, we find no point defects prohibiting the use of fluorinated chemistry for device-making purposes.

Root uptake and translocation of perfluorinated alkyl acids by three hydroponically grown crops

NARCIS (Netherlands)

Felizeter, S.; McLachlan, M.S.; de Voogt, P.

2014-01-01

Tomato, cabbage, and zucchini plants were grown hydroponically in a greenhouse. They were exposed to 14 perfluorinated alkyl acids (PFAAs) at four different concentrations via the nutrient solution. At maturity the plants were harvested, and the roots, stems, leaves, twigs (where applicable), and

Charge collection efficiency in SI GaAs grown from melts with variable composition as a material for solar neutrino detection

International Nuclear Information System (INIS)

Verbitskaya, E.; Eremin, V.; Ivanov, A.; Strokan, N.; Vasilev, V.; Markov, A.; Polyakov, A.; Gavrin, V.; Kozlova, Yu.; Veretenkin, E.; Bowles, T.J.

2000-01-01

The results on electrical characteristics and charge collection efficiency in the detectors from bulk SI GaAs developed as a material for solar neutrino spectroscopy are presented. SI GaAs crystals were grown by the Czochralski method. The changes in the stoichiometric components are permanently controlled. It is shown that the performance of GaAs p + -i-n + structures provided the range of operational reverse voltage up to 1 kV. Measurement of deep level spectra and their analysis reveal the dominant deep levels - hole traps E v +0.51 and +0.075 eV in GaAs grown from stoichiometric and nonstoichiometric melts, respectively. Investigation of carrier transport properties and bulk homogeneity evinced in charge collection efficiency has shown advantageous results for SI GaAs grown from stoichiometric melt. The reduction of carrier transport parameters and charge collection efficiency in GaAs grown from nonstoichiometric melt is analyzed taking into consideration formation of the hole trap E v +0.075 eV, presumably assigned to Ga antisite and its influence on the concentration of the ionized deep donor level EL2 +

Structural and electrical properties of Ge(111) films grown on Si(111) substrates and application to Ge(111)-on-Insulator

Energy Technology Data Exchange (ETDEWEB)

Sawano, K., E-mail: sawano@tcu.ac.jp [Advanced Research Laboratories, Tokyo City University, 8-15-1 Todoroki, Setagaya-ku, Tokyo (Japan); Hoshi, Y.; Kubo, S. [Advanced Research Laboratories, Tokyo City University, 8-15-1 Todoroki, Setagaya-ku, Tokyo (Japan); Arimoto, K.; Yamanaka, J.; Nakagawa, K. [Center for Crystal Science and Technology, University of Yamanashi, 7 Miyamae-cho, Kofu (Japan); Hamaya, K. [Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka (Japan); Miyao, M. [Department of Electronics, Kyushu University, 744 Motooka, Fukuoka (Japan); Shiraki, Y. [Advanced Research Laboratories, Tokyo City University, 8-15-1 Todoroki, Setagaya-ku, Tokyo (Japan)

2016-08-31

Structural and electrical properties of a Ge(111) layer directly grown on a Si(111) substrate are studied. Via optimized two-step growth manner, we form a high-quality relaxed Ge layer, where strain-relieving dislocations are confined close to a Ge/Si interface. Consequently, a density of holes, which unintentionally come from crystal defects, is highly suppressed below 4 × 10{sup 16} cm{sup −3}, which leads to significantly high hole Hall mobility exceeding 1500 cm{sup 2}/Vs at room temperature. By layer transfer of the grown Ge layer, we also fabricate a Ge(111)-on-Insulator, which is a promising template for high-performance Ge-based electronic and photonic devices. - Highlights: • A high-quality Ge layer is epitaxially grown on a Si(111) by two-step growth manner. • Growth conditions, such as growth temperatures, are optimized. • Very high hole mobility is obtained from Ge(111) grown on Si(111). • High-quality thin Ge-on-Insulator with (111) orientation is obtained.

Biochemical and biological responses in V79 cells grown in different background radiation environment

International Nuclear Information System (INIS)

Amicarelli, F.; Colafarina, S.; Ara, C.; Antonelli, F.; Balata, M.; Belli, M.; Simone, G.; Satta, L.

2003-01-01

Full text: In order to investigate the influence of a low background radiation environment on the biochemical and biological responses of mammalian cells cultured in vitro, a cell culture laboratory has been set up at the Gran Sasso National Laboratory (LNGS) of the Istituto Nazionale di Fisica Nucleare (INFN), located under the Gran Sasso d'Italia mountain, where cosmic rays are reduced by a factor of 10 6 and neutrons by a factor of 10 3 respect to the outside environment. Chinese hamster V79 cells were grown in parallel for up to nine months at LNGS and at the Istituto Superiore di Sanita (ISS). At the LNGS the exposure due to radon was reduced by a factor of about 25 with respect to the ISS. The biological end points addressed concerned cells proliferation, the expression of enzymes specific for the reduction of superoxydes, mutation induction by gamma-rays at the hprt locus and apoptotic sensitivity. After 9 months of culture, the cells grown at the LNGS, compared to the cells grown at the ISS, exhibit: i) a significant increase of the cell density at confluence; ii) a significantly higher capacity to scavenge organic and inorganic hydroperoxydes but a reduced scavenging capacity towards superoxide anions; iii) an increase in both the basal hprt mutation frequency and the sensitivity to the mutagenic effect of gamma-rays. The cells grown at the LNGS also show greater apoptotic sensitivity at the third month of culture that is no longer detected after nine months. Overall, these data suggest that cell response to ionizing radiation may be more complex than that predicted by a linear relationship with the dose and are consistent with the occurrence of an adaptive response related to the background radiation. However, other possibilities cannot be excluded such as the selection, in the two cultures, of clones having different characteristics, independently of the different radiation background. Work is in progress to better elucidate this point

Elastically strained and relaxed La0.67Ca0.33MnO3 films grown on lanthanum aluminate substrates with different orientations

Science.gov (United States)

Boikov, Yu. A.; Serenkov, I. T.; Sakharov, V. I.; Claeson, T.

2016-12-01

Structure of 40-nm thick La0.67Ca0.33MnO3 (LCMO) films grown by laser evaporation on (001) and (110) LaAlO3 (LAO) substrates has been investigated using the methods of medium-energy ion scattering and X-ray diffraction. The grown manganite layers are under lateral biaxial compressive mechanical stresses. When (110)LAO wafers are used as the substrates, stresses relax to a great extent; the relaxation is accompanied by the formation of defects in a (3-4)-nm thick manganite-film interlayer adjacent to the LCMO-(110)LAO interface. When studying the structure of the grown layers, their electro- and magnetotransport parameters have been measured. The electroresistance of the LCMO films grown on the substrates of both types reached a maximum at temperature T M of about 250 K. At temperatures close to T M magnetoresistance of the LCMO/(110)LAO films exceeds that of the LCMO/(001)LAO films by 20-30%; however, the situation is inverse at low temperatures ( T < 150 K). At T < T M , the magnetotransport in the grown manganite films significantly depends on the spin ordering in ferromagnetic domains, which increase with a decrease in temperature.

Electronic and surface properties of pentacene films deposited on SiO{sub 2} prepared by the sol–gel and thermally grown methods

Energy Technology Data Exchange (ETDEWEB)

Dai, Chi-Jie [Department of Physics, National Changhua University of Education, Changhua 500, Taiwan (China); Tsao, Hou-Yen [Institute of Photonics, National Changhua University of Education, Changhua 500, Taiwan (China); Lin, Yow-Jon, E-mail: rzr2390@yahoo.com.tw [Institute of Photonics, National Changhua University of Education, Changhua 500, Taiwan (China); Liu, Day-Shan [Graduate Institute of Electro-Optical and Materials Science, National Formosa University, Huwei 632, Taiwan (China)

2014-02-03

This study investigates the effect of different types of SiO{sub 2} on the electronic and surface properties of pentacene films. Developing better contacts on dielectrics is one of the main challenges for pentacene-based transistor technology. The water contact angle variation indicates more hydrophobic thermally grown SiO{sub 2} surfaces than sol–gel SiO{sub 2} surfaces, suggesting that the thermally grown SiO{sub 2} dielectric enables a better molecular arrangement as the pentacene layer is deposited. It is found that the carrier mobility in pentacene on thermally grown SiO{sub 2} dielectrics is higher than that in pentacene on sol–gel SiO{sub 2} dielectrics. The Hall-effect analysis by using the polaron theory revealed that the enhanced carrier mobility is due to the increased spacing between molecules. - Highlights: • The carrier mobility of pentacene on thermally grown and sol–gel SiO{sub 2} was researched. • The enhanced carrier mobility of pentacene on thermally grown SiO2 was observed. • The dominance of tunneling (hopping) at low (high) temperatures was observed. • The carrier mobility is correlated with the morphology of pentacene films.

Development of bimetal-grown multi-scale carbon micro-nanofibers as an immobilizing matrix for enzymes in biosensor applications

Energy Technology Data Exchange (ETDEWEB)

Hood, Amit R. [Department of Chemical Engineering, Indian Institute of Technology, Kanpur (India); Saurakhiya, Neelam; Deva, Dinesh [DST Unit on Nanosciences, Kanpur, 208016 (India); Sharma, Ashutosh [Department of Chemical Engineering, Indian Institute of Technology, Kanpur (India); DST Unit on Nanosciences, Kanpur, 208016 (India); Verma, Nishith, E-mail: nishith@iitk.ac.in [Department of Chemical Engineering, Indian Institute of Technology, Kanpur (India); Center for Environmental Science and Engineering, Kanpur 208016 (India)

2013-10-15

This study describes the development of a novel bimetal (Fe and Cu)-grown hierarchical web of carbon micro-nanofiber-based electrode for biosensor applications, in particular to detect glucose in liquids. Carbon nanofibers (CNFs) are grown on activated carbon microfibers (ACFs) by chemical vapor deposition (CVD) using Cu and Fe as the metal catalysts. The transition metal-fiber composite is used as the working electrode of a biosensor applied to detect glucose in liquids. In such a bi-nanometal-grown multi-scale web of ACF/CNF, Cu nanoparticles adhere to the ACF-surface, whereas Fe nanoparticles used to catalyze the growth of nanofibers attach to the CNF tips. By ultrasonication, Fe nanoparticles are dislodged from the tips of the CNFs. Glucose oxidase (GOx) is subsequently immobilized on the tips by adsorption. The dispersion of Cu nanoparticles at the substrate surface results in increased conductivity, facilitating electron transfer from the glucose solution to the ACF surface during the enzymatic reaction with glucose. The prepared Cu-ACF/CNF/GOx electrode is characterized for various surface and physicochemical properties by different analytical techniques, including scanning electron microscopy (SEM), electron dispersive X-ray analysis (EDX), Fourier-transform infrared spectroscopy (FTIR), BET surface area analysis, and transmission electron microscopy (TEM). The electrochemical tests show that the prepared electrode has fast response current, electrochemical stability, and high electron transfer rate, corroborated by CV and calibration curves. The prepared transition metal-based carbon electrode in this study is cost-effective, simple to develop, and has a stable immobilization matrix for enzymes. - Graphical abstract: A novel bimetal (Fe and Cu)-grown hierarchical web of carbon micro-nanofiber-based electrode is synthesized for biosensor applications, in particular to detect glucose in liquids. Carbon nanofibers are grown on activated carbon microfibers by

Development of bimetal-grown multi-scale carbon micro-nanofibers as an immobilizing matrix for enzymes in biosensor applications

International Nuclear Information System (INIS)

Hood, Amit R.; Saurakhiya, Neelam; Deva, Dinesh; Sharma, Ashutosh; Verma, Nishith

2013-01-01

This study describes the development of a novel bimetal (Fe and Cu)-grown hierarchical web of carbon micro-nanofiber-based electrode for biosensor applications, in particular to detect glucose in liquids. Carbon nanofibers (CNFs) are grown on activated carbon microfibers (ACFs) by chemical vapor deposition (CVD) using Cu and Fe as the metal catalysts. The transition metal-fiber composite is used as the working electrode of a biosensor applied to detect glucose in liquids. In such a bi-nanometal-grown multi-scale web of ACF/CNF, Cu nanoparticles adhere to the ACF-surface, whereas Fe nanoparticles used to catalyze the growth of nanofibers attach to the CNF tips. By ultrasonication, Fe nanoparticles are dislodged from the tips of the CNFs. Glucose oxidase (GOx) is subsequently immobilized on the tips by adsorption. The dispersion of Cu nanoparticles at the substrate surface results in increased conductivity, facilitating electron transfer from the glucose solution to the ACF surface during the enzymatic reaction with glucose. The prepared Cu-ACF/CNF/GOx electrode is characterized for various surface and physicochemical properties by different analytical techniques, including scanning electron microscopy (SEM), electron dispersive X-ray analysis (EDX), Fourier-transform infrared spectroscopy (FTIR), BET surface area analysis, and transmission electron microscopy (TEM). The electrochemical tests show that the prepared electrode has fast response current, electrochemical stability, and high electron transfer rate, corroborated by CV and calibration curves. The prepared transition metal-based carbon electrode in this study is cost-effective, simple to develop, and has a stable immobilization matrix for enzymes. - Graphical abstract: A novel bimetal (Fe and Cu)-grown hierarchical web of carbon micro-nanofiber-based electrode is synthesized for biosensor applications, in particular to detect glucose in liquids. Carbon nanofibers are grown on activated carbon microfibers by

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

Extraction and characterization of seed oil from naturally-grown Chinese tallow trees

Science.gov (United States)

Xiao-Qin Yang; Hui Pan; Tao Zeng; Todd F. Shupe; Chung-Yun Hse

2013-01-01

Seeds were collected from locally and naturally grown Chinese tallow trees (CTT) and characterized for general physical and chemical properties and fatty acid composition of the lipids. The effects of four different solvents (petroleum ether, hexane, diethyl ether, and 95 % ethanol) and two extraction methods (supercritical carbon dioxide (SC-CO2) and conventional...

Estimating leaf area and leaf biomass of open-grown deciduous urban trees

Science.gov (United States)

David J. Nowak

1996-01-01

Logarithmic regression equations were developed to predict leaf area and leaf biomass for open-grown deciduous urban trees based on stem diameter and crown parameters. Equations based on crown parameters produced more reliable estimates. The equations can be used to help quantify forest structure and functions, particularly in urbanizing and urban/suburban areas.

Role of arbuscular mycorrhiza in alleviating salinity stress in wheat (Triticum aestivum L.) grown under ambient and elevated CO2

DEFF Research Database (Denmark)

Zhu, X.; Song, F.; Liu, S.

2016-01-01

fungi enhanced NUE by altering plant C assimilation and N uptake. AM plants had higher soluble sugar concentration and [K+]: [Na+] ratio compared with non-AM plants. It is concluded that AM symbiosis improves wheat plant growth at vegetative stages through increasing stomatal conductance, enhancing NUE...... role of AM fungus in alleviating salinity stress in wheat (Triticum aestivum L.) plants grown under ambient and elevated CO2 concentrations. Wheat plants inoculated or not inoculated with AM fungus were grown in two glasshouses with different CO2 concentrations (400 and 700 μmol l−1) and salinity......, accumulating soluble sugar, and improving ion homeostasis in wheat plants grown at elevated CO2 and salinity stress....